YAP/STAT3 inhibited CD8+ T cells activity in the breast cancer immune microenvironment by inducing M2 polarization of tumor-associated macrophages

Structure, function, signaling pathways and clinical therapeutics: The translational potential of STAT3 as a target for cancer therapy

Cancer remains one of the most difficult human diseases to overcome because of its complexity and diversity. Signal transducers and transcriptional activators 3 (STAT3) protein has been found to be overexpressed in a wide range of cancer types. Hyperactivation of STAT3 is particularly associated with low survival in cancer patients. This review summarizes the specific molecular mechanisms of STAT3 in cancer development. STAT3 is activated by extracellular signals in the cytoplasm, interacts with different enzymes in the nucleus, mitochondria or endoplasmic reticulum, and subsequently participates in cancer development. The phosphorylated STAT3 at tyrosine 705 site (YP-STAT3) enters the nucleus and regulates a number of tumor-related biological processes such as angiogenesis, migration invasion, cell proliferation and cancer cell stemness. In contrast, the phosphorylated STAT3 at serine 727 site (SP-STAT3) is found on the mitochondria, affects electron respiration transport chain activity and thereby prevents tumor cell apoptosis. SP-STAT3 also appears on the mitochondria-associated endoplasmic reticulum membrane, influences the flow of Ca2+, and affects tumor progression. In addition, we summarize the direct and indirect inhibitors of STAT3 which are currently undergoing clinical studies. Some of them such as TTI101 and BBI608 have been approved by the FDA for the treatment of certain cancers. All in all, STAT3 plays an important role in cancer progression and becomes a potential target for cancer treatment.

Transcriptional regulation of DLGAP5 by AR suppresses p53 signaling and inhibits CD8+T cell infiltration in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a challenging subtype with unclear biological mechanisms. Recently, the transcription factor androgen receptor (AR) and its regulation of the DLGAP5 gene have gained attention in TNBC pathogenesis. In this study, we found a positive correlation between high AR expression and TNBC cell proliferation and growth. Furthermore, we confirmed DLGAP5 as a critical downstream regulator of AR with high expression in TNBC tissues. Knockdown of DLGAP5 significantly inhibited TNBC cell proliferation, migration, and invasion. AR was observed to directly bind to the DLGAP5 promoter, enhancing its transcriptional activity and suppressing the activation of the p53 signaling pathway. In vivo experiments further validated that downregulation of AR or DLGAP5 inhibited tumor growth and enhanced CD8+T cell infiltration. This study highlights the crucial roles of AR and DLGAP5 in TNBC growth and immune cell infiltration. Taken together, AR inhibits the p53 signaling pathway by promoting DLGAP5 expression, thereby impacting CD8+T cell infiltration in TNBC.

Prognostic Impact of Acute and Chronic Inflammatory Interleukin Signatures in the Tumor Microenvironment of Early Breast Cancer

Interleukins play dual roles in breast cancer, acting as both promoters and inhibitors of tumorigenesis within the tumor microenvironment, shaped by their inflammatory functions. This study analyzed the subtype-specific prognostic significance of an acute inflammatory versus a chronic inflammatory interleukin signature using microarray-based gene expression analysis. Correlations between these interleukin signatures and immune cell markers (CD8, IgKC, and CD20) and immune checkpoints (PD-1) were also evaluated. This study investigated the prognostic significance of an acute inflammatory IL signature (IL-12, IL-21, and IFN-γ) and a chronic inflammatory IL signature (IL-4, IL-5, IL-10, IL-13, IL-17, and CXCL1) for metastasis-free survival (MFS) using Kaplan-Meier curves and Cox regression analyses in a cohort of 461 patients with early breast cancer. Correlations were analyzed using the Spearman-Rho correlation coefficient. Kaplan-Meier curves revealed that the prognostic significance of the acute inflammatory IL signature was specifically pronounced in the basal-like subtype (p = 0.004, Log Rank). This signature retained independent prognostic significance in multivariate Cox regression analysis (HR 0.463, 95% CI 0.290-0.741; p = 0.001). A higher expression of the acute inflammatory IL signature was associated with longer MFS. The chronic inflammatory IL signature showed a significant prognostic effect in the whole cohort, with higher expression associated with shorter MFS (p = 0.034). Strong correlations were found between the acute inflammatory IL signature and CD8 expression (ρ = 0.391; p < 0.001) and between the chronic inflammatory IL signature and PD-1 expression (ρ = 0.627; p < 0.001). This study highlights the complex interaction between acute and chronic inflammatory interleukins in breast cancer progression and prognosis. These findings provide insight into the prognostic relevance of interleukin expression patterns in breast cancer and may inform future therapeutic strategies targeting the immune-inflammatory axis.

PAARH promotes M2 macrophage polarization and immune evasion of liver cancer cells through VEGF protein

OBJECTIVE

This study aims to investigate the mechanism by which PAARH promotes M2 macrophage polarization and immune evasion of liver cancer cells through VEGF, in order to reveal its role in the progression of liver cancer.

METHODS

The expressions of PAARH, VEGF, and HIF-1α in liver cancer cells were detected using qRT-PCR and Western blot. Flow cytometry was utilized to analyze the polarization status of macrophages and assess the impact on immune evasion-related markers. The relationship between PAARH and VEGF in macrophage polarization was further explored. Additionally, a tumor-bearing mouse model was established to observe tumor growth.

RESULTS

The results show that PAARH is upregulated in liver cancer cells, and silencing PAARH significantly inhibits tumor malignancy progression. Under hypoxic conditions, overexpression of PAARH significantly increases VEGF expression, and PAARH regulates M2 macrophage polarization through VEGF. Overexpression of PAARH significantly promotes M2 macrophage polarization, increases levels of PD-L1 and Th2 immune response markers, and enhances cell proliferation, migration, and invasion; it also suppresses M1 macrophage polarization, decreases levels of PD-L2 and Th1 immune response markers, and inhibits cell apoptosis. Silencing VEGF reverses these effects. Silencing PAARH or overexpressing VEGF weakens the malignant phenotype of the cells and immune evasion. Results from the tumor-bearing mouse model indicate that silencing PAARH significantly reduces tumor size and weight, while overexpressing VEGF significantly increases tumor volume and weight.

CONCLUSION

PAARH enhances the immune evasion capability of liver cancer cells by upregulating VEGF to promote M2 macrophage polarization, suggesting that PAARH may serve as a new therapeutic target for liver cancer.

Calculus bovis inhibits M2 tumor-associated macrophage polarization via Wnt/β-catenin pathway modulation to suppress liver cancer

BACKGROUND

Calculus bovis (CB), used in traditional Chinese medicine, exhibits anti-tumor effects in various cancer models. It also constitutes an integral component of a compound formulation known as Pien Tze Huang, which is indicated for the treatment of liver cancer. However, its impact on the liver cancer tumor microenvironment, particularly on tumor-associated macrophages (TAMs), is not well understood.

AIM

To elucidate the anti-liver cancer effect of CB by inhibiting M2-TAM polarization via Wnt/β-catenin pathway modulation.

METHODS

This study identified the active components of CB using UPLC-Q-TOF-MS, evaluated its anti-neoplastic effects in a nude mouse model, and elucidated the underlying mechanisms via network pharmacology, transcriptomics, and molecular docking. In vitro assays were used to investigate the effects of CB-containing serum on HepG2 cells and M2-TAMs, and Wnt pathway modulation was validated by real-time reverse transcriptase-polymerase chain reaction and Western blot analysis.

RESULTS

This study identified 22 active components in CB, 11 of which were detected in the bloodstream. Preclinical investigations have demonstrated the ability of CB to effectively inhibit liver tumor growth. An integrated approach employing network pharmacology, transcriptomics, and molecular docking implicated the Wnt signaling pathway as a target of the antineoplastic activity of CB by suppressing M2-TAM polarization. In vitro and in vivo experiments further confirmed that CB significantly hinders M2-TAM polarization and suppresses Wnt/β-catenin pathway activation. The inhibitory effect of CB on M2-TAMs was reversed when treated with the Wnt agonist SKL2001, confirming its pathway specificity.

CONCLUSION

This study demonstrated that CB mediates inhibition of M2-TAM polarization through the Wnt/β-catenin pathway, contributing to the suppression of liver cancer growth.

Transcriptomic analysis of Paraoxonase 1 expression in hepatocellular carcinoma and its potential impact on tumor immunity

BACKGROUND

Hepatocellular carcinoma (HCC) is characterized by a complex pathogenesis that confers aggressive malignancy, leading to a lack of dependable biomarkers for predicting invasion and metastasis, which results in poor prognoses in patients with HCC. Glycogen storage disease (GSD) is an uncommon metabolic disorder marked by hepatomegaly and liver fibrosis. Notably, hepatic adenomas in GSD patients present a heightened risk of malignancy compared to those in individuals without the disorder. In this investigation, PON1 emerged as a potential pivotal gene for HCC through bioinformatics analysis.

METHODS

Transcriptomic profiling data of liver cancer were collected and integrated from TCGA and GEO databases. Bioinformatics analysis was conducted to identify mutated mRNAs associated with GSD, and the PON1 gene was selected as a key gene. Patients were grouped based on the expression levels of PON1, and differences in clinical characteristics, biological pathways, immune infiltration, and expression of immune checkpoints were compared.

RESULTS

The expression levels of the PON1 gene showed significant differences between the high-expression group and the low-expression group in HCC patients. Further analysis indicated that the PON1 gene at different expression levels might influence the clinical manifestations, biological processes, immune infiltration, and expression of immune checkpoints in HCC. Additionally, immunohistochemistry (IHC) results revealed high expression of PON1 in normal tissues and low expression in HCC tissues. These findings provide important clues and future research directions for the early diagnosis, prognosis, immunotherapy, and potential molecular interactions of HCC.

CONCLUSION

Our investigation underscores the noteworthy prognostic significance of PON1 in HCC, suggesting its potential pivotal role in modulating tumor progression and immune cell infiltration. These findings establish PON1 as a novel tumor biomarker with significant implications for the prognosis, targeted therapy, and immunotherapy of patients with HCC.

Matrix stiffness affects tumor-associated macrophage functional polarization and its potential in tumor therapy

The extracellular matrix (ECM) plays critical roles in cytoskeletal support, biomechanical transduction and biochemical signal transformation. Tumor-associated macrophage (TAM) function is regulated by matrix stiffness in solid tumors and is often associated with poor prognosis. ECM stiffness-induced mechanical cues can activate cell membrane mechanoreceptors and corresponding mechanotransducers in the cytoplasm, modulating the phenotype of TAMs. Currently, tuning TAM polarization through matrix stiffness-induced mechanical stimulation has received increasing attention, whereas its effect on TAM fate has rarely been summarized. A better understanding of the relationship between matrix stiffness and macrophage function will contribute to the development of new strategies for cancer therapy. In this review, we first introduced the overall relationship between macrophage polarization and matrix stiffness, analyzed the changes in mechanoreceptors and mechanotransducers mediated by matrix stiffness on macrophage function and tumor progression, and finally summarized the effects of targeting ECM stiffness on tumor prognosis to provide insight into this new field.

FAT4 expression in peripheral blood mononuclear cells is associated with prognosis and immune cell infiltration in hepatocellular carcinoma

Peripheral blood mononuclear cell (PBMC) genes reflect the host immune status and could be suitable for evaluating the prognosis of patients with hepatocellular carcinoma (HCC), for which a reliable biomarker is unavailable and the host immune responses to cancer cells. This study aimed to investigate prognostically relevant genes in HCC PBMCs and assessed whether their expression represents tumor immune infiltration. Gene expression in PBMCs from patients with advanced or terminal HCC who had survived or died was examined. Correlations among FAT atypical cadherin 4 (FAT4) expression, cancer immune characteristics, and infiltrated immune cell gene marker sets were analyzed. FAT4 expression was lower in the PBMCs of patients with advanced or terminal HCC who had died than that in patients who survived. Kaplan-Meier analysis indicated that FAT4 downregulation was associated with a relatively poor prognosis while overexpression was positively correlated with immune cell infiltration, several immune cell markers, and immune checkpoint expression. Hsa-miR-93-5p represented the most probable upstream microRNA of FAT4. Thus, upregulated FAT4 in PBMCs and HCC tissues might indicate a favorable prognosis and increased immune cell infiltration, while miRNA-93-5p could be a modulator of FAT4 expression. Collectively, these findings suggest novel immunotherapy targets for HCC.