Toll-interacting protein may affect doxorubicin resistance in hepatocellular carcinoma cell lines

BACKGROUND

Liver cancer is the third leading cause of cancer-related deaths worldwide, and hepatocellular carcinoma (HCC) is the most common type of liver cancer. Transarterial interventions are among the chemotherapeutic approaches used in hardly operable regions prior to transplantation, and in electrochemotherapy, where doxorubicin is used. However, the efficacy of treatment is affected by resistance mechanisms. Previously, we showed that overexpression of the CUE5 gene results in doxorubicin resistance in Saccharomyces cerevisiae (S. cerevisiae). In this study, the effect of Toll-interacting protein (TOLLIP), the human ortholog of CUE5, on doxorubicin resistance was evaluated in HCC cells to identify its possible role in increasing the efficacy of transarterial interventions.

METHODS AND RESULTS

The NIH Gene Expression Omnibus (GEO) and Oncomine datasets were analyzed for HCC cell lines with relatively low and high TOLLIP expression, and SNU449 and Hep3B cell lines were chosen, respectively. TOLLIP expression was increased by plasmid transfection and decreased by TOLLIP-siRNA in both cell lines and evaluated by RT-PCR and ELISA. Cell proliferation and viability were examined using xCELLigence and MTT assays after doxorubicin treatment, and growth inhibitory 50 (GI 50) concentrations were evaluated. Doxorubicin GI 50 concentrations decreased approximately 2-folds in both cell lines upon silencing TOLLIP after 48 h of drug treatment.

CONCLUSIONS

Our results showed for the first time that silencing TOLLIP in hepatocellular carcinoma cells may help sensitize these cells to doxorubicin and increase the efficacy of chemotherapeutic regimens where doxorubicin is used.

Implications of Possible HBV-Driven Regulation of Gene Expression in Stem Cell-like Subpopulation of Huh-7 Hepatocellular Carcinoma Cell Line

Elevated levels of STIM1, an endoplasmic reticulum Ca²⁺ sensor/buffering protein, appear to be correlated with poor cancer prognosis in which microRNAs are also known to play critical roles. The purpose of this study is to investigate possible HBV origins of specific microRNAs we identified in a stem cell-like subpopulation of Huh-7 hepatocellular carcinoma (HCC) cell lines with enhanced STIM1 and/or Orai1 expression that mimicked poor cancer prognosis. Computational strategies including phylogenetic analyses were performed on miRNome data we obtained from an EpCAM- and CD133-expressing Huh-7 HCC stem cell-like subpopulation with enhanced STIM1 and/or Orai1 expression originally cultured in the present work. Results revealed two putative regions in the HBV genome based on the apparent clustering pattern of stem loop sequences of microRNAs, including miR3653. Reciprocal analysis of these regions identified critical human genes, of which their transcripts are among the predicted targets of miR3653, which was increased significantly by STIM1 or Orai1 enhancement. Briefly, this study provides phylogenetic evidence for a possible HBV-driven epigenetic remodeling that alters the expression pattern of Ca²⁺ homeostasis-associated genes in STIM1- or Orai1 overexpressing liver cancer stem-like cells for a possible mutual survival outcome. A novel region on HBV-X protein may affect liver carcinogenesis in a genotype-dependent manner. Therefore, detection of the viral genotype would have a clinical impact on prognosis of HBV-induced liver cancers.

Analysis of Three Mutations in Italian Strains of SARS-CoV-2: Implications for Pathogenesis

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an enveloped virus initially detected in Wuhan in December 2019, responsible for coronavirus disease 2019 (COVID-19), a respiratory syndrome currently affecting >220 countries around the world, with >80 million cases registered and >1.8 million deaths.

Objective

As several vaccines are still being developed and 2 have been approved, it is particularly important to perform evolutionary surveillance to identify mutations potentially affecting vaccine efficacy.

Methods

DynaMut server has been used to evaluate the impact of the mutation found on SARS-CoV-2 isolates available on GISAID.

Results

In this article, we analyze whole genomes sequenced from Italian patients, and we report the characterization of 3 mutations, one of which presents in the spike protein.

Conclusion

The mutations analyzed in this article can be useful to evaluate the evolution of SARS-CoV-2.

Questioning How to Define the "Ultra-High-Risk" Subgroup of Neuroblastoma Patients

Neuroblastic tumours exhibit heterogeneity, which results in different therapeutic outcomes. Neuroblastoma is categorized into three major risk groups (low, intermediate, high risk). Recent identification of new genes raised the possibility of new biomarkers to identify sub-risk groups. In this retrospective cross-sectional study, we aimed to assess new biomarkers defining the ultra-high-risk subgroup within the high-risk group that differ in clinical situation with very bad prognosis. Twenty-five low- and 29 high-risk groups of patients were analysed for their expression of ALK, ATRX, HIF1a, HIF2a (EPAS), H2AFX, and ETV5 genes at the RNA level. Immunohistochemistry was performed to confirm the protein expression level of ALK. The risk group of patients was determined according to the International Neuroblastoma Risk Group Stratification System. Spearman correlation analysis and Mann-Whitney-U nonparametric test were used to assess the importance of expression levels among the groups. P < 0.05 was considered as significant. Sensitivity of the results was checked by ROC curve analysis. All analysed genes were found to be highly expressed in the high-risk group compared to the low-risk group, except for ETV5. When the ultra-high-risk and highrisk groups were compared, ALK was found to be highly expressed in the ultra-high-risk group. Our results show that ALK may be a candidate gene whose mRNA expression levels can distinguish the ultrahigh- risk subgroup of patients in the high-risk group of patients with non-familial neuroblastoma.

Evidence for mutations in SARS-CoV-2 Italian isolates potentially affecting virus transmission

Italy is the first western country suffering heavy severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) transmission and disease impact after coronavirus disease‐2019 pandemia started in China. Even though the presence of mutations on spike glycoprotein and nucleocapsid in Italian isolates has been reported, the potential impact of these mutations on viral transmission has not been evaluated. We have compared SARS‐CoV‐2 genome sequences from Italian patients with virus sequences from Chinese patients. We focussed upon three nonsynonymous mutations of genes coding for S(one) and N (two) viral proteins present in Italian isolates and absent in Chinese ones, using various bioinformatics tools. Amino acid analysis and changes in three‐dimensional protein structure suggests the mutations reduce protein stability and, particularly for S1 mutation, the enhanced torsional ability of the molecule could favor virus binding to cell receptor(s). This theoretical interpretation awaits experimental and clinical confirmation.

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two highly prevalent mutation have been developed by SARS‐CoV‐2, one on the Spike glycoprotein and one on the Nucleocapsid protein

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The enhanced torsional ability of Spike protein could favor virus binding to human cell receptors

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mutations on the Nucleocapsid region could influence the modulation of a number of virus properties, including cell signaling

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the study of SARS‐CoV‐2 mutations could be important for vaccines developmen

Migrants rescued on the Mediterranean Sea route: nutritional, psychological status and infectious disease control

INTRODUCTION

North Africa has become a key migratory hub where a large number of migrants attempt the journey by sea from the Libyan coastline to the south of Europe. In this humanitarian disaster scenario, the Mediterranean route has been one of the most used by illegal boats.

METHODOLOGY

In this report, the state of physical and psychological health of a cluster of Eritrean migrants, escaped from Libya and rescued in the Mediterranean Sea after a shipwreck, was described by epidemiological, clinical and laboratory investigations.

RESULTS

Data suggest that despite the majority  of the migrants being apparently in good health upon a syndromic surveillance approach, most of them suffered a decline in psychological status as well as severe malnutrition. The emergence of infectious diseases, related to poor living conditions during the journey, is not a rare event.

CONCLUSION

The present report highlights the risks of failures of the syndromic medical approach in the setting of the extremely challenging migration route and underlines migrant frailties consequent to a prolonged journey and long period of detention. These stressors, which can degrade the initial health condition of traveling migrants, can lead to a premature "exhausted migrant effect" that should be carefully investigated in order to avoid the early emergence of diseases related to frailty.

Linking Peroxiredoxin and Vacuolar-ATPase Functions in Calorie Restriction-Mediated Life Span Extension

Calorie restriction (CR) is an intervention extending the life spans of many organisms. The mechanisms underlying CR-dependent retardation of aging are still poorly understood. Despite mechanisms involving conserved nutrient signaling pathways proposed, few target processes that can account for CR-mediated longevity have so far been identified. Recently, both peroxiredoxins and vacuolar-ATPases were reported to control CR-mediated retardation of aging downstream of conserved nutrient signaling pathways. In this review, we focus on peroxiredoxin-mediated stress-defence and vacuolar-ATPase regulated acidification and pinpoint common denominators between the two mechanisms proposed for how CR extends life span. Both the activities of peroxiredoxins and vacuolar-ATPases are stimulated upon CR through reduced activities in conserved nutrient signaling pathways and both seem to stimulate cellular resistance to peroxide-stress. However, whereas vacuolar-ATPases have recently been suggested to control both Ras-cAMP-PKA- and TORC1-mediated nutrient signaling, neither the physiological benefits of a proposed role for peroxiredoxins in H2O2-signaling nor downstream targets regulated are known. Both peroxiredoxins and vacuolar-ATPases do, however, impinge on mitochondrial iron-metabolism and further characterization of their impact on iron homeostasis and peroxide-resistance might therefore increase our understanding of the beneficial effects of CR on aging and age-related diseases.

Identification of respiratory chain gene mutations that shorten replicative life span in yeast

Aging is the progressive accumulation of alterations in cells that elevates the risk of death. The mitochondrial theory of aging postulates that free radicals produced by the mitochondrial respiratory system contribute to the aging process. However, the roles of individual electron transfer chain (ETC) components in cellular aging have not been elucidated. In this study, we analyzed the replicative life span of 73 yeast deletion mutants lacking the genes of the mitochondrial electron transfer chain system, and found that nine of these mutants (Δnde1, Δtcm62, Δrip1, Δcyt1, Δqrc8, Δpet117, Δcox11, Δatp11, Δfmc1) had significantly shorter life spans. These mutants had lower rates of respiration and were slightly sensitive to exogenous administration of hydrogen peroxide. However, only two of them, Δnde1 and Δfmc1, produced higher amounts of intrinsic superoxide radicals in the presence of glucose compared to that of wild type cells. Interestingly, there were no significant alterations in the mitochondrial membrane potentials of these mutants. We speculate that the shorter life spans of ETC mutants result from multiple mechanisms including the low respiration rate and low energy production rather than just a ROS-dependent path.

Assessment of chronological lifespan dependent molecular damages in yeast lacking mitochondrial antioxidant genes

The free radical theory of aging states that oxidative damage to biomolecules causes aging and that antioxidants neutralize free radicals and thus decelerate aging. Mitochondria produce most of the reactive oxygen species, but at the same time have many antioxidant enzymes providing protection from these oxidants. Expecting that cells without mitochondrial antioxidant genes would accumulate higher levels of oxidative damage and, therefore, will have a shorter lifespan, we analyzed oxidative damages to biomolecules in young and chronologically aged mutants lacking the mitochondrial antioxidant genes: GRX2, CCP1, SOD1, GLO4, TRR2, TRX3, CCS1, SOD2, GRX5, and PRX1. Among these mutants, ccp1Δ, trx3Δ, grx5Δ, prx1Δ, mutants were sensitive to diamide, and ccs1Δ and sod2Δ were sensitive to both diamide and menadione. Most of the mutants were less viable in stationary phase. Chronologically aged cells produced higher amount of superoxide radical and accumulated higher levels of oxidative damages. Even though our results support the findings that old cells harbor higher amount of molecular damages, no significant difference was observed between wild type and mutant cells in terms of their damage content.