Cannabinoids and Prostate Cancer: A Systematic Review of Animal Studies

Prostate cancer is a major cause of death among men worldwide. Recent preclinical evidence implicates cannabinoids as powerful regulators of cell growth and differentiation, as well as potential anti-cancer agents. The aim of this review was to evaluate the effect of cannabinoids on in vivo prostate cancer models. The databases searched included PubMed, Embase, Scopus, and Web of Science from inception to August 2020. Articles reporting on the effect of cannabinoids on prostate cancer were deemed eligible. We identified six studies that were all found to be based on in vivo/xenograft animal models. Results: In PC3 and DU145 xenografts, WIN55,212-2 reduced cell proliferation in a dose-dependent manner. Furthermore, in LNCaP xenografts, WIN55,212-2 reduced cell proliferation by 66–69%. PM49, which is a synthetic cannabinoid quinone, was also found to result in a significant inhibition of tumor growth of up to 90% in xenograft models of LNCaP and 40% in xenograft models of PC3 cells, respectively. All studies have reported that the treatment of prostate cancers in in vivo/xenograft models with various cannabinoids decreased the size of the tumor, the outcomes of which depended on the dose and length of treatment. Within the limitation of these identified studies, cannabinoids were shown to reduce the size of prostate cancer tumors in animal models. However, further well-designed and controlled animal studies are warranted to confirm these findings.

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Essential role of p21/waf1 in the mediation of the anti-proliferative effects of GHRH antagonist JMR-132

Journal of Molecular Endocrinology ◽

10.1677/jme-08-0106 ◽

2008 ◽

Vol 41 (5) ◽

pp. 389-392 ◽

Cited By ~ 9

Author(s):

Aspasia-Athina Volakaki ◽

Daniel Lafkas ◽

Eva Kassi ◽

Andrew V Schally ◽

Athanasios G Papavassiliou ◽

...

Keyword(s):

Cell Proliferation ◽

Molecular Mechanism ◽

A549 Cells ◽

Significant Inhibition ◽

Human Lung Cancer ◽

Dependent Manner ◽

Ghrh Antagonists ◽

P21 Waf1

GHRH, besides its neuroendocrine action in controlling the release of GH from the pituitary, stimulates the growth of various cancers in vivo and in vitro by direct mechanism(s). However, the molecular mechanism that mediates these proliferative effects of GHRH in extrapituitary tissues remains poorly characterized. In the present study, we investigated whether the tumor suppressor p21/waf1 is involved in the mediation of the proliferative effects of GHRH in A549 human lung cancer epithelial cells. Exposure of A549 cells to the GHRH antagonist JMR-132 caused a significant inhibition in the rate of cell proliferation. In A549 cells, GHRH suppressed while JMR-132 increased the levels of p21 expression in a dose-dependent manner. This suggests that GHRH could regulate p21 levels. We then evaluated whether p21 is required in A549 cells for the regulation of cell proliferation by GHRH. To this end, we knocked-down p21 expression in A549 cells by siRNA and assessed the effects of antagonist JMR-132 on cell proliferation. We found that the loss of p21 expression abolished the anti-proliferative effects of JMR-132. Suppression of p21 expression by siRNA in human HT29 colon cancer cells and non-transformed mouse osteoblasts KS483 also blocked the anti-proliferative effects of JMR-132 suggesting that the regulation of cell proliferation by GHRH is p21 dependent. These results shed light on the molecular mechanism of action of GHRH antagonists in tumor tissues and suggest that the antineoplastic activity of GHRH antagonists could be considered for the treatment of cancers expressing p21.

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Scutellaria Barbata D.Don (SBD) Extracts Suppressed Tumor Growth, Metastasis and Angiogenesis in Prostate Cancer Via PI3K/Akt Pathway

10.21203/rs.3.rs-1105578/v1 ◽

2021 ◽

Author(s):

Dongya Sheng ◽

Bei Zhao ◽

Wenjing Zhu ◽

Tiantian Wang ◽

yu peng

Keyword(s):

Prostate Cancer ◽

Cell Cycle ◽

Cell Proliferation ◽

Cell Apoptosis ◽

Signalling Pathway ◽

Growth Effect ◽

Dependent Manner ◽

Scutellaria Barbata ◽

Mouse Xenograft Model

Abstract Background: Scutellaria barbata D.Don (SBD) is derived from the dried whole plant of Labiate that has been widely used to treat patients with multiple cancer. It was previously reported that the ethanol extract of SBD is able to promote apoptosis, and inhibit cell proliferation and angiogenesis in cancer.Materials and methods: CCK8, Edu assays and colony formation assay were performed to assess the effect of SBD on PCa cell growth. Effect of SBD on apoptosis and cell cycle was detected by flow cytometry. Transwell and wounding healing assay were performed to detected the invasion and migration activities of PCa cells. Western blot was employed to detect the protein expression. 2RRV1 mouse xenograft model was established to detect the effect of SBD on prostate cancer. Angiogenesis was analysed by coculturing PCa cell lines and HUVECs.Results: The results showed that SBD induced a significant decrease in cell viability and clonogenic growth in a dose-dependent manner. SBD induced cell apoptosis and cell cycle G2/M phase arrest by inactivating PI3K/AKT signalling pathway. Treatment with SBE also significantly decreased the cell migration and invasion via phenotypic inversion of EMT that was characterized by the increased expression of E-cadherin and Vimentin, and decreased expression of N-cadherin, which could be partially attributed to inhibiting PI3K/AKT signalling pathway. Subsequently, using AKT inhibitor MK2206, we performed that PI3K/AKT are also involved in cell apoptosis and metastasis of PCa cells stimulated by SBE. In addition, to its direct effects on PCa cells, SBD also exhibited anti-angiogenic properties. SBD alone or conditioned media from SBD-treated PCa cells inhibited HUVEC tube formation on Matrigel without affecting HUVEC viability. Furthermore, 22RV1 xenograft C57BL/6 mice treated with SBE in vivo showed a significant decrease in tumour size and tumour weight without toxicity. In addition, administration with medium- or high-dose of SBE significantly inhibited the cell proliferation and promoted the damage of tumour tissues.Conclusions: Collectively, our in vitro and in vivo findings suggest that SBE had the potential to develop into a safe and potent alternative therapy for PCa patients.

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6-Thioguanine and Its Analogs Promote Apoptosis of Castration-Resistant Prostate Cancer Cells in a BRCA2-Dependent Manner

Cancers ◽

10.3390/cancers11070945 ◽

2019 ◽

Vol 11 (7) ◽

pp. 945 ◽

Cited By ~ 1

Author(s):

Luna Laera ◽

Nicoletta Guaragnella ◽

Sergio Giannattasio ◽

Loredana Moro

Keyword(s):

Prostate Cancer ◽

Cell Proliferation ◽

Cancer Cells ◽

Breast Cancer Susceptibility Gene ◽

Dependent Manner ◽

Castration Resistant Prostate Cancer ◽

Prostate Cancer Cells ◽

Normal Prostate ◽

Castration Resistant ◽

Prostate Cancers

Background: Mutations in the oncosuppressor gene BReast CAncer susceptibility gene 2 (BRCA2) predispose to aggressive forms of prostate cancer which show poor response to taxane-based therapy, the standard treatment for castration-resistant, aggressive prostate cancer. Herein, we addressed the question whether changes in BRCA2 expression, a potential surrogate marker for BRCA2 activity, may affect the response of castration-resistant prostate cancer cells to 6-thioguanine (6-TG), a thiopurine used in the treatment of haematological malignancies. Methods: Yeast, normal prostate cells and castration-resistant prostate cancer cells were treated with 6-TG or its analogues, in presence or absence of paclitaxel, or with olaparib, a poly-(ADP-ribose) polymerase (PARP) inhibitor currently in clinical trials for treatment of metastatic castration-resistant prostate cancer, and cell proliferation, apoptosis and androgen receptor (AR) levels were measured. Results: 6-TG inhibited cell proliferation in yeast, normal and castration-resistant prostate cancer cells but promoted apoptosis only in cancer cells. Suppression of BRCA2 expression by siRNA or shRNA increased the sensitivity to 6-TG- and olaparib-induced apoptosis but did not affect cancer cell response to taxane. Intriguingly, 6-TG reduced AR expression levels independently on BRCA2 expression. Instead, olaparib decreased AR levels only in BRCA2-knockdown prostate cancer cells. Notably, overexpression of BRCA2 resulted in resistance of castration-resistant prostate cancer cells to 6-TG-, taxane- and olaparib-based treatment but promoted sensitivity to apoptosis induced by 2-amino-6-bromopurine and 2,6–dithiopurine, two 6-TG analogues. Conclusions: Our results provide a pre-clinical rationale for the use of 6-TG in the treatment of BRCA2-deficient castration-resistant prostate cancers, and of certain 6-TG analogues for treatment of BRCA2-proficient prostate cancers.

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Silencing of PSMC2 inhibits development and metastasis of prostate cancer through regulating proliferation, apoptosis and migration

Cancer Cell International ◽

10.1186/s12935-021-01934-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Qingke Chen ◽

Lingmin Fu ◽

Jieping Hu ◽

Guanghua Guo ◽

An Xie

Keyword(s):

Prostate Cancer ◽

Cell Cycle ◽

Cell Proliferation ◽

Cell Migration ◽

Tumor Growth ◽

Colony Formation ◽

26S Proteasome ◽

Tumor Tissues ◽

Xenograft Models

Abstract Background Prostate cancer is the most common malignant tumor of male genitourinary system, molecular mechanism of which is still not clear. PSMC2 (proteasome 26S subunit ATPase 2) is a key member of the 19S regulatory subunit of 26S proteasome, whose relationship with prostate cancer is rarely studied. Methods Here, expression of PSMC2 in tumor tissues or cells of prostate cancer was detected by qPCR, western blotting and immunohistochemical analysis. The effects of PSMC2 knockdown on cell proliferation, colony formation, cell migration, cell cycle and apoptosis were assessed by Celigo cell counting assay, colony formation assay, wound-healing assay, Transwell assay and flow cytometry, respectively. The influence of PSMC2 knockdown on tumor growth in vivo was evaluated by mice xenograft models. Results The results demonstrated that PSMC2 was upregulated in tumor tissues of prostate cancer and its high expression was significantly associated with advanced Gleason grade and higher Gleason score. Knockdown of PSMC2 could inhibited cell proliferation, colony formation and cell migration of prostate cancer cells, while promoting cell apoptosis and cell cycle arrest. The suppression of tumor growth in vivo by PSMC2 knockdown was also showed by using mice xenograft models. Moreover, the regulation of prostate cancer by PSMC2 may be mediated by Akt/Cyclin D1/CDK6 signaling pathway. Conclusions Therefore, our studies suggested that PSMC2 may act as a tumor promotor in the development and progression of prostate cancer, and could be considered as a novel therapeutic target for prostate cancer treatment.

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A molecule inducing androgen receptor degradation and selectively targeting prostate cancer cells

Life Science Alliance ◽

10.26508/lsa.201800213 ◽

2019 ◽

Vol 2 (4) ◽

pp. e201800213 ◽

Cited By ~ 2

Author(s):

Serge Auvin ◽

Harun Öztürk ◽

Yusuf T Abaci ◽

Gisele Mautino ◽

Florence Meyer-Losic ◽

...

Keyword(s):

Prostate Cancer ◽

Androgen Receptor ◽

Ex Vivo ◽

Castration Resistant Prostate Cancer ◽

Clinical Issue ◽

Castration Resistant ◽

Clinical Resistance ◽

Xenograft Models ◽

Prostate Cancers

Aberrant androgen signaling drives prostate cancer and is targeted by drugs that diminish androgen production or impede androgen–androgen receptor (AR) interaction. Clinical resistance arises from AR overexpression or ligand-independent constitutive activation, suggesting that complete AR elimination could be a novel therapeutic strategy in prostate cancers. IRC117539 is a new molecule that targets AR for proteasomal degradation. Exposure to IRC117539 promotes AR sumoylation and ubiquitination, reminiscent of therapy-induced PML/RARA degradation in acute promyelocytic leukemia. Critically, ex vivo, IRC117539-mediated AR degradation induces prostate cancer cell viability loss by inhibiting AR signaling, even in androgen-insensitive cells. This approach may be beneficial for castration-resistant prostate cancer, which remains a clinical issue. In xenograft models, IRC117539 is as potent as enzalutamide in impeding growth, albeit less efficient than expected from ex vivo studies. Unexpectedly, IRC117539 also behaves as a weak proteasome inhibitor, likely explaining its suboptimal efficacy in vivo. Our studies highlight the feasibility of AR targeting for degradation and off-target effects’ importance in modulating drug activity in vivo.

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IRE1α Expedites the Progression of Castration-Resistant Prostate Cancers via the Positive Feedback Loop of IRE1α/IL-6/AR

Frontiers in Oncology ◽

10.3389/fonc.2021.671141 ◽

2021 ◽

Vol 11 ◽

Author(s):

Fan Yang ◽

Chong Yuan ◽

Dan Wu ◽

Jing Zhang ◽

Xingchun Zhou

Keyword(s):

Prostate Cancer ◽

Cell Proliferation ◽

Positive Feedback ◽

Feedback Loop ◽

Castration Resistant Prostate Cancer ◽

Positive Feedback Loop ◽

Castration Resistant ◽

Prostate Cancers

Castration-resistant prostate cancer (CRPC) is the lethal form of prostate cancer (PCa), and the underlying molecular mechanism has not been fully elucidated. Inositol requiring enzyme 1 alpha (IRE1α), a key regulator of unfolded protein response (UPR), is intimately associated with PCa progression. However, whether IRE1α is implicated in CRPC development remains unknown. Here, we showed that IRE1α expression was significantly increased in CRPC tissues and high-grade PCa tissues. Overexpression of IRE1α promoted PCa cell proliferation under the androgen deficiency condition in vitro and in vivo. Mechanistically, increased IRE1α expression induced IL-6 secretion via the IRE1α/XBP-1s signal pathway. IRE1α-induced IL-6 activated androgen receptor (AR), and the activation of AR by IL-6, in turn, promoted IRE1α expression. IRE1α formed a positive feedback loop with IL-6 and AR to promote prostate cancer cell proliferation under the androgen-deficient condition. In clinical PCa samples, high IRE1α expression correlated with elevated IL-6 and increased PSA expression. Our findings demonstrated a novel mechanism of CRPC progression and suggest targeting IRE1α may be a potential target for the prevention and treatment of CRPC.

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Hispidulin inhibits proliferation, migration, and invasion by promoting autophagy via regulation of PPARγ activation in prostate cancer cells and xenograft models

Bioscience Biotechnology and Biochemistry ◽

10.1093/bbb/zbaa108 ◽

2020 ◽

Author(s):

Yuanyuan Wang ◽

Shanqi Guo ◽

Yingjie Jia ◽

Xiaoyu Yu ◽

Ruiyu Mou ◽

...

Keyword(s):

Prostate Cancer ◽

Flavonoid Compound ◽

Migration And Invasion ◽

Prostate Cancer Cells ◽

Invasion And Migration ◽

Beneficial Effects ◽

Anticancer Properties ◽

Xenograft Models ◽

And Migration

ABSTRACT Prostate cancer (PCa) is one of the important factors of cancer deaths especially in the western countries. Hispidulin (4′,5,7-trihydroxy-6-methoxyflavone) is a phenolic flavonoid compound proved to possess anticancer properties, but its effects on PCa are left to be released. The aims of this study were to investigate the effects and the relative mechanisms of Hispidulin on PCa development. Hispidulin administration inhibited proliferation, invasion, and migration, while accelerated apoptosis in Du145 and VCaP cells, which was accompanied by PPARγ activation and autophagy enhancement. The beneficial effects of Hispidulin could be diminished by PPARγ inhibition. Besides, Hispidulin administration suppressed PCa tumorigenicity in Xenograft models, indicating the anticancer properties in vivo. Therefore, our work revealed that the anticancer properties of Hispidulin might be conferred by its activation on PPARγ and autophagy.

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Dandelion Root and Lemongrass Extracts Induce Apoptosis, Enhance Chemotherapeutic Efficacy, and Reduce Tumour Xenograft Growth In Vivo in Prostate Cancer

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2019/2951428 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Christopher Nguyen ◽

Ali Mehaidli ◽

Kiruthika Baskaran ◽

Sahibjot Grewal ◽

Alaina Pupulin ◽

...

Keyword(s):

Prostate Cancer ◽

Root Extract ◽

Natural Health Products ◽

Anticancer Efficacy ◽

Adjuvant Therapies ◽

Anticancer Effects ◽

Health Products ◽

Xenograft Models ◽

Pharmaceutical Uses

Many conventional chemotherapies have indicated side effects due to a lack of treatment specificity and are thus not suitable for long-term usage. Natural health products are well-tolerated and safe for consumption, and some have pharmaceutical uses particularly for their anticancer effects. We have previously reported the anticancer efficacy of dandelion (Taraxacum officinale) root and lemongrass (Cymbopogon citratus) extracts. However, their efficacy on prostate cancer and their interactions with standard chemotherapeutics have not been studied to determine if they will be suitable for adjuvant therapies. If successful, these extracts could potentially be used in conjunction with chemotherapeutics to minimize the risk of drug-related toxicity and enhance the efficacy of the treatment. We have demonstrated that both dandelion root extract (DRE) and lemongrass extract (LGE) exhibit selective anticancer activity. Importantly, DRE and LGE addition to the chemotherapeutics taxol and mitoxantrone was determined to enhance the induction of apoptosis when compared to individual chemotherapy treatment alone. Further, DRE and LGE were able to significantly reduce the tumour burden in prostate cancer xenograft models when administered orally, while also being well-tolerated. Thus, the implementation of these well-tolerated extracts in adjuvant therapies could be a selective and efficacious approach to prostate cancer treatment.

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A MYBL2 complex for RRM2 transactivation and the synthetic effect of MYBL2 knockdown with WEE1 inhibition against colorectal cancer

Cell Death and Disease ◽

10.1038/s41419-021-03969-1 ◽

2021 ◽

Vol 12 (7) ◽

Author(s):

Qian Liu ◽

Lijuan Guo ◽

Hongyan Qi ◽

Meng Lou ◽

Rui Wang ◽

...

Keyword(s):

Colorectal Cancer ◽

Cell Proliferation ◽

Dna Synthesis ◽

Ectopic Expression ◽

Building Blocks ◽

Small Subunit ◽

S Phase ◽

Clinical Samples ◽

Dependent Manner

AbstractRibonucleotide reductase (RR) is a unique enzyme for the reduction of NDPs to dNDPs, the building blocks for DNA synthesis and thus essential for cell proliferation. Pan-cancer profiling studies showed that RRM2, the small subunit M2 of RR, is abnormally overexpressed in multiple types of cancers; however, the underlying regulatory mechanisms in cancers are still unclear. In this study, through searching in cancer-omics databases and immunohistochemistry validation with clinical samples, we showed that the expression of MYBL2, a key oncogenic transcriptional factor, was significantly upregulated correlatively with RRM2 in colorectal cancer (CRC). Ectopic expression and knockdown experiments indicated that MYBL2 was essential for CRC cell proliferation, DNA synthesis, and cell cycle progression in an RRM2-dependent manner. Mechanistically, MYBL2 directly bound to the promoter of RRM2 gene and promoted its transcription during S-phase together with TAF15 and MuvB components. Notably, knockdown of MYBL2 sensitized CRC cells to treatment with MK-1775, a clinical trial drug for inhibition of WEE1, which is involved in a degradation pathway of RRM2. Finally, mouse xenograft experiments showed that the combined suppression of MYBL2 and WEE1 synergistically inhibited CRC growth with a low systemic toxicity in vivo. Therefore, we propose a new regulatory mechanism for RRM2 transcription for CRC proliferation, in which MYBL2 functions by constituting a dynamic S-phase transcription complex following the G1/early S-phase E2Fs complex. Doubly targeting the transcription and degradation machines of RRM2 could produce a synthetic inhibitory effect on RRM2 level with a novel potential for CRC treatment.

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Recruitment of β-Catenin by Wild-Type or Mutant Androgen Receptors Correlates with Ligand-Stimulated Growth of Prostate Cancer Cells

Molecular Endocrinology ◽

10.1210/me.2003-0436 ◽

2004 ◽

Vol 18 (10) ◽

pp. 2388-2401 ◽

Cited By ~ 46

Author(s):

David Masiello ◽

Shao-Yong Chen ◽

Youyuan Xu ◽

Manon C. Verhoeven ◽

Eunis Choi ◽

...

Keyword(s):

Prostate Cancer ◽

Cell Growth ◽

Cancer Cells ◽

Nuclear Receptor ◽

Specific Antigen ◽

Prostate Cancer Cells ◽

Prostate Cell ◽

Nuclear Receptor Corepressor ◽

Prostate Cancers

Abstract Prostate cancers respond to treatments that suppress androgen receptor (AR) function, with bicalutamide, flutamide, and cyproterone acetate (CPA) being AR antagonists in clinical use. As CPA has substantial agonist activity, it was examined to identify AR coactivator/corepressor interactions that may mediate androgen-stimulated prostate cancer growth. The CPA-liganded AR was coactivated by steroid receptor coactivator-1 (SRC-1) but did not mediate N-C terminal interactions or recruit β-catenin, indicating a nonagonist conformation. Nonetheless, CPA did not enhance AR interaction with nuclear receptor corepressor, whereas the AR antagonist RU486 (mifepristone) strongly stimulated AR-nuclear receptor corepressor binding. The role of coactivators was further assessed with a T877A AR mutation, found in LNCaP prostate cancer cells, which converts hydroxyflutamide (HF, the active flutamide metabolite) into an agonist that stimulates LNCaP cell growth. The HF and CPA-liganded T877A ARs were coactivated by SRC-1, but only the HF-liganded T877A AR was coactivated by β-catenin. L-39, a novel AR antagonist that transcriptionally activates the T877A AR, but still inhibits LNCaP growth, similarly mediated recruitment of SRC-1 and not β-catenin. In contrast, β-catenin coactivated a bicalutamide-responsive mutant AR (W741C) isolated from a bicalutamide-stimulated LNCaP subline, further implicating β-catenin recruitment in AR-stimulated growth. Androgen-stimulated prostate-specific antigen gene expression in LNCaP cells could be modulated by β-catenin, and endogenous c-myc expression was repressed by dihydrotestosterone, but not CPA. These results indicate that interactions between AR and β-catenin contribute to prostate cell growth in vivo, although specific growth promoting genes positively regulated by AR recruitment of β-catenin remain to be identified.

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