G-quadruplexe ( Kd = 490 nM )

吡格菌素 (RR82)（10 μM；48 小时）可诱导细胞周期停滞 [1]。一种名为吡啶球蛋白的微小化学物质选择性地与 DNA 中的 G-四链体结构结合，与其形成复合物以稳定 DNA。哌啶他汀会引起剂量依赖性神经元死亡、神经突回缩和突触丧失。在培养的原代神经元中，吡格菌素会导致 DNA 双链断裂。值得注意的是，BRCA1 蛋白（保护和修复神经元基因组）会被吡啶球蛋白（1-5 μM，过夜）转录下调 [3]。

Pyridostatin对BRCA2缺陷异种移植物具有抗肿瘤活性[4]
结合和稳定G4s的化合物已被证明对小鼠建立的BRCA1/2缺失异种移植物肿瘤有活性(RHPS4和CX‐5461)。然而，这些尚未被证明对BRCA突变患者有益。此外，BRCA突变的肿瘤很难治疗，因为它们对靶向治疗(例如PARP抑制剂;PARPi)。因此，必须找到新的G4配体，不仅可以消除BRCA缺陷肿瘤，还可以抵抗耐药疾病。我们之前发表的结果(Zimmer et al, 2016)表明，G4配体pyridostatin对体外BRCA2缺陷细胞具有特异性毒性。在这项研究中，研究人员评估了pyridostatin在体内消除BRCA2缺陷异种移植物肿瘤中的潜力。为了解决这个问题，我们使用等基因BRCA2 +/+ (BRCA2‐精通)和BRCA2−/−(BRCA2‐缺乏)人结直肠癌DLD1细胞在CB17‐SCID小鼠中产生异种移植物(图1A和B)。研究人员广泛优化了pyridostatin在体内使用的条件，并确定了7.5 mg/kg/天的剂量计划静脉注射连续5天，然后休息2天，第二个5天的治疗耐受性良好。没有明显的体重减轻，没有不良的临床症状(附录表S1)。在这些条件下，研究人员发现pyridostatin有效且特异性地抑制BRCA2‐缺陷DLD1细胞建立的异种移植物肿瘤的生长(图1B)。作为对照，研究人员使用了PARPi talazoparib，该药物以其根除小鼠BRCA1/2缺失肿瘤的能力而闻名(Shen et al .， 2013)，最近被许可用于携带BRCA1/2种系突变的转移性乳腺癌患者(Litton et al .， 2018)。pyridostatin对BRCA2 -缺陷肿瘤的抗肿瘤作用与talazoparib相似，两种药物都不会损害BRCA2 -精通肿瘤的生长。

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此外，研究人员使用第二种肿瘤模型研究了pyridostatin在体内的反应，该模型是由等基因BRCA2 +/+和BRCA2 - / -结直肠癌HCT116细胞建立的(Xu et al .， 2014)。Pyridostatin显示出对BRCA2缺失HCT116细胞源性肿瘤的选择性毒性(附录图S1A和B;附录表S2)，其作用与DLD1细胞来源的异种移植物相似[4]
研究人员之前的研究表明，pyridostatin治疗会导致HR修复受损的细胞(包括BRCA2缺陷细胞)中DNA损伤的积累(Zimmer等，2016)。一致地，免疫组织化学(IHC)分析显示，BRCA2‐缺乏，但不是BRCA2‐完全，肿瘤在暴露于pyridostatin或talazoparib时显示出DNA损伤标记γH2AX水平增加(附录图S1C-F)。这些结果表明，pyridostatin不仅可以特异性抑制细胞的生长(Zimmer等，2016)，还可以特异性抑制缺乏BRCA2的肿瘤，并通过造成DNA损伤在体内起作用[4]。

细胞活力测定 [1]
细胞类型：超过 60 种不同的癌细胞系
测试浓度： 10 μM
孵育时间： 48小时
实验结果：主要在60多种不同癌细胞系的细胞周期G2期积累。

CB17‐SCID mice
7.5 mg/kg
i.v.

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In vivo xenograft experiments[4]
CB17‐SCID mice (CB17/Icr‐Prkdcscid/IcrIcoCrl, male or female), FVB female mice were purchased from Charles River Laboratories. The mice were maintained in high‐efficiency, particulate air HEPA‐filtered racks and were fed autoclaved laboratory rodent diet.[4]
To generate xenografts derived from DLD1 and HCT116 BRCA2‐proficient or ‐deficient cells, CB17‐SCID male mice 6 weeks old were injected intramuscularly, into the hind leg muscles, with 5 × 106 cells per mouse. When a tumour volume of approximately 250 mm3 was evident, mice were randomised to start the treatments.[4]
To generate the PARPi‐resistant mouse tumour model, FVB female mice 6 weeks old were injected intramuscularly into the hind leg muscles with 4 × 106 KP3.33 (Brca1 +/+) cells or KB1PM5 (Brca1 −/− Tp53bp1 −/−) mouse mammary tumour cells. Each experimental group included five mice. When a tumour volume of approximately 250 mm3 was evident, mice were randomised and the treatment started.[4]
To generate xenografts derived from MDA‐MB‐436 cells, CB17‐SCID female mice 6 weeks old were injected intramuscularly with 4 × 106 cells per mouse. When a tumour volume of approximately 220 mm3 was evident (6 days after cell injection), treatment was initiated. Each experimental group included five mice.[4]

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Talazoparib (BMN 673, Selleckchem) was dissolved in 10% of dimethylacetamide, 6% of solutol HS, 84% of PBS and administered orally at doses of 0.33 mg/kg/day for five consecutive days, followed by 2‐day break and five more days of treatment (Wang et al, 2016). pyridostatin was dissolved in saline solution and administered intravenously at doses of 7.5 mg/kg/day for five consecutive days, followed by 2‐day break and five more days of treatment. NU‐7441 (Selleckchem) was dissolved in 5% of DMSO, 40% PEG300, 5% of Tween‐80 and administered intraperitoneally at doses of 10 mg/kg/day for five consecutive days, followed by 2‐day break and five more days of treatment (Zhao et al, 2006). Paclitaxel was dissolved in saline solution and administered intravenously at doses of 20 mg/kg/day at day 1 and day 8 of treatment (Bizzaro et al, 2018). When combined with other compounds, paclitaxel was administered intravenously at day 5 and 12 of treatment, pyridostatin and NU‐7441 were administered intravenously and intraperitoneally, respectively, for four consecutive days, followed by a 3‐day break and four more days of treatment. NU‐7441 was administered 2 h before pyridostatin. At indicated time points, tumour volumes were measured in two dimensions using a caliper and tumour weight was estimated from tumour volume (1 mg = 1 mm3). The student’s t‐test (unpaired, two‐tailed) was used for single pair‐wise comparisons. Differences were considered statistically significant when P < 0.05. Survival curves of mice were processed using the Kaplan–Meier method, and statistical significance was assessed by log‐rank test. Data were plotted using GraphPad Prism Software 8.3.[4]

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Generation of PDTX models[4]
Fresh tumour samples from patients with gBRCA breast cancer were prospectively collected for implantation into mice under an institutional IRB‐approved protocol and the associated informed consent, or by the National Research Ethics Service, Cambridgeshire 2 REC (REC reference number: 08/H0308/178) (Bruna et al, 2016). The VHI0179 patient‐derived tumour xenografts (PDTXs) were generated from a patient breast tumour with a BRCA1 germline truncation and resistant to Olaparib due to REV7 mutation. Written informed consent was obtained from all patients and the experiments conformed to the principles set out in the WMA Declaration of Helsinki and the Department of Health and Human Services Belmont Report. Frozen tumour fragments (15–20 mm3) were coated in Matrigel and implanted using a small incision in a subcutaneous pocket made in one side of the lower back into one CB17‐SCID female mice 6 weeks old. When the tumour reached approximately 400 mm3, tumour was explanted from the sacrificed mouse, cut into fragments of about 15–20 mm3 and implanted again subcutaneously in fourteen CB17‐ SCID female mice. When the tumour reached approximately 200 mm3, mice were randomised in vehicle and treated group to start the treatments. Each experimental group included seven mice.

[1]. Small-molecule-induced DNA damage identifies alternative DNA structures in human genes. Nat Chem Biol. 2012;8(3):301-310. Published 2012 Feb 5.

[2]. A single-molecule platform for investigation of interactions between G-quadruplexes and small-molecule ligands. Nat Chem. 2011;3(10):782-787. Published 2011 Aug 28.

[3]. The G-quadruplex DNA stabilizing drug pyridostatin promotes DNA damage and downregulates transcription of Brca1 in neurons. Aging (Albany NY). 2017;9(9):1957-1970.

C35H34N10O7

706.70726

596.249

1085412-37-8

Pyridostatin hydrochloride;1781882-65-2; 1472611-44-1 (TFA salt)

25227847

Typically exists as solid at room temperature

1.4±0.1 g/cm3

753.8±60.0 °C at 760 mmHg

409.7±32.9 °C

0.0±2.5 mmHg at 25°C

1.726

0.59

202.62

5

11

13

44

850

0

VGHSATQVJCTKEF-UHFFFAOYSA-N

InChI=1S/C31H32N8O5/c32-9-12-42-19-15-24(30(40)38-28-17-26(43-13-10-33)20-5-1-3-7-22(20)36-28)35-25(16-19)31(41)39-29-18-27(44-14-11-34)21-6-2-4-8-23(21)37-29/h1-8,15-18H,9-14,32-34H2,(H,36,38,40)(H,37,39,41)

4-(2-aminoethoxy)-2-N,6-N-bis[4-(2-aminoethoxy)quinolin-2-yl]pyridine-2,6-dicarboxamide

Pyridostatin; 1085412-37-8; Pyridostain; 4-(2-Aminoethoxy)-N2,N6-bis(4-(2-aminoethoxy)quinolin-2-yl)pyridine-2,6-dicarboxamide; RR-82; RR 82; 4-(2-aminoethoxy)-2-N,6-N-bis[4-(2-aminoethoxy)quinolin-2-yl]pyridine-2,6-dicarboxamide; RR82 hydrochloride;

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

注意: 如下所列的是一些常用的体内动物实验溶解配方，主要用于溶解难溶或不溶于水的产品（水溶度<1 mg/mL）。 建议您先取少量样品进行尝试，如该配方可行，再根据实验需求增加样品量。

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注射用配方1: DMSO : Tween 80： Saline = 10 : 5 : 85 (如： 100 μL DMSO → 50 μL Tween 80 → 850 μL Saline)
*生理盐水/Saline的制备：将0.9g氯化钠/NaCl溶解在100 mL ddH ₂ O中，得到澄清溶液。
注射用配方 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL DMSO → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)
注射用配方 3: DMSO : Corn oil = 10 : 90 (如： 100 μL DMSO → 900 μL Corn oil)
示例: 以注射用配方 3 (DMSO : Corn oil = 10 : 90) 为例说明, 如果要配制 1 mL 2.5 mg/mL的工作液, 您可以取 100 μL 25 mg/mL 澄清的 DMSO 储备液，加到 900 μL Corn oil/玉米油中, 混合均匀。

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注射用配方 4: DMSO : 20% SBE-β-CD in Saline = 10 : 90 [如：100 μL DMSO → 900 μL (20% SBE-β-CD in Saline)]
*20% SBE-β-CD in Saline的制备（4°C，储存1周）：将2g SBE-β-CD (磺丁基-β-环糊精) 溶解于10mL生理盐水中，得到澄清溶液。
注射用配方 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (如： 500 μL 2-Hydroxypropyl-β-cyclodextrin (羟丙基环胡精)→ 500 μL Saline)
注射用配方 6: DMSO : PEG300 : Castor oil : Saline = 5 : 10 : 20 : 65 (如： 50 μL DMSO → 100 μL PEG300 → 200 μL Castor oil → 650 μL Saline)
注射用配方 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (如： 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
注射用配方 8: 溶解于Cremophor/Ethanol (50 : 50), 然后用生理盐水稀释。
注射用配方 9: EtOH : Corn oil = 10 : 90 (如： 100 μL EtOH → 900 μL Corn oil)
注射用配方 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL EtOH → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)

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口服配方 1: 悬浮于0.5% CMC Na (羧甲基纤维素钠)
口服配方 2: 悬浮于0.5% Carboxymethyl cellulose (羧甲基纤维素)
示例: 以口服配方 1 (悬浮于 0.5% CMC Na)为例说明, 如果要配制 100 mL 2.5 mg/mL 的工作液, 您可以先取0.5g CMC Na并将其溶解于100mL ddH2O中，得到0.5%CMC-Na澄清溶液；然后将250 mg待测化合物加到100 mL前述 0.5%CMC Na溶液中，得到悬浮液。

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口服配方 3: 溶解于 PEG400 (聚乙二醇400)
口服配方 4: 悬浮于0.2% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 5: 溶解于0.25% Tween 80 and 0.5% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 6: 做成粉末与食物混合

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注意: 以上为较为常见方法，仅供参考， InvivoChem并未独立验证这些配方的准确性。具体溶剂的选择首先应参照文献已报道溶解方法、配方或剂型，对于某些尚未有文献报道溶解方法的化合物，需通过前期实验来确定（建议先取少量样品进行尝试），包括产品的溶解情况、梯度设置、动物的耐受性等。

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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。