MNX1

Gene Summary

Gene:MNX1; motor neuron and pancreas homeobox 1
Aliases: HB9, HLXB9, SCRA1, HOXHB9
Location:7q36.3
Summary:This gene encodes a nuclear protein, which contains a homeobox domain and is a transcription factor. Mutations in this gene result in Currarino syndrome, an autosomic dominant congenital malformation. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2009]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:motor neuron and pancreas homeobox protein 1
Source:NCBIAccessed: 31 August, 2019

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 31 August 2019 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (7)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: MNX1 (cancer-related)

Yang X, Pan Q, Lu Y, et al.
MNX1 promotes cell proliferation and activates Wnt/β-catenin signaling in colorectal cancer.
Cell Biol Int. 2019; 43(4):402-408 [PubMed] Related Publications
Aberrant Wnt/β-catenin signaling is a characteristic feature of colorectal cancer (CRC), therefore, understanding the underlying mechanisms of aberrant Wnt/β-catenin signaling will improve the treatment outcome of CRC. Expression of MNX1 in paired fresh CRC tissues and corresponding adjacent normal tissues were examined by qPCR and Western blotting. The levels of MNX1 in paraffin-embedded CRC specimens were detected by immunohistochemistry (IHC). The role of MNX1 in growth and proliferation of CRC cells was evaluated by MTT and colony formation assay. Luciferase reporter analysis and western blotting were carried out to explore the influence of MNX1 on Wnt/β-catenin signaling. The results showed that expression of MNX1 is markedly upregulated in CRC tissues and positively correlated with level of Ki67, and overexpression of MNX1 significantly promotes the proliferation of CRC cells. Further study showed that ectopic expression of MNX1 activates the Wnt/β-catenin signaling and upregulates the expression of c-Myc and CCND1, the downstream genes of Wnt/β-catenin signaling. Therefore, MNX1 plays an indispensable role in promoting of human CRC progression and may represent a novel therapeutic target for CRC.

Jiang L, Chen S, Zhao D, et al.
MNX1 reduces sensitivity to anoikis by activating TrkB in human glioma cells.
Mol Med Rep. 2018; 18(3):3271-3279 [PubMed] Free Access to Full Article Related Publications
Glioma is the most common type of malignant intracranial tumor in adults and is associated with the highest mortality rate. Although surgery, radiotherapy, chemotherapy and other treatment methods have progressed, the median survival of patients with glioma is only 14‑15 months. Glioma cells are able to penetrate along blood vessels and invade into the surrounding normal brain tissue so that an overall resection of the tumor cannot be performed. In the process of metastasis, the resistance of cancer cells to anoikis has an important role. When tumor cells escape from their original environment, anoikis resistance aids their survival. In the present study, reverse transcription‑semi‑quantitative polymerase chain reaction (RT‑sqPCR), RT‑quantitative PCR and western blotting demonstrated that the transcription factor, motor neuron and pancreas homeobox 1 (MNX1), was ectopically expressed in glioma cells compared with normal HUVEC‑C human umbilical vein endothelial cells. Furthermore, its expression was higher in more malignant glioma cell lines (T98G and M059K) compared with the less malignant glioma cell line (U‑87 MG) and normal HUVEC‑C cells. An adhesion assay using fibronectin demonstrated that MNX1 and tyrosine kinase receptor B (TrkB) overexpression in HUVEC‑C and U‑87 MG cells reduced adhesion and forced them to suspend. Additionally, MNX1 and TrkB overexpression was demonstrated to increase the ability of cells to bypass anoikis. MNX1 and TrkB knockdown increased adhesion and promoted apoptosis after suspension. It was further demonstrated that MNX1 functioned as a transcription factor binding in the upstream regulatory region of TrkB to activate its expression. The results of the present study suggested that MNX1 may suppress the adhesion and apoptosis rates of tumor cells by activating TrkB. The results of the present study suggest that MNX1 may represent a novel therapeutic target for the treatment of gliomas.

Chen M, Wu R, Li G, et al.
Motor neuron and pancreas homeobox 1/HLXB9 promotes sustained proliferation in bladder cancer by upregulating CCNE1/2.
J Exp Clin Cancer Res. 2018; 37(1):154 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Uncontrolled proliferation is thought to be the most fundamental characteristic of cancer. Detailed knowledge of cancer cell proliferation mechanisms would not only benefit understanding of cancer progression, but may also provide new clues for developing novel therapeutic strategies.
METHODS: In vitro function of MNX1 (Motor neuron and pancreas homeobox 1) in bladder cancer cell was evaluated using MTT assay, colony formation assay, and bromodeoxyuridine incorporation assay. Real-time PCR and western blotting were performed to detect MNX1 and CCNE1/2 expressions. In vivo tumor growth was conducted in BALB/c-nu mice.
RESULTS: We reported that MNX1 is responsible for sustaining bladder cancer cell proliferation. Abnormal MNX1 upregulation in bladder cancer cell lines and 167 human tissue specimens; high MNX1 expression levels correlated significantly with shorter 5-year overall and relapse-free survival in the bladder cancer patients. Furthermore, MNX1 overexpression accelerated bladder cancer cell proliferation and tumorigenicity both in vitro and in vivo, whereas MNX1 downregulation arrested it. In addition, MNX1 transcriptionally upregulated CCNE1 and CCNE2 by directly bounding to their promoters, which promoted G1-S transition in the bladder cancer cells.
CONCLUSION: These findings reveal an oncogenic role and novel regulatory mechanism of MNX1 in bladder cancer progression and suggest that MNX1 is a potential prognostic biomarker and therapeutic target.

Serratrice N, Fievet L, Albader F, et al.
Multiple neurosurgical treatments for different members of the same family with Currarino syndrome.
Neurochirurgie. 2018; 64(3):211-215 [PubMed] Related Publications
INTRODUCTION: Currarino's syndrome (CS) is an autosomal dominant disorder of embryonic development causing a rare malformating syndrome characterized by a triad of an anorectal malformations, presacral mass (most commonly an anterior sacral meningocele) and sacral bony defects. Mutations of the HLXB9 gene have been identified in most CS cases, but a precise genotype-phenotype correlation has not been described so far. Family screening is obligatory. The diagnosis is usually made during childhood and rarely in adulthood. In this context, imaging, and especially MRI plays a major role in the diagnosis of this syndrome. Surgical management is provided by pediatric surgeons or neurosurgeons.
FAMILIAL CASE REPORT: Here, we present a family case report with CS requiring different neurosurgical management. The son, a 3-year-old boy, developed a tethered spinal cord syndrome associated to a lipoma of the filum terminale, a sacro-coccygeal teratoma and an anal adhesion. A combined surgical approach permitted a good evolution on the urinary and digestive functions despite a persistent fecal incontinence. The 2-year-old daughter presented with a cyst of the thyreoglossal tract infected and fistulized to the skin. She was also followed for a very small lipoma of the filum terminale that required a neurosurgical approach. The father, 44-year-old, manifested functional digestive and urinary disorders caused by a giant anterior sacral meningocele. The ligation of the neck of the cyst and aspiration of the liquid inside in full through a posterior partial approach permit a complete collapse of the cyst with an instantly satisfactory clinical outcome.
CONCLUSION: In these cases, cooperation between pediatric surgeons and neurosurgeons was crucial. The follow-up of these patients should be done in a spina bifida clinic. A geneticist evaluation must be offered to the patient in the case of a CS as well as a clinical evaluation of the relatives (parents, siblings).

Gao Y, Xu Y, Wang J, et al.
lncRNA MNX1-AS1 Promotes Glioblastoma Progression Through Inhibition of miR-4443.
Oncol Res. 2019; 27(3):341-347 [PubMed] Related Publications
Long noncoding RNAs (lncRNAs) have been acknowledged as important regulators in various human cancers. lncRNA MNX1-AS1 has been shown to be an oncogene in epithelial ovarian cancer. However, the function of MNX1-AS1 in glioblastoma (GBM) remains largely unknown. Here we found that the expression of MNX1-AS1 was significantly upregulated in GBM tissues and cell lines. Knockdown of MNX1-AS1 significantly inhibited the proliferation, migration, and invasion of GBM cells. In terms of mechanism, we found that MNX1-AS1 could bind to miR-4443 in GBM cells. Overexpression of miR-4443 significantly inhibited the expression of MNX1-AS1 and vice versa. Moreover, there was an inverse correlation between the expression levels of MNX1-AS1 and miR-4443 in GBM tissues. We found that overexpression of miR-4443 inhibited the proliferation, migration, and invasion of GBM cells. We also showed that inhibition of miR-4443 reversed the effects of MNX1-AS1 knockdown on GBM cell proliferation, migration, and invasion. Taken together, we found that MNX1-AS1 promoted the proliferation, migration, and invasion of GBM cells through inhibiting miR-4443.

Espersen ADL, Noren-Nyström U, Abrahamsson J, et al.
Acute myeloid leukemia (AML) with t(7;12)(q36;p13) is associated with infancy and trisomy 19: Data from Nordic Society for Pediatric Hematology and Oncology (NOPHO-AML) and review of the literature.
Genes Chromosomes Cancer. 2018; 57(7):359-365 [PubMed] Related Publications
The t(7;12)(q36;p13) (MNX1/ETV6) is not included in the WHO classification but has been described in up to 30% of acute myeloid leukemia (AML) in children <2 years and associated with a poor prognosis. We present the clinical and cytogenetics characteristics of AML cases with t(7;12)(p36;p13). A literature review identified 35 patients with this translocation, published between 2000 and 2015. Outcome data were available in 22 cases. The NOPHO-AML (Nordic Society for Pediatric Hematology and Oncology) database contained 651 patients with AML from 1993 to 2014 and seven (1.1%) had the translocation. The t(7;12) was only present in patients <2 years of age (median age 6 months) but none was diagnosed as newborn. These patients constituted 4.3% of the patients <2 years of age. There was a strong association with trisomy 19 (literature: 86%, NOPHO: 100%) and +8 (literature: 19%, NOPHO: 14%). Seventeen of 22 patients from the literature with t(7;12) and four of seven patients from the NOPHO database suffered from relapse. The patients with t(7;12) had a 3-year event free survival of 24% (literature) vs. 43% (NOPHO) and a 3-year overall survival of 42% (literature) vs. 100% (NOPHO). None of the NOPHO patients was treated with hematopoietic stem cell transplantation (HSCT) in first complete remission. Relapse was frequent but the salvage rate using HSCT was high. We conclude that t(7;12)(q36;13) is a unique subgroup of childhood AML with presentation before 2 years of age with most cases being associated with +19.

Federico C, Leotta CG, Bruno F, et al.
Nuclear Repositioning of the Non-Translocated HLXB9 Allele in the Leukaemia Cell Line GDM-1 Harbouring a t(6;7)(q23;q36).
Cytogenet Genome Res. 2017; 153(1):10-17 [PubMed] Related Publications
Transcriptionally active and inactive topologically associated domains (TADs) occupy different areas in the cell nucleus, and chromosomal rearrangements relocating TADs could determine ectopic expression of the repositioned genes. In this study, we investigated the HLXB9 gene in a myeloid leukaemia cell line, GDM-1, known to harbour a rearrangement involving chromosome 7 with a breakpoint distal to HLXB9, highly expressed in these cells. We used FISH to target the regions involved in the translocation and to distinguish the translocated chromosome from the non-translocated one in interphase nuclei. Two-dimensional analysis of the interphase FISH data indicated that the 2 HLXB9 alleles had a different localisation in the cell nuclei, with the translocated allele consistently positioned in the nuclear periphery and the normal one in the more internal portion of the nucleus, known as the transcriptionally active compartment. Our data may indicate that HLXB9 transcripts in the GDM-1 cell line do not arise from the allele located in rearranged chromosome 7, suggesting that regulation of gene expression in cancer cells harbouring chromosomal translocations might be more complex than previously thought, paving the path to further investigations on mechanisms of gene expression.

Wang Y, Wang J, Zhang L, et al.
RGS12 Is a Novel Tumor-Suppressor Gene in African American Prostate Cancer That Represses AKT and MNX1 Expression.
Cancer Res. 2017; 77(16):4247-4257 [PubMed] Free Access to Full Article Related Publications
African American (AA) men exhibit a relatively high incidence and mortality due to prostate cancer even after adjustment for socioeconomic factors, but the biological basis for this disparity is unclear. Here, we identify a novel region on chromosome 4p16.3 that is lost selectively in AA prostate cancer. The negative regulator of G-protein signaling RGS12 was defined as the target of 4p16.3 deletions, although it has not been implicated previously as a tumor-suppressor gene. RGS12 transcript levels were relatively reduced in AA prostate cancer, and prostate cancer cell lines showed decreased RGS12 expression relative to benign prostate epithelial cells. Notably, RGS12 exhibited potent tumor-suppressor activity in prostate cancer and prostate epithelial cell lines

Lv Y, Li H, Li F, et al.
Long Noncoding RNA MNX1-AS1 Knockdown Inhibits Cell Proliferation and Migration in Ovarian Cancer.
Cancer Biother Radiopharm. 2017; 32(3):91-99 [PubMed] Related Publications
Long noncoding RNAs (lncRNAs) have recently emerged as pivotal regulators that govern fundamental biological processes and disease pathogenesis. LncRNA MNX1-AS1 has been reported to promote cell proliferation and invasion in gallbladder cancer, but its biological role and regulatory mechanism in ovarian cancer are poorly defined. In this study, it was found that higher expression of lncRNA MNX1-AS1 is closely associated with International Federation of Gynecology and Obstetrics stage and lymphatic metastasis in ovarian cancer patients. RNA interference (RNAi) to downregulate the expression of lncRNA MNX1-AS1 was used in the ovarian cancer cell lines, OVCA433 and SKOV-3. CCK-8, EdU staining, and colony formation assays was used to test the viability and proliferation ability of these cells. Wound healing and transwell migration assays were performed to determine the migration ability of the cells. Cell cycle progression and apoptotic assays were carried out using flow cytometry. These in vitro loss-of-function experiments revealed that downregulation of lncRNA MNX1-AS1 suppressed cell proliferation, colony formation, cell migration ability, induced cell cycle arrest at the G0/G1 phase, and promoted apoptosis. Furthermore, MNX1-AS1 knockdown altered the protein expressions of CDK4, cyclin D, Bax, and Bcl-2. These findings demonstrated for the first time that lncRNA MNX1-AS1 functions as an oncogene in ovarian cancer and could be a potential target for this disease.

Zhang L, Wang J, Wang Y, et al.
MNX1 Is Oncogenically Upregulated in African-American Prostate Cancer.
Cancer Res. 2016; 76(21):6290-6298 [PubMed] Free Access to Full Article Related Publications
Incidence and mortality rates for prostate cancer are higher in African-American (AA) men than in European-American (EA) men, but the biologic basis for this disparity is unclear. We carried out a detailed analysis of gene expression changes in prostate cancer compared with their matched benign tissues in a cohort of AA men and compared them with existing data from EA men. In this manner, we identified MNX1 as a novel oncogene upregulated to a relatively greater degree in prostate cancer from AA men. Androgen and AKT signaling play a central role in the pathogenesis of prostate cancer and we found that both of these signaling pathways increased MNX1 expression. MNX1 in turn upregulated lipid synthesis by stimulating expression of SREBP1 and fatty acid synthetase. Our results define MNX1 as a novel targetable oncogene increased in AA prostate cancer that is associated with aggressive disease. Cancer Res; 76(21); 6290-8. ©2016 AACR.

Bailey P, Chang DK, Nones K, et al.
Genomic analyses identify molecular subtypes of pancreatic cancer.
Nature. 2016; 531(7592):47-52 [PubMed] Related Publications
Integrated genomic analysis of 456 pancreatic ductal adenocarcinomas identified 32 recurrently mutated genes that aggregate into 10 pathways: KRAS, TGF-β, WNT, NOTCH, ROBO/SLIT signalling, G1/S transition, SWI-SNF, chromatin modification, DNA repair and RNA processing. Expression analysis defined 4 subtypes: (1) squamous; (2) pancreatic progenitor; (3) immunogenic; and (4) aberrantly differentiated endocrine exocrine (ADEX) that correlate with histopathological characteristics. Squamous tumours are enriched for TP53 and KDM6A mutations, upregulation of the TP63∆N transcriptional network, hypermethylation of pancreatic endodermal cell-fate determining genes and have a poor prognosis. Pancreatic progenitor tumours preferentially express genes involved in early pancreatic development (FOXA2/3, PDX1 and MNX1). ADEX tumours displayed upregulation of genes that regulate networks involved in KRAS activation, exocrine (NR5A2 and RBPJL), and endocrine differentiation (NEUROD1 and NKX2-2). Immunogenic tumours contained upregulated immune networks including pathways involved in acquired immune suppression. These data infer differences in the molecular evolution of pancreatic cancer subtypes and identify opportunities for therapeutic development.

Hu N, Kadota M, Liu H, et al.
Genomic Landscape of Somatic Alterations in Esophageal Squamous Cell Carcinoma and Gastric Cancer.
Cancer Res. 2016; 76(7):1714-23 [PubMed] Free Access to Full Article Related Publications
Gastric cancer and esophageal cancer are the second and sixth leading causes of cancer-related death worldwide. Multiple genomic alterations underlying gastric cancer and esophageal squamous cell carcinoma (ESCC) have been identified, but the full spectrum of genomic structural variations and mutations have yet to be uncovered. Here, we report the results of whole-genome sequencing of 30 samples comprising tumor and blood from 15 patients, four of whom presented with ESCC, seven with gastric cardia adenocarcinoma (GCA), and four with gastric noncardia adenocarcinoma. Analyses revealed that an A>C mutation was common in GCA, and in addition to the preferential nucleotide sequence of A located 5 prime to the mutation as noted in previous studies, we found enrichment of T in the 5 prime base. The A>C mutations in GCA suggested that oxidation of guanine may be a potential mechanism underlying cancer mutagenesis. Furthermore, we identified genes with mutations in gastric cancer and ESCC, including well-known cancer genes, TP53, JAK3, BRCA2, FGF2, FBXW7, MSH3, PTCH, NF1, ERBB2, and CHEK2, and potentially novel cancer-associated genes, KISS1R, AMH, MNX1, WNK2, and PRKRIR Finally, we identified recurrent chromosome alterations in at least 30% of tumors in genes, including MACROD2, FHIT, and PARK2 that were often intragenic deletions. These structural alterations were validated using the The Cancer Genome Atlas dataset. Our studies provide new insights into understanding the genomic landscape, genome instability, and mutation profile underlying gastric cancer and ESCC development. Cancer Res; 76(7); 1714-23. ©2016 AACR.

Leotta CG, Federico C, Brundo MV, et al.
HLXB9 gene expression, and nuclear location during in vitro neuronal differentiation in the SK-N-BE neuroblastoma cell line.
PLoS One. 2014; 9(8):e105481 [PubMed] Free Access to Full Article Related Publications
Different parts of the genome occupy specific compartments of the cell nucleus based on the gene content and the transcriptional activity. An example of this is the altered nuclear positioning of the HLXB9 gene in leukaemia cells observed in association with its over-expression. This phenomenon was attributed to the presence of a chromosomal translocation with breakpoint proximal to the HLXB9 gene. Before becoming an interesting gene in cancer biology, HLXB9 was studied as a developmental gene. This homeobox gene is also known as MNX1 (motor neuron and pancreas homeobox 1) and it is relevant for both motor neuronal and pancreatic beta cells development. A spectrum of mutations in this gene are causative of sacral agenesis and more broadly, of what is known as the Currarino Syndrome, a constitutional autosomal dominant disorder. Experimental work on animal models has shown that HLXB9 has an essential role in motor neuronal differentiation. Here we present data to show that, upon treatment with retinoic acid, the HLXB9 gene becomes over-expressed during the early stages of neuronal differentiation and that this corresponds to a reposition of the gene in the nucleus. More precisely, we used the SK-N-BE human neuroblastoma cell line as an in vitro model and we demonstrated a transient transcription of HLXB9 at the 4th and 5th days of differentiation that corresponded to the presence, predominantly in the cell nuclei, of the encoded protein HB9. The nuclear positioning of the HLXB9 gene was monitored at different stages: a peripheral location was noted in the proliferating cells whereas a more internal position was noted during differentiation, that is while HLXB9 was transcriptionally active. Our findings suggest that HLXB9 can be considered a marker of early neuronal differentiation, possibly involving chromatin remodeling pathways.

Kole MJ, Fridley JS, Jea A, Bollo RJ
Currarino syndrome and spinal dysraphism.
J Neurosurg Pediatr. 2014; 13(6):685-9 [PubMed] Related Publications
Currarino syndrome is a rare constellation of congenital anomalies characterized by the triad of sacral dysgenesis, presacral mass, and anorectal malformation. It is frequently associated with other congenital anomalies, often including occult spinal dysraphism. Mutations in the MNX1 gene are identified in the majority of cases. The authors report a rare case of Currarino syndrome in an infant with tethered cord syndrome and a dorsal lipomyelomeningocele continuous with a presacral intradural spinal lipoma, in addition to an imperforate anus and a scimitar sacrum. They review the literature to highlight patterns of occult spinal dysraphism in patients with Currarino syndrome and their relationship to tethered cord syndrome. Approximately 60% of the patients with Currarino syndrome reported in the literature have an occult spinal dysraphism. Published studies suggest that the risk of tethered cord syndrome may be higher among patients with a lipoma and lower among those with a teratoma or anterior meningocele.

Desai SS, Modali SD, Parekh VI, et al.
GSK-3β protein phosphorylates and stabilizes HLXB9 protein in insulinoma cells to form a targetable mechanism of controlling insulinoma cell proliferation.
J Biol Chem. 2014; 289(9):5386-98 [PubMed] Free Access to Full Article Related Publications
Insulinomas (pancreatic islet β cell tumors) are the most common type of functioning pancreatic neuroendocrine tumors that occur sporadically or as a part of the MEN1 syndrome that is caused by germ line mutations in MEN1. Tissue-specific tumor predisposition from germ line mutations in ubiquitously expressed genes such as MEN1 could occur because of functional consequences on tissue-specific factors. We previously reported the proapoptotic β cell differentiation factor HLXB9 as a downstream target of menin (encoded by MEN1). Here we show that GSK-3β inactivates the proapoptotic activity of HLXB9 by phosphorylating HLXB9 at Ser-78/Ser-80 (pHLXB9). Although HLXB9 is found in the nucleus and cytoplasm, pHLXB9 is predominantly nuclear. Both pHLXB9 and active GSK-3β are elevated in β cells with menin knockdown, in MEN1-associated β cell tumors (insulinomas), and also in human sporadic insulinomas. Pharmacologic inhibition of GSK-3β blocked cell proliferation in three different rodent insulinoma cell lines by arresting the cells in G2/M phase and caused apoptosis. Taken together, these data suggest that the combination of GSK-3β and pHLXB9 forms a therapeutically targetable mechanism of insulinoma pathogenesis. Our results reveal that GSK-3β and pHLXB9 can serve as novel targets for insulinoma treatment and have implications for understanding the pathways associated with β cell proliferation.

Nagel S, Ehrentraut S, Meyer C, et al.
Oncogenic deregulation of NKL homeobox gene MSX1 in mantle cell lymphoma.
Leuk Lymphoma. 2014; 55(8):1893-903 [PubMed] Related Publications
NKL homeobox gene MSX1 is physiologically expressed during embryonic hematopoiesis. Here, we detected MSX1 overexpression in three examples of mantle cell lymphoma (MCL) and one of acute myeloid leukemia (AML) by screening 96 leukemia/lymphoma cell lines via microarray profiling. Moreover, in silico analysis identified significant overexpression of MSX1 in 3% each of patients with MCL and AML, confirming aberrant activity in subsets of both types of malignancies. Comparative expression profiling analysis and subsequent functional studies demonstrated overexpression of histone acetyltransferase PHF16 together with transcription factors FOXC1 and HLXB9 as activators of MSX1 transcription. Additionally, we identified regulation of cyclin D1/CCND1 by MSX1 and its repressive cofactor histone H1C. Fluorescence in situ hybridization in MCL cells showed that t(11;14)(q13;q32) results in detachment of CCND1 from its corresponding repressive MSX1 binding site. Taken together, we uncovered regulators and targets of homeobox gene MSX1 in leukemia/lymphoma cells, supporting the view of a recurrent genetic network that is reactivated in malignant transformation.

Shi K, Parekh VI, Roy S, et al.
The embryonic transcription factor Hlxb9 is a menin interacting partner that controls pancreatic β-cell proliferation and the expression of insulin regulators.
Endocr Relat Cancer. 2013; 20(1):111-22 [PubMed] Free Access to Full Article Related Publications
The multiple endocrine neoplasia type 1 (MEN1) syndrome is caused by germline mutations in the MEN1 gene encoding menin, with tissue-specific tumors of the parathyroids, anterior pituitary, and enteropancreatic endocrine tissues. Also, 30-40% of sporadic pancreatic endocrine tumors show somatic MEN1 gene inactivation. Although menin is expressed in all cell types of the pancreas, mouse models with loss of menin in either pancreatic α-cells, or β-cells, or total pancreas develop β-cell-specific endocrine tumors (insulinomas). Loss of widely expressed tumor suppressor genes may produce tissue-specific tumors by reactivating one or more embryonic-specific differentiation factors. Therefore, we determined the effect of menin overexpression or knockdown on the expression of β-cell differentiation factors in a mouse β-cell line (MIN6). We show that the β-cell differentiation factor Hlxb9 is posttranscriptionally upregulated upon menin knockdown, and it interacts with menin. Hlxb9 reduces cell proliferation and causes apoptosis in the presence of menin, and it regulates genes that modulate insulin level. Thus, upon menin loss or from other causes, dysregulation of Hlxb9 predicts a possible combined mechanism for β-cell proliferation and insulin production in insulinomas. These observations help to understand how a ubiquitously expressed protein such as menin might control tissue-specific tumorigenesis. Also, our findings identify Hlxb9 as an important factor for β-cell proliferation and insulin regulation.

Wildenhain S, Ingenhag D, Ruckert C, et al.
Homeobox protein HB9 binds to the prostaglandin E receptor 2 promoter and inhibits intracellular cAMP mobilization in leukemic cells.
J Biol Chem. 2012; 287(48):40703-12 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: HB9 is highly expressed in translocation t(7;12) positive infant AML.
RESULTS: HB9 binds to the PTGER2 promoter, down-regulates PTGER2 gene expression and subsequently represses cAMP synthesis in hematopoietic cells.
CONCLUSION: Expression of HLXB9 represses PTGER2 mediated signaling.
SIGNIFICANCE: First molecular report of HB9-dependent target gene regulation in hematopoietic cells. The transcription factor HB9, encoded by the homeobox gene B9 (HLXB9), is involved in the development of pancreatic beta- and motor neuronal cells. In addition, HLXB9 is recurrently rearranged in young children with acute myeloid leukemia characterized by a chromosomal translocation t(7;12)-HLXB9/TEL and concomitant high expression of the unrearranged, wild-type HLXB9 allele. However, target genes of HB9 in hematopoietic cells are not known to date. In this study, we used ChIP-on-chip analysis together with expression profiling and identified PTGER2 (prostaglandin E receptor 2) as a target gene of HB9 in a hematopoietic cell line. The functional HB9 homeodomain as well as the HB9 binding domain within the PTGER2 promoter are essential for binding of HB9 to the PTGER2 promoter region and down-regulation of PTGER2 expression. Functionally, HB9 conducted down-regulation of PTGER2 results in a reduced content of intracellular cAMP mobilization and furthermore the decreased PTGER2 gene expression is valid in bone marrow cells from translocation t(7;12) positive patients. Among the primary and secondary target genes of HB9 in the myeloid cell line HL60, 78% of significantly regulated genes are down-regulated, indicating an overall repressive function of HB9. Differentially regulated genes were preferentially confined to pathways involved in cell-adhesion and cell-cell interactions, similar to the gene expression footprint of HLXB9-expressing cells from t(7;12) positive patients.

Halldórsdóttir AM, Kanduri M, Marincevic M, et al.
Mantle cell lymphoma displays a homogenous methylation profile: a comparative analysis with chronic lymphocytic leukemia.
Am J Hematol. 2012; 87(4):361-7 [PubMed] Related Publications
Mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL) are mature CD5(+) B-cell malignancies with different biological/clinical characteristics. We recently reported an association between different prognostic subgroups of CLL (i.e., IGHV mutated and unmutated) and genomic methylation pattern. However, the relationship between DNA methylation and prognostic markers, such as the proliferation gene expression signature, has not been investigated in MCL. We applied high-resolution methylation microarrays (27,578 CpG sites) to assess the global DNA methylation profiles in 20 MCL (10 each with high/low proliferation signature) and 30 CLL (15 poor-prognostic IGHV unmutated subset #1 and 15 good-prognostic IGHV mutated subset #4) samples. Notably, MCL and each CLL subset displayed distinct genomic methylation profiles. After unsupervised hierarchical clustering, 17/20 MCL cases formed a cluster separate from CLL, while CLL subsets #1 and #4 formed subclusters. Surprisingly, few differentially methylated genes (n = 6) were identified between high vs. low proliferation MCL. In contrast, distinct methylation profiles were demonstrated for MCL and CLL. Importantly, certain functional classes of genes were preferentially methylated in either disease. For instance, developmental genes, in particular homeobox transcription factor genes (e.g., HLXB9, HOXA13), were more highly methylated in MCL, whereas apoptosis-related genes were enriched among targets methylated in CLL (e.g., CYFIP2, NR4A1). Results were validated using pyrosequencing, RQ-PCR and reexpression of specific genes. In summary, the methylation profile of MCL was homogeneous and no correlation with the proliferation signature was observed. Compared to CLL, however, marked differences were discovered such as the preferential methylation of homeobox genes in MCL.

Lin YH, Huang RL, Lai HC
Presacral teratoma in a Curarrino syndrome woman with an unreported insertion in MNX1 gene.
Taiwan J Obstet Gynecol. 2011; 50(4):512-4 [PubMed] Related Publications
OBJECTIVE: Currarino syndrome (CS) comprises a presacral mass, anorectal malformation, and a sacral bony defect. It is rarely reported in the gynecological field.
CASE REPORT: We describe here the case of a 26-year-old married woman with Currarino syndrome who presented with a presacral teratoma and a previously unreported insertion in MNX1 gene. She had had a pelvic teratoma diagnosed by laparoscopy 8 years previously. She was referred to our clinic because of the increasing size of the teratoma and associated compression symptoms. Computed tomography demonstrated a heterogeneous 12 cm mass in the presacral region. Spina bifida at S2eS5 was also noted. Laparotomy confirmed the diagnosis of presacral teratoma. Genetic analysis disclosed a triple CGC repeat insertion in exon 1 of MNX1, resulting in three in-frame shifts encoding for the amino acid alanine. No siblings had known similar symptoms.
CONCLUSION: Currarino syndrome is known to be an autosomal dominant disorder. The presence of constipation can lead to a diagnosis of the syndrome early in childhood. In sporadic cases diagnosis is late because of atypical symptoms. Delayed treatment of a presacral tumor may cause serious complications such as central nervous system infection or subsequent neurological dysfunction. In clinical practice, a presacral tumor with a sacral bony defect may indicate Currarino syndrome. Genetic analysis of the family may provide information on the hereditary traits of specific MNX1 mutation.

Ciotti P, Mandich P, Bellone E, et al.
Currarino syndrome with pelvic neuroendocrine tumor diagnosed by post-mortem genetic analysis of tissue specimens.
Am J Med Genet A. 2011; 155A(11):2750-3 [PubMed] Related Publications
Currarino syndrome (CS) is an autosomal dominant disorder of embryonic development characterized by the triad of anorectal abnormalities, partial sacral agenesis, and presacral mass. Mutations of the HLXB9 gene have been identified in most CS cases, but a precise genotype-phenotype correlation has not been described so far. We report the clinical case of a 44-year-old Caucasian woman with malignant neuroendocrine transformation of a pre-sacrococcygeal mass combined with bicornuate uterus, dermoid cyst of the ovaries, and chronic constipation. After the patient died, a sacrococcygeal malformation and anterior meningocele were diagnosed in her 22-year-old son. CS diagnosis was then retrospectively confirmed by molecular analysis of normal and pathological tissue specimens of the mother, with identification of a HLXB9 mutation (c.727C>T; p.R243W). CS should be considered, and genetic counseling recommended, to all patients with presacral masses. Since malignant neuroendocrine transformation of presacral mass in CS is a possible complication, even thought rare, close follow up in these patients is advisable.

Zu S, Winberg J, Arnberg F, et al.
Mutation analysis of the motor neuron and pancreas homeobox 1 (MNX1, former HLXB9) gene in Swedish patients with Currarino syndrome.
J Pediatr Surg. 2011; 46(7):1390-5 [PubMed] Related Publications
BACKGROUND: Currarino syndrome (CS) is a triad consisting of partial sacral agenesis, presacral mass, and anorectal malformations, typically anal stenosis but the phenotype varies. The main cause of this monogenic disorder is mutations in the motor neuron and pancreas homeobox 1 gene. We describe the clinical and genetic findings in 4 unrelated Swedish cases with CS and their relatives.
METHODS: We performed mutation analysis of the motor neuron and pancreas homeobox 1 gene in 4 cases with CS by DNA sequence analysis as well as multiplex ligation-dependent probe amplification. In addition, array comparative genome hybridization was performed in 2 cases. Including relatives, totally, 14 individuals were analyzed.
RESULTS: We found 2 previously described mutations, 1 de novo nonsense mutation (p.Gln212X) and 1 maternally inherited frameshift mutation (p.Pro18ProfsX38). In the family with the frameshift mutation, we also detected the same maternally inherited mutation in 3 of the proband's 4 brothers, who displayed varying symptoms. All mutation carriers had presacral tumors, although 2 were asymptomatic.
CONCLUSION: Our findings emphasize the need for genetic counseling and mutation analysis in patients with CS to detect tumors early. It shows the importance of evaluation of the sacrum and the presacral region in patients with anal stenosis with or without funnel anus. Family members of index cases should be considered for evaluation even if they are asymptomatic.

Wilkens L, Jaggi R, Hammer C, et al.
The homeobox gene HLXB9 is upregulated in a morphological subset of poorly differentiated hepatocellular carcinoma.
Virchows Arch. 2011; 458(6):697-708 [PubMed] Related Publications
The prognostic outcome for hepatocellular carcinoma (HCC) remains poor. Disease progression is accompanied by dedifferentiation of the carcinoma, a process that is not well understood. The aim of this study was to get more insight into the molecular characteristics of dedifferentiated carcinomas using high throughput techniques. Microarray-based global gene expression analysis was performed on five poorly differentiated HCC cell lines compared with non-neoplastic hepatic controls and a set of three cholangiolar carcinoma (CC) cell lines. The gene with the highest upregulation was HLXB9. HLXB9 is a gene of the homeobox genfamily important for the development of the pancreas. RT-PCR confirmed the upregulation of HLXB9 in surgical specimens of carcinoma tissue, suggesting its biological significance. Interestingly, HLXB9 upregulation was primary observed in poorly differentiated HCC with a pseudoglandular pattern compared with a solid pattern HCC or in moderate or well-differentiated HCC. Additional the expression of translated HLXB9, the protein HB9 (NCBI: NP_001158727), was analyzed by western blotting. Expression of HB9 was only detected in the cytoplasm but not in the nuclei of the HCC cells. For validation CC were also investigated. Again, we found an upregulation of HLXB9 in CC cells accompanied by an expression of HB9 in the cytoplasms of these tumor cells, respectively. In conclusion, homeobox HLXB9 is upregulated in poorly differentiated HCC with a pseudoglandular pattern. The translated HB9 protein is found in the cytoplasm of these HCC and CC. We therefore assume HLXB9 as a possible link in the understanding of the development of HCC and CC, respectively.

Ferguson S, Gautrey HE, Strathdee G
The dual role of HLXB9 in leukemia.
Pediatr Blood Cancer. 2011; 56(3):349-52 [PubMed] Related Publications
BACKGROUND: The HLXB9 gene encodes a homeodomain containing transcription factor which has been implicated in the development of both solid and hematological malignancies. In leukemia it is one of the two fused genes, along with ETV6, in a recurrent translocation frequently observed in infant AML.
PROCEDURE: Here we investigate the role of epigenetic inactivation of the HLXB9 gene in leukemia. Quantitative DNA methylation analysis was performed using the COBRA assay, and qRT-PCR was used to assess the effects of methylation on expression in hematological cell lines and primary ALL samples.
RESULTS: Hypermethylation of the HLXB9 gene was found to be a frequent event in childhood ALL, occurring in 33% of cases. However, it was rarely or never observed in other types of leukemia, including AML, CML, and CLL, with the exception of adult ALL, in which 39% of cases were hypermethylated. Furthermore, hypermethylation of HLXB9 results in loss of expression in hematological cell lines and primary ALL samples.
CONCLUSION: These results suggest that HLXB9 may have a dual role in childhood leukemia, as an oncogene in infant AML but as a tumor suppressor in childhood ALL.

Bartels SA, van Koperen PJ, van der Steeg AF, et al.
Presacral masses in children: presentation, aetiology and risk of malignancy.
Colorectal Dis. 2011; 13(8):930-4 [PubMed] Related Publications
AIM: The risk of malignant changes in presacral tumours in children was investigated in relation to age at diagnosis, type of presentation and origin of the tumour.
METHOD: A retrospective review was carried out in 17 patients surgically treated for congenital presacral masses over a 22-year period.
RESULTS: Constipation was the main symptom in 14 (82%) of 17 patients. The lesions were evident on digital examination in 14 patients. Mature teratoma (n = 9, 64%) was the most common lesion, including three malignancies. Currarino syndrome was diagnosed in 10 (71%) patients. Two unclassified variant HLXB9 gene mutations were found in five (29%) patients who underwent genetic testing.
CONCLUSION: Congenital presacral tumours in children were mostly mature teratomas, either as sacrococcygeal teratomas or as part of the Currarino syndrome. The risk of malignancy in patients older than 1 year necessitates early surgical resection.

Park J, Kim M, Lim J, et al.
Three-way complex translocations in infant acute myeloid leukemia with t(7;12)(q36;p13): the incidence and correlation of a HLXB9 overexpression.
Cancer Genet Cytogenet. 2009; 191(2):102-5 [PubMed] Related Publications
The t(7;12)(q36;p13) is one of the recurrent cytogenetic abnormalities that involves the ETV6 gene. It is found in patients suffering with infantile acute myeloid leukemia (AML). We reviewed the cytogenetic and clinical findings of 215 pediatric patients (ages

Taketani T, Taki T, Sako M, et al.
MNX1-ETV6 fusion gene in an acute megakaryoblastic leukemia and expression of the MNX1 gene in leukemia and normal B cell lines.
Cancer Genet Cytogenet. 2008; 186(2):115-9 [PubMed] Related Publications
Patients with infant acute myeloid leukemia (AML) who carry a t(7;12)(q36;p13) translocation have been reported to have a poor clinical outcome. MNX1-ETV6 fusion transcripts (previously HLXB9-ETV6) were rarely detected in AML patients having t(7;12)(q36;p13). A 23-month-old girl with acute megakaryoblastic leukemia (AMKL) exhibited chromosome abnormalities, including add(7)(q22), and del(12)(p12p13). Southern blot analysis of bone marrow cells showed an ETV6 gene rearrangement. Reverse transcriptase-polymerase chain reaction (RT-PCR) followed by sequence analysis revealed the presence of an MNX1-ETV6 fusion gene. The patient responded well to chemotherapy, achieved complete remission, and at writing had been in complete remission for 60 months. The MNX1 expression by RT-PCR was significantly more frequent in Epstein-Barr virus-transformed B-cell lines derived from normal adult lymphocytes than in leukemic cell lines. This represents a novel case of an AMKL patient with MNX1-ETV6 fusion transcripts who had a good prognosis.

Novotny GW, Nielsen JE, Sonne SB, et al.
Analysis of gene expression in normal and neoplastic human testis: new roles of RNA.
Int J Androl. 2007; 30(4):316-26; discussion 326-7 [PubMed] Related Publications
Large-scale methods for analysing gene expression, such as microarrays, have yielded a wealth of information about gene expression at the mRNA level. However, expression of alternative transcripts, together with the presence of a wide range of largely undescribed RNA transcripts combined with regulation from the RNA interference pathway, may cause misinterpretations when trying to base conclusions from expression data derived from studies at the mRNA level. With HLXB9, PRM1, DICER and E2F1 as examples, we here show a range of situations that can occur when investigating gene expression, and give recommendations for the complementary methods that can verify gene expression data from large-scale studies, as well as give new information regarding the regulation of specific genes. Especially, we show that the absence of a protein despite high expression of the corresponding mRNA can be caused by expression of miRNAs targeting the mRNA. Additionally, we show through cloning the presence of both known and new miRNAs in the testis emphasizing the necessity for following up mRNA expression data by investigating expression at the protein level.

Almstrup K, Leffers H, Lothe RA, et al.
Improved gene expression signature of testicular carcinoma in situ.
Int J Androl. 2007; 30(4):292-302; discussion 303 [PubMed] Related Publications
The carcinoma in situ (CIS) stage is the common precursor of testicular germ cell tumours (TGCTs) that arise in young adults. Within the past decade genome wide gene expression tools have been developed and have greatly advanced the insight into the biology of TGCTs. Two independent data sets on global gene expression in testicular CIS have been previously published. We have merged the two data sets on CIS samples (n = 6) and identified the shared gene expression signature in relation to expression in normal testis. Among the top-20 highest expressed genes, one-third was transcription factors and the list included some 'novel' CIS markers (i.e. DOCK11 and ANXA3). Genes related to biological terms 'nucleic acid binding' and 'translational activity' (e.g. transcription factors and ribosomal proteins, respectively) were consistently and significantly over-represented. Some of the significantly over-expressed genes in CIS cells were selected for validation by RT-PCR (IFI16, DOCK11, and ANXA3), immunohistochemistry (HLXB9), or in situ hybridization (IFI16). High-level analysis utilizing the Ingenuity pathway analysis tool indicated that networks relating to 'gene expression in cancer' and 'embryonic development' were significantly altered and could collectively affect cellular pathways like the WNT signalling cascade, which thus may be disrupted in testicular CIS. The merged CIS data from two different microarray platforms, to our knowledge, provide the most precise CIS gene expression signature to date.

von Bergh AR, van Drunen E, van Wering ER, et al.
High incidence of t(7;12)(q36;p13) in infant AML but not in infant ALL, with a dismal outcome and ectopic expression of HLXB9.
Genes Chromosomes Cancer. 2006; 45(8):731-9 [PubMed] Related Publications
The t(7;12)(q36;p13) is a recurrent translocation involving the ETV6/TEL gene (12p13) and a heterogeneous breakpoint at 7q36. A fusion transcript between HLXB9 and ETV6 in AML with t(7;12) is occasionally found. To study the incidence of t(7;12) in infant and childhood acute leukemia, we screened 320 cases <36 months using FISH. Additionally, 28 pediatric cases >36 months with cytogenetic breakpoints at 12p and 7q were investigated. We studied the presence of an HXLB9-ETV6 fusion transcript and quantified the expression of various genes located in the 7q36 breakpoint region. In total, six AML patients carried the t(7;12) of which five were infants and one child of 18 months. Only one out of 99 infant ALL patients harbored the t(7;12). No t(7;12) was found in older children with AML or ALL. AML patients carrying a t(7;12) had a poor outcome with a 3-year EFS of 0%. A fusion of HLXB9 to ETV6 was found in four AML cases with t(7;12). The 7q36 genes NOM1, LMBR1, RNF32, and SHH were equally expressed among t(7;12)-positive AML versus t(7;12)-negative AML, t(7;12)-negative ALL, or normal bone marrow. However, the HLXB9 expression was highly increased in t(7;12)-positive cases, including those with an HLXB9-ETV6 fusion. We conclude that the t(7;12) is almost exclusively present in infant AML and covers 30% of infant AML, while it is extremely rare in infant ALL and older children. The t(7;12) is associated with a poor outcome and an ectopic expression of HLXB9 is commonly involved in this genetic subtype of leukemia.

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