Taccalonolide A is a microtubule stabilizer, which is a steroid isolated from Tacca chantrieri, with cytotoxic and antimalarial activities[1][2]. Taccalonolide A causes G2-M accumulation, Bcl-2 phosphorylation and initiation of apoptosis[1]. Taccalonolide A is effective in vitro against cell lines that overexpress P-glycoprotein (Pgp) and multidrug resistance protein 7 (MRP7), with an IC50 of 622 nM for SK-OV-3 cells[3].
CCB02 is a selective CPAP-tubulin interaction inhibitor, binding to tubulin and competing for the CPAP binding site of β-tubulin, with an IC50 of 689 nM, and shows potent anti-tumor activity. CCB02 shows no inhibition on the cell cycle- and centrosome-related kinases, or the phosphorylation status of Aurora A, Plk1, Plk2, CDK2, and CHK1[1].
HDAC-IN-39 (compound 16c) is a potent HDAC inhibitor, with IC50 values of 1.07 μM (HDAC1), 1.47 μM (HDAC2), and 2.27 μM (HDAC3), respectively. HDAC-IN-39 also significantly inhibits microtubule polymerization. HDAC-IN-39 induces cell cycle arrest at the G2/M phase. HDAC-IN-39 displays promising anticancer activity against resistant cancer cells[1].
BRD9876 is the “rigor” inhibitor that locks kinesin-5 (Eg5) in a state with enhanced microtubules (MTs) binding, leading to bundling and stabilization of MTs. BRD9876 interacts with the tyrosine 104 residue that is part of the α4-α6 allosteric binding pocket. BRD9876 specifically targets microtubule-bound Eg5 and selectively inhibits myeloma over CD34 cells. BRD9876 has the potential for multiple myeloma (MM) research[1][2][3][4].
DHA-paclitaxel is an inert prodrug composed of the natural fatty acid DHA covalently linked to the C2'-position of paclitaxel. The paclitaxel moiety binds to tubulin and inhibits the disassembly of microtubules, thereby resulting in the inhibition of cell division. Compared to Paclitaxel, DHA-Paclitaxel targets tumor cells more specifically because tumor cells absorb large amounts of natural fatty acids for use as biochemical precursors and energy sources.
CHM-1, a microtubule-destabilizing agent, inhibits tubulin polymerization. CHM-1 is a potent and selective antimitotic antitumor activity against human hepatocellular carcinoma. CHM-1 induces growth inhibition and apoptosis via G2-M phase arrest in human hepatocellular carcinoma cells by activation of Cdc2 kinase activity[1][2][3].
Glochidiol is an orally active tubulin polymerization inhibitor with an IC50 of 2.76 μM. Glochidiol shows anti-cancer activity[1].
αβ-Tubulin-IN-1 is a potent and orally active αβ-Tubulin inhibitor. αβ-Tubulin-IN-1 induces cell cycle arrest at G2/M and efficient apoptosis. αβ-Tubulin-IN-1 inhibits tumor cell migration and Metastasis. αβ-Tubulin-IN-1 shows significant antitumor efficacy in a dose dependent manner[1].
10-Deacetyl-7-xylosyl paclitaxel is a Paclitaxel derivative with improved pharmacological features and higher water solubility.IC50 value:Target: Microtubule inhibitor10-Deacetyl-7-xylosyl paclitaxel induced mitotic cell cycle arrest and apoptosis as measured by flow cytometry, DNA laddering, and transmission electron microscopy. Pro-apoptotic Bax and Bad protein expression was up-regulated and anti-apoptotic Bcl-2 and Bcl-XL expression down-regulated, which lead to a disturbance of the mitochondrial membrane permeability and to the activation of caspase-9. In turn, caspase-9 activated downstream caspases-3 and -6, but not caspase-8. Bid was also activated by caspase-3. Reversely, treatment with a caspase-10-specific inhibitor could not protect PC-3 cells from 7-xylosyl-10-deacetyl-paclitaxel-triggered apoptosis. Moreover, 7-xylosyl-10-deacetylpaclitaxel had no effect on the expression of CD95 and NF-kappaB proteins, indicating that apoptosis was induced through the mitochondrial-dependent pathway in PC-3 cells.
Plinabulin (NPI-2358) is a vascular disrupting agents (VDA) against tubulin-depolymerizing with IC50 of 9.8~18 nM in tumor cells.IC50 Value: 9.8~18 nMTarget: Microtubule/Tubulinin vitro: NPI-2358 binds to the colchicine-binding site of tubulin and has potent inhibitory to human tumor cell lines which have overexpressed Pgp or reduced nuclear Topo II catalytic activity, with IC50 from 9.8 to 18 nM. NPI-2358 is able to rapidly induce tubulin depolymerization in HUVECs and monolayer permeability even at 20 nM. NPI-2358 induces cell death in MM cells with IC50 of 8-10 nM, which due to trigger early mitotic arrest in MM cells. NPI-2358 also inhibits tubule formation and migration of endothelial as well as MM cells, which leads to disrupt tumor vasculature. NPI-2358 could induces cell death in patient MM (CD138+) cells without effecting viability of normal mononuclear cells. Blockade of JNK abrogates NPI-2358-induced mitotic arrest or MM cell death. in vivo: NPI-2358 (7.5 mg/kg) inhibits tumor growth in human plasmacytoma mouse xenograft models at well-tolerated doses. NPI-2358 induces a time- and dose-dependent decrease in tumour perfusion. NPI-2358 is more sensitive to the KHT sarcoma than the C3H tumour, while radiation response could enhance the antitumor activity in both models.
Eribulin mesylate is a microtubule targeting agent that is used in the treatment of metastatic breast cancer. It inhibits the proliferation of cancer cells by binding microtubule proteins and microtubules.
Tubulin polymerization-IN-9 is a potent tubulin inhibitor with IC50 of 1.82 μM. Tubulin polymerization-IN-9 causes cell cycle arrest at G2/M phase, and induces cell apoptosis and depolarized mitochondria of K562 cells. Tubulin polymerization-IN-9 has potent anti-vascular and antitumor activities[1].
Cabazitaxel is a semi-synthetic derivative of the natural taxoid 10-deacetylbaccatin III with potential antineoplastic activity.
Cevipabulin(TTI-237) is a novel, potent, synthetic small molecule, inhibits binding of vinblastine at the Vinca alkaloid site of the αβ-tubulin heterodimer.IC50 value: Target: Antimicrotubule agentin vitro: TTI-237 inhibited the binding of [(3)H]vinblastine to tubulin, but it caused a marked increase in turbidity development that more closely resembled the effect observed with docetaxel than that observed with vincristine. When applied to cultured human tumor cells at concentrations near its IC(50) value for cytotoxicity (34 nmol/L), TTI-237 induced multiple spindle poles and multinuclear cells, as did paclitaxel, but not vincristine or colchicine. Flow cytometry experiments revealed that, at low concentrations (20-40 nmol/L), TTI-237 produced sub-G(1) nuclei and, at concentrations above 50 nmol/L, it caused a strong G(2)-M block. The compound was a weak substrate of multidrug resistance 1 (multidrug resistance transporter or P-glycoprotein). In a cell line expressing a high level of P-glycoprotein, the IC(50) of TTI-237 increased 25-fold whereas those of paclitaxel and vincristine increased 806-fold and 925-fold, respectively. TTI-237 was not recognized by the MRP or MXR transporters [1]. TTI-237 inhibited the exchange of [(3)H]GTP at the exchangeable nucleotide site of the tubulin heterodimer, and was similar to vincristine in its effects on the phosphorylation of eight intracellular proteins in HeLa cells [3].in vivo: TTI-237 was active in vivo in several nude mouse xenograft models of human cancer, including LoVo human colon carcinoma and U87-MG human glioblastoma, when dosed i.v. or p.o [1].
Aha1/Hsp90-IN-1 (Compound 17) is an Aha1/Hsp90 complex inhibitor. Aha1/Hsp90-IN-1 disrupts Aha1/Hsp90 interactions with an IC50 of 3.32 μM. Aha1/Hsp90-IN-1 inhibits tau aggregation[1].
Vc-MMAD consists the ADCs linker(Val-Cit) and potent tubulin inhibitor (MMAD), Vc-MMAD is an antibody drug conjugate.IC50 Valu: N/ATarget: tubulin; ADCsMonomethyl auristatin D (MMAD), a potent tubulin inhibitor, is a toxin payload and antibody drug conjugate.For comparison purposes, the ADC A1 -mc-MMAD and/or A1 -vc-MMAD were used. The linker payload, mc-MMAD (6-maleimidocaproyl-monomethylauristatin-D) was conjugated to the A1 anti-5T4 monoclonal antibody through a cysteine residue at a ratio of approximately 4 drug moieties per antibody molecule. The linker payload mc- Val-Cit-PABA-MMAD or vc-MMAD (maleimidocapronic -valine-citruline-p- aminobenzyloxycarbonyl- monomethylauristatin-D) was conjugated to the A1 anti-5T4 monoclonal antibody through a cysteine residue at a ratio of approximately 4 drug moieties per antibody molecule (Antibody-drug conjugates Patent: WO 2013068874 A1).
Auristatin F is a cytotoxic tubulin modifier with potent and selective antitumor activity; MMAF analog and cytotoxin in Antibody-drug conjugates.
BTB-1 is a potent, selective and reversible mitotic motor protein Kif18A inhibitor with an IC50 of 1.69 μM.
Microtubule inhibitor 4 (compound 2) is a potent microtubule inhibitor. Microtubule inhibitor 4 shows cytotoxicity with IC50s of 4.0, 3.2, 2.1 nM for NCI-H460, BxPC-3, HT-29 cells, respectively. Microtubule inhibitor 4 shows the inhibition of tubulin polymerization[1].
Amphethinile is an anti-tubulin agent. The affinity constant for the association (Ka) of Amphethinile with tubulin is 1.3 μM.
Tubulin polymerization-IN-30 (compound 6e) is a potent Tubulin polymerization inhibitor. Tubulin polymerization-IN-30 is a colchicine binding site inhibitor. Tubulin polymerization-IN-30 can disrupt intracellular microtubule organization, arrest cell cycle at the G2/M phase. Tubulin polymerization-IN-30 exhibits the high potency against the cancer cell lines including SGC-7901, A549 and HeLa, with IC50 values of 2.16, 2.21, and 0.403 μM[1].
Wikstrol A is a potent antifungal, antimitotic and anti-HIV-1 Agent. Wikstrol A induces morphological deformation of P. oryzae mycelia with an MMDC value of 70.1 µM. Wikstrol A shows activity against microtubule polymerization with an IC50 value of 131 µM. Wikstrol A shows anti-HIV-1 activity with an IC50 value of 67.8 µM[1].
Taltobulin trifluoroacetate (HTI-286; SPA-110) is an analogue of Hemiasterlin; potent tubulin inhibitor; ADCs cytotoxin.IC50 value:Target: tubulinin vitro: HTI-286 significantly inhibited proliferation of all three hepatic tumor cell lines (mean IC50 = 2 nmol/L +/- 1 nmol/L) in vitro. Interestingly, no decrease in viable primary human hepatocytes (PHH) was detected under HTI-286 exposure [1]. In all cell lines tested, HTI-286 was a potent inhibitor of proliferation and induced marked increases in apoptosis. Despite similar transcriptomic changes regarding cell death and cell cycle regulating genes after exposure to HTI-286 or docetaxel, array analysis revealed distinct molecular signatures for both compounds [2].in vivo: Intravenous administration of HTI-286 significantly inhibited tumor growth in vivo (rat allograft model) [1]. HTI-286 significantly inhibited growth of PC-3 and LNCaP xenografts and retained potency in PC-3dR tumors. Simultaneous castration plus HTI-286 therapy was superior to sequential treatment in the LNCaP model [2].
KIF18A-IN-4 is a moderately potent ATP and microtubule (MT) noncompetitive KIF18A inhibitor (IC50=6.16 μM). KIF18A-IN-4 has selectivity against a large panel of mitotic kinesins and kinases, and does not show any direct effects on tubulin assembly. KIF18A-IN-4 exhibits anti-tumor activity[1].
Tubulin polymerization-IN-52 (compound SC23) is a potent tubulin polymerization inhibitor, with an IC50 of 2.9 μM[1].
Taccalonolide AJ is a semi-synthesis compound with cellular microtubule stabilizing activity. Taccalonolide AJ exhibits high potency antiproliferative activity against cancer cells, with an IC50 of 4.2 nM for HeLa cells[1].
Sertaconazole (FI7056 free base) is a broad-spectrum topical antifungal agent, exhibits anti-inflammatory activity via activation of a p38-COX-2-PGE2 pathway. Sertaconazole is also a microtubule inhibitor, shows antiproliferative effect, induces apoptosis and autophagy, and can also inhibit the migration of cells[1][2][3][4].
SS28, a SRT501 analog with oral bioavailability, inhibits tubulin polymerization to cause cell cycle arrest at G2/M phase. SS28 results in apoptosis rather than necrosis tubulin[1].
Eribulin (E7389; ER-086526), a synthetic analogue of halichondrin B in phase III clinical trials for breast cancer, binds to tubulin and microtubules.Target: Microtubule/TubulinEribulin suppressed centromere dynamics at concentrations that arrest mitosis. At 60 nmol/L eribulin (2 x mitotic IC(50)), the relaxation rate was suppressed 21%, the time spent paused increased 67%, and dynamicity decreased 35% (but without reduction in mean centromere separation), indicating that eribulin decreased normal microtubule-dependent spindle tension at the kinetochores, preventing the signal for mitotic checkpoint passage [1]. [(3)H]eribulin binds soluble tubulin at a single site; however, this binding is complex with an overall K(d) of 46 microM, but also showing a real or apparent very high affinity (K(d) = 0.4 microM) for a subset of 25% of the tubulin. Eribulin also binds microtubules with a maximum stoichiometry of 14.7 +/- 1.3 molecules per microtubule (K(d) = 3.5 microM), strongly suggesting the presence of a relatively high-affinity binding site at microtubule ends. At 100 nM, the concentration that inhibits microtubule plus end growth by 50%, we found that one molecule of eribulin is bound per two microtubules, indicating that the binding of a single eribulin molecule at a microtubule end can potently inhibit its growth. Eribulin does not suppress dynamic instability at microtubule minus ends [2]. Eribulin's in vivo superiority derives from its ability to induce irreversible mitotic blockade, which appears related to persistent drug retention and sustained Bcl-2 phosphorylation [3].
Tubulin polymerization-IN-21 (compound 9a) is a tubulin polymerization inhibitor. Tubulin polymerization-IN-21 exhibits anti-cancer activity through disrupting cellular integrity and affecting glucose metabolism[1].