Niltubacin

Biological Activity

Niltubacin, as an inactive derivative of Tubacinis, is a highly potent and selective, reversible cell-permeable inhibitor of HDAC6. Histone deacetylase 6 (HDAC6) is structurally and functionally unique among the 11 human zinc-dependent histone deacetylases. HDAC6-selective inhibitor tubacin significantly enhances cell death induced by the topoisomerase II inhibitors etoposide and doxorubicin and the pan-HDAC inhibitor SAHA (vorinostat) in transformed cells (LNCaP, MCF-7), an effect not observed in normal cells. The inactive analogue of tubacin, nil-tubacin, does not sensitize transformed cells to these anticancer agents.

Product Citations

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  EMBO J. 2019 Jan 15;38(2).

  Prominin-1 controls stem cell activation by orchestrating ciliary dynamics.
  Niltubacin purchased from AbMole

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  J Cell Biochem. 2017 Apr 27.

  The HDAC6 Inhibitor Tubacin Induces Release of CD133þ Extracellular Vesicles From Cancer Cells
  Niltubacin purchased from AbMole

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  Mol Cell Biol. 2016 Oct 28;36(22):2838-2854.

  Activated Transcription Factor 3 in Association with Histone Deacetylase 6 Negatively Regulates MicroRNA 199a2 Transcription by Chromatin Remodeling and Reduces Endothelin-1 Expression.
  Niltubacin purchased from AbMole

Customer Product Validations & Biological Datas

	Source	J Cell Biochem (2017). Figure 5. Niltubacin (Abmole Bioscience Inc.)
	Method	Clonogenic survival assay
	Cell Lines	FEMX-I cell line
	Concentrations	200 µm
	Incubation Time	24 h
	Results	This effect was specific for tubacin, as TSA, niltubacin and ACY-1215 did not inhibit the formation of cell aggregates. Similar effects were observed in Caco-2 cell line (Supplementary Fig. S5).

	Source	J Cell Biochem (2017). Figure 2. Niltubacin (Abmole Bioscience Inc.)
	Method	Cell Aggregation Assay
	Cell Lines	FEMX-I cell line
	Concentrations
	Incubation Time	24 h
	Results	The effect was specific, as the inactive analog of tubacin, niltubacin, at the same concentration did not increase CD133, CD9, or b-actin levels (Fig. 2c).

	Source	Mol. Cell. Biol. (2016). Figure 9. Tubacin and Niltubacin for animal studies were obtained from AbMole Bioscience Inc. (Houston, TX)
	Method	BK-SS mice
	Cell Lines
	Concentrations	0.5mg/kg i.p.
	Incubation Time	5 or 10 or 30 days
	Results	These drug regimens showed a time dependent reduction of PlGF (Fig. 9C) and ET-1 (Fig. 9D) in plasma, compared to Niltubacin. The 30 day drug treatment effectively reduced plasma levels of PlGF by ~60% (p <0.001, Fig. 9C) and plasma levels of ET-1 by ~60% (p<0.001, Fig. 9D).

	Source	Mol. Cell. Biol. (2016). Figure 7. Tubacin and Niltubacin for animal studies were obtained from AbMole Bioscience Inc. (Houston, TX)
	Method	FAIRE-qPCR
	Cell Lines	HMEC-1 cells
	Concentrations	5 µM
	Incubation Time	30 min
	Results	Taken together, these data showed PlGF induced chromatin condensation to repress DNM3os transcription, while Tubacin prevented the repressive effect following PlGF signaling.

	Source	Mol. Cell. Biol. (2016). Figure 6. Tubacin and Niltubacin for animal studies were obtained from AbMole Bioscience Inc. (Houston, TX)
	Method	qRT-PCR and reporter luciferase activity
	Cell Lines	HMEC-1 cells
	Concentrations	5 µM
	Incubation Time	30 min
	Results	We concluded that HDAC6 required functional ATF3 binding sites in the DNM3os promoter and any antagonism of PlGF effects by Tubacin was not due to a general effect on transcription of the endogenous DNM3os gene or the wt DNM3os reporter construct.

Protocol (for reference only)

Cell Experiment
Cell lines	Raji cells
Preparation method	Cell adhesion assay Prior to SDF-1α (100 ng/ml) stimulation, Raji cells were treated with DMSO, NaB (1 μM), or tubacin (1 μM) for 3 hours. Then cells were plated into a 96-well plate which were precoated with Fibronectin (50 ng/ml) to allow cell adherence for 30 minutes. Subsequently cells were washed with PBS three times to remove the non-adherent cells, and adherent cells were measured by CellTiter-Glo luminescent cell viability assay kit.
Concentrations	1μM
Incubation time	3h

Animal Experiment
Animal models	PLD animal model 3-week-old PCK rats
Formulation	saline
Dosages	30 mg/kg body
Administration	intraperitoneally

Chemical Information

Molecular Weight	706.85
Formula	C41H42N2O7S
Solubility (25°C)	DMSO ≥5 mg/mL
Storage	Powder          -20°C   3 years ;  4°C   2 years In solvent       -80°C   6 months ;  -20°C   1 month

Conversion of different model animals based on BSA (PMID: 27057123)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of Compound A used for a mouse (20 mg/kg) to a dose based on the BSA for a rat, multiply 20 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for Compound A of 10 mg/kg.

References

[1] Namdar et al. Proc Natl Acad Sci U S A. Selective inhibition of histone deacetylase 6 (HDAC6) induces DNA damage and sensitizes transformed cells to anticancer agents.

[2] Ding et al. J Neurochem. Histone deacetylase 6 interacts with the microtubule-associated protein tau.