Abstract 81P
Background
TRAIL-induced apoptosis pathway is a potential therapeutic target, but the majority of tumors are TRAIL-resistant. TRAIL receptors translocation is associated to TRAIL resistance. Besides TRAIL receptors, DR4 and DR5, other potentially TRAIL-induced apoptosis pathway regulatory proteins are: Apaf-1, CUL3, CLTA (clathrin chain A , involved in TRAIL receptors nuclear translocation) and KPNA-1 ( involved in TRAIL receptors internalization). Overcome TRAIL resistance is essential to therapeutic strategies development.
Methods
A549 cell line was used. Expression of miR-23b, miR-133a, DR4, DR5, Apaf-1, CUL3, CLTA/CLTC and KPNA-1 were estimated by RT-qPCR. Transfection effects of miR-23b inhibitor and Mimic-133a on TRAIL apoptosis pathway components expression. Western Blotting to TRAIL receptors compartmentalization after Mimic-133a and TRAIL stimulus. MTT cell viability assay to evaluate TRAIL-induced cytotoxicity of miR-23b inhibition and Mimic-133a transfection.
Results
A549 was TRAIL resistant. miR-23b was superexpressed and miR-23b inhibition upregulated Apaf-1 and CUL3 expression. miR-133a was undetectable. Mimic-133a transfection downregulated CLTA and DR5 expression. miR-23b inhibition and Mimic-133a transfection promoted TRAIL sensitization.TRAIL receptors were predominantly located in nuclear compartment. Mimic-133a downregulated CLTA expression but did not alter receptors compartmentalization. Mimic-133a and TRAIL associated stimulus leaded to predominant nuclear TRAIL receptors localization in comparison to control cells.
Conclusions
Both miR-23b and -133a are involved in TRAIL cells resistance. Apaf-1 and CUL3 expression downregulation by miR-23b can contribute to resistance. miR-133a role on TRAIL sensitization mechanisms must be further investigated. Mimic-133a downregulated CLTA expression but did not alter TRAIL receptors compartmentalization, suggesting that receptors translocation is clathrin independent.CLTA expression control by miR-133a, however, can contribute to drug-resistance research. Although more research is needed to fully clarify miRs roles on TRAIL-induced apoptosis, our findings deepen TRAIL resistance understanding.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
FAPESP.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
56P - SLC34A2-ROS1 L2026M+G2032R confers resistance to ROS1 tyrosine kinase inhibitors in Ba/F3 cells through a reduced ATP binding pocket volume
Presenter: Christa Dijkhuizen
Session: Poster session 09
57P - Metastasis organotropism: Unveiling associated proteins using network biology
Presenter: Margarida Carrolo
Session: Poster session 09
59P - Correlation of tumor microenvironment signature in advanced stage non-small cell lung cancer with EGFR mutation who received EGFR-TKIs
Presenter: Chaiyapong Ngamchokwathana
Session: Poster session 09
60P - Establishment and characterization of a novel lung adenocarcinoma cell line HX-JCJ harboring MET ex14 skipping mutation
Presenter: Xuejin Ou
Session: Poster session 09
61P - Next generation sequencing and its clinical utility in advanced cancer: Single institute experience from low-middle income country
Presenter: Amit Badola
Session: Poster session 09
62P - Prebiotics modulate gut microbiota-mediated T cell immunity to enhance sintilimab inhibition of lung cancer
Presenter: QIN YAN
Session: Poster session 09
63P - Addition of human chorionic gonadotropin to the current standard mobilization approach with granulocyte-colony stimulating factor increases overall survival in a murine model of peripheral blood stem cell transplantation: Are we far enough for therapy?
Presenter: Andrei Cismaru
Session: Poster session 09
64P - Developing novel therapeutics for bladder cancer leveraging drosophila models
Presenter: Takuya Moriguchi
Session: Poster session 09
65P - Ionizing radiation induces vascular smooth muscle cell senescence through activating NF-κB-CTCF-p16 pathway
Presenter: xuefeng zheng
Session: Poster session 09
66P - Exploring the radiobiology and dosimetry of targeted alpha therapy as a tool to optimize its clinical application: A preclinical study
Presenter: Maria Filomena Botelho
Session: Poster session 09