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
4079 - Triggering anti-GBM immune response with EGFR-mediated photoimmunotherapy
Presenter: Gabriela Kramer-marek
Session: Poster Display session 1
Resources:
Abstract
4364 - Upregulation of sFRP3 circulating expression levels correlates survival outcomes in glioblastoma
Presenter: Gema Bruixola
Session: Poster Display session 1
Resources:
Abstract
2327 - Characterization and pre-clinical modeling of genetic aberrations in pediatric gliomas
Presenter: Itai Moshe
Session: Poster Display session 1
Resources:
Abstract
3154 - Preclinical Study of Novel Tetracyclic Small Molecule, CC12, for Brain Cancer
Presenter: Liyun Fann
Session: Poster Display session 1
Resources:
Abstract
5759 - CHLOROBRAIN phase IB trial: The addition of chloroquine, an autophagy inhibitor, to concurrent radiation and temozolomide for newly diagnosed glioblastoma
Presenter: Inge Compter
Session: Poster Display session 1
Resources:
Abstract
1382 - A Phase II Clinical Trial Evaluating the Efficacy and Safety of Apatinib Combined with dose-dense Temozolomide in Recurrent Glioblastoma
Presenter: Yong Wang
Session: Poster Display session 1
Resources:
Abstract
4407 - Phase 0 Trial of Ceritinib in Brain Metastases and Recurrent Glioblastoma
Presenter: Shwetal Mehta
Session: Poster Display session 1
Resources:
Abstract
1469 - Pembrolizumab (Pem) in recurrent high-grade glioma (HGG) patients with mismatch repair deficiency (MMRd): an observational study
Presenter: Mario Caccese
Session: Poster Display session 1
Resources:
Abstract
4217 - Outcome of high-grade gliomas (HGGs) treated into immunotherapeutic early-phase clinical trials (ieCTs): a single-center experience
Presenter: Matteo Simonelli
Session: Poster Display session 1
Resources:
Abstract
5107 - Tolerability of PCV in Low Grade Glioma: a Real World Experience
Presenter: Razia Aslam
Session: Poster Display session 1
Resources:
Abstract