Sir Ganga Ram hospital, India
Sangeeta Choudhury is Associate Professor & Senior Consultant @ Sir Ganga Ram hospital, New Delhi, INDIA. She has obtained her Doctoral degree from one of the premier institute of the country, Bhabha Atomic Energy Research Centre, Mumbai, India. Thereafter she was a Research Fellow at Department of Anatomy, Division of Cell Biology, University of New South Wales (UNSW), Sydney, AU and also did her Post Doctoral Fellowship at Division of Infectious Diseases, Centers for Disease Control and Prevention (CDC), Atlanta, USA. On returning to the country, she was positioned as Research Scientist (Indian Council of Medical Research), National Institute of Immunology, New Delhi, India. She has been the recipient of national awards (Lady Tata Grants, Department of Atomic Energy, INDO-US Vaccine Action Program). Her major areas of interests are solid tumor biology and stem cell, cancer & obesity related metabolic disorders, transplantation immunology. She is in the review board of national journals and also scientific committee. She is a member of Cancer bodies and also Immunology & biochemistry national bodies [American Association for Cancer Research (USA); Indian Society of Oncology (India); American Society for Microbiology (USA), Society for Biological Chemists, India (India), Association of Clinical Biochemists India]. She has authored about 28 scientific articles and 3 book chapters too.
Over the years, pancreatic cancer has been established as a complicated disease with poor prognosis and survival rate. Standard chemotherapeutic agents/drugs have not shown any significant advancement in its regression. Several studies have indicated anti-angiogenesis and blocking the cancerous growth of breast, prostate, lung and colon by micronutrients like vitamin D, E, B12. Although, pancreatic cancer tissue expresses Vitamin D (VitD) receptor, the potential mechanism to exert anti-cancer effect remains underexplored.
Thus, our study aimed to find out the mechanistic effect caused by the VitD analogue (Calcitriol) in pancreatic cancer cells. Pancreatic cancer cells (PCC lines; MiaPaCa2 and PanC-1) treated with calcitirol for longer duration (24hrs-to-96hrs) showed decreased expression of metastatic phenotype, CXCR4/CCL12, EpCAM/Vimentin along with decreased chemoresistant-MUC-1 expression, although no inhibitory effect was observed on their proliferative capacity. But, addition of Gemcitabine (Gem) to calcitirol-treated PCC lines increased their apoptotic capacity than cells treated only with Gem, suggesting that calcitirol treated-PCC cells are susceptible to chemotherapeutic drug. Further, with the emergence of stroma playing a major role in pancreatic cancer, we attempted to elicit the involvement of VitD in Sonic Hedgehog (SHH) signaling. Enhanced apoptosis was observed when salinomycin (SHH inhibitor) was administered to calcitirol treated-PCC cells. Copy numbers of transcription factors C-myc, SMO, PTCH1, PTCH2, and hypoxia-induced factor (HIF1-α) were observed to show increased expression in treated PCC lines in comparison to untreated cells.
In conclusion, our experimental evidence postulates a potential mechanism by which VitD- analogue, calcitirol modulated its stromal interaction via its action on the cell-membrane protein MUC-1.