Abstract 1657
Background
In HT29 cells, an interplay between self-DNA-induced TLR9- and autophagy responses was found with remarkable effects on survival and differentiation of tumor cells. c-Met activation is known to drive the progression of colorectal cancer by promoting signaling cascades that mainly result in alterations of cell motility, survival and proliferation. c-Met inhibition was shown to inhibit autophagy. In cancer cells the interrelated role of c-Met inhibition and TLR9/autophagy signaling has not yet been clarified, so we aimed to assess this complex interplay.
Methods
HT29 cells were incubated for 72 h with genomic (g), hypermethylated (m), and fragmented (f) tumor self-DNAs, and with/without inhibitors of c-Met (diisothiocyanatostilbene), autophagy (chloroquine) and TLR9 (ODN2088), respectively. Cell viability was measured by MTT assay. Transcriptional changes of TLR9-signaling, PI3K, CD95, c-Met, Bcl2, cytochrome-c, and the autophagy process were assayed by Human v3 miRNA Assay (NanoString). Autophagy proteins were detected by immunocytochemistry, while morphology of apoptosis and autophagy by transmission electron microscopy (TEM).
Results
Self-DNAs g and f resulted in significant upregulation of Beclin1, Atg16L1, LC3 mRNAs, and downregulation of PI3K, Bcl2, CD95, and cytochrome-c, verified by immunocytochemistry, as well. c-Met inhibition alone altered inversely the autophagy-associated gene- and protein-expressions. In each group of tumor cells using combined inhibition of autophagy, TLR9 and/or c-Met-signaling varying degree of autophagy was observed according to NanoString and TEM. Following combined incubation with c-Met inhibitor and m-DNAs no expected suppression of tumor cell survival and induction of apoptosis and mitophagy were detected. Further, c-Met inhibition changed the cell-protective effect f-DNA on macroautophagy.
Conclusions
Our study provided evidence for an intense crosstalk between the inhibited c-Met canonical and non-canonical signaling pathways, and the TLR9/autophagy response with profound impacts on survival, proliferation and death of HT29 cells subjected to intact/modified self-DNAs.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Ferenc Sipos.
Funding
StartUp.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5444 - Analysis of the tumor microenvironment and tumor genotype through different stages of lung adenocarcinoma
Presenter: Peter Zink
Session: Poster Display session 1
Resources:
Abstract
3124 - Does Progress achieved in the Treatment of Patients with Metastatic Non-Small-Cell Lung Cancer (NSCLC) reach the Elderly Population?
Presenter: Jorune Suipyte
Session: Poster Display session 1
Resources:
Abstract
5142 - Prognostic factors for non-small cell lung cancer patients with driver mutation negative and brain metastases (HOT 1701)
Presenter: Yoshihito Ohhara
Session: Poster Display session 1
Resources:
Abstract
1580 - A novel risk classification system based on nomogram scores to predict survival of patients presenting with brain metastases at the first diagnosis of NSCLC
Presenter: Pengfei Cui
Session: Poster Display session 1
Resources:
Abstract
4442 - Comparison of real-world response rate (rwRR) to RECIST-based response rate in patients with advanced non-small cell lung cancer (aNSCLC)
Presenter: Xinran Ma
Session: Poster Display session 1
Resources:
Abstract
5405 - Estimating the cost and survival impact of new aNSCLC therapies in Canada with the iTEN model
Presenter: Parneet Kaur Cheema
Session: Poster Display session 1
Resources:
Abstract
1893 - SMARCA4 Deficient Non-Small Cell Lung Cancer (NSCLC): A Comprehensive Genomic Profiling (CGP) Study
Presenter: Stephen Graziano
Session: Poster Display session 1
Resources:
Abstract
5582 - Exploring Resistance to Nivolumab [NIV] applying an Immune Genomic Signature (IGS) in advanced pretreated NSCLC [PRINCiPe study]
Presenter: Sara Pilotto
Session: Poster Display session 1
Resources:
Abstract
1408 - DNA damage repair deficiency is associated with early resistance to crizotinib: whole-genome analysis in non-small cell lung cancer patients with ALK-fusion
Presenter: Dongyun He
Session: Poster Display session 1
Resources:
Abstract
5751 - Phase 3 ALTA-3 study of brigatinib (BRG) vs alectinib (ALC) in patients (pts) with advanced anaplastic lymphoma kinase (ALK)−positive non–small cell lung cancer (NSCLC) that progressed on crizotinib (CRZ)
Presenter: Sanjay Popat
Session: Poster Display session 1
Resources:
Abstract