Objective: To explore the expression of caspase 9(CASP9) gene in non-small cell lung cancer (NSCLC) and single nucleotide polymorphism (SNP) distribution of CASP9 in NSCLC patients and normal people.
Methods: Reverse transcription-PCR (RT-PCR) was used to analyze the expression of CASP9 in 81 NSCLC and normal lung tissues. Two SNPs in CASP9 gene were chosen to be investigated. Genotypes of rs1052576 and rs1052571 in 81 NSCLC patients and 100 normal people were analyzed by PCR-restriction fragment length polymorphism (PCR-RFLP). Legally constituted authority statistical analysis was applied to analyze SNP genotype frequency and allele frequency in patients and control group.
Results: In comparision with normal lung tissues, CASP9 gene expression was obviously down-regulated in 44.4% (36/81) NSCLC tissues. rs1052571 located in exon 1 of CASP9 gene had no significant difference between two groups, rs1052576 located in exon 5 of CASP9 gene had significant difference between two groups, the G allele frequency in NSCLC patients was higher than those in healthy controls (P< 0.05); the AG genotype frequency in patients with lymph node metastasis was higher than those without lymph node metastasis (P< 0.05).
Conclusion: This study confirms the association between CASP9 gene and NSCLC oncogenesis, rs1052576 which locates in exon 5 of CASP9 gene is associated with NSCLC. AG genotype has association with lymph node metastasis.