1-Methyl-D-tryptophan activates aryl hydrocarbon receptor, a pathway associated with bladder cancer progression

The role of cytokine licensing in shaping the therapeutic potential of wharton's jelly MSCs: metabolic shift towards immunomodulation at the expense of differentiation

BACKGROUND

Cytokine licensing with pro-inflammatory molecules, such as tumour necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), has emerged as a promising strategy to enhance the therapeutic potential of multipotent mesenchymal stromal cells (MSCs). While licensing has demonstrated benefits for immunomodulation, its effects on other key MSC functions, including differentiation and paracrine activity, remain incompletely explored. In this study, we evaluated the transcriptomic, metabolomic, and functional changes induced by short-term TNF-α/IFN-γ priming of Wharton's jelly-derived MSCs (WJ-MSCs).

METHODS

WJ-MSCs were expanded and exposed to TNF-α and IFN-γ (10 ng/ml each) for 24 h. Transcriptomic analysis was performed using RNA sequencing to identify differentially expressed genes related to immune modulation and lineage commitment. Metabolomic profiling was conducted using high-resolution mass spectrometry to assess changes in metabolic pathways. Functional assays evaluated the effects of cytokine priming on induced differentiation and growth factor secretion.

RESULTS

Cytokine licensing induced notable alterations in gene expression, upregulating pathways linked to immune response, inflammation, and cytokine signalling. However, short-term cytokine treatment significantly attenuated the osteogenic and adipogenic differentiation of MSCs, as evidenced by the reduced expression of RUNX2, ALP, CEBPA, and PPARG. The priming had a negligible effect on EGF, FGF-2, HGF, LIF, and SCF secretion. The production of VEGF-A and VEGF-C was elevated, although the levels remained low. Metabolomic analysis revealed enhanced kynurenine pathway activity, indicative of increased tryptophan catabolism, accompanied by elevated levels of fatty acids and polyamines.

CONCLUSIONS

Our findings demonstrate that TNF-α/IFN-γ priming reprograms WJ-MSCs by enhancing their immunomodulatory capacity at the expense of differentiation potential. These results highlight the need for tailored strategies to optimize MSC functionality for specific clinical applications.

Biological function of d-tryptophan: a bibliometric analysis and review

Background

d-Tryptophan is recognised for its unique physiological properties. In this study, we aimed to explore the dynamic trends and emerging topics in d-tryptophan research to offer fresh perspectives for future studies.

Methods

Employing bibliometric analysis, we examined the literature on d-tryptophan indexed in the Web of Science Core Collection from January 1987 to December 2023. The "Bibliometrix" R package and CiteSpace were utilised for data processing.

Results

Analyses of 865 publications revealed 2209 keywords, 4068 authors, 2094 institutions, and contributors from 302 regions. The USA was at the forefront of publications concerning d-tryptophan, but the European Journal of Pharmacology, Journal of Biological Chemistry, and Journal of Medicinal Chemistry were notable for their contributions, co-citations, and impact, respectively. This literature review reveals that since 1987, studies have developed from a focus on d-tryptophan metabolism to the exploration of its functions in organic and medicinal chemistry and food science. Recent findings highlight the potential of d-tryptophan as a non-nutritional sweetener and food preservative as well as its role in inhibiting the growth of bacterial biofilms. Additionally, its immunomodulatory properties are being investigated in relation to allergic diseases. Furthermore, d-tryptophan plays a role in the therapy of atherosclerosis, osteoporosis, tuberculosis, and cancer.

Conclusion

The results of bibliometric analysis highlight that future research should focus on the biological functions of d-tryptophan as a food preservative and its use in immunomodulation and drug development, providing strong guidance for future research.

Breaking Barriers: Modulation of Tumor Microenvironment to Enhance Bacillus Calmette-Guérin Immunotherapy of Bladder Cancer

The clinical management of bladder cancer continues to present significant challenges. Bacillus Calmette-Guérin (BCG) immunotherapy remains the gold standard of treatment for non-muscle invasive bladder cancer (NMIBC), but many patients develop recurrence and progression to muscle-invasive disease (MIBC), which is resistant to BCG. This review focuses on the immune mechanisms mobilized by BCG in bladder cancer tumor microenvironments (TME), mechanisms of BCG resistance, the dual role of the BCG-triggered NFkB/TNFα/PGE2 axis in the regulation of anti-tumor and tumor-promoting aspects of inflammation, and emerging strategies to modulate their balance. A better understanding of BCG resistance will help develop new treatments and predictive biomarkers, paving the way for improved clinical outcomes in bladder cancer patients.

Metabolic changes preceding bladder cancer occurrence among Korean men: a nested case-control study from the KCPS-II cohort

BACKGROUND

Bladder cancer (BLCA) research in Koreans is still lacking, especially in focusing on the prediction of BLCA. The current study aimed to discover metabolic signatures related to BLCA onset and confirm its potential as a biomarker.

METHODS

We designed two nested case-control studies using Korean Cancer Prevention Study (KCPS)-II. Only males aged 35-69 were randomly selected and divided into two sets by recruitment organizations [set 1, BLCA (n = 35) vs. control (n = 35); set 2, BLCA (n = 31) vs. control (n = 31)]. Baseline serum samples were analyzed by non-targeted metabolomics profiling, and OPLS-DA and network analysis were performed. Calculated genetic risk score (GRS) for BLCA from all KCPS participants was utilized for interpreting metabolomics data.

RESULTS

Critical metabolic signatures shown in the BLCA group were dysregulation of lysine metabolism and tryptophan-indole metabolism. Furthermore, the prediction model consisting of metabolites (lysine, tryptophan, indole, indoleacrylic acid, and indoleacetaldehyde) reflecting these metabolic signatures showed mighty BLCA predictive power (AUC: 0.959 [0.929-0.989]). The results of metabolic differences between GRS-high and GRS-low groups in BLCA indicated that the pathogenesis of BLCA is associated with a genetic predisposition. Besides, the predictive ability for BLCA on the model using GRS and five significant metabolites was powerful (AUC: 0.990 [0.980-1.000]).

CONCLUSION

Metabolic signatures shown in the present research may be closely associated with BLCA pathogenesis. Metabolites involved in these could be predictive biomarkers for BLCA. It could be utilized for early diagnosis, prognostic diagnosis, and therapeutic targets for BLCA.

Risk Classification of Bladder Cancer by Gene Expression and Molecular Subtype

This study evaluated a panel including the molecular taxonomy subtype and the expression of 27 genes as a diagnostic tool to stratify bladder cancer patients at risk of aggressive behavior, using a well-characterized series of non-muscle invasive bladder cancer (NMIBC) as well as muscle-invasive bladder cancer (MIBC). The study was conducted using the novel NanoString nCounter gene expression analysis. This technology allowed us to identify the molecular subtype and to analyze the gene expression of 27 bladder-cancer-related genes selected through a recent literature search. The differential gene expression was correlated with clinicopathological variables, such as the molecular subtypes (luminal, basal, null/double negative), histological subtype (conventional urothelial carcinoma, or carcinoma with variant histology), clinical subtype (NMIBC and MIBC), tumor stage category (Ta, T1, and T2–4), tumor grade, PD-L1 expression (high vs. low expression), and clinical risk categories (low, intermediate, high and very high). The multivariate analysis of the 19 genes significant for cancer-specific survival in our cohort study series identified TP53 (p = 0.0001), CCND1 (p = 0.0001), MKI67 (p < 0.0001), and molecular subtype (p = 0.005) as independent predictors. A scoring system based on the molecular subtype and the gene expression signature of TP53, CCND1, or MKI67 was used for risk assessment. A score ranging from 0 (best prognosis) to 7 (worst prognosis) was obtained and used to stratify our patients into two (low [score 0–2] vs. high [score 3–7], model A) or three (low [score 0–2] vs. intermediate [score 3–4] vs. high [score 5–7], model B) risk categories with different survival characteristics. Mean cancer-specific survival was longer (122 + 2.7 months) in low-risk than intermediate-risk (79.4 + 9.4 months) or high-risk (6.2 + 0.9 months) categories (p < 0.0001; model A); and was longer (122 + 2.7 months) in low-risk than high-risk (58 + 8.3 months) (p < 0.0001; model B). In conclusion, the molecular risk assessment model, as reported here, might be used better to select the appropriate management for patients with bladder cancer.

Effect of pharmacological modulation of the kynurenine pathway on pain-related behavior and opioid analgesia in a mouse model of neuropathic pain

Dysfunction of the central nervous system are accompanied by changes in tryptophan metabolism, with the kynurenine pathway (KP) being the main route of its catabolism. Recently, KP metabolites, which are collectively called kynurenines, have become an area of intense research due to their ability to directly and indirectly affect a variety of classic neurotransmitter systems. However, the significance of KP in neuropathic pain is still poorly understood. Therefore, we designed several experiments to verify changes in the mRNA levels of KP enzymes in parallel with other factors related to this metabolic route after chronic constriction injury of the sciatic nerve (CCI model) in mice. The analysis revealed an increase in, Kmo, Kynu and Haoo mRNA levels in the spinal cord on the 7th day after CCI, while Kat1, Kat2, Tdo2, Ido2 and Qprt mRNA levels remain unchanged. Subsequent pharmacological studies provided evidence that modulation of KP by single intrathecal administration of 1-D-MT, UPF468 or L-kynurenine attenuates mechanical and thermal hypersensitivity and increases the effectiveness of selected opioids in mice as measured on day 7 after CCI. Moreover, our results provide the first evidence that the injection of L-kynurenine preceded by UPF468 (KMO inhibitor) is more effective at reducing hypersensitivity in animals with neuropathic pain. Importantly, L-kynurenine also exerts an analgesic effect after intravenous injections, which is enhanced by the administration of minocycline, an inhibitor of microglial activation. Additionally, L-kynurenine administered intrathecally and intravenously enhances analgesia evoked by all tested opioids (morphine, buprenorphine and oxycodone). Overall, our results indicate that the modulation of KP at different levels might be a new pharmacological tool in neuropathy management.

AhRR methylation contributes to disease progression in urothelial bladder cancer

BACKGROUND

Bladder Cancer (BCa) is the tenth most incidental malignancy worldwide. BCa is mostly attributed to environmental exposure and lifestyle, particularly tobacco smoking. The Aryl Hydrocarbon Receptor Repressor (AhRR) participates in the induction of many enzymes involved in metabolizing carcinogens, including tobacco smoke components. Additionally, studies have shown that smoking demethylates the (AhRR) gene in blood, suggesting AhRR demethylation as a specific serum smoking biomarker.

OBJECTIVE

This study aimed to validate AhRR demethylation as a smoking biomarker in the target tissue and investigate its contribution to bladder carcinogenesis.

METHODS

AhRR percent methylation was tested for its association with patient smoking status and oncogenic outcome indicators, particularly p53, RB1, and FGFR3 activating mutations, muscle-invasiveness, and tumor grade, in 180 BCa tissue-based DNA.

RESULTS

Results showed significantly higher AhRR percent methylation in muscle-invasive compared to non-muscle invasive tumors (42.86% vs. 33.98%; p= 0.011), while lower AhRR methylation was significantly associated with FGFR3 Codon 248 mutant genotype compared to wild-type (28.11% ± 9.44 vs. 37.87% ± 22.53; p= 0.036). All other tested associations were non-statistically significant.

CONCLUSIONS

Although AhRR methylation did not predict smoking status in BCa tumors, it seems to play a role in carcinogenesis and disease progression. Our findings make a basis for further research.

Analysis of copy number alterations in bladder cancer stem cells revealed a prognostic role of LRP1B

Purpose

Bladder cancer is the most common malignancy of the urinary tract and one of the most prevalent cancers worldwide. It represents a spectrum of diseases, from recurrent non-invasive tumors (NMIBCs) managed chronically, to muscle infiltrating and advanced-stage disease (MIBC) that requires multimodal and invasive treatment. Multiple studies have underlined the complexity of bladder tumors genome, highlighting many specific genetic lesions and genome-wide occurrences of copy-number alterations (CNAs). In this study, we analyzed CNAs of selected genes in our cohorts of cancer stem cells (CSCs) and in The Cancer Genome Atlas (TCGA-BLCA) cohort with the aim to correlate their frequency with patients’ prognosis.

Methods

CNAs have been verified on our array-CGH data previously reported on 19 bladder cancer biopsies (10 NMIBCs and 9 MIBCs) and 16 matched isolated CSC cultures. In addition, CNAs data have been consulted on the TCGA database, to search correlations with patients’ follow-up. Finally, mRNA expression levels of LRP1B in TGCA cohort were obtained from The Human Protein Atlas.

Results

We firstly identified CNAs differentially represented between TGCA data and CSCs derived from NMIBCs and MIBCs, and we correlated the presence of these CNAs with patients’ follow-up. LRP1B loss was significantly increased in CSCs and linked to short-term poor prognosis, both at genomic and transcriptomic level, confirming its pivotal role in bladder cancer tumorigenesis.

Conclusion

Our study allowed us to identify potential "predictive" prognostic CNAs for bladder cancer, implementing knowledge for the ultimate goal of personalized medicine.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04093-1.

Correlation between aryl hydrocarbon receptor and IL-17+ and Foxp3+ T-cell infiltration in bladder cancer

Bladder cancer (BC) is one of the most prevalent cancers around the world and, if not treated well, has high morbidity and mortality. Many studies have indicated that there may be various roles for the aryl hydrocarbon receptor (AHR) in the immune system. The aim of this study was to determine the frequency of Foxp3⁺ regulatory T (Treg) and T helper 17 cells (Th17) in BC tissue in comparison with controls and determine the relationship between AHR, Foxp3⁺ Treg and Th17 cells in BC. A total of 40 patients with BC were enrolled in this study. The control group was selected from non-tumoural parts of bladder tissues from the patients who have undergone cystoscopy. The percentage of regulatory T cells (Foxp3⁺ /CD4⁺ ) and Th17 (IL-17⁺ /CD4⁺ ), as well as AHR⁺ cells in BC tissues and controls, were determined by immunohistochemistry. The results of this study showed that the number of Foxp3⁺ Treg and Th17 is significantly higher in bladder tumour tissues in comparison with non-tumoural tissues. Also, the percentage of AHR⁺ lymphocytes and AHR⁺ cells was increased significantly in bladder tumour tissues rather than non-tumoural tissues. This study also found a relation between AHR and Foxp3⁺ /CD4⁺ T lymphocytes ratio cells in BC. The percentage of Foxp3⁺ Tregs and AHR⁺ cells were significantly correlated with the grade and stage of BC. An increase in the percentage of Foxp3⁺ Treg and Th17 cells may play an important role in tumour immunity; and determining the relationship between AHR and differentiation of Th17/Foxp3⁺ Treg in BC can lead to a potential cancer therapeutic possibility.

AhR and Cancer: From Gene Profiling to Targeted Therapy

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that has been shown to be an essential regulator of a broad spectrum of biological activities required for maintaining the body’s vital functions. AhR also plays a critical role in tumorigenesis. Its role in cancer is complex, encompassing both pro- and anti-tumorigenic activities. Its level of expression and activity are specific to each tumor and patient, increasing the difficulty of understanding the activating or inhibiting roles of AhR ligands. We explored the role of AhR in tumor cell lines and patients using genomic data sets and discuss the extent to which AhR can be considered as a therapeutic target.