Key result
FLOT1 depletion enhanced radiation-induced DNA damage and promoted radiation-mediated tumor regression by activating the STING signaling pathway in non-small cell lung cancer.
Why the study?
PD-L1 alone was not a reliable predictor of radiotherapy efficacy in NSCLC, and the role of its interacting candidate protein flotillin-1 (FLOT1) in radiation resistance was largely unknown.
Does FLOT1 depletion enhance radiotherapy efficacy and reduce radioresistance in non-small cell lung cancer?
Does FLOT1 depletion enhance radiotherapy efficacy and reduce radioresistance in non-small cell lung cancer?
FLOT1 is a positive regulator of PD-L1 and its depletion enhances radiotherapy efficacy in NSCLC by increasing DNA damage and promoting anti-tumor immunity via the STING pathway.
Radiation resistance results in the recurrence and metastasis of non-small cell lung cancer (NSCLC) after radiotherapy. A major cause of radiation resistance is subversion of immune surveillance and clearance. Although our previous research has demonstrated that programmed death-ligand 1 (PD-L1) is responsible for radiation resistance in NSCLC, PD-L1 alone was not a reliable predictor of radiotherapy efficacy. For further exploration of the predictors of radiotherapy efficacy, which could add accuracy to the single biomarker - PD-L1, immunoprecipitation followed by mass spectrometry assay was performed to identify proteins that interact with PD-L1, and flotillin-1 (FLOT1) was detected as a candidate. However, the role of FLOT1 in radiation resistance in NSCLC is largely unknown. Here, we defined FLOT1 as a positive regulator of PD-L1 at the cell level, and the expression of PD-L1 was reduced following FLOT1 depletion. Furthermore, we found that the knockdown of FLOT1 impeded radiation-mediated cell migration and epithelial-mesenchymal transition process. Moreover, FLOT1 depletion enhanced radiation-induced DNA damage, thereby increasing the radiation lethality for NSCLC cells and promoting radiation-mediated tumor regression in animal models and patients with NSCLC. Furthermore, FLOT1 depletion-boosted DNA damage activated STING signaling pathway and promoted the production of CCL5 and CXCL10 that can drive CD8+ T lymphocytes chemotaxis, thereby reprogramming tumor immune microenvironment and triggering the antitumor immune response. Indeed, FLOT1 expression correlated with infiltration of immune cells in NSCLC tumor tissue samples. Taken together, our findings reported an unexplored role of FLOT1 in radiotherapy and also provided an evidence base for FLOT1 as a promising biomarker to predict the response to radiotherapy and a potential therapeutic target for enhancing radiotherapy effects.
No takes yet. Share an insight, caveat, or question.
Wang et al. (2023) studied non-small cell lung cancer (NSCLC). FLOT1 depletion was evaluated on radiation resistance and tumor regression. FLOT1 depletion enhanced radiation-induced DNA damage and promoted radiation-mediated tumor regression by activating the STING signaling pathway in non-small cell lung cancer.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: