The Expression Of ALK、K-ras Protein And Somatic Gene Mutation And Its Significance In Non-small Cell Lung Cancer

Objective:To investigate the expression and significance of ALK (anaplastic lymphoma kinase)、K-ras (Kirsten rat sarcoma) protein and somatic gene mutation in non-small cell lung cancer (NSCLC), and then explore the correlation between the expression of protein and somatic mutation gene.Methods:1. The expression of ALK and K-ras protein in100specimens from surgical resected tissues of NSCLC were detected by immunohistochemical enlarge polymer method and Elivison immunohistochemical staining.2. The EML4-ALK fusion and K-ras somatic mutation gene in100specimens from surgical resected tissues of NSCLC were examined by ARMS fluorescence quantitative PCR.Results:1. The positive percentage of ALK protein was14.0%, and the differences in the positive expression rate were significant between histological type, smoking history and the degree of tumor differentiation (p<0.05), but the differences between age, sex, clinical stage and lymph node metastasis were neither significant (p>0.05).2. The positive percentage of K-ras protein was55.0%, and the differences in the positive expression rate were significant between histological type, smoking history and the degree of tumor differentiation (p<0.05), but the differences between age, sex, clinical stage and lymph node metastasis were neither significant (p>0.05).3.4.0%of the tumors specimens contained EML4-ALK translocations, while the K-ras somatic mutation prevalence was1.0%.4. There was positive correlation between the expression of ALK protein and ALK translocations (r=0.359, p<0.01), while it was no correlation between the expression of K-ras protein and K-ras somatic mutation (r=0.091, p>0.05).5. EML4-ALK fusion was found to be of coexistence with K-ras somatic mutation in one cases.Conclusions:1. The EML4-ALK fusion and K-ras somatic mutation gene standard the new molecular subtypes of NSCLC, but they were rare among NSCLC in China.2. There was positive correlation between the expression of ALK protein and ALK translocations.3. EML4-ALK fusion can be coexistence with K-ras somatic mutation in the same cases.4. Immunohistochemistry staining for ALK can probably serves as a conventional ancillary test for detecting ALK rearrangements before genetic examination; Screening by both immunohistochemistry and ARMS fluorescence quantitative PCR will efficiently identify patients with EML4-ALK translocations.