• Keywords
• VIRACEPT,
• MeSH
• HIV Infections drug therapy   MeSH
• Humans MeSH
• Nelfinavir MeSH
• Check Tag
• Humans MeSH

Nelfinavir mesylate (NFV), a human immunodeficiency virus (HIV) protease inhibitor, is an integral component of highly active anti retro viral therapy (HAART) for management of AIDS. NFV possesses pH-dependent solubility and has low and variable bioavailability hampering its use in therapeutics. Lipid-based particulates have shown to improve solubility of poorly water soluble drugs and oral absorption, thereby aiding in improved bioavailability. The current study compares potential of vesicular and solid lipid nanocarriers of NFV with drug nanocrystallites and microvesicular systems like cochleates in improving bioavailability of NFV. The paper outlines investigation of systems using in vitro models like in vitro lipolysis, in vitro release, and permeation through cell lines to predict the in vivo potential of nanocarriers. Finally, in vivo pharmacokinetic study is reported which provided proof of concept in sync with results from in vitro studies. Graphical Abstract ᅟ.

• MeSH
• Biological Availability MeSH
• Caco-2 Cells MeSH
• HIV Protease Inhibitors chemistry   MeSH
• Rats MeSH
• Humans MeSH
• Lipids chemistry   MeSH
• Nelfinavir chemistry   pharmacokinetics   MeSH
• Rats, Sprague-Dawley MeSH
• Solubility MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH

Human immunodeficiency virus (HIV) encodes an aspartic protease (PR) that cleaves viral polyproteins into mature proteins, thus leading to the formation of infectious particles. Protease inhibitors (PIs) are successful virostatics. However, their efficiency is compromised by antiviral resistance. In the PR sequence of viral variants resistant to the PI nelfinavir, the mutations D30N and L90M appear frequently. However, these two mutations are seldom found together in vivo, suggesting that there are two alternative evolutionary pathways leading to nelfinavir resistance. Here we analyze the proteolytic activities, X-ray structures, and thermodynamics of inhibitor binding to HIV-1 PRs harboring the D30N and L90M mutations alone and in combination with other compensatory mutations. Vitality values obtained for recombinant mutant proteases and selected PR inhibitors confirm the crucial role of mutations in positions 30 and 90 for nelfinavir resistance. The combination of the D30N and L90M mutations significantly increases the enzyme vitality in the presence of nelfinavir, without a dramatic decrease in the catalytic efficiency of the recombinant enzyme. Crystal structures, molecular dynamics simulations, and calorimetric data for four mutants (D30N, D30N/A71V, D30N/N88D, and D30N/L90M) were used to augment our kinetic data. Calorimetric analysis revealed that the entropic contribution to the mutant PR/nelfinavir interaction is less favorable than the entropic contribution to the binding of nelfinavir by wild-type PR. This finding is supported by the structural data and simulations; nelfinavir binds most strongly to the wild-type protease, which has the lowest number of protein-ligand hydrogen bonds and whose structure exhibits the greatest degree of fluctuation upon inhibitor binding.

• MeSH
• Enzyme Activation MeSH
• Financing, Organized MeSH
• HIV-1 enzymology   genetics   MeSH
• HIV Protease genetics   chemistry   MeSH
• HIV Protease Inhibitors chemistry   MeSH
• Kinetics MeSH
• Protein Conformation MeSH
• Crystallography, X-Ray MeSH
• Models, Molecular MeSH
• Mutation MeSH
• Nelfinavir MeSH
• Thermodynamics MeSH
• Protein Binding MeSH
• Drug Resistance, Viral MeSH

OBJECTIVES: To assess the potential of second-generation proteasome inhibition by carfilzomib and its combination with the human immunodeficiency virus (HIV) protease inhibitors (HIV-PIs) lopinavir and nelfinavir in vitro for improved treatment of clear cell renal cell cancer (ccRCC). MATERIALS AND METHODS: Cytotoxicity, reactive oxygen species (ROS) production, and unfolded protein response (UPR) activation of proteasome inhibitors, HIV-PIs, and their combination were assessed in three cell lines and primary cells derived from three ccRCC tumours by MTS assay, flow cytometry, quantitative reverse transcriptase-polymerase chain reaction and western blot, respectively. Proteasome activity was determined by activity based probes. Flow cytometry was used to assess apoptosis by annexin V/propidium iodide assay and ATP-binding cassette sub-family B member 1 (ABCB1) activity by MitoTrackerTM Green FM efflux assay (Thermo Fisher Scientific, MA, USA). RESULTS: Lopinavir and nelfinavir significantly increased the cytotoxic effect of carfilzomib in all cell lines and primary cells. ABCB1 efflux pump inhibition, induction of ROS production, and UPR pre-activation by lopinavir were identified as underlying mechanisms of this strong synergistic effect. Combined treatment led to unresolved protein stress, increased activation of pro-apoptotic UPR pathway, and a significant increase in apoptosis. CONCLUSION: The combination of the proteasome inhibitor carfilzomib and the HIV-PIs lopinavir and nelfinavir has a strong synergistic cytotoxic activity against ccRCCin vitro at therapeutically relevant drug concentrations. This effect is most likely explained by synergistic UPR triggering and ABCB1-modulation caused by HIV-PIs. Our findings suggest that combined treatment of second-generation proteasome inhibitors and HIV-PIs should be investigated in patients with metastatic RCC within a clinical trial.

• MeSH
• Drug Resistance, Neoplasm MeSH
• HIV Protease Inhibitors therapeutic use   MeSH
• Proteasome Inhibitors therapeutic use   MeSH
• Carcinoma, Renal Cell drug therapy   MeSH
• Humans MeSH
• Lopinavir therapeutic use   MeSH
• Cell Line, Tumor MeSH
• Kidney Neoplasms drug therapy   MeSH
• Nelfinavir therapeutic use   MeSH
• Antineoplastic Agents therapeutic use   MeSH
• Endoplasmic Reticulum Stress drug effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Proteasome inhibitors are the backbone of multiple myeloma therapy. However, disease progression or early relapse occur due to development of resistance to the therapy. One important cause of resistance to proteasome inhibition is the so-called bounce-back response, a recovery pathway driven by the TCF11/Nrf1 transcription factor, which activates proteasome gene re-synthesis upon impairment of the proteasome function. Thus, inhibiting this recovery pathway potentiates the cytotoxic effect of proteasome inhibitors and could benefit treatment outcomes. DDI2 protease, the 3D structure of which resembles the HIV protease, serves as the key player in TCF11/Nrf1 activation. Previous work found that some HIV protease inhibitors block DDI2 in cell-based experiments. Nelfinavir, an oral anti-HIV drug, inhibits the proteasome and/or pAKT pathway and has shown promise for treatment of relapsed/refractory multiple myeloma. Here, we describe how nelfinavir inhibits the TCF11/Nrf1-driven recovery pathway by a dual mode of action. Nelfinavir decreases the total protein level of TCF11/Nrf1 and inhibits TCF11/Nrf1 proteolytic processing, likely by interfering with the DDI2 protease, and therefore reduces the TCF11/Nrf1 protein level in the nucleus. We propose an overall mechanism that explains nelfinavir's effectiveness in the treatment of multiple myeloma.

• Publication type
• Journal Article MeSH

Cíl: Srovnat chronické účinky antiretrovirotické léčby (lamivudin, stavudin, delavirdin, nelfinavir, amprenaviru a kombinace lopinaviru/ritonaviru) u březích potkanů albínů. Typ studie: Review. Název a sídlo pracoviště: Gynekologicko-porodnická klinika, Federal University of S?o Paulo (UNIFESP), Sao Paulo, SP, Brazílie. Metodika: Retrospektivní srovnávací studie se zabývala 18 skupinami po 10 březích samičkách potkanů, které byly téměř tři měsíce staré a vážily 200 gramů. Každé z nich byla denně aplikována léčba pomocí žaludeční sondy, zatímco kontrolní skupině byl aplikován 1 ml destilované vody. Studijní skupiny obdržely lamivudin (5, 15 a 45 mg/kg/den); stavudin (na 1, 3 a 9 mg/kg/den); nelfinavir (40, 120 a 360 mg/kg/den); amprenavir (na 46, 138 a 414 mg/kg/den); lopinavir/ritonavir (12.8/3.2, a 38.4/9.6 115/28.8 mg/kg/den) a delavirdin (20 a 60 mg/kg/den). To představuje jedno-, troj- a devítinásobek terapeutické dávky pro člověka, s výjimkou posledního léku, kde nebyla nejvyšší dávka podána. Byla hodnocena hmotnost samice, plodu a placenty, počet implantací a reabsorpcí, hlavní zevní malformace plodu a odumření samice nebo plodu. Pro statistické zpracování byly použity test Kruskalův-Wallisův a χ2 test. Výsledky: U všech tří dávek stavudin zvyšoval hmotnost samice (p = 0,001), zatímco lamivudin při trojnásobné a devítinásobné dávce hmotnost snižoval (p < 0,001). Amprenavir u všech dávek, a lopinavir//ritonavir u troj- a devítinásobné dávky zvyšoval úmrtnost samic (p < 0,001). Z hlediska plodů nebylo žádné z antiretrovirotik škodlivé, pokud jde o implantaci, reabsorpci, teratogenitu a úmrtnost (p > 0,05). Stavudin při všech dávkách snižoval hmotnost mláďat(p < 0,001); Nicméně lamivudin u trojnásobné, delavirdin u trojnásobné a amprenavir u trojnásobné dávky hmotnost mláďat zvyšoval (p < 0,001). Závěr: U březích samic jsme pozorovali letální toxicitu u krys, kterým byl aplikován amprenavir a ritonavir/lopinavir; hmotnost krys se měnila při užití lamivudinu a stavudinu . U plodů byly pozorovány nežádoucí účinky v souvislosti s hmotností mláďat u stavudinu, lamivudinu, amprenaviru a delavirdinu..

Objective: To compare the chronic effects of antiretrovirals (lamivudine, stavudine, delavirdine, nelfinavir, amprenavir and an association of lopinavir/ritonavir) on albino pregnant rats. Design: Review. Setting: Department of Obstetrics, Federal University of S?o Paulo (UNIFESP), S?o Paulo, SP, Brazil. Methods: This was a comparative retrospective study formed by 18 groups of 10 pregnant rats each, which were nearly three months of age and weighed 200 g. All of them were medicated every day using a stomach probe, while the control group was given 1 mL of distilled water. The study groups received lamivudine (at 5, 15 and 45 mg/kg/day); stavudine (at 1, 3 and 9 mg/kg/day); nelfinavir (at 40, 120 and 360 mg/kg/day); amprenavir (at 46, 138 and 414 mg/kg/day); lopinavir/ritonavir (at 12.8/3.2, 38.4/9.6 and 115/28.8 mg/kg/day) and delavirdine (at 20 and 60 mg/kg/day). These represented 1, 3 and 9 times the human therapeutic dose, except for the last drug, for which the 9-times dose was not used. Maternal, litter and placental weights, implantation and reabsorption numbers, major external fetal malformations and fetal and maternal deaths were evaluated. The Kruskal-Wallis test was used to compare quantitative variables and the chi-square test was used to compare qualitative variables. Results: At all three doses, stavudine increased the maternal weight (p=0.001), while lamivudine at 3- and 9-times doses reduced it (p<0.001). Amprenavir at all of the doses, and lopinavir/ritonavir at 3- and 9-times doses, caused higher rates of maternal death (p<0.001). Regarding the fetuses, none of the antiretroviral drugs studied were harmful with regard to implantation, reabsorption, teratogenity and mortality (p>0.05). Stavudine at all doses reduced the litter weights (p<0.001); however, lamivudine at the usual and 3-times doses, delavirdine at 3-times dose, and amprenavir at 3-times dose increased the litter weight (p<0.001). Conclusion: In the maternal compartment, we observed lethal toxicity in the pregnant rats that received amprenavir and ritonavir/lopinavir; and maternal weight change with lamivudine and stavudine. In the fetal compartment, adverse effects were observed in relation to litter weight from stavudine, lamivudine, delavirdine and amprenavir. Keywords: pregnant rats, antiretroviral drugs, teratology, biological assay

• MeSH
• Anti-Retroviral Agents * administration & dosage   classification   therapeutic use   MeSH
• HIV Infections * drug therapy   MeSH
• HIV Protease Inhibitors administration & dosage   classification   adverse effects   therapeutic use   MeSH
• Reverse Transcriptase Inhibitors administration & dosage   classification   adverse effects   therapeutic use   MeSH
• Anti-HIV Agents administration & dosage   classification   adverse effects   therapeutic use   MeSH
• Disease Models, Animal * MeSH
• Fetus drug effects   MeSH
• Rats, Wistar MeSH
• Retrospective Studies MeSH
• Statistics as Topic MeSH
• Pregnancy MeSH
• Body Weight drug effects   MeSH
• Teratology MeSH
• Animals MeSH
• Check Tag
• Pregnancy MeSH
• Animals MeSH

HIV-1 protease (PR) is a homodimeric enzyme that is autocatalytically cleaved from the Gag-Pol precursor. Known PR inhibitors bind the mature enzyme several orders of magnitude more strongly than the PR precursor. Inhibition of PR at the precursor level, however, may stop the process at its rate-limiting step before the proteolytic cascade is initiated. Due to its structural heterogeneity, limited solubility and autoprocessing, the PR precursor is difficult to access by classical methods, and limited knowledge regarding precursor inhibition is available. Here, we describe a cell-based assay addressing precursor inhibition. We used a reporter molecule containing the transframe (TFP) and p6* peptides, PR, and N-terminal fragment of reverse transcriptase flanked by the fluorescent proteins mCherry and EGFP on its N- and C- termini, respectively. The level of FRET between EGFP and mCherry indicates the amount of unprocessed reporter, allowing specific monitoring of precursor inhibition. The inhibition can be quantified by flow cytometry. Additionally, two microscopy techniques confirmed that the reporter remains unprocessed within individual cells upon inhibition. We tested darunavir, atazanavir and nelfinavir and their combinations against wild-type PR. Shedding light on an inhibitor's ability to act on non-mature forms of PR may aid novel strategies for next-generation drug design.

• MeSH
• Atazanavir Sulfate pharmacology   MeSH
• Cell Line MeSH
• Darunavir pharmacology   MeSH
• Fluorescent Dyes MeSH
• HIV-1 enzymology   MeSH
• HIV Protease Inhibitors pharmacology   MeSH
• Anti-HIV Agents pharmacology   MeSH
• Humans MeSH
• Nelfinavir pharmacology   MeSH
• Protein Precursors antagonists & inhibitors   MeSH
• Proteolysis MeSH
• Flow Cytometry MeSH
• Fluorescence Resonance Energy Transfer MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: Resistance to chemotherapy is a major problem in the treatment of patients with triple-negative breast cancer (TNBC). Preclinical data suggest that TNBC is dependent on proteasomes; however, clinical observations indicate that the efficacy of proteasome inhibitors in TNBC may be limited, suggesting the need for combination therapies. METHODS: We compared bortezomib and carfilzomib and their combinations with nelfinavir and lopinavir in TNBC cell lines and primary cells with regard to their cytotoxic activity, functional proteasome inhibition, and induction of the unfolded protein response (UPR). Furthermore, we evaluated the involvement of sXBP1, ABCB1, and ABCG2 in the cytotoxic activity of drug combinations. RESULTS: Carfilzomib, via proteasome β5 + β2 inhibition, is more cytotoxic in TNBC than bortezomib, which inhibits β5 + β1 proteasome subunits. The cytotoxicity of carfilzomib was significantly potentiated by nelfinavir or lopinavir. Carfilzomib with lopinavir induced endoplasmic reticulum stress and pro-apoptotic UPR through the accumulation of excess proteasomal substrate protein in TNBC in vitro. Moreover, lopinavir increased the intracellular availability of carfilzomib by inhibiting carfilzomib export from cells that express high levels and activity of ABCB1, but not ABCG2. CONCLUSION: Proteasome inhibition by carfilzomib combined with nelfinavir/lopinavir represents a potential treatment option for TNBC, warranting further investigation.

• MeSH
• ATP Binding Cassette Transporter, Subfamily G, Member 2 * metabolism   antagonists & inhibitors   MeSH
• Apoptosis drug effects   MeSH
• Bortezomib * pharmacology   MeSH
• HIV Protease Inhibitors * pharmacology   MeSH
• Proteasome Inhibitors pharmacology   MeSH
• Humans MeSH
• Lopinavir * pharmacology   MeSH
• Cell Line, Tumor MeSH
• Neoplasm Proteins antagonists & inhibitors   metabolism   MeSH
• Nelfinavir * pharmacology   MeSH
• Oligopeptides * pharmacology   MeSH
• ATP Binding Cassette Transporter, Subfamily B metabolism   MeSH
• Antineoplastic Combined Chemotherapy Protocols pharmacology   MeSH
• Unfolded Protein Response * drug effects   MeSH
• Endoplasmic Reticulum Stress drug effects   MeSH
• Drug Synergism * MeSH
• Triple Negative Breast Neoplasms * drug therapy   pathology   MeSH
• X-Box Binding Protein 1 metabolism   genetics   MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

• Keywords
• ZALCITABIN, SANQUINAVIR,
• MeSH
• Antiviral Agents therapeutic use   MeSH
• Adult MeSH
• HIV Infections drug therapy   therapy   MeSH
• Indinavir MeSH
• Reverse Transcriptase Inhibitors administration & dosage   therapeutic use   MeSH
• Lamivudine MeSH
• Humans MeSH
• Nelfinavir MeSH
• Ritonavir MeSH
• Stavudine MeSH
• Pregnancy MeSH
• Zidovudine MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Review MeSH

Enzým cytochróm P450 2C19 je jedným z hlavných faktorov farmakokinetickej variability bežne užívaných liečiv. Niekoľko štúdií poukázalo na významný vplyv polymorfizmu enzýmu CYP2C19 s možným výskytom klinicky závažných nežiadúcich účinkov. Cieľom tretej časti tohoto článku je popísať vplyv genetického polymorfizmu cytochrómu P450 2C19 na účinok liečiv.

Cytochrome P450 2C19 is the important cause for great differences in the pharmacokinetics of a number of clinically used drugs. Several studies have demonstrated that the CYP2C19 polymorphism is important for several drugs and may be associated with the occurrence of clinically relevant side effects. The third part of this paper focuses on the influence of genetic polymorphism of cytochrome P450 2C19 on drug effect.

• MeSH
• Antidepressive Agents pharmacokinetics   therapeutic use   MeSH
• Antifungal Agents pharmacokinetics   therapeutic use   MeSH
• Antiviral Agents MeSH
• Aryl Hydrocarbon Hydroxylases genetics   MeSH
• Benzodiazepines pharmacokinetics   therapeutic use   MeSH
• Cyclophosphamide pharmacokinetics   therapeutic use   MeSH
• Enzymes genetics   MeSH
• Pharmacogenetics MeSH
• Phenytoin pharmacokinetics   therapeutic use   MeSH
• Genotype MeSH
• Platelet Aggregation Inhibitors pharmacokinetics   therapeutic use   MeSH
• Proton Pump Inhibitors pharmacokinetics   therapeutic use   MeSH
• Pharmaceutical Preparations metabolism   MeSH
• Humans MeSH
• Nelfinavir pharmacokinetics   therapeutic use   MeSH
• Polymorphism, Genetic MeSH
• Cytochrome P-450 Enzyme System genetics   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH