Angiogenesis In Prostate Cancer Research Articles

AZGP1 deficiency promotes angiogenesis in prostate cancer

BackgroundLoss of AZGP1 expression is a biomarker associated with progression to castration resistance, development of metastasis, and poor disease-specific survival in prostate cancer. However, high expression of AZGP1 cells in prostate cancer has been reported to increase proliferation and invasion. The exact role of AZGP1 in prostate cancer progression remains elusive.MethodAZGP1 knockout and overexpressing prostate cancer cells were generated using a lentiviral system. The effects of AZGP1 under- or over-expression in prostate cancer cells were evaluated by in vitro cell proliferation, migration, and invasion assays. Heterozygous AZGP1± mice were obtained from European Mouse Mutant Archive (EMMA), and prostate tissues from homozygous knockout male mice were collected at 2, 6 and 10 months for histological analysis. In vivo xenografts generated from AZGP1 under- or over-expressing prostate cancer cells were used to determine the role of AZGP1 in prostate cancer tumor growth, and subsequent proteomics analysis was conducted to elucidate the mechanisms of AZGP1 action in prostate cancer progression. AZGP1 expression and microvessel density were measured in human prostate cancer samples on a tissue microarray of 215 independent patient samples.ResultNeither the knockout nor overexpression of AZGP1 exhibited significant effects on prostate cancer cell proliferation, clonal growth, migration, or invasion in vitro. The prostates of AZGP1−/− mice initially appeared to have grossly normal morphology; however, we observed fibrosis in the periglandular stroma and higher blood vessel density in the mouse prostate by 6 months. In PC3 and DU145 mouse xenografts, over-expression of AZGP1 did not affect tumor growth. Instead, these tumors displayed decreased microvessel density compared to xenografts derived from PC3 and DU145 control cells, suggesting that AZGP1 functions to inhibit angiogenesis in prostate cancer. Proteomics profiling further indicated that, compared to control xenografts, AZGP1 overexpressing PC3 xenografts are enriched with angiogenesis pathway proteins, including YWHAZ, EPHA2, SERPINE1, and PDCD6, MMP9, GPX1, HSPB1, COL18A1, RNH1, and ANXA1. In vitro functional studies show that AZGP1 inhibits human umbilical vein endothelial cell proliferation, migration, tubular formation and branching. Additionally, tumor microarray analysis shows that AZGP1 expression is negatively correlated with blood vessel density in human prostate cancer tissues.ConclusionAZGP1 is a negative regulator of angiogenesis, such that loss of AZGP1 promotes angiogenesis in prostate cancer. AZGP1 likely exerts heterotypical effects on cells in the tumor microenvironment, such as stromal and endothelial cells. This study sheds light on the anti-angiogenic characteristics of AZGP1 in the prostate and provides a rationale to target AZGP1 to inhibit prostate cancer progression.

Abstract 3007: AZGP1 inhibits angiogenesis in prostate cancer

Abstract AZGP1 is involved in various biological processes, including lipid metabolism, regulation of cell proliferation, migration and invasion, and immune response. The loss of AZGP1 is associated with worse clinical outcomes, and AZGP1 has been indicated as a potential biomarker for prostate cancer. However, the underlying mechanisms of AZGP1 function in prostate cancer are unknown. This study reports AZGP1's pivotal involvement in angiogenesis within the prostate cancer tumor environment. Neither knockout nor overexpression of AZGP1 affects in vitro prostate cancer cell proliferation, migration, or invasion. Morphologically, AZGP1-deficient mouse prostates appear normal, but exhibit increased fibroblast growth in periglandular stroma after 6 months. The overexpression of AZGP1 does not impact the growth of PC3 and DU145 tumors; instead, these tumors significantly reduced microvessel density, suggesting AZGP1 exhibits anti-angiogenic properties. Proteomic profiling shows distinct profile of angiogenesis-related proteins between PC3-AZGP1-OV and PC3 control cells, featuring proteins like PDCD6 and MMP9. This study provides insights into the anti-angiogenic attributes of AZGP1 in prostate cancer, underscoring its potential as a therapeutic target for prostate cancer. Citation Format: Ru Wen, G Edward Wen, Zhengyuan Qiu, Eric E Peterson, Fernando Jose Garcia Marques, Abel Bermudez, Jonathan R Pollack, Hongjuan Zhao, Sharon Pitteri, James Brooks. AZGP1 inhibits angiogenesis in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3007.

Harnessing tumor-derived exosomes: A promising approach for the expansion of clinical diagnosis, prognosis, and therapeutic outcome of prostate cancer.

Prostate cancer is the second leading cause of men's death worldwide. Although early diagnosis and therapy for localized prostate cancer have improved, the majority of men with metastatic disease die from prostate cancer annually. Therefore, identification of the cellular-molecular mechanisms underlying the progression of prostate cancer is essential for overcoming controlled proliferation, invasion, and metastasis. Exosomes are small extracellular vesicles that mediate most cells' interactions and contain membrane proteins, cytosolic and nuclear proteins, extracellular matrix proteins, lipids, metabolites, and nucleic acids. Exosomes play an essential role in paracrine pathways, potentially influencing Prostate cancer progression through a wide variety of mechanisms. In the present review, we outline and discuss recent progress in our understanding of the role of exosomes in the Prostate cancer microenvironment, like their involvement in prostate cancer occurrence, progression, angiogenesis, epithelial-mesenchymal transition, metastasis, and drug resistance. We also present the latest findings regarding the function of exosomes as biomarkers, direct therapeutic targets in prostate cancer, and the challenges and advantages associated with using exosomes as natural carriers and in exosome-based immunotherapy. These findings are a promising avenue for the expansion of potential clinical approaches.

CDK12 regulates angiogenesis of advanced prostate cancer by IGFBP3.

Prostate cancer (PCa) is a prevalent malignancy among men, with a majority of patients presenting with distant metastases at the time of initial diagnosis. These patients are at a heightened risk of developing more aggressive castration‑resistant PCa following androgen deprivation therapy, which poses a greater challenge for treatment. Notably, the inhibition of tumor angiogenesis should not be considered an ineffective treatment strategy. The regulatory role of CDK12 in transcriptional and post‑transcriptional processes is essential for the proper functioning of various cellular processes. In the present study, the expression of CDK12 was first knocked down in cells using CRISPR or siRNA technology. Subsequently, RNA‑seq analysis, co‑immunoprecipitation, western blotting, reverse transcription‑quantitative polymerase chain reaction and the LinkedOmics database were employed to reveal that CDK12 inhibits insulin like growth factor binding protein 3 (IGFBP3). Western blot analysis also demonstrated that CDK12 promoted VEGFA expression by inhibiting IGFBP3, which involves the Akt signaling pathway. Then, CDK12 was found to promote PCa cell proliferation, cell migration and angiogenesis by inhibiting IGFBP3 through cell proliferation assays, cell migration assays and tube formation assays, respectively. Finally, animal experiments were performed for invivo validation. It was concluded that CDK12 promoted PCa and its angiogenesis by inhibiting IGFBP3.

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.

A novel GRK3-HDAC2 regulatory pathway is a key direct link between neuroendocrine differentiation and angiogenesis in prostate cancer progression

The mechanisms underlying the progression of prostate cancer (PCa) to neuroendocrine prostate cancer (NEPC), an aggressive PCa variant, are largely unclear. Two prominent NEPC phenotypes are elevated NE marker expression and heightened angiogenesis. Identifying the still elusive direct molecular links connecting angiogenesis and neuroendocrine differentiation (NED) is crucial for our understanding and targeting of NEPC. Here we found that histone deacetylase 2 (HDAC2), whose role in NEPC has not been reported, is one of the most upregulated epigenetic regulators in NEPC. HDAC2 promotes both NED and angiogenesis. G protein-coupled receptor kinase 3 (GRK3), also upregulated in NEPC, is a critical promoter for both phenotypes too. Of note, GRK3 phosphorylates HDAC2 at S394, which enhances HDAC2's epigenetic repression of potent anti-angiogenic factor Thrombospondin 1 (TSP1) and master NE-repressor RE1 Silencing Transcription Factor (REST). Intriguingly, REST suppresses angiogenesis while TSP1 suppresses NE marker expression in PCa cells, indicative of their novel functions and their synergy in cross-repressing the two phenotypes. Furthermore, the GRK3-HDAC2 pathway is activated by androgen deprivation therapy and hypoxia, both known to promote NED and angiogenesis in PCa. These results indicate that NED and angiogenesis converge on GRK3-enhanced HDAC2 suppression of REST and TSP1, which constitutes a key missing link between two prominent phenotypes of NEPC.

Exosomal PGAM1 promotes prostate cancer angiogenesis and metastasis by interacting with ACTG1

Tumor-derived exosomes and their contents promote cancer metastasis. Phosphoglycerate mutase 1 (PGAM1) is involved in various cancer-related processes. Nevertheless, the underlying mechanism of exosomal PGAM1 in prostate cancer (PCa) metastasis remains unclear. In this study, we performed in vitro and in vivo to determine the functions of exosomal PGAM1 in the angiogenesis of patients with metastatic PCa. We performed Glutathione-S-transferase pulldown, co-immunoprecipitation, western blotting and gelatin degradation assays to determine the pathway mediating the effect of exosomal PGAM1 in PCa. Our results revealed a significant increase in exosomal PGAM1 levels in the plasma of patients with metastatic PCa compared to patients with non-metastatic PCa. Furthermore, PGAM1 was a key factor initiating PCa cell metastasis by promoting invadopodia formation and could be conveyed by exosomes from PCa cells to human umbilical vein endothelial cells (HUVECs). In addition, exosomal PGAM1 could bind to γ-actin (ACTG1), which promotes podosome formation and neovascular sprouting in HUVECs. In vivo results revealed exosomal PGAM1 enhanced lung metastasis in nude mice injected with PCa cells via the tail vein. In summary, exosomal PGAM1 promotes angiogenesis and could be used as a liquid biopsy marker for PCa metastasis.

Abstract 2334: Reprogramming M2-like tumor associated macrophages using a natural compound, glycyrrhizin, as a potential therapeutic strategy against prostate cancer

Abstract Tumor Associated Macrophages (TAMs), copiously found in the Tumor Microenvironment (TME) are key players in creating an immunosuppressive environment, increasing angiogenesis and metastasis in prostate cancer (PCa). They are plastic in nature and usually exist as, M1 (anti-tumorigenic) or M2 (pro-tumorigenic) phenotype, with relative abundance of M2. In this study, we aimed to explore the phenotypic effects of TAMs on PCa and investigate the potential of glycyrrhizin, a natural compound, to reprogram M2 TAMs, as a feasible treatment approach against PCa. THP-1 monocytes and RAW 264.7 were used to study macrophage differentiation and glycyrrhizin-mediated repolarization. THP-1 cells were cultured in conditioned media (CM) of LNCaP and BPH-Cd to obtain PCa associated macrophages. Flow cytometric analysis revealed increase in expression of surface markers CD32, CD64, CD206 and CD163 confirming M1/M2 differentiation. qPCR analysis also demonstrated upregulation of CD80, CD86, CD68, TGF-β and IL10. M2 markers such as CD68, CD163, CCL2, CCL5 and TGF-β were expressed in BPH-Cd TAMs. LNCaP TAMs also co-expressed CD68 and CD163. In spheroid assay on BPH-Cd cells, treatment with BPH-Cd TAM resulted in abnormally shaped, enlarged spheroids. Furthermore, the CM enhanced migration of BPH-Cd cells in transwell migration assay and downregulated P21 in western blot analysis, thus confirming its tumor-promoting role. MTT assay performed prior to studying the polarization potential of glycyrrhizin showed an increase in viability of glycyrrhizin-treated THP-1 and RAW 264.7 and selectively promoted viability in M1. The M1-polarizing properties of glycyrrhizin was revealed in the qPCR analysis of glycyrrhizin-treated M0 macrophages. The reduction in the size of the spheroids and decreased migration of BPH-Cd upon treatment with glycyrrhizin-treated M0 CM confirmed the same. Differentiation media (DM) of glycyrrhizin-treated M2 TAMs resulted in smaller, disintegrated BPH-Cd spheroids indicating possible reprogramming effect. Interestingly, glycyrrhizin-treated M2 CM downregulated the gene expression of stemness-associated markers such as NANOG, SNAIL, OCT3/4 and COX2 with concurrent suppression of EMT marker, N-Cadherin in LNCaP cells. Cell cycle analysis on LNCaP revealed a decrease in the percentage of cells in S phase compared to glycyrrhizin-treated M2 CM, suggesting hindered proliferation. A notable observation to help understand the plausible mechanism of M2 TAM suppression was the decrease in Reactive Oxygen Species (ROS) levels in glycyrrhizin-treated M1 and M2 TAMs derived from THP-1 cells. The glycyrrhizin-mediated inhibition of ROS was also confirmed in RAW 264.7. In conclusion, our findings suggest that glycyrrhizin could potentially reprogram TAMs to intercept proliferation, metastasis and stemness characteristics in PCa. Citation Format: Amy Thomas, Gnanasekar Munirathinam. Reprogramming M2-like tumor associated macrophages using a natural compound, glycyrrhizin, as a potential therapeutic strategy against prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2334.

The Role οf Ion Channels in the Development and Progression of Prostate Cancer.

Ion channels have major regulatory functions in living cells. Apart from their role in ion transport, they are responsible for cellular electrogenesis and excitability, and may also regulate tissue homeostasis. Although cancer is not officially classified as a channelopathy, it has been increasingly recognized that ion channel aberrations play an important role in virtually all cancer types. Ion channels can exert pro-tumorigenic activities due to genetic or epigenetic alterations, or as a response to molecular signals, such as growth factors, hormones, etc. Increasing evidence suggests that ion channels and pumps play a critical role in the regulation of prostate cancer cell proliferation, apoptosis evasion, migration, epithelial-to-mesenchymal transition, and angiogenesis. There is also evidence suggesting that ion channels might play a role in treatment failure in patients with prostate cancer. Hence, they represent promising targets for diagnosis, staging, and treatment, and their effects may be of particular significance for specific patient populations, including those undergoing anesthesia and surgery. In this article, the role of major types of ion channels involved in the development and progression of prostate cancer are reviewed. Identifying the underlying molecular mechanisms of the pro-tumorigenic effects of ion channels may potentially inform the development of novel therapeutic strategies to counter this malignancy.

CHD1 deletion stabilizes HIF1α to promote angiogenesis and glycolysis in prostate cancer.

Chromodomain-helicase-DNA-binding protein 1 (CHD1) deletion is among the most common mutations in prostate cancer (PCa), but its role remains unclear. In this study, RNA sequencing was conducted in PCa cells after clustered regularly interspaced palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9)-based CHD1 knockout. Gene set enrichment analysis (GSEA) indicated upregulation of hypoxia-related pathways. A subsequent study confirmed that CHD1 deletion significantly upregulated hypoxia-inducible factor 1α (HIF1α) expression. Mechanistic investigation revealed that CHD1 deletion upregulated HIF1α by transcriptionally downregulating prolyl hydroxylase domain protein 2 (PHD2), a prolyl hydroxylase catalyzing the hydroxylation of HIF1α and thus promoting its degradation by the E3 ligase von Hippel-Lindau tumor suppressor (VHL). Functional analysis showed that CHD1 deletion promoted angiogenesis and glycolysis, possibly through HIF1α target genes. Taken together, these findings indicate that CHD1 deletion enhances HIF1α expression through PHD2 downregulation and therefore promotes angiogenesis and metabolic reprogramming in PCa.

RF19 | PSUN344 Control of Androgen Signaling and Metastasis by CARF in Prostate Cancer

Abstract Background Prostate cancer (PCa) is a leading cause of cancer-associated death among men worldwide. Although localized prostate cancer can be cured by surgery and radiation therapy, metastatic PCa remains a challenge. Androgen therapy (ADT) and androgen signaling inhibitors are the first line of therapy against PCa. However, resistance against these treatments develops, leading to the emergence of castration resistance prostate cancer (CRPC). Studies are required to identify the pathways that contribute to the emergence of CRPC and identify pharmaceutical targets. CARF is a putative transcription regulator reported to play a pivotal role in different cancers, including breast cancer and hepatocarcinoma. We observed that CARF is highly expressed in prostate tumors, but the biological function of CARF in PCa is unknown yet. Methods We performed RNA seq, RT-PCR, and western blot (WB) analyses to show how knockdown of CARF affects the global gene expression in PC3 cells. Gene sort enrichment analysis (GSEA) and Ingenuity Pathway Analysis (IPA) of differentially expressed genes were done to identify the cellular pathways affected upon silencing of CARF. Scratch assay and trans-well migration assay were conducted to show how CARF overexpression influences the motility of the cells. The effect of CARF on PC3 cells growth and proliferation was evaluated by colony-forming and MTT assays. In addition, we analyzed patient datasets to show the relevance of CARF expression, androgen signaling, and epithelial-mesenchymal transformation (EMT) pathways in PCa. Results The silencing of CARF inhibited the growth and proliferation of PC3 cells, suggesting the necessity of CARF for PC3 growth and survival. In agreement, overexpression of CARF enhanced the PC3 cells proliferation. We found that silencing of CARF reduced PC3 cells motility in trans-well assay. Mechanistically, RNA seq analysis after CARF knockdown uncovered that gene of AR signaling and EMT pathways were significantly altered in PC3 cells. RT-PCR and WB data confirmed that silencing of CARF enhanced E-cadherin expression and reduced the expression of N-cadherin in PC3 cells, suggesting that CARF regulates EMT in PCa. Silencing of CARF altered the AR-regulated metastatic genes expression in PC3 cells. Our data revealed that the expression of PMEPA1, a negative regulator of metastasis, was increased, but the expression of SGK1, an inducer of EMT, was decreased in CARF cells. Furthermore, CARF could regulate the prostaglandins metabolism by suppressing the expression of HGPD1 and triggering inflammation and angiogenesis in prostate cancer. Conclusion We conclude that by controlling the AR and EMT signaling pathways, CARF may play a crucial role in the development of metastatic CRPC. Future studies by integrating the RNA seq and Chip-Seq will uncover how CARF regulates the AR and EMT signaling pathways contributing to the development and progression of CRPC and paving a way to find a target for intervention. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Sunday, June 12, 2022 1:18 p.m. - 1:23 p.m.

HIF1α lactylation enhances KIAA1199 transcription to promote angiogenesis and vasculogenic mimicry in prostate cancer

Prostate cancer (PCa) is one of the most prevalent malignancies in adult males. However, PCa is resistant to multi-kinase inhibitors-based anti-angiogenic therapies, and the mechanism and effective targeting thereof remains unclear. In this study, single-cell and bulk-transcriptomic datasets analysis revealed that KIAA1199, a hyaluronic acid (HA) binding protein, was involved in glycolysis, hypoxia and angiogenesis pathways. Moreover, boosted KIAA1199 expression in PCa tissues was positively correlated with tumor stage, hypoxia-inducible factor (HIF)-1α overexpression, as well as angiogenesis markers. Tube formation, Western blot, enzyme-linked immunosorbent assay, and in vivo tumorigenesis results demonstrated that KIAA1199 silencing significantly inhibited angiogenesis and vasculogenic mimicry (VM), both in vitro and in vivo, by increasing semaphoring 3A (sema3A) expression while decreasing expressions of VEGFA, VE-cadherin, phosphorylated EphA2, and depolymerized HA levels. KIAA1199 overexpression was also found to promote angiogenesis and VM via increasing secretory VEGFA, however, this activity could be reversed by the HA biosynthesis inhibitor 4-methylumbelliferone (4MU). Furthermore, dual-luciferase and ChIP-PCR revealed that HIF1α is the transcriptional enhancer of KIAA1199, while lactate imported to PCa cells by monocarboxylate transporter 1 (MCT1) stabilizes HIF1α under normoxia via HIF1α lactylation. Our findings may provide a better understanding of angiogenesis and a promising therapeutic target of PCa.

Acetylated HOXB13 Regulated Super Enhancer Genes Define Therapeutic Vulnerabilities of Castration-Resistant Prostate Cancer.

Androgen receptor (AR) antagonism is exacerbated by HOXB13 in castration-resistant prostate cancers (CRPC). However, it is unclear when and how HOXB13 primes CRPCs for AR antagonism. By mass-spectrometry analysis of CRPC extract, we uncovered a novel lysine 13 (K13) acetylation in HOXB13 mediated by CBP/p300. To determine whether acetylated K13-HOXB13 is a clinical biomarker of CRPC development, we characterized its role in prostate cancer biology. We identified tumor-specific acK13-HOXB13 signal enriched super enhancer (SE)-regulated targets. We analyzed the effect of loss of HOXB13K13-acetylation on chromatin binding, SE proximal target gene expression, self-renewal, enzalutamide sensitivity, and CRPC tumor growth by employing isogenic parental and HOXB13K13A mutants. Finally, using primary human prostate organoids, we evaluated whether inhibiting an acK13-HOXB13 target, ACK1, with a selective inhibitor (R)-9b is superior to AR antagonists in inhibiting CRPC growth. acK13-HOXB13 promotes increased expression of lineage (AR, HOXB13), prostate cancer diagnostic (FOLH1), CRPC-promoting (ACK1), and angiogenesis (VEGFA, Angiopoietins) genes early in prostate cancer development by establishing tumor-specific SEs. acK13-HOXB13 recruitment to key SE-regulated targets is insensitive to enzalutamide. ACK1 expression is significantly reduced in the loss of function HOXB13K13A mutant CRPCs. Consequently, HOXB13K13A mutants display reduced self-renewal, increased sensitivity to enzalutamide, and impaired xenograft tumor growth. Primary human prostate tumor organoids expressing HOXB13 are significantly resistant to AR antagonists but sensitive to (R)-9b. In summary, acetylated HOXB13 is a biomarker of clinically significant prostate cancer. Importantly, PSMA-targeting agents and (R)-9b could be new therapeutic modalities to target HOXB13-ACK1 axis regulated prostate cancers.

Oligometastatic Prostate Cancer: Is there a Role for Surgery? A Narrative Review.

Oligometastatic prostate cancer is commonly considered a transition between high metastatic and local- ized disease and includes a large spectrum of conditions with a polymorphic clinical behavior. The current management of these patients contemplates systemic therapy (i.e., androgen-deprivation drugs, chemothera- peutic drugs, or both treatments administered simultaneously) which have been shown to improve survival. Radiotherapy has also been introduced, into a multimodal setting, among the therapeutic treatments forpatients who are defined as oligometastatic prostate cancer according to Chemohormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) criteria.The role of surgical debulking in patients with oligometastatic prostate cancer has always been considered impracticable, both for a marginal therapeutic role and for the greater risk of sequelae and/or complications related to the procedure itself. Several authors have demonstrated some mechanisms by which the persistence of the primary tumor can facilitate the clinical progression of the disease itself and promote carcinogenesis, differentiation, migration, and angiogenesis in prostate cancer. From these studies emerges the hypothesis of a possible therapeutic advantage in oncological terms also for cytoreductive radical prostatectomy, in a multimodal therapy setting, compared to systemic therapy alone. The present review summarizes the main knowledge regarding the safety, feasibility, and oncological outcomes of cytoreductive radical prostatectomy in oligometastatic prostate cancer patients.

Binding of pleiotrophin to cell surface nucleolin mediates prostate cancer cell adhesion to osteoblasts

Pleiotrophin (PTN) is a growth factor that appears to play an important role in prostate cancer growth and angiogenesis. We have previously shown that decreased PTN expression in human prostate cancer PC3 cells leads to decreased adhesion of prostate cancer cells to osteoblasts, suggesting that PTN mediates this interaction. In the current work, using peptides that correspond to different regions of the PTN protein, we identified that a domain responsible for the adhesion of prostate cancer cells to osteoblasts corresponds to amino acids 16–24 of the mature PTN protein. Given that a synthetic PTN16–24 peptide which disturbs the interaction of PTN with nucleolin (NCL) was found to inhibit prostate cancer cells’ adhesion to osteoblasts, it seems that NCL mediates the cellular interactions involved in the adhesion process. Two pseudopeptides that bind to cell surface NCL and an anti-NCL antibody also decrease prostate cancer cell adhesion to osteoblasts to the same degree as PTN16–24, further supporting the involvement of cell surface NCL in this interaction. Collectively, our data suggest that NCL on the cell surface of osteoblasts may mediate adhesion of prostate cancer cells through PTN and identify peptides that could be exploited therapeutically to target this component of prostate cancer bone metastases.

Establishment of an orthotopic prostate cancer xenograft mouse model using microscope-guided orthotopic injection of LNCaP cells into the dorsal lobe of the mouse prostate

BackgroundOrthotopic LNCaP xenograft mouse models closely mimic the progression of androgen-dependent prostate cancer in humans; however, orthotopic injection of LNCaP cells into the mouse prostate remains a challenge.MethodsUnder the guidance of a stereoscopic microscope, the anatomy of the individual prostate lobes in male Balb/c athymic nude mice was investigated, and LNCaP cells were inoculated into the mouse dorsal prostate (DP) to generate orthotopic tumors that mimicked the pathophysiological process of prostate cancer in humans. Real-time ultrasound imaging was used to monitor orthotopic prostate tumorigenesis, contrast-enhanced ultrasonography (CEUS) was used to characterize tumor angiogenesis, and macroscopic and microscopic characteristics of tumors were described.ResultsThe DP had a trigonal bipyramid-shape and were located at the base of the seminal vesicles. After orthotopic inoculation, gray scale ultrasound imaging showed progressive changes in tumor echotexture, shape and location, and tumors tended to protrude into the bladder. After 8 weeks, the tumor take rate was 65% (n = 13/20 mice). On CEUS, signal intensity increased rapidly, peaked, and decreased gradually. Observations of gross specimens showed orthotopic prostate tumors were well circumscribed, round, dark brown, and soft, with a smooth outer surface and a glossy appearance. Microscopically, tumor cells were arranged in acini encircled by fibrous septa with variably thickened walls, mimicking human adenocarcinoma.ConclusionsThis study describes a successful approach to establishing an orthotopic LNCaP xenograft Balb/c athymic nude mouse model. The model requires a thorough understanding of mouse prostate anatomy and proper technique. The model represents a valuable tool for the in vivo study of the biological processes involved in angiogenesis in prostate cancer and preclinical evaluations of novel anti-angiogenic therapies.

Angiogenesis as Therapeutic Target in Metastatic Prostate Cancer - Narrowing the Gap Between Bench and Bedside.

Angiogenesis in metastatic castration-resistant prostate cancer (mCRPC) has been extensively investigated as a promising druggable biological process. Nonetheless, targeting angiogenesis has failed to impact overall survival (OS) in patients with mCRPC despite promising preclinical and early clinical data. This discrepancy prompted a literature review highlighting the tumor heterogeneity and biological context of Prostate Cancer (PCa). Narrowing the gap between the bench and bedside appears critical for developing novel therapeutic strategies. Searching clinicaltrials.gov for studies examining angiogenesis inhibition in patients with PCa resulted in n=20 trials with specific angiogenesis inhibitors currently recruiting (as of September 2021). Moreover, several other compounds with known anti-angiogenic properties – such as Metformin or Curcumin – are currently investigated. In general, angiogenesis-targeting strategies in PCa include biomarker-guided treatment stratification – as well as combinatorial approaches. Beyond established angiogenesis inhibitors, PCa therapies aiming at PSMA (Prostate Specific Membrane Antigen) hold the promise to have a substantial anti-angiogenic effect – due to PSMA´s abundant expression in tumor vasculature.

Longitudinal trajectories of lifetime body shape and prostate cancer angiogenesis.

Angiogenesis potentially underlies the pathway between excess adiposity and prostate carcinogenesis. This study examined the association between lifetime body shape trajectories and prostate cancer angiogenesis. 521 prostate cancer patients who underwent prostatectomy or transurethral resection between 1986 and 2000 were enrolled from the Health Professionals Follow-up Study. Cancers were immunostained and quantitated for cancer vessel regularity, diameter, area, and density, and composite angiogenesis (factor analysis). To identify distinct groups of body shape change, we conducted group-based trajectory modeling. We used multivariable linear regression to estimate the percentage difference in angiogenesis score and 95% confidence interval (CI) between body shape change trajectories during lifetime (age 5-60years), early life (age 5-30years), or later life (age 30-60years). Compared to men with lifetime lean or medium body shape, higher angiogenesis scores were observed in men with moderate increase [percentage difference of 35% (95% CI 5-64)], marked increase [24% (95% CI - 2 to 51)], and constantly heavy with mild increase body shape [38% (95% CI 8-69)]. However, a lower angiogenesis score was noted in men with early-life marked increase (- 22%, 95% CI - 44 to 0) and stable medium body shape (- 14%, 95% CI - 40 to 12), compared to moderate increase body shape. Increased angiogenesis was also found for absolute weight gain from age 21-60years. Lifetime body fatness accumulation, especially after age 21, was associated with increased prostate cancer angiogenesis, while weight gain in early-life adulthood was associated with lower cancer angiogenesis.

Angiogenic Index as a Measure of Angiogenesis in Prostate Cancer and Its Correlation with Gleason Grade and Score

Introduction: Microvessel density, as a measure of angiogenesis, predicts prognosis in prostate cancer. Angiogenic Index (AI, numerical value of angiogenesis) minimises the possible variation concerning the width of the microscopic field, stromal epithelial relations and cellular tumour size. Aim: To study AI in prostate cancer and its correlation with Gleason Grade (GG) and Gleason Score (GS). Materials and Methods: The present cross-sectional, study was done at Postgraduate Department of Pathology, Sarojini Naidu Medical College, Agra, India, from September 2019 to December 2020. Twenty five histopathologically confirmed prostate adenocarcinoma specimens from radical prostatectomy, Transurethral Resection of Prostate (TURP), and needle biopsy were included in the study. These cases were categorised according to Gleason Grade (GG); Gleason Score (GS) was assigned to each case. The GSs were simplified into three groups: low (GS 2-6), intermediate (GS 7) and high-grade (GS 8-10). Immunohistochemical {Cluster Differentiation (CD) 31} blood vessel staining was done to calculate AI. Statistical significance was determined by Unpaired t-test. Results: All the cases were males with age range from 55 to 76 years (mean age was 65.48±5.62 years). Mean AI was 13.74, 83.76, 163.27, 299.12 for the GG1, GG3, GG4, GG5 respectively. Mean AI was 29.72, 82.67, 129.15, 186.65, 191.93, 307.34 for GS 2, 6, 7, 8, 9, 10 respectively. Comparing GG among themselves, statistically significant difference in AI was found between GG3 vs GG4 (p-value=0.0056, r-value=0.5269). Difference was also statistically significant between GG3 vs GG5 (p-value=0.000011, r-value=0.8030) and GG4 vs GG5 (p-value=0.0036, r-value=0.5806). In all scores combined, the mean AI was 56.20 for low-grade (GS 2-6), 129.15 for intermediate-grade (GS 7), 247.35 for high-grade (GS 8-10). Statistically significant difference was found in between AI (p-value<0.05) in all Gleason scores. Conclusion: Positive correlation was observed between AI, GG and GS in prostatic adenocarcinoma. AI may be of immense value to predict prognosis of prostatic adenocarcinoma.

Nimbolide inhibits 2D and 3D prostate cancer cells migration, affects microtubules and angiogenesis and suppresses B-RAF/p.ERK-mediated in vivo tumor growth

BackgroundProstate cancer (PCa) is the most prominent malignancy among men worldwide. PCa cells have a high tendency to metastasize to various distant organs, and this activity is the main cause of PCa mortality. Nimbolide is a promising phytochemical constituent of neem Azadirachta indica (Meliaceae). Previous studies showed that nimbolide exhibited potent anticancer activity however, its role against PCa tumorigenesis has not been fully elucidated. PurposeOur work aims to explore the role of nimbolide in regulating the essential tumor-associated processes involved in the metastatic cascade in PCa cells. Study designCytotoxicity assay, wound healing and spheroid invasion assays, western blotting, immunofluorescence, tube-formation assay, in vivo and immunohistochemistry. MethodsThe cytotoxicity of nimbolide towards PCa cell lines was assessed by resazurin assays. The cell mobility and migration of nimbolide-treated DU145 cells were determined by wound healing and spheroid invasion assays. Tubulin network was visualized using U2OS cells and DU145 cells. The effect of nimbolide on E-cadherin, β-catenin, acetylated α-tubulin and HDAC6 protein expressions levels were measured by Western blot. The potentiality of nimbolide to inhibit angiogenesis was revealed by HUVEC tube-formation assay. Nimbolide antitumor effect was studied in a syngeneic model of murine prostate cancer. ResultsThe current study indicated that nimbolide negatively affected the migratory and invasive capacity of DU145 prostate cancer cells in 2D and three-dimensional (3D) spheroid cultures. Interestingly, nimbolide induced downregulation of E-cadherin without any influence on the expression level of β-catenin. Additionally, we demonstrated that nimbolide influenced the microtubule network which was supported by the upregulation of acetylated α-tubulin and the reduction in HDAC6 protein. Moreover, the inhibitory effect of nimbolide on angiogenesis was clearly observed in HUVEC tube formation assay. In vivo experiments revealed the significant suppression of PCa growth and targeting of the B-RAF/p.ERK signaling pathway by nimbolide. ConclusionOur results showed that nimbolide inhibited 2D and 3D prostate cancer cells migration and downregulated E-cadherin protein expression, a marker for metastatic chemoresistance and tumor recurrence. Nimbolide stabilized the microtubules, combated angiogenesis and suppressed B.RAF/ERK-mediated in vivo tumor growth. Nimbolide may be considered as potential therapeutic agent for metastatic and advanced PCa patients and merits further investigations.