The interplay of TLR9-mediated autophagy response and growth factor signaling inhibition in colon adenocarcinoma cells: cell-free DNA experiments
Bohusné Barta Bettina Aranka
KÁROLY RÁCZ CONSERVATIVE MEDICINE PROGRAM
Dr. Reusz György
Semmelweis Egyetem I. sz. Patológiai és Kisérleti Rákkutató Intézet Arányi Lajos előadóterem (1. emelet)
2024-10-24 15:00:00
Gastroenterology
Dr. Molnár Béla
Sipos Ferenc
Dr. Rubovszky Gábor
Dr. Miheller Pál
Dr. Buzás Edit
Dr. Hidvégi Bernadett
Dr. Juhász Márk
Self-DNA-induced TLR9 signaling and autophagy response in HT29 colon cancer
cells were closely related, affecting cell survival and differentiation. Interfering with
HGFR hinders autophagy and promotes colorectal cancer. IGF1R activation drives
colorectal cancer development and progression. Debate surrounds the effect of IGF1R
inhibition on autophagy. The exact methods by which HGFR or IGF1R suppression
affects TLR9/autophagy signaling in HT29 cancer cells are unclear. We investigated how
suppressing HGFR or IGF1R impacts TLR9-autophagy signaling in HT29 cells. We
examined how these components interact by measuring cell proliferation, metabolism,
TLR9, HGFR, IGF1R, and autophagy inhibitory tests. Gene expression,
immunocytochemistry, transmission electron microscopy and WES Simple autophagy
flux measurements were also examined.
In HGFR inhibitory tests, we found that MyD88 and caspase-3 promoted HT29 cell
growth. Incubation with self-DNAs may decrease apoptosis-induced compensatory cell
growth. HGFR inhibition blocks the proliferation-reducing impact of genomic and
hypermethylated DNA, while fragmented DNA is unaffected. Chloroquine, HGFR
inhibitor, and genomic DNA showed the least cell proliferation. The HGFR-mTOR-ULK1
molecular cascade may be implicated in HGFR inhibitor-mediated autophagy since LC3B
inhibited STAT3 overexpression and reversed its proliferation-stimulating action. When
given together, hypermethylated DNA, TLR9, and HGFR inhibitors increased cell
proliferation the most. Autophagy-related genes and conventional and non-canonical
HGFR signaling pathways were downregulated. Ultrastructural alterations support the
context-dependent effect of HGFR inhibition and autophagy on cell survival and
proliferation. In IGF1R inhibitory assays, tumor-derived self-DNA and IGF1R inhibitors
have anti-proliferative potential. TLR9 signaling inhibition reverses this effect.
Picropodophyllin, ODN2088, and chloroquine all had different effects on HT29 cell
proliferation and autophagy. This suggests that autophagy mechanisms have "Janusfaced" effects on cell proliferation, depending on whether they are linked to or not linked
to the IGF1R. Self-DNA and inhibitors do not promote autophagy, but they let CD133-
positive stem-like HT29 cells survive. In the development of more individualized antitumor therapies for colorectal cancer, the discovery of novel forms of combined inhibitors
of HGFR or IGF1R, autophagy, and/or TLR9 signaling would be instrumental.
