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MCF-7 cell tubulin is isolated from the human breast cancer cell line MCF-7 (ATCC, cat. # HTB-22), a model system to study many aspects of tumor cell growth. MCF-7 cell tubulin may be used in all situations where previously bovine brain tubulin has been employed, for example drug screening, motility assays and biochemical studies including microtubule dynamics. The advantage of using this novel tubulin is that it is derived from an actively dividing cell line, which often, in contrast to brain derived tubulins, more accurately portrays the situation that many researchers are trying to reconstruct in vitro.
The specificity of ligands for for a particular tubulin variant can be determined by performing comparative studies with both cancer cell and neuronal tubulins. Cytoskeleton, Inc. has advanced this concept by developing the Tubulin Ligand Index (TLI) system (patent pending). In this system, IC50 values for inhibitory compounds or EC50 values for stabilizing compounds are determined in in polymerization assays using cancer cell and neuronal tubulins. The IC50 or EC50 values for each tubulin variant are analyzed as a ratio (neuronal/cancer cell) and allow for determinations of the relative specificity for each tested compound. TLI values greater than 1.0 indicate that the particular compound is more active on cancer cell tubulin. Conversely, TLI values less than 1.0 suggest that a compound is more specific for neuronal tubulin. Table 1 summarizes data from a study comparing the specificity of several tubulin ligands using the TLI system.
|Table 1. Tubulin ligand index values from studies with cancer cell and neuronal tubulins|
EC50/IC50 Value (µM)
The protein is supplied as a lyophilized powder.
For another human cancer cell derived tubulin, see our HeLa cell tubulin (Cat. # H001)
H005 contains >90% pure MCF-7 cell tubulin. Purity is determined by scanning densitometry of proteins on SDS-PAGE gels.
Figure 1: An H001 sample (20 µg) was run on a 10% SDS-PAGE gel and stained with Coomassie Blue stain
One unit of tubulin is defined as 24 µg of purified protein (as determined by the Precision Red Advanced Protein Assay Reagent, Cat. # ADV02). MCF-7 cell tubulin will polymerize efficiently at a concentration of 2.0 mg/ml in the presence of 20% (v/v) glycerol. The MCF-7 tubulin polymerization assay has been miniaturized to 12 µl (1 unit/reaction) in order to make anti-cancer drug development feasible. Visit the page on CytoDYNAMIX screens for more information. Tubulin from cervical cancer cells (HeLa) is also available (Cat. # H001).
M.S. Feizabadi and Y. Jun. 2014. Kinesin-1 translocation: Surprising differences between bovine brain and MCF7-derived microtubules. Biochem. Biophys. Res. Commun. DOI: 10.1016/j.bbrc.2014.10.119.
M.L. Antony et al. 2014. Growth arrest by the antitumor steroidal lactone withaferin A in human breast cancer cells is associated with downregulation and covalent binding at cysteine-303 of β-tubulin. J. Biol. Chem.