HL-10 Peptide as a Potential Therapeutic Agent for Cervical SiHa Cancer Cells

Abstract

Background: The peptide HL-10, derived from the venom of Hemiscorpius lepturus, has several biological functions, notably its ability to inhibit cancer growth. Objectives: This research aimed to evaluate the tumor-suppressing properties of the HL-10 peptide in SiHa cancer cells, investigating its effects in both in vitro and in vivo models. Methods: The study assessed cytotoxicity using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, analyzed gene expression through real-time PCR, and measured caspase activity via ELISA to gain insights into the peptide's mechanisms of action. For in vivo experiments, BALB/c mice bearing SiHa cervical cancer were used. The ELISA technique was employed to evaluate the activity levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzymes in serum, as well as the concentrations of intra-tumoral cytokines, including TNF-α, IFN-γ, IL-1β, IL-4, and IL-10. Results: Our results demonstrated a significant (P < 0.05) dose- and time-dependent decrease in the viability percentage of SiHa cancer cells. The analysis revealed a marked upregulation in the expression of p53, cyt c, bax, caspase-3, and caspase-9 genes as the peptide concentration was elevated from 5 to 10 μM. In contrast, there was a significant decrease (P < 0.05) in bcl-2 gene expression, while caspase-8 gene expression showed no significant change (P > 0.05). The analysis of caspase activity indicated a significant rise (P < 0.05) in the activities of caspase-9 and caspase-3 in cancer cells exposed to the HL-10 peptide, while the activity of caspase-8 remained unchanged. The findings from in vivo experiments conducted on cancer mice demonstrated a substantial reduction in tumor volume over time in cancer mice treated with HL-10 peptide plus carboplatin (5 mg/kg) compared to cancer mice that were not treated (P < 0.05). In comparison to untreated cancer mice, the tumor microenvironment of cancer mice treated with HL-10 peptide and carboplatin exhibited a substantial increase in IL-1β, IFN-γ, and TNF-α levels. The levels of IL-4 and IL-10 in the tumor were significantly reduced (P < 0.05), indicating a substantial decrease in these cytokines. This reduction suggests potential modulation of the tumor microenvironment in response to the treatment. Conclusions: In conclusion, this research showed that the HL-10 peptide effectively initiates apoptosis and inhibits the proliferation of SiHa cervical cancer cells through the activation of the mitochondrial signaling cascade. Additionally, the HL-10 peptide is believed to contribute to cancer immunotherapy by modulating the immune system.