Introduction: Well-differentiated thyroid carcinomas are classified into papillary (PTC) and follicular thyroid carcinoma (FTC), and are the most frequent endocrine malignancy, consisting over 70% of the cases. The estimated incidence of thyroid cancer is > 3 fold higher in women. Environmental, genetic and hormonal factors are the most important triggers in the etiology and increased prevalence of human cancers, with genetic mutations playing the most important role in tumorigenesis.
Aim: The aim of the present study was to investigate the association between matrix metalloproteinase-9 (MMP-9) expression with BRAF V600E** mutation and clinicopathological features, in Iranian papillary thyroid cancer (PTC) patients.
In this study 90 participants including 60 PTC patients (15 males and 45 females) and 30 individuals with benign multinodular goiter (MNG) (5 males and 25 females) which were confirmed by surgical pathology, were investigated.
Results: Mean age of PTC and MNG patients was 37.6 ± 12.6 and 48.1 ± 13.3 years, respectively (P = 0.001). BRAF V600E mutation was found in 24 of the 60 (40%) PTC cases, with mean tumor size of 1.59 ± 1.20 cm. MMP-9 mRNA levels were elevated in tumoral compared to the adjacent non-tumoral tissues (P = 0.039); moreover, this rise was also observed in PTC patients compared to MNG patients (P = 0.001). The mRNA levels of MMP-9 increased in patients aged≥45 years (P = 0.015), those with lymphovascular invasion (P = 0.003), and higher tumor stages (III and IV) (P = 0.011). The protein level of MMP-9 increased in tumoral compared to adjacent non-tumoral tissues (P < 0.001); this increase was also found in PTC patients compared to MNG participants (P = 0.004). MMP-9 protein level was higher in patients aged≥45 years (P = 0.001), those with lymphovascular invasion (P = 0.036) and higher TNM stages (III and IV) (P = 0.001).
Conclusion: The mRNA and protein levels of MMP-9 had no association with BRAF V600E mutation in Iranian PTC patients. These levels were associated with age, TNM stages, and lymphovascular invasion, being defined as malignant factors. Thus, elevated levels of MMP-9 in PTC patients compared to MNG participants illustrated that it can be used as a potential biomarker to differentiate PTC patients from those with MNG.
*Biomarker: A biomarker in the medical field is a measurable indicator for the diagnosis of a disease. It can be a sign of a specific disease.
** BRAF is a gene in the human body that was established in 2002, a mutation in it can cause cancer in the individual.
