Thrombopoietin ameliorates doxorubicin-induced toxicities in H9c2 myocardiocytes by inhibiting oxidative stress through the SIRT1/p38 MAPK signaling pathway

Objective:To explore whether thrombopoietin can exert a protective effect against doxorubicin-induced cardiotoxicity by modulating the sirtuin 1(SIRT1)signaling pathway.Methods:H9c2 cell viability was determined by CCK-8 and cardiomyocyte apoptosis was detected by TUNEL assay.The protein expressions of SIRT1 and p38 MAPK were measured by Western blot.RT-qPCR was also used to determine SIRT1 mRNA expression.In addition,intracellular reactive oxygen species levels and antioxidant enzyme activities were evaluated.Results:Thrombopoietin treatment reversed doxorubicin-induced decline in H9c2 cell viability.It also increased SIRT1 and decreased p-p38 MAPK protein expressions.In addition,thrombopoietin significantly attenuated doxorubicin-induced apoptosis and oxidative stress,and enhanced antioxidant enzyme activities.However,silencing SIRT1 abrogated the protective effects of thrombopoietin,as evidenced by reduced cell viability and increased oxidative stress and reactive oxygen species levels.Conclusions:Thrombopoietin alleviates doxorubicin-induced cardiomyocyte injury by reducing oxidative stress and apoptosis via the SIRT1/p38 MAPK pathway.However,its protective effects need to be further verified in animal tests.

Charcoal Nanoparticles as a Delivery System for Doxorubicin and Sorafenib in Treatment of Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is the most common type of liver cancer and one of the leading causes of cancer-related death worldwide. Advanced HCC displays strong resistance to chemotherapy, and traditional chemotherapy drugs do not achieve satisfactory therapeutic efficacy. The delivery of therapeutic compounds to the target site is a major challenge in the treatment of many diseases. Objective: This study aims to evaluate activated charcoal nanoparticles as a drug delivery system for anticancer agents (Sorafenib and Doxorubicin) in Hepatocellular Cancer Stem Cells. Method: The percent efficiency of entrapment (% EE) of the doxorubicin and sorafenib entrapped onto the activated charcoal was obtained by determining the free doxorubicin and sorafenib concentration in the supernatant-prepared solutions. Then the characterizations of nanoparticles were formed by determination of the particle size distribution, zeta potential, and polydispersity index (PDI). The anticancer activity of activated Charcoal, Doxorubicin-ACNP, sorafenib-ACNP, free doxorubicin, and free sorafenib solutions was measured based on cell viability percentage in HepG2 cell lines (ATCC-CCL 75). In vitro RBC’s toxicity of Doxorubicin/sorafenib loaded charcoal was estimated by hemolysis percentage. Results: The synthesized Doxorubicin-ACNP and Sorafenib-ACNP were evaluated and their physiochemical properties were also examined. Essentially, the percent Efficiency of Entrapment (EE %) was found to be 87.5% and 82.66% for Doxorubicin-ACNP and Sorafenib-ACNP, respectively. The loading capacity was 34.78% and 24.31% for Doxorubicin-ACNP and Sorafenib-ACNP. Using the Dynamic Light scattering [DLS] for the determination of the hydrodynamic size and surface zeta potential, a narrow sample size distribution was obtained of (18, 68, and 190 nm for charcoal, 105, 255, and 712 nm for doxorubicin, and 91, 295, and 955 nm for sorafenib), respectively. A surface charge of −13.2, −15.6 and −17 was obtained for charcoal, doxorubicin/charcoal, and sorafenib/charcoal nanoparticles. The cytotoxic activity of Doxorubicin-ACNP and Sorafenib-ACNP was evaluated in-vitro against HepG2 cell lines and it was observed that Drug loaded ACNP improved anticancer activity when compared to Doxorubicin or Sorafenib alone. Moreover, testing the toxicity potential of DOX-ACNP and Sorafenib-ACNP showed a significant reduction in the hemolysis of red blood cells when compared to Doxorubicin and Sorafenib alone. Conclusion: In conclusion, it is notable to state that this study is regarded as the first to investigate the use of Activated charcoal for the loading of Doxorubicin and Sorafenib for further use in the arena of hepatocellular carcinoma. Doxorubicin-ACNP and Sorafenib-ACNP showed noteworthy anticancer activity along with a reduced potential of RBCs hemolysis rendering it as an efficacious carrier with a low toxicity potential.

负载化疗药物阿霉素(doxorubicin,DOX)的聚多巴胺包裹纳米金粒子用于化疗与光热协同治疗在骨肉瘤中的应用效果

分析负载化疗药物阿霉素(DOX)的聚多巴胺包裹纳米金粒子用于化疗与光热协同治疗在骨肉瘤中的应用效果。方法 此次实验的研究时间2020年8月—2022年8月,选择25只K7M2荷瘤小鼠作为此次研究对象,分析不同治疗方式下小鼠的生存情况。结果 分析发现,在小鼠的生存率上,BSA-CaZol组为40%,生理盐水组为20%,MTX@BSA-CaZol组为60%、CpG-MTX@BSA-CaZol组80%,CpGaBSA-CaZol组60%。结论 DOX的聚多巴胺包裹纳米金粒子+化疗+光热,可以实现对骨肉瘤的协同治疗,延长生存期。

p53 Contributes to the Chemotherapeutic Drug Doxorubicin-Induced Cell Death in Colorectal Cancer Cell Line HCT116

Doxorubicin is a commonly used chemotherapy drug for cancer treatment,although its effectiveness varies across different cancer types.p53 is a key factor involved in cell death induced by therapeutic agents,and it can be upregulated by doxorubicin,exhibiting a function of apoptosis.To further investigate the mechanism between p53 and doxorubicin,this study explored whether p53 plays a role in doxorubicin-induced cell death in the colorectal cancer line HCT116.The findings revealed that p53 was upregulated in HCT116 cells when treated with doxorubicin,and the knockdown of p53 decreased the sensitivity of HCT116 cells to doxorubicin.These results suggest that p53 plays an important role in doxorubicin-induced cell death in HCT116 cells,potentially contributing to more effective treatment approaches.

Targeted hyperalkalization with NaOH-loaded starch implants enhances doxorubicin efficacy in tumor treatment

High-alkali treatment using sodium hydroxide(NaOH)injection can be a therapeutic approach for killing tumor cells.Alkalization can damage cellular structures and lead to cell death.Increased alkalinity can also enhance the efficacy of certain chemotherapeutic drugs such as doxorubicin(DOX).In this study,NaOH-loaded starch implants(NST implants)were used to induce hyperalkalization(increase pH)in the tumor environment,thereby inducing necrosis and enhancing the effects of DOX.NaOH is a strongly alkaline substance that can increase the pH when injected into a tumor.However,the administration of NaOH can have toxic side effects because it increases the pH of the entire body,not just at the tumor site.To overcome this problem,we developed an injectable NST implant,in which NaOH can be delivered directly into the tumor.This study showed that NST implants could be easily administered intratumorally in mice bearing 4T1 tumors and that most of the NaOH released from the NST implants was delivered to the tumors.Although some NaOH from NST implants can be systemically absorbed,it is neutralized by the body’s buffering effect,thereby reducing the risk of toxicity.This study also confirmed both in vitro and in vivo that DOX is more effective at killing 4T1 cells when alkalized.It has been shown that administration of DOX after injection of an NST implant can kill most tumors.Systemic absorption and side effects can be reduced using an NST implant to deliver NaOH to the tumor.In addition,alkalinization induced by NST implants not only exerts anticancer effects but can also enhance the effect of DOX in killing cancer cells.Therefore,the combination of NaOH-loaded starch implants and DOX treatment has the potential to be a novel therapy for tumors.

Nonclinical Study of the Active Components of Doxorubicin Hydrochloride Liposome Injection in Vivo

Objectives: A non-clinical study was performed to establish a LC-MS/MS method to determine the in vivo active components of doxorubicin hydrochloride liposome injection in the plasma of Sprague-Dawley rats. Methods: Ten male SD rats were administered tail vein with a single dose of 10 mg/kg, and the concentrations of doxorubicin hydrochloride in plasma, heart, liver, spleen, lung, and kidney were determined by liquid chromatography-tandem mass spectrometry, and the pharmacokinetic parameters were calculated. Results: The final concentration of doxorubicin hydrochloride ranged from 500 ng/mL to 250,000 ng/mL, and the lower limit of quantification was 500 ng/mL;the main pharmacokinetic parameters: T1/2 was (19.282 ± 10.305) h, Cmax was (118514.828 ± 26155.134) ng/mL, AUC0-24 and AUC0-∞ were (1216659.205 ± 192706.268) ng/mL⋅h and (2082244.523 ± 860139.487) ng/mL⋅h, MRT0-24 and MRT0-∞ were (9.237 ± 0.423) h and (26.52 ± 14.015) h, respectively, and clearance (CL) was (0.005 ± 0.002) mL/h⋅ng. Conclusions: The method is simple, rapid, and sensitive, which can be used for the determination of doxorubicin hydrochloride concentration in the plasma of SD rats and pharmacokinetic non-clinical studies.

Microwave ablation combined with transarterial chemoembolization containing doxorubicin hydrochloride liposome for treating primary and metastatic liver cancers

Aims:To determine the safety and efficacy of microwave ablation(MWA)and transarterial chemoembolization(TACE)with doxorubicin hydrochloride liposome(DHL)in patients with primary liver cancer(PLC)and metastatic liver cancer(MLC).Materials and methods:The medical records of patients with primary or metastatic liver cancer who underwent MWA combined with TACE containing DHL from March 2019 to March 2022 were collected and analyzed.Treatment-related adverse events(AEs)were recorded.Local tumor response was evaluated according to the modified RECIST criteria.Local tumor progression-free survival(LTPFS)and overall survival(OS)were calculated using the Kaplan-Meier method.Results:Altogether,96 patients with liver cancer were included(PLC,n=45;MLC,n=51).Forty(41.7%)patients experienced AEs during treatment,and eight(8.3%)patients developed grade 3 AEs.Compared to before treatment,the serum total bilirubin level and neutrophil to lymphocyte ratio significantly increased after treatment.The median LTPFS was 14.5 months in patients with PLC and 10.7 months in patients with MLC.The median OS was not reached in patients with PLC or MLC.The 1-month and 3-month disease control rates reached more than 80%in both groups.Conclusion:MWA combined with TACE with DHL may be a safe and effective method for the treatment of liver cancer.

Research progress on cardiotoxicity mechanism of doxorubicin and prevention and treatment of traditional Chinese medicine

Doxorubicin is an anthracycline antibiotic.As a broad-spectrum antitumor drug,it is widely used in clinic.However,doxorubicin is dose-dependent and shows obvious cardiotoxicity,which limits its clinical application.At present,the mechanism of doxorubicin induced cardiotoxicity has not been fully clarified.Reducing cardiotoxicity and improving the scope of clinical application have become the focus of research in recent years.This paper reviews the mechanism of doxorubicin cardiotoxicity and the prevention and treatment of doxorubicin cardiotoxicity with traditional Chinese medicine,in order to provide reference for the combined application of doxorubicin.

低频低强度超声辐照微泡对三阴性乳腺癌MDA-MB 231/DOX细胞耐药性的影响

目的探讨低频低强度超声辐照微泡(LILFU-MB)对三阴性乳腺癌MDA-MB-231/DOX细胞耐药性的影响。方法筛选LILFU-MB最佳非毒性辐照时间,计算细胞存活率;将MDA-MB-231/DOX细胞分为LILFU-MB辐照组和非LILFU-MB辐照组,绘制药物抑制拟合曲线图获得两组药物的半抑制浓度(IC_(50)),并筛选阿霉素最佳剂量。根据不同处理方式将细胞分为对照组、阿霉素组、LILFU-MB组、LILFU-MB+阿霉素组,观察细胞增殖活性,并计算细胞迁移率。使用倒置荧光显微镜观察细胞形态,并记录细胞核荧光强度及细胞核型;使用流式细胞仪检测细胞凋亡率;Westernblot检测细胞蛋白表达情况。结果LILFU-MB最佳非毒性辐照时间为30 s,该条件下细胞存活率为(92.33±2.58)%,故后续实验中LILFU-MB辐照时间均采用此条件。LILFU-MB辐照组中阿霉素对耐药细胞的IC_(50)低于非LILFU-MB辐照组(7.51μmol/Lvs.35.40μmol/L),后续实验采用35.40μmol/L为阿霉素最佳剂量。阿霉素组和LILFU-MB+阿霉素组细胞增殖活性均受到明显抑制,增殖速度减慢,其中LILFU-MB+阿霉素组抑制效果最明显。对照组、阿霉素组、LILFU-MB组、LILFU-MB+阿霉素组细胞迁移率分别为(56.79±1.11)%、(51.34±4.66)%、(46.09±9.42)%、(22.01±6.02)%,其中LILFU-MB+阿霉素组细胞迁移率低于其余各组,差异均有统计学意义(均P<0.01)。倒置荧光显微镜观察显示,LILFU-MB+阿霉素组中大部分细胞核明显皱缩和碎裂,胞核蓝染高亮,染色质呈浓缩和边缘化,表现出较强的细胞凋亡核型改变。流式细胞仪检测结果显示,对照组、阿霉素组、LILFU-MB组、LILFU-MB+阿霉素组细胞凋亡率分别为(13.30±0.66)%、(22.68±2.85)%、(20.60±3.72)%、(31.84±2.87)%,其中LILFU-MB+阿霉素组细胞凋亡率高于其余各组,差异均有统计学意义(均P<0.05)。LILFU-MB+阿霉素组P-gp、Bcl-2蛋白表达均显著下调,Cyt-c、Cl-caspase3蛋白表达均显著上调,与其余各组比较差异均有统计学意义(均P<0.05)。结论LILFU-MB能够显著抑制MDA-MB-231/DOX细胞增殖、迁移,并促进细胞凋亡,进而逆转三阴性乳腺癌MDA-MB-231/DOX细胞耐药性。

CeNPs在DOX诱导的心脏毒性中的作用及对SOD的影响

目的 探究CeNPs(纳米氧化铈)在DOX(阿霉素)诱导的心肌细胞损伤中的作用,以及CeNPs对DOX心肌细胞损伤中SOD活性的影响。方法 实验使用H9C2大鼠心肌细胞,DOX处理建立损伤模型,并将细胞随机分为5组:空白对照组、DOX损伤组、CeNPs组、DOX+CeNPs组、DOX+DEX(右丙亚胺,阳性保护药)组进行实验。通过CCK-8法测定存活率、Western Blot法测定蛋白表达量、生化法检测氧化应激指标SOD活性。结果 CCK-8法:DOX+CeNPs组相对于DOX组,细胞存活率显著增高(P<0.0001)。Western Blot法:DOX+CeNPs组与DOX组对比,Bax蛋白表达水平下降(P<0.0001),Bcl-2蛋白表达水平增高(P<0.05)。生化法检测:DOX+CeNPs组与DOX组对比,SOD活力升高(P<0.05)。结论 CeNPs能够提高DOX处理后的细胞存活率;CeNPs调控相关凋亡蛋白的表达减轻DOX处理后的细胞凋亡;CeNPs通过提高SOD活性改善DOX处理后的细胞氧化应激失平衡。

槲皮素基于PI3K/AKT/GSK-3β/β-Catenin通路改善Dox诱导小鼠心肌损伤的机制

目的:研究槲皮素(Que)改善多柔比星(Dox)所致小鼠心肌损伤作用机制。方法:将50只小鼠随机分为正常组(Control)、模型组(Dox)、槲皮素低、中、高剂量组(Que-L、Que-M、Que-H),除Control外腹腔注射Dox建立心肌损伤模型。心脏超声及血流动力学评价小鼠心脏功能,ELISA法检测小鼠血清中肌酸激酶同工酶(CK-MB)与乳酸脱氢酶(LDH)含量,HE染色、Tunel染色、WGA染色分别观察小鼠心肌组织病理变化、心肌细胞凋亡、心肌细胞横截面积变化;免疫荧光检测心肌组织中p-GSK-3β表达,Western blot法检测小鼠心肌组织PI3K/AKT/GSK-3β通路与凋亡蛋白表达。结果:与Control组比较,Dox组小鼠左室射血分数(LVEF)与左室短轴缩短率(LVFS)极显著下降(P<0.01),左心室舒张末期内径(LVEDd)与左心室收缩末期内径(LVEDs)极显著增加(P<0.01),血清中CK-MB与LDH含量极显著增加(P<0.01),心肌细胞肿胀且排列紊乱;心肌组织中PI3K、p-AKT、p-GSK-3β、β-catenin表达极显著降低(P<0.01),Bax/Bcl-2、Cleaved Caspase-3表达极显著增加(P<0.01)。与Dox组比较,Que各给药组小鼠心肌损伤均有不同程度改善,LVEF与LVFS极显著升高(P<0.01),(LVEDd)与(LVEDs)极显著降低(P<0.01),血清中CK-MB、LDH含量极显著减少(P<0.01),心脏功能增强;心肌细胞肿胀、凋亡、纤维增生减轻,心肌组织中PI3K、p-AKT、p-GSK-3β、β-catenin蛋白表达极显著升高(P<0.01),PI3K/AKT/GSK-3β/β-catenin被激活,凋亡蛋白Bax/Bcl-2、Cleaved Caspase-3表达极显著降低(P<0.01),其中Que-H组治疗效果最佳。结论:Que具有一定的心肌保护作用,可通过激活PI3K/AKT/GSK-3β/β-catenin通路改善Dox引起的心肌损伤与凋亡。

配位交联的DOX纳米颗粒的制备与质量评价

目的:以单宁酸(TA)和三氯化铁(FeCl_(3))为载体材料,盐酸阿霉素(DOX)为主药,通过配位交联法制备纳米颗粒,并进行质量评价。方法:超声条件下将TA、FeCl_(3)、DOX依次混合制备纳米颗粒;使用粒径仪测量粒径和PDI值,并在透射电子显微镜(TEM)下观察纳米颗粒的形貌;考察纳米颗粒的稳定性及其体外药物释放行为;通过MTT法研究其在肿瘤细胞4T1上的毒性。结果:成功制备了以TA、FeCl_(3)为载体的DOX纳米颗粒(TA-Fe-DOX)。该纳米颗粒呈类球形,粒径为190nm;在一周内保持稳定;体外释放实验证明纳米颗粒在酸性环境的释药速率高于中性环境,具有明显的pH敏感性释药特征;细胞毒性实验结果表明TA-Fe空白载体没有明显毒性,而制备的TAFe-DOX纳米颗粒相对于游离药物DOX具有较高的抗肿瘤作用。结论:制备的TA-Fe-DOX纳米颗粒具有良好的pH敏感释药特性,能够提高肿瘤靶向性,为肿瘤治疗提供新的思路。

Doxorubicin Stealth Liposomes Prepared with PEG-Distearoyl Phosphatidylethanolamine and Distribution as well as Antitumor Activity in Mice

目的：研制出能够逃避体内网状内皮细胞的阿霉素隐形脂质体，并考察其在生物体内的分布以及比较阿霉素隐形脂质体与阿霉素普通脂质体的抗肿瘤活性。方法：将聚乙二醇－二硬脂酰磷脂酰乙醇胺（PEG－DSPE）同磷脂酰胆碱和胆固醇材料加在一起，用硫酸铵梯度法制备阿霉素隐形脂质体，同法制备阿霉素普通脂质体（但脂膜中不含PEG－DSPE）；通过尾静脉注射给药，比较隐形脂质体阿霉素、普通脂质体阿霉素和游离型阿霉素（盐酸阿霉素注射液）给药后在小鼠各主要脏器组织和血液中的分布情况；采用动物移植性肿瘤实验法，用H22小鼠肝癌细胞接种于小鼠右侧腋皮下形成实体瘤，考察阿霉素隐形脂质体和普通脂质体给药后对实体瘤的瘤重抑制率。结果：通过硫酸铵梯度法制备出了包封率高达95％的阿霉素隐形脂质体；同游离型阿霉素和普通脂质体阿霉素相比，隐形脂质体阿霉素在血液中浓度显著提高，循环时间显著延长，在心脏中分布的浓度显著降低；按5mg·kg^-1剂量治疗，第二天给药和第七天给药治疗方案，阿霉素隐形脂质体给药组的瘤重抑制率均显著高于普通脂质体给药组的瘤重抑制率；按10mg·kg^-1剂量治疗，隐形脂质体给药组的瘤重抑制率比普通脂质体给药组的瘤重抑制率稍高。结论：用普通脂质体给药相比，隐形脂质体阿霉素给药后延长了其在小鼠血液中的循环时间，说明经过PEG－DSPE修饰后的脂质体有逃避网状内皮细胞吞噬的功能（隐形），并且隐形脂质体阿霉素的抗肿瘤活性显著地提高。

DL1106与doxorubicin和paclitaxel协同作用及其机制研究

目的探讨DL1106与doxorubicin和paclitaxel对三阴性乳腺癌细胞协同作用效果及研究机制。方法将三阴性乳腺癌细胞MDA-MB-231和BT549分为4组,对照组,DL1106,DL1106+doxorubicin,DL1106+paclitaxel组作用24和48 h。用流式细胞仪检测细胞凋亡率和细胞周期;用JC-1检测细胞膜电位;用Caspase-Glo?3/7 assay检测细胞内胱天蛋白酶活性;用Western blotting检测细胞周期、细胞凋亡相关蛋白表达。采用si RNA技术敲低P53和PUMA的表达后检测药物联合对细胞的作用效果。结果与DL1106单独作用组细胞相比,DL1106与doxorubicin和paclitaxel联合作用组的细胞在48 h后凋亡率显著下降。DL1106与doxorubicin和paclitaxel联合作用导致细胞膜电位大幅下降并使细胞内胱天蛋白酶活性显著升高。同对照组相比,DL1106,DL1106+doxorubicin,DL1106+paclitaxel作用组的细胞均抑制MDM2的表达,促进P53和PUMA的表达。DL1106+doxorubicin,DL1106+paclitaxel协同作用抑制细胞Cyclin D1和Bcl-2的表达,促进BAX的表达。用P53si RNA和PUMA si RNA分别敲低细胞P53和PUMA的表达后,发现DL1106+doxorubicin,DL1106+paclitaxel联合作用效果明显减弱。结论 DL1106与doxorubicin和paclitaxel对三阴性乳腺癌细胞均具有协同作用,且这种协同作用通过P53/PUMA/BAX/caspase途径发挥作用。

Hesperidin as a preventive resistance agent in MCF-7 breast cancer cells line resistance to doxorubicin

Objective:To evaluate of hesperidin to overcome resistance of doxorubicin in MCF-7 resistant doxorubicin cells(MCF-7/Dox)in cytotoxicity apoptosis and P-glycoprotein(Pgp)expression in combination with doxorubicin.Methods:The cytotoxic properties.50%inhibition concentration(IC_(50))and its combination with doxorubicin in MCF-7 cell lines resistant to doxorubicin(MCF-7/Dox)cells were determined using MTT assay.Apoptosis induction was examined by double staining assay using ethidium bromide-acridine orange.Immunocytochemistry assay was performed to determine the level and localization of Pgp.Results:Single treatment of hesperidin showed cytotoxic activity on MCF-7/Dox cells with IC_(50)value of 11μmol/L.Thus,combination treatment from hesperidin and doxorubicin showed addictive and antagonist effect(CI>1.0).Hesperidin did not increase the apoptotic induction,but decreased the Pgp expressions level when combined with doxorubicin in low concentration.Conclusions:Hesperidin has cytotoxic effect on MCF-7/Dox cells with IC_(50)of 11μmol/L.Hesperidin did not increased the apoptotic induction combined with doxorubicin.Cochemotherapy application of doxorubicin and hesperidin on MCF-7/Dox cells showed synergism effect through inhibition of Pgp expression.

Preparation and evaluation of poly(L-histidine) based pH-sensitive micelles for intracellular delivery of doxorubicin against MCF-7/ADR cells

In this study, a p H-sensitive micelle self-assembled from poly(L-histidine) based triblock copolymers of poly(ethylene glycol)–poly(D,L-lactide)–poly(L-histidine)(mPEG-PLA-PHis) was prepared and used as the intracellular doxorubicin(Dox) delivery for cancer chemotherapy. Dox was loaded into the micelles by thin-film hydration method and a Box–Behnken design for three factors at three levels was used to optimize the preparations. The optimized mPEG-PLA-Phis/Dox micelles exhibited good encapsulation efficiency of 91.12%,a mean diameter of 45 nm and narrow size distribution with polydispersity index of 0.256.In vitro drug release studies demonstrated that Dox was released from the micelles in a p Hdependent manner. Furthermore, the cellular evaluation of Dox loaded micelles displayed that the micelles possessed high antitumor activity in vitro with an IC50 of 35.30 μg/ml against MCF-7/ADR cells. The confocal microscopy and flow cytometry experiments indicated that m PEG-PLA-Phis micelles mediated efficient cytoplasmic delivery of Dox with the aid of poly(Lhistidine) mediated endosomal escape. In addition, blank m PEG-PLA-Phis micelles were shown to be nontoxic to MCF-7/ADR cells even at a high concentration of 200 μg/ml. The pHsensitive mPEG-PLA-PHis micelles have been demonstrated to be a promising nanosystem for the intracellular delivery of Dox for MDR reversal.

MiR-34a overexpression enhances the inhibitory effect of doxorubicin on HepG2 cells

BACKGROUND Hepatocellular carcinoma(HCC) is the third leading cause of death from malignant tumors worldwide. More than 50% of HCC cases occur in China. The prognosis remains poor and overall efficacy is still unsatisfactory. Chemotherapy resistance is the most important reason for the poor outcome. Much progress has been made in the study of chemotherapy resistance of HCC;however, the specific mechanisms of progression of HCC have still only been partially established.Therefore, the mechanism of chemotherapy resistance in HCC requires more research.AIM To investigate the effect of miR-34 a expression on the growth inhibition of HepG2 cells by doxorubicin.METHODS A recombinant lentiviral vector containing miR-34 a was constructed and transfected into HepG2 cells. The expression of miR-34 a was detected by reverse transcription-polymerase chain reaction(commonly known as RT-PCR) before and after transfection. Cells were exposed to 2 μM doxorubicin or phosphatebuffered saline before and after transfection. Cell viability in each group was detected by MTT assay, and cell cycle and apoptosis were detected by flow cytometry. Changes in expression levels of phospho(p)-p53, sirtuin(SIRT) 1,cyclin D1, cyclin-dependent kinase(CDK) 4, CDK6, BCL-2, multidrug resistance protein(MDR) 1/P glycoprotein(P-gp), and AXL were detected by Western blotting.RESULTS Recombinant lentiviral vector LV-hsa-mir-34 a was successfully constructed by restriction endonuclease digestion and sequencing. RT-PCR showed that expression of miR-34 a in HepG2 cells was significantly upregulated after transfection(P < 0.01). MTT assay showed that growth of HepG2 cells was inhibited after upregulation of miR-34 a, and viability was significantly decreased after combined treatment with doxorubicin(P < 0.01). Flow cytometry showed that the number of HepG2 cells in G1 phase increased, and G1 phase arrest was more obvious after intervention with doxorubicin(P < 0.01). The apoptosis rate of HepG2 cells was increased after upregulation of miR-34 a, and became more obvious after intervention with doxorubicin(P < 0.01). Western blotting showed that upregulation of miR-34 a combined with treatment with doxorubicin caused significant changes in the expression levels of p-p53, SIRT1, cyclin D1, CDK4,CDK6, BCL-2, MDR1/P-gp and AXL proteins(P < 0.01).CONCLUSION MiR-34 a may enhance the inhibitory effect of doxorubicin by downregulating MDR1/P-gp and AXL, which may be related to p53 expression.

Melatonin and Doxorubicin synergistically induce cell apoptosis in human hepatoma cell lines

AIM:To investigate whether Melatonin has synergistic effects with Doxorubicin in the growth-inhibition and apoptosis-induction of human hepatoma cell lines HepG2 and Bel-7402.METHODS:The synergism of Melatonin and Doxorubicin inhibited the cell growth and induced cell apoptosis in human hepatoma cell lines HepG2 and Bel-7402.Cell viability was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT)assay.Cell apoptosis was evaluated using TUNEL method and flow cytometry.Apoptosis-related protein Bax,Bcl-2 and caspase-3 expressions were measured by immunohistochemical staining.RESULTS:Treatment with Melatonin(10 -8 -10 -5 mol/L) alone had a dose-related inhibitory effect on cell proliferation but no cytotoxic effect on hepatoma cell lines HepG2 and Bel-7402.Interestingly,when combined with Doxorubicin,Melatonin significantly increased the effects of cell growth inhibition and cell apoptosis.Furthermore,TUNEL staining and flow cytometry revealed that cooperative apoptosis induction was associated with decreased expression of Bcl-2 as well as increased expression of Bax and Caspase3.CONCLUSION:The synergism of Melatonin and Doxorubicin inhibits hepatoma cell growth and induces cell apoptosis.

PEComa of the colon resistant to sirolimus but responsive to doxorubicin/ifosfamide

A 23-year-old male presented with a three-week-history of crampy abdominal pain and melaena.Colonoscopy revealed a friable mass filling the entire lumen of the cecum;histologically,it was classified as perivascular epithelioid cell tumor(PEComa).An magnetic resonance imaging scan showed,in addition to the primary tumor,two large mesenteric lymph node metastases and four metastatic lesions in the liver.The patient underwent right hemicolectomy and left hemihepatectomy combined with wedge resections of metastases in the right lobe of the liver,the resection status was R0.Subsequently,the patient was treated with sirolimus.After 4 mo of adjuvant mammalian target of rapamycin inhibition he developed two new liver metastases and a local pelvic recurrence.The visible tumor formations were again excised surgically,this time the resection status was R2 with regard to the pelvic recurrence.The patient was treated with 12 cycles of doxorubicin and ifosfamide under which the disease was stable for 9 mo.The clinical course was then determined by rapid tumor growth in the pelvic cavity.Second line chemotherapy with gemcitabine and docetaxel was ineffective,and the patient died 23 mo after the onset of disease.This case report adds evidence that,in malignant PEComa,the mainstay of treatment is curative surgery.If not achievable,the effects of adjuvant or palliative chemotherapy are unpredictable.

Characterization and in vitro release studies of oral microbeads containing thiolated pectin–doxorubicin conjugates for colorectal cancer treatment

Novel oral microbeads were developed based on a biopolymer–drug conjugate of doxorubicin(DOX) conjugated with thiolated pectin via reducible disulfide bonds. The microbeads were fabricated by ionotropic gelation with cations such as Al3+, Ca2+ and Zn2+. The results showed that using zinc acetate can produce the strongest microbeads with spherical shape.However, the microbeads prepared from thiolated pectin–DOX conjugate were very soft and irregular in shape. To produce more spherical microbeads with suitable strength, the native pectin was then added to the formulations. The particle size of the microbeads ranged from 0.87 to 1.14 mm. The morphology of the microbeads was characterized by optical and scanning electron microscopy. DOX was still in crystalline form when used in preparing the microbeads, as confirmed by powder X-ray diffractometry. Drug release profiles showed that the microbeads containing thiolated pectin–DOX conjugate exhibited reduction-responsive character;in reducing environments, the thiolated pectin–DOX conjugate could uncouple resulting from a cleavage of the disulfide linkers and consequently release the DOX. The best-fit release kinetics of the microbeads containing thiolated pectin–DOX conjugate, in the medium without reducing agent, fit the Korsmeyer–Peppas model while those in the medium with reducing agent fit a zero-order release model. These results suggested that the microbeads containing thiolated pectin–DOX conjugate may be a promising platform for cancer-targeted delivery of DOX, exploiting the reducing environment typically found in tumors.