Biology subjects

Tijore, A.

Publications and source records attributed to Tijore, A..

2 recordsLinked to original sources

bioRxiv2020

Ultrasound-mediated mechanical forces selectively kill tumor cells

Ultrasound has been used to target tumors either through local heating or local nanobubbles but these methods damage surrounding normal cells in the target area. Recent studies show that tumor cells are susceptible to mechanical stresses and undergo calcium-dependent apoptosis under conditions that promote normal cell growth. Here we report that low-frequency ultrasound causes apoptosis of tumor cells by activating a calpain-dependent mitochondrial pathway that depends upon calcium entry through the mechanosensitive Piezo1 channels. This is a general property of all tumor cell lines tested so far irrespective of tissue origin. In animals, ultrasound irradiation causes tumor killing in the chick chorioallantoic membrane (CAM) model with relatively little damage to the chick embryos. Further, patient-derived pancreatic tumor organoids are killed by ultrasound treatment. Because low-level ultrasound causes apoptosis of tumor cells from many different tissues in different microenvironments, it may offer a safe non-invasive approach to augment tumor treatments.

cancer biology↗

bioRxiv2018

Mechanical Stretch Kills Transformed Cancer Cells

Transformed cancer cells differ from normal cells in several important features like anchorage independence, Warburg effect and mechanosensing. Consequently, transformed cancer cells develop an anaplastic morphology and respond aberrantly to external mechanical forces. Consistent with altered mechano-responsiveness, here we show that transformed cancer cells from many different tissues have reduced growth and become apoptotic upon cyclic stretch as do normal cells after the transformation. When matrix rigidity sensing is restored in transformed cancer cells, they survive and grow faster on soft surface upon cyclic stretch like normal cells but undergo anoikis without stretch by activation of death associated protein kinase1 (DAPK1). In contrast, stretch-dependent apoptosis (mechanoptosis) of transformed cells is driven by stretch-mediated calcium influx and calcium-dependent calpain 2 protease activation on both collagen and fibronectin matrices. Further, mechanosensitive calcium channel, Piezo1 is needed for mechanoptosis. Thus, cyclic stretching of transformed cells from different tissues activates apoptosis, whereas similar stretching of normal cells stimulates growth.

cell biology↗