scholarly journals Newly developed dual topoisomerase inhibitor P8-D6 is highly active in ovarian cancer

2021 ◽  
Vol 13 ◽  
pp. 175883592110598
Author(s):  
Inken Flörkemeier ◽  
Tamara N. Steinhauer ◽  
Nina Hedemann ◽  
Magnus Ölander ◽  
Per Artursson ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Topoisomerase I ◽  
Ex Vivo ◽  
Chemotherapy Resistance ◽  
Membrane Integrity ◽  
Three Dimensional ◽  
New Drugs ◽  
Highly Active ◽  
Gynaecologic Neoplasms

Background: Ovarian cancer (OvCa) constitutes a rare and highly aggressive malignancy and is one of the most lethal of all gynaecologic neoplasms. Due to chemotherapy resistance and treatment limitations because of side effects, OvCa is still not sufficiently treatable. Hence, new drugs for OvCa therapy such as P8-D6 with promising antitumour properties have a high clinical need. The benzo[ c]phenanthridine P8-D6 is an effective inductor of apoptosis by acting as a dual topoisomerase I/II inhibitor. Methods: In the present study, the effectiveness of P8-D6 on OvCa was investigated in vitro. In various OvCa cell lines and ex vivo primary cells, the apoptosis induction compared with standard therapeutic agents was determined in two-dimensional monolayers. Expanded by three-dimensional and co-culture, the P8-D6 treated cells were examined for changes in cytotoxicity, apoptosis rate and membrane integrity via scanning electron microscopy (SEM). Likewise, the effects of P8-D6 on non-cancer human ovarian surface epithelial cells and primary human hepatocytes were determined. Results: This study shows a significant P8-D6-induced increase in apoptosis and cytotoxicity in OvCa cells which surpasses the efficacy of well-established drugs like cisplatin or the topoisomerase inhibitors etoposide and topotecan. Non-cancer cells were affected only slightly by P8-D6. Moreover, no hepatotoxic effect in in vitro studies was detected. Conclusion: P8-D6 is a strong and rapid inductor of apoptosis and might be a novel treatment option for OvCa therapy.

scholarly journals Newly Developed Dual Topoisomerase Inhibitor P8-D6 is Highly Active in Ovarian Cancer

2021 ◽  
Author(s):  
Inken Flörkemeier ◽  
Tamara N. Steinhauer ◽  
Nina Hedemann ◽  
Magnus Ölander ◽  
Per Artursson ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Topoisomerase I ◽  
Ex Vivo ◽  
Chemotherapy Resistance ◽  
Membrane Integrity ◽  
New Drugs ◽  
Highly Active ◽  
Ovarian Surface Epithelial ◽  
Gynaecologic Neoplasms

Abstract Background: Ovarian cancer (OvCa) constitutes a rare and highly aggressive malignancy and is one of the most lethal of all gynaecologic neoplasms. Due to chemotherapy resistance and treatment limitations because of side effects, OvCa is still not sufficiently treatable. Hence, new drugs for OvCa therapy such as P8-D6 with promising antitumour properties have a high clinical need. The benzo[c]phenanthridine P8-D6 is an effective inductor of apoptosis by acting as a dual topoisomerase I/II inhibitor. Methods: In the present study, the effectiveness of P8-D6 on OvCa was investigated in vitro. In various OvCa cell lines and ex vivo primary cells, the apoptosis induction compared to standard therapeutic agents was determined in 2D monolayers. Expanded by 3D and co-culture, the P8-D6 treated cells were examined for changes in cytotoxicity, apoptosis rate and membrane integrity via scanning electron microscopy (SEM). Likewise, the effects of P8-D6 on non-cancer human ovarian surface epithelial cells and primary human hepatocytes were determined. Results: This study shows a significant P8-D6-induced increase in apoptosis and cytotoxicity in OvCa cells which surpasses the efficacy of standard therapeutic drugs. Non-cancer cells were affected only slightly by P8-D6. Moreover, no hepatotoxic effect in in vitro studies was detected.Conclusions: P8-D6 is a strong and rapid inductor of apoptosis and might be a novel treatment option for OvCa therapy.

The regulation of RNA Polymerase II mediated transcription by Caspase-8 in ovarian cancer.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e18082-e18082
Author(s):  
Sven Becker ◽  
Ranadip Mandal ◽  
Monika Raab ◽  
Mourad Sanhaji ◽  
Klaus Strebhardt
Keyword(s):  
Ovarian Cancer ◽  
Rna Polymerase Ii ◽  
Ex Vivo ◽  
New Drugs ◽  
Caspase 8 ◽  
Low Grade ◽  
Apoptotic Pathway ◽  
Rna Pol Ii ◽  
Pol Ii

e18082 Background: According to the WHO, in 2018, the number of new cases and mortality worldwide due to ovarian cancer, were 295,414 and 184,799, respectively, making it one of the most lethal gynaecological cancers in the world. The standard therapy of ovarian cancers is still comprehensive cytoreductive surgery followed by a combination of platinum-taxane based primary chemotherapy. Second line therapies include Carboplatin or Cisplatin in combination with Paclitaxel, PLD or Gemcitabine, with or without Bevacizumab. Unfortunately, late stage ovarian cancer cases are still incurable, however, several new drugs are under development or are undergoing clinical trials. At present, these new approaches can only stabilize the disease or delay its recurrence. Caspase-8, the predominant initiator of the extrinsic apoptotic pathway, also plays critical roles in a number of other non-apoptotic functions. It is also frequently down-regulated in ovarian cancer and we wanted to understand how this down-regulation could support the development of ovarian cancer. Methods: The analysis of the association between CASP8 expression and patient prognosis in ovarian cancer patients found that low CASP8 expression was significantly correlated with poor OS, with a median OS of 37.43 (low expression) and 49.97 (high expression) months, and higher clinical stages. CRISPR/Cas9 mediated CASP8 KO in multiple high- and low-grade ovarian cancer cell lines resulted in significant increases in their invasiveness. Results: Caspase-8 interactome analysis revealed that it can regulate the RNA Pol II mediated transcription, which was corroborated through multiple in vitro and ex vivo experiments. Global Transcriptomics and Proteomics analysis of the KO cells revealed significant upregulation of genes involved in metastasis, which was again verified in in vitro and ex vivo experiments. Additionally, the KO cells were significantly resistant towards standard chemotherapeutics like Carboplatin, a transcription inhibitor, either alone or in combination with Paclitaxel. Conclusions: Presently, we are working on orthotopic ovarian cancer mouse models to validate - the potential of Caspase-8 to regulate metastasis; and the targeting of RNA Pol II to sensitize them to standard chemotherapeutics. We are also developing organoid banks from patient derived ovarian cancer tissues, with low Caspase-8 expression, to validate the upregulation of genes identified in our ‘omics’ data and the potential of targeting them, along with RNA Pol II, to sensitize them to standard chemotherapeutics.

scholarly journals Synergism of AZD6738, an ATR Inhibitor, in Combination with Belotecan, a Camptothecin Analogue, in Chemotherapy-Resistant Ovarian Cancer

2021 ◽  
Vol 22 (3) ◽  
pp. 1223
Author(s):  
Jin Hur ◽  
Mithun Ghosh ◽  
Tae Heon Kim ◽  
Nahee Park ◽  
Kamal Pandey ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Topoisomerase I ◽  
Chemotherapy Resistance ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Cell Cycle Analysis ◽  
Preclinical Model ◽  
Repair System

Epithelial ovarian cancer remains the leading cause of mortality among all gynecologic malignancies owing to recurrence and ultimate development of chemotherapy resistance in the majority of patients. In the chemotherapy-resistant ovarian cancer preclinical model, we investigated whether AZD6738 (an ataxia telangiectasia and Rad3-related (ATR) inhibitor) could synergize with belotecan (a camptothecin analog and topoisomerase I inhibitor). In vitro, both chemotherapy-resistant and chemotherapy-sensitive ovarian cancer cell lines showed synergistic anti-proliferative activity with a combination treatment of belotecan and AZD6738. The combination also demonstrated synergistic tumor inhibition in mice with a chemotherapy-resistant cell line xenograft. Mechanistically, belotecan, a DNA-damaging agent, increased phospho-ATR (pATR) and phospho-Chk1 (pChk1) in consecutive order, indicating the activation of the DNA repair system. This consequently induced G2/M arrest in the cell cycle analysis. However, when AZD6738 was added to belotecan, pATR and pChk1 induced by belotecan alone were suppressed again. A cell cycle analysis in betotecan showed a sub-G1 increase as well as a G2/M decrease, representing the release of G2/M arrest and the induction of apoptosis. In ascites-derived primary cancer cells from both chemotherapy-sensitive and -resistant ovarian cancer patients, this combination was also synergistic, providing further support for our hypothesis. The combined administration of ATR inhibitor and belotecan proved to be synergistic in our preclinical model. This combination warrants further investigation in a clinical trial, with a particular aim of overcoming chemotherapy resistance in ovarian cancer.

scholarly journals CD133 Promotes Adhesion to the Ovarian Cancer Metastatic Niche

2018 ◽  
Vol 11 ◽  
pp. 117906441876788 ◽  
Author(s):  
Lynn Roy ◽  
Alexander Bobbs ◽  
Rachel Sattler ◽  
Jeffrey L Kurkewich ◽  
Paige B Dausinas ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Metastasis ◽  
Ex Vivo ◽  
Surface Protein ◽  
Ovarian Cancer Cells ◽  
Metastatic Niche ◽  
Attractive Therapeutic Target ◽  
Peritoneal Mesothelium

Cancer stem cells (CSCs) are an attractive therapeutic target due to their predicted role in both metastasis and chemoresistance. One of the most commonly agreed on markers for ovarian CSCs is the cell surface protein CD133. CD133+ ovarian CSCs have increased tumorigenicity, resistance to chemotherapy, and increased metastasis. Therefore, we were interested in defining how CD133 is regulated and whether it has a role in tumor metastasis. Previously we found that overexpression of the transcription factor, ARID3B, increased the expression of PROM1 (CD133 gene) in ovarian cancer cells in vitro and in xenograft tumors. We report that ARID3B directly regulates PROM1 expression. Importantly, in a xenograft mouse model of ovarian cancer, knockdown of PROM1 in cells expressing exogenous ARID3B resulted in increased survival time compared with cells expressing ARID3B and a control short hairpin RNA. This indicated that ARID3B regulation of PROM1 is critical for tumor growth. Moreover, we hypothesized that CD133 may affect metastatic spread. Given that the peritoneal mesothelium is a major site of ovarian cancer metastasis, we explored the role of PROM1 in mesothelial attachment. PROM1 expression increased adhesion to mesothelium in vitro and ex vivo. Collectively, our work demonstrates that ARID3B regulates PROM1 adhesion to the ovarian cancer metastatic niche.

Abstract 2413: TP53 gene mutations differently regulate ovarian cancer metabolism: Ex vivo and in vitro studies

2018 ◽  
Author(s):  
Stephanie Antoun ◽  
David Atallah ◽  
Roula Tahtouh ◽  
Malak Moubarak ◽  
Nada Alaeddine ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Metabolism ◽  
Ex Vivo ◽  
Gene Mutations ◽  
Tp53 Gene ◽  
In Vitro Studies ◽  
Tp53 Gene Mutations

Rational humanization of the powerful antithrombotic anti-GPIbα antibody: 6B4

2006 ◽  
Vol 96 (11) ◽  
pp. 671-684 ◽  
Author(s):  
Alexandre Fontayne ◽  
Karen Vanhoorelbeke ◽  
Inge Pareyn ◽  
Isabel Van Rompaey ◽  
Muriel Meiring ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Three Dimensional ◽  
Vector System ◽  
Dimensional Structure ◽  
Fab Fragment ◽  
Variable Regions ◽  
Significant Prolongation ◽  
Von Willebrand ◽  
First Time

SummaryFab-fragments of the monoclonal antibody 6B4, raised against human glycoprotein Ibα (GPIbα), have a powerful antithrombotic effect in baboons by blocking the GPIbα binding site for von Willebrand factor (VWF), without significant prolongation of the skin bleeding time. In order to bring this antibody to the clinic,we here humanized for the first time an anti-human GPIbα by variable-domain resurfacing guided by computer modeling. First, the genes coding for the variable regions of the heavy and light chains of 6B4 were cloned and sequenced. Based on this,a three-dimensional structure of the Fv-fragment was constructed by using homology-based modeling, and with this and comparison with antibodies with known structure,”murine” putative immunogenic residues which are exposed, were changed for “human-like” residues. The humanized Fab-fragment, h6B4-Fab, was constructed in the pKaneo vector system, expressed and purified and showed in vitro an unaltered, even slightly higher binding affinity for its antigen than the murine form as determined by different ELISA set-ups and surface plasmon resonance. Finally, injection of doses of 0.1 to 1.5 mg/kg of h6B4-Fab in baboons showed that both pharmacokinetics and ex-vivo bio-activity of the molecule were to a large extent preserved.In conclusion, the method used here to humanize 6B4 by resurfacing resulted in a fully active derivative, which is now ready for further development.

scholarly journals Ex Vivo Expanded Human Vγ9Vδ2 T-Cells Can Suppress Epithelial Ovarian Cancer Cell Growth

2019 ◽  
Vol 20 (5) ◽  
pp. 1139 ◽  
Author(s):  
Tsui Mao ◽  
Carol Miao ◽  
Yi Liao ◽  
Ying Chen ◽  
Chia Yeh ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
T Cells ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Γδ T Cells ◽  
Ovarian Cancer Cells ◽  
Cytotoxic Activities ◽  
Antitumor Effects ◽  
Peripheral Blood Mononuclear

γδ-T-cells have attracted attention because of their potent cytotoxicity towards tumors. Most γδ-T-cells become activated via a major histocompatibility complex (MHC)-independent pathway by the interaction of their receptor, Natural Killer Group 2 Member D (NKG2D) with the tumor-specific NKG2D ligands, including MHC class I-related chain A/B (MICA/B) and UL16-binding proteins (ULBPs), to kill tumor cells. However, despite their potent antitumor effects, the treatment protocols specifically targeting ovarian tumors require further improvements. Ovarian cancer is one of the most lethal and challenging female malignancies worldwide because of delayed diagnoses and resistance to traditional chemotherapy. In this study, we successfully enriched and expanded γδ-T-cells up to ~78% from peripheral blood mononuclear cells (PBMCs) with mostly the Vγ9Vδ2-T-cell subtype in the circulation. We showed that expanded γδ-T-cells alone exerted significant cytotoxic activities towards specific epithelial-type OVCAR3 and HTB75 cells, whereas the combination of γδ-T cells and pamidronate (PAM), a kind of aminobisphosphonates (NBPs), showed significantly enhanced cytotoxic activities towards all types of ovarian cancer cells in vitro. Furthermore, in tumor xenografts of immunodeficient NSG mice, γδ-T-cells not only suppressed tumor growth but also completely eradicated preexisting tumors with an initial size of ~5 mm. Thus, we concluded that γδ-T-cells alone possess dramatic cytotoxic activities towards epithelial ovarian cancers both in vitro and in vivo. These results strongly support the potential of clinical immunotherapeutic application of γδ-T-cells to treat this serious female malignancy.

Sign in / Sign up

Export Citation Format

Share Document