Ethynylcytidine (ECyD), a nucleoside analog and a potent inhibitor of RNA synthesis, inhibits RNA polymerases I, II and II. Ethynylcytidine has robust antitumor activity in a wide range of models of cancer^[1][2][3].

nucleoside antimetabolite^[1]

The IC₅₀ values of Ethynylcytidine in the five human tumors with 4, 24 and 72 h exposure range from 0.114 to 1.032 μM, 0.015 to 0.067 μM, and 0.008 to 0.058 μM, respectively. These results suggest that the cytotoxicity of Ethynylcytidine tends to become stronger as the exposure time becomes longer. The differences in IC₅₀ values between the 24 and 72 h exposure times are not large, and Ethynylcytidine appeares to show sufficiently potent cytotoxicity at the 24 h exposure time in all 5 human tumors. Even at the 4 h exposure time, Ethynylcytidine clearly shows potent cytotoxicity with IC₅₀ values at submicromolar concentrations in 4 of the 5 human tumors^[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.

In both OCUM-2MD3 and LX-1 xenografts, tumor regression is noted and a very potent antitumor effect with an tumor growth inhibition rate (IR) on day 15 of approximately 90% or even higher is observed at the minimum toxic doses of Ethynylcytidine (TAS-106) on all three administration schedules. In particular, administration of Ethynylcytidine at 6 mg/kg once weekly exhibits a marked tumor shrinking effect with an IR of 98% against the LX-1 tumor. While Ethynylcytidine treatment on an either 3 or 5 times weekly schedule has a potent antitumor effect with an IR of approximately 85%, the IR of Ethynylcytidine once weekly is less than 60% and its antitumor effect is rather weak^[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.

267.24

C₁₁H₁₃N₃O₅

180300-43-0

Room temperature in continental US; may vary elsewhere.

DMSO : 250 mg/mL (935.49 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。

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: ≥ 2.08 mg/mL (7.78 mM); Clear solution

  此方案可获得 ≥ 2.08 mg/mL (7.78 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 20.8 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% (20% SBE-β-CD in saline)

  Solubility: ≥ 2.08 mg/mL (7.78 mM); Clear solution

  此方案可获得 ≥ 2.08 mg/mL (7.78 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 20.8 mg/mL 的澄清 DMSO 储备液加到 900 μL 20% 的 SBE-β-CD 生理盐水水溶液中，混合均匀。

  将 2 g 磺丁基醚 β-环糊精加入 5 mL 生理盐水中，再用生理盐水定容至 10 mL，完全溶解，澄清透明
• 3.

  请依序添加每种溶剂： 10% DMSO    90% corn oil

  Solubility: ≥ 2.08 mg/mL (7.78 mM); Clear solution

  此方案可获得 ≥ 2.08 mg/mL (7.78 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 20.8 mg/mL 的澄清 DMSO 储备液加到 900 μL玉米油中，混合均匀。

• [1]. Shimamoto Y, et al. Antitumor activity and pharmacokinetics of TAS-106, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine. Jpn J Cancer Res. 2001 Mar;92(3):343-51.

  [2]. Abdelrahim M, et al. TAS-106: preclinical, clinical and beyond. Oncology. 2013;85(6):356-363.

  [3]. Hammond-Thelin LA, et al. Phase I and pharmacokinetic study of 3′-C-ethynylcytidine (TAS-106), an inhibitor of RNA polymerase I, II and III,in patients with advanced solid malignancies. Invest New Drugs. 2012;30(1):316-326.

MIAPaCa-2 cells are maintained in Dulbecco’s modified Eagle’s medium supplemented with 10% FCS and 2.5% horse serum. Cells in the exponential growth phase are seeded onto 6-well plates (5×10⁴ cells/1.8 mL/well) on day 0. Twenty-four hours after seeding, on day 1, Ethynylcytidine (TAS-106) (6 concentrations range from 0 to 100 μM) is added to cultured cells (3 wells at each concentration) at a volume of 0.2 mL/well. After 4 and 24 h, on the 4 and 24 h Ethynylcytidine exposure schedules, the drug-containing medium is removed, and the cells are washed twice with Dulbecco’s phosphate buffered saline and subsequently cultured in drug-free medium until day 4. On the 72 h exposure schedule, after adding the Ethynylcytidine, cells are cultured continuously until day 4. On day 4, cell numbers are determined and converted to values related to the cell numbers on day 1. The concentration of Ethynylcytidine which inhibits cell growth by 50% (IC₅₀) is calculated from this relative cell growth. Two or three individual experiments are conducted on each cell line to confirm reproducibility^[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.

Nude rats s.c. transplanted with LX-1 human lung tumors are given a single i.v. dose of [³H]Ethynylcytidine (TAS-106) (6 mg/kg, 3.7 MBq/kg). For analysis of the distribution of radioactivity and intratumoral Ethynylcytidine metabolism, serum and various tissues (tumor, skin, lung, liver, kidney, spleen, small intestine, large intestine, testis, brain, and bone marrow cells) are sampled from 3 rats at each of the following 6 time points: 0.5, 1, 2, 4, 8 and 24 h after i.v. administration. At each point in time, bone marrow cells are collected from the 3 rats and combined into a cell pellet. All samples of serum, bone marrow cell pellets, and tissues are immediately frozen on dry ice and stored at -30°C until used^[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]. Shimamoto Y, et al. Antitumor activity and pharmacokinetics of TAS-106, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine. Jpn J Cancer Res. 2001 Mar;92(3):343-51.

  [2]. Abdelrahim M, et al. TAS-106: preclinical, clinical and beyond. Oncology. 2013;85(6):356-363.

  [3]. Hammond-Thelin LA, et al. Phase I and pharmacokinetic study of 3′-C-ethynylcytidine (TAS-106), an inhibitor of RNA polymerase I, II and III,in patients with advanced solid malignancies. Invest New Drugs. 2012;30(1):316-326.