Enhanced drug delivery to melanoma cells using PMPC-PDPA polymersomes

We present the efficient and stable encapsulation of doxorubicin within pH sensitive polymeric vesicles (polymersomes) for intracellular and nuclear delivery to melanoma cells. We demonstrate that PMPC₂₅-PDPA₇₀ polymersomes can encapsulate doxorubicin for long periods of time without significant drug release. We demonstrate that empty polymersomes are non-toxic and that they are quickly and more efficiently internalised by melanoma cells compared to healthy cells. Encapsulated doxorubicin has a strong cytotoxic effect on both healthy and cancerous cells, but when encapsulated it had a preferential effect on melanoma cells indicating that this formulation can be used to achieve an enhanced drug delivery to cancerous cells rather than to the healthy surrounding cells.     

5氮杂胞苷联合干扰素-γ上调神经母细胞瘤细胞Caspase 8表达的研究

  目的  探讨半胱-天冬氨酸蛋白酶8(Caspase 8)和死亡受体(DR)在肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导神经母细胞瘤(NB)细胞凋亡中的作用。  方法  应用RT-PCR方法检测γ干扰素(IFN-γ)作用前后NB细胞Caspase 8 mRNA的表达; 应用Western blot方法检测Caspase 8、DR4和DR5蛋白表达; 应用四甲基偶氮唑蓝(MTT)比色法及流式细胞术检测IFN-γ, TRAIL, IFN-γ+TRAIL, Caspase 8抑制剂+TRAIL及IFN-γ+阿霉素/依托泊苷+TRAIL对NB细胞株生长及凋亡的影响。  结果  IFN-γ在NB细胞株SKNDZ中诱导了Caspase 8mRNA及蛋白表达。SY5Y细胞对TRAIL不敏感, 而IFN-γ与TRAIL或阿霉素, 依托泊苷联用对SY5Y细胞有明显诱导凋亡作用。IFN-γ+TRAIL组SY5Y细胞早期凋亡率(23.09+2.35)%高于TRAIL组[(6.15±0.54)%(P< 0.01)], 但低于IFN-γ+阿霉素/依托泊苷+TRAIL组[(43.41±6.46)%/(38.86±7.29)%, P< 0.01]。阿霉素或依托泊苷可以诱导NB细胞株DR5蛋白表达, 但未诱导DR4蛋白表达。IFNγ诱导后表达Caspase 8的SKNDZ细胞对TRAIL的诱导凋亡作用仍不敏感, 而阿霉素或依托泊苷处理后同时表达DR5的SKNDZ细胞对TRAIL的诱导凋亡作用相对敏感。IFN-γ+阿霉素/依托泊苷+TRAIL组SKNDZ细胞早期凋亡率(11.54±2.49)%/(13.38±1.65)%高于IFN-γ+TRAIL组(P< 0.01)。  结论  IFN-γ上调Caspase 8表达及化疗药阿霉素或依托泊苷诱导DR5表达可以恢复NB细胞对TRAIL的敏感性, Caspase 8和DR5在TRAIL诱导NB细胞凋亡中起着十分关键的作用。     

Circ_0081143 Contributes to Gastric Cancer Malignant Development and Doxorubicin Resistance by Elevating the Expression of YES1 by Targeting mziR-129-2-3p

Background/AimsThe increased mortality of gastric cancer (GC) is mainly attributed to the development of chemoresistance. Circular RNAs, as the novel type of biomarkers in GC, have attracted wide attention. The purpose of this study was to investigate the functional role of circ_0081143 in GC with doxorubicin (DR) resistance and its potential action mechanism.MethodsThe expression of circ_0081143, miR-129-2-3p and YES proto-oncogene 1 (YES1) in GC tissues and cells was measured by quantitative real-time polymerase chain reaction. The half maximal inhibitory concentration value was calculated based on the MTT cell viability assay. Cell proliferation and apoptosis were monitored by MTT and flow cytometry assays. Transwell assays were employed to check cell migration and invasion. The protein levels of YES1 and apoptosis-related proteins were detected by western blotting. The interaction between miR-129-2-3p and circ_0081143 or YES1 was verified by dual-luciferase reporter and pull-down assays. A tumorigenicity assay was conducted to verify the role of circ_0081143 in vivo.ResultsCirc_0081143 was highly expressed in DR-resistant GC tumor tissues and cells. Depletion of circ_0081143 reduced DR resistance and inhibited DR-resistant GC cell proliferation, migration and invasion. Circ_0081143 targeted miR-129-2-3p and inhibited the role of miR-129-2-3p. In addition, YES1 was a target of miR-129-2-3p, and its function was suppressed by miR-129-2-3p. Importantly, circ_0081143 positively modulated the expression of YES1 through mediating miR-129-2-3p. Circ_0081143 knockdown weakened the DR-resistant GC tumor growth in vivo.ConclusionsCirc_0081143 knockdown weakened DR resistance and blocked the development of DR-resistant GC by regulating the miR-129-2-3p/YES1 axis. Our data suggest that circ_0081143 is a promising target for the treatment of GC with DR resistance.     

不同剂量附子水煎液对慢性心力衰竭小鼠的干预作用

目的：探讨不同剂量附子水煎液对慢性心力衰竭（CHF）小鼠的影响。方法：将53只C57/6J小鼠雄性随机分为对照组、模型组、附子水煎液低剂量组、附子水煎液中剂量组、附子水煎液高剂量组,用盐酸阿霉素（Dox）腹腔注射诱导CHF小鼠模型,药物干预给予不同浓度（0.2、0.6、2 mg/kg）的附子水煎液进行灌胃治疗,1次/d,连续干预30 d,统计小鼠生存率和一般指标,评价小鼠心脏功能,观察心肌组织病理形态学的变化,检测血清中脑钠肽（BNP）和心肌肌钙蛋白I（cTnI）的含量,检测心钠尿肽（ANP）和BNP的mRNA表达水平,检测活化的天冬氨酸特异性半胱氨酸蛋白酶（Cleaved-caspase3）和凋亡蛋白Bax（Bax）的表达情况。结果：与模型组比较,不同剂量附子水煎液组小鼠心脏功能均得到改善（P<0.05）,且高剂量附子水煎剂组改善最为显著,具体表现为心肌组织横截面积增大,血清BNP和cTnI的含量降低（P<0.05）,BNP的mRNA表达水平和Cleaved-caspase3及Bax蛋白表达水平明显降低（P<0.05）。结论：附子水煎液能剂量依赖性地抑制心肌细胞凋亡,减轻小鼠心功能及其病理结构的改变,进而改善Dox诱导的CHF。     

Brostallicin versus doxorubicin as first-line chemotherapy in patients with advanced or metastatic soft tissue sarcoma: An European Organisation for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group randomised phase II and pharmacogenetic study

AimBrostallicin is a DNA minor groove binder that has shown activity in patients with soft tissue sarcoma (STS) failing first-line therapy. The present study assessed the safety and efficacy of first-line brostallicin in patients with advanced or metastatic STS > 60 years or not fit enough to receive combination chemotherapy. A prospective explorative pharmacogenetic analysis was undertaken in parallel.MethodsPatients were randomised in a 2:1 ratio between IV brostallicin 10 mg/m² and doxorubicin 75 mg/m² once every 3 weeks for a maximum of six cycles. Disease stabilisation at 26 weeks (primary end-point) was considered a ‘success’. Further testing of brostallicin was warranted if ⩾35 ‘successes’ were observed in the first 72 eligible patients treated with brostallicin. In addition, patients were genotyped for glutathione S transferase (GST) polymorphisms.ResultsOne hundred and eighteen patients were included (79 brostallicin and 39 doxorubicin). Brostallicin was well tolerated in comparison to doxorubicin with less grade 3–4 neutropenia (67% versus 95%), grade 2–3 systolic dysfunction (0% versus 11%), alopecia (17% versus 61%) and grade 2–3 mucositis (0% versus 18%). For brostallicin versus doxorubicin, ‘successes’ were observed in 5/77 versus 10/36, progression free survival at 1 year was 6.5% versus 15.6%, objective response rate was 3.9% versus 22.2% and overall survival at 1 year was 50.5% versus 57.9%, respectively. Only GSTA1 genotype was significantly associated with success rate of doxorubicin treatment.ConclusionBrostallicin cannot be recommended at this dose and schedule in this patient population as first-line therapy. GSTA1 genotype may be predictive for doxorubicin efficacy but warrants further study.     

Effects of Ectopic Expression of NGAL on Doxorubicin Sensitivity

Neutrophil gelatinase-associated lipocalin (NGAL, a.k.a Lnc2) is a member of the lipocalin family which has diverse roles including stabilizing matrix metalloproteinase-9 from auto-degradation and as siderocalins which are important in the transport of iron. NGAL also has important biological functions involved in immunity and inflammation as well as responses to kidney damage. NGAL expression has also been associated with certain neoplasia and is important in the metastasis of breast cancer. Many advanced cancer patients have elevated levels of NGAL in their urine and it has been proposed that NGAL may be a prognostic indicator for certain cancers (e.g. breast, brain, and others). NGAL expression is detected in response to various chemotherapeutic drugs including doxorubicin and docetaxel. We were interested in the roles of NGAL expression in cancer and whether it is associated with chemotherapeutic drug resistance. In the present study, we investigated whether increased NGAL expression led to resistance to the chemotherapeutic drug doxorubicin in normal breast epithelial cells (MCF-10A), breast cancer cells (MCF-7), and colorectal cancer cells (HT-29). We infected the various cell lines with a retrovirus encoding NGAL which we constructed. Increased NGAL expression was readily detected in the NGAL-infected cells but not the empty vector-infected cells. However, increased NGAL expression did not alter the sensitivity of the cells to the chemotherapeutic drug doxorubicin. Thus, although NGAL expression is often detected after chemotherapeutic drug treatment, it by itself, does not lead to doxorubicin resistance.     

Hyperthermic potentiation of doxorubicin and 4'-epi-doxorubicin in a transplantable neurogenic rat tumor (BT4A) in BD IX rats

The combined effect of hyperthermia and doxorubicin on the neurogenic rat cell line BT4C was found to be synergistic in vitro. The present investigation was initiated to study if this synergistic effect also could be obtained in vivo. An enhanced effect occurred when doxorubicin and 4'-epi-doxorubicin 7 mg/kg body weight were given 30 minutes prior to local water bath hyperthermia (one hour at 44.0 degrees C). The local side effects of the combined treatment did not increase above that of hyperthermia alone. Therefore, local hyperthermia may become a useful modality for enhancement of the effect of anthracyclines on tumors with marginal drug sensitivity or bulky tumors with poor drug penetration.