Identification and characterization of SSE15206, a microtubule depolymerizing agent that overcomes multidrug resistance

Abstract

Microtubules are highly dynamic structures that form spindle fibres during mitosis and are one of the most validated cancer targets. The success of drugs targeting microtubules, however, is often limited by the development of multidrug resistance. Here we describe the discovery and characterization of SSE15206, a pyrazolinethioamide derivative [3-phenyl-5-(3,4,5-trimethoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide] that has potent antiproliferative activities in cancer cell lines of different origins and overcomes resistance to microtubule-targeting agents. Treatment of cells with SSE15206 causes aberrant mitosis resulting in G2/M arrest due to incomplete spindle formation, a phenotype often associated with drugs that interfere with microtubule dynamics. SSE15206 inhibits microtubule polymerization both in biochemical and cellular assays by binding to colchicine site in tubulin as shown by docking and competition studies. Prolonged treatment of cells with the compound results in apoptotic cell death [increased Poly (ADP-ribose) polymerase cleavage and Annexin V/PI staining] accompanied by p53 induction. More importantly, we demonstrate that SSE15206 is able to overcome resistance to chemotherapeutic drugs in different cancer cell lines including multidrug-resistant KB-V1 and A2780-Pac-Res cell lines overexpressing MDR-1, making it a promising hit for the lead optimization studies to target multidrug resistance.

CPPF, A Novel Microtubule Targeting Anticancer Agent, Inhibits the Growth of a Wide Variety of Cancers

“…When microtubule polymerization/depolymerization are disrupted, tubulin dynamics are reduced, causing multiple cellular problems [ 23 ]. To test the influence of CPPF on tubulin dynamics, we carried out microtubule regrowth assays [ 24 ]. HeLa cells were incubated on ice for 30 min as a cold shock to disturb microtubule networks.…”

Current advances of tubulin inhibitors as dual acting small molecules for cancer therapy

“…DJ101 targeted the colchicine binding site, which was confirmed through X‐ray crystallography, potently reduced cell viability in MDR cell lines, and also significantly inhibited tumor growth in taxane‐resistant prostate cancer xenografts without causing toxicity to the mice . SSE15206 also circumvented drug resistance in KB‐V1 and A2780‐Pac‐Res cell lines that overexpressed P‐gp . IMB5046 was not a P‐gp substrate and displayed potent cytotoxicity against a panel of tumor cell lines and multidrug‐resistant cell lines that were resistant to colchicine, vincristine, and paclitaxel treatment .…”

“…125,126 SSE15206 also circumvented drug resistance in KB-V1 and A2780-Pac-Res cell lines that overexpressed P-gp. 127 IMB5046 was not a P-gp substrate and displayed potent cytotoxicity against a panel of tumor cell lines and multidrug-resistant cell lines that were resistant to colchicine, vincristine, and paclitaxel treatment. 128 D4-9-31, a pyridine-pyrimidine amide, showed strong efficacy in isogenic paclitaxel-resistant breast cancer cells and also evaded P-gp-mediated drug efflux.…”

Transcriptomic analysis reveals differential gene expression, alternative splicing, and novel exons during mouse trophoblast stem cell differentiation

“…Immunoblotting was performed from 4 days undifferentiated TSCs and differentiated TGCs as described previously [32]. Briefly, cells were lysed with Triton lysis buffer (50 mM NaCl, 20 mM Tris pH 7.5, 1 mM EDTA, 1% Triton X100, 50 mM NaF, protease inhibitors and phosphatase inhibitors) on ice.…”