Long non-coding RNAs (lncRNAs) are a novel class of regulatory genes that play critical roles in various processes ranging from normal development to human diseases such as cancer progression. Recent studies have shown that lncRNAs regulate the gene expression by chromatin remodelling, transcription, splicing and RNA decay control, enhancer function, and epigenetic regulation. However, little is known about translation regulation by lncRNAs. We identified a translational regulatory lncRNA (treRNA) through genomewide computational analysis. We found that treRNA is upregulated in paired clinical breast cancer primary and lymph-node metastasis samples, and that its expression stimulates tumour invasion in vitro and metastasis in vivo. Interestingly, we found that treRNA downregulates the expression of the epithelial marker E-cadherin by suppressing the translation of its mRNA. We identified a novel ribonucleoprotein (RNP) complex, consisting of RNA-binding proteins (hnRNP K, FXR1, and FXR2), PUF60 and SF3B3, that is required for this treRNA functions. Translational suppression by treRNA is dependent on the 3 0 UTR of the E-cadherin mRNA. Taken together, our study indicates a novel mechanism of gene regulation by lncRNAs in cancer progression.

Purpose The oncogenic microRNA miR-155 is upregulated in many human cancers and its expression is increased in more aggressive and therapy resistant tumors, but the molecular mechanisms through which miR-155 increases therapy resistance are not fully understood. The main objectives of this study were to determine the role of miR-155 in resistance to chemotherapy and to evaluate anti-miR-155 treatment to chemosensitize tumors. Experimental Design We performed in vitro studies on cell lines to investigate the role of miR-155 in therapy resistance. To assess the effects of miR-155 inhibition on chemoresistance, we used an in vivo orthotopic lung cancer model of athymic nude mice, which we treated with anti-miR-155 alone or in combination with chemotherapy. To analyze the association of miR-155 expression and the combination of miR-155 and TP53 expression with cancer survival, we studied 956 patients with lung cancer, chronic lymphocytic leukemia and acute lymphoblastic leukemia. Results We demonstrate that miR-155 induces resistance to multiple chemotherapeutic agents in vitro, and that downregulation of miR-155 successfully resensitizes tumors to chemotherapy in vivo. We show that miR-155 and TP53, the most frequently deregulated tumor suppressor, are linked in a negative feedback mechanism, and demonstrate that a combination of high expression of miR-155 and low expression of TP53 is significantly associated with shorter survival in lung cancer. Conclusions Our findings support the existence of a miR-155/TP53 feedback loop, which is involved in resistance to chemotherapy and which can be specifically targeted to overcome drug resistance, still the main cause of cancer-related deaths.

Objective: Regenerating islet-derived family, member 4 (regenerating gene type IV, Reg IV) is overexpressed in colorectal cancer (CRC). The aim of this study was to investigate the diagnostic utility of Reg IV determination in sera from patients with CRC. Methods: We examined the expression and distribution of Reg IV in CRC by immunohistochemistry and determined Reg IV levels in sera from patients with CRC by enzyme-linked immunosorbent assay. Results: Immunostaining revealed that 23 of 80 (29%) CRC cases were positive for Reg IV. CRC cases with metastatic recurrence in the liver showed more frequently Reg IV staining than those without (p = 0.0102). Patients with CRC showing Reg IV staining had a significantly worse survival than those without Reg IV staining (p = 0.0117). Preoperatively, serum Reg IV concentrations were not elevated in CRC patients at stage 0–III, being in contrast to the significantly increased preoperative levels in stage IV CRC patients with liver metastasis. Conclusion: These results suggest that Reg IV is a prognosticator for poor survival. Serum Reg IV concentration may predict CRC recurrence in the liver.

Analysis of ADH1B and ALDH2 variants is valuable for secondary prevention of OSCC in high-risk patients who smoke and drink alcohol. In this study, SNP genotyping demonstrated that the ADH1B and/or ALDH2 risk alleles had an interaction with smoking and, especially, alcohol consumption. These findings, if replicated in other groups, could demonstrate new pathophysiological pathways for the development of OSCC.