High O6-methylguanine methyl transferase activity is frequently found in human oral cancer cells with p53 inactivation.

Guo,W; Liu,X; Lee,S; Park,N H

doi:10.3892/ijo.15.4.817

Oct 1999 Volume 15 Issue 4

Full Size Image

Cover Legend PDF

Journals

International Journal of Molecular Medicine

International Journal of Molecular Medicine is an international journal devoted to molecular mechanisms of human disease.

International Journal of Oncology

International Journal of Oncology is an international journal devoted to oncology research and cancer treatment.

Molecular Medicine Reports

Covers molecular medicine topics such as pharmacology, pathology, genetics, neuroscience, infectious diseases, molecular cardiology, and molecular surgery.

Oncology Reports

Oncology Reports is an international journal devoted to fundamental and applied research in Oncology.

Experimental and Therapeutic Medicine

Experimental and Therapeutic Medicine is an international journal devoted to laboratory and clinical medicine.

Oncology Letters

Oncology Letters is an international journal devoted to Experimental and Clinical Oncology.

Biomedical Reports

Explores a wide range of biological and medical fields, including pharmacology, genetics, microbiology, neuroscience, and molecular cardiology.

Molecular and Clinical Oncology

International journal addressing all aspects of oncology research, from tumorigenesis and oncogenes to chemotherapy and metastasis.

World Academy of Sciences Journal

Multidisciplinary open-access journal spanning biochemistry, genetics, neuroscience, environmental health, and synthetic biology.

International Journal of Functional Nutrition

Open-access journal combining biochemistry, pharmacology, immunology, and genetics to advance health through functional nutrition.

International Journal of Epigenetics

Publishes open-access research on using epigenetics to advance understanding and treatment of human disease.

Medicine International

An International Open Access Journal Devoted to General Medicine.

Oct 1999 Volume 15 Issue 4

Full Size Image

Cover Legend PDF

Article

High O6-methylguanine methyl transferase activity is frequently found in human oral cancer cells with p53 inactivation.

Authors:
- W Guo
- X Liu
- S Lee
- N H Park
View Affiliations / Copyright

Affiliations: UCLA School of Dentistry, Los Angeles, CA 90024, USA.
Pages: 817-838
|
Published online on: October 1, 1999

https://doi.org/10.3892/ijo.15.4.817
Expand metrics +

Abstract

Many studies have indicated that cancer cells expressing mutant (mt) p53 are resistant to genotoxic stress such as chemotherapy and radiation therapy. Inasmuch as most human oral cancer cells either express mt p53 or are infected with human papillomavirus (HPV), we determined the sensitivity to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a genotoxic chemical carcinogen, the activity of a DNA repair enzyme O6-methylguanine methyl transferase (MGMT) and the status of p53 in 11 human oral cancer cell lines, 2 HPV-immortalized human oral keratinocytes and 3 normal human oral keratinocyte (NHOK) cultures. Ten cancer cell lines demonstrated significantly higher level of MGMT activities compared to normal or immortalized non-tumorigenic cells, while one cancer cell line showed negligible MGMT activity. All immortalized cells and NHOK showed very low MGMT activity. Interestingly, all cancer cells with high MGMT activity expressed either mt p53 or harbored HPV DNA. However, infection of one cancer cell line (that does not demonstrate the MGMT activity) with retrovirus expressing an mt p53 protein did not alter the sensitivity of cells to MNNG and the enzyme activity. These data indicate that most human oral cancer cells contain moderately high DNA repair enzyme activity, and in doing so may be resistant to genotoxic stress, but the association of p53 with MGMT activities should further be investigated.

Journals

International Journal of Molecular Medicine

International Journal of Oncology

Molecular Medicine Reports

Oncology Reports

Experimental and Therapeutic Medicine

Oncology Letters

Biomedical Reports

Molecular and Clinical Oncology

World Academy of Sciences Journal

International Journal of Functional Nutrition

International Journal of Epigenetics

Medicine International

High O6-methylguanine methyl transferase activity is frequently found in human oral cancer cells with p53 inactivation.

This article is mentioned in:

Abstract

Related Articles