Inhibition of NOTCH signaling pathway chemosensitizes HCC CD133+ cells to vincristine and 5-fluorouracil through upregulation of BBC3.

Hamed Hemati, Jagdeep Kaur, R C Sobti, Nirupma Trehanpati

Biochemical and biophysical research communications 2020 May 14

filter terms:

In hepatocellular carcinoma (HCC), the poor response to the chemotherapeutic agents is partially attributed to the chemoresistance property of cancer stem cells (CSCs). NOTCH signaling pathway plays a crucial role in the chemoresistance through the maintenance of the CSCs. We observed that the NOTCH pathway was activated in HCC CD133+ cells treated with vincristine (VIN)1 and 5-fluorouracil (5-FU)2. Therefore, we examined whether inhibition of the NOTCH can improve sensitization of HCC CD133+ cells to VIN and 5-FU. The Huh7 cell line was pre-incubated γ-secretase DAPT, as a NOTCH inhibitor, and then treated with IC50 dose of VIN or 5-FU. The CD133+ cells were then isolated and analyzed for the cell viability, apoptosis, migration and spheroid formation capacities, and gene and protein expression. It was observed that pre-incubation with DAPT significantly downregulated the expression of NOTCH-related genes and led to a significant reduction in VIN- and 5-FU-CD133+ population. In addition, DAPT pre-incubated VIN- and 5-FU-treated-CD133+ cells formed fewer spheroids in 3D culture and had a lesser migration capacity in 2D culture. Importantly, DAPT enhanced the apoptosis rate of VIN- and 5-FU-treated CD133+ cells for 3- and 2-fold, which was correlated with the enhanced expression of pro-apoptotic BBC3 (BCL-2-binding component 3) and decreased expression of HES1 that was reported to regulate BBC3 negatively. Collectively, it was observed that NOTCH inhibition sensitized the HCC CD133+ cells to VIN and 5-FU through enhancing BBC3-mediated apoptosis. The results highlighted the role of NOTCH/HES1/BBC3 axis in resistance of CD133+ cells to VIN and 5-FU. Understanding the molecular mechanisms underlying chemoresistance in HCC CD133+ cells may help in designing the novel targeted therapies to chemosensitize them. Copyright © 2020 Elsevier Inc. All rights reserved.

Citation

Hamed Hemati, Jagdeep Kaur, R C Sobti, Nirupma Trehanpati. Inhibition of NOTCH signaling pathway chemosensitizes HCC CD133+ cells to vincristine and 5-fluorouracil through upregulation of BBC3. Biochemical and biophysical research communications. 2020 May 14;525(4):941-947