Selenium Overcomes Doxorubicin Resistance in Their Nano-platforms Against Breast and Colon Cancers.

Colon cancer in men and breast cancer in women are regarded as major health burdens, accounting for majority of cancer diagnoses globally. Doxorubicin (DOX) resistance in breast and colon cancers represents the main reason of unsuccessful therapy. The rationale of this study is to explore whether selenium nanoparticles (nano-Se) can overcome this resistance obstacle of DOX nanoparticles (nano-DOX) in these cancerous cells. Nano-Se and nano-DOX were manufactured and characterized using electron microscopy and Malvern ZetaSizer, applied separately or in the form of combinatorial regimen against human breast cancer cells (MCF7 and MDA-MB-231) and human colorectal cancer cells (HCT 116 and Caco-2). Cytotoxicity, early/late apoptosis, necrosis, cellular zinc, glucose uptake, and redox status were assessed after applying different nano-treatments versus their free counterparts. Nano-DOX induces cytotoxicity in MCF7 and Caco-2 more than MDA-MB-231 and HCT 116 cancerous cells. In addition, nano-DOX plus nano-Se diminish MCF7 and Caco-2 chemoresistance higher than MDA-MB-231 and HCT 116 cancerous cells. Moreover, Se and DOX nano-platforms inhibit glucose uptake. Furthermore, nano-DOX increases nitric oxide (NO) and malondialdehyde (MDA) in cancer cells' media, while nano-DOX combination with nano-Se rebalances the redox status with zinc augmentation. We reported that Caco-2 cancer cells are more sensitive than HCT 116 cancer cells to nano-DOX and nano-Se. Nano-DOX plus nano-Se induces cytotoxicity-mediated late apoptosis in Caco-2 more than HCT 116 cell lines. This de novo strategy could have great power to overcome the problem of DOX resistance during colon cancer therapy.