Abstract 307: TRIB3 regulates cell cycle progression and programmed cell death in non-small cell lung cancer

Abstract

Abstract Introduction: The pseudokinase Tribbles pseudokinase 3 (TRIB3) is known as a regulator in cellular responses to a variety of stresses such as glucose insufficiency and (ER) stress. TRIB3 has been described in some studies as a tumor suppressor due to its effect on inactivating PI3K/Akt pathway, but other studies suggest TRIB3 as a stimulator of tumor progression. In this study, we aimed to define the functions of TRIB3 in in non-small cell lung cancer. Methods: TRIB3 expression was altered using a lentiviral vector to overexpress TRIB3 in non-small cell lung cancer. A CRISPR-CAS9 construct with guiding sequence matching to TRIB3 gene was used to knock out its expression. Cell proliferation was evaluated using MTS and trypan blue assays. Boyden chamber assay was used to assess the cell migration while cell cycle phases were determined using flow cytometry. Heatmap analysis was performed to assess the changes in the expressions of genes in cell cycle progression and apoptosis. Results: TRIB3 overexpression led to reduced cell proliferation and migration. Moreover, it contributed to the increased of cell cycle arrest at G0/G1 phase. QPCR analyses of cell cycle related genes showed an upregulation of CDK inhibitors in (NCI-H358) TRIB3 overexpression cells, while depletion of TRIB3 led to the down-regulation of CDK inhibitors. TRIB3 overexpression led to downregulation of LC3B and other autophagy markers while increasing the expression of apoptotic genes. Conclusion: Increased TRIB3 expression in non-small cell lung cancer cells inhibited proliferation by blocking cell cycle progression through the upregulation of CDK inhibitors, led to activation of cell death through apoptosis. Our study reveals a significant role of TRIB3 in regulating cell cycle progression, apoptosis and autophagy. Citation Format: Abeer Almiman, Daotai Nie, Jamila Adom. TRIB3 regulates cell cycle progression and programmed cell death in non-small cell lung cancer [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 307. doi:10.1158/1538-7445.AM2017-307