Loss of heterozygosity at APC and MCC genes of oral cancer and leukoplakia tissues from Indian tobacco chewers.
BACKGROUND
Loss of heterozygosity (LOH) at tumor suppressor genes, such as adenomatous polyposis coli (APC) and mutated in colon cancer (MCC) genes, is one of the early events in carcinogenesis of oral tissue in Caucasian and Chinese patients. We wanted to check whether it is also true in Indian oral pre-cancer and cancer patients.


METHODS
Loss of heterozygosity at APC and MCC genes was investigated in 57 and 40 unrelated primary oral leukoplakia (a pre-cancerous lesion) and squamous cell carcinomas (SCC), respectively, by polymerase chain reaction.


RESULTS
In these samples, most of the leukoplakia patients had tobacco smoking habit whereas majority of cancer patients had tobacco chewing habit. LOH at APC gene was observed in 4 of 16 (25%) and 1 of 29 (3%) informative tumor and leukoplakia DNAs from tobacco chewers, respectively. LOH at MCC gene was not detected either in tumor or in leukoplakia DNAs.


CONCLUSIONS
This infrequent LOH at APC gene of pre-cancer and cancer tissues suggests that it may not be an early event in oral carcinogenesis in these patients.
Sikdar
Nilabja
N
Anthropology and Human Genetics Unit, Biological Sciences Division, Indian Statistical Institute, 203 B. T. Road, Kolkata 700 08, India.
Paul
Ranjan Rashmi
RR
Panda
Chinmay K
CK
Banerjee
Sanat K
SK
Roy
Bidyut
B
D000328:Adult; D000368:Aged; D001114:Areca / Q000009:adverse effects; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D017491:Genes, APC; D017431:Genes, MCC / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007194:India; D007972:Leukoplakia, Oral / Q000235:genetics*; D019656:Loss of Heterozygosity / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D011230:Precancerous Conditions / Q000235:genetics; D012907:Smoking / Q000009:adverse effects; D014030:Tobacco, Smokeless / Q000009:adverse effects*
D004273:DNA, Neoplasm