Project description:Arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) combination safely cures fatal acute promyelocytic leukemia, but the mechanisms underlying their action and synergy remain elusive. ATRA inhibits APL, breast and liver cancers by targeting isomerase Pin1, a master regulator of oncogenic signaling. Here we show that ATO targets Pin1 and cooperates with ATRA to exert potent anticancer activity. ATO inhibits and degrades Pin1, and suppresses its oncogenic function by noncovalent binding to Pin1’s active site. ATRA increases cellular ATO uptake through upregulating aquaporin-9. ATO and ATRA, at clinically safe doses, cooperatively ablate Pin1 to block numerous cancer-driving pathways and inhibit the growth of triple-negative breast cancer cells and tumor-initiating cells in cell and animal models including patient-derived orthotopic xenografts, similar to Pin1 CRISPR knockout, which is substantiated by comprehensive protein and microRNA analyses. Thus, synergistic Pin1 inhibition by ATO and ATRA offers an attractive approach to combating breast and other cancers.
Project description:To investigate the specific gene expression program by which mutant-p53 and Pin1 control invasion and metastasis in breast cancer cells, we compared the transcriptomic profile of control, mutant-p53 depleted or Pin1 depleted MDA-MB-231 cells.
Project description:To investigate the specific gene expression program by which mutant-p53 and Pin1 control invasion and metastasis in breast cancer cells, we compared the transcriptomic profile of control, mutant-p53 depleted or Pin1 depleted MDA-MB-231 cells. MDA-MB-231 cells were transfected twice with siRNA against Pin1, p53 or LacZ as a control. Transfections were performed by using Lifofectamine 2000 (Invitrogen) according to manufacture's procedure. Forty-eight hours after second transfection, samples were then processed for total RNA extraction and hybridization on Affymetrix microarrays. Three biological replicas (A, B, C) were used for each of the three conditions, for a total of 9 samples
Project description:ATRA was identified as a Pin1 inhibitor via fluorescence polarization-based high throughput screening. We performed microarray expression profiling to demonstrate the similarity between ATRA and Pin1 KD at the genome-wide level APL NB4 cells in response to ATRRA or inducible Pin1 knockdown for 3 days were collected for RNA extraction and hybridization on Affymetrix microarrays. We sought to validate in genome-wide level whether similarity occurred between ATRA and Pin1 knockdown-treated NB4 cells.
Project description:Arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) combination safely cures fatal acute promyelocytic leukemia, but the mechanisms underlying their action and synergy remain elusive. ATRA inhibits APL, breast and liver cancers by targeting isomerase Pin1, a master regulator of oncogenic signaling. Here we show that ATO targets Pin1 and cooperates with ATRA to exert potent anticancer activity. ATO inhibits and degrades Pin1, and suppresses its oncogenic function by noncovalent binding to Pin1’s active site. ATRA increases cellular ATO uptake through upregulating aquaporin-9. ATO and ATRA, at clinically safe doses, cooperatively ablate Pin1 to block numerous cancer-driving pathways and inhibit the growth of triple-negative breast cancer cells and tumor-initiating cells in cell and animal models including patient-derived orthotopic xenografts, similar to Pin1 CRISPR knockout, which is substantiated by comprehensive protein and microRNA analyses. Thus, synergistic Pin1 inhibition by ATO and ATRA offers an attractive approach to combating breast and other cancers.
Project description:ATRA was identified as a Pin1 inhibitor via fluorescence polarization-based high throughput screening. We performed microarray expression profiling to demonstrate the similarity between ATRA and Pin1 KD at the genome-wide level