Abnormal methylation characteristics predict chemoresistance and poor prognosis in advanced high-grade serous ovarian cancer.

BACKGROUND: Primary or acquired chemoresistance is a key link in the high mortality rate of ovarian cancer. There is no reliable method to predict chemoresistance in ovarian cancer. We hypothesized that specific methylation characteristics could distinguish chemoresistant and chemosensitive ovarian cancer patients. METHODS: In this study, we used 450 K Infinium Methylation BeadChip to detect the different methylation CpGs between ovarian cancer patients. The differential methylation genes were analyzed by GO and KEGG Pathway bioinformatics analysis. The candidate CpGs were confirmed by pyrosequencing. The expression of abnormal methylation gene was identified by QRT-PCR and IHC. ROC analysis confirmed the ability to predict chemotherapy outcomes. Prognosis was evaluated using Kaplan-Meier. RESULTS: In advanced high-grade serous ovarian cancer, 8 CpGs (ITGB6:cg21105318, cg07896068, cg18437633; NCALD: cg27637873, cg26782361, cg16265707; LAMA3: cg20937934, cg13270625) remained hypermethylated in chemoresistant patients. The sensitivity, specificity and AUC of 8 CpGs (ITGB6:cg21105318, cg07896068, cg18437633; NCALD: cg27637873, cg26782361, cg16265707; LAMA3: cg20937934, cg13270625) methylation to predict chemotherapy sensitivity were 63.60-97.00%, 46.40-89.30% and 0.774-0.846. PFS of 6 candidate genes (ITGB6:cg21105318, cg07896068; NCALD: cg27637873, cg26782361, cg16265707; LAMA3: cg20937934) hypermethylation patients was significantly shorter. The expression of NCALD and LAMA3 in chemoresistant patients was lower than that of chemosensitive patients. Spearman analysis showed that NCALD and LAMA3 methylations were negatively correlated with their expression. CONCLUSIONS: As a new biomarker of chemotherapy sensitivity, hypermethylation of NCALD and LAMA3 is associated with poor PFS in advanced high-grade serous ovarian cancer. In the future, further research on NCALD and LAMA3 will be needed to provide guidance for clinical stratification of demethylation therapy.

LAMA3 DNA methylation and transcriptome changes associated with chemotherapy resistance in ovarian cancer.

OBJECTIVE: LAMA3 is a widely studied methylated gene in multiple tumors, but the relationship between chemotherapy resistance in ovarian cancer is unclear. In this study, LAMA3 methylation was predicted by bioinformatics, and the ability of LAMA3 methylation to predict the chemotherapy resistance and prognosis of ovarian cancer was confirmed in experiments. METHODS: Multiple databases have performed the bioinformatics analysis of methylation and transcription factor binding site (TFBS) on the promoter region of LAMA3 gene. Pyrosequencing detected the methylation of LAMA3. QRT-PCR and immunohistochemistry detected the expression of LAMA3. Real Time Cell Analyzer (RTCA) detects changes in cell proliferation, migration and invasion ability. Flow cytometry was used to detect apoptosis. RESULTS: CPG islands of 176 bp, 134 bp, 125 bp and 531 bp were predicted in the promoter region of LAMA3 gene. The 4 prediction results are basically overlapped. 7 transcription factor binding sites were predicted, and the one with the highest score was on the predicted CpG island located in the proximal promoter region. LAMA3 hypermethylation and low expression are both associated with chemotherapy resistance and poor prognosis in ovarian cancer. LAMA3 methylation was negatively correlated with expression. After upregulation of LAMA3, the proliferation ability of chemoresistant ovarian cancer cell decreased, while the ability of apoptosis, invasion and migration increased. CONCLUSION: LAMA3 hypermethylation is associated with chemotherapy resistance and poor prognosis. As a typical CpG island gene, LAMA3(cg20937934) and LAMA3(cg13270625) hypermethylation is negatively correlated with low expression. LAMA3 promotes the invasion, migration and apoptosis of SKOV3DDP. In the future, the mechanism of LAMA3 methylation in ovarian cancer will need to be further studied.

Polymorphisms of transforming growth factor beta 1 (RS#1800468 and RS#1800471) and esophageal squamous cell carcinoma among Zhuangese population, China.

Epidemiological evidence has shown two polymorphisms (namely RS#1800468G>A and RS#1800471G>C) of transforming growth factor-beta 1 (TGF-ß1) gene may be involved in the cancer development. However, their role in the carcinogenic process of esophageal squamous cell carcinoma (ESCC) has been less well elaborated. We conducted a hospital-based case-control study including 391 ESCC cases and 508 controls without any evidence of tumors to evaluate the association between these two polymorphisms and ESCC risk and prognosis for Zhuangese population by means of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation system (ARMS)-PCR techniques. We found that individuals with the genotypes with RS#1800471 C allele (namely RS#1800471-GC or -CC) had an increased risk of ESCC than those without above genotypes (namely RS#1800471-GG, adjusted odds ratio 3.26 and 5.65, respectively). Further stratification analysis showed that this polymorphism was correlated with tumor histological grades and TNM (tumor, node, and metastasis) stage, and modified the serum levels of TGF-ß1. Additionally, RS#1800471 polymorphism affected ESCC prognosis (hazard ratio, 3.40), especially under high serum levels of TGF-ß1 conditions. However, RS#1800468 polymorphism was not significantly related to ESCC risk. These findings indicated that TGF-ß1 RS#1800471G>C polymorphism may be a genetic modifier for developing ESCC in Zhuangese population.

Comparisons of morphologic characteristics between thin-flap LASIK and SBK.

AIM: To compare the morphologic characteristics between thin-flap laser in situ keratomileusis (LASIK) and Sub-Bowman keratomileusis (SBK), and to evaluate the uniformity of flap and to explore the correlative factors of corneal flap thickness. METHODS: A prospective, randomized, comparative clinical study was performed in Department of Ophthalmology, West Hospital of China, Chengdu, Sichuan Province, China. Totally 59 patients 114 eyes underwent LASIK or SBK to correct myopia, 29 patients 57 eyes underwent SBK, 30 patients 57 eyes underwent LASIK. Anterior optical coherence tomography(OCT) was used to measure corneal flap thickness in all the patients 1 week after surgeries, 16 positions were set to be measured in each eye. Comparisons of flap thickness in each group and between 2 groups were evaluated. Correlative factors of flap thickness were evaluated. RESULTS: Coefficient of variation (CV, s/×%) in SBK group were lesser than that in LASIK group, t test showed there was significant statistical difference between 2 groups(P=0.000). Comparisons of the difference of 2 paired positions(temporal-nasal; superior-inferior) showed there were no significant differences in each group, but between 2 groups, there were statistical significance of value of difference (D-value) of superior and inferior positions between SBK and LASIK group(P=0.036). Linear regression analysis of correlative factors of flap thickness showed there were no statistic significances related to central corneal thickness(CCT)(P=0.060, t=1.921) and corneal curvature(P=0.083, t=1.766). CONCLUSION: SBK is better than LASIK in creating much uniform corneal flap. There was no evidence showing correlations between flap thickness and CCT or corneal curvature.

Genetic polymorphism of XRCC3 codon 241 and Helicobacter pylori infection-related gastric antrum adenocarcinoma in Guangxi Population, China: a hospital-based case-control study.

BACKGROUND: The relationship between Helicobacter pylori infection and gastric antrum adenocarcinoma (GAA) has previously been demonstrated and supported with strong epidemiological evidence. However, the role of genetic polymorphism of X-ray cross-complementing group 3 (XRCC3) Thr241Met (rs#861539), which may be involved in the repair of DNA double-strand breaks caused by carcinogens such as CagA, a protein produced by H. pylori, has been less well elaborated. METHODS: We conducted a hospital-based case-control study, including 721 patients with pathologically confirmed GAA and 989 individually matched controls without any evidence of tumors or precancerous lesions to evaluate the associations between this polymorphism and GAA risk in the Guangxi population. XRCC3 codon 241 genotypes and CagA status were determined using TaqMan-PCR and PCR, respectively. RESULTS: Increased risks of GAA were found for cagA-positive individuals [odds ratio (OR), 7.31; 95% confidence interval (CI), 5.87-9.09]. We also found that individuals with the XRCC3 genotypes with codon 241 Met (namely XRCC3-TM or XRCC3-MM) had an increased risk of GAA compared with those with the homozygote of XRCC3 codon 241 Thr alleles (namely XRCC3-TT, adjusted ORs 1.76 and 3.73; 95% CIs 1.37-2.24 and 2.66-5.23, respectively). The risk of GAA, moreover, appeared to differ more significantly among individuals featuring cagA-positive status, whose adjusted ORs (95% CIs) were 11.31 (8.34-15.33) and 27.48 (15.17-49.78), respectively. CONCLUSION: These results suggest that XRCC3 Thr241Met polymorphism may be associated with the risk of GAA related to CagA.

DNA repair gene XRCC7 polymorphisms (rs#7003908 and rs#10109984) and hepatocellular carcinoma related to AFB1 exposure among Guangxi population, China.

AIM: The X-ray repair cross-complementing group 7 (XRCC7) plays an important role in the repair of DNA double-strand breaks by nonhomologous end-joining repair (NEJR) pathway. However, the role of XRCC7 polymorphisms (rs#7003908 and rs#10109984) possibly influencing NEJR capacity in hepatocellular carcinoma (HCC) induced by aflatoxin B1 (AFB1) has not been well elaborated. METHODS: This hospital-based case-control study, including 348 patients with newly diagnosed HCC and 597 controls without any evidence of liver diseases, was conducted to elucidate the association between these two polymorphisms and the risk of HCC related to AFB1 exposure among a Guangxi population from a high AFB1-exposure area by means of TaqMAN-polymerase chain reaction technique. RESULTS: We observed that HCC patients featured higher AFB1 exposure than control group (odds ratios [OR] = 6.49 and 6.75 for exposure years and exposure levels, respectively). Furthermore, these individuals with the genotypes of XRCC7 rs#7003908 G alleles (namely XRCC7-TG or -GG), compared the homozygote of XRCC7 rs#7003908 T alleles (XRCC7-TT), faced increasing risk of HCC (OR, 3.45 and 5.04; 95% confidence intervals [CIs], 2.40-4.94 and 3.28-7.76, respectively). We also found some evidence that this polymorphism interacted with AFB1-expousure years or levels in the process of HCC carcinogenesis. Additionally, XRCC7 rs#7003908 polymorphism was correlated with the levels of AFB1-DNA adducts (r = 0.142, P < 0.001). XRCC7 rs#10109984 polymorphism, however, did not modify the risk of HCC related to AFB1 exposure (P > 0.05). CONCLUSION: These data suggest that XRCC7 rs#7003908 polymorphism may be one of the genetic modifiers for AFB1-related HCC among Guangxi population.

Genetic polymorphisms in DNA repair genes XPC, XPD, and XRCC4, and susceptibility to Helicobacter pylori infection-related gastric antrum adenocarcinoma in Guangxi population, China.

Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity, which may be associated with risk of gastric antrum adenocarcinoma (GAA) related to Helicobacter pylori infection. This study, including 361 GAAs and 616 controls without any evidence of tumors, was designed to evaluate the association between the polymorphisms of DNA repair genes XPC Ala499Val (RS#2228000) and Lys939Gln (RS#2228001), XPD Lys751Gln (RS#13181), and XRCC4 Ala247Ser (RS#3734091) and Ser298Asn (RS#1805377), and GAA risk for Guangxi population by means of TaqMan-PCR analysis. Increased risks of GAA were found for individuals with H. pylori positive [odds ratio (OR), 2.48; 95% confidence interval (CI), 1.84-3.33] or cagA positive (OR, 7.34; 95% CI, 5.46-9.87). No differences were observed among the studied groups with regard to the genotype distribution of XPC codons 499 and 939 and of XRCC4 codon 247; but XPD codon 751 genotypes with Gln [ORs (95% CI) were 2.67 (1.98-3.58) and 3.97 (2.64-5.99) for Lys/Gln and Gln/Gln, respectively] and XRCC4 codon 298 genotypes with Asn [ORs (95% CI) were 3.01 (2.21-4.10) and 4.78 (3.24-7.05) for Ser/Asn and Asn/Asn, respectively] increased the risk of GAA. Interestingly, there was an interactive effect between the risk genotypes of these two genes and cagA-positive status in the GAA risk (OR(interact) = 2.05 and 2.08, respectively). However, we did not find the gene-H. pylori-status interaction effects on the risk of GAA (P(interact) > 0.05). The results suggested that the polymorphisms of XPD codon 751 and XRCC4 codon 298 are associated with an increased risk of developing H. pylori-related GAA among Guangxi population.

XPD codon 312 and 751 polymorphisms, and AFB1 exposure, and hepatocellular carcinoma risk.

BACKGROUND: Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity, which may be associated with risk of hepatocellular carcinoma (HCC) related to the exposure of aflatoxin B1 (AFB1). In this study, we have focused on the polymorphisms of xeroderma pigmentosum complementation group D (XPD) codon 312 and 751 (namely Asp312Asn and Lys751Gln), involved in nucleotide excision repair. METHODS: We conducted a case-control study including 618 HCC cases and 712 controls to evaluate the associations between these two polymorphisms and HCC risk for Guangxi population by means of TaqMan-PCR and PCR-RFLP analysis. RESULTS: We found that individuals featuring the XPD genotypes with codon 751 Gln alleles (namely XPD-LG or XPD-GG) were related to an elevated risk of HCC compared to those with the homozygote of XPD codon 751 Lys alleles [namely XPD-LL, adjusted odds ratios (ORs) were 1.75 and 2.47; 95% confidence interval (CIs) were 1.30-2.37 and 1.62-3.76, respectively]. A gender-specific role was evident that showed an higher risk for women (adjusted OR was 8.58 for XPD-GG) than for men (adjusted OR = 2.90 for XPD-GG). Interestingly, the interactive effects of this polymorphism and AFB1-exposure information showed the codon 751 Gln alleles increase the risk of HCC for individuals facing longer exposure years (Pinteraction = 0.011, OR = 0.85). For example, long-exposure-years (> 48 years) individuals who carried XDP-GG had an adjusted OR of 470.25, whereas long-exposure-years people with XDP-LL were at lower risk (adjusted OR = 149.12). However, we did not find that XPD codon 312 polymorphism was significantly associated with HCC risk. CONCLUSION: These findings suggest that XPD Lys751Gln polymorphism is an important modulator of AFB1 related-HCC development in Guangxi population.

[Association of the Thr241Met polymorphism of DNA repair gene XRCC3 with genetic susceptibility to AFB1-related hepatocellular carcinoma in Guangxi population].

OBJECTIVE: To explore the association of the Thr241Met polymorphism of X-ray cross-complementing group 3 (XRCC3) gene with genetic susceptibility to aflatoxin B1(AFB-1)-related hepatocellular carcinoma (HCC)in Guangxi population. METHODS: We conducted a hospital-based case-control study, including 257 HCC cases and 711 controls without cancers or liver diseases. The XRCC3 Thr241Met polymorphism was analyzed by PCR. RESULTS: The XRCC3 genotypes XRCC3-Thr/Met or XRCC3-Met/Met were related with an elevated risk of HCC. The risk of HCC was associated with the number of mutant Met copies (adjusted OR were 2.20 and 8.56 for XRCC3-Thr/Met and Met/Met, respectively); moreover, there seemed to be combined effects for HCC risk between the variant genotypes and AFB1-DNA adduct levels from peripheral blood leukocytes (adjusted OR was 2.34 to 20.44, P < 0.01). CONCLUSION: These results suggested that XRCC3 polymorphism may be associated with the risk of AFB1- related HCC among the Guangxi population, and interacts with AFB1 exposure in the development of HCC induced by AFB1.

The polymorphism of XRCC3 codon 241 and AFB1-related hepatocellular carcinoma in Guangxi population, China.

PURPOSE: The relationship between aflatoxin B1 (AFB1) exposure and hepatocellular carcinoma (HCC) has been previously demonstrated and supported with strong epidemiological evidence. However, the role of genetic polymorphism of X-ray cross-complementing group 3 (XRCC3) codon 241 (namely: Thr241Met), which may be involved in the repair of DNA double-strand breaks caused by carcinogens such as AFB1, been less well elaborated. METHODS: We conducted a case-control study including 491 cases and 862 controls to evaluate the associations between this polymorphism and HCC risk for Guangxi population by means of polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS: We found that individuals with the XRCC3 genotypes with codon 241 Met (namely XRCC3-TM or XRCC3-MM) had an increased risk of HCC than those with the homozygote of XRCC3 codon 241 Thr alleles (namely XRCC3-TT, adjusted odds ratios 2.22 and 7.19; 95% confidence intervals 1.72-2.88 and 4.52-11.42, respectively). The risk of HCC, moreover, did appear to differ more significantly among individuals featuring high-level AFB1-DNA adducts, whose adjusted odds ratios (95% confidence intervals) were 11.59 (5.73-23.47) and 37.54 (16.32-86.32), respectively. CONCLUSIONS: These findings support the hypothesis that the XRCC3 Thr241Met polymorphism may be associated with the risk of AFB1-related HCC among the Guangxi population.