The involvement of promoter methylation and DNA methyltransferase-1 in the regulation of EpCAM expression in oral squamous cell carcinoma

Oral Oncology ◽  
2009 ◽  
Vol 45 (1) ◽  
pp. e1-e8 ◽  
Author(s):  
Shine-Gwo Shiah ◽  
Long-Chang Chang ◽  
Kang-Yu Tai ◽  
Ghien-Hsing Lee ◽  
Cheng-Wen Wu ◽  
...  
2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Vikram Bhatia ◽  
Madhu Mati Goel ◽  
Annu Makker ◽  
Shikha Tewari ◽  
Alka Yadu ◽  
...  

Promoter methylation and relative gene expression of O6-methyguanine-DNA-methyltransferase (MGMT) andp16genes were examined in tissue and blood samples of patients with premalignant oral lesions (PMOLs) and oral squamous cell carcinoma (OSCC). Methylation-specific PCR and reverse transcriptase PCR were performed in 146 tissue and blood samples from controls and patients with PMOLs and OSCC. In PMOL group, significant promoter methylation ofMGMTandp16genes was observed in 59% (P=0.0010) and 57% (P=0.0016) of tissue samples, respectively, and 39% (P=0.0135) and 33% (P=0.0074) of blood samples, respectively. Promoter methylation of both genes was more frequent in patients with OSCC, that is, 76% (P=0.0001) and 82% (P=0.0001) in tissue and 57% (P=0.0002) and 70% (P=0.0001) in blood, respectively. Significant downregulation ofMGMTandp16mRNA expression was observed in both tissue and blood samples from patients with PMOLs and OSCC. Hypermethylation-induced transcriptional silencing ofMGMTandp16genes in both precancer and cancer suggests important role of these changes in progression of premalignant state to malignancy. Results support use of blood as potential surrogate to tissue samples for screening or diagnosing PMOLs and early OSCC.


2013 ◽  
Vol 28 (3) ◽  
pp. 298-302 ◽  
Author(s):  
Nisreen S. Alyasiri ◽  
Asgar Ali ◽  
Zakia Kazim ◽  
Sunita Gupta ◽  
Ashish K. Mandal ◽  
...  

Background and aims Oral cancer is the second most common cancer in men and accounts for 50%-70% of the total cancer mortality in India. PTEN is a tumor suppressor gene that plays a critical role in controlling cell growth and survival. Promoter hypermethylation of the PTEN gene has been reported in many tumors. However, little is known about the association between promoter methylation and oral squamous cell carcinoma (OSCC). Therefore, we aimed to detect the role of PTEN hypermethylation in OSCC patients in the Indian population. Methods Genomic DNA was isolated from 100 fresh oral tumor specimens and was subjected to bisulfite conversion. Methylation-specific PCR was employed on the converted DNA to investigate the methylation status. Results Of the total cases examined for PTEN promoter methylation we found that 35% were positive and 65% were negative. When evaluated in connection with tumor differentiation it was found that 82% of poorly differentiated, 24% of moderately differentiated and 32% of well differentiated OSCC samples were methylated. Methylation was further correlated with patient age, sex and tumor grade. Interestingly, we found that patient age and grade of differentiation were significantly associated with PTEN promoter methylation (p=0.05 and 0.0019, respectively) while sex was not (p=0.9). Conclusions The present study underlines the importance of PTEN hypermethylation among Indian OSCC patients.


2019 ◽  
Vol 2 (2) ◽  
pp. 99-105
Author(s):  
Nanan Nuraeny ◽  
Dzulfikal DL Hakim ◽  
Fransisca S Susilaningsih ◽  
Dewi MD Herawati

Pengaruh lingkungan eksternal pada gen manusia akan berpengaruh pada patogenesis penyakit, dan hal ini dapat diturunkan. Studi tentang perubahan gen fenotip yang diwariskan yang tidak disebabkan oleh perubahan urutan DNA disebut epigenetik. Salah satu mekanisme epigenetik adalah metilasi DNA yang penting dalam mengatur ekspresi gen. Ulasan ini akan menjelaskan studi tentang metilasi DNA pada mukosa mulut. Metode pencarian sistematis Google Scholar dan Pubmed dilakukan untuk semua studi dalam sepuluh tahun terakhir. Hasil pencarian mendapatkan sebanyak tujuh artikel dengan ukuran sampel yang bervariasi, 16 hingga 177 sampel, sebagian besar studi kasus-kontrol padaoral premalignan lesions (OPL), oral lichenoid disease (OLD), mucositis oral pada acute lymphoblactic leukemia (ALL), dan oral squamous cell carcinoma (OSCC). Metilasi DNA pada kanker mulut menunjukkan bahwa terdapat hipermetilasi beberapa gen, walaupun status metilasi DNA dalam beberapa kasus belum menunjukkan perbedaan yang signifikan antara gen yang diperiksa. Hasil penelitian lain menunjukkan bahwa tidak ada korelasi antara metilasi DNA dan perkembangan mukositis oral pada ALL yang menerima terapi metotreksat (MTX). Mekanisme metilasi DNA pada sel malignanadalah dengan menambahkan gugus metil ke sitosin dinukleotida di CpG (cytosine phosphate guanine) pada daerah promoter oleh enzim DNA methyltransferase sehingga dapat menghambat ekspresi beberapa gen terkait pertumbuhan sel, perbaikan DNA, dan penghambat metastasis. Metilasi DNA adalah biomarker penting dalam perkembangan penyakit mukosa mulut.


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