Use of the Comet Assay and Molecular Docking Techniques to Evaluate the Effect of Nicotine in Human Breast Cancer Cell Line

Abstract

The harmful effects of tobacco use and nicotine are well known. There is a strong epidemiological evidence for smoking as a risk factor for lung cancer and oral cavity cancer. The evidence for second-hand smoke as a risk factor for breast cancer is rapidly accumulating. The single-cell gel electrophoresis (Comet) assay has been widely used to measure DNA damage in human breast cancer cells in a variety of physiological and pathological conditions. These damages occured in DNA are some structural damages such as single- and double- strand breaks, oxidative base damage, and DNA-DNA, DNA-protein, DNA- Drug crosslinking and mutations in DNA. Single cell gel electrophoresis (SCGE) or so-called “Comet assay” is a rapid, simple and very sensitive fluorescent microscopic method to examine DNA damage at individual cell level in living populations. We investigated the effects of nicotine on breast cancer cells (MCF-7) in vitro and examined breast cancer cells line by using the Comet assay. This was seen most clearly when changes in the Comet tail length were measured when there were discrete undamaged and damaged populations. After increasing doses of nicotine, an increasing proportion of cells were found in the damaged population. These observations led to the hypothesis that nicotine might be playing a direct role in the promotion and progression of human breast cancers. Here, we study on the role and the effects of nicotine on breast cancer cell growth and physiology. However, the mechanisms by which nicotine promotes cancer development and metastasis are not fully understood. We determined the interaction between nicotine and the receptor is a protein (galectin-3) by molecular docking technique. It has recently been determined that development of breast cancer is originated from cancer stem cells, which are a minor population of breast cancer. In the present study; it is thought that the DNA damage is related to cancer stem cell number increase.

Keywords: Nicotine, breast cancer, docking, comet assay, DNA damage