Alteration of the p53 and Rb tumor suppressor pathways by p16/INK4a and p14/ARF promoter methylation and loss of protein expression in recurrent and nonrecurrent meningiomas.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 2064-2064
Author(s):  
Juan Carlos Martinez ◽  
Santiago Ropero ◽  
Concepcion Mateos ◽  
Maria DEL VAL Toledo ◽  
Rafael Samaniego ◽  
...  

2064 Background: Promoter methylation inactivates tumor suppressor genes (TSG). The INK4a/ARF locus encodes p16INKa and p14ARF cell cycle regulatory proteins, which control Rb and p53 TSG pathways. Most meningiomas are slow growing tumors, but in spite of complete surgical removal, the recurrence rate at 5 years is 5%, rising to 19% in long-term follow-up. However, there are no markers predictive of this evolution. Epigenetic changes in low-grade meningiomas have not been previously addressed. To get insights into the possible role of p16INK4a and p14ARF TSG alterations in grade 1 meningiomas, we study the methylation status and protein expression of these genes in 140 specimens of meningiomas: 29 nonrecurrent and 57 recurrent in one, two or three times. Methods: Methylation specific PCR and bisulfate modification followed by bisulfate genomic sequencing of CpG islands and staining with p16INKa and p14ARF antibodies (Ab’s). Results: Our data show p16INK4a and p14ARF methylation in 43.4% and14.2% meningiomas respectively. Methylation of p16INK4a is found in a similar proportion in non-recurrent meningiomas (37.9%) and the first biopsy of recurrent cases (38.8%) and increases to a 52.3% in successive biopsies of recurrent cases. Methylation of p14ARF occurs in 13.8% of nonrecurrent vs. 9.6% recurrent meningiomas (first biopsy) and 19.6% of successive recurrent meningiomas. Loss of p16INK4a and p14ARF protein expression was shown in 52.7% and 18.6% of meningiomas respectively. p16INK4a and p14ARF methylation was associated with loss of protein expression in 54.7% and 18.8% of meningiomas. Loss of p16INK4a and p14ARF expression was associated with unmethylated promoters in 52.9% and 17.6% of cases respectively. Conclusions: Epigenetic changes of p16INK4a and p14ARF genes and loss of protein expression leading to Rb and p53 TSG pathways alterations, may have a pathogenic role in human meningiomas. Loss of p16INK4a and p14ARF protein expression associated with unmethylated promoters, could be due to loss of heterozigosity or gen mutation. Increase of p16INK4a and p14ARF methylation along the following biopsies of recurrent cases suggests a possible role of methylation in tumor progression.

2020 ◽  
Author(s):  
Mohammad Amin Kerachian ◽  
Sahar Tavakolian ◽  
Matineh Barati Bagherabad ◽  
Dor Mohammad Kordi-Tamandani ◽  
Mohammad Reza Abbaszadegan

Aberrant promoter methylation of CpG islands of tumor-suppressor genes has been recognized as one of the important tumor markers for cancer detection. The aim of this study was to investigate the promoter methylation status of protocadherin 10 (PCDH10), a tumor suppressor gene, in Iranian colorectal cancer (CRC) patients. Cancerous and the adjacent normal tissues obtained from 38 CRC patients were used to assess the methylation status of PCDH10 with Methylation Specific PCR, in addition, to study the expression level of this gene by quantitative PCR. The relationship between hypermethylation and the demographic characteristics of these patients was analyzed. The promoter methylation level of PCDH10 was statistically different between tumoral and normal tissues in CRC patients. Twenty-seven out of 38 patients showed hypermethylation with a sensitivity of 73% and a specificity of 97%. PCDH10 expression decreased in 15 cases (46%) as 16 cases (50 %) showed overexpression and 1 case (4%) had no changes. Not a significant association was reported between PCDH10 hypermethylation and the clinicopathological characteristics (P>0.05). Our results indicated that PCDH10 methylation has a critical function in CRC, with a nearly elevated sensitivity and a high specificity in the Iranian population, qualify it as a potential candidate biomarker. © 2019 Tehran University of Medical Sciences. All rights reserved. Acta Med Iran 2019;57(8):472-477.


2021 ◽  
Vol 6 (2) ◽  
pp. 155-160
Author(s):  
Suddhasattwa Ray ◽  
Mona Malekzadehmoghani ◽  
Sonia S Ray ◽  
Partha Sen ◽  
Sayan Chakraborty

Background: RIZ1 is one of the tumor-suppressor genes that is silenced in many human cancers. Change in RIZ1 expression has not been reported in ESCC patients. Therefore, the aim of this study was to investigate the role of RIZ1 in ESCC in the Indian population. Methods: Twelve esophageal squamous-cell carcinoma (ESCC) patients in stage IV and 12 healthy individuals were used in this study. Tissue sampling was taken from individuals and total RNA was isolated and then cDNA was synthesized using PCR. RIZ1 primers were then designed, and RIZ1 expression was quantified by qRT-PCR. Mapping of CpG islands in RIZ1 promoter was performed using bioinformatics tools. The promoter methylation status of this gene was studied using u methylation-specific PCR (MSP). T-student test was used to analyze the data.Results: Decreased RIZ1 expression was observed in ESCC compared with healthy controls. The results showed a relatively higher density of CpG dinucleotides in the RIZ1 promoter. No significant difference in promoter methylation was observed in blood and tissue samples.Conclusion: The study showed a significant down-regulation of RIZ-1 gene in the blood and tissue samples of ESCC patients that did not related to the altered promoter methylation.


Author(s):  
Bonnie C Carney ◽  
Ryan D Dougherty ◽  
Lauren T Moffatt ◽  
Cynthia M Simbulan-Rosenthal ◽  
Jeffrey W Shupp ◽  
...  

Abstract Burn injuries frequently result in hypertrophic scars (HTSs), specifically when excision and grafting are delayed due to limited resources or patient complications. In patient populations with dark baseline pigmentation, one symptom of HTS that often occurs is dyspigmentation. The mechanism behind dyspigmentation has not been explored, and, as such, prevention and treatment strategies for this morbidity are lacking. The mechanism by which cells make pigment is controlled at the apex of the pathway by pro-opiomelanocortin (POMC), which is cleaved to its products alpha-melanocyte-stimulating hormone (α-MSH) and adrenocorticotropin hormone (ACTH). α-MSH and ACTH secreted by keratinocytes bind to melanocortin 1 receptor (MC1R), expressed on melanocytes, to initiate melanogenesis. POMC protein expression is upregulated in hyperpigmented scar compared to hypopigmented scar by an unknown mechanism in a Duroc pig model of HTS. POMC RNA levels, as well as the POMC gene promoter methylation status were investigated as a possible mechanism. DNA was isolated from biopsies obtained from distinct areas of hyper- or hypopigmented scar and normal skin. DNA was bisulfite-converted, and amplified using two sets of primers to observe methylation patterns in two different CpG islands near the POMC promoter. Amplicons were then sequenced and methylation patterns were evaluated. POMC gene expression was significantly downregulated in hypopigmented scar compared to normal skin, consistent with previously reported protein expression levels. There were significant changes in methylation of the POMC promoter; however, none that would account for the development of hyper- or hypopigmentation. Future work will focus on other areas of POMC transcriptional regulation.


2010 ◽  
Vol 55 (12) ◽  
pp. 3449-3457 ◽  
Author(s):  
Tomomitsu Tahara ◽  
Tomoyuki Shibata ◽  
Masakatsu Nakamura ◽  
Hiromi Yamashita ◽  
Daisuke Yoshioka ◽  
...  

2012 ◽  
Vol 27 (4) ◽  
pp. 389-394 ◽  
Author(s):  
Annamaria La Torre ◽  
Lucia Anna Muscarella ◽  
Paola Parrella ◽  
Teresa Balsamo ◽  
Michele Bisceglia ◽  
...  

Disturbances in the epigenetic landscape by aberrant methylation of CpG islands can lead to inactivation of cancer-related genes in solid tumors. We analyzed the promoter methylation status of 6 genes previously reported as cancer-specific methylated (MCAM, SSBP2, NISCH, B4GALT1, KIF1A and RASSF1A) in 38 neural crest-derived tumors by quantitative methylation-specific real-time PCR (QMSP). The results demonstrated that the determination of the methylation status of RASSF1A is able to distinguish between normal and tumor samples in cutaneous melanomas, lung carcinoids and small bowel carcinoids. MCAM methylation levels were significantly higher in lung carcinoids tumors (p=0.001), suggesting that this alteration may represent a molecular biomarker in this tumor type.


PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0134687 ◽  
Author(s):  
Farman Ullah ◽  
Taimoor Khan ◽  
Nawab Ali ◽  
Faraz Arshad Malik ◽  
Mahmood Akhtar Kayani ◽  
...  

Author(s):  
Sha Sumei ◽  
Kong Xiangyun ◽  
Chen Fenrong ◽  
Sun Xueguang ◽  
Hu Sijun ◽  
...  

Background/AimsThe role of DHRS3 in human cancer remains unclear. Our study explored the role of DHRS3 in gastric cancer (GC) and its clinicopathological significance and associated mechanisms.MaterialsBisulfite-assisted genomic sequencing PCR and a Mass-Array system were used to evaluate and quantify the methylation levels of the promoter. The expression levels and biological function of DHRS3 was examined by both in vitro and in vivo assays. A two-way hierarchical cluster analysis was used to classify the methylation profiles, and the correlation between the methylation status of the DHRS3 promoter and the clinicopathological characteristics of GC were then assessed.ResultsThe DHRS3 promoter was hypermethylated in GC samples, while the mRNA and protein levels of DHRS3 were significantly downregulated. Ectopic expression of DHRS3 in GC cells inhibited cell proliferation and migration in vitro, decreased tumor growth in vivo. DHRS3 methylation was correlated with histological type and poor differentiation of tumors. GC patients with high degrees of CpG 9.10 methylation had shorter survival times than those with lower methylation.ConclusionDHRS3 was hypermethylated and downregulated in GC patients. Reduced expression of DHRS3 is implicated in gastric carcinogenesis, which suggests DHRS3 is a tumor suppressor.


2017 ◽  
Vol 16 (4) ◽  
pp. 38-45
Author(s):  
D. A. Ryabchikov ◽  
I. K. Vorotnikov ◽  
T. P. Kazubskaya ◽  
S. S. Lukina ◽  
E. A. Filippova ◽  
...  

Background. Epigenetic changes of TSG are supposed as the most fine and active genes regulation mechanism in particular breast cancer (BC) genes pathway development. The most valuable results are awaited for methylation role of genes located on the short arm of chromosome 3 with also MGMT gene (10q26) in BC pathogenesis because of their ambiguous data for methylation status in tumors. Objective: to illustrate the specific methylation role of the RASSF1A, SEMA3B, RARß2, RHOA, GPX1, USP4, DAG1, NKIRAS1 and MGMT genes promoter regions in BC pathogenesis. Materials and methods. Sample set of 174 BC patients consists of tumor and surrounding histologically normal tissue that were collected and clinically characterized in the N.N. Blokhin National Medical Research Center of Oncology. Two substantive methods were used to evaluate DNA methylation status. To analyse RASSF1A, SEMA3B, RARß2 and MGMT genes methylation we used polymerase chain reaction specific for the methylated allele. Whereas for analyses RHOA, GPX1, USP4, DAG1, NKIRAS1 promoter regions genes methylation status was used methyl sensitive restriction analyses with 2 methyl sensitive endonuclaeses HpaII and HhaI with subsequent polymerase chain reaction. Results. A statistically significant high frequency of RASSF1A, SEMA3B, RARß2, and MGMT genes methylation in epithelial breast tumors compared with histologically normal tissue from the same patients was shown. Significant correlation of RARß2 and MGMT genes methylation frequency considering the different clinical and morphological characteristics of the malignant process was revealed. The statistically significant relationship between methylation of RASSF1A, RARß2 and MGMT genes and patient survival is shown for the first time. Conclusion. The findings of epigenetic changes in the luminal BC supplement the “molecular picture” of this cancer and contribute to an understanding of its pathogenesis. The revealed features of investigated genes methylation can find clinical application for the development of modern approaches to prognosis, prevention and choice of tactics for treatment of BC in females of the Moscow region.


2017 ◽  
Vol 23 (2) ◽  
pp. 17-19
Author(s):  
Aleksandra Nikolic ◽  
Filip Opincal ◽  
Momcilo Ristanovic ◽  
Jovanka Trifunovic ◽  
Srbislav Knezevic ◽  
...  

Background. Promoter hypermethylation of the SMAD4 gene has been registered in some cancer types, but in general doesn?t appear to be a frequent event in carcinogenesis. However, only a few published studies deal with this topic and not many cancer types have been analyzed. The aim of this study was to establish SMAD4 gene promoter methylation status in pancreatic and endometrial cancers. Methods. Patients included in the study (62 subjects) were diagnosed and surgically treated at the University of Belgrade, Clinical Center of Serbia. Patients with pancreatic carcinoma (17 subjects) underwent surgical removal of the pancreatic adenocarcinoma at the First Surgical Clinic, while the patients with endometrial carcinoma (45 subjects) underwent hysterectomy with adnexectomy at the Institute for Gynecology and Obstetrics. Extraction of DNA from fresh tissue samples was performed and the methylation status of the SMAD4 gene promoter was studied by a previously designed PCR-based HpaII and MspI restriction enzyme assay. The resulting PCR products were analyzed by electrophoresis in 2% agarose gels. Results. Neither of the analyzed samples was found to be hypermethylated. Conclusion. This is the first report on SMAD4 methylation status in pancreatic and endometrial tumor specimens, and supports the viewpoint that SMAD4 hypermethylation is not a common event in malignant tumors. Nevertheless, promoter hypermethylation remains a candidate mechanism for SMAD4 inactivation in malignant tissue as a potential cause of decreased or lost SMAD4 expression in certain tumor types, and should be further investigated in different tumor types and larger cohorts of patients.


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