Aurintricarboxylic Acid Inhibits Protein Synthesis Independent, Sanguinarine-Induced Apoptosis and Oncosis

Abstract

Sanguinarine, a benzophenanthridine alkaloid, has anticancer potential through induction of cell death. We previously demonstrated that sanguinarine treatment at a low concentration (1.5 μg/ml) induced apoptosis in K562 human erythroleukemia cells, and a high concentration (12.5 μg/ml) induced the morphology of blister formation or oncosis-blister cell death (BCD). Treatment of cells at an intermediate sanguinarine concentration (6.25 μg/ml) induced diffuse swelling or oncosis-diffuse cell swelling (DCS). To assess the underlying mechanism of sanguinarine-induced apoptosis and oncosis-BCD in K562 cells, we studied their response to pre-treatment with two chemical compounds: aurintricarboxylic acid (ATA) and cycloheximide (CHX). The pretreatment effects of both chemical compounds on apoptosis and oncosis-BCD were evaluated by measuring multiple parameters using quantitative morphology, electron microscopy, terminal deoxynucleotidyl transferase (TdT) end-labeling and annexin-V-binding. ATA, a DNA endonuclease inhibitor, efficiently prevented DNA nicking and inhibited apoptosis almost completely and oncosis-BCD by about 40%, while CHX, a protein synthesis inhibitor, failed to inhibit both apoptosis and oncosis-BCD. These results demonstrate, first, the importance of endonuclease in sanguinarine-induced apoptosis and to some extent in oncosis-BCD and, second, that this inhibition does not require de novo protein synthesis.

Oncolytic Group B Adenovirus Enadenotucirev Mediates Non-apoptotic Cell Death with Membrane Disruption and Release of Inflammatory Mediators

“…In contrast, cells treated with EnAd and Ad11p usually clumped together, showed little evidence of apoptosis, and underwent sudden formation of large single membrane blisters at the time of death 9 (Movies S1, S2, S3, S4, and S5). This dramatic cellular demise, termed single blister cell death (BCD) is a typical marker of cell death by oncosis10, 11 and is thought to reflect loss of control over ion transport and consequent osmotic rupture. Figures 1I–1L shows individual frame images, taken from the movies, and the single membrane blisters caused by EnAd are clearly visible.…”

“…To investigate whether cells infected with EnAd and Ad11p were undergoing oncosis, we evaluated the expression of typical oncosis markers, 16 including early loss of membrane integrity, a rapid fall in intracellular ATP, and rise in intracellular calcium, as well as single blister formation (see above) 11, 17…”

Genomic c-Myc Quadruplex DNA Selectively Kills Leukemia

“…c-Myc transcriptionally upregulates target glycolytic genes involved in aerobically converting glucose to lactate (35, 36). Cell death by oncosis has previously been shown to occur in U937 cells in response to NaN 3 , a chemical blocking ATP production at complex IV of the mitochondria inducing oxidative stress (32) as well as in K562 chronic myelogenous leukemia cells in response to sanguinarine (37) or arsenic trioxide (38). …”

Oncosis: An important non-apoptotic mode of cell death

“…Sanguinarine-induced bimodal cell death has been studied at the cellular and molecular levels (Hallock et al, 2007;Weerasinghe et al, 2001aWeerasinghe et al, , 2001bWeerasinghe et al, , 2001cWeerasinghe et al, , 2006. Several cell lines including the tumor cell lines of leukemia (K562), lymphoma (CEM-VLB and CEM-T4), prostate (DU145 and LNCap), breast (MDA-MB-435 and MCF-7), cervical and neuroblastoma undergo the classic pattern of bimodal cell death, when exposed to sanguinarine.…”