Hepatocellular carcinoma and multidrug resistance: Past, present and new challenges for therapy improvement

Hepatocellular carcinoma (HCC) is the most common malignancy of the liver and the third cause of cancer death worldwide. Chronic hepatitis due to HBV and HCV infection are two major risk factors for HCC worldwide. Advances in early detection and treatment have improved life expectancy of patients with HCC. However, this disorder remains as a disease with poor prognosis. In fact, epidemiological studies have shown that the median survival of patients is 8 months and approximately 20% of them survive one year, while only 5% remain alive after three years. Additionally, HCC is particularly difficult to treat because of its high recurrence rate, and its resistance to conventional chemotherapy due to, among other mechanisms, the over-expression of several members of the ATP-Binding Cassette (ABC) protein family involved in drugs transport. Fortunately, there is evidence that these patients may benefit from alternative molecular-targeted therapies. This manuscript reviews the current knowledges on the etiology, molecular mechanisms involved in HCC development and the current therapy strategies for the management of this malignancy. The challenges in the development of drug delivery systems for the targeting of antitumoral drugs to the liver parenchyma are also discussed. Finally, perspectives in the design of a more efficient pharmacotherapy to overcome multidrug resistance are reviewed.Fil: Cuestas, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Oubiña, Jose Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Mathet, Veronica Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Antiviral activity against the hepatitis C virus (HCV) of 1-indanone thiosemicarbazones and their inclusion complexes with hydroxypropyl-β- cyclodextrin

The hepatitis C virus (HCV) is a major cause of acute and chronic hepatitis in humans. Approximately 5% of the infected people die from cirrhosis or hepatocellular carcinoma. The current standard therapy comprises a combination of pegylated-interferon alpha and ribavirin. Due to the relatively low effectiveness, the prohibitive costs and the extensive side effects of the treatment, an intense research for new direct-acting anti-HCV agents is taking place. Furthermore, NS3 protease inhibitors recently introduced into the market are not effective against all HCV subgenotypes. Thiosemicarbazones (TSCs) have shown antiviral activity against a wide range of DNA and RNA viruses. However, their extremely low aqueous solubility and high self-aggregation tendency often preclude their reliable biological evaluation in vitro. In this work, we investigated and compared for the first time the anti-HCV activity of two 1-indanone TSCs, namely 5,6-dimethoxy-1-indanone TSC and 5,6-dimethoxy-1- indanone N4-allyl TSC, and their inclusion complexes with hydroxypropyl-β- cyclodextrin (HPβ-CD) in Huh-7.5 cells containing the full-length and the subgenomic subgenotype 1b HCV replicon system. Studies of physical stability in culture medium showed that free TSCs precipitated rapidly and formed submicron aggregates. Conversely, TSC complexation with HPβ-CD led to more stable systems with minimal size growth and drug concentration loss. More importantly, both TSCs and their inclusion complexes displayed a potent suppression of the HCV replication in both cell lines with no cytotoxic effects. The mechanism likely involves the inhibition of non-structural proteins of the virus. In addition, findings suggested that the cyclodextrin released the drug to the culture medium over time. This platform could be exploited for the study of the drug toxicity and pharmacokinetics animal models.Fil: Glisoni, Romina Julieta. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cuestas, María Luján. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mathet, Veronica Lidia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Área Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Oubiña, Jose Raul. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Área Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moglioni, Albertina Gladys. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sosnik, Alejandro Dario. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Interferon-γ and IL-10 release assay for patients with ocular toxoplasmosis

Peripheral blood mononuclear cells (PBMC) from patients with ocular toxoplasmosis were challenged with total antigens from Toxoplasma gondii lysate (TATL) in a cytokine release assay (CRA), run during the inactive period of the disease. Increased interferon gamma (IFN-γ) levels were detected after PBMC stimulation with either ME49 reference strain (P = 0.0015) or local TgCkAr-11-9 isolate (P = 0.0012), as compared with those recorded under basal conditions. TATL from TgCkAr11-9 isolate induced a higher release of IFN-γ than ME49 strain in CRA from all tested patients (P = 0.02). The median value of IFN-γ release on TgCkAr-11-9 stimulation (26.03 pg/mL) allowed the classification of patients into high- or low-/non-IFN-γ releasers. Clinical correlations were established with both groups. The results obtained in this study suggest the need to include local strains when performing CRA with TATL.Facultad de Ciencias Veterinaria

Hepatitis C virus strategies to evade the specific-T cell response: A possible mission favoring its persistence

Hepatitis C virus (HCV) is a small, enveloped RNA virus. The number of HCV-infected individuals worldwide is estimated to be approximately 200 million. The vast majority of HCV infections persist, with up to 80% of all cases leading to chronic hepatitis associated with liver fibrosis, cirrhosis, and hepatocellular carcinoma. The interaction between HCV and the host have a pivotal role in viral fitness, persistence, pathogenicity, and disease progression. The control of HCV infection requires both effective innate and adaptive immune responses. The HCV clearance during acute infection is associated with an early induction of the innate and a delayed initiation of the adaptive immune responses. However, in the vast majority of acute HCV infections, these responses are overcome and the virus persistence almost inexorably occurs. Recently, several host-and virus-related mechanisms responsible for the failure of both the innate and the adaptive immune responses have been recognized. Among the latter, the wide range of escape mutations to evade the specific-T-and B-cell responses as well as the T cell anergy and the CD8+ T cell exhaustion together with the interference with its function after prolonged virus exposure hold a pivotal role. Other HCV strategies include the modification or manipulation of molecules playing key roles in the induction of the interferon response and its induced effector proteins. In this review, we attempt to gain insights on the main T cell immune evasion strategies used by the virus in order to favor its persistence.Fil: Quarleri, Jorge Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Oubiña, Jose Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Síndrome Respiratorio Agudo Severo

A comienzos de 2003, los primeros casos de pacientes afectados con una neumonía atípica severa sin causa aparente fueron reportados en Hong Kong. Sin embargo, posteriormente se conoció que, en noviembre de 2002, había ocurrido un brote en la provincia china de Guangdong que no había sido notificado. Rápidamente, reportes de casos similares se presentaron en varios países del sudeste asiático, Europa y América, resultando Canadá, China, Hong Kong, Singapur, Taiwán y Vietnam las áreas más afectadas. En marzo de 2003, este síndrome fue designado Severe acute respiratory syndrome (SARS) o Síndrome Respiratorio Agudo Severo, caracterizado por fiebre, tos, disnea y el desarrollo de neumonía que puede progresar a compromiso pulmonar bilateral y falla respiratoria. Se trata de una enfermedad infecciosa de muy alta contagiosidad y con una tasa de mortalidad global cercana al 10%. A partir de ese momento, esfuerzos globales se aunaron para detectar el agente etiológico de esta epidemia y evitar su diseminación...Fil: Trinks, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Área Virología; ArgentinaFil: Oubiña, Jose Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Hepatitis D virus infection in patients with hepatitis B virus occult infection

Aguilera et al. have clearly confirmed the usefulness of looking for hepatitis D virus (HDV) in patients showing HBsAg reactivity in serum. However, Ponzetto et al. ,have accurately emphasized the fact that HDV infection may also occur even in the absence of HBsAg detection in serum,as previously showed both in animal models, as well as in humans. Moreover, such results have been recently supported by the dazzling discovery that HDV might be transmitted from infected hepatocytes to descendent cells in spite of the absence of a concomitant HBV infection..Fil: Oubiña, Jose Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Delfino, Cecilia María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Mathet, Veronica Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Specific primer sets used to amplify by PCR the hepatitis B virus overlapping S/Pol region select different viral variants

PCR detection of viral genomes has provided new insights into viral diagnosis. Nowadays, it is the most frequently used nucleic acid testing (qualitative and quantitative) technique. The aim of this study was to analyse the major circulating hepatitis B virus (HBV) variants PCR-amplified by three sets of primers in a patient infected with genotype E. The HBV S/Pol overlapping genomic region was amplified from the serum of an infected child using three primer sets previously described. Sequence analysis corresponding to the HBV S/Pol region revealed the presence of different viral populations depending on the set of primers used. D144A S-escape mutant was detected with two of the primer sets, while the rtL217R mutant within the Pol - conferring resistance to Adefovir - could be picked up with a different pair of primer sets. This study undoubtedly implies that the description of viral polymorphisms should be stated together with the sequence of the primers used for PCR amplification when studies of escape and/or antiviral-resistant HBV mutants are carried out.Fil: Cuestas, María Luján. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mathet, Veronica Lidia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Oubiña, Jose Raul. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effect of several PEO-PPO amphiphiles on bax, bcl-2, and hTERT mRNAs: An insight into apoptosis and cell immortalization induced in hepatoma cells by these polymeric excipients

Recent data have shown that synthetic polymers and nanomaterials display phenotypic effects in cells and signal transduction mechanisms involved in inflammation, differentiation, proliferation, and apoptosis. Aim: This article aims to investigate the effect of poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) block copolymers with a wide range of biomedical and pharmaceutical applications on apoptosis and/or cell immortalization, by flow cytometry and multiplex RT-PCR for bax, bcl-2, and human telomerase reverse transcriptase (hTERT). Results: PEO-PPO amphiphiles upregulated bax and hTERT and induced apoptosis of two human hepatoma cell lines. Conclusions: PEO-PPO block copolymers - considered safe for human use - can drastically alter gene expression profiles of genes related to apoptosis/cell proliferation.Fil: Castronuovo, Cynthia Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Cuestas, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Oubiña, Jose Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Mathet, Veronica Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Drug delivery systems and liver targeting for the improved pharmacotherapy of the hepatitis B virus (HBV) infection

In spite of the progress made in vaccine and antiviral therapy development, hepatitis B virus (HBV) infection is still the most common cause of liver cirrhosis and hepatocellular carcinoma, with more than 400 million people chronically infected worldwide. Antiviral therapy with nucleos(t)ide analogues and/or immunomodulating peptides is the only option to control and prevent the progression of the disease in chronic hepatitis B (CHB)-infected patients. So far, the current antiviral monotherapy remains unsatisfactory because of the low efficacy and the development of drug resistance mutants. Moreover, viral rebound is frequently observed following therapy cessation, since covalent closed circular DNA (cccDNA) is not removed from hepatocytes by antiviral therapy. First, this review describes the current pharmacotherapy for the management of CHB and the new drug candidates being investigated. Then, the challenges in the development of drug delivery systems for the targeting of antiviral drugs to the liver parenchyma are discussed. Finally, perspectives in the design of a more efficient pharmacotherapy to eradicate the virus from the host are addressed.Fil: Cuestas, María Luján. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mathet, Veronica Lidia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Oubiña, Jose Raul. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Area Virologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sosnik, Alejandro Dario. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Immune Mediators against Toxoplasma Gondii during Reactivation of Toxoplasmic Retinochoroiditis

Purpose: The purpose of this article is to analyze possible associations between systemic and ocular cytokine levels and specific clinical ophthalmologic signs from patients with a reactivation of toxoplasmic retinochoroiditis (RTR). Methods: A total of 18 patients with an active RTR episode, 8 patients with inactive scars, and 14 control patients were included in the study. Serum samples and aqueous humor (AH) samples were analyzed for IFN (interferon)-ã, interleukin (IL)-10, and IL-6 levels by ELISA. Inflammation grade, location, and size of the retinochoroidal active lesion, sampling time, and time to resolution were recorded. Results: A significantly negative correlation between AH and serum levels of IFN-ã was detected (p < 0.05). Patients with an AH IFN-ã/IL-10 ratio lower than 1 were associated with the longest time to resolution and/or severe complications. Conclusion: Serum IFN-ã levels may be used as a prognostic marker for both time to resolution and the development of possible severe complications during a given RTR episode.Fil: Rudzinski, Marcelo Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Catolica de Las Misiones; ArgentinaFil: Argüelles, Carina. Universidad Catolica de Las Misiones; ArgentinaFil: Couto, Cristóbal. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Oubiña, Jose Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Reina, Silvia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Catolica de Las Misiones; Argentin