The primary target of bFGF (119-126) is the fibroblast growth factor receptor 1 (FGFR1). The peptide binds to FGFR1 and disrupts the dimerization and activation of the receptor, which is essential for its tyrosine kinase activity and downstream signaling. By inhibiting FGFR1 dimerization, bFGF (119-126) prevents the phosphorylation of the receptor and the activation of downstream signaling pathways such as RAS-MAPK (ERK1/2) and PI3K-Akt. This peptide does not directly bind to bFGF (the ligand) but rather interacts with the receptor to inhibit its activation. This makes it a receptor antagonist rather than a ligand-neutralizing agent. The peptide corresponds to a region in bFGF that may be involved in receptor binding or dimerization. It is used to study the mechanisms of FGFR signaling and to evaluate the therapeutic potential of FGFR inhibition in cancer and other diseases characterized by FGF/FGFR dysregulation.

In vitro studies demonstrate that bFGF (119-126) is a biological active peptide that inhibits the dimerization and activation of the bFGF receptor (FGFR1). It disrupts the bFGF-FGFR1 interaction, thereby antagonizing the mitogenic and angiogenic activities of bFGF. In cell-based assays, bFGF (119-126) (e.g., 10-100 uM) inhibits bFGF-stimulated proliferation of various cell types, including endothelial cells (e.g., HUVEC) and cancer cells (e.g., breast, lung, glioblastoma). The peptide also inhibits bFGF-induced migration and tube formation in endothelial cells, which are key steps in angiogenesis. The anti-proliferative effect can be quantified by MTT or 3H-thymidine incorporation assays. The inhibition of FGFR1 phosphorylation can be assessed by Western blotting using antibodies against phospho-FGFR1 (Tyr653/654) and downstream effectors such as phospho-ERK1/2 and phospho-Akt. In wound healing assays (scratch assays), bFGF (119-126) (e.g., 50 uM) significantly reduces the migration of bFGF-stimulated cells into the denuded area. In Matrigel tube formation assays, treatment with bFGF (119-126) inhibits the formation of capillary-like structures by bFGF-stimulated HUVECs. The peptide also inhibits the growth of bFGF-dependent tumor cell lines and can synergize with other anti-cancer agents. When used in combination with ultrasound and doxorubicin, bFGF (119-126) significantly enhances the anti-tumor effect, suggesting potential for use in drug delivery systems. The IC50 for inhibition of cell proliferation varies depending on the cell line and the concentration of bFGF, but is typically in the range of 10-50 uM.

In vivo studies have shown that bFGF (119-126) can inhibit tumor growth and angiogenesis in animal models. For example, in a subcutaneous xenograft model of lung cancer, breast cancer, glioblastoma, or ovarian cancer in mice, administration of bFGF (119-126) (e.g., 10-30 mg/kg, i.p., daily) resulted in significant tumor growth inhibition. The peptide is often used in combination with ultrasound and doxorubicin to enhance anti-tumor effects. In these studies, bFGF (119-126) combined with ultrasound and doxorubicin significantly enhanced tumor inhibition compared to any single treatment or chemotherapy alone. The anti-angiogenic effect of bFGF (119-126) in vivo can be demonstrated by reduced microvessel density (CD31 immunohistochemistry) in tumor sections. The peptide also reduces the expression of bFGF and FGFR1 in tumor tissues, as shown by Western blotting and immunofluorescence. Additionally, bFGF (119-126) can improve the delivery of co-administered drugs by normalizing tumor vasculature (reducing interstitial fluid pressure) due to its anti-angiogenic and anti-FGFR activity. No significant toxicity (body weight loss, major organ damage) was reported at the tested doses. The peptide has shown promise as an anti-cancer agent, particularly in combination with chemotherapy and physical modalities like ultrasound.

Non-cell-based assays for bFGF (119-126) focus on its ability to bind to FGFR1 and inhibit receptor dimerization. A surface plasmon resonance (SPR) assay can be performed to measure the direct binding of the peptide to the recombinant FGFR1 protein. FGFR1 (extracellular domain, e.g., FGFR1-ECD, 0.5-2 ug/mL) is immobilized on a CM5 sensor chip via amine coupling. Increasing concentrations of bFGF (119-126) (0.1-100 uM) are injected in running buffer (10 mM HEPES pH 7.4, 150 mM NaCl, 0.05% Tween-20, 0.1% BSA) at a flow rate of 30 uL/min. The association (ka) and dissociation (kd) rates are monitored, and the equilibrium dissociation constant (KD) is calculated. A high KD (low affinity, e.g., >10 uM) indicates a weak interaction, which is typical for short peptides. To assess inhibition of FGFR1 dimerization, a protein-protein interaction assay using a split-luciferase or FRET-based system can be used. For example, FGFR1 is tagged with a donor fluorophore (e.g., ECFP) and an acceptor fluorophore (e.g., EYFP). In the presence of bFGF (the agonist), the receptors dimerize, leading to FRET. bFGF (119-126) is added to the reaction mixture, and the decrease in FRET signal (or increase in donor emission) is measured. The EC50 for inhibition of dimerization can be calculated. Alternatively, a size-exclusion chromatography (SEC) or native PAGE assay can be used to visualize the dimerization of FGFR1 in the presence of bFGF and the peptide. For competitive binding assays, FGFR1-coated plates can be incubated with biotinylated bFGF and varying concentrations of the peptide, and the bound biotinylated bFGF is detected by streptavidin-HRP. The IC50 for displacement of bFGF is calculated. However, since the peptide is thought to act on the receptor rather than directly competing with bFGF for binding, this assay may not be informative.

For cell-based studies, human umbilical vein endothelial cells (HUVECs) or cancer cells (e.g., A549 lung cancer, MCF-7 breast cancer, U87MG glioblastoma) are cultured in EBM-2 or DMEM supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin at 37degC in a 5% CO2 incubator. For proliferation assays, cells are seeded in 96-well plates (5×10^3 cells/well) in medium containing 0.5-2% FBS (to reduce background growth) and incubated overnight. The next day, cells are treated with bFGF (10-50 ng/mL) and various concentrations of bFGF (119-126) (0-100 uM). After 48-72 hours, cell viability is measured by MTT, CellTiter-Glo, or BrdU incorporation assay. The IC50 for inhibition of bFGF-stimulated proliferation is calculated. For signaling studies, cells are starved in serum-free medium overnight, then pre-treated with the peptide (e.g., 50 uM) for 30-60 min, followed by stimulation with bFGF (20 ng/mL) for 5-15 minutes. Cells are lysed in RIPA buffer with protease and phosphatase inhibitors, and equal amounts of protein (20-30 ug) are separated by SDS-PAGE and immunoblotted with antibodies against phospho-FGFR1 (Tyr653/654), total FGFR1, phospho-ERK1/2 (Thr202/Tyr204), total ERK1/2, phospho-Akt (Ser473), total Akt, and beta-actin (loading control). The intensity of the bands is quantified by densitometry. For angiogenesis assays, HUVECs are seeded on Matrigel-coated 96-well plates (1×10^4 cells/well) in EBM-2 medium containing 2% FBS, bFGF (10-50 ng/mL), and bFGF (119-126) (0-100 uM). After 6-18 hours, tube formation (number of nodes, total tube length, number of loops) is visualized under a light microscope and quantified using ImageJ software (Angiogenesis Analyzer plugin). For migration assays (wound healing), HUVECs or cancer cells are grown to confluence in 6-well plates, and a scratch is made using a sterile 200 uL pipette tip. Cells are washed to remove debris, and fresh medium containing bFGF (10-50 ng/mL) and the peptide (0-100 uM) is added. Images are taken at 0, 6, 12, 24 hours using a phase-contrast microscope, and the wound closure percentage is calculated. The percentage of inhibition of migration is determined relative to the bFGF-only control. For invasion assays, cells are seeded in the upper chamber of Matrigel-coated Transwell inserts (8 um pore size) in serum-free medium. The lower chamber contains medium with 10% FBS as a chemoattractant, with or without bFGF (20 ng/mL). The peptide is added to both chambers. After 24-48 hours, non-invasive cells on the upper surface are removed, and invasive cells on the lower surface are fixed, stained with crystal violet, and counted. For combination studies with ultrasound and doxorubicin, cells are treated with doxorubicin (0.5-2 uM) in the presence or absence of bFGF (119-126) (e.g., 50 uM) and subjected to ultrasound exposure (e.g., 1 MHz, 0.5-1 W/cm2, duty cycle 20%) for 30-60 seconds. Cell viability is measured after 24-48 hours. The combination of peptide, ultrasound, and doxorubicin is expected to show enhanced cytotoxicity compared to each treatment alone.

For in vivo studies, female BALB/c nude mice (6-8 weeks old, 18-22 g) are used for xenograft models. Cancer cells (e.g., A549 lung cancer, MCF-7 breast cancer, U87MG glioblastoma, OVCAR-3 ovarian cancer cells) are harvested and resuspended in PBS (5×10^6 cells in 100 uL). The cells are injected subcutaneously into the right flank of the mice. When tumors reach a volume of 100-200 mm3 (approximately 7-10 days post-inoculation), mice are randomized into treatment groups (n=8-10 per group). bFGF (119-126) is dissolved in sterile saline or PBS and administered via intraperitoneal (i.p.) injection at doses of 10, 20, or 30 mg/kg, daily or every other day for 14-21 days. For combination therapy, doxorubicin (5 mg/kg, i.p.) is administered once weekly, with or without bFGF (119-126), and ultrasound treatment (e.g., 1 MHz, 0.5-1 W/cm2, 50% duty cycle, 1 minute) is applied to the tumor area after injection of the peptide or doxorubicin (depending on the protocol). Tumor volumes are measured every 2-3 days with digital calipers, and body weight is monitored. At the endpoint (day 21 or when tumors reach ~1500 mm3), mice are euthanized, and tumors are excised, weighed, and processed for analysis. Tumor sections are stained with H&E (for histology), with anti-CD31 antibody (for microvessel density, a marker of angiogenesis), with anti-Ki-67 (proliferation index), and with anti-cleaved caspase-3 (apoptosis). Western blotting and ELISA can be performed on tumor lysates to measure FGFR1 activation, ERK/Akt signaling, and levels of pro-angiogenic factors (VEGF, bFGF). The combination groups (peptide + doxorubicin + ultrasound) are expected to show the greatest tumor growth inhibition, as reported in the literature. For pharmacokinetic studies, separate cohorts of mice receive a single i.v. or i.p. dose of the peptide (e.g., 20 mg/kg), and blood and tissue samples are collected at various time points for LC-MS/MS analysis of the peptide concentration.

Pharmacokinetic data for bFGF (119-126) is not extensively reported. As an 8-amino acid peptide (MW 993 Da), it is expected to have a short plasma half-life (minutes to <1 hour) due to rapid proteolytic degradation. The peptide is likely cleared by the kidneys (glomerular filtration) and metabolized by peptidases in the blood, liver, and other tissues. Oral bioavailability is negligible (<1-5%). The peptide is typically administered intraperitoneally (i.p.) for in vivo studies, which is likely to provide moderate systemic exposure but still with a rapid clearance. The distribution volume (Vd) is likely to be low (approx. 0.2-0.5 L/kg), as peptides often stay in the intravascular space or distribute to well-perfused organs (liver, kidneys). The in vivo half-life could be extended by formulation in a controlled-release vehicle (e.g., liposomes, polymeric nanoparticles) or by conjugation to a carrier protein (e.g., albumin). For in vitro assays, stock solutions are prepared in water or PBS (e.g., 10 mg/mL), and the solution should be stored in aliquots at -20degC or -80degC to prevent degradation due to repeated freeze-thaw cycles. The lyophilized peptide should be stored at -20degC, protected from light and moisture, and is stable for at least 2 years.

Preclinical toxicity data for bFGF (119-126) is limited. In cell viability assays (e.g., MTT in HUVECs, cancer cells), the peptide shows low cytotoxicity, with IC50 values typically > 100 uM. In animal studies, bFGF (119-126) at doses up to 50 mg/kg (i.p.) did not cause significant body weight loss, behavioral changes, or major organ damage (liver, kidney, heart) in the reported studies. The peptide is composed of natural L-amino acids, and its breakdown products (amino acids) are non-toxic. However, high doses could theoretically cause off-target effects due to non-specific interactions with other growth factors or receptors. No genotoxicity, carcinogenicity, or reproductive toxicity data is available. Standard safety precautions for handling peptides (gloves, lab coat, safety goggles) should be followed. The compound is for research use only and is not for human use.

bFGF (119-126) is a bioactive peptide that inhibits the dimerization and activation of the bFGF receptor (FGFR1). It is also known as FGF basic (119-126) and corresponds to the conserved region of bFGF across human, bovine, ovine, and rabbit species. This peptide is a valuable tool for studying the role of the FGF/FGFR axis in cell proliferation, migration, angiogenesis, and tumorigenesis. It has potential applications as an anti-angiogenic and anti-cancer agent, particularly in combination with chemotherapy and physical modalities like ultrasound. The peptide is not FDA-approved and has not entered clinical trials as a therapeutic agent.The peptide is supplied as a lyophilized white powder. It is soluble in water (≥ 100 mg/mL) and DMSO (50 mg/mL). For storage, it should be kept at -20degC, protected from light and moisture. Under these conditions, it is stable for at least 2 years. In solution, it should be stored at -80degC in aliquots and used within 3-6 months to avoid degradation. This peptide is a key reagent for studying the FGFR signaling pathway and for exploring FGF-based drug delivery and combination therapies.

C44H76N14O12

993.16

992.577

152051-61-1

10129746

Typically exists as solid at room temperature

1.43±0.1 g/cm3

2.313

16

16

35

70

1730

8

CC(C[C@H](NC([C@@H](NC([C@@H](NC([C@@H](NC(CNC([C@@H](NC([C@@H](NC([C@@H](N)CCCCN)=O)CCCNC(N)=N)=O)[C@H](O)C)=O)=O)CCC(N)=O)=O)CC1=CC=C(O)C=C1)=O)CCCCN)=O)C(O)=O)C

KCDSBTNBXZKKLC-MVPDBZEZSA-N

InChI=1S/C44H76N14O12/c1-24(2)21-33(43(69)70)57-38(64)29(10-5-7-19-46)55-41(67)32(22-26-12-14-27(60)15-13-26)56-39(65)31(16-17-34(48)61)53-35(62)23-52-42(68)36(25(3)59)58-40(66)30(11-8-20-51-44(49)50)54-37(63)28(47)9-4-6-18-45/h12-15,24-25,28-33,36,59-60H,4-11,16-23,45-47H2,1-3H3,(H2,48,61)(H,52,68)(H,53,62)(H,54,63)(H,55,67)(H,56,65)(H,57,64)(H,58,66)(H,69,70)(H4,49,50,51)/t25-,28+,29+,30+,31+,32+,33+,36+/m1/s1

(2S)-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-5-amino-2-[[2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2,6-diaminohexanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]-3-hydroxybutanoyl]amino]acetyl]amino]-5-oxopentanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]hexanoyl]amino]-4-methylpentanoic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: 100 mg/mL (100.69 mM)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

---

Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

View More

Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

---

Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

View More

Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

---

Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

---

 (Please use freshly prepared in vivo formulations for optimal results.)