Background:
Recently Notch signaling pathway has gained attention as a potential therapeutic target for chemotherapeutic
intervention. However, the efficacy of previously known Notch inhibitors in colon cancer is still unclear. The purpose of this study was to
investigate the effect of andrographolide on aberrantly activated Notch signaling in SW-480 cells in vitro.
Methods:
The cytostatic potential of andrographolide on SW-480 cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl
tetrazolium bromide (MTT) assay, morphology assessment and colony formation assay. The apoptotic activity was evaluated by FITC
Annexin V assay, 4′,6-diamidino-2-phenylindole (DAPI), Hoechst, Rhodamine 123 and Mito Tracker CMXRos staining. Scratch assay
for migratory potential assessment. 7’-Dichlorodihydrofluorescein Diacetate (DCFH-DA) staining was used to evaluate the Reactive
Oxygen Species (ROS) generation. Relative mRNA expression of Bax, Bcl2, NOTCH 1 and JAGGED 1 was estimated by Real-Time
Quantitative Reverse Transcription PCR (qRT-PCR). Cell cycle phase distribution was evaluated Annexin V-FITC/PI staining.
Results:
MTT assay demonstrated dose and time dependent cytoxicity of andrographolide on SW-480 cells. It also inhibited the
migratory and colony forming potential of SW-480 cells. Furthermore, andrographolide also showed disruption of mitochondrial
membrane potential and induced apoptosis through nuclear condensation. Flow cytometric evaluation showed andrographolide enhanced
early and late apoptotic cells and induced upregulation of proapoptotic (Bax and Bad) and downregulation of antiapoptotic Bcl2 in treated
SW-480 cells. Andrographolide augmented intracellular ROS generation and induced G0/G1 phase cell cycle arrest in colon cancer SW480 cells. Furthermore, andrographolide repressed the Notch signaling by decreasing the expression of NOTCH 1 and JAGGED 1.
Conclusion:
Our findings suggested that andrographolide constraint the growth of SW-480 cells through the inhibition of Notch
signaling pathway.
SATB1 promotes epithelial-mesenchymal transition via Notch signaling pathway in colorectal cancer
