Previous studies have demonstrated that the dysregulation of microRNAs (miRs) is frequently associated with cancer progression. Deregulation of miR‑106b‑3p has been observed in various types of human cancer. However, the biological function of miR‑106b‑3p in esophageal squamous cell carcinoma (ESCC) remains unclear. Thus, the aim of this study was to investigate the role of miR‑106b‑3p in ESCC. In the current study, the results indicated that miR‑106b‑3p was upregulated in ESCC cell lines and tissues. An increase in miR‑106b‑3p using miR mimics significantly promoted the proliferation of ESCC cells in vitro. Furthermore, the results demonstrated that miR‑106b‑3p overexpression promoted migration, invasion and epithelial‑mesenchymal transition (EMT) of ESCC cells. In addition, zinc and ring finger 3 (ZNRF3) was identified as a target of miR‑106b‑3p in ESCC cells, and the ZNRF3 expression level was inversely associated with miR‑106b‑3p. It was also demonstrated that miR‑106b‑3p has a role in EMT by regulating Wnt/β‑catenin signaling pathway in ESCC. In conclusion, these data suggested that miR‑106b‑3p promotes cell proliferation and invasion, partially by downregulating ZNRF3 and inducing EMT via Wnt/β‑catenin signaling in ESCC cells. Thus, miR‑106b‑3p and ZNRF3 may be novel molecular targets for the future treatment of ESCC.

BACKGROUND: The genetic profile for human papilloma virus positive (HPV+) oropharyngeal squamous cell carcinomas (OPSCC) remains largely unknown. The purpose of this study was to sequence tissue material from a large cohort of locoregionally-advanced HPV+ OPSCCs.
METHODS: We performed targeted deep sequencing of 395 cancer-associated genes in 114 matched tumor/normal loco-regionally advanced HPV+ OPSCCs. Mutations and copy number aberrations were determined.
RESULTS: We identified a total of 3459 mutations with an average of 10 mutations per megabase and a median of 28 variants per sample. The most frequently mutated genes were KALRN (28%), SPTBN1 (32%), KMT2A (31%), ZNRF3 (9%), BNC2 (12%), NOTCH2 (25%), FGFR2 (12%), SMAD2 (6%), and AR (13%). Our findings were dominated by COSMIC signature 5 and 12, represented in other head and neck cancers and in hepatocellular carcinomas, respectively.
CONCLUSIONS: We have identified multiple genetic aberrations in HPV+ OPSCCs, and the COSMIC signature 12 as most prevalent. The mutations harbour both therapeutic and prognostic potential.

β‑catenin/CTNNB1 is an intracellular scaffold protein that interacts with adhesion molecules (E‑cadherin/CDH1, N‑cadherin/CDH2, VE‑cadherin/CDH5 and α‑catenins), transmembrane‑type mucins (MUC1/CD227 and MUC16/CA125), signaling regulators (APC, AXIN1, AXIN2 and NHERF1/EBP50) and epigenetic or transcriptional regulators (BCL9, BCL9L, CREBBP/CBP, EP300/p300, FOXM1, MED12, SMARCA4/BRG1 and TCF/LEF). Gain‑of‑function CTTNB1 mutations are detected in bladder cancer, colorectal cancer, gastric cancer, liver cancer, lung cancer, pancreatic cancer, prostate cancer and uterine cancer, whereas loss‑of‑function CTNNB1 mutations are also detected in human cancer. ABCB1, ALDH1A1, ASCL2, ATF3, AXIN2, BAMBI, CCND1, CD44, CLDN1, CTLA4, DKK1, EDN1, EOMES, FGF18, FGF20, FZD7, IL10, JAG1, LEF1, LGR5, MITF, MSX1, MYC, NEUROD1, NKD1, NODAL, NOTCH2, NOTUM, NRCAM, OPN, PAX3, PPARD, PTGS2, RNF43, SNAI1, SP5, TCF7, TERT, TNFRSF19, VEGFA and ZNRF3 are representative β‑catenin target genes. β‑catenin signaling is involved in myofibroblast activation and subsequent pulmonary fibrosis, in addition to other types of fibrosis. β‑catenin and NF‑κB signaling activation are involved in field cancerization in the stomach associated with Helicobacter pylori (H. pylori) infection and in the liver associated with hepatitis C virus (HCV) infection and other etiologies. β‑catenin‑targeted therapeutics are functionally classified into β‑catenin inhibitors targeting upstream regulators (AZ1366, ETC‑159, G007‑LK, GNF6231, ipafricept, NVP‑TNKS656, rosmantuzumab, vantictumab, WNT‑C59, WNT974 and XAV939), β‑catenin inhibitors targeting protein‑protein interactions (CGP049090, CWP232228, E7386, ICG‑001, LF3 and PRI‑724), β‑catenin inhibitors targeting epigenetic regulators (PKF118‑310), β‑catenin inhibitors targeting mediator complexes (CCT251545 and cortistatin A) and β‑catenin inhibitors targeting transmembrane‑type transcriptional outputs, including CD44v6, FZD7 and LGR5. Eradicating H. pylori and HCV is the optimal approach for the first‑line prevention of gastric cancer and hepatocellular carcinoma (HCC), respectively. However, β‑catenin inhibitors may be applicable for the prevention of organ fibrosis, second‑line HCC prevention and treating β‑catenin‑driven cancer. The multi‑layered prevention and treatment strategy of β‑catenin‑related human diseases is necessary for the practice of personalized medicine and implementation of precision medicine.

In the setting of Cushing syndrome, genomic analyses can be performed either in tumors responsible for endogenous Cushing, or in patients exposed to glucocorticoid excess. Genomics of tumors identified several new genes - including ZNRF3 in adrenocortical carcinomas, PRKACA in cortisol-producing adrenal adenomas, ARMC5 in primary macronodular adrenal hyperplasia and USP8 in pituitary corticotroph adenomas. These genes shed new lights on the mechanisms responsible for these tumors. Integrated genomic studies of adrenal carcinomas identified distinct molecular classes, with remarkably different prognostic outcome. Beyond the mechanistic novelties, a new generation of prognostic markers emerges, with potentially important impact on patients care. For the future, genomic efforts should be pursued, focusing on poorly characterized tumors responsible for Cushing syndrome - including endocrine tumors secreting ACTH. In addition, epigenomics is emerging as an outstanding set of tools for characterizing tumors, unraveling unprecedented aspects of tumorigenesis. Applying these tools to endocrine tumors responsible for Cushing syndrome may also lead to important discoveries. Genomics of patients exposed to glucocorticoid excess is an emerging research field. Proof of principle studies have been performed, identifying molecular markers of glucocorticoid excess in blood. Research efforts should now concentrate on markers of mild glucocorticoid excesses - endogenous or exogenous -, owing to their high prevalence in general population. In addition, markers of individual susceptibility to each type of glucocorticoid complication are needed. It remains to be determined whether genomics can identify such markers.

Molecular characterization of adrenocortical carcinoma has been recently established, but the correlation between molecular profiles and clinical and pathological characteristics is still poorly defined with no data available about genetic heterogeneity along disease progression. In this scenario, a detailed molecular profile was correlated with clinical and pathological characteristics in adrenocortical carcinoma patients to identify potentially novel biomarkers. Targeted next-generation sequencing and copy number variation analyses for 18 most frequently altered genes in adrenocortical carcinoma were assessed on 62 adult cases (including 10 with matched primary and metastatic/recurrence samples) and results correlated with major clinical and pathological characteristics of tumors. A total of 433 somatic deleterious genetic alterations (328 gene mutations and 105 copy number variations) were identified in 57/62 cases, five resulted wild type for all genes tested. TERT, CDK4, ZNRF3,and RB1 were altered in more than 30% of cases. Among histological variants genotypes were significantly different. Lowest mutation burden was found in the oncocytic type (p = 0.006), whereas the highest with a prevalence of RB1 (p = 0.001) and CDK4 (p = 0.002) was found in the conventional and myxoid ones, respectively. None of the 10 cases with matched samples showed a stable genotype along tumor progression, although allelic frequencies or percentages of altered nuclei at fluorescence in situ hybridization were in most cases similar among different tumor samples for genes that were stable along tumor progression. Among individual genes, an altered p53/Rb1 pathway was the strongest adverse molecular signature, being associated with high Ki-67 index, high tumor stage, aggressive disease status, and shorter disease-free survival. The genomic signature in adrenocortical carcinoma is changing along tumor progression and is associated with specific clinical and pathological features, including histological variant and prognosis.

This review describes the molecular alterations observed in the various types of tumors of the adrenal cortex, excluding Conn adenomas, especially the alterations identified by genomic approaches these last five years. Two main forms of bilateral adrenocortical tumors can be distinguished according to size and aspect of the nodules: primary pigmented nodular adrenal disease (PPNAD), which can be sporadic or part of Carney complex and primary bilateral macro nodular adrenal hyperplasia (PBMAH). The bilateral nature of the tumors suggests the existence of an underlying genetic predisposition. PPNAD and Carney complex are mainly due to germline-inactivating mutations of

Oral leukoplakia and erythroleukoplakia are common oral potentially malignant disorders diagnosed in the oral cavity. The specific outcome of these lesions remains to be elucidated, as their malignant transformation rate exhibits great variation. The ability to predict which of those potentially malignant lesions are likely to progress to cancer would be vital to guide their future clinical management. The present study reported two patients with tongue squamous cell carcinoma: Case study 1 was diagnosed with a simultaneous leukoplakia and case study 2 developed an erythroleukoplakia following the primary tumor treatment. Whole genome copy number alterations were analyzed using array comparative genomic hybridization. The present study determined more genomic imbalances in the tissues from leukoplakia and erythroleukoplakia compared with their respective tumors. The present study also identified in tumor and potentially malignant lesions common alterations of chromosomal regions and genes, including FBXL5, UGT2B15, UGT2B28, KANSL1, GSTT1 and DUSP22, being some of these typical aberrations described in oral cancer and others are linked to chemoradioresistance. Several putative genes associated with hallmarks of malignancy that may have an important role in predicting the progression of leukoplakia and erythroleukoplakia to squamous cell carcinoma, namely gains in BNIPL, MCL1, STAG2, CSPP1 and ZNRF3 genes were also identified.

Sessile serrated adenoma/polyps (SSA/Ps) are believed to be the major precursor of serrated pathway-derived colorectal carcinomas. To better characterize the process of progression from SSA/Ps to carcinomas, we analyzed 46 SSA/Ps with dysplasia and 45 SSA/Ps without dysplasia using targeted next-generation sequencing and immunohistochemistry. Among the WNT pathway genes analyzed, protein-truncating mutations of RNF43, APC, and ZNRF3 were identified in 23 (50%), 4 (9%), and 3 (7%) SSA/Ps with dysplasia, respectively. In contrast, SSA/Ps without dysplasia rarely had WNT pathway gene mutations, except for 3 lesions with RNF43 mutations (7%). None of the SSA/Ps had CTNNB1 mutations or RSPO fusions. Thus, WNT pathway gene mutations were more common in SSA/Ps with dysplasia than in SSA/Ps without dysplasia (P=3.0×10). Consistently, nuclear β-catenin accumulation and MYC overexpression, indicative of active WNT signaling, were present in most of the SSA/Ps with dysplasia, but were rare in those without dysplasia. BRAF (86%) or KRAS mutations (7%) were identified in the majority of SSA/Ps, regardless of the presence or absence of dysplasia. MLH1 expression was lost in 14 SSA/Ps with dysplasia (30%). The majority of MLH1-deficient SSA/Ps with dysplasia had RNF43 mutations (86%), most of which were frameshift mutations involving mononucleotide repeats. In contrast, MLH1-retained lesions had less frequent RNF43 mutations with no hot spots (34%), and 4 had APC mutations (13%). These results suggest that WNT pathway gene mutations are involved in the development of dysplasia in SSA/Ps and that MLH1-deficient and MLH1-retained SSA/Ps with dysplasia exhibit distinct mutation profiles of WNT pathway genes.

Zinc and ring finger 3 (ZNRF3) is a transmembrane E3 ubiquitin ligase that has emerged as an important regulator of cancer development; however, its cancer-related function remains controversial. Here, we investigated the possible role of ZNRF3 in thyroid carcinoma (TC). We found that ZNRF3 is downregulated in papillary thyroid carcinoma (PTC) compared to normal thyroid tissues and inversely correlated with the degree of cell differentiation. Overexpression of ZNRF3 significantly suppressed cell malignant behaviors, including cell proliferation, migration, and invasion in vitro, as well as tumor growth in vivo. Consistent with recent studies showing that ZNRF3 is involved in the Wnt/β-catenin pathway, ZNRF3 overexpression negatively regulated β-catenin activation, modulating PTC cell behaviors. Clinical specimens revealed a significant inverse correlation between ZNRF3 and β-catenin mRNA levels. Taken together, these results provide insight into a potential tumor suppressor role of ZNRF3 in PTC progression, and may have potential clinical relevance for the prognosis and treatment of PTC.

Zinc and ring finger 3 (ZNRF3), which belongs to the E3 ubiquitin ligase family, is involved in the progression and development of cancer. However, the expression and function of ZNRF3 in human nasopharyngeal carcinoma (NPC) remain unclear. Thus, the aim of this study was to investigate the role of ZNRF3 in human NPC. Our results showed that ZNRF3 was downregulated in NPC cell lines. Restoration of ZNRF3 significantly inhibited the proliferation of NPC cells and tumor xenograft growth in vivo. In addition, overexpression of ZNRF3 suppressed migration and invasion, as well as attenuated the epithelial-mesenchymal transition (EMT) process in NPC cells. Furthermore, restoration of ZNRF3 obviously downregulated the expression levels of β-catenin, cyclin D1, and c-Myc in NPC cells. In conclusion, these data suggest that ZNRF3 inhibited the metastasis and tumorigenesis via suppressing the Wnt/β-catenin signaling pathway in NPC cells. Thus, ZNRF3 may act as a novel molecular target for the treatment of NPC.

Serrated pathway colorectal cancers (CRCs) are characterised by a BRAF mutation and half display microsatellite instability (MSI). The Wnt pathway is commonly upregulated in conventional CRC through APC mutation. By contrast, serrated cancers do not mutate APC. We investigated mutation of the ubiquitin ligases RNF43 and ZNRF3 as alternate mechanism of altering the Wnt signal in serrated colorectal neoplasia. RNF43 was mutated in 47/54(87%) BRAF mutant/MSI and 8/33(24%) BRAF mutant/microsatellite stable cancers compared to only 3/79(4%) BRAF wildtype cancers (p<0.0001). ZNRF3 was mutated in 16/54(30%) BRAF mutant/MSI and 5/33(15%) BRAF mutant/microsatellite stable compared to 0/27 BRAF wild type cancers (p=0.004). An RNF43 frameshift mutation (X659fs) occurred in 80% BRAF mutant/MSI cancers. This high rate was verified in a second series of 25/35(71%) BRAF mutant/MSI cancers. RNF43 and ZNRF3 had lower transcript expression in BRAF mutant compared to BRAF wildtype cancers and less cytoplasmic protein expression in BRAF mutant/MSI compared to other subtypes. Treatment with a porcupine inhibitor reduced RNF43/ZNRF3 mutant colony growth by 50% and synergised with a MEK inhibitor to dramatically reduce growth. This study suggests inactivation of RNF43 and ZNRF3 is important in serrated tumorigenesis and has identified a potential therapeutic strategy for this cancer subtype.

The last decade witnessed the emergence of genomics, a set of high-throughput molecular measurements in biological samples. These pan-genomic and agnostic approaches have revolutionized the molecular biology and genetics of malignant and benign tumors. These techniques have been applied successfully to adrenocortical tumors. Exome sequencing identified new major drivers in all tumor types, including KCNJ5, ATP1A1, ATP2B3 and CACNA1D mutations in aldosterone-producing adenomas (APA), PRKACA mutations in cortisol-producing adenomas (CPA), ARMC5 mutations in primary bilateral macronodular adrenocortical hyperplasia (PBMAH) and ZNRF3 mutations in adrenocortical carcinomas (ACC). Moreover, the various genomic approaches - including exome sequencing, transcriptome, miRNome, genome and methylome - converge into a single molecular classification of adrenocortical tumors. Especially for ACC, two main molecular groups have emerged, showing major differences in outcomes. These ACC groups differ by their gene expression profiles, but also by recurrent mutations and specific DNA hypermethylation patterns in the subgroup of poor outcome. The clinical impact of these findings is just starting. The main altered signaling pathways now become therapeutic targets. The molecular groups of diseases individualize robust subtypes within diseases such as APA, CPA, PBMAH and ACC. A revised nosology of adrenocortical tumors should impact the clinical research. Obvious consequences also include genetic counseling for the new genetic diseases such as ARMC5 mutations in PBMAH, and a better prognostication of ACC based on targeted measurements of a few discriminant molecular alterations. Identifying the main molecular groups of adrenocortical tumors by extensively gathering the molecular variations is a significant step forward towards precision medicine.

Osteosarcoma is the most common human primary malignant bone tumor and recurrences are common due to the development of chemoresistance. However, the underlying molecular mechanism for chemoresistance remains unclear. Recent studies demonstrated that miR-146b-5p, an important regulator in tumorigenesis, was involved in chemoresistance in thyroid cancer, lymphoma. Thus, to confirm the role of miR‑146b-5p in osteosarcoma, the study was divided into three steps: first, miR-146b-5p in paired samples were assessed using a quantitative real-time PCR (qRT-PCR) assay from osteosarcoma patients. Second, to confirm the role of miR-146b-5p, we applied lentivirus system to overexpression and knockdown of miR-146b-5p, respectively, in MG-63 osteosarcoma cell line. Third, luciferase assays were performed to determine whether Wnt/β-catenin pathway participated in the role of miR-146b-5p on chemoresistance. As a result, miR-146b-5p was highly expressed in human osteosarcoma tissues and an elevated expression of miR-146b-5p was observed in human osteosarcoma tissues after chemotherapy. Furthermore, it was shown that miR-146b-5p overexpression promoted migration and invasiveness. miR-146b-5p overexpression also increased resistance to chemotherapy. Moreover, knockdown of miR-146b-5p substantially inhibited migration and invasion of osteosarcoma cells as well as rendered them significantly more sensitive to chemotherapy. Results of western blot assay indicated that miR-146b-5p increased MMP-16 protein expression and showed a decrease of ZNRF3 protein. Whereas, IWR-1-endo, an inhibitor of Wnt/β-catenin, suppressed the decrease in apoptosis of osteosarcoma cells caused by miR-146b-5p overexpression. These results indicated that miR-146b-5p promoted proliferation, migration and invasiveness. It also increased resistance to chemotherapy through the regulation of ZNRF3, and suggested novel potential therapeutic targets for the treatment of osteosarcoma.

Pancreatic cancer is the fourth leading cause of cancer death in the developed world. Both inherited high-penetrance mutations in BRCA2 (ref. 2), ATM, PALB2 (ref. 4), BRCA1 (ref. 5), STK11 (ref. 6), CDKN2A and mismatch-repair genes and low-penetrance loci are associated with increased risk. To identify new risk loci, we performed a genome-wide association study on 9,925 pancreatic cancer cases and 11,569 controls, including 4,164 newly genotyped cases and 3,792 controls in 9 studies from North America, Central Europe and Australia. We identified three newly associated regions: 17q25.1 (LINC00673, rs11655237, odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.19-1.34, P = 1.42 × 10(-14)), 7p13 (SUGCT, rs17688601, OR = 0.88, 95% CI = 0.84-0.92, P = 1.41 × 10(-8)) and 3q29 (TP63, rs9854771, OR = 0.89, 95% CI = 0.85-0.93, P = 2.35 × 10(-8)). We detected significant association at 2p13.3 (ETAA1, rs1486134, OR = 1.14, 95% CI = 1.09-1.19, P = 3.36 × 10(-9)), a region with previous suggestive evidence in Han Chinese. We replicated previously reported associations at 9q34.2 (ABO), 13q22.1 (KLF5), 5p15.33 (TERT and CLPTM1), 13q12.2 (PDX1), 1q32.1 (NR5A2), 7q32.3 (LINC-PINT), 16q23.1 (BCAR1) and 22q12.1 (ZNRF3). Our study identifies new loci associated with pancreatic cancer risk.

Rnf43 (RING finger protein 43) and Znrf3 (zinc/RING finger protein 3) (RZ) are two closely related transmembrane E3 ligases, encoded by Wnt target genes, that remove surface Wnt (wingless-int) receptors. The two genes are mutated in various human cancers. Such tumors are predicted to be hypersensitive to, yet still depend on, secreted Wnts. We previously showed that mutation of RZ in the intestine yields rapidly growing adenomas containing LGR5(+) (leucine-rich repeat-containing G-protein coupled receptor 5) stem cells and Wnt3-producing Paneth cells. We now show that removal of Paneth cells by Math1 mutation inhibits RZ(-/-) tumor formation. Similarly, deletion of Wnt3 inhibits tumorigenesis. Treatment of mice carrying RZ(-/-) intestinal neoplasia with a small molecule Wnt secretion inhibitor (porcupine inhibitor C59) strongly inhibited growth, whereas adjacent normal crypts remained intact. These results establish that paracrine Wnt secretion is an essential driver of RZ(-/-) tumor growth and imply that a therapeutic window exists for the use of porcupine inhibitors for RZ-mutant cancers.

BACKGROUND/AIMS: Micro-RNA (miR)-146b-5p is overexpressed in papillary thyroid carcinoma (PTC) and associated with extrathyroidal invasion and advanced tumor stage. In the present study, we showed that miR-146b-5p is upregulated in PTC with lymph node metastasis.
METHODS: A computational search and luciferase assay identified zinc RING finger 3 (ZNRF3), a negative regulator of Wnt/β-catenin signaling, as a direct target of miR-146b-5p in PTC.
RESULTS: MiR-146b-5p promoted migration and invasiveness and induced epithelial-mesenchymal transition (EMT) of PTC cells, whereas ZNRF3 overexpression reversed this effect. MiR-146b-5p increased the cell surface levels of the Wnt receptors Frizzled-6 and LRP6 and enhanced Wnt/β-catenin signaling by downregulating ZNRF3, whereas an inhibitor of Wnt/β-catenin suppressed the effect of miR-146b-5p on migration, invasiveness and EMT of PTC cells.
CONCLUSION: These results indicate that miR-146b-5p induces EMT and may promote PTC metastasis through the regulation of Wnt/β-catenin signaling, and suggest novel potential therapeutic targets for the treatment of PTC.

CONTEXT: Adrenocortical carcinoma (ACC) is a rare and lethal malignancy with a poorly defined etiology, and the molecular genetics of ACC are incompletely understood.
OBJECTIVE: To utilize whole-exome sequencing for genetic characterization of the underlying somatic mutations and copy number alterations present in ACC.
DESIGN: Screening for somatic mutation events and copy number alterations (CNAs) was performed by comparative analysis of tumors and matched normal samples from 41 patients with ACC.
RESULTS: In total, 966 nonsynonymous somatic mutations were detected, including 40 tumors with a mean of 16 mutations per sample and one tumor with 314 mutations. Somatic mutations in ACC-associated genes included TP53 (8/41 tumors, 19.5%) and CTNNB1 (4/41, 9.8%). Genes with potential disease-causing mutations included GNAS, NF2, and RB1, and recurrently mutated genes with unknown roles in tumorigenesis comprised CDC27, SCN7A, and SDK1. Recurrent CNAs included amplification at 5p15.33 including TERT (6/41, 14.6%) and homozygous deletion at 22q12.1 including the Wnt repressors ZNRF3 and KREMEN1 (4/41 9.8% and 3/41, 7.3%, respectively). Somatic mutations in ACC-established genes and recurrent ZNRF3 and TERT loci CNAs were mutually exclusive in the majority of cases. Moreover, gene ontology identified Wnt signaling as the most frequently mutated pathway in ACCs.
CONCLUSIONS: These findings highlight the importance of Wnt pathway dysregulation in ACC and corroborate the finding of homozygous deletion of Wnt repressors ZNRF3 and KREMEN1. Overall, mutations in either TP53 or CTNNB1 as well as focal CNAs at the ZNRF3 or TERT loci denote mutually exclusive events, suggesting separate mechanisms underlying the development of these tumors.

Adrenocortical carcinomas (ACCs) are aggressive cancers originating in the cortex of the adrenal gland. Despite overall poor prognosis, ACC outcome is heterogeneous. We performed exome sequencing and SNP array analysis of 45 ACCs and identified recurrent alterations in known driver genes (CTNNB1, TP53, CDKN2A, RB1 and MEN1) and in genes not previously reported in ACC (ZNRF3, DAXX, TERT and MED12), which we validated in an independent cohort of 77 ACCs. ZNRF3, encoding a cell surface E3 ubiquitin ligase, was the most frequently altered gene (21%) and is a potential new tumor suppressor gene related to the β-catenin pathway. Our integrated genomic analyses further identified two distinct molecular subgroups with opposite outcome. The C1A group of ACCs with poor outcome displayed numerous mutations and DNA methylation alterations, whereas the C1B group of ACCs with good prognosis displayed specific deregulation of two microRNA clusters. Thus, aggressive and indolent ACCs correspond to two distinct molecular entities driven by different oncogenic alterations.

Osteoblastoma is a bone forming tumor with histological features highly similar to osteoid osteoma; the discrimination between the tumor types is based on size and growth pattern. The vast majority of osteoblastomas are benign but there is a group of so-called aggressive osteoblastomas that can be diagnostically challenging at the histopathological level. The genetic aberrations required for osteoblastoma development are not known and no genetic difference between conventional and aggressive osteoblastoma has been reported. In order to identify recurrent genomic aberrations of importance for tumor development we applied cytogenetic and/or SNP array analyses on nine conventional and two aggressive osteoblastomas. The conventional osteoblastomas showed few or no acquired genetic aberrations while the aggressive tumors displayed heavily rearranged genomes. In one of the aggressive osteoblastomas, three neighboring regions in chromosome band 22q12 were homozygously deleted. Hemizygous deletions of these regions were found in two additional cases, one aggressive and one conventional. In total, 10 genes were recurrently and homozygously lost in osteoblastoma. Four of them are functionally involved in regulating osteogenesis and/or tumorigenesis. MN1 and NF2 have previously been implicated in the development of leukemia and solid tumors, and ZNRF3 and KREMEN1 are inhibitors of the Wnt/beta-catenin signaling pathway. In line with deletions of the latter two genes, high beta-catenin protein expression has previously been reported in osteoblastoma and aberrations affecting the Wnt/beta-catenin pathway have been found in other bone lesions, including osteoma and osteosarcoma.

E3 ubiquitin ligases regulate a variety of biological processes through the ubiquitin-proteasome system, together with ubiquitin activating enzyme E1 and ubiquitin-conjugating enzyme E2. Previous studies have demonstrated that zinc and ring finger 3 (ZNRF3), which belongs to the E3 ubiquitin ligases family is involved in the Wnt signalling pathway, which plays an important role in causing cancer. However, the expression and function of ZNRF3 in human gastric adenocarcinoma still remains unclear. Immunohistochemical and western blot analysis showed a significant down-regulation of ZNRF3 protein in gastric adenocarcinoma tissues compared with adjacent normal gastric tissues. In addition, there was a correlation between the down-regulation of ZNRF3 and poor tissue differentiation in gastric adenocarcinoma. To investigate the potential function of ZNRF3 in cell proliferation and apoptosis, a gastric cell line SGC7901 was employed. The over-expression of wild-type ZNRF3, which was accomplished by the transient transfection of recombinant pEGFP-ZNRF3 (or empty plasmids as control) into the cell line SGC7901, was confirmed by western blot analysis. Flow-cytometry-based and Cell Counting Kit-8 assays showed that over-expression of wt ZNRF3 induced apoptosis and suppressed proliferation. ZNRF3-overexpressing gastric cells displayed partly attenuated protein levels of beta-catenin and TCF-4 compared with those transfected with the empty plasmid. Our study demonstrates a novel gastric adenocarcinoma suppressor and reveals that ZNRF3 inhibits gastric cancer cell growth and promotes the cell apoptosis by affecting the Wnt/beta-catenin/TCF signalling pathway.

Aberrant activation of the Wnt/β-catenin pathway occurs in cancers. This review presents several important cancer-related aspects of Wnt/β-catenin signalling relevant to the epididymis, provides evidence of such epididymal gene expression and suggests a new direction for further research. The data presented here indicate that besides containing many Wnt/β-catenin-pathway components, the normal adult human epididymis expresses much more β-catenin than the colorectal carcinoma cell line HCT116, which possesses elevated β-catenin expression. The low cancer incidence in the epididymis may be due to factors present in the human epididymis that regulate this oncogenic Wnt/β-catenin pathway, including (i) 14 of 17 secreted pathway inhibitors, (ii) the majority of the micro-RNAs known to target this pathway, (iii) plasma membrane-associated E-cadherin and CEACAM1 that anchor β-catenin, preventing its availability for nuclear entry and oncogenic transcriptional activity, (iv) the recently identified membrane-located tumourigenesis inhibitors RNF43 and ZNRF3 that mediate the degradation of the Wnt receptor components Fzds and Lrp5/6 and (v) nuclear KLF4, which competes with TCF for β-catenin, limiting its transcriptional activity and stabilizing telomeres, thereby reducing mutation incidence. The above regulatory factors expressed by the human epididymis, and the absence of androgen receptor translocation known to promote nuclear translocation of β-catenin in tumourigenesis in an animal model, may act synergistically to provide hostility in different cell compartments towards tumour formation. The lack of evidence for β-catenin in epididymal nuclei is noteworthy. Studying this phenomenon may help reveal the mechanisms underlying oncogenic Wnt/β-catenin signalling and shed new light on cancer therapy and prevention.

LGR5+ stem cells reside at crypt bottoms, intermingled with Paneth cells that provide Wnt, Notch and epidermal growth factor signals. Here we find that the related RNF43 and ZNRF3 transmembrane E3 ubiquitin ligases are uniquely expressed in LGR5+ stem cells. Simultaneous deletion of the two genes encoding these proteins in the intestinal epithelium of mice induces rapidly growing adenomas containing high numbers of Paneth and LGR5+ stem cells. In vitro, growth of organoids derived from these adenomas is arrested when Wnt secretion is inhibited, indicating a dependence of the adenoma stem cells on Wnt produced by adenoma Paneth cells. In the HEK293T human cancer cell line, expression of RNF43 blocks Wnt responses and targets surface-expressed frizzled receptors to lysosomes. In the RNF43-mutant colorectal cancer cell line HCT116, reconstitution of RNF43 expression removes its response to exogenous Wnt. We conclude that RNF43 and ZNRF3 reduce Wnt signals by selectively ubiquitinating frizzled receptors, thereby targeting these Wnt receptors for degradation.

Asbestos-related lung cancer accounts for 4-12% of all lung cancers worldwide. Since putative mechanisms of carcinogenesis differ between asbestos and tobacco induced lung cancers, tumors induced by the two agents may be genetically distinct. To identify gene expression biomarkers associated with asbestos-related lung tumorigenicity we performed gene expression array analysis on tumors of 36 patients with primary lung adenocarcinoma, comparing 12 patients with lung asbestos body counts above levels associated with urban dwelling (ARLC-AC: asbestos-related lung cancer-adenocarcinoma) with 24 patients with no asbestos bodies (NARLC-AC: non-asbestos related lung cancer-adenocarcinoma). Genes differentially expressed between ARLC-AC and NARLC-AC were identified on fold change and P value, and then prioritized using gene ontology. Candidates included ZNRF3, ADAM28, PPP1CA, IRF6, RAB3D, and PRDX1. Expression of these six genes was technically and biologically replicated by qRT-PCR in the training set and biologically validated in three independent test sets. ADAM28, encoding a disintegrin and metalloproteinase domain protein that interacts with integrins, was consistently upregulated in ARLC across all four datasets. Further studies are being designed to investigate the possible role of this gene in asbestos lung tumorigenicity, its potential utility as a marker of asbestos related lung cancer for purposes of causal attribution, and its potential as a treatment target for lung cancers arising in asbestos exposed persons.