The Functional Role of LncRNA UCA1 in Pancreatic Cancer: a mini-review.

Pancreatic cancer (PaC) is a common malignant tumor of the digestive tract, with a 5-year survival rate of less than 5% and high mortality rate in the world. LncRNAs have been showed to possess multiple biological functions in growth, differentiation, and proliferation, which play an important role in different biological processes and diseases, especially in the development of tumors. LncRNA UCA1, which is firstly identified in human bladder cancer, has been showed to be a tumor promoter in pancreatic cancer. Recent researches have showed that UCA1 might promote pancreatic carcinogenesis and progression, and correlate with drug resistance. In this review, we address the biological function and regulatory mechanism of UCA1 in pancreatic cancer, which might give a new approach for clinical diagnosis and treatment.

Profiling of gene fusion involving targetable genes in Chinese gastric cancer.

BACKGROUND: Approximately half of all new cases of gastric cancer (GC) and related deaths occur in China. More than 80% of patients with GC are diagnosed at an advanced stage, which results in poor prognosis. Although HER2-directed therapy and immune checkpoint inhibitors have been somewhat successful, new drugs are still needed for the treatment of GC. Notably, several gene fusion-targeted drugs have been approved by the United States Food and Drug Administration for solid tumors, including GC, such as larotrectinib for NTRK fusion-positive cancers and zenocutuzumab for NRG1 fusion-positive cancers. However, gene fusions involving targetable genes have not been well characterized in Chinese patients with GC. AIM: To identify the profile of fusions involving targetable genes in Chinese patients with GC using clinical specimens and determine the distribution of patients with gene fusion variants among the molecular subtypes of GC. METHODS: We retrospectively analyzed gene fusion events in tumor tissue samples from 954 Chinese patients with GC. Clinicopathological characteristics were obtained from their medical records. Genetic alterations, such as single nucleotide variants, indels, amplifications, and gene fusions, were identified using a targeted sequencing panel containing 825 genes. Fusions were validated by fluorescence in situ hybridization (FISH) using break-apart probes. The microsatellite instability (MSI) status was evaluated using MSIsensor from the targeted sequencing panel data. Tumor mutational burden (TMB) was calculated using the total number of nonsynonymous mutations divided by the total genomic targeted region. Chi-square analysis was used to determine the enrichment of gene fusions associated with the molecular subtypes of GC. RESULTS: We found that 1.68% (16/954) of patients harbored 20 fusion events involving targetable genes. RARA fusions (n = 5) were the most common, followed by FGFR2, BRAF, MET, FGFR3, RET, ALK, EGFR, NTRK2, and NRG1 fusions. Two of the RARA fusions, EML4-ALK (E6:E20) and EGFR-SEPTIN14 (E7:E10), have been identified in other tumors but not in GC. Surprisingly, 18 gene fusion events were previously not reported in any cancer types. Twelve of the eighteen novel gene fusions included complete exons encoding functional domains of targetable genes, such as the tyrosine kinase domain of receptor tyrosine kinases and the DNA- and ligand-binding domains of RARA. Consistent with the results of detection using the targeted sequencing fusion panel, the results of FISH (fluorescence in situ hybridization) confirmed the rearrangement of FGFR2 and BRAF in tumors from patients 04 and 09, respectively. Genetic analysis indicated that the fusion genes were significantly enriched in patients with ERBB2 amplification (P = 0.02); however, there were no significant differences between fusion-positive and fusion-negative patients in age, sex, MSI status, and TMB. CONCLUSION: We characterized the landscape of fusions involving targetable genes in a Chinese GC cohort and found that 1.68% of patients with GC harbor potential targetable gene fusions, which were enriched in patients with ERBB2 amplification. Gene fusion detection may provide a potential treatment strategy for patients with GC with disease progression following standard therapy.

High expression of YKT6 associated with progression and poor prognosis of hepatocellular carcinoma.

BACKGROUND AND OBJECTIVE: The N-ethylmaleimide-sensitive fusion protein attachment protein receptor YKT6 is a key protein that controls the release of exosomes, was reported to play important roles in multiple cancers. However, the role of YKT6 in hepatocellular carcinoma (HCC) is still unknown. METHODS: Here we first used bioinformatics tools to analyze the YKT6 mRNA expression in HCC. In addition, we retrospectively collected 330 cancer tissue specimens from HCC patients and 180 para-cancerous tissue specimens, and detected YKT6 expression using immunohistochemical staining. Then the relationship between YKT6 expression and the clinical characteristics of HCC was analyzed, Kaplan-Meier analysis and Cox regression model were also performed to evaluate the impact of YKT6 expression on prognosis of HCC. Protein-protein interaction network of YKT6, and the gene enrichment analysis (GSEA) database were used to predict possible signal pathways regulated by YKT6 in HCC. RESULTS: The high expression rate of YKT6 in HCC (72.40%, 239/330) was higher than that in adjacent tissues (17.80%, 32/180, p < .001), and high expression of YKT6 was correlated with tumor size (p = 0.002), Edmondson Grade (p < .001), metastasis (p < .001), microvascular invasion (p = .005), AFP level (p = .002). Kaplan-Meier survival analysis showed that HCC patients with high YKT6 expression level had poorer prognosis. Meanwhile, multivariate Cox regression analysis showed that Edmondson grade (p = .009), metastasis (p = .049), YKT6 expression (p = .037) are independent risk factors for poor prognosis of HCC. Conclusions: Our results suggested that the upregulated expression of YKT6 is closely related to the progression HCC, which may be used as a potential biomarker for poor prognosis in HCC.

High level of homeobox A9 and PBX homeobox 3 expression in gastric cancer correlates with poor prognosis.

The homeobox protein homeobox (HOXA9) is a transcriptional factor that regulates patterning during embryogenesis and controls cell differentiation. HOXA9 dysfunction has been implicated in certain cancers. However, the role of HOXA9 in gastric cancer is poorly understood. The present study investigated HOXA9 and its cofactor PBX homeobox 3 (PBX3) expression in patients with gastric cancer. Paired tissue samples from 24 patients and paraffin embedded tissues of gastric cancer patients (104 males and 24 females) were included. HOXA9 and PBX3 expression levels were determined by reverse transcription quantitative polymerase chain reaction in fresh tissues, and by immunohistochemical staining in paraffin embedded tissues. The association between HOXA9/PBX3 expression and clinicopathological features was established. The results demonstrated that HOXA9 and PBX3 mRNA levels were significantly upregulated (P=0.032 for HOXA9 and P=0.031 for PBX3) in gastric cancer tissue. Immunohistochemical staining revealed that HOXA9 expression was associated with differentiation, lymph node metastasis and tumor-node-metastasis (TNM) stage, and PBX3 expression was associated with lymph node metastasis and TNM stage. Correlation analysis revealed a high coincidental expression of HOXA9 and PBX3 levels in gastric cancer (r=0.391; P<0.001). Survival analysis showed that high expression of HOXA9 or PBX3 was associated with poor survival of gastric cancer, and multivariate analysis using Cox's regression model showed that PBX3 expression was an independent prognostic factor in gastric cancer. There was elevated expression of HOXA9 and PBX3 in gastric cancer patients, and high-level expression of those proteins was associated with poor prognosis of gastric cancer. The present study underlines the significance of HOXA9/PBX3 in the development of gastric cancer.

PHD3 affects gastric cancer progression by negatively regulating HIF1A.

Prolyl hydroxylase 3 (PHD3) is widely accepted as a tumor suppressor; however, the expression of PHD3 in various cancer types remains controversial. The present study aimed to investigate the association between PHD3 expression and the clinicopathological features of gastric cancer using reverse transcription­quantitative polymerase chain reaction and immunohistochemistry. The effects of PHD3 in gastric cancer cell lines were assessed using western blot analysis and transwell migration assays. The present results revealed that PHD3 expression was increased in adjacent non­cancerous tissue compared with in gastric cancer tissue, and PHD3 overexpression was correlated with the presence of well­differentiated cancer cells, early cancer stage classification and the absence of lymph node metastasis. In vitro experiments demonstrated that PHD3 may act as a negative regulator of hypoxia­inducible factor­1α and vascular endothelial growth factor, both of which participate in tumor angiogenesis. In conclusion, the present results suggested that PHD3 may act as a tumor suppressor in gastric cancer. Therefore, the targeted regulation of PHD3 may have potential as a novel therapeutic approach for the treatment of patients with gastric cancer.

The CDH1 -160C/A polymorphism is associated with breast cancer: evidence from a meta-analysis.

BACKGROUND: Numerous epidemiological studies have evaluated the association between the CDH1 -160C/A polymorphism and the risk of breast cancers. However, these studies have yielded conflicting results. To derive a more precise estimation of this association, this meta-analysis was conducted. METHODS: A comprehensive search using the keywords "CDH1," "E-Cadherin," "polymorphism," "SNP," and "variant" combined with "breast," "cancer," "tumor," or "carcinomas" was conducted. Pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were appropriately calculated using a fixed effect or random effect model. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 checklist was used for this meta-analysis. RESULTS: Four publications including five studies were identified. It was found that the CDH1 -160C/A polymorphism was significantly associated with breast cancer risk in the dominant model (CA + AA vs. CC: OR = 1.207, 95 % CI = 1.031-1.412, P = 0.019). CONCLUSIONS: Our meta-analysis demonstrated that the -160C/A polymorphism in the CDH1 gene might contribute to breast cancer susceptibility. Further investigations using a much larger sample including different ethnicities are still needed to verify this association.