Broad targeting of resistance to apoptosis in cancer

Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer

Mycobacterium tuberculosis Pyrazinamide Resistance Determinants: a Multicenter Study

Pyrazinamide (PZA) is a prodrug that is converted to pyrazinoic acid by the enzyme pyrazinamidase, encoded by the pncA gene in Mycobacterium tuberculosis. Molecular identification of mutations in pncA offers the potential for rapid detection of pyrazinamide resistance (PZA(r)). However, the genetic variants are highly variable and scattered over the full length of pncA, complicating the development of a molecular test. We performed a large multicenter study assessing pncA sequence variations in 1,950 clinical isolates, including 1,142 multidrug-resistant (MDR) strains and 483 fully susceptible strains. The results of pncA sequencing were correlated with phenotype, enzymatic activity, and structural and phylogenetic data. We identified 280 genetic variants which were divided into four classes: (i) very high confidence resistance mutations that were found only in PZA(r) strains (85%), (ii) high-confidence resistance mutations found in more than 70% of PZA(r) strains, (iii) mutations with an unclear role found in less than 70% of PZA(r) strains, and (iv) mutations not associated with phenotypic resistance (10%). Any future molecular diagnostic assay should be able to target and identify at least the very high and high-confidence genetic variant markers of PZA(r); the diagnostic accuracy of such an assay would be in the range of 89.5 to 98.8%

GENETIC CHARACTERISTICS OF INFLUENZA A/H3N2 AND В VIRUSES THAT HAD CIRCULATED IN RUSSIA IN 2013 - 2015

Aim. Establish genetic characteristics, carry out phylogenetic analysis and determination of molecular markers of resistance to etiotropic preparations against influenza A/H3N2 and В viruses that had circulated in Russia in 2013 - 2015. Materials and methods. 80 biological samples containing influenza A/H3N2 virus RNA and 31 samples containing influenza В virus RNA were studied. Sequencing of PCR fragments was carried out in ABI-3100 PRIZMTM GeneticAnalyzer (AppliedBiosystems, USA) and using MiSeq (Illumina, USA). Data treatment and analysis was carried out using CLC v.3.6.5., DNASTAR and BioNumerics v.6.5. programs. Results. In 2013 - 2014 A/Texas/50/2012-like clade 3C.3 influenza A/H3N2 viruses dominated, 10% belonged to subclade 3C.2a and 10% - to ЗС.ЗЬ. Most of the viruses (81%) of 2014 - 2015 were of 3C.2a clade, the portion of viruses belonging to ЗС.ЗЬ and ЗС.За was 9 and 10%. Yamagata-like viruses predominated among the studied influenza В viruses, only 1 virus of 2014 - 2015 belonged to Victoria lineage, 1 reassortant of Yamagata and Victoria lineages was detected. Rimantadine-resistance mutation S31N (М2 protein) was detected in all the influenza A/H3N2 viruses. Mutations determining resistance to oseltamivir (NA gene) were not detected in influenza A/H3N2 and В viruses. Conclusion. Increase of influenza morbidity in 2014 - 2015 was determined by the emergence of influenza A/H3N2 and В viruses, antigenically distinct from those that had circulated previously and those included into the vaccine, thus resulting in the WHO decision to change А/ H3N2 and В components of the 2015 - 2016 vaccine. Simultaneous circulation of 2 lineages of influenza В virus and emergence of their reassortants gives evidence on the necessity of use of quadrivalent vaccines, containing both lineages

The Study of Viral RNA Diversity in Bird Samples Using De Novo Designed Multiplex Genus-Specific Primer Panels

Advances in the next generation sequencing (NGS) technologies have significantly increased our ability to detect new viral pathogens and systematically determine the spectrum of viruses prevalent in various biological samples. In addition, this approach has also helped in establishing the associations of viromes with many diseases. However, unlike the metagenomic studies using 16S rRNA for the detection of bacteria, it is impossible to create universal oligonucleotides to target all known and novel viruses, owing to their genomic diversity and variability. On the other hand, sequencing the entire genome is still expensive and has relatively low sensitivity for such applications. The existing approaches for the design of oligonucleotides for targeted enrichment are usually involved in the development of primers for the PCR-based detection of particular viral species or genera, but not for families or higher taxonomic orders. In this study, we have developed a computational pipeline for designing the oligonucleotides capable of covering a significant number of known viruses within various taxonomic orders, as well as their novel variants. We have subsequently designed a genus-specific oligonucleotide panel for targeted enrichment of viral nucleic acids in biological material and demonstrated the possibility of its application for virus detection in bird samples. We have tested our panel using a number of collected samples and have observed superior efficiency in the detection and identification of viral pathogens. Since a reliable, bioinformatics-based analytical method for the rapid identification of the sequences was crucial, an NGS-based data analysis module was developed in this study, and its functionality in the detection of novel viruses and analysis of virome diversity was demonstrated