Wnt/β-catenin signaling contributes to prostate cancer heterogeneity through reciprocal suppression of H3K27 trimethylation

Ethionine-induced S-adenosylmethionine deficiency suppressed H3K27me3 and cell differentiation during neural tube development in mice

S-adenosylmethionine (SAM) as a major methyl donor plays a key role in methylation modification in vivo, and its disorder was closely related to neural tube defects (NTDs). However, the exact mechanism between SAM deficiency and NTDs remained unclearly. Hence, we investigated the association between histone methylation modification and cell differentiation in NTDs mice induced by SAM deficiency. The levels of SAM and SAH (S-adenosylhomocysteine) were determined by enzyme linked immunosorbent assay (ELISA). The level of histone methylation, β-catenin were analyzed by Western blot, reversing transcription and quantitative PCR (RT-qPCR) and immunofluorescence. The results showed that the incidence rate of NTDs induced by ethionine were 46.2%. Post treatment of ethionine combined with SAM, the incidence rate of NTDs was reduced to 26.2%. The level of SAM was significantly decreased (p < 0.05) and a reduction in the SAM/SAH ratio was observed after entionine treatment. The SAM deficiency caused the reduction of H3K27me3 modifications and the elevated UTX activity (p < 0.05), and inhibited the expressions of β-catenin. The differentiations of NSCs into neurons and oligodendrocytes were inhibited under SAM deficiency (p < 0.05). These results indicated that the SAM deficiency led to reduce H3K27me3 modifications, prevented the β-catenin signaling pathway and NSCs differentiation, which provided an understanding of the novel function of epigenetic regulation in NTDs.

Highlighting function of Wnt signalling in urological cancers: Molecular interactions, therapeutic strategies, and (nano)strategies

Cancer is a complex, multistep process characterized by abnormal cell growth and metastasis as well as the capacity of the tumor cells in therapy resistance development. The urological system is particularly susceptible to a group of malignancies known as urological cancers, where an accumulation of genetic alterations drives carcinogenesis. In various human cancers, Wnt singalling is dysregulated; following nuclear transfer of β-catenin, it promotes tumor progression and affects genes expression. Elevated levels of Wnt have been documented in urological cancers, where its overexpression enhances growth and metastasis. Additionally, increased Wnt singalling contributes to chemoresistance in urological cancers, leading to reduced sensitivity to chemotherapy agents like cisplatin, doxorubicin, and paclitaxel. Wnt upregulation can change radiotherapy response of urological cancers. The regulation of Wnt involves various molecular pathways, including Akt, miRNAs, lncRNAs, and circRNAs, all of which play roles in carcinogenesis. Targeting and silencing Wnt or its associated pathways can mitigate tumorigenesis in urological cancers. Anti-cancer compounds such as curcumin and thymoquinone have shown efficacy in suppressing tumorigenesis through the downregulation of Wnt singalling. Notably, nanoparticles have proven effective in treating urological cancers, with several studies in prostate cancer (PCa) using nanoparticles to downregulate Wnt and suppress tumor growth. Future research should focus on developing small molecules that inhibit Wnt singalling to further suppress tumorigenesis and advance the treatment of urological cancers. Moreover, Wnt can be used as reliable biomarker for the diagnosis and prognosis of urological cancers.

Epigenetic regulation of androgen dependent and independent prostate cancer

Prostate cancer is one of the most common malignancies among men worldwide. Besides genetic alterations, epigenetic modulations including DNA methylation, histone modifications and miRNA mediated alteration of gene expression are the key driving forces for the prostate tumor development and cancer progression. Aberrant expression and/or the activity of the epigenetic modifiers/enzymes, results in aberrant expression of genes involved in DNA repair, cell cycle regulation, cell adhesion, apoptosis, autophagy, tumor suppression and hormone response and thereby disease progression. Altered epigenome is associated with prostate cancer recurrence, progression, aggressiveness and transition from androgen-dependent to androgen-independent phenotype. These epigenetic modifications are reversible and various compounds/drugs targeting the epigenetic enzymes have been developed that are effective in cancer treatment. This chapter focuses on the epigenetic alterations in prostate cancer initiation and progression, listing different epigenetic biomarkers for diagnosis and prognosis of the disease and their potential as therapeutic targets. This chapter also summarizes different epigenetic drugs approved for prostate cancer therapy and the drugs available for clinical trials.

Trifuhalol A, a phlorotannin from the brown algae Agarum cribrosum, reduces adipogenesis of human primary adipocytes through Wnt/β-catenin and AMPK-dependent pathways

Trifuhalol A, a fucol-type phlorotannin, was extracted and identified from the brown algae Agarum cribrosum. The total yield and purity of trifuhalol A from A. cribrosum were 0.98% and 86%, respectively. Trifuhalol A at 22 and 44 μM inhibited lipid accumulation in human primary adipocytes. Consistently trifuhalol A suppressed the expression of adipogenesis-related genes, such as proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein-alpha (C/EBP-α), fatty acid synthase (FAS), and sterol regulatory element-binding protein-1 (SREBP-1), in a dose-dependent manner. Trifuhalol A increased the level of proteins such as wingless/integrated (Wnt)10b, nuclear-β-catenin, total-β-catenin, phospho-AMP-activated protein kinase (pAMPK), and phospho-liver kinase B1 (pLKB1) as well as the expression of genes such as Wnt10b, Frizzled 1, and low-density lipoprotein receptor-related protein 6 (LRP6). Additionally, trifuhalol A decreased the expression of the glycogen synthase kinase-3beta (GSK3β) gene. These results suggest that trifuhalol A reduces fat accumulation in human adipocytes via the Wnt/β-catenin- and AMPK-dependent pathways.

Wnt Signaling and Therapeutic Resistance in Castration-Resistant Prostate Cancer

Purpose of Review

Castration-resistant prostate cancer (CRPC) is a lethal form of prostate cancer (PCa) due to the development of resistance to androgen deprivation therapy and anti-androgens. Here, we review the emerging role of Wnt signaling in therapeutic resistance of CRPC.

Recent Findings

Convincing evidence have accumulated that Wnt signaling is aberrantly activated through genomic alterations and autocrine and paracrine augmentations. Wnt signaling plays a critical role in a subset of CRPC and in resistance to anti-androgen therapies. Wnt signaling navigates CRPC through PCa heterogeneity, neuroendocrine differentiation, DNA repair, PCa stem cell maintenance, epithelial-mesenchymal-transition and metastasis, and immune evasion.

Summary

Components of Wnt signaling can be harnessed for inhibiting PCa growth and metastasis and for developing novel therapeutic strategies to manage metastatic CRPC. There are many Wnt pathway-based potential drugs in different stages of pre-clinical development and clinical trials but so far, no Wnt signaling-specific drug has been approved by FDA for clinical use in CRPC.

Pretreatment of prostate cancer cells with salinomycin and Wnt inhibitor increases the efficacy of cabazitaxel by inducing apoptosis and decreasing cancer stem cells

Cancer stem cells (CSCs) are associated with metastasis and recurrence in prostate cancer as well as other cancers. We aimed to enhance the sensitivity of cabazitaxel in prostate cancer cell therapy by targeting CSCs with a Wnt inhibitor and salinomycin pretreatment. PC3, DU-145, and LNCaP human prostate cancer cells were exposed to Wnt/β-catenin pathway inhibitor CCT036477 (iWnt) with salinomycin for 48 h, followed by cabazitaxel treatment for 48 h. Cell viability, mRNA, and protein expression changes were evaluated by MTT, RT-qPCR, and Western blot assays, respectively. Apoptosis was determined by image-based cytometry, and cell migration was assessed by wound healing assay. Three-dimensional culture was established to assess the malignant phenotype and stemness potential of transformed or cancer cells. CD44 + CSCs were isolated using magnetic-activated cell sorting system. Pretreatment of PC3, DU-145, and LNCaP cells with salinomycin iWnt significantly sensitized the cells to cabazitaxel therapy. Spheroid culture confirmed that the treatment modality was more effective than a single administration of chemotherapy. The pretreatment of PC3 cells increased the rate of apoptosis compared to single administration of cabazitaxel, which downregulated Bcl-2 and upregulated caspase 3, caspase 8 expressions. The pretreatment suppressed cell migration, downregulated the expression of Sox2 and Nanog, and significantly reduced CD44 + CSC numbers. Notably, the treatment modality reduced pAKT, p-P38 MAPK, and pERK1/2. The data suggest that pretreatment of prostate cancer cells with salinomycin and Wnt inhibitor may increase the efficacy of cabazitaxel therapy by inhibiting cell proliferation and migration, and eliminating cancer stem cells.

miRNAs as potential game-changers in bone diseases: Future medicinal and clinical uses

MicroRNAs (miRNAs), short, highly conserved non-coding RNA, influence gene expression by sequential mechanisms such as mRNA breakdown or translational repression. Many biological processes depend on these regulating substances, thus changes in their expression have an impact on the maintenance of cellular homeostasis and result in the emergence of a variety of diseases. Relevant studies have shown in recent years that miRNAs are involved in many stages of bone development and growth. Additionally, abnormal production of miRNA in bone tissues has been closely associated with the development of numerous bone disorders, such as osteonecrosis, bone cancer, and bone metastases. Many pathological processes, including bone loss, metastasis, the proliferation of osteosarcoma cells, and differentiation of osteoblasts and osteoclasts, are under the control of miRNAs. By bringing together the most up-to-date information on the clinical relevance of miRNAs in such diseases, this study hopes to further the study of the biological features of miRNAs in bone disorders and explore their potential as a therapeutic target.

Glucocorticoid Receptor and β-Catenin Interact in Prostate Cancer Cells and Their Co-Inhibition Attenuates Tumorsphere Formation, Stemness, and Docetaxel Resistance

Therapy resistance hinders the efficacy of anti-androgen therapies and taxane-based chemotherapy for advanced prostate cancer (PCa). Glucocorticoid receptor (GR) signaling mediates resistance to androgen receptor signaling inhibitors (ARSI) and has also been recently implicated in PCa resistance to docetaxel (DTX), suggesting a role in therapy cross-resistance. Like GR, β-catenin is upregulated in metastatic and therapy-resistant tumors and is a crucial regulator of cancer stemness and ARSI resistance. β-catenin interacts with AR to promote PCa progression. Given the structural and functional similarities between AR and GR, we hypothesized that β-catenin also interacts with GR to influence PCa stemness and chemoresistance. As expected, we observed that treatment with the glucocorticoid dexamethasone promotednuclear accumulation of GR and active β-catenin in PCa cells. Co-immunoprecipitation studies showed that GR and β-catenin interact in DTX-resistant and DTX-sensitive PCa cells. Pharmacological co-inhibition of GR and β-catenin, using the GR modulator CORT-108297 and the selective β-catenin inhibitor MSAB, enhanced cytotoxicity in DTX-resistant PCa cells grown in adherent and spheroid cultures and decreased CD44+/CD24- cell populations in tumorspheres. These results indicate that GR and β-catenin influence cell survival, stemness, and tumorsphere formation in DTX-resistant cells. Their co-inhibition could be a promising therapeutic strategy to overcome PCa therapy cross-resistance.

The role of lysine-specific demethylase 6A (KDM6A) in tumorigenesis and its therapeutic potentials in cancer therapy

Histone demethylation is a key post-translational modification of chromatin, and its dysregulation affects a wide array of nuclear activities including the maintenance of genome integrity, transcriptional regulation, and epigenetic inheritance. Lysine specific demethylase 6A (KDM6A, also known as UTX) is an Fe²⁺- and α-ketoglutarate- dependent oxidase which belongs to KDM6 Jumonji histone demethylase subfamily, and it can remove mono-, di- and tri-methyl groups from methylated lysine 27 of histone H3 (H3K27me1/2/3). Mounting studies indicate that KDM6A is responsible for driving multiple human diseases, particularly cancers and pharmacological inhibition of KDM6A is an effective strategy to treat varieties of KDM6A-amplified cancers in cellulo and in vivo. Although there are several reviews on the roles of KDM6 subfamily in cancer development and therapy, all of them only simply introduce the roles of KDM6A in cancer without systematically summarizing the specific mechanisms of KDM6A in tumorigenesis, which greatly limits the advances on the understanding of roles KDM6A in varieties of cancers, discovering targeting selective KDM6A inhibitors, and exploring the adaptive profiles of KDM6A antagonists. Herein, we present the structure and functions of KDM6A, simply outline the functions of KDM6A in homeostasis and non-cancer diseases, summarize the role of KDM6A and its distinct target genes/ligand proteins in development of varieties of cancers, systematically classify KDM6A inhibitors, sum up the difficulties encountered in the research of KDM6A and the discovery of related drugs, and provide the corresponding solutions, which will contribute to understanding the roles of KDM6A in carcinogenesis and advancing the progression of KDM6A as a drug target in cancer therapy.

KDM6 Demethylases and Their Roles in Human Cancers

Cancer therapy is moving beyond traditional chemotherapy to include epigenetic approaches. KDM6 demethylases are dynamic regulation of gene expression by histone demethylation in response to diverse stimuli, and thus their dysregulation has been observed in various cancers. In this review, we first briefly introduce structural features of KDM6 subfamily, and then discuss the regulation of KDM6, which involves the coordinated control between cellular metabolism (intrinsic regulators) and tumor microenvironment (extrinsic stimuli). We further describe the aberrant functions of KDM6 in human cancers, acting as either a tumor suppressor or an oncoprotein in a context-dependent manner. Finally, we propose potential therapy of KDM6 enzymes based on their structural features, epigenetics, and immunomodulatory mechanisms, providing novel insights for prevention and treatment of cancers.