Ataxia–telangiectasia group D complementing gene (ATDC) upregulates matrix metalloproteinase 9 (MMP-9) to promote lung cancer cell invasion by activating ERK and JNK pathways

Although the expression pattern and biological functions of ataxia–telangiectasia group D complementing gene (ATDC) had been implicated in several types of cancer, the roles and potential mechanisms of ATDC in lung cancer cell invasion are still ambiguous. In this study, we used gain- and loss-of-function analyses to explore the roles and potential mechanisms of ATDC in lung cancer cell invasion. siRNA knockdown of ATDC impaired cell invasion in A549 and H1299 cell lines, and its overexpression promoted cell invasion in HBE cell line. ATDC may contribute to the invasive ability of lung cancer cells by promoting the expression of invasion-related matrix metalloproteinase 9 (MMP-9). In addition, ATDC increased activating protein 1 (AP-1) reporter luciferase activity and the protein and mRNA levels of c-Jun and c-Fos. We further demonstrated that the roles of ATDC on cell invasion, MMP-9 upregulation, and AP-1 activation were dependent on extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK) pathway activation, and ERK inhibitor U0126 or JNK inhibitor SP600125 blocked these effects of ATDC. These results suggested that ATDC upregulates MMP-9 to promote lung cancer cell invasion by activating ERK and JNK pathways.     

Expression of matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinases 1 (TIMP-1) by colorectal cancer cells and adjacent stroma cells – Associations with histopathology and patients outcome

AimTo elucidate cellular features accountable for colorectal cancers’ (CRC) capability to invade normal tissue and to metastasize, we investigated the level of the collagenase matrix metalloproteinase 9 (MMP-9) and its physiological inhibitor tissue inhibitor of metalloproteinases 1 (TIMP-1) in cancer cells and supporting stroma cells of CRC.MethodsImmunoreactivity of MMP-9 and TIMP-1 by carcinoma cells, lymphocytes and fibroblasts in archival specimens of paraffin-embedded primary tumours were retrospectively associated with outcome in 340 consecutive patients completely resected for CRC stages II–IV and subsequently treated with adjuvant 5-fluorouracil.ResultsExpression of MMP-9 by carcinoma cells was demonstrated in 9% of specimens without association to recurrence free survival (RFS) (HR = 1.0; 95% CI: 0.6–1.8; P = 0.9) or overall survival (OS) (HR = 0.9; 95% CI: 0.5–1.6; P = 0.6). TIMP-1 expression by carcinoma cells, which appeared in 64% of the specimens, was inversely related with RFS (HR = 1.3; 95% CI: 0.9–1.8; P = 0.08) and OS (HR = 1.5; 95% CI: 1.1–2.1; P = 0.02). Expression of TIMP-1 by fibroblasts at the invasive border was directly related to RFS (HR = 0.7; 95% CI: 0.6–0.9; P = 0.02) and OS (HR = 0.7; 95% CI: 0.6–1.0; P = 0.05). Expression of MMP-9 by lymphocytes correlated significantly with the degree of peritumoural inflammation (P = 0.02) but not with RFS (HR = 0.9; 95% CI: 0.7–1.1; P = 0.2) or OS (HR = 0.8; 95% CI: 0.7–1.0; P = 0.07).ConclusionTIMP-1 in cancer cells is associated with poor prognosis independent of its function as inhibitor of MMP-9. MMP-9 and TIMP-1 are important mediators of the host–cancer cell interaction in the tumour microenvironment with significant influence on the histopathology and on prognosis of CRC.