Clinicopathologic features of TDO2 overexpression in renal cell carcinoma

TDO2 + cancer-associated fibroblasts mediate cutaneous squamous cell carcinoma immune escape via impeding infiltration of CD8 + T cells

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, originating from the malignant proliferation of squamous epithelial cells. However, its pathogenesis remains unclear. To further explore the mechanisms underlying cSCC, we analyzed the data from one single-cell RNA sequencing study and discovered a significant upregulation of tryptophan 2,3-dioxygenase (TDO2) in the cancer-associated fibroblasts (CAFs). Nonetheless, the specific expression and potential biological significance of TDO2 in cSCC have not yet been reported. In this study, we confirmed that TDO2 is highly expressed in CAFs of cSCC. Clinical correlation analysis indicated that high TDO2 expression was significantly associated with poor tumor differentiation. Furthermore, increased TDO2 expression in cSCC correlated with reduced CD8 + T cell infiltration, suggesting its role in modulating immune responses. TDO2 inhibitors significantly reduced the size and number of tumors in mice and effectively increased CD8 + T cell infiltration. RNA sequencing analysis revealed that TDO2 inhibitors modulate immune cell activity and downregulate the PI3K-Akt signaling pathway. In summary, our study demonstrates that TDO2 + CAFs induce immune evasion by inhibiting CD8 + T cell infiltration in cSCC. Inhibiting TDO2 could enhance antitumor immune responses, providing a promising strategy to improve treatment outcomes in cSCC.

Oxymatrine Inhibits Malignant Behaviors of Breast Cancer Cells by Inhibiting miR-188 Expression to Up-Regulate Phosphatase and Tensin Homolog (PTEN)

Oxymatrine has been applied to anti-cancer therapies for various cancers. The present study aimed to investigate the potential impact of miR-188 on breast cancer (BC) cell progression and underlying mechanism. After establishment of a rat model of BC, rats were administered with oxymatrine (4 mg/kg, 8 mg/kg), Xihuang pill (XH) (positive control), and miR-188 mimic (1 mg/kg) followed by analysis of tumor growth, the expression of miR-188, MMP-9, MMP-2, and PTEN, and BC cell behaviors. Oxymatrine significantly decreased tumor incidence and reduced tumor mass (p<0.05) with 8 mg/kg intervention group and positive control group exhibiting higher tumor inhibition rate (p<0.05). In addition, oxymatrine or XH effectively reduced cell proliferation, invasion and migration rate. Of note, compared to 4 mg/kg oxymatrine, 8 mg/kg oxymatrine and XH showed more significantly inhibitory effects on BC cells. Moreover, oxymatrine or XH significantly downregulated miR-188, MMP-9, and MMP-2 and upregulated PTEN. Mechanically, PTEN was indicated as the target of miR-188 with specific binding between them. In conclusion, Oxymatrine inhibits BC cell behaviors through down-regulation of miR-188 to increase PTEN expression. This study might provide a new basis for the management of BC.

Whole transcriptome expression profiles in kidney samples from rats with hyperuricaemic nephropathy

Hyperuricaemic nephropathy (HN) is a common clinical complication of hyperuricaemia (HUA) and poses a huge threat to human health. Hence, we aimed to prospectively investigate the dysregulated genes, pathways and networks involved in HN by performing whole transcriptome sequencing using RNA sequencing. Six kidney samples from HN group (n = 3) and a control group (n = 3) were obtained to conduct RNA sequencing. To disclose the relevant signalling pathways, we conducted the analysis of differentially expressed genes (DEGs), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. A competitive endogenous RNA (ceRNA) network was established to reveal the interactions between lncRNAs, circRNAs, mRNAs and miRNAs and investigate the potential mechanisms of HN. Ultimately, 2250 mRNAs, 306 lncRNAs, 5 circRNAs, and 70 miRNAs were determined to be significantly differentially expressed in the HN group relative to the control group. We further authenticated 8 differentially expressed (DE)-ncRNAs by quantitative real-time polymerase chain reaction, and these findings were in accordance with the sequencing results. The analysis results evidently showed that these DE-ncRNAs were significantly enriched in pathways related to inflammatory reaction. In conclusion, HUA may generate abnormal gene expression changes and regulate signalling pathways in kidney samples. Potentially related genes and pathways involved in HN were identified.

A novel anoikis-related prognostic signature associated with prognosis and immune infiltration landscape in clear cell renal cell carcinoma

Background: Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype of renal cell carcinoma (RCC). Anoikis plays an essential function in tumourigenesis, whereas the role of anoikis in ccRCC remains unclear. Methods: Anoikis-related genes (ARGs) were collected from the MSigDB database. According to univariate Cox regression analysis, the least absolute shrinkage and selection operator (LASSO) algorithm was utilized to select the ARGs associated with the overall rate (OS). Multivariate Cox regression analysis was conducted to identify 5 prognostic ARGs, and a risk model was established. The Kaplan-Meier survival analysis was used to evaluate the OS rate of ccRCC patients. Gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and Gene set enrichment analysis (GSVA) were utilized to investigate the molecular mechanism of patients in the low- and high-risk group. ESTIMATE, CIBERSOT, and single sample gene set enrichment analysis (ssGSEA) algorithms were conducted to estimate the immune infiltration landscape. Consensus clustering analysis was performed to divide the patients into different subgroups. Results: A fresh risk model was constructed based on the 5 prognostic ARGs (CHEK2, PDK4, ZNF304, SNAI2, SRC). The Kaplan-Meier survival analysis indicated that the OS rate of patients with a low-risk score was significantly higher than those with a high-risk score. Consensus clustering analysis successfully clustered the patients into two subgroups, with a remarkable difference in immune infiltration landscape and prognosis. The ESTIMATE, CIBERSORT, and ssGSEA results illustrated a significant gap in immune infiltration landscape of patients in the low- and high-risk group. Enrichment analysis and GSVA revealed that immune-related signaling pathways might mediate the role of ARGs in ccRCC. The nomogram results illustrated that the ARGs prognostic signature was an independent prognostic predictor that distinguished it from other clinical characteristics. TIDE score showed a promising immunotherapy response of ccRCC patients in different risk subgroups and cluster subgroups. Conclusion: Our study revealed that ARGs play a carcinogenic role in ccRCC. Additionally, we firstly integrated multiple ARGs to establish a risk-predictive model. This study highlights that ARGs could be implemented as a stratification factor for individualized and precise treatment in ccRCC patients.

Pancancer Analysis of Revealed TDO2 as a Biomarker of Prognosis and Immunotherapy

Background

Tryptophan 2,3-dioxygenase (TDO) encoded by TDO2, a rate-limiting enzyme in the kynurenine pathway, catabolizes tryptophan to kynurenine, evades immune surveillance, and promotes tumor growth. Although accumulating evidence suggests a crucial role of TDO2 during tumor formation and development, systematic evaluation of TDO2 across human cancers has rarely been reported.

Methods

To shed more light on the role of TDO2 in human cancer, we explored the expression profiles of TDO2 and identified its prognostic value in pancancer analysis through TCGA, CCLE, and GTEx databases. We further utilized TCGA data to evaluate the association between TDO2 and tumor immunological features, such as mismatch repair (MMR), tumor immune infiltration, immune checkpoint-related genes, tumor mutational burden (TMB), microsatellite instability (MSI), and DNA methyltransferase (DNMT).

Results

TDO2 exhibited different expression levels in various cancer cell lines. Frequently, TDO2 was detected to be highly expressed in the majority of cancers. In addition, high TDO2 expression was correlated with an unfavorable prognosis for patients in KIRP, LGG, TGCT, and UVM. Moreover, high TDO2 expression level positively correlated with higher immune infiltration, especially dendritic cells. Additionally, there is a close relationship between TDO2 and immune checkpoint-related gene markers, such as LAIR1, CD276, NRP1, CD80, and CD86. Finally, correlation analysis has demonstrated a high-correlation between TDO2 and TMB, MSI, MMR, and DNMT of multiple cancer types.

Conclusion

Therefore, our results suggest that TDO2 can function as a potential prognostic biomarker due to its role in tumor immunity regulation.

Dexamethasone Promotes a Stem-Like Phenotype in Human Melanoma Cells via Tryptophan 2,3 Dioxygenase

In addition to its well-established immunosuppressive actions, tryptophan 2,3-dioxygenase (TDO) appears to elicit direct effects on tumor cell function. Although TDO has been associated with cancer stemness, its involvement in melanoma stem cell biology remains largely unknown. Since we showed that by upregulating TDO, dexamethasone (dex) promotes proliferation and migration of SK-Mel-28 human melanoma cells, we sought to investigate dex effects on melanoma spherogenesis and stemness, and whether these events are mediated by TDO. We demonstrate here that dex significantly upregulates TDO in A375, a more aggressive melanoma cell line, confirming that dex effects are not limited to SK-Mel-28 cells. Moreover, dex stimulates spherogenesis of both cell lines, which is mediated by TDO, evident by its suppression with 680C91, a TDO inhibitor. The formed melanospheres appear to be enriched with embryonic stem cell marker mRNAs, the expression of which is potentiated by dex. Expression of cancer stem cell markers (CD133, CD44, ganglioside GD2) was significantly increased in A375 spheres, as detected by flow cytometry. Taken together, our results suggest that TDO could represent a promising target in the management of melanoma and that dex, routinely used as a co-medication also in advanced melanoma, may stimulate melanoma cell function/tumor-supporting properties, a rather debilitating and undesired side effect.