Variation at 8q24 and 9p24 and risk of epithelial ovarian cancer

FAM84B promotes breast cancer tumorigenesis through activation of the NF-κB and death receptor signaling pathways

Breast cancer (BC) occurs predominantly in women and leads to numerous deaths every year. The identification of effective therapeutic targets will benefit BC patients and increase the likelihood of finding a cure. Family with similar sequence 84, member B (FAM84B) has been implicated in the progression of many kinds of cancers, but its function in BC remains to be explored. In this study, online database analysis revealed that FAM84B expression was higher in BC patient tissues, especially in luminal BC tissues, than in the corresponding normal tissues; furthermore, increased FAM84B expression was related to poor prognosis. Additionally, western blot (WB) analysis revealed that the FAM84B protein was highly expressed in luminal BC cell lines compared to normal and basal-like BC cell lines. Moreover, clinical BC patient tissues were collected and subjected to WB and immunohistochemical (IHC) analyses, and the results showed that FAM84B was expressed mainly in luminal BC samples. Therefore, to determine the function of FAM84B in luminal BC cells, luminal BC cell lines with FAM84B knockout and overexpression were generated. In addition, the functions of FAM84B were evaluated in vitro (via cell proliferation, wound healing, colony formation and invasion assays) and in vivo (via a subcutaneous xenograft experiment), and the results showed that FAM84B regulated cell proliferation but not cell invasion. Furthermore, the results of RNA sequencing analysis in ZR-75-1 FAM84B knockout and FAM84B-overexpressing cells showed that FAM84B could affect the TNF signaling pathway. Subsequently, WB analysis of death receptor signaling and immunofluorescence (IF) analysis of NF-κB p65 localization revealed that FAM84B affected death receptor signaling and promoted NF-κB p65 nuclear entry. In conclusion, we found that FAM84B promotes luminal BC tumorigenesis through the activation of the NF-κB and death receptor signaling pathways.

Does Subtelomeric Position of COMMD5 Influence Cancer Progression?

The COMMD proteins are a family of ten pleiotropic factors which are widely conserved throughout evolution and are involved in the regulation of many cellular and physiological processes. COMMD proteins are mainly expressed in adult tissue and their downregulation has been correlated with tumor progression and poor prognosis in cancer. Among this family, COMMD5 emerged as a versatile modulator of tumor progression. Its expression can range from being downregulated to highly up regulated in a variety of cancer types. Accordingly, two opposing functions could be proposed for COMMD5 in cancer. Our studies supported a role for COMMD5 in the establishment and maintenance of the epithelial cell phenotype, suggesting a tumor suppressor function. However, genetic alterations leading to amplification of COMMD5 proteins have also been observed in various types of cancer, suggesting an oncogenic function. Interestingly, COMMD5 is the only member of this family that is located at the extreme end of chromosome 8, near its telomere. Here, we review some data concerning expression and role of COMMD5 and propose a novel rationale for the potential link between the subtelomeric position of COMMD5 on chromosome 8 and its contrasting functions in cancer.

FAM84B, amplified in pancreatic ductal adenocarcinoma, promotes tumorigenesis through the Wnt/β-catenin pathway

Altered expression of family with sequence similarity 84, member B (FAM84B) has been found in various human cancers. However, the expression and function of FAM84B in pancreatic ductal adenocarcinoma (PDAC) has not been studied. Here, by analyzing The Cancer Genome Atlas cohort, we found that FAM84B amplification was observed in 11% of 141 PDAC patients, and FAM84B amplification was correlated with higher mRNA expression of FAM84B. FAM84B amplification and overexpression was significantly correlated with poor overall survival. Moreover, knockdown of FAM84B in PDAC cell lines suppressed cell proliferation and induced apoptosis. FAM84B knockdown also suppressed mitochondrial function and glycolysis of PDAC cells. Interestingly, knockdown of FAM84B decreased the nuclear accumulation of β-catenin, and the expression of c-Myc and lactate dehydrogenase A, but enhanced the expression of Survivin. On the contrary, FAM84B overexpression displayed reversed effects in cell proliferation, apoptosis, mitochondrial function, and glycolysis, which was blocked by the Wnt/β-catenin pathway inhibitor (XAV939). In addition, PDAC cells with lower expression of FAM84B were more sensitive to gemcitabine-induced cell proliferation inhibition both in vitro and in vivo. In conclusion, FAM84B plays an important role in aerobic glycolysis and tumorigenesis in PDAC and Wnt/β-catenin may be involved in this process.

Long non-coding RNA FAM84B-AS promotes resistance of gastric cancer to platinum drugs through inhibition of FAM84B expression

PURPOSE

To investigate the expression and significance of the long non-coding RNA (lncRNA) FAM84B-AS in gastric cancer tissues and its effect on platinum drug resistance in gastric cancer.

METHODS

(1) The expression of FAM84B-AS was detected in samples from 228 cases of fresh gastric cancer to analyze its association with clinical data and gastric cancer prognosis. (2) An lncRNA interference cell line model was established and used to study the effects of FAM84B-AS on the malignant biological behaviors of gastric cancer cells and platinum drug resistance at the cellular level. (3) The mechanisms underlying the effect of FAM84B-AS on gastric cancer were investigated using Western blotting.

RESULTS

(1) FAM84B-AS was closely associated with the differentiation level, T stage, and N stage of gastric cancer and could be used as an independent risk factor of the prognosis of gastric cancer. (2) FAM84B-AS interference significantly inhibited the proliferation and invasion abilities of gastric cancer cells and significantly increased the percentage of apoptosis. FAM84B-AS could partially restore the sensitivity of drug resistant cells to platinum drugs. The above results were also confirmed in in vivo studies. (3) Western blot results demonstrated that FAM84B-AS interference could activate apoptosis signaling pathways in gastric cancer cells to promote apoptosis in gastric cells.

CONCLUSION

FAM84B-AS could be used as a molecular marker of the malignancy of gastric cancer and offers a certain predictive function for gastric cancer prognosis. FAM84B-AS promotes gastric cancer proliferation through inhibition of apoptosis signaling pathways and promotes drug resistance of gastric cancer cells to platinum drugs through its apoptosis-inhibiting functions.

Risk of eighteen genome-wide association study-identified genetic variants for colorectal cancer and colorectal adenoma in Han Chinese

Background

Recent genome-wide association studies (GWAS) identified eighteen single-nucleotide polymorphisms (SNPs) to be significantly associated with the risk of colorectal cancer (CRC). However, overall results of the following replications are inconsistent and little is known about whether these associations also exit in colorectal adenomas (CRA).

Methods

The SNP genotyping was performed using a Sequenom MassARRAY to investigate the association of these eighteen SNPs with colorectal neoplasm in a case-control study consisted of 1049 colorectal cancers, 283 adenomas, and 1030 controls.

Results

Two of these SNPs, rs10505477 and rs719725, showed evidence of an association in both CRC and CRA in our study population. Besides, seven SNPs (rs10808555, rs7014346, rs7837328, rs704017, rs11196172, rs4779584, and rs7229639) were significantly associated with CRC, and another one SNP rs11903757 was over-represented in CRA compared with controls. The strongest association was provided by rs11196172 (OR = 2.02, 95% CI = 1.66 - 2.46, P < 0.0001) and rs11903757 (OR = 1.96, 95% CI = 1.28 - 3.00, P = 0.0026).

Conclusion

These results suggest that some previously reported SNP associations also have impact on CRC and CRA predispositions in the Han Chinese population. A part of genetic risk to CRC is possibly mediated by susceptibility to adenomas.

Altered interphase fluorescence in situ hybridization profiles of chromosomes 4, 8q24, and 9q34 in pancreatic ductal adenocarcinoma are associated with a poorer patient outcome

Most patients with pancreatic ductal adenocarcinoma (PDAC) die within 6 months of diagnosis. However, 20% to 25% patients undergoing total tumor resection remain alive and disease-free 5 years after diagnostic surgery. Few studies on tumor markers have predicted patient prognosis and/or survival. We evaluated the effect of tumor cytogenetic copy number changes detected by interphase fluorescence in situ hybridization on overall survival (OS) of 55 PDAC patients. The prognostic value of copy number changes showing an effect on OS was validated in an external cohort of 44 surgically resected PDAC patients by comparative genomic hybridization arrays, and the genes coded in altered chromosomes with prognostic value were identified by high-density single-nucleotide polymorphism arrays in 20 cases. Copy number changes of chromosomes 4 and 9q34 with gains of 8q24 were independently associated with shorter OS. On the basis of these three chromosomal alterations, a score is proposed that identifies patients with significantly different (P < 0.001) 5-year OS rates: 60% ± 20%, 16% ± 8%, and 0% ± 0%, respectively. Our results show an association between tumor cytogenetics and OS of PDAC patients and provide the basis for further prognostic stratification of patients undergoing complete tumor resection. Further studies to identify specific genes coded in these chromosomes and their functional consequences are necessary to understand the clinical effect of these changes.

Clinical significance of POU5F1P1 rs10505477 polymorphism in Chinese gastric cancer patients receving cisplatin-based chemotherapy after surgical resection

This study aimed to investigate the association between POU class5 homeobox 1 pseudogene 1 gene (POU5F1P1) rs10505477 polymorphism and the prognosis of Chinese gastric cancer patients, who received cisplatin-based chemotherapy after surgical resection. POU5F1P1 rs10505477 was genotyped using the SNaPshot method in 944 gastric cancer patients who received gastrectomy. The association of rs10505477 G > A polymorphism with the progression and prognosis in gastric cancer patients was statistically analyzed using the SPSS version 18.0 for Windows. The results reveal that rs10505477 polymorphism has a negatively effect on the overall survival of gastric cancer patients in cisplatin-based chemotherapy subgroup (HR = 1.764, 95% CI = 1.069–2.911, p = 0.023). Our preliminary study indicates for the first time that POU5F1P1 rs10505477 is correlated with survival of gastric cancer patients who receving cisplatin-based chemotherapy after gastrectomy. Further studies are warranted to investigate the mechanism and to verify our results in different populations.

Genome scan study of prostate cancer in Arabs: identification of three genomic regions with multiple prostate cancer susceptibility loci in Tunisians

Background

Large databases focused on genetic susceptibility to prostate cancer have been accumulated from population studies of different ancestries, including Europeans and African-Americans. Arab populations, however, have been only rarely studied.

Methods

Using Affymetrix Genome-Wide Human SNP Array 6, we conducted a genome-wide association study (GWAS) in which 534,781 single nucleotide polymorphisms (SNPs) were genotyped in 221 Tunisians (90 prostate cancer patients and 131 age-matched healthy controls). TaqMan^® SNP Genotyping Assays on 11 prostate cancer associated SNPs were performed in a distinct cohort of 337 individuals from Arab ancestry living in Qatar and Saudi Arabia (155 prostate cancer patients and 182 age-matched controls). In-silico expression quantitative trait locus (eQTL) analysis along with mRNA quantification of nearby genes was performed to identify loci potentially cis-regulated by the identified SNPs.

Results

Three chromosomal regions, encompassing 14 SNPs, are significantly associated with prostate cancer risk in the Tunisian population (P = 1 × 10^-4 to P = 1 × 10^-5). In addition to SNPs located on chromosome 17q21, previously found associated with prostate cancer in Western populations, two novel chromosomal regions are revealed on chromosome 9p24 and 22q13. eQTL analysis and mRNA quantification indicate that the prostate cancer associated SNPs of chromosome 17 could enhance the expression of STAT5B gene.

Conclusion

Our findings, identifying novel GWAS prostate cancer susceptibility loci, indicate that prostate cancer genetic risk factors could be ethnic specific.

The 8q24 gene desert: an oasis of non-coding transcriptional activity

Understanding the functional effects of the wide-range of aberrant genetic characteristics associated with the human chromosome 8q24 region in cancer remains daunting due to the complexity of the locus. The most logical target for study remains the MYC proto-oncogene, a prominent resident of 8q24 that was first identified more than a quarter of a century ago. However, many of the amplifications, translocation breakpoints, and viral integration sites associated with 8q24 are often found throughout regions surrounding large expanses of the MYC locus that include other transcripts. In addition, chr.8q24 is host to a number of single nucleotide polymorphisms associated with cancer risk. Yet, the lack of a direct correlation between cancer risk alleles and MYC expression has also raised the possibility that MYC is not always the target of these genetic associations. The 8q24 region has been described as a "gene desert" because of the paucity of functionally annotated genes located within this region. Here we review the evidence for the role of other loci within the 8q24 region, most of which are non-coding transcripts, either in concert with MYC or independent of MYC, as possible candidate gene targets in malignancy.

Common variation in Nemo-like kinase is associated with risk of ovarian cancer

BACKGROUND

Overexpression of mitotic kinases has been associated with prognosis, histologic grade, and clinical stage in ovarian cancer, but the relationship between inherited variation in these genes and ovarian cancer risk has not been well defined.

METHODS

We measured associations between 397 single nucleotide polymorphisms (SNPs) from 67 mitotic kinases and invasive epithelial ovarian cancer risk in two case-control studies (n = 671 cases; n = 939 controls). Thirty-six candidate SNPs (P < 0.05) were assessed in a replication analysis consisting of three additional studies (n = 1,094 cases; n = 829 controls).

RESULTS

In initial analysis, thirty-six SNPs were suggestive of association with risk of serous ovarian cancer, all subtypes of ovarian cancer, or both (P < 0.05). Replication analyses suggested an association between rs2125846 in the Nemo-like kinase (NLK) gene and ovarian cancer (serous OR = 1.36, 95% CI: 1.11-1.67, P = 1.77 × 10(-3); all subtypes OR = 1.30, 95% CI: 1.08-1.56, P = 2.97 × 10(-3)). Furthermore, rs2125846 was associated with risk in the combined discovery and replication sets (serous OR = 1.33, 95% CI: 1.15-1.54; all subtypes OR = 1.27, 95% CI: 1.12-1.45).

CONCLUSIONS

Variation in NLK may be associated with risk of invasive epithelial ovarian cancer. Further studies are needed to confirm and understand the biologic relationship between this mitotic kinase and ovarian cancer risk.

IMPACT

An association between SNPs in NLK and ovarian cancer may provide biologic insight into the development of this disease.

Assessment of hepatocyte growth factor in ovarian cancer mortality

BACKGROUND

Invasive ovarian cancer is a significant cause of gynecologic cancer mortality.

METHODS

We examined whether this mortality was associated with inherited variation in approximately 170 candidate genes/regions [993 single-nucleotide polymorphisms (SNPs)] in a multistage analysis based initially on 312 Mayo Clinic cases (172 deaths). Additional analyses used The Cancer Genome Atlas (TCGA; 127 cases, 62 deaths). For the most compelling gene, we immunostained Mayo Clinic tissue microarrays (TMA, 326 cases) and conducted consortium-based SNP replication analysis (2,560 cases, 1,046 deaths).

RESULTS

The strongest initial mortality association was in HGF (hepatocyte growth factor) at rs1800793 (HR = 1.7, 95% CI = 1.3-2.2, P = 2.0 × 10(-5)) and with overall variation in HGF (gene-level test, P = 3.7 × 10(-4)). Analysis of TCGA data revealed consistent associations [e.g., rs5745709 (r(2) = 0.96 with rs1800793): TCGA HR = 2.4, CI = 1.4-4.1, P = 2.2 × 10(-3); Mayo Clinic + TCGA HR = 1.6, CI = 1.3-1.9, P = 7.0 × 10(-5)] and suggested genotype correlation with reduced HGF mRNA levels (P = 0.01). In Mayo Clinic TMAs, protein levels of HGF, its receptor MET (C-MET), and phospho-MET were not associated with genotype and did not serve as an intermediate phenotype; however, phospho-MET was associated with reduced mortality (P = 0.01) likely due to higher expression in early-stage disease. In eight additional ovarian cancer case series, HGF rs5745709 was not associated with mortality (HR = 1.0, CI = 0.9-1.1, P = 0.87).

CONCLUSIONS

We conclude that although HGF signaling is critical to migration, invasion, and apoptosis, it is unlikely that HGF genetic variation plays a major role in ovarian cancer mortality. Furthermore, any minor role is not related to genetically-determined expression.

IMPACT

Our study shows the utility of multiple data types and multiple data sets in observational studies.

Genetic variants on chromosome 8q24 and colorectal neoplasia risk: a case-control study in China and a meta-analysis of the published literature

Previous studies have found that common genetic variants on chromosome 8q24 are associated with the risk of developing colorectal neoplasia. We conducted a hospital-based case-control study, including 435 cases and 788 unrelated controls to investigate the associations between common variants on 8q24 and the risk of colorectal cancer in a Chinese population. We also evaluated the association of rs6983267 with colorectal neoplasia in the published literature via a meta-analysis study. We found that rs6983267 was significantly associated with the risk of colorectal cancer in the Chinese population, with an adjusted odds-ratio (OR) for the GT heterozygotes and GG homozygotes of 1.30 (95% CI  = 0.98–1.71, P = 0.069) and 1.66 (95% CI  = 1.18–2.34, P = 0.004), respectively, compared to the TT homozygotes, with a P-trend value of 0.003. No association was found for the other three loci (rs16901979, rs1447295 and rs7837688). In the meta-analysis of the published genetic association studies, the rs6983267 variant was found to be associated with an increased risk of colorectal neoplasia. The heterozygous GT carriers showed a 20% increased risk of colorectal neoplasia (OR  = 1.20, 95% CI  = 1.16–1.25; random effects model) with a summary OR for homozygous GG carriers of 1.39 (95% CI  = 1.32–1.48; random effects model) compared to the TT genotype carriers. We found no significant differences between the association of rs6983267 and colorectal cancer and colorectal adenomas. In summary, our study confirms that the variant rs6983267 is a risk factor for colorectal neoplasia in various populations, including the Chinese population.