Ponnari Gottipati

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Expression of BRCA1 is commonly decreased in sporadic breast tumors, and this correlates with poor prognosis of breast cancer patients. Here we show that BRCA1 transcripts are selectively enriched in the Argonaute/miR-182 complex and miR-182 downregulates BRCA1 expression. Antagonizing miR-182 enhances BRCA1 protein levels and protects them from IR-induced(More)
Homologous recombination (HR) is an important DNA repair pathway and is essential for cellular survival. It plays a major role in repairing replication-associated lesions and is functionally connected to replication. Transcription is another cellular process, which has emerged to have a connection with HR. Transcription enhances HR, which is a ubiquitous(More)
Poly(ADP-ribose) (PAR) polymerase 1 (PARP1) is activated by DNA single-strand breaks (SSB) or at stalled replication forks to facilitate DNA repair. Inhibitors of PARP efficiently kill breast, ovarian, or prostate tumors in patients carrying hereditary mutations in the homologous recombination (HR) genes BRCA1 or BRCA2 through synthetic lethality. Here, we(More)
Familial breast and ovarian cancers are often defective in homologous recombination (HR) due to mutations in the BRCA1 or BRCA2 genes. Cisplatin chemotherapy or poly(ADP-ribose) polymerase (PARP) inhibitors were tested for these tumors in clinical trials. In a screen for novel drugs that selectively kill BRCA2-defective cells, we identified 6-thioguanine(More)
Transcription can enhance recombination; this is a ubiquitous phenomenon from prokaryotes to higher eukaryotes. However, the mechanism of transcription-associated recombination in mammalian cells is poorly understood. Here we have developed a construct with a recombination substrate in which levels of recombination can be studied in the presence or absence(More)
Acute and chronic hypoxia exists within the three-dimensional microenvironment of solid tumors and drives therapy resistance, genetic instability, and metastasis. Replicating cells exposed to either severe acute hypoxia (16 hours with 0.02% O(2)) followed by reoxygenation or moderate chronic hypoxia (72 hours with 0.2% O(2)) treatments have decreased(More)
Homologous recombination (HR) is intricately associated with replication, transcription and DNA repair in all organisms studied. However, the interplay between all these processes occurring simultaneously on the same DNA molecule is still poorly understood. Here, we study the interplay between transcription and HR during ultraviolet light (UV)-induced DNA(More)
Transcription, replication and homologous recombination are intrinsically connected and it is well established that an increase of transcription is associated with an increase in homologous recombination. Here, we have studied how homologous recombination is affected during transcription inhibition by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB),(More)
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