Genetic variation of the CYP17 and susceptibility to endometrial cancer: a meta-analysis. Mol Biol Rep. 2013;40:5085-5091. [PMID: 23649771 DOI: 10.1007/s11033-013-2609-0]

Risk factors for endometrial cancer: An umbrella review of the literature

Although many risk factors could have causal association with endometrial cancer, they are also prone to residual confounding or other biases which could lead to over- or underestimation. This umbrella review evaluates the strength and validity of evidence pertaining risk factors for endometrial cancer. Systematic reviews or meta-analyses of observational studies evaluating the association between non-genetic risk factors and risk of developing or dying from endometrial cancer were identified from inception to April 2018 using PubMed, the Cochrane database and manual reference screening. Evidence was graded strong, highly suggestive, suggestive or weak based on statistical significance of random-effects summary estimate, largest study included, number of cases, between-study heterogeneity, 95% prediction intervals, small study effects, excess significance bias and sensitivity analysis with credibility ceilings. We identified 171 meta-analyses investigating associations between 53 risk factors and endometrial cancer incidence and mortality. Risk factors were categorised: anthropometric indices, dietary intake, physical activity, medical conditions, hormonal therapy use, biochemical markers, gynaecological history and smoking. Of 127 meta-analyses including cohort studies, three associations were graded with strong evidence. Body mass index and waist-to-hip ratio were associated with increased cancer risk in premenopausal women (RR per 5 kg/m2 1.49; CI 1.39-1.61) and for total endometrial cancer (RR per 0.1unit 1.21; CI 1.13-1.29), respectively. Parity reduced risk of disease (RR 0.66, CI 0.60-0.74). Of many proposed risk factors, only three had strong association without hints of bias. Identification of genuine risk factors associated with endometrial cancer may assist in developing targeted prevention strategies for women at high risk.

Sex steroid hormones and sex hormone binding globulin levels, CYP17 MSP AI (-34T:C) and CYP19 codon 39 (Trp:Arg) variants in children with developmental stuttering

Developmental stuttering is known to be a sexually dimorphic and male-biased speech motor control disorder. In the present case-control study, we investigated the relationship between developmental stuttering and steroid hormones. Serum levels of testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), oestradiol, progesterone, cortisol, and sex hormone binding globulin (SHBG), as well as the 2nd/4th digit ratio (2D:4D), an indicator of prenatal testosterone level, were compared between children who stutter (CWS) and children who do not stutter (CWNS). Moreover, two SNPs (CYP17 -34 T:C (MSP AI) and CYP19 T:C (Trp:Arg)) of cytochrome P450, which is involved in steroid metabolism pathways, were analysed between the groups. Our results showed significantly higher levels of testosterone, DHT, and oestradiol in CWS in comparison with CWNS. The severity of stuttering was positively correlated with the serum levels of testosterone, DHEA, and cortisol, whereas no association was seen between the stuttering and digit ratio, progesterone, or SHBG. The CYP17CC genotype was significantly associated with the disorder.

Genetic biomarkers for hepatocellular cancer risk in a caucasian population

AIM

To uncover novel genetic markers that could contribute to predicting hepatocellular carcinoma (HCC) susceptibility in Caucasians.

METHODS

The present retrospective case-control study compared genotype frequencies between a cohort of HCC cases and two, independent, HCC-free, age/sex-matched control groups. The HCC cohort comprised 192 homogeneous patients that had undergone orthotopic liver transplantation. The first control group comprised 167 patients that were matched to the HCC cohort for the percentage of hepatitis B (HBV) and/or hepatitis C (HCV) infections. A second control group included 192 virus-free, healthy individuals that were used to evaluate the generalizability of the identified predictive markers. All cases and controls were Caucasian. The three study populations were characterized with a panel of 31 markers derived from 21 genes that encoded key proteins involved in hepatocarcinogenesis-related pathways. The study end-point was to assess the association between genetic variants and HCC onset.

RESULTS

Five genetic markers were identified as risk factors for HCC in high-risk patients infected with HBV/HCV. According to a dominant model, reduced HCC risk was associated with three polymorphisms: ERCC1 rs3212986 (OR = 0.46, 95%CI: 0.30-0.71, P = 0.0005), GST-P1 rs1138272 (OR = 0.41, 95%CI: 0.21-0.81, P = 0.0097), and CYP17A1 rs743572 (OR = 0.50, 95%CI: 0.31-0.79, P = 0.0032). Conversely, according to a recessive model, increased HCC risk was associated with two polymorphisms: XRCC3 rs1799794 (OR = 3.70, 95%CI: 1.02-13.39, P = 0.0461) and ABCB1 rs1128503 (OR = 2.06, 95%CI: 1.18-3.61, P = 0.0111). These associations remained significant in a subgroup analysis, where patients were stratified according to viral status (HBV- or HCV-positive serology). Two variants exhibited a serology-specific effect: ABCB1 rs1128503 (OR = 4.18, 95%CI: 1.55-11.29, P = 0.0048) showed an effect in the HBV-positive subgroup; and ERCC1 rs3212986 (OR = 0.33, 95%CI: 0.18-0.60, P = 0.0003) showed an effect in the HCV-positive subgroup. Among the five markers identified, ERCC1 rs3212986 (OR = 0.43, P < 0.0001) and CYP17A1 rs743572 (OR = 0.73, P = 0.0310) had a different distribution in patients with HCC compared to healthy individuals. With a recursive partitioning approach, we also demonstrated that significant gene-gene interactions between ERCC1 rs3212986, CYP17A1 rs743572, GST-P1 rs1138272, and the previously described UGT1A7*3 predictive marker, played a role in the complex trait of HCC susceptibility.

CONCLUSION

We identified five polymorphisms and interactions that contributed crucially to predicting HCC risk. These findings represented an important step towards improving HCC diagnosis and management.

Identification of novel mutations in endometrial cancer patients by whole-exome sequencing

The aim of the present study was to identify genomic alterations in Taiwanese endometrial cancer patients. This information is vitally important in Taiwan, where endometrial cancer is the second most common gynecological cancer. We performed whole-exome sequencing on DNA from 14 tumor tissue samples from Taiwanese endometrial cancer patients. We used the Genome Analysis Tool kit software package for data analysis, and the dbSNP, Catalogue of Somatic Mutations in Cancer (COSMIC) and The Cancer Genome Atlas (TCGA) databases for comparisons. Variants were validated via Sanger sequencing. We identified 143 non-synonymous mutations in 756 canonical cancer-related genes and 1,271 non-synonymous mutations in non-canonical cancer-related genes in 14 endometrial samples. PTEN, KRAS and PIK3R1 were the most frequently mutated canonical cancer-related genes. Our results revealed nine potential driver genes (MAPT, IL24, MCM6, TSC1, BIRC2, CIITA, DST, CASP8 and NOTCH2) and 21 potential passenger genes (ARMCX4, IGSF10, VPS13C, DCT, DNAH14, TLN1, ZNF605, ZSCAN29, MOCOS, CMYA5, PCDH17, UGT1A8, CYFIP2, MACF1, NUDT5, JAKMIP1, PCDHGB4, FAM178A, SNX6, IMP4 and PCMTD1). The detected molecular aberrations led to putative activation of the mTOR, Wnt, MAPK, VEGF and ErbB pathways, as well as aberrant DNA repair, cell cycle control and apoptosis pathways. We characterized the mutational landscape and genetic alterations in multiple cellular pathways of endometrial cancer in the Taiwanese population.

Increased mood symptoms in postmenopausal women related to the polymorphism rs743572 of the CYP17 A1 gene

BACKGROUND

Menopausal and depressive symptoms are highly prevalent after the menopause; but may vary from one population to another and genetics play a key role.

OBJECTIVE

To analyze the intensity of these symptoms in relation to the genetic variants of the rs743572 polymorphism of the CYP17 A1 gene in postmenopausal women.

METHODS

DNA was extracted from the whole blood of 168 natural postmenopausal women (40-65 years) and tested for the rs743572 polymorphism of the CYP17 A1 gene. Intensity of menopausal (Menopause Rating Scale, MRS) and depressive symptoms (Hospital Anxiety and Depressive Scale, HADS) were correlated to polymorphism genotypes.

RESULTS

Women with the GG genotype of the rs743572 polymorphism displayed significantly higher scores for the MRS (items 5 and 6 [irritability and anxiety] and the psychological subscale) and the HADS (total and subscales).

CONCLUSION

The intensity of menopausal symptoms related to mood was found higher among postmenopausal women presenting the GG genotype of the rs743572 polymorphism of the CYP17 A1 gene. There is a need for more research in this regard.

Identification of Susceptibility Loci and Genes for Colorectal Cancer Risk

BACKGROUND & AIMS

Known genetic factors explain only a small fraction of genetic variation in colorectal cancer (CRC). We conducted a genome-wide association study to identify risk loci for CRC.

METHODS

This discovery stage included 8027 cases and 22,577 controls of East-Asian ancestry. Promising variants were evaluated in studies including as many as 11,044 cases and 12,047 controls. Tumor-adjacent normal tissues from 188 patients were analyzed to evaluate correlations of risk variants with expression levels of nearby genes. Potential functionality of risk variants were evaluated using public genomic and epigenomic databases.

RESULTS

We identified 4 loci associated with CRC risk; P values for the most significant variant in each locus ranged from 3.92 × 10(-8) to 1.24 × 10(-12): 6p21.1 (rs4711689), 8q23.3 (rs2450115, rs6469656), 10q24.3 (rs4919687), and 12p13.3 (rs11064437). We also identified 2 risk variants at loci previously associated with CRC: 10q25.2 (rs10506868) and 20q13.3 (rs6061231). These risk variants, conferring an approximate 10%-18% increase in risk per allele, are located either inside or near protein-coding genes that include transcription factor EB (lysosome biogenesis and autophagy), eukaryotic translation initiation factor 3, subunit H (initiation of translation), cytochrome P450, family 17, subfamily A, polypeptide 1 (steroidogenesis), splA/ryanodine receptor domain and SOCS box containing 2 (proteasome degradation), and ribosomal protein S2 (ribosome biogenesis). Gene expression analyses showed a significant association (P < .05) for rs4711689 with transcription factor EB, rs6469656 with eukaryotic translation initiation factor 3, subunit H, rs11064437 with splA/ryanodine receptor domain and SOCS box containing 2, and rs6061231 with ribosomal protein S2.

CONCLUSIONS

We identified susceptibility loci and genes associated with CRC risk, linking CRC predisposition to steroid hormone, protein synthesis and degradation, and autophagy pathways and providing added insight into the mechanism of CRC pathogenesis.

Insulin resistance and endometrial cancer risk: A systematic review and meta-analysis

AIM

It has been suggested that chronic hyperinsulinemia from insulin resistance is involved in the etiology of endometrial cancer (EC). We performed a systematic review and meta-analysis to assess whether insulin resistance is associated with the risk of EC.

METHODS

We searched PubMed-Medline, Embase, Scopus, and Web of Science for articles published from database inception through 30th September 2014. We included all observational studies evaluating components defining insulin resistance in women with and without EC. Quality of the included studies was assessed by Newcastle-Ottawa scale. Random-effects models and inverse variance method were used to meta-analyze the association between insulin resistance components and EC.

RESULTS

Twenty-five studies satisfied our inclusion criteria. Fasting insulin levels (13 studies, n = 4088) were higher in women with EC (mean difference [MD] 33.94 pmol/L, 95% confidence interval [CI] 15.04-52.85, p = 0.0004). No differences were seen in postmenopausal versus pre- and postmenopausal subgroup analysis. Similarly, non-fasting/fasting C-peptide levels (five studies, n = 1938) were also higher in women with EC (MD 0.14 nmol/L, 95% CI 0.08-0.21, p < 0.00001). Homeostatic model assessment - insulin resistance (HOMA-IR) values (six studies, n = 1859) in EC patients were significantly higher than in women without EC (MD 1.13, 95% CI 0.20-2.06, p = 0.02). There was moderate-to-high heterogeneity among the included studies.

CONCLUSION

Currently available epidemiologic evidence is suggestive of significantly higher risk of EC in women with high fasting insulin, non-fasting/fasting C-peptide and HOMA-IR values.

Association study of two steroid biosynthesis genes (COMT and CYP17) with Alzheimer's disease in the Italian population

The greater predisposition of women to Alzheimer's disease (AD), owing to the decrease in postmenopausal estrogen, may be influenced by polymorphic variation in genes regulating estrogen metabolism (e.g., COMT) and estrogen biosynthesis (e.g., CYP17). In order to better understand how the estrogen pathway genetic variation might affect AD onset, we conducted a case-control study of two single nucleotide polymorphisms (SNPs) of these two genes (COMT rs4680 and CYP17 rs743572) in a sample of AD patients of Italian origin. The COMT allele and genotype were found associated neither with AD onset nor with parameters of AD severity, such as cognitive impairment, age at onset, or disease duration. In contrast, CYP17 was found to affect the age at disease onset mainly in males and, as compared with noncarriers, people carrying the A2 (C) allele had a 2.2-fold increased risk for AD. These findings suggest that the CYP17 A2 allele influences AD susceptibility in a sex-specific way by acting not only on AD risk but also on the age at disease onset, an important parameter of AD severity.

The rs7003908 (T>G) polymorphism in the XRCC7 gene and the risk of cancers

The association between the rs7003908 (T>G) polymorphism in the XRCC7 gene and the risk of cancers had been widely studied; however, the results were inconsistent. The objective of the current study was to investigate the association between the rs7003908 polymorphism in the XRCC7 gene and the risk of cancers by meta-analysis. We searched PubMed, EMbase, CNKI and Wanfang databases; the last search was performed on January 10th, 2014. Statistical analysis was performed using the Revman4.2 and STATA10.0 softwares. A total of 3,684 cancer cases and 5,232 controls from 11 case-control studies were included for data analysis. In the dominant model analysis, the results suggested a lack of association between the polymorphism and the risk of cancers: OR 1.01, 95% CI 0.83-1.16, P = 0.70. In the subgroup analysis by ethnicity, no significant association was found either for Asians or Caucasians. In the subgroup analysis by cancer types, significant association was found for prostate cancer, but not for bladder cancer, breast cancer and glioma. In summary, the current meta-analysis confirmed that the rs7003908 polymorphism in the XRCC7 gene might be a risk factor for prostate cancer. In the future, more studies are needed to validate these results.