Down-Regulation of mir-424 Contributes to the Abnormal Angiogenesis via MEK1 and Cyclin E1 in Senile Hemangioma: Its Implications to Therapy

Abstract

BackgroundSenile hemangioma, so-called cherry angioma, is known as the most common vascular anomalies specifically seen in the aged skin. The pathogenesis of its abnormal angiogenesis is still unclear.Methodology/Principal FindingsIn this study, we found that senile hemangioma consisted of clusters of proliferated small vascular channels in upper dermis, indicating that this tumor is categorized as a vascular tumor. We then investigated the mechanism of endothelial proliferation in senile hemangioma, focusing on microRNA (miRNA). miRNA PCR array analysis revealed the mir-424 level in senile hemangioma was lower than in other vascular anomalies. Protein expression of MEK1 and cyclin E1, the predicted target genes of mir-424, was increased in senile hemangioma compared to normal skin or other anomalies, but their mRNA levels were not. The inhibition of mir-424 in normal human dermal microvascular ECs (HDMECs) using specific inhibitor in vitro resulted in the increase of protein expression of MEK1 or cyclin E1, while mRNA levels were not affected by the inhibitor. Specific inhibitor of mir-424 also induced the cell proliferation of HDMECs significantly, while the cell number was decreased by the transfection of siRNA for MEK1 or cyclin E1.Conclusions/SignificanceTaken together, decreased mir-424 expression and increased levels of MEK1 or cyclin E1 in senile hemangioma may cause abnormal cell proliferation in the tumor. Senile hemangioma may be the good model for cutaneous angiogenesis. Investigation of senile hemangioma and the regulatory mechanisms of angiogenesis by miRNA in the aged skin may lead to new treatments using miRNA by the transfection into senile hemangioma.

The miR-424(322)/503 cluster orchestrates remodeling of the epithelium in the involuting mammary gland

“…Interestingly, our data did not validate previous data reporting CCNE1 as a target of this miRNA cluster (Forrest et al 2010;Nakashima et al 2010). Since the relevance of the different miRNA targets is contextdependent (Liu and Kohane 2009;Inui et al 2010), it is important to mention that we used HMECs for our studies and achieved mature miRNA expression levels comparable with the observed during involution in vivo.…”

“…Although this miRNA has been studied in the context of monocyte differentiation (Rosa et al 2007;Forrest et al 2010) and endothelial cell regulation (Ghosh et al 2010;Nakashima et al 2010;Kim et al 2013), a potential role in mammary epithelial architecture remodeling has not yet been described. The characterization of the mammary epithelium of miR-424(322)/503 knockout females during development revealed a defect during involution.…”

The expression of miR-124 increases in aged skin to cause cell senescence and it decreases in squamous cell carcinoma

“…miRNAs have been implicated in the pathogenesis of various human diseases such as cancers and inflammatory disorders. The current authors previously found that the miR-424 level in senile hemangioma, the most common vascular anomaly seen specifically in aged skin, was lower than levels in other vascular anomalies (2): Decreased miR-424 expression and increased levels of target molecules (MEK1 and cyclin E1) in endothelial cells of senile hemangioma may cause abnormal cell proliferation in the tumor.…”

“…Small RNAs were extracted from paraffin sections using the miRNeasy FFPE kit and from cultured cells using the RNeasy mini kit (Qiagen, Valencia, CA) as described previously (2,3). For the RT 2 Profiler PCR Array (SABiosciences, Frederick, MD), the RNAs were reverse-transcribed into first-strand cDNA using the RT 2 miRNA First Strand Kit (SABiosciences).…”

MicroRNAs Looping Around Angiogenesis

“…The interference of respective signaling cascades inhibits EC migration and proliferation in vitro and in vivo, consequently altering essential EC characteristics. Because of the putative role of miR-15, -16, and -424 in cancer biology, 17,18 these miRNAs came into focus to analyze EC-intrinsic functional aspects. Another important hallmark of the chosen miRNAs is their common and identical seed sequence, implicating a similar miRNA targetome.…”