Relationship between gene mutations and protein expressions of PDGFR α and C-kit in gastrointestinal stromal tumors.

OBJECTIVE To investigate the relationship between gene mutations and protein expressions of PDGFR α and C-kit in gastrointestinal stromal tumors (GIST) and its significance in tumorigenesis. METHODS Single strand conformation polymorphism-polymerase chain reaction (PCR-SSCP), immunohistochemistry and Western blot were used to detect the gene mutations in PDGFR α and C-kit and their protein expressions in 105 cases of GIST specimens. RESULTS In 105 cases of GIST, PDGFR α gene mutation was found in 12 cases (11.4%), which was common in the stomach- derived spindle cell GIST. C-kit gene mutation was found in 58 cases (55.2%), which was common in the small intestine. Mutations of PDGFR α is in 12 cases of GIST were stronger than the C-kit mutations in GIST, normal gastrointestinal tissues and schwannomas. No significant correlation was found between mutations and C-kit protein expression (P>0.05), while the protein expression of PDGFR α was significantly correlated with mutations (P<0.0001). CONCLUSION Mutations of PDGFR α and C-kit plays an important role in part of GIST tumorigenesis. Mutation sites were related with original sites and histological types. Most protein expressions were closely related to their gene mutations in GIST.