OBJECTIVEThis article aims to review recent studies on the biological characteristics of long non-coding RNAs (lncRNAs), transcription regulation by lncRNAs, and the results of recent studies on the mechanism of action of lncRNAs in tumor development.

DATA SOURCESThe data cited in this review were mainly obtained from the articles listed in PubMed and HighWire that were published from January 2002 to June 2010. The search terms were "long non-coding RNA", "gene regulation", and "tumor".

STUDY SELECTIONThe mechanism of lncRNAs in gene expression regulation, and tumors concerned with lncRNAs and the role of lncRNAs in oncogenesis.

RESULTSlncRNAs play an important role in transcription regulation by controlling chromatin remodeling, transcriptional control, and post-transcriptional controlling. lncRNAs are involved in many kinds of tumors and play key roles as both suppressing and promoting factors.

CONCLUSIONlncRNAs could perfectly regulate the balance of gene expression system and play important roles in oncogenic cellular transformation.

Animals ; Cell Transformation, Neoplastic ; genetics ; Gene Expression Regulation ; genetics ; physiology ; Humans ; Neoplasms ; genetics ; RNA, Untranslated ; genetics

Activating protein-2 (AP-2) is a cell type-specific DNA binding transcription factor family with the ability to regulate the expression of specific target genes. Five isoforms of AP-2 have been discovered, they are AP-2alpha, AP-2beta, AP-2gamma, AP-2delta and AP-2epsilon. AP-2s are involved in the regulation of cell proliferation, differentiation and apoptosis as well as embryogenesis of mammary animals. Recently, the function of AP-2 in neoplasm has attracted increasing attention. Researches reveal that the modulation of AP-2 in tumorigenesis may be dual, either inhibitory or promoting, which depends on the specific tissues,stages of cancer progression and difference between five family members. This review summarizes recent research progress on the role of AP-2 in the oncogenesis and their potential applications in clinical practice.
Animals ; Cell Transformation, Neoplastic ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Neoplasms ; etiology ; genetics ; Transcription Factor AP-2 ; genetics

OBJECTIVETo analyze the alteration in alternative polyadenylation (APA) sites of tumor-related genes in gastric cancer cells.

METHODSWe used 3'RACE to capture the APA sites of two tumor-related genes (HSP90α and SEC11A) in gastric cancer cell lines MKN45, MKN28 and AGS, and compared the results with annotated poly(A) sites in UCSC database.

RESULTSWe found new APA sites in the two tumor-related genes in gastric cancer cells to produce new mRNA isoforms with different 3'UTRs.

CONCLUSIONSThere are new mRNA isoforms of HSP90α and SEC11A derived from ATA in gastric cancer cells, which provides new insights into the mechanisms of gastric tumorigenesis.

Cell Line, Tumor ; Cell Transformation, Neoplastic ; Genes, Neoplasm ; Humans ; Polyadenylation ; Stomach Neoplasms ; genetics

Long non-coding RNA (lncRNA) is a hot topic in the field of researching tumor pathogenesis, and the importance in hematologic malignancies has been gradually being elucidated. LncRNA not only regulates hematological tumorigenesis and progression through affecting various biological processes such as cell proliferation, differentiation, pluripotency and apoptosis; moreover, abnormal expression and mutation of lncRNA are closely related to drug resistance and prognosis. Thus lncRNA can be used as novel biomarker and potential therapeutic target for hematological tumors. In this review, we will focus on the latest progress of lncRNA in hematological tumors to provide new ideas for the clinical diagnosis, prognostic evaluation together with research and development of target drugs for hematologic malignancies.
Humans ; RNA, Long Noncoding/metabolism* ; Hematologic Neoplasms/genetics* ; Neoplasms ; Carcinogenesis/pathology* ; Cell Transformation, Neoplastic/genetics* ; Gene Expression Regulation, Neoplastic

ObjectiveThe objective of the study was to summarize the role of DNA methylation in the development and metastasis of uveal melanoma (UM).

Data SourcesThe relevant studies in MEDLINE were searched.

Study SelectionIn this review, we performed a comprehensive literature search in MEDLINE using "uveal melanoma" AND ("DNA methylation" OR "epigenetics") for original research/review articles published before February 2018 on the relationship between DNA methylation and UM. References of the retrieved studies were also examined to search for potentially relevant papers.

ResultsPrevious studies on the relationship between DNA methylation and UM covered many genes including tumor suppressor genes (TSGs), cyclin-dependent kinase genes, and other genes. Among them, the TSG genes such as RASSF1A and p16INK4a, which encodes a cyclin-dependent kinase inhibitor, are relatively well-studied genes. Specifically, a high percentage of promoter methylation of RASSF1A was observed in UM cell lines and/or patients with UM. Promoter methylation of RASSF1A was also associated with the development of metastasis. Similarly, a high percentage of promoter hypermethylation of p16INK4a was found in UM cell lines. DNA promoter methylation can control the expression of p16INK4a, which affect cell growth, migration, and invasion in UM. Many other genes might also be involved in the pathogenesis of UM such as the Ras and EF-hand domain containing (RASEF) gene, RAB31, hTERT, embryonal fyn-associated substrate, and deleted in split-hand/split-foot 1.

ConclusionsOur review reveals the complex mechanisms underlying the tumorigenesis of UM and highlights the great needs of future studies to discover more genes/5'-C-phosphate-G-3' sites contributing to the development/metastasis of UM and explore the mechanisms through which epigenetic changes exert their function in UM.

Cell Transformation, Neoplastic ; genetics ; DNA Methylation ; genetics ; Epigenesis, Genetic ; genetics ; Humans ; Melanoma ; genetics ; Promoter Regions, Genetic ; genetics ; Uveal Neoplasms ; genetics

Myelodysplastic syndromes (MDS) are a group of clonal hematopioetic disorders characterized by myelodysplasia, decreased peripheral blood cells and high-risk of transformation into acute leukemia. MDS are often accompanied by a variety of chromosomal aberrations which play a role in disease pathogenesis, and are crucial in diagnosis and prognostic evaluation of this disease. About half of the patients with MDS have chromosomal abnormalities, mainly unbalanced chromosomal aberration. Different chromosomal aberration types are associated with different clinical outcome of this disease. Though balanced chromosomal translocations are not common in MDS, it seems that the patients with them have a higher leukemia transformation rate than those with other type of chromosomal aberrations. In this review, the chromosomal aberrations in MDS and their clinical significance for diagnosis and prognosis are briefly summarized.
Acute Disease ; Cell Transformation, Neoplastic ; Chromosome Aberrations ; Chromosome Disorders ; Humans ; Leukemia ; Myelodysplastic Syndromes ; genetics ; Prognosis

In order to elucidate the dynamic changes of oncogene expression in the sequential cascade of squamous metaplasia, dysplasia, and squamous cell carcinoma of the bronchial epithelium, hybridization in situ was employed with a biotinylated oncogene probe. The expression of c-myc was localized exclusively in nuclei. While normal bronchial epithelium revealed no discernible clumps of c-myc grains, except occasional grains less than 3 per cell, squamous metaplasia showed increased number of grains and a few clusters of c-myc grains. In dysplasia, c-myc expression was more intensive than in squamous metaplasia. Approximately, 1/3 to 2/3 of tumor cell populations of squamous cell carcinomas of the lung revealed tremendously increased c-myc expression. In addition clumpy grains of c-myc in squamous cell carcinoma appeared more frequently than in squamous metaplasia or dysplasia. The c-myc expression was found to vary between different samples and within each cancer, and not all cancer cells expressed c-myc. These data indicate that c-myc oncogene plays it's role on reprogramming for growth control of cell populations particularly in multistage carcinogenesis and progression of lung cancer. These dynamic alterations of c-myc expression suggest that neoplastic transformation may occur conceivably at the dysplastic phase eventually resulting in carcinoma in situ. This means, in turn, squamous dysplasia is a putative precancerous lesion of the human lung.
Bronchial Neoplasms/*genetics/pathology ; Carcinoma, Squamous Cell/*genetics/pathology ; Cell Transformation, Neoplastic/*genetics ; DNA ; Humans ; Metaplasia ; Nucleic Acid Hybridization ; *Oncogenes

Integrins are a family of transmembrane receptors that connect the extracellular matrix and actin skeleton, which mediate cell adhesion, migration, signal transduction, and gene transcription. As a bi-directional signaling molecule, integrins can modulate many aspects of tumorigenesis, including tumor growth, invasion, angiogenesis, metastasis, and therapeutic resistance. Therefore, integrins have a great potential as antitumor therapeutic targets. In this review, we summarize the recent reports of integrins in human hepatocellular carcinoma (HCC), focusing on the abnormal expression, activation, and signaling of integrins in cancer cells as well as their roles in other cells in the tumor microenvironment. We also discuss the regulation and functions of integrins in hepatitis B virus-related HCC. Finally, we update the clinical and preclinical studies of integrin-related drugs in the treatment of HCC.
Humans ; Integrins/metabolism* ; Carcinoma, Hepatocellular/genetics* ; Liver Neoplasms/genetics* ; Cell Adhesion ; Carcinogenesis ; Cell Transformation, Neoplastic ; Tumor Microenvironment

Owing to a unique set of attributes, human pluripotent stem cells (hPSCs) have emerged as a promising cell source for regenerative medicine, disease modeling and drug discovery. Assurance of genetic stability over long term maintenance of hPSCs is pivotal in this endeavor, but hPSCs can adapt to life in culture by acquiring non-random genetic changes that render them more robust and easier to grow. In separate studies between 12.5% and 34% of hPSC lines were found to acquire chromosome abnormalities over time, with the incidence increasing with passage number. The predominant genetic changes found in hPSC lines involve changes in chromosome number and structure (particularly of chromosomes 1, 12, 17 and 20), reminiscent of the changes observed in cancer cells. In this review, we summarize current knowledge on the causes and consequences of aneuploidy in hPSCs and highlight the potential links with genetic changes observed in human cancers and early embryos. We point to the need for comprehensive characterization of mechanisms underpinning both the acquisition of chromosomal abnormalities and selection pressures, which allow mutations to persist in hPSC cultures. Elucidation of these mechanisms will help to design culture conditions that minimize the appearance of aneuploid hPSCs. Moreover, aneuploidy in hPSCs may provide a unique platform to analyse the driving forces behind the genome evolution that may eventually lead to cancerous transformation.
Aneuploidy ; Animals ; Cell Differentiation ; Cell Transformation, Neoplastic ; genetics ; pathology ; Humans ; Neoplasms ; genetics ; pathology ; Pluripotent Stem Cells ; pathology

OBJECTIVETo investigate the expression of Yin Yang 1 (YY1) protein in human insulinoma and explore its clinical significance.

METHODSNineteen pancreatic neuroendocrine tumor tissue were collected from patients treated in Nanfang Hospital between 2000 and 2014. The protein expression of YY1 in benign and malignant insulinoma tissues were detected by immunohistochemistry.

RESULTSPositive expression for YY1 protein was detected in both benign and malignant tumor tissues, but the malignant tissues had a significantly greater intensity of YY1 expression than the benign tissues (P=0.042). The intensity of YY1 expression was positively correlated with the nature of the tumor, and the insulinomas with high expressions of YY1 had significantly greater malignant potentials (P=0.037).

CONCLUSIONThe high expression of YY1 protein is associated with the development of insulinima. YY1 may serve as a new tumor marker for detecting the malignant transformation of insulinoma.

Biomarkers, Tumor ; metabolism ; Cell Transformation, Neoplastic ; Humans ; Immunohistochemistry ; Insulinoma ; genetics ; metabolism ; Pancreatic Neoplasms ; genetics ; metabolism ; YY1 Transcription Factor ; genetics ; metabolism