BRAF Mutation is associated with early stage disease and improved outcome in patients with low‐grade serous ovarian cancer

BACKGROUND:

Low‐grade serous (LGS) ovarian cancer is a chemoresistant disease that accounts for 10% of serous ovarian cancers. Prior studies have reported that 28% to 35% of serous borderline (SB)/LGS ovarian tumors harbor a BRAF mutation, suggesting that BRAF inhibitors may be a rational therapeutic approach for this disease. In the current study, the authors sought to determine whether BRAF or KRAS mutation status was associated with disease stage and/or histology in patients with SB and LGS ovarian cancer.

METHODS:

Genetic profiles were constructed for 75 SB and LGS ovarian tumors to determine BRAF and KRAS mutation status. The incidence and identity of BRAF and KRAS mutations were defined, and the results were correlated with disease stage, response to treatment, and overall survival.

RESULTS:

Of 75 samples examined, 56 tumors (75%) had SB histology, and 19 tumors (25%) had LGS histology. Fifty‐seven percent of tumors harbored either a KRAS mutation (n = 17) or a BRAF mutation (a valine‐to‐glutamate substitution at residue 600 [V600E]; n = 26). The BRAF V600E mutation was associated significantly with early disease stage (stage I/II; P < .001) and SB histology (P = .002). KRAS mutations were not associated significantly with disease stage or histology. Of the 22 patients (29%) who required chemotherapy, 20 had tumors with wild‐type KRAS/BRAF, 2 had KRAS mutant tumors, and none had tumors that harbored a BRAF mutation. All patients with BRAF tumors remained alive at a median follow‐up of 3.6 years (range, 1.9–129.3 months).

CONCLUSIONS:

V600E BRAF mutations were present in 35% of patients who had SB/LGS ovarian cancers. The presence of the BRAF V600E mutation in SB/LGS ovarian cancer was associated with early stage disease and improved prognosis. The authors concluded that patients with SB/LGS ovarian cancer who require systemic therapy are unlikely to have BRAF mutant tumors. Cancer 2013. © 2012 American Cancer Society.     

Human papillomavirus type 16 E6 variants and HLA class II alleles among Japanese women with cervical cancer

The enhanced oncogenicity of particular human papillomavirus type 16 (HPV16) E6 variants is population-dependent, implying the involvement of additional genetic cofactors. This study was designed to investigate the association between E6 variants and human leukocyte antigen (HLA) polymorphism within a Japanese population. Fifty-seven women with HPV16-positive cervical cancer were analyzed for E6 sequence variation and its relationship to HLA class II alleles. Compared with local controls (n = 138) and published controls (n = 916), DRB1*1501 and DQB1*0602 frequencies were significantly increased among patients with HPV16 E6 prototype (n = 11). Additionally, DRB1*1502 was positively associated with a particular E6 variant designated D25E (n = 25), although we could not find a significant association between HLA class II alleles and L83V variants (n = 16). Our observations suggest that a specific match between E6 variant proteins and HLA types may contribute to HPV16-related cervical carcinogenesis.     

Impact of lympho‐vascular space invasion on tumor characteristics and survival outcome of women with low‐grade serous ovarian carcinoma

Background and Objectives

To examine association of lympho‐vascular space invasion (LVSI) with clinico‐pathological factors and to evaluate survival of women with low‐grade serous ovarian carcinoma containing areas of LVSI.

Methods

This is a multicenter retrospective study examining consecutive cases of surgically treated stage I‐IV low‐grade serous ovarian carcinoma (n = 178). Archived histopathology slides for the ovarian tumors were reviewed, and LVSI was scored as present or absent. LVSI status was correlated to clinico‐pathological findings and survival outcome.

Results

LVSI was seen in 79 cases (44.4%, 95% confidence interval [CI] 37.1‐51.7). LVSI was associated with increased risk of omental metastasis (87.0% vs 64.9%, odds ratio [OR] 3.62, P = 0.001), high pelvic lymph node ratio (median 12.9% vs 0%, P = 0.012), and malignant ascites (49.3% vs 32.6%, OR 2.01, P = 0.035). On multivariable analysis, controlling for age, stage, and cytoreductive status, presence of LVSI in the ovarian tumor remained an independent predictor for decreased progression‐free survival (5‐year rates 21.0% vs 35.7%, adjusted‐hazard ratio 1.57, 95%CI 1.06‐2.34, P = 0.026). LVSI was significantly associated with increased risk of recurrence in lymph nodes (OR 2.62, 95%CI 1.08‐6.35, P = 0.047).

Conclusion

LVSI in the ovarian tumor is associated with adverse clinico‐pathological characteristics and decreased progression‐free survival in women with low‐grade serous ovarian carcinoma.

     

Induction of human tumor‐associated differentially expressed gene‐12 (TADG‐12/TMPRSS3)‐specific cytotoxic T lymphocytes in human lymphocyte antigen‐A2.1–positive healthy donors and patients with advanced ovarian cancer

BACKGROUND:

Tumor‐associated differentially expressed gene‐12 (TADG‐12) is a serine protease recently found highly differentially expressed in epithelial ovarian cancer. The goal of this study was to identify potential immunogenic peptides derived from TADG‐12 for immunotherapy of ovarian carcinoma.

METHODS:

A bioinformatics approach (ie, the BIMAS algorithm, National Institutes of Health, http://bimas.dcrt.nih.gov/molbio/hla_bind ) was used to identify multiple immunogenic peptides derived from TADG‐12 that bind to human leukocyte antigen‐A2.1 and elicit peptide‐specific human cytotoxic T lymphocyte (CTL) responses in healthy individuals and in patients with advanced stage ovarian cancer.

RESULTS:

CD8+ CTL populations generated against 5 TADG‐12–derived peptides were consistently able to induce lysis of autologous peptide‐loaded target cells above background. Importantly, TADG‐12 YLPKSWTIQV peptide‐specific CTLs from healthy donors and ovarian cancer patients were found to effectively kill ovarian cancer cells naturally expressing TADG‐12. Cytotoxicity was significantly inhibited by anti–human lymphocyte antigen (HLA)‐A2.1 (BB7‐2) and anti–HLA class I (W6 of 32) monoclonal antibodies, whereas natural killer–sensitive K562 cells were not lysed. TADG‐12 YLPKSWTIQV peptide‐specific CTL precursor frequency was low in peripheral blood leukocytes of normal donors and ovarian cancer patients, as determined by interferon‐γ production in enzyme‐linked immunosorbent spot‐forming cell assays. Intracellular cytokine expression measured by flow cytometry after OKT‐3 monoclonal antibody stimulation showed a type 1 cytokine profile in YLPKSWTIQV peptide‐specific CTLs.

CONCLUSIONS:

The TADG‐12 YLPKSWTIQV peptide is an immunogenic epitope in ovarian tumors and may represent an attractive target for immunotherapy of ovarian cancer. These data may pave the way for TADG‐12 peptide‐derived cell‐based therapy, including dendritic cell immunotherapy, for the vaccination of ovarian cancer patients harboring chemotherapy‐resistant or residual disease. Cancer 2009. © 2008 American Cancer Society.     

Gene expression profiles in primary ovarian serous papillary tumors and normal ovarian epithelium: identification of candidate molecular markers for ovarian cancer diagnosis and therapy

With the goal of identifying genes with a differential pattern of expression between ovarian serous papillary carcinomas (OSPCs) and normal ovarian (NOVA) epithelium and using this knowledge for the development of novel diagnostic and therapeutic markers for ovarian cancer, we used oligonucleotide microarrays with probe sets complementary to 12,533 genes to analyze the gene expression profiles of 10 primary OSPC cell lines, 2 established OSPC cell lines (UCI-101, UCI-107) and 5 primary NOVA epithelial cultures. Unsupervised analysis of gene expression data identified 129 and 170 genes that exhibited >5-fold upregulation and downregulation, respectively, in primary OSPC compared to NOVA. Genes overexpressed in established OSPC cell lines had little correlation with those overexpressed in primary OSPC, highlighting the divergence of gene expression that occurs as a result of long-term in vitro growth. Hierarchical clustering of the expression data readily distinguished normal tissue from primary OSPC. Laminin, claudin 3, claudin 4, tumor-associated calcium signal transducers 1 and 2 (TROP-1/Ep-CAM, TROP-2), ladinin 1, S100A2, SERPIN2 (PAI-2), CD24, lipocalin 2, osteopontin, kallikrein 6 (protease M), kallikrein 10, matriptase (TADG-15) and stratifin were among the most highly overexpressed genes in OSPC compared to NOVA. Downregulated genes in OSPC included transforming growth factor-beta receptor III, platelet-derived growth factor receptor alpha, SEMACAP3, ras homolog gene family member I (ARHI), thrombospondin 2 and disabled-2/differentially expressed in ovarian carcinoma 2 (Dab2/DOC2). Differential expression of some of these genes, including claudin 3, claudin 4, TROP-1 and CD24, was validated by quantitative RT-PCR and flow cytometry on primary OSPC and NOVA. Immunohistochemical staining of formalin-fixed, paraffin-embedded tumor specimens from which primary OSPC cultures were derived further confirmed differential expression of CD24 and TROP-1/Ep-CAM markers on OSPC vs. NOVA. These results, obtained with highly purified primary cultures of ovarian cancer, highlight important molecular features of OSPC and may provide a foundation for the development of new type-specific therapies against this disease.     

Clinicodemographic factors influencing outcomes in patients with low-grade serous ovarian carcinoma

BACKGROUND:

Low‐grade serous carcinoma (LGSC) of the ovary is a rare tumor that is distinct from its high‐grade counterpart. The objective of this study was to determine whether patient demographic factors and clinical treatment histories affected survival in a population of women with LGSC.

METHODS:

A review of patients who had pathologically confirmed LGSC of the ovary diagnosed between 1977 and 2009 was performed. Abstracted data included medical and social histories, anthropometric measurements, and details about diagnosis, treatment, and follow‐up. Statistical analyses included Fisher exact tests, Cox proportional hazards models, and the Kaplan‐Meier method.

RESULTS:

The study sample included 194 patients who had a median follow‐up of 60.9 months (range, 1‐383 months). In multivariate analyses, smoking had a negative association with both overall survival (OS) (hazard ratio [HR], 1.73; 95% confidence interval [CI], 1.03‐2.92; P = .04) and progression‐free survival (PFS) (HR, 1.72; 95% CI, 1.00‐2.96; P = .05). The median OS was shorter in current smokers than in former/never smokers (48.0 months vs 79.9 months; P = .002). PFS also was predicted by year of diagnosis >1994 (HR, 1.74; P = .01). Although the difference was not statistically significant, hormone consolidation appeared to be associated with better OS (HR, 0.15; P = .06) and better PFS (HR, 0.44; P = .07). A smaller proportion of the patients who received hormone consolidation experienced disease recurrence compared with the patients who did not receive hormone consolidation (66.7% vs 87.6%; P = .07).

CONCLUSIONS:

Smoking was associated negatively with survival outcomes in women with LGSC of the ovary, whereas consolidation treatment with hormone antagonists demonstrated a protective associative trend with survival. Both lifestyle modification and innovative treatment plans should be considered in this group of patients. Cancer 2011. © 2011 American Cancer Society.     

BRCA1与SIRT1在浆液性上皮性卵巢癌组织中的表达及意义

目的:本研究分别从蛋白质表达方面比较正常卵巢组织、卵巢良性肿瘤组织与浆液性上皮性卵巢癌组织中乳腺癌易感基因1(breast cancer susceptibility gene 1,BRCA1)与沉默信息调节因子1 (silent information regulator type 1,SIRT1)表达的变化,探讨BRCA1与SIRT1在浆液性上皮性卵巢癌发生过程中的作用及二者之间的相关性,为进一步明确浆液性上皮性卵巢癌的发病机制、早期诊断、预防及药物治疗奠定理论基础.方法:利用免疫组织化学法分别检测BRCA1和SIRT1在正常卵巢组织、卵巢良性肿瘤组织与浆液性上皮性卵巢癌组织中蛋白的表达情况并进行统计学处理.结果:BRCA1蛋白在正常卵巢组织中的阳性表达率为93.33%,卵巢浆液性囊腺瘤组织为66.67%,卵巢浆液性囊腺癌组织为47.50%,各组间比较差异有显著性(P<0.05).SIRT1蛋白在正常卵巢组织中的阳性表达率为86.67%,卵巢浆液性囊腺瘤组织为50.00%,卵巢浆液性囊腺癌组织为40.00%,正常与恶性、良性与恶性组织间比较差异具有统计学意义(P<0.05),正常与良性组织间比较差异无统计学意义(P>0.05).卵巢浆液性囊腺癌组织中,BRCA1在不同年龄、淋巴结转移分组中,阳性表达率无统计学差异(P>0.05),在不同手术病理分期、组织学分级分组中,阳性表达率具有统计学差异(P<0.05).SIRT1在不同年龄、手术病理分期、淋巴结转移分组中,阳性表达率无统计学差异(P>0.05),在不同组织学分级中,阳性表达率具有统计学差异(P<0.05).BRCA1、SIRT1在卵巢浆液性囊腺癌组织中的表达呈正相关(r=0.664,P<0.001).结论:BRCA1、SIRT1的低表达与浆液性上皮性卵巢癌的发生、发展有关,SIRT1可能是BRCA1的下游靶分子,未来有可能成为诊断与治疗浆液性上皮性卵巢癌的新靶点.     

miR -542-5p 在浆液性卵巢癌中的表达及意义

目的：检测 miR -542-5p 在浆液性卵巢癌中的表达,并分析 miR -542-5p 的表达与浆液性卵巢癌临床病理特征之间的关系,探讨其意义。方法：采用实时荧光定量 PCR 技术分析100例浆液性卵巢癌组织及50例正常输卵管伞端组织中 miR -542-5p 的表达。结果：浆液性卵巢癌组织中 miR -542-5p 的表达显著低于正常输卵管伞端组织（P ﹤0.05）。miR -542-5p 的表达与浆液性卵巢癌各临床病理特征之间差异均无统计学意义（P ﹥0.05）。结论：miR -542-5p 可能作为抑癌基因参与了浆液性卵巢癌的发生,对于卵巢癌的早期诊断及治疗具有潜在意义。     

MSLN、HE4和Ki67在高级别浆液性卵巢癌组织中的表达及意义

目的:探讨MSLN、HE4和Ki67在高级别浆液性卵巢癌(high grade serous ovarian cancer,HGSOC)组织中的表达及临床病理学意义.方法:应用免疫组织化学链霉菌抗生物素蛋白-过氧化酶连接法(SP法)检测MSLN和HE4在40例高级别浆液性卵巢癌组织、10例卵巢良性肿瘤、30例正常卵巢组织中的表达情况,结合分析Ki67在40例高级别浆液性卵巢癌组织中的表达情况,对比分析三者之间的临床及病理学意义.结果:MSLN在卵巢癌、卵巢良性肿瘤、正常卵巢组织中的阳性表达率分别为77.5％、20.0％和13.3％;HF4在卵巢癌、卵巢良性肿瘤、正常卵巢组织中的阳性表达率分别为80.0％、10.0％和6.7％;卵巢癌组织中MSLN和HE4阳性表达率分别高于良性和正常卵巢组织,差异均具有统计学意义(P＜0.05),二者分别在良性与正常卵巢组织中表达无统计学差异.MSLN、HE4和Ki67在卵巢癌组织中的阳性表达率分别为77.5％、80.0％和85.0％,MSLN、HE4和Ki67在卵巢癌组织的表达与临床分期有关(P＜0.05).MSLN、HE4和Ki67的表达与卵巢癌患者是否绝经无关(P＞0.05).MSLN、HE4和Ki67在卵巢癌组织中的阳性表达率两两之间存在正相关(P＜0.05).结论:MSLN、HE4和Ki67在高级别浆液性卵巢癌组织中的表达均与临床分期有关,与患者是否淋巴结转移有关,但是否合并腹水关系不统一.MSLN、HE4和Ki67的高表达可能与高级别浆液性卵巢癌的发生、发展有一定关系.     

Tissue array analysis of expression microarray candidates identifies markers associated with tumor grade and outcome in serous epithelial ovarian cancer

Molecular profiling is a powerful approach to identify potential clinical markers for diagnosis and prognosis as well as providing a better understanding of the biology of epithelial ovarian cancer. On the basis of the analysis of HuFL expression data, we have previously identified genes that distinguish low malignant potential and invasive serous epithelial ovarian tumors. In this study, we used immunohistochemistry to monitor a subset of differently expressed candidates (Ahr, Paep, Madh3, Ran, Met, Mek1, Ccne1, Ccd20, Cks1 and Cas). A tissue array composed of 244 serous tumors of different grades (0-3) and stages (I-IV) was used in this analysis. All markers assayed presented differential protein expression between serous tumors of low and high grade. Significant differences in Ccne1 and Ran expression were observed in a comparison of low malignant potential and grade 1 tumor samples (p<0.01). In addition, irrespective of the grade, Ccne1, Ran, Cdc20 and Cks1 showed significant differences of expression in association with the clinical stage of disease. While high level of Ccne1 have previously been associated with poor outcomes, here we found that high level of either Ran or Cdc20 appear to be more tightly associated with a poor prognosis (p<0.001, 0.03, respectively). The application of these biomarkers in both the initial diagnosis and prognostic attributes of patients with epithelial ovarian tumors should prove to be useful in patient management.     

Ets-1在卵巢浆液性腺癌中的表达及意义

目的:探讨E26转录因子(E26 transformation-specific-1,Ets-1)在卵巢浆液性腺癌组织中的表达及意义.方法:收集2014年12月至2016年5月在中国医科大学附属盛京医院妇科住院手术的浆液性卵巢癌患者新鲜组织30例、石蜡组织40例、正常卵巢组织30例.分别采用实时荧光定量PCR(RT-PCR)、蛋白免疫印迹及免疫组织化学方法检测组织中Ets-1 mRNA及蛋白表达情况,并分析其与临床病理参数之间的关系.结果:Ets-1蛋白在卵巢浆液性腺癌组织中的阳性表达率(75%)明显高于正常卵巢组织(13.3%),两组比较差异有统计学意义(P<0.05).临床病理参数分析发现:Ets-1表达量与卵巢癌FIGO分期及淋巴结是否转移有关(P<0.05),与患者年龄、分级、CA125水平及腹水量均无明显统计学差异(P>0.05).RT-PCR显示正常卵巢组织和卵巢浆液性腺癌组织中Ets-1 mRNA相对表达量分别为1.549±0.252、0.644±0.091,两组比较差异有统计学意义(P<0.05).Western blot结果显示Ets-1蛋白相对表达分别为3.967±0.787、0.970±0.198,两组比较差异有统计学意义(P<0.05).结论:Ets-1在卵巢癌组织中不同表达水平可能与其不同作用机制有关,Ets-1可能参与卵巢癌的发生.     

The E3 ubiquitin ligase EDD is an adverse prognostic factor for serous epithelial ovarian cancer and modulates cisplatin resistance in vitro

Despite a high initial response rate to first-line platinum/paclitaxel chemotherapy, most women with epithelial ovarian cancer relapse with recurrent disease that becomes refractory to further cytotoxic treatment. We have previously shown that the E3 ubiquitin ligase, EDD, a regulator of DNA damage responses, is amplified and overexpressed in serous ovarian carcinoma. Given that DNA damage pathways are linked to platinum resistance, the aim of this study was to determine if EDD expression was associated with disease recurrence and platinum sensitivity in serous ovarian cancer. High nuclear EDD expression, as determined by immunohistochemistry in a cohort of 151 women with serous ovarian carcinoma, was associated with an approximately two-fold increased risk of disease recurrence and death in patients who initially responded to first-line chemotherapy, independently of disease stage and suboptimal debulking. Although EDD expression was not directly correlated with relative cisplatin sensitivity of ovarian cancer cell lines, sensitivity to cisplatin was partially restored in platinum-resistant A2780-cp70 ovarian cancer cells following siRNA-mediated knockdown of EDD expression. These results identify EDD as a new independent prognostic marker for outcome in serous ovarian cancer, and suggest that pathways involving EDD, including DNA damage responses, may represent new therapeutic targets for chemoresistant ovarian cancer.     

Intratumoral expression analysis reveals that OX40 and TIM-3 are prominently expressed and have variable associations with clinical outcomes in high grade serous ovarian cancer

Patients with ovarian cancer exhibit low response rates to anti-programmed cell death protein-1 (PD-1) based therapies, despite ovarian tumors demonstrating measurable immune responses. Therefore, the aim of the present study was to comparatively examine expression of notable immune co-stimulatory and co-inhibitory receptors in order identify the most abundant receptors that could potentially serve as therapeutic targets to enhance immunotherapy response in high grade serous ovarian cancer (HGSOC). The Cancer Genome Atlas (TCGA) was employed to compare levels of various HGSOC and pan-cancer cohorts. To confirm these findings at the protein level, immunofluorescence of select receptors was performed in 29 HGSOC patient tissue samples. TCGA and Kaplan Meier analysis was employed to determine the association of highly expressed immune receptors with clinical outcomes. TIM-3 and OX40 exhibited the highest expression in HGSOC at both the gene and protein level, with TIM-3 demonstrating highest levels on both CD8⁺ and CD4⁺ T cell subsets. Pan-cancer analysis determined that TIM-3 and OX40 levels were similar to those in immunotherapy-responsive cancers, while PD-1 exhibited much lower expression in HGSOC. Finally, OX40 was most strongly associated with improved patient survival. Overall, the current study suggested that TIM-3 and OX40 are frequently expressed intratumoral immune receptors in HGSOC and thus represent promising immune targets. Furthermore, the present analysis strongly suggested that OX40 was significantly associated with a longer survival and could potentially be utilized as a prognostic factor for improved patient outcomes in HGSOC.     

Human papillomavirus 16 E6 polymorphisms in cervical lesions from different European populations and their correlation with human leukocyte antigen class II haplotypes.

Infection with high-risk human papillomavirus (HPV) is necessary for the development of a cervical lesion, but only a fraction of precursor lesions progress to cancer. Additional factors, other than HPV type per se, are likely to increase the probability for progression. Intratype genome variations have been reported to be associated with viral persistence and the development of a major cervical disease. We have recently shown that the prevalence of specific HPV16-E6 variants in invasive cervical cancer (ICC) varies between Italian and Swedish women. To extend our initial study we have analyzed E6 variants in cervical lesions from Czech women, ranging from low-grade cervical intraepithelial neoplasia (LCIN) to ICC and scaled up the sample size of our initial study of Swedish and Italian women. In addition, we have correlated the cases of cancers with human leukocyte antigen (HLA) class II haplotypes. In line with our earlier observation, the distribution of specific HPV16-E6 genotypes in CIN and ICC varied in the 3 cohorts. For instance, the HPV16-E6 L83V variant, which has been found to be positively associated with ICC in Swedish women (p = 0.002), was more prevalent in LCIN than in ICC in Italian and Czech women (p = 0.01 and = 0.03, respectively). These data indicate that host genetic factors, such as HLA polymorphism, may determine the potential oncogenicity of the HPV16-E6 L83V variant. Indeed, the DR04-DQ03 haplotype, which is approximately 3-fold more abundant in the normal Swedish population than in those in Italy and the Czech Republic, was found to be positively associated with HPV16-E6 L83V in the 3 cohorts investigated (p = 0.01). This observation may explain why L83V is a risk factor more in Sweden than in the other 2 countries.     

Clinical significance of HLA class I heavy chain expression in patients with gastric cancer

BACKGROUND: Little is known about the relation between HLA-I expression and the prognosis of patients with gastric cancer. The aim of this retrospective study was to clarify the clinical significance of HLA-I heavy chain expression in gastric cancer. METHODS: The study subjects were 202 patients with gastric cancer who had undergone curative surgery. Tumors were examined for expression of HLA-I heavy chain antigens by immunohistochemistry. We analyzed the association of HLA-I heavy chain expression with clinicopathological parameters and patient prognosis. RESULTS: HLA-B/C expression showed association with deeper tumor invasion, higher incidence of lymph node metastasis, more advanced tumor stage, and higher incidence of recurrence. Patients with positive HLA-B/C expression had shorter 5-year overall and 5-year disease-free survival compared with patients whose tumors showed mixed and negative expression (P < 0.05 and 0.01, respectively). In multivariate analysis, although HLA-B/C expression was not recognized as an independent prognostic factor, it was an independent factor in predicting peritoneal recurrence after curative surgery in patients with gastric cancer [relative risk (RR): 9.924, P = 0.003]. CONCLUSION: Expression of HLA-B/C heavy chain is associated with tumor progression, and it could be a significant predictor of peritoneal recurrence after curative surgery in patients with gastric cancer.     

Loss of HSulf‐1 expression enhances tumorigenicity by inhibiting Bim expression in ovarian cancer

The expression of human Sulfatase1 (HSulf‐1) is downregulated in the majority of primary ovarian cancer tumors, but the functional consequence of this downregulation remains unclear. Using two different shRNAs (Sh1 and Sh2), HSulf‐1 expression was stably downregulated in ovarian cancer OV202 cells. We found that HSulf‐1‐deficient OV202 Sh1 and Sh2 cells formed colonies in soft agar. In contrast, nontargeting control (NTC) shRNA‐transduced OV202 cells did not form any colonies. Moreover, subcutaneous injection of OV202 HSulf‐1‐deficient cells resulted in tumor formation in nude mice, whereas OV202 NTC cells did not. Also, ectopic expression of HSulf‐1 in ovarian cancer SKOV3 cells significantly suppressed tumor growth in nude mice. Here, we show that HSulf‐1‐deficient OV202 cells have markedly decreased expression of proapoptotic Bim protein, which can be rescued by restoring HSulf‐1 expression in OV202 Sh1 cells. Enhanced expression of HSulf‐1 in HSulf‐1‐deficient SKOV3 cells resulted in increased Bim expression. Decreased Bim levels after loss of HSulf‐1 were due to increased p‐ERK, because inhibition of ERK activity with PD98059 resulted in increased Bim expression. However, treatment with a PI3 kinase/AKT inhibitor, LY294002, failed to show any change in Bim protein level. Importantly, rescuing Bim expression in HSulf‐1 knockdown cells significantly retarded tumor growth in nude mice. Collectively, these results suggest that loss of HSulf‐1 expression promotes tumorigenicity in ovarian cancer through regulating Bim expression.     

Genome‐wide expression profiling‐based copy number variations and colorectal cancer risk in Chinese

Genetic factors play important roles in colorectal carcinogenesis. This study was aimed to evaluate the effects of gene expression‐related copy number variations (CNVs) on the risk of colorectal cancer in Chinese. Expression Quantitative Trait Locus (eQTL) mapping was conducted to explore the most regulatable gene expressions by CNVs among the whole genome based on publicly available data. Then a case‐control study was performed to evaluate the associations between copy numbers of the most regulatable genes and colorectal cancer. The influence of the target CNVs on the expression of corresponding gene and protein was verified in colorectal tissue, and the biological effects of these CNVs on cell‐cycle arrest and apoptosis of colon cancer cell lines were further detected. The eQTL revealed the most significant association between CNV of HM3_CNP_342 and gene expressions of human leukocyte antigen (HLA)‐DQA1 and HLA‐DQB1 among the whole genome. The later case‐control study found that amplified HLA‐DQB1 was inversely associated with colorectal cancer risk (odds ratio = 0.73; 95% confidence interval: 0.58‐0.93), especially among those with a family history of cancer. The positive association between amplified HLA‐DQB1 and upregulation of gene and protein was validated in colorectal tissue. In addition, overexpression of HLA‐DQB1 in dendritic cells promoted cell‐cycle arrest and apoptosis of cocultured SW480 and HCT116 cell lines, and vice versa. Our study suggests that the amplified copy number of HLA‐DQB1 is associated with lower risk of colorectal cancer and able to induce the apoptosis of colon cancer cells, which implies the potential of HLA class II in cancer predisposition and immunotherapy.