The association between hypoxia-inducible factor 1a, autophagy and cell stemness in tumor cells

Colorectal cancer is a very common tumor type that resulting the cause of cancer-related deaths in worldwide. Many studies have shown the recurrence and metastasis of colorectal cancer is one of the reasons for its high mortality. The root cause of the recurrence and metastasis is that the cancer cells have not been completely eliminated by treatment, and there are often residual tumor cells with strong stemness. Therefore, exploring the survival of dry cells and their mode of action is critical for the prevention and treatment of colorectal cancer. The enhancement of the ability of cells to form spheroids suggests that the stemness of the cells is enhanced, but the maintenance mechanism of the stemness of the cells after forming a spheroid needs to be further elucidated. We conducted experiments before and after cell sphered and found that the hypoxia-inducible factor HIF-1a increased significantly after cells sphered, and its increase is particularly important for the maintenance of cell stemness. Recalling the relationship between hypoxia and autophagy, we detected the changes in the autophagy level of cells after sphered, and we found that the autophagy level of cells after sphered was significantly increased. Further research found that the enhanced level of autophagy provided for sufficient nutrient requirements of cells to maintain their dryness seem to be related to the increased expression of HIF-1a. Therefore, our results confirm the new view of maintaining the dryness of cells under hypoxic conditions and lay the foundation for the further development of new therapeutic strategies.