The authors, following their personal experience based on the reported data, went back to using the simple filtered fat after some years of use of centrifuged fat.

In the recent years the importance of the role played by non-coding RNA on the regulation of gene expression was increased by numerous studies. The research mainly focused on small ncRNAs, such as miRNAs, while the functions of long non-coding RNA (lncRNA) have been much less studied. lncRNAs can be transcribed from intergenic, intragenic or specific chromosomal regions. Compared to miRNAs, lncRNAs have a complex secondary and tertiary structure which allows to bind proteins, RNA, DNA and to carry out their regulatory functions. Several studies showed that extracellular ncRNAs can circulate in the blood of both healthy and diseased patients. Most of the circulating ncRNAs are included in lipid or lipoprotein vesicles, such as apoptotic bodies, macrovesicles or exosomes, in which they are highly stable. The presence of circulating ncRNAs in the blood of cancer patients versus normal subjects suggested the possibility that these molecules may represent new diagnostic markers. HOTAIR is a HOX transcript antisense RNA, located in the HOXC locus, able to repress transcription in the posterior region of the HOXD locus. HOTAIR has been involved in the evolution of several primary tumors, wherein increase of HOTAIR expression has endorsed invasion and metastasis. In this review, we describe the experimental evidences on the potential role as circulating marker of lncRNA HOTAIR.

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The molecular mechanisms responsible for the metastatic progression of melanoma have not been fully defined yet. We have recently shown that an important role in this process is certainly played by HOX genes, whose regulation is under control of particular non-coding RNAs, some of which are present within the HOX locus. HOTAIR is the most studied among them, whose aberrant expression is associated with the metastatic progression of many malignancies. The aim of this study was to verify the role played by HOTAIR in metastatic progression of melanoma and to evaluate the circulating levels of HOTAIR in the blood of patients with metastatic melanoma. A series of melanocytic lesions were selected to evaluate the potential changes in the expression of HOTAIR during the evolution of the disease through in situ and molecular approaches. None of the benign melanocytic lesions showed the presence of HOTAIR. The staining of HOTAIR resulted very weak in the primary pT1 lesions, while it was very strong in all pairs of primary tissues and corresponding metastases. Surprisingly, we found the presence of HOTAIR in some intratumoral lymphocytes, while this positivity decreased in lymphocyte component further away from the tumor. HOTAIR was also detected in the serum of selected metastatic patients. These data allowed us to speculate on the fundamental role played by HOTAIR in tumor evolution of melanoma. Its presence in intratumoral lymphocytes might suggest that its involvement in the modulation of tumor microenvironment and the detection in the serum could be used in the management of melanoma patients.

We show that human osteosarcoma cells (Saos-2) have downregulation of a3b1-integrin compared to normal bone cells; this was further described in human osteosarcomas and in a primary murine sarcoma. The a3 gene was silenced in Saos-2 cells causing a low expression of a3b1-integrin and reduction in collagen attachment with increasing migratory capacity. Chromatin immunoprecipitation assay performed on a3 promoter established that Myc and Yin Yang protein (YY1) cooperate in tandem to downregulate the a3 gene. This silencing mechanism involves the binding of Myc and YY1 to DNA and formation of complexes among Myc/Max, YY1, CREBbinding protein and deacetylation activity. The promoter containing deletions of E-boxes or YY1 cassettes failed to downregulate the transcription of a reporter gene as well as the inhibition of deacetylation activity. Overexpression of both Myc and YY1 was necessary to determine the a3-integrin promoter downregulation in normal osteoblasts. This downregulation of a3b1-integrin can contribute to the acquisition of a more aggressive phenotype. YY1 regulated negatively the Myc activity through a direct interaction with the Myc/Max and deacetylase complexes. This represents a novel silencing mechanism with broad implications in the transcription machinery of tumours.