CHALONE SIGNAL TRANSDUCTION PATHWAY IN DICTYOSTELIUM DISCOIDEUM: A POSSIBLE SIGNALING MECHANISM FOR CELL PROLIFERATION INHIBITION

Abstract

Cancer is a group of diseases characterized by uncontrolled cell proliferation. Cancer is responsible for nearly 1 of every 4 deaths, and ranks as the second highest cause of death worldwide, and costs the American population more than $216 billion annually. The fundamental mechanism that controls cell density regulation in cancer and in healthy tissues is not well understood. Some healthy cells appear to secrete a diffusible, extracellular factor called a chalone. The chalone is involved in a signal transduction pathway, which inhibits cell proliferation once a desired concentration or size is reached. However, currently there is not a solid understanding of the genetic components and proteins involved in this pathway.

Dictyostelium discoideum, often referred to as a slime mold, was used as the model organism. Many Dictyostelium discoideum genes are homologous to human genes. This makes it a valuable model organism applicable to human cancer research.

Dictyostelium discoideum is a eukaryote model organism, which uses a chalone mechanism to control cell density. Dictyostelium discoideum will be used as a model organism to elucidate the components involved in the chalone pathway by comparing differences in the rate of proliferation, maximum population size reached, and length of cell survival between wild type cells and cells missing a specific genetic component when exposed to various chalone concentrations. Understanding this pathway could lead to possible therapeutics for inhibiting cell proliferation in cancer. The results of this research will be important to the biomedical field and useful in future scientific research on cell density regulation via the chalone mechanism.