Interplay Between SOX9, Wnt/β-Catenin and Androgen Receptor Signaling in Castration-Resistant Prostate Cancer

The Activation of the CCND1 Promoter by AP-1 and SOX Transcription Factors in PC3 Prostate Cancer Cells Can Be Prevented by Anacardic Acid Analogs

Targeting more than one in nine men before age 70, prostate cancer is the most common type of cancer in men. The increased levels of cyclins, leading to activation of cyclin-dependent kinases (CDKs), play a critical role in the increased proliferation of prostate cancer cells. In this study, the regulation of the cyclin D1 (CCND1) promoter activity by activator protein-1 (AP-1) and SRY-related HMG-box (SOX) transcription factors has been characterized in PC3 prostate cancer cells. The SOX and AP-1 transcription factors can cooperate to activate the CCND1 promoter in PC3 prostate cancer cells and such cooperation can be enhanced by protein kinase A (PKA) and/or mitogen-activated protein kinase kinase 1 (ERK kinase 1, MAP2K1) signaling pathways. Moreover, anacardic acid analogs have been assessed for their potential in reducing cell viability and CCND1 promoter activity. The anacardic acid analog 8b, obtained from γ-resorcylic acid, reduces the viability and proliferation of PC3 cells by decreasing CCND1 promoter activity. The effect of analog 8b, which perfectly mimics the structure of anacardic acid, can be attributed to the inhibition of the activities of the transcription factors SOX and AP-1, which are important regulators of CCND1 promoter activity in prostate cancer cells.

Combination therapies with Wnt signaling inhibition: A better choice for prostate cancer treatment

The intractability and high mortality rate of castration-resistant prostate cancer (CRPC) remain the most challenging problems in the field of prostate cancer (PCa). Emerging evidence has shown that the dysregulation of Wnt signaling pathways, which are highly conserved cascades that regulate embryonic development and maintain tissue homeostasis, is involved in various stages of PCa occurrence and progression. In this review, we systemically discuss the mechanisms by which the androgen receptor (AR) signaling pathway and Wnt signaling pathways participate in the occurrence of PCa and its progression to CRPC. Specifically, we elaborate on how Wnt signaling pathways induce the malignant transformation of prostate cells, promote the malignant progression of PCa and establish an immunosuppressive prostate tumor microenvironment through interaction with the AR pathway or in an AR-independent manner. We also discuss how Wnt signaling pathways enhances the stemness characteristics of prostate cancer stem cells (PCSCs) to induce the occurrence and metastasis of CPPC. Additionally, we discuss the latest progress in the use of different types of drugs that inhibit the Wnt signaling pathways in the treatment of PCa. We believe that the combination of Wnt signaling-based drugs with endocrine and other therapies is necessary and may enhance the clinical efficacy in the treatment of all types of PCa.

AR expression-independent XRCC3 mediates DNA damage-induced p53/Bax signaling pathway activation against prostate cancer

BACKGROUND

Androgen deprivation therapy (ADT) resistance is closely associated with altered AR status. Aberrant AR expression is critical for the induction of ADT resistance, necessitating the identification of an anti-PCa target independent of AR expression.

METHODS

Transcriptomic data and clinical information of PRAD were obtained from TCGA database. Genes with PCa-related and AR expression-independent were screened by bioinformatics, and characterized by PPI and GO functional enrichment analyses. Candidate genes were locked by co-expression correlation and disease-free survival (DFS) analyses. A prognostic gene set was established using LASSO Cox regression algorithm. Cox proportional risk regression was performed to identify a key prognostic gene. Expression of the target protein in PCa tissues was verified by The Human Protein Atlas database. In vitro validation of cellular function and molecular mechanism by knockdown and overexpression of the target gene.

RESULTS

Two AR expression-independent genes (SLC43A1 and XRCC3) were available for the optimal prognostic model. This gene set effectively predicted PRAD patients' DFS at 1-, 3- and 5-year, where XRCC3 and tumor (T) stage were independent risk factors. XRCC3 was higher expressed in PRAD patients with T3-T4 stages and accompanied by poorer DFS. IHC staining also validated its higher expression in high-risk PCa tissues. In vitro experiments demonstrated that silencing XRCC3 significantly inhibited 22Rv1 and DU145 cell proliferation, migration and invasion, while promoted apoptosis. Further, silencing XRCC3 promoted DNA damage-induced p53/Bax signaling pathway activation, which was absent with overexpression.

CONCLUSION

Silencing XRCC3 exerts anti-PCa effects by promoting DNA damage-induced p53/Bax signaling pathway activation in an AR expression-independent manner.

Characterization of Wnt Signaling Pathway Aberrations in Metastatic Prostate Cancer

Wnt (wingless-type) signaling pathway (WSP) alterations have been identified in patients with prostate cancer and are implicated in disease progression and hormonal resistance. In this study, we utilized a multi-institutional dataset to characterize molecular alterations in the canonical and noncanonical WSPs in prostate cancer. Patients with prostate cancer who underwent tissue-based genomic sequencing were investigated. Tumors with somatic activating mutations in CTNNB1 or RSPO2 or inactivating mutations in either APC or RNF43 were characterized as having aberrant canonical Wnt signaling (WSP-activated). Overall survival analyses were restricted to microsatellite-stable (MSS) tumors lacking RNF43 G659fs* mutations. We also investigated noncanonical WSP by evaluation of ROR1, ROR2, and WNT5 in WSP-activated versus WSP wild-type (WSP-WT) tumors. Of 4,138 prostate cancer samples, 3,684 were MSS. Among MSS tumors, 42.4% were from metastatic sites, of which 19.1% were WSP activated, and 57.6% were from the prostate, of which 10.1% were WSP activated. WSP-activated tumors were more prevalent in metastatic sites than in primary prostate cancer. WSP-activated prostate cancer exhibited more SPOP mutations and higher expression of canonical WSP activators than WSP-WT tumors. ROR1 gene expression was elevated in WSP-activated tumors from both primary and metastatic sites. M2 macrophages predominated the tumor microenvironment in WSP-activated tumors. There was no significant difference in overall survival between patients with WSP-activated and WSP-WT prostate cancer. WSP-activated prostate cancer demonstrated a more immunosuppressed tumor microenvironment and a pronounced upregulation of ROR1 gene expression, underscoring its potential involvement in the crosstalk between canonical and noncanonical WSPs. Implications: Our findings may provide a rationale for developing novel therapeutic strategies targeting Wnt-activated prostate cancer.

Synergistic Strategies for Castration-Resistant Prostate Cancer: Targeting AR-V7, Exploring Natural Compounds, and Optimizing FDA-Approved Therapies

Castration-resistant prostate cancer (CRPC) remains a significant therapeutic challenge due to its resistance to standard androgen deprivation therapy (ADT). The emergence of androgen receptor splice variant 7 (AR-V7) has been implicated in CRPC progression, contributing to treatment resistance. Current treatments, including first-generation chemotherapy, androgen receptor blockers, radiation therapy, immune therapy, and PARP inhibitors, often come with substantial side effects and limited efficacy. Natural compounds, particularly those derived from herbal medicine, have garnered increasing interest as adjunctive therapeutic agents against CRPC. This review explores the role of AR-V7 in CRPC and highlights the promising benefits of natural compounds as complementary treatments to conventional drugs in reducing CRPC and overcoming therapeutic resistance. We delve into the mechanisms of action underlying the anti-CRPC effects of natural compounds, showcasing their potential to enhance therapeutic outcomes while mitigating the side effects associated with conventional therapies. The exploration of natural compounds offers promising avenues for developing novel treatment strategies that enhance therapeutic outcomes and reduce the adverse effects of conventional CRPC therapies. These compounds provide a safer, more effective approach to managing CRPC, representing a significant advancement in improving patient care.

Nuclear receptor NURR1 functions to promote stemness and epithelial-mesenchymal transition in prostate cancer via its targeting of Wnt/β-catenin signaling pathway

Dysregulated activation of Wnt/β-catenin signaling pathway is a frequent or common event during advanced progression of multiple cancers. With this signaling activation, it enhances their tumorigenic growth and facilitates metastasis and therapy resistance. Advances show that this signaling pathway can play dual regulatory roles in the control of cellular processes epithelial-mesenchymal transition (EMT) and cancer stemness in cancer progression. Aberrant activation of Wnt/β-catenin signaling pathway is shown to be common in prostate cancer and also castration-resistant prostate cancer (CRPC). However, the transcriptional regulators of this pathway in prostate cancer are still not well characterized. NURR1 (NR4A2) is an orphan nuclear receptor and plays an important role in the development of dopaminergic neurons. Previously, we have shown that NURR1 exhibits an upregulation in isolated prostate cancer stem-like cells (PCSCs) and a xenograft model of CRPC. In this study, we further confirmed that NURR1 exhibited an upregulation in prostate cancer and also enhanced expression in prostate cancer cell lines. Functional and molecular analyses showed that NURR1 could act to promote both in vitro (cancer stemness and EMT) and also in vivo oncogenic growth of prostate cancer cells (metastasis and castration resistance) via its direct transactivation of CTNNB1 (β-catenin) and activation of β-catenin to mediate the activation of Wnt/β-catenin signaling pathway. Moreover, we also demonstrated that NURR1 activity in prostate cancer cells could be modulated by small molecules, implicating that NURR1 could be a potential therapeutic target for advanced prostate cancer management.

Influence of dexamethasone on the interaction between glucocorticoid receptor and SOX9: A molecular dynamics study

The glucocorticoid receptor (GR) is a nuclear receptor that controls critical biological processes by regulating the transcription of specific genes. GR transcriptional activity is modulated by a series of ligands and coenzymes, where a ligand can act as an agonist or antagonist. GR agonists, such as the glucocorticoids dexamethasone (DEX) and prednisolone, are widely prescribed to patients with inflammatory and autoimmune diseases. DEX is also used to induce osteogenic differentiation in vitro. Recently, it has been highlighted that DEX induces changes in the osteogenic differentiation of human mesenchymal stromal cells by downregulating the transcription factor SRY-box transcription factor 9 (SOX9) and upregulating the peroxisome proliferator-activated receptor γ (PPARG). SOX9 is fundamental in the control of chondrogenesis, but also in osteogenesis by acting as a dominant-negative of RUNX2. Many processes remain to be clarified during cell fate determination, such as the interplay between the key transcription factors. The main objective pursued by this work is to shed light on the interaction between GR and SOX9 in the presence and absence of DEX at an atomic level of resolution using molecular dynamics simulations. The outcome of this research could help the understanding of possible molecular interactions between GR and SOX9 and their role in the determination of cell fate. The results highlight the key residues at the interface between GR and SOX9 involved in the complexation process and shed light on the mechanism through which DEX modulates GR-SOX9 binding and exerts its biological activity.

Upregulation of SOX9 promotes the self-renewal and tumorigenicity of cervical cancer through activating the Wnt/β-catenin signaling pathway

Sry-box9 (SOX9) maintains stem cell properties and plays crucial roles in many cancers. However, whether SOX9 is correlated with cervical cancer cell stemness and its detailed mechanism remains obscure. We studied the relationship between SOX9 and prognosis of cervical cancer through public database, and SOX9 was related to poor prognosis of cervical cancer. Elevated SOX9 expression enhanced the self-renewal properties and promotes tumorigenicity in cervical cancer. Overexpression of SOX9 could promote the expression of stem cell-related factors in cervical cancer cells and xenografts. Meanwhile, overexpression of SOX9 could also enhance the expressions of FZD10, β-catenin, and c-Myc in cervical cancer cells and xenografts, while inhibiting the expression of DDK1. The activation of Wnt pathway by chir-99 021 raised the tumor spheroid ability of SOX9 knockdown HeLa cells. In addition, SOX9 could transcriptional inhibit DKK1 and activate FZD10 and MYC by binding to their promoters to affect the Wnt/β-catenin pathway. These results demonstrated SOX9 regulated the self-renewal and tumorigenicity of cervical cancer through Wnt/β-catenin pathway by directly transcriptional activation of FZD10, MYC and transcriptional inhibition of DKK1.

Unlocking the role of non-coding RNAs in prostate cancer progression: exploring the interplay with the Wnt signaling pathway

Prostate cancer (PCa) is one of the most common cancers in males, exhibiting a wide spectrum of clinical manifestations that pose challenges in its diagnosis and treatment. The Wnt signaling pathway, a conserved and complex pathway, is crucial for embryonic development, tissue homeostasis, and various physiological processes. Apart from the classical Wnt/β-catenin signaling pathway, there exist multiple non-classical Wnt signaling pathways, including the Wnt/PCP and Wnt/Ca2+ pathways. Non-coding RNAs (ncRNAs) are involved in the occurrence and development of PCa and the response to PCa treatment. ncRNAs are known to execute diverse regulatory roles in cellular processes, despite their inability to encode proteins. Among them, microRNAs, long non-coding RNAs, and circular RNAs play key roles in the regulation of the Wnt signaling pathway in PCa. Aberrant expression of these ncRNAs and dysregulation of the Wnt signaling pathway are one of the causes of cell proliferation, apoptosis, invasion, migration, and angiogenesis in PCa. Moreover, these ncRNAs affect the characteristics of PCa cells and hold promise as diagnostic and prognostic biomarkers. Herein, we summarize the role of ncRNAs in the regulation of the Wnt signaling pathway during the development of PCa. Additionally, we present an overview of the current progress in research on the correlation between these molecules and clinical features of the disease to provide novel insights and strategies for the treatment of PCa.

Genetic and histological relationship between pheromone-secreting tissues of the musk gland and skin of juvenile Chinese forest musk deer (Moschus berezovskii Flerov, 1929)

BACKGROUND: The musk glands of adult male Chinese forest musk deer (Moschus berezovskii Flerov, 1929) (FMD), which are considered as special skin glands, secrete a mixture of sebum, lipids, and proteins into the musk pod. Together, these components form musk, which plays an important role in attracting females during the breeding season. However, the relationship between the musk glands and skin of Chinese FMD remains undiscovered. Here, the musk gland and skin of Chinese FMD were examined using histological analysis and RNA sequencing (RNA-seq), and the expression of key regulatory genes was evaluated to determine whether the musk gland is derived from the skin. METHODS: A comparative analysis of musk gland anatomy between juvenile and adult Chinese FMD was conducted. Then, based on the anatomical structure of the musk gland, skin tissues from the abdomen and back as well as musk gland tissues were obtained from three juvenile FMD. These tissues were used for RNA-seq, hematoxylin-eosin (HE) staining, immunohistochemistry (IHC), western blot (WB), and quantitative real-time polymerase chain reaction (qRT-PCR) experiments. RESULTS: Anatomical analysis showed that only adult male FMD had a complete glandular organ and musk pod, while juvenile FMD did not have any well-developed musk pods. Transcriptomic data revealed that 88.24% of genes were co-expressed in the skin and musk gland tissues. Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analysis found that the genes co-expressed in the abdomen skin, back skin, and musk gland were enriched in biological development, endocrine system, lipid metabolism, and other pathways. Gene Ontology (GO) enrichment analysis indicated that the genes expressed in these tissues were enriched in biological processes such as multicellular development and cell division. Moreover, the Metascape predictive analysis tool demonstrated that genes expressed in musk glands were skin tissue-specific. qRT-PCR and WB revealed that sex-determining region Y-box protein 9 (Sox9),Caveolin-1 (Cav-1), andandrogen receptor (AR) were expressed in all three tissues, although the expression levels differed among the tissues. According to the IHC results, Sox9 and AR were expressed in the nuclei of sebaceous gland, hair follicle, and musk gland cells, whereas Cav-1 was expressed in the cell membrane. CONCLUSIONS: The musk gland of Chinese FMD may be a derivative of skin tissue, and Sox9, Cav-1, and AR may play significant roles in musk gland development.

Inhibition of Wnt/β-catenin pathway overcomes therapeutic resistance to abiraterone in castration-resistant prostate cancer

Abiraterone acetate has been clinically approved for the treatment of patients with advanced-stage prostate cancer. It reduces testosterone production by blocking the enzyme cytochrome P450 17 alpha-hydroxylase. Despite improved survival outcomes with abiraterone, almost all patients develop therapeutic resistance and disease recurrence, progressing to a more aggressive and lethal phenotype. Bioinformatics analyses predicted activation of canonical Wnt/β-catenin and involvement of stem cell plasticity in abiraterone-resistant prostate cancer. Increased expression of androgen receptor (AR) and β-catenin and their crosstalk causes activation of AR target genes and regulatory networks for which overcoming acquired resistance remains a major challenge. Here we show that co-treatment with abiraterone and ICG001, a β-catenin inhibitor, overcomes therapeutic resistance and significantly inhibited markers of stem cell and cellular proliferation in abiraterone-resistant prostate cancer cells. Importantly, this combined treatment abrogated the association between AR and β-catenin; diminished SOX9 expression from the complex more prominently in abiraterone-resistant cells. In addition, combined treatment inhibited tumor growth in an in vivo abiraterone-resistant xenograft model, blocked stemness, migration, invasion, and colony formation ability of cancer cells. This study opens new therapeutic opportunity for advanced-stage castration-resistant prostate cancer patients.

Hormone-Dependent Cancers: New Aspects on Biochemistry and Molecular Pathology

Hormones, especially steroids, are closely involved in the physiological functions and proliferation of various target tissues and have long been known to play a key role in the tumorigenesis or carcinogenesis of these target tissues [...].

SOX9 and HMGB3 co-operatively transactivate NANOG and promote prostate cancer progression

BACKGROUND

The homeodomain-containing transcription factor NANOG is overexpressed in prostate adenocarcinoma (PCa) and predicts poor prognosis. The SOX family transcription factor SOX9, as well as the transcription co-activator HMGB3 of the HMGB family, are also overexpressed and may play pivotal roles in PCa. However, it is unknown whether SOX9 and HMGB3 interact with each other, or if they regulate NANOG gene transcription.

METHODS

We identified potential SOX9 responsive elements in NANOG promoter, and investigated if SOX9 regulated NANOG transcription in co-operation with HMGB3 by experimental analysis of potential SOX9 binding sites in NANOG promoter, reporter gene transcription assays with or without interference or artificial overexpression of SOX9 and/or HMGB3, and protein-binding assays of SOX9-HMGB3 interaction. Clinicopathologic and prognostic significance of SOX9-HMGB3 overexpression in PCa was analyzed.

RESULTS

SOX9 activated NANOG gene transcription by preferentially binding to a highly conserved consensus cis-regulatory element (-573 to -568) in NANOG promoter, and promoted the expression of NANOG downstream oncogenic genes. Importantly, HMGB3 functioned as a partner of SOX9 to co-operatively enhance transactivation of NANOG by interacting with SOX9, predominantly via the HMG Box A domain of HMGB3. Overexpression of SOX9 and/or HMGB3 enhanced PCa cell survival and cell migration and were significantly associated with PCa progression. Notably, Cox proportional regression analysis showed that co-overexpression of both SOX9 and HMGB3 was an independent unfavorable prognosticator for both CRPC-free survival (relative risk [RR] = 3.779，95% confidence interval [CI]: 1.159-12.322, p = 0.028) and overall survival (RR = 3.615，95% CI: 1.101-11.876, p = 0.034).

CONCLUSIONS

These findings showed a novel SOX9/HMGB3/NANOG regulatory mechanism, deregulation of which played important roles in PCa progression.

Targeting Transcription Factors in Cancer: From "Undruggable" to "Druggable"

Deregulation of transcription factors is critical to hallmarks of cancer. Genetic mutations, gene fusions, amplifications or deletions, epigenetic alternations, and aberrant post-transcriptional modification of transcription factors are involved in the regulation of various stages of carcinogenesis, including cancer initiation, progression, and metastasis. Thus, targeting the dysfunctional transcription factors may lead to new cancer therapeutic strategies. However, transcription factors are conventionally considered as "undruggable." Here, we summarize the recent progresses in understanding the regulation of transcription factors in cancers and strategies to target transcription factors and co-factors for preclinical and clinical drug development, particularly focusing on c-Myc, YAP/TAZ, and β-catenin due to their significance and interplays in cancer.

Sox9 is required in regeneration of pancreatic β cells following injury

The reduction of insulin secretion due to pancreatic β cell injury caused by autoimmune reaction is the pathological basis of Type 1 diabetes mellitus (T1DM). Therefore, seeking new molecular targets for alleviating pancreatic β cell injury will provide experimental basis for the prevention and treatment of T1DM. SRY-box 9 (Sox9) is not only an important molecule regulating the development of various organs, but also its high expression can aggravate the pathological process of various diseases. In addition, Sox9⁺ cells are also pancreatic progenitor cells, participating in pancreatic repair reaction induced by injury. In our study, elevated blood glucose and lack of pancreatic β cells almost returned to normal over time after streptozotocin (STZ)-induced pancreatic β cell damage, implying that pancreatic β cells were regenerated after STZ-induced injury. In particular, the expression of Sox9 was significantly elevated during pancreatic β cell regeneration. On this basis, we conducted in vitro experiments to verify whether overexpression of Sox9 could inhibit the damage of pancreatic β cells by inflammatory factors. Our results showed that overexpression of Sox9 alleviated the damage of pancreatic β cells by inflammatory factors and improved the inhibitory effect of inflammatory factors on insulin secretion of pancreatic β cells. Unsurprising, blood glucose levels, insulin content and pancreatic β cell number failed to return to near-normal levels timely after pancreatic β cells specific knockout Sox9 mice were treated with STZ, further confirming the importance of Sox9 in facilitating pancreatic β cell repair or regeneration. Our study indicate that enhanced Sox9 activity might protect pancreatic β cells from autoimmune induced damage and thus improve the pathological process of T1DM.

LL-37 as a Powerful Molecular Tool for Boosting the Performance of Ex Vivo-Produced Human Dendritic Cells for Cancer Immunotherapy

Ex vivo-produced dendritic cells (DCs) constitute the core of active cellular immunotherapy (ACI) for cancer treatment. After many disappointments in clinical trials, the current protocols for their preparation are attempting to boost their therapeutic efficacy by enhancing their functionality towards Th1 response and capability to induce the expansion of cytotoxic tumor-specific CD8⁺ T cells. LL-37 is an antimicrobial peptide with strong immunomodulatory potential. This potential was previously found to either enhance or suppress the desired anti-tumor DC functionality when used at different phases of their ex vivo production. In this work, we show that LL-37 can be implemented during the whole process of DC production in a way that allows LL-37 to enhance the anti-tumor functionality of produced DCs. We found that the supplementation of LL-37 during the differentiation of monocyte-derived DCs showed only a tendency to enhance their in vitro-induced lymphocyte enrichment with CD8⁺ T cells. The supplementation of LL-37 also during the process of DC antigen loading (pulsation) and maturation significantly enhanced the cell culture enrichment with CD8⁺ T cells. Moreover, this enrichment was also associated with the downregulated expression of PD-1 in CD8⁺ T cells, significantly higher frequency of tumor cell-reactive CD8⁺ T cells, and superior in vitro cytotoxicity against tumor cells. These data showed that LL-37 implementation into the whole process of the ex vivo production of DCs could significantly boost their anti-tumor performance in ACI.

The Crucial Role of AR-V7 in Enzalutamide-Resistance of Castration-Resistant Prostate Cancer

Simple Summary

Androgen receptor splice variant 7 (AR-V7) has always been considered a key driver for triggering enzalutamide resistance of castration-resistant prostate cancer (CRPC). In recent years, both the homeostasis of AR-V7 protein and AR-V7’s relationship with LncRNAs have gained great attention with in-depth studies. Starting from protein stability and LncRNA, the paper discusses and summarizes the mechanisms and drugs that affect the CRPC patients’ sensitivity to enzalutamide by regulating the protein or transcriptional stability of AR-V7, hoping to provide therapeutic ideas for subsequent research to break through the CRPC therapeutic bottleneck.

Abstract

Prostate cancer (PCa) has the second highest incidence of malignancies occurring in men worldwide. The first-line therapy of PCa is androgen deprivation therapy (ADT). Nonetheless, most patients progress to castration-resistant prostate cancer (CRPC) after being treated by ADT. As a second-generation androgen receptor (AR) antagonist, enzalutamide (ENZ) is the current mainstay of new endocrine therapies for CRPC in clinical use. However, almost all patients develop resistance during AR antagonist therapy due to various mechanisms. At present, ENZ resistance (ENZR) has become challenging in the clinical treatment of CRPC. AR splice variant 7 (AR-V7) refers to a ligand-independent and constitutively active variant of the AR and is considered a key driver of ENZR in CRPC. In this review, we summarize the mechanisms and biological behaviors of AR-V7 in ENZR of CRPC to contribute novel insights for CRPC therapy.

Osteoblast Secretome Modulated by Abiraterone Treatment Affects Castration Resistant Prostate Cancer Cell Proliferation

Abiraterone is a selective inhibitor of androgen biosynthesis approved for the treatment of metastatic patients affected by castration-resistant or castration-sensitive prostate cancer. Intriguingly, clinical data revealed that abiraterone also delayed disease progression in bone improving bone-related endpoints. Our group has previously demonstrated in vitro a direct effect of abiraterone on osteoclast and osteoblast function suggesting its ability to modulate bone microenvironment. Here, we performed an extensive proteomic analysis to investigate how abiraterone influences osteoblast cell secretome and, consequently, osteoblast/prostate cancer cells interaction. A panel of 507 soluble molecules were analyzed in osteoblast conditioned media (OCM) obtained from osteoblast treated or not with abiraterone. Subsequently, OCM was added to prostate cancer cells to investigate its potential effect on prostate cancer cell proliferation and androgen receptor (AR) activation status. Out of 507 screened molecules, 39 of them were differentially expressed in OCM from osteoblasts treated with abiraterone (OCM ABI) compared to OCM obtained from untreated OBs (OCM CTRL). Pathway enrichment analysis revealed that abiraterone down-modulated the release of specific osteoblast soluble factors, positively associated with cell proliferation pathways (false discovery rate adjusted p-value = 0.0019). In vitro validation data showed that OCM ABI treatment significantly reduced cancer proliferation in C4-2B cells (p = 0.022), but not in AR- negative PC-3 cells. Moreover, we also found a reduction in AR activation in C4-2B cells (p = 0.017) confirming the “indirect” anti-tumor AR-dependent effect of abiraterone mediated by osteoblasts. This study provides the first evidence of an additional antitumor effect of abiraterone through the modulation of multiple osteoblast proliferative signals.

Advances in the research of plant-derived natural products against retinoblastoma

Retinoblastoma (RB) is a highly aggressive ocular tumor, and due to socioeconomic and medical constraints, many children receive treatment only in the metaphase and advanced clinical stages, resulting in high rates of blindness and disability. Although several approaches exist in the treatment of RB, some children with the disease do not have satisfactory results because of various factors. Plant-derived natural products have shown definite therapeutic effects in the treatment of various tumors and are also widely used in the study of RB. We review plant-derived natural products used in the study of anti-RB to provide ideas for the clinical application of these drugs and the development of new therapeutic drugs.

Advances in the Current Understanding of the Mechanisms Governing the Acquisition of Castration-Resistant Prostate Cancer

Despite aggressive treatment and androgen-deprivation therapy, most prostate cancer patients ultimately develop castration-resistant prostate cancer (CRPC), which is associated with high mortality rates. However, the mechanisms governing the development of CRPC are poorly understood, and androgen receptor (AR) signaling has been shown to be important in CRPC through AR gene mutations, gene overexpression, co-regulatory factors, AR shear variants, and androgen resynthesis. A growing number of non-AR pathways have also been shown to influence the CRPC progression, including the Wnt and Hh pathways. Moreover, non-coding RNAs have been identified as important regulators of the CRPC pathogenesis. The present review provides an overview of the relevant literature pertaining to the mechanisms governing the molecular acquisition of castration resistance in prostate cancer, providing a foundation for future, targeted therapeutic efforts.

CDK6 is upregulated and may be a potential therapeutic target in enzalutamide-resistant castration-resistant prostate cancer

Background

Androgen deprivation therapy (ADT) is still the first-line treatment of prostate cancer (PCa). However, after a certain period of therapy, primary PCa inevitably progresses into castration-resistant PCa (CRPC). Enzalutamide (Enz) is an androgen receptor (AR) signal inhibitor which can delay the progression of CRPC and increase survival of patients with metastatic CRPC. However, the mechanisms involved in enzalutamide-resistant (EnzR) CRPC are still controversial. In the study, we used bioinformatic methods to find potential genes that correlated with the occurrence of EnzR CRPC.

Methods

We collected RNA sequencing data of the EnzR CRPC cell line LNCaP (EnzR LNCaP) from GSE44905, GSE78201, and GSE150807. We found the hub genes from the three datasets. Then we tested the expression of the hub genes in different databases and the potential drugs that can affect the hub genes. Finally, we verified the hub gene expression and drug function.

Results

From GSE44905, GSE78201 and GSE150807, we found 45 differentially expressed genes (DEGs) between LNCaP and EnzR LNCaP. Ten hub genes were found in the protein–protein interaction (PPI) network. The expression of hub gene and survival analysis were analyzed by different databases. We found that cyclin-dependent kinase 6 (CDK6) was highly expressed in both the EnzR LNCaP cell and PCa patients. Ten potential small molecules could suppress CDK6 expression as per “CLUE COMMAND” findings. Finally, we found the expression of CDK6 increased in both PCa patients’ samples, CRPC and EnzR PCa cell lines. Three potential CDK6 inhibitors, namely apigenin, chrysin and fisetin, can decrease cell proliferation.

Conclusions

The study proved that the abnormal overexpression of CDK6 may be a reason behind EnzR CRPC occurrence and suppression CDK6 expression may help treat EnzR CRPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00730-y.

Androgen/Wnt/β-catenin signal axis augments cell proliferation of the mouse erectile tissue, corpus cavernosum

The murine penile erectile tissues including corpus cavernosum (CC) are composed of blood vessels, smooth muscle, and connective tissue, showing marked sexual differences. It has been known that the androgens are required for sexually dimorphic organogenesis. It is however unknown about the features of androgen signaling during mouse CC development. It is also unclear how androgen-driven downstream factors are involved such processes. In the current study, we analyzed the onset of sexually dimorphic CC formation based on histological analyses, the dynamics of androgen receptor (AR) expression, and regulation of cell proliferation. Of note, we identified Dickkopf-related protein 2 (Dkk2), an inhibitor of β-catenin signaling, was predominantly expressed in female CC compared with male. Furthermore, administration of androgens resulted in activation of β-catenin signaling. We have found the Sox9 gene, one of the essential markers for chondrocyte, was specifically expressed in the developing CC. Hence, we utilized CC-specific, Sox9 ^CreERT2 , β-catenin conditional mutant mice. Such mutant mice showed defective cell proliferation. Furthermore, introduction of activated form of β-catenin mutation (gain of function mutation for Wnt/β-catenin signaling) in CC induced augmented cell proliferation. Altogether, we revealed androgen-Wnt/β-catenin signal dependent cell proliferation was essential for sexually dimorphic CC formation. These findings open new avenues for understanding developmental mechanisms of androgen-dependent cell proliferation during sexual differentiation.

Circular RNA hsa_circ_0000277 promotes tumor progression and DDP resistance in esophageal squamous cell carcinoma

Background

Circular RNAs (circRNAs) are well-known regulators of cancer progression and chemoresistance in various types of cancers. This study was performed to investigate the function of hsa_circ_0000277 in esophageal squamous cell carcinoma (ESCC).

Methods

RNA levels were analyzed via the reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8) assay was applied to determine cell proliferation and half maximal inhibitory concentration (IC50) of cisplatin (DDP). Colony formation ability was evaluated by colony formation assay. Cell cycle and apoptosis were measured using flow cytometry. RNA immunoprecipitation (RIP), pull-down assay and dual-luciferase reporter assays were performed for target interaction analysis. The protein levels were determined through western blot. Xenograft models were established for researching hsa_circ_0000277 function in vivo.

Results

Hsa_circ_0000277 expression was increased in ESCC cells and tissues, and it had important clinical significance. Downregulation of hsa_circ_0000277 repressed ESCC cell proliferation, colony formation, cell cycle, and DDP resistance. Hsa_circ_0000277 acted as a microRNA-873-5p (miR-873-5p) sponge and Sry-related high-mobility group box 4 (SOX4) was validated as a target of miR-873-5p. Moreover, hsa_circ_0000277/miR-873-5p axis and miR-873-5p/SOX4 axis regulated ESCC cell progression and DDP resistance. Hsa_circ_0000277/miR-873-5p axis activated SOX4/Wnt/β-catenin signaling pathway. Hsa_circ_0000277 facilitated tumorigenesis and DDP resistance by miR-873-5p/SOX4 axis in vivo.

Conclusion

These findings unraveled that hsa_circ_0000277 promoted ESCC progression and DDP resistance via miR-873-5p/SOX4/Wnt/β-catenin axis, showing a specific molecular mechanism of carcinogenesis and chemoresistance in ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09241-9.

Exploring the Wnt Pathway as a Therapeutic Target for Prostate Cancer

Aberrant activation of the Wnt pathway is emerging as a frequent event during prostate cancer that can facilitate tumor formation, progression, and therapeutic resistance. Recent discoveries indicate that targeting the Wnt pathway to treat prostate cancer may be efficacious. However, the functional consequence of activating the Wnt pathway during the different stages of prostate cancer progression remains unclear. Preclinical work investigating the efficacy of targeting Wnt signaling for the treatment of prostate cancer, both in primary and metastatic lesions, and improving our molecular understanding of treatment responses is crucial to identifying effective treatment strategies and biomarkers that help guide treatment decisions and improve patient care. In this review, we outline the type of genetic alterations that lead to activated Wnt signaling in prostate cancer, highlight the range of laboratory models used to study the role of Wnt genetic drivers in prostate cancer, and discuss new mechanistic insights into how the Wnt cascade facilitates prostate cancer growth, metastasis, and drug resistance.

Circ_0075825 promotes gastric cancer progression via adsorbing miR-432-5p to modulate SOX9

METHODS

Circ_0075825 expression in adjacent tissues and GC tissues was evaluated by bioinformatics method and quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR). How circ_0075825 regulated GC cell growth, migration, invasion, and apoptosis were investigated by cell counting kit-8 assay, transwell assay and flow cytometry. The targeted interplays among circ_0075825, and miR-432-5p and Sex-Determining Region Y-related high-mobility group box 9 (SOX9) were explored by bioinformatics analysis and luciferase reporter gene assay. The regulatory effects of circ_0075825 and miR-432-5p on SOX9 protein expression were probed by western blot.

RESULTS

Circ_0075825 expression was raised in GC tissues and cell lines. Circ_0075825 overexpression promoted the proliferative, migrative and invasive abilities of GC cells, while inhibiting apoptosis, while depletion of circ_0075825 suppressed the malignant biological behaviors of GC cells. SOX9 was identified as one of the direct target genes of miR-432-5p, and circ_0075825 repressed the expression of miR-432-5p, to induce the expression of SOX9. Furthermore, miR-432-5p overexpression counteracted the promoting effect of circ_0075825 on the malignancy of GC cells.

CONCLUSION

Circ_0075825 promotes GC progression via sponging miR-432-5p to regulate SOX9 expression level, and it may be a novel therapeutic target for treating GC.

miR-381 Reverses Multidrug Resistance by Negative Regulation of the CTNNB1/ABCB1 Pathway in HepG2/Dox Cells, and the Diagnostic and Prognostic Values of CTNNB1/ABCB1 Are Identified in Patients with LIHC

Multidrug resistance (MDR) is the biggest challenge in cancer therapy. In this study, we explored the molecular mechanism of MDR in human liver cancer and explored the related diagnostic and prognostic values of the targeted genes in patients with hepatocellular carcinoma. We constructed a multidrug-resistant liver cancer cell line, HepG2/Dox, using the parental subline HepG2. The (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay was used to test the viability of the liver cancer cells. Western blotting was performed to test the expression of ABCB1, β-catenin, and β-actin. Luciferase assays were performed to confirm the relationship between miR-381 and its target genes. The diagnostic and prognostic values of target genes were analyzed using publicly available data from The Cancer Genome Atlas. The Mann-Whitney U test and logistic regression were performed to evaluate the association between ABCB1 or CTNNB1 expression and clinical features in patients with liver hepatocellular carcinoma (LIHC). Finally, Kaplan-Meier and Cox regression analyses were performed to test the effect of ABCB1 or CTNNB1 expression on the overall survival of patients with LIHC. ABCB1 expression was upregulated in HepG2/Dox cells. ABCB1 was found to be a direct target of hsa-miR-381 and was negatively regulated by has-miR-381. Moreover, hsa-miR-381 directly targeted the CTNNB1 3' UTR and decreased the luciferase activity of CTNNB1. Transfection with miR-183 partially reversed chemotherapeutic drug resistance by downregulating the expression of ABCB1 and CTNNB1 in HepG2/Dox cells. Spearman's analysis results showed that CTNNB1 and ABCB1 were positively correlated in patients with liver cancer, and increased CTNNB1 and ABCB1 expression occurred in patients with liver cancer. High expression of ABCB1 and CTNNB1 indicated poor prognosis in patients with liver cancer; however, neither ABCB1 nor CTNNB1 expression was an independent diagnostic factor in patients with LIHC. Overexpression of hsa-miR-381 partially reversed the MDR of HepG2 cells by directly targeting and negatively regulating the expression of CTTNB1 and ABCB1. Moreover, high expression of ABCB1 or CTNNB1 indicated poor prognosis in patients with liver cancer.

Bortezomib potentiates antitumor activity of mitoxantrone through dampening Wnt/β-catenin signal pathway in prostate cancer cells

BACKGROUND

Bortezomib (BZM), alone or in combination with other chemotherapies, has displayed strong anticancer effects in several cancers. The efficacy of the combination of BZM and mitoxantrone (MTX) in treating prostate cancer remains unknown.

METHODS

Anticancer effects of combination of BZM and MTX were determined by apoptosis and proliferation assay in vivo and in vitro. Expression of β-Catenin and its target genes were characterized by western blot and Real-time PCR.

RESULTS

BZM significantly enhanced MTX-induced antiproliferation in vivo and in vitro. Mice administered a combination of BZM and MTX displayed attenuated tumor growth and prolonged survival. BZM significantly attenuated MTX-induced apoptosis. Moreover, the combination of BZM and MTX contributed to inhibition of the Wnt/β-Catenin signaling pathway compared to monotherapy.

CONCLUSIONS

This study demonstrates that BZM enhances MTX-induced anti-tumor effects by inhibiting the Wnt/β-Catenin signaling pathway in prostate cancer cells.

Wnt/β-catenin signal transduction pathway in prostate cancer and associated drug resistance

Globally, prostate cancer ranks second in cancer burden of the men. It occurs more frequently in black men compared to white or Asian men. Usually, high rates exist for men aged 60 and above. In this review, we focus on the Wnt/β-catenin signal transduction pathway in prostate cancer since many studies have reported that β-catenin can function as an oncogene and is important in Wnt signaling. We also relate its expression to the androgen receptor and MMP-7 protein, both critical to prostate cancer pathogenesis. Some mutations in the androgen receptor also impact the androgen-β-catenin axis and hence, lead to the progression of prostate cancer. We have also reviewed MiRNAs that modulate this pathway in prostate cancer. Finally, we have summarized the impact of Wnt/β-catenin pathway proteins in the drug resistance of prostate cancer as it is a challenging facet of therapy development due to the complexity of signaling pathways interaction and cross-talk.

The role of Wnt/β-catenin signaling pathway in the pathogenesis and treatment of multiple myeloma (review)

Multiple myeloma (MM) is a refractory hematological malignancy characterized by aberrant accumulation of plasma cells. Patients with MM are susceptible to becoming resistant to chemotherapy, eventually leading to relapse. Progression of MM is largely dependent on the bone marrow microenvironment. Stromal cells in the bone marrow microenvironment secrete Wnt ligands to activate Wnt signaling in MM, which is mediated through the transcription regulator β-catenin. In addition, Wnt/β-catenin pathway encourages osteoblast differentiation and bone formation, dysregulation of which is responsible for proliferation and drug resistance of MM cells. As a result, direct inhibition or silencing of β-catenin or associated genes in the Wnt/β-catenin pathway has been proposed to be an effective therapeutic anti-MM strategy. However, the underlying regulatory mechanism of the Wnt/β-catenin pathway in MM remains to be fully elucidated. Herein, we summarized research advances on the specific genes and molecular biology process of Wnt/β-catenin pathway involved in tumorigenesis of MM, as well as the interaction with bone marrow microenvironment. Additionally, comprehensive summaries of drugs or small molecule inhibitors acting on Wnt/β-catenin pathway and targeting MM were introduced. This review intends to provide an overview of theoretical supports for novel Wnt/β-catenin pathway based treatment strategies in MM.

Phosphorylated LASS2 inhibits prostate carcinogenesis via negative regulation of Wnt/β-catenin signaling

LASS2 is a novel tumor-suppressor gene and has been characterized as a ceramide synthase, which synthesizes very-long acyl chain ceramides. However, LASS2 function and pathway-related activity in prostate carcinogenesis are still largely unexplored. Here, we firstly report that LASS2 promotes β-catenin degradation through physical interaction with STK38, SCYL2, and ATP6V0C via the ubiquitin-proteasome pathway, phosphorylation of LASS2 is essential for β-catenin degradation, and serine residue 248 of LASS2 is illustrated to be a key phosphorylation site. Furthermore, we find that dephosphorylation of LASS2 at serine residue 248 significantly enhances prostate cancer cell growth and metastasis in vivo, indicating that phosphorylated LASS2 inhibits prostate carcinogenesis through negative regulation of Wnt/β-catenin signaling. Thus, our findings implicate LASS2 as a potential biomarker and therapeutic target of prostate cancer.

Oleanolic acid inhibits osteosarcoma cell proliferation and invasion by suppressing the SOX9/Wnt1 signaling pathway

Osteosarcoma is the most common primary bone malignancy in children and adolescents. Inhibition of SOX9/Wnt1-mediated signaling might suppress osteosarcoma metastasis, and oleanolic acid (OA) might decrease the activity of the SOX9/Wnt1 signaling pathway. The aim of the present study was to determine the role of OA in osteosarcoma cell proliferation and invasion. Osteosarcoma cell lines (KHOS and U2OS) and an osteoblastic cell line (hFOB1.19) were used for cell viability, proliferation and invasion analysis. The data suggested that OA significantly inhibited cell viability on days 3, 4 and 5 compared with the control (Ctrl) group in both U2OS and KHOS cells. Cell proliferation in the OA-treated group was significantly decreased compared with the Ctrl group in the osteosarcoma cell lines. Analysis of the cell cycle indicated that OA significantly reduced the percentage of U2OS and KHOS cells in the S phase compared with the Ctrl group. The wound healing assay results indicated that the OA group displayed significantly decreased cell re-colonization of the wound at 48 h compared with the Ctrl group. The Transwell chamber assay results also indicated that cell invasion was significantly inhibited by OA compared with the Ctrl group. Furthermore, OA significantly increased osteosarcoma cell apoptosis compared with the Ctrl group. Similarly, the protein expression levels of SOX9 and Wnt1 were significantly decreased in OA-treated U2OS and KHOS cells compared with Ctrl cells. OA-mediated downregulation of Wnt1 expression was reversed following SOX9 small interfering RNA transfection. Collectively, the results indicated that OA inhibited SOX9/Wnt1-associated osteosarcoma cell proliferation, migration and invasion.

Natural Compounds in Sex Hormone-Dependent Cancers: The Role of Triterpenes as Therapeutic Agents

Sex hormone-dependent cancers currently contribute to the high number of cancer-related deaths worldwide. The study and elucidation of the molecular mechanisms underlying the progression of these tumors was a double-edged sword, leading to the expansion and development of new treatment options, with the cost of triggering more aggressive, therapy resistant relapses. The interaction of androgen, estrogen and progesterone hormones with specific receptors (AR, ER, PR) has emerged as a key player in the development and progression of breast, ovarian, prostate and endometrium cancers. Sex hormone-dependent cancers share a common and rather unique carcinogenesis mechanism involving the active role of endogenous and exogenous sex hormones to maintain high mitotic rates and increased cell proliferation thus increasing the probability of aberrant gene occurrence and accumulation highly correlated with abnormal cell division and the occurrence of malignant phenotypes. Cancer related hormone therapy has evolved, currently being associated with the blockade of other signaling pathways often associated with carcinogenesis and tumor progression in cancers, with promising results. However, despite the established developments, there are still several shortcomings to be addressed. Triterpenes are natural occurring secondary metabolites biosynthesized by various pathways starting from squalene cyclization. Due to their versatile therapeutic potential, including the extensively researched antiproliferative effect, these compounds are most definitely a cornerstone in the research and development of new natural/semisynthetic anticancer therapies. The present work thoroughly describes the ongoing research related to the antitumor activity of triterpenes in sex hormone-dependent cancers. Also, the current review highlights both the biological activity of various triterpenoid compounds and their featured mechanisms of action correlated with important chemical structural features.

The Role of Noncoding RNAs in the Regulation of Anoikis and Anchorage-Independent Growth in Cancer

Cancer is a global health concern, and the prognosis of patients with cancer is associated with metastasis. Multistep processes are involved in cancer metastasis. Accumulating evidence has shown that cancer cells acquire the capacity of anoikis resistance and anchorage-independent cell growth, which are critical prerequisite features of metastatic cancer cells. Multiple cellular factors and events, such as apoptosis, survival factors, cell cycle, EMT, stemness, autophagy, and integrins influence the anoikis resistance and anchorage-independent cell growth in cancer. Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are dysregulated in cancer. They regulate cellular signaling pathways and events, eventually contributing to cancer aggressiveness. This review presents the role of miRNAs and lncRNAs in modulating anoikis resistance and anchorage-independent cell growth. We also discuss the feasibility of ncRNA-based therapy and the natural features of ncRNAs that need to be contemplated for more beneficial therapeutic strategies against cancer.

Mechanisms of enzalutamide resistance in castration-resistant prostate cancer and therapeutic strategies to overcome it

Prostate cancer is the second most common malignancy in men and androgen deprivation therapy is the first-line therapy. However, most cases will eventually develop castration-resistant prostate cancer after androgen deprivation therapy treatment. Enzalutamide is a second-generation androgen receptor antagonist approved by the Food and Drug Administration to treat patients with castration-resistant prostate cancer. Unfortunately, patients receiving enzalutamide treatment will ultimately develop resistance via various complicated mechanisms. This review examines the emerging information on these resistance mechanisms, including androgen receptor-related signalling pathways, glucocorticoid receptor-related pathways and metabolic effects. Notably, lineage plasticity and phenotype switching, gene polymorphisms and the relationship between microRNAs and drug resistance are addressed. Furthermore, potential therapeutic strategies for enzalutamide-resistant castration-resistant prostate cancer treatment are suggested, which can help discover more effective and specific regimens to overcome enzalutamide resistance.

Circ_0109046 promotes the malignancy of endometrial carcinoma cells through the microRNA-105/SOX9/Wnt/β-catenin axis

Emerging evidence suggests the important involvements of circular RNAs (circRNAs) in cancer progression. This study focuses on the function of Circ_0109046 on the malignancy of endometrial carcinoma (EC) cells and the molecules involved. First, high expression of Circ_0109046 was found in EC tissues compared to the adjacent tissues, and it predicted unfavorable prognosis in patients. Similarly, high expression of Circ_0109046 was confirmed in EC cells relative to that in normal endometrial epithelial cells. Silencing of Circ_0109046 in AN3-CA cells inhibited proliferation and aggressiveness but increased apoptosis of cells. Circ_0109046 was mainly sub-localized in cytoplasm, and it mediated SOX9 expression through sponging microRNA (miR)-105. The proliferation and aggressiveness of EC cells suppressed by Circ_0109046 downregulation was recovered upon SOX9 overexpression. SOX9 activated the Wnt/β-catenin pathway. Furthermore, downregulation of Circ_0109046 reduced the growth of xenograft tumors in nude mice. This study evidenced that Circ_0109046 upregulates SOX9 expression through sponging miR105, leading to activation of Wnt/β-catenin signaling and the malignant growth of EC. This study may offer novel understanding in EC treatment.

Phylostratic Shift of Whole-Genome Duplications in Normal Mammalian Tissues towards Unicellularity Is Driven by Developmental Bivalent Genes and Reveals a Link to Cancer

Tumours were recently revealed to undergo a phylostratic and phenotypic shift to unicellularity. As well, aggressive tumours are characterized by an increased proportion of polyploid cells. In order to investigate a possible shared causation of these two features, we performed a comparative phylostratigraphic analysis of ploidy-related genes, obtained from transcriptomic data for polyploid and diploid human and mouse tissues using pairwise cross-species transcriptome comparison and principal component analysis. Our results indicate that polyploidy shifts the evolutionary age balance of the expressed genes from the late metazoan phylostrata towards the upregulation of unicellular and early metazoan phylostrata. The up-regulation of unicellular metabolic and drug-resistance pathways and the downregulation of pathways related to circadian clock were identified. This evolutionary shift was associated with the enrichment of ploidy with bivalent genes (p < 10⁻¹⁶). The protein interactome of activated bivalent genes revealed the increase of the connectivity of unicellulars and (early) multicellulars, while circadian regulators were depressed. The mutual polyploidy-c-MYC-bivalent genes-associated protein network was organized by gene-hubs engaged in both embryonic development and metastatic cancer including driver (proto)-oncogenes of viral origin. Our data suggest that, in cancer, the atavistic shift goes hand-in-hand with polyploidy and is driven by epigenetic mechanisms impinging on development-related bivalent genes.

Analysis of novel enzalutamide-resistant cells: upregulation of testis-specific Y-encoded protein gene promotes the expression of androgen receptor splicing variant 7

Background

Enzalutamide, a second-generation antiandrogen, is an approved medicine for the treatment of metastatic castration-resistant prostate cancer (CRPC); however, the mechanisms behind the resistance are not completely understood. In the present study, we established enzalutamide-resistant cells derived from lymph node carcinoma of the prostate (LNCaP) cells and characterized their androgen receptor (AR) status and changes in the gene expression with an aim to elucidate these mechanisms.

Methods

SAS MDV No. 3–14 enzalutamide-resistant cells were established from LNCaP xenograft castrated male mice under continuous administration of enzalutamide. Then, the AR status and expression of AR target genes were evaluated by western blotting or real-time polymerase chain reaction analysis. The role of AR in the proliferation was also analyzed using the AR siRNA approach. The gene expression profiling in SAS MDV No. 3–14 cells was evaluated by microarray analysis. The role of testis-specific Y-encoded protein (TSPY), one of the upregulated genes, in the expression of AR and AR target genes and cell growth was also verified using siRNA.

Results

SAS MDV No. 3–14 cells expressed AR-v7, leading to the increased expression of AR target genes. Gene silencing of AR showed that both AR-FL and AR-v7 function as proliferative drivers in SAS MDV No. 3–14 cells. Microarray analysis revealed that TSPY is upregulated genes in these cells. TSPY siRNA inhibited cell proliferation, decreased the expression of AR-v7 and AR-v7 targeted genes.

Conclusions

This study demonstrated that SAS MDV No. 3–14 cells increase the expression of AR-v7 by upregulating TSPY, leading to acquired resistance to enzalutamide.

miR-145 attenuates cardiac fibrosis through the AKT/GSK-3β/β-catenin signaling pathway by directly targeting SOX9 in fibroblasts

Myocardial infarction (MI) will inevitably result in cardiac fibrosis. In this study, we investigated the effect of microRNA-145 (miR-145) and transcription factor sex-determining region Y box 9 (SOX9) in the production of cardiac fibrosis induced by MI. MI rat models were established by left anterior descending coronary artery (LAD) occlusion. Four weeks after LAD, the cardiac fibrosis level was assessed by Masson's trichrome staining. Cardiac fibroblasts (CFs) exposed to hypoxia were used to simulate MI-induced fibrosis. Flow cytometry, cell counting kit-8, and transwell assays were used to examine changes in CF apoptosis, proliferation, and migration, respectively. miR-145 expression was measured by quantitative real-time polymerase chain reaction. Immunofluorescence and Western blot analysis were performed to determine the relative expression of proteins. In comparison to the sham-operated group, the expression of miR-145 was significantly downregulated in the infarction peripheral area, whereas, SOX9 was upregulated. In the infarcted heart, the overexpression of miR-145 significantly ameliorated cardiac fibrosis and cardiac function, and there was a negative correlation between miR-145 and SOX9 expressions in hypoxic CFs in vitro. In addition, SOX9 was verified to be a functional target of miR-145. Overexpression of miR-145 or inhibition of SOX9 decreased CF proliferation, migration, and fibrosis, but augmented their apoptotic rate. Moreover, the upregulation of miR-145 or suppression of SOX9 inhibited AKT and β-catenin signaling in hypoxic CFs. Taken together, this study highlights a potential treatment for cardiac fibrosis through the targeted regulation of SOX9 by miR-145, and our findings indicate that miR-145 exerts anti-fibrotic effects in MI via the negative regulation of SOX9 and its downstream AKT/GSK-3β/β-catenin pathways.

A Japanese patient with ductal carcinoma of the prostate carrying an adenomatosis polyposis coli gene mutation: a case report

Background

Ductal carcinoma of the prostate is a histological subtype with a higher mortality than acinar adenocarcinoma. The number of cases is small and there are no treatment guidelines. We believe that this is the first report of ductal carcinoma of the prostate with an adenomatosis polyposis coli (APC) gene mutation in Japan.

Case presentation

An 85-year-old man presented with gross hematuria, and a papillary tumor in the prostatic urethra that was diagnosed as ductal carcinoma of the prostate following transurethral resection. Genetic analysis found an APC mutation with loss of heterozygosity. Immunostaining revealed focal nuclear translocation of β-catenin. APC mutations associated with loss of β-catenin degradation in the Wnt signaling pathway and result in over accumulation of β-catenin are thought to increase mortality. In this patient, β-catenin migrated into tumor cell nuclei.

Conclusion

To the best of our knowledge, this is the first report of ductal carcinoma of the prostate with an APC mutation in Japan. The development of a therapeutic Wnt inhibitor is discussed.

Activation of β-Catenin Signaling and its Crosstalk With Estrogen and Histone Deacetylases in Human Uterine Fibroids

CONTEXT

Uterine fibroids (UF) are the most common benign tumor of the myometrium (MM) in women of reproductive age. However, the mechanism underlying the pathogenesis of UF is largely unknown.

OBJECTIVE

To explore the link between nuclear β-catenin and UF phenotype and β-catenin crosstalk with estrogen and histone deacetylases (HDACs).

DESIGN

Protein/RNA levels of β-catenin (CTNNB1 gene), its responsive markers cyclin D1 and c-Myc, androgen receptor (AR), p27, and class-I HDACs were measured in matched UF/MM tissues or cell populations. The effects of chemical inhibition/activation and genetic knockdown of CTNNB1 on UF phenotype were measured. The anti-UF effect of 2 HDAC inhibitors was evaluated.

MAIN OUTCOME MEASURE

β-catenin nuclear translocation in response to β-catenin inhibition/activation, estrogen, and HDAC inhibitors in UF cells.

RESULTS

UF tissues/cells showed significantly higher expression of nuclear β-catenin, cyclin D1, c-Myc, and HDACs 1, 2, 3, and 8 than MM. Estradiol induced β-catenin nuclear translocation and consequently its responsive genes in both MM and UF cells, while an estrogen receptor antagonist reversed this induction effect. Treatment with β-catenin or HDAC inhibitors led to dose-dependent growth inhibition, while Wnt3a treatment increased proliferation compared with control. Chemical inhibition of β-catenin decreased cyclin D1 and c-Myc expression levels, while β-catenin activation increased expression of the same markers. Genetic knockdown of CTNNB1 resulted in a marked decrease in β-catenin, cyclin D1, c-Myc, and AR expression. Treatment of UF cells with HDAC inhibitors decreased nuclear β-catenin, cyclin D1, and c-Myc expression. Moreover, HDAC inhibitors induced apoptosis of UF cells and cell cycle arrest.

CONCLUSION

β-catenin nuclear translocation contributes to UF phenotype, and β-catenin signaling is modulated by estradiol and HDAC activity.

Bardoxolone-Methyl (CDDO-Me) Suppresses Androgen Receptor and Its Splice-Variant AR-V7 and Enhances Efficacy of Enzalutamide in Prostate Cancer Cells

Androgen receptor (AR) signaling is fundamental to prostate cancer (PC) progression, and hence, androgen deprivation therapy (ADT) remains a mainstay of treatment. However, augmented AR signaling via both full length AR (AR-FL) and constitutively active AR splice variants, especially AR-V7, is associated with the recurrence of castration resistant prostate cancer (CRPC). Oxidative stress also plays a crucial role in anti-androgen resistance and CRPC outgrowth. We examined whether a triterpenoid antioxidant drug, Bardoxolone-methyl, known as CDDO-Me or RTA 402, can decrease AR-FL and AR-V7 expression in PC cells. Nanomolar (nM) concentrations of CDDO-Me rapidly downregulated AR-FL in LNCaP and C4-2B cells, and both AR-FL and AR-V7 in CWR22Rv1 (22Rv1) cells. The AR-suppressive effect of CDDO-Me was evident at both the mRNA and protein levels. Mechanistically, acute exposure (2 h) to CDDO-Me increased and long-term exposure (24 h) decreased reactive oxygen species (ROS) levels in cells. This was concomitant with an increase in the anti-oxidant transcription factor, Nrf2. The anti-oxidant N-acetyl cysteine (NAC) could overcome this AR-suppressive effect of CDDO-Me. Co-exposure of PC cells to CDDO-Me enhanced the efficacy of a clinically approved anti-androgen, enzalutamide (ENZ), as evident by decreased cell-viability along with migration and colony forming ability of PC cells. Thus, CDDO-Me which is in several late-stage clinical trials, may be used as an adjunct to ADT in PC patients.

Abdominal aortic aneurysm in prostate cancer patients: the "road map" from incidental detection to advanced predictive, preventive, and personalized approach utilizing common follow-up for both pathologies

Abdominal aortic aneurysm (AAA) is often a hidden pathological process showing no clinical symptoms. Genetic burden, smoking, male gender, age > 65 years, and white race have been identified as the main risk factors. A regular screening program has been introduced but is, as yet, unclear and is not performed in most countries. Prostate cancer is the most frequent male malignant disease in Western countries. Prostate cancer is a disease of older age with a median primary diagnosis of over 60 years. In recent years, advanced imaging methods have been established as important diagnostic tools in prostate cancer diagnostics. The incidental detection of AAA during diagnostic imaging performed due to prostate cancer diagnosis could reveal some asymptomatic aneurysms. Using our experience, the incidental detection of AAA during 18F-fluoromethylcholine PET/CT imaging, performed due to the staging, follow-up, and restaging of the prostate cancer, was reworked into a regular tool of secondary prevention within the framework of personalized medicine strategies. Experience with this type of AAA detection is demonstrated by a cohort of 500 patients who underwent 18F-fluorometylcholine PET/CT examination due to the staging or restaging of prostate cancer. A total of 28 aneurysms were detected (26 aneurysms < 50 mm, 2 aneurysms > 50 mm). In 2 cases (diameter < 50 mm), serious complications were found (penetrating aortic ulcer). The detection and monitoring of AAA in patients undergoing 18F-fluorometylcholine PET/CT due to the prostate cancer offers the possibility of a secondary prevention of AAA, patient stratification, and common follow-up for both pathologies.

Future Aspects of CDK5 in Prostate Cancer: From Pathogenesis to Therapeutic Implications

Cyclin-dependent kinase 5 (CDK5) is a unique member of the cyclin-dependent kinase family. CDK5 is activated by binding with its regulatory proteins, mainly p35, and its activation is essential in the development of the central nervous system (CNS) and neurodegeneration. Recently, it has been reported that CDK5 plays important roles in regulating various biological and pathological processes, including cancer progression. Concerning prostate cancer, the androgen receptor (AR) is majorly involved in tumorigenesis, while CDK5 can phosphorylate AR and promotes the proliferation of prostate cancer cells. Clinical evidence has also shown that the level of CDK5 is associated with the progression of prostate cancer. Interestingly, inhibition of CDK5 prevents prostate cancer cell growth, while drug-triggered CDK5 hyperactivation leads to apoptosis. The blocking of CDK5 activity by its small interfering RNAs (siRNA) or Roscovitine, a pan-CDK inhibitor, reduces the cellular AR protein level and triggers the death of prostate cancer cells. Thus, CDK5 plays a crucial role in the growth of prostate cancer cells, and AR regulation is one of the important pathways. In this review paper, we summarize the significant studies on CDK5-mediated regulation of prostate cancer cells. We propose that the CDK5–p35 complex might be an outstanding candidate as a diagnostic marker and potential target for prostate cancer treatment in the near future.

Cellular and Molecular Mechanisms Underlying Prostate Cancer Development: Therapeutic Implications

Prostate cancer is the most frequent nonskin cancer and second most common cause of cancer-related deaths in man. Prostate cancer is a clinically heterogeneous disease with many patients exhibiting an aggressive disease with progression, metastasis, and other patients showing an indolent disease with low tendency to progression. Three stages of development of human prostate tumors have been identified: intraepithelial neoplasia, adenocarcinoma androgen-dependent, and adenocarcinoma androgen-independent or castration-resistant. Advances in molecular technologies have provided a very rapid progress in our understanding of the genomic events responsible for the initial development and progression of prostate cancer. These studies have shown that prostate cancer genome displays a relatively low mutation rate compared with other cancers and few chromosomal loss or gains. The ensemble of these molecular studies has led to suggest the existence of two main molecular groups of prostate cancers: one characterized by the presence of ERG rearrangements (~50% of prostate cancers harbor recurrent gene fusions involving ETS transcription factors, fusing the 5' untranslated region of the androgen-regulated gene TMPRSS2 to nearly the coding sequence of the ETS family transcription factor ERG) and features of chemoplexy (complex gene rearrangements developing from a coordinated and simultaneous molecular event), and a second one characterized by the absence of ERG rearrangements and by the frequent mutations in the E3 ubiquitin ligase adapter SPOP and/or deletion of CDH1, a chromatin remodeling factor, and interchromosomal rearrangements and SPOP mutations are early events during prostate cancer development. During disease progression, genomic and epigenomic abnormalities accrued and converged on prostate cancer pathways, leading to a highly heterogeneous transcriptomic landscape, characterized by a hyperactive androgen receptor signaling axis.