Mutational analysis of the BAK gene in 192 advanced gastric and colorectal cancers.

The evasion of apoptosis has been linked to the development of cancer. A recent study of a small number of gastric and colorectal cancers found that the BAK gene, which encodes a pro-apoptotic protein, contained somatic mutations in approximately 17% of the samples analyzed. To investigate the precise frequency of BAK mutations, we examined the entire coding sequence of the BAK gene in gastric and colorectal cancers, using polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) analysis and direct sequencing. We could not detect any somatic mutations of the BAK gene in 192 colorectal and gastric cancers. We found only four single-nucleotide substitutions in the coding sequences, which were also found in corresponding normal samples. We conclude that somatic alterations of the BAK gene are rare in colorectal and gastric cancers.