Nelfinavir, an HIV-1 Protease Inhibitor, Induces Oxidative Stress–Mediated, Caspase-Independent Apoptosis in Leishmania Amastigotes

Visceral leishmaniasis is the most severe form of disease caused by the parasite Leishmania. It is a major concern in South America, Africa, India and the Middle East. Additionally, it has now emerged as an important opportunistic disease in patients coinfected with HIV-1. This is due, in part, to the increasing overlap between urban centers and rural areas endemic for Leishmania. Although more efficient combinatorial antiviral drug regimens for treating HIV-1 infection have been developed, the impact of such therapies on HIV-1/Leishmania coinfection is yet to be explored. In this study, we investigated the effect of nelfinavir, a well-characterized anti-HIV-1 drug, on Leishmania. Treating the parasite with nelfinavir activates events that are hallmarks of programmed cell death (also called apoptosis). Among these are oxidative stress, changes in DNA replication and fragmentation, and release of mitochondrial enzymes. Furthermore, these events occur without the participation of caspases, which are classically linked to apoptosis; however, this atypical apoptosis requires the translocation of endonuclease G from mitochondria to the cytoplasm. These findings provide insights for the design of new anti-parasitic therapies, particularly in the case of Leishmania/HIV-1 coinfections

Gene expression profile in human prostate cancer cell lines

Since the beginning of this work in 1998, it is estimated that 1780 men died of prostate cancer in Quebec. Molecular analysis of prostate cancer will eventually lead to the discovery of key genes involved in its onset and progression. The present project was to compare gene expression profiles in human non-tumorigenic versus tumorigenic prostate cell lines generated in our laboratory. A putative tumor suppressor gene present on 12q13 would be responsible for the non-tumorigenic phenotype of one cell line as discovered earlier by our team.In order to compare gene expression patterns, expression arrays from Clontech, bearing 588 genes known to be involved in human cancers, were hybridized with cDNA derived from two related cell lines available in our laboratory. This one experiment provided interesting hints on differentially expressed genes that could be involved in human prostate cancer. Interesting clones were confirmed by Northern blots. When commercial antibody was available, analysis was extended at the protein level. A combination of these analyses revealed no striking difference in the level of expression for the genes previously identified by the arrays hybridization.Simultaneously, differential display PCR techniques, allowing the discovery of unknown differentially expressed molecules and thus complementing the previous approach, were applied to compare related cell lines and unique hybrids. Cloning and sequencing of differential fragments brought us to what could be a new cDNA expressed in many human cell lines.Prostate cancer is not well characterized enough to allow accurate diagnosis or appropriate therapy strategies. Differentially expressed molecules analyzed in this project as well as the putative new cDNA might fulfil part of this lack in the understanding of this disease

Poétiques de la Liste et Imaginaire Sériel dans les Lettres (XXe et XXIe siècles)

Sixteen researchers from Quebec, the United States, Belgium, France, the United Kingdom, Switzerland and Australia are wondering here about the poetics of the list - and by extension on the enumeration, the series, litany, inventory, collection, etc. - in French and French contemporary literature. On the program (in bulk): the list and the sciences; the list and the doubt; the list and the animal; the list and the name; list and encyclopedism; the list and the writing of oneself; the list and the story; the list and the constraint; the list and the voice; the list and the museum; the list and the ruins; the list and idiocy; the list and the Tour de France; the list and the policy; list and syntax; the list and the time; the list and the daily; the list and the comic strip; the list and the scene; the list and dada; the list and the real. -- publisherhttps://digitalcommons.bucknell.edu/books/1052/thumbnail.jp

Intracellular survival of Leishmania species that cause visceral leishmaniasis is significantly reduced by HIV-1 protease inhibitors

Visceral leishmaniasis is now recognized as an opportunistic disease in individuals infected with human immunodeficiency virus type 1 (HIV-1). Although the usefulness of HIV-1 protease inhibitors (PIs) in antiretroviral regimens is well documented, little is known about their potential impact in the setting of Leishmania/HIV-1 coinfections. We now report that, although selected PIs do not inhibit the growth of Leishmania infantum promastigotes alone in culture, these drugs significantly inhibit the intracellular survival of parasites in phorbol myristate acetate-differentiated THP-1 macrophages and human primary monocyte-derived macrophages (MDMs). Furthermore, a field isolate of Leishmania donovani resistant to sodium stibogluconate (SbV), one of the drugs most commonly used to treat leishmaniasis, is equally susceptible to the tested PIs compared with a sensitive strain, thus suggesting that resistance to SbV does not result in cross-resistance to PIs. Importantly, the efficacy of PIs to reduce the intracellular growth of Leishmania parasites is also observed inMDMscoinfected with HIV-1

Identification of Morphologic Criteria Associated with Biochemical Recurrence in Intraductal Carcinoma of the Prostate

Intraductal carcinoma of the prostate (IDC-P) is an aggressive subtype of prostate cancer strongly associated with an increased risk of biochemical recurrence (BCR). However, approximately 40% of men with IDC-P remain BCR-free five years after radical prostatectomy. In this retrospective multicenter study, we aimed to identify histologic criteria associated with BCR for IDC-P lesions. A total of 108 first-line radical prostatectomy specimens were reviewed. In our test cohort (n = 39), presence of larger duct size (>573 µm in diameter), cells with irregular nuclear contours (CINC) (≥5 CINC in two distinct high-power fields), high mitotic score (>1.81 mitoses/mm2), blood vessels, and comedonecrosis were associated with early BCR (p n = 69), the presence of CINC or blood vessels was independently associated with an increased risk of BCR (hazard ratio [HR] 2.32, 95% confidence interval [CI] 1.09–4.96, p = 0.029). When combining the criteria, the presence of any CINC, blood vessels, high mitotic score, or comedonecrosis showed a stronger association with BCR (HR 2.74, 95% CI 1.21–6.19, p = 0.015). Our results suggest that IDC-P can be classified as low versus high-risk of BCR. The defined morphologic criteria can be easily assessed and should be integrated for clinical application following validation in larger cohorts

Modulation of gene expression in Leishmania drug resistant mutants as determined by targeted DNA microarrays

In the protozoan parasite Leishmania, drug resistance can be a complex phenomenon. Several metabolic pathways and membrane transporters are implicated in the resistance phenotype. To monitor the expression of these genes, we generated custom DNA microarrays with PCR fragments corresponding to 44 genes involved with drug resistance. Transcript profiling of arsenite and antimony resistant mutants with these arrays pinpointed a number of genes overexpressed in mutants, including the ABC transporter PGPA, the glutathione biosynthesis genes γ-glutamylcysteine synthetase (GSH1) and the glutathione synthetase (GSH2). Competitive hybridisations with total RNA derived from sensitive and methotrexate resistant cells revealed the overexpression of genes coding for dihydrofolate reductase (DHFR-TS), pteridine reductase (PTR1) and S-adenosylmethionine synthase (MAT2) and a down regulation of one gene of the folate transporter (FT) family. By labelling the DNA of sensitive and resistant parasites we could also detect several gene amplification events using DNA microarrays including the amplification of the S-adenosyl homocysteine hydrolase gene (SAHH). Alteration in gene expression detected by microarrays was validated by northern blot analysis, while Southern blots indicated that most genes overexpressed were also amplified, although other mechanisms were also present. The microarrays were useful in the study of resistant parasites to pinpoint several genes linked to drug resistance

GSH1 overexpression suppresses NFV-induced cell death in parasites.

<p>Stably transfected <i>L. infantum</i> strains carrying either the empty control vector Pspαzeoα (i.e. Li-pSP) or the GSH1-encoding vector PspαzeoαGSH1 were exposed to NFV (40 µM) for 24 h. Cell death was measured in terms of DNA degradation. Light gray bars refer to untreated parasites, whereas black bars relate to NFV-treated parasites (<i>n</i> = 3) (***, <i>P</i><0.001).</p

NFV induces an increase in the sub-G1 DNA-containing population.

<p>The DNA content degradation profiles of drug-sensitive and NFV-resistant axenic amastigotes (i.e. usually maintained under a constant drug pressure of 12.5 µM), which were either left untreated or treated with NFV (10 µM), were assessed by flow cytometry after cell permeabilisation and PI staining. DNA fragmentation was quantified by measuring the cell population in the sub-G1 DNA region indicated by M1 and G1 DNA peak indicated by M2. The data shown are representative of three independent experiments.</p