Dabrafenib Mesylate

Biological Activity

Dabrafenib (GSK2118436) is a selective, orally bioavailable inhibitor of Mutant B-raf (BRAF) protein kinase with potential antineoplastic activity. B-raf belongs to the the raf/mil family of serine/threonine protein kinases and plays a role in regulating the MAP kinase/ERKs signaling pathway, which may be constitutively activated due to BRAF gene mutations. Mutations in BRAF are associated with increased growth and proliferation of cancer cells. Dabrafenib (GSK2118436) selectively binds to and inhibits the activity of B-raf, which may inhibit the proliferation of tumor cells which contain a mutated BRAF gene. Administration of the mutant BRAFi dabrafenib is associated with induction of keratinocytic proliferation, which in some cases develops features of low-grade malignancy.

Product Citations

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  2024 Jan.

  MAPK pathway modulation and its implications in KRAS mutant lung adenocarcinoma
  Dabrafenib Mesylate purchased from AbMole

• 

  Immunobiology. 2023 Jan;228(1):152311.

  Characterization of the impact of immune checkpoint inhibitors on platelet activation and aggregation
  Dabrafenib Mesylate purchased from AbMole

Protocol (for reference only)

Cell Experiment
Cell lines	A375P, SKMEL28 and Colo205 cell lines
Preparation method	A375P-F11 assay: A375P cells were plated in 96-well plates by limiting dilution and single cell-derived clones were harvested and tested for sensitivity to B-Raf inhibitors. The F11 clone was selected for future studies and was named A375P-F11. Cellular pSmad Assay to Measure Anti-TGF-β Activity: Activity of compounds was tested in a mechanistic assay in HepG2 cells. Cells were seeded in 12-well plates at a density of 500,000 cells/well and allowed to adhere overnight at 37℃/5% CO2. Media (BME+10% serum) was removed and compound in serum free media was added to the cells for 45 minutes at 37oC/5% CO2. Cells were stimulated with 1 ng/ml TGF-β (R&D systems) for 60 minutes. Cells were lysed in buffer (25 mM Tris-HCl ph: 7.5, 2 mM EDTA, 2 mM EGTA,1% Triton X-100, 0.1 % SDS, 50 mM sodium-β-glycerophosphate, 2 mM sodium orthovanadate, 12.5 mM sodium pyrophosphate, protease and phosphatase inhibitor cocktails) for 30 minutes, scraped, collected, clarified by centrifugation and prepared for western blots in LDS/reducing reagent (Invitogen). Samples were resolved on 4-12% Bis-Tris gels, transferred to PVDF, and probed for total and phospho-Smad2 using antibodies from Cell Signaling. Gels were imaged using the odyssey blot scanner (Licor) and quantified using Licor software. Phospho:total Smad2 ratios were determined and the IC50 was defined as the concentration of compound which decreased the phospho:total ratio by 50%.
Concentrations	0~10 nM
Incubation time

Animal Experiment
Animal models	A375P F11 Melanoma Xenograft in nude mice
Formulation	0.5% hydroxypropylmethylcellulose (Sigma) and 0.2% Tween-80 in distilled water pH 8.0
Dosages	0.2 mL/20g daily
Administration	oral gavage

Chemical Information

Molecular Weight	615.67
Formula	C23H20F3N5O2S2.CH4O3S
CAS Number	1195768-06-9
Solubility (25°C)	DMSO 22 mg/mL
Storage	Powder          -20°C   3 years ;  4°C   2 years In solvent       -80°C   6 months ;  -20°C   1 month

References

[1] Rheault TR, et al. ACS Med Chem Lett. Discovery of Dabrafenib: A Selective Inhibitor of Raf Kinases with Antitumor Activity against B-Raf-Driven Tumors.

[2] Anforth et al. Br J Dermatol. Cutaneous Manifestations of Dabrafenib (GSK2118436): A Selective Inhibitor of Mutant BRAF in patients with Metastatic Melanoma.

[3] Hauschild et al. Lancet. Dabrafenib in BRAF-mutated metastatic melanoma: a multicentre, open-label, phase 3 randomised controlled trial.

[4] Falchook et al. Lancet. Dabrafenib in patients with melanoma, untreated brain metastases, and other solid tumours: a phase 1 dose-escalation trial.