Evaluation of Novel Diketones as Anti-cancer Agents

Ali, Muhammad

Abstract

Recent studies indicated high levels of cytotoxicity of dibenzoylmethane (DBM) and its derivatives on some mammalian cancer cells. On the other hand, p53 tumour suppressor is a DNA damage inducible transcription factor mutated in over half of human cancers. The aim of this study is to analyse the effects of DBM derivatives on osteosarcoma, mesothelioma and lung cancer cell lines and correlate it with p53 status.
We analysed the cytotoxic effects of 8 DBM derivates on the cell lines using MTT assay. Results demonstrated that drug 5 (DBM+Cobalt) and drug 6 (DBM+Nickel) both demonstrated significant toxicity towards all cell lines. At higher concentrations these drugs demonstrated mostly greater toxicity than with clinically relevant drug etoposide that causes DNA damage and activates p53 pathway. Therefore, out of these 8 drugs, two (DBM+Cobalt metal complex and DBM+Nickel metal complex) demonstrated the greatest cytotoxic effects against the osteosarcoma and mesothelioma cancer cell lines while displaying a lesser toxic effect on the normal human cell lines. IC50 values reflected these observations.
To investigate if the studied drugs affect cancer cells migratory potential relevant for metastatic process, scratch assays were performed on osteosarcoma and mesothelioma cells in control samples, there was a gradual increase in cells closing the gap over time, whereas etoposide and drugs 5 and 6 treated cells showed gradual inhibitory effect on migration. Effects were more prominent in osteosarcoma and mesothelioma than normal cells.
To determine how studied compounds affect p53 pathway, mRNA expression was determined using Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). P53 and its transcriptional targets (p21 that controls cell cycle arrest, BAX that induces apoptosis and MDM2 ubiquitin ligase that downregulates p53 protein levels) mRNA levels were analysed. Drugs 5 and 6 upregulated P21, BAX and MDM2 mRNA expression in bone cell lines. Effects depended on the drug dose and were the most pronounced in U2OS cells.
P53 pathway was analysed using western blot analysis to determine drug effects on p53, p21, BAX and MDM2 protein levels. Preliminary results demonstrate no significant effects of studied drugs in HFOB normal bone and SAOS 2 osteosarcoma cells although downward trend was observed for MDM2 protein levels in SAOS2 cells treated with DBM 5 and 6. Effects on p21 and BAX resulted in inconclusive results and need further investigation. Drug 5 and 6 treatments caused upward trend of MDM2 protein levels in U2OS cells.
In summary, DBM derivates demonstrate cytotoxic effects on bone cancer cell lines in comparison to a known anticancer agent, etoposide. Two drugs, named drugs 5 (DBM+Cobalt) and 6 (DBM+Nickel) demonstrated greater cytotoxicity than DBM alone and greater cytotoxicity than etoposide under certain experimental conditions. In addition, drugs 5 and 6 showed the anti-migratory effects on cancer cells studied that was comparable to standard clinically relevant drug etoposide. Analysis of p53 pathway indicated that drugs 5 and 6 upregulate p53 transcriptional target genes under certain experimental conditions. Therefore, drugs 5 and 6 are potential anticancer agents that upon further testing could be used in future medical treatments.

Citation

Ali, M. (2024). Evaluation of Novel Diketones as Anti-cancer Agents. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: May 14, 2024
• Publicly Available Date: Jun 1, 2026
• Award Date: May 31, 2024