The Effect of Nonsteroidal Anti-Inflammatory Drugs on Chick Embryo Fibroblast Cells and Its Relation to Colon Carcinogenesis

The Effect of Nonsteroidal anti-inflammatory drugs on chick embryo fibroblast cells and its relation to colon carcinogenesis

Abstract

NSAID's are chemopreventive mediators of colon carcinogenesis, although their molecular pathway is unknown. Previous studies suggest that NSAID's best known effect is its inhibition of prostaglandin, a lipid that is derived from fatty acids. To study the effect of NSAID's on chick fibroblast cells, we sought to apply aspirin (a common NSAID) to these cells in varying dilutions to determine if aspirin had a role in the proliferation or apoptosis of these cells. When the cells were actively treated with aspirin in varying dilutions we postulated that in higher concentrations we would see a decrease in cell proliferation and more cell death would occur and in lower concentrations that we would see a higher amount of cell proliferation and less cell death. This would be due to the fact that NSAID's inhibit PHS, an enzyme that catalyzes the biosynthesis of prostaglandins and would explain that at high doses, aspirin has a positive effect on colon carcinogenesis. This inhibition of PHS would incur apoptosis and/or colon carcinogenesis depending on whether a PHS dependent mechanism was essential. Our results showed that at higher concentrations of aspirin being applied to the chick embryo fibroblast cells that there was a decrease in cell proliferation. We also saw that at lower concentrations that there was an increase in cell proliferation. These and other observations suggest that a PHS dependent mechanism is essential in minimizing cell proliferation on chick fibroblast cells and in colon carcinogenesis.

Introduction

Nonsteroidal anti-inflammatory drugs commonly referred to as NSAID's are drugs with analgesic properties that are used to relieve pain and reduce inflammation. The most common NSAID's are aspirin and ibuprofen, because they are available over the counter in many countries and don't require a doctor's prescription unlike steroids. Most NSAID's act as non-selective inhibitors of the enzyme cyclooxgenase, inhibiting both the cyclooxgenase-1 (COX-1) and cyclooxgenase-2 (COX-2) isoenzymes. Cyclooxgenase catalyzes the formation of prostaglandins and thromboxane from arachidonic acid (derived from the phospholipid bilayer by phospholipase A2). NSAID's are able to exert these properties by inhibiting the synthesis of prostaglandins. Prostaglandins also have the ability to act as messenger molecules in the process of inflammation. This would explain how this PHS cascade is essential in cells that are responsible for responding to the signal of inflammation of tissue.

Fibroblasts are in the family of connective tissue cells and are jointly responsible for the architectural framework of the body. They are the least specialized cell type and they secrete an extracellular matrix that is rich in type I and/or type II collagen. When the tissue is injured the fibroblasts nearby migrate into the wound, proliferate and produce large amounts of the matrix that helps to isolate and repair the damaged tissue. This would be important in colon carcinogenesis as when the cells are becoming cancerous and avoiding the signal that tells them to stop dividing then taking aspirin at a higher dosage would lessen the severity of cancerous cells dividing thus inhibiting the prostaglandin H synthase, which causes apoptosis. For the present study, we designed experiments to test whether different concentrations of a NSAID would have an effect on chick embryo fibroblast cells thereby causing either apoptosis or cell proliferation. To test the role of aspirin (an NSAID) on chick embryo fibroblast cells we developed varying dilutions of a stock solution of aspirin and added it to the cells and observed them using a Giemsa stain and an inverted microscope to visualize the mitotic cells. Our results indicate that in the presence of a high concentration of aspirin that the amount of chick embryo fibroblast cells should be lesser than if they were placed in a low concentration of aspirin.

Materials and Methods

Animal