Genetic alteration and expression of ING1 in human lung carcinoma
- Author:
Zhi-Gang LUO
1
Author Information
1. Department of Pathology
- Publication Type:Journal Article
- Keywords:
Gene expression;
Genes, ING1;
Immunohistochemistry;
LOH;
Lung neoplasms;
Tissue Microarray
- From:
Tumor
2007;27(5):393-397
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To detect the loss of heterozygosity (LOH) of ING1 gene microsatellite and the expression of p33ING1b protein in lung carcinoma and to investigate their association with the carcinogenesis of lung cancer. Methods: Seventy cases of fresh-frozen lung cancers and 217 cases formalin-fixed, paraffin-embedded specimens were examined. The LOH frequency of ING1 gene microsatellite was detected by polymerase chain reaction-single strand conformation polymorphisms (PCR-SSCP) method. The expression of p33ING1b protein was determined by immunohistochemical method and tissue microarray technology. Results: The total LOH frequency of four microsatellites of ING1 gene was 55.7% (39/70) in lung carcinomas. The LOH had higher frequency if it was closer to the ING1 locus. But the LOH frequency had no correlation with clinicopathological parameters. The total LOH frequency of p33ING1b protein was 47.0% (102/217) in lung carcinomas. The positivity of p33ING1b in squamous carcinoma was significantly higher than that in adenocarcinoma (AC), adenosquamous carcinoma (AdCa), and bronchioloalveolar carcinoma (BAC) (P <0.05), while there was no significant difference between AC, AdCa, and BAC. The expression of p33ING1b protein was not associated with the clinicopathological characteristics but a negative correlation with LOH frequency was observed (P <0.05). Conclusion: There existes higher frequency of low expression or deletion of ING1 protein in lung carcinoma tissues. The LOH of ING1 gene microsatellites also have a higher frequency. LOH is one of the important reasons for the abnormal expression of ING1 gene, which causes the down-regulation of ING1 gene and inactivation of ING1 protein. Finally ING looses its inhibitory effect on the growth of tumor cells and results in carcinogenesis of lung cancer.
