ABSTRACT
<p><b>OBJECTIVE</b>To explore the association between the polymorphisms of oncogenes H-ras and L-myc and colorectal cancer risk, and the interaction of those genes.</p><p><b>METHODS</b>The genotypes of H-ras and L-myc genes were determined by polymerase chain reaction-based restriction fragment length polymorphism analysis. Stratified analysis and logistic model were used to detect the gene-gene interaction. The gene-gene interaction was validated by multifactor dimensionality reduction (MDR) analysis.</p><p><b>RESULTS</b>The single SNP model showed that the polymorphisms of H-ras and L-myc genes were not significantly related with colorectal cancer risk (P > 0.05). Stratified analysis revealed that among the L-myc LS + SS genotype carriers, those with H-ras TC + CC genotype showed significantly increased risk of rectal cancer than those with TT genotype (OR = 1.81, P = 0.005). The positive interaction between L-myc and H-ras was detected by logistic regression model. The OR of the interaction effect was 2.74 (P = 0.024). This result was confirmed in the MDR model, with 54.83% testing balanced accuracy and 10/10 cross-validation consistency, and the model was still significant after the 1000 times permutation test (P = 0.001).</p><p><b>CONCLUSION</b>Our findings suggest that the polymorphism of H-ras and L-myc genes is not related to colorectal cancer risk, but there is a synergy between H-ras and L-myc polymorphisms in the development of rectal cancer.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Colonic Neoplasms , Genetics , Colorectal Neoplasms , Genetics , Genes, myc , Genes, ras , Genetic Predisposition to Disease , Genotype , Logistic Models , Multifactor Dimensionality Reduction , Polymerase Chain Reaction , Methods , Polymorphism, Restriction Fragment Length , Polymorphism, Single Nucleotide , Rectal Neoplasms , Genetics , Risk , Surveys and QuestionnairesABSTRACT
<p><b>OBJECTIVE</b>To explore association of miR-149 and miR-605 polymorphisms with other risk factors of lung cancer susceptibility among Chinese population.</p><p><b>METHODS</b>Two hundred and forty-four patients with lung cancer and 243 cancer-free controls matched by age and sex were enrolled from 2002 to 2008. Peripheral venous blood samples were collected from all subjects. Single nucleotide polymorphisms (SNPs) of miR-149 and miR-605 were genotyped by PCR-RFLP. Multiple-variable logistic regression model was used to assess the association of SNPs and cancer related risk factors for lung cancer.</p><p><b>RESULT</b>There was not significant association of SNPs of miR-149 and miR-605 with lung cancer. A marginal significance was observed while the males with at least one G allele of miR-605 had higher risk of lung cancer (OR=1.5, 95% CI:1.0-2.3) than those with AA genotype. Increased frequency of smoking was associated with lung cancer risk. Compared with no-smoker, the subjects with <20 and >20 cigarettes/day had higher risk of lung cancer: OR (95%CI)=1.7(1.0-3.0) for <20 cigarettes, OR (95%CI)=4.2(2.3-7.6) for >20 cigarettes. There was no interaction between two genes and smoking on lung cancer.</p><p><b>CONCLUSION</b>miR-149 polymorphisms may not affect lung cancer susceptibility. miR-605 gene mutant might be increase the risk of lung cancer among males. Cigarette smoking increased a risk of lung cancer, but there were not interactive effects between two gene and smoking on lung cancer.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Asian People , Genetic Predisposition to Disease , Genotype , Logistic Models , Lung Neoplasms , Genetics , MicroRNAs , Genetics , Polymorphism, Single Nucleotide , Risk Factors , SmokingABSTRACT
<p><b>OBJECTIVE</b>To investigate mRNA expression of caspase apoptosis pathway genes in colorectal cancer, polyps and normal mucosa.</p><p><b>METHODS</b>Nineteen patients with colorectal cancer, 86 patients with polyps and 10 normal controls were enrolled from 2008 to 2010. Fluorescence quantitative RT-PCR was performed to detect the mRNA expression of caspase apoptosis pathway genes (caspase-2,-3,-6,-7,-8,-9 and -10) in colorectal cancer, polyps and normal mucosa.</p><p><b>RESULT</b>There were no statistically significant differences of demographic characteristics between patients with colorectal cancer, patients with polyps and normal controls. Compared with normal control group, the mRNA expression of all selected genes except for caspase-3 were lower; however, the P values did not reach statistic significance. Highly positive correlations were observed between mRNA expression of all selected genes except caspase-9.</p><p><b>CONCLUSION</b>There are no significant changes in mRNA expression levels of caspase apoptosis pathway genes from normal mucosa to polyps to cancer. The mRNA expressions of most caspase pathway genes are highly correlated with each other.</p>