Crosstalk Between Prostate Cancer Cells and Tumor-Associated Fibroblasts Enhances the Malignancy by Inhibiting the Tumor Suppressor PLZF

The Mechanism by Which Hedgehog Interacting Protein (HHIP) in Cancer-Associated Fibroblasts Regulate the Secretion of Inflammatory Factors Through the JAK1/STAT3 Pathway Affecting Prostate Cancer Stemness

Purpose

Prostate cancer (PCa) is seriously affecting men's health and quality of life. Existing studies indicate that PCa stem cells are responsible for promoting the growth and contributing to the high recurrence rate of PCa.

Methods

We retrieved and downloaded PCa-related datasets from both the GEO and TCGA database. These datasets were subsequently analyzed using single-cell analysis, difference analysis, WGCNA, and machine learning algorithms. WB was performed to detect the expression of Hedgehog interacting protein (HHIP), JAK1/STAT3 pathway-related protein, CD133 and CD44. Immunohistochemistry was conducted to assess the distribution of HHIP and Ki67. The levels of inflammatory factors were measured using ELISA. The tumor cell stemness was evaluated through spheroid formation assay and flow cytometry.

Results

Through bioinformatics analysis, we identified eight genes (ARHGAP24, HHIP, MITF, CBX7, PPP1R12B, PLEKHA1, ADGRA2, and PGR). Among these genes, we selected HHIP for follow-up experiments and confirmed its low expression in PCa tumor tissues. Primary cancer-associated fibroblasts (CAFs) were extracted, and to further explore the mechanism of HHIP, we overexpressed or knocked down HHIP in CAFs. Overexpression of HHIP was found to inhibit the JAK1/STAT3 pathway and the secretion of inflammatory factors, thus suppressing both the proliferation and stemness of PCa cells. Treatment of CAFs with the JAK1/STAT3 pathway inhibitor AG490 led to a decrease in inflammatory factor secretion, along with inhibition of PCa cell proliferation and stemness. On this basis, knockdown of HHIP partially reversed the inhibitory effects of AG490 on PCa cells. Finally, we constructed a mouse subcutaneous tumor model and found that HHIP inhibited tumor proliferation and densification.

Conclusion

In summary, HHIP in CAFs can regulate the JAK1/STAT3 pathway and affect the secretion of inflammatory factors, thus affecting the proliferation of PCa.

Cancer associated fibroblasts and metabolic reprogramming: unraveling the intricate crosstalk in tumor evolution

Metabolic reprogramming provides tumors with an energy source and biofuel to support their survival in the malignant microenvironment. Extensive research into the intrinsic oncogenic mechanisms of the tumor microenvironment (TME) has established that cancer-associated fibroblast (CAFs) and metabolic reprogramming regulates tumor progression through numerous biological activities, including tumor immunosuppression, chronic inflammation, and ecological niche remodeling. Specifically, immunosuppressive TME formation is promoted and mediators released via CAFs and multiple immune cells that collectively support chronic inflammation, thereby inducing pre-metastatic ecological niche formation, and ultimately driving a vicious cycle of tumor proliferation and metastasis. This review comprehensively explores the process of CAFs and metabolic regulation of the dynamic evolution of tumor-adapted TME, with particular focus on the mechanisms by which CAFs promote the formation of an immunosuppressive microenvironment and support metastasis. Existing findings confirm that multiple components of the TME act cooperatively to accelerate the progression of tumor events. The potential applications and challenges of targeted therapies based on CAFs in the clinical setting are further discussed in the context of advancing research related to CAFs.

Polyphyllin I exerts anti-hepatocellular carcinoma activity by targeting ZBTB16 to activate the PPARγ/RXRα signaling pathway

BACKGROUND

Studies have reported that polyphyllin I (PPI) had effective anti-tumor activity against hepatocellular carcinoma (HCC). However, the precise molecular mechanism of this action and the direct target remain unclear. The aim of this study was to discover the molecular targets and the exact mechanism of PPI in the treatment of HCC.

METHODS

Various HCC cells and Zebrafish xenotransplantation models were used to examine the efficacy of PPI against HCC. A proteome microarray, surface plasmon resonance (SPR) analysis, small molecule transfection, and molecular docking were conducted to confirm the direct binding targets of PPI. Transcriptome and Western blotting were then used to determine the exact responding mechanism. Finally, the anticancer effect and its precise mechanism, as well as the safety of PPI, were verified using a mouse tumor xenograft study.

RESULTS

The results demonstrated that PPI had significant anticancer activity against HCC in both in vitro studies of two cells and the zebrafish model. Notably, PPI selectively enhanced the action of the Zinc finger and BTB domain-containing 16 (ZBTB16) protein by directly binding to it. Furthermore, specific knockdown of ZBTB16 markedly attenuated PPI-dependent inhibition of HCC cell proliferation and migration caused by overexpression of the gene. The transcriptome and Western blotting also confirmed that the interaction between ZBTB16 and PPI also activated the PPARγ/RXRα pathway. Finally, the mouse experiments confirmed the efficacy and safety of PPI to treat HCC.

CONCLUSIONS

Our results indicate that ZBTB16 is a promising drug target for HCC and that PPI as a potent ZBTB16 agonist has potential as a therapeutic agent against HCC by regulating the ZBTB16/PPARγ/RXRα signaling axis.

The Current and Future of Biomarkers of Immune Related Adverse Events

With their groundbreaking clinical responses, immune checkpoint inhibitors (ICIs) have ushered in a new chapter in cancer therapeutics. However, they are often associated with life-threatening or organ-threatening autoimmune/autoinflammatory phenomena, collectively termed immune-related adverse events (irAEs). In this review, we will first describe the mechanisms of action of ICIs as well as irAEs. Next, we will review biomarkers for predicting the development of irAEs or stratifying risks.

Signaling pathways in cancer-associated fibroblasts and targeted therapy for cancer

To flourish, cancers greatly depend on their surrounding tumor microenvironment (TME), and cancer-associated fibroblasts (CAFs) in TME are critical for cancer occurrence and progression because of their versatile roles in extracellular matrix remodeling, maintenance of stemness, blood vessel formation, modulation of tumor metabolism, immune response, and promotion of cancer cell proliferation, migration, invasion, and therapeutic resistance. CAFs are highly heterogeneous stromal cells and their crosstalk with cancer cells is mediated by a complex and intricate signaling network consisting of transforming growth factor-beta, phosphoinositide 3-kinase/AKT/mammalian target of rapamycin, mitogen-activated protein kinase, Wnt, Janus kinase/signal transducers and activators of transcription, epidermal growth factor receptor, Hippo, and nuclear factor kappa-light-chain-enhancer of activated B cells, etc., signaling pathways. These signals in CAFs exhibit their own special characteristics during the cancer progression and have the potential to be targeted for anticancer therapy. Therefore, a comprehensive understanding of these signaling cascades in interactions between cancer cells and CAFs is necessary to fully realize the pivotal roles of CAFs in cancers. Herein, in this review, we will summarize the enormous amounts of findings on the signals mediating crosstalk of CAFs with cancer cells and its related targets or trials. Further, we hypothesize three potential targeting strategies, including, namely, epithelial-mesenchymal common targets, sequential target perturbation, and crosstalk-directed signaling targets, paving the way for CAF-directed or host cell-directed antitumor therapy.