Characterizing the Wnt Pathway in Advanced Prostate Cancer: When, Why, and How

Targeting signaling pathways in cancer stem cells: A potential approach for developing novel anti-cancer therapeutics

Cancer stem cells (CSCs) have emerged as prime players in the intricate landscape of cancer development, progression, and resistance to traditional treatments. These unique cellular subpopulations own the remarkable capability of self-renewal and differentiation, giving rise to the diverse cellular makeup of tumors and fostering their recurrence following conventional therapies. In the quest for developing more effective cancer therapeutics, the focus has now shifted toward targeting the signaling pathways that govern CSCs behavior. This chapter underscores the significance of these signaling pathways in CSC biology and their potential as pivotal targets for the development of novel chemotherapy approaches. We delve into several key signaling pathways essential for maintaining the defining characteristics of CSCs, including the Wnt, Hedgehog, Notch, JAK-STAT, NF-κB pathways, among others, shedding light on their potential crosstalk. Furthermore, we highlight the latest advancements in CSC-targeted therapies, spanning from promising preclinical models to ongoing clinical trials. A comprehensive understanding of the intricate molecular aspects of CSC signaling pathways and their manipulation holds the prospective to revolutionize cancer treatment paradigms. This, in turn, could lead to more efficacious and personalized therapies with the ultimate goal of eradicating CSCs and enhancing overall patient outcomes. The exploration of CSC signaling pathways represents a key step towards a brighter future in the battle against cancer.

TCF7L1 regulates cytokine response and neuroendocrine differentiation of prostate cancer

Neuroendocrine differentiation (NED) is associated with WNT signaling activation and can be significantly observed after failure of androgen-deprivation therapy (ADT) for prostatic adenocarcinomas. Cytokine signaling is stimulated in NED prostate cancer; however, how ADT-upregulated WNT signaling promotes activation of cytokine signaling and contributes to NED of prostate cancer is poorly understood. In this study, we identified ADT-mediated upregulation of transcription factor 7 like 1 (TCF7L1), which increases the cytokine response and enhances NED of prostate cancer through interleukin (IL)-8/C-X-C motif chemokine receptor type 2 (CXCR2) signaling activation. ADT induced the secretion of WNT4 which upon engagement of TCF7L1 in prostate cancer cells, enhanced IL-8 and CXCR2 expressions. TCF7L1 directly binds to the regulatory sequence region of IL-8 and CXCR2 through WNT4 activation, thus upregulating IL-8/CXCR2 signaling-driven NED and cell motility. Analysis of prostate tissue samples collected from small-cell neuroendocrine prostate cancer (SCPC) and castration-resistant prostate cancer (CRPC) tumors showed an increased intensity of nuclear TCF7L1 associated with CXCR2. Our results suggest that induction of WNT4/TCF7L1 results in increased NED and malignancy in prostate cancer that is linked to dysregulation of androgen receptor signaling and activation of the IL-8/CXCR2 pathway.

Wnt-C59 Attenuates Pressure Overload-Induced Cardiac Hypertrophy via Interruption of Wnt Pathway

Background

Cardiac hypertrophy usually results in heart failure and is an important cause of mortality worldwide. Wnt/β-catenin signaling pathway hyper-activation is involved in the pathogenesis and progression of cardiac hypertrophy. Wnt-C59 is a small molecular compound, which strongly and specifically targets at Porcupine to pharmacologically inhibit Wnt palmitoylation, secretion, and other biological activities. However, the role of Wnt-C59 in cardiac hypertrophy remains unknown.

Material/Methods

We performed transverse aortic constriction (TAC) in adult male mice to induce pressure overload and establish an in vivo model of cardiac hypertrophy. Angiotensin II (Ang-II) was utilized to culture cardiomyocyte to establish a model of in vitro cardiomyocyte hypertrophy. Daily administration of Porcupine inhibitor Wnt-C59 was performed for 4 weeks after TAC surgery.

Results

Wnt-C59 significantly improved cardiac function and enhanced survival of mice subjected to TAC surgery. Histologically, Wnt-C59 attenuated TAC-induced increase in heart mass, cross-section area of cardiomyocyte, cardiac fibrosis, cardiomyocyte apoptosis, and expression of the hypertrophic biomarkers β-MHC, ANP, and BNP. TAC-induced oxidative stress was also ameliorated by Wnt-C59. Wnt-C59 attenuated Ang-II-induced in vitro cardiomyocyte hypertrophy, as indicated by decreased cell size and lower expression of ANP, BNP, and β-MHC. Moreover, Wnt/β-catenin activation was blocked by Wnt-C59 in cardiac hypertrophy, as indicated by decreased protein expression of Wnt3a and β-catenin and the Wnt target genes cyclin D1 and c-Myc.

Conclusions

Collectively, Porcupine inhibitor Wnt-C59 attenuates pressure overload-induced cardiac hypertrophic via interruption of the Wnt/β-catenin signaling pathway, and it might be a promising drug for patients with cardiac hypertrophy.