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 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.

scholarly journals NFATC4 Promotes Quiescence and Chemotherapy Resistance in Ovarian Cancer

2019 ◽  
Author(s):  
Alexander J. Cole ◽  
Mangala Iyengar ◽  
Patrick O’Hayer ◽  
Daniel Chan ◽  
Greg Delgoffe ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Poor Prognosis ◽  
Nuclear Translocation ◽  
Marked Decrease ◽  
Chemotherapy Resistance ◽  
Chemotherapy Response ◽  
Cycle Arrest

AbstractDevelopment of chemotherapy resistance is a major problem in ovarian cancer. One understudied mechanism of chemoresistance is the induction of quiescence, a reversible non-proliferative state. Unfortunately, little is known about regulators of quiescence. Here we identify the master transcription factor NFATC4 as a regulator of quiescence in ovarian cancer. NFATC4 is enriched in ovarian cancer stem-like cells (CSC) and correlates with decreased proliferation and poor prognosis. Treatment of cancer cells with cisplatin results in NFATC4 nuclear translocation and activation of NFATC4 pathway, while inhibition of the pathway increased chemotherapy response. Induction of NFATC4 activity results in a marked decrease in proliferation, G0 cell cycle arrest and chemotherapy resistance, both in vitro and in vivo. Finally, NFATC4 drives a quiescent phenotype in part via downregulation of MYC. Together these data identify that NFATC4 as a driver of quiescence and a potential new target to combat chemoresistance in ovarian cancer.

scholarly journals Genotoxic Effects of Green Tea Extract on Human Laryngeal Carcinoma Cells In Vitro

2011 ◽  
Vol 62 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Ksenija Durgo ◽  
Sandra Kostić ◽  
Katarina Gradiški ◽  
Draženka Komes ◽  
Maja Osmak ◽  
...  
Keyword(s):  
Cell Line ◽  
Green Tea ◽  
Laryngeal Carcinoma ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Green Tea Extract ◽  
Carcinoma Cells ◽  
Tea Extract ◽  
Human Laryngeal Carcinoma

Genotoxic Effects of Green Tea Extract on Human Laryngeal Carcinoma Cells In VitroGreen tea (Camellia sinensis) contains several bioactive compounds which protect the cell and prevent tumour development. Phytochemicals in green tea extract (mostly flavonoids) scavenge free radicals, but also induce pro-oxidative reactions in the cell. In this study, we evaluated the potential cytotoxic and prooxidative effects of green tea extract and its two main flavonoid constituents epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) on human laryngeal carcinoma cell line (HEp2) and its cross-resistant cell line CK2. The aim was to see if the extract and its two flavonoids could increase the sensitivity of the cisplatin-resistant cell line CK2 in comparison to the parental cell line. The results show that EGCG and green tea extract increased the DNA damage in the CK2 cell line during short exposure. The cytotoxicity of EGCG and ECG increased with the time of incubation. Green tea extract induced lipid peroxidation in the CK2 cell line. The pro-oxidant effect of green tea was determined at concentrations higher than those found in traditionally prepared green tea infusions.

scholarly journals Cell Cycle Analysis of Chicken Lymphocytes Stimulated to Grow in vitro using PHA and Labelled with BrdU

1989 ◽  
Vol 60 (2) ◽  
pp. 178-184
Author(s):  
Shin OKAMOTO ◽  
Mie OHWAKI ◽  
Yoshizane MAEDA ◽  
Tsutomu HASHIGUCHI
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Analysis

Epigenetic approaches to cancer therapy

2004 ◽  
Vol 32 (6) ◽  
pp. 1095-1097 ◽  
Author(s):  
J.A. Plumb ◽  
N. Steele ◽  
P.W. Finn ◽  
R. Brown
Keyword(s):  
Dna Methylation ◽  
Cell Line ◽  
Gene Promoter ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Tumour Suppressor Genes ◽  
Control Of Gene Expression ◽  
Hmlh1 Gene

Histone deacetylation and DNA methylation have a central role in the control of gene expression, including transcriptional repression of tumour suppressor genes. Loss of DNA mismatch repair due to methylation of the hMLH1 gene promoter results in resistance to cisplatin in vitro and in vivo. The cisplatin-resistant cell line A2780/cp70 is 8-fold more resistant to cisplatin than the non-resistant cell line, and has the hMLH1 gene methylated. Treatment with an inhibitor of DNA methyltransferase, DAC (2-deoxy-5′-azacytidine), results in a partial reversal of DNA methylation, re-expression of MLH1 (mutL homologue 1) and sensitization to cisplatin both in vitro and in vivo. PXD101 is a novel hydroxamate type histone deacetylase inhibitor that shows antitumour activity in vivo and is currently in phase I clinical evaluation. Treatment of A2780/cp70 tumour-bearing mice with DAC followed by PXD101 results in a marked increase in the number of cells that re-express MLH1. Since the clinical use of DAC may be limited by toxicity and eventual re-methylation of genes, we suggest that the combination of DAC and PXD101 could have a role in increasing the efficacy of chemotherapy in patients with tumours that lack MLH1 expression due to hMLH1 gene promoter methylation.

Detection of the 170 kDa P-Glycoprotein in Neoplastic and Normal Tissues

1989 ◽  
Vol 75 (6) ◽  
pp. 542-546 ◽  
Author(s):  
Enrico Ronchi ◽  
Ornella Sanfilippo ◽  
Giovanni Di Fronzo ◽  
Maria Rosa Bani ◽  
Gabriella Della Torre ◽  
...  
Keyword(s):  
Protein A ◽  
Resistant Cell ◽  
Nodal Metastasis ◽  
Resistant Cell Line ◽  
Resistant Variant ◽  
Normal Tissues ◽  
Immunoblotting Assay ◽  
Human Solid Tumors

A membrane purification procedure and an immunoblotting assay have been designed to allow screening of human solid tumors for overexpression of the GP170 glycoprotein without employing a disaggregation method to obtain cell suspensions. The electrophoresed membrane proteins were probed, after Western Blotting, with the C219 monoclonal antibody and iodinated Protein A. The labeling intensity of the bands on the autoradioimmunoblots were quantified by densitometry. To test for the presence of GP170, we used membranes from the UV 2237 fibrosarcoma line and its adriamycin-resistant variant ADMR, grown in vitro or as solid tumor in mice. Membranes of human normal and tumor tissues obtained from previously untreated patients were also tested. An immunoreaction was observed in the adriamycin-resistant UV 2237 lines grown in vitro or in vivo. Quantitatively, the binding of the resistant cell line grown in vitro was higher than that observed in cells grown in mice. Bands in the GP 170 region were observed in 4/7 normal and in 7/7 tumor colon tissues and in the normal medulla from 2 patients with cancer of the renal cortex. No reaction could be found in samples from normal tissue, primary tumor or nodal metastasis from 7 patients with breast cancer.

scholarly journals Hydroxytyrosol Promotes Proliferation of Human Schwann Cells: An In Vitro Study

2020 ◽  
Vol 17 (12) ◽  
pp. 4404
Author(s):  
Khidhir Kamil ◽  
Muhammad Dain Yazid ◽  
Ruszymah Bt Hj Idrus ◽  
Jaya Kumar
Keyword(s):  
Cell Cycle ◽  
Protein Expression ◽  
Schwann Cells ◽  
Growth Factor Receptor ◽  
In Vitro Study ◽  
Cell Cycle Analysis ◽  
Proliferation Index ◽  
Proliferation Markers ◽  
Diphenyltetrazolium Bromide

Recent advances in phytomedicine have explored some potential candidates for nerve regeneration, including hydroxytyrosol (HT). This study was undertaken to explore the potential effects of HT on human Schwann cells’ proliferation. Methods: The primary human Schwann cell (hSC) was characterized, and the proliferation rate of hSC supplemented with various concentrations of HT was determined via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle analysis and protein expression of glial fibrillary acidic protein (GFAP) and p75 nerve growth factor receptor (p75 NGFR) were evaluated via the immunofluorescence technique. Results: In vitro culture of hSCs revealed spindle-like, bipolar morphology with the expression of specific markers of hSC. Hydroxytyrosol at 10 and 20 ng/mL significantly increased the proliferation of hSCs by 30.12 ± 5.9% and 47.8 ± 6.7% compared to control (p < 0.05). Cell cycle analysis showed that HT-treated hSCs have a higher proliferation index (16.2 ± 0.2%) than the control (12.4 ± 0.4%) (p < 0.01). In addition, HT significantly increased the protein expression of GFAP and p75NGFR (p < 0.05). Conclusion: HT stimulates the proliferation of hSCs in vitro, indicated by a significant increase in the hSC proliferation index and protein expression of hSCs’ proliferation markers, namely p75 NGFR and GFAP.

Sign in / Sign up

Export Citation Format

Share Document