Telomere and Telomerase in Cancer

The linear ends of chromosome are protected by specialized ribonucleoprotein (RNP) termed as telomere. These specialized terminal elements with tandem repeated sequence are the protective cap that alleviate end replication problem and cell senescence. The telomere length maintenance is essential to avoid cell death and apoptosis. Telomere shortening has been related to chronic stress due to several factors, which include not only psychological stress but also diseases such as cardiovascular diseases and cancer. Telomerase enzyme which maintains telomere length is the major factor responsible for evading cell death. Telomere length maintenance and telomerase expression put together are the prerequisite for immortality, an essential character for cancer cells. Understanding the mechanism of telomere and telomerase functions paves way for eradicating the diseases such as cancer

Mycoremediation of Benzo[a]pyrene by Pleurotus ostreatus in the presence of heavy metals and mediators

Benzo[a]pyrene is considered as a priority pollutant because of its carcinogenic, teratogenic and mutagenic effects. The highly recalcitrant nature of Benzo[a]pyrene poses a major problem for its degradation. White-rot fungi such as Pleurotus ostreatus can degrade Benzo[a]pyrene by enzymes like laccase and manganese peroxidase. The present investigation was carried out to determine the extent of Benzo[a]pyrene degradation by the PO-3, a native isolate of P. ostreatus, in the presence of heavy metals and ligninolytic enzyme mediators. Modified mineral salt medium was supplemented with 5 mM concentration of different heavy metal salts and ethylenediaminetetraacetic acid. Vanillin and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (1 and 5 mM) were used to study the effect of mediators. Results indicated that P. ostreatus PO-3 degraded 71.2 % of Benzo[a]pyrene in the presence of copper ions. Moderate degradation was observed in the presence of zinc and manganese. Both biomass formation and degradation were severely affected in the presence of all other heavy metal salts used in the study. Copper at 15 mM concentration supported the best degradation (74.2 %), beyond which the degradation progressively reduced. Among the mediators, 1 mM 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) supported 78.7 % degradation and 83.6 % degradation was observed under the influence of 5 mM vanillin. Thus, metal ion like copper is essential for better biodegradation of Benzo[a]pyrene. Compared to synthetic laccase mediator like 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate), natural mediator such as vanillin may play a significant role in the degradation of aromatic compounds by white-rot fungi

SCREENING AND PRODUCTION OF ANTICARCINOGENIC ENZYME FROM ESCHERICHIA COLI CTLS20: L - ASPARAGINASE

Objective: The objective of this study was attempted to screen the production of L-asparaginase from bacteria isolated from soil samples and its enzymatic activity.Methods: Screening of L-asparaginase was performed using phenol red indicator growth medium from which the positive strains were chosen based on the colour change. The enzyme production of L-asparaginase was established by submerged fermentation followed by the molecular detection of the efficient bacterial strains.Results: The enzyme production was undertaken by submerged fermentation with the evaluation of enzymatic activity and protein content. This revealed that the strain Escherichia coli CTLS20 produced a higher yield of L-asparaginase (30.22 IU/mg), 16.91 µg/ml of protein with the specific activity of 1.787 IU/mg when compared with other bacterial strains. The efficient bacterial strains were also confirmed by 16S rRNA sequence as Escherichia coli, Acinetobacter baumnnii, Klebsiella pneumoniae and the phylogenetic tree construction revealed the evolutionary relationship of the bacterial strains.Conclusion: This study indicated that the bacterial strain E. coli CTLS20 had the ability for the higher production of L-asparaginase. This novel higher yielding bacterial asparaginase is highly desirable as better alternatives in cancer therapy.Keywords: Soil, L-asparaginase, Submerged fermentation, E. coli, Phylogenetic tre

PRODUCTION AND PURIFICATION OF ANGIOTENSIN-CONVERTING ENZYME INHIBITOR BY SELECTED BACTERIAL STRAIN FOR CANCER THERAPY

Objective: The present study was planned to explore safer, innovative and economic Angiotensin-converting enzyme inhibitors (ACEi) from beef extract by the action of a proteolytic Micrococcus luteus. Cytotoxicity of the stable peptide was predicted using MCF-7 cell line in vitro.Methods: ACEi was purified by sequential steps of ethanol precipitation, ion exchange column chromatography (MonoQ) and gel filtration column chromatography (Sephadex G25). The apparent molecular mass was determined by SDS-PAGE. The anticancer property was analyzed by studying the cytotoxicity effects of angiotensin converting enzyme inhibitor using Breast cancer MCF-7 cell linesResults: The peptide was purified and molecular mass was determined as 4.5 kDa. The IC50 value of peptide was found to be 59.5 µg/ml. The DNA fragmentation was not observed in the treated cells. The purified peptide has demonstrated to induce apoptosis of cancer cell. The results proved that the peptide has the ability to be used for cancer therapy.Conclusion: The presence of ACE inhibition activities in the fermentation of beef extract using Micrococcus luteus has been investigated. The Peptide has been determined as an active compound that inhibited the activity of ACE. These properties indicate the possibilities of the use of purified protein as a potent anticancer agent.Keywords: Angiotensin-converting enzyme inhibitors, Micrococcus luteus, Anti-proliferative, Anti-metastatic, MCF-7 cell line, Anticancer activity

ISOLATION OF ANGIOTENSIN-CONVERTING ENZYME INHIBITOR PRODUCING BACTERIA FROM COW MILK

Objective: To evaluate the potential of protease producing organism for the production of Angiotensin I–converting enzyme (ACE) inhibitor by fermentation of various protein substrates.Methods: Bacterial strains were isolated from cow milk collected in Coimbatore, Tamil Nadu, India by using serial dilution technique, plated on nutrient agar medium. The identity of the strain was ascertained by 16s rRNA gene sequencing method and was submitted to the NCBI GenBank nucleotide database. Various substrates were screened for ACE inhibitor production by the fermentation with the isolated strain.Results: The isolated coded as BUCTL09, which showed a significant zone of clearance was selected and identified as Micrococcus luteus (KF303592.1). Among the seven substrates, only beef extract fermented broth showed an inhibition of 79% and was reported as the best substrate.Conclusion: In the search for non-toxic, and economic ACE inhibitors as an alternative to the synthetic drugs, many natural ACE inhibitors have been isolated from a microbial source. In the present study, isolate BUCTL09 was selected for the production of ACE inhibitor from the beef extract. Findings from this study lead us to investigate this potent ACE inhibitor further for its biological properties and to explore the impending efficacy of the ACE inhibitor which may conceivably be developed into a prospective drug

Molecularly Self-Assembled Nucleic Acid Nanoparticles for Targeted In Vivo siRNA Delivery

Nanoparticles are employed for delivering therapeutics into cells1,2. However, size, shape, surface chemistry and the presentation of targeting ligands on the surface of nanoparticles can affect circulation half-life and biodistribution, cell specific internalization, excretion, toxicity, and efficacy3-7. A variety of materials have been explored for delivering small interfering RNAs (siRNAs) - a therapeutic agent that suppresses the expression of targeted genes8,9. However, conventional delivery nanoparticles such as liposomes and polymeric systems are heterogeneous in size, composition and surface chemistry, and this can lead to suboptimal performance, lack of tissue specificity and potential toxicity10-12. Here, we show that self-assembled DNA tetrahedral nanoparticles with a well-defined size can deliver siRNAs into cells and silence target genes in tumours. Monodisperse nanoparticles are prepared through the self-assembly of complementary DNA strands. Because the DNA strands are easily programmable, the size of the nanoparticles and the spatial orientation and density of cancer targeting ligands (such as peptides and folate) on the nanoparticle surface can be precisely controlled. We show that at least three folate molecules per nanoparticle is required for optimal delivery of the siRNAs into cells and, gene silencing occurs only when the ligands are in the appropriate spatial orientation. In vivo, these nanoparticles showed a longer blood circulation time (t1/2 ∼ 24.2 min) than the parent siRNA (t1/2 ∼ 6 min)

DNA Specificity Determinants Associate with Distinct Transcription Factor Functions

To elucidate how genomic sequences build transcriptional control networks, we need to understand the connection between DNA sequence and transcription factor binding and function. Binding predictions based solely on consensus predictions are limited, because a single factor can use degenerate sequence motifs and because related transcription factors often prefer identical sequences. The ETS family transcription factor, ETS1, exemplifies these challenges. Unexpected, redundant occupancy of ETS1 and other ETS proteins is observed at promoters of housekeeping genes in T cells due to common sequence preferences and the presence of strong consensus motifs. However, ETS1 exhibits a specific function in T cell activation; thus, unique transcriptional targets are predicted. To uncover the sequence motifs that mediate specific functions of ETS1, a genome-wide approach, chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq), identified both promoter and enhancer binding events in Jurkat T cells. A comparison with DNase I sensitivity both validated the dataset and also improved accuracy. Redundant occupancy of ETS1 with the ETS protein GABPA occurred primarily in promoters of housekeeping genes, whereas ETS1 specific occupancy occurred in the enhancers of T cell–specific genes. Two routes to ETS1 specificity were identified: an intrinsic preference of ETS1 for a variant of the ETS family consensus sequence and the presence of a composite sequence that can support cooperative binding with a RUNX transcription factor. Genome-wide occupancy of RUNX factors corroborated the importance of this partnership. Furthermore, genome-wide occupancy of co-activator CBP indicated tight co-localization with ETS1 at specific enhancers, but not redundant promoters. The distinct sequences associated with redundant versus specific ETS1 occupancy were predictive of promoter or enhancer location and the ontology of nearby genes. These findings demonstrate that diversity of DNA binding motifs may enable variable transcription factor function at different genomic sites

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Production of Xylanase by Litter Degrading Fungal Species Using Agro-industrial Wastes as Substrates by Solid State Fermentation

ABSTRACT Xylan is a heterogeneous polysaccharide which are mainly constituted by β-1,4-linked-D-xylopyranose. Xylan forms a main constituent of hemicellulose, a plant polysaccharide. The most important enzyme in the xylan biodegradation is the endo-1, 4-β-xylanase (EC 3.2.1.8) that releases xylopyranose units. Agricultural wastes are found in staggering amounts in our country. These residues represent one of the most energy-rich resources available and when not properly discharged or used, add to environmental pollution. In the present study, thirty fungal species of various genera were isolated from litter soil. The objective of the study is to find the fungus that produces high titres of endo-β-1, 4-xylanase in solid state fermentation using various agro-industrial wastes as substrate. Three fungal species were selected and solid state fermentation was carried out. Aspergillus nidulans and Trichoderma viride produced higher enzyme production of 561.75 U/g and 446.25 U/g respectively when grown on rice bran. Penicillium frequentans produced the highest among the three producers when grown on paddy straw to an extent of 735 U/g. These results indicate that agro-industrial wastes can be used to produce xylanase and thus reduce the risk of environmental pollution