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
4321 - Health-related quality of life of advanced melanoma survivors treated with CTLA-4 immune checkpoint inhibition: a matched cohort study
Presenter: Annelies Boekhout
Session: Poster Display session 1
Resources:
Abstract
779 - Capecitabine vs Cisplatin along with concurrent radiotherapy in the treatment of inoperable lower esophageal cancers focusing on TWISTT score and QOL
Presenter: Goutham Anugu
Session: Poster Display session 1
Resources:
Abstract
5914 - Cancer, Mental Health and End Life Simulation (CAMhELS): A novel effectiveness evaluation.
Presenter: Asanga Fernando
Session: Poster Display session 1
Resources:
Abstract
2597 - Cancer patients’ expectations and understanding about their disease
Presenter: Mónica Pinho
Session: Poster Display session 1
Resources:
Abstract
5187 - Impact of patients’ death on oncologists and coping strategies: An online survey
Presenter: Soumaya Labidi
Session: Poster Display session 1
Resources:
Abstract
4579 - Clinical benefit from late lines of therapy offered to patients treated in a tertiary referral centre
Presenter: Andrea Sbrana
Session: Poster Display session 1
Resources:
Abstract
5058 - Preparedness for caregiving in caregivers of cancer patients
Presenter: Hatice Yakar
Session: Poster Display session 1
Resources:
Abstract
5917 - Oncologic Emergency Medicine in the real world: A survey and proposal for improvement
Presenter: Carintia Dorta Pérez
Session: Poster Display session 1
Resources:
Abstract
4077 - The Reality of Critical Cancer Patients in a Polyvalent Intensive Care Unit
Presenter: Tiago Filipe Da Cruz Tomas
Session: Poster Display session 1
Resources:
Abstract
1728 - A phase III trial evaluating olanzapine 5 mg for the prevention of chemotherapy-induced nausea and vomiting in patients receiving cisplatin: J-FORCE Study
Presenter: Hironobu Hashimoto
Session: Poster Display session 1
Resources:
Abstract