miRNA as regulators of prostate carcinogenesis and endocrine and chemoresistance

2021 ◽  
Vol 20 ◽  
Author(s):  
Zoran Culig
Keyword(s):  
Prostate Cancer ◽  
Cancer Progression ◽  
Epithelial To Mesenchymal Transition ◽  
Growth Factor Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Therapeutic Effects ◽  
Androgen Independence ◽  
Mesenchymal Transition ◽  
Androgen Synthesis ◽  
Mitogen Activated Protein

: More therapy options are available for advanced prostate cancer, including novel inhibitors of androgen synthesis, anti-androgens, chemotherapeutics and targeted therapies. Although patients´ survival has been improved, management of castration therapy-resistant prostate cancer remains a challenge. Regulation of cellular events in cancer by small non-coding miRNAs is therefore an area of special interest. Overexpression of selected miRNA may lead to androgen independence and prostate cancer progression. miRNA may be considered also a biomarker in patients with prostate cancer. In contrast, diminished expression of tumor-suppressive miRNA in prostate cancer leads to enhanced proliferation, reduced apoptosis, increased migration, invasion and epithelial-to-mesenchymal transition. miRNA may be directly involved in regulation of chemosensitivity in prostate cancer. Experimental overexpression of selected miRNA in chemoresistant prostate cancer leads to inhibition of cellular stemness and epithelial-to-mesenchymal transition. Reduction of tumorsuppressive miRNA may also lead to hyperactivity of signaling pathways such as that of the epidermal growth factor receptor and mitogen-activated protein kinase. Although a considerable progress on miRNA research in prostate cancer has been achieved, therapeutic effects could be improved on the basis of development of novel delivery methods.

scholarly journals The TGFβ-induced phosphorylation and activation of p38 mitogen-activated protein kinase is mediated by MAP3K4 and MAP3K10 but not TAK1

Open Biology ◽  
2013 ◽  
Vol 3 (6) ◽  
pp. 130067 ◽  
Author(s):  
Gopal P. Sapkota
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Transforming Growth Factor Beta ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Transforming Growth Factor ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Phosphorylation ◽  
Mesenchymal Transition ◽  
Mitogen Activated Protein

The signalling pathways downstream of the transforming growth factor beta (TGFβ) family of cytokines play critical roles in all aspects of cellular homeostasis. The phosphorylation and activation of p38 mitogen-activated protein kinase (MAPK) has been implicated in TGFβ-induced epithelial-to-mesenchymal transition and apoptosis. The precise molecular mechanisms by which TGFβ cytokines induce the phosphorylation and activation of p38 MAPK are unclear. In this study, I demonstrate that TGFβ-activated kinase 1 (TAK1/MAP3K7) does not play a role in the TGFβ-induced phosphorylation and activation of p38 MAPK in MEFs and HaCaT keratinocytes. Instead, RNAi -mediated depletion of MAP3K4 and MAP3K10 results in the inhibition of the TGFβ-induced p38 MAPK phosphorylation. Furthermore, the depletion of MAP3K10 from cells homozygously knocked-in with a catalytically inactive mutant of MAP3K4 completely abolishes the TGFβ-induced phosphorylation of p38 MAPK, implying that among MAP3Ks, MAP3K4 and MAP3K10 are sufficient for mediating the TGFβ-induced activation of p38 MAPK.

scholarly journals Transforming Growth Factor β/NR4A1-Inducible Breast Cancer Cell Migration and Epithelial-to-Mesenchymal Transition Is p38α (Mitogen-Activated Protein Kinase 14) Dependent

2017 ◽  
Vol 37 (18) ◽  
Author(s):  
Erik Hedrick ◽  
Stephen Safe
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Growth Factor ◽  
Nuclear Export ◽  
Epithelial To Mesenchymal Transition ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Mitogen Activated Protein Kinase ◽  
Mesenchymal Transition ◽  
Mitogen Activated Protein

ABSTRACT Transforming growth factor β (TGF-β)-induced migration of triple-negative breast cancer (TNBC) cells is dependent on nuclear export of the orphan receptor NR4A1, which plays a role in proteasome-dependent degradation of SMAD7. In this study, we show that TGF-β induces p38α (mitogen-activated protein kinase 14 [MAPK14]), which in turn phosphorylates NR4A1, resulting in nuclear export of the receptor. TGF-β/p38α and NR4A1 also play essential roles in the induction of epithelial-to-mesenchymal transition (EMT) and induction of β-catenin in TNBC cells, and these TGF-β-induced responses and nuclear export of NR4A1 are blocked by NR4A1 antagonists, the p38 inhibitor SB202190, and kinase-dead [p38(KD)] and dominant-negative [p38(DN)] forms of p38α. Inhibition of NR4A1 nuclear export results in nuclear export of TGF-β-induced β-catenin, which then undergoes proteasome-dependent degradation. TGF-β-induced β-catenin also regulates NR4A1 expression through formation of the β-catenin–TCF-3/TCF-4/LEF-1 complex on the NR4A1 promoter. Thus, TGF-β-induced nuclear export of NR4A1 in TNBC cells plays an essential role in cell migration, SMAD7 degradation, EMT, and induction of β-catenin, and all of these pathways are inhibited by bis-indole-derived NR4A1 antagonists that inhibit nuclear export of the receptor and thereby block TGF-β-induced migration and EMT.

scholarly journals Skp2 and Slug Are Coexpressed in Aggressive Prostate Cancer and Inhibited by Neddylation Blockade

2021 ◽  
Vol 22 (6) ◽  
pp. 2844
Author(s):  
Alena Mickova ◽  
Gvantsa Kharaishvili ◽  
Daniela Kurfurstova ◽  
Mariam Gachechiladze ◽  
Milan Kral ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Progression ◽  
Epithelial To Mesenchymal Transition ◽  
Treatment Strategies ◽  
Therapy Resistance ◽  
Mesenchymal Transition ◽  
Slug Expression ◽  
Chemical Inhibition ◽  
Novel Treatment Strategies ◽  
E Cadherin

Prostate cancer (PCa) is the second leading cause of cancer-related deaths in men in Western countries, and there is still an urgent need for a better understanding of PCa progression to inspire new treatment strategies. Skp2 is a substrate-recruiting component of the E3 ubiquitin ligase complex, whose activity is regulated through neddylation. Slug is a transcriptional repressor involved in the epithelial-to-mesenchymal transition, which may contribute to therapy resistance. Although Skp2 has previously been associated with a mesenchymal phenotype and prostate cancer progression, the relationship with Slug deserves further elucidation. We have previously shown that a high Gleason score (≥8) is associated with higher Skp2 and lower E-cadherin expression. In this study, significantly increased expression of Skp2, AR, and Slug, along with E-cadherin downregulation, was observed in primary prostate cancer in patients who already had lymph node metastases. Skp2 was slightly correlated with Slug and AR in the whole cohort (Rs 0.32 and 0.37, respectively), which was enhanced for both proteins in patients with high Gleason scores (Rs 0.56 and 0.53, respectively) and, in the case of Slug, also in patients with metastasis to lymph nodes (Rs 0.56). Coexpression of Skp2 and Slug was confirmed in prostate cancer tissues by multiplex immunohistochemistry and confocal microscopy. The same relationship between these two proteins was observed in three sets of prostate epithelial cell lines (PC3, DU145, and E2) and their mesenchymal counterparts. Chemical inhibition of Skp2, but not RNA interference, modestly decreased Slug protein in PC3 and its docetaxel-resistant subline PC3 DR12. Importantly, chemical inhibition of Skp2 by MLN4924 upregulated p27 and decreased Slug expression in PC3, PC3 DR12, and LAPC4 cells. Novel treatment strategies targeting Skp2 and Slug by the neddylation blockade may be promising in advanced prostate cancer, as recently documented for other aggressive solid tumors.

scholarly journals ZBTB46, SPDEF, and ETV6: Novel Potential Biomarkers and Therapeutic Targets in Castration-Resistant Prostate Cancer

2019 ◽  
Vol 20 (11) ◽  
pp. 2802 ◽  
Author(s):  
AbdulFattah Salah Fararjeh ◽  
Yen-Nien Liu
Keyword(s):  
Prostate Cancer ◽  
Epithelial To Mesenchymal Transition ◽  
Kinase Inhibitor ◽  
Therapeutic Targets ◽  
Growth Factor Receptor ◽  
Castration Resistant Prostate Cancer ◽  
Mesenchymal Transition ◽  
Castration Resistant ◽  
Therapeutic Regime ◽  
Potential Biomarkers

Prostate cancer (PCa) is the second most common killer among men in Western countries. Targeting androgen receptor (AR) signaling by androgen deprivation therapy (ADT) is the current therapeutic regime for patients newly diagnosed with metastatic PCa. However, most patients relapse and become resistant to ADT, leading to metastatic castration-resistant PCa (CRPC) and eventually death. Several proposed mechanisms have been proposed for CRPC; however, the exact mechanism through which CRPC develops is still unclear. One possible pathway is that the AR remains active in CRPC cases. Therefore, understanding AR signaling networks as primary PCa changes into metastatic CRPC is key to developing future biomarkers and therapeutic strategies for PCa and CRPC. In the current review, we focused on three novel biomarkers (ZBTB46, SPDEF, and ETV6) that were demonstrated to play critical roles in CRPC progression, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) drug resistance, and the epithelial-to-mesenchymal transition (EMT) for patients treated with ADT or AR inhibition. In addition, we summarize how these potential biomarkers can be used in the clinic for diagnosis and as therapeutic targets of PCa.

scholarly journals Molecular aspects of gefitinib antiproliferative and pro-apoptotic effects in PTEN-positive and PTEN-negative prostate cancer cell lines

2005 ◽  
Vol 12 (4) ◽  
pp. 983-998 ◽  
Author(s):  
C Festuccia ◽  
P Muzi ◽  
D Millimaggi ◽  
L Biordi ◽  
G L Gravina ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Growth Factor ◽  
Growth Inhibition ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Growth Factor Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Growth Modulation ◽  
Mitogen Activated Protein ◽  
Phosphoinositide 3 Kinase

To date, no effective therapeutic treatment allows abrogation of the progression of prostate cancer (PCa) to more invasive forms. One of the major targets for the therapy in PCa can be epidermal growth factor receptor (EGFR), which signals via the phosphoinositide 3′-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) pathways, among others. Despite multiple reports of overexpression in PCa, the reliance on activated EGFR and its downstream signalling to the PI3K and/or MAPK/extracellular signal-regulated kinase (ERK) pathways has not been fully elucidated. We reported that the EGFR-selective tyrosine kinase inhibitor gefitinib (ZD1839; Iressa) is able to induce growth inhibition, G1 arrest and apoptosis in PCa cells and that its effectiveness is associated primarily with phosphatase and tensin homologue deleted from chromosome 10 (PTEN) expression (and thus Akt activity). In fact PTEN-negative PCa cells are slowly sensitive to gefitinib treatment, because this molecule is unable to downregulate PI3K/Akt activity. PI3K inhibition, by LY294002 or after PTEN transfection, restores EGFR-stimulated Akt signalling and sensitizes the cells to pro-apoptotic action of gefitinib. The MAPK pathway seems to be involved primarily on cell-growth modulation because dual blockade of EGFR and ERK1/2 phosphorylation potentiates growth inhibition (both not cell apoptosis) in PTEN-positive PCa cells and reduced EGF-mediated growth in PTEN-negative cells. Thus the effectiveness of gefitinib requires growth factor receptor-stimulated PI3K/Akt and MAPK signalling to be intact and functional. The loss of the PTEN activity leads to uncoupling of this signalling pathway, determining a partial gefitinib resistance. Moreover, gefitinib sensitivity may be maintained in these cells through its inhibitory potential in MAPK/ERK pathway activity, modulating proliferative EGFR-triggered events. Therefore, our data suggest that the inhibition of EGFR signalling can result in a significant growth reduction and in increased apoptosis in EGFR-overexpressing PCa cells with different modalities, which are regulated by PTEN status, and this may have relevance in the clinical setting of PCa.

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