Acta histochemica
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Melanoma is a highly invasive malignant skin tumor having high metastatic rate and poor prognosis. The biology of melanoma is controled by miRNAs. The miRNA-183 cluster, which is composed of miRNA-183∼96∼182 genes, plays an important roles in tumor development. ⋯ Furthmore, overexpression and knockdown of the miRNA-183 cluster in B16 cells decreased and increased the expression of mRNA and protein of melangenic genes tyrosinase (TYR), and tyrosinase-related protein 1 (TYRP1), dopachrome-tautomerase (DCT), as well as the production of melanins and eumelanin production, respectively. On the proliferation and migration pathway, overexpression and knockdown of miRNA-183 cluster increased and decreased, respectively the expression of mRNA and protein of mitogen-activated protein kinase 1 (MEK1), extracellular regulated protein kinases1/2 (ERK1/2) and cAMP-responsive-element binding protein (CREB). These results indicated that miRNA-183 cluster regulated melanogenesis in B16 cells as well as cell proliferation and migration by directly targeting MITF through migration pathway.
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Telocytes (TCs) have recently emerged as a peculiar type of stromal cells located in both perivascular and interstitial compartments of multiple anatomical sites in humans, other mammals and vertebrates. Pioneer electron microscopy studies have ultrastructurally defined TCs as "stromal cells with telopodes" (i.e. very long and thin cell processes with a moniliform morphology conferred by the irregular alternation of slender segments and small, bead-like, dilated portions), whereupon it has become apparent that TCs largely correspond to the CD34+ stromal/interstitial cells detectable by immunohistochemical assays. Besides CD34, TCs are also characterized by the expression of platelet-derived growth factor receptor (PDGFR)α. ⋯ For this purpose, we carried out a series of double immunofluorescence analyses simultaneously detecting the CD34 or PDGFRα antigen and a marker of LECs, either PDPN or lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1). In the connective tissue compartment of different organs, TCs were CD34+/PDGFRα+/PDPN-/LYVE-1- while LECs were CD34-/PDGFRα-/PDPN+/LYVE-1+, thus representing two definitely distinct, though spatially close, cell entities. The arrangement of telopodes to intimately surround the abluminal side of LECs suggests a possible role of TCs in the regulation of lymphatic capillary functionality, which is worth investigating further.