Antitumor agent-138 (compound 5b), with an IC 50 of 1.87 μM, inhibits tubulin polymerization at the tubulin colchicine-binding sites. It arrests the cell cycle at the G2/M phase and induces apoptosis in MCF-7 cells. Additionally, this compound suppresses cell migration and angiogenesis [1].

Antitumor agent-138 exhibits antiproliferative activity in several cell lines including MCF-7, A549, MDA-MB-231, HT-29, HeLa, and L02 with IC 50 values of 0.04, 0.39, 0.04, 0.06, 0.11, and 2.73 μM, respectively [1]. At concentrations of 5-20 nM, it inhibits colony formation in human breast cancer MCF-7 cells [1], induces microtubule collapse in MCF-7 cells at 25-200 nM [1], and dose-dependently inhibits tube formation in HUVEC cells at 6.25-50 nM, thereby inhibiting angiogenesis [1]. In a Cell Migration Assay, Antitumor agent-138 suppresses cell migration in A549 cells at 6.25-50 nM over 24 hours in a dose-dependent manner [1]. The Cell Proliferation Assay reveals low-concentration antiproliferative properties in cancer cells such as MCF-7, A549, MDA-MB-231, HT-29, and HeLa when treated with 0-5 μM for 48 hours [1]. Western Blot Analysis shows that the treatment increases P21, Cyclin B1, Cdc25c, cdk7, Bax, Cleaved-PARP, Bim, and Cleaved Caspase-9, whilst decreasing Bcl-2 in a dose- and time-dependent manner in MCF-7 cells at 6.25-25 nM over 24 hours [1]. Immunofluorescence demonstrates dot-like appearances in the microtubule network in MCF-7 cells treated with 25-200 nM for 8 hours [1].

Antitumor agent-138, administered at a dosage of 20 mg/kg through intraperitoneal injection for 21 days, demonstrated tumor inhibition activity in MCF-7 xenograft BALB/c nude mice, achieving a tumor growth inhibition (TGI) rate of 68.95% [1]. Animal Model: MCF-7 xenograft in BALB/c nude mice [1].