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Handy NB, Xu Y, Moon D, Sowizral JJ, Moon E, Ho M, Wilson BA. Hierarchical determinants in cytotoxic necrotizing factor (CNF) toxins driving Rho G-protein deamidation versus transglutamination. mBio 2024; 15:e0122124. [PMID: 38920360 PMCID: PMC11253639 DOI: 10.1128/mbio.01221-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Accepted: 05/22/2024] [Indexed: 06/27/2024] Open
Abstract
The cytotoxic necrotizing factor (CNF) family of AB-type bacterial protein toxins catalyze two types of modification on their Rho GTPase substrates: deamidation and transglutamination. It has been established that E. coli CNF1 and its close homolog proteins catalyze primarily deamidation and Bordetella dermonecrotic toxin (DNT) catalyzes primarily transglutamination. The rapidly expanding microbial genome sequencing data have revealed that there are at least 13 full-length variants of CNF1 homologs. CNFx from E. coli strain GN02091 is the most distant from all other members of the CNF family with 50%-55% sequence identity at the protein level and 0.45-0.52 nucleotide substitutions per site at the DNA level. CNFx modifies RhoA, Rac1, and Cdc42, and like CNF1, activates downstream SRE-dependent mitogenic signaling pathways in human HEK293T cells, but at a 1,000-fold higher EC50 value. Unlike other previously characterized CNF toxins, CNFx modifies Rho proteins primarily through transglutamination, as evidenced by gel-shift assay and confirmed by MALDI mass spectral analysis, when coexpressed with Rho-protein substrates in E. coli BL21 cells or through direct treatment of HEK293T cells. A comparison of CNF1 and CNFx sequences identified two critical active-site residues corresponding to positions 832 and 862 in CNF1. Reciprocal site-specific mutations at these residues in each toxin revealed hierarchical rules that define the preference for deamidase versus a transglutaminase activity in CNFs. An additional unique Cys residue at the C-terminus of CNFx was also discovered to be critical for retarding cargo delivery.IMPORTANCECytotoxic necrotizing factor (CNF) toxins not only play important virulence roles in pathogenic E. coli and other bacterial pathogens, but CNF-like genes have also been found in an expanding number of genomes from clinical isolates. Harnessing the power of evolutionary relationships among the CNF toxins enabled the deciphering of the hierarchical active-site determinants that define whether they modify their Rho GTPase substrates through deamidation or transglutamination. With our finding that a distant CNF variant (CNFx) unlike other known CNFs predominantly transglutaminates its Rho GTPase substrates, the paradigm of "CNFs deamidate and DNTs transglutaminate" could finally be attributed to two critical amino acid residues within the active site other than the previously identified catalytic Cys-His dyad residues. The significance of our approach and research findings is that they can be applied to deciphering enzyme reaction determinants and substrate specificities for other bacterial proteins in the development of precision therapeutic strategies.
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Affiliation(s)
- Nicholas B. Handy
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yiting Xu
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Damee Moon
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jacob J. Sowizral
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Eric Moon
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Mengfei Ho
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Brenda A. Wilson
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Sadeghi M, Mestivier D, Sobhani I. Contribution of pks+ Escherichia coli ( E. coli) to Colon Carcinogenesis. Microorganisms 2024; 12:1111. [PMID: 38930493 PMCID: PMC11205849 DOI: 10.3390/microorganisms12061111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 05/24/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024] Open
Abstract
Colorectal cancer (CRC) stands as a significant global health concern, ranking second in mortality and third in frequency among cancers worldwide. While only a small fraction of CRC cases can be attributed to inherited genetic mutations, the majority arise sporadically due to somatic mutations. Emerging evidence reveals gut microbiota dysbiosis to be a contributing factor, wherein polyketide synthase-positive Escherichia coli (pks+ E. coli) plays a pivotal role in CRC pathogenesis. pks+ bacteria produce colibactin, a genotoxic protein that causes deleterious effects on DNA within host colonocytes. In this review, we examine the role of the gut microbiota in colon carcinogenesis, elucidating how colibactin-producer bacteria induce DNA damage, promote genomic instability, disrupt the gut epithelial barrier, induce mucosal inflammation, modulate host immune responses, and influence cell cycle dynamics. Collectively, these actions foster a microenvironment conducive to tumor initiation and progression. Understanding the mechanisms underlying pks+ bacteria-mediated CRC development may pave the way for mass screening, early detection of tumors, and therapeutic strategies such as microbiota modulation, bacteria-targeted therapy, checkpoint inhibition of colibactin production and immunomodulatory pathways.
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Affiliation(s)
- Mohammad Sadeghi
- EA7375–EC2M3: Early, Detection of Colonic Cancer by Using Microbial & Molecular Markers, Paris East Créteil University (UPEC), 94010 Créteil, France;
| | - Denis Mestivier
- EA7375–EC2M3: Early, Detection of Colonic Cancer by Using Microbial & Molecular Markers, Paris East Créteil University (UPEC), 94010 Créteil, France;
| | - Iradj Sobhani
- EA7375–EC2M3: Early, Detection of Colonic Cancer by Using Microbial & Molecular Markers, Paris East Créteil University (UPEC), 94010 Créteil, France;
- Department of Gastroenterology, Assistance Publique–Hôpitaux de Paris (APHP), Henri Mondor Hospital, 94010 Créteil, France
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3
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Zaidi AH, Pratama MY, Omstead AN, Gorbonova A, Mansoor R, Melton-Kreft R, Jobe BA, Wagner PL, Kelly RJ, Goel A. A blood-based circulating microbial metagenomic panel for early diagnosis and prognosis of oesophageal adenocarcinoma. Br J Cancer 2022; 127:2016-2024. [PMID: 36097175 PMCID: PMC9681745 DOI: 10.1038/s41416-022-01974-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Emerging evidence indicates the potential clinical significance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in oesophageal adenocarcinoma (EAC) patients, particularly as novel non-invasive, early detection, surveillance and prognostic classifiers. METHODS Metagenome sequencing was performed on 81 serum specimens collected across EAC spectrum, with sequencing reads classified using Bracken and MetaPhlAn3. Followed by the Linear Discriminant Analysis effect size (LEfSe) method to identify microbial profiles between groups. Logistic regression and Kaplan-Meier analyses were used to build classifiers. RESULTS A significant loss of alpha and beta diversity was identified in serum specimens from EAC patients. We observed a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 (95% CI: 0.78-0.95; P < 0.001) and this panel in conjunction with the TNM stage was a robust predictor of overall survival (≥24 months; AUC = 0.84 (95% CI: 0.66-0.92; P = 0.006)). CONCLUSION This study firstly describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC. TRANSLATIONAL RELEVANCE Accumulating data indicates the clinical relevance of specific microbial signatures as diagnostic and prognostic biomarkers, in multiple cancers. However, to date, no studies have systematically interrogated circulating metagenome profiling in patients with oesophageal adenocarcinoma (EAC). Herein, we performed metagenome sequencing in serum specimens from EAC patients 81 collected across EAC spectrum and observed a significant loss of alpha and beta diversity, with a shift in microbial taxa between each group-at the phylum, genus, and species level-with Lactobacillus sakei as the most prominent species in gastroesophageal reflux (GERD) vs other patient groups. Interestingly, LEfSe analysis identified a complete loss of Lactobacillus (L. Sakei and L. Curvatus), Collinsella stercoris and Bacteroides stercoris but conversely a significant increase in Escherichia coli in patients with EAC. Finally, we developed a metagenome panel that discriminated EAC from GERD patients with an AUC value of 0.89 and this panel, in conjunction with the TNM stage, was a robust predictor of overall survival. This study for the first time describes unique blood-based microbial profiles in patients across EAC carcinogenesis, that are further utilised to establish a novel circulating diagnostic and prognostic metagenomic signature for EAC.
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Affiliation(s)
- Ali H Zaidi
- Allegheny Health Network Cancer Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Muhammad Yogi Pratama
- Department of Molecular Diagnostics and Experimental Therapeutics, Beckman Research Institute of City of Hope, Monrovia, CA, USA
| | - Ashten N Omstead
- Allegheny Health Network Cancer Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Anastasia Gorbonova
- Allegheny Health Network Cancer Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Rubab Mansoor
- Allegheny Health Network Cancer Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Rachael Melton-Kreft
- The Allegheny Health Network, Center of Excellence in Biofilm Research, Pittsburgh, PA, USA
| | - Blair A Jobe
- Allegheny Health Network Cancer Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Patrick L Wagner
- Allegheny Health Network Cancer Institute, Allegheny Health Network, Pittsburgh, PA, USA
| | - Ronan J Kelly
- The Charles A. Sammons Cancer Center, Baylor University Medical Center, Dallas, TX, USA
| | - Ajay Goel
- Department of Molecular Diagnostics and Experimental Therapeutics, Beckman Research Institute of City of Hope, Monrovia, CA, USA.
- City of Hope Comprehensive Cancer Center, Duarte, CA, USA.
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Markelova NN, Semenova EF, Sineva ON, Sadykova VS. The Role of Cyclomodulins and Some Microbial Metabolites in Bacterial Microecology and Macroorganism Carcinogenesis. Int J Mol Sci 2022; 23:ijms231911706. [PMID: 36233008 PMCID: PMC9570213 DOI: 10.3390/ijms231911706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/24/2022] [Accepted: 09/26/2022] [Indexed: 11/16/2022] Open
Abstract
A number of bacteria that colonize the human body produce toxins and effectors that cause changes in the eukaryotic cell cycle—cyclomodulins and low-molecular-weight compounds such as butyrate, lactic acid, and secondary bile acids. Cyclomodulins and metabolites are necessary for bacteria as adaptation factors—which are influenced by direct selection—to the ecological niches of the host. In the process of establishing two-way communication with the macroorganism, these compounds cause limited damage to the host, despite their ability to disrupt key processes in eukaryotic cells, which can lead to pathological changes. Possible negative consequences of cyclomodulin and metabolite actions include their potential role in carcinogenesis, in particular, with the ability to cause DNA damage, increase genome instability, and interfere with cancer-associated regulatory pathways. In this review, we aim to examine cyclomodulins and bacterial metabolites as important factors in bacterial survival and interaction with the host organism to show their heterogeneous effect on oncogenesis depending on the surrounding microenvironment, pathological conditions, and host genetic background.
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Affiliation(s)
- Natalia N. Markelova
- Gause Institute of New Antibiotics, ul. Bolshaya Pirogovskaya, 11, 119021 Moscow, Russia
- Correspondence: (N.N.M.); (V.S.S.)
| | - Elena F. Semenova
- Institute of Biochemical Technology, Ecology and Pharmacy, V.I. Vernadsky Crimean Federal University, 295007 Simferopol, Russia
| | - Olga N. Sineva
- Gause Institute of New Antibiotics, ul. Bolshaya Pirogovskaya, 11, 119021 Moscow, Russia
| | - Vera S. Sadykova
- Gause Institute of New Antibiotics, ul. Bolshaya Pirogovskaya, 11, 119021 Moscow, Russia
- Correspondence: (N.N.M.); (V.S.S.)
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The Cytotoxic Necrotizing Factors (CNFs)-A Family of Rho GTPase-Activating Bacterial Exotoxins. Toxins (Basel) 2021; 13:toxins13120901. [PMID: 34941738 PMCID: PMC8709095 DOI: 10.3390/toxins13120901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 11/17/2022] Open
Abstract
The cytotoxic necrotizing factors (CNFs) are a family of Rho GTPase-activating single-chain exotoxins that are produced by several Gram-negative pathogenic bacteria. Due to the pleiotropic activities of the targeted Rho GTPases, the CNFs trigger multiple signaling pathways and host cell processes with diverse functional consequences. They influence cytokinesis, tissue integrity, cell barriers, and cell death, as well as the induction of inflammatory and immune cell responses. This has an enormous influence on host-pathogen interactions and the severity of the infection. The present review provides a comprehensive insight into our current knowledge of the modular structure, cell entry mechanisms, and the mode of action of this class of toxins, and describes their influence on the cell, tissue/organ, and systems levels. In addition to their toxic functions, possibilities for their use as drug delivery tool and for therapeutic applications against important illnesses, including nervous system diseases and cancer, have also been identified and are discussed.
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Abstract
Colorectal cancer (CRC) is one of the most prevalent, most lethal cancers in the world. Increasing evidence suggests that the intestinal microbiota is closely related to the pathogenesis and prognosis of CRC. The normal microbiota plays an essential role in maintaining gut barrier function and the immune microenvironment. Recent studies have identified carcinogenic bacteria such as enterotoxigenic Bacteroides fragilis (ETBF) and Streptococcus gallolyticus (S. gallolyticus), as well as protective bacterial such as Akkermansia muciniphila (A. muciniphila), as potential targets of CRC treatment. Gut microbiota modulation aims to restore gut dysbiosis, regulate the intestinal immune system and prevent from pathogen invasion, all of which are beneficial for CRC prevention and prognosis. The utility of probiotics, prebiotics, postbiotics, fecal microbiota transplantation and dietary inventions to treat CRC makes them novel microbe-based management tools. In this review, we describe the mechanisms involved in bacteria-derived colorectal carcinogenesis and summarized novel bacteria-related therapies for CRC. In summary, we hope to facilitate clinical applications of intestinal bacteria for preventing and treating CRC.
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Carlini F, Maroccia Z, Fiorentini C, Travaglione S, Fabbri A. Effects of the Escherichia coli Bacterial Toxin Cytotoxic Necrotizing Factor 1 on Different Human and Animal Cells: A Systematic Review. Int J Mol Sci 2021; 22:ijms222212610. [PMID: 34830494 PMCID: PMC8621085 DOI: 10.3390/ijms222212610] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/19/2021] [Accepted: 11/20/2021] [Indexed: 12/13/2022] Open
Abstract
Cytotoxic necrotizing factor 1 (CNF1) is a bacterial virulence factor, the target of which is represented by Rho GTPases, small proteins involved in a huge number of crucial cellular processes. CNF1, due to its ability to modulate the activity of Rho GTPases, represents a widely used tool to unravel the role played by these regulatory proteins in different biological processes. In this review, we summarized the data available in the scientific literature concerning the observed in vitro effects induced by CNF1. An article search was performed on electronic bibliographic resources. Screenings were performed of titles, abstracts, and full-texts according to PRISMA guidelines, whereas eligibility criteria were defined for in vitro studies. We identified a total of 299 records by electronic article search and included 76 original peer-reviewed scientific articles reporting morphological or biochemical modifications induced in vitro by soluble CNF1, either recombinant or from pathogenic Escherichia coli extracts highly purified with chromatographic methods. Most of the described CNF1-induced effects on cultured cells are ascribable to the modulating activity of the toxin on Rho GTPases and the consequent effects on actin cytoskeleton organization. All in all, the present review could be a prospectus about the CNF1-induced effects on cultured cells reported so far.
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Affiliation(s)
- Francesca Carlini
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161 Rome, Italy; (F.C.); (Z.M.); (S.T.)
| | - Zaira Maroccia
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161 Rome, Italy; (F.C.); (Z.M.); (S.T.)
| | - Carla Fiorentini
- Associazione Ricerca Terapie Oncologiche Integrate, ARTOI, 00165 Rome, Italy;
| | - Sara Travaglione
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161 Rome, Italy; (F.C.); (Z.M.); (S.T.)
| | - Alessia Fabbri
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161 Rome, Italy; (F.C.); (Z.M.); (S.T.)
- Correspondence: ; Tel.: +39-06-4990-2939
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Li M, Sun X, Yao H, Chen W, Zhang F, Gao S, Zou X, Chen J, Qiu S, Wei H, Hu Z, Chen W. Genomic methylation variations predict the susceptibility of six chemotherapy related adverse effects and cancer development for Chinese colorectal cancer patients. Toxicol Appl Pharmacol 2021; 427:115657. [PMID: 34332992 DOI: 10.1016/j.taap.2021.115657] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/08/2021] [Accepted: 07/26/2021] [Indexed: 02/07/2023]
Abstract
Colorectal cancer (CRC) remains a major concern with high morbidity and mortality worldwide. Despite the positive influence of chemotherapy on the decline in CRC mortality, the negative influence of chemotherapy-related adverse effects (CRAEs) caused by capecitabine (Cap) remains a challenging problem. DNA methylation alteration plays a pivotal role in gene expression regulation. Here, we aimed to screen reliable and novel biomarkers for CRC diagnosis and CRAE prediction using the advanced Illumina Infinium MethylationEPIC (850 K) BeadChip. Paired tumor and normal tissues from 21 Chinese CRC patients who received Cap-based adjuvant chemotherapy were analyzed. CRC-related methylation was characterized by hypermethylated promoter islands and hypomethylated intragenic openseas; CRAE-related methylation was characterized by hyper- (or hypo-) methylated intragenic (or intergenic) regions. Based on three types of methylation profiles (differentially methylated probes, differentially methylated regions, and gene-function-differentially methylated regions), pathway enrichment analyses revealed that CRC-related genes were significantly enriched in the neuronal system, metabolism of RNA, and extracellular matrix organization; CRAE-related genes were abundantly enriched in pathways controlling regeneration functions and immune response. Finally, based on genes within the mostly related pathways and LASSO logistic regression selection, the integrated-methylation-marker systems developed here demonstrated high discriminative accuracy in both CRC diagnosis (AUROC = 1) and CRAE prediction (AUROC = 0.817-1). In conclusion, we conducted a comprehensive DNA methylation analysis of CRC patients with chemotherapy, which provided new insights into the formation of CRC and CRAEs. Most importantly, our findings identified potentially CRAE-related metabolic pathways and markers, providing a valuable reference for personalized medicine promising better safety. Trail registration:ClinicalTrials.gov,NCT03030508, Registered 25 January 2017,https://www.clinicaltrials.gov/ct2/show/NCT03030508?term=NCT03030508&draw=2&rank=1.
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Affiliation(s)
- Mingming Li
- Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China
| | - Xiaomeng Sun
- Research Institute, GloriousMed Clinical Laboratory Co., Ltd., Shanghai 201318, China
| | - Houshan Yao
- Department of General Surgery, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China
| | - Wei Chen
- Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China
| | - Feng Zhang
- Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China
| | - Shouhong Gao
- Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China
| | - Xun Zou
- Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China
| | - Jiani Chen
- Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China
| | - Shi Qiu
- Traditional Chinese Medicine Resource and Technology Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Hua Wei
- Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China; Department of Pharmacy, 905th Hospital of PLA Navy, Naval Medical University, Shanghai 200052, China.
| | - Zhiqian Hu
- Department of General Surgery, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China; Department of Gastrointestinal Surgery, Tongji Hospital, Medical College of Tongji University, Shanghai 200065, China.
| | - Wansheng Chen
- Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China; Traditional Chinese Medicine Resource and Technology Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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Morgan RN, Saleh SE, Farrag HA, Aboulwafa MM. Bacterial cyclomodulins: types and roles in carcinogenesis. Crit Rev Microbiol 2021; 48:42-66. [PMID: 34265231 DOI: 10.1080/1040841x.2021.1944052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Various studies confirmed that bacterial infections contribute to carcinogenesis through the excessive accumulation of reactive oxygen species (ROS) and the expression of toxins that disrupt the cell cycle phases, cellular regulatory mechanisms and stimulate the production of tumorigenic inflammatory mediators. These toxins mimic carcinogens which act upon key cellular targets and result in mutations and genotoxicities. The cyclomodulins are bacterial toxins that incur cell cycle modulating effects rendering the expressing bacterial species of high carcinogenic potentiality. They are either cellular proliferating or cell cycle arrest cyclomodulins. Notably, cyclomodulins expressing bacterial species have been linked to different human carcinomas. For instance, Escherichia coli species producing the colibactin were highly prevalent among colorectal carcinoma patients, CagA+ Helicobacter pylori species were associated with MALT lymphomas and gastric carcinomas and Salmonella species producing CdtB were linked to hepatobiliary carcinomas. These species stimulated the overgrowth of pre-existing carcinomas and induced hyperplasia in in vivo animal models suggesting a role for the cyclomodulins in carcinogenesis. Wherefore, the prevalence and mode of action of these toxins were the focus of many researchers and studies. This review discusses different types of bacterial cyclomodulins highlighting their mode of action and possible role in carcinogenesis.
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Affiliation(s)
- Radwa N Morgan
- Drug radiation research Department, Egyptian Atomic Energy Authority (EAEA), National Center for Radiation Research and Technology (NCRRT), Cairo, Egypt
| | - Sarra E Saleh
- Faculty of Pharmacy, Microbiology and Immunology Department, Ain Shams University, Cairo, Egypt
| | - Hala A Farrag
- Drug radiation research Department, Egyptian Atomic Energy Authority (EAEA), National Center for Radiation Research and Technology (NCRRT), Cairo, Egypt
| | - Mohammad M Aboulwafa
- Faculty of Pharmacy, Microbiology and Immunology Department, Ain Shams University, Cairo, Egypt.,Faculty of Pharmacy, King Salman International University, Ras-Sedr, Egypt
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10
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Chaoprasid P, Lukat P, Mühlen S, Heidler T, Gazdag E, Dong S, Bi W, Rüter C, Kirchenwitz M, Steffen A, Jänsch L, Stradal TEB, Dersch P, Blankenfeldt W. Crystal structure of bacterial cytotoxic necrotizing factor CNF Y reveals molecular building blocks for intoxication. EMBO J 2021; 40:e105202. [PMID: 33410511 PMCID: PMC7883292 DOI: 10.15252/embj.2020105202] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 11/12/2020] [Accepted: 11/23/2020] [Indexed: 12/30/2022] Open
Abstract
Cytotoxic necrotizing factors (CNFs) are bacterial single-chain exotoxins that modulate cytokinetic/oncogenic and inflammatory processes through activation of host cell Rho GTPases. To achieve this, they are secreted, bind surface receptors to induce endocytosis and translocate a catalytic unit into the cytosol to intoxicate host cells. A three-dimensional structure that provides insight into the underlying mechanisms is still lacking. Here, we determined the crystal structure of full-length Yersinia pseudotuberculosis CNFY . CNFY consists of five domains (D1-D5), and by integrating structural and functional data, we demonstrate that D1-3 act as export and translocation module for the catalytic unit (D4-5) and for a fused β-lactamase reporter protein. We further found that D4, which possesses structural similarity to ADP-ribosyl transferases, but had no equivalent catalytic activity, changed its position to interact extensively with D5 in the crystal structure of the free D4-5 fragment. This liberates D5 from a semi-blocked conformation in full-length CNFY , leading to higher deamidation activity. Finally, we identify CNF translocation modules in several uncharacterized fusion proteins, which suggests their usability as a broad-specificity protein delivery tool.
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Affiliation(s)
- Paweena Chaoprasid
- Institute of InfectiologyCenter for Molecular Biology of Inflammation (ZMBE)University of MünsterMünsterGermany
- Molecular Infection BiologyHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Peer Lukat
- Structure and Function of ProteinsHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Sabrina Mühlen
- Institute of InfectiologyCenter for Molecular Biology of Inflammation (ZMBE)University of MünsterMünsterGermany
- Molecular Infection BiologyHelmholtz Centre for Infection ResearchBraunschweigGermany
- Deutsches Zentrum für InfektionsforschungBraunschweigGermany
| | - Thomas Heidler
- Molecular Structural BiologyHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Emerich‐Mihai Gazdag
- Structure and Function of ProteinsHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Shuangshuang Dong
- Structure and Function of ProteinsHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Wenjie Bi
- Cellular ProteomicsHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Christian Rüter
- Institute of InfectiologyCenter for Molecular Biology of Inflammation (ZMBE)University of MünsterMünsterGermany
| | - Marco Kirchenwitz
- Cell BiologyHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Anika Steffen
- Cell BiologyHelmholtz Centre for Infection ResearchBraunschweigGermany
| | - Lothar Jänsch
- Cellular ProteomicsHelmholtz Centre for Infection ResearchBraunschweigGermany
- Institute of ZoologyTechnische Universität BraunschweigBraunschweigGermany
| | - Theresia E B Stradal
- Cell BiologyHelmholtz Centre for Infection ResearchBraunschweigGermany
- Institute of ZoologyTechnische Universität BraunschweigBraunschweigGermany
| | - Petra Dersch
- Institute of InfectiologyCenter for Molecular Biology of Inflammation (ZMBE)University of MünsterMünsterGermany
- Molecular Infection BiologyHelmholtz Centre for Infection ResearchBraunschweigGermany
- Deutsches Zentrum für InfektionsforschungBraunschweigGermany
- Institute of MicrobiologyTechnische Universität BraunschweigBraunschweigGermany
| | - Wulf Blankenfeldt
- Structure and Function of ProteinsHelmholtz Centre for Infection ResearchBraunschweigGermany
- Institute for Biochemistry, Biotechnology and BioinformaticsTechnische Universität BraunschweigBraunschweigGermany
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11
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Morgan RN, Farrag HA, Aboulwafa MM, Saleh SE. "Effect of Subinhibitory Concentrations of Some Antibiotics and Low Doses of Gamma Radiation on the Cytotoxicity and Expression of Colibactin by an Uropathogenic Escherichia coli isolate". Curr Microbiol 2021; 78:544-557. [PMID: 33388934 DOI: 10.1007/s00284-020-02331-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 12/10/2020] [Indexed: 01/10/2023]
Abstract
Colibactin and cytotoxic necrotizing factor 1 (Cnf 1) are cyclomodulins secreted by uropathogenic E. coli. In this study, uropathogenic E. coli expressing colibactin and Cnf 1 was exposed to antibiotics subMICs and gamma radiation to investigate their effects on its cytotoxicity and expression of colibactin. The test isolate was exposed to three subMIC levels of levofloxacin, ciprofloxacin, trimethoprim/sulfamethoxazole and ceftriaxone and irradiated with gamma rays at 10 and 24.4 Gy. The cytotoxicity for either antibiotic or gamma rays treated cultures was measured using MTT assay and the expression of colibactin encoding genes was determined by RT-PCR. Treatment with fluoroquinolones nearly abolished the cytotoxicity of E. coli isolate and significantly downregulated clbA gene expression at the tested subMICs (P ≤ 0.05) while trimethoprim/sulfamethoxazole treated cultures exerted significant downregulation of clbA and clbQ genes at 0.5 MIC only (P ≤ 0.05). Ceftriaxone treated cultured exhibited reduction in the cytotoxicity and insignificant effects on expression of clbA, clbQ and clbM genes. On contrast, significant upregulation in the expression of clbA and clbQ genes was observed in irradiated cultures (P ≤ 0.05). Fluoroquinolones reduced both the cytotoxicity of UPEC isolate and colibactin expression at different subMICs while ceftriaxone at subMICs failed to suppress the expression of genotoxin, colibactin, giving an insight to the risks associated upon their choice for UTI treatment. Colibactin expression was enhanced by gamma irradiation at doses resembling these received during pelvic radiotherapy which might contribute to post-radiotherapy complications.
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Affiliation(s)
- Radwa N Morgan
- National Centre for Radiation Research and Technology (NCRRT), Drug Radiation Research Department, Egyptian Atomic Energy Authority (EAEA), Ahmed El-Zomor Street, Nasr city, Cairo, 11787, Egypt
| | - Hala A Farrag
- National Centre for Radiation Research and Technology (NCRRT), Drug Radiation Research Department, Egyptian Atomic Energy Authority (EAEA), Ahmed El-Zomor Street, Nasr city, Cairo, 11787, Egypt
| | - Mohammad M Aboulwafa
- Microbiology and Immunology Department, Faculty of Pharmacy, Ain Shams University, African union organization Street, Abbassia, Cairo, 11566, Egypt.
- Faculty of Pharmacy, King Salman International University, South Sinai, Ras-Sedr, Egypt.
| | - Sarra E Saleh
- Microbiology and Immunology Department, Faculty of Pharmacy, Ain Shams University, African union organization Street, Abbassia, Cairo, 11566, Egypt
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12
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Gut Microbiota and Colon Cancer: A Role for Bacterial Protein Toxins? Int J Mol Sci 2020; 21:ijms21176201. [PMID: 32867331 PMCID: PMC7504354 DOI: 10.3390/ijms21176201] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 02/06/2023] Open
Abstract
Accumulating evidence indicates that the human intestinal microbiota can contribute to the etiology of colorectal cancer. Triggering factors, including inflammation and bacterial infections, may favor the shift of the gut microbiota from a mutualistic to a pro-carcinogenic configuration. In this context, certain bacterial pathogens can exert a pro-tumoral activity by producing enzymatically-active protein toxins that either directly induce host cell DNA damage or interfere with essential host cell signaling pathways involved in cell proliferation, apoptosis, and inflammation. This review is focused on those toxins that, by mimicking carcinogens and cancer promoters, could represent a paradigm for bacterially induced carcinogenesis.
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13
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Kuźmycz O, Stączek P. Prospects of NSAIDs administration as double-edged agents against endometrial cancer and pathological species of the uterine microbiome. Cancer Biol Ther 2020; 21:486-494. [PMID: 32174282 PMCID: PMC7515452 DOI: 10.1080/15384047.2020.1736483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Many types of cancers, including endometrial cancer, were found to have cyclooxygenase-2 (COX-2) overexpression. Because this enzyme belongs to the group of pro-inflammatory enzymes, so-called NSAIDs (non-steroidal anti–inflammatory drugs) directly inhibit its activity. An increasing number of reports on COX-2 involvement in cancer, as well as on the role of microbiota in abnormal metabolism and signaling of cells, forces the development of new NSAID types. Besides, NSAIDs can affect some bacteria, which are vaginal/endometrial microbiome members. The overgrowth of those species was found to be a major cause of some uterus diseases. Those infections can lead to chronic inflammatory response and suppress anti-tumorigenic cell pathways. The purpose of this review is to highlight the COX-2 enzyme role in endometrial cancer, the potential effect of the endometrial microbiome on COX-2 enzyme overexpression, and the prospects of NSAIDs use in terms of this type of cancer.
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Affiliation(s)
- Olga Kuźmycz
- Department of Microbial Genetics, Institute of Microbiology, Biotechnology, and Immunology, Faculty of Biology, University of Łódź, Łódź, Poland
| | - Paweł Stączek
- Department of Microbial Genetics, Institute of Microbiology, Biotechnology, and Immunology, Faculty of Biology, University of Łódź, Łódź, Poland
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14
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Xu S, Yin W, Zhang Y, Lv Q, Yang Y, He J. Foes or Friends? Bacteria Enriched in the Tumor Microenvironment of Colorectal Cancer. Cancers (Basel) 2020; 12:cancers12020372. [PMID: 32041122 PMCID: PMC7072156 DOI: 10.3390/cancers12020372] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 12/12/2022] Open
Abstract
Colorectal cancer (CRC) is the second most commonly diagnosed cancer and the third cause of cancer death in the world, while intestinal microbiota is a community of microbes living in human intestine that can potentially impact human health in many ways. Accumulating evidence suggests that intestinal microbiota, especially that from the intestinal bacteria, play a key role in the CRC development; therefore, identification of bacteria involved in CRC development can provide new targets for the CRC diagnosis, prevention, and treatment. Over the past decade, there have been considerable advances in applying 16S rDNA sequencing data to verify associated intestinal bacteria in CRC patients; however, due to variations of individual and environment factors, these results seem to be inconsistent. In this review, we scrutinized the previous 16S rDNA sequencing data of intestinal bacteria from CRC patients, and identified twelve genera that are specifically enriched in the tumor microenvironment. We have focused on their relationship with the CRC development, and shown that some bacteria could promote CRC development, acting as foes, while others could inhibit CRC development, serving as friends, for human health. Finally, we highlighted their potential applications for the CRC diagnosis, prevention, and treatment.
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15
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Fabbri A, Travaglione S, Rosadi F, Ballan G, Maroccia Z, Giambenedetti M, Guidotti M, Ødum N, Krejsgaard T, Fiorentini C. The Escherichia coli protein toxin cytotoxic necrotizing factor 1 induces epithelial mesenchymal transition. Cell Microbiol 2019; 22:e13138. [PMID: 31698538 DOI: 10.1111/cmi.13138] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/18/2019] [Accepted: 10/28/2019] [Indexed: 12/14/2022]
Abstract
Some toxigenic bacteria produce protein toxins with carcinogenic signatures, which either directly damage DNA or stimulate signalling pathways related to cancer. So far, however, only a few of them have been proved to favour the induction or progression of cancer. In this work, we report that the Rho-activating Escherichia coli protein toxin, cytotoxic necrotising factor 1 (CNF1), induces epithelial to mesenchymal transition (EMT) in intestinal epithelial cells. EMT is a crucial step in malignant tumour conversion and invasiveness. In the case of CNF1, it occurs by up-regulation of the transcription factors ZEB1 and Snail1, delocalisation of E-cadherin and β-catenin, activation of the serine/threonine kinase mTOR, accelerated wound healing, and invasion. However, our results highlight that nontransformed epithelial cells entail the presence of inflammatory factors, in addition to CNF1, to acquire a mesenchymal-like behaviour. All this suggests that the surrounding microenvironment, as well as the cell type, dramatically influences the CNF1 ability to promote carcinogenic traits.
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Affiliation(s)
- Alessia Fabbri
- Italian Center for Global Health, Istituto Superiore di Sanità, Rome, Italy
| | - Sara Travaglione
- Italian Center for Global Health, Istituto Superiore di Sanità, Rome, Italy
| | - Francesca Rosadi
- Italian Center for Global Health, Istituto Superiore di Sanità, Rome, Italy
| | - Giulia Ballan
- Italian Center for Global Health, Istituto Superiore di Sanità, Rome, Italy
| | - Zaira Maroccia
- Italian Center for Global Health, Istituto Superiore di Sanità, Rome, Italy
| | | | - Marco Guidotti
- Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Niels Ødum
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Thorbjørn Krejsgaard
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Carla Fiorentini
- Italian Center for Global Health, Istituto Superiore di Sanità, Rome, Italy.,Preclinical Research Section, Associazione Ricerca Terapie Oncologiche Integrate (ARTOI), Rome, Italy
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16
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Ho M, Mettouchi A, Wilson BA, Lemichez E. CNF1-like deamidase domains: common Lego bricks among cancer-promoting immunomodulatory bacterial virulence factors. Pathog Dis 2018; 76:4992304. [PMID: 29733372 DOI: 10.1093/femspd/fty045] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 05/01/2018] [Indexed: 12/28/2022] Open
Abstract
Alterations of the cellular proteome over time due to spontaneous or toxin-mediated enzymatic deamidation of glutamine (Gln) and asparagine (Asn) residues contribute to bacterial infection and might represent a source of aging-related diseases. Here, we put into perspective what is known about the mode of action of the CNF1 toxin from pathogenic Escherichia coli, a paradigm of bacterial deamidases that activate Rho GTPases, to illustrate the importance of determining whether exposure to these factors are risk factors in the etiology age-related diseases, such as cancer. In particular, through in silico analysis of the distribution of the CNF1-like deamidase active site Gly-Cys-(Xaa)n-His sequence motif in bacterial genomes, we unveil the wide distribution of the super-family of CNF-like toxins and CNF-like deamidase domains among members of the Enterobacteriacae and in association with a large variety of toxin delivery systems. We extent our discussion with recent findings concerning cellular systems that control activated Rac1 GTPase stability and provide protection against cancer. These findings point to the urgency for developing holistic approaches toward personalized medicine that include monitoring for asymptomatic carriage of pathogenic toxin-producing bacteria and that ultimately might lead to improved public health and increased lifespans.
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Affiliation(s)
- Mengfei Ho
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Illinois 61801, USA
| | - Amel Mettouchi
- Bacterial Toxins Unit, Department of Microbiology, Institut Pasteur, 25 Rue du Docteur Roux, 75724 Paris, France
| | - Brenda A Wilson
- Department of Microbiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Illinois 61801, USA
| | - Emmanuel Lemichez
- Bacterial Toxins Unit, Department of Microbiology, Institut Pasteur, 25 Rue du Docteur Roux, 75724 Paris, France
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17
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Wassenaar TM. E. coli and colorectal cancer: a complex relationship that deserves a critical mindset. Crit Rev Microbiol 2018; 44:619-632. [DOI: 10.1080/1040841x.2018.1481013] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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18
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Tantillo E, Colistra A, Vannini E, Cerri C, Pancrazi L, Baroncelli L, Costa M, Caleo M. Bacterial Toxins and Targeted Brain Therapy: New Insights from Cytotoxic Necrotizing Factor 1 (CNF1). Int J Mol Sci 2018; 19:ijms19061632. [PMID: 29857515 PMCID: PMC6032336 DOI: 10.3390/ijms19061632] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 05/07/2018] [Accepted: 05/12/2018] [Indexed: 01/17/2023] Open
Abstract
Pathogenic bacteria produce toxins to promote host invasion and, therefore, their survival. The extreme potency and specificity of these toxins confer to this category of proteins an exceptionally strong potential for therapeutic exploitation. In this review, we deal with cytotoxic necrotizing factor (CNF1), a cytotoxin produced by Escherichia coli affecting fundamental cellular processes, including cytoskeletal dynamics, cell cycle progression, transcriptional regulation, cell survival and migration. First, we provide an overview of the mechanisms of action of CNF1 in target cells. Next, we focus on the potential use of CNF1 as a pharmacological treatment in central nervous system’s diseases. CNF1 appears to impact neuronal morphology, physiology, and plasticity and displays an antineoplastic activity on brain tumors. The ability to preserve neural functionality and, at the same time, to trigger senescence and death of proliferating glioma cells, makes CNF1 an encouraging new strategy for the treatment of brain tumors.
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Affiliation(s)
- Elena Tantillo
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
- Fondazione Pisana per la Scienza Onlus (FPS), via Ferruccio Giovannini 13, San Giuliano Terme, 56017 Pisa, Italy.
| | - Antonella Colistra
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
- Departement of Biology, University of Pisa, via Luca Ghini 13, 56126 Pisa, Italy.
| | - Eleonora Vannini
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
| | - Chiara Cerri
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
- Fondazione Umberto Veronesi, Piazza Velasca 5, 20122 Milano, Italy.
| | - Laura Pancrazi
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
| | - Laura Baroncelli
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
| | - Mario Costa
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
| | - Matteo Caleo
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
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19
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Maroccia Z, Loizzo S, Travaglione S, Frank C, Fabbri A, Fiorentini C. New therapeutics from Nature: The odd case of the bacterial cytotoxic necrotizing factor 1. Biomed Pharmacother 2018; 101:929-937. [PMID: 29635902 DOI: 10.1016/j.biopha.2018.02.140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 02/19/2018] [Accepted: 02/26/2018] [Indexed: 12/13/2022] Open
Abstract
Natural products may represent a rich source of new drugs. The enthusiasm toward this topic has recently been fueled by the 2015 Nobel Prize in Physiology or Medicine, awarded for the discovery of avermectin and artemisinin, natural products from Bacteria and Plantae, respectively, which have targeted one of the major global health issues, the parasitic diseases. Specifically, bacteria either living in the environment or colonizing our body may produce compounds of unexpected biomedical value with the potentiality to be employed as therapeutic drugs. In this review, the fascinating history of CNF1, a protein toxin produced by pathogenic strains of Escherichia coli, is divulged. Even if produced by bacteria responsible for a variety of diseases, CNF1 can behave as a promising benefactor to mankind. By modulating the Rho GTPases, this bacterial product plays a key role in organizing the actin cytoskeleton, enhancing synaptic plasticity and brain energy level, rescuing cognitive deficits, reducing glioma growth in experimental animals. These abilities strongly suggest the need to proceed with the studies on this odd drug in order to pave the way toward clinical trials.
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Affiliation(s)
- Zaira Maroccia
- Italian Centre for Global Health, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy
| | - Stefano Loizzo
- Italian Centre for Global Health, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy
| | - Sara Travaglione
- Italian Centre for Global Health, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy
| | - Claudio Frank
- Italian Centre for Rare Diseases, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy
| | - Alessia Fabbri
- Italian Centre for Global Health, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy
| | - Carla Fiorentini
- Italian Centre for Global Health, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy.
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20
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Du P, Xu B, Zhang D, Shao Y, Zheng X, Li X, Xiong Y, Wu C, Jiang J. Hierarchical investigating the predictive value of p53, COX2, EGFR, nm23 in the post-operative patients with colorectal carcinoma. Oncotarget 2018; 8:954-966. [PMID: 27888614 PMCID: PMC5352209 DOI: 10.18632/oncotarget.13512] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 11/07/2016] [Indexed: 12/11/2022] Open
Abstract
The aim of this study was to evaluate the correlations between p53, COX2, EGFR, nm23 expression and the progression free survival (PFS) of post-operative patients with colorectal carcinoma. Immunohistochemistry was used to detect the expression of p53, COX2, EGFR and nm23 in 459 specimens from colorectal carcinoma patients. Kaplan-Meier estimates, Cox proportional hazard regression analyses and hierarchical analyses were performed on the collected data. Kaplan-Meier estimates analysis suggested that EGFR expression was as a negative predictor, the median PFS of patients with EGFR high expression was 21.73 months, and the median PFS of patients with low EGFR expression was 57.83 months (χ2=20.880, P<0.001); nm23 expression was positive predictive factor for the prognosis of patients with colorectal carcinoma, the median PFS of patients with high nm23 expression was 37.77 months, and the median PFS was 21.47 months in the patients with low nm23 expression (χ2=7.364, P=0.007). Cox regression analysis revealed that comparing with the patients with low expression of EGFR, the patients with high EGFR expression were at higher risk of tumor progression (HR=1.667, P=0.004); Comparing with the patients with high nm23 expression, the patients with nm23 low expression had a higher risk of tumor progression (HR=0.412, P<0.001); and the risk of tumor progression was higher in the patients with high EGFR expression and low nm23 expression (HR=0.245, P<0.001). Hierarchical analysis showed that EGFR expression mainly correlates with the PFS of TNM stage I-II colorectal cancer patients, the median PFS was 33.53 months in the TNM stage I-II colorectal cancer patients with high EGFR expression patients; The median PFS of the TNM stage I-II colorectal cancer patients with low EGFR expression was 70.43 months (χ2=9.530, P=0.002); The median PFS was 19.2 months in the TNM stage III-IV colorectal cancer patients with high expression EGFR, the PFS of the TNM stage III-IV colorectal cancer patients with low EGFR expression was 37.87 months (χ2=7.97, P=0.005). nm23 expression mainly correlates with the PFS of TNM stage III-IV colorecatal cancer patients. The median PFS was 47.27 months in TNM stage I-II colorectal cancer patients with nm23 high expression, the median PFS was 48.85 months in TNM stage I-II colorectal cancer patients with low nm23 expression (χ2=0.101, P=0.750); The median PFS was 28.8 months in TNM stage III-IV colorectal cancer patients with nm23 high expression, the median PFS was 14.7 months in TNM stage III-IV colorectal cancer patients with low nm23 expression (χ2=13.213, P<0.001). EGFR is mainly a predictive factor for the prognosis of post-operative patients with TNM stage I-II colorectal cancer, and nm23 is important for predicting the prognosis of patients with stage III-IV, and EGFR and nm23 could be as predictor of combination.
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Affiliation(s)
- Peng Du
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China.,The Second People's Hospital of Gansu Province, Lanzhou 730000, Gansu, China.,Institute of Cell Therapy, Soochow University, Changzhou, 213003, Jiangsu, China
| | - Bin Xu
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China.,Institute of Cell Therapy, Soochow University, Changzhou, 213003, Jiangsu, China
| | - Dachuan Zhang
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China
| | - Yingjie Shao
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China.,Department of Radiation Oncology, The Third Affiliated Hospital of Soochow University, Changzhou 213003, Jiangsu, China
| | - Xiao Zheng
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China.,Institute of Cell Therapy, Soochow University, Changzhou, 213003, Jiangsu, China
| | - Xiaodong Li
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Department of Oncology, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China
| | - Yuqi Xiong
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China.,Institute of Cell Therapy, Soochow University, Changzhou, 213003, Jiangsu, China
| | - Changping Wu
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Department of Oncology, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China
| | - Jingting Jiang
- Department of Tumor Biological Treatment, The Third Affiliated Hospital, Soochow University, Changzhou 213003, Jiangsu, China.,Jiangsu Engineering Research Center for Tumor Immunotherapy, Changzhou 213003, Jiangsu, China.,Institute of Cell Therapy, Soochow University, Changzhou, 213003, Jiangsu, China
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21
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Khan AA, Khan Z, Malik A, Kalam MA, Cash P, Ashraf MT, Alshamsan A. Colorectal cancer-inflammatory bowel disease nexus and felony of Escherichia coli. Life Sci 2017; 180:60-67. [PMID: 28506682 DOI: 10.1016/j.lfs.2017.05.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 04/24/2017] [Accepted: 05/12/2017] [Indexed: 12/19/2022]
Abstract
Colorectal cancer (CRC) has a multifactorial etiology. Although the exact cause of CRC is still elusive, recent studies have indicated microbial involvement in its etiology. Escherichia coli has emerged as an important factor in CRC development since the bacterium can cause changes in the gut that lead to cancerous transformation. A number of studies indicate that chronic inflammation induced by microorganisms, including E. coli, during inflammatory bowel disease (IBD) predisposes an individual to CRC. The evidence that support the role of E. coli in the etiology of CRC, through IBD, is not limited only to chronic inflammation. The growth of E. coli as an intracellular pathogen during IBD and CRC enable the bacteria to modulate the host cell cycle, induce DNA damage and accumulate mutations. These are some of the contributing factors behind the etiology of CRC. The present article considers the current status of the involvement of E. coli, through IBD, in the etiology of CRC. We discuss how intracellular E. coli infection can cause changes in the gut that can eventually lead to cellular transformation. In addition, the recent management strategies that target E. coli for prevention of CRC are also discussed.
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Affiliation(s)
- Abdul Arif Khan
- Nanomedicine Research Unit, Department of Pharmaceutics, College of Pharmacy, PO Box 2457, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Zakir Khan
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Baverly Blvd., Los Angeles, CA 90048, USA
| | - Abdul Malik
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11451, Saudi Arabia
| | - Mohd Abul Kalam
- Nanomedicine Research Unit, Department of Pharmaceutics, College of Pharmacy, PO Box 2457, King Saud University, Riyadh 11451, Saudi Arabia
| | - Phillip Cash
- The Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | | | - Aws Alshamsan
- Nanomedicine Research Unit, Department of Pharmaceutics, College of Pharmacy, PO Box 2457, King Saud University, Riyadh 11451, Saudi Arabia; King Abdullah Institute for Nanotechnology, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
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22
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Ulc A, Gottschling C, Schäfer I, Wegrzyn D, van Leeuwen S, Luft V, Reinhard J, Faissner A. Involvement of the guanine nucleotide exchange factor Vav3 in central nervous system development and plasticity. Biol Chem 2017; 398:663-675. [DOI: 10.1515/hsz-2016-0275] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/10/2017] [Indexed: 12/13/2022]
Abstract
Abstract
Small GTP-hydrolyzing enzymes (GTPases) of the RhoA family play manifold roles in cell biology and are regulated by upstream guanine nucleotide exchange factors (GEFs). Herein, we focus on the GEFs of the Vav subfamily. Vav1 was originally described as a proto-oncogene of the hematopoietic lineage. The GEFs Vav2 and Vav3 are more broadly expressed in various tissues. In particular, the GEF Vav3 may play important roles in the developing nervous system during the differentiation of neural stem cells into the major lineages, namely neurons, oligodendrocytes and astrocytes. We discuss its putative regulatory roles for progenitor differentiation in the developing retina, polarization of neurons and formation of synapses, migration of oligodendrocyte progenitors and establishment of myelin sheaths. We propose that Vav3 mediates the response of various neural cell types to environmental cues.
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23
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Microbial carcinogenic toxins and dietary anti-cancer protectants. Cell Mol Life Sci 2017; 74:2627-2643. [PMID: 28238104 PMCID: PMC5487888 DOI: 10.1007/s00018-017-2487-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/03/2017] [Accepted: 02/06/2017] [Indexed: 12/16/2022]
Abstract
Several toxins are known which account for the ability of some bacteria to initiate or promote carcinogenesis. These ideas are summarised and evidence is discussed for more specific mechanisms involving chymotrypsin and the bacterial chymotryptic enzyme subtilisin. Subtilisin and Bacillus subtilis are present in the gut and environment and both are used commercially in agriculture, livestock rearing and meat processing. The enzymes deplete cells of tumour suppressors such as deleted in colorectal cancer (DCC) and neogenin, so their potential presence in the food chain might represent an important link between diet and cancer. Over-eating increases secretion of chymotrypsin which is absorbed from the gut and could contribute to several forms of cancer linked to obesity. Inhibition of these serine proteases by Bowman–Birk inhibitors in fruit and vegetables could account for some of the protective effects of a plant-rich diet. These interactions represent previously unknown non-genetic mechanisms for the modification of tumour suppressor proteins and provide a plausible explanation contributing to both the pro-oncogenic effects of meat products and the protective activity of a plant-rich diet. The data suggest that changes to farming husbandry and food processing methods to remove these sources of extrinsic proteases might significantly reduce the incidence of several cancers.
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Rosadi F, Fiorentini C, Fabbri A. Bacterial protein toxins in human cancers. Pathog Dis 2015; 74:ftv105. [DOI: 10.1093/femspd/ftv105] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2015] [Indexed: 12/16/2022] Open
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Manzat-Saplacan RM, Mircea PA, Balacescu L, Chira RI, Berindan-Neagoe I, Balacescu O. Can we change our microbiome to prevent colorectal cancer development? Acta Oncol 2015; 54:1085-95. [PMID: 26073561 DOI: 10.3109/0284186x.2015.1054949] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Colorectal cancer represents an important disease as one of the major causes of death worldwide. Although a lot of genetic and epigenetic research has been conducted, all the pieces of the puzzle of colorectal cancer carcinogenesis have not yet been identified. New recent data has highlighted that gut microbiota could have an influence on colorectal carcinogenesis. Gut microbiota represents the microbe population living in the human intestine and contains tens of trillions of microorganisms. MATERIAL AND METHODS A systematic search in Medline and PubMed for studies reporting the influence of gut microbiota and inflammation on patients with colorectal cancer was made. RESULTS In this review we discuss many of the specific bacteria, as well as their metabolites which may have an important role in development of colorectal cancer. Furthermore, we emphasize the molecular mechanisms modulated by gut microbiota, which promote inflammation, toxic metabolites, DNA damaging and pro-carcinogenic compounds, as support for colorectal carcinogenesis. The interrelation between microbiota and inflammation is complex because bacteria and inflammation could mutually impact upon each other. In this context, both endogenous and exogenous miRNAs may have an important role to modulate tumor-related inflammation in colorectal cancer. CONCLUSIONS Better understanding of the role of gut microbiota in colorectal carcinogenesis could provide promising new directions to improve both prevention and treatment of colorectal cancer. Moreover, the discovery of novel biomarkers in the gut microbiome in order to detect colorectal cancer in an early stage or even in a precancerous stage is of outmost importance.
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Affiliation(s)
- Roberta M Manzat-Saplacan
- a University of Medicine and Pharmacy "Iuliu Hatieganu" Cluj-Napoca, 1st Medical Clinic , Cluj-Napoca , Romania
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Abstract
Microbiome analysis has identified a state of microbial imbalance (dysbiosis) in patients with chronic intestinal inflammation and colorectal cancer. The bacterial phylum Proteobacteria is often overrepresented in these individuals, with Escherichia coli being the most prevalent species. It is clear that a complex interplay between the host, bacteria and bacterial genes is implicated in the development of these intestinal diseases. Understanding the basic elements of these interactions could have important implications for disease detection and management. Recent studies have revealed that E. coli utilizes a complex arsenal of virulence factors to colonize and persist in the intestine. Some of these virulence factors, such as the genotoxin colibactin, were found to promote colorectal cancer in experimental models. In this Review, we summarize key features of the dysbiotic states associated with chronic intestinal inflammation and colorectal cancer, and discuss how the dysregulated interplay between host and bacteria could favor the emergence of E. coli with pathological traits implicated in these pathologies.
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Affiliation(s)
- Ye Yang
- Department of Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Christian Jobin
- Department of Medicine, University of Florida, Gainesville, FL 32611, USA. Department of Infectious Diseases and Pathology, University of Florida, Gainesville, FL 32611, USA.
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Abstract
Patients with cutaneous T-cell lymphoma (CTCL) are frequently colonized with Staphylococcus aureus (SA). Eradication of SA is, importantly, associated with significant clinical improvement, suggesting that SA promotes the disease activity, but the underlying mechanisms remain poorly characterized. Here, we show that SA isolates from involved skin express staphylococcal enterotoxins (SEs) that induce crosstalk between malignant and benign T cells leading to Stat3-mediated interleukin-10 (IL-10) production by the malignant T cells. The SEs did not stimulate the malignant T cells directly. Instead, SEs triggered a cascade of events involving cell-cell and asymmetric cytokine interactions between malignant and benign T cells, which stimulated the malignant T cells to express high levels of IL-10. Much evidence supports that malignant activation of the Stat3/IL-10 axis plays a key role in driving the immune dysregulation and severe immunodeficiency that characteristically develops in CTCL patients. The present findings thereby establish a novel link between SEs and immune dysregulation in CTCL, strengthening the rationale for antibiotic treatment of colonized patients with severe or progressive disease.
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Candela M, Turroni S, Biagi E, Carbonero F, Rampelli S, Fiorentini C, Brigidi P. Inflammation and colorectal cancer, when microbiota-host mutualism breaks. World J Gastroenterol 2014; 20:908-922. [PMID: 24574765 PMCID: PMC3921544 DOI: 10.3748/wjg.v20.i4.908] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 11/26/2013] [Accepted: 12/13/2013] [Indexed: 02/06/2023] Open
Abstract
Structural changes in the gut microbial community have been shown to accompany the progressive development of colorectal cancer. In this review we discuss recent hypotheses on the mechanisms involved in the bacteria-mediated carcinogenesis, as well as the triggering factors favoring the shift of the gut microbiota from a mutualistic to a pro-carcinogenic configuration. The possible role of inflammation, bacterial toxins and toxic microbiota metabolites in colorectal cancer onset is specifically discussed. On the other hand, the strategic role of inflammation as the keystone factor in driving microbiota to become carcinogenic is suggested. As a common outcome of different environmental and endogenous triggers, such as diet, aging, pathogen infection or genetic predisposition, inflammation can compromise the microbiota-host mutualism, forcing the increase of pathobionts at the expense of health-promoting groups, and allowing the microbiota to acquire an overall pro-inflammatory configuration. Consolidating inflammation in the gut, and favoring the bloom of toxigenic bacterial drivers, these changes in the gut microbial ecosystem have been suggested as pivotal in promoting carcinogenesis. In this context, it will become of primary importance to implement dietary or probiotics-based interventions aimed at preserving the microbiota-host mutualism along aging, counteracting deviations that favor a pro-carcinogenic microbiota asset.
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Gómez-Moreno R, Robledo IE, Baerga-Ortiz A. Direct Detection and Quantification of Bacterial Genes Associated with Inflammation in DNA Isolated from Stool. ACTA ACUST UNITED AC 2014; 4:1065-1075. [PMID: 25635239 PMCID: PMC4307837 DOI: 10.4236/aim.2014.415117] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Although predominantly associated with health benefits, the gut microbiota has also been shown to harbor genes that promote inflammation. In this work, we report a method for the direct detection and quantification of these pro-inflammatory bacterial genes by PCR and qPCR in DNA extracted from human stool samples. PCR reactions were performed to detect (i) the pks island genes, (ii) tcpC, which is present in some strains of Escherichia coli and (iii) gelE presented in some strains of Enterococcus faecalis. Additionally, we screened for the presence of the following genes encoding cyclomodulins that disrupted mammalian cell division: (iv) cdt (which encodes the cytolethal distending toxin) and (v) cnf-1 (which encodes the cytotoxic necrotizing factor-1). Our results show that 20% of the samples (N = 41) tested positive for detectable amounts of pks island genes, whereas 10% of individuals were positive for tcpC or gelE and only one individual was found to harbor the cnf-1 gene. Of the 13 individuals that were positive for at least one of the pro-inflammatory genes, 5 were found to harbor more than one. A quantitative version of the assay, which used real-time PCR, revealed the pro-inflammatory genes to be in high copy numbers: up to 1.3 million copies per mg of feces for the pks island genes. Direct detection of specific genes in stool could prove useful toward screening for the presence of pro-inflammatory bacterial genes in individuals with inflammatory bowel diseases or colorectal cancer.
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Affiliation(s)
- Ramón Gómez-Moreno
- Department of Biochemistry, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico ; Molecular Sciences Building, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Iraida E Robledo
- Department of Microbiology and Medical Zoology, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Abel Baerga-Ortiz
- Department of Biochemistry, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico ; Molecular Sciences Building, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
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Cytotoxic necrotizing factor 1 contributes to Escherichia coli meningitis. Toxins (Basel) 2013; 5:2270-80. [PMID: 24284829 PMCID: PMC3847726 DOI: 10.3390/toxins5112270] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 11/13/2013] [Accepted: 11/18/2013] [Indexed: 11/17/2022] Open
Abstract
E. coli is the most common Gram-negative bacteria causing neonatal meningitis, and E. coli meningitis continues to be an important cause of mortality and morbidity throughout the world. Recent reports of E. coli meningitis caused by antimicrobial resistant strains are a particular concern. These findings indicate that a novel strategy is needed to identify new targets for prevention and therapy of E. coli meningitis. Cytotoxic necrotizing factor 1 (CNF1) is a bacterial virulence factor associated principally with E. coli strains causing urinary tract infection and meningitis. We have shown that CNF1 contributes to E. coli invasion of the blood-brain barrier and penetration into the brain, the essential step in the development of E. coli meningitis, and identified the host receptor for CNF1, 37-kDa laminin receptor precursor (37LRP). CNF1, however, is a cytoplasmic protein and its contribution to E. coli invasion of the blood-brain barrier requires its secretion from the bacterial cytoplasm. No signal peptide is found in the CNF1 sequence. CNF1 secretion is, therefore, a strategy utilized by meningitis-causing E. coli to invade the blood-brain barrier. Elucidation of the mechanisms involved in CNF1 secretion, as shown in this report with the involvement of Fdx and YgfZ provides the novel information on potential targets for prevention and therapy of E. coli meningitis by virtue of targeting the secretion of CNF1.
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