K858 Racemic is an ATP-uncompetitive inhibitor of kinesin Eg5 with an IC₅₀ of 1.3 μM.

K858 Racemic is an ATP-uncompetitive inhibitor of Eg5 with an IC₅₀ of 1.3 μM. K858 does not inhibit the ATPase activity of the mitotic kinesins CENP-E and MKLP1, or the conventional kinesin heavy chain even at 200 μM. K858 induces mitotic arrest and growth inhibition via the activation of the Mad2-mediated spindle checkpoint. K858 (5 μM) induces mitotic cell death in cancer cells but not in normal cells^[1]. K858 (1, 10, 100 μM) inhibits the MCF7, BT474 and SKBR3 cell lines, and only at 10 and 100 μM suppresses MDA-MB231 cell line after treatment for 24 h. K858 incereases Bax/Bcl2 RNA ratio and survivin in the four cell lines. Furthermore, the up-regulation of survivin is totally reversed by wortmannin (phosphoinositide 3-kinase AKT) in MCF7 cells^[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.

K858 (50, 150 mg/kg, p.o.) shows antitumor activity in an A2780 ovarian cancer xenograft model, also inhibits tumor grwoth in a HCT116 colon cancer xenograft model via 100 mg/kg twice a day orally for 5 days. K858 (100 mg/kg, p.o., qd ×5) displays no neurotoxic side effects in mice^[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.

277.34

C₁₃H₁₅N₃O₂S

72926-24-0

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 : 100 mg/mL (360.57 mM; Need ultrasonic)

*

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。

In Vivo:

请根据您的实验动物和给药方式选择适当的溶解方案。以下溶解方案都请先按照 In Vitro 方式配制澄清的储备液，再依次添加助溶剂：

——为保证实验结果的可靠性，澄清的储备液可以根据储存条件，适当保存；体内实验的工作液，建议您现用现配，当天使用； 以下溶剂前显示的百
分比是指该溶剂在您配制终溶液中的体积占比；如在配制过程中出现沉淀、析出现象，可以通过加热和/或超声的方式助溶

• 1.

  请依序添加每种溶剂： 10% DMSO    40% PEG300    5% Tween-80    45% saline

  Solubility: ≥ 2.5 mg/mL (9.01 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (9.01 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀；向上述体系中加入50 μL Tween-80，混合均匀；然后继续加入 450 μL生理盐水定容至 1 mL。

  将 0.9 g 氯化钠，完全溶解于 100 mL ddH₂O 中，得到澄清透明的生理盐水溶液

• 2.

  请依序添加每种溶剂： 10% DMSO    90% corn oil

  Solubility: ≥ 2.5 mg/mL (9.01 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (9.01 mM，饱和度未知) 的澄清溶液，此方案不适用于实验周期在半个月以上的实验。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL玉米油中，混合均匀。

• [1]. Nakai R, et al. K858, a novel inhibitor of mitotic kinesin Eg5 and antitumor agent, induces cell death in cancer cells. Cancer Res. 2009 May 1;69(9):3901-9.

  [2]. De Iuliis F, et al. The kinesin Eg5 inhibitor K858 induces apoptosis but also survivin-related chemoresistance in breast cancer cells. Invest New Drugs. 2016 Aug;34(4):399-406.

To determine cytotoxicity, sulforhodamine B colorimetric assay is performed: 1.5 × 10⁴ cells are plated on 96 well plates, grown for 24 h (h) and treated with different concentrations of K858 (1 μM, 10 μM, 100 μM) for 24 and 48 h. Cells are then fixed with 50 % trichloroacetic acid for 1 h at 4°C and stained for 30 min at room temperature (RT) with 0.4 % sulforhodamine B in 1 % acetic acid. Excess dye is removed by washing four times with 1 % acetic acid. Protein bound dye is dissolved in 10 mM TRIS pH 10, and optical density (OD) is determined at 510 nm using a microplate reader^[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.

A2780 cells (5 × 10⁶ cells) are inoculated s.c. into BALB/cAJcl-nu mice. K858 is administered orally twice daily on days 0 to 4, and 7 to 11 at 150 and 50 mg/kg. Doses and schedules are determined by the tolerability studies performed in advance. Vehicle (0.5% methylcellulose 400) is administered orally as a control twice daily on days 0 to 4, and 7 to 11. Paclitaxel is administered i.v. on day 0 at 25 mg/kg. Carboplatin is administered i.v. on day 0 at 60 mg/kg. Drug efficacy is expressed as the ratio of the mean experimental V/V0 value to that of the control group [treated versus control (T/C) ratio], where V is the tumor volume at the day of evaluation and V0 is the tumor volume at the day of the initial treatment with the drug. Statistical analysis is performed using the nonparametric rank-sum test^[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.

• [1]. Nakai R, et al. K858, a novel inhibitor of mitotic kinesin Eg5 and antitumor agent, induces cell death in cancer cells. Cancer Res. 2009 May 1;69(9):3901-9.

  [2]. De Iuliis F, et al. The kinesin Eg5 inhibitor K858 induces apoptosis but also survivin-related chemoresistance in breast cancer cells. Invest New Drugs. 2016 Aug;34(4):399-406.