Abstract 5269: Impact of K-ras status on differential expression of TIMP-1 in lung adenocarcinoma

Abstract

Abstract Tissue inhibitor of metalloproteinase-1 exhibits a range of novel functions in addition to its initially recognized activity as a physiological inhibitor of MMPs. Two specific activities have been of significant interest in the context of oncology - inhibition of apoptosis and induction of cell proliferation. Previously we have shown that over-expressing TIMP-1 in a lung adenocarcinoma cell line H2009 results in more aggressive and larger tumors in vivo with increased invasion and colony formation in vitro. Subsequently we demonstrated elevated levels of Bcl-2 with a concomitant reduction in apoptosis induced by staurosporine. In the present study, we have sought to define a relationship between TIMP-1 expression levels in non-small-cell-lung-carcinoma (NSCLC) cell lines in relation to K-ras mutation. We identified a differential expression pattern of TIMP-1 in various NSCLC cell lines and also found that TIMP-1 overexpressing cell lines also had higher levels of Bcl-2 and vice versa. Upon further analysis, we were able to correlate a low TIMP-1 expression with K-ras dependence and high levels of E-cadherin expression as in H2009 and H441. Similarly, K-ras independent cell line A549, expressed low levels of E-cadherin and elevated TIMP-1. E-cadherin distribution was confirmed in A549 and H2009 cells by immunofluorescence. Since N-cadherin cleavage has been shown to be inhibited by TIMP-1, we examined N-cadherin levels by western blot. Results indicate that A549 exhibiting high levels of TIMP-1 had increased levels of N-cadherin whereas the low TIMP-1 expressing cell lines had lower N-cadherin levels. A spheroid formation assay to determine the aggressiveness of cell lines revealed that K-ras dependent cell line formed spheroids that were smaller and less migratory than K-ras independent cell line whereas the K-ras independent cell line A549 formed spheroids that were larger, more spread out exhibiting wider migratory properties. The present study underscores the multiple biologic properties of TIMP-1. It provides further mechanistic understanding of its documented role as a prognostic marker and a potential therapeutic target in various malignancies, particularly lung carcinoma. This study was supported in part by a Distinguished Cancer Scientist Award to AMR from the Georgia Research Alliance. Citation Format: Ammar Kutiyanawalla, Sampa Gupta-Ghoshal, Byung Rho Lee, Ravindra Kolhe, Amyn M. Rojiani, Mumtaz V. Rojiani. Impact of K-ras status on differential expression of TIMP-1 in lung adenocarcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5269. doi:10.1158/1538-7445.AM2014-5269