Investigation of anti-cancer activity of new palladium complexes in colon cancer cells

Colon cancer is the third most common type of cancer in the world. Each year, one million new colon cancer cases are diagnosed every year, and more than half of those cases are death. Colon cancer is a slow-going malignancy, and only 40% of patients with colon cancer can be diagnosed early. A large number of drugs are used in the treatment of colon cancer, but these drugs are not very effective in late stages of colon cancer. For this reason, new anti -cancer agents needed to be developed for the treatment of colon cancer. Cancer cells can obtain resistance to the treatments and survive with several mechanisms. It is difficult to develop an effective treatment and new approaches are needed. In the treatment of colon cancer, several enzymes or proteins can be targeted that involved in different pathways. To target those pathways, many different types of compounds have been used. Compounds containing metal ion are widely used in cancer treatment. In this study, we tested anticancer effects of 4 different new synthesized palladium complexes on the SW620 colon cancer cell line and CCD-18CO normal colon cells. Those complexes were synthesized bye Professor Fatih Mehmet Emen lab at Department of Chemistry of Arts and Sciences Faculty. First, cell lines were treated with those at ranged concentrations from 1 to 200 µm and IC50 values were calculated by performing cell vitality tests. Next, the effects of the palladium complex, that named P4, on apoptosis, autophagy and cell cycle were investigated on the normal cell line and colon cancer cell line at IC50 or lower doses. In addition, we performed western blot assay to test expression of apoptosis, autophagy and cell cycle marker genes. Moreover, both dead cell distribution and cell cycle stages were analyzed by flow cytometry method. In conclusion, we found out that the P4 compound induces apoptosis and cell cycle arrest in colon cancer cells at low doses.