Association of matrix metalloproteinase 2 and matrix metalloproteinase 9 gene polymorphism in aggressive and nonaggressive odontogenic lesions: A pilot study.

Context: The exact factors that determine the biological behavior of odontogenic lesions have not been thoroughly established yet. The influence of the matrix metalloproteinases (MMPs) on the clinical behavior of these lesions was recently brought to light.

Aims: We did a pioneer study to investigate the association of MMP9 (rs3918242 [-1562 C/T] and rs17576) and MMP2 (rs243865 [-1306 C/T] and rs865094) gene polymorphisms and aggressiveness of ameloblastomas, keratocystic odontogenic tumors (KCOT) and dentigerous cysts (DC).

Settings and Design: A case-control study conducted in the Department of Oral Pathology and Microbiology, Government Dental College, Trivandrum and Human Molecular Genetics Laboratory, Rajiv Gandhi Institute of Biotechnology and Poojappura, Trivandrum, Kerala.

Subjects and Methods: DNA from the blood samples of histopathologically proven ameloblastoma ( n = 15), KCOT ( n = 11) and DC ( n = 13) patients were extracted using standard protocols. Primers were designed based on the functionality and relevance for polymerase chain reaction (PCR). PCR products were analyzed by PCR-restriction fragment length polymorphism and sequencing.

Statistical Analysis Used: Chi-square analysis was done to assess the association of gene polymorphisms among the cases and controls.

Results: Ameloblastomas showed a higher frequency of mutant allele (T = 0.43; P = 0.05) of MMP9 rs3918242 (-1562C/T) compared to the control population. All the cases showed a statistically significant difference in the distribution of genotype ( P = 0.046) and allele ( P = 0.03; odds ratio [OR] = 2.06 [1.08-3.95]) frequency of MMP2 rs2438659 (-1306C/T). KCOT samples also showed a significant association in distribution of both genotype ( P = 0.01) and allele ( P = 0.01 with an OR at 3.42 [1.31-8.92]) frequency, on comparison with control population.

Conclusions: MMP2 rs243865 polymorphism has a plausible role in increasing the aggressiveness of ameloblastomas and KCOT compared to that of the control population. Furthermore, MMP9 rs3918242 polymorphism may contribute to the aggressive behavior of ameloblastomas.