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
3345 - Escalation plans and DNACPR discussions in the unwell oncology patient
Presenter: Raghad Elghadi
Session: Poster Display session 1
Resources:
Abstract
4165 - The Relation between the Symptom Burden of Hospitalized Patients with Incurable Cancer and the Quality-of-Life of Their Family Caregivers
Presenter: Eman Tawfik
Session: Poster Display session 1
Resources:
Abstract
1784 - Clinical predictors for analgesic response to radiotherapy in patients with painful bone metastases
Presenter: Ragnhild Habberstad
Session: Poster Display session 1
Resources:
Abstract
5323 - 30-Day Mortality in Palliative Radiotherapy
Presenter: Shing Fung Lee
Session: Poster Display session 1
Resources:
Abstract
3942 - The relationship between Naldemedine administration and the maximum dose of oral opioids
Presenter: Shinya Kajiura
Session: Poster Display session 1
Resources:
Abstract
3698 - Exposure to low energy amplitude modulated radiofrequency electromagnetic fields (EMF) is associated with rapid improvement in quality of life (QoL) status in patients with advanced hepatocellular carcinoma (HCC), using various analyses of EORTC-C30.
Presenter: Elizabeth Santana
Session: Poster Display session 1
Resources:
Abstract
3885 - Olanzapine Combined with 5-HT3 RA Plus Dexamethasone for Prevention and Treatment of Chemotherapy-Induced Nausea and Vomiting in High and Moderate Emetogenic Chemotherapy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Presenter: Jian-Guo Zhou
Session: Poster Display session 1
Resources:
Abstract
5700 - Early Palliative care in advanced cancer, is it really effective?
Presenter: Raquel Gómez Bravo
Session: Poster Display session 1
Resources:
Abstract
5924 - Deprescribing Potentially Inappropriate Medication in Cancer Patients
Presenter: Simon Reuter
Session: Poster Display session 1
Resources:
Abstract
5314 - Spirituality and religious coping for Cancer patients and providers: An ‘Almighty’ belief for palliative care
Presenter: Vibhay Pareek
Session: Poster Display session 1
Resources:
Abstract