Author(s)

Jiading Mao, Pei Wu, Jian Wu, Liang Tao, Ping Wu, Guang Yang, Wenwen Guo, Jun Wang

Department of General Surgery, The First Affiliated Yijishan Hospital of Wannan Medical College, Wuhu, China.

Objective: To investigate the effects and mechanisms of p38 signaling pathway in pentagastrin-regulated cell proliferation of colorectal carcinoma cell line HT-29. Methods: HT-29 cell line of colorectal carcinoma was in vitro incubated and divided into the control group, pentagastrin group, proglumide group, and pentagastrin + proglumide group. MTT reduction assay was performed to detect the proliferation status of HT-29 cell line and determine the optimal dosage of pentagastrin and proglumide. Annexin V-fluorescein isothiocyanate flow cytometry was used to detect the proliferation index (PI) and apoptosis rate (AR) of HT-29 cells. Reverse transcriptase polymerase chain reaction was performed to detect the mRNA expression of the pentagastrin receptor/cholecystokinin-B receptor (CCK-BR) and p38. The protein and phosphorylation levels of p38 were estimated by western blotting. Results: RT-PCR detection showed that CCK-BR mRNA was expressed in the HT-29 cell line. Pentagatrin improved HT-29 cell proliferation in dosage of 6.25 - 100 mg/L, and the optimal dosage of pentagastrin was 25.0 mg/L. Proglumide had no significant effect on the proliferation of HT-29 cells, but significantly inhibited the proliferation of HT-29 cells stimulated by pentagastrin when the dosage of proglumide was 8.0 - 128.0 mg/L, and the optimal dosage was 32.0 mg/L. The AR in the pentagastrin group was significantly lower than that in the control group and in the pentagastrin + proglumide group. The PI in the pentagastrin group was significantly higher than that in the control group and in the pentagastrin + proglumide group. P38 phosphorylation level in the pentagastrin group was significantly lower than that in the control group, and in the pentagastrin + proglumide group. There were no significant differences in the mRNA and protein expression of p38 in the control, pentagastrin, proglumide and pentagastrin + proglumide groups. Conclusion: Pentagastrin can improve proliferation of the CRC cell line HT-29 and inhibit apoptosis via the p38 signal transduction pathway. This mechanism may be associated with suppressed p38 protein phosphorylation level due to inhibition of proglumide, a gastrin receptor antagonist.

Gastrin, p38, Proglumide, Proliferation Index, Apoptosis Rate, MAPK, Colorectal Carcinoma

Mao, J. , Wu, P. , Wu, J. , Tao, L. , Wu, P. , Yang, G. , Guo, W. and Wang, J. (2016) Role of p38 Signaling Pathway in Pentagastrin-Regulated Cell Proliferation of Colorectal Carcinoma Cell Line HT-29. Journal of Cancer Therapy, 7, 378-387. doi: 10.4236/jct.2016.76041.