Plasma Exosomal miRNA Levels after Radiotherapy Are Associated with Early Progression and Metastasis of Cervical Cancer: A Pilot Study

Abstract

Plasma exosomal miRNAs are key regulators of cell-cell interactions associated with several biological functions in patients with cancer. This pilot study aimed to investigate the log2 fold change (log2FC) of the expression of exosomal miRNAs and related mRNAs in the blood of patients with cervical cancer to identify prognostic markers better than those currently available. We sequenced plasma exosomal RNA from 56 blood samples collected from 28 patients with cervical cancer, who had been treated with concurrent chemoradiotherapy (CCRT). Changes in the expression of miRNAs and mRNAs before and after CCRT were represented as log2FC. Their biological functions were studied by miRNA-mRNA network analysis, using ingenuity pathway analysis, after the selection of two groups of miRNAs, each associated with early progression (EP) and metastasis, also described as initial stage. Seven patients experienced EP, three of whom died within four months after progression. Reduced levels of miR-1228-5p, miR-33a-5p, miR-3200-3p, and miR-6815-5p and increased levels of miR-146a-3p in patients with EP revealed unresolved inflammation, with accompanying increased expression of PCK1 and decreased expression of FCGR1A. Increased levels of miR-605-5p, miR-6791-5p, miR-6780a-5p, and miR-6826-5p and decreased levels of miR-16-1-3p (or 15a-3p) were associated with the degree of metastasis and led to the systemic activation of myeloid, endothelial, and epithelial cells, as well as neurons, phagocytes, and platelets. Log2FCs in the expression of miRNAs and mRNAs from plasma exosomes after CCRT are associated with EP and metastasis, reflecting unresolved inflammation and systemic microenvironmental factors, respectively. However, this study, supported by preliminary data insufficient to reach clear conclusions, should be verified in larger prospective cohorts.

Screening Plasma Exosomal RNAs as Diagnostic Markers for Cervical Cancer: An Analysis of Patients Who Underwent Primary Chemoradiotherapy

“…We attempted to overcome the bias of the RNA sequencing analytic process by performing paired comparisons of the 60 samples from 30 patients before and during CCRT. Moreover, the 30 samples collected during CCRT were irradiated at a constant dosage per time point (approximately 18 Gy every 2 weeks) and cisplatin regimen (30–70 mg/m 2 every week), as reported in a previous study [ 17 ]. However, the reliability of the reported methodology should be validated by applying a similar method to select plasma exosomal RNAs for diagnosis using various sizes of datasets from different cancer patients treated with RT.…”

“…Regional lymph node metastasis and distant metastasis were evaluated using magnetic resonance imaging and positron emission tomography-computed tomography. Detailed treatment and follow-up procedures were previously reported for most of the current patients [ 17 ]. Clinical data, such as information regarding age, 2018 International Federation of Gynecology and Obstetrics stage, pathology, radiation therapy (RT) field, pretreatment hemoglobin levels, pretreatment absolute lymphocyte count (ALC), ALC after two weeks of CCRT (ALC2), and the levels of pretreatment tumor markers SCC antigen and cytokeratin fragment 21-1 were collected retrospectively from electronic medical records.…”

“…The screening methods used in these studies depended on differentially expressed gene (DEG) analysis and preclinical studies using cancer cells, with the screening range confined to a few specific RNA classes such as microRNA (miRNA), small nucleolar RNA (snoRNA), and messenger RNA (mRNA). A previous study analyzed a network of mRNAs relative to a log 2 -fold change (log 2 FC) in the expression of candidate miRNAs before and two weeks after cisplatin-based concurrent chemoradiotherapy (CCRT) to predict clinical results in patients with cervical cancer, and suggested their potential biological functions using ingenuity pathway analysis (IPA) [ 17 ]. This study suggested that biological functions or diseases can be detected from the association between ncRNAs and mRNAs that are altered by clinical treatments if the exosome sequencing data are paired with the specific treatment.…”

Exosomes in Liquid Biopsy: A Nanotool for Postradiotherapy Cancer Monitoring

“…miRNAs in patients with early progression (EP) suggested that inflammation was not resolved. The levels of miR-1228-5p, miR-33a-5p, miR-3200-3p and miR-6815-5p decreased, and the level of miR-146a-3p increased [92]. These miRNAs are involved in the EP of cervical cancer by regulating mRNAs.…”

“…These cargoes are involved in pathways in the cancer microenvironment that regulate the aggressive phenotype of cancer (Table 2, Ref. [16,17,[87][88][89][90][91][92][93][94][95][96][97][98][99][100]). On the one hand, exosomes after radiotherapy suppress aggressive phenotypes of tumor cells, such as proliferation and migration; on the other hand, exosome-mediated signaling after irradiation promotes the aggressive phenotype of cancer cells, such as drug resistance and radiotherapy resistance, by establishing communication between tumor cells and their microenvironment.…”