University of Guilan Aquatic Physiology and Biotechnology 2345-3966 11 2 2023 09 22 Induction of apoptosis in 4T1 breast cancer cell line by a peptide derived from tuna (Thunnus tonggol) by-products Induction of apoptosis in 4T1 breast cancer cell line by a peptide derived from tuna (<i>Thunnus tonggol</i>) by-products 33 53 7170 10.22124/japb.2022.22541.1472 FA Reyhane Chamani Assistant Professor in Department of Biology, Yazd University, Yazd, Iran Journal Article 2022 06 24 Cancer is one of the leading causes of death worldwide. Chemotherapy drugs have many toxicities and side effects. Therefore, designing effective natural medicines with the least toxicity is very important. Aquatic organisms are a rich source of bioactive compounds including peptides with anti-cancer properties. In studies, it was shown that an 11-amino acid peptide derived from the hydrolysates of dark muscle by-products of tuna (<em>Thunnus tonggol</em>) has anticancer properties. In the present study, the effect of this peptide on the viability of 4T1 breast cancer cell line was evaluated using MTT assay and induction of apoptosis in these cells was assessed using flowcytometry and Real-time PCR. The results showed that this peptide inhibited cancer cell viability and induced 30.3% of apoptosis in these cells. The peptide acts through reducing the relative expression of the anti-apoptotic <em>BCL2</em> gene and increasing the relative expression of the pro-apoptotic <em>BAX</em> gene. Therefore, it can be suggested that this peptide has the potential to be more investigated for therapeutic purposes as well as for supplements with cancer prevention properties. Cancer is one of the leading causes of death worldwide. Chemotherapy drugs have many toxicities and side effects. Therefore, designing effective natural medicines with the least toxicity is very important. Aquatic organisms are a rich source of bioactive compounds including peptides with anti-cancer properties. In studies, it was shown that an 11-amino acid peptide derived from the hydrolysates of dark muscle by-products of tuna (<em>Thunnus tonggol</em>) has anticancer properties. In the present study, the effect of this peptide on the viability of 4T1 breast cancer cell line was evaluated using MTT assay and induction of apoptosis in these cells was assessed using flowcytometry and Real-time PCR. The results showed that this peptide inhibited cancer cell viability and induced 30.3% of apoptosis in these cells. The peptide acts through reducing the relative expression of the anti-apoptotic <em>BCL2</em> gene and increasing the relative expression of the pro-apoptotic <em>BAX</em> gene. Therefore, it can be suggested that this peptide has the potential to be more investigated for therapeutic purposes as well as for supplements with cancer prevention properties. https://japb.guilan.ac.ir/article_7170_cb8ce9451b301e8a1f8f0b33b13bdb35.pdf