Multi-proteomics investigation of the early response to X-rays and carbon ion irradiations of HeLa cells

Abstract Despite the considerable decline of cervical cancer incidence in developed countries, the disease remains a public health problem in low-income and middle-income countries due to the low popularity of human papillomavirus vaccination and cervical cancer screening. Mainly treated with radiotherapy, the number of recurrences linked to radioresistance increases in women suffering from this disease and constitutes major obstacle. Here, we perform a combined proteomic and phosphoproteomic profiling of HeLa cervical cancer cells after in vitro treatment with X-rays and carbon ions. We observed differential and extensive alterations at the proteins and phosphoproteins levels. In total, we observed 96 and 102 differentially expressed proteins (DEPs) after X-rays and C-ions irradiation, respectively. For phosphoproteins, our results revealed 21 and 41 DEPs in response to C-ions and X-rays ionizing radiation respectively. Furthermore, our study revealed several mechanisms significantly activated by cells in response to ionizing radiation, potentially related to cancer radioresistance, including sister chromatid segregation, rRNA processing, ribosomal large subunit biogenesis, positive regulation of phagocytosis, engulfment, peptidase regulatory activity and negative regulation of ERK1/2 cascade. We also identified three proteins IPM3, DUSP3 and COQ7, oppositely expressed across the C-ions and X-rays groups while MX2 phosphorylation was downregulated in both radiation qualities. Finally, our study revealed a specific kinase signature, associated with Hela cells radioresistance: CDK5, MTOR and CDK2 kinases were predicted in the group of X-rays irradiation while CDK1, PLK1 SRC and MAPK1 kinases were predicted in the group of C-ions irradiation. Taken together, these findings could help to define new potential pathways and biomarkers to be targeted in the treatment of cervical cancer. Insight Box Statement of Integration, Innovation and Insight In this study, a robust proteomic and phospho-proteomic strategy was developed in order to display HELA cells responses to radiations. Two time points were selected to highlight the early responses of cells, following irradiation with low and high LET. CDK1, SRC, MAPK1 kinases were predicted to be activated in response to carbon ions irradiation, while CDK5, MTOR, ATM kinases were predicted in response to X-rays. Several accessions, playing pivotal role in cell proliferation and resistance, were upregulated in X-rays irradiated cells and down regulated in carbon ions irradiated cells. This study gives an accurate picture of molecular events linked with HELA cells radioresistance and offer potential drug targets for optimization of cervical cancer radiotherapy.