K-ras Gene Mutation And Expression Of VEGF In Colorectal Cancer And Their Clinical Significance

Purpose To investigate K-ras gene mutation and expression of vascularendothelial growth factor (VEGF) in colorectal cancer and their clinical significance.It will provide a theoretical basis for further clarifying the pathogenesis and seekingnew treatments of colorectal cancer.Methods40specimens of colorectal cancer were detected K-ras gene by directsequencing. The expression of VEGF in40colorectal carcinoma tissues,40adenoma tissues, and20normal controls were studied by immunohistochemicalmethods.Results (1) There were13cases be detected K-ras mutation in40cases ofcolorectal cancer tissue. Mutation of10cases were tested in codon12(7cases wereGGT�'GAT, the others were GGT�'GTT). Mutation of3cases occurred in codon13(GGC�'GAC). The positive rate of K-ras gene mutation in colorectal cancertissue was32.5％（13/40）.(2) K-ras mutation was not related with the age, gender,tumor size, the location of tumor and TNM stage in colorectal cancer (P＞0.05).(3)21cases were detected positive expression of VEGF in40cases colorectalcarcinoma specimens, the positive rate in cancer tissue was52.5％；while there were14cases of adenoma specimens in the control group expressed VEGF, the positive rate was35％,which was significantly lower than in cancer specimens (P <0.05).The expression of VEGF was not detected in20normal tissues.(4) The positive rateof VEGF in colorectal cancer tissue which had K-ras mutation(76.9％) is higher thanthat didn’t occur(40.7％). K-ras gene mutation and the expression of VEGF have asignificantly correlation (P <0.05) in colorectal cancer.Conclusions Both K-ras gene mutation and overexpression of VEGF relatedwith development and progression of colorectal cancer. Mutant K-ras gene mayupregulate the expression of VEGF, which may be very important to angiogenesis oftumor.1.13cases were found K-ras mutation in40cases of colorectal tumor tissue. Theproportion of K-ras gene mutation in colorectal tumor tissue was32.5％.2. K-ras mutation was not associated with patients’ age, gender, tumor size, location,TNM stage in colorectal cancer.3. The positive rate of VEGF in colorectal carcinoma tissue was significantly higherthan that in adenoma tissue. The expression of VEGF was not detected in20normaltissues. It implies that overexpression of VEGF participates in the occurrence andprogression of colorectal carcinoma.4. The positive rate of VEGF in colorectal cancer tissue which had K-ras mutation ishigher than that didn’t occur. It implies that they have a significantly positivecorrelation, and mutant K-ras gene may play an important role in angiogenesis oftumor by upregulating the expression of VEGF.