scholarly journals Oncogenes - the basics

2018 ◽  
Vol 3 (4) ◽  
pp. 35-37
Author(s):  
Arnab Ghosh ◽  
Diasma Ghartimagar ◽  
Sushma Thapa
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Repair ◽  
Tumor Suppressor ◽  
Tumor Suppressor Genes ◽  
Normal Cell ◽  
Tumor Formation ◽  
Precursor Cell ◽  
Single Precursor ◽  
Normal Cell Cycle

Normal cell cycle and cell proliferation are regulated by several genes which can be broadly classified into 4 groups viz, proto-oncogenes, tumor suppressor genes, genes regulating apoptosis and genes involved in DNA repair. These genes may be defective due to different factors. The defective genes may lead to production of abnormal proteins which may lead to disruption of the normal cell cycle and proliferation. A single precursor cell with defective gene proliferates surpassing the normal physiologic regulatory process and leads to tumor formation, so, traditionally,it is said that “tumors are clonal”.

scholarly journals ING3 and ING4 immunoexpression and their relation to the development of benign odontogenic lesions

2021 ◽  
Vol 32 (4) ◽  
pp. 74-82
Author(s):  
Yailit del Carmen Martinez-Vargas ◽  
Tiago João da Silva-Filho ◽  
Denise Hélen Imaculada Pereira de Oliveira ◽  
Rani Iani Costa Gonçalo ◽  
Lélia Maria Guedes Queiroz
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Repair ◽  
Tumor Suppressor ◽  
Epithelial Cells ◽  
Gene Family ◽  
Tumor Suppressor Genes ◽  
Cell Cycle Control ◽  
P Value ◽  
Proliferation And Apoptosis

Abstract The Inhibitor of Growth (ING) gene family is a group of tumor suppressor genes that play important roles in cell cycle control, senescence, DNA repair, cell proliferation, and apoptosis. However, inactivation and downregulation of these proteins have been related in some neoplasms. The present study aimed to evaluate the immunohistochemical profiles of ING3 and ING4 proteins in a series of benign epithelial odontogenic lesions. Methods: The sample comprised of 20 odontogenic keratocysts (OKC), 20 ameloblastomas (AM), and 15 adenomatoid odontogenic tumors (AOT) specimens. Nuclear and cytoplasmic immunolabeling of ING3 and ING4 were semi-quantitatively evaluated in epithelial cells of the odontogenic lesions, according to the percentage of immunolabelled cells in each case. Descriptive and statistics analysis were computed, and the p-value was set at 0.05. Results: No statistically significant differences were found in cytoplasmic and nuclear ING3 immunolabeling among the studied lesions. In contrast, AOTs presented higher cytoplasmic and nuclear ING4 labeling compared to AMs (cytoplasmic p-value = 0.01; nuclear p-value < 0.001) and OKCs (nuclear p-value = 0.007). Conclusion: ING3 and ING4 protein downregulation may play an important role in the initiation and progression of more aggressive odontogenic lesions, such as AMs and OKCs.

scholarly journals MiR-5195-3p Functions as a Tumor Suppressor in Prostate Cancer via Targeting CCNL1

2020 ◽  
Author(s):  
Xing Zeng ◽  
Zhiquan Hu ◽  
Yuanqing Shen ◽  
Xian Wei ◽  
Jiahua Gan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Suppressor ◽  
Clinical Significance ◽  
Cox Regression ◽  
Tumor Formation ◽  
Luciferase Reporter ◽  
Cell Cycle Distribution ◽  
Survival Prognosis

Abstract BackgroundAccumulating evidence indicates miR-5195-3p exerts tumor suppressive role in several tumors. However, there is limited research on the clinical significance and biological function of miR-5195-3p in prostate cancer (PCa).MethodsExpression levels of miR-5195-3p and Cyclin L1 (CCNL1) were determined using quantitative real-time PCR. The clinical significance of miR-5195-3p in PCa patients was evaluated using Kaplan-Meier survival analysis and Cox regression models. Cell proliferation and cell cycle distribution were measured by CCK-8 assay and flow cytometry, respectively. The association between miR-5195-3p and CCNL1 was analyzed by luciferase reporter assay.ResultsMiR-5195-3p expression levels were significantly downregulated in 69 paired PCa tissues compared with matched adjacent normal tissues. The decreased miR-5195-3p expression was associated with Gleason score and TNM stage, as well as worse survival prognosis. The in vitro experiments showed that miR-5195-3p overexpression suppressed the proliferation and cell cycle G1/S transition in PC-3 and DU145 cells. Elevated miR-5195-3p abundance was also demonstrated to impair tumor formation in vivo using PC-3 xenografts. Mechanistically, Cyclin L1 (CCNL1) was a direct target of miR-5195-3p in PCa cells, which was inversely correlated with miR-5195-3p in PCa tissues. Importantly, CCNL1 knockdown imitated, while overexpression reversed the effects of miR-5195-3p overexpression on PCa cell proliferation and cell cycle G1/S transition.ConclusionsOur data suggests that miR-5195-3p functions as a tumor suppressor via downregulating G1/S related CCNL1 expression in PCa.

scholarly journals Potassium channels in cell cycle and cell proliferation

2014 ◽  
Vol 369 (1638) ◽  
pp. 20130094 ◽  
Author(s):  
Diana Urrego ◽  
Adam P. Tomczak ◽  
Farrah Zahed ◽  
Walter Stühmer ◽  
Luis A. Pardo
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Potassium Channels ◽  
Normal Cell ◽  
Cell Cycle Progression ◽  
Cell Cycle Control ◽  
Control Mechanisms ◽  
Cycle Progression ◽  
Uncontrolled Cell Proliferation ◽  
Normal Cell Cycle

Normal cell-cycle progression is a crucial task for every multicellular organism, as it determines body size and shape, tissue renewal and senescence, and is also crucial for reproduction. On the other hand, dysregulation of the cell-cycle progression leading to uncontrolled cell proliferation is the hallmark of cancer. Therefore, it is not surprising that it is a tightly regulated process, with multifaceted and very complex control mechanisms. It is now well established that one of those mechanisms relies on ion channels, and in many cases specifically on potassium channels. Here, we summarize the possible mechanisms underlying the importance of potassium channels in cell-cycle control and briefly review some of the identified channels that illustrate the multiple ways in which this group of proteins can influence cell proliferation and modulate cell-cycle progression.

scholarly journals p53 connects tumorigenesis and reprogramming to pluripotency

2010 ◽  
Vol 207 (10) ◽  
pp. 2045-2048 ◽  
Author(s):  
Natalia Tapia ◽  
Hans R. Schöler
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Tumor Suppressor ◽  
Cell Cycle Arrest ◽  
Suppressor Gene ◽  
Tumor Formation ◽  
Nuclear Reprogramming ◽  
Differentiation Process ◽  
Cycle Arrest ◽  
Tumor Suppressor Gene P53

The tumor suppressor gene p53 prevents the initiation of tumor formation by inducing cell cycle arrest, senescence, DNA repair, and apoptosis. Recently, the absence or mutation of p53 was described to facilitate nuclear reprogramming. These findings suggest an influence of p53 on the de-differentiation process, and highlight the similarities between induction of pluripotency and tumor formation.

scholarly journals Transposon Mutagenesis-Guided CRISPR/Cas9 Screening Strongly Implicates Dysregulation of Hippo/YAP Signaling in Malignant Peripheral Nerve Sheath Tumor Development

Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1584
Author(s):  
Germán L. Vélez-Reyes ◽  
Nicholas Koes ◽  
Ji Hae Ryu ◽  
Gabriel Kaufmann ◽  
Mariah Berner ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Schwann Cell ◽  
Peripheral Nerve ◽  
Cell Line ◽  
Schwann Cells ◽  
Tumor Suppressor Genes ◽  
Tumor Formation ◽  
Loss Of Function ◽  
Suppressor Genes ◽  
Nerve Sheath

Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive, genomically complex, have soft tissue sarcomas, and are derived from the Schwann cell lineage. Patients with neurofibromatosis type 1 syndrome (NF1), an autosomal dominant tumor predisposition syndrome, are at a high risk for MPNSTs, which usually develop from pre-existing benign Schwann cell tumors called plexiform neurofibromas. NF1 is characterized by loss-of-function mutations in the NF1 gene, which encode neurofibromin, a Ras GTPase activating protein (GAP) and negative regulator of RasGTP-dependent signaling. In addition to bi-allelic loss of NF1, other known tumor suppressor genes include TP53, CDKN2A, SUZ12, and EED, all of which are often inactivated in the process of MPNST growth. A sleeping beauty (SB) transposon-based genetic screen for high-grade Schwann cell tumors in mice, and comparative genomics, implicated Wnt/β-catenin, PI3K-AKT-mTOR, and other pathways in MPNST development and progression. We endeavored to more systematically test genes and pathways implicated by our SB screen in mice, i.e., in a human immortalized Schwann cell-based model and a human MPNST cell line, using CRISPR/Cas9 technology. We individually induced loss-of-function mutations in 103 tumor suppressor genes (TSG) and oncogene candidates. We assessed anchorage-independent growth, transwell migration, and for a subset of genes, tumor formation in vivo. When tested in a loss-of-function fashion, about 60% of all TSG candidates resulted in the transformation of immortalized human Schwann cells, whereas 30% of oncogene candidates resulted in growth arrest in a MPNST cell line. Individual loss-of-function mutations in the TAOK1, GDI2, NF1, and APC genes resulted in transformation of immortalized human Schwann cells and tumor formation in a xenograft model. Moreover, the loss of all four of these genes resulted in activation of Hippo/Yes Activated Protein (YAP) signaling. By combining SB transposon mutagenesis and CRISPR/Cas9 screening, we established a useful pipeline for the validation of MPNST pathways and genes. Our results suggest that the functional genetic landscape of human MPNST is complex and implicate the Hippo/YAP pathway in the transformation of neurofibromas. It is thus imperative to functionally validate individual cancer genes and pathways using human cell-based models, to determinate their role in different stages of MPNST development, growth, and/or metastasis.

scholarly journals ZIC1 Is a Putative Tumor Suppressor in Thyroid Cancer by Modulating Major Signaling Pathways and Transcription Factor FOXO3a

2014 ◽  
Vol 99 (7) ◽  
pp. E1163-E1172 ◽  
Author(s):  
Wei Qiang ◽  
Yuan Zhao ◽  
Qi Yang ◽  
Wei Liu ◽  
Haixia Guan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Transcription Factor ◽  
Thyroid Cancer ◽  
Tumor Suppressor ◽  
Cancer Cells ◽  
Colony Formation ◽  
Promoter Hypermethylation ◽  
Migration And Invasion ◽  
Thyroid Cancer Cells

Context: ZIC1 has been reported to be overexpressed and plays an oncogenic role in some brain tumors, whereas it is inactivated by promoter hypermethylation and acts as a tumor suppressor in gastric and colorectal cancers. However, until now, its biological role in thyroid cancer remains totally unknown. Objectives: The aim of this study is to explore the biological functions and related molecular mechanism of ZIC1 in thyroid carcinogenesis. Setting and Design: Quantitative RT-PCR (qRT-PCR) was performed to evaluate mRNA expression of investigated genes. Methylation-specific PCR was used to analyze promoter methylation of the ZIC1 gene. The functions of ectopic ZIC1 expression in thyroid cancer cells were determined by cell proliferation and colony formation, cell cycle and apoptosis, as well as cell migration and invasion assays. Results: ZIC1 was frequently down-regulated by promoter hypermethylation in both primary thyroid cancer tissues and thyroid cancer cell lines. Moreover, our data showed that ZIC1 hypermethylation was significantly associated with lymph node metastasis in patients with papillary thyroid cancer. Notably, restoration of ZIC1 expression in thyroid cancer cells dramatically inhibited cell proliferation, colony formation, migration and invasion, and induced cell cycle arrest and apoptosis by blocking the activities of the phosphatidylinositol-3-kinase (PI3K)/Akt and RAS/RAF/MEK/ERK (MAPK) pathways, and enhancing FOXO3a transcriptional activity. Conclusions: Our data demonstrate that ZIC1 is frequently inactivated by promoter hypermethyaltion and functions as a tumor suppressor in thyroid cancer through modulating PI3K/Akt and MAPK signaling pathways and transcription factor FOXO3a.

scholarly journals Modification of Epigenetic Histone Acetylation in Hepatocellular Carcinoma

Cancers ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 8 ◽  
Author(s):  
Kwei-Yan Liu ◽  
Li-Ting Wang ◽  
Shih-Hsien Hsu
Keyword(s):  
Hepatocellular Carcinoma ◽  
Tumor Suppressor ◽  
Tumor Suppressor Genes ◽  
Chemical Sensor ◽  
Enzyme Level ◽  
Tumor Therapy ◽  
Tumor Formation ◽  
Current Evidence ◽  
Epigenetic Changes ◽  
Suppressor Genes

Cells respond to various environmental factors such as nutrients, food intake, and drugs or toxins by undergoing dynamic epigenetic changes. An imbalance in dynamic epigenetic changes is one of the major causes of disease, oncogenic activities, and immunosuppressive effects. The aryl hydrocarbon receptor (AHR) is a unique cellular chemical sensor present in most organs, and its dysregulation has been demonstrated in multiple stages of tumor progression in humans and experimental models; however, the effects of the pathogenic mechanisms of AHR on epigenetic regulation remain unclear. Apart from proto-oncogene activation, epigenetic repressions of tumor suppressor genes are involved in tumor initiation, procession, and metastasis. Reverse epigenetic repression of the tumor suppressor genes by epigenetic enzyme activity inhibition and epigenetic enzyme level manipulation is a potential path for tumor therapy. Current evidence and our recent work on deacetylation of histones on tumor-suppressive genes suggest that histone deacetylase (HDAC) is involved in tumor formation and progression, and treating hepatocellular carcinoma with HDAC inhibitors can, at least partially, repress tumor proliferation and transformation by recusing the expression of tumor-suppressive genes such as TP53 and RB1.

Nucleoside diphosphokinase, an enzyme with step changes in activity during the cell cycle of the fission yeast Schizosaccharomyces pombe. I. Persistence of steps after a block to the DNA-division cycle

1986 ◽  
Vol 86 (1) ◽  
pp. 207-215
Author(s):  
J. Creanor ◽  
J.M. Mitchison
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Normal Cell ◽  
Normal Cell Cycle

In confirmation of earlier results, nucleoside diphosphokinase is shown to be a ‘step’ enzyme in Schizosaccharomyces pombe with a sharp doubling in activity at the beginning of the cell cycle. These doubling steps occur at the same time in the cycle in the smaller cells of the mutant wee1.6. An important result is that the activity steps persist with normal cell cycle timing after a block to the DNA-division cycle imposed by the cycle mutants cdc2.33 and cdc2.33wee1.6. This is clear proof that oscillatory controls of some cell cycle events can persist after the main periodic events of the DNA-division cycle have been abolished.

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