The effect of fendiline on cytosolic free Ca(2+) concentrations ([Ca(2+)](i)) and proliferation has not been explored in human oral cancer cells. This study examined whether fendiline altered Ca(2+) levels and caused cell death in OC2 human oral cancer cells. [Ca(2+)](i) and cell viability were measured using the fluorescent dyes fura-2 and WST-1, respectively. Fendiline at concentrations above 10 microM increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced partly by removing extracellular Ca(2+). The fendiline-induced Ca(2+) influx was sensitive to blockade of L-type Ca(2+) channel blockers. In Ca(2+)-free medium, after pretreatment with 50 microM fendiline, 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor)-induced [Ca(2+)](i) rises were inhibited; and conversely, thapsigargin pretreatment nearly abolished fendiline-induced [Ca(2+)](i) rises. Inhibition of phospholipase C with 2 microM U73122 did not change fendiline-induced [Ca(2+)](i) rises. At concentrations between 5 and 25 microM, fendiline killed cells in a concentration-dependent manner. The cytotoxic effect of 15 microM fendiline was not reversed by prechelating cytosolic Ca(2+) with BAPTA/AM. Collectively, in OC2 cells, fendiline induced [Ca(2+)](i) rises by causing Ca(2+) release from the endoplasmic reticulum and Ca(2+) influx from L-type Ca(2+) channels. Furthermore, fendiline-caused cytotoxicity was not via a preceding [Ca(2+)](i) rise.
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http://dx.doi.org/10.1177/0960327108097436 | DOI Listing |
Acta Physiol (Oxf)
February 2025
Institute for Molecular Medicine, Health and Medical University Potsdam, Potsdam, Germany.
Ca and Mg are essential nutrients, and deficiency can cause serious health problems. Thus, lack of Ca and Mg can lead to osteoporosis, with incidence rising both in absolute and age-specific terms, while Mg deficiency is associated with type II diabetes. Prevention via vitamin D or estrogen is controversial, and the bioavailability of Ca and Mg from supplements is significantly lower than that from milk products.
View Article and Find Full Text PDFPhytomedicine
January 2025
Cancer Center, Faculty of Health Sciences, University of Macau, Macau (SAR), China. MOE Frontiers Science Center for Precision Oncology, University of Macau, Macau (SAR), PR China. Electronic address:
Biochim Biophys Acta Mol Cell Res
January 2025
Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/4 EAST, 8010 Graz, Austria; BioTechMed, Graz, Austria. Electronic address:
The uptake of Ca by mitochondria is an important and tightly controlled process in various tissues. Even small changes in the key proteins involved in this process can lead to significant cellular dysfunction and, ultimately, cell death. In this study, we used stimulated emission depletion (STED) microscopy and developed an unbiased approach to monitor the sub-mitochondrial distribution and dynamics of the mitochondrial calcium uniporter (MCU) and mitochondrial calcium uptake 1 (MICU1) under resting and stimulated conditions.
View Article and Find Full Text PDFJ Anesth
January 2025
Division of Anesthesiology, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
Proc Natl Acad Sci U S A
January 2025
National Key Laboratory of Space Medicine, China Astronaut Research and Training Center, Beijing 100094, China.
TMEM16A, a key calcium-activated chloride channel, is crucial for many physiological and pathological processes such as cancer, hypertension, and osteoporosis, etc. However, the regulatory mechanism of TMEM16A is poorly understood, limiting the discovery of effective modulators. Here, we unveil an allosteric gating mechanism by presenting a high-resolution cryo-EM structure of TMEM16A in complex with a channel inhibitor that we identified, Tamsulosin, which is resolved at 2.
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