MMP2 and colorectal carcinoma: We next over-expressed COX-2 protein in CRC SW620 and LoVo cells by transfection, and found increased levels of pJAK2 and pSTAT3, and decreased expression levels of MMP-2, MMP-9, which are transcriptionally regulated downstream of JAK2/STAT3 signaling; on the other hand, the shRNA construct mediated COX-2 gene knockdown had the opposite effect (Fig 5A and 5B).