GDC-0941 (Pictilisib)

Biological Activity

GDC-0941, a selective and potent PI3K inhibitor, is highly efficacious both in combination with trastuzumab and in the treatment of trastuzumab-resistant cells and tumors. GDC-0941 inhibited the growth of >70% of breast cancer cell lines tested, with EC50's <1 µM. GDC-0941 also demonstrated antitumor activity in preclinical models of breast cancer.

Product Citations

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  J Nucl Med. 2018 Nov 21.

  MEK inhibition induces therapeutic iodine uptake in a murine model of anaplastic thyroid cancer.
  GDC-0941 (Pictilisib) purchased from AbMole

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  ChemMedChem. 2018 Dec 6.

  Identifying Lysophosphatidic Acid Acyltransferase β (LPAAT-β) as the Target of a Nanomolar Angiogenesis Inhibitor from a Phenotypic Screen Using the Polypharmacology Browser PPB2.
  GDC-0941 (Pictilisib) purchased from AbMole

• 

  Mol Cancer Res. 2018 Aug 14.

  Comprehensive Genomic Profiling of Patient-matched Head and Neck Cancer Cells: A Preclinical Pipeline for Metastatic and Recurrent Disease.
  GDC-0941 (Pictilisib) purchased from AbMole

• 

  J Exp Clin Cancer Res. 2018 Sep 21;37(1):234.

  The LAT1 inhibitor JPH203 reduces growth of thyroid carcinoma in a fully immunocompetent mouse model.
  GDC-0941 (Pictilisib) purchased from AbMole

• 

  BioRxiv. 2017 July 18;1-45.

  PIK3CAH1047R-induced paradoxical ERK activation results in resistance to BRAFV600E specific inhibitors in BRAFV600E PIK3CAH1047R double mutant thyroid tumors.
  GDC-0941 (Pictilisib) purchased from AbMole

• 

  Mol Cancer. 2017 May 22;16(1):93.

  PIK3CA hotspot mutations differentially impact responses to MET targeting in MET-driven and non-driven preclinical cancer models
  GDC-0941 (Pictilisib) purchased from AbMole

• 

  Oncotarget. 2017 Apr 11;8(15): 24604–24620.

  Combined MEK and Pi3’-kinase inhibition reveals synergy in targeting thyroid cancer in vitro and in vivo
  GDC-0941 (Pictilisib) purchased from AbMole

Customer Product Validations & Biological Datas

	Source	Journal of Nuclear Medicine (2018 Nov). Figure 3. GDC-0941 (AbMole Bioscience Inc.)
	Method	oral gavage
	Cell Lines	single mutant BRAFV600E mice
	Concentrations	50 mg/kg
	Incubation Time	10 days
	Results	The selective BRAFV600E inhibitor PLX-4720 did not increase Nis mRNA transcription, nor did the PI3K inhibitor GDC-0941 alone or in combination with PD-325901 or PLX-4720.

	Source	Journal of Experimental & Clinical Cancer Research (2018). Figure 4. GDC-0941 (Abmole Bioscience)
	Method	oral gavage
	Cell Lines	BRAFV600E/PIK3CAH1047R double-mutant mouse
	Concentrations	50 mg/kg
	Incubation Time	10 days
	Results	While Pi3K inhibition did not induced any change in Slc7a5 transcript abundance, MEK inhibition induced more than 50% reduction.

	Source	Molecular Cancer Research (2018). Figure 2. GDC-0941 (Abmole Bioscience)
	Method	cell viability assay
	Cell Lines	M-SCC-14A, UM-SCC-14B, and UM-SCC-14C cells
	Concentrations
	Incubation Time	72 hours
	Results	Interestingly, pictilisib was less effective at impairing proliferation in UM-SCC-14B than in the other two matched cell lines.

	Source	BioRxiv (2017). Figure 6. GDC-0941 (Abmole Bioscience, Hong-Kong, China)
	Method	western blot
	Cell Lines	8505c cells
	Concentrations	1 μM
	Incubation Time
	Results	Paradoxical ERK hyperphosphorylation was not detectable when cells were subjected to GDC-0941 in addition to PLX-4032 drug dilutions. When we treated them with the same concentrations of PLX-4032, 8505c and SW1736 cells did not exhibit paradoxical ERK activation.

	Source	BioRxiv (2017). Figure 4. GDC-0941 (Abmole Bioscience, Hong-Kong, China)
	Method	paradoxical activation
	Cell Lines	Thyroglobulin Cre ERT2 mice
	Concentrations	50 mg/kg
	Incubation Time	10 d
	Results	Only GDC-0941 and drug combination treated animals showed tumor burden reduction. PLX-4720 treated animals displayed an elevation in tumor burden that was not statistically different from the controls but from the two other groups.

	Source	BioRxiv (2017). Figure 3. GDC-0941 (Abmole Bioscience, Hong-Kong, China)
	Method	paradoxical activation
	Cell Lines	Thyroglobulin Cre ERT2 mice
	Concentrations	50 mg/kg
	Incubation Time	70 d
	Results	When treated with drug combination, ERK paradoxical activation was abolished resulting in ERK phosphorylation level comparable to controls. AKT phosphorylation was not affected by PLX-4720 while GDC-0941 treatment resulted in a small but significant reduction of AKT phosphorylation.

	Source	BioRxiv (2017). Figure 2. GDC-0941 (Abmole Bioscience, Hong-Kong, China)
	Method	Histological presentation
	Cell Lines	Thyroglobulin Cre ERT2 mice
	Concentrations	50 mg/kg
	Incubation Time	70 d
	Results	GDC-0941-treated mice had smaller thyroid sections, while presenting a similar histology compared to controls (Fig. 2B) with a mixture of PTC containing small ATC foci.

	Source	BioRxiv (2017). Figure 1. GDC-0941 (Abmole Bioscience, Hong-Kong, China)
	Method	tumor burden assay
	Cell Lines	Thyroglobulin Cre ERT2 mice
	Concentrations	50 mg/kg
	Incubation Time	70 d
	Results	GDC-0941 treated animals presented an initial tumor burden reduction of 20% then tumor size stabilized for the rest of the treatment period. Interestingly, when a drug combination of PLX-4720 and GDC-0941 was administered, mice showed a robust response with 60% lower tumor burden after 6 weeks followed by stabilization until the end of the experiment.

	Source	Oncotarget (2017). GDC-0941, Figure 4. (AbMole Bioscience, Hong-Kong, China)
	Method	Western blot
	Cell Lines	ATC cell
	Concentrations	50 mg/kg
	Incubation Time	24 h
	Results	Interestingly, PD-325901 treated mice showed a clear improvement in histology with some almost normal follicles and smaller PTC areas. GDC-0941 did not induce a beneficial effect at the histological level. Finally, mice treated with the combination, although resulting in smaller sections, seemed to have a similar histological presentation to PD-325901 alone treated animals (Figure 4C).

	Source	Oncotarget (2017). GDC-0941, Figure 3. (AbMole Bioscience, Hong-Kong, China)
	Method	Western blot
	Cell Lines	ATC cell
	Concentrations
	Incubation Time	24 h
	Results	ERK1/2 and AKT phosphorylation were assessed first to demonstrate the drug efficiency. ERK1/2 phosphorylation ratio (p-ERK1/2 normalized to total ERK) was strongly decreased in all cell lines when treated with PD-325901 alone or in combination with GDC-0941. Similarly, GDC-0941 induced a strong reduction of AKT phosphorylation ratio (Figure 3).

	Source	Oncotarget (2017). GDC-0941, Figure 2. (AbMole Bioscience, Hong-Kong, China)
	Method	apoptosis assay
	Cell Lines	OCUT-2 cells
	Concentrations	1 μM
	Incubation Time	24 h
	Results	Only the OCUT-2 cell line already showed increased apoptosis (double positive annexinV and PI cells) when treated with the combination for 24 h (Figure 2A). However, after 48 h of combination treatment, all three cell lines (Figure 2B and Supplementary Figure 1) had elevated double positive annexinV/PI cells (late apoptosis) and annexinV positive cells (early apoptosis).

	Source	Oncotarget (2017). GDC-0941, Figure 1. (AbMole Bioscience, Hong-Kong, China)
	Method
	Cell Lines	SW1736 and OCUT-2 cell lines
	Concentrations	2 μM, 400 nM, 80 nM, 16 nM, 3.2 nM
	Incubation Time	72 h
	Results	We investigated the effect of the drugs on cell cycling. PD-325901 alone or in combination with GDC-0941 induced a G1 cycle arrest in SW1736 and 8505c cell lines. However, in OCUT-2, a significant effect was only observed for the combination (Figure 1C).

	Source	Mol Cancer (2017). GDC-0941, Figure 5. (AbMole BioScience, Hongkong, China)
	Method	cell proliferation assay
	Cell Lines	NIH3T3 cells
	Concentrations	0-100 nM
	Incubation Time	16 h
	Results	Combination treatment led to more effective abrogation of AKT phosphorylation than either tepotinib or pictilisib alone, but p-S6 levels were generally unaltered (Fig. 5b).

	Source	Mol Cancer (2017). GDC-0941, Figure 4. (AbMole BioScience, Hongkong, China)
	Method	In vivo tumor growth delay experiments
	Cell Lines
	Concentrations	50 mg/kg
	Incubation Time	5 d
	Results	Comparison of average tumor sizes of vector vs. H1047R at the experimental endpoint showed significant resistance to tepotinib in H1047R tumors (p = 0.012), as well as higher efficacy of pictilisib in the same group (p = 0.026; Fig. 4d).

	Source	Mol Cancer (2017). GDC-0941, Figure 1. (AbMole BioScience, Hongkong, China)
	Method	Cell viability/toxicity assays
	Cell Lines	NIH3T3 cells
	Concentrations	0-100 nM
	Incubation Time	16 h
	Results	PI3K inhibition by pictilisib was similarly effective in reducing p-AKT levels in these three cell lines, but at a concentration of 100 nM p-S6 levels were lower in cells harboring PIK3CA mutations (Fig. 1b).

Protocol (for reference only)

Cell Experiment
Cell lines	U87MG cell line
Preparation method	Proliferation Assay. The human tumor cell lines used wereobtained from the ATCC. Cells were plated at 4 × 104 cells/ mL and cultured at 37 °C with 5% CO2 in DMEM supplemented with 10% fetal calf serum, and L-glutamine. Test compound was added to replicate wells in a volume of 10 µL such that the final DMSO concentration did not exceed 0.2%. After 4 days of incubation, 10 µL of Alamar Blue reagent was added and developed for 6 h at 37 °C before measuring the fluorescence excitation/emission (wavelength 540/595 nm) using a Victor plate reader. The reported IC50 values are means of at least two independent experiments with variations of less than 20%.
Concentrations	0~10µM
Incubation time	4 days

Animal Experiment
Animal models	Human tumor xenografts of U87MG glioblastoma of female NCr athymic mice
Formulation	10% DMSO, 5% Tween 20, 85% water
Dosages	75 mg/kg once daily
Administration	oral gavage

Chemical Information

Molecular Weight	513.64
Formula	C23H27N7O3S2
CAS Number	957054-30-7
Solubility (25°C)	DMSO 40 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] Nishida et al. Hypertension. Phosphatidylinositol 3-Kinase/Akt Signaling Pathway Activates the WNK-OSR1/SPAK-NCC Phosphorylation Cascade in Hyperinsulinemic db/db Mice.

[2] Bressanin et al. Oncotarget. Harnessing the PI3K/Akt/mTOR pathway in T-cell acute lymphoblastic leukemia: Eliminating activity by targeting at different levels.

[3] Zhu et al. Chem Pharm Bull (Tokyo). Design, Synthesis and Anticancer Activity of 4-Morpholinothieno[3,2-d]pyrimidine Derivatives Bearing Arylmethylene Hydrazine Moiety.

[4] Wallin et al. Clin Cancer Res. GDC-0941, a novel class I selective PI3K inhibitor, enhances the efficacy of docetaxel in human breast cancer models by increasing cell death in vitro and in vivo.

[5] Foreman et al. Mol Cancer Ther. ErbB3 inhibitory surrobodies inhibit tumor cell proliferation in vitro and in vivo.