Oxidized 5-methylcytosine modulates synthetic lethality to poly-ADP-ribose polymerase inhibitors in acute myeloid leukemia
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus Homo sapiens
PROVIDER: GSE217587 | GEO | 2022/11/12
REPOSITORIES: GEO
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Project description:TET2 haploinsufficiency is a driving event in myeloid cancers and is associated with a worse prognosis in patients with AML. Enhancing residual TET2 activity using vitamin C increases oxidized 5-methylcytosine (mC) formation and promotes active DNA demethylation via BER that slows leukemia progression. We utilized genetic and compound library screening approaches to identify rational combination treatment strategies to improve the use of vitamin C as an adjuvant therapy for AML. In addition to increasing the efficacy of several FDA approved drugs, vitamin C treatment with PARPi elicited a strong synergistic effect at blocking AML self-renewal in murine and human AML models. Vitamin C-mediated TET activation combined with PARPi caused an enrichment of chromatin-bound PARP1 at oxidized mCs, and H2AX accumulation during mid-S phase leading to cell-cycle stalling and differentiation. Given most AML subtypes maintain residual TET2 expression, vitamin C could elicit broad efficacy as a PARPi therapeutic adjuvant.
2022-11-12 | GSE217586 | GEO
Project description:TET2 haploinsufficiency is a driving event in myeloid cancers and is associated with a worse prognosis in patients with AML. Enhancing residual TET2 activity using vitamin C increases oxidized 5-methylcytosine (mC) formation and promotes active DNA demethylation via BER that slows leukemia progression. We utilized genetic and compound library screening approaches to identify rational combination treatment strategies to improve the use of vitamin C as an adjuvant therapy for AML. In addition to increasing the efficacy of several FDA approved drugs, vitamin C treatment with PARPi elicited a strong synergistic effect at blocking AML self-renewal in murine and human AML models. Vitamin C-mediated TET activation combined with PARPi caused an enrichment of chromatin-bound PARP1 at oxidized mCs, and H2AX accumulation during mid-S phase leading to cell-cycle stalling and differentiation. Given most AML subtypes maintain residual TET2 expression, vitamin C could elicit broad efficacy as a PARPi therapeutic adjuvant.
2022-11-12 | GSE217585 | GEO
Project description:Prior studies have demonstrated that inhibition of CHK1 can promote the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and phosphorylation of histone H2AX and that inhibition of poly(ADP-ribose) polymerase 1 (PARP1) can affect growth factor-induced ERK1/2 activation. The present studies were initiated to determine whether CHK1 inhibitors interacted with PARP1 inhibition to facilitate apoptosis. Transient expression of dominant-negative CHK1 raised basal ERK1/2 activity and prevented CHK1 inhibitors from activating ERK1/2. CHK1 inhibitors modestly increased the levels of PARP1 ADP ribosylation and molecular or small-molecule inhibition of PARP1 blocked CHK1 inhibitor-stimulated histone H2AX phosphorylation and activation of ERK1/2. Stimulated histone H2AX phosphorylation was ataxia telangiectasia-mutated protein-dependent. Multiple CHK1 inhibitors interacted in a greater than additive fashion with multiple PARP1 inhibitors to cause transformed cell-killing in short-term viability assays and synergistically killed tumor cells in colony-formation assays. Overexpression of BCL-xL or loss of BAX/BAK function, but not the function of BID, suppressed CHK1 inhibitor + PARP1 inhibitor lethality. Inhibition of BCL-2 family protein function enhanced CHK1 inhibitor + PARP1 inhibitor lethality and restored drug-induced cell-killing in cells overexpressing BCL-xL. Thus, PARP1 plays an important role in regulating the ability of CHK1 inhibitors to activate ERK1/2 and the DNA damage response. An inability of PARP1 to modulate this response results in transformed cell death mediated through the intrinsic apoptosis pathway.
| S-EPMC2981366 | biostudies-literature
Project description:Oxidized 5-methylcytosine modulates synthetic lethality to poly-ADP-ribose polymerase inhibitors in acute myeloid leukemia
| PRJNA899655 | ENA
Project description:The present studies sought to define whether checkpoint kinase 1 (CHK1) inhibitors and poly(ADP-ribose) polymerase 1 (PARP1) inhibitors interact in vitro and in vivo to kill breast cancer cells. PARP1 and CHK1 inhibitors interacted to kill estrogen receptor (ER)+, ER+ fulvestrant-resistant, HER2+, or triple-negative mammary carcinoma cells in a manner that was not apparently affected by phosphatase and tensin homolog deleted on chromosome 10 functional status. Expression of dominant-negative CHK1 enhanced and overexpression of wild-type CHK1 suppressed the toxicity of PARP1 inhibitors in a dose-dependent fashion. Knockdown of PARP1 enhanced the lethality of CHK1 inhibitors in a dose-dependent fashion. PARP1 and CHK1 inhibitors interacted in vivo both to suppress the growth of large established tumors and to suppress the growth of smaller developing tumors; the combination enhanced animal survival. PARP1 and CHK1 inhibitors profoundly radiosensitized cells in vitro and in vivo. In conclusion, our data demonstrate that the combination of PARP1 and CHK1 inhibitors has antitumor activity in vivo against multiple mammary tumor types and that translation of this approach could prove to be a useful anticancer therapeutic approach.
| S-EPMC3400842 | biostudies-other
Project description:Although improvements in radiation therapy were made over the years, radioresistance is still a major challenge. Cancer cells are often deficient for DNA repair response, a feature that is currently exploited as a new anti-cancer strategy. In this context, combination of inhibitors targeting complementary pathways is of interest to sensitize cells to radiation. In this work, we used PARP (Olaparib) and RAD51 (B02) inhibitors to radiosensitize cancer cells to proton and X-ray radiation. More particularly, Olaparib and B02 were used at concentration leading to limited cytotoxic (alone or in combination) but increasing cell death when the cells were irradiated. We showed that, although at limited concentration, Olaparib and B02 were able to radiosensitize different cancer cell lines, i.e. lung and pancreatic cancer cells. Antagonistic, additive or synergistic effects were observed and correlated to cell proliferation rate. The inhibitors enhanced persistent DNA damage, delayed apoptosis, prolonged cell cycle arrest and senescence upon irradiation. These results demonstrated that radiation-induced synthetic lethality might widen the therapeutic window, hence extending the use of PARP inhibitors to patients without BRCAness.
| S-EPMC6649553 | biostudies-literature
Project description:ObjectivePathogenic variations in the homologous recombination (HR) gene, BRCA1 interacting protein C-terminal helicase 1 (BRIP1) increase the risk for ovarian cancer. PARP inhibitors (PARPi) exert a synthetic lethal effect in BRCA-mutated ovarian cancers. Effective HR requires cooperation between BRCA1 and BRIP1; therefore, BRIP1-incompetancy may predict vulnerability to synthetic lethality. Here we investigated the response of ovarian epithelial cells with defective BRIP1 function to PARPi, and compared these cells to those lacking BRCA1 activity.MethodsWe engineered Chinese Hamster ovarian (CHO) epithelial cells to express deficient BRIP1 or BRCA1, and exposed them to olaparib with or without carboplatin or cisplatin. We assessed cellular proliferation and survival; we calculated inhibitory concentrations and combination and reduction drug indices.ResultsBRIP1 and BRCA1 inactivation impedes HR activity, decreases cellular proliferation and compromises DNA damage recovery. Platinum agent exposure impairs cellular survival. Olaparib exposure alone decreases cell viability in BRCA1-deficient cells, although has no effect on BRIP1-deficient cells. Combining carboplatin or cisplatin with olaparib synergistically attenuates cellular survival, consistent with synthetic lethality.ConclusionsBRIP1-deficient ovarian epithelial cells exhibit defective HR, resulting in synthetic lethality when exposed to a platinum agent/PARPi combination. PARPi alone had no effect; this lack of effect may result from distinguishing molecular properties of BRIP1and/or consequences of genomic background. Our study identifies altered BRIP1 as a target for precision medicine-based therapies for ovarian cancers. This investigation supports consideration of the use of a platinum agent/PARPi combination in ovarian cancers depending upon genetic profile and genomic background.
| S-EPMC9893519 | biostudies-literature
Project description:Oxidized 5-methylcytosine modulates synthetic lethality to poly-ADP-ribose polymerase inhibitors in acute myeloid leukemia [cell line RNA-seq]
| PRJNA899656 | ENA
Project description:Oxidized 5-methylcytosine modulates synthetic lethality to poly-ADP-ribose polymerase inhibitors in acute myeloid leukemia [murine AE9a RNA-seq]
| PRJNA899657 | ENA
Project description:PURPOSE OF REVIEW:In 2012, two publications revealed a particular sensitivity of Ewing sarcoma cells to the inhibition of poly(ADP-ribose) polymerase (PARP). This review updates the reader on PARP function, the development of PARP inhibitors (PARPi) and the evidence for targeting PARP in Ewing sarcoma. It concludes with a description of ongoing/emerging PARPi clinical trials in patients with Ewing sarcoma. RECENT FINDINGS:PARP has a major role in DNA repair, and is a transcription regulator. The oncoprotein in Ewing sarcoma, EWS-FLI1, is proposed to interact with PARP-1, driving PARP-1 expression, which further promotes transcriptional activation by EWS-FLI1. Thus, there are two rationales for PARPi in the treatment of Ewing sarcoma: to disrupt the interaction between EWS-FLI1 and PARP, and for chemo-potentiation or radio-potentiation. The first clinical trial with a single agent PARPi failed to show significant responses, but preclinical evidence for combinations of PARPi with chemotherapy or radiotherapy is very promising. SUMMARY:Despite initial excitement for the potential of PARPi as single agent therapy in Ewing sarcoma, the emerging preclinical data now strongly support testing PARPi in combination with chemo/radiotherapy clinically.
| S-EPMC4059819 | biostudies-literature