Inhibition of 3‐D Tumor Spheroids by Timed‐Released Hydrophilic and Hydrophobic Drugs from Multilayered Polymeric Microparticles

First‐line cancer chemotherapy necessitates high parenteral dosage and repeated dosing of a combination of drugs over a prolonged period. Current commercially available chemotherapeutic agents, such as Doxil and Taxol, are only capable of delivering single drug in a bolus dose. The aim of this study is to develop dual‐drug‐loaded, multilayered microparticles and to investigate their antitumor efficacy compared with single‐drug‐loaded particles. Results show hydrophilic doxorubicin HCl (DOX) and hydrophobic paclitaxel (PTX) localized in the poly(dl ‐lactic‐co‐glycolic acid, 50:50) (PLGA) shell and in the poly(l ‐lactic acid) (PLLA) core, respectively. The introduction of poly[(1,6‐bis‐carboxyphenoxy) hexane] (PCPH) into PLGA/PLLA microparticles causes PTX to be localized in the PLLA and PCPH mid‐layers, whereas DOX is found in both the PLGA shell and core. PLGA/PLLA/PCPH microparticles with denser shells allow better control of DOX release. A delayed release of PTX is observed with the addition of PCPH. Three‐dimensional MCF‐7 spheroid studies demonstrate that controlled co‐delivery of DOX and PTX from multilayered microparticles produces a greater reduction in spheroid growth rate compared with single‐drug‐loaded particles. This study provides mechanistic insights into how distinctive structure of multilayered microparticles can be designed to modulate the release profiles of anticancer drugs, and how co‐delivery can potentially provide better antitumor response.     

ABV方案化疗对艾滋病相关晚期卡波氏肉瘤外周血CD4淋巴细胞的影响

Objective: The combination of highly active antiretroviral therapy (HAART) and chemotherapy with ABV regimen (doxorubicin, bleomycln and vincristine) is a promising approach for the treatment of advanced HIV-related Kaposi's sarcoma (KS). Here we analyzed the relationship between the CD4 lymphocyte cell count and the clinical response to chemotherapy.Methods: The 176 HIV infected patients with advanced KS who failed to respond to prior HAART were selected. All these patients were then preceded to chemotherapy with ABV regimen which was administered at 3 weekly intervals for 6 cycles.For each patient CD4 cell count was done before starting chemotherapy and after finishing 6 cycles of chemotherapy. The difference of CD4 cell counts pre chemotherapy and post chemotherapy was compared with the clinical progress of the patients after 6 cycles of chemotherapy. Results: The overall clinical remission was shown in 93.7% patients. Progressive disease (PD) and no change in clinical condition (NC) was shown in 6.3% patients. The increase in CD4 cell count post chemotherapy was found in 89.8% patients and the decrease in CD4 cell count was seen in 10.2% patients. The difference of the mean CD4call counts for patients in group CR + PR (complete relief + partial relief) before and after chemotherapy was highly significant.The difference of the mean CD4 cell counts for patients in group NC + PD before and after chemotherapy was not significant.The difference in CD4 cell counts in CR + PR and NC + PD groups before and after chemotherapy was highly significant.Conclusion: The HIV related KS patients on HAART benefit from the chemotherapy as it increases the CD4 cell count and it has positive impact on clinical remission of KS.     

序贯诱导法治疗高危急性非淋巴细胞白血病

目的 探讨小剂量HA(LD-HA)方案及标准方案序贯诱导法治疗高危急性非淋巴细胞白血病(ANLL)的疗效.方法 对50例不适合常规诱导的高危ANLL患者(LD-HA组)进行了序贯诱导.第1个周期诱导方案为LD-HA,首次诱导仍未缓解者,更换为标准方案(DA或HA)诱导.选择同期以DA或HA方案诱导治疗的23例ANLL患者(DA/HA组)作为对照,最多诱导2个周期.结果 LD-HA组患者完全缓解率为80.0%(40/50),诱导过程死亡2例;中位无瘤生存时间为19.6个月,中位生存时间为12.2个月;1、3、5年生存率分别为57.0%、24.1%、18.8%.DA/HA组共17例完全缓解,缓解率为73.9%;中位无瘤生存时间为19.8个月,中位生存时间为12.1个月;1、3、5年生存率分别为56.58%、27.1%、27.1%,两组相比,1、3、5年生存率差异无统计学意义(x2值分别为0.009、0.237、1.807,P值均＞0.05).结论 以LD-HA及标准方案序贯诱导高危ANLL患者,可获得较高的完全缓解率及长期生存率.     

Long Noncoding RNA GAS5 in Breast Cancer: Epigenetic Mechanisms and Biological Functions

Long noncoding RNAs (lncRNAs) have been identified as contributors to the development and progression of cancer through various functions and mechanisms. LncRNA GAS5 is downregulated in multiple cancers and acts as a tumor suppressor in breast cancer. GAS5 interacts with various proteins (e.g., E2F1, EZH2, and YAP), DNA (e.g., the insulin receptor promoter), and various microRNAs (miRNAs). In breast cancer, GAS5 binds with miR-21, miR-222, miR-221-3p, miR-196a-5p, and miR-378a-5p that indicates the presence of several elements for miRNA binding (MREs) in GAS5. Mediated by the listed miRNAs, GAS5 is involved in the upregulation of a number of mRNAs of suppressor proteins such as PTEN, PDCD4, DKK2, FOXO1, and SUFU. Furthermore, the aberrant promoter methylation is involved in the regulation of GAS5 gene expression in triple-negative breast cancer and some other carcinomas. GAS5 can stimulate apoptosis in breast cancer via diverse pathways, including cell death receptors and mitochondrial signaling pathways. GAS5 is also a key player in the regulation of some crucial signal pathways in breast cancer, such as PI3K/AKT/mTOR, Wnt/β-catenin, and NF-κB signaling. Through epigenetic and other mechanisms, GAS5 can increase sensitivity to multiple drugs and improve prognosis. GAS5 is thus a promising target in the treatment of breast cancer patients.     

Synthesis and antimalarial activities of a diverse set of triazole-containing furamidine analogues

Four different series of triazole diamidines have been prepared by the Pinner method from the corresponding triazole dinitriles. Copper‐catalyzed “click chemistry” was used for the synthesis of 1,4‐ and 4,5‐substituted triazoles, aryl magnesium acetylide reagents for the 1,5‐substituted triazoles, with a thermal dipolar addition reaction employed for the 2,4‐substituted triazoles. In vitro antimalarial activity against two different PfCRT‐modified parasite lines (Science 2002 , 298, 210–213) of Plasmodium falciparum and inhibition of hemozoin formation were determined for each compound. Several diamidines with potent nanomolar antimalarial activities were identified, and selected molecules were resynthesized as their diamidoxime triazole prodrugs. One of these prodrugs, OB216, proved to be highly potent in vivo with an ED₅₀ value of 5 mg kg^?1 (po) and an observed 100 % cure rate (CD₁₀₀) of just 10 mg kg^?1 by oral (po) administration in mice infected with P. vinckei.     

Enhanced Inhibition of Bladder Cancer Cell Growth by Simultaneous Knockdown of Antiapoptotic Bcl-xL and Survivin in Combination with Chemotherapy

The overexpression of antiapoptotic genes, such as Bcl-xL and survivin, contributes to the increased survival of tumor cells and to the development of treatment resistances. In the bladder cancer cell lines EJ28 and J82, the siRNA-mediated knockdown of survivin reduces cell proliferation and the inhibition of Bcl-xL sensitizes these cells towards subsequent chemotherapy with mitomycin C and cisplatin. Therefore, the aim of this study was to analyze if the simultaneous knockdown of Bcl-xL and survivin might represent a more powerful treatment option for bladder cancer than the single inhibition of one of these target genes. At 96 h after transfection, reduction in cell viability was stronger after simultaneous inhibition of Bcl-xL and survivin (decrease of 40%–48%) in comparison to the single target treatments (decrease of 29% at best). Furthermore, simultaneous knockdown of Bcl-xL and survivin considerably increased the efficacy of subsequent chemotherapy. For example, cellular viability of EJ28 cells decreased to 6% in consequence of Bcl-xL and survivin inhibition plus cisplatin treatment whereas single target siRNA plus chemotherapy treatments mediated reductions down to 15%–36% only. In conclusion, the combination of simultaneous siRNA-mediated knockdown of antiapoptotic Bcl-xL and survivin—a multitarget molecular-based therapy—and conventional chemotherapy shows great potential for improving bladder cancer treatment.     

Study of the efficacy of antimalarial drugs delivered inside targeted immunoliposomal nanovectors

Paul Ehrlich''s dream of a ''magic bullet'' that would specifically destroy invading microbes is now a major aspect of clinical medicine. However, a century later, the implementation of this medical holy grail continues being a challenge in three main fronts: identifying the right molecular or cellular targets for a particular disease, having a drug that is effective against it, and finding a strategy for the efficient delivery of sufficient amounts of the drug in an active state exclusively to the selected targets. In a previous work, we engineered an immunoliposomal nanovector for the targeted delivery of its contents exclusively to Plasmodium falciparum-infected red blood cells [pRBCs]. In preliminary assays, the antimalarial drug chloroquine showed improved efficacy when delivered inside immunoliposomes targeted with the pRBC-specific monoclonal antibody BM1234. Because difficulties in determining the exact concentration of the drug due to its low amounts prevented an accurate estimation of the nanovector performance, here, we have developed an HPLC-based method for the precise determination of the concentrations in the liposomal preparations of chloroquine and of a second antimalarial drug, fosmidomycin. The results obtained indicate that immunoliposome encapsulation of chloroquine and fosmidomycin improves by tenfold the efficacy of antimalarial drugs. The targeting antibody used binds preferentially to pRBCs containing late maturation stages of the parasite. In accordance with this observation, the best performing immunoliposomes are those added to Plasmodium cultures having a larger number of late form-containing pRBCs. An average of five antibody molecules per liposome significantly improves in cell cultures the performance of immunoliposomes over non-functionalized liposomes as drug delivery vessels. Increasing the number of antibodies on the liposome surface correspondingly increases performance, with a reduction of 50% parasitemia achieved with immunoliposomes encapsulating 4 nM chloroquine and bearing an estimated 250 BM1234 units. The nanovector prototype described here can be a valuable platform amenable to modification and improvement with the objective of designing a nanostructure adequate to enter the preclinical pipeline as a new antimalarial therapy.     

X-rays Actuate Anticancer Drugs: Opening New Vistas in Prodrug Therapy

Chemotherapy is the primary treatment modality employed in the clinic for the treatment of cancer. Despite proven clinical success, adverse side effects are one of the drawbacks of this approach. The prodrug strategy has emerged as an alternative approach with the aim of alleviating these drawbacks. Prodrug activation is typically achieved by either endogenous or exogenous triggers. Exogenous triggers like light are appealing as they are independent of inherent patient and/or cancer-type variations. However, tissue penetration depth remains the Achilles’ heel of this approach. In this context, usage of X-rays as the external trigger with infinite tissue penetration depth opens up exciting prospects in prodrug activation strategies.