Project description:p53 mutation is common and highly related to radiotherapy resistance in rectal cancer. APR-246, as a small molecule, can restore the tumor-suppressor function to mutant p53. There is no study on combining APR-246 with radiation in rectal cancer; therefore, we examined whether APR-246 sensitized colorectal cancer cells with different p53 status to radiation. The combination treatment had synergistic effects on HCT116p53-R248W/-(p53Mut) cells, followed by HCT116p53+/+(p53WT) cells, and exhibited an additive effect on HCT116p53-/-(p53Null) cells through inhibiting proliferation, enhancing reactive oxygen species, and apoptosis. The results were confirmed in zebrafish xenografts. Comparison of the transcriptome in colorectal cancer cells with different p53 status 72hrs post-treatment with APR-246, irradiation, or the combination of APR-246 with irradiation was carried out. p53Mut and p53WT cells shared more activated pathways and differentially expressed genes following the combination treatment, compared to p53Null cells, although the combination treatment regulated individual pathways in the different cell lines. APR-246 mediated radio-sensitization effects through p53-dependent and -independent ways.
Project description:Identification of ovarian cancer (OvCa) patient subpopulations with increased sensitivity to targeted therapies could offer significant clinical benefit. We report that 22 % of the high grade OvCa tumors at diagnosis express CIP2A oncoprotein at low levels. Further, regardless of their significantly lower likelihood of disease relapse after standard chemotherapy, a portion of relapsed tumors retain their CIP2A-deficient phenotype. Through a screen for therapeutics that would preferentially kill CIP2A-deficient OvCa cells, we identified reactive oxygen species inducer APR-246, tested previously in OvCa clinical trials. Consistent with CIP2A-deficient OvCa subtype in humans, CIP2A is dispensable for development of MISIIR-Tag-driven mouse OvCa tumors. Nevertheless, CIP2A null OvCa tumor cells from MISIIR-Tag mice displayed APR-246 hypersensitivity both in vitro and in vivo. Mechanistically, the lack of CIP2A expression hypersensitizes the OvCa cells to APR-246 by inhibition of NF-kB activity. Accordingly, combination of APR-246 and NF-kB inhibitor compounds strongly synergized in killing of CIP2A positive OvCa cells. Collectively, the results warrant consideration of clinical testing of APR-246 for CIP2A-deficient OvCa tumor subtype patients. Results also reveal CIP2A as a candidate APR-246 combination therapy target for ovarian cancer.
Project description:p53 mutation is common and highly related to radiotherapy resistance in rectal cancer. APR-246, as a small molecule, can restore the tumor-suppressor function to mutant p53. As there is currently no existing study on combining APR-246 with radiation in rectal cancer, our objective was to investigate whether APR-246 could enhance the sensitivity of colorectal cancer cells, regardless of their p53 status, to radiation treatment. The combination treatment had synergistic effects on HCT116p53-R248W/- (p53Mut) cells, followed by HCT116p53+/+ [wild-type p53 (p53WT)] cells, and exhibited an additive effect on HCT116p53-/- (p53Null) cells through inhibiting proliferation, enhancing reactive oxygen species, and apoptosis. The results were confirmed in zebrafish xenografts. Mechanistically, p53Mut and p53WT cells shared more activated pathways and differentially expressed genes following the combination treatment, compared with p53Null cells, although the combination treatment regulated individual pathways in the different cell lines. APR-246 mediated radiosensitization effects through p53-dependent and -independent ways. The results may provide evidence for a clinical trial of the combination in patients with rectal cancer.
Project description:Though p53 mutations are rare in Ewing sarcoma, there is a strong indication that p53-mutant tumors form a particularly bad prognosis group. As such, novel treatment strategies are warranted that would specifically target and eradicate tumor cells containing mutant-p53 in this subset of ES patients. PRIMA-1Met/APR-246 is a small organic molecule which has been shown to restore tumor suppressor function primarily to mutant p53 and to also induce cell death in various cancer cell types. We analyzed the apoptosis inducibility on Ewing sarcoma cells harbouring different p53 mutations upon exposure to APR-246. Gene expression profiles of three STA-ET-7 cell lines established from the same patient at different stages of the disease was assessed by microarray analysis as these cell lines responded variably to APR-246.
Project description:Expression of genes in sorted CD4, CD8 and non-T CD45 cells isolated from TME of B16 tumors in wildtype B6, APR-246 treated wildtype B6 and Super p53 mice.
Project description:Though p53 mutations are rare in Ewing sarcoma, there is a strong indication that p53-mutant tumors form a particularly bad prognosis group. As such, novel treatment strategies are warranted that would specifically target and eradicate tumor cells containing mutant-p53 in this subset of ES patients. PRIMA-1Met/APR-246 is a small organic molecule which has been shown to restore tumor suppressor function primarily to mutant p53 and to also induce cell death in various cancer cell types.
Project description:In order to explain the synergistic effects observed by the combination APR+AZA in MDS cells by synergistic activated pathways, we performed a transcriptomic analysis of MDS cells treated with each drug alone and compared it to the combination.