KRIBB11 is an inhibitor of Heat shock factor 1 (HSF1), with IC₅₀ of 1.2 μM.

KRIBB11 blocks the induction of HSF1 downstream target proteins such as HSP27 and HSP70. KRIBB11 induces growth arrest and apoptosis of HCT-116 cells. KRIBB11 inhibits HSF1-dependent recruitment of p-TEFb (positive transcription elongation factor b) to the hsp70 promoter^[1]. PARP and caspase-3 cleavage is increased in cells treated with KRIBB11. Incubating RKO with KRIBB11, shows a toxic threshold of about 10 µM, and an IC₅₀ of 20-30 µM^[2].

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

KRIBB11 (50 mg/kg, i.p.) results in a 47.4% inhibition of tumor growth in nude mice, without body weight loss^[1].

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

284.27

C₁₃H₁₂N₆O₂

342639-96-7

Room temperature in continental US; may vary elsewhere.

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	6 months
	-20°C	1 month

In Vitro: 

DMSO : ≥ 27 mg/mL (94.98 mM)

* “≥” means soluble, but saturation unknown.

*

请根据产品在不同溶剂中的溶解度选择合适的溶剂配制储备液；一旦配成溶液，请分装保存，避免反复冻融造成的产品失效。
储备液的保存方式和期限：-80°C, 6 months; -20°C, 1 month。-80°C 储存时，请在 6 个月内使用，-20°C 储存时，请在 1 个月内使用。

• [1]. Yoon YJ, et al. KRIBB11 inhibits HSP70 synthesis through inhibition of heat shock factor 1 function by impairing the recruitment of positive transcription elongation factor b to the hsp70 promoter. J Biol Chem. 2011 Jan 21;286(3):1737-47

  [2]. Samarasinghe B, et al. Heat shock factor 1 confers resistance to Hsp90 inhibitors through p62/SQSTM1 expression and promotion of autophagic flux. Biochem Pharmacol. 2014 Feb 1;87(3):445-55

HCT-116 cells are washed with PBS and then homogenized with a 27-gauge syringe in binding buffer (10 mm Tris-HCl (pH 7.4), 50 mm KCl, 5 mm MgCl₂, 1 mm EDTA, and 0.1 mm Na₃VO₄). The cell lysate is centrifuged at 13,000 rpm for 30 min at 4°C, and the supernatant is collected. The HCT-116 cell lysate supernatant is precleared by incubating with Dynabeads M-280 streptavidin for 30 min at 4°C and captured by magnet separation. The cleared supernatants are incubated with biotinyl-KRIBB11 compound. After overnight incubation at 4°C, proteins associated with the biotinyl-KRIBB11 compound are precipitated with Dynabeads M-280 streptavidin. Precipitated samples are separated by a magnet. Samples are washed with 1 mL of ishing buffer containing 50 mm HEPES (pH 7.5), 50 mm NaCl, 1 mm EDTA, 1 mm EGTA, 0.1% Tween 20, 10% (v/v) glycerol, 1 mm NaF, 0.1 mm Na₃VO₄, and protease inhibitor mixture tablets (1 tablet/10 mL). Samples are boiled in SDS-PAGE sample buffer, separated by 10% polyacrylamide gel, and immunoblotted with antibodies against HSF1, HSF2, HSP90, or CDK9.

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

Cells are seeded onto 96-well plates at a density of 6×10³ cells per well in McCoy’s 5A medium with 10% FBS. After 24 h, the medium is replenwashed with fresh complete medium containing chemicals or 0.1% DMSO. After incubation for 48 h, the cell proliferation reagent WST-1 is added to each well. The amount of WST-1 formazan produced is measured at 450 nm using an ELISA reader.

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

Seven-week-old female inbred specific pathogen-free Balb/c nude mice are housed under sterile conditions with 12-h light/dark cycles, and fed food and water ad libitum. For the evaluation of the in vivo anti-tumor activity of KRIBB11, HCT-116 cells (0.3 mL of 4×10⁷ cells/mL) are implanted subcutaneously into the right flank of the mice on day 0. KRIBB11 is dissolved in 10% dimethylacetamide, 50% PEG300, and 40% distilled water. When the size of tumors reached 72.2 mm³, the compound is administered intraperitoneally at a dose of 50 mg/kg/day for 18 days. Tumor volumes are estimated by using the formula length (mm) × width (mm) × height (mm)/2. To determine the toxicity of the compound, the body weight of tumor-bearing animals is recorded. On day 18, the mice are sacrificed, and the tumors are weighed.

上海金畔生物科技有限公司 has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Yoon YJ, et al. KRIBB11 inhibits HSP70 synthesis through inhibition of heat shock factor 1 function by impairing the recruitment of positive transcription elongation factor b to the hsp70 promoter. J Biol Chem. 2011 Jan 21;286(3):1737-47

  [2]. Samarasinghe B, et al. Heat shock factor 1 confers resistance to Hsp90 inhibitors through p62/SQSTM1 expression and promotion of autophagic flux. Biochem Pharmacol. 2014 Feb 1;87(3):445-55