Objective To investigate the effects of chronic starvation stress on the proliferation and migration of colorectal cancer cells, as well as the underlying mechanisms.

Methods By using prolonged serum starvation to simulate chronic starvation stress in tumor cells, we established enduring serum-deprived models of SW480 and DLD-1 cells and observed cellular morphological change. Effects of prolonged serum starvation on SW480 and DLD-1 proliferative and migratory capabilities were assessed using CCK-8 and Transwell assays. Differential gene-expression analysis on SW480 cultured with 1% FBS or 10% FBS medium was followed by GO and KEGG pathway assessments. Migration-related protein interactions were explored using String database and Metascape software, leading to 16 genes being selected for RT-qPCR validation. Protein levels of ITGB1 and key molecules in the relevant pathways were measured. Mobility changes in SW480 were observed through Transwell assay after ITGB1 knockdown or STAT3 inhibition.

Results Prolonged serum starvation significantly inhibited the proliferation of SW480 and DLD-1 cells, and DLD-1 mobility, while enhanced SW480 migration. Transcriptome analysis revealed that prolonged serum deprivation caused the upregulation of 3016 genes, among which 283 were involved in cell migration. Metascape analysis identified the correlations among potential core genes ITGB1, CD44, TNS1, STAT3, etc. Prolonged serum deprivation increased the mRNA levels of VTN, TNS1, VEGFA, STAT3, and ITGB1 while also increasing the protein levels of ITGB1 and MMP2 and the phosphorylation levels of JAK2 and STAT3. Mobility reduction in prolonged serum-starved SW480 cells was achieved through ITGB1 knockdown or a STAT3 inhibitor.

Conclusion Colorectal cancer cells can endure chronic starvation stress which enhances migration capability by upregulating ITGB1 expression.