Limosilactobacillus fermentum, Lactococcus lactis and Thomasclavelia ramosa are enriched and Methanobrevibacter smithii is depleted in patients with non-alcoholic steatohepatitis.

Non-alcoholic fatty liver (NAFLD), and its complicated form, non-alcoholic steatohepatitis (NASH), have been associated with gut dysbiosis with specific signatures. Endogenous ethanol production by Klebsiella pneumoniae or yeasts has been identified as a potential physio-pathological mechanism. A species-specific association between Lactobacillus and obesity and metabolic diseases has been reported. In this study, the microbial composition of ten cases of NASH and ten controls was determined using v3v4 16S amplicon sequencing as well as quantitative PCR (qPCR). Using different statistical approaches, we found an association of Lactobacillus and Lactoccocus with NASH, and an association of Methanobrevibacter, Faecalibacterium and Romboutsia with controls. At the species level, Limosilactobacillus fermentum and Lactococcus lactis, two species producing ethanol, and Thomasclavelia ramosa, a species already associated with dysbiosis, were associated with NASH. Using qPCR, we observed a decreased frequency of Methanobrevibacter smithii and confirmed the high prevalence of L. fermentum in NASH samples (5/10), while all control samples were negative (p = 0.02). In contrast, Ligilactobacillus ruminis was associated with controls. This supports the critical importance of taxonomic resolution at the species level, notably with the recent taxonomic reclassification of the Lactobacillus genus. Our results point towards the potential instrumental role of ethanol-producing gut microbes in NASH patients, notably lactic acid bacteria, opening new avenues for prevention and treatment.

Description of Agathobaculum massiliense sp. nov., a new bacterial species prevalent in the human gut and predicted to produce indole and tryptophan based on genomic analysis.

The novel bacterial strain Marseille-P4005T was isolated from the stool sample of a healthy donor. It is a Gram-stain negative, non-motile, non-spore-forming rod. It grew optimally at 37 °C and at pH 7.0 on 5% sheep blood-enriched Columbia agar after preincubation in a blood-culture bottle supplemented with rumen and blood. This strain does not ferment monosaccharides (except D-tagatose), disaccharides, or polymeric carbohydrates. The major cellular fatty acids were hexadecenoic (24.6%), octadecanoic (22.8%), and tetradecanoic (20.1%) acids. Next-generation sequencing revealed a genome size of 3.2 Mbp with a 56.4 mol% G + C. Phylogenetic analysis based on the 16S rRNA gene highlighted Agathobaculum desmolans strain ATCC 43058T as the closest related strain. The OrthoANI, AAI, and digital DNA-DNA hybridization values were below the critical thresholds of 95%, 95-96%, and 70%, respectively, to define a novel bacterial species. Antibiotic resistance genes APH(3')-IIIa, erm(B), and tet(W) were detected with high identity percentages of 100%, 98.78%, and 97.18% for each gene, respectively. The APH(3')-IIIa gene confers resistance to amikacin, erm(B) gene confers resistance to erythromycin, lincomycin, and clindamycin, while tet(W) gene confers resistance to doxycycline and tetracycline. Based on KEGG BlastKOALA analyses, the annotation results showed that our strain could use glucose to produce L-lactate and pyruvate but not acetate or ethanol. Also, strain Marseille-P4005T was predicted to use phenylalanine to produce indole, a major intercellular signal molecule within the gut microbial ecosystem. Through having a gene coding for tryptophan synthase beta chain (trpB), strain Marseille-P4005T could produce L-tryptophan (an essential amino acid) from indole. Strain Marseille-P4005T showed its highest prevalence in the human gut (34.19%), followed by the reproductive system (17.98%), according to a query carried out on the Integrated Microbial NGS (IMNGS) platform. Based on phylogenetic, phenotypic, and genomic analyses, we classify strain Marseille-P4005T (= CSUR P4005 = CECT 9669), a novel species within the genus Agathobaculum, for which the name of Agathobaculum massiliense sp. nov. is proposed.

Draft genome and description of Cohnella massiliensis sp. nov., a new bacterial species isolated from the blood culture of a hemodialysis patient.

Strain 6021052837T was isolated from the blood culture of a hemodialysis patient on Chocolat PolyViteX medium at 37 °C after 2 days of incubation. Colonies could not be identified by our systematic MALDI-TOF Mass Spectrometry screening. The16S rRNA gene sequencing showed that the strain had 96% sequence identity with Cohnella formosensis (Genbank accession number JN806384), the phylogenetic closely related type strain of a species with standing in nomenclature, which putatively classifies it as a new species. The colonies cultivated on Columbia agar with 5% sheep blood medium at 37 °C after 24 h of incubation, are white pigmented, their size varied from 1.5 to 2 mm in diameter. Strain 6021052837T is an aerobic, Gram-negative, motile, spore forming rod, which cannot grow microaerophilically or under anaerobic conditions. The major fatty acids are branched saturated fatty acids: 14-methyl-pentadecanoic acid (34%) and 12-methyl-tetradecanoic acid (31%). The 6.328 Mb long genome, composed of 25 contigs, has a G+C content of 57.24%. Out of the 5710 predicted genes, 5646 were protein-coding genes and 64 were RNAs. A total of 3239 genes (57.37%) were assigned as putative function (by COGs) and 288 genes were identified as ORFans (5.1%). Average genomic identity of orthologous gene sequences (AGIOS) of strain 6021052837T against genomes of the type strains of related species ranged between 58.26 and 79.63%, respectively. According to our taxonogenomics results, we propose the creation of Cohnella massiliensis sp. nov. that contains the type strain 6021052837T (= CSUR P2659, =DSM103435).

Description and genomic characterization of Massiliimalia massiliensis gen. nov., sp. nov., and Massiliimalia timonensis gen. nov., sp. nov., two new members of the family Ruminococcaceae isolated from the human gut.

Using the culturomics approach, we isolated two strains, Marseille-P2963 and Marseille-P3753, from the intestinal microbiota of a 19-year-old healthy Saudi Arabian Bedouin male and from a 32-year-old healthy Senegalese male faecal transplant donor. Here, we studied their phenotypic, phylogenetic and genomic characteristics. Both strains were phylogenetically related, but different from Ruminococcus species. Bacterial cells were anaerobic, rod-shaped, non-spore-forming and not motile, with neither catalase nor oxidase activities. Their growth temperatures ranged from 28 to 45 °C, with an optimal growth at 37 °C. The genomes are 2,842,720 bp- and 2,707,061 bp-long respectively. The G + C contents are 47.18% and 46.90%, respectively. Based on these characteristics, we propose the creation of a new genus within the family Ruminococcaceae named Massiliimalia gen. nov., that contains the new species Massiliimalia massiliensis gen. nov., sp. nov., and Massiliimalia timonensis gen. nov., sp. nov. Strains Marseille-P2963T (= CSUR P2963 = DSM 106837) and Marseille-P3753T (= CSUR P3753 = CCUG 71632) are their type strains, respectively.

Genome sequence and description of Haloferax massiliense sp. nov., a new halophilic archaeon isolated from the human gut.

By applying the culturomics concept and using culture conditions containing a high salt concentration, we herein isolated the first known halophilic archaeon colonizing the human gut. Here we described its phenotypic and biochemical characterization as well as its genome annotation. Strain Arc-HrT (= CSUR P0974 = CECT 9307) was mesophile and grew optimally at 37 °C and pH 7. Strain Arc-HrT was also extremely halophilic with an optimal growth observed at 15% NaCl. It showed gram-negative cocci, was strictly aerobic, non-motile and non-spore-forming, and exhibited catalase and oxidase activities. The 4,015,175 bp long genome exhibits a G + C% content of 65.36% and contains 3911 protein-coding and 64 predicted RNA genes. PCR-amplified 16S rRNA gene of strain Arc-HrT yielded a 99.2% sequence similarity with Haloferax prahovense, the phylogenetically closest validly published species in the Haloferax genus. The DDH was of 50.70 ± 5.2% with H. prahovense, 53.70 ± 2.69% with H. volcanii, 50.90 ± 2.64% with H. alexandrinus, 52.90 ± 2.67% with H. gibbonsii and 54.30 ± 2.70% with H. lucentense. The data herein represented confirm strain Arc-HrT as a unique species and consequently we propose its classification as representative of a novel species belonging to the genus Haloferax, as Haloferax massiliense sp. nov.

Characterization of a New Ezakiella Isolated from the Human Vagina: Genome Sequence and Description of Ezakiella massiliensis sp. nov.

The study of the vaginal microbiota using the "culturomics concept" allowed us to isolate, from the vaginal swab of an asymptomatic 20-year-old woman who had sexual relations with another woman with bacterial vaginosis, an unknown Gram-positive anaerobic coccus-shaped bacterium that was designated strain Marseille-P2951T and characterized using taxono-genomics. Strain Marseille-P2951T is non-motile and non-spore forming and exhibits catalase and oxidase activities. Its 16S rRNA gene-based identification showed 98.5% identity with Ezakiella peruensis, the phylogenetically closest species. The major fatty acids are C18:1n9 (58%) and C16:0 (22%). With a 1,741,785 bp length, the G+C content of the genome is 36.69%. Of a total of 1657 genes, 1606 are protein-coding genes and 51 RNAs. Also, 1123 genes are assigned a putative function and 127 are ORFans. Phenotypic, phylogenetic, and genomics analyses revealed that strain Marseille-P2951T (=CSUR P2951 =DSM 103122) is distinct and represents a new species of the genus Ezakiella, for which the name Ezakiella massiliensis sp. nov. is proposed.

Inediibacterium massiliense gen. nov., sp. nov., a new bacterial species isolated from the gut microbiota of a severely malnourished infant.

A novel strain, Mt12T (=CSUR P1907 = DSM 100590), was isolated from the fecal sample of a 7-month-old girl from Senegal afflicted with severe acute malnutrition. This bacterium is a strictly anaerobic, spore-forming Gram-stain positive bacillus. The major cellular fatty acid was identified as tetradecanoic acid. Its 16S rRNA gene sequence exhibited 94.9% similarity with that of Crassaminicella profunda strain Ra1766HT, currently the closest species with a validly published name. The draft genome of strain Mt12T is 3,497,275-bp long with a 30.45% of G+C content. 3397 genes were predicted, including 3268 protein-coding genes and 129 RNAs, including eight 16S rRNAs. Genomic comparison with closely related species with an available genome showed a lower quantitative genomic content. The phylogenetic analysis alongside the dDDH values under 30% and phenotypic characteristics suggest that strain Mt12T represents a new genus within the family Clostridiaceae, for which the name Inediibacterium massiliense gen. nov., sp. nov. is proposed.

The functional landscape of Hsp27 reveals new cellular processes such as DNA repair and alternative splicing and proposes novel anticancer targets.

Previously, we identified the stress-induced chaperone, Hsp27, as highly overexpressed in castration-resistant prostate cancer and developed an Hsp27 inhibitor (OGX-427) currently tested in phase I/II clinical trials as a chemosensitizing agent in different cancers. To better understand the Hsp27 poorly-defined cytoprotective functions in cancers and increase the OGX-427 pharmacological safety, we established the Hsp27-protein interaction network using a yeast two-hybrid approach and identified 226 interaction partners. As an example, we showed that targeting Hsp27 interaction with TCTP, a partner protein identified in our screen increases therapy sensitivity, opening a new promising field of research for therapeutic approaches that could decrease or abolish toxicity for normal cells. Results of an in-depth bioinformatics network analysis allying the Hsp27 interaction map into the human interactome underlined the multifunctional character of this protein. We identified interactions of Hsp27 with proteins involved in eight well known functions previously related to Hsp27 and uncovered 17 potential new ones, such as DNA repair and RNA splicing. Validation of Hsp27 involvement in both processes in human prostate cancer cells supports our system biology-predicted functions and provides new insights into Hsp27 roles in cancer cells.

Anaerococcus rubiinfantis sp. nov., isolated from the gut microbiota of a Senegalese infant with severe acute malnutrition.

Anaerococcus rubiinfantis sp. nov. strain mt16(T) is a new species within the genus Anaerococcus, which was isolated by the culturomics approach from the gut microbiota of an infant suffering from kwashiorkor. A phenotypic, biochemical and proteomic description of this strain is hereby presented alongside a complete annotation of its genome. This strictly anaerobic species forms Gram-positive non-sporeforming cocci. The major fatty acid was hexadecanoic acid. The phylogenetic analysis of strain mt16(T) showed a 97.9% similarity level with Anaerococcus vaginalis, the closest validly published species. Its genome is 1,929,161 bp long with 29.5% G + C content and contains 1808 protein-coding genes and 56 RNA genes, among which are six rRNA genes. Genomic analysis identified 41/1864 coding genes as ORFans (2.2%) and at least 620/1808 (34.9%) orthologous proteins which are not shared with the closest phylogenetic species. We believe that the extension of the human anaerobic gut compendium by culturomics is one of the first steps that will improve the understanding of the links between the microbiome and health or disease.

Targeting TCTP as a new therapeutic strategy in castration-resistant prostate cancer.

Heat shock protein 27 (Hsp27) is highly overexpressed in castration-resistant prostate cancer (CRPC) and an antisense inhibitor (OGX-427) is currently in phase II clinical trials. In order to understand mechanisms of action of Hsp27 and find new therapeutic targets specific of CRPC, we screened for Hsp27 client proteins. Here, we report that translationally controlled tumor protein (TCTP) is a new Hsp27 client protein involved in Hsp27 cytoprotection. We found that TCTP expression is absent or weak in normal prostate cells, moderately expressed in 18.5% of treatment naive PC, and becomes uniformly and strongly expressed in 75% of CRPC. To define TCTP function, we developed and worldwide patented a TCTP antisense oligonucleotide (ASO). Interestingly, we found that CRPC progression correlates with TCTP overexpression and loss of P53. TCTP knockdown restored P53 expression and function, suggesting that castration-sensitivity is directly linked to P53 expression. Collectively, these findings provide a new Hsp27 cytoprotection mechanism in CRPC, and preclinical proof-of-concept that combining ASO-mediated TCTP knockdown with castration and/or docetaxel therapy could serve as a novel strategy to treat CRPC, with no or little toxicity for normal prostate cells.

Ethanol-Producing Enterocloster bolteae Is Enriched in Chronic Hepatitis B-Associated Gut Dysbiosis: A Case-Control Culturomics Study.

BACKGROUND: Hepatitis B virus (HBV) infection is a global health epidemic that causes fatal complications, leading to liver cirrhosis and hepatocellular carcinoma. The link between HBV-related dysbiosis and specific bacterial taxa is still under investigation. Enterocloster is emerging as a new genus (formerly Clostridium), including Enterocloster bolteae, a gut pathogen previously associated with dysbiosis and human diseases such as autism, multiple sclerosis, and inflammatory bowel diseases. Its role in liver diseases, especially HBV infection, is not reported. METHODS: The fecal samples of eight patients with chronic HBV infection and ten healthy individuals were analyzed using the high-throughput culturomics approach and compared to 16S rRNA sequencing. Quantification of ethanol, known for its damaging effect on the liver, produced from bacterial strains enriched in chronic HBV was carried out by gas chromatography-mass spectrometry. RESULTS: Using culturomics, 29,120 isolated colonies were analyzed by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-TOF); 340 species were identified (240 species in chronic HBV samples, 254 species in control samples) belonging to 169 genera and 6 phyla. In the chronic HBV group, 65 species were already known in the literature; 48 were associated with humans but had not been previously found in the gut, and 17 had never been associated with humans previously. Six species were newly isolated in our study. By comparing bacterial species frequency, three bacterial genera were serendipitously found with significantly enriched bacterial diversity in patients with chronic HBV: Enterocloster, Clostridium, and Streptococcus (p = 0.0016, p = 0.041, p = 0.053, respectively). However, metagenomics could not identify this enrichment, possibly concerning its insufficient taxonomical resolution (equivocal assignment of operational taxonomic units). At the species level, the significantly enriched species in the chronic HBV group almost all belonged to class Clostridia, such as Clostridium perfringens, Clostridium sporogenes, Enterocloster aldenensis, Enterocloster bolteae, Enterocloster clostridioformis, and Clostridium innocuum. Two E. bolteae strains, isolated from two patients with chronic HBV infection, showed high ethanol production (27 and 200 mM). CONCLUSIONS: Culturomics allowed us to identify Enterocloster species, specifically, E. bolteae, enriched in the gut microbiota of patients with chronic HBV. These species had never been isolated in chronic HBV infection before. Moreover, ethanol production by E. bolteae strains isolated from the chronic HBV group could contribute to liver disease progression. Additionally, culturomics might be critical for better elucidating the relationship between dysbiosis and chronic HBV infection in the future.

TP53INP1 overexpression in prostate cancer correlates with poor prognostic factors and is predictive of biological cancer relapse.

BACKGROUND: Tumor protein 53-induced nuclear protein 1 (TP53INP1) is a proapoptotic protein involved in cell stress response. Whereas there is an overexpression of TP53INP1 in numerous tissues submitted to stress agents, TP53INP1 is down-expressed in stomach, pancreatic, and inflammation-mediated colic carcinomas. In medullary thyroid carcinomas, TP53INP1 overexpression correlates with poor prognosis. TP53INP1 expression has never been reported in Prostate Cancer (PC). Our aim was to investigate variations of TP53INP1 expression and their correlation to clinicopathological parameters in PC. METHODS: Quantitative measurements of immunohistochemical expression of TP53INP1 using high-throughput densitometry, assessed on digitized microscopic tissue micro-array images, were correlated with clinicopathological parameters in 91 human PC. Treatment of LNCaP tumor cells in vitro with cytokines and with TP53INP1 antisense oligonucleotide (ASO) was also analyzed. RESULTS: In normal prostate tissues, TP53INP1 is only expressed in prostate basal cells. There is a de novo TP53INP1 expression in prostate luminal cells in inflammatory prostate tissues, high grade PIN lesions and in PC. Stimulation of LNCaP cells with inflammatory cytokines enhances the level of TP53INP1 mRNA. In PC, TP53INP1 overexpression correlates with high Gleason grade, unfavorable D'Amico score and lymph node invasion, and is an independent factor of biological cancer relapse. Moreover, treatment of LNCaP cells with a TP53INP1 ASO down-regulates TP53INP1 protein level, inhibits proliferation, and induces apoptosis. CONCLUSION: TP53INP1 overexpression in PC seems to be a worse prognostic factor, particularly predictive of biological cancer relapse. Results in vitro suggest that TP53INP1 could be considered as a relevant target for potential specific therapy.

TP53INP1 as new therapeutic target in castration-resistant prostate cancer.

BACKGROUND: Prostate cancer (PC) is one of the most common malignancies in industrialized countries, and the second leading cause of cancer-related death in the United States. We recently showed that over-expression of tumor protein 53-induced nuclear protein 1 (TP53INP1), a cell stress response protein, is a worse prognostic factor in PC, particularly predictive of biological cancer relapse. Moreover, treatment of castration-sensitive (CS) LNCaP tumor cells with a TP53INP1 antisense oligonucleotide (TP53INP1 ASO) inhibits proliferation and induces apoptosis. The aim of this study was to investigate variations of TP53INP1 expression in PC during androgen withdrawal therapy and in castration-resistant prostate cancer (CRPC). METHODS: Quantitative measurements of immunohistochemical expression of TP53INP1 using high-throughput densitometry, assessed on digitized microscopic tissue micro-array images were correlated with hormone therapy (HT) status in human PC. Northern blot analysis of TP53INP1 after castration was performed in LNCaP xenograft. Treatment of CR C4-2 tumor cells in vitro with TP53INP1 ASO was analyzed. We also analyzed the effect of TP53INP1 ASO treatment in vivo on tumor xenograft growth. RESULTS: TP53INP1 protein expression decreases during HT and increases after HT in human CRPC. TP53INP1 mRNA increases significantly in CR tumors of LNCaP xenograft. Moreover, treatment of CR C4-2 cells with TP53INP1 ASO downregulates TP53INP1 protein level, inhibits proliferation, and induces apoptosis. Finally, in vivo, TP53INP1 ASO treatment significantly inhibits the tumoral progression of CR C4-2 xenograft and enhances docetaxel cytotoxicity. CONCLUSIONS: These results suggest that TP53INP1 could be considered as a relevant-specific target for molecular therapy of CRPC.

Nucleoside-Lipid-Based Nanoparticles for Phenazine Delivery: A New Therapeutic Strategy to Disrupt Hsp27-eIF4E Interaction in Castration Resistant Prostate Cancer.

Heat shock protein 27 (Hsp27) has an established role in tumor progression and chemo-resistance of castration-resistant prostate cancer (CRPC). Hsp27 protects eukaryotic translation initiation factor 4E (eIF4E) from degradation, thereby maintaining survival during treatment. Phenazine derivative compound #14 was demonstrated to specifically disrupt Hsp27/eIF4E interaction and significantly delay castration-resistant tumor progression in prostate cancer xenografts. In the present work, various strategies of encapsulation of phenazine #14 with either DOTAU (N-[5'-(2',3'-dioleoyl)uridine]-N',N',N'-trimethylammonium tosylate) and DOU-PEG2000 (5'-PEG2000-2',3'-dioleoyluridine) nucleolipids (NLs) were developed in order to improve its solubilization, biological activity, and bioavailability. We observed that NLs-encapsulated phenazine #14-driven Hsp27-eIF4E interaction disruption increased cytotoxic effects on castration-resistant prostate cancer cell line and inhibited tumor growth in castration-resistant prostate cancer cell xenografted mice compared to phenazine #14 and NLs alone. Phenazine #14 NL encapsulation might represent an interesting nanostrategy for CRPC therapy.

Analysis of SARS-CoV-2 Variants From 24,181 Patients Exemplifies the Role of Globalization and Zoonosis in Pandemics.

After the end of the first epidemic episode of SARS-CoV-2 infections, as cases began to rise again during the summer of 2020, we at IHU Méditerranée Infection in Marseille, France, intensified the genomic surveillance of SARS-CoV-2, and described the first viral variants. In this study, we compared the incidence curves of SARS-CoV-2-associated deaths in different countries and reported the classification of SARS-CoV-2 variants detected in our institute, as well as the kinetics and sources of the infections. We used mortality collected from a COVID-19 data repository for 221 countries. Viral variants were defined based on ≥5 hallmark mutations along the whole genome shared by ≥30 genomes. SARS-CoV-2 genotype was determined for 24,181 patients using next-generation genome and gene sequencing (in 47 and 11% of cases, respectively) or variant-specific qPCR (in 42% of cases). Sixteen variants were identified by analyzing viral genomes from 9,788 SARS-CoV-2-diagnosed patients. Our data show that since the first SARS-CoV-2 epidemic episode in Marseille, importation through travel from abroad was documented for seven of the new variants. In addition, for the B.1.160 variant of Pangolin classification (a.k.a. Marseille-4), we suspect transmission from farm minks. In conclusion, we observed that the successive epidemic peaks of SARS-CoV-2 infections are not linked to rebounds of viral genotypes that are already present but to newly introduced variants. We thus suggest that border control is the best mean of combating this type of introduction, and that intensive control of mink farms is also necessary to prevent the emergence of new variants generated in this animal reservoir.

Botulinum toxin type A inhibits the growth of LNCaP human prostate cancer cells in vitro and in vivo.

INTRODUCTION AND OBJECTIVE: Botulinum toxin type A (BTA) intraprostatic injection induces an improvement of urinary symptoms related to benign prostatic hypertrophy (BPH). Infra-clinical prostate cancer (PCa) foci and pre-neoplasic lesions occur concomitantly with BPH in a significant number of patients. The objective of this study was to address whether BTA influences the growth of prostate tumors. METHODS: Proliferation of PC-3 and LNCaP cell lines exposed or not to BTA (Botox) was assessed and compared. Presence of synaptic vesicle 2 (SV2) protein, the membrane receptor of BTA, was studied in both cell lines. After nude mice bearing LNCaP xenografts received intra-tumoral BTA or saline injection, tumor volume, serum PSA, histopathology and detection of apoptosis were comparatively assessed. RESULTS: BTA significantly reduced LNCaP cell proliferation and increased apoptosis in a dose-dependent manner but did not affect PC-3. The SV2 receptor was present in both cell lines at a ratio of 4:1 (LNCaP/PC-3). One unit of BTA resulted in a significantly lower growth rate and slower PSA progression over 28 days compare to controls. The tumors were morphologically similar. There were significantly more apoptotic cells compared to controls. CONCLUSION: BTA inhibits the growth of LNCaP human PCa cells in vitro and in vivo. These findings indicate that intra-prostatic BTA injections to treat BPH are unlikely to promote the growth of co-existing infra-clinical PCa foci in men. A potential inhibitory effect of BTA on the growth of human PCa should be further studied.

Correction: Targeting Hsp27/eIF4E interaction with phenazine compound: a promising alternative for castration-resistant prostate cancer treatment.

[This corrects the article DOI: 10.18632/oncotarget.20469.].

Targeting Hsp27/eIF4E interaction with phenazine compound: a promising alternative for castration-resistant prostate cancer treatment.

The actual strategy to improve current therapies in advanced prostate cancer involves targeting genes activated by androgen withdrawal, either to delay or prevent the emergence of the castration-refractory phenotype. However, these genes are often implicated in several physiological processes, and long-term inhibition of survival proteins might be accompanied with cytotoxic effects. To avoid this problem, an alternative therapeutic strategy relies on the identification and use of compounds that disrupt specific protein-protein interactions involved in androgen withdrawal. Specifically, the interaction of the chaperone protein Hsp27 with the initiation factor eIF4E leads to the protection of protein synthesis initiation process and enhances cell survival during cell stress induced by castration or chemotherapy. Thus, in this work we aimed at i) identifying the interaction site of the Hsp27/eIF4E complex and ii) interfere with the relevant protein/protein association mechanism involved in castration-resistant progression of prostate cancer. By a combination of experimental and modeling techniques, we proved that eIF4E interacts with the C-terminal part of Hsp27, preferentially when Hsp27 is phosphorylated. We also observed that the loss of this interaction increased cell chemo-and hormone-sensitivity. In order to find a potential inhibitor of Hsp27/eIF4E interaction, BRET assays in combination with molecular simulations identified the phenazine derivative 14 as the compound able to efficiently interfere with this protein/protein interaction, thereby inhibiting cell viability and increasing cell death in chemo- and castration-resistant prostate cancer models in vitro and in vivo.

Hugonella massiliensis gen. nov., sp. nov., genome sequence, and description of a new strictly anaerobic bacterium isolated from the human gut.

The human gut is composed of a large diversity of microorganisms, which have been poorly described. Here, using culturomics, a new concept based on the variation in culture conditions and MALDI-TOF MS identification, we proceed to explore the microbial diversity of the complex ecosystem of the human gut. Using this approach, we isolated strain AT8T (=CSUR P2118 =  DSM 101782) from stool specimens collected from a 51-year-old obese French woman. Strain AT8T is a strictly anaerobic, nonmotile, nonspore-forming gram-positive coccus that do not exhibit catalase and oxidase activities. 16S rDNA-based identification of strain AT8T demonstrated 92% gene sequence similarity with Eggerthella lenta DSM 2243, the phylogenetically closed validly named type species. Here, we present a set of features for the strain AT8T and the description of its complete genome sequence and annotation. The 2,091,845 bp long genome has a G+C content of 63.46% and encodes1,849 predicted genes; 1,781 were protein-coding genes, and 68 were RNAs. On the basis of the characteristics reported here, we propose the creation of a new bacterial genus Hugonella gen. nov., belonging to the Eggerthellaceae family and including Hugonella massiliensis gen. nov., sp. nov., strain AT8T as the type strain.

Microbial Culturomics to Map Halophilic Bacterium in Human Gut: Genome Sequence and Description of Oceanobacillus jeddahense sp. nov.

Culturomics is a new omics subspecialty to map the microbial diversity of human gut, coupled with a taxono-genomic strategy. We report here the description of a new bacterial species using microbial culturomics: strain S5T, (= CSUR P1091=DSM 28586) isolated from a stool specimen of a 25-year-old obese patient from Saudi Arabia. The strain S5T was a Gram-positive, strictly aerobic rod, which was motile by a polar flagellum, spore-forming, and exhibited catalase and oxidase activities. It grows optimally at 37°C, with a pH of 7.5 and 10% of NaCl. 16S rRNA gene-based identification revealed that strain S5T has 98.6% 16S rRNA sequence similarity with the reference O. oncorhynchi, phylogenetically the closest validated Oceanobacillus species. Here, we further describe the phenotypic characteristics of this organism and its complete genome sequence and annotation. The 5,388,285 bp long genome exhibits a G+C content of 37.24% and contains 5109 protein-coding genes and 198 RNA genes. Based on the characteristics reported here, we propose classifying this novel bacterium as representative of a new species belonging to the genus Oceanobacillus, Oceanobacillus jeddahense sp. nov. In a broader context, it is noteworthy that halophilic bacteria have long been overlooked in the human gut, and their role in human health and disease has not yet been investigated. This study thus further underscores the usefulness of the culturomics approach exploring the bacterial diversity of the gut.