Assessment of novel calpain inhibitors

Azzah Ahmed Baashirah, Tennessee State University


Calpains are intracellular Ca2+ -activated proteases and important mediators of the action of calcium. They are involved in numerous physiological and pathological phenomena, from embryogenesis to cell adhesion, diabetes, and Alzheimer’s disease. Calpains exist in the cytosol as an inactive enzyme and translocates to membranes in response to increased cellular calcium level. At the membrane, calpains are activated in the presence of calcium and phospholipids. Several studies have markedly highlighted the effects of calpains in processes critical for cancer development and progression, including cell transformation, migration, and tumor invasion. As a result, calpains are considered by several researchers as potential anti-cancer targets. In this study, the effect of calpain inhibitors KR-161 and KR-185 on 3T3-L1 preadipocytes, Lung cancer A549, HeLa cancer cells, and Breast cancer BT549, is investigated on some biochemical parameters. These parameters are cell viability, calpain activity, Caspase-9 expression levels, and RT-qPCR, which are essential for cancer development in humans. In this study, A549 lung cancer cells, HeLa cells, and 3T3-L1 preadipocytes were exposed to different doses of the newly synthesized calpain inhibitors KR-161 (1 μM, 10 μM, 100 μM, and 1 mM) for 24, 48, and 72 hours. The effect of calpain inhibitor KR-161 on cytotoxicity was at 100 μM and 1 mM concentration. Calpain activity was tested by treating all three cells with KR-161 (250 μM, 500 μM, 750 μM, and 1mM). The results indicate that calpain activity was decreased by the increase of calpain inhibitor KR-161 dosages. Another calpain inhibitor, KR-185, was tested for induction of apoptosis through caspase-9 with ELISA and for alteration of mRNA levels of caspase-9, caspase-3, and calpain-7. Results indicate that KR-185 decreased the expression of caspase-9 in A549 lung cancer cells, HeLa cells, and BT549 breast cancer cells. KR-185 treatment at 70 μM did not affect mRNA levels of caspase-3, -9 and calpain 7.

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Recommended Citation

Azzah Ahmed Baashirah, "Assessment of novel calpain inhibitors" (2016). ETD Collection for Tennessee State University. Paper AAI10158596.