Azithromycin’s Cytotoxic Effects and CASP۸ Expression Modulation in HT-۲۹ Colorectal Cancer Cells In Vitro

Colorectal cancer has been one major cause of cancer deaths all around the world, thus demanding some new therapeutic approaches to face the problems posed by resistance and side effects in the present conventional treatments. In this study, azithromycin was explored to determine whether it could be repurposed—by interfering with cytotoxicity in HT-۲۹ CRC cells—and to examine CASP۸ gene expression, an important signal-transducing actor in extrinsic apoptotic pathways. The cells were cultured in DMEM, supplemented with FBS and antibiotics, and treated with azithromycin concentrations ranging from ۱۰ to ۱۰۰۰ μg/ml. Post-treatment at ۲۴ hours, cytotoxicity was studied by MTT assays, while CASP۸ was examined through qRT-PCR employing GAPDH as the reference gene. Statistical analyses included one-way ANOVA followed by Dunnett post-hoc test, ROC curve plotting for viability, and unpaired t-test for gene expression. Dose-dependent cytotoxicity from azithromycin was observed with cell viability declining from ۱۰۰% in controls to approximately ۲-۳% in concentrations ≥۱۰۰ μg/ml (P < ۰.۰۰۰۱), which was so much so that it plateaued with increasing concentration, with a perfect discriminatory power level (ROC AUC = ۱.۰۰۰). Transcript levels of CASP۸ revealed no significant difference between groups (treated versus controls) with a P-value of ۰.۵۱۰۶. These results indicate an azithromycin potential for antiproliferative effects on CRC, potentially through CASP۸-independent mechanisms such as the inhibition of autophagy; however, mRNA data alone are insufficient to confirm pathway involvement, justifying further in vivo, mechanistic, and protein-level investigations for its repositioning as an adjunctive treatment.

کلیدواژه ها:

Azithromycin ، Colorectal Cancer ، CASP۸ ، Apoptosis ، cytotoxicity ، HT-۲۹ cell line