Role of nitric oxide and antioxidant enzymes in the pathogenesis of oral cancer.
BACKGROUND
Oral cancer is the leading malignancy in India. Nitric oxide and antioxidant enzymes play an important role in etiology of oral cancer. Therefore, the present study evaluates nitric oxide and antioxidant enzyme levels in healthy individual without tobacco habits (NHT, N=30) and healthy individuals with tobacco habits (WHT, n=90), patients with oral precancers (OPC, n=15) and oral cancer patients (n=126).


METHODS
Blood samples were collected from the subjects. NO2 + NO3 (nitrite+nitrate), superoxide dismutase (SOD) and catalase levels were estimated using highly specific spectrophotometeric methods. Statistical analysis was done by SPSS statistical software version 10.


RESULTS
Mean plasma NO2 + NO3 levels were elevated in patients with OPC and oral cancer patients as compared to the controls. Mean activities of erythrocyte SOD and catalase were higher in WHT than NHT. Erythrocyte SOD and catalase levels were higher in WHT and patients with OPC as compared to NHT. The erythrocyte SOD and catalase activities were lower in oral cancer patients than patients with OPC. The erythrocyte SOD activity was higher in advanced oral cancer than the early disease. Erythrocyte catalase activity was lower in poorly differentiated tumors than well and moderately differentiated tumors. Pearson's correlation analysis revealed that alterations in plasma NO2 + NO3 levels were negatively associated with changes in erythrocyte SOD activities.


CONCLUSIONS
The data revealed that the alterations in antioxidant activities were associated with production of nitric oxide in oral cancer, which may have significant role in oral carcinogenesis.
Patel
Jayendrakumar B
JB
Biochemistry Research Division, The Gujarat cancer and Research Institute, Ahmadabad-380 016, India.
Shah
Franky D
FD
Shukla
Shilin N
SN
Shah
Pankaj M
PM
Patel
Prabhudas S
PS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D002374:Catalase / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D009367:Neoplasm Staging; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000097:blood; D011230:Precancerous Conditions / Q000378:metabolism*; D012907:Smoking; D013482:Superoxide Dismutase / Q000097:blood; D055815:Young Adult
D000975:Antioxidants; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D002374:Catalase; D013482:Superoxide Dismutase