High throughput sequencing reveals the Upregulation of PNMA3 and RASSF2 associated with chemotherapy resistance in cervical cancer patients

Cervical cancer (CC) is a major global health issue and affect women critically, representing a fourth cause of cancer death among women worldwide, mostly associated to chemoradiotherapy resistance and CC recurrence. The chemoradiotherapy resistance and CC recurrence is related to many cellular pathways, including the inhibition to cell death, a hallmark of cancer. In this study, we evaluated the differential expression genes (DEGs) in Cervical cancer non-stem cells (CCNSCs) as biomarkers linked to apoptosis and involved in chemoradiotherapy response in CC. Together, the number of tumor-infiltrating lymphocites (TILs) and tumor-associated tissue eosinophilia (TATE) were analysed in the stromal and intratumoral regions. A total of 31 patients with locally advanced CC and referred to Mario Penna Institute (Belo Horizonte, Brazil) from August 2017 to May 2019 were recruited for the study. In morphometric analysis to the evaluation of TILs and TATEs only 23 of these patients achieve the inclusion criteria. Fluorescence-activated cell sorting (FACS) was used to select CCNSCs from tumor biopsies. Transcriptome was performed using ultra-low input RNA sequencing and only DEGs with Log2FoldChange > 1 or < -1 and p adjusted value < 0.05 were considered. The biomarkers were choosed according to GO biological processes (BP) terms with padjusted value < 0.05 and associated with apoptosis, and then were performed statistical and decision tree analyses to determine those relevants. The 2519 DEGs comparing Responder (n = 21) to Non-Responder (n = 10) groups to the chemoradiotherapy were found. The statistical and decision tree analyses showed PNMA3 and RASSF2 as potentially related to chemoradiotherapy resistance and the others 6 DEGs possibly linked to chemoradiotherapy sensitivity. A high number of TILs was found in intratumoral regions of R patients, while in NR patients these cells were prevalent in stroma. The TATES were more prominent in R group, even no significant differences were observed in the median numbers of TILs and TATES between the R and NR women. This study showed PNMA3 and RASSF2 as potential biomarkers in CC prognosis and treatment outcome, as well as a larger number of intratumoral TILs as mediators in chemoradiotherapy response.