TFPI-2 silencing increases tumour progression and promotes metalloproteinase 1 and 3 induction through tumour-stromal cell interactions.
Bottom Line: Tissue factor pathway inhibitor-2 (TFPI-2) is a potent inhibitor of plasmin which activates matrix metalloproteinases (MMPs) involved in degradation of the extracellular matrix.Its secretion in the tumour microenvironment makes TFPI-2 a potential inhibitor of tumour invasion and metastasis.This study also reveals for the first time that pulmonary fibroblasts incubated with conditioned media from TFPI-2 silencing cancer cells exhibited increased expression of MMPs, particularly MMP-1, -3 and -7, that are likely involved in lung cancer cell invasion through the surrounding stromal tissue, thus enhancing formation of metastases.
Affiliation: Inserm, U618, Université François Rabelais, Tours, France.Show MeSH
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Mentions: Levels of MMP-1, -2, -3, -7, -9, -13, -14 and EMMPRIN transcripts were quantified in miRNA-Neg, miRNA-1b and -2b clones using RT and real-time PCR (Fig. 5A). Varying amounts of MMP transcripts were quantified in all cell clones, with fewer than 10 copies for MMP-9, -13 and -14 to more than 105 copies for MMP-1 and EMMPRIN. A 5.5-fold and an 8.6-fold increase in MMP-1 transcripts were found for miRNA-1b and -2b clones, respectively, when compared to miRNA-Neg cells (P < 0.001). Similar results were observed with MMP-3 since mRNA levels were significantly increased (P < 0.01) in miRNA-1b and -2b cell clones (11.3-fold and 10.4-fold, respectively) compared to the miRNA-Neg clone. Immunocytochemical staining also clearly showed that this increase in MMP-1 and -3 transcript levels was associated with enhanced protein expression (Fig. 5B). No significant differences were found in mRNA expression for MMP-9, -13, -14 and EMM-PRIN in either miRNA-1b or -2b compared to the control clone (Fig. 3A). In contrast, MMP-7 and MMP-2 transcript levels were significantly decreased in miRNA-1b (P < 0.01) and -2b (P < 0.001 and P < 0.01, respectively) clones. As shown in Fig. 5(B), MMP-7 protein expression was slightly decreased in both miRNA clones.
Affiliation: Inserm, U618, Université François Rabelais, Tours, France.