Dissecting the mechanism of colorectal tumorigenesis based on RNA-sequencing data

Roles of fusion genes in digestive system cancers: dawn for cancer precision therapy

For advanced and advanced tumors of the digestive system, personalized, precise treatment could be a lifesaving medicine. With the development of next-generation sequencing technology, detection of fusion genes in solid tumors has become more extensive. Some fusion gene targeting therapies have been written into the guidelines for digestive tract tumors, such as for neurotrophic receptor tyrosine kinase, fibroblast growth factor receptor 2. There are also many fusion genes being investigated as potential future therapeutic targets. This review focuses on the current detection methods for fusion genes, fusion genes written into the digestive system tumor guidelines, and potential fusion gene therapy targets in different organs to discuss the possibility of clinical treatments for these targets in digestive system tumors.

A narrative review of the roles of muscle segment homeobox transcription factor family in cancer

Deregulation of many homeobox genes has been observed in various cancers and has caused functional implications in the tumor progression. In this review, we will focus on the roles of the human muscle segment homeobox (MSX) transcription factor family in the process of tumorigenesis. The MSX transcription factors, through complex downstream regulation mechanisms, are promoters or inhibitors of diverse cancers by participating in cell proliferation, cell invasion, cell metastasis, cell apoptosis, cell differentiation, drug resistance of tumors, maintenance of tumor stemness, and tumor angiogenesis. Moreover, their upstream regulatory mechanisms in cancers may include: gene mutation and chromosome aberration; DNA methylation and chromatin modification; regulation by non-coding RNAs; regulation by other transcription factors and post-translational modification. These mechanisms may provide a better understanding of why MSX transcription factors are abnormally expressed in tumors. Notably, intermolecular interactions and post-translational modification can regulate the transcriptional activity of MSX transcription factors. It is also crucial to know what affects the transcriptional activity of MSX transcription factors in tumors for possible interventions in them in the future. This systematic summary of the regulatory patterns of the MSX transcription factor family may help to further understand the mechanisms involved in transcriptional regulation and also provide new therapeutic approaches for tumor progression.

Interaction between miR-572 and PPP2R2C, and their effects on the proliferation, migration, and invasion of nasopharyngeal carcinoma (NPC) cells

We investigated the how miR-572 regulates PPP2R2C, and studied the effects of miR-572 and PPP2R2C on proliferation and migration as well as invasion of nasopharyngeal carcinoma (NPC) cells. NPC tissues and normal tissues were collected, and the expressions of miR-572 and PPP2R2C were detected by real-time PCR. Western blot was applied to detect the expression of PPP2R2C protein. The target relationship between miR-572 and PPP2R2C was confirmed by dual luciferase reporter gene assay. MTT assay and flow cytometry were applied to investigate the viability and apoptosis levels of NPC cells. Transwell as well as wound healing assays were used, respectively, to detect the invasiveness and migration of NPC cells. MiR-572 was highly expressed in NPC tissues as well as NPC cells, and there was lower expression of PPP2R2C in NPC tissues compared with normal samples. MiR-572 could bind to the 3' UTR of PPP2R2C and decrease its expression. Over-expressed miR-572 and decreased PPP2R2C expression could both inhibit proliferation and invasion and induce apoptosis of NPC cells. Thus, miR-572 promotes the proliferation and invasion of NPC by directly down-regulating PPP2R2C.

RNA-Seq技术及其在胃肠肿瘤研究中的应用现状

转录组是特定的细胞或组织在特定的时间或状态下转录出来的RNA集合, 转录组研究能够从整体水平研究基因功能以及基因结构, 并能很好的显示处于表达状态的基因数量和活跃程度. 作为转录组学新一代高通量测序技术之一, RNA-Seq技术能够更为快速、准确地为人们提供更多的生物体转录信息, 在生物医学研究中已经得到广泛应用. 随着全球胃肠肿瘤发病率的逐年提高, RNA-Seq技术在胃肠肿瘤研究领域进行全转录组测序分析的应用越来越多, 并取得了一些新的进展. 本文将就RNA-Seq技术原理、优势及其在胃肠肿瘤研究中的具体应用进行论述.

High throughput RNA sequencing utility for diagnosis and prognosis in colon diseases

RNA sequencing is the use of high throughput next generation sequencing technology to survey, characterize, and quantify the transcriptome of a genome. RNA sequencing has been used to analyze the pathogenesis of several malignancies such melanoma, lung cancer, and colorectal cancer. RNA sequencing can identify differential expression of genes (DEG’s), mutated genes, fusion genes, and gene isoforms in disease states. RNA sequencing has been used in the investigation of several colorectal diseases such as colorectal cancer, inflammatory bowel disease (ulcerative colitis and Crohn’s disease), and irritable bowel syndrome.

Identification of Genetic and Epigenetic Variants Associated with Breast Cancer Prognosis by Integrative Bioinformatics Analysis

INTRODUCTION

Breast cancer being a multifaceted disease constitutes a wide spectrum of histological and molecular variability in tumors. However, the task for the identification of these variances is complicated by the interplay between inherited genetic and epigenetic aberrations. Therefore, this study provides an extrapolate outlook to the sinister partnership between DNA methylation and single-nucleotide polymorphisms (SNPs) in relevance to the identification of prognostic markers in breast cancer. The effect of these SNPs on methylation is defined as methylation quantitative trait loci (meQTL).

MATERIALS AND METHODS

We developed a novel method to identify prognostic gene signatures for breast cancer by integrating genomic and epigenomic data. This is based on the hypothesis that multiple sources of evidence pointing to the same gene or pathway are likely to lead to reduced false positives. We also apply random resampling to reduce overfitting noise by dividing samples into training and testing data sets. Specifically, the common samples between Illumina 450 DNA methylation, Affymetrix SNP array, and clinical data sets obtained from the Cancer Genome Atlas (TCGA) for breast invasive carcinoma (BRCA) were randomly divided into training and test models. An intensive statistical analysis based on log-rank test and Cox proportional hazard model has established a significant association between differential methylation and the stratification of breast cancer patients into high- and low-risk groups, respectively.

RESULTS

The comprehensive assessment based on the conjoint effect of CpG–SNP pair has guided in delaminating the breast cancer patients into the high- and low-risk groups. In particular, the most significant association was found with respect to cg05370838–rs2230576, cg00956490–rs940453, and cg11340537–rs2640785 CpG–SNP pairs. These CpG–SNP pairs were strongly associated with differential expression of ADAM8, CREB5, and EXPH5 genes, respectively. Besides, the exclusive effect of SNPs such as rs10101376, rs140679, and rs1538146 also hold significant prognostic determinant.

CONCLUSIONS

Thus, the analysis based on DNA methylation and SNPs have resulted in the identification of novel susceptible loci that hold prognostic relevance in breast cancer.

The biological significance of methylome differences in human papilloma virus associated head and neck cancer

In recent years, studies have suggested that promoter methylation in human papilloma virus (HPV) positive head and neck squamous cell carcinoma (HNSCC) has a mechanistic role and has the potential to improve patient survival. The present study aimed to replicate key molecular findings from previous analyses of the methylomes of HPV positive and HPV negative HNSCC in an independent cohort, to assess the reliability of differentially methylated markers in HPV-associated tumors. HPV was measured using real-time quantitative PCR and the biological significance of methylation differences was assessed by Ingenuity Pathway Analysis (IPA). Using an identical experimental design of a 450K methylation platform, 7 of the 11 genes were detected to be significantly differentially methylated and all 11 genes were either hypo- or hypermethylated, which was in agreement with the results of a previous study. IPA's enriched networks analysis identified one network with msh homeobox 2 (MSX2) as a central node. Locally dense interactions between genes in networks tend to reflect significant biology; therefore MSX2 was selected as an important gene. Sequestration in the top four canonical pathways was noted for 5-hydroxytryptamine receptor 1E (serotonin signaling), collapsin response mediator protein 1 (semaphorin signaling) and paired like homeodomain 2 (bone morphogenic protein and transforming growth factor-β signaling). Placement of 9 of the 11 genes in highly ranked pathways and bionetworks identified key biological processes to further emphasize differences between HNSCC HPV positive and negative pathogenesis.