Abstract: This article mainly explored the mechanism of mitochondrial protein HIGD1A enhancing the radiosensitivity of cervical cancer cells (HeLa) by regulating autophagy. Using control cells and HIGD1A knockdown HeLa cells as research subjects, cells were treated with autophagy inducer Earle’s balanced salt solution (EBSS) and ionizing radiation. The expression levels of cell autophagy marker proteins LC3 and P62 were detected by Western Blot, and the fluorescence expression level of Ad-mCherry-GFP-LC3B recombinant adenovirus infected cells was detected. Cells were irradiated after the pretreatment of chloroquine/rapamycin for 2 hours, then their viabilities were detected using CCK-8 48 hours later. The expression levels of caspase-7 and cleaved caspase-3 proteins were detected by Western Blot after rapamycin treatment. The results showed that compared with the control cells, knocking down HIGD1A inhibited the generation of LC3, P62 degradation, and the generation of yellow and red spots in mCherry-GFP-LC3B after EBSS or ionizing radiation treatment. CCK-8 assay results showed that knockdown of HIGD1A combined with chloroquine treatment reduced cell viability after ionizing radiation treatment. In addition, knocking down HIGD1A significantly increased the expression levels of caspase-7 and cleaved caspase-3 proteins in tumor cells, and there were still high levels of apoptosis in HIGD1A knocked down cells after rapamycin treatment. The results indicated that HIGD1A was involved in regulating the radiation sensitivity of tumor cells through the autophagy pathway.

Key words: HIGD1A, apoptosis, autophagy, cell viability, radiosensitivity