ABSTRACT
BACKGROUND: Human papillomavirus (HPV) infection is a risk factor for penile cancer (PC). The miR-145 expression has been correlated to this virus genomic amplification. In this context, this work aims to determine the expression level of miR-145 in penile tumors infected by high-risk HPV and correlate it with the clinicopathological characteristics of the tumor and protein expression of p53. METHODS: Formalin-fixed paraffin-embedded from 52 patients with PC, at diagnosis and prior to any cancer treatment, were obtained. HPV identification was performed by nested type PCR, and miR-145 expression was obtained by qRT-PCR. Immunohistochemical analysis of p53 and Ki-67 was performed. RESULTS: Tumoral miR-145 expression was significantly lower compared to adjacent tissue. Additionally, there was a significant reduction of miR-145 expression in invasion perineural, histological associated HPV, and absence of p53 expression in positive HPV cases. HPV infection was detected in 86.5%, the most frequent HPV16. Reduced disease-free survival was observed in patients with low expression of miR-145. CONCLUSIONS: Our data suggest that the underexpression of miR-145 may be triggered by HPV action, decreasing protein expression of p53, and being correlated with perineural invasion. Therefore, the deregulation of miR-145 provides clues as to the potential role in penile carcinogenesis and is also a potential candidate for validation in noninvasive samples.
ABSTRACT
BACKGROUND: Inguinal lymph node involvement is the main prognostic factor in patients with penile cancer. However, there is a lack of marker/s for lymph node metastasis. microRNAs have been investigated as potential markers for prognosis of various types of cancer. Taking this into consideration, our main goal was to determine the association of miR-223-3p, miR-107, and miR-21-5p expression with clinicopathological characteristics, as well as presence of lymph node metastasis in patients with penile cancer. METHODS: Formalin-fixed paraffin-embedded penile squamous cell carcinoma specimens from 50 patients, at diagnosis and prior to any cancer treatment, were obtained. Tissue samples comprising at least 70% malignant cells and adjacent non-tumor tissues were evaluated by using qRT-PCR for expression level of miR-223-3p, miR-107 and miR-21-5p. Additionally, molecular identification of HPV was performed by PCR, and the expression levels of PTEN were analyzed by immunohistochemistry. RESULTS: Penile squamous cell carcinoma primary tumors presented higher expression of miR-223-3p, miR-107, and miR-21-5p when compared to non-tumor adjacent tissues. Upregulation of miR-223-3p was associated lymph node metastasis. Higher expression of miR-107 was associated with worsening of prognosis (as observed by histological grade II and III, tumors bigger than 2.0 cm, stage III and IV, and lower disease-free survival). In addition, higher expression of miR-107 and miR-21-5p was correlated to the absence of PTEN protein expression. CONCLUSIONS: Our data demonstrate that higher expression of miR-223-3p, miR-107, and miR-21-5p is correlated with poor prognosis in penile cancer. The upregulation of these microRNAs potentially affect critical cancer pathways and may be important for the prognosis and response to therapy in penile cancer.
