Integrative miRNA and mRNA analysis in penile carcinomas reveals markers and pathways with potential clinical impact

Abstract

Penile carcinoma (PeCa) is an important public health issue in poor and developing countries, and has only recently been explored in terms of genetic and epigenetic studies. Integrative data analysis is a powerful method for the identification of molecular drivers involved in cancer development and progression. miRNA and mRNA expression profiles followed by integrative analysis were investigated in 23 PeCa and 12 non-neoplastic penile tissues (NPT). Expression levels of eight miRNAs and 10 mRNAs were evaluated in the same set of samples used for microarray and in a validation set of cases (PeCa = 36; NPT = 27). Eighty-one miRNAs and 2,697 mRNAs were identified as differentially expressed in PeCa. Integrative data analysis revealed 255 mRNAs potentially regulated by 68 miRNAs. Using RT-qPCR, eight miRNAs and nine transcripts were confirmed as altered in PeCa. We identified that MMP1, MMP12 and PPARG and hsa-miR-31-5p, hsa-miR-224-5p, and hsa-miR-223-3p were able to distinguish tumors from NPT with high sensitivity and specificity. Higher MMP1 expression was detected as a better predictor of lymph node metastasis than the clinical-pathological data. In addition, PPARG and EGFR were highlighted as potential pathways for targeted therapy in PeCa. The analysis based on HPV positivity (7 of 23 cases) revealed five miRNA and 13 mRNA differentially expressed. Although in a limited number of cases, HPV positive PeCa presented less aggressive phenotype in comparison with negative cases. Overall, an integrative analysis using mRNA and miRNA profiles revealed markers related with tumor development and progression. Furthermore, MMP1 expression level was a predictive marker for lymph node metastasis in patients with PeCa.

Genomic profiling reveals the pivotal role of hrHPV driving copy number and gene expression alterations, including mRNA downregulation of TP53 and RB1 in penile cancer

“…1,11,12 Other molecular mechanisms have been described, including new targets of E6 and E7 oncoproteins, which might interact or modulate the activity of proteins involved in the epigenetic regulation or in the differential expression of host cell miRNAs. [13][14][15][16][17] In parallel, the chronic inflammatory process has been investigated as a risk factor to PeCa, which can be triggered by phimosis, lichen sclerosus, and balanitis. [18][19][20][21] This process can provide a favorable microenvironment for malignant cell transformation and progression due to the release of reactive oxygen or nitrogen species, as well due to the extensive tissue damage and remodeling that is mediated by the immune system cells.…”

“…Interestingly, in our study, the ADAM6 member was observed amplified in 100% of the PeCa analyzed, reinforcing the involvement of EGFR, and matrix metalloproteinase pathways in PeCa. 15 Considering that the majority of the tumors was positive for hrHPV, it is worth noting that the HPV oncogene E5 product is a transmembrane protein that regulates activation of EGFR, which leads to a decrease in E-cadherin expression and it is also associated with increase in matrix metalloproteinase (MMP)-9, resulting in decreased cell-to-cell adhesion. 60 Peta et al 61 showed that EGFR overexpression in PeCa can be mediated by high-risk HPV E6 through downregulation of miR-146a.…”

Nuclear loss and cytoplasmic expression of androgen receptor in penile carcinomas: role as a driver event and as a prognosis factor

“…Molecular alterations in PeCa have been described only recently by our group and others [19,[21][22][23][24][25][26][27][28][29][30]. Interestingly, contrary to the findings described in breast and prostate cancers, AR mRNA is down-expressed in PeCa [19]. Moreover, AR alteration was pointed out as one of the main putative drivers in PeCa [28].…”

“…Penile cancer is a rare disease in developed countries; however, it is more common in poor regions [12]. The human papillomavirus (HPV) infection has been described in 22.2 to 63% of penile carcinomas [13][14][15][16][17][18][19], being the HPV16 the predominant type. The large range of the HPV positivity among different studies may be due to sampling methods, HPV detection procedures, histopathological subtypes, and population cohorts [20].…”

“…The molecular mechanism leading to AR down-expression in PeCa is poorly clarified. Nonetheless, X chromosome loss [31], overexpression of microRNAs targeting the AR gene [19,28], and hypermethylation of the AR gene promoter [23] have been described as mechanisms leading to AR downregulation.…”