/ / EN
JOINT WEBSITE OF THE HONG KONG THORACIC SOCIETY AND THE CHEST DELEGATION HONG KONG AND MACAU
back to home

2002

2002 Promoter Hypermethylation of the Ras – association Domain Family 1A (RASSF1A) Gene in NSCLC in HK Chinese

Dr Lam Chi-Ieung, Queen Mary Hospital

Abstract Background
Lung cancer is a major cause of cancer deaths, in both sexes and both smokers and non-smokers. Surgery offers the only chance of cure for resectable tumour. For unresectable or advanced lung cancer, chemoirradiation are not curative but can be used for symptom palliation; but the response rate is suboptimal, only 30 - 40% at best. Investigation into new therapeutic strategy is urgently needed. Study into the molecular abnormalities of lung cancer would help improve our understanding on the pathogenesis and may offer insight into new potential therapeutic target in lung cancer. Loss of genetic material from chromosome 3p21.3 is a common phenomenon in lung cancer. One gene located on this region has a predicted Ras-association domain and homology to the Ras-effecter homologue. Methylation of CpG islands of promoter regions of this RASSFIA gene, leading to loss of gene transcription and expression, could be one stage involved in the multi-step carcinogenesis in NSCLC.

Aim
To investigate the pattern and presence of promoter hypermethylation of the RASSFIA gene in primary NSCLC and the correlation of such changes with characteristics, such as gender, smoking history and histopathological changes to look for potential molecular-c1inico-pathologicalrelation.

Method
The study will involve both (1) Molecular laboratory processing ofNSCLC tumour tissue by means of genomic DNA extraction, bisulphite reaction, methylation specific-polymerase chain reaction (MS-PCR); and (2) Review and correlation of methylation data with corresponding patient's demographic data.

Results
Promotor hypermethylation of the RASSFIA gene is present in at least 57.8% of our lung cancer specimens. Among 98 adenocarcinoma cases, 57/98 (58.2%) were methylated. No statistically significant relationship was found between the methylation status and sex, smoking history and histological subtypes.

Conclusion
Promotor hypermethylation of the RASSFIA gene is a commonly observed phenomenon in NSCLC in our patients. There is no statistical significance found in the methylation status of this gene between sexes, smoking habit and also histological subtypes.

Top