OBJECTIVE: The protein interacting with carboxyl terminus-1 (PICT-1) gene has been implicated as a tumor suppressor gene, and its alterations have been reported in several cancers. This study investigated the association of PICT-1 alterations with endometrial carcinogenesis.
METHODS: We analyzed the entire coding region of the PICT-1 gene using polymerase chain reaction-single-strand conformation polymorphism and DNA sequencing to examine PICT-1 mutations in endometrial cancer. Western blotting and immunohistochemical staining were performed to analyze the protein expression and cellular localization of PICT-1 in endometrial cancer cell lines and patient samples.
RESULTS: The codon 389 polymorphism of PICT-1 increased the risk of endometrial cancer. Interestingly, 2 of 13 endometrial cancers somatically acquired this mutation compared to normal counterparts. Immunohistochemical staining revealed lower levels of PICT-1 in samples from atypical endometrial hyperplasia and endometrial cancer tissues compared to normal endometrial tissues (p < 0.01). This decrease in PICT-1 expression was significantly correlated with histological grade and lymph node metastasis (p < 0.05).
CONCLUSIONS: The findings of this study suggest that disruption of PICT-1 protein expression and codon 389 polymorphism can contribute to the pathogenesis or neoplastic progression of endometrial cancer.

Neuroblastoma is the most common extracranial solid tumor in childhood. The vast majority of metastatic (M) stage patients present with disseminated tumor cells (DTCs) in the bone marrow (BM) at diagnosis and relapse. Although these cells represent a major obstacle in the treatment of neuroblastoma patients, insights into their expression profile remained elusive. The present RNA-Seq study of stage 4/M primary tumors, enriched BM-derived diagnostic and relapse DTCs, as well as the corresponding BM-derived mononuclear cells (MNCs) from 53 patients revealed 322 differentially expressed genes in DTCs as compared to the tumors (q < 0.001, |log

The nucleolus is a distinct compartment of the nucleus responsible for ribosome biogenesis. Mis-regulation of nucleolar functions and of the cellular translation machinery has been associated with disease, in particular with many types of cancer. Indeed, many tumor suppressors (p53, Rb, PTEN, PICT1, BRCA1) and proto-oncogenes (MYC, NPM) play a direct role in the nucleolus, and interact with the RNA polymerase I transcription machinery and the nucleolar stress response. We have identified Dicer and the RNA interference pathway as having an essential role in the nucleolus of quiescent Schizosaccharomyces pombe cells, distinct from pericentromeric silencing, by controlling RNA polymerase I release. We propose that this novel function is evolutionarily conserved and may contribute to the tumorigenic pre-disposition of DICER1 mutations in mammals.

PICT-1 is a nucleolar protein with various tumor suppressor functions. Recently, PICT-1 expression was reported to be dramatically reduced in several cancers. To investigate the role of PICT-1 in uterine cervical carcinogenesis, we examined its gene mutations, protein expression, cellular localization, and effect on p53 stabilization. PCR-SSCP analysis of the entire coding region of PICT-1 showed that a polymorphism at codon 389 may increase the risk of uterine cervical cancers, and also identified a novel missense mutation. Expression of wild-type PICT-1 inhibited the degradation of p53 in the presence or absence of HPV 18 E6 viral protein in vitro, while the expression of codon 389 polymorphic PICT-1 had a diminished inhibitory effect on p53 degradation. Moreover, we observed that PICT-1 degradation was induced both independently and cooperatively by E6 and E7 proteins from high-risk HPVs, but only marginal degradation was observed with proteins from low-risk HPV. Immunohistochemical staining of tumor samples revealed that lower levels of PICT-1 were observed in samples from CIN III and cervical cancer tissues, compared to normal cervical epithelium and CIN I, II tissues (P < 0.05). The reduction of PICT-1 may therefore be an early event in uterine cervical tumorigenesis. Our results indicated that PICT-1 counteracts HPV-induced p53 degradation and that aberrant PICT-1 function may contribute towards inactivating p53. Therefore, PICT-1 may play a critical role during the pathogenesis of uterine cervical cancers.

PICT-1 was originally identified as a tumor suppressor. Here, we found that PICT-1 overexpression triggered pro-death autophagy without nucleolar disruption or p53 accumulation in U251 and MCF7 cells. Truncated PICT-1 fragments 181-346 and 1-346, which partly or totally lack nucleolar localization, showed weaker autophagy-inducing effects than full-length PICT-1 and a well-defined nucleolar mutant (181-479). Furthermore, PICT-1 partly localizes to the nucleolar fibrillar center (FC) and directly binds to ribosomal DNA (rDNA) gene loci, where it interacts with upstream binding factor (UBF). Overexpression of PICT-1 or the 181-479 mutant, but not the 1-346 or 181-346 mutants, markedly inhibited the phosphorylation of UBF and the recruitment of rRNA polymerase I (Pol I) to the rDNA promoter in response to serum stimulation, thereby suppressing rRNA transcription, suggesting that rRNA transcription inhibition might be an important contributor to PICT-1-induced autophagy. This is supported by the finding that CX-5461, a specific Pol I inhibitor, also induced autophagy. In addition, both CX-5461 and PICT-1, but not the 1-346 or 181-346 mutants, significantly suppressed the activation of the Akt/mTOR/p70S6K signaling pathway. Our data show that PICT-1 triggers pro-death autophagy through inhibition of rRNA transcription and the inactivation of AKT/mTOR/p70S6K pathway, independent of nucleolar disruption and p53 activation.

Nucleolar protein PICT-1/GLTSCR2 (GLTSCR2) has both tumor suppressive and oncogenic activities, depending on the types of cancer tissue and its expression level. The role of GLTSCR2 in renal cell carcinoma (RCC) has not yet been addressed. The aims of this study were to evaluate GLTSCR2 expression in RCC tissue and to determine pathological significance of GLTSCR2 in terms of tumor grade. RCC and adjacent normal tissue from 84 different patients was retrieved from nephrectomy specimens. The expression level of GLTSCR2 in RCC tissues was determined via immunohistochemical staining and invasion was determined using transwell chambers with Matrigel-coated membranes. The expression of GLTSCR2 was suppressed in about 80% of the carcinoma specimens compared to noncancerous renal tissue and inversely correlated with Fuhrman nuclear grade (r=-0.40, p<0.05). Knockdown of GLTSCR2 expression increased the invasiveness of SNU267 RCC cells. The expression of GLTSCR2 was suppressed in RCCs and its downregulation accentuated the malignant phenotype.

The contributing molecular pathways underlying the pathogenesis of breast cancer need to be better characterized. The principle of our study was to better understand the genetic mechanism of oncogenesis for human breast cancer and to discover new possible tumor markers for use in clinical practice. We used complimentary DNA (cDNA) microarrays to compare gene expression profiles of treated Michigan Cancer Foundation-7 (MCF-7) with recombinant bromelain and untreated MCF-7. SpringGene analysis was carried out of differential expression followed by Ingenuity Pathway Analysis (IPA), to understand the underlying consequence in developing disease and disorders. We identified 1,102 known genes differentially expressed to a significant degree (p<0.001) changed between the treatment. Within this gene set, 20 genes were significantly changed between treated cells and the control cells with cutoff fold change of more than 1.5. These genes are RNA-binding motif, single-stranded interacting protein 1 (RBMS1), ribosomal protein L29 (RPL29), glutathione S-transferase mu 2 (GSTM2), C15orf32, Akt3, B cell translocation gene 1 (BTG1), C6orf62, C7orf60, kinesin-associated protein 3 (KIFAP3), FBXO11, AT-rich interactive domain 4A (ARID4A), COPS2, TBPL1|SLC2A12, TMEM59, SNORD46, glioma tumor suppressor candidate region gene 2 (GLTSCR2), and LRRFIP. Our observation on gene expression indicated that recombinant bromelain produces a unique signature affecting different pathways, specific for each congener. The microarray results give a molecular mechanistic insight and functional effects, following recombinant bromelain treatment. The extent of changes in genes is related to and involved significantly in gap junction signaling, amyloid processing, cell cycle regulation by BTG family proteins, and breast cancer regulation by stathmin1 that play major roles.

Glioma tumor-suppressor candidate region gene2 (GLTSCR2) is a recently identified nucleolus-localized protein participating in the regulation of cell cycle progression and apoptosis. Down-regulation of GLTSCR2 in several types of cancers and increased transforming activity in GLTSCR2-downregulated cancer cells indicated its tumor suppressive potential. The aim of this study was to evaluate GLTSCR2 expression in breast cancer and to investigate the question of whether reduced expression of GLTSCR2 may have any pathological significance in breast cancer development or progression. In this study, we performed quantitative RT-PCR and immunohistochemistry to evaluate the expression of GLTSCR2 and relevance with clinicopathological factors in the invasive ductal carcinoma (IDC). GLTSCR2 expression was reduced in 48% of IDC (n=426) by a semi-quantitative scoring system using tissue microarray. GLTSCR2 mRNA was significantly reduced by 0.16 fold in 15 out of 17 (88%) cases of IDC. Reduction of GLTSCR2 was significantly correlated with increased histological grade (p<0.005), increased tumor size (p<0.001), axillary lymph node involvement (p<0.001) and decreased disease free survival (p<0.025). In addition, we show that upregulation of GLTSCR2 decreases the invasive potential of breast cancer cells. Taken together, our data suggest that GLTCR2 may play a role in the tumorigenesis, progression and biological behavior in breast cancer.

GLTSCR2 is a nuclear/nucleolar protein that translocates to the nucleoplasm, suppressed and mutated in human cancers. Our aim in this study was to investigate whether downregulation or cytoplasmic expression of GLTSCR2 has any pathological significance in prostatic cancer development or progression. In this study we show that GLTSCR2 is suppressed in prostatic cancers and its expression is significantly associated with Gleason's scores. Furthermore, we investigated the pathogenetic mechanism of downregulation and cytoplasmic expression of GLTSCR2 in development or progression of prostatic cancers. Taken together, our results indicate that GLTSCR2 functions as a tumor suppressor in prostatic adenocarcinomas.

Malignant peripheral nerve sheath tumors (MPNSTs) are malignant tumors with a high rate of local recurrence and a significant tendency to metastasize. Its dismal outcome points to the urgent need to establish better therapeutic strategies for patients harboring MPNSTs. The investigations of genomic and molecular aberrations in MPNSTs which detect many chromosomal aberrations, pathway abnormalities, and specific molecular aberrant events would supply multiple potential therapy targets and contribute to achievement of personalized medicine. The involved genes in the significant gains aberrations include BIRC5, CCNE2, DAB2, DDX15, EGFR, DAB2, MSH2, CDK6, HGF, ITGB4, KCNK12, LAMA3, LOXL2, MET, and PDGFRA. The involved genes in the significant deletion aberrations include CDH1, GLTSCR2, EGR1, CTSB, GATA3, SULT2A1, GLTSCR2, HMMR/RHAMM, LICAM2, MMP13, p16/INK4a, RASSF2, NM-23H1, and TP53. These genetic aberrations involve in several important signaling pathways such as TFF, EGFR, ARF, IGF1R signaling pathways. The genomic and molecular aberrations of EGFR, IGF1R, SOX9, EYA4, TOP2A, ETV4, and BIRC5 exhibit great promise as personalized therapeutic targets for MPNST patients.

BACKGROUND: TP53 is one of the most widely known cancer suppressor genes. Mutations in TP53 are ubiquitously observed in almost all cancers. Incidences of mutations range from ~15-70 % in patients with hepatocellular carcinoma (HCC). Moreover, patients with mutated TP53 have poorer prognoses than those with wild-type TP53; therefore, it would be beneficial to predict the prognosis of HCC patients with wild-type TP53. We previously reported that PICT1, coding a nucleolus protein, regulates TP53 through indirect association.
METHODS: In this study, we examined PICT1 expression levels and the status of TP53 in 51 primary HCC tissues in order to determine the clinical significance of PICT1 expression and the function of PICT1 in HCC cells.
RESULTS: We detected 6 mutations in the 51 samples. In 45 patients with wild-type TP53, those with high PICT1 expression (n = 11) had poorer prognoses than those with low PICT1 expression (n = 34), and there were no significant associations with other clinicopathological factors. According to gene set enrichment analysis, PICT1 expression was inversely correlated with the gene set of TP53. In vitro assays indicated that suppression of PICT1 expression caused an increase in TP53 expression, reduction in cell proliferation, and arrest at the G1 phase of the cell cycle in HCC cells expressing wild-type TP53.
CONCLUSIONS: PICT1 should be a useful prognostic marker in HCC patients having wild-type TP53. Furthermore, PICT1 may become a promising therapeutic target because of its ability to increase the expression and activation of TP53.

Tumor hypoxia may be an indicator of poor survival in cancer patients. Thus, an understanding of the molecular mechanism responsible for hypoxic tumor selection is essential to gain further insight into tumor biology. Our aim in this study was to investigate whether hypoxia-responsive GLTSCR2 contributes to death resistance and increased invasiveness of hypoxia-selected glioblastoma cells. We found that repeated hypoxia downregulates p53-upstream regulator, GLTSCR2, which resulted in increased death resistance and invasive potential of glioblastoma cells. Restoration of GLTSCR2 expression suppressed the malignant potential of hypoxia-selected cells. Our results indicate that GLTSCR2 participates in hypoxia-induced malignant potential.

Cell growth demands new protein synthesis, which requires nucleolar ribosomal functions. Ribosome biogenesis consumes a large proportion of the cell's resources and energy, and so is tightly regulated through an intricate signaling network to guarantee fidelity. Thus, events that impair ribosome biogenesis cause nucleolar stress. In response to this stress, several nucleolar ribosomal proteins (RPs) translocate to the nucleoplasm and bind to MDM2. MDM2-mediated ubiquitination and degradation of the tumor suppressor p53 is then blocked, resulting in p53 accumulation and the induction of p53-dependent cell cycle arrest and apoptosis. Nucleolar stress is therefore a quality control surveillance mechanism that monitors the synthesis and assembly of the rRNA and protein components of ribosomes. Although nucleolar stress signaling pathways have been extensively analyzed, critical questions remain about their regulatory mechanisms. For example, how do RPs translocate from the nucleolus to the nucleoplasm to exert their functions, and do these p53-regulating RPs influence the prognosis of human cancer patients? Our laboratory recently identified the nucleolar protein PICT1 as a novel regulator of nucleolar stress. PICT1 sequesters the ribosomal protein RPL11 in the nucleolus, preventing it from binding to MDM2. MDM2 is then free to degrade p53, favoring tumor cell growth. Accordingly, the level of PICT1 in a tumor is becoming a useful prognostic marker for human cancers. This review summarizes the evidence that links nucleolar stress to tumorigenesis, and casts PICT1 as an oncogenic player in human cancer biology.

The classification of follicular thyroid neoplasms requires surgical resection for histologic evaluation of malignancy. Because variable clinical behavior exists, genomic expression profiling may lead to the identification of novel markers that facilitate better biologic classification. We performed for the first time gene expression analysis on clinically aggressive and nonaggressive follicular carcinomas (FCs) from patients for whom long-term follow-up data were available. We examined matched fresh-frozen tissue from 15 histopathologically diagnosed follicular carcinomas (7 patients with documented distant metastasis and/or death from disease and 8 patients without recurrence). For categorical comparison, we analyzed 4 follicular adenomas (FAs). The biologic control comprised 11 normal thyroid tissue specimens. High-quality RNA was extracted from the tissues, labeled, and hybridized to an Affymetrix (Santa Clara, CA) oligonucleotide microarray (HG-U133A). With the exceptions of 1 follicular adenoma and 1 follicular carcinoma, unsupervised hierarchical cluster analysis revealed 2 distinct groups--one containing normal thyroid tissue and follicular adenomas and another containing follicular carcinomas. We identified 421 genes that were differentially expressed between histologically normal thyroid tissues and all follicular neoplasms (P < 0.01; fold-change >2), 94 genes that distinguished follicular carcinomas from follicular adenomas (including PBP and CKS2), and 4 genes that distinguished aggressive follicular carcinomas from nonaggressive follicular carcinomas (NID2, TM7SF2, TRIM2, and GLTSCR2). Comparative genomic groupings identified differentially expressed genes that may lead to better classification of follicular thyroid neoplasms. Such genes may be used in future prospective validation studies to establish clinically useful and complementary diagnostic markers.

Moesin-ezrin-radixin-like protein (merlin) has long been considered a unique tumour suppressor that inhibits mitogenic signalling only at the membrane-cytoskeleton interface. However, the nucleocytoplasmic shuttling of merlin in a cell cycle-dependent manner has recently been observed, indicating that merlin may also exert its tumour-suppressive activity by interacting with specific nuclear protein partners. We have identified protein interacting with carboxyl terminus 1 (PICT-1) as a novel merlin-binding partner. Although the detailed mechanisms are not fully understood, several lines of evidence have previously implicated PICT-1 as a candidate tumour suppressor, including its phosphatase and tensin homolog deleted on chromosome 10 (PTEN)-dependent growth-suppression and cell-killing activities. We show here that PICT-1 is localised to the nucleolus, and Ser518-dephosphorylated merlin (the growth-inhibitory form of merlin) can interact with PICT-1 in the nucleolus. Ectopic expression of PICT-1, both in PTEN-positive HeLa cells and in PTEN-deficient U251 cells, effectively represses cyclin D1 expression, arrests the cell cycle at G0/G1, and promotes cell apoptosis. PICT-1 (1-356), a carboxyl-terminus truncated mutant that has lost the ability to bind merlin, has a markedly reduced inhibitory effect on the cell cycle and proliferation. Knockdown of merlin expression by siRNA attenuates the inhibitory effects induced by PICT-1 over-expression. We propose that merlin mediates PICT-1-induced growth inhibition by translocating to the nucleolus and binding PICT-1.

BACKGROUND: The malignant potential of serous ovarian tumors, the most common ovarian tumor subtype, varies from benign to low malignant potential (LMP) tumors to frankly invasive cancers. Given the uncertainty about the relationship between these different forms, we compared their patterns of gene expression.
METHODS: Expression profiling was carried out on samples of 7 benign, 7 LMP and 28 invasive (moderate and poorly differentiated) serous tumors and four whole normal ovaries using oligonucleotide microarrays representing over 21,000 genes.
RESULTS: We identified 311 transcripts that distinguished invasive from benign tumors, and 20 transcripts that were significantly differentially expressed between invasive and LMP tumors at p < 0.01 (with multiple testing correction). Five genes that were differentially expressed between invasive and either benign or normal tissues were validated by real time PCR in an independent panel of 46 serous tumors (4 benign, 7 LMP, 35 invasive). Overexpression of SLPI and WNT7A and down-regulation of C6orf31, PDGFRA and GLTSCR2 were measured in invasive and LMP compared with benign and normal tissues. Over-expression of WNT7A in an ovarian cancer cell line led to increased migration and invasive capacity.
CONCLUSION: These results highlight several genes that may play an important role across the spectrum of serous ovarian tumorigenesis.

Glioma tumour-suppressor candidate region gene 2 (GLTSCR2/PICT-1) is localized within the well-known 1.4 Mb tumour-suppressive region of chromosome 19q, which is frequently altered in various human tumours, including diffuse gliomas. Aside from its chromosomal localization, several lines of evidence, including PTEN-phosphorylating and cell-killing activities, suggests that GLTSCR2 participates in the suppression of tumour growth and development. However, little is known about the biological functions and molecular mechanisms of GLTSCR2 as a tumour suppressor gene. We investigated the pathological significance of GLTSCR2 expression in association with the development and progression of glioblastomas, the most common malignant brain tumour. We used real-time PCR and western blot analysis to examine the expression levels of GLTSCR2 mRNA and protein in glioblastomas, normal brain tissue and in non-glial tumour tissue of different origin, and found that GLTSCR2 expression is down-regulated in glioblastomas. In addition, direct sequencing analysis and fluorescence in situ hybridization clearly demonstrates the presence of genetic alterations, such as a nonsense mutation and deletion, in the GLTSCR2 gene in glioblastomas. Finally, our immunohistochemical study demonstrates that GLTSCR2 is sequentially down-regulated according to the histological malignant progression of the astrocytic glial tumour. Taken together, our results suggest that GLTSCR2 is involved in astrocytic glioma progression.

An shRNA tumor suppressor panel was screened using reverse infection of an A549 tumorigenic cell line and exposing it to a predetermined concentration of paclitaxel, an anticancer drug. The shRNAs targeting a positive control gene, MDR1, were found to effectively decrease mRNA levels and cause cells to become more sensitive to the chemotherapeutic drug. A set of genes were identified in the screen of a panel of tumor suppressors which, when down-regulated, were found to increase or decrease cell sensitivity in regards to treatment with paclitaxel. In many cases, there were multiple clones to a single gene that provided a positive result. The shRNAs targeting SMAD4, LZTS2, ST14 and VHL all increased the cell's sensitivity to paclitaxel. The loss of other tumor suppressors such as GLTSCR2, LATS1, NF1, PTEN, TP53 and WT1 induced a protective effect in the cell, making it more resistant to the effect of the drug. Further investigation of VHL mRNA levels after down-regulation with shRNA show a direct correlation between gene expression levels and paclitaxel sensitivity. This study credits the identified genes with the potential to act as prognostic biomarkers for use in genetic profiling, or even as targets in pathways of tumorigenesis yet to be fully understood.

Pancreatic carcinoma has an extremely bad prognosis due to lack of early diagnostic markers and lack of effective therapeutic strategies. Recently, we have established an in vitro model recapitulating the first steps in the carcinogenesis of the pancreas. SV40 large T antigen-immortalized bovine pancreatic duct cells formed intrapancreatic adenocarcinoma tumors on k-ras(mut) transfection after orthotopic injection in the nude mouse pancreas. Here we identified genes and proteins differentially expressed in the course of malignant transformation using reciprocal suppression subtractive hybridization and 2D gel electrophoresis and mass spectrometry, respectively. We identified 34 differentially expressed genes, expressed sequence tags, and 15 unique proteins. Differential expression was verified for some of the genes or proteins in samples from pancreatic carcinoma. Among these genes and proteins, the majority had already been described either to be influenced by a mutated ras or to be differentially expressed in pancreatic adenocarcinoma, thus proving the feasibility of our model. Other genes and proteins (e.g., BBC1, GLTSCR2, and rhoGDIalpha), up to now, have not been implicated in pancreatic tumor development. Thus, we were able to establish an in vitro model of pancreatic carcinogenesis, which enabled us to identify genes and proteins differentially expressed during the early steps of malignant transformation.

The tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) regulates diverse cellular functions by dephosphorylating the lipid second messenger, phosphatidylinositol 3,4,5-trisphosphate (PIP(3)). Recent study revealed that PICT-1/GLTSCR2 bound to and stabilized PTEN protein in cells, implicating its roles in PTEN-governed PIP(3) signals. In this study, we demonstrate that RNA interference-mediated knockdown of PICT-1 in HeLa cells down-regulated endogenous PTEN and resulted in the activation of PIP(3) downstream effectors, such as protein kinase B/Akt. Furthermore, the PICT-1 knockdown promoted HeLa cell proliferation; however the proliferation of PTEN-null cells was not altered by the PICT-1 knockdown, suggesting its dependency on PTEN status. In addition, apoptosis of HeLa cells induced by staurosporine or serum-depletion was alleviated by the PICT-1 knockdown in the similar PTEN-dependent manner. Most strikingly, the PICT-1 knockdown in HeLa and NIH3T3 cells promoted anchorage-independent growth, a hallmark of tumorigenic transformation. Furthermore, PICT-1 was aberrantly expressed in 18 (41%) of 44 human neuroblastoma specimens, and the PICT-1 loss was associated with reduced PTEN protein expression in spite of the existence of PTEN mRNA. Collectively, these results suggest that PICT-1 plays a role in PIP(3) signals through controlling PTEN protein stability and the impairment in the PICT-1-PTEN regulatory unit may become a causative factor in human tumor(s).

Malignant peripheral nerve sheath tumors (MPNSTs) are highly malignant tumors affecting adolescents and adults. There have been a few reports on chromosomal aberrations of MPNSTs; however, the tumor-specific alteration remains unknown. We characterized the genomic alterations in 8 MPNSTs and 8 schwannomas by metaphase comparative genomic hybridization (CGH). In 5 of 8 MPNSTs, microarray CGH was added for more detailed analyses. Frequent gains were identified on 3q13-26, 5p13-14, and 12q11-23 and frequent losses were at 1p31, 10p, 11q24-qter, 16, and 17. Microarray CGH revealed frequent gains of EGFR, DAB2, MSH2, KCNK12, DDX15, CDK6, and LAMA3, and losses of CDH1, GLTSCR2, EGR1, CTSB, GATA3, and SULT2A1. These genes seem to be responsible for developing MPNSTs. The concordance rate between metaphase CGH and microarray CGH was 66%. Metaphase CGH was useful for identifying chromosomal alterations before applying microarray CGH.

ERCC2 and ERCC1 are important in DNA nucleotide excision repair and lie on chromosome 19q13.3 near a putative glioma suppressor region. We genotyped constitutive variants ERCC1 C8092A and ERCC2 K751Q and R156R in approximately 450 adults with glioma and 500 controls from two independent population-based series, uniformly reviewed patients' tumors to determine histopathologic category, and determined a variety of tumor markers among astrocytic tumors. Odds ratios (ORs) for glioblastoma for those carrying two ERCC1 A alleles versus none or one were 1.67 in series 1 and 1.64 in series 2, which yielded a combined OR of 1.67 (95% CI, 0.93-3.02; P = 0.09), adjusted for age, gender, ethnicity, and series. Odds ratios for the ERCC2 variants were not consistently elevated or reduced for the two series in all cases versus controls. However, among whites, for those with ERCC2 K751Q genotype QQ versus QK/KK, the OR for nonglioblastoma histologies versus controls was 1.82 (95% CI, 0.97-3.44; P = 0.06). Also, among whites, glioma patients were significantly more likely than controls to be homozygous for variants in both ERCC1 C8092A and ERCC2 K751Q (OR, 3.2; 95% CI, 1.1-9.3). Given the numbers of comparisons made, these findings could be due to chance. However, the results might warrant clarification in additional series in conjunction with the nearby putative glioma suppressor genes (GLTSCR1 and GLTSCR2).

BACKGROUND: Deletions of 19q have been associated with gliomas, especially oligodendrogliomas. In addition, cases with oligodendrogliomas with the 19q deletion have been observed to have a better survival compared with cases without the 19q deletion. The authors have previously described a 150-kilobase minimal deletion region in gliomas that maps to 19q13.33 and contains 3 novel candidate genes (GLTSCR1, EHD2, and GLTSCR2).
METHODS: The authors performed an association study using 141 cases with gliomas (61 cases with astrocytomas, 40 cases with oligodendrogliomas, 40 cases with mixed oligoastrocytomas) and 108 general controls. They evaluated 7 single nucleotide polymorphisms (SNPs) in 6 genes within and nearby the minimal 19q deletion region (ERCC2, RAI, ASE-1, ERCC1, GLTSCR1, and LIG1).
RESULTS: The prevalence of a germline GLTSCR1-exon-1 T allele (SNP rs1035938) was 40% in cases with oligodendrogliomas compared with 27% in controls (P = 0.029), and the prevalence of an ERCC2-exon-22 T allele (SNP rs1052555) was 35% in cases with oligodendrogliomas compared with 18% in controls (P = 0.043). One high-risk and 1 low-risk haplotype were associated with oligodendroglioma development (P = 0.003 and 0.026, respectively). Cases with oligodendrogliomas with the 19q deletion had a significantly higher frequency of the GLTSCR1-exon-1 T allele compared with cases without the 19q deletion (P = 0.01). It was noteworthy that cases with gliomas who were homozygous for the GLTSCR1-exon-1 T allele had a significantly better survival: 77% and 68% survival at 2 and 5 years compared with 56% and 34% for other genotypes (P = 0.02, log-rank test). Multivariable analysis identified grade, age, and the GLTSCR1-exon-1 and ERCC2-exon-22 genotypes as independent predictors for survival.
CONCLUSIONS: These results suggested that alterations in GLTSCR1 (or a closely linked gene) were associated with the development and progression of oligodendroglioma.

Allelic loss of the chromosome 19q arm is a frequent event in human diffuse gliomas, suggesting that it contains a tumor suppressor gene. Recent deletion mapping studies have broadly implicated a 1.6-Mb interval between D19S241E and D19S596, with a limited subset of tumors, suggesting that the region may be as narrow as 150 kb. Focusing on this smaller interval, we have used cDNA selection, exon amplification, and genomic sequencing to identify three novel transcripts (EHD2, GLTSCR1, and GLTSCR2) and to map two known genes (SEPW1 and CRX). A partial transcript map of 19 transcripts and two EST markers has been constructed for the 1.6-Mb interval D19S241E-D19S596. Ten of these transcripts, including the 5 mapped to the 150-kb deletion interval, have been examined for alterations in a panel of gliomas with allelic loss of 19q. Tumor-specific alterations have not been identified in the transcripts examined thus far. Collectively, these data should facilitate subsequent efforts to identify and characterize the remaining transcripts in the 1.6-Mb interval.