Mutation analysis of key genes in RAS/RAF and PI3K/PTEN pathways in Chinese patients with hepatocellular carcinoma

The RAS/RAF and PI3K/PTEN signaling pathways play central roles in hepatocarcinogenesis. KRAS,NRAS,HRAS, BRAF, PIK3CA, PIK3RI and PTEN are key cancer-related genes in the RAS/RAF and PI3K/PTEN signaling pathways. Genetic alterations in these genes often lead to the dysregulation of the two cascades. Little is known regarding the frequency of hotspot mutations in these critical components among Chinese patients with hepatocellular carcinoma (HCC). In the current study, 57 somatic hotspot mutations in 36 HCCs samples collected from Chinese patients using direct DNA sequencing method were examined. Two cases of KRAS somatic mutations (KRAS codon 61; Gln to His) were identified among 36 HCCs (5.6%). However, no mutations were found in the NRAS,HRAS, BRAF, PIK3CA, PIK3RI and PTEN genes. These findings indicated that point mutations in the KRAS gene, but not mutations in NRAS, HRAS, BRAF, PIK3CA, PIK3RI and PTEN genes, at a somatic level contribute to the abnormal activation of the RAS/RAF and PI3K/PTEN pathways in HCC.