ABSTRACT
Penile cancer (PeCa) is a rare tumor, generally associated with socioeconomic conditions in low-income countries. Hence, a delay in diagnosis and treatment leads in more advanced tumors, to higher comorbidity, and mortality. Human papillomavirus (HPV) infection has been identified as one of the major risk factors for PeCa. In addition, viral integration sites have been related to copy number alterations, impacting miRNAs/mRNA interactions and, consequently, the molecular pathways related to them. Nonetheless, studies on differentially expressed miRNAs (miRDEs) in PeCa are still scarce, especially in PeCa associated with high-risk HPV (hrHPV). To investigate the role of these gene regulators in PeCa progression, 827 miRNAs (Nanostring Technologies™, Seattle, WA, USA) were evaluated in 22 hrHPV-associated penile squamous cell carcinomas and five non-tumor penile tissues. For functions of miRNAs/target genes and relationship with HPV we conducted an integrated analysis by Diana Tools, KEGG, HPVbase, and InterSPPI-HVPPI platforms. We found that 25 miRNAs of the most differentially expressed impact 43 top molecular pathways, of which the fatty acid biosynthesis pathway, prions, miRNAs in cancer and hippo signaling (P<1.0-325, for each) were the most statistically significant. Notably, 23 out of 25 are located at HPV integration sites (HPVis). MiR-1206, miR-376b-3p and miR-495-3p were downregulated and associated with perineural invasion. In addition, a comparison between advanced and early diseases revealed 143 miRDEs. ROC analysis of a single (miR-376a-2-5p), paired (miR-376a-2-5p, miR-551b-3p) or combination of five miRDEs (miR-99a-5p, miR-150-5p, miR-155-5p, let-7c-5p, miR-342-3p) showed robust discriminatory power (AUC = 0.9; P = 0.0114, for each). Strikingly, miR-376a-2-5p exhibited the highest values of sensitivity and specificity, with 100% and 83.3%, respectively, indicating this miRNA as a potential prognostic marker in hrHPV-penile carcinogenesis.
ABSTRACT
Background: MicroRNAs are related to human cancers, including cervical cancer (CC) caused by HPV. In 2018, approximately 56.075 cases and 28.252 deaths from this cancer were registered in Latin America and the Caribbean according to GLOBOCAN reports. The main molecular mechanism of HPV in CC is related to integration of viral DNA into the hosts' genome. However, the different variants in the human genome can result in different integration mechanisms, specifically involving microRNAs (miRNAs). Methods: The miRNAs associated with CC were obtained from literature, the miRNA sequences and four human genome variants (HGV) from Latin American populations were obtained from miRBase and 1000 Genomes Browser, respectively. HPV integration sites near cell cycle regulatory genes were identified. miRNAs were mapped on HGV. miRSNPs were identified in the miRNA sequences located at HPV integration sites on the Latin American HGV. Results: Two hundred seventy-two miRNAs associated with CC were identified in 139 reports from different geographic locations. By mapping with Blast-Like Alignment Tool (BLAT), 2028 binding sites were identified from these miRNAs on the human genome (version GRCh38/hg38); 42 miRNAs were located on unique integration sites; and miR-5095, miR-548c-5p and miR-548d-5p were involved with multiple genes related to the cell cycle. Thirty-seven miRNAs were mapped on the Latin American HGV (PUR, MXL, CLM and PEL), but only miR-11-3p, miR-31-3p, miR-107, miR-133a-3p, miR-133a-5p, miR-133b, miR-215-5p, miR-491-3p, miR-548d-5p and miR-944 were conserved. Conclusions: Ten miRNAs were conserved in the four HGV. In the remaining 27 miRNAs, substitutions, deletions or insertions were observed. These variation patterns can imply differentiated mechanisms towards each genomic variant in human populations because of specific genomic patterns and geographic features. These findings may help in determining susceptibility for CC development. Further identification of cellular genes and signalling pathways involved in CC progression could lead new therapeutic strategies based on miRNAs.