Linc-ROR and its spliced variants 2 and 4 are significantly up-regulated in esophageal squamous cell carcinoma

Objective(s): Similar characteristics of molecular pathways between cellular reprogramming events and tumorigenesis have been accentuated in recent years. Reprogramming-related transcription factors, also known as Yamanaka factors (OCT4, SOX2, KLF4, and c-MYC), are also well-known oncogenes promoting cancer initiation, progression, and cellular transformation into cancer stem cells. Long non-coding RNAs (lncRNAs) are a major class of RNA molecules with emerging roles in stem cell pluripotency, cellular reprogramming, cellular transformation, and tumorigenesis. The long intergenic non-coding RNA ROR (lincRNA-ROR, linc-ROR) acts as a regulator of cellular reprograming through sponging miR-145 that normally negatively regulates the expression of the stemness factors NANOG, OCT4, and SOX2. Materials and Methods: Here, we employed a real-time PCR approach to determine the expression patterns of linc-ROR and its two novel spliced variants (variants 2 and 4) in esophageal squamous cell carcinoma (ESCC). Results: The quantitative real-time RT-PCR results revealed a significant up-regulation of linc-ROR (P=0.0098) and its variants 2 (P=0.0250) and 4 (P=0.0002) in tumor samples of ESCC, compared to their matched non-tumor tissues obtained from the margin of same tumors. Our data also demonstrated a significant up-regulation of variant 4 in high-grade tumor samples, in comparison to the low-grade ones (P=0.04). Moreover, the ROC curve analysis demonstrated that the variant 4 of ROR has a potential to discriminate between tumor and non-tumor samples (AUC=0.66, P<0.05). Conclusion: Our data suggest a significant up-regulation of linc-ROR and its variants 2 and 4 in ESCC tissue samples. � 2016, Mashhad University of Medical Sciences. All rights reserved

p16INK4a hypermethylation and p53, p16 and MDM2 protein expression in Esophageal Squamous Cell Carcinoma

<p>Abstract</p> <p>Background</p> <p>Tumor suppressor genes <it>p53 </it>and <it>p16</it>^INK4aand the proto-oncogene <it>MDM2 </it>are considered to be essential G1 cell cycle regulatory genes whose loss of function is associated with ESCC carcinogenesis. We assessed the aberrant methylation of the <it>p16 </it>gene and its impact on <it>p16</it>^{<it>INK4a </it>}protein expression and correlations with <it>p53 </it>and <it>MDM2 </it>protein expressions in patients with ESCC in the Golestan province of northeastern Iran in which ESCC has the highest incidence of cancer, well above the world average.</p> <p>Methods</p> <p>Cancerous tissues and the adjacent normal tissue obtained from 50 ESCC patients were assessed with Methylation-Specific-PCR to examine the methylation status of <it>p16</it>. The expression of <it>p16</it>, <it>p53 </it>and <it>MDM2 </it>proteins was detected by immunohistochemical staining.</p> <p>Results</p> <p>Abnormal expression of <it>p16 </it>and <it>p53</it>, but not <it>MDM2</it>, was significantly higher in the tumoral tissue. <it>p53 </it>was concomitantly accumulated in ESCC tumor along with <it>MDM2 </it>overexpression and <it>p16 </it>negative expression. Aberrant methylation of the <it>p16</it>^{<it>INK4a </it>}gene was detected in 31/50 (62%) of esophageal tumor samples, while two of the adjacent normal mucosa were methylated (P < 0.001). <it>p16</it>^{<it>INK4a </it>}aberrant methylation was significantly associated with decreased <it>p16 </it>protein expression (P = 0.033), as well as the overexpression of <it>p53 </it>(P = 0.020).</p> <p>Conclusions</p> <p><it>p16 </it>hypermethylation is the principal mechanism of <it>p16 </it>protein underexpression and plays an important role in ESCC development. It is associated with p53 protein overexpression and may influence the accumulation of abnormally expressed proteins in <it>p53-MDM2 </it>and <it>p16-Rb </it>pathways, suggesting a possible cross-talk of the involved pathways in ESCC development.</p

B3GALNT2 mutations associated with non-syndromic autosomal recessive intellectual disability reveal a lack of genotype-phenotype associations in the muscular dystrophy-dystroglycanopathies.

BACKGROUND: The phenotypic severity of congenital muscular dystrophy-dystroglycanopathy (MDDG) syndromes associated with aberrant glycosylation of α-dystroglycan ranges from the severe Walker-Warburg syndrome or muscle-eye-brain disease to mild, late-onset, isolated limb-girdle muscular dystrophy without neural involvement. However, muscular dystrophy is invariably found across the spectrum of MDDG patients. METHODS: Using linkage mapping and whole-exome sequencing in two families with an unexplained neurodevelopmental disorder, we have identified homozygous and compound heterozygous mutations in B3GALNT2. RESULTS: The first family comprises two brothers of Dutch non-consanguineous parents presenting with mild ID and behavioral problems. Immunohistochemical analysis of muscle biopsy revealed no significant aberrations, in line with the absence of a muscular phenotype in the affected siblings. The second family includes five affected individuals from an Iranian consanguineous kindred with mild-to-moderate intellectual disability (ID) and epilepsy without any notable neuroimaging, muscle, or eye abnormalities. Complementation assays of the compound heterozygous mutations identified in the two brothers had a comparable effect on the O-glycosylation of α-dystroglycan as previously reported mutations that are associated with severe muscular phenotypes. CONCLUSIONS: In conclusion, we show that mutations in B3GALNT2 can give rise to a novel MDDG syndrome presentation, characterized by ID associated variably with seizure, but without any apparent muscular involvement. Importantly, B3GALNT2 activity does not fully correlate with the severity of the phenotype as assessed by the complementation assay

p16INK4a Suppression by Glucose Restriction Contributes to Human Cellular Lifespan Extension through SIRT1-Mediated Epigenetic and Genetic Mechanisms

Although caloric restriction (CR) has been shown to increase lifespan in various animal models, the mechanisms underlying this phenomenon have not yet been revealed. We developed an in vitro system to mimic CR by reducing glucose concentration in cell growth medium which excludes metabolic factors and allows assessment of the effects of CR at the cellular and molecular level. We monitored cellular proliferation of normal WI-38, IMR-90 and MRC-5 human lung fibroblasts and found that glucose restriction (GR) can inhibit cellular senescence and significantly extend cellular lifespan compared with cells receiving normal glucose (NG) in the culture medium. Moreover, GR decreased expression of p16INK4a (p16), a well-known senescence-related gene, in all of the tested cell lines. Over-expressed p16 resulted in early replicative senescence in glucose-restricted cells suggesting a crucial role of p16 regulation in GR-induced cellular lifespan extension. The decreased expression of p16 was partly due to GR-induced chromatin remodeling through effects on histone acetylation and methylation of the p16 promoter. GR resulted in an increased expression of SIRT1, a NAD-dependent histone deacetylase, which has positive correlation with CR-induced longevity. The elevated SIRT1 was accompanied by enhanced activation of the Akt/p70S6K1 signaling pathway in response to GR. Furthermore, knockdown of SIRT1 abolished GR-induced p16 repression as well as Akt/p70S6K1 activation implying that SIRT1 may affect p16 repression through direct deacetylation effects and indirect regulation of Akt/p70S6K1 signaling. Collectively, these results provide new insights into interactions between epigenetic and genetic mechanisms on CR-induced longevity that may contribute to anti-aging approaches and also provide a general molecular model for studying CR in vitro in mammalian systems

Abrogated expression of DEC1 during oesophageal squamous cell carcinoma progression is age- and family history-related and significantly associated with lymph node metastasis

BACKGROUND: Oesophageal squamous cell carcinoma (SCC) causes the highest number of cancer deaths in some regions of Northern China. Previously, we narrowed down a critical region at 9q33-34, identified to be associated with tumour-suppressive function of deleted in oesophageal cancer 1 (DEC1) in oesophageal SCC. METHODS: We generated DEC1 antibody and constructed tissue microarrays (TMAs) utilising tissue specimens from Henan, a high-risk region for oesophageal SCC, to investigate the importance of DEC1 expression in this cancer. RESULTS: Tissue microarray immunohistochemical staining reveals significant loss of DEC1 from hyperplasia, to tumour, and to lymph node metastasis. In addition, the loss of DEC1 in tumour is age-dependent. Interestingly, there is significant abrogation of DEC1 expression in patients with a family history of oesophageal SCC. Deleted in oesophageal cancer 1 localises to both the cytoplasm and nucleus. The vesicular pattern of DEC1 in the cytoplasm appears to localise at the Golgi and Golgi-endoplasmic reticulum intermediate compartment. CONCLUSION: This is the first TMA study to suggest a clinical association of DEC1 in lymph node metastatic oesophageal SCC, early onset oesophageal SCC and familial oesophageal SCC development. Subcellular localisation of DEC1 and its expression in oesophageal SCC tissues provide important insight for further deciphering the molecular mechanism of DEC1 in oesophageal SCC development. British Journal of Cancer (2011) 104, 841-849. doi:10.1038/bjc.2011.25 www.bjcancer.com Published online 15 February 2011 (C) 2011 Cancer Research U