scholarly journals Olaparib and Enzalutamide synergistically suppress HCC progression via the AR-mediated miR-146a-5p/BRCA1 signaling

2019 ◽  
Author(s):  
Jie Zhao ◽  
Yin Sun ◽  
Hui Lin ◽  
Fuju Chou ◽  
Yao Xiao ◽  
...  
Keyword(s):  
Malignant Tumors ◽  
Parp Inhibitor ◽  
Preclinical Study ◽  
Brca1 Expression ◽  
Novel Therapy ◽  
Damage Response ◽  
Synergistic Mechanism ◽  
Direct Binding

AbstractHepatocellular carcinoma (HCC) is one of most common malignant tumors worldwide, however, the treatment for advanced HCC remains unsatisfactory. Here we found that Olaparib, a FDA approved PARP inhibitor, could enhance the cytotoxicity in HCC cells with a lower BRCA1 expression, and suppressing the AR with either Enz or AR-shRNA could further increase the Olaparib sensitivity to better suppress the HCC cell growth via a synergistic mechanism that may involve suppressing the expression of BRCA1 and other DNA damage response (DDR) genes. Mechanism studies revealed that Enz/AR signaling might transcriptional regulting the miR-146a-5p expression via binding to the AREs on its 5’ promoter region, which could then lead to suppress the homologous recombination-related BRCA1 expression via direct binding to its 3’ UTR of mRNA. Preclinical study using an in vivo mouse model also proved that combined Enz plus Olaparib led to better suppression of the HCC progression. Together, these in vitro/in vivo data suggest that combining Enz and Olaparib may help in the development of a novel therapy to better suppress the HCC progression.

scholarly journals [18F]AZD2461, an Insight on Difference in PARP Binding Profiles for DNA Damage Response PET Imaging

2020 ◽  
Vol 22 (5) ◽  
pp. 1226-1234
Author(s):  
Florian Guibbal ◽  
Samantha L. Hopkins ◽  
Anna Pacelli ◽  
Patrick G. Isenegger ◽  
Michael Mosley ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Parp Inhibitor ◽  
Parp Inhibitors ◽  
Cell Uptake ◽  
Pancreatic Cell ◽  
Anti Cancer ◽  
Damage Response ◽  
Automated Procedures

Abstract Background Poly (ADP-ribose) polymerase (PARP) inhibitors are extensively studied and used as anti-cancer drugs, as single agents or in combination with other therapies. Most radiotracers developed to date have been chosen on the basis of strong PARP1–3 affinity. Herein, we propose to study AZD2461, a PARP inhibitor with lower affinity towards PARP3, and to investigate its potential for PARP targeting in vivo. Methods Using the Cu-mediated 18F-fluorodeboronation of a carefully designed radiolabelling precursor, we accessed the 18F-labelled isotopologue of the PARP inhibitor AZD2461. Cell uptake of [18F]AZD2461 in vitro was assessed in a range of pancreatic cell lines (PSN-1, PANC-1, CFPAC-1 and AsPC-1) to assess PARP expression and in vivo in xenograft-bearing mice. Blocking experiments were performed with both olaparib and AZD2461. Results [18F]AZD2461 was efficiently radiolabelled via both manual and automated procedures (9 % ± 3 % and 3 % ± 1 % activity yields non-decay corrected). [18F]AZD2461 was taken up in vivo in PARP1-expressing tumours, and the highest uptake was observed for PSN-1 cells (7.34 ± 1.16 %ID/g). In vitro blocking experiments showed a lesser ability of olaparib to reduce [18F]AZD2461 binding, indicating a difference in selectivity between olaparib and AZD2461. Conclusion Taken together, we show the importance of screening the PARP selectivity profile of radiolabelled PARP inhibitors for use as PET imaging agents.

scholarly journals Pharmacodynamic, pharmacokinetic, and phase 1a study of bisthianostat, a novel histone deacetylase inhibitor, for the treatment of relapsed or refractory multiple myeloma

2021 ◽  
Author(s):  
Yu-bo Zhou ◽  
Yang-ming Zhang ◽  
Hong-hui Huang ◽  
Li-jing Shen ◽  
Xiao-feng Han ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Drug Targets ◽  
Single Agent ◽  
Hdac Inhibitors ◽  
Preclinical Study ◽  
Parp Cleavage ◽  
Rpmi 8226 ◽  
Ongoing Phase

AbstractHDAC inhibitors (HDACis) have been intensively studied for their roles and potential as drug targets in T-cell lymphomas and other hematologic malignancies. Bisthianostat is a novel bisthiazole-based pan-HDACi evolved from natural HDACi largazole. Here, we report the preclinical study of bisthianostat alone and in combination with bortezomib in the treatment of multiple myeloma (MM), as well as preliminary first-in-human findings from an ongoing phase 1a study. Bisthianostat dose dependently induced acetylation of tubulin and H3 and increased PARP cleavage and apoptosis in RPMI-8226 cells. In RPMI-8226 and MM.1S cell xenograft mouse models, oral administration of bisthianostat (50, 75, 100 mg·kg-1·d-1, bid) for 18 days dose dependently inhibited tumor growth. Furthermore, bisthianostat in combination with bortezomib displayed synergistic antitumor effect against RPMI-8226 and MM.1S cell in vitro and in vivo. Preclinical pharmacokinetic study showed bisthianostat was quickly absorbed with moderate oral bioavailability (F% = 16.9%–35.5%). Bisthianostat tended to distribute in blood with Vss value of 0.31 L/kg. This distribution parameter might be beneficial to treat hematologic neoplasms such as MM with few side effects. In an ongoing phase 1a study, bisthianostat treatment was well tolerated and no grade 3/4 nonhematological adverse events (AEs) had occurred together with good pharmacokinetics profiles in eight patients with relapsed or refractory MM (R/R MM). The overall single-agent efficacy was modest, stable disease (SD) was identified in four (50%) patients at the end of first dosing cycle (day 28). These preliminary in-patient results suggest that bisthianostat is a promising HDACi drug with a comparable safety window in R/R MM, supporting for its further phase 1b clinical trial in combination with traditional MM therapies.

scholarly journals 64Cu-ATSM/64Cu-Cl2 and their relationship to hypoxia in glioblastoma: a preclinical study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Elodie A. Pérès ◽  
Jérôme Toutain ◽  
Louis-Paul Paty ◽  
Didier Divoux ◽  
Méziane Ibazizène ◽  
...  
Keyword(s):  
Ex Vivo ◽  
In Vitro Study ◽  
Tumor Location ◽  
Preclinical Study ◽  
Significant Rise ◽  
Lower Oxygen ◽  
Cu Complexes ◽  
Ex Vivo Study

Abstract Background Diacetyl-bis(N4-methylthiosemicarbazone), labeled with 64Cu (64Cu-ATSM) has been suggested as a promising tracer for imaging hypoxia. However, various controversial studies highlighted potential pitfalls that may disable its use as a selective hypoxic marker. They also highlighted that the results may be tumor location dependent. Here, we first analyzed uptake of Cu-ATSM and its less lipophilic counterpart Cu-Cl2 in the tumor over time in an orthotopic glioblastoma model. An in vitro study was also conducted to investigate the hypoxia-dependent copper uptake in tumor cells. We then further performed a comprehensive ex vivo study to compare 64Cu uptake to hypoxic markers, specific cellular reactions, and also transporter expression. Methods μPET was performed 14 days (18F-FMISO), 15 days (64Cu-ATSM and 64Cu-Cl2), and 16 days (64Cu-ATSM and 64Cu-Cl2) after C6 cell inoculation. Thereafter, the brains were withdrawn for further autoradiography and immunohistochemistry. C6 cells were also grown in hypoxic workstation to analyze cellular uptake of Cu complexes in different oxygen levels. Results In vivo results showed that Cu-ASTM and Cu-Cl2 accumulated in hypoxic areas of the tumors. Cu-ATSM also stained, to a lesser extent, non-hypoxic regions, such as regions of astrogliosis, with high expression of copper transporters and in particular DMT-1 and CTR1, and also characterized by the expression of elevated astrogliosis. In vitro results show that 64Cu-ATSM showed an increase in the uptake only in severe hypoxia at 0.5 and 0.2% of oxygen while for 64Cu-Cl2, the cell retention was significantly increased at 5% and 1% of oxygen with no significant rise at lower oxygen percentages. Conclusion In the present study, we show that Cu-complexes undoubtedly accumulate in hypoxic areas of the tumors. This uptake may be the reflection of a direct dependency to a redox metabolism and also a reflection of hypoxic-induced overexpression of transporters. We also show that Cu-ATSM also stained non-hypoxic regions such as astrogliosis.

scholarly journals Double-targeting CDCA8 and E2F1 inhibits the growth and migration of malignant glioma

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Xiaoxiong Wang ◽  
Heping Wang ◽  
Jiajun Xu ◽  
Xu Hou ◽  
Haoqiang Zhan ◽  
...  
Keyword(s):  
Malignant Glioma ◽  
Malignant Tumors ◽  
Disease Free Survival ◽  
High Grade Glioma ◽  
Poor Overall Survival ◽  
Survival Prognosis ◽  
Who Grade ◽  
And Migration

AbstractHigh-grade glioma is the most common and aggressive primary brain tumor in adults with poor therapeutic efficiency and survival prognosis. Cell division cycle associated 8 (CDCA8) has been well known as a cell cycle regulator and tumor promotor in various malignant tumors. However, its biological role in glioma still remains unclear. Our results showed that high level of CDCA8 was significantly correlated with advanced WHO grade and poor overall survival and disease-free survival prognosis. In vitro and in vivo investigations demonstrated that CDCA8 promoted the glioma malignancy by promoting cell proliferation, cell migration, and inhibiting cell apoptosis. Moreover, we found its synergetic biological protein—E2F1 by the gene microarray chip. In this study, we revealed that CDCA8 synergized with E2F1 facilitated the proliferation and migration of glioma. In conclusion, our study provides a novel promising therapeutic targets and prognostic biomarkers for malignant glioma treatment.

scholarly journals The DNA damage inducible lncRNA SCAT7 regulates genomic integrity and topoisomerase 1 turnover in lung adenocarcinoma

NAR Cancer ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Luisa Statello ◽  
Mohamad M Ali ◽  
Silke Reischl ◽  
Sagar Mahale ◽  
Subazini Thankaswamy Kosalai ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Cancer Biology ◽  
Topoisomerase I ◽  
Cell Cycle Checkpoints ◽  
Topoisomerase 1 ◽  
Damage Response ◽  
Promote Cell Survival

Abstract Despite the rapid improvements in unveiling the importance of lncRNAs in all aspects of cancer biology, there is still a void in mechanistic understanding of their role in the DNA damage response. Here we explored the potential role of the oncogenic lncRNA SCAT7 (ELF3-AS1) in the maintenance of genome integrity. We show that SCAT7 is upregulated in response to DNA-damaging drugs like cisplatin and camptothecin, where SCAT7 expression is required to promote cell survival. SCAT7 silencing leads to decreased proliferation of cisplatin-resistant cells in vitro and in vivo through interfering with cell cycle checkpoints and DNA repair molecular pathways. SCAT7 regulates ATR signaling, promoting homologous recombination. Importantly, SCAT7 also takes part in proteasome-mediated topoisomerase I (TOP1) degradation, and its depletion causes an accumulation of TOP1–cc structures responsible for the high levels of intrinsic DNA damage. Thus, our data demonstrate that SCAT7 is an important constituent of the DNA damage response pathway and serves as a potential therapeutic target for hard-to-treat drug resistant cancers.

scholarly journals lncRNA CASC19 Contributes to Radioresistance of Nasopharyngeal Carcinoma by Promoting Autophagy via AMPK-mTOR Pathway

2021 ◽  
Vol 22 (3) ◽  
pp. 1407
Author(s):  
Hongxia Liu ◽  
Wang Zheng ◽  
Qianping Chen ◽  
Yuchuan Zhou ◽  
Yan Pan ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Cell Line ◽  
Malignant Tumors ◽  
Underlying Mechanism ◽  
Mtor Pathway ◽  
Rna Seq ◽  
Cellular Autophagy ◽  
First Time

Nasopharyngeal carcinoma (NPC) is one of the most frequent head and neck malignant tumors and is majorly treated by radiotherapy. However, radiation resistance remains a serious obstacle to the successful treatment of NPC. The aim of this study was to discover the underlying mechanism of radioresistance and to elucidate novel genes that may play important roles in the regulation of NPC radiosensitivity. By using RNA-seq analysis of NPC cell line CNE2 and its radioresistant cell line CNE2R, lncRNA CASC19 was screened out as a candidate radioresistance marker. Both in vitro and in vivo data demonstrated that a high expression level of CASC19 was positively correlated with the radioresistance of NPC, and the radiosensitivity of NPC cells was considerably enhanced by knockdown of CASC19. The incidence of autophagy was enhanced in CNE2R in comparison with CNE2 and another NPC cell line HONE1, and silencing autophagy with LC3 siRNA (siLC3) sensitized NPC cells to irradiation. Furthermore, CASC19 siRNA (siCASC19) suppressed cellular autophagy by inhibiting the AMPK/mTOR pathway and promoted apoptosis through the PARP1 pathway. Our results revealed for the first time that lncRNA CASC19 contributed to the radioresistance of NPC by regulating autophagy. In significance, CASC19 might be a potential molecular biomarker and a new therapeutic target in NPC.

scholarly journals Splicing factor USP39 promotes ovarian cancer malignancy through maintaining efficient splicing of oncogenic HMGA2

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Shourong Wang ◽  
Zixiang Wang ◽  
Jieyin Li ◽  
Junchao Qin ◽  
Jianping Song ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Malignant Tumors ◽  
Splicing Factor ◽  
Ovarian Cancer Cells ◽  
Nuclear Speckles ◽  
Aberrant Expression ◽  
Intergenic Regions

AbstractAberrant expression of splicing factors was found to promote tumorigenesis and the development of human malignant tumors. Nevertheless, the underlying mechanisms and functional relevance remain elusive. We here show that USP39, a component of the spliceosome, is frequently overexpressed in high-grade serous ovarian carcinoma (HGSOC) and that an elevated level of USP39 is associated with a poor prognosis. USP39 promotes proliferation/invasion in vitro and tumor growth in vivo. Importantly, USP39 was transcriptionally activated by the oncogene protein c-MYC in ovarian cancer cells. We further demonstrated that USP39 colocalizes with spliceosome components in nuclear speckles. Transcriptomic analysis revealed that USP39 deletion led to globally impaired splicing that is characterized by skipped exons and overrepresentation of introns and intergenic regions. Furthermore, RNA immunoprecipitation sequencing showed that USP39 preferentially binds to exon-intron regions near 5′ and 3′ splicing sites. In particular, USP39 facilitates efficient splicing of HMGA2 and thereby increases the malignancy of ovarian cancer cells. Taken together, our results indicate that USP39 functions as an oncogenic splicing factor in ovarian cancer and represents a potential target for ovarian cancer therapy.

scholarly journals Targeting IDH1/2 mutant cancers with combinations of ATR and PARP inhibitors

NAR Cancer ◽  
2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Amrita Sule ◽  
Jinny Van Doorn ◽  
Ranjini K Sundaram ◽  
Sachita Ganesa ◽  
Juan C Vasquez ◽  
...  
Keyword(s):  
Kinase Inhibitors ◽  
Parp Inhibitor ◽  
Parp Inhibitors ◽  
Protein Kinase Inhibitors ◽  
Isocitrate Dehydrogenase 1 ◽  
Normal Product ◽  
Synthetic Lethal Interactions ◽  
Mutant Cells

Abstract Mutations in the isocitrate dehydrogenase-1 and -2 (IDH1/2) genes were first identified in glioma and acute myeloid leukemia (AML), and subsequently found in multiple other tumor types. These neomorphic mutations convert the normal product of enzyme, α-ketoglutarate (αKG), to the oncometabolite 2-hydroxyglutarate (2HG). Our group recently demonstrated that 2HG suppresses the high-fidelity homologous recombination (HR) DNA repair pathway, resulting in a state referred to as ‘BRCAness’, which confers exquisite sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors. In this study, we sought to elucidate sensitivity of IDH1/2-mutant cells to DNA damage response (DDR) inhibitors and, whether combination therapies could enhance described synthetic lethal interactions. Here, we report that ATR (ataxia telangiectasia and Rad3-related protein kinase) inhibitors are active against IDH1/2-mutant cells, and that this activity is further potentiated in combination with PARP inhibitors. We demonstrate this interaction across multiple cell line models with engineered and endogenous IDH1/2 mutations, with robust anti-tumor activity in vitro and in vivo. Mechanistically, we found ATR and PARP inhibitor treatment induces premature mitotic entry, which is significantly elevated in the setting of IDH1/2-mutations. These data highlight the potential efficacy of targeting HR defects in IDH1/2-mutant cancers and support the development of this combination in future clinical trials.

Sign in / Sign up

Export Citation Format

Share Document