Human SW480 colonic cancer cell line was evaluated for its growth response to pentagastrin, gastrin receptor antagonist proglumide (PGL) in vitro by MTT assay and flow cytometry. The results showed that gastrin possessed a proliferative effect on SW480 cell, PGL alone had no obvious effect on SW480 cell, but it inhibited gastrin-induced growth of SW480 cell with dosage dependent when it was used with gastrin, its inhibitive effect did not steadly increase at a dose＞32μg/ml. This suggests that effect of gastrin is achieved via gastrin receptor. Gastrin promoted the sythesis of DNA, protein and triggered the cancer cell shifting from phase G0/G1 to phase S, G2M. PLG inhibited the effect of gastrin, it suggests that gastrin possessed a proliferation on SW480 cell at post receptor is achieved by the effect of gastrin on cell cycle.
Human SW480 colonic cancer cell line was evaluated for its growth response to Octa peptide somatostatin (SMS 201·995, SMS) in vitro by MTT assay and flow cytometry. The results showed that SMS possessed an inhibitive effect on SW480 cell at dose 1.563－200ng/ml, the maximal effective dose was 50ng/ml. Inhibitive effect of SMS did not steadily increase at a dose ＞50ng/ml. It suggests that effect of SMS is achieved via somatotatin receptor. SMS obviously inhibited the synthesis of DNA and protein, and prohibited the SW480 cell shifting from phase G0/G1 in phase S, G2M, which suggests that somatostatin (SS) possessed an inhibitive effect on large intestinal at cancer cell, it is achieved at receptor by inhibiting the synthesis of DNA and protein and prohibiting cell cycle of cancer.