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
2273 - High performance of serial tumor biopsies in first in human (FIH) phase I trials.
Presenter: Jun Sato
Session: Poster Display session 1
Resources:
Abstract
5933 - Response rates and lesion-level progression patterns of solid tumor patients in an academic phase 1 program: implications for tumor heterogeneity
Presenter: Christopher Chen
Session: Poster Display session 1
Resources:
Abstract
3569 - Clinical Benefit and Response Rate in Early Phase Clinical Trials: First Report from a Single-Institution Study
Presenter: Antonio Marra
Session: Poster Display session 1
Resources:
Abstract
4139 - Patient (pt) selection for immunotherapeutic early-phase clinical trials (ieCTs): a single Phase I Unit experience
Presenter: Matteo Simonelli
Session: Poster Display session 1
Resources:
Abstract
4451 - Improving patient selection for immuno-oncology phase 1 trials: an external validation of five prognostic scores at Claudius Regaud Institute of Toulouse, Oncopôle (IUCT-O).
Presenter: Ghassan Al Darazi
Session: Poster Display session 1
Resources:
Abstract
1696 - Demonstrating the Changing Trends in Phase 1 Clinical Trials
Presenter: Christina Guo
Session: Poster Display session 1
Resources:
Abstract
3202 - Participation of Women in phase 1 oncology clinical trials
Presenter: Laura Vidal
Session: Poster Display session 1
Resources:
Abstract
4518 - Predictors for early trial discontinuation of patients with cancer participating in phase I clinical trials
Presenter: Joeri Douma
Session: Poster Display session 1
Resources:
Abstract
4368 - Safety of Tumor Treating Fields delivery to the torso: Meta analysis from TTFields clinical trials
Presenter: Federica Grosso
Session: Poster Display session 1
Resources:
Abstract
4615 - Proteomic Profiling Identifies Molecular Basis of Adverse Event to BPM31510 Exposure: Rationale for Comprehensive Molecular Pharmacodynamics (PD) in Phase 1 Clinical Trial Design
Presenter: Vivek Subbiah
Session: Poster Display session 1
Resources:
Abstract