Characterising cytotoxicity and genotoxicity of chemotherapeutic agents (Etoposide and Vincristine) on TK6, a human lymphoblastoid cell line

Abstract

The ability of the chemotherapeutic agents namely etoposide and vincristine to cause cytotoxic and genotoxic damage to the human lymphoblastoid cell line, TK6, was at the centre of this study. Four different cytotoxic assays were tested for their ability to assess the cytotoxicity of the agents as well as two genotoxic assays to examine their ability to induce DNA damage. The TK6 cell line was exposed to increasing doses of the chemotherapeutic agents and cytoxicity assessed by in vitro trypan blue, neutral red uptake, LDH leakage and the glucose oxidase assays. The trypan blue assay was deemed to be the most beneficial due to its ease and speed of quantifying the number of non-viable cells as through the loss of their membrane integrity they stain the characteristic blue colour. Genotoxicity on the other hand was measured by two assays; the micronucleus and Comet assays. Both are currently used within the laboratory setting but this study concluded the Comet assay was the best method for measuring DNA damage. Additionally, vincristine was found to be more cytotoxic than etoposide and also exerted further genotoxic effects upon the cells. Although only a pilot study, this work aimed to define the best cytotoxic and genotoxic detection methods using two widely used chemotherapeutic agents and show how they can impact upon cells and cancer/leukemic treatment regimens.