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
2459 - Does bevacizumab increase joint pain ? Preliminary results of BEVARTHRALGIA Study
Presenter: Vauleon Enora
Session: Poster Display session 1
Resources:
Abstract
4913 - Prostatic cancer androgen deprivation therapy and bone health in carcinoma prostate.
Presenter: Gouri Shankar Bhattacharyya
Session: Poster Display session 1
Resources:
Abstract
1352 - Patterns of care for patients with metastatic bone disease in solid tumors – a cross-sectional study (SAKK 95/16)
Presenter: Michael Mark
Session: Poster Display session 1
Resources:
Abstract
6002 - Infection-Related Mortality in Different Types of Cancers
Presenter: Mohamed Gouda
Session: Poster Display session 1
Resources:
Abstract
5643 - Survival Trends in Critically ill Oncology Patients: impact of patient’s eligibility to post-ICU chemotherapy
Presenter: Edith Borcoman
Session: Poster Display session 1
Resources:
Abstract
3097 - Development and validation of a multivariable prediction model for 6-month mortality in older cancer patients: the GeriAtrIc-Tumor Score of PrEdiction for Early Death (GAIT SPEED)
Presenter: Angeli Angeli
Session: Poster Display session 1
Resources:
Abstract
856 - A Longitudinal Tracking and Quantitative Assessment of Paclitaxel-Induced Peripheral Neurotoxicity
Presenter: Ayumu Matsuoka
Session: Poster Display session 1
Resources:
Abstract
1662 - Efficiency of controlled cryotherapy in prevention of chemotherapy induced peripheral neuropathy (CIPN)
Presenter: Trudi Schaper
Session: Poster Display session 1
Resources:
Abstract
2766 - The Validity of Evaluations for Chemotherapy-Induced Peripheral Neuropathy (CIPN)
Presenter: Teppei Yamada
Session: Poster Display session 1
Resources:
Abstract
5683 - Prevention of chemoradiation-related mucositis in patients with head and neck cancer using dexamethasone-based mouthwash: A phase II randomized double-blind, placebo-controlled study
Presenter: Naiyarat Prasongsook
Session: Poster Display session 1
Resources:
Abstract