FOXA1 inhibits prostate cancer neuroendocrine differentiation

ENO2, a Glycolytic Enzyme, Contributes to Prostate Cancer Metastasis: A Systematic Review of Literature

Prostate cancer (PCa) is the second leading cause of male cancer deaths in the UK and the fifth worldwide. The presence of distant PCa metastasis can reduce the 5-year survival rate from 100% to approximately 30%. Enolase 2 (ENO2), a crucial glycolytic enzyme in cancer metabolism, is associated with the metastasis of multiple cancers and is also used as a marker for neuroendocrine tumours. However, its role in PCa metastasis remains unclear. In this study, we systematically reviewed the current literature to determine the association between ENO2 and metastatic PCa. Medline, Web of Science, and PubMed were searched for eligible studies. The search yielded five studies assessing ENO2 expression in PCa patients or cell lines. The three human studies suggested that ENO2 expression is correlated with late-stage, aggressive PCa, including castrate-resistant PCa (CRPC), metastatic CRPC, and neuroendocrine PCa (NEPC). This was further supported by two in vitro studies indicating that ENO2 expression can be regulated by the tumour microenvironment, such as androgen deprived conditions and the presence of bone-forming osteoblasts. Therefore, ENO2 may functionally contribute to PCa metastasis, possibly due to the unique metabolic features of PCa, which are glycolysis dependent only at the advanced metastatic stage.

Lycopene inhibits pyroptosis of endothelial progenitor cells induced by ox-LDL through the AMPK/mTOR/NLRP3 pathway

The malfunction of endothelial progenitor cells (EPCs) due to ox-LDL is a risk contributor for arteriosclerotic disease. Meanwhile, lycopene possesses anti-inflammatory and antioxidative qualities. This investigation aimed to determine if lycopene can protect EPCs from ox-LDL-induced damage and to elucidate the underlying mechanism. The effects of lycopene on the survival, migration, and tube-forming capacity of EPCs were determined via in vitro assays. Expression of proteins related to pyroptosis and cellular proteins related to AMPK/mTOR/NLRP3 signaling was determined by western blot/flow cytometry. Our results demonstrated that lycopene treatment significantly enhanced proliferation, tube formation, and migration of EPCs stimulated by ox-LDL. Additionally, lycopene was found to suppress pyroptosis in ox-LDL-induced EPCs through the activation of AMPK, which led to the inhibition of mTOR phosphorylation and subsequent downregulation of the downstream NLRP3 inflammasome. In summary, our study suggests that lycopene mitigates ox-LDL-induced dysfunction in EPCs and inhibits pyroptosis via AMPK/mTOR/NLRP3 signaling. Our study suggests that lycopene may act as promising therapies for preventing atherosclerosis.

FOXA2 rewires AP-1 for transcriptional reprogramming and lineage plasticity in prostate cancer

FOXA family proteins act as pioneer factors by remodeling compact chromatin structures. FOXA1 is crucial for the chromatin binding of the androgen receptor (AR) in both normal prostate epithelial cells and the luminal subtype of prostate cancer (PCa). Recent studies have highlighted the emergence of FOXA2 as an adaptive response to AR signaling inhibition treatments. However, the role of the FOXA1 to FOXA2 transition in regulating cancer lineage plasticity remains unclear. Our study demonstrates that FOXA2 binds to distinct classes of developmental enhancers in multiple AR-independent PCa subtypes, with its binding depending on LSD1. Moreover, we reveal that FOXA2 collaborates with JUN at chromatin and promotes transcriptional reprogramming of AP-1 in lineage-plastic cancer cells, thereby facilitating cell state transitions to multiple lineages. Overall, our findings underscore the pivotal role of FOXA2 as a pan-plasticity driver that rewires AP-1 to induce the differential transcriptional reprogramming necessary for cancer cell lineage plasticity.

FOXA1 and FOXA2: the regulatory mechanisms and therapeutic implications in cancer

FOXA1 (Forkhead Box A1) and FOXA2 (Forkhead Box A2) serve as pioneering transcription factors that build gene expression capacity and play a central role in biological processes, including organogenesis and differentiation, glycolipid metabolism, proliferation, migration and invasion, and drug resistance. Notably, FOXA1 and FOXA2 may exert antagonistic, synergistic, or complementary effects in the aforementioned biological processes. This article focuses on the molecular mechanisms and clinical relevance of FOXA1 and FOXA2 in steroid hormone-induced malignancies and highlights potential strategies for targeting FOXA1 and FOXA2 for cancer therapy. Furthermore, the article describes the prospect of targeting upstream regulators of FOXA1/FOXA2 to regulate its expression for cancer therapy because of the drug untargetability of FOXA1/FOXA2.

CDHu40: a novel marker gene set of neuroendocrine prostate cancer (NEPC)

Prostate cancer (PCa) is the most prevalent cancer affecting American men. Castration-resistant prostate cancer (CRPC) can emerge during hormone therapy for PCa, manifesting with elevated serum prostate-specific antigen (PSA) levels, continued disease progression, and/or metastasis to the new sites, resulting in a poor prognosis. A subset of CRPC patients shows a neuroendocrine (NE) phenotype, signifying reduced or no reliance on androgen receptor (AR) signaling and a particularly unfavorable prognosis. In this study, we incorporated computational approaches based on both gene expression profiles and protein-protein interaction (PPI) networks. We identified 500 potential marker genes, which are significantly enriched in cell cycle and neuronal processes. The top 40 candidates, collectively named as CDHu40, demonstrated superior performance in distinguishing NE prostate cancer (NEPC) and non-NEPC samples based on gene expression profiles compared to other published marker sets. Notably, some novel marker genes in CDHu40, absent in the other marker sets, have been reported to be associated with NEPC in the literature, such as DDC, FOLH1, BEX1, MAST1, and CACNA1A. Importantly, elevated CDHu40 scores derived from our predictive model showed a robust correlation with unfavorable survival outcomes in patients, indicating the potential of the CDHu40 score as a promising indicator for predicting the survival prognosis of those patients with the NE phenotype. Motif enrichment analysis on the top candidates suggests that REST and E2F6 may serve as key regulators in the NEPC progression.

Significance

our study integrates gene expression variances in multiple NEPC studies and protein-protein interaction network to pinpoint a specific set of NEPC maker genes namely CDHu40. These genes and scores based on their gene expression levels effectively distinguish NEPC samples and underscore the clinical prognostic significance and potential mechanism.

ENO2 promotes anoikis resistance in anaplastic thyroid cancer by maintaining redox homeostasis

Background

Anoikis presents a significant barrier in the metastasis of cancer. As the most aggressive type of thyroid cancer, anaplastic thyroid cancer (ATC) exhibits a high risk of metastasis and is characterized by high mortality. Therefore, investigating the molecular mechanisms of anoikis resistance in ATC is important for devising therapeutic targets in clinical research.

Methods

Differentially Expressed Genes were screened in ATC cells under attached and detached culture conditions with RNA-seq. Investigate the impact of enolase 2 (ENO2) on apoptosis and spheroid formation by gain and loss of function. Changes of reactive oxygen species (ROS), glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH) were detected to assess redox balance. The transcriptional regulatory role of signal transducer and activator of transcription 1 (STAT1) on ENO2 was validated through Dual-Luciferase Reporter Gene Assay. Explore the impact of ENO2 expression on the formation of lung metastases in nude mice.

Results

We found that the glycolysis process was activated in detached ATC cells. Several genes in the glycolysis process, particularly ENO2, a member of the enolase superfamily was upregulated in ATC cells cultured in suspension. The upregulation of ENO2 enabled the maintenance of redox balance by supplying GSH and NADPH, thereby preventing cells from undergoing anoikis. In terms of mechanism, the expression of STAT1 was enhanced in anoikis resistance cells, which in turn positively regulated the expression of ENO2. In vivo, ENO2-suppressed ATC cells resulted in a significantly lower rate of lung colonization compared to control ATC cells.

Conclusions

Stable expression of ENO2 and the maintenance of redox balance played a pivotal role in facilitating anoikis resistance of ATC.

Subtype Transdifferentiation in Human Cancer: The Power of Tissue Plasticity in Tumor Progression

The classification of tumors into subtypes, characterized by phenotypes determined by specific differentiation pathways, aids diagnosis and directs therapy towards targeted approaches. However, with the advent and explosion of next-generation sequencing, cancer phenotypes are turning out to be far more heterogenous than initially thought, and the classification is continually being updated to include more subtypes. Tumors are indeed highly dynamic, and they can evolve and undergo various changes in their characteristics during disease progression. The picture becomes even more complex when the tumor responds to a therapy. In all these cases, cancer cells acquire the ability to transdifferentiate, changing subtype, and adapt to changing microenvironments. These modifications affect the tumor's growth rate, invasiveness, response to treatment, and overall clinical behavior. Studying tumor subtype transitions is crucial for understanding tumor evolution, predicting disease outcomes, and developing personalized treatment strategies. We discuss this emerging hallmark of cancer and the molecular mechanisms involved at the crossroads between tumor cells and their microenvironment, focusing on four different human cancers in which tissue plasticity causes a subtype switch: breast cancer, prostate cancer, glioblastoma, and pancreatic adenocarcinoma.

Molecular biomarkers in prostate cancer tumorigenesis and clinical relevance

Prostate cancer (PCa) is the second most frequent type of cancer in men and assessing circulating tumor cells (CTCs) by liquid biopsy is a promising tool to help in cancer early detection, staging, risk of recurrence evaluation, treatment prediction and monitoring. Blood-based liquid biopsy approaches enable the enrichment, detection and characterization of CTCs by biomarker analysis. Hence, comprehending the molecular markers, their role on each stage of cancer development and progression is essential to provide information that can help in future implementation of these biomarkers in clinical assistance. In this review, we studied the molecular markers most associated with PCa CTCs to better understand their function on tumorigenesis and metastatic cascade, the methodologies utilized to analyze these biomarkers and their clinical significance, in order to summarize the available information to guide researchers in their investigations, new hypothesis formulation and target choice for the development of new diagnostic and treatment tools.

Decoding the basis of histological variation in human cancer

Molecular abnormalities that shape human neoplasms dissociate their phenotypic landscape from that of the healthy counterpart. Through the lens of a microscope, tumour pathology optically captures such aberrations projected onto a tissue slide and has categorized human epithelial neoplasms into distinct histological subtypes based on the diverse morphogenetic and molecular programmes that they manifest. Tumour histology often reflects tumour aggressiveness, patient prognosis and therapeutic vulnerability, and thus has been used as a de facto diagnostic tool and for making clinical decisions. However, it remains elusive how the diverse histological subtypes arise and translate into pleiotropic biological phenotypes. Molecular analysis of clinical tumour tissues and their culture, including patient-derived organoids, and add-back genetic reconstruction of tumorigenic pathways using gene engineering in culture models and rodents further elucidated molecular mechanisms that underlie morphological variations. Such mechanisms include genetic mutations and epigenetic alterations in cellular identity codes that erode hard-wired morphological programmes and histologically digress tumours from the native tissues. Interestingly, tumours acquire the ability to grow independently of the niche-driven stem cell ecosystem along with these morphological alterations, providing a biological rationale for histological diversification during tumorigenesis. This Review comprehensively summarizes our current understanding of such plasticity in the histological and lineage commitment fostered cooperatively by molecular alterations and the tumour environment, and describes basic and clinical implications for future cancer therapy.

Lysosome-dependent FOXA1 ubiquitination contributes to luminal lineage of advanced prostate cancer

Changes in FOXA1 (forkhead box protein A1) protein levels are well associated with prostate cancer (PCa) progression. Unfortunately, direct targeting of FOXA1 in progressive PCa remains challenging due to variations in FOXA1 protein levels, increased FOXA1 mutations at different stages of PCa, and elusive post-translational FOXA1 regulating mechanisms. Here, we show that SKP2 (S-phase kinase-associated protein 2) catalyzes K6- and K29-linked polyubiquitination of FOXA1 for lysosomal-dependent degradation. Our data indicate increased SKP2:FOXA1 protein ratios in stage IV human PCa compared to stages I-III, together with a strong inverse correlation (r = -0.9659) between SKP2 and FOXA1 levels, suggesting that SKP2-FOXA1 protein interactions play a significant role in PCa progression. Prostate tumors of Pten/Trp53 mice displayed increased Skp2-Foxa1-Pcna signaling and colocalization, whereas disruption of the Skp2-Foxa1 interplay in Pten/Trp53/Skp2 triple-null mice demonstrated decreased Pcna levels and increased expression of Foxa1 and luminal positive cells. Treatment of xenograft mice with the SKP2 inhibitor SZL P1-41 decreased tumor proliferation, SKP2:FOXA1 ratios, and colocalization. Thus, our results highlight the significance of the SKP2-FOXA1 interplay on the luminal lineage in PCa and the potential of therapeutically targeting FOXA1 through SKP2 to improve PCa control.

ENO2-derived phosphoenolpyruvate functions as an endogenous inhibitor of HDAC1 and confers resistance to antiangiogenic therapy

Metabolic reprogramming is associated with resistance to antiangiogenic therapy in cancer. However, its molecular mechanisms have not been clearly elucidated. Here, we identify the glycolytic enzyme enolase 2 (ENO2) as a driver of resistance to antiangiogenic therapy in colorectal cancer (CRC) mouse models and human participants. ENO2 overexpression induces neuroendocrine differentiation, promotes malignant behaviour in CRC and desensitizes CRC to antiangiogenic drugs. Mechanistically, the ENO2-derived metabolite phosphoenolpyruvate (PEP) selectively inhibits histone deacetylase 1 (HDAC1) activity, which increases the acetylation of β-catenin and activates the β-catenin pathway in CRC. Inhibition of ENO2 with enolase inhibitors AP-III-a4 or POMHEX synergizes the efficacy of antiangiogenic drugs in vitro and in mice bearing drug-resistant CRC xenograft tumours. Together, our findings reveal that ENO2 constitutes a useful predictive biomarker and therapeutic target for resistance to antiangiogenic therapy in CRC, and uncover a previously undefined and metabolism-independent role of PEP in regulating resistance to antiangiogenic therapy by functioning as an endogenous HDAC1 inhibitor.

Targeting Key Players of Neuroendocrine Differentiation in Prostate Cancer

Neuroendocrine prostate cancer (NEPC) is a highly aggressive subtype of prostate cancer (PC) that commonly emerges through a transdifferentiation process from prostate adenocarcinoma and evades conventional therapies. Extensive molecular research has revealed factors that drive lineage plasticity, uncovering novel therapeutic targets to be explored. A diverse array of targeting agents is currently under evaluation in pre-clinical and clinical studies with promising results in suppressing or reversing the neuroendocrine phenotype and inhibiting tumor growth and metastasis. This new knowledge has the potential to contribute to the development of novel therapeutic approaches that may enhance the clinical management and prognosis of this lethal disease. In the present review, we discuss molecular players involved in the neuroendocrine phenotype, and we explore therapeutic strategies that are currently under investigation for NEPC.

ASCL1 is activated downstream of the ROR2/CREB signaling pathway to support lineage plasticity in prostate cancer

Lineage plasticity is a form of therapy-induced drug resistance. In prostate cancer, androgen receptor (AR) pathway inhibitors potentially lead to the accretion of tumor relapse with loss of AR signaling and a shift from a luminal state to an alternate program. However, the molecular and signaling mechanisms orchestrating the development of lineage plasticity under the pressure of AR-targeted therapies are not fully understood. Here, a survey of receptor tyrosine kinases (RTKs) identifies ROR2 as the top upregulated RTK following AR pathway inhibition, which feeds into lineage plasticity by promoting stem-cell-like and neuronal networks. Mechanistically, ROR2 activates the ERK/CREB signaling pathway to modulate the expression of the lineage commitment transcription factor ASCL1. Collectively, our findings nominate ROR2 as a potential therapeutic target to reverse the ENZ-induced plastic phenotype and potentially re-sensitize tumors to AR pathway inhibitors.

Chemokine receptor CXCR7 activates Aurora Kinase A and promotes neuroendocrine prostate cancer growth

CXCR7 is an atypical chemokine receptor that recruits β-arrestin (ARRB2) and internalizes into clathrin-coated intracellular vesicles where the complex acts as a scaffold for cytoplasmic kinase assembly and signal transduction. Here, we report that CXCR7 was elevated in the majority of prostate cancer (PCa) cases with neuroendocrine features (NEPC). CXCR7 markedly induced mitotic spindle and cell cycle gene expression. Mechanistically, we identified Aurora Kinase A (AURKA), a key regulator of mitosis, as a novel target that was bound and activated by the CXCR7-ARRB2 complex. CXCR7 interacted with proteins associated with microtubules and golgi, and, as such, the CXCR7-ARRB2-containing vesicles trafficked along the microtubules to the pericentrosomal golgi apparatus, where the complex interacted with AURKA. Accordingly, CXCR7 promoted PCa cell proliferation and tumor growth, which was mitigated by AURKA inhibition. In summary, our study reveals a critical role of CXCR7-ARRB2 in interacting and activating AURKA, which can be targeted by AURKA inhibitors to benefit a subset of patients with NEPC.

Lineage plasticity and treatment resistance in prostate cancer: the intersection of genetics, epigenetics, and evolution

Androgen deprivation therapy is a cornerstone of treatment for advanced prostate cancer, and the development of castrate-resistant prostate cancer (CRPC) is the primary cause of prostate cancer-related mortality. While CRPC typically develops through a gain in androgen receptor (AR) signaling, a subset of CRPC will lose reliance on the AR. This process involves genetic, epigenetic, and hormonal changes that promote cellular plasticity, leading to AR-indifferent disease, with neuroendocrine prostate cancer (NEPC) being the quintessential example. NEPC is enriched following treatment with second-generation anti-androgens and exhibits resistance to endocrine therapy. Loss of RB1, TP53, and PTEN expression and MYCN and AURKA amplification appear to be key drivers for NEPC differentiation. Epigenetic modifications also play an important role in the transition to a neuroendocrine phenotype. DNA methylation of specific gene promoters can regulate lineage commitment and differentiation. Histone methylation can suppress AR expression and promote neuroendocrine-specific gene expression. Emerging data suggest that EZH2 is a key regulator of this epigenetic rewiring. Several mechanisms drive AR-dependent castration resistance, notably AR splice variant expression, expression of the adrenal-permissive 3βHSD1 allele, and glucocorticoid receptor expression. Aberrant epigenetic regulation also promotes radioresistance by altering the expression of DNA repair- and cell cycle-related genes. Novel therapies are currently being developed to target these diverse genetic, epigenetic, and hormonal mechanisms promoting lineage plasticity-driven NEPC.

Aerobic glycolysis in colon cancer is repressed by naringin via the HIF1Α pathway

Metabolic reprogramming is a common phenomenon in cancer, with aerobic glycolysis being one of its important characteristics. Hypoxia-inducible factor-1α (HIF1Α) is thought to play an important role in aerobic glycolysis. Meanwhile, naringin is a natural flavanone glycoside derived from grapefruits and many other citrus fruits. In this work, we identified glycolytic genes related to HIF1Α by analyzing the colon cancer database. The analysis of extracellular acidification rate and cell function verified the regulatory effects of HIF1Α overexpression on glycolysis, and the proliferation and migration of colon cancer cells. Moreover, naringin was used as an inhibitor of colon cancer cells to illustrate its effect on HIF1Α function. The results showed that the HIF1Α and enolase 2 (ENO2) levels in colon cancer tissues were highly correlated, and their high expression indicated a poor prognosis for colon cancer patients. Mechanistically, HIF1Α directly binds to the DNA promoter region and upregulates the transcription of ENO2; ectopic expression of ENO2 increased aerobic glycolysis in colon cancer cells. Most importantly, we found that the appropriate concentration of naringin inhibited the transcriptional activity of HIF1Α, which in turn decreased aerobic glycolysis in colon cancer cells. Generally, naringin reduces glycolysis in colon cancer cells by reducing the transcriptional activity of HIF1Α and the proliferation and invasion of colon cancer cells. This study helps to elucidate the relationship between colon cancer progression and glucose metabolism, and demonstrates the efficacy of naringin in the treatment of colon cancer.

miRNAs in prostate cancer: Intercellular and extracellular communications

Prostate cancer is the most prevalent male cancer in Western Europe and North America. Although new drugs were recently approved, clinical challenges such as accurately predicting and screening drug-resistant prostate cancer remain. microRNAs are short noncoding RNA molecules that participate in gene regulation at the post-transcriptional level by targeting messenger RNAs. There is accumulating evidence that intracellular microRNAs play important roles as promoters or inhibitors of prostate cancer progression. Additionally, recent studies showed that microRNAs are encapsulated in extracellular vesicles and shuttled into the extracellular space. Transfer of extracellular microRNAs contributes to intercellular communication between prostate cancer cells and components of the tumor microenvironment, which can promote prostate cancer progression. Furthermore, due to their encapsulation in extracellular vesicles, extracellular microRNAs can be stably present in body fluids which contain high levels of RNase. Thus, circulating microRNAs have great potential as noninvasive diagnostic and prognostic biomarkers for prostate cancer. Here, we summarize the roles of intracellular and extracellular microRNAs in prostate cancer progression and discuss the potential of microRNA-based therapeutics as a novel treatment strategy for prostate cancer.

FOXA1 repression drives lineage plasticity and immune heterogeneity in bladder cancers with squamous differentiation

Cancers arising from the bladder urothelium often exhibit lineage plasticity with regions of urothelial carcinoma adjacent to or admixed with regions of divergent histomorphology, most commonly squamous differentiation. To define the biologic basis for and clinical significance of this morphologic heterogeneity, here we perform integrated genomic analyses of mixed histology bladder cancers with separable regions of urothelial and squamous differentiation. We find that squamous differentiation is a marker of intratumoral genomic and immunologic heterogeneity in patients with bladder cancer and a biomarker of intrinsic immunotherapy resistance. Phylogenetic analysis confirms that in all cases the urothelial and squamous regions are derived from a common shared precursor. Despite the presence of marked genomic heterogeneity between co-existent urothelial and squamous differentiated regions, no recurrent genomic alteration exclusive to the urothelial or squamous morphologies is identified. Rather, lineage plasticity in bladder cancers with squamous differentiation is associated with loss of expression of FOXA1, GATA3, and PPARG, transcription factors critical for maintenance of urothelial cell identity. Of clinical significance, lineage plasticity and PD-L1 expression is coordinately dysregulated via FOXA1, with patients exhibiting morphologic heterogeneity pre-treatment significantly less likely to respond to immune checkpoint inhibitors.

Molecular mechanisms underlying the development of neuroendocrine prostate cancer

Prostate cancer is the most common non-cutaneous cancer and the second leading cause of cancer-associated deaths among men in the United States. Androgen deprivation therapy (ADT) is the standard of care for advanced prostate cancer. While patients with advanced prostate cancer initially respond to ADT, the disease frequently progresses to a lethal metastatic form, defined as castration-resistant prostate cancer (CRPC). After multiple rounds of anti-androgen therapies, 20-25% of metastatic CRPCs develop a neuroendocrine (NE) phenotype. These tumors are classified as neuroendocrine prostate cancer (NEPC). De novo NEPC is rare and accounts for less than 2% of all prostate cancers at diagnosis. NEPC is commonly characterized by the expression of NE markers and the absence of androgen receptor (AR) expression. NEPC is usually associated with tumor aggressiveness, hormone therapy resistance, and poor clinical outcome. Here, we review the molecular mechanisms underlying the emergence of NEPC and provide insights into the future perspectives on potential therapeutic strategies for NEPC.

Histologic transformation in lung cancer: when one door shuts, another opens

Histologic transformation (HT) is a major cause of drug resistance to therapy in patients with lung cancer. HTs to small-cell lung cancer (SCLC) have been reported frequently in patients with epidermal growth factor receptor (EGFR)-mutated lung cancer. Although HTs have an impact on the clinical outcomes in patients owing to a high refractoriness to treatments, there is limited data on the prevalence, causes, mechanisms, treatment efficacy, and future treatment strategies. In this review, we assess the literature regarding HTs comprehensively, including those describing EGFR-tyrosine kinase inhibitors, other molecular targeted drugs, and immune checkpoint inhibitors. Furthermore, we discuss the mechanisms of HTs and the lineage plasticity to SCLC and squamous cell carcinoma in lung cancer. In addition, we summarize the treatment efficacy and future perspectives of HTs in patients with lung cancer, and propose better management strategies for this group of patients.

FOXA1 in prostate cancer

Most prostate cancers initially respond to androgen deprivation therapy (ADT). With the long-term application of ADT, localized prostate cancer will progress to castration-resistant prostate cancer (CRPC), metastatic CRPC (mCRPC), and neuroendocrine prostate cancer (NEPC), and the transcriptional network shifted. Forkhead box protein A1 (FOXA1) may play a key role in this process through multiple mechanisms. To better understand the role of FOXA1 in prostate cancer, we review the interplay among FOXA1-targeted genes, modulators of FOXA1, and FOXA1 with a particular emphasis on androgen receptor (AR) function. Furthermore, we discuss the distinct role of FOXA1 mutations in prostate cancer and clinical significance of FOXA1. We summarize possible regulation pathways of FOXA1 in different stages of prostate cancer. We focus on links between FOXA1 and AR, which may play different roles in various types of prostate cancer. Finally, we discuss FOXA1 mutation and its clinical significance in prostate cancer. FOXA1 regulates the development of prostate cancer through various pathways, and it could be a biomarker for mCRPC and NEPC. Future efforts need to focus on mechanisms underlying mutation of FOXA1 in advanced prostate cancer. We believe that FOXA1 would be a prognostic marker and therapeutic target in prostate cancer.

FOXA1 inhibits hypoxia programs through transcriptional repression of HIF1A

Intratumoral hypoxia is associated with castration-resistant prostate cancer (CRPC), a lethal disease. FOXA1 is an epithelial transcription factor that is down-regulated in CRPC. We have previously reported that FOXA1 loss induces epithelial-mesenchymal transition (EMT) and cell motility through elevated TGFβ signaling. However, whether FOXA1 directly regulates hypoxia pathways of CRPC tumors has not been previously studied. Here we report that FOXA1 down-regulation induces hypoxia transcriptional programs, and FOXA1 level is negatively correlated with hypoxia markers in clinical prostate cancer (PCa) samples. Mechanistically, FOXA1 directly binds to an intragenic enhancer of HIF1A to inhibit its expression, and HIF1A, in turn, is critical in mediating FOXA1 loss-induced hypoxia gene expression. Further, we identify CCL2, a chemokine ligand that modulates tumor microenvironment and promotes cancer progression, as a crucial target of the FOXA1-HIF1A axis. We found that FOXA1 loss leads to immunosuppressive macrophage infiltration and increased cell invasion, dependent on HIF1A expression. Critically, therapeutic targeting of HIF1A-CCL2 using pharmacological inhibitors abolishes FOXA1 loss-induced macrophage infiltration and PCa cell invasion. In summary, our study reveals an essential role of FOXA1 in controlling the hypoxic tumor microenvironment and establishes the HIF1A-CCL2 axis as one mechanism of FOXA1 loss-induced CRPC progression.

Focus on the tumor microenvironment: A seedbed for neuroendocrine prostate cancer

The tumor microenvironment (TME) is a microecology consisting of tumor and mesenchymal cells and extracellular matrices. The TME plays important regulatory roles in tumor proliferation, invasion, metastasis, and differentiation. Neuroendocrine differentiation (NED) is a mechanism by which castration resistance develops in advanced prostate cancer (PCa). NED is induced after androgen deprivation therapy and neuroendocrine prostate cancer (NEPC) is established finally. NEPC has poor prognosis and short overall survival and is a major cause of death in patients with PCa. Both the cellular and non-cellular components of the TME regulate and induce NEPC formation through various pathways. Insights into the roles of the TME in NEPC evolution, growth, and progression have increased over the past few years. These novel insights will help refine the NEPC formation model and lay the foundation for the discovery of new NEPC therapies targeting the TME.

Molecular mechanisms of neuroendocrine differentiation in prostate cancer progression

Background

Rapid evolution of the therapeutic management of prostate cancer, especially in in second-generation androgen inhibitors, has increased the opportunity of transformation from prostate cancer (PCa) to neuroendocrine prostate cancer (NEPC). NEPC still lacks effective diagnostic and therapeutic interventions. Researches into the molecular characteristics of neuroendocrine differentiation is undoubtedly crucial to the discovery of new target genes for accurate diagnostic and therapeutic targets.

Purpose

In this review, we focus on the relevant genes and molecular mechanisms that have contributed to the transformation in the progression of PCa and discuss the potential targeted molecule that might improve diagnostic accuracy and therapeutic effectiveness.

Methods

The relevant literatures from PubMed have been reviewed for this article.

Conclusion

Several molecular characteristics influence the progression of neuroendocrine differentiation of prostate cancer which will provide a novel sight for accurate diagnosis and target therapeutic intervention for patients with NEPC.

MYBL2 accelerates epithelial-mesenchymal transition and hepatoblastoma metastasis via the Smad/SNAI1 pathway

Hepatoblastoma (HB) accounts for the majority of hepatic malignancies in children. Although the prognosis of patients with HB has improved in past decades, metastasis is an indicator of poor overall survival. Herein, we applied single-cell RNA sequencing to explore the transcriptomic profiling of 25,264 metastatic cells isolated from the lungs of two patients with HB. The transcriptomes uncovered the heterogeneity of malignant cells after metastatic lung colonization, and these cells had varied expression signatures associated with the cell cycle, epithelial-mesenchymal plasticity, and hepatic differentiation. Single-cell regulatory network inference and clustering (SCENIC) was utilized to identify the co-expressed transcriptional factors which regulated and represented the different cell states. We further screened the key factor by bioinformatics analysis and found that MYBL2 upregulation was significantly associated with metastasis and poor prognosis. The relationship between ectopic MYBL2 and metastasis was subsequently proved by immunohistochemistry (IHC) of HB tissues, and the functions of MYBL2 in promoting proliferation, migration, and epithelial-to-mesenchymal transition (EMT) were verified by in vitro and in vivo assays. Importantly, the levels of Smad2/3 phosphorylation and SNAI1 expression were increased in MYBL2-transfected cells. Consequently, these results indicated that the MYBL2-controlled Smad/SNAI1 pathway induced EMT and promoted HB tumorigenesis and metastasis.

Role of MicroRNAs in Neuroendocrine Prostate Cancer

Therapy-induced neuroendocrine prostate cancer (t-NEPC/NEPC) is an aggressive variant of prostate cancer (PCa) that frequently emerges in castration-resistant prostate cancer (CRPC) under the selective pressure of androgen receptor (AR)-targeted therapies. This variant is extremely aggressive, metastasizes to visceral organs, tissues, and bones despite low serum PSA, and is associated with poor survival rates. It arises via a reversible trans-differentiation process, referred to as ‘neuroendocrine differentiation’ (NED), wherein PCa cells undergo a lineage switch and exhibit neuroendocrine features, characterized by the expression of neuronal markers such as enolase 2 (ENO2), chromogranin A (CHGA), and synaptophysin (SYP). The molecular and cellular mechanisms underlying NED in PCa are complex and not clearly understood, which contributes to a lack of effective molecular biomarkers for diagnosis and therapy of this variant. NEPC is thought to derive from prostate adenocarcinomas by clonal evolution. A characteristic set of genetic alterations, such as dual loss of retinoblastoma (RB1) and tumor protein (TP53) tumor suppressor genes and amplifications of Aurora kinase A (AURKA), NMYC, and EZH2, has been reported to drive NEPC. Recent evidence suggests that microRNAs (miRNAs) are important epigenetic players in driving NED in advanced PCa. In this review, we highlight the role of miRNAs in NEPC. These studies emphasize the diverse role that miRNAs play as oncogenes and tumor suppressors in driving NEPC. These studies have unveiled the important role of cellular processes such as the EMT and cancer stemness in determining NED in PCa. Furthermore, miRNAs are involved in intercellular communication between tumor cells and stromal cells via extracellular vesicles/exosomes that contribute to lineage switching. Recent studies support the promising potential of miRNAs as novel diagnostic biomarkers and therapeutic targets for NEPC.

Repurposing Multiple-Molecule Drugs for COVID-19-Associated Acute Respiratory Distress Syndrome and Non-Viral Acute Respiratory Distress Syndrome via a Systems Biology Approach and a DNN-DTI Model Based on Five Drug Design Specifications

The coronavirus disease 2019 (COVID-19) epidemic is currently raging around the world at a rapid speed. Among COVID-19 patients, SARS-CoV-2-associated acute respiratory distress syndrome (ARDS) is the main contribution to the high ratio of morbidity and mortality. However, clinical manifestations between SARS-CoV-2-associated ARDS and non-SARS-CoV-2-associated ARDS are quite common, and their therapeutic treatments are limited because the intricated pathophysiology having been not fully understood. In this study, to investigate the pathogenic mechanism of SARS-CoV-2-associated ARDS and non-SARS-CoV-2-associated ARDS, first, we constructed a candidate host-pathogen interspecies genome-wide genetic and epigenetic network (HPI-GWGEN) via database mining. With the help of host-pathogen RNA sequencing (RNA-Seq) data, real HPI-GWGEN of COVID-19-associated ARDS and non-viral ARDS were obtained by system modeling, system identification, and Akaike information criterion (AIC) model order selection method to delete the false positives in candidate HPI-GWGEN. For the convenience of mitigation, the principal network projection (PNP) approach is utilized to extract core HPI-GWGEN, and then the corresponding core signaling pathways of COVID-19-associated ARDS and non-viral ARDS are annotated via their core HPI-GWGEN by KEGG pathways. In order to design multiple-molecule drugs of COVID-19-associated ARDS and non-viral ARDS, we identified essential biomarkers as drug targets of pathogenesis by comparing the core signal pathways between COVID-19-associated ARDS and non-viral ARDS. The deep neural network of the drug–target interaction (DNN-DTI) model could be trained by drug–target interaction databases in advance to predict candidate drugs for the identified biomarkers. We further narrowed down these predicted drug candidates to repurpose potential multiple-molecule drugs by the filters of drug design specifications, including regulation ability, sensitivity, excretion, toxicity, and drug-likeness. Taken together, we not only enlighten the etiologic mechanisms under COVID-19-associated ARDS and non-viral ARDS but also provide novel therapeutic options for COVID-19-associated ARDS and non-viral ARDS.

Histone methyltransferase KMT2C plays an oncogenic role in prostate cancer

PURPOSE

Prostate cancer (PCa) is a leading cause of morbidity and mortality in males. Epigenetic modifier abnormalities are becoming a driving event in PCa. The specific role of KMT2C, a histone methyltransferase that is frequently aberrant in various tumors, is poorly understood in PCa. This study aimed to reveal the potential carcinogenic role of KMT2C in PCa.

METHODS

We first examined the expression levels of KMT2C in prostate cancer tissues. Then, we assessed the function of KMT2C in prostate cancer cell proliferation, colony formation, and migration. To explore the mechanism of the biological consequences, RNA-seq and CHIP-qPCR were performed. We also analyzed the effects of overexpression of the KMT2C downstream genes CLDN8 and ITGAV to reverse the effects of KMT2C on prostate cancer cells.

RESULTS

Herein, we first confirmed KMT2C overexpression in PCa at the transcript and protein levels. Knocking down KMT2C in VCaP and LNCaP cells inhibited cell viability, colony formation, and migration. Consistently, stable KMT2C depletion effectively decreased tumor growth by approximately 70% in vivo. Mechanistically, the results suggested that CLDN8 and ITGAV are two key downstream genes of KMT2C and further regulate the MAPK/ERK and EMT pathways.

CONCLUSION

Our study suggests that KMT2C plays an oncogenic role in PCa. One of the mechanisms may be the epigenetic regulation of CLDN8 and ITGAV by KMT2C to modulate tumor-signaling pathways. Therefore, KMT2C may serve as a potential therapeutic target for PCa patients.

Aggressive variants of prostate cancer: underlying mechanisms of neuroendocrine transdifferentiation

Prostate cancer is a hormone-driven disease and its tumor cell growth highly relies on increased androgen receptor (AR) signaling. Therefore, targeted therapy directed against androgen synthesis or AR activation is broadly used and continually improved. However, a subset of patients eventually progresses to castration-resistant disease. To date, various mechanisms of resistance have been identified including the development of AR-independent aggressive variant prostate cancer based on neuroendocrine transdifferentiation (NED). Here, we review the highly complex processes contributing to NED. Genetic, epigenetic, transcriptional aberrations and posttranscriptional modifications are highlighted and the potential interplay of the different factors is discussed. Background Aggressive variant prostate cancer (AVPC) with traits of neuroendocrine differentiation emerges in a rising number of patients in recent years. Among others, advanced therapies targeting the androgen receptor axis have been considered causative for this development. Cell growth of AVPC often occurs completely independent of the androgen receptor signal transduction pathway and cells have mostly lost the typical cellular features of prostate adenocarcinoma. This complicates both diagnosis and treatment of this very aggressive disease. We believe that a deeper understanding of the complex molecular pathological mechanisms contributing to transdifferentiation will help to improve diagnostic procedures and develop effective treatment strategies. Indeed, in recent years, many scientists have made important contributions to unravel possible causes and mechanisms in the context of neuroendocrine transdifferentiation. However, the complexity of the diverse molecular pathways has not been captured completely, yet. This narrative review comprehensively highlights the individual steps of neuroendocrine transdifferentiation and makes an important contribution in bringing together the results found so far.

Endocrine and paracrine characteristics of neuroendocrine prostate cancer

Prostate cancer is a common malignancy affecting men worldwide. While the vast majority of newly diagnosed prostate cancers are categorized as adenocarcinomas, a spectrum of uncommon tumor types occur including those with small cell and neuroendocrine cell features. Benign neuroendocrine cells exist in the normal prostate microenvironment, and these cells may give rise to primary neuroendocrine carcinomas. However, the more common development of neuroendocrine prostate cancer is observed after therapeutics designed to repress the signaling program regulated by the androgen receptor which is active in the majority of localized and metastatic adenocarcinomas. Neuroendocrine tumors are identified through immunohistochemical staining for common markers including chromogranin A/B, synaptophysin and neuron specific enolase (NSE). These markers are also common to neuroendocrine tumors that arise in other tissues and organs such as the gastrointestinal tract, pancreas, lung and skin. Notably, neuroendocrine prostate cancer shares biochemical features with nerve cells, particularly functions involving the secretion of a variety of peptides and proteins. These secreted factors have the potential to exert local paracrine effects, and distant endocrine effects that may modulate tumor progression, invasion, and resistance to therapy. This review discusses the spectrum of factors derived from neuroendocrine prostate cancers and their potential to influence the pathophysiology of localized and metastatic prostate cancer.

Superselective Prostate Artery Embolization for Treatment of Severe Haematuria Secondary to Rapid Progression of Treatment-Induced Neuroendocrine Prostate Cancer: A Case Report

Background

Treatment-induced neuroendocrine prostate cancer (t-NEPC) represents a highly aggressive subtype of castration-resistant prostate cancer that commonly arises from prostate adenocarcinoma (AdPC) after continuous androgen deprivation therapy (ADT). However, current treatments for t-NEPC are limited and far from satisfactory. According to our limited knowledge, report regarding the management of t-NEPC related hemorrhage is rare. Here, we report a case of t-NEPC formation after chronic hormonal therapy accompanying with severe bleeding in primary tumor and share our experiences to deal with the severe hematuria resulting from the progression of t-NEPC tumor.

Case Presentation

An 80-year-old man with a significantly high prostate-specific antigen was diagnosed via pathology as advanced AdPC due to multiple bone metastases. He then received ADT including bicalutamide and goserelin. After 20 months of stable disease, the cancer rapidly progressed and presented with severe gross hematuria caused by bleeding of the primary tumor. The histopathologic analysis of a secondary biopsy of the primary tumor confirmed neuroendocrine prostate cancer, and subsequent genetic testing revealed germ-line mutations in the RB1 and FOXA1. To control the bleeding and relieve symptoms, the patient was treated with superselective prostate artery embolization (PAE). After the left internal pudendal artery and the right prostatic artery were embolized, hematuria was quickly alleviated and disappeared. However, the patient was not a suitable candidate to platinum-based chemotherapy due to weak constitution. Goserelin was continuously applied to maintain castration level of serum testosterone. Meanwhile, palliative radiotherapy to the prostate tumor, high-risk lymph node drainage areas (including iliac and para-aortic lymph nodes, internal iliac lymph nodes, presacral lymph nodes and obturator nerve lymph nodes) and bone metastases (right sacroiliac joint and thoracic vertebra) was performed and relieved the pain. Unfortunately, this patient eventually died of cachexia and multiple organ failure nearly 27 months after initial diagnosis.

Conclusion

To treat severe hematuria caused by progression of t-NEPC, superselective PAE may be a rapid and efficient way to stop bleeding.

The Crosstalk of Long Non-Coding RNA and MicroRNA in Castration-Resistant and Neuroendocrine Prostate Cancer: Their Interaction and Clinical Importance

Prostate cancer is featured by its heterogeneous nature, which indicates a different prognosis. Castration-resistant prostate cancer (CRPC) is a hallmark of the treatment-refractory stage, and the median survival of patients is only within two years. Neuroendocrine prostate cancer (NEPC) is an aggressive variant that arises from de novo presentation of small cell carcinoma or treatment-related transformation with a median survival of 1–2 years from the time of diagnosis. The epigenetic regulators, such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), have been proven involved in multiple pathologic mechanisms of CRPC and NEPC. LncRNAs can act as competing endogenous RNAs to sponge miRNAs that would inhibit the expression of their targets. After that, miRNAs interact with the 3’ untranslated region (UTR) of target mRNAs to repress the step of translation. These interactions may modulate gene expression and influence cancer development and progression. Otherwise, epigenetic regulators and genetic mutation also promote neuroendocrine differentiation and cancer stem-like cell formation. This step may induce neuroendocrine prostate cancer development. This review aims to provide an integrated, synthesized overview under current evidence to elucidate the crosstalk of lncRNAs with miRNAs and their influence on castration resistance or neuroendocrine differentiation of prostate cancer. Notably, we also discuss the mechanisms of lncRNA–miRNA interaction in androgen receptor-independent prostate cancer, such as growth factors, oncogenic signaling pathways, cell cycle dysregulation, and cytokines or other transmembrane proteins. Conclusively, we underscore the potential of these communications as potential therapeutic targets in the future.

Disruption of Cell-Cell Communication in Anaplastic Thyroid Cancer as an Immunotherapeutic Opportunity

Thyroid cancer incidence is increasing at an alarming rate, almost tripling every decade. About 44,280 new cases of thyroid cancer (12,150 in men and 32,130 in women) are estimated to be diagnosed in 2021, with an estimated death toll of around 2200. Although most thyroid tumors are treatable and associated with a favorable outcome, anaplastic thyroid cancer (ATC) is extremely aggressive with a grim prognosis of 6-9 months post-diagnosis. A large contributing factor to this aggressive nature is that ATC is completely refractory to mainstream therapies. Analysis of the tumor microenvironment (TME) associated with ATC can relay insight to the pathological realm that encompasses tumors and aids in cancer progression and proliferation. The TME is defined as a complex niche that surrounds a tumor and involves a plethora of cellular components whose secretions can modulate the environment in order to favor tumor progression. The cellular heterogeneity of the TME contributes to its dynamic function due to the presence of both immune and nonimmune resident, infiltrating, and interacting cell types. Associated immune cells discussed in this chapter include macrophages, dendritic cells (DCs), natural killer (NK) cells, and tumor-infiltrating lymphocytes (TILs). Nonimmune cells also play a role in the establishment and proliferation of the TME, including neuroendocrine (NE) cells, adipocytes, endothelial cells (ECs), mesenchymal stem cells (MSCs), and fibroblasts. The dynamic nature of the TME contributes greatly to cancer progression.Recent work has found ATC tissues to be defined by a T cell-inflamed "hot" tumor immune microenvironment (TIME) as evidenced by presence of CD3+ and CD8+ T cells. These tumor types are amenable to immune checkpoint blockade (ICB) therapy. This therapeutic avenue, as of 2021, has remained unexplored in ATC. New studies should seek to explore the therapeutic feasibility of a combination therapy, through the use of a small molecule inhibitor with ICB in ATC. Screening of in vitro model systems representative of papillary, anaplastic, and follicular thyroid cancer explored the expression of 29 immune checkpoint molecules. There are higher expressions of HVEM, BTLA, and CD160 in ATC cell lines when compared to the other TC subtypes. The expression level of HVEM was more than 30-fold higher in ATC compared to the others, on average. HVEM is a member of tumor necrosis factor (TNF) receptor superfamily, which acts as a bidirectional switch through interaction with BTLA, CD160, and LIGHT, in a cis or trans manner. Given the T cell-inflamed hot TIME in ATC, expression of HVEM on tumor cells was suggestive of a possibility for complex crosstalk of HVEM with inflammatory cytokines. Altogether, there is emerging evidence of a T cell-inflamed TIME in ATC along with the expression of immune checkpoint proteins HVEM, BTLA, and CD160 in ATC. This can open doors for combination therapies using small molecule inhibitors targeting downstream effectors of MAPK pathway and antagonistic antibodies targeting the HVEM/BTLA axis as a potentially viable therapeutic avenue for ATC patients. With this being stated, the development of adaptive resistance to targeted therapies is inevitable; therefore, using a combination therapy that targets the TIME can serve as a preemptive tactic against the characteristic therapeutic resistance that is seen in ATC. The dynamic nature of the TME, including the immune cells, nonimmune cells, and acellular components, can serve as viable targets for combination therapy in ATC. Understanding the complex interactions of these associated cells and the paradigm in which their secretions and components can serve as immunomodulators are critical points of understanding when trying to develop therapeutics specifically tailored for the anaplastic thyroid carcinoma microenvironment.

Regulation of Neuroendocrine-like Differentiation in Prostate Cancer by Non-Coding RNAs

Neuroendocrine prostate cancer (NEPC) represents a variant of prostate cancer that occurs in response to treatment resistance or, to a much lesser extent, de novo. Unravelling the molecular mechanisms behind transdifferentiation of cancer cells to neuroendocrine-like cancer cells is essential for development of new treatment opportunities. This review focuses on summarizing the role of small molecules, predominantly microRNAs, in this phenomenon. A published literature search was performed to identify microRNAs, which are reported and experimentally validated to modulate neuroendocrine markers and/or regulators and to affect the complex neuroendocrine phenotype. Next, available patients’ expression datasets were surveyed to identify deregulated microRNAs, and their effect on NEPC and prostate cancer progression is summarized. Finally, possibilities of miRNA detection and quantification in body fluids of prostate cancer patients and their possible use as liquid biopsy in prostate cancer monitoring are discussed. All the addressed clinical and experimental contexts point to an association of NEPC with upregulation of miR-375 and downregulation of miR-34a and miR-19b-3p. Together, this review provides an overview of different roles of non-coding RNAs in the emergence of neuroendocrine prostate cancer.

Toward a mechanistic understanding of DNA binding by forkhead transcription factors and its perturbation by pathogenic mutations

Forkhead box (FOX) proteins are an evolutionarily conserved family of transcription factors that play numerous regulatory roles in eukaryotes during developmental and adult life. Dysfunction of FOX proteins has been implicated in a variety of human diseases, including cancer, neurodevelopment disorders and genetic diseases. The FOX family members share a highly conserved DNA-binding domain (DBD), which is essential for DNA recognition, binding and function. Since the first FOX structure was resolved in 1993, >30 FOX structures have been reported to date. It is clear now that the structure and DNA recognition mechanisms vary among FOX members; however, a systematic review on this aspect is lacking. In this manuscript, we present an overview of the mechanisms by which FOX transcription factors bind DNA, including protein structures, DNA binding properties and disease-causing mutations. This review should enable a better understanding of FOX family transcription factors for basic researchers and clinicians.

Molecular events in neuroendocrine prostate cancer development

Neuroendocrine prostate cancer (NEPC) is a lethal subtype of prostate cancer. NEPC arises de novo only rarely; the disease predominantly develops from adenocarcinoma in response to drug-induced androgen receptor signalling inhibition, although the mechanisms behind this transdifferentiation are a subject of debate. The survival of patients with NEPC is poor, and few effective treatment options are available. To improve clinical outcomes, understanding of the biology and molecular mechanisms regulating NEPC development is crucial. Various NEPC molecular drivers make temporal contributions during NEPC development, and despite the limited treatment options available, several novel targeted therapeutics are currently under research.

FOXA1 promotes prostate cancer angiogenesis by inducing multiple pro-angiogenic factors expression

PURPOSE

FOXA1, as a pioneering transcription factor, has been shown to drive prostate cancer progression. Previous studies showed that FOXA1 expression in prostate cancer was positively associated with cancer angiolymphatic invasion and metastasis. However, the mechanism underlying the correlation between FOXA1 and prostate cancer angiolymphatic invasion and metastasis remains largely unclear.

METHODS

Herein, we set out to investigate the role of FOXA1 in the interactions between prostate cancer cells and endothelial cells. Endothelial cells' phenotypes were assessed through CCK-8 assay, Transwell migration assay, and tube formation assay. The angiogenic factors acting on endothelial cells mediated by FOXA1were characterized by RNA-seq, qPCR array, angiogenesis cytokines array, and ELISA assay. The impact of FOXA1 on tumor angiogenesis was examined in a xenograft model in nude mice. The effect of FOXA1 on prostate cancer angiogenesis was validated on a primary prostate cancer tissue microarray.

RESULTS

FOXA1 expression in prostate cancer cells promoted endothelial cell proliferation, migration, and tube formation in vitro. Mechanistically, FOXA1 increased pro-angiogenic factors production, including EGF, Endothelin-1, and Endoglin. Moreover, in vivo study showed that FOXA1 facilitated tumor angiogenesis. Furthermore, clinical samples investigation indicated that FOXA1 enhanced prostate cancer angiogenesis.

CONCLUSION

Overall, these findings illustrated a tumor angiogenesis-promoting role of FOXA1 in prostate cancer.

Untargeted metabolomics and lipidomics analysis identified the role of FOXA1 in remodeling the metabolic pattern of BaP-transformed 16HBE cells

Benzo[a]pyrene (BaP) is a strong carcinogen for lung cancer, and forkhead-box A1 (FOXA1) plays an oncogenic role in BaP-transformed cell THBEc1. To explore the remodeling of metabolic pattern caused by BaP-induced transformation and the possible role FOXA1 might play in it, we compared metabolic patterns between THBEc1 cells and control using untargeted metabolomics and lipidomics analysis, and determined the effects of FOXA1 knockout on the metabolic pattern of THBEc1 cells. Metabolomics and lipidomics identified a total of 15 and 46 differential metabolites and lipids between THBEc1 and 16HBE cells, respectively, and a total of 4 and 1 differential metabolites and lipids between FOXA1 knockout cell THBEc1-ΔFOXA1-c34 and control cell THBEc1-ctrl, respectively. Analysis results of metabolites and metabolic pathways indicated the metabolic pattern remodeling may be related to the alteration in glucose metabolism during BaP-induced transformation. Western blotting revealed the up-regulation of enolase-2 (ENO2), pyruvate carboxylase (PCB), aconitase-2 (ACO2) and phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) (Thr202/Tyr204), the down-regulation of succinate dehydrogenase complex subunit A (SDHA) and phosphoenolpyruvate carboxykinase 2 (PCK2) in THBEc1 cells. The detection results of metabolites related to glucose metabolism demonstrated the decreasing of lactic acid content in cells, lactic acid production in culture medium and citric acid content in mitochondria, and the increasing of ATP production of THBEc1 cells. FOXA1 knockout partially reversed the changes of ENO2, SDHA, PCK2 and p-ERK1/2 (Thr202/Tyr204) levels, lactic acid release, citric acid content in mitochondria of THBEc1 cells. In conclusion, FOXA1 knockout partially reversed the remodeling of glucose metabolism caused by BaP-induced malignant transformation. Our findings provide a clue for the possible role of FOXA1 in glucose metabolism regulation.

Transcription Factors: The Fulcrum Between Cell Development and Carcinogenesis

Higher eukaryotic development is a complex and tightly regulated process, whereby transcription factors (TFs) play a key role in controlling the gene regulatory networks. Dysregulation of these regulatory networks has also been associated with carcinogenesis. Transcription factors are key enablers of cancer stemness, which support the maintenance and function of cancer stem cells that are believed to act as seeds for cancer initiation, progression and metastasis, and treatment resistance. One key area of research is to understand how these factors interact and collaborate to define cellular fate during embryogenesis as well as during tumor development. This review focuses on understanding the role of TFs in cell development and cancer. The molecular mechanisms of cell fate decision are of key importance in efforts towards developing better protocols for directed differentiation of cells in research and medicine. We also discuss the dysregulation of TFs and their role in cancer progression and metastasis, exploring TF networks as direct or indirect targets for therapeutic intervention, as well as specific TFs' potential as biomarkers for predicting and monitoring treatment responses.

HDAC2-mediated proliferation of trophoblast cells requires the miR-183/FOXA1/IL-8 signaling pathway

Pre-eclampsia (PE) is a major cause of maternal and perinatal death. Previous research has indicated the role of histone deacetylase 2 (HDAC2) in the pathogenesis of PE but the relevant molecular mechanisms are unknown. However, there is hitherto little information concerning the molecular mechanism behind HDAC2 in PE. Herein, we hypothesized that HDAC2 promotes trophoblast cell proliferation and this requires the involvement of microRNA-183 (miR-183), forkhead box protein A1 (FOXA1), and interleukin 8 (IL-8). We collected placental specimens from 30 PE affected and 30 normal pregnant women. HDAC2 and FOXA1 were poorly expressed while miR-183 and IL-8 were highly expressed in placental tissues in PE. In vitro, HDAC2 overexpression enhanced the proliferation, migration, and invasion of human trophoblast cells HTR-8/SVNEO. HDAC2 inhibited the expression of miR-183 by diminishing H4 acetylation in the miR-183 promoter region. miR-183 inhibition by its specific inhibitor increased the expression of FOXA1 and thus enhanced HTR-8/SVNEO cell proliferation, migration, and invasion. FOXA1, a transcriptional factor, enhanced HTR-8/SVNEO cell proliferation, migration, and invasion by inhibiting the transcription of IL-8. We also observed HDAC2 knockdown was lost upon FOXA1 overexpression, suggesting that HDAC2 could promote HTR-8/SVNEO proliferation, migration, and invasion through the miR-183/FOXA1/IL-8 pathway. In summary, the results highlighted the role of the HDAC2/miR-183/FOXA1/IL-8 pathway in PE pathogenesis and thus suggest a novel molecular target for PE.

Reprogramming of the FOXA1 cistrome in treatment-emergent neuroendocrine prostate cancer

Lineage plasticity, the ability of a cell to alter its identity, is an increasingly common mechanism of adaptive resistance to targeted therapy in cancer. An archetypal example is the development of neuroendocrine prostate cancer (NEPC) after treatment of prostate adenocarcinoma (PRAD) with inhibitors of androgen signaling. NEPC is an aggressive variant of prostate cancer that aberrantly expresses genes characteristic of neuroendocrine (NE) tissues and no longer depends on androgens. Here, we investigate the epigenomic basis of this resistance mechanism by profiling histone modifications in NEPC and PRAD patient-derived xenografts (PDXs) using chromatin immunoprecipitation and sequencing (ChIP-seq). We identify a vast network of cis-regulatory elements (N~15,000) that are recurrently activated in NEPC. The FOXA1 transcription factor (TF), which pioneers androgen receptor (AR) chromatin binding in the prostate epithelium, is reprogrammed to NE-specific regulatory elements in NEPC. Despite loss of dependence upon AR, NEPC maintains FOXA1 expression and requires FOXA1 for proliferation and expression of NE lineage-defining genes. Ectopic expression of the NE lineage TFs ASCL1 and NKX2-1 in PRAD cells reprograms FOXA1 to bind to NE regulatory elements and induces enhancer activity as evidenced by histone modifications at these sites. Our data establish the importance of FOXA1 in NEPC and provide a principled approach to identifying cancer dependencies through epigenomic profiling.

PKCα mediated by the PI3K/Akt-FOXA1 cascade facilitates cypermethrin-induced hyperthyroidism

Cypermethrin (CYP), a broad-spectrum pyrethroid insecticide is extensively used. CYP is also considered as a potential endocrine disruptor with the thyroid-disturbing property. Protein kinase C alpha (PKCα) is a pleiotropic signal transduction molecule that functions crucially in thyroid hormone (TH) homeostasis and thyroid functions. To explore underlying roles of PKCα in CYP-mediated disturbance of TH homeostasis, Sprague-Dawley rats and rat thyroid cells were used in this study. Results showed that β-CYP stimulated TH biosynthesis, as shown by the increase in plasma levels of TT4, FT4, TT3, FT3, and TSH. After β-CYP treatment, expressions of PKCα, three miRNAs (miR-17-5p, miR-330-3p, and miR-331-3p), thyroid transcription factor TTF-1, and thyroid-specific proteins (TSHr, TPO, and Tg) were significantly increased, while expressions of PI3K p110α, p-Akt, FOXA1, and thyroid transcription factors (TTF-2 and Pax8) were decreased. Further studies found that β-CYP induced PKCα translation by the miR-330-3p-targeted PI3K/Akt-FOXA1 cascade and then PKCα positively regulated TTF-1 to promote TPO and Tg expressions, which in turn facilitated TH biosynthesis. Likewise, PKCα positively modulated TSHr expressions to strengthen the TSH/TSHr signal in the HPT axis, thereby synergistically contributing to TH biosynthesis. Moreover, β-CYP also disturbed TH biotransformation and biotransport by inducing DIO1 and inhibiting DIO3 in thyroids and TTR expressions in livers. Taken together, β-CYP has the thyroid-disturbing effect and could promote TH biosynthesis, and PKCα plays vital roles in β-CYP-caused hyperthyroidism.

Current advances of targeting epigenetic modifications in neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) is the most lethal malignancy of prostate cancer (PCa). Treatment with next-generation androgen receptor (AR) pathway inhibitors (ARPIs) has successfully extended patients' lifespan. However, with the emergence of drug resistance, PCa tumors increasingly adapt to potent ARPI therapies by transitioning to alternative cellular lineage. Such therapy-induced drug resistance is largely driven from the cellular plasticity of PCa cells to alter their phenotypes of AR independence for cell growth and survival. Some of the resistant PCa cells undergo cellular reprogramming to form neuroendocrine phenotypes. Recent evidences suggest that this cellular reprogramming or the lineage plasticity is driven by dysregulation of the epigenome and transcriptional networks. Aberrant DNA methylation and altered expression of epigenetic modifiers, such as enhancer of zeste-homolog 2, transcription factors, histone demethylases, are hallmarks of NEPC. In this review, we discuss the nature of the epigenetic and transcriptional landscapes of PCa cells which lose their AR independence and transition to the neuroendocrine lineage. We also discuss how oncogenic signaling and metabolic reprogramming fuel epigenetic and transcriptional alterations. In addition, the current state of epigenetic therapies for NEPC is addressed.

Molecular and Functional Links between Neurodevelopmental Processes and Treatment-Induced Neuroendocrine Plasticity in Prostate Cancer Progression

Simple Summary

Treatment-induced neuroendocrine prostate cancer (t-NEPC) is a subtype of castration-resistant prostate cancer (CRPC) which develops under prolonged androgen deprivation therapy. The mechanisms and pathways underlying the t-NEPC are still poorly understood and there are no effective treatments available. Here, we summarize the literature on the molecules and pathways contributing to neuroendocrine phenotype in prostate cancer in the context of their known cellular neurodevelopmental processes. We also discuss the role of tumor microenvironment in neuroendocrine plasticity, future directions, and therapeutic options under clinical investigation for neuroendocrine prostate cancer.

Abstract

Neuroendocrine plasticity and treatment-induced neuroendocrine phenotypes have recently been proposed as important resistance mechanisms underlying prostate cancer progression. Treatment-induced neuroendocrine prostate cancer (t-NEPC) is highly aggressive subtype of castration-resistant prostate cancer which develops for one fifth of patients under prolonged androgen deprivation. In recent years, understanding of molecular features and phenotypic changes in neuroendocrine plasticity has been grown. However, there are still fundamental questions to be answered in this emerging research field, for example, why and how do the prostate cancer treatment-resistant cells acquire neuron-like phenotype. The advantages of the phenotypic change and the role of tumor microenvironment in controlling cellular plasticity and in the emergence of treatment-resistant aggressive forms of prostate cancer is mostly unknown. Here, we discuss the molecular and functional links between neurodevelopmental processes and treatment-induced neuroendocrine plasticity in prostate cancer progression and treatment resistance. We provide an overview of the emergence of neurite-like cells in neuroendocrine prostate cancer cells and whether the reported t-NEPC pathways and proteins relate to neurodevelopmental processes like neurogenesis and axonogenesis during the development of treatment resistance. We also discuss emerging novel therapeutic targets modulating neuroendocrine plasticity.

Neuroendocrine cells of the prostate: Histology, biological functions, and molecular mechanisms

Prostate cancer (PCa) is a common cause of cancer-related mortality in men worldwide. Although most men are diagnosed with low grade, indolent tumors that are potentially curable, a significant subset develops advanced disease where hormone therapy is required to target the androgen receptor (AR). Despite its initial effect, hormone therapy eventually fails and the tumor progresses to lethal stages even through continued inhibition of AR. This review article focuses on the role of PCa cellular heterogeneity in therapy resistance and disease progression. Although AR-positive luminal-type cells represent the vast majority of PCa cells, there exists a minor component of AR-negative neuroendocrine (NE) cells that are resistant to hormonal therapy and are enriched by the treatment. In addition, it is now well accepted that a significant subset of hormonally treated tumors recur as small cell neuroendocrine carcinoma (SCNC), further highlighting the importance of targeting NE cells in addition to the more abundant luminal-type cancer cells. Although it has been long recognized that NE cells are present in PCa, their underlying function in benign prostate and molecular mechanisms contributing to PCa progression remains poorly understood. In this article, we review the morphology and function of NE cells in benign prostate and PCa as well as underlying molecular mechanisms. In addition, we review the major reported mechanisms for transformation from common adenocarcinoma histology to the highly lethal SCNC, a significant clinical challenge in the management of advanced PCa.

Histone demethylase PHF8 drives neuroendocrine prostate cancer progression by epigenetically upregulating FOXA2

Neuroendocrine prostate cancer (NEPC) is a more aggressive subtype of castration-resistant prostate cancer (CRPC). Although it is well established that PHF8 can enhance prostate cancer cell proliferation, whether PHF8 is involved in prostate cancer initiation and progression is relatively unclear. By comparing the transgenic adenocarcinoma of the mouse prostate (TRAMP) mice with or without Phf8 knockout, we systemically examined the role of PHF8 in prostate cancer development. We found that PHF8 plays a minimum role in initiation and progression of adenocarcinoma. However, PHF8 is essential for NEPC because not only is PHF8 highly expressed in NEPC but also animals without Phf8 failed to develop NEPC. Mechanistically, PHF8 transcriptionally upregulates FOXA2 by demethylating and removing the repressive histone markers on the promoter region of the FOXA2 gene, and the upregulated FOXA2 subsequently regulates the expression of genes involved in NEPC development. Since both PHF8 and FOXA2 are highly expressed in NEPC tissues from patients or patient-derived xenografts, the levels of PHF8 and FOXA2 can either individually or in combination serve as NEPC biomarkers and targeting either PHF8 or FOXA2 could be potential therapeutic strategies for NEPC treatment. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

WLS-Wnt signaling promotes neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) is a lethal prostate cancer subtype arising as a consequence of more potent androgen receptor (AR) targeting in castration-resistant prostate cancer (CRPC). Its molecular pathogenesis remains elusive. Here, we report that the Wnt secretion mediator Wntless (WLS) is a major driver of NEPC and aggressive tumor growth in vitro and in vivo. Mechanistic studies showed that WLS is a transcriptional target suppressed by AR that activates the ROR2/PKCδ/ERK signaling pathway to support the neuroendocrine (NE) traits and proliferative capacity of NEPC cells. Analysis of clinical samples and datasets revealed that WLS was highly expressed in CRPC and NEPC tumors. Finally, treatment with the Wnt secretion inhibitor LGK974 restricted NE prostate tumor xenograft growth in mice. These findings collectively characterize the contribution of WLS to NEPC pathogenesis and suggest that WLS is a potential therapeutic target in NEPC.

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WLS is highly expressed in neuroendocrine prostate cancer clinical samples

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WLS is a transcriptional target suppressed by androgen receptor

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WLS drives neuroendocrine prostate cancer through the ROR2/PKCδ/ERK pathway

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Wnt secretion inhibitor treatment limits neuroendocrine prostate tumor growth in mice

Post-transcriptional Gene Regulation by MicroRNA-194 Promotes Neuroendocrine Transdifferentiation in Prostate Cancer

Potent therapeutic inhibition of the androgen receptor (AR) in prostate adenocarcinoma can lead to the emergence of neuroendocrine prostate cancer (NEPC), a phenomenon associated with enhanced cell plasticity. Here, we show that microRNA-194 (miR-194) is a regulator of epithelial-neuroendocrine transdifferentiation. In clinical prostate cancer samples, miR-194 expression and activity were elevated in NEPC and inversely correlated with AR signaling. miR-194 facilitated the emergence of neuroendocrine features in prostate cancer cells, a process mediated by its ability to directly target a suite of genes involved in cell plasticity. One such target was FOXA1, which encodes a transcription factor with a vital role in maintaining the prostate epithelial lineage. Importantly, a miR-194 inhibitor blocked epithelial-neuroendocrine transdifferentiation and inhibited the growth of cell lines and patient-derived organoids possessing neuroendocrine features. Overall, our study reveals a post-transcriptional mechanism regulating the plasticity of prostate cancer cells and provides a rationale for targeting miR-194 in NEPC.

Small molecule JQ1 promotes prostate cancer invasion via BET-independent inactivation of FOXA1

Recent findings have shown that inhibitors targeting bromodomain and extraterminal domain (BET) proteins, such as the small molecule JQ1, are potent growth inhibitors of many cancers and hold promise for cancer therapy. However, some reports have also revealed that JQ1 can activate additional oncogenic pathways and may affect epithelial-to-mesenchymal transition (EMT). Therefore, it is important to address the potential unexpected effect of JQ1 treatment, such as cell invasion and metastasis. Here, we showed that in prostate cancer, JQ1 inhibited cancer cell growth but promoted invasion and metastasis in a BET protein-independent manner. Multiple invasion pathways including EMT, bone morphogenetic protein (BMP) signaling, chemokine signaling, and focal adhesion were activated by JQ1 to promote invasion. Notably, JQ1 induced upregulation of invasion genes through inhibition of Forkhead box protein A1 (FOXA1), an invasion suppressor in prostate cancer. JQ1 directly interacted with FOXA1 and inactivated FOXA1 binding to its interacting repressors TLE3, HDAC7, and NFIC, thereby blocking FOXA1-repressive function and activating the invasion genes. Our findings indicate that JQ1 has an unexpected effect of promoting invasion in prostate cancer. Thus, the ill effect of JQ1 or its derived therapeutic agents cannot be ignored during cancer treatment, especially in FOXA1-related cancers.