Investigator

Kshama Kundu

Scientific Officer · Bhabha Atomic Research Centre, Bio-Organic Division

KKKshama Kundu
Papers(1)
Targeting Replication…
Collaborators(7)
Muskan SharmaNitish ChauhanPapiya DeySankarsingh Kesharsin…Birija Sankar PatroGanesh Pai BellareKrupa Thankam Philip
Institutions(1)
Bhabha Atomic Researc…

Papers

Targeting Replication Fork Processing Synergizes with PARP Inhibition to Potentiate Lethality in Homologous Recombination Proficient Ovarian Cancers

AbstractSynthetic lethality in homologous recombination (HR)‐deficient cancers caused by Poly (ADP‐ribose) polymerase inhibitors (PARPi) has been classically attributed to its role in DNA repair. The mode of action of PARPi and resistance thereof are now believed to be predominantly replication associated. Therefore, effective combinatorial approaches of targeting replication fork processing along with HR‐downregulation to target HR‐proficient and possibly PARPi‐resistant tumors are warranted. Stilbenes are a privileged class of molecules, which include resveratrol, pterostilbene, piceatannol, etc, that modulate both replication processes and RAD51‐expression. In this investigation, by screening a small library of stilbenes, including in‐house synthesized molecules, trans‐4,4′‐dihydroxystilbene (DHS) was discovered as a potent natural agent, which downregulates RAD51 expression and HR repair (GFP‐reporter assay). DHS induces extensive synergistic cell death in ovarian cancers when combined with talazoparib (PARPi). Mechanistically, DHS elicits replication‐stress through severely impeding replication fork progress, speed, and inducing fork‐asymmetry. This leads to robust induction of single stranded DNA (ssDNA) gaps and poly‐ADP‐ribosylation (PARylation) in S‐phase cells, signifying issues related to lagging (Okazaki) strand synthesis. PARPi, which abrogates PARylation, potentiates DHS induced ssDNA gaps, and their conversion into lethal double strand breaks through MRE11 action. Furthermore, the combination is highly effective in mitigating ovarian tumor xenograft growth in SCID mice and exhibited a good therapeutic‐index with no/minimal tissue‐toxicity.

21Works
1Papers
7Collaborators
Ovarian NeoplasmsCell Line, TumorXenograft Model Antitumor Assays

Positions

2007–

Scientific Officer

Bhabha Atomic Research Centre · Bio-Organic Division

Education

2016

Ph.D.

Homi Bhabha National Institute · Bio-Organic Division

2006

M.Sc.

Indian Institute of Technology Madras · Chemistry Department

2004

B.Sc.

University of Calcutta

2001

Higher Secondary

Kamala Girls High School