Benzyl Isothiocyanate-Induced Cytotoxicity via the Inhibition of Autophagy and Lysosomal Function in AGS Cells

Area of Science:

• Oncology
• Cell Biology
• Biochemistry

Background:

• Gastric adenocarcinoma is a leading cause of cancer mortality globally.
• Benzyl isothiocyanate (BITC) shows promise in inhibiting gastric cancer metastasis and inducing apoptosis.
• Autophagy plays a complex role in cancer, potentially acting as a survival mechanism.

Purpose of the Study:

• To investigate the impact of Benzyl isothiocyanate (BITC) on the autophagy mechanism in gastric adenocarcinoma AGS cells.
• To determine if BITC affects the initiation and/or degradation phases of autophagy.
• To elucidate the role of autophagy inhibition in BITC-induced cell death.

Main Methods:

• AGS cells were treated with varying concentrations of BITC (5, 10, 15 μM) for 24 hours.
• Autophagy protein levels (LC3B, p62/SQSTM1, Atg5-Atg12, Beclin1, p-mTOR/mTOR, class III PI3K) were assessed using qPCR, western blotting, and immunocytochemistry.
• Lysosomal function was evaluated via cathepsin activity assays, Bafilomycin A1 treatment, acridine orange staining, and omnicathepsin assay.
• LC3B gene knockdown was performed using siRNA.

Main Results:

• BITC treatment led to a reduction in key autophagy initiation proteins, including Beclin 1, class III PI3K, and the Atg5-Atg12 complex.
• BITC induced lysosomal dysfunction, evidenced by decreased cathepsin activity and protein levels, and enlarged acidic vesicles.
• Analysis indicated that BITC inhibits autophagy at both the initiation and degradation stages.

Conclusions:

• Benzyl isothiocyanate (BITC) inhibits gastric cancer cell autophagy, affecting both initiation and degradation processes.
• The observed lysosomal dysfunction and reduced autophagy contribute to BITC-mediated cell death in AGS cells.
• Targeting autophagy may be a viable strategy in combination with BITC for gastric cancer treatment.