Genomic inversions and GOLGA core duplicons underlie disease instability at the 15q25 locus.

Human chromosome 15q25 is involved in several disease-associated structural rearrangements, including microdeletions and chromosomal markers with inverted duplications. Using comparative fluorescence in situ hybridization, strand-sequencing, single-molecule, real-time sequencing and Bionano optical mapping analyses, we investigated the organization of the 15q25 region in human and nonhuman primates. We found that two independent inversions occurred in this region after the fission event that gave rise to phylogenetic chromosomes XIV and XV in humans and great apes. One of these inversions is still polymorphic in the human population today and may confer differential susceptibility to 15q25 microdeletions and inverted duplications. The inversion breakpoints map within segmental duplications containing core duplicons of the GOLGA gene family and correspond to the site of an ancestral centromere, which became inactivated about 25 million years ago. The inactivation of this centromere likely released segmental duplications from recombination repression typical of centromeric regions. We hypothesize that this increased the frequency of ectopic recombination creating a hotspot of hominid inversions where dispersed GOLGA core elements now predispose this region to recurrent genomic rearrangements associated with disease.

Expression of Cellular and Extracellular TERRA, TERC and TERT in Hepatocellular Carcinoma.

Non-coding RNAs are transcribed from telomeres and the telomeric repeat-containing RNAs (TERRA) are implicated in telomere homeostasis and in cancer. In this study, we aimed to assess in hepatocellular carcinoma (HCC) the cellular and extracellular expression of TERRA, the telomerase RNA subunit (TERC) and the telomerase catalytic subunit (TERT). We determined by qPCR the expression level of TERRA 1_2_10_13q, TERRA 15q, TERRA XpYp, TERC and of TERT mRNA in HCC tissues and in the plasma of HCC patients. Further, we profiled the same transcripts in the HCC cell lines, HA22T/VGH and SKHep1C3, and in the extracellular vesicles (EVs) derived from their secretomes. We found that the expression of TERRA and TERT mRNA was significantly deregulated in HCC, being TERRA downregulated and TERT mRNA upregulated in HCC tissues vs. the peritumoral (PT) ones, and the receiver operating characteristic (ROC) curve analyses revealed a significant ability in discriminating HCC from PT tissue. Further, the determinations of circulating TERRA and TERC showed higher amounts of these transcripts in the plasma of HCC patients vs. controls and ROC analyses gave significant results. The expression characterization of the cultured HCC cells showed their ability to produce and secrete TERRA and TERC into the EVs; the ability to produce TERT mRNA that was not detectable in the EVs; and the ability to respond to sorafenib treatment increasing TERRA expression. Our results highlight that: (i) both cellular and extracellular expressions of TERRA and TERC are dysregulated in HCC as well as the cellular expression of TERT mRNA and (ii) the combined detection of TERRA and TERC in plasma may represent a promising approach for non-invasive diagnostic molecular indicators of HCC.

Tomatine Displays Antitumor Potential in In Vitro Models of Metastatic Melanoma.

There is a growing interest in the cytotoxic effects of bioactive glycoalkaloids, such as α-tomatine on tumor cells. Here, for the first time, we determine the antitumor potential of tomatine, a mixture of α-tomatine and dehydrotomatine, in metastatic melanoma (MM) cell lines harboring different BRAF and MC1R variants. We performed cytotoxicity experiments and annexin-V/propidium iodide staining to assess the apoptotic/necrotic status of the cells. ER stress and autophagy markers were revealed by Western Blot, whereas antiangiogenic and vascular-disrupting effects were evaluated through a capillary tube formation assay on matrigel and by ELISA kit for VEGF release determination. Cell invasion was determined by a Boyden chamber matrigel assay. Tomatine reduced 50% of cell viability and induced a concentration-dependent increase of apoptotic cells in the range of 0.5-1 µM in terms of α-tomatine. The extent of apoptosis was more than two-fold higher in V600BRAF-D184H/D184H MC1R cells than in BRAF wild-type cells and V600BRAF-MC1R wild-type cell lines. Additionally, tomatine increased the LC3I/II autophagy marker, p-eIF2α, and p-Erk1/2 levels in BRAF wild-type cells. Notably, tomatine strongly reduced cell invasion and melanoma-dependent angiogenesis by reducing VEGF release and tumor-stimulating effects on capillary tube formation. Collectively, our findings support tomatine as a potential antitumor agent in MM.

The influence of MC1R on dermal morphological features of photo-exposed skin in women revealed by reflectance confocal microscopy and optical coherence tomography.

BACKGROUND: The melanocortin 1 receptor (MC1R) gene is one of the major determinants of skin pigmentation. It is a highly polymorphic gene and some of its polymorphisms have been related to specific skin phenotypes, increased risk of skin cancers and skin photoageing. Currently, its contribution to changes in dermal features in photo-exposed skin is unknown. OBJECTIVE: The main objective of this study is to evaluate the potential correlation between MC1R status and specific healthy photo-exposed skin characteristics. MATERIALS AND METHODS: Skin facial features were estimated by evaluation with standard digital photography with automated features count, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) in 100 healthy women. Skin of the forearms was used as a control. RESULTS: The study found an association between RHC MC1R polymorphisms and dermal features in photo-exposed areas being represented by increased vessel density and pixel density in OCT (P = .025 and P = .001, respectively) and increased coarse collagen in RCM (P = .034), as compared to non-RHC subjects. To our knowledge this is previously unreported. Additionally, previously reported correlations between light hair colour and pigmented spots with MC1R RHC polymorphisms have been confirmed. CONCLUSIONS: Our results suggest the role of RHC MC1R variants in dermal variations of facial skin, as compared to non-RHC variants. To our knowledge this is previously unreported.

Behind the Scene: Exploiting MC1R in Skin Cancer Risk and Prevention.

Melanoma and non-melanoma skin cancers (NMSCs) are the most frequent cancers of the skin in white populations. An increased risk in the development of skin cancers has been associated with the combination of several environmental factors (i.e., ultraviolet exposure) and genetic background, including melanocortin-1 receptor (MC1R) status. In the last few years, advances in the diagnosis of skin cancers provided a great impact on clinical practice. Despite these advances, NMSCs are still the most common malignancy in humans and melanoma still shows a rising incidence and a poor prognosis when diagnosed at an advanced stage. Efforts are required to underlie the genetic and clinical heterogeneity of melanoma and NMSCs, leading to an optimization of the management of affected patients. The clinical implications of the impact of germline MC1R variants in melanoma and NMSCs' risk, together with the additional risk conferred by somatic mutations in other peculiar genes, as well as the role of MC1R screening in skin cancers' prevention will be addressed in the current review.

Longitudinal Circulating Levels of miR-23b-3p, miR-126-3p and lncRNA GAS5 in HCC Patients Treated with Sorafenib.

Human hepatocellular carcinoma (HCC) is the most frequent primary tumor of the liver and the third cause of cancer-related deaths. The multikinase inhibitor sorafenib is a systemic drug for unresectable HCC. The identification of molecular biomarkers for the early diagnosis of HCC and responsiveness to treatment are needed. In this work, we performed an exploratory study to investigate the longitudinal levels of cell-free long ncRNA GAS5 and microRNAs miR-126-3p and -23b-3p in a cohort of 7 patients during the period of treatment with sorafenib. We used qPCR to measure the amounts of GAS5 and miR-126-3p and droplet digital PCR (ddPCR) to measure the levels of miR-23b-3p. Patients treated with sorafenib displayed variable levels of GAS5, miR-126-3p and miR-23b-3p at different time-points of follow-up. miR-23b-3p was further measured by ddPCR in 37 healthy individuals and 25 untreated HCC patients. The amount of miR-23b-3p in the plasma of untreated HCC patients was significantly downregulated if compared to healthy individuals. The ROC curve analysis underlined its diagnostic relevance. In conclusion, our results highlight a potential clinical significance of circulating miR-23b-3p and an exploratory observation on the longitudinal plasmatic levels of GAS5, miR-126-3p and miR-23b-3p during sorafenib treatment.

Differential expression profiling of long non-coding RNA GAS5 and miR-126-3p in human cancer cells in response to sorafenib.

Long non-coding RNAs (lncRNAs) and microRNAs are involved in numerous physio-pathological conditions included cancer. To better understand the molecular mechanism of the oral antitumor multikinase inhibitor sorafenib, we profiled the expression of a panel of lncRNAs and miRNAs by qPCR array in a sorafenib-treated hepatocellular carcinoma (HCC) cell line. Among the most affected ncRNAs, we found that sorafenib mediated the dysregulation of the lncRNAs GAS5, HOTTIP and HOXA-AS2 and the miR-126-3p, in a panel of human cancer cell lines (HCC, renal and breast carcinomas). By luciferase gene reporter assay, we discovered that GAS5 may act as a sponge for miR-126-3p in HCC cells. The expression level of GAS5 and miR-126-3p was verified in human liquid and/or solid biopsies from HCC patients. miR-126-3p expression in HCC tissues was decreased respect to their correspondent peritumoral tissues. The levels of plasmatic circulating miR-126-3p and GAS5 were significantly higher and lower in HCC patients compared to healthy subjects, respectively. This study highlighted the capability of sorafenib to modulate the expression of a wide range of ncRNAs and specifically, GAS5 and miR-126-3p were involved in the response to sorafenib of different cancer cell types.