scholarly journals TLK1-MK5 axis drives prostate cancer cell motility and pathologic features of aggressiveness

Author(s):  
Md Imtiaz Khalil ◽  
Vibha Singh ◽  
Judy King ◽  
Arrigo De Benedetti

Abstract Background: Majority of prostate cancer (PCa) related fatalities occur due to metastasis of cancer cells to adjacent and distal organs. We identified the novel interaction between two kinases (TLK1-MK5) that in part may initiate a signaling cascade promoting PCa metastasis. In PCa, TLK1-MK5 signaling might be crucial as androgen deprivation therapy leads to increased expression of TLK1 and compensatory activation of MK5 in metastatic castration-resistant prostate cancer patients. Methods: We performed scratch wound repair and 3D chemotactic migration assays to determine the motility rates of different TLK1 and MK5 perturbed cells. Co-IP, His, and GST pull down, in vitro kinase (IVK) assays and mass spectrometry (MS) were conducted to determine TLK1-MK5 interaction and phosphorylation. Western blotting (WB), immunohistochemistry (IHC) and bioinformatic analysis were used to examine TLK1 and pMK5 levels in PCa cell lines, mice prostate tumors and PCa tissue microarray (TMA). Results: Both genetic depletion and pharmacologic inhibition of TLK1 and MK5 can significantly reduce wound healing rate in MEF and LNCaP cells. However, TLK1 overexpression alone in the MK5 −/− MEF cells did not increase the wound healing which suggested that TLK1 cannot enhance cellular migration in absence of MK5. Our reciprocal co-IPs, His- and GST pull down assays confirmed TLK1-MK5 interaction in cultured cells. Incubation of purified recombinant TLK1B and MK5 increases the phosphorylation of MK5 and its kinase activity. MS analysis identified three unique phosphorylation sites in MK5 (S160, S354, S386) by TLK1B. While our WB detected substantial amount of pMK5 S354 and TLK1 in all major PCa cell lines, anti-androgen treatment increased pMK5 S354 level in a dose-dependent manner and pharmacologic inhibition of TLK1 reduces pMK5 S354 level in LNCaP cells. IHC staining of TRAMP mice prostate tissues also exhibited increased pMK5 S354 level in aggressive tumor compared to benign regions. Finally, IHC analysis of PCa TMA indicated a correlation between elevated pMK5 S354 level and generally higher Gleason scores as well as nodal metastatic status of the tumors. Conclusion: Our data support that TLK1-MK5 signaling is functionally involved in driving PCa cell motility and clinical aggressiveness, hence, disruption of this axis may inhibit the metastasis of PCa.

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2168 ◽  
Author(s):  
Reem T. Attia ◽  
Mai F. Tolba ◽  
Ruchit Trivedi ◽  
Mariane G. Tadros ◽  
Hossam M.M. Arafa ◽  
...  

Background. Glufosfamide (GLU) is a glucose conjugate of ifosfamide in which isophosphoramide mustard is glycosidically linked to theβ-D-glucose molecule. Based on GLU structure, it is considered a targeted chemotherapy with fewer side effects. The main objective of the current study is to assess the cytotoxic potential of GLU for the first time in prostate cancer (PC) cells representing different stages of the tumor. Furthermore, this study examined the potential synergistic activity of GLU in combination with docetaxel (DOC).Methods. Two different cell lines were used, LNCaP and PC-3. Concentration-response curves were assessed. The tested groups per cell line were, control, GLU, DOC and combination. Treatment duration was 72 h. Cytotoxicity was assessed using sulforhodamine B (SRB) assay and half maximal inhibitory concentration (IC50) was calculated. Synergy analyses were performed using Calcusyn®software. Subsequent mechanistic studies includedβ-glucosidase activity assay, glucose uptake and apoptosis studies, namely annexin V-FITC assay and the protein expression of mitochondrial pathway signals including Bcl-2, Bax, Caspase 9 and 3 were assessed. Data are presented as mean ± SD; comparisons were carried out using one way analysis of variance (ANOVA) followed by Tukey-Kramer’s test for post hoc analysis.Results. GLU induced cytotoxicity in both cell lines in a concentration-dependent manner. The IC50 in PC-3 cells was significantly lower by 19% when compared to that of LNCaP cells. The IC50 of combining both drugs showed comparable effect to DOC in PC-3 but was tremendously lowered by 49% compared to the same group in LNCaP cell line.β-glucosidase activity was higher in LNCaP by about 67% compared to that determined in PC-3 cells while the glucose uptake in PC-3 cells was almost 2 folds that found in LNCaP cells. These results were directly correlated to the efficacy of GLU in each cell line. Treatment of PC cells with GLU as single agent or in combination with DOC induced significantly higher apoptosis as evidenced by Annexin V-staining. Apoptosis was significantly increased in combination group by 4.9 folds and by 2.1 Folds when compared to control in LNCaP cells and PC-3 cells; respectively. Similarly, the expression of Bcl-2 was significantly decreased while Bax, caspase 9 and 3 were significantly increased in the combined treatment groups compared to the control.Conclusion. GLU has a synergistic effect in combination with DOC as it increases the cell kill which can be attributed at least partially to apoptosis in both the tested cell lines and it is suggested as a new combination regimen to be considered in the treatment of the prostate cancer. Further experiments and clinical investigations are needed for assessment of that regimen.


1992 ◽  
Vol 68 (06) ◽  
pp. 662-666 ◽  
Author(s):  
W Hollas ◽  
N Hoosein ◽  
L W K Chung ◽  
A Mazar ◽  
J Henkin ◽  
...  

SummaryWe previously reported that extracellular matrix invasion by the prostate cancer cell lines, PC-3 and DU-145 was contingent on endogenous urokinase being bound to a specific cell surface receptor. The present study was undertaken to characterize the expression of both urokinase and its receptor in the non-invasive LNCaP and the invasive PC-3 and DU-145 prostate cells. Northern blotting indicated that the invasive PC-3 cells, which secreted 10 times more urokinase (680 ng/ml per 106 cells per 48 h) than DU-145 cells (63 ng/ml per 106 cells per 48 h), had the most abundant transcript for the plasminogen activator. This, at least, partly reflected a 3 fold amplification of the urokinase gene in the PC-3 cells. In contrast, urokinase-specific transcript could not be detected in the non-invasive LNCaP cells previously characterized as being negative for urokinase protein. Southern blotting indicated that this was not a consequence of deletion of the urokinase gene. Crosslinking of radiolabelled aminoterminal fragment of urokinase to the cell surface indicated the presence of a 51 kDa receptor in extracts of the invasive PC-3 and DU-145 cells but not in extracts of the non-invasive LNCaP cells. The amount of binding protein correlated well with binding capacities calculated by Scatchard analysis. In contrast, the steady state level of urokinase receptor transcript was a poor predictor of receptor display. PC-3 cells, which were equipped with 25,000 receptors per cell had 2.5 fold more steady state transcript than DU-145 cells which displayed 93,000 binding sites per cell.


Cancers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 409
Author(s):  
Alicja Chrzanowska ◽  
Wioletta Olejarz ◽  
Grażyna Kubiak-Tomaszewska ◽  
Andrzej K. Ciechanowicz ◽  
Marta Struga

Purpose: To assess cytotoxic effect of ciprofloxacin conjugates with fatty acids on prostate cancer cells (LNCaP and DU-145) with different hormone sensitivity, based on previous promising results from the PC3 cells. Methods: Cytotoxicity were estimated using MTT and LDH tests, whereas its mechanisms were estimated by apoptosis and IL-6 assays. The intensity of proteins involved in lipid metabolism was determined using ML-CS assay. Results: The hormone insensitive DU-145 cells were more vulnerable than the hormone sensitive LNCaP cells. The IC50 values for oleic (4), elaidic (5) and docosahexaenoic acid (8) conjugates were 20.2 µM, 17.8 µM and 16.5 µM, respectively, in DU-145 cells, whereas in LNCaP cells IC50 exceeded 20 µM. The strong conjugate cytotoxicity was confirmed in the LDH test, the highest (70.8%) for compound (5) and 64.2% for compound (8) in DU-145 cells. This effect was weaker for LNCaP cells (around 60%). The cytotoxic effect of unconjugated ciprofloxacin and fatty acids was weaker. The early apoptosis was predominant in LNCaP while in DU-145 cells both early and late apoptosis was induced. The tested conjugates decreased IL-6 release in both cancer cell lines by almost 50%. Proteomic analysis indicated influence of the ciprofloxacin conjugates on lipid metabolic proteins in prostatic cancer. Conclusion: Our findings suggested the cytotoxic potential of ciprofloxacin conjugates with reduction in proteins involved in prostate cancer progress.


2015 ◽  
Vol 23 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Jan Kroon ◽  
Martin Puhr ◽  
Jeroen T Buijs ◽  
Geertje van der Horst ◽  
Daniëlle M Hemmer ◽  
...  

Resistance to docetaxel is a major clinical problem in advanced prostate cancer (PCa). Although glucocorticoids (GCs) are frequently used in combination with docetaxel, it is unclear to what extent GCs and their receptor, the glucocorticoid receptor (GR), contribute to the chemotherapy resistance. In this study, we aim to elucidate the role of the GR in docetaxel-resistant PCa in order to improve the current PCa therapies. GR expression was analyzed in a tissue microarray of primary PCa specimens from chemonaive and docetaxel-treated patients, and in cultured PCa cell lines with an acquired docetaxel resistance (PC3-DR, DU145-DR, and 22Rv1-DR). We found a robust overexpression of the GR in primary PCa from docetaxel-treated patients and enhanced GR levels in cultured docetaxel-resistant human PCa cells, indicating a key role of the GR in docetaxel resistance. The capability of the GR antagonists (RU-486 and cyproterone acetate) to revert docetaxel resistance was investigated and revealed significant resensitization of docetaxel-resistant PCa cells for docetaxel treatment in a dose- and time-dependent manner, in which a complete restoration of docetaxel sensitivity was achieved in both androgen receptor (AR)-negative and AR-positive cell lines. Mechanistically, we demonstrated down-regulation of Bcl-xL and Bcl-2 upon GR antagonism, thereby defining potential treatment targets. In conclusion, we describe the involvement of the GR in the acquisition of docetaxel resistance in human PCa. Therapeutic targeting of the GR effectively resensitizes docetaxel-resistant PCa cells. These findings warrant further investigation of the clinical utility of the GR antagonists in the management of patients with advanced and docetaxel-resistant PCa.


2017 ◽  
Vol 24 (1) ◽  
pp. 17-30 ◽  
Author(s):  
K M Biernacka ◽  
R A Persad ◽  
A Bahl ◽  
D Gillatt ◽  
J M P Holly ◽  
...  

The incidence of many common cancers varies between different populations and appears to be affected by a Western lifestyle. Highly proliferative malignant cells require sufficient levels of nutrients for their anabolic activity. Therefore, targeting genes and pathways involved in metabolic pathways could yield future therapeutics. A common pathway implicated in energetic and nutritional requirements of a cell is the LKB1/AMPK pathway. Metformin is a widely studied anti-diabetic drug, which improves glycaemia in patients with type 2 diabetes by targeting this pathway. We investigated the effect of metformin on prostate cancer cell lines and evaluated its mechanism of action using DU145, LNCaP, PC3 and VCaP prostate cancer cell lines. Trypan blue dye-exclusion assay was used to assess levels of cell death. Western immunoblotting was used to determine the abundance of proteins. Insulin-like growth factor-binding protein-2 (IGFBP-2) and AMPK genes were silenced using siRNA. Effects on cell morphology were visualised using microscopy. IGFBP-2 gene expression was assessed using real-time RT-PCR. With DU145 and LNCaP cells metformin alone induced cell death, but this was reduced in hyperglycaemic conditions. Hyperglycaemia also reduced the sensitivity to Docetaxel, but this was countered by co-treatment with metformin. LKB1 was required for the activation of AMPK but was not essential to mediate the induction of cell death. An alternative pathway by which metformin exerted its action was through downregulation of IGFBP-2 in DU145 and LNCaP cells, independently of AMPK. This finding could have important implications in relation to therapeutic strategies in prostate cancer patients presenting with diabetes.


2020 ◽  
Vol 7 ◽  
Author(s):  
Priscila E. Kobayashi ◽  
Patrícia F. Lainetti ◽  
Antonio F. Leis-Filho ◽  
Flávia K. Delella ◽  
Marcio Carvalho ◽  
...  

Canine prostate cancer (PC) presents a poor antitumor response, usually late diagnosis and prognosis. Toceranib phosphate (TP) is a nonspecific inhibitor of receptor tyrosine kinases (RTKs), including vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and c-KIT. This study aimed to evaluate VEGFR2, PDGFR-β, and c-KIT protein expression in two established canine PC cell lines (PC1 and PC2) and the transcriptome profile of the cells after treatment with TP. Immunofluorescence (IF) analysis revealed VEGFR2 and PDGFR-β protein expression and the absence of c-KIT protein expression in both cell lines. After TP treatment, only the viability of PC1 cells decreased in a dose-dependent manner. Transcriptome and enrichment analyses of treated PC1 cells revealed 181 upregulated genes, which were related to decreased angiogenesis and cell proliferation. In addition, we found upregulated PDGFR-A, PDGFR-β, and PDGF-D expression in PC1 cells, and the upregulation of PDGFR-β was also observed in treated PC1 cells by qPCR. PC2 cells had fewer protein-protein interactions (PPIs), with 18 upregulated and 22 downregulated genes; the upregulated genes were involved in the regulation of parallel pathways and mechanisms related to proliferation, which could be associated with the resistance observed after treatment. The canine PC1 cell line but not the PC2 cell line showed decreased viability after treatment with TP, although both cell lines expressed PDGFR and VEGFR receptors. Further studies could explain the mechanism of resistance in PC2 cells and provide a basis for personalized treatment for dogs with PC.


2021 ◽  
Vol 14 (7) ◽  
pp. 670
Author(s):  
Mariana Brütt Pacheco ◽  
Vânia Camilo ◽  
Nair Lopes ◽  
Filipa Moreira-Silva ◽  
Margareta P. Correia ◽  
...  

Among the well-established alterations contributing to prostate cancer (PCa) pathogenesis, epigenetics is an important player in its development and aggressive disease state. Moreover, since no curative therapies are available for advanced stage disease, there is an urgent need for novel therapeutic strategies targeting this subset of patients. Thus, we aimed to evaluate the combined antineoplastic effects of DNA methylation inhibitor hydralazine and histone deacetylase inhibitors panobinostat and valproic acid in several prostate cell lines. The effect of these drugs was assessed in four PCa (LNCaP, 22Rv1, DU145 and PC-3) cell lines, as well as in non-malignant epithelial (RWPE-1) and stromal (WPMY-1) cell lines, using several assays to evaluate cell viability, apoptosis, proliferation, DNA damage and clonogenic potential. We found that exposure to each epidrug separately reduced viability of all PCa cells in a dose-dependent manner and that combined treatments led to synergic growth inhibitory effects, impacting also on colony formation, invasion, apoptotic and proliferation rates. Interestingly, antitumoral effects of combined treatment were particularly expressive in DU145 cells. We concluded that hydralazine and panobinostat attenuate malignant properties of PCa cells, constituting a potential therapeutic tool to counteract PCa progression.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A1010-A1011
Author(s):  
Zhiguang Xiao ◽  
Stephen R Hammes

Abstract Neutrophil elastase (NE) is a serine protease stored in neutrophil azurophilic granules. Growing evidence indicates that NE is intimately involved in the activities of proinflammatory cytokines / chemokines, growth factors, and cell surface receptors. These molecular regulations can modulate innate immune responses as well as directly promote cancer cell outgrowth. To date, however, little is known regarding the molecular mechanisms underlying the stimulatory properties of NE in cancer cells. Here we examine NE effects on prostate cells, demonstrating that NE triggers proliferative signals and cell migration in six prostate cell lines representing the spectrum of prostate cell malignancy, including normal prostatic epithelium, benign prostatic hypertrophy, and metastatic prostate cancer. Using ERK activation as a read-out, we show that NE promotes ERK phosphorylation in a dose dependent manner, and time course study further reveal a sustained ERK activation upon NE treatment. Western blot evaluation demonstrates strong EGFR expression in cell lines derived from normal and benign prostatic gland, and preferential expression in hormone resistant versus hormone responsive cells. In agreement with EGFR-dependent mitogenic signaling, activation of ERK is abrogated by siRNA-mediated EGFR knockdown, as well as by pretreatment of cells with irreversible EGFR inhibitor AG1478. Importantly, NE evokes cancer cell migration at a lower range of NE concentrations relative to nonneoplastic cells. In prostate cells, from a total of seven EGFR ligands, amphiregulin (AREG) is predominantly expressed, and the addition of NE results in the release of AREG. Moreover, AREG gene silencing by siRNA or inhibition of AREG biological activity by neutralizing antibody, prevents NE-induced ERK phosphorylation and cell migration. Together, our study reveals a distinct and essential role of AREG-EGFR signaling axis in NE-triggered prostatic cellular response.


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