GlyH-101 and CaCC_inh-A01 Inhibited HT-29 Proliferation by Activating the Mitochondrial Apoptosis Pathway and Arresting the Cell Cycle

Abstract

Background/Aim: GlyH-101 and CaCC_inh-A01 are effective blockers of cystic fibrosis transmembrane conductance regulator (CFTR) and Ca²⁺-activated chloride channels (CaCCs), respectively. Available evidence suggests that GlyH-101 and CaCC_inh-A01 can suppress cell proliferation, block invasion and metastasis, and cause several cancer cell types to undergo apoptosis, demonstrating their anti-tumor properties. The aim of this study was to investigate the effect of GlyH-101 and CaCC_inh-A01 on HT-29 cell activity and to suggest the possible molecular mechanisms by which inhibitors of CFTR and CaCCs inhibit HT-29 cell activity. Materials and Methods: Human colon HT-29 cancer cells were treated with GlyH-101 or CaCC_inh-A01 or GlyH-101 plus CaCC_inh-A01 complex. Cell viability was determined by MTT assay, the apoptosis and cell cycle were determined by flow cytometry, and reactive oxygen species (ROS) leves were determined by 2′,7′-Dichlorodihydrofluorescein diacetate staining. The expression of proteins related to apoptosis and cell cycle regulation was measured by western blotting. Results: The proliferative ability of HT-29 cells was dose- and time-dependently reduced by GlyH-101 and CaCC_inh-A01. Treatment with GlyH-101 and CaCC_inh-A01 resulted in cell necrosis and apoptosis, up-regulated ROS levels, activated the mitochondrial apoptosis pathway, prompted arrest of the cell cycle in S phase, and increased the levels of proteins related to the cell cycle. Additionally, the combination of these two inhibitors had a stronger regulatory effect on HT-29 cell proliferation than either GlyH-101 or CaCC_inh-A01 treated alone. Conclusion: GlyH-101 and CaCC_inh-A01 inhibited cell proliferation through cell cycle arrest and mitochondrial-related pathways in vitro. The combination of these inhibitors could further enhance their anti-proliferative effects. Our findings propose new lead compounds with anti-colon cancer activity, and also provide new evidence for the effectiveness of chloride channels-targeted therapy in anticancer therapy.