Quinacrine-Mediated Autophagy and Apoptosis in Colon Cancer Cells Is Through a p53- and p21-Dependent Mechanism
Authors: Mohapatra, Purusottam; Preet, Ranjan; Das, Dipon; Satapathy, Shakti Ranjan; Choudhuri, Tathagata; Wyatt, Michael D.; Kundu, Chanakya Nath
Source: Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics, Volume 20, Numbers 2-3, 2012 , pp. 81-91(11)
Publisher: Cognizant Communication Corporation
Abstract:We previously showed that quinacrine (QC), a small molecule antimalarial agent, also presented anticancer activity in breast cancer cells through activation of p53, p21, and inhibition of topoisomerase activity. Here we have systematically studied the detailed cell death mechanism of this drug using three colon cancer cell lines (HCT-116 parental, isogenic HCT-116 p53−/−, and HCT-116 p21−/− sublines). QC caused a dose-dependent reduction in cell viability in all three cell lines. However, the parental cells were more susceptible to QC-mediated cell death, suggesting that p53- and p21-dependent processes were involved. QC-mediated cell death was measured with the following endpoints: the Bax/Bcl-xL ratio, cleaved PARP, apoptotic nuclei visualized by DAPI staining, and COMET formation. In addition, markers of autophagy were measured. Acridine orange staining revealed increased accumulation of autophagic vacuoles (AVs) after QC treatment in a dose-dependent manner in parental cells, and decreased staining in isogenic HCT-116 p53−/− and HCT-116 p21−/− cells. Immunofluorescence of LC3B was significantly lowered in QC-treated cells lacking p53 or p21, compared to the parental cells. Interestingly, the expression of the autophagy marker LC3B-II after exposure to QC was decreased in either p53 or p21 null cells compared to parental cells. After deletion of p21 in HCT-116 p53−/− cells, no change in LC3B-II expression was noted following QC treatment. Collectively, the results suggest that QC-mediated autophagy and apoptosis dependent on p53 and p21.
Document Type: Research Article
Publication date: 2012
- Formerly: Oncology Research Incorporating Anti-Cancer Drug Design
Oncology Research Featuring Preclinical and Clincal Cancer Therapeutics publishes research of the highest quality that contributes to an understanding of cancer in areas of molecular biology, cell biology, biochemistry, biophysics, genetics, biology, endocrinology, and immunology, as well as studies on the mechanism of action of carcinogens and therapeutic agents, reports dealing with cancer prevention and epidemiology, and clinical trials delineating effective new therapeutic regimens.