Cell experiment:

8505C and FTC133 cells are grown in DMEM/F12 suppplemented with 10% FCS and 1% PenStrep and incubated at 37℃, 5% CO2. For B-CPAP RPMI 1640 medium is used. FGFR1 inhibition experiments are performed on FTC133 cells by employment of Receptor Tyrosine Kinase Inhibitors TKI-258 (Dovitinib) and SU 5402 (20μM). Inhibition is conducted over 4 h with the indicated inhibitor concentrations. Control cells receive corresponding concentrations of DMSO[2].

Animal experiment:

Mice[3] Male ΔF508 mice (CFTRtm1Eur on a 129/FVB background) and their wild-type littermates of 9-12 weeks are intraperitoneally injected with DMSO or SU 5402 (dissolved in DMSO at the concentration of 6 mg/mL) at 25 mg/kg body weight, every day for 1 week. The mice are weighed daily and the dosages adjusted accordingly. The mice are then anesthetized by inhaling isoflurane until the end of the procedure. Cholinergic antagonist, Atropine (1 mM, 50 μL) is subcutaneously injected into the right cheek to block potential cholinergic stimulation of the salivary gland. A small strip of filter paper is placed against the injected cheek, for 4 min. Isoprenaline (10 mM, 37.5 μL) is subsequently injected in the same spot to stimulate an adrenergic secretion of saliva (time 0). Filter strips (pre-weighed in an Eppendorf tube) are replaced every 5 min, over a period of 30 min. All six filter strips are weighed at the end of the collection and the results are normalized relative to mg/g body weight. Rats[4] To assess the potential effects of the FGFR1 inhibitor SU 5402 on established PH, adult male Wistar rats (200-250 g) are given MCT (60 mg/kg s.c.), left untreated for 21 days, then randomly divided into 2 groups (10 animals in each group), of which one is treated with SU 5402 (25 mg/kg/day) and the other given the vehicle, from day 21 to day 42. All treatments are given once a day by s.c. injection.

IC50: 0.02, 0.03, 0.51 and >100 μM for VEGFR2, FGFR1, PDGFRβ and EGFR, respectively

SU 5402 is an inhibitor of VEGF, FGF, and PDGF receptor tyrosine kinases. Receptor tyrosine kinases have been recognized as therapeutic targets for the treatment of human diseases including cancers, inflammatory diseases, and cardiovascular diseases.

In vitro: SU5402 could inhibit FGFR3 phosphorylation in vitro. B cells dependent on FGFR3 for survival were sensitive to SU5402 specifically. A panel of 11 human myeloma cell lines was studied, among which five beared t(4;14) translocation. The KMS11 human myeloma cell line expressesing constitutively active mutant FGFR3, displayed a 95% increase in G0/G1 cells as well as 45-fold increase in apoptotic cells after SU5402 treatment. In addition, the activated signal-regulated kinases 1 and 2 and signal activator of transcription 3 were down-regulated after SU5402 treatment rapidly. In human myeloma cell lines with wild-type FGFR3, the stimulating effect of aFGF ligand was abrogated by SU5402 [1].

In vivo: BALB/c mice were inoculated with syngeneic pre-B-TD cells and these established tumours were treated with 300 ng/kg SU5402 or carrier alone administered by either direct subcutaneous or intraperitoneal injection. Tumours were collected 24 h later and Western blot analyses indicated a treatment-related decrease in the levels of activated ERK1/2 in the harvested tumors [1].

Clinical trial: N/A

Reference:
[1] Paterson JL,Li Z,Wen XY,Masih-Khan E,Chang H,Pollett JB,Trudel S,Stewart AK.  Preclinical studies of fibroblast growth factor receptor 3 as a therapeutic target in multiple myeloma. Br J Haematol.2004 Mar;124(5):595-603.