MC-SN38

Camptothecins/DNA Topoisomerase I; Drug-linker conjugate for ADC

众所周知，喜树碱（CPT）的半合成衍生物7-乙基-10-[4-（1-哌啶基）-1-哌啶基]羰基氧基喜树碱（CPT-11）在体内具有很强的抗肿瘤活性，但CPT-11的代谢产物7-乙基-10-羟基喜树碱（SN-38）在体外显示出比CPT-11更强的细胞毒性。在这项研究中，我们证明了由P388小鼠白血病细胞制备的I型DNA拓扑异构酶对SV40 DNA质粒的松弛作用在约1微M时被SN-38抑制了50%，尽管1 mM的CPT-11略微抑制了松弛作用。SN-38和CPT对P388细胞的DNA合成显示出强烈的、时间依赖性的抑制活性。然而，CPT-11弱抑制DNA合成，与时间无关，同时抑制细胞对胸苷的总摄取。通过碱性和中性洗脱试验，证明SN-38在P388细胞中引起的DNA单链断裂比CPT-11更频繁。在用0.1微M的SN-38或100微M的CPT-11处理的细胞中检测到相同含量的SN-358和相似频率的单链断裂。因此，CPT-11的单链断裂似乎是由于细胞中CPT-11产生的SN-38引起的。这些结果表明，CPT-11本身具有微弱的抗增殖作用，但SN-38在CPT-11的作用机制中起着至关重要的作用[2]。

[1]. Characterization of DNA topoisomerase I in three SN-38 resistant human colon cancer cell lines reveals a newpair of resistance-associated mutations. J Exp Clin Cancer Res. 2016 Mar 31;35:56.

[2]. Intracellular roles of SN-38, a metabolite of the camptothecin derivative CPT-11, in the antitumor effect of CPT-11. Cancer Res. 1991;51(16):4187-4191.

DNA topoisomerase I (Top1) is a DNA unwinding protein and the specific target of the camptothecin class of chemotherapeutic drugs. One of these, irinotecan, acting through its active metabolite SN-38, is used in the treatment of metastatic colorectal cancer. However, resistance to irinotecan represents a major clinical problem. Since molecular alterations in Top1 may result in resistance to irinotecan, we characterized Top1 in three human colon cancer cell lines with acquired resistance to SN-38. Methods: Three SN-38 resistant (20-67 fold increased resistance) cell lines were generated and compared to wild-type parental cells with regards to: TOP1 gene copy number and gene sequence, Top1 expression (mRNA and protein), Top1 enzymatic activity in the absence and presence of drug, and Top1-DNA cleavage complexes in drug treated cells. TOP1 mutations were validated by PCR using mutant specific primers. Furthermore, cross-resistance to two indenoisoquinoline Top1-targeting drugs (NSC 725776 and NSC 743400) and two Top2-targeting drugs (epirubicin and etoposide) was investigated. Results: Two of three SN-38 resistant cell lines carried TOP1 gene copy number aberrations: A TOP1 gene copy gain and a loss of chromosome 20, respectively. One resistant cell line harbored a pair of yet unreported TOP1 mutations (R364K and G717R) in close proximity to the drug binding site. Mutant TOP1 was expressed at a markedly higher level than wild-type TOP1. None or very small reductions were observed in Top1 expression or Top1 activity in the absence of drug. In all three SN-38 resistant cell lines Top1 activity was maintained in the presence of high concentrations of SN-38. None or only partial cross-resistance were observed for etoposide and epirubicin, respectively. SN-38 resistant cells with wild-type TOP1 remained sensitive to NSC 743400, while cells with mutant TOP1 was fully cross-resistant to both indenoisoquinolines. Top1-DNA cleavage complex formation following drug treatment supported the other findings. Conclusions: This study adds to the growing knowledge about resistance mechanisms for Top1-targeting chemotherapeutic drugs. Importantly, two yet unreported TOP1 mutations were identified, and it was underlined that cross-resistance to the new indenoisoquinoline drugs depends on the specific underlying molecular mechanism of resistance to SN-38.[1]

C32H31N3O8

585.60

585.211

C, 65.63; H, 5.34; N, 7.18; O, 21.86

1473403-87-0

146673122

White to yellow solid powder

2.3

143

1

9

10

43

1300

1

O=C1C=CC(=O)N1CCCCCC(O[C@@]1(C(OCC2C(N3CC4=C(CC)C5=CC(=CC=C5N=C4C3=CC=21)O)=O)=O)CC)=O

ACRMADURFCYBAU-YTTGMZPUSA-N

InChI=1S/C32H31N3O8/c1-3-19-20-14-18(36)9-10-24(20)33-29-21(19)16-35-25(29)15-23-22(30(35)40)17-42-31(41)32(23,4-2)43-28(39)8-6-5-7-13-34-26(37)11-12-27(34)38/h9-12,14-15,36H,3-8,13,16-17H2,1-2H3/t32-/m0/s1

[(19S)-10,19-diethyl-7-hydroxy-14,18-dioxo-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4(9),5,7,10,15(20)-heptaen-19-yl] 6-(2,5-dioxopyrrol-1-yl)hexanoate

MC-SN38; 1473403-87-0; AKOS040756843; [(19S)-10,19-diethyl-7-hydroxy-14,18-dioxo-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4(9),5,7,10,15(20)-heptaen-19-yl] 6-(2,5-dioxopyrrol-1-yl)hexanoate;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

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

DMSO : 140 mg/mL (239.07 mM)

配方 1 中的溶解度: ≥ 5.75 mg/mL (9.82 mM) (饱和度未知) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将100 μL 57.5 mg/mL澄清的DMSO储备液加入到400 μL PEG300中，混匀；再向上述溶液中加入50 μL Tween-80，混匀；然后加入450 μL生理盐水定容至1 mL。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

---

配方 2 中的溶解度: 5.75 mg/mL (9.82 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (这些助溶剂从左到右依次添加，逐一添加), 悬浊液; 超声助溶。
例如，若需制备1 mL的工作液，可将 100 μL 57.5mg/mL澄清的DMSO储备液加入到900μL 20％SBE-β-CD生理盐水中，混匀。
*20% SBE-β-CD 生理盐水溶液的制备（4°C，1 周）：将 2 g SBE-β-CD 溶解于 10 mL 生理盐水中，得到澄清溶液。

---

请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。