Methylation analysis of cancer-related genes in non-neoplastic cells from patients with oral squamous cell carcinoma

Abstract

Early detection of Oral Squamous Cell Carcinoma (OSCC) is important to reduce mortality rates and to help provide successful cancer treatment. Hypermethylation of CpG islands is a common epigenetic mechanism that leads to gene silencing in tumors and could be a useful biomarker in OSCC. Abnormal DNA hypermethylation can occur very early in cancer development and may be induced by exposure to environmental carcinogens. We set out to investigate the methylation status of cancer-related genes in normal oral exfoliated cells from OSCC patients and healthy volunteers, as well as possible associations with alcohol/tobacco exposure or specific tumor characteristics. The methylation status of CDKN2A (cyclin-dependent kinase inhibitor 2A or p16), SFN (stratifin or 14-3-3 σ), EDNRB (endothelin receptor B) and RUNX3 (runt-related transcript factor-3) was evaluated by MSP (Methylation-Specific Polymerase Chain Reaction) analysis in non-neoplastic oral epithelial cells from OSCC patients (n = 70) and cancer-free subjects (n = 41). Hypermethylation was observed in CDKN2A, EDNRB and SFN genes, whereas no methylation was found in the RUNX3 gene. CDKN2A hypermethylation occurred only in the OSCC group (5.7%) while SFN and EDNRB hypermethylation occurred in both groups. There was no association between hypermethylation and smoking, drinking habits or specific tumor characteristics.

Epigenetic mechanisms of chronic pain

“…These mechanisms include DNA methylation, several types of histone modifications (e.g., acetylation, methylation, phosphorylation, and ADP-ribosylation), and expression of microRNAs (miRNAs). Epigenetic mechanisms can be dynamic and responsive to changes in experience, thus representing a complex interplay between an organism and its environment [32, 33]. Acetylation of most histone subunits, at any of several Lysine (Lys) residues, typically promotes gene transcription, while histone methylation can either repress or activate gene transcription depending on the amino acid residue undergoing methylation.…”

“…Cancer is another leading cause of chronic pain [31], and hypermethylation of CpG islands, a common feature of cancer cells [32], has recently been implicated in cancer related chronic pain conditions [31]. Specifically, enhanced secretion of the peptide, endothelin 1, has been observed in multiple malignancies, and it is thought to have a major role in cancer induced pain [33].…”

Hypermethylation of EDNRB promoter contributes to the risk of colorectal cancer

“…For the PCR reaction, 2 μl of modified DNA was amplified in a 20 μl reaction containing 0.3 μM each of forward and reverse primers, 0.2 mM dNTPs, 10 × PCR Buffer and 2.5 U of Hot Start DNA Polymerase (Qiagen, Hilden, Germany) under the following conditions: 15 min of denaturation at 95°C followed by 35 cycles of 45 s at 94°C, 45 s at 62°C for methylated primers, 1 min at 72°C and a final extension for 10 min at 72°C. The sequences of methylated and unmethylated primers were given in the previous study [20] (Table 1). Water blank was used as a negative control.…”

Comparison of RNA Extraction Methods for Molecular Analysis of Oral Cytology

“…(7) za dijagnostiku cervikalnih neoplazija, a poslije je korištena u dijagnostici bolesti usne šupljine (8). Citološki uzorci mogu se promatrati u nekoliko pristupa primjenom qPCR-a, uvijek radi razumijevanja promjena tkiva (3,9,10),…”