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1.
Phytochemistry ; 222: 114101, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38636687

RESUMO

Bafilomycins are macrocyclic polyketides with intriguing structures and therapeutic value. Genomic analysis of Streptomyces sp. SCSIO 66814 revealed a type I polyketide synthase biosynthetic gene cluster (BGC), namely blm, which encoded bafilomycins and featured rich post-modification genes. The One strain many compounds (OSMAC) strategy led to the discovery of six compounds related to the blm BGC from the strain, including two previously undescribed 6,6-spiroketal polyketides, streptospirodienoic acids D (1) and E (2), and four known bafilomycins, bafilomycins P (3), Q (4), D (5), and G (6). The structures of 1 and 2 were determined by extensive spectroscopic analysis, quantum calculation, and biosynthetic analysis. Additionally, the absolute configurations of the 6/5/5 tricyclic ring moiety containing six consecutive chiral carbons in the putative structures of 3 and 4 were corrected through NOE analysis, DP4+ calculation, and single-crystal X-ray diffraction data. Bioinformatic analysis uncovered a plausible biosynthetic pathway for compounds 1-6, indicating that both streptospirodienoic acids and bafilomycins were derived from the same blm BGC. Additionally, sequence analysis revealed that the KR domains of module 2 from blm BGC was B1-type, further supporting the configurations of 1-4. Notably, compounds 3 and 4 displayed significant cytotoxic activities against A-549 human non-small cell lung cancer cells and HCT-116 human colon cancer cells.


Assuntos
Policetídeos , Streptomyces , Streptomyces/química , Streptomyces/metabolismo , Streptomyces/genética , Policetídeos/química , Policetídeos/farmacologia , Policetídeos/isolamento & purificação , Humanos , Estereoisomerismo , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Macrolídeos/química , Macrolídeos/farmacologia , Macrolídeos/isolamento & purificação , Macrolídeos/metabolismo , Proliferação de Células/efeitos dos fármacos , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Compostos de Espiro/isolamento & purificação , Relação Estrutura-Atividade , Policetídeo Sintases/metabolismo , Policetídeo Sintases/genética , Linhagem Celular Tumoral , Genoma Bacteriano , Família Multigênica
2.
Hum Vaccin Immunother ; 20(1): 2337987, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38658133

RESUMO

There is a growing interest in development of novel vaccines against respiratory tract infections, due to COVID-19 pandemic. Here, we examined mucosal adjuvanticity and the mucosal booster effect of membrane vesicles (MVs) of a novel probiotic E. coli derivative lacking both flagella and potentially carcinogenic colibactin (ΔflhDΔclbP). ΔflhDΔclbP-derived MVs showed rather strong mucosal adjuvanticity as compared to those of a single flagellar mutant strain (ΔflhD-MVs). In addition, glycoengineered ΔflhDΔclbP-MVs displaying serotype-14 pneumococcal capsular polysaccharide (CPS14+MVs) were well-characterized based on biological and physicochemical parameters. Subcutaneous (SC) and intranasal (IN) booster effects of CPS14+MVs on systemic and mucosal immunity were evaluated in mice that have already been subcutaneously prime-immunized with the same MVs. With a two-dose regimen, an IN boost (SC-IN) elicited stronger IgA responses than homologous prime-boost immunization (SC-SC). With a three-dose regimen, serum IgG levels were comparable among all tested regimens. Homologous immunization (SC-SC-SC) elicited the highest IgM responses among all regimens tested, whereas SC-SC-SC failed to elicit IgA responses in blood and saliva. Furthermore, serum IgA and salivary SIgA levels were increased with an increased number of IN doses administrated. Notably, SC-IN-IN induced not only robust IgG response, but also the highest IgA response in both serum and saliva among the groups. The present findings suggest the potential of a heterologous three-dose administration for building both systemic and mucosal immunity, e.g. an SC-IN-IN vaccine regimen could be beneficial. Another important observation was abundant packaging of colibactin in MVs, suggesting increased applicability of ΔflhDΔclbP-MVs in the context of vaccine safety.


Assuntos
Adjuvantes Imunológicos , Escherichia coli , Imunidade nas Mucosas , Imunização Secundária , Camundongos Endogâmicos BALB C , Policetídeos , Probióticos , Animais , Camundongos , Probióticos/administração & dosagem , Escherichia coli/imunologia , Imunização Secundária/métodos , Feminino , Adjuvantes Imunológicos/administração & dosagem , Imunoglobulina A , Peptídeos/imunologia , Administração Intranasal , Imunoglobulina G/sangue , Imunoglobulina M , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem
3.
J Agric Food Chem ; 72(17): 9555-9566, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38648511

RESUMO

The filamentous fungus Penicillium sclerotiorum is significant in ecological and industrial domains due to its vast supply of secondary metabolites that have a diverse array of biological functions. We have gathered the metabolic potential and biological activities associated with P. sclerotiorum metabolites of various structures, based on extensive research of the latest literature. The review incorporated literature spanning from 2000 to 2023, drawing from reputable databases including Google Scholar, ScienceDirect, Scopus, and PubMed, among others. Ranging from azaphilones, meroterpenoids, polyketides, and peptides group exhibits fascinating potential pharmacological activities such as antimicrobial, anti-inflammatory, and antitumor effects, holding promise in pharmaceutical and industrial sectors. Additionally, P. sclerotiorum showcases biotechnological potential through the production of enzymes like ß-xylosidases, ß-d-glucosidase, and xylanases, pivotal in various industrial processes. This review underscores the need for further exploration into its genetic foundations and cultivation conditions to optimize the yield of valuable compounds and enzymes, highlighting the unexplored potential of P. sclerotiorum in diverse applications across industries.


Assuntos
Penicillium , Metabolismo Secundário , Penicillium/metabolismo , Humanos , Animais , Policetídeos/metabolismo , Policetídeos/química , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Anti-Inflamatórios/metabolismo , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia
5.
J Nat Prod ; 87(3): 591-599, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38442389

RESUMO

A new polyol polyketide, named retinestatin (1), was obtained and characterized from the culture of a Streptomyces strain, which was isolated from a subterranean nest of the termite Reticulitermes speratus kyushuensis Morimoto. The planar structure of 1 was elucidated on the basis of the cumulative analysis of ultraviolet, infrared, mass spectrometry, and nuclear magnetic resonance spectroscopic data. The absolute configuration of 1 at 12 chiral centers was successfully assigned by employing a J-based configuration analysis in combination with ROESY correlations, a quantum mechanics-based computational approach to calculate NMR chemical shifts, and a 3 min flash esterification by Mosher's reagents followed by NMR analysis. Biological evaluation of retinestatin (1) using an in vitro model of Parkinson's disease revealed that 1 protected SH-SY5Y dopaminergic cells from MPP+-induced cytotoxicity, indicating its neuroprotective effects.


Assuntos
Isópteros , Neuroblastoma , Policetídeos , Polímeros , Streptomyces , Animais , Humanos , Policetídeos/química , Estrutura Molecular , Streptomyces/química
6.
ISME J ; 18(1)2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38547398

RESUMO

The hypervirulent lineages of Klebsiella pneumoniae (HvKp) cause invasive infections such as Klebsiella-liver abscess. Invasive infection often occurs after initial colonization of the host gastrointestinal tract by HvKp. Over 80% of HvKp isolates belong to the clonal group 23 sublineage I that has acquired genomic islands (GIs) GIE492 and ICEKp10. Our analysis of 12 361 K. pneumoniae genomes revealed that GIs GIE492 and ICEKp10 are co-associated with the CG23-I and CG10118 HvKp lineages. GIE492 and ICEKp10 enable HvKp to make a functional bacteriocin microcin E492 (mccE492) and the genotoxin colibactin, respectively. We discovered that GIE492 and ICEKp10 play cooperative roles and enhance gastrointestinal colonization by HvKp. Colibactin is the primary driver of this effect, modifying gut microbiome diversity. Our in vitro assays demonstrate that colibactin and mccE492 kill or inhibit a range of Gram-negative Klebsiella species and Escherichia coli strains, including Gram-positive bacteria, sometimes cooperatively. Moreover, mccE492 and colibactin kill human anaerobic gut commensals that are similar to the taxa found altered by colibactin in the mouse intestines. Our findings suggest that GIs GIE492 and ICEKp10 enable HvKp to kill several commensal bacterial taxa during interspecies interactions in the gut. Thus, acquisition of GIE492 and ICEKp10 could enable better carriage in host populations and explain the dominance of the CG23-I HvKp lineage.


Assuntos
Ilhas Genômicas , Klebsiella pneumoniae , Peptídeos , Policetídeos , Animais , Camundongos , Humanos , Virulência , Klebsiella pneumoniae/genética , Fatores de Virulência/genética , Antibacterianos/farmacologia
7.
Cancer Cell ; 42(3): 487-496.e6, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38471458

RESUMO

Co-culture of intestinal organoids with a colibactin-producing pks+E. coli strain (EcC) revealed mutational signatures also found in colorectal cancer (CRC). E. coli Nissle 1917 (EcN) remains a commonly used probiotic, despite harboring the pks operon and inducing double strand DNA breaks. We determine the mutagenicity of EcN and three CRC-derived pks+E. coli strains with an analytical framework based on sequence characteristic of colibactin-induced mutations. All strains, including EcN, display varying levels of mutagenic activity. Furthermore, a machine learning approach attributing individual mutations to colibactin reveals that patients with colibactin-induced mutations are diagnosed at a younger age and that colibactin can induce a specific APC mutation. These approaches allow the sensitive detection of colibactin-induced mutations in ∼12% of CRC genomes and even in whole exome sequencing data, representing a crucial step toward pinpointing the mutagenic activity of distinct pks+E. coli strains.


Assuntos
Neoplasias Colorretais , Escherichia coli , Peptídeos , Policetídeos , Humanos , Escherichia coli/genética , Mutação , Dano ao DNA , Mutagênicos , Organoides
9.
Cancer Sci ; 115(4): 1184-1195, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38297479

RESUMO

A significant association exists between the gut microbiome and colorectal carcinogenesis, as well as cancer progression. It has been reported that Escherichia coli (E. coli) containing polyketide synthetase (pks) island contribute to colorectal carcinogenesis by producing colibactin, a polyketide-peptide genotoxin. However, the functions of pks+ E. coli in initiation, proliferation, and metastasis of colorectal cancer (CRC) remain unclear. We investigated the clinical significance of pks+ E. coli to clarify its functions in CRC. This study included 413 patients with CRC. Pks+ E. coli of tumor tissue and normal mucosal tissue were quantified using droplet digital PCR. Pks+ E. coli was more abundant in Stages 0-I tumor tissue than in normal mucosal tissue or in Stages II-IV tumor tissue. High abundance of pks+ E. coli in tumor tissue was significantly associated with shallower tumor depth (hazard ratio [HR] = 5.0, 95% confidence interval [CI] = 2.3-11.3, p < 0.001) and absence of lymph node metastasis (HR = 3.0, 95% CI = 1.8-5.1, p < 0.001) in multivariable logistic analyses. Pks+ E. coli-low and -negative groups were significantly associated with shorter CRC-specific survival (HR = 6.4, 95% CI = 1.7-25.6, p = 0.005) and shorter relapse-free survival (HR = 3.1, 95% CI = 1.3-7.3, p = 0.01) compared to the pks+ E. coli-high group. Pks+ E. coli was abundant in Stages 0-I CRC and associated with CRC prognosis. These results suggest that pks+ E. coli might contribute to carcinogenesis of CRC but might not be associated with tumor progression.


Assuntos
Neoplasias Colorretais , Policetídeos , Humanos , Escherichia coli/genética , Recidiva Local de Neoplasia , Mucosa , Carcinogênese
10.
Microbiology (Reading) ; 170(2)2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38314762

RESUMO

The biosynthetic machinery for the production of colibactin is encoded by 19 genes (clbA - S) within the pks pathogenicity island harboured by many E. coli of the B2-phylogroup. Colibactin is a potent genotoxic metabolite which causes DNA-damage and which has potential roles in microbial competition and fitness of pks+ bacteria. Colibactin has also been strongly implicated in the development of colorectal cancer. Given the genotoxicity of colibactin and the metabolic cost of its synthesis, the regulatory system governing the clb cluster is accordingly highly complex, and many of the mechanisms remain to be elucidated. In this review we summarise the current understanding of regulation of colibactin biosynthesis by internal molecular components and how these factors are modulated by signals from the external environment.


Assuntos
Proteínas de Escherichia coli , Policetídeos , Escherichia coli/genética , Escherichia coli/metabolismo , Peptídeos/genética , Peptídeos/metabolismo , Proteínas de Escherichia coli/metabolismo , Policetídeos/metabolismo
11.
Mar Drugs ; 22(2)2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38393041

RESUMO

Marine fungi, such as species from the Penicillium and Aspergillus genera, are prolific producers of a diversity of natural products with cytotoxic properties. These fungi have been successfully isolated and identified from various marine sources, including sponges, coral, algae, mangroves, sediment, and seawater. The cytotoxic compounds derived from marine fungi can be categorized into five distinct classes: polyketides, peptides, terpenoids and sterols, hybrids, and other miscellaneous compounds. Notably, the pre-eminent group among these compounds comprises polyketides, accounting for 307 out of 642 identified compounds. Particularly, within this collection, 23 out of the 642 compounds exhibit remarkable cytotoxic potency, with IC50 values measured at the nanomolar (nM) or nanogram per milliliter (ng/mL) levels. This review elucidates the originating fungal strains, the sources of isolation, chemical structures, and the noteworthy antitumor activity of the 642 novel natural products isolated from marine fungi. The scope of this review encompasses the period from 1991 to 2023.


Assuntos
Antineoplásicos , Produtos Biológicos , Policetídeos , Fungos/química , Aspergillus , Antineoplásicos/farmacologia , Produtos Biológicos/química , Policetídeos/química
12.
Gut Microbes ; 16(1): 2320291, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38417029

RESUMO

Intratumoral bacteria flexibly contribute to cellular and molecular tumor heterogeneity for supporting cancer recurrence through poorly understood mechanisms. Using spatial metabolomic profiling technologies and 16SrRNA sequencing, we herein report that right-sided colorectal tumors are predominantly populated with Colibactin-producing Escherichia coli (CoPEC) that are locally establishing a high-glycerophospholipid microenvironment with lowered immunogenicity. It coincided with a reduced infiltration of CD8+ T lymphocytes that produce the cytotoxic cytokines IFN-γ where invading bacteria have been geolocated. Mechanistically, the accumulation of lipid droplets in infected cancer cells relied on the production of colibactin as a measure to limit genotoxic stress to some extent. Such heightened phosphatidylcholine remodeling by the enzyme of the Land's cycle supplied CoPEC-infected cancer cells with sufficient energy for sustaining cell survival in response to chemotherapies. This accords with the lowered overall survival of colorectal patients at stage III-IV who were colonized by CoPEC when compared to patients at stage I-II. Accordingly, the sensitivity of CoPEC-infected cancer cells to chemotherapies was restored upon treatment with an acyl-CoA synthetase inhibitor. By contrast, such metabolic dysregulation leading to chemoresistance was not observed in human colon cancer cells that were infected with the mutant strain that did not produce colibactin (11G5∆ClbQ). This work revealed that CoPEC locally supports an energy trade-off lipid overload within tumors for lowering tumor immunogenicity. This may pave the way for improving chemoresistance and subsequently outcome of CRC patients who are colonized by CoPEC.


Assuntos
Neoplasias Colorretais , Microbioma Gastrointestinal , Peptídeos , Policetídeos , Humanos , Escherichia coli/genética , Escherichia coli/metabolismo , Microambiente Tumoral , Resistencia a Medicamentos Antineoplásicos , Mutagênicos/metabolismo , Recidiva Local de Neoplasia , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/microbiologia , Policetídeos/metabolismo , Lipídeos
13.
Gut Microbes ; 16(1): 2310215, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38374654

RESUMO

Human colorectal cancers (CRCs) are readily colonized by colibactin-producing E. coli (CoPEC). CoPEC induces DNA double-strand breaks, DNA mutations, genomic instability, and cellular senescence. Infected cells produce a senescence-associated secretory phenotype (SASP), which is involved in the increase in tumorigenesis observed in CRC mouse models infected with CoPEC. This study investigated whether CoPEC, and the SASP derived from CoPEC-infected cells, impacted chemotherapeutic resistance. Human intestinal epithelial cells were infected with the CoPEC clinical 11G5 strain or with its isogenic mutant, which is unable to produce colibactin. Chemotherapeutic resistance was assessed in vitro and in a xenograft mouse model. Expressions of cancer stem cell (CSC) markers in infected cells were investigated. Data were validated using a CRC mouse model and human clinical samples. Both 11G5-infected cells, and uninfected cells incubated with the SASP produced by 11G5-infected cells exhibited an increased resistance to chemotherapeutic drugs in vitro and in vivo. This finding correlated with the induction of the epithelial to mesenchymal transition (EMT), which led to the emergence of cells exhibiting CSC features. They grew on ultra-low attachment plates, formed colonies in soft agar, and overexpressed several CSC markers (e.g. CD133, OCT-3/4, and NANOG). In agreement with these results, murine and human CRC biopsies colonized with CoPEC exhibited higher expression levels of OCT-3/4 and NANOG than biopsies devoid of CoPEC. Conclusion: CoPEC might aggravate CRCs by inducing the emergence of cancer stem cells that are highly resistant to chemotherapy.


Assuntos
Microbioma Gastrointestinal , Neoplasias , Peptídeos , Policetídeos , Humanos , Camundongos , Animais , Escherichia coli/genética , Escherichia coli/metabolismo , Transição Epitelial-Mesenquimal , Mutagênicos/metabolismo , Policetídeos/farmacologia , Policetídeos/metabolismo , Modelos Animais de Doenças , Células-Tronco Neoplásicas/metabolismo
14.
Molecules ; 29(3)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38338359

RESUMO

In this study, two previously undescribed nitrogen-containing compounds, penisimplicins A (1) and B (2), were isolated from Penicillium simplicissimum JXCC5. The structures of 1 and 2 were elucidated on the basis of comprehensive spectroscopic data analysis, including 1D and 2D NMR and HRESIMS data. The absolute configuration of 2 was determined by Marfey's method, ECD calculation, and DP4+ analysis. Both structures of 1 and 2 feature an unprecedented manner of amino acid-derivatives attaching to a polyketide moiety by C-C bond. The postulated biosynthetic pathways for 1 and 2 were discussed. Additionally, compound 1 exhibited significant acetylcholinesterase inhibitory activity, with IC50 values of 6.35 µM.


Assuntos
Alcaloides , Penicillium , Policetídeos , Estrutura Molecular , Policetídeos/química , Acetilcolinesterase/metabolismo , Penicillium/química , Peptídeos/metabolismo , Alcaloides/química
15.
J Cancer Res Clin Oncol ; 150(2): 58, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38294686

RESUMO

OBJECTIVE: The purpose of this study was to compare the antitumor efficacy of anlotinib with gemcitabine-based chemotherapy as subsequent treatment regimens in patients with advanced non-specific soft tissue sarcoma (STS) after the failure of anthracycline-based chemotherapy. METHODS: Patients diagnosed with advanced STS who were treated with either anlotinib or gemcitabine-based chemotherapy between May 2009 and May 2023 in our center were eligible. All patients experienced disease progression or recurrence after the anthracycline-based chemotherapy. The primary endpoint was progression-free survival (PFS). Secondary endpoints were disease control rate (DCR), overall survival (OS) and safety. RESULTS: We included 49 patients receiving anlotinib and 45 patients receiving gemcitabine-based chemotherapy. The median follow-up time was 76.9 weeks (range 2.9-678.9 weeks). The DCR (65.3% vs. 57.8%; p = 0.610), PFS (24.0 weeks vs. 18.6 weeks; p = 0.669) and OS (79.4 weeks vs. 87.0 weeks; p = 0.471) of anlotinib and gemcitabine-based chemotherapy indicated similar clinical efficacy. Moreover, exploratory subgroup analyses showed that patients with STS originating from limbs and trunk were inclined to benefit from anlotinib treatment (median PFS: 31.3 weeks vs. 12.4 weeks; p = 0.045). ECOG PS was an independent predictor of the PFS [Hazard Ratio (HR) 0.31; 95% confidence interval (CI) 0.11-0.85; p = 0.023] and OS (HR 0.26, 95%CI 0.10-0.70; p = 0.008) in the anlotinib group. While neutrophil-to-lymphocyte ratio (NLR) was an independent prognostic factor of the PFS (HR 0.33, 95%CI 0.11-0.98; p = 0.045) in the gemcitabine-based chemotherapy group. The incidence of grade 3 or higher related AEs in anlotinib and gemcitabine-based chemotherapy was 20.4% (n = 10) and 20.0% (n = 9), respectively. CONCLUSION: Our research suggested that anlotinib and gemcitabine-based chemotherapy showed similar clinical efficacy and safety in the subsequent treatment of advanced STS after the failure of anthracycline-based chemotherapy.


Assuntos
Policetídeos , Quinolinas , Sarcoma , Humanos , Gencitabina , Antraciclinas , Indóis/efeitos adversos , Antibióticos Antineoplásicos , Sarcoma/tratamento farmacológico
16.
Cancer Epidemiol Biomarkers Prev ; 33(4): 534-546, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38252034

RESUMO

BACKGROUND: The genotoxin colibactin causes a tumor single-base substitution (SBS) mutational signature, SBS88. It is unknown whether epidemiologic factors' association with colorectal cancer risk and survival differs by SBS88. METHODS: Within the Genetic Epidemiology of Colorectal Cancer Consortium and Colon Cancer Family Registry, we measured SBS88 in 4,308 microsatellite stable/microsatellite instability low tumors. Associations of epidemiologic factors with colorectal cancer risk by SBS88 were assessed using multinomial regression (N = 4,308 cases, 14,192 controls; cohort-only cases N = 1,911), and with colorectal cancer-specific survival using Cox proportional hazards regression (N = 3,465 cases). RESULTS: 392 (9%) tumors were SBS88 positive. Among all cases, the highest quartile of fruit intake was associated with lower risk of SBS88-positive colorectal cancer than SBS88-negative colorectal cancer [odds ratio (OR) = 0.53, 95% confidence interval (CI) 0.37-0.76; OR = 0.75, 95% CI 0.66-0.85, respectively, Pheterogeneity = 0.047]. Among cohort studies, associations of body mass index (BMI), alcohol, and fruit intake with colorectal cancer risk differed by SBS88. BMI ≥30 kg/m2 was associated with worse colorectal cancer-specific survival among those SBS88-positive [hazard ratio (HR) = 3.40, 95% CI 1.47-7.84], but not among those SBS88-negative (HR = 0.97, 95% CI 0.78-1.21, Pheterogeneity = 0.066). CONCLUSIONS: Most epidemiologic factors did not differ by SBS88 for colorectal cancer risk or survival. Higher BMI may be associated with worse colorectal cancer-specific survival among those SBS88-positive; however, validation is needed in samples with whole-genome or whole-exome sequencing available. IMPACT: This study highlights the importance of identification of tumor phenotypes related to colorectal cancer and understanding potential heterogeneity for risk and survival.


Assuntos
Neoplasias Colorretais , Instabilidade de Microssatélites , Peptídeos , Policetídeos , Humanos , Dano ao DNA , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/genética , Fatores Epidemiológicos , Fatores de Risco
17.
Cell Rep Med ; 5(2): 101376, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38228147

RESUMO

The bacterial genotoxin colibactin promotes colorectal cancer (CRC) tumorigenesis, but systematic assessment of its impact on DNA repair is lacking, and its effect on response to DNA-damaging chemotherapeutics is unknown. We find that CRC cell lines display differential response to colibactin on the basis of homologous recombination (HR) proficiency. Sensitivity to colibactin is induced by inhibition of ATM, which regulates DNA double-strand break repair, and blunted by HR reconstitution. Conversely, CRC cells chronically infected with colibactin develop a tolerant phenotype characterized by restored HR activity. Notably, sensitivity to colibactin correlates with response to irinotecan active metabolite SN38, in both cell lines and patient-derived organoids. Moreover, CRC cells that acquire colibactin tolerance develop cross-resistance to SN38, and a trend toward poorer response to irinotecan is observed in a retrospective cohort of CRCs harboring colibactin genomic island. Our results shed insight into colibactin activity and provide translational evidence on its chemoresistance-promoting role in CRC.


Assuntos
Neoplasias Colorretais , Escherichia coli , Peptídeos , Policetídeos , Humanos , Irinotecano/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Estudos Retrospectivos , DNA/metabolismo , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/microbiologia
18.
Life Sci ; 341: 122462, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38281542

RESUMO

Colorectal cancer (CRC) remains a significant global health concern, necessitating continuous investigation into its etiology and potential risk factors. Recent research has shed light on the potential role of pKs-positive Escherichia coli (pKs + E. coli) and colibactin in the development and progression of CRC. Therefore, this review aimed to provide an updated analysis of the prevalence and implications of pKs + E. coli in colorectal cancer. We conducted a literature review search in major scientific databases to identify relevant studies exploring the association between pKs + E. coli and CRC. The search strategy included studies published up to the present date, and articles were carefully selected based on predefined inclusion criteria. Thus, the present study encompasses scientific evidence from clinical and epidemiological studies supporting the presence of pKs + E. coli in CRC patients, demonstrating a consistent and significant association in multiple studies. Furthermore, we highlighted the potential mechanisms by which colibactin may promote tumorigenesis and cancer progression within the colorectal mucosa, including the production of genotoxic virulence factors. Additionally, we explored current diagnostic methods for detecting pKs + E. coli in clinical settings, emphasizing the importance of accurate identification. Moreover, we discussed future strategies that could utilize the presence of this strain as a biomarker for CRC diagnosis and treatment. In conclusion, this review consolidated existing evidence on the prevalence and implications of pKs + E. coli in colorectal cancer. The findings underscore the importance of further research to elucidate the precise mechanisms linking this strain to CRC pathogenesis and to explore its potential as a therapeutic target or diagnostic marker. Ultimately, a better understanding of the role of pKs + E. coli in CRC may pave the way for innovative strategies in CRC management and patient care.


Assuntos
Neoplasias Colorretais , Escherichia coli , Policetídeos , Humanos , Prevalência , Peptídeos , Neoplasias Colorretais/epidemiologia
19.
Cancer Med ; 13(3): e6857, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38204211

RESUMO

BACKGROUND: Myocardial work (MW) is a new echocardiographic tool with a high sensitivity to detect early and subtle alterations of myocardial function. We aimed to evaluate the late effects of anthracyclines by assessing the global and segmental MW and intraventricular mechanical dispersion from speckle tracking echocardiography in childhood lymphoma survivors (CLS). METHODS: Thirty-one young adults including CLS and age-matched healthy controls were enrolled. All underwent echocardiography including an evaluation of left ventricular (LV) morphology and regional function. We assessed LV longitudinal (differentiating sub-endocardial and sub-epicardial layers), circumferential strains and twist, global and regional MW index (MWI). LV mechanical dispersion was assessed from the time dispersion of LV longitudinal strain, from myocardial wasted work (MWW) and myocardial work efficiency (MWE). RESULTS: The longitudinal strains both at the level of the sub-endocardium and sub-epicardium were reduced in CLS compared to controls. The global MWI was also decreased (1668 ± 266 vs 1870 ± 264%.mmHg in CLS patients and controls, respectively, p < 0.05), especially on the apical segments. An increase of LV intraventricular mechanical dispersion was observed in CLS. MWW and MWE remained unchanged compared to controls. CONCLUSION: Our results strongly support that cardiac remodeling is observed in CLS, characterized by a decrease in MW and an increase in LV mechanical dispersion. The apex is specifically altered, but its clinical significance remains uncertain. MW as a complement to strain seems interesting in cancer survivors to detect myocardial dysfunction at early stage and adapt their follow-up.


Assuntos
Linfoma , Policetídeos , Humanos , Adolescente , Adulto Jovem , Cardiotoxicidade/etiologia , Antraciclinas/efeitos adversos , Miocárdio , Coração , Antibióticos Antineoplásicos
20.
Int J Mol Sci ; 25(1)2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38203818

RESUMO

Epirubicin hydrochloride (EPI) is an anticancer drug widely used in the treatment of many solid tumors, including ovarian cancer. Because of its anatomical location, ovarian cancer shows symptoms when it is already in an advanced stage and is thus more difficult to treat. Epirubicin hydrochloride kills cancer cells effectively, but its dose escalation is limited by its severe toxicity. By encapsulating epirubicin in dextran-based nanoparticles (POLEPI), we expected to deliver higher and thus clinically more effective doses directly to tumors, where epirubicin would be released and retained longer in the tumor. The antitumor activity of POLEPI compared to EPI was first tested ex vivo in a series of ovarian cancer patient-derived tumor xenografts (PDX). The most promising PDX was then implanted orthotopically into immunocompromised mice, and tumor growth was monitored via magnetic resonance imaging (MRI). Although we succeeded in suppressing the growth of ovarian cancer derived from a patient, in a mouse model by 70% compared to 40% via EPI in 5 days after only one injection, we could not eliminate serious side effects, and the study was terminated prematurely for humane reasons.


Assuntos
Nanopartículas , Neoplasias Ovarianas , Policetídeos , Humanos , Animais , Camundongos , Feminino , Epirubicina/farmacologia , Epirubicina/uso terapêutico , Xenoenxertos , Antraciclinas , Neoplasias Ovarianas/tratamento farmacológico , Modelos Animais de Doenças
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