Comparison of DPPIV Levels in Serum and Tumour of OSCC Patients and Its Correlation with Active Matrix Metalloproteinases 2 and 9

INTRODUCTION: The important role of Dipeptidyl Peptidase IV (DPPIV) has been reported in tumour progression of several human cancers. This study demonstrates the DPPIV mRNA expression level and activity in tumour and paired non-tumour tissues of oral squamous cell carcinoma (OSCC) patients and the potential modulation of DPPIV in the metastasis of tumour through regulating MMP2 and MMP9 activities. MATERIALS AND METHODS: This study was conducted on 16 OSCC patients. The mRNA expression level of DPPIV was evaluated by RT-qPCR in tumour of OSCC patientsand compared with their paired non-tumour tissues. Additionally, DPPIV activity was measured in serum, tumour and paired non-tumour tissues of OSCC patients. Zymography was performed to measure and compare the activities of MMP2 and MMP9 between tumour and paired non-tumour tissues of OSCC patients. RESULTS: The results showed significantly higher DPPIV mRNA level and activity in tumour of OSCC patients compared to their paired non-tumour tissues. Tumour DPPIV mRNA expression and activity were positively correlated with activities of MMP2 and MMP9, respectively. Serum DPPIV activity of OSCC patients was lower compared to healthy control and did not show correlation with tumour DPPIV mRNA level. CONCLUSION: These data indicate that secreted DPPIV may not originate from the tumour tissue of OSCC patients. Furthermore, increased DPPIV gene expression and activity in tumour of OSCC patients might be involved in the ECM degradation and invasion of OSCC through regulation of MMP2 and MMP9 activities.