ABT-263

Biological Activity

ABT-263, a novel, orally bioavailable, BH3 mimetic, binds with high affinity (Ki ≤ 1nM) and inhibits multiple antiapoptotic Bcl-2 family proteins. ABT-263 displays activity (EC50 ≤ 1µM) against human lymphoid and small cell lung cancer cell lines. Mechanism based preclinical toxicities include reductions in circulating lymphocytes, apoptosis of circulating platelets, and decreased spermatogenesis, mediated by inhibition of Bcl-2, Bcl-XL and Bcl-w with IC50 values of ≤ 1 nM, ≤0.5 nM and ≤ 1 nM, respectively.

Product Citations

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  Cancers (Basel). 2021 Jan 19;13(2):361.

  Identification of a Dexamethasone Mediated Radioprotection Mechanism Reveals New Therapeutic Vulnerabilities in Glioblastoma
  ABT-263 purchased from AbMole

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  Clin Cancer Res. 2019 Jan 1;25(1):312-324.

  NOTCH1 Represses MCL-1 Levels in GSI-resistant T-ALL, Making them Susceptible to ABT-263
  ABT-263 purchased from AbMole

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  Cancer Res. 2020 Apr 1;80(7):1387-1400.

  Inhibition of BCL2 Family Members Increases the Efficacy of Copper Chelation in BRAF V600E-Driven Melanoma.
  ABT-263 purchased from AbMole

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  Cell Death and Disease. 2018 Jan 26;9:137-52.

  Downregulation of MCL-1 and upregulation of PUMA using mTOR inhibitors enhance antitumor efficacy of BH3 mimetics in triple-negative breast cancer
  ABT-263 purchased from AbMole

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  Clin Cancer Res. 2017 Oct 19;pii: clincanres.1577.2017.

  Epithelial-to-mesenchymal transition antagonizes response to targeted therapies in lung cancer by suppressing BIM
  ABT-263 purchased from AbMole

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  Proc Natl Acad Sci U S A. 2015 Mar 17;112(11):E1288-96.

  Assessment of ABT-263 activity across a cancer cell line collection leads to a potent combination therapy for small-cell lung cancer.
  ABT-263 purchased from AbMole

Customer Product Validations & Biological Datas

	Source	Cell Death & Disease (2018). Figure 6. ABT263 (Abmole Bioscience)
	Method	IHC analysis
	Cell Lines	Tumor-bearing nude mice
	Concentrations	25 mg/kg
	Incubation Time	4 weeks
	Results	Following BEZ235 treatment with or without ABT263, the expression of MCL-1 was suppressed while PUMA was increased; correspondingly, the expressions of p-AKT and p-4EBP1 were significantly suppressed.

	Source	Cell Death & Disease (2018). Figure 5. ABT263 (Abmole Bioscience)
	Method	i.p.
	Cell Lines	Tumor-bearing nude mice
	Concentrations	25 mg/kg
	Incubation Time	4 weeks
	Results	Our results showed that combination therapy of BEZ235 and ABT263 significantly suppressed tumor growth, comparing with each drug treatment alone.

	Source	Cell Death & Disease (2018). Figure 4. ABT263 (Abmole Bioscience)
	Method	CO-IP analysis
	Cell Lines	MDA-MB-231, MDA-MB-157, and MDA-MB-468 cells
	Concentrations	1 μM
	Incubation Time	24 h
	Results	Additionally, the interaction between MCL-1 and BAK was also significantly increased following mono treatment of ABT263.

	Source	Cell Death & Disease (2018). Figure 3. ABT263 (Abmole Bioscience)
	Method	Immunoblotting analysis
	Cell Lines	MDA-MB-231, MDA-MB-157, and MDA-MB-468 cells
	Concentrations	1 μM
	Incubation Time	24 h
	Results	Of note, we found that, besides MCL-1, the expression of PUMA but not other members was significantly increased following treatment of BEZ235 with or without ABT263 in MDA-MB-231, MDA-MB-157, and MDA-MB-468 cells.

	Source	Cell Death & Disease (2018). Figure 2. ABT263 (Abmole Bioscience)
	Method	Cell viability analysis
	Cell Lines	MDA-MB-231, MDA-MB-157, and MDA-MB-468 cells
	Concentrations	1 μM
	Incubation Time	24 h
	Results	The cell viability following indicated treatments was observed and the result showed that mTORC1/2 inhibitors (BEZ235 or AZD8055) incombination with ABT263 significantly inhibited cell viability in MDA-MB-231, MDA-MB-157, and MDAMB- 468 cells, comparing with each compound treatment alone.

	Source	Clin Cancer Res (2017). Figure 4. ABT-263 (Abmole Bioscience)
	Method	vitro observations
	Cell Lines	Mice harboring H1975 ER-TWIST+4-OHT tumors
	Concentrations	80mg/kg
	Incubation Time	5 d
	Results	The pharmaceutical approach of combining ABT-263 and an EGFRi could be successful in both EGFR mutant lung cancers with EMT-mediated acquired resistance, as well as mesenchymal cancers in the upfront setting.

	Source	Proc Natl Acad Sci U S A. (2015). Figure 3. ABT-263 and AZD8055 were purchased from Active Biochemicals (Hong Kong, China) and Abmole Bioscience (Houston, TX)
	Method	FACS analysis(Apoptosis), Western blotting, Immunoprecipitation (IP),Traditional human cell-line xenograft experiments
	Cell Lines	SCLC H82 and H1048 cells
	Concentrations	500 nM AZD8055, 1 μM ABT-263
	Incubation Time	2,16, 72h
	Results	Combination treatment with ABT-263 and the TORC1/2 inhibitor AZD8055 leads to robust apoptosis and antitumor activity in vivo.

	Source	Proc Natl Acad Sci U S A. (2015). Figure 2. ABT-263 and AZD8055 were purchased from Active Biochemicals (Hong Kong, China) and Abmole Bioscience (Houston, TX)
	Method	FACS analysis(Apoptosis),quantitative (q)RT-PCR, Western blotting, Immunoprecipitation (IP)
	Cell Lines	SCLC SW1271 and H1048 cells
	Concentrations	1µM
	Incubation Time	6,48,72h
	Results	BIM and MCL-1 mediate ABT-263–induced apoptosis in SCLC, and the ratio of BIM to MCL-1 expression predicts the magnitude of apoptosis in SCLC cell lines.

	Source	Proc Natl Acad Sci U S A. (2015). Figure 1. ABT-263 and AZD8055 were purchased from Active Biochemicals (Hong Kong, China) and Abmole Bioscience (Houston, TX)
	Method	quantitative (q)RT-PCR
	Cell Lines	SCLC cell lines
	Concentrations	1µM
	Incubation Time	72h
	Results	we found a modest, but significant, correlation between BIM expression and sensitivity to ABT-263.ABT-263 across both data sets (SI Appendix, Fig. S1 B and C). However, the ratio of BIM to MCL-1 predicted sensitivity to ABT-263 more effectively than the expression of either biomarker alone. SCLC lines have increased BIM expression compared with other solid tumor types along with enhanced sensitivity to ABT-263 compared with other solid tumor types across a large panel of cancer cell lines.

Protocol (for reference only)

Cell Experiment
Cell lines	H1048 cells
Preparation method	Flourescence Activated Cell Sorting (FACS) for death assays and cell cycle analysis Cells were plated in triplicate in 6-well plates or 6-cm dishes to reach ~30-40% confluency the next day. On the next day, cells were treated with the indicated drugs or no drug control. Apoptosis and cell cycle experiments were performed essentially as previously described and analyzed on a BD LSR III (Becton Dickenson, Franklin Lanes, NJ). The cell cycle experiments were gated to include only viable cells in order for the cell cycle distribution to be determined from this population. For apoptosis assays, the number of cells in quadrants II and IV (Annexin positive) were counted as apoptotic, where cells with subG0/G1 DNA3 were quantified and counted as apoptotic following staining with PI. The Annexin stain was conjugated to FITC and the analysis was done on a Guava easyCyte flow cytometer (EMD Millipore (Temecula, CA)). In the engineered H1048 cells, apoptosis determined by ABT-263 treatment and combination ABT-263/AZD8055 treatment were performed within the same experiment.
Concentrations	500 nM AZD8055, 1 μM ABT-2631
Incubation time	72h

Animal Experiment
Animal models	Traditional human cell-line xenograft(6-10 week-old mice with a Nu/Nu background with exponentially growing NCI-H1048 or NCI-H82 cells into the right rear flanks)
Formulation	AZD8055 was dissolved in Captisol ®. ABT-263 was dissolved in a mixture of 60% Phosal 50 PG, 30% PEG 400 and 10% EtOH.
Dosages	16 mg/kg/qd AZD8055, 80 mg/kg/qd ABT-263
Administration	oral gavage

Chemical Information

Molecular Weight	974.61
Formula	C47H55ClF3N5O6S3
CAS Number	923564-51-6
Solubility (25°C)	DMSO ≥100 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] Faber AC,et.al. Proc Natl Acad Sci U S A. Assessment of ABT-263 activity across a cancer cell line collection leads to a potent combination therapy for small-cell lung cancer.

[2] Yamaguchi et al. PLoS One. Efficient elimination of cancer cells by deoxyglucose-ABT-263/737 combination therapy.

[3] Shi et al. Cancer Res. Navitoclax (ABT-263) accelerates apoptosis during drug-induced mitotic arrest by antagonizing Bcl-xL.

[4] Gandhi et al. J Clin Oncol. Phase I study of Navitoclax (ABT-263), a novel Bcl-2 family inhibitor, in patients with small-cell lung cancer and other solid tumors.

[5] Tahir et al. Mol Cancer Ther. Identification of expression signatures predictive of sensitivity to the Bcl-2 family member inhibitor ABT-263 in small cell lung carcinoma and leukemia/lymphoma cell lines.