Background: MMP9, as a member of the MMPs family, codes a protein that is able to provide suitable infrastructures for the migration of cancer cells and angiogenesis within tumor. The aim of this study was to investigate the relationship between -1562 C> T polymorphism in MMP9 promoter and progression of breast cancer in northwest of Iran.

Materials and Methods:  In this case-control study, 187 females from northwest of Iran were involved. Polymorphism of interest was determined by PCR-RFLP method using enzyme PaeI and statistical analysis was done by Med Calc software.

Results: Distribution of CC genotype in cancer and control groups was,44 and 62.5, tespectively and distribution of CT genotype in cancer and control groups was 56 and 37.5, respectively, In the statistical analysis, χ² and p value were respectively, 5.4 and 0.01. There is a significant association between this polymorphism and lymph nodes involvement and presence of tumor larger than 2cm³ (respectively p= 0.005 and p = 0.03). The results of this study showed -1562 C> T polymorphism in MMP9 promoter is associated with stage II and higher stages of breast cancer in our population. Furthermore, CT genotype may increase the risk of lymph node metastasis and presence of tumor larger than 2 cm³ (OR= 4).

Conclusion: According to the results of this study, MMP9 (-1562 C> T) polymorphism may be used as a biomarker for breast cancer prognosis. Although, to achieve more definitive results, it is necessary to examine a larger population.

Background and Aim: Tendon, like the skeletal muscle, exhibits mechanical and morphological adaptations resulted from exercise training; however, little is known about the basic cellular and molecular mechanisms that regulate these responses. The aim of the present study was therefore to investigate the effect of 6 weeks of aerobic training on the TGF-β1, myostatin and MMP9 mRNAs expression in the tendon of fast- and slow-twitch muscles. 
Methods & Materials For this purpose, 12 male Wistar rats at 8 weeks of age were randomly divided into two groups: experimental (n=6) and control (n=6). The exercise group performed aerobic training for 6 weeks, 5 sessions per week. Forty-eight hours after the last training session, all rats were sacrificed and the tendons of soleus and Extensor Digitorum Longus (EDL) muscles were extracted. Expression of TGF-β1, myostatin and MMP9 mRNAs were assayed using RealTime-PCR. Independent t-test was also used for statistical analysis.
Ethical Considerations: All stages of the study were conducted according to the ethical guidelines and authorization of Research Deputy of Islamic Azad University, Central Tehran Branch No. IR.IAU.PS.REC.1398.296. 
Results: The results showed that the expression of TGF-β1 mRNA in EDL and soleus tendons significantly increased (P≤0.001), whereas the expression of myostatin in EDL tendon was significantly reduced (P≤ 0.001). Increased mRNA expression of MMP9 in the tendon of EDL and soleus muscles was not statistically significant (P>0.05).
Conclusion: It seems that aerobic exercise can modulate the expression of genes involved in the regulation of tendon collagen in a muscle type-dependent manner.