Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) displays a broad range of antitumor properties including cancer-specific induction of apoptosis, inhibition of tumor angiogenesis and modulation of antitumor immune responses. In our study, we elucidated the role of MDA-7/IL-24 in inhibiting growth of breast cancer-initiating/stem cells. Ad.mda-7 infection decreased proliferation of breast cancer-initiating/stem cells without affecting normal breast stem cells. Ad.mda-7 induced apoptosis and endoplasmic reticulum stress in breast cancer-initiating/stem cells similar to unsorted breast cancer cells and inhibited the self-renewal property of breast cancer-initiating/stem cells by suppressing Wnt/β-catenin signaling. Prevention of inhibition of Wnt signaling by LiCl increased cell survival upon Ad.mda-7 treatment, suggesting that Wnt signaling inhibition might play a key role in MDA-7/IL-24-mediated death of breast cancer-initiating/stem cells. In a nude mouse subcutaneous xenograft model, Ad.mda-7 injection profoundly inhibited growth of tumors generated from breast cancer-initiating/stem cells and also exerted a potent “bystander” activity inhibiting growth of distant uninjected tumors. Further studies revealed that tumor growth inhibition by Ad.mda-7 was associated with a decrease in proliferation and angiogenesis, two intrinsic features of MDA-7/IL-24, and a reduction in vivo in the percentage of breast cancer-initiating/stem cells. Our findings demonstrate that MDA-7/IL-24 is not only nontoxic to normal cells and normal stem cells but also can kill both unsorted cancer cells and enriched populations of cancer-initiating/stem cells, providing further documentation that MDA-7/IL-24 might be a safe and effective way to eradicate cancers and also potentially establish disease-free survival.
MDA-7/IL-24; apoptosis; Wnt signaling; cancer-initiating/stem cells; breast cancer
The contribution of melanocortin-1 receptor (MC1R) gene variants to the development of early-onset melanoma is unknown. Using an Australian population-based, case-control-family study, we sequenced MC1R for 565 cases with invasive cutaneous melanoma diagnosed between ages 18–39 years, 409 unrelated controls and 518 sibling controls. Variants were classified a priori into `R' variants (D84E, R142H, R151C, I155T, R160W, D294H) and `r' variants (all other nonsynonymous variants). We estimated odds ratios (OR) for melanoma using unconditional (unrelated controls) and conditional (sibling controls) logistic regression. The prevalence of having at least one R or r variant was 86% for cases, 73% for unrelated controls and 81% for sibling controls. R151C conferred the highest risk (per allele OR 2.57, 95% confidence interval 1.86–3.56 for the case-unrelated-control analysis and 1.70 (1.12–2.60) for the case-sibling-control analysis). When mutually adjusted, the ORs per R allele were 2.23 (1.77–2.80) and 2.06 (1.47–2.88), respectively from the two types of analysis, and the ORs per r allele were 1.69 (1.33–2.13) and 1.25 (0.88–1.79), respectively. The associations were stronger for men and those with none or few nevi or with high childhood sun exposure. Adjustment for phenotype, nevi and sun exposure attenuated the overall log OR for R variants by approximately 18%, but had lesser influence on r variant risk estimates. MC1R variants explained about 21% of the familial aggregation of melanoma. Some MC1R variants are important determinants of early-onset melanoma. The strength of association with melanoma differs according to the type and number of variants.
MC1R; melanoma; early-onset; phenotype; nevi; sun exposure
Populations in north central China are at high risk for gastric cancers (GC), and altered FAS-mediated cell signaling and/or apoptosis may contribute to this risk. We examined the association of 554 single nucleotide polymorphisms (SNPs) in 53 Fas signaling-related genes using a pathway-based approach in 1758 GC cases (1126 gastric cardia adenocarcinomas (GCA) and 632 gastric noncardia adenocarcinomas (GNCA)), and 2111 controls from a genome-wide association study (GWAS) of GC in ethnic Chinese. SNP associations with risk of overall GC, GCA and GNCA were evaluated using unconditional logistic regressions controlling for age, sex and study. Gene- and pathway-based associations were tested using the adaptive rank-truncated product (ARTP) method. Statistical significance was evaluated empirically by permutation. Significant pathway-based associations were observed for Fas signaling with risk of overall GC (P = 5.5E-04) and GCA (P = 6.3E-03), but not GNCA (P = 8.1E-02). Among examined genes in the Fas signaling pathway, MAP2K4, FAF1, MAPK8, CASP10, CASP8, CFLAR, MAP2K1, CAP8AP2, PAK2 and IKBKB were associated with risk of GC (nominal P < 0.05), and FAF1 and MAPK8 were significantly associated with risk of both GCA and GNCA (nominal P < 0.05). Our examination of genetic variation in the Fas signaling pathway is consistent with an association of altered Fas signaling and/or apoptosis with risk of GC. As one of the first attempts to investigate a pathway-level association, our results suggest that these genes and the Fas signaling pathway warrant further evaluation in relation to GC risk in other populations.
Gastric cancer; gastric cardia; gastric noncardia; Fas signaling; genetic variants; GWAS; single nucleotide polymorphisms; pathway genes
Postmenopausal women with higher circulating estrogen levels are at increased risk of developing breast and endometrial carcinomas. In the endometrium, excess estrogen relative to progesterone produces a net proliferative stimulus, which may result in endometrial thickening. Therefore, we tested the hypothesis that endometrial thickness is a biological marker of excess estrogen stimulation that is associated with risk of breast and endometrial carcinomas. Endometrial thickness was measured in 1,272 postmenopausal women, aged 55–74, who underwent transvaginal ultrasound (TVU) screening as part of the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Serial endometrial thickness measurements were available for a subset of women at one (n=1,018), two (n=869) and three years (n=641) after baseline. We evaluated associations between endometrial thickness and breast (n=91) and endometrial (n=14) carcinoma by estimating relative risks (RRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression with age as the time metric. Models incorporating baseline endometrial thickness and as a time-varying covariate using all measurements were examined. Median follow-up among study participants was 12.5 years (range: 0.3–13.8 years). Compared to baseline endometrial thickness of 1.0 – 2.99 mm, women with baseline endometrial thickness greater than or equal to 5.0 mm had an increased risk of breast (RR: 2.00, 95% CI 1.15, 3.48) and endometrial (RR: 5.02, 95% CI 0.96, 26.36) carcinomas in models adjusted for menopausal hormone use and BMI. Our data suggest that increased endometrial thickness as assessed by TVU was associated with increased risk of breast and endometrial carcinomas.
transvaginal ultrasound; screening; etiology
Cirrhosis is the primary risk factor for the development of hepatocellular carcinoma (HCC), yet the mechanisms by which cirrhosis predisposes to carcinogenesis are poorly understood. Using a mouse model that recapitulates many aspects of the pathophysiology of human liver disease, we explored the mechanisms by which changes in the liver microenvironment induce dysplasia and HCC. Hepatic expression of platelet-derived growth factor-c (PDGF-C) induces progressive fibrosis, chronic inflammation, neoangiogenesis, and sinusoidal congestion, as well as global changes in gene expression. Using reporter mice, immunofluorescence, immunohistochemistry and liver cell isolation, we demonstrate that receptors for PDGF-CC are localized on hepatic stellate cells (HSCs), which proliferate, and transform into myofibroblast-like cells that deposit extracellular matrix (ECM) and lead to production of growth factors and cytokines. We demonstrate induction of cytokines genes at two months, and stromal cell-derived hepatocyte growth factors that coincide with the onset of dysplasia at four months. Our results support a paracrine signaling model wherein hepatocyte-derived PDGF-C stimulates widespread HSC activation throughout the liver leading to chronic inflammation, liver injury, and architectural changes. These complex changes to the liver microenvironment precede the development of HCC. Further, increased PDGF-CC levels were observed in livers of patients with non-alcoholic fatty steatohepatitis (NASH) and correlate with the stage of disease, suggesting a role for this growth factor in chronic liver disease in humans. PDGF-C transgenic mice provide a unique model for the in vivo study of tumor-stromal interactions in the liver.
PDGF; hepatocellular carcinoma; stromal cell; microenvironment
Helicobacter pylori is the primary cause of gastric cancer. However, monoclonal Epstein-Barr virus (EBV) nucleic acid is also present in up to 10% of these tumors worldwide. EBV prevalence is increased with male sex, non-antral localization and surgically disrupted anatomy. To further examine associations between EBV and gastric cancer, we organized an international consortium of 11 studies with tumor EBV status assessed by in situ hybridization. We pooled individual-level data on 2,648 gastric cancer patients, including 184 (7%) with EBV-positive cancers; all studies had information on cigarette use (64% smokers) and 9 had data on alcohol (57% drinkers). We compared patients with EBV-positive and EBV-negative tumors to evaluate smoking and alcohol interactions with EBV status. To account for within-population clustering, multi-level logistic regression models were used to estimate interaction odds ratios (OR) adjusted for distributions of sex (72% male), age (mean 59 years), tumor histology (56% Lauren intestinal-type), anatomic subsite (61% noncardia) and year of diagnosis (1983–2012). In unadjusted analyses, the OR of EBV positivity with smoking was 2.2 (95% confidence interval [CI], 1.6–3.2). The OR was attenuated to 1.5 (95% CI, 1.01–2.3) by adjustment for the possible confounders. There was no significant interaction of EBV status with alcohol drinking (crude OR, 1.4; adjusted OR, 1.0). Our data indicate the smoking association with gastric cancer is stronger for EBV-positive than EBV-negative tumors. Conversely, the null association with alcohol does not vary by EBV status. Distinct epidemiologic characteristics of EBV-positive cancer further implicate the virus as a co-factor in gastric carcinogenesis.
Alcohol; EBV; gastric cancer; smoking; pooled-analysis
Cigarette smoking; Smoking cessation; non-small cell lung cancer; coexisting chronic obstructive pulmonary disease; risk
The tumor microenvironment plays an important role in regulating cell growth and metastasis. Recently, we developed an ex vivo lung cancer model (4D) that forms perfusable tumor nodules on a lung matrix that mimics human lung cancer histopathology and protease secretion pattern. We compared the gene expression profile (Human OneArray v5 chip) of A549 cells, a human lung cancer cell line, grown in a petri dish (2D), and of the same cells grown in the matrix of our ex vivo model (4D). Furthermore, we obtained gene expression data of A549 cells grown in a petri dish (2D) and matrigel (3D) from a previous study and compared the 3D expression profile with that of 4D. Expression array analysis showed 2,954 genes differentially expressed between 2D and 4D. Gene ontology (GO) analysis showed upregulation of several genes associated with extracellular matrix, polarity, and cell fate and development. Moreover, expression array analysis of 2D versus 3D showed 1006 genes that were most differentially expressed, with only 36 genes (4%) having similar expression patterns as observed between 2D and 4D. Finally, the differential gene expression signature of 4D cells (versus 2D) correlated significantly with poor survival in patients with lung cancer (n = 1,492), while the expression signature of 3D versus 2D correlated with better survival in lung cancer patients with lung cancer. Since patients with larger tumors have a worse rate of survival, the ex vivo 4D model may be a good mimic of natural progression of tumor growth in lung cancer patients.
Lung cancer; matrigel; ex vivo 4D model; gene expression profile; survival
Vitamin E includes several tocopherol isoforms which may reduce lung cancer risk, but past studies evaluating the association between vitamin E intake and lung cancer risk were inconsistent. We prospectively investigated the associations between tocopherol intake from diet and from supplements with lung cancer risk among 72,829 Chinese female nonsmokers aged 40-70 years and participating in the Shanghai Women’s Health Study (SWHS). Dietary and supplement tocopherol exposure was assessed by a validated food-frequency questionnaire at baseline, and also reassessed for change in intake during follow-up. Cox proportional hazards models with time-dependent covariates were used to calculate multivariate-adjusted hazard ratios (HRs) and 95% confidence interval (CIs) for lung cancer. After 12.02 years of follow-up, 481 women were diagnosed with lung cancer. Total dietary tocopherol was inversely associated with lung cancer risk among women meeting dietary guidelines for adequate intake (AI) of tocopherol (14 mg/day or more: HR: 0.78; 95% CI 0.60-0.99; compared to the category less than AI). The protective association between dietary tocopherol intake and lung cancer was restricted to women exposed to side-stream smoke in the home and workplace (HR=0.53 (0.29-0.97), p-trend = 0.04). In contrast, vitamin E supplement use was associated with increased lung cancer risk (HR: 1.33; 95% CI 1.01-1.73), more so for lung adenocarcinoma risk (HR: 1.79; 95% CI 1.23-2.60). In summary, dietary tocopherol intake may reduce the risk of lung cancer among female non-smokers, however supplements may increase lung adenocarcinoma risk and requires further investigation.
diet; dietary supplements; lung neoplasm; prospective study; tocopherols; women
T cell infiltration into the metastatic melanoma microenvironment (MME) correlates with improved patient survival. However, diffuse infiltration into tumor occurs in only 8% of melanoma metastases. Little is known about mechanisms governing T cell infiltration into human melanoma metastases or about how those mechanisms may be altered therapeutically. We hypothesized that T cells in the MME would be enriched for chemokine receptors CCR4, CCR5, CXCR3, and homing receptors relevant to the tissue site. Viably cryopreserved single cell suspensions from nineteen melanoma metastases representing three metastatic sites (tumor-infiltrated lymph node (TIN), skin, and small bowel) were evaluated by multiparameter flow cytometry and compared to benign lymph nodes (NLN) and peripheral blood mononuclear cells (PBMC) from patients with Stage IIB-IV melanoma. T cells in the melanoma metastases contained large effector memory populations, high proportions of activated, moderately differentiated cells and few regulatory T cells. Site specific homing was suggested in bowel, with high expression of CCR9. We did not encounter the anticipated enrichment of integrin α4β7 in bowel, cutaneous leukocyte antigen (CLA) in skin, nor integrin α4β1 or receptor CXCR3 in metastatic sites. Retention integrins αEβ7, α1β1 and α2β1 were significantly elevated in metastases. These data suggest limited tissue site-specific homing to human melanoma metastases, but a significant role for retention integrins in maintaining intratumoral T cells. Our findings also raise the possibility that T cell homing, infiltration, and retention in melanoma metastases may be increased by increasing expression of ligands for CLA, α4β1 and CXCR3 on intratumoral endothelium.
Metastatic melanoma; integrin; chemokine receptor; cancer immunology; tumor microenvironment
Paclitaxel is widely used to treat cancer patients through the blocking of mitosis and result in formation of polyploidy giant cancer cells (PGCCs), which are generally believed to be non-dividing cells or in mitotic catastrophe. Here we showed that PGCCs following the treatment of paclitaxel of MCF-7 breast cancer cell line have capability to generate regular-sized progeny cells through budding. The PGCCs not only grew into well differentiated cancer cells that formed cancer organotypic structures in vitro but also trans-differentiated into multiple tumor stromal cells including myoepithelial, endothelial, and erythroid cells. PGCCs formed glandular and vessel-like cancer organotypic structures that expressed normal stem cell markers. These progeny cells generated from PGCCs showed decreased ability of proliferation, invasion and tumor growth and became more resistant to paclitaxel than parental MCF-7 cells. These results demonstrated that paclitaxel-induced PGCCs have properties of cancer stem cells that can generate both epithelial cancer cells and multi-lineage of stromal cells. PGCCs are not only the morphogenic determinant to tumor histogenesis and but also contribute to paclitaxel resistance.
Polyploidy giant cancer cells; Paclitaxel; Cancer organotypic structure
A simple and accurate test to detect early-stage breast cancer has not been developed. Previous studies indicate that the level of human endogenous retrovirus type K (group HERV-K(HML-2)) transcription may be increased in human breast tumors. We hypothesized that HERV-K(HML-2) reactivation can serve as a biomarker for early detection of breast cancer. Serum samples were collected from women without cancer (controls) and patients with ductal carcinoma in situ (DCIS) and invasive breast cancer. ELISA assays were employed to detect serum anti-HERV-K(HML-2) antibody titers. RNA was extracted from sera and analyzed by real-time RT-PCR to quantitate the level of HERV-K(HML-2) mRNA. We measured significantly higher serum mRNA and serum antibody titers against HERV-K(HML-2) proteins in women with DCIS and stage I disease than in women without cancer. At optimized cutoffs for the antibody titers, the assay produced an area under the ROC curve (AUC) of 0.89 (95% confidence interval 0.77 to 1.00) for DCIS and of 0.95 (95% confidence interval 0.89 to 1.00) for invasive breast cancer. These AUCs are comparable to those observed for mammograms. We also found that serum HERV-K(HML-2) mRNA tended to be higher in breast cancer patients with a primary tumor who later on developed the metastatic disease than in patients who did not develop cancer metastasis. Our results show that HERV-K(HML-2) antibodies and mRNA are already elevated in the blood at an early stage of breast cancer, and further increase in patients who are at risk of developing a metastatic disease.
HERV-K; endogenous retroviruses; early detection; biomarkers; breast cancer; metastasis
Barrett's esophagus (BE) is characterized by the native stratified squamous epithelium (N) lining the esophagus being replaced by a columnar epithelium with intestinal differentiation (Barrett's mucosa; BM). BM is considered as the main risk factor for esophageal adenocarcinoma (Barrett's adenocarcinoma; BAc). MicroRNAs (miRNAs) are a class of small noncoding RNAs that control gene expression by targeting messenger RNAs and they are reportedly dysregulated in BM. To test the hypothesis that a specific miRNA expression signature characterizes BM development and progression, we performed miRNA microarray analysis comparing native esophageal mucosa with all the phenotypic lesions seen in the Barrett's carcinogenic process. Specimens were collected from 14 BE patients who had undergone esophagectomy, including: 14 with N, 14 with BM, 7 with low-grade intraepithelial neoplasia, 5 with high-grade intra-epithelial neoplasia and 11 with BAc. Microarray findings were further validated by quantitive real-time polymerase chain reaction and in situ hybridization analyses using a different series of consecutive cases (162 biopsy samples and 5 esophagectomies) of histologically proven, long-segment BE. We identified a miRNA signature of Barrett's carcinogenesis consisting of an increased expression of 6 miRNAs and a reduced expression of 7 miRNAs. To further support these results, we investigated target gene expression using the Oncomine database and/or immunohistochemical analysis. We found that target gene expression correlated significantly with miRNA dysregulation. Specific miRNAs are directly involved in BE progression to cancer. miRNA profiling significantly expands current knowledge on the molecular history of Barrett's carcinogenesis, also identifying molecular markers of cancer progression.
miRNA; Barrett's esophagus; gene target; expression signature
Recent cohort findings suggest that women who undergo a hysterectomy have an elevated relative risk of kidney cancer, although evidence from past studies has been inconsistent. We conducted a systematic review and meta-analysis of published cohort and case-control studies to summarize the epidemiologic evidence investigating hysterectomy and kidney cancer. Studies published from 1950 through 2012 were identified through a search of PubMed and of references from relevant publications. Meta-analyses were conducted using random-effects models to estimate summary relative risks (SRRs) and 95% confidence intervals (CIs) for hysterectomy, age at hysterectomy (<45, 45+ years), and time since hysterectomy (<10, 10+ years). The SRR for hysterectomy and kidney cancer for all published studies (7 cohort, 6 case-control) was 1.29 (95% CI, 1.16 to 1.43), with no evidence of between-study heterogeneity or publication bias. The summary effect was slightly weaker, although still significant, for cohorts (SRR, 1.26; 95% CI, 1.11 to 1.42) compared to case-control findings (1.37; 95% CI, 1.09 to 1.73), and was observed irrespective of age at hysterectomy, time since the procedure, and model adjustment for body mass index, smoking status and hypertension. Women undergoing a hysterectomy have an approximate 30% increased relative risk of subsequent kidney cancer. Additional research is needed to elucidate the biological mechanisms underlying this association.
hysterectomy; kidney cancer; meta-analysis
Rhabdomyosarcoma (RMS) is a highly malignant tumor of developing muscle that can occur anywhere in the body. Due to its rarity, relatively little is known about the epidemiology of RMS. Atopic disease is hypothesized to be protective against several malignancies; however, to our knowledge, there have been no assessments of atopy and childhood RMS. Therefore, we explored this association in a case-control study of 322 childhood RMS cases and 322 pair-matched controls. Cases were enrolled in a trial run by the Intergroup Rhabdomyosarcoma Study Group. Controls were matched to cases on race, sex, and age. The following atopic conditions were assessed: allergies, asthma, eczema, and hives; in addition we examined other immune-related factors: birth order, day-care attendance, and breastfeeding. Conditional logistic-regression models were used to calculate an odds ratio (OR) and 95% confidence interval (CI) for each exposure, adjusted for age, race, sex, household income, and parental education. As the two most common histologic types of RMS are embryonal (n=215) and alveolar (n=66), we evaluated effect heterogeneity of these exposures. Allergies (OR=0.60, 95% CI: 0.41–0.87), hives (OR=0.61, 95% CI: 0.38–0.97), day-care attendance (OR=0.48, 95% CI: 0.32–0.71), and breastfeeding for ≥12 months (OR=0.36, 95% CI: 0.18–0.70) were inversely associated with childhood RMS. These exposures did not display significant effect heterogeneity between histologic types (p>0.52 for all exposures). This is the first study indicating that atopic exposures may be protective against childhood RMS, suggesting additional studies are needed to evaluate the immune system’s role in the development of this tumor.
Allergies; atopy; epidemiology; rhabdomyosarcoma; soft tissue sarcoma
While persistent carcinogenic human papillomvirus (HPV) infection is necessary for cervical carcinogenesis, the co-factors involved in HPV persistence and disease progression are poorly understood. Chronic cervical inflammation may increase risk, but few studies have measured immune markers (cytokines/chemokines/soluble receptors) in cervical secretions. We evaluated the performance of 74 multiplexed, bead-based immune markers in cervical secretions from three groups of women with biopsy evaluation of cervical intraepithelial neoplasia (CIN): 1) 25% detectability and >80% interclass correlation coefficients (ICC) acceptable for epidemiologic studies. Within-batch coefficients of variation (CV) of ≥25% indicated room for assay improvement. Secondarily, we explored associations between marker levels and CIN/HPV status adjusted for matching variables, assay batch, age, and number of sexual partners. Sixty-two markers (84%) had >25% detectability and ICCs>80%. Of those, 53 (85%) had CVs<25%. Using these preliminary data, we found that HPV-positivity was associated with increased eotaxin-1 (OR: 15.63, 95% CI: 1.26–200.00) and G-CSF (OR: 12.99, 95% CI: 1.10–142.86) among CIN-negative women. There was suggestive evidence that higher chemoattractant marker levels were associated with CIN2/3 (e.g., MIP-1delta, OR: 4.48, 95% CI: 0.87–23.04 versus
The cytochrome P450 2B6 (CYP2B6) is involved in the metabolism of testosterone. Functional changes in this enzyme may influence endogenous hormone exposure, which has been associated with risk of breast cancer. To assess potential associations between two functional polymorphisms CYP2B6_516_G>T (rs3745274) and CYP2B6_785_A>G (rs2279343) and breast cancer risk we established a specific matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) assay. The GENICA breast cancer case-control study showed associations between the variant genotypes CYP2B6_516_TT and CYP2B6_785_GG and breast cancer risk with odds ratios (ORs) of 1.34 (p = 0.001) and 1.31 (p = 0.002), respectively. A similar effect was observed for carriers of the CYP2B6_516_T allele in a validation study including four independent studies from Germany, Sweden and USA. In a pooled analysis of all five studies involving 4,638 breast cancer cases and 3,594 controls of European ancestry, carriers of the CYP2B6_516_G and the CYP2B6_785_G variant had an increased breast cancer risk with ORs of 1.10 (p = 0.027) and 1.10 (p = 0.031), respectively. We conclude that the genetic variants CYP2B6_516_G and CYP2B6_785_G (designated CYP2B6*6), which are known to decrease activity of the CYP2B6 enzyme, contribute to an increased breast cancer risk.
CYP2B6; polymorphism; testosterone; breast cancer risk
Genital infection with the oncogenic human papillomavirus (HPV) is the necessary cause of cervical cancer and of a large fraction of vulvar cancers. The toll-like receptor (TLR) and the nuclear factor κB (NF-κB) signaling pathways have been implicated in inflammation, autoimmune disease and cancer, but whether common nucleotide variation in these pathways is associated with the risk of cervical and vulvar cancers has received little study. Using data from a population-based case-control study of cervical and vulvar cancers, we genotyped 205 single nucleotide polymorphisms (SNPs) in and around 32 candidate gene regions within these pathways. Gene-based analyses were employed to estimate the associations between individual gene regions and the risk of cervical and vulvar cancers. Odds ratio (OR) and 95% confidence intervals (CI) were calculated to assess the risk of cervical and vulvar cancers for each SNP. P-values were adjusted for multiple testing. A total of 876 cervical cancer cases, 517 vulvar cancer cases and 1,100 controls were included in the analysis. The TNF region was significantly associated with the risks of cervical cancer (gene-based P-value: 2.0×10−4) and vulvar cancer (gene-based P-value: 1.0×10−4). The rare allele (A) of SNP rs2239704 in the 5′ UTR of the LTA gene was significantly associated with increased risks of cervical cancer (OR=1.31, 95% CI: 1.15–1.50; adjusted P-value: 0.013) and vulvar cancer (OR=1.51, 95% CI: 1.30–1.75; adjusted P-value: 1.9×10−5). These findings add to the evidence of the importance of the immune system in the etiology of cervical and vulvar cancers.
cervical cancer; vulvar cancer; toll-like receptor; nuclear factor-κB; tumor necrosis factor
Like other members of the γ-herpesvirus family, human herpes virus 8 (HHV-8), the etiologic agent of classic and HIV-related Kaposi’s sarcoma (HIV-KS) acquired and evolved several human genes with key immune modulatory and cellular growth control functions. The encoded viral homologs substitute for their human counterparts but escape cellular regulation, leading to uncontrolled cell proliferation. We postulated that DNA variants in the human homologs of viral genes that potentially alter the expression or the binding of the encoded factors controlling the antiviral response may facilitate viral interference. To test whether cellular homologs are candidate susceptibility genes, we evaluated the association of DNA variants in 92 immune-related genes including 7 cellular homologs with the risk for HIV-KS in a matched case and control study nested in the Multicenter AIDS Cohort Study. Low- and high-risk gene-by-gene interactions were estimated by multifactor dimensionality reduction and used as predictors in conditional logistic models. Among the most significant gene interactions at risk (OR=2.84–3.92; Bonferroni-adjusted p= 9.9×10−3−2.6×10−4), three comprised human homologs of two latently expressed viral genes, cyclin D1 (CCND1) and interleukin-6 (IL-6), in conjunction with angiogenic genes (VEGF, EDN-1 and EDNRB). At lower significance thresholds (adjusted p < 0.05), human homologs related to apoptosis (CFLAR) and chemotaxis (CCL2) emerged as candidates. This “proof of concept” study identified human homologs involved in the regulation of type I interferon-induced signaling, cell cycle and apoptosis potentially as important determinants of HIV-KS
Kaposi’s sarcoma; Immunodeficiency; Herpes Virus 8; Multifactor Dimensionality Reduction; Polymorphism; Genetic association
Results 1-25 (1032)
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