Abstract 1659
Background
In HT29 cells, an interplay between self-DNA-induced TLR9-signaling and autophagy response was found with significant effects on cell survival and kinetic parameters. The IGF/IGF1R system plays a determinant role in the pathogenesis and progression of colorectal cancer. This pathway is upstream of mTORC1, a negative regulator of autophagy. I mammalian systems chronic IGF1R inhibition was shown to attenuate autophagosome formation. The interrelated action of IGF1R inhibition and TLR9/autophagy signaling in cancer cells has not yet been clarified. The present study was designed to assess this complex network using HT29 colon carcinoma cells.
Methods
HT29 cells were incubated for 72 h with genomic (g), hypermethylated (m), and fragmented (f) tumor self-DNAs, and with/without inhibitors of IGF1R (picropodophyllin), autophagy (chloroquine) and TLR9 (ODN2088), respectively. Cell viability was measured by MTT assay. Transcriptional changes of TLR9-signaling, IGF1R, mTORC, Akt, 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
In case of autophagy g- and f-DNAs caused significant upregulation of Beclin1, Atg16L1, LC3 mRNAs, and downregulation of mTORC, and Akt, verified by immunocytochemistry, as well. IGF1R-inhibition alone altered inversely the autophagy-associated gene- and protein-expressions. Upon combined inhibition of autophagy, TLR9 and/or IGF1R-signaling varying degree of autophagy was detected in all groups of tumor cells according to NanoString and TEM. Incubation with IGF1R inhibitor and with m-DNA no expected suppression of tumor cell survival, induction of apoptotic death, and activation of mitophagy were found. Moreover, IGF1R inhibition affected negatively the cell-protective effect f-DNA on macroautophagy and lipophagy.
Conclusions
Our study provided evidence for an interaction between the inhibited IGF1R and TLR9/autophagy signaling with major influences on survival, proliferation and death of HT29 cells subjected to intact/modified self-DNAs. (Funded by StartUp.).
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