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
2831 - Interleukin-6 as a Predictive Marker for Early Response to Induction Chemotherapy in Acute Myeloblastic Leukaemia
Presenter: Salah Khallaf
Session: Poster Display session 1
Resources:
Abstract
6014 - Impact of FLT3-ITD mutation on post-transplant outcome of adult AML is modified by the concomitant NPM1 mutation and pre-transplant remission status: A report from Taiwan Bone Marrow Transplant Registry (TBMTR)
Presenter: Su-peng Yeh
Session: Poster Display session 1
Resources:
Abstract
2914 - Efficacy endpoints studied in clinical trials for early-onset leukaemia
Presenter: Dylan Said
Session: Poster Display session 1
Resources:
Abstract
4691 - High triglyceride is a major risk factor of DIC and differentiation syndrome in acute promyelocytic leukemia
Presenter: Tomohiro Yamakawa
Session: Poster Display session 1
Resources:
Abstract
4395 - DREAMM 4: A Phase I/II single-arm open-label study to explore safety and clinical activity of belantamab mafodotin (GSK2857916) administered in combination with pembrolizumab in patients with relapsed/refractory multiple myeloma (RRMM)
Presenter: Suzanne Trudel
Session: Poster Display session 1
Resources:
Abstract
2808 - A Phase 1 Study of HMPL-523, a Selective Oral Anti-Spleen Tyrosine Kinase Inhibitor, in Patients with Relapsed or Refractory Lymphoma
Presenter: Nathan Fowler
Session: Poster Display session 1
Resources:
Abstract
4403 - A Phase 1 Study of HMPL-689, a Selective Oral Phosphoinositide 3-Kinase-Delta Inhibitor, in Patients with Relapsed or Refractory Lymphoma
Presenter: Jonathon Cohen
Session: Poster Display session 1
Resources:
Abstract
3357 - A global patient-driven Facebook study in a very rare sarcoma: Health-related quality of life in Epithelioid Hemangioendothelioma (EHE) patients
Presenter: Marije Weidema
Session: Poster Display session 1
Resources:
Abstract
2475 - Qualitative study of patients’ experiences of living with and beyond a soft tissue sarcoma diagnosis: the impact of sarcoma specialist services
Presenter: Ana Martins
Session: Poster Display session 1
Resources:
Abstract
2640 - Health-related quality of life issues of patients affected by desmoid-type fibromatosis; experiences from two countries
Presenter: Milea Timbergen
Session: Poster Display session 1
Resources:
Abstract