Fibroblast growth factor receptor 4 Gly388Arg polymorphism in Chinese gastric cancer patients.

AIM: To investigate the contribution of the fibroblast growth factor receptor 4 (FGFR4) Gly388Arg polymorphism as a genetic risk factor for gastric cancer (GC) and to investigate any associations between this polymorphism and clinicopathological parameters and survival. METHODS: Tumors and matched adjacent non-cancer tissues were collected from 304 GC patients, and 5 mL of venous blood was collected from 62 GC patients and 392 age- and sex-matched healthy controls without cancer history from the same ethnic population. DNA was extracted, and direct sequencing analyses were performed to genotype the FGFR4 Gly388Arg polymorphism in all the samples. Differences in the genotype frequencies of the FGFR4 Gly388Arg polymorphism between GC patients and healthy controls were estimated using the χ(2) test. Binary logistic regression was used for all analysis variables to estimate risk as the ORs with 95%CIs. The relationships between the FGFR4 genotype and clinicopathological parameters were tested with the χ(2) test. The Kaplan-Meier product-limit method, the log-rank test, and the Cox regression model were applied to evaluate the effect of the FGFR4 genotype on the overall survival of patients with GC. RESULTS: In the present GC cohort, 118 patients (38.8%) were homozygous for the Gly388 allele, 124 patients (40.8%) were heterozygous, and 62 patients (20.4%) were homozygous for the Arg388 allele. The frequencies of the Gly/Gly, Gly/Arg, and Arg/Arg genotypes in the healthy controls were 33.6%, 48.0%, and 18.4%, respectively. The distributions of genotypes (χ(2) = 3.589, P = 0.166) and alleles (χ(2) = 0.342, P = 0.559) of the FGFR4 Gly388Arg polymorphism were not different between the GC patients and the healthy controls. Although we observed no correlation between the FGFR4 Gly388Arg polymorphism and clinicopathological parameters or survival in the total cohort of GC patients, the presence of the Arg388 allele was associated with shorter survival time in patients with GC if the tumor was small (log rank χ(2) = 5.449, P = 0.020), well differentiated (log rank χ(2) = 12.798, P = 0.000), T1 or T2 stage (log rank χ(2) = 4.745, P = 0.029), without lymph node involvement (log rank χ(2) = 6.647, P= 0.010), and at an early clinical stage (log rank χ(2) = 4.615, P = 0.032). CONCLUSION: Our results suggest that the FGFR4 Gly388Arg polymorphism is not a risk factor for GC cancer initiation but that it is a useful prognostic marker for GC patients when the tumor is relatively small, well differentiated, or at an early clinical stage.

KRAS and PIK3CA but not BRAF genes are frequently mutated in Chinese cholangiocarcinoma patients.

Cholangiocarcinoma (CCA) is a rare but lethal malignancy arising from the biliary tract epithelium. It has a poor prognosis largely due to the difficulties of early diagnosis and the lack of effective therapies. It is thus imperative to develop new and effective treatments for CCA, which depends heavily on the mechanistic understanding of the disease. Previous studies have suggested that somatic mutations in KRAS, BRAF, and PIK3CA genes are frequently found in several types of human cancers including colon, breast, and lung carcinomas as well as CCA. Yet, the frequency and the involvement of these oncogenic mutations in CCA in Chinese population have not been investigated. In this study, we evaluated the hotspot mutations of KRAS, BRAF, and PIK3CA genes in 34 Chinese CCA patients. Sequencing analysis revealed 13 (38.2%) and 11 (32.4%) patients bearing KRAS and PIK3CA mutations, in which two (5.9%) of them harbored both KRAS and PIK3CA mutations. Surprisingly, no BRAF mutation was detected in all 34 CCA samples. Our findings indicate that somatic mutations in KRAS and PIK3CA but not BRAF oncogenes are closely associated with the development of CCA in Chinese population and provide new potential targets for future therapeutic treatments of the disease.

Association of p53 codon 72 polymorphism with liver metastases of colorectal cancers positive for p53 overexpression.

OBJECTIVE: To evaluate the association between p53 codon 72 polymorphism (R72P) and the risk of colorectal liver metastases. METHODS: The p53 R72P genotype was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 78 consecutive colorectal cancer patients with liver metastases and 214 age- and sex-matched cases with nonmetastatic colorectal cancer. RESULTS: The R allele of the p53 R72P polymorphism was more frequently found in metastatic cases than in nonmetastatic cases (P=0.075). Carriers of the 72R allele had a 2.25-fold (95% CI (confidence interval)=1.05 to approximately 4.83) increased risk of liver metastases. On the stratification analysis, 72R-carrying genotype conferred a 3.46-fold (95% CI=1.02 to approximately 11.72) and a 1.05-fold (95% CI=0.36 to approximately 3.08) increased risk of liver metastases for p53 overexpression-positive and negative colorectal cancers, respectively. CONCLUSION: These results demonstrate for the first time that the 72R allele of the p53 polymorphism has an increased risk for liver metastases in colorectal cancers positive for p53 overexpression.

[The relationship between alpha-IFN anti-virus treatment and HLA-DRB1*11 gene mononucleotide polymorphism].

OBJECTIVE: To investigate the relationship between the distribution of mononucleotide polymorphism of five regulation regions of alpha-IFN among HLA-DRB1*11 gene episodes and the therapeutic effects of alpha-IFN treatment in chronic hepatitis B patients. METHODS: One hundred seven chronic hepatitis patients from Nanjing Second Hospital who were treated by alpha-IFN for 12 months and then followed at least six months without the treatment were randomly selected for this regressive analysis. They were grouped into a continuous responsive group and a non-continuous responsive group. Hepatitis B virus X interacting protein gene locus was searched in NCBI. Single nucleotide polymorphism (SNP) gene locus was detected based on a pooling sequencing method. Primer and TaqMan-MGB probes referring to different mononucleotide loci were designed respectively to detect SNP in five regulation regions of alpha-IFN. Then gene sequencing differences between the two groups were analyzed. RESULTS: Among the 107 cases there were 30 cases (28.0%) in the continuous responsive group and 77 cases (71.9%) in the non-continuous responsive group. CT occupation rate in five regulation regions of IFN reached 18.0% in the continuous responsive group and 23.8% in the non-continuous responsive group. AG occupation rate reached 10.8% in the former group and 15.8% in the latter group. The differences in CT and AG between the two groups were significant. CONCLUSIONS: The distribution of mononucleotide polymorphism of five regulation regions of alpha-IFN among HLA-DRB1*11 gene episodes affects the IFN anti-virus treatment. Detecting the gene distribution of mononucleotide in five regulation regions of alpha-IFN helps in predicting the therapeutic effects of alpha-IFN.

[The glutamate-cysteine ligase catalytic subunit gene C-129T and modifier subunit gene G-23T polymorphisms and risk for coronary diseases].

OBJECTIVE: To investigate the possible association between the glutamate-cysteine ligase catalytic subunit gene (GCLC) C-129T and modifier subunit gene (GCLM) G-23T polymorphisms with coronary heart disease (CHD) in Chinese population. METHODS: GCLC C-129T and GCLM G-23T genotypes were determined in 212 CHD patients and 218 healthy individuals using a PCR-based restriction fragment length polymorphism (RFLP) method. Odds ratio (OR) for CHD and 95% confidence interval (CI) from unconditional logistic regression models were used to evaluate relative risks. RESULTS: The T allele of the GCLC C-129T polymorphism was more frequently found in CHD cases than in controls (P < 0.01) and individuals with GCLC-129T allele had a significantly higher risk for CHD (OR = 2.38, 95% CI: 1.25 - 4.54) as compared to individuals with the -129C allele. When compared with CC homozygote, CT heterozygote had a 2.14-fold higher risk for CHD (95% CI: 1.08 - 4.24, P < 0.05) and carriers of the-129T allele (CT or TT genotype) also had a similarly 2.28-fold higher risk for CHD (95% CI: 1.16 - 4.49, P < 0.05). In contrast, the frequency of T allele of the GCLM G-23T polymorphism was lower in CHD patients than that of controls (0.174 vs. 0.264) and individuals with the GCLM-23T allele had a significantly lower risk for CHD (OR = 0.59, 95% CI: 0.42 - 0.82, P < 0.01) as compared to the -23G allele. When compared with GG homozygote, the OR of CHD for GT heterozygote was 0.71 (95% CI: 0.47 - 1.08, P > 0.05), for TT homozygote was 0.18 (95% CI: 0.06 - 0.55, P < 0.01), and for carriers of the -23T allele (GT or TT genotype) was 0.61 (95% CI: 0.42 - 0.92, P < 0.05). CONCLUSION: The GCLC C-129T polymorphism may be one of the genetic risk factor while the GCLM G-23T polymorphism may be one of the genetic protective factors for CHD in this Chinese population.

[TP53 gene polymorphisms and colorectal cancer risk in Chinese population].

OBJECTIVE: To investigate the association between the single nucleotide polymorphisms (SNPs) in TP53 gene and susceptibility to colorectal cancer (CRC) in Chinese population. METHODS: Peripheral blood samples were collected and white cell genomic DNA was extracted from 345 CRC patients, 198 males and 1447 females, aged (58.7 +/- 13.5), and 670 sex, age, smoking and drinking situations-matched controls in Ningbo city, Zhejiang province The genotypes of the SNPs of C-8343G, C-1863T, and R72P in TP53 gene were determined by either TaqMan assays or PCR-based restriction fragment length polymorphism method. Unconditional logistic regression was used to calculate the odds ratio (OR) for CRC after adjustment of the covariates, such as sex, age, cigarette smoking, alcohol drinking, body mass index and first-degree family history of CRC, and 95% confidence intervals (CI) so as to evaluate relative risk. RESULTS: There were not significant differences in the above mentioned covariates between these 2 groups. No significant association of C-8343G or C-1863T polymorphism with CRC risk was observed (both P > 0.05). The CRC risk of the 72P genotype was 50.3%, 1.53 times that of the 72R genotype (39.6%) (95% CI = 1.27 - 1.85, P < 0.01). The CRC risk of the RP heterozygotes was 1.60 times that of the RP homozygote (95% CI = 1.17 - 2.18, P < 0.01), and the CRC risk of the PP homozygotes was 2.37 times that of the RP heterozygotes (95% CI = 1.61 - 3.47, P < 0.01). A dose-response relationship was shown (P < 0.01). Stratified analysis indicated that the 72P allele conferred a more pronounced increase in CRC risk among the alcohol consumers: the CRC risk was 3.01 times for the RP heterozygotes (95% CI = 1.48 - 6.12), and 4.71 times for the PP homozygotes (95% CI = 1.90 - 11.68). CONCLUSION: TP53 C-8343G and C-1863T polymorphisms are not associated with CRC risk. R72P polymorphism contributes to the etiology of CRC in the Chinese population, particularly among the alcohol consumers.

[Mutational analysis of EGFR and K-RAS in Chinese patients with non-small cell lung cancer].

OBJECTIVE: To investigate gene mutations of the epidermal growth factor receptor (EGFR) and K-RAS in Chinese non-small cell lung cancers (NSCLCs). METHODS: Mutations of exons 18, 19 and 21 of the EGFR and codons 12, 13 of the K-RAS in 101 NSCLCs were detected by PCR-amplifying and gene sequencing, and the relationship between mutations and clinical characters of NSCLCs and response to gefitinib were analyzed. RESULTS: Overall, 26 EGFR mutations (25.7%), 3 K-RAS mutations (2.9%) were detected, and EGFR mutation frequencies in adenocarcinomas, nonsmoker and female were found to be high (44.2%, 65.7% and 48.3% respectively). Nine out of 10 gefitinib treated patients with disease control was found with EGFR mutation. CONCLUSION: The data suggest that mutation frequency of EGFR in NSCLCs from Chinese patients is higher than that of western ethnicities, such mutations are well correlated with tumor response to gefitinib, and gefitinib is more fit for Chinese NSCLC patients.

[Association of p53 codon 72 polymorphism with genetic susceptibility to hepatocellular carcinoma in Chinese population].

OBJECTIVE: A functional single nucleotide polymorphism (SNP) at codon 72 of the gene for p53 protein (p53 R72P) has been implicated in a variety of human cancers, but the relationship between this SNP and hepatocellular carcinoma (HCC) remains obscure despite the fact that the critical role of p53 protein in HCC has been documented. This study was conducted to evaluate the link between the polymorphism with HCC stratified by chronic hepatitis B infection status in a Chinese population. METHODS: Four hundred and sixty-nine HCC cases (359 HbsAg-positive, 110 HbsAg-negative) and 567 controls (137 HbsAg-positive, 430 HbsAg-negative) were studied. The p53 genotypes were determined by a PCR based restriction fragment length polymorphism (RFLP) method. RESULTS: Overall, no correlation between HCC and the R72P genotypes was found when comparing all cases to controls or when comparing the HbsAg-positive HCC subgroup to controls. However, in HbsAg-negative subjects, the 72P allele was significantly associated with the presence of HCC (P=0.01) and had a higher risk (OR=1.69, 95% CI: 1.25-2.27) of HCC as compared to the 72R allele. By comparison to R/R homozygotes, the R/P heterozygotes and P/P homozygotes had a 1.73-fold (95% CI: 0.96-3.11) and a 3.29-fold (95% CI: 1.58-6.86) increased risk for HCC, respectively. The subjects with the 72P allele and a family history of HCC and those with the 72P allele and male gender also yielded an 11.14-fold (95% CI: 1.62-76.67) and a 9.39 fold (95% CI: 3.08-28.62) increased risk of HCC, respectively. CONCLUSION: The P allele of the p53 R72P polymorphism has an increased risk for HCC in HbsAg-negative subjects, and exerts a synergistic influence on the risk for HCC when combined with HCC family history and the male gender.

A p53 polymorphism modifies the risk of hepatocellular carcinoma among non-carriers but not carriers of chronic hepatitis B virus infection.

To clarify the modifying effect of the codon 72 p53 polymorphism on hepatocellular carcinoma (HCC) stratified by chronic hepatitis B virus (HBV) infection status, 111 incident cases of HCC and 424 controls in HBV-negative subjects and 135 cases and 125 controls in HBV-positive subjects were identified. No correlation between the polymorphism and HCC risk was found when comparing the HBV-positive cases to controls. However, in HBV-negative subjects, Arg/Pro and Pro/Pro genotypes had a 1.97-fold and a 3.36-fold increased risk for HCC, respectively. In subjects with the Pro allele and family history of HCC yielded an 11.81-fold increased risk of HCC.

[p53 gene codon 72 polymorphism and genetic susceptibility to hepatocellular carcinoma in Chinese population].

OBJECTIVE: To investigate the possible association between the p53 Arg72Pro polymorphism and susceptibility to hepatocellular carcinoma (HCC) in Chinese population. METHODS: Genomic DNA of the normal liver tissues was extracted from 507 patients with HCC confirmed by histopathological examination and 541 patients with benign liver diseases. PCR-based restriction fragment length polymorphism (RFLP) method was used to determine the p53 Arg72Pro genotypes. Odds ratios (ORs) for HCC and 95% confidence intervals (CIs) from unconditional logistic regression models were used to evaluate the relative risks. Potential HCC risk factors were included in the logistic regression models as covariates in the multivariate analyses on genotype and HCC risk. RESULTS: The frequencies for Pro and Arg alleles were 0.445 and 0.555 respectively in the HCC cases, and 0.403 and 0.597 respectively in the controls. The Pro allele was marginally significantly associated with the presence of HCC (P = 0.053) and had an increased risk for HCC (OR = 1.19, 95% CI = 1.00 - 1.41) as compared to the Arg allele. Carriers of the Pro, or the "risk" allele, had a 1.33-fold increased risk (95% CI = 0.92 - 1.92, P = 0.133) of HCC compared to the Arg-only carriers. Compared to Arg/Arg homozygote, Arg/Pro heterozygote had a 1.21-fold increased risk (95% CI = 0.82 - 1.78, P = 0.341), whereas Pro/Pro homozygote had a 1.79-fold increased risk (95% CI = 1.06 - 3.01, P = 0.029) of HCC (Armitage's trend test, P = 0.046). CONCLUSION: The Pro allele of p53 Arg72Pro is associated with the presence of HCC and Pro/Pro homozygote is potentially one of the risk genetic risk factors for HCC in Chinese population.

Homozygosity for Pro of p53 Arg72Pro as a potential risk factor for hepatocellular carcinoma in Chinese population.

AIM: Codon 72 exon 4 polymorphism (Arg72Pro) of the p53 gene has been implicated in cancer risk. Our objective was to investigate the possible association between p53 Arg72Pro polymorphism and susceptibility to hepatocellular carcinoma (HCC) among Chinese population. METHODS: The p53 Arg72Pro genotypes were determined by PCR-based restriction fragment length polymorphism (RFLP) analysis in 507 HCC cases and 541 controls. Odds ratios (ORs) for HCC and 95% confidence intervals (CIs) from unconditional logistic regression models were used to evaluate relative risks. Potential risk factors were included in the logistic regression models as covariates in the multivariate analyses on genotype and HCC. RESULTS: The frequencies for Pro and Arg alleles were 44.5%, 55.5% in HCC cases, and 40.3% and 59.7% in controls, respectively. The Pro allele was significantly associated with the presence of HCC (P = 0.05) and had a higher risk for HCC (OR = 1.19, 95% CI 1.00-1.41) as compared with the Arg allele. After adjusted for potential risk factors, Arg/Pro heterozygotes had an 1.21-fold increased risk (95% CI 0.82-1.78, P = 0.34) of HCC compared with Arg homozygotes, whereas the risk for Pro homozygotes was 1.79 (95% CI 1.06-3.01, P = 0.03) times higher than that for Arg homozygotes. Pro-allele carriers had a higher relative risk of HCC than the Arg-only carriers (adjusted OR = 1.33, 95% CI 0.92-1.92, P = 0.13), although the difference was not statistically significant. CONCLUSION: Homozygosity for Pro of p53 Arg72Pro is potentially one of the genetic risk factors for HCC in Chinese population. The p53 Arg72Pro polymorphism may be used as a stratification marker in screening individuals at a high risk of HCC.

[Coding single nucleotide polymorphism is an ideal marker for detecting gene imprinting by 5' nuclease assay].

OBJECTIVE: To establish a novel approach for quick and high throughput verification of human gene imprinting. METHODS: By use of a pair of dye-labeled probes, 5' nuclease assay was combined with reverse transcriptase-PCR(RT-PCR) to genotype a coding single nucleotide polymorphism (cSNP), rs705(C/T) of a known imprinted gene, small nuclear ribonucleotide protein N (SNRPN), on both genomic DNA and cDNA of human lymphoblast cell lines. RESULTS: Allele discrimination showed a clear monoallelic expression pattern of SNRPN, which was confirmed by RT-PCR based restriction fragment length polymorphisms. Pedigree analysis verified the paternal origin of expressed allele, which is in consistency with previous report. CONCLUSION: Coding SNP is an ideal marker for detecting gene imprinting by 5' nuclease assay. This approach has also a potentiality to discover differential allele expression of non-imprinted genes in order to find gene cis-acting functional polymorphism.