Inhibition of Carbonic Anhydrase IX Promotes Apoptosis through Intracellular pH Level Alterations in Cervical Cancer Cells

Abstract

Carbonic anhydrase IX (CAIX) is a hypoxia-related protein that plays a role in proliferation in solid tumours. However, how CAIX increases proliferation and metastasis in solid tumours is unclear. The objective of this study was to investigate how a synthetic CAIX inhibitor triggers apoptosis in the HeLa cell line. The intracellular effects of CAIX inhibition were determined with AO/EB, AnnexinV-PI, and γ-H2AX staining; measurements of intracellular pH (pHi), reactive oxygen species (ROS), and mitochondrial membrane potential (MMP); and analyses of cell cycle, apoptotic, and autophagic modulator gene expression (Bax, Bcl-2, caspase-3, caspase-8, caspase-9, caspase-12, Beclin, and LC3), caspase protein level (pro-caspase 3 and cleaved caspase-3, -8, -9), cleaved PARP activation, and CAIX protein level. Sulphonamide CAIX inhibitor E showed the lowest IC50 and the highest selectivity index in CAIX-positive HeLa cells. CAIX inhibition changed the morphology of HeLa cells and increased the ratio of apoptotic cells, dramatically disturbing the homeostasis of intracellular pHi, MMP and ROS levels. All these phenomena consequent to CA IX inhibition triggered apoptosis and autophagy in HeLa cells. Taken together, these results further endorse the previous findings that CAIX inhibitors represent an important therapeutic strategy, which is worth pursuing in different cancer types, considering that presently only one sulphonamide inhibitor, SLC-0111, has arrived in Phase Ib/II clinical trials as an antitumour/antimetastatic drug.

Fabrication of a Polymeric Inhibitor of Proximal Metabolic Enzymes in Hypoxia for Synergistic Inhibition of Cancer Cell Proliferation, Survival and Migration

“…Furthermore, the PGA-U19T15 treatment induced cell death: 4.9% of apoptotic and 8.1% of necrotic cells were observed; for the cells without treatment, 0.6% of apoptotic and 2.0% of necrotic cells were observed. Since it has been reported that CAIX inhibition induces the acidification of intracellular pH, resulting in cancer cell acidosis, 55 PGA-U19T15 may induce the intracellular acidosis of cancer cells in the same manner.…”

Expression and prognostic value of carbonic anhydrase IX (CA-IX) in bladder urothelial carcinoma

“…This study retrospectively analyzed the clinical data of 194 cases diagnosed and treated in our hospital, and found that the positive rate of CA-IX in bladder urothelial carcinoma was 68.1% (132/194), and the positive rate in adjacent tissues was 44.3% (86/194), the positive rate of normal tissue was 27.3% (53/194). This revealed that CA-IX is signi cantly expressed in bladder urothelial carcinoma and is a meaningful tumor marker for bladder urothelial carcinoma, which may provide a new method for molecular diagnosis of bladder urothelial carcinoma [23] .…”

Expression and prognostic value of carbonic anhydrase IX (CA-IX) in bladder urothelial carcinoma

“…This study retrospectively analyzed the clinical data of 194 patients diagnosed and treated in our hospital, and found that the positive rate of CA-IX in bladder urothelial carcinoma was 68.1% (132/194), and the positive rate in adjacent tissues was 44.3% (86/194), the positive rate of normal tissue was 27.3% (53/194). This revealed that CA-IX is significantly expressed in bladder urothelial carcinoma and is a meaningful tumor marker for bladder urothelial carcinoma, which may provide a new method for molecular diagnosis of bladder urothelial carcinoma [ 23 ].…”