123P - Curcumin downregulates FAT1 expression via NFkB in glioblastoma (123P)

Date 18 November 2017
Event ESMO Asia 2017 Congress
Session Poster lunch
Topics Central Nervous System Malignancies
Translational Research
Presenter Chitrangda Srivastava
Citation Annals of Oncology (2017) 28 (suppl_10): x35-x38. 10.1093/annonc/mdx657
Authors C. Srivastava1, Y. Gupta1, K. Irshad1, P. Chattopadhaya1, C. Sarkar2, A. Suri3, S. Sinha4, K. Chosdol1
  • 1Biochemistry, AIIMS, 110029 - New Delhi/IN
  • 2Pathology, AIIMS, 110029 - New Delhi/IN
  • 3Neurosurgery, AIIMS, 110029 - New Delhi/IN
  • 4Neuro-oncology, NBRC, Gurgaon/IN

Abstract

Background

Glioblastoma (GBM) is the most aggressive brain cancer. Curcumin, a natural dietary polyphenol extracted from Curcuma longa L, has a demonstrated promising outcome against the GBM. Many molecular targets of curcumin are still undefined. Our lab is focused on the functional role of FAT1 which is a transmembrane protein and found to have oncogenic role in GBM. This study is designed to analyze the regulation of FAT1 expression by curcumin.

Methods

U87MG cells were treated with Curcumin (5uM, 10uM and 20uM) for 24 hours, PDTC (Pyrrolidine dithiocarbamate) (5uM and 10uM) for 1 hour and TNFα (100ng/ml) for 24 hours. FAT1 promoter pGL3F1 [1kb; -200bp/+848bp from transcription start site (TSS) (+1)] was cloned in luciferase vector (pGL3Basic) and promoter activity was analysed in U87MG, A172, and U373MG. Characterization of NFkB binding sites was done by FAT1 deletion constructs (5’ and 3’ NFkB site deletion), site directed mutagenesis (SDM) and ChIP assay. FAT1 and NFkB expression were correlated in GBM tumors (n = 16) and TCGA GBM data set.

Results

FAT1 and NFkB was significantly downregulated in U87MG cells treated with curcumin. Also, PDTC (NFkB inhibitor) treatment showed significant decrease in FAT1 expression. But, TNFα (NFkB stimulator) treatment showed increased FAT1 expression in U87MG cells. Transfac (in-silico) analysis predicted three NFkB sites at -90bp/-80bp, +347bp/+356bp and +360bp/+368bp on 1kb FAT1 promoter. Glioma cell lines were transfected with cloned FAT1 promoter constrcut (pGL3F1), showed significant increase in promoter activity. Interestingly, FAT1 promoter activity was downregulated in curcumin treated cells and upregulated in TNFα treated cells. The most potential binding site for NFkB was found to be at-90bp/-80bp on FAT1 promoter upstream to TSS (+1). In our inhouse GBM tumors (n = 16), increased expression and a positive correlation between FAT1 and NFkB (r = 0.70, p 

Conclusions

Our in-vitro and GBM tumor analysis for the first time confirms the regulation of FAT1 by curcumin via NFkB transcription factor in glioblastoma and also validating a novel link between NFkB and FAT1.

Clinical trial identification

Legal entity responsible for the study

AIIMS

Funding

Indian council for medical research (ICMR)

Disclosure

All authors have declared no conflicts of interest.