Qualification: 
MSc, BSc
drishyag@am.amrita.edu

Drishya G. currently serves as Junior Research Fellow at the School of Biotechnology. She received his masters in Biotechnology from Amrita Vishwa Vidyapeetham, Amritapuri in 2012.

ALMA MATER

  • M. Sc. Biotechnology, Amrita Vishwa Vidyapeetham (2012)
  • B. Sc. Biotechnology and Botany, M. G. University (2010)

EARLIER AFFILIATION

  • Junior Research Fellow, Amrita School of Biotechnology (current)
  • Project Trainee at Regional Cancer Centre (RCC), Trivandrum (2012)

AWARDS / HONOURS

  • Junior Research Fellowship from Amrita School of Biotechnology

Publications

Publication Type: Journal Article

Year of Publication Title

2020

Drishya G., Dr. Jyotsna Nambiar, Sanu K. Shaji, Muralidharan Vanuopadath, A., A., Abishek, K., Ashna, A., Ayesha Sherif, Catherine Joseph, Divya P., Damu Sunilkumar, Chinchu Bose, Dr. Sobha V. Nair, S. Sudarslal, Dr. Geetha Kumar, S., L., and Dr. Bipin G. Nair, “RECK and TIMP-2 mediate inhibition of MMP-2 and MMP-9 by Annona muricata”, Journal of Biosciences, vol. 45, no. 1, p. 89, 2020.[Abstract]


Up-regulation of MMP-2 and MMP-9 plays a significant role in promoting cancer progression by degrading the components of the extracellular matrix, thereby enhancing the migration of tumor cells. Although the anti-proliferative and apoptotic effect of Annona muricata is well established, its effect on MMP-2 and MMP-9, a major target in several types of cancers, has not been studied. Powdered samples of various parts of A. muricata like fruit, stem, seed, and twig extracted using aqueous methanol showed significant dose-dependent inhibition of MMP-2 and MMP-9 in a highly metastatic fibrosarcoma cell line, HT1080. Additionally, these extracts also up-regulated the expression of several endogenous inhibitors of MMP-2 and MMP-9 like REversion-inducing Cysteine-rich protein with Kazal motifs (RECK) and Tissue Inhibitor of Metalloproteinase-2 (TIMP-2). Furthermore, primary cells developed from tumor tissues obtained from patients not exposed to chemotherapy, also exhibited similar results. Remarkably, the inhibition of MMP-2 and MMP-9 observed was tumor specific, with the A. muricata fruit extract showing only 2% inhibition in cells obtained from normal tissues, when compared to 60% inhibition observed in cells obtained from tumor samples. The present study elucidates a novel mechanism by which A. muricata extracts selectively exhibit their anti-cancer activity in tumor cells by down-regulating MMP-2 and MMP-9 that are important biomarkers in cancer.

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2019

Damu Sunilkumar, Drishya G., Chandrasekharan, A., Shaji, S. K., Chinchu Bose, Jossart, J., J. Jefferson P. Perry, Dr. Nandita Mishra, Dr. Geetha Kumar, and Dr. Bipin G. Nair, “Oxyresveratrol drives caspase-independent apoptosis-like cell death in MDA-MB-231 breast cancer cells through the induction of ROS.”, Biochem Pharmacol, p. 113724, 2019.[Abstract]


Earlier studies from our laboratory have demonstrated that Oxyresveratrol (OXY), a hydroxyl-substituted stilbene, exhibits potent inhibition of human melanoma cell proliferation. The present study defines a cytotoxic effect of OXY on the highly chemo-resistant, triple-negative human breast cancer cell line MDA-MB-231. OXY-mediated cell death resulted in accumulation of cells at the sub-G1 phase of the cell cycle, induced chromatin condensation, DNA fragmentation, phosphatidylserine externalization and PARP cleavage, indicative of apoptosis. Interestingly, morphology and cell viability studies with the pan-caspase inhibitor, QVD-OPH revealed that OXY-induced cell death was caspase-independent.Docking studies also showed that OXY can bind to the S1 site of caspase-3, and could also exert an inhibitory effect on this executioner caspase. The immunoblot analysis demonstrating the absence of caspase cleavage during cell death further confirmed these findings. OXY was also observed to induce the production of reactive oxygen species, which caused the depolarization of the mitochondrial membrane resulting in translocation of Apoptosis Inducing Factor (AIF) into the nucleus. Pretreatment of the cells with N-Acetyl Cysteine antioxidant prevented cell death resulting from OXY treatment. Thus, OXY initiates ROS-mediated, apoptosis-like cell death, involving mitochondrial membrane depolarization, translocation of AIF into the nucleus, and DNA fragmentation, resulting in caspase-independent cell death in MDA-MB-231 cells. The cytotoxicity manifested by OXY was also observed in 3D cell culture models and primary cells, thereby providing a basis for the utilization of OXY as a novel template for the future design of anticancer therapeutics.

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Publication Type: Conference Proceedings

Year of Publication Title

2017

Sanu K Shaji, Damu Sunilkumar, Drishya G., Dr. Geetha Kumar, and Dr. Bipin G. Nair, “MicroRNA-491 functions to down regulate both matrix metalloproteinase-9 and epidermal growth factor receptor expression and inhibit cell migration in MDA-MB-231 triple negative breast cancer cells (Poster)”, 27th Swadeshi Science Congress. Amritapuri, 2017.

Publication Type: Conference Paper

Year of Publication Title

2015

Drishya G., Lavanya Ashokan, Dr. Jyotsna Nambiar, Sanu K Shaji, Lakshmi S, Geetha B. Kumar, and Dr. Bipin G. Nair, “In Vitro Culture of Primary Cells from Cancer Patients- Screening for Potent MMP-9 Inhibitors”, in The XXXIX All India Cell Biology Conference , 2015.[Abstract]


Breast cancer is the most prevalent form of cancer among women worldwide. Established cancer cell lines generated over years have been used for studying the biology of breast cancer. These cell lines which have been passaged innumerable times creates genetic drift which makes the observations biologically less relevant. In vitro culture of primary cells from fresh surgical specimens provides a more accurate means for understanding the behavior of cancer cells and the adjacent normal cells. We have developed a simple and rapid method for isolating primary cultures from breast tumor and normal cells. Two different methods were employed for isolating primary cultures- one involving enzymatic digestion and the other using explant culture which is independent of enzymatic treatment and feeder cells. The primary cells obtained were further characterized by immunocytochemistry staining for Vimentin and Cytokeratin 18. The cells stained positive for Vimentin and negative for Cytokeratin 18 which indicated that they are of mesenchymal origin. Since gelatinases play a prominent role in promoting breast cancer metastasis, the primary cells were assessed for gelatinase activity. Our observations clearly show that the cancer cells had up-regulated gelatinases activity compared to the adjacent normal cells. These cells when treated with several natural products showed a dose-dependent inhibition of gelatinase activity. The results obtained were consistent in all the primary cell lines generated from different patient samples. These studies with the primary cell lines will therefore help in obtaining biological responses that more accurately mimics the tumor/cancer micro environment.

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CONTACT

Drishya G.
School of Biotechnology,
Amrita Vishwa Vidyapeetham (Amritapuri Campus),
Clappana P.O., Kollam, Kerala, India. 690525.