The establishment of CDK9/RNA PolII/H3K4me3/DNA methylation feedback promotes HOTAIR expression by RNA elongation enhancement in cancer.

Long non-coding RNA HOX Transcript Antisense RNA (HOTAIR) is overexpressed in multiple cancers with diverse genetic profiles. Importantly, since HOTAIR heavily contributes to cancer progression by promoting tumor growth and metastasis, HOTAIR becomes a potential target for cancer therapy. However, the underlying mechanism leading to HOTAIR deregulation is largely unexplored.

EBV-encoded miRNAs can sensitize nasopharyngeal carcinoma to chemotherapeutic drugs by targeting BRCA1.

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated epithelial malignancy. The high expression of BART-miRNAs (miR-BARTs) during latent EBV infection in NPC strongly supports their pathological importance in cancer progression. Recently, we found that several BART-miRNAs work co-operatively to modulate the DNA damage response (DDR) by reducing Ataxia-telangiectasia-mutated (ATM) activity.

Distinct Molecular Landscape of Epstein-Barr Virus Associated Pulmonary Lymphoepithelioma-Like Carcinoma Revealed by Genomic Sequencing.

Pulmonary lymphoepithelioma-like carcinoma (LELC) is a subtype of non-small cell lung cancer (NSCLC) characterized by marked lymphocytic infiltration and association with Epstein-Barr virus (EBV). The molecular basis underlying the disease remains unclear. We sought to study the molecular landscape by multiple approaches including whole genomic sequencing, capture-based targeted sequencing, fluorescent in situ hybridization and immunohistochemistry.

LLGL1 Regulates Gemcitabine Resistance by Modulating the ERK-SP1-OSMR Pathway in Pancreatic Ductal Adenocarcinoma.

Background & Aims: Gemcitabine resistance is rapidly acquired by pancreatic ductal adenocarcinoma (PDAC) patients. Novel approaches that predict the gemcitabine response of patients and enhance gemcitabine chemosensitivity are important to improve patient survival. We aimed to identify genes as novel biomarkers to predict the gemcitabine response and the therapeutic targets to attenuate chemoresistance in PDAC cells.

Development of a Novel Inflammation-Based Index for Hepatocellular Carcinoma.

Background: The aim of current study was to (1) construct and validate a novel hepatocellular carcinoma (HCC)-specific inflammatory index; (2) compare the performances of the Integrated Liver Inflammatory Score (ILIS) to existing 4 inflammatory indices in HCC; (3) explore the association between the inflammatory indices and systemic/intratumoral inflammatory markers.

Methods: Two cohorts from Hong Kong (HK; = 1,315) and Newcastle ( = 574) were studied. A novel index was constructed from the HK training set ( = 627).

Ectopic HOTTIP expression induces noncanonical transactivation pathways to promote growth and invasiveness in pancreatic ductal adenocarcinoma.

HOXA transcript at the distal tip (HOTTIP), a long noncoding RNA, is upregulated in pancreatic ductal adenocarcinoma (PDAC), but the HOTTIP-mediated oncogenic pathway is not fully understood. We identified canonical HOTTIP-HOXA13 targets, CYP26B1, CLIC5, CHI3L1 and UCP2-responsible for cell growth and cell invasion. Genome-wide analysis revealed that 38% of HOTTIP-regulated genes contain H3K4me3 and HOTTIP enrichment at their promoters, without HOXA13 binding.

EGFR mutation exists in squamous cell lung carcinoma.

Whether EGFR mutation occurs in lung squamous cell carcinoma (SCC) remains a controversial issue. Although numerous trials have shown positive response to tyrosine kinase inhibitors in SCC, these observations have not been well correlated with presence or absence of EGFR mutation. A complicating issue is that adenosquamous carcinoma, a mimic of SCC, frequently harbours EGFR mutations.

Targeting the Oncogenic p53 Mutants in Colorectal Cancer and Other Solid Tumors.

Colorectal cancer (CRC) is a kind of solid tumor and the third most common cancer type in the world. It is a heterogeneous disease characterized by genetic and epigenetic aberrations. The mutation is the key step driving the transition from adenoma to adenocarcinoma.

A comparability study of immunohistochemical assays for PD-L1 expression in hepatocellular carcinoma.

Programmed death ligand 1 (PD-L1) protein expression by immunohistochemistry is a promising biomarker for PD-1/PD-L1 blockade in hepatocellular carcinoma. There are a number of commercially available PD-L1 assays. Our study aimed to compare the analytical performance of different PD-L1 assays and evaluate the reliability of pathologists in PD-L1 scoring.

RASAL2 promotes tumor progression through LATS2/YAP1 axis of hippo signaling pathway in colorectal cancer.

Background: Patients with colorectal cancer (CRC) have a high incidence of regional and distant metastases. Although metastasis is the main cause of CRC-related death, its molecular mechanisms remain largely unknown.

Methods: Using array-CGH and expression microarray analyses, changes in DNA copy number and mRNA expression levels were investigated in human CRC samples.

Granulin epithelin precursor promotes colorectal carcinogenesis by activating MARK/ERK pathway.

Background: Granulin epithelin precursor (GEP) is reported to function as a growth factor stimulating proliferation and migration, and conferring chemoresistance in many cancer types. However, the expression and functional roles of GEP in colorectal cancer (CRC) remain elusive. The aim of this study was thus to investigate the clinical significance of GEP in CRC and reveal the molecular mechanism of GEP in CRC initiation and progression.

Downregulation of long non-coding RNA MEG3 in nasopharyngeal carcinoma.

In our previous whole-transcriptome sequencing analysis, downregulation of a long non-coding RNA, maternally expressed gene 3 (MEG3), was identified in NPC samples. This finding suggests the possible role of MEG3 as a tumor suppressor in this distinctive disease. In the present study, two MEG3 variants, AF119863 (MEG3-AF) and BX247998 (MEG3-BX), were found abundantly expressed in a normal nasopharyngeal epithelial cell line, NP69.

EZH2 coupled with HOTAIR to silence MicroRNA-34a by the induction of heterochromatin formation in human pancreatic ductal adenocarcinoma.

MicroRNA-34a (miR-34a) is frequently downregulated in pancreatic ductal adenocarcinoma (PDAC) cells, however, the silencing mechanism remains unclear. Enhancer of zeste homolog 2 (EZH2) is overexpressed in PDAC, and our previous miRNA profiling showed that inhibition of EZH2 in PDAC cells led to the re-expression of a group of tumor suppressor miRNAs including miR-34a. Here, we studied the effect of ectopic EZH2 expression to the silencing of miR-34a, and identified HOTAIR as an interacting partner to induce heterochromatin formation during miR-34a repression.

Dysregulated expression of arginine metabolic enzymes in human intestinal tissues of necrotizing enterocolitis and response of CaCO2 cells to bacterial components.

The small intestine is the exclusive site of arginine synthesis in neonates. Low levels of circulating arginine have been associated with the occurrence of necrotizing enterocolitis (NEC) but the mechanism of arginine dysregulation has not been fully elucidated. We aimed to investigate (i) expressional changes of arginine synthesizing and catabolic enzymes in human intestinal tissues of NEC, spontaneous intestinal perforation (SIP) and noninflammatory surgical conditions (Surg-CTL) and to investigate the (ii) mechanisms of arginine dysregulation and enterocyte proliferation upon stimulation by bacterial components, arginine depletion, ARG1 overexpression and nitric oxide (NO) supplementation.

Emerging roles of small Epstein-Barr virus derived non-coding RNAs in epithelial malignancy.

Latent Epstein-Barr virus (EBV) infection is an etiological factor in the progression of several human epithelial malignancies such as nasopharyngeal carcinoma (NPC) and a subset of gastric carcinoma. Reports have shown that EBV produces several viral oncoproteins, yet their pathological roles in carcinogenesis are not fully elucidated. Studies on the recently discovered of EBV-encoded microRNAs (ebv-miRNAs) showed that these small molecules function as post-transcriptional gene regulators and may play a role in the carcinogenesis process.

Enhancer of zeste homolog 2 silences microRNA-218 in human pancreatic ductal adenocarcinoma cells by inducing formation of heterochromatin.

Background & Aims: Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that is overexpressed by pancreatic ductal adenocarcinoma (PDAC) cells and increases their aggressiveness. We identified microRNAs (miRs) that are regulated by EZH2 and studied their functions in PDAC cells.

Methods: We performed miR profile analysis of PDAC cells incubated with EZH2 inhibitor 3-deazaneplanocin A, and pancreatic ductal epithelial cells that overexpressed EZH2.

A single nucleotide polymorphism in microRNA-146a is associated with the risk for nasopharyngeal carcinoma.

A common GC polymorphism within miRNA-146a precursor region (rs2910164) has been associated with the risk of various cancers despite the underlying mechanism is unclear. In the current study, we aimed to examine the role of rs2910164 in the pathogenesis and predisposition to nasopharyngeal carcinoma (NPC). The GC polymorphism in 233 NPC patients, 173 matched controls and 3613 healthy elderly subjects in our locality were first determined using melting temperature (T(m))-shift allele-specific genotyping method.

Modulation of LMP2A expression by a newly identified Epstein-Barr virus-encoded microRNA miR-BART22.

Infection with the Epstein-Barr virus (EBV) is a strong predisposing factor in the development of nasopharyngeal carcinoma (NPC). Many viral gene products including EBNA1, LMP1, and LMP2 have been implicated in NPC tumorigenesis, although the de novo control of these viral oncoproteins remains largely unclear. The recent discovery of EBV-encoded viral microRNA (miRNA) in lymphoid malignancies has prompted us to examine the NPC-associated EBV miRNA.

Generation of monoclonal antibodies against Hong Kong nasopharyngeal carcinoma-associated Epstein-Barr virus latent membrane protein 1 (LMP1).

A panel of monoclonal antibodies specific to Hong Kong Chinese nasopharyngeal carcinoma (NPC)-associated Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) variants has been generated. These monoclonal antibodies not only differentiate the Hong Kong Chinese NPC-associated LMP1 variants from the prototype B95-8 LMP1, derived from Caucasian infectious mononucleosis, but also differentiate the 2 highly homologous LMP1 deletion variants commonly found in Hong Kong primary NPC. The predominant deletion type variant, DV-Asp335, is characterized by an aspartic acid at residue 335 located in the cytoplasmic C-terminal region, whereas the other minor deletion variant, DV-Gly335, has a glycine in the same residue position.