Abstract 1636
Background
Even though new molecular targeted agents are now being developed, they are still premature in application of clinical use for triple negative breast cancers (TNBCs). Therefore, it is highly demanded to explore the effective antitumor agents against TNBCs. Novel non-camptothecin topoisomerase I inhibitors are discovered and evaluated in this study.
Methods
Human MDA-MB-231 (BCRC-60425), BT-549 (ATCC® HTB-122™) and MCF-7 (BCRC-60436) were used in this study. Top1 assay was determined by gel mobility assay to validate the Top1-mediated DNA cleavages at different concentrations of non-camptothecin compounds. Cell viability analysis (MTT assay), comet assay and flow cytometry analysis were used to evaluate their growth inhibitory activity, DNA damage, and induction of cell arrest. Mechanistic pathways were studied and validated through western blot analysis, flow cytometry and confocal microscopy analysis. Binding interactions between top1 and non-camptothecin compound were analyzed by computational analysis (Discovery Studio).
Results
The IC50 values (growth inhibitory activity) of these non-camptothecin compounds are in the micromolar to nanomolar range (1.8 μM to 190 nM) against MDA-MB-231, BT-549 and MCF-7 cell lines. These compounds significantly inhibited the process in which supercoiled DNA strand transforms into its relaxed state and showed antitumor spectra similar to camptothecin rather than doxorubicin. Comet tails were observed to increase significantly with various doses of compounds in a dose-dependent manner. In addition, their mode of actions were shown to involve G2/M arrest of the cell cycle along with a dose-dependent increase in protein levels of cleaved caspase-3 and cleavage of cPARP. Except apoptosis pathway, non-camptothecin compounds also induce necrosis, and autophagy. Favorable ADMET characteristics of non-camptothecin compounds were observed using ADMET Descriptors.
Conclusions
Our results have provided evidence for therapeutic intervention in the treatment of TNBC using new top1 inhibitors, non-camptothecin compounds.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Wen-Shan Li.
Funding
Ministry of Science and Technology, Taiwan and Academia Sinica, Taiwan.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1271 - A large scale prospective concordance study of oncogene driver detection between plasma- and tissue-based NGS analysis in advanced non-small cell lung cancer (NSCLC).
Presenter: Ryo Itotani
Session: Poster Display session 1
Resources:
Abstract
1132 - Biomarker status as a mediator of age-related overall survival (OS) in advanced non-small cell lung cancer (aNSCLC)
Presenter: Aaron Cohen
Session: Poster Display session 1
Resources:
Abstract
1502 - An exploratory analysis of on-treatment ctDNA measurement as a potential surrogate for overall survival for atezolizumab benefit in the OAK Study
Presenter: David Gandara
Session: Poster Display session 1
Resources:
Abstract
3912 - Disease monitoring of EGFR mutation-positive NSCLC patients via circulating tumor DNA
Presenter: Wei Fang Hsu
Session: Poster Display session 1
Resources:
Abstract
3856 - Incidence of T790M in NSCLC patients progressed to gefitinib, erlotinib, and afatinib: a study on circulating tumor DNA
Presenter: Romano Danesi
Session: Poster Display session 1
Resources:
Abstract
1330 - Folate receptor-positive circulating tumor cells as a predictive biomarker for the efficacy of first-line pemetrexed-based therapy in patients with non-squamous non-small cell lung cancer
Presenter: Xiaoxia Chen
Session: Poster Display session 1
Resources:
Abstract
3512 - Carcinoembryonic Antigen of Cerebrospinal Fluid Predict Prognosis of Leptomeningeal Metastasis from Non-Small Cell Lung Cancer
Presenter: Junjie Zhen
Session: Poster Display session 1
Resources:
Abstract
3852 - Liquid biopsy in clinical pratice of Non-Small-Cell-Lung Cancer (NSCLC): a multi-institutional experience
Presenter: Giovanna De Maglio
Session: Poster Display session 1
Resources:
Abstract
1205 - A Phase III Study Comparing SB8, a Proposed Bevacizumab Biosimilar, and Reference Bevacizumab in Patients with Metastatic or Recurrent Non-squamous NSCLC
Presenter: Martin Reck
Session: Poster Display session 1
Resources:
Abstract
2432 - Retrospective comparative study of the efficacy and safety in docetaxel and ramucirumab combination chemotherapy with or without previous immune checkpoint inhibitor treatment.
Presenter: Daijiro Harada
Session: Poster Display session 1
Resources:
Abstract