Abstract 5790: Assessing the effects of TIMP2 knockout on lung cancer cell lines cultured in 3D

Abstract

Abstract Tissue inhibitor of matrix metalloproteinases (TIMPs) are a small family of endogenous proteins that classically function to inhibit metalloproteinase activity. Since the original description of this protein family in the 80s and 90s, various MMP-independent biological functions of TIMPs have been described. This built the impression that MMP/TIMP ratios may play an important role in tissue homeostasis, an idea which is supported by the observation that altered MMP/TIMP expression ratios are often associated with a number of human conditions such as cancer, cardiovascular and CNS disease. TIMP2 is the most abundantly expressed protein in this family and has previously been shown to interact with several membrane proteins including MT1-MMP, insulin-like growth factor-1 receptor (IGF-I-R) and alpha3 beta1 integrin (α3β1) to mediate downstream intracellular signaling. In addition, TIMP2 has been shown to inhibit growth factor stimulated proliferation, angiogenesis and tumor cell invasion and metastasis, highlighting the potential for TIMP2-based cancer bio-therapies that can be used in conjunction with conventional treatments. Recent studies in our lab highlight that syngeneic lung tumors (LL2 cells; Lewis lung carcinoma) developed in C57BL mice harboring a loss-of-function mutation in TIMP2 are significantly larger than tumors grown in their WT counterparts. To gain a deeper understanding of the role of TIMP2 in tumor initiation and progression we have used CRISPR-Cas9 to develop stable TIMP2 knockout (T2KO) human lung cancer cell lines. Although indistinguishable in 2D culture, T2KO tumor cells display a morphologically distinct phenotype when grown in spheroids. Preliminary data show that, when grown in spheroids, T2KO cells exhibit enhanced EGFR activation in comparison to WT cells. By assessing the functional characteristics and gene expression of T2KO cells grown in 3D culture conditions we hope to gain further insight into the biological functions of TIMP2 and to provide a mechanistic link between the loss of TIMP2 activity and enhanced tumor formation that is observed in our mouse model. Citation Format: David Peeney. Assessing the effects of TIMP2 knockout on lung cancer cell lines cultured in 3D [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5790. doi:10.1158/1538-7445.AM2017-5790