Gastric cancer (GC) is a malignant neoplasm displaying highly cancer-related mortality globally. Although our previous studies have confirmed that vitamin D possessed a direct anti-cancer effect on GC cells, the regulatory role of vitamin D on gastric tumor microenvironment (TME) remains unexplored. This study aims to expound the modulation of vitamin D on TME especially on GC-associated fibroblasts (CAFs) and to further elucidate the essential role of the CAFs-derived exosomal ingredients in tumor-stroma crosstalk. Patient-derived primary CAFs enhanced the aggressive characteristics of GC cells. When co-cultured with GC cells, CAFs pretreated with 1,25(OH)2D3 (1,25D3), the active form of vitamin D exhibited a significant inhibitory effect on cancer cell invasion and migration. Additionally, exosomes isolated from 1,25D3-pretreated CAFs were found to mediate this inhibitory effect, significantly reducing the migratory and invasive capacity of GC cells. Exosomal RNA sequencing revealed a significant upregulation of miR-378c in CAF-derived exosomes following 1,25D3 treatment. Fluorescence tracing assays confirmed that this treatment augmented the transfer of CAF-derived exosomal miRNA-378c into GC cells. Mechanistically, this elevated miR-378c directly targeted ketodihydrosphinganine reductase (KDSR) in GC cells, further leading to the attenuation of tumor growth in a 615 mice model. Immunophenotypic analysis further revealed that treatment with ago-miR-378c significantly increased intratumoral Granzyme B and CD3 levels and downregulated Foxp3 expression, indicating an activated state of antitumor immunity and a relief from immune suppression within the TME. Correspondingly, the expression of TNF-α and IL-6 was found to be up-regulated, while the immunosuppressive factor IL-10 was reduced in the ago-miR-378c group in comparison to the control group. Moreover, systemic administration of vitamin D suppressed CAF-mediated promotion of in vivo tumor growth, concomitant with elevated intratumoral miR-378c and diminished KDSR expression in a nude mice model. Taken together, our results demonstrate that vitamin D reprograms CAFs to impede GC progression and to promote an anti-tumor immune microenvironment, which might be mediated by exosomal miR-378c/KDSR axis, highlighting a potential therapeutic strategy of using vitamin D to counteract CAF-driven oncogenesis in GC.
Chlorogenic acid (CA), a principal bioactive constituent prevalent in numerous Chinese herbal medicines, exhibits well-documented antibacterial efficacy. However, CA is rapidly metabolized in the intestine and liver, and the specific mechanisms of its metabolites against Pseudomonas aeruginosa (P. aeruginosa) biofilms remain unclear. This study demonstrated that shikimic acid, a key metabolite of CA, effectively inhibits biofilm formation in clinical P. aeruginosa strains without impeding bacterial growth. This antibiofilm activity was linked to the significant suppression of extracellular polymeric substance (EPS) and alginate production, as well as the impairment of bacterial motility. By integrating transcriptome analysis with RT-PCR validation, it is postulated that the antibiofilm action of shikimic acid may be attributed to its regulatory effects on the constituents of the EPS within the biofilm, especially extracellular polysaccharides. Moreover, shikimic acid predominantly downregulated genes associated with alginate synthesis, among which algD exhibited the most significant expression alteration. In order to ascertain the role of algD in the antibiofilm action of shikimic acid, an algD knockout strain, PA2209ΔalgD, was constructed. The results demonstrated that shikimic acid did not exerted notable inhibitory effects on biofilm formation or alginate production in the algD knockout strains, suggesting that the algD gene is essential for the antibiofilm effect of shikimic acid. These findings elucidate a novel mechanism by which a CA-derived metabolite disrupts biofilm integrity by targeting the algD-dependent alginate biosynthesis pathway, positioning shikimic acid as a potential lead for developing non-bactericidal anti-biofilm agents.
Erycristagallin, a prenylated flavonoid natural product, has remained underexplored due to limited availability and incomplete mechanistic characterization. We herein report the first total synthesis of erycristagallin, which was accomplished in 7 linear steps from commercially available starting materials and was readily performed on a gram scale. Mechanistic studies revealed a concentration-dependent membrane-targeting mode of action. At lower concentrations, erycristagallin caused membrane perturbation and functional impairment, whereas at higher concentrations, it caused extensive membrane damage. Erycristagallin also showed in vivo efficacy in a murine MRSA-infected skin wound model, and together these findings establish it as a promising anti-MRSA lead for further optimization and development.
Bacterial biofilms, spatially and physiologically heterogeneous communities, protect pathogens from antibiotics and drive persistent infections, particularly those caused by the clinically challenging methicillin-resistant Staphylococcus aureus (MRSA). Such biofilm-mediated protection poses a major obstacle to antibiotic therapy, rendering quinolone antibiotics markedly less effective owing to their limited penetration into the biofilm matrix and the intrinsic tolerance of sessile bacteria. Therefore, strategies capable of overcoming biofilm-associated resistance and restoring the therapeutic potential of legacy quinolone antibiotics are urgently needed. Herein, a multifunctional molecular platform, AFQ-BP, was rationally developed to serve as a dual antibiofilm and antibacterial agent. Nineteen novel derivatives were designed and synthesized, 21 and 22 exhibited strong antibacterial activity, comparable to that of frontline antibiotics such as ampicillin and ciprofloxacin. Notably, the lead candidate 22 (MIC = 2 µg/mL against MRSA 21-5) suppressed biofilm formation by 69.6
The rising prevalence of multidrug-resistant pathogens poses a substantial threat to global healthcare systems, demanding urgent therapeutic interventions. Microorganisms exhibit diverse resistance mechanisms against various classes of antibiotics, highlighting the urgent need to discover novel antimicrobial agents for combating bacterial infections. Anti-virulence therapy has emerged as a promising therapeutic strategy that neutralizes pathogens by targeting their virulence determinants. The strategies for screening virulence arresting drugs (VADs) in bacteria represent a multifaceted approach that involves elucidating molecular pathogenesis mechanisms of bacterial pathogenicity, identifying evolutionarily conserved virulence factors across different pathogens, and employing integrated approaches combining in silico prediction with experimental validation. Recent technological advancements have established standardized protocols for effective identification and validation of anti-virulence compounds. This review systematically examines contemporary screening methodologies, primarily focusing on quorum-sensing disruption and biofilm suppression strategies, including in silico screening, activity-based screening with bioassays, in vitro and in vivo models. Additionally, we emphasize the imperative for standardized preclinical validation through physiologically relevant animal models, while proposing framework recommendations for developing next-generation VAD screening platforms. This synthesis not only outlines current best practices but also proposes innovative avenues for future antimicrobial discovery research.
Lupalbigenin (1) is an antibacterial isoflavone isolated from Maclura cochinchinensis (Lour.) Corner (Moraceae). In this study, we achieved the first gram-scale synthesis of lupalbigenin (1) from commercially available genistein (2), with a yield of 47.7%. The key step was a Claisen rearrangement that simultaneously installed two prenyl groups at the C-6 and C-11 positions of lupalbigenin (1). Antimicrobial activity assays revealed that lupalbigenin (1) exhibited rapid bactericidal activity, inhibited α-hemolysin and biofilm formation, and disrupted bacterial cell membranes. These findings suggest that lupalbigenin (1) is a promising candidate for the development of novel antibiotics to combat bacterial infections.
Extracellular polymeric substances (EPS) constitutes crucial elements within bacterial biofilms, facilitating accelerated antimicrobial resistance and conferring defense against the host's immune cells. Developing precise and effective antibiofilm approaches and strategies, tailored to the specific characteristics of EPS composition, can offer valuable insights for the creation of novel antimicrobial drugs. This, in turn, holds the potential to mitigate the alarming issue of bacterial drug resistance. Current analysis of EPS compositions relies heavily on colorimetric approaches with a significant bias, which is likely due to the selection of a standard compound and the cross-interference of various EPS compounds. Considering the pivotal role of EPS in biofilm functionality, it is imperative for EPS research to delve deeper into the analysis of intricate compositions, moving beyond the current focus on polymeric materials. This necessitates a shift from heavy reliance on colorimetric analytic methods to more comprehensive and nuanced analytical approaches. In this study, we have provided a comprehensive summary of existing analytical methods utilized in the characterization of EPS compositions. Additionally, novel strategies aimed at targeting EPS to enhance biofilm penetration were explored, with a specific focus on highlighting the limitations associated with colorimetric methods. Furthermore, we have outlined the challenges faced in identifying additional components of EPS and propose a prospective research plan to address these challenges. This review has the potential to guide future researchers in the search for novel compounds capable of suppressing EPS, thereby inhibiting biofilm formation. This insight opens up a new avenue for exploration within this research domain.
Objective: Protein disulfide isomerase A3 (PDIA3) promotes the correct folding of newly synthesized glycoproteins in the endoplasmic reticulum. PDIA3 is overexpressed in most tumors, and it may become a biomarker of cancer prognosis and immunotherapy. Our study aims to detect the expression level of PDIA3 in gastric cancer (GC) and its association with GC development as wells as the underlying mechanisms. Methods: GC cell lines with PDIA3 knockdown by siRNA, CRISPR-cas9 sgRNAs or a pharmacological inhibitor of LOC14 were prepared and used. PDIA3 knockout GC cells were established by CRISPR-cas9-PDIA3 system. The proliferation, migration, invasion and cell cycle of GC cells were analyzed by cell counting kit-8 assay, wound healing assay, transwell assay and flow cytometry, respectively. Immunodeficient nude mice was used to evaluate the role of PDIA3 in tumor formation. Quantitative PCR and western blot were used for examining gene and protein expressions. RNA sequencing was performed to see the altered gene expression. Results: The expressions of PDIA3 in GC tissues and cells were increased significantly, and its expression was negatively correlated with the three-year survival rate of GC patients. Down-regulation of PDIA3 by siRNA, LOC14 or CRISPR-cas9 significantly inhibited proliferation, invasion and migration of GC cells TMK1 and AGS, with cell cycle arrested at G2/M phase. Meanwhile, decreased PDIA3 significantly inhibited growth of tumor xenograft in vivo. It was found that cyclin G1 (encoded by CCNG1 gene) expression was decreased by downregulation of PDIA3 in GC cells both in vitro and in vivo. In addition, protein levels of other cell cycle related factors including cyclin D1, CDK2, and CDK6 were also significantly decreased. Further study showed that STAT3 was associated with PDIA3-mediated cyclin G1 regulation. Conclusion: PDIA3 plays an oncogenic role in GC. Our findings unfolded the functional role of PDIA3 in GC development and highlighted a novel target for cancer therapeutic strategy.
AbstractRectal neuroendocrine neoplasms (rNENs) are among the most frequent gastrointestinal neuroendocrine neoplasms and pose a serious challenge for clinical management. The size of the primary neoplasm is considered to be the most important predictor of disease progression, but the genetic alterations that occur during the progression of rNENs remain unknown. Here, we performed a comprehensive whole-exome sequencing study on 54 tumor-normal paired, formalin-fixed paraffin-embedded specimens from patients locally diagnosed with rNENs. Of these, 81.5% (n = 44) were classified as small-sized (≤2 cm) rNENs, while the remainder (18.5%, n = 10) were classified as large-sized (>2 cm) rNEN samples. Comparative analysis revealed marked disparities in the mutational landscape between small- and large-sized rNEN samples, and between large-sized rNEN samples with or without lymph node metastases. The high-confidence driver genes RHPN2, MUC16, and MUC4 were significantly mutated in both small- and large-sized rNEN specimens, whereas mutations in MAN2A1, and BAG2 were only identified in large-sized specimens diagnosed with lymph node metastases. Correspondingly, we observed that the mTOR and MAPK pathways were preferentially enriched in the large-sized rNEN specimens. Signature-based analysis revealed that mutational processes associated with defective DNA base excision repair (SBS30) significantly accumulated in large-sized rNEN samples with lymph node metastases, highlighting the important role of this mutagenic process in promoting rNEN progression. We further found that most rNEN subjects, regardless of tumor size, harbored at least one alteration with targeted therapeutic implications. Taken together, these results elucidate the genetic features associated with tumor size and lymphatic metastasis in rNEN patients, which will deepen our understanding of the genetic changes during rNEN progression and potentially directing improvements in rNEN treatment strategies.
Smoking is a serious global health issue. Cigarette smoking contains over 7000 different chemicals. The main harmful components include nicotine, acrolein, aromatic hydrocarbons and heavy metals, which play the key role for cigarette-induced inflammation and carcinogenesis. Growing evidences show that cigarette smoking and its components exert a remarkable impact on regulation of immunity and dysregulated immunity promotes inflammation and cancer. Therefore, this comprehensive and up-to-date review covers four interrelated topics, including cigarette smoking, inflammation, cancer and immune system. The known harmful chemicals from cigarette smoking were summarized. Importantly, we discussed in depth the impact of cigarette smoking on the formation of inflammatory or tumor microenvironment, primarily by affecting immune effector cells, such as macrophages, neutrophils, and T lymphocytes. Furthermore, the main molecular mechanisms by which cigarette smoking induces inflammation and cancer, including changes in epigenetics, DNA damage and others were further summarized. This article will contribute to a better understanding of the impact of cigarette smoking on inducing inflammation and cancer.
Supplementary Figure S3: Overexpression of SMARCD1 but not PCBP2 in gastric cancer cell lines.
采用结晶紫染色法、扫描电镜法观察亚抑菌浓度川银花水煎液对耐药铜绿假单胞菌生物被膜形成的影响,并从整体水平上运用转录组学技术分析耐药铜绿假单胞菌基因表达情况,对差异基因进行功能富集及通路分析.结果显示,转录组测序共筛选出362个差异表达基因,其中下调基因206个,上调基因156个,可为耐药铜绿假单胞菌在临床上感染造成的相关疾病的治疗提供新思路.
Kuwanons A (1) and B (2) are two natural prenylated flavones isolated from the root bark of Morus alba L. In this study, the first total syntheses of kuwanons A (1) and B (2) were achieved from a common intermediate with overall yields of 6.6% and 11.6%, respectively. Kuwanon B (2) exhibited antibacterial activity against Gram-positive bacteria and concentration-dependent bactericidal activity against Staphylococcus aureus bacteria. Preliminary mechanism of action studies suggested that this compound killed bacteria rapidly by disrupting bacterial membrane integrity
Supplementary Figure S5: Attenuation of tumor-suppressing effects of miR-490-3p by SMARCD1 overexpression.
Supplementary Figure S4: Effects of SMARCD1 knockdown and overexpression on oncogenic phenotypes of gastric cancer cells.
Objective: Emerging evidence indicates that long non-coding RNA (lncRNA) RP11-93B14.5 facilitates tumor progression in variety of malignancies. The present study proposed to study the functional effect of lncRNA RP11-93B14.5 in gastric cancer (GC) as well as the underlying mechanism. Methods: Bioinformatics analysis was utilized to analyze lncRNA expression in GC tissues. siRNA was used for knockdown of RP11-93B14.5 in GC cells MKN45 and KATO III. The stable knockdown cell lines were constructed by CRISPR-Cas9. Cell counting kit-8 (CCK-8) assay and soft agar colony formation assay were used to analyze GC cell viability. Flow cytometry analysis was performed to analyze the cell cycle distribution of MKN45 and KATO III. RNA sequencing (RNA-seq) was employed to detect differential genes after transfection with siRP11-93B14.5. Quantitative PCR (Q-PCR) was used to examine gene expression in GC cell lines. Western-blot assay was used to measure protein levels. RNA fluorescent in situ hybridization (FISH) was conducted for lncRNA cellular location and expression. Results: Based on the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) database, RP11-93B14.5 was upregulated in GC tissue, which was also verified in GC cell lines in comparison to the normal gastric epithelial HFE145 cells. Knockdown of RP11-93B14.5 decreased cell viability and the colony number of MKN45 and KATO III cells, and altered cell cycle distribution in vitro. RNA-seq analysis revealed RP11-93B14.5 may modulate genes expression of S100A2 and TIMP2 in MKN45 and KATO III cells. Mechanistically, RP11-93B14.5 may drive the progression of GC via S100A2 related-PI3K/AKT signaling pathway. Conclusions: LncRNA RP11-93B14.5 knockdown alleviated the malignant phenotypes of GC cells through regulating PI3K/AKT. Our results provide evidence for the role of lncRNAs in regulating tumor progression.
Antimicrobial resistance (AMR) emerges as a severe crisis to public health and requires global action. The occurrence of bacterial pathogens with multi-drug resistance appeals to exploring alternative therapeutic strategies. Antivirulence treatment has been a positive substitute in seeking to circumvent AMR, which aims to target virulence factors directly to combat bacterial infections. Accumulated evidence suggests that plant-derived natural products, which have been utilized to treat infectious diseases for centuries, can be abundant sources for screening potential virulence-arresting drugs (VADs) to develop advanced therapeutics for infectious diseases. This review sums up some virulence factors and their actions in various species of bacteria, as well as recent advances pertaining to plant-derived natural products as VAD candidates. Furthermore, we also discuss natural VAD-related clinical trials and patents, the perspective of VAD-based advanced therapeutics for infectious diseases and critical challenges hampering clinical use of VADs, and genomics-guided identification for VAD therapeutic. These newly discovered natural VADs will be encouraging and optimistic candidates that may sustainably combat AMR.
The total syntheses of the natural prenylated flavones cudraflavones A-C (1-3), artoheterophyllin D (28) and artelasticin (29) are reported, along with the evaluations of their antibacterial activities. The key steps of the synthesis involved a Baker-Venkataraman rearrangement and an intramolecular cyclization for the construction of the flavone core and the regioselective formation of the pyran and isopentenyl scaffolds. The tested natural flavones 1-3 and 27-29 exhibited potent activity against S. aureus ATCC 29213, S. epidermidis ATCC 14990, E. faecalis ATCC 29212 and B. subtilis ATCC 6633 with MIC values ranging from 0.125 & mu;g/mL to 16 & mu;g/mL. Compound 3 displayed the strongest potency, with MIC values in the range between 0.125 and 1 & mu;g/mL, as a potential candidate to combat G+ bacterial infections. Preliminary mechanism of action studies suggested that this compound killed bacteria by disrupting bacterial membrane integrity.