Snake venom causes apoptosis by increasing the reactive oxygen species in colorectal and breast cancer cell lines

Abdulrahman Khazim Al-Asmari,1 Anvarbatcha Riyasdeen,1 Mohammad Hamed Al-Shahrani,2 Mozaffarul Islam1 1Research Center, 2Pediatric Hematology/Oncology and Bone Marrow Transplant Unit, Prince Sultan Military Medical City, Riyadh, Kingdom of Saudi Arabia Abstract: Snake venom possesses various kinds of proteins and neurotoxic polypeptides, which can negatively interfere with the neurotransmitter signaling cascade. This phenomenon occurs mainly due to the blocking of ion channels in the body system. Envenomation prevents or severely interrupts nerve impulses from being transmitted, inhibition of adenosine triphosphate synthesis, and proper functioning of the cardiac muscles. However, some beneficial properties of venoms have also been reported. The aim of this study was to examine the snake venom as an anticancer agent due to its inhibitory effects on cancer progression such as cell motility, cell invasion, and colony formation. In this study, the effect of venoms on phenotypic changes and the change on molecular level in colorectal and breast cancer cell lines were examined. A reduction of 60%–90% in cell motility, colony formation, and cell invasion was observed when these cell lines were treated with different concentrations of snake venom. In addition, the increase in oxidative stress that results in an increase in the number of apoptotic cancer cells was significantly higher in the venom-treated cell lines. Further analysis showed that there was a decrease in the expression of pro-inflammatory cytokines and signaling proteins, strongly suggesting a promising role for snake venom against breast and colorectal cancer cell progression. In conclusion, the snake venoms used in this study showed significant anticancer properties against colorectal and breast cancer cell lines. Keywords: colorectal cancer, breast cancer, cell motility, colony formation, oxidative stress, apoptosis, IL-8, IL-6, RhoC, p-Erk1/

In vitro antiproliferative and apoptosis-inducing properties of a mononuclear copper(II) complex with dppz ligand, in two genotypically different breast cancer cell lines

In the background that there is concerted effort to discover newer metal-based cancer chemotherapeutic agents that could overcome the limitations in cisplatin and that copper, a biocompatible and redox-active metal, offers potential as alternative to cisplatin, the present study was undertaken to investigate the in vitro anti-proliferative properties of the mononuclear copper(II)complex [Cu(L)(diimine)] + where LH = 2-[(2-dimethylaminoethylimino)methyl]phenol and diimine = dipyrido[3,2-a:2',3'-c]phenazine (dppz) using breast cancer cell lines MCF-7 (ER+ve and p53(WT)) and MDA-MB-231(ER-ve and p53(mutant)) when cisplatin was used as positive control. The complex affected the viability of both the cell lines in dose-as well as duration-dependent manner as revealed in the MTT assay. The 24 and 48 h IC50 of the complex were several times lesser than those of cisplatin, and within this huge difference the efficacy of the complex was much superior with MCF-7 cell compared to MDA-MB-231 cell. The cell death was preferentially apoptosis, though necrosis also occurred to a certain extent. These inferences were substantiated by AO/EB fluorescent staining, Hoechst staining, assessment of mitochondrial transmembrane potential, comet assay for DNA damage, DCFH assay for reactive oxygen species (ROS) generation and Western blot of apoptosis-related proteins. Thus, the copper(II) dppz complex under investigation is much more efficient than cisplatin in affecting viability of the breast cancer cells. The underlying mechanism appears to be DNA damage-primed (in view of the known intercalation mode of binding of the complex with DNA) and ROS-associated mitochondria-mediated intrinsic apoptosis to a great extent but necrosis also has a role to a certain extent, which may also be a PARP-mediated cell death independent of apoptosis. Within the purview of this conclusion, the results indicate that the ER and/or p53 genotypes have a bearing on the efficacy of the complex as a cytotoxic agent since the response in the ER-ve and p53(mutant) MDA-MB-231 cell was not so prominent as in ER+ve and p53(WT) MCF-7 cell. Taken together, the complex has been shown to be a potential DNA damaging agent and, in the light of the superiority of the complex over cisplatin, we are further investigating the possibility of targeted nano-delivery of the complex to the tumor cells. When tested on a normal cell, 3T3, Cu(II)dppz was found to affect its viability but at concentrations very high compared to those for the breast cancer cells. Yet, this is a cause of concern and, therefore, we are working out a strategy for targeted delivery of this complex to the cancer cells only

Human serum albumin binding and cytotoxicity studies of surfactant–cobalt(III) complex containing 1,10-phenanthroline ligand

The characteristics of the binding reaction of surfactant-cobalt(III) complex, cis-[Co(phen)(2)(C14H29NH2)]Cl-2 center dot 3H(2)O (phen =1,10-phenanthroline, C14H29NH2 = tetradecylamine) with human serum albumin (HSA) were studied by fluorescence and UV-vis absorption spectroscopy. In addition, the effect of the surfactant-cobalt(III) complex on the conformation of HSA was analysed using synchronous fluorescence spectroscopy. The experimental results showed that surfactant-cobalt( Ill) complex caused the fluorescence quenching of HSA through a combination of static and dynamic quenching. The number of binding sites (n) and apparent binding constant (K-a) of surfactant-cobalt(III) complex (above and below the critical micelle concentration (cmc) were determined at various temperatures. According to the thermodynamic parameters, it is likely that hydrophobic interactions are involved in the binding process. The cancer chemotherapeutic potential of surfactant-cobalt(III) complex on ME-180 cervical cancer cell was determined using MTT assay and specific staining techniques. The complex affected the viability of the cells significantly and the cells succumbed through an apoptosis process as seen in the nuclear morphology and cytoplasmic features. In addition, single-cell electrophoresis indicated DNA damage. (C) 2011 Elsevier B.V. All rights reserved