GAS5 modulated autophagy is a mechanism modulating cisplatin sensitivity in NSCLC cells

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Non-small cell lung cancer (NSCLC) remains a leading cause of cancer mortality worldwide.
• Cisplatin (DDP) is a cornerstone chemotherapy agent for NSCLC, but acquired resistance significantly limits its clinical efficacy.
• The role of long non-coding RNAs (lncRNAs) in regulating drug resistance and cellular processes like autophagy in NSCLC is an active area of research.

Purpose of the Study:

• To investigate the association between lncRNA GAS5 expression and cisplatin resistance in NSCLC.
• To elucidate the regulatory effect of GAS5 on autophagy and its impact on DDP resistance in NSCLC cells.

Main Methods:

• Quantitative real-time PCR (qRT-PCR) was used to measure GAS5 expression in NSCLC tissues and adjacent normal tissues from 15 patients.
• In vitro studies using A549 and A549/DDP cell lines involved GAS5 gain-and-loss experiments to assess its effects on autophagy and cisplatin sensitivity.
• Autophagy inhibition was studied using 3-methyladenine (3-MA).

Main Results:

• NSCLC tissues exhibited significantly lower GAS5 expression compared to adjacent normal tissues, with further downregulation observed in patients with progressive disease.
• GAS5 knockdown increased DDP IC50 in A549 cells, while GAS5 overexpression decreased DDP IC50 in A549/DDP cells, indicating a role in DDP resistance.
• GAS5 knockdown reduced autophagy in A549 cells, whereas GAS5 overexpression increased autophagy in A549/DDP cells. Autophagy inhibition with 3-MA mimicked GAS5's effects on DDP sensitivity and apoptosis.

Conclusions:

• Downregulation of GAS5 is significantly associated with cisplatin resistance in NSCLC.
• GAS5 functions to inhibit autophagy, thereby enhancing cisplatin sensitivity in NSCLC cells.
• Targeting GAS5 or modulating autophagy pathways may represent a therapeutic strategy to overcome DDP resistance in NSCLC.