scholarly journals Sublethal concentrations of 17-AAG suppress homologous recombination DNA repair and enhance sensitivity to carboplatin and olaparib in HR proficient ovarian cancer cells

Oncotarget ◽  
2014 ◽  
Vol 5 (9) ◽  
pp. 2678-2687 ◽  
Author(s):  
Young Eun Choi ◽  
Chiara Battelli ◽  
Jacqueline Watson ◽  
Joyce Liu ◽  
Jennifer Curtis ◽  
...  
Endocrinology ◽  
2012 ◽  
Vol 153 (4) ◽  
pp. 1638-1648 ◽  
Author(s):  
Lisa K. Mullany ◽  
Zhilin Liu ◽  
Erin R. King ◽  
Kwong-Kwok Wong ◽  
JoAnne S. Richards

Loss of Pten in the KrasG12D;Amhr2-Cre mutant mice leads to the transformation of ovarian surface epithelial (OSE) cells and rapid development of low-grade, invasive serous adenocarcinomas. Tumors occur with 100% penetrance and express elevated levels of wild-type tumor repressor protein 53 (TRP53). To test the functions of TRP53 in the Pten;Kras (Trp53+) mice, we disrupted the Trp53 gene yielding Pten;Kras(Trp53−) mice. By comparing morphology and gene expression profiles in the Trp53+ and Trp53− OSE cells from these mice, we document that wild-type TRP53 acts as a major promoter of OSE cell survival and differentiation: cells lacking Trp53 are transformed yet are less adherent, migratory, and invasive and exhibit a gene expression profile more like normal OSE cells. These results provide a new paradigm: wild-type TRP53 does not preferentially induce apoptotic or senescent related genes in the Pten;Kras(Trp53+) cancer cells but rather increases genes regulating DNA repair, cell cycle progression, and proliferation and decreases putative tumor suppressor genes. However, if TRP53 activity is forced higher by exposure to nutlin-3a (a mouse double minute-2 antagonist), TRP53 suppresses DNA repair genes and induces the expression of genes that control cell cycle arrest and apoptosis. Thus, in the Pten;Kras(Trp53+) mutant mouse OSE cells and likely in human TP53+ low-grade ovarian cancer cells, wild-type TRP53 controls global molecular changes that are dependent on its activation status. These results suggest that activation of TP53 may provide a promising new therapy for managing low-grade ovarian cancer and other cancers in humans in which wild-type TP53 is expressed.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248941
Author(s):  
Mona Al-Mugotir ◽  
Jeffrey J. Lovelace ◽  
Joseph George ◽  
Mika Bessho ◽  
Dhananjaya Pal ◽  
...  

Synthetic lethality is a successful strategy employed to develop selective chemotherapeutics against cancer cells. Inactivation of RAD52 is synthetically lethal to homologous recombination (HR) deficient cancer cell lines. Replication protein A (RPA) recruits RAD52 to repair sites, and the formation of this protein-protein complex is critical for RAD52 activity. To discover small molecules that inhibit the RPA:RAD52 protein-protein interaction (PPI), we screened chemical libraries with our newly developed Fluorescence-based protein-protein Interaction Assay (FluorIA). Eleven compounds were identified, including FDA-approved drugs (quinacrine, mitoxantrone, and doxorubicin). The FluorIA was used to rank the compounds by their ability to inhibit the RPA:RAD52 PPI and showed mitoxantrone and doxorubicin to be the most effective. Initial studies using the three FDA-approved drugs showed selective killing of BRCA1-mutated breast cancer cells (HCC1937), BRCA2-mutated ovarian cancer cells (PE01), and BRCA1-mutated ovarian cancer cells (UWB1.289). It was noteworthy that selective killing was seen in cells known to be resistant to PARP inhibitors (HCC1937 and UWB1 SYr13). A cell-based double-strand break (DSB) repair assay indicated that mitoxantrone significantly suppressed RAD52-dependent single-strand annealing (SSA) and mitoxantrone treatment disrupted the RPA:RAD52 PPI in cells. Furthermore, mitoxantrone reduced radiation-induced foci-formation of RAD52 with no significant activity against RAD51 foci formation. The results indicate that the RPA:RAD52 PPI could be a therapeutic target for HR-deficient cancers. These data also suggest that RAD52 is one of the targets of mitoxantrone and related compounds.


2019 ◽  
Vol 19 (1) ◽  
pp. 199-210 ◽  
Author(s):  
Lu Liu ◽  
Shurui Cai ◽  
Chunhua Han ◽  
Ananya Banerjee ◽  
Dayong Wu ◽  
...  

2019 ◽  
Vol 167 ◽  
pp. 125-132 ◽  
Author(s):  
Asima Mukhopadhyay ◽  
Yvette Drew ◽  
Elizabeth Matheson ◽  
Mo Salehan ◽  
Lucy Gentles ◽  
...  

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