scholarly journals AKT-Independent Protection of Prostate Cancer Cells from Apoptosis Mediated through Complex Formation between the Androgen Receptor and FKHR

2003 ◽  
Vol 23 (1) ◽  
pp. 104-118 ◽  
Author(s):  
Pengfei Li ◽  
Heehyoung Lee ◽  
Shaodong Guo ◽  
Terry G. Unterman ◽  
Guido Jenster ◽  
...  

ABSTRACT Recent studies suggested that the protection of cell apoptosis by AKT involves phosphorylation and inhibition of FKHR and related FOXO forkhead transcription factors and that androgens provide an AKT-independent cell survival signal in prostate cancer cells. Here, we report receptor-dependent repression of FKHR function by androgens in prostate cancer cells. Transcriptional analysis demonstrated that activation of the androgen receptor caused an inhibition of both wild-type FKHR and a mutant in which all three known AKT sites were mutated to alanines, showing that the repression is AKT independent. In vivo and in vitro coprecipitation studies demonstrated that the repression is mediated through protein-protein interaction between FKHR and the androgen receptor. Mapping analysis localized the interacting domains to the carboxyl terminus between amino acids 350 and 655 of FKHR and to the amino-terminal A/B region and the ligand binding domain of the receptor. Further analysis demonstrated that the activated androgen receptor blocked FKHR's DNA binding activity and impaired its ability to induce Fas ligand expression and prostate cancer cell apoptosis and cell cycle arrest. These studies identify a new mechanism for androgen-mediated prostate cancer cell survival that appears to be independent of the activity of the receptor on androgen response element-mediated transcription and establish FKHR and related FOXO forkhead proteins as important nuclear targets for both AKT-dependent and -independent survival signals in prostate cancer cells.

Proceedings ◽  
2020 ◽  
Vol 40 (1) ◽  
pp. 42
Author(s):  
Kashani ◽  
Kilbas ◽  
Yerlikaya ◽  
Gurkan ◽  
Arisan

Prostate cancer is the second common cause of death among men worldwide. In the treatment of prostate cancer, conventional chemotherapeutics are commonly used. The plant alkaloid Paclitaxel and platinum-based cisplatin are the most common chemotherapy drugs. The transcription factor p53 has a potential target in the regulation of cell response to DNA damage of prostate cancer. Although the effectiveness of these drugs on prostate cancer cell progression had been proved, the mechanistic action of these drugs on the progression of the disease is not detailed explained. In this study, we aim to examine the function of p53 overexpression in prostate cancer cell survival. Therefore, we treated wild type (wt) and p53 overexpressed PC3 (p53+) prostate cancer cells with cisplatin or paclitaxel. According to the MTT Cell Viability assay, cisplatin (12.5–25–50 µM) was found to be more effective decreasing PC3 and PC3 p53+ cell viability in a dose-dependent manner compared to paclitaxel (12.5–25–50 nM). Colony formation assay showed that treatment of cells with cisplatin or paclitaxel caused the loss of colony forming ability of PC3 and PC3 p53+ cells. In addition, the critical apoptotic markers Caspase-3 and Caspase-9 expressions were altered with cisplatin or paclitaxel treated PC3 wt and p53+ cells.


2021 ◽  
Author(s):  
◽  
Leia A. Jones

The prognosis of localised prostate cancer is generally promising, as many tumours remain dormant and therefore do not require immediate intervention. In contrast, once metastasised, the prognosis for aggressive prostate cancer is often poor, highlighting the need for novel, effective treatment approaches. The expression of the six transmembrane epithelial antigen of the prostate2 (STEAP2) cell surface protein is increased in aggressive prostate cancer compared to normal prostate tissue. In vitro studies have shown STEAP2 to aid in prostate cancer progression, and as such this molecule shows promise as a potential novel therapeutic target in the treatment of advanced disease. The aim of this thesis was to develop a comprehensive understanding of the mechanistic role of STEAP2 in promoting aggressive prostate cancer traits and evaluate if its knock-out has the capacity to reduce the invasive potential of prostate cancer cells in vitro. As prostate cancer is a largely androgen dependent disease, this thesis also aimed to evaluate the effects of STEAP2 inhibition on the expression of the androgen receptor and androgen-regulated genes. This study developed and optimised a protocol for generating a set of 3D prostate cancer spheroids to provide more representative models of the in vivo prostate cancer environment. In this thesis, one commercial anti-STEAP2 polyclonal antibody and a panel of anti-STEAP2 monoclonal antibodies were selected for proof-of-concept studies where their effects on reducing prostate cancer cell viability were assessed. Receptor internalisation of STEAP2 was evaluated upon anti-STEAP2 monoclonal antibody binding to determine its suitability for use with antibody-drug conjugate technology. STEAP2 expression was knocked out using CRISPR/Cas9 genome engineering technology in two prostate cancer cell lines to evaluate its impact on cell proliferation, migration and invasion. Furthermore, gene expression profiling was conducted to explore interactions between STEAP2, the androgen receptor and a panel of androgen-regulated genes (PSA, FKBP5, GPRC6A and TMPRSS2) following: 1) anti-STEAP2 antibody treatment, 2) STEAP2-knockout and 3) the growth of prostate cancer cells in androgen-depleted conditions. The data presented in this thesis demonstrate that inhibition of STEAP2 by both the polyclonal anti-STEAP2 antibody and lead anti-STEAP2 monoclonal antibody significantly reduced prostate cancer cell viability. STEAP2 receptor internalisation was triggered following treatment of prostate cancer cells with the anti-STEAP2 monoclonal antibody, demonstrating its potential utility with antibody-drug conjugate technology in the future. STEAP2 knockout prostate cancer cells exhibited decreased cell proliferation, migration and invasion in comparison to wild-type cells. These promising findings highlight the therapeutic value of STEAP2-knockout in inhibiting invasive tumour cell traits. Gene expression data from both STEAP2-knockout cells and androgen-depleted cells suggest that STEAP2 may be involved in crosstalk between the androgen receptor and androgen-regulated genes. STEAP2 could therefore provide a novel target in conjunction with current conventional androgen deprivation therapy. In conclusion, the in vitro findings presented herein suggest STEAP2 as a viable target for the development of more tailored and personalised therapeutic agents to improve the clinical management of men with aggressive prostate cancer.


2019 ◽  
Vol 8 (3) ◽  
pp. 354 ◽  
Author(s):  
Kouji Izumi ◽  
Atsushi Mizokami

Androgen/androgen receptor (AR) signaling is a significant driver of prostate cancer progression, therefore androgen-deprivation therapy (ADT) is often used as a standard form of treatment for advanced and metastatic prostate cancer patients. However, after several years of ADT, prostate cancer progresses to castration-resistant prostate cancer (CRPC). Androgen/AR signaling is still considered an important factor for prostate cancer cell survival following CRPC progression, while recent studies have reported dichotomic roles for androgen/AR signaling. Androgen/AR signaling increases prostate cancer cell proliferation, while simultaneously inhibiting migration. As a result, ADT can induce prostate cancer metastasis. Several C-C motif ligand (CCL)-receptor (CCR) axes are involved in cancer cell migration related to blockade of androgen/AR signaling. The CCL2-CCR2 axis is negatively regulated by androgen/AR signaling, with the CCL22-CCR4 axis acting as a further downstream mediator, both of which promote prostate cancer cell migration. Furthermore, the CCL5-CCR5 axis inhibits androgen/AR signaling as an upstream mediator. CCL4 is involved in prostate carcinogenesis through macrophage AR signaling, while the CCL21-CCR7 axis in prostate cancer cells is activated by tumor necrotic factor, which is secreted when androgen/AR signaling is inhibited. Finally, the CCL2-CCR2 axis has recently been demonstrated to be a key contributor to cabazitaxel resistance in CRPC.


2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Abrar Samiea ◽  
Jeff S. J. Yoon ◽  
Christopher J. Ong ◽  
Amina Zoubeidi ◽  
Thomas C. Chamberlain ◽  
...  

Interleukin-10 (IL10) is best studied for its inhibitory action on immune cells and ability to suppress an antitumour immune response. But IL10 also exerts direct effects on nonimmune cells such as prostate cancer epithelial cells. Elevated serum levels of IL10 observed in prostate and other cancer patients are associated with poor prognosis. After first-line androgen-deprivation therapy, prostate cancer patients are treated with androgen receptor antagonists such as enzalutamide to inhibit androgen-dependent prostate cancer cell growth. However, development of resistance inevitably occurs and this is associated with tumour differentiation to more aggressive forms such as a neuroendocrine phenotype characterized by expression of neuron specific enolase and synaptophysin. We found that treatment of prostate cancer cell lines in vitro with IL10 or enzalutamide induced markers of neuroendocrine differentiation and inhibited androgen receptor reporter activity. Both also upregulated the levels of PDL1, which could promote tumour survival in vivo through its interaction with the immune cell inhibitory receptor PD1 to suppress antitumour immunity. These findings suggest that IL10’s direct action on prostate cancer cells could contribute to prostate cancer progression independent of IL10’s suppression of host immune cells.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marzia Di Donato ◽  
Carmine Ostacolo ◽  
Pia Giovannelli ◽  
Veronica Di Sarno ◽  
Isabel M. Gomez Monterrey ◽  
...  

AbstractTransient receptor potential melastatin-8 (TRPM8) represents an emerging target in prostate cancer, although its mechanism of action remains unclear. Here, we have characterized and investigated the effects of TRPM8 modulators in prostate cancer aggressiveness disclosing the molecular mechanism underlying their biological activity. Patch-clamp and calcium fluorometric assays were used to characterize the synthesized compounds. Androgen-stimulated prostate cancer-derived cells were challenged with the compounds and the DNA synthesis was investigated in a preliminary screening. The most effective compounds were then employed to inhibit the pro-metastatic behavior of in various PC-derived cells, at different degree of malignancy. The effect of the compounds was then assayed in prostate cancer cell-derived 3D model and the molecular targets of selected compounds were lastly identified using transcriptional and non-transcriptional reporter assays. TRPM8 antagonists inhibit the androgen-dependent prostate cancer cell proliferation, migration and invasiveness. They are highly effective in reverting the androgen-induced increase in prostate cancer cell spheroid size. The compounds also revert the proliferation of castrate-resistant prostate cancer cells, provided they express the androgen receptor. In contrast, no effects were recorded in prostate cancer cells devoid of the receptor. Selected antagonists interfere in non-genomic androgen action and abolish the androgen-induced androgen receptor/TRPM8 complex assembly as well as the increase in intracellular calcium levels in prostate cancer cells. Our results shed light in the processes controlling prostate cancer progression and make the transient receptor potential melastatin-8 as a ‘druggable’ target in the androgen receptor-expressing prostate cancers.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sukhneeraj P. Kaur ◽  
Arti Verma ◽  
Hee. K. Lee ◽  
Lillie M. Barnett ◽  
Payaningal R. Somanath ◽  
...  

AbstractCancer-associated fibroblasts (CAFs) are the most abundant stromal cell type in the tumor microenvironment. CAFs orchestrate tumor-stromal interactions, and contribute to cancer cell growth, metastasis, extracellular matrix (ECM) remodeling, angiogenesis, immunomodulation, and chemoresistance. However, CAFs have not been successfully targeted for the treatment of cancer. The current study elucidates the significance of glypican-1 (GPC-1), a heparan sulfate proteoglycan, in regulating the activation of human bone marrow-derived stromal cells (BSCs) of fibroblast lineage (HS-5). GPC-1 inhibition changed HS-5 cellular and nuclear morphology, and increased cell migration and contractility. GPC-1 inhibition also increased pro-inflammatory signaling and CAF marker expression. GPC-1 induced an activated fibroblast phenotype when HS-5 cells were exposed to prostate cancer cell conditioned media (CCM). Further, treatment of human bone-derived prostate cancer cells (PC-3) with CCM from HS-5 cells exhibiting GPC-1 loss increased prostate cancer cell aggressiveness. Finally, GPC-1 was expressed in mouse tibia bone cells and present during bone loss induced by mouse prostate cancer cells in a murine prostate cancer bone model. These data demonstrate that GPC-1 partially regulates the intrinsic and extrinsic phenotype of human BSCs and transformation into activated fibroblasts, identify novel functions of GPC-1, and suggest that GPC-1 expression in BSCs exerts inhibitory paracrine effects on the prostate cancer cells. This supports the hypothesis that GPC-1 may be a novel pharmacological target for developing anti-CAF therapeutics to control cancer.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kristen A. Marcellus ◽  
Tara E. Crawford Parks ◽  
Shekoufeh Almasi ◽  
Bernard J. Jasmin

Abstract Background Prostate cancer is one of the most common malignant cancers with the second highest global rate of mortality in men. During the early stages of disease progression, tumour growth is local and androgen-dependent. Despite treatment, a large percentage of patients develop androgen-independent prostate cancer, which often results in metastases, a leading cause of mortality in these patients. Our previous work on the RNA-binding protein Staufen1 demonstrated its novel role in cancer biology, and in particular rhabdomyosarcoma tumorigenesis. To build upon this work, we have focused on the role of Staufen1 in other forms of cancer and describe here the novel and differential roles of Staufen1 in prostate cancer. Methods Using a cell-based approach, three independent prostate cancer cell lines with different characteristics were used to evaluate the expression of Staufen1 in human prostate cancer relative to control prostate cells. The functional impact of Staufen1 on several key oncogenic features of prostate cancer cells including proliferation, apoptosis, migration and invasion were systematically investigated. Results We show that Staufen1 levels are increased in all human prostate cancer cells examined in comparison to normal prostate epithelial cells. Furthermore, Staufen1 differentially regulates growth, migration, and invasion in the various prostate cancer cells assessed. In LNCaP prostate cancer cells, Staufen1 regulates cell proliferation through mTOR activation. Conversely, Staufen1 regulates migration and invasion of the highly invasive, bone metastatic-derived, PC3 prostate cells via the activation of focal adhesion kinase. Conclusions Collectively, these results show that Staufen1 has a direct impact in prostate cancer development and further demonstrate that its functions vary amongst the prostate cancer cell types. Accordingly, Staufen1 represents a novel target for the development of much-needed therapeutic strategies for prostate cancer.


2011 ◽  
Vol 108 (3) ◽  
pp. 424-430 ◽  
Author(s):  
Mu Yao ◽  
Chanlu Xie ◽  
Maryrose Constantine ◽  
Sheng Hua ◽  
Brett D. Hambly ◽  
...  

We have developed a blend of food extracts commonly consumed in the Mediterranean and East Asia, named blueberry punch (BBP), with the ultimate aim to formulate a chemoprevention strategy to inhibit prostate cancer progression in men on active surveillance protocol. We demonstrated previously that BBP inhibited prostate cancer cell proliferation in vitro and in vivo. The purpose of this study was to determine the molecular mechanism responsible for the suppression of prostate cancer cell proliferation by BBP. Treatment of lymph node-metastasised prostate cancer cells (LNCaP) and bone-metastasised prostate cancer cells (PC-3 and MDA-PCa-2b) with BBP (up to 0·8 %) for 72 h increased the percentage of cells at the G0/G1 phase and decreased those at the S and G2/M phases. The finding was supported by the reduction in the percentage of Ki-67-positive cells and of DNA synthesis measured by the incorporation of 5-ethynyl-2′-deoxyuridine. Concomitantly, BBP treatment decreased the protein levels of phosphorylated retinoblastoma, cyclin D1 and E, cyclin-dependent kinase (CDK) 4 and 2, and pre-replication complex (CDC6 and MCM7) in LNCaP and PC-3 cells, whereas CDK inhibitor p27 was elevated in these cell lines. In conclusion, BBP exerts its anti-proliferative effect on prostate cancer cells by modulating the expression and phosphorylation of multiple regulatory proteins essential for cell proliferation.


Author(s):  
Qiang Fu ◽  
Zhenye Sun ◽  
Fan Yang ◽  
Tianci Mao ◽  
Yanyao Gao ◽  
...  

Abstract Background Sex-determining region Y-box containing gene 30 (SOX30) is a newly identified tumor-associated gene in several types of cancer. However, whether SOX30 is involved in the development and progression of prostate cancer remains unknown. This study investigated the potential role of SOX30 in prostate cancer. Methods Prostate cancer cell lines and a normal prostate epithelial cell line were used for the experiments. The expression of SOX30 was determined using quantitative real-time PCR and western blot analysis. The malignant cellular behaviors of prostate cancer were assessed using the Cell Counting Kit-8, colony formation and Matrigel invasion assays. The miRNA–mRNA interaction was validated using the dual-luciferase reporter assay. Results SOX30 expression was lower in cells of prostate cancer lines than in cells of the normal prostate epithelial line. Its overexpression repressed the proliferation and invasion of prostate cancer cells. SOX30 was identified as a target gene of microRNA-653-5p (miR-653-5p), which is upregulated in prostate cancer tissues. MiR-653-5p overexpression decreased SOX30 expression, while its inhibition increased SOX30 expression in prostate cancer cells. MiR-653-5p inhibition also markedly restricted prostate cancer cell proliferation and invasion. SOX30 overexpression or miR-653-5p inhibition significantly reduced β-catenin expression and downregulated the activation of Wnt/β-catenin signaling. SOX30 knockdown significantly reversed the miR-653-5p inhibition-mediated inhibitory effect on the proliferation, invasion and Wnt/β-catenin signaling in prostate cancer cells. Conclusions These results reveal a tumor suppressive function for SOX30 in prostate cancer and confirmed the gene as a target of miR-653-5p. SOX30 upregulation due to miR-653-5p inhibition restricted the proliferation and invasion of prostate cancer cells, and this was associated with Wnt/β-catenin signaling suppression. These findings highlight the importance of the miR-653-5p–SOX30–Wnt/β-catenin signaling axis in prostate cancer progression.


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