Role of GADD45α as a potential therapeutic target for prostate cancer

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 10566-10566
Author(s):  
R. Singal ◽  
K. Ramachandran ◽  
G. Gopisetty ◽  
L. Navarro ◽  
E. Gordian ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Therapeutic Target ◽  
Recombinant Expression ◽  
Proximal Promoter ◽  
Lncap Cells ◽  
Potential Therapeutic Target ◽  
Du145 Cells ◽  
Docetaxel Chemotherapy

10566 Background: Defects in the apoptotic pathway contribute to uncontrolled cell proliferation of cancer cells and confer resistance to chemotherapeutic drugs. Understanding the mechanisms of deregulation of apoptosis related genes would enable targeted treatment methods to improve the efficacy of chemotherapy. Growth Arrest and DNA Damage inducible, alpha (GADD45a) mediates cytotoxicity of docetaxel chemotherapy. We examined the mechanism of regulation of GADD45a in prostate cancer cells and the effect of its upregulation on sensitivity to docetaxel chemotherapy. Methods: Levels of GADD45a in Du145, LNCaP and PC3 were analyzed by real time reverse transcriptase PCR and western blotting. DNA methylation was studied by bisulfite sequencing. Chromatin immunoprecipitation was used to study interaction of methyl binding proteins to GADD45 5’ sequence. Cytotoxicity after drug treatment was measured by MTT cell proliferation assay. Apoptosis assays were done by Annexin V/propidium iodide staining followed by flow cytometry. Results: Levels of expression of GADD45a in Du145 and LNCaP cells were lower than that in PC3. A 4 CpG region upstream of the proximal promoter region was methylated in Du145 and LNCaP cells. Methylation was reversed by treatment of Du145 and LNCaP cells with DNA methyl transferase (DNMT) inhibitors such as 5- Azacytidine or 5- Aza deoxycytidine leading to reactivation of GADD45a expression in these cells. This region was also frequently methylated in prostate cancer tissues. Methyl binding protein, MeCP2 was associated with the methylated 4 CpGs in Du145 and knock down of MeCP2 by transfection of MeCP2 siRNA vector in Du145 cells (Du145-MeCP2-ve) led to increased expression of GADD45a, without affecting the methylation status of the gene. Enhanced sensitivity to docetaxel was observed by upregulation of GADD45a in Du145 cells by (a) recombinant expression of GADD45a (b) downregulation of MeCP2 and (c) pretreatment with 5-Azacytidine. Conclusions: GADD45a is frequently deregulated in prostate cancer by methylation of 5’ 4 CpG region and is a potential therapeutic target for treatment of prostate cancer. [Table: see text]

scholarly journals The effects of IGF-I on prostate cancer progression and the influence of hyperglycaemia

2019 ◽  
Vol 10 (SPL1) ◽  
Author(s):  
Rehanna Mansor ◽  
Jeff Holly ◽  
Claire Perks
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Blue Dye ◽  
Normal Prostate ◽  
Mesenchymal Transition ◽  
Igf I ◽  
Epithelial Marker ◽  
Du145 Cells ◽  
E Cadherin

Epithelial to mesenchymal transition (EMT) is a necessary process in the conversion of benign tumor to aggressive and highly invasive cancer. Dysregulation of the IGF system and impaired metabolic regulation have been implicated in the progression of prostate cancer. However, the mechanisms underlying these effects require further investigation. We used normal prostate epithelial cells PNT2 and DU145 prostate cancer cells. Western immunoblotting was used to determine changes in protein abundance. Trypan blue dye exclusion assay was employed to assess cell proliferation and transwell migration assays to assess cells migration. Under normal glucose conditions, IGF-I inhibited EMT in PNT2 cells demonstrated by an upregulation in the epithelial marker E-cadherin together with loss of mesenchymal markers; vimentin and fibronectin. In contrast to PNT2 cells, IGF-I induced EMT in DU145 cells, as shown by the reduction of E-cadherin level and upregulation of vimentin and fibronectin. We observed that exposure to hyperglycaemia (25mM glucose concentration) alone induced EMT in both PNT2 and DU145 cells. The changes in EMT markers induced by hyperglycaemia (loss of epithelial marker and increase of mesenchymal markers) associated with increased cell proliferation and migration.  In high glucose conditions, IGF-I was still able to inhibit EMT in PNT2 cells, whereas in DU145 cancer cells, the addition of IGF-I could not enhance EMT any further.  In conclusion, IGF-I and hyperglycaemia play important roles in promoting prostate cancer cell progression through the regulation of EMT programme.  

scholarly journals Clinical Utility of Ghrelin-O-Acyltransferase (GOAT) Enzyme as a Diagnostic Tool and Potential Therapeutic Target in Prostate Cancer

2019 ◽  
Vol 8 (12) ◽  
pp. 2056 ◽  
Author(s):  
Juan M. Jiménez-Vacas ◽  
Enrique Gómez-Gómez ◽  
Antonio J. Montero-Hidalgo ◽  
Vicente Herrero-Aguayo ◽  
Fernando L-López ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Therapeutic Target ◽  
Xenograft Model ◽  
Grey Zone ◽  
Pathophysiological Role ◽  
Expression Activity ◽  
Du145 Cells

Recent data suggested that plasma Ghrelin O-Acyl Transferase enzyme (GOAT) levels could represent a new diagnostic biomarker for prostate cancer (PCa). In this study, we aimed to explore the diagnostic and prognostic/aggressiveness capacity of GOAT in urine, as well as to interrogate its putative pathophysiological role in PCa. We analysed urine/plasma levels of GOAT in a cohort of 993 patients. In vitro (i.e., cell-proliferation) and in vivo (tumor-growth in a xenograft-model) approaches were performed in response to the modulation of GOAT expression/activity in PCa cells. Our results demonstrate that plasma and urine GOAT levels were significantly elevated in PCa patients compared to controls. Remarkably, GOAT significantly outperformed PSA in the diagnosis of PCa and significant PCa in patients with PSA levels ranging from 3 to 10 ng/mL (the so-called PSA grey-zone). Additionally, urine GOAT levels were associated to clinical (e.g., Gleason-score, PSA levels) and molecular (e.g., CDK2/CDK6/CDKN2A expression) aggressiveness parameters. Indeed, GOAT overexpression increased, while its silencing/blockade decreased cell-proliferation in PCa cells. Moreover, xenograft tumors derived from GOAT-overexpressing PCa (DU145) cells were significantly higher than those derived from the mock-overexpressing cells. Altogether, our results demonstrate that GOAT could be used as a diagnostic and aggressiveness marker in urine and a therapeutic target in PCa.

scholarly journals Expression and Function of Lysophosphatidic Acid LPA1 Receptor in Prostate Cancer Cells

Endocrinology ◽  
2006 ◽  
Vol 147 (10) ◽  
pp. 4883-4892 ◽  
Author(s):  
Rishu Guo ◽  
Elizabeth A. Kasbohm ◽  
Puneeta Arora ◽  
Christopher J. Sample ◽  
Babak Baban ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Lysophosphatidic Acid ◽  
Cell Cycle Progression ◽  
Receptor Activation ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
And Migration

The bioactive phospholipid lysophosphatidic acid (LPA) promotes cell proliferation, survival, and migration by acting on cognate G protein-coupled receptors named LPA1, LPA2, and LPA3. We profiled gene expression of LPA receptors in androgen-dependent and androgen-insensitive prostate cancer cells and found that LPA1 gene is differentially expressed in androgen-insensitive and LPA-responsive but not androgen-dependent and LPA-resistant cells. In human prostate specimens, expression of LPA1 gene was significantly higher in the cancer compared with the benign tissues. The androgen-dependent LNCaP cells do not express LPA1 and do not proliferate in response to LPA stimulation, implying LPA1 transduces cell growth signals. Accordingly, stable expression of LPA1 in LNCaP cells rendered them responsive to LPA-induced cell proliferation and decreased their doubling time in serum. Implantation of LNCaP-LPA1 cells resulted in increased rate of tumor growth in animals compared with those tumors that developed from the wild-type cells. Growth of LNCaP cells depends on androgen receptor activation, and we show that LPA1 transduces Gαi-dependent signals to promote nuclear localization of androgen receptor and cell proliferation. In addition, treatment with bicalutamide inhibited LPA-induced cell cycle progression and proliferation of LNCaP-LPA1 cells. These results suggest the possible utility of LPA1 as a drug target to interfere with progression of prostate cancer.

scholarly journals hPEBP4 Resists TRAIL-induced Apoptosis of Human Prostate Cancer Cells by Activating Akt and Deactivating ERK1/2 Pathways

2006 ◽  
Vol 282 (7) ◽  
pp. 4943-4950 ◽  
Author(s):  
Hongzhe Li ◽  
Xiaojian Wang ◽  
Nan Li ◽  
Jianming Qiu ◽  
Yuanyuan Zhang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Treatment ◽  
Cancer Cells ◽  
Potential Candidate ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
Efficient Treatment ◽  
Akt Activation ◽  
Du145 Cells ◽  
Induced Apoptosis

The treatment options available for prostate cancer are limited because of its resistance to therapeutic agents. Thus, a better understanding of the underlying mechanisms of the resistance of prostate cancer will facilitate the discovery of more efficient treatment protocols. Human phosphatidylethanolamine-binding protein 4 (hPEBP4) is recently identified by us as an anti-apoptotic molecule and a potential candidate target for breast cancer treatment. Here we found the expression levels of hPEBP4 were positively correlated with the severity of clinical prostate cancer. Furthermore, hPEBP4 was not expressed in TRAIL-sensitive DU145 prostate cancer cells, but was highly expressed in TRAIL-resistant LNCaP cells, which show highly activated Akt. Interestingly, hPEBP4 overexpression in TRAIL-sensitive DU145 cells promoted Akt activation but inhibited ERK1/2 activation. The hPEBP4-overexpressing DU145 cells became resistant to TRAIL-induced apoptosis consequently, which could be reversed by PI3K inhibitors. In contrast, silencing of hPEBP4 in TRAIL-resistant LNCaP cells inhibited Akt activation but increased ERK1/2 activation, resulting in their sensitivity to TRAIL-induced apoptosis that was restored by the MEK1 inhibitor. Therefore, hPEBP4 expression in prostate cancer can activate Akt and deactivate ERK1/2 signaling, leading to TRAIL resistance. We also demonstrated that hPEBP4-mediated resistance to TRAIL-induced apoptosis occurred downstream of caspase-8 and at the level of BID cleavage via the regulation of Akt and ERK pathways, and that hPEBP4-regulated ERK deactivation was upstream of Akt activation in prostate cancer cells. Considering that hPEBP4 confers cellular resistance to TRAIL-induced apoptosis and is abundantly expressed in poorly differentiated prostate cancer, silencing of hPEBP4 suggests a promising approach for prostate cancer treatment.

Stimulation of prostate cancer cell proliferation by bone-derived factors.

2011 ◽  
Vol 29 (7_suppl) ◽  
pp. 32-32
Author(s):  
P. Sluka ◽  
G. Whitty ◽  
I. D. Davis
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Cell Survival ◽  
Cell Lines ◽  
Mrna Level ◽  
Receptor Expression ◽  
Cancer Cell Proliferation ◽  
Lncap Cells ◽  
Du145 Cells ◽  
And Migration

32 Background: Interactions between cancer cells and their microenvironment affect the establishment and metastasis of cancer. The most common site of prostate cancer (PC) metastasis is bone. This study examined the effects of selected factors known to be produced by bone stroma (EGF, aFGF, HGF, β-NGF, TGF-β, and TNFα) on the proliferation of PC cells. The effect of cell culture medium (CM) conditioned by osteoblasts (OBCM) was also examined. Methods: The PC-derived cell lines PC3, LNCaP, and DU145 were used. Expression of receptors for the above-mentioned cytokines was assessed using real-time RT-PCR. After 5 days of continuous cytokine treatment, proliferation was assessed by MTS conversion, and cell survival and apoptosis was assessed by 7-AAD staining and flow cytometry. OBCM was generated using the HOS, MG63, and SaOs2 cell lines. CM from the HT1080 fibrosarcoma cell line was used as a non-bone control. Results: The PC cell lines expressed receptors for all of the cytokines examined at the mRNA level. LNCaP cell proliferation was increased by aFGF and decreased by TGF-β. Treatment with TNFα decreased proliferation of all PC cell lines. These effects were not due to apoptosis. EGF, HGF, and β-NGF did not affect proliferation of any line despite receptor expression. OBCM increased proliferation of PC3 and DU145 cells but not LNCaP cells, while HT1080 CM did not affect proliferation of any line. Conclusions: PC cells are able to respond to defined bone-derived factors and that the nature of this response varies between individual cancers. Acidic FGF increased proliferation of LNCaP cells while TGF-β and TNFα decreased proliferation of LNCaP and all cell lines, respectively; an effect not mediated by apoptosis. Current studies are examining the effect of these cytokines on other functional parameters (cell survival, adhesion and migration) and on primary PC epithelial cells. No significant financial relationships to disclose.

scholarly journals Midkine Is a Potential Therapeutic Target of Tumorigenesis, Angiogenesis, and Metastasis in Non-Small Cell Lung Cancer

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2402
Author(s):  
Dong Hoon Shin ◽  
Jeong Yeon Jo ◽  
Sun Ha Kim ◽  
Minyoung Choi ◽  
Chungyong Han ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cancer Cells ◽  
Brain Cancer ◽  
Stromal Cells ◽  
Therapeutic Target ◽  
Target Genes ◽  
Endothelial Cell Migration ◽  
Heparin Binding ◽  
Potential Therapeutic Target

Hypoxia-inducible factors (HIFs) induced by reduced O2 availability activate the transcription of target genes encoding proteins that play important roles in communication between cancer and stromal cells. Cancer cells were incubated under hypoxic conditions: H1299, A549 (NSCLC); Hep3B, HepG2 (HCC); HCT116, CT26 (Colon cancer); MCF-7, MDAMB231 (Breast cancer); MKN1, MKN5 (Gastric cancer); U87MG, SHSY5Y (Brain cancer); and SKOV3, SNU840 (Ovary cancer). All cells expressed HIF-1α and HIF-2α mRNA and proteins. However, cell proliferation of NSCLC, breast, gastric, and brain cancer cells under hypoxia was more dependent on HIF-1α except for HCC cells where it was more dependent on HIF-2α. Among HIF-1α dependent cells H1299 was the most affected in terms of cell proliferation by HIF-1α knockdown. To examine which cytokines are secreted in NSCLC cells by HIF-1α to communicate with stromal cells, we performed a cytokine-profiling array with H1299. We screened the top 14 cytokines which were dependent on the HIF-1α expression pattern. Among them, midkine (MDK) expression was affected the most in response to HIF-1α. MDK is a heparin-binding growth factor that promotes angiogenesis and carcinogenesis. Indeed, MDK significantly increased HUVEV endothelial cell migration and neo- vascularization in chick chorioallantoic membrane assay (CAM) assay via paracrine signaling. In addition, MDK secreted from NSCLC cells interacted with Notch2 which activated the Notch signaling pathway and induced EMT, upregulated NF-κB, and increased cancer promotion. However, in response to MDK knock down, siRNA or the MDK inhibitor, iMDK treatment not only decreased MDK-induced migration and angiogenesis of endothelial cells but also abrogated the progression and metastasis of NSCLC cells in in vitro and in vivo orthotopic and spontaneous lung metastasis models. Consequently, iMDK treatment significantly increased mice survival rates compared with the control or MDK expression group. MDK plays a very important role in the progression and metastasis of NSCLC cells. Moreover, the MDK targeting strategy provides a potential therapeutic target for the treatment of MDK-expressing lung cancers.

Mechanism of Transcriptional Repression of GADD45a in Prostate Cancer and Its Potential Role as a Therapeutic Target.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4209-4209
Author(s):  
Kavitha Ramachandran ◽  
Gopal Gopisetty ◽  
Loida Navarro ◽  
Edna Gordian ◽  
Rakesh Singal
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Transcriptional Repression ◽  
Promoter Region ◽  
Transcriptional Start Site ◽  
Specific Interaction ◽  
Proximal Promoter ◽  
Prostate Cancer Cells ◽  
Cpg Dinucleotides ◽  
Du145 Cells

Abstract Methylation-mediated repression of tumor-suppressor genes or genes involved in cell death pathway is a common event in most human malignancies. We examined the mechanism of regulation of a gene involved in cell-cycle and apoptotic pathways, Growth Arrest and DNA Damage inducible, alpha (GADD45a), in prostate cancer cells. GADD45a is expressed at a low level in LNCaP and Du145 prostate cancer cells as compared to PC3 prostate cancer cells. Bisulfite genomic sequencing was used to determine the methylation pattern of CpG dinucleotides in GADD45a promoter region. Transcriptional repression of GADD45a occurs by an atypical pattern of methylation. Unlike the commonly reported methylation pattern of tumor-suppressor genes in human malignancies, the CpG islands of the proximal promoter region are unmethylated in all three prostate cancer cell lines Du145, LNCaP and PC3. However, methylation of 4 CpGs located approximately 700 bp upstream of the transcriptional start site correlates inversely with the expression of GADD45a in Du145, LNCaP, and PC3 cells. Treatment of Du145 and LNCaP cells with DNA methyl transferase (DNMT) inhibitors, 5-Azacytidine and 5 Aza-2′deoxycytidine led to an enhanced GADD45a expression concomitant with demethylation of the 4 CpGs. Frequent methylation of the 4 CpGs was also seen in prostate cancer tissues. Methylation-mediated transcriptional repression involves binding of specific proteins, Methyl-CpG binding proteins (MBDs) at methylated CpG dinucleotides. Using chromatin immunoprecipitation (ChIP), we analyzed the interaction of GADD45a- 4-CpG region with MeCP2, the archetypical MBD protein. Cell specific interaction of MeCP2 was observed: MeCP2 was associated with the methylated four CpGs in Du145 whereas no binding was detected in LNCaP cells. Stable transfection of MeCP2 siRNA vector in Du145 (Du145-MeCP2-ve) resulted in down regulation of MeCP2, release of MeCP2 from GADD45a promoter and upregulation of GADD45a expression suggesting a role of MeCP2 in mediating transcriptional repression in Du145 cells. Since GADD45a has been implicated in cell cycle arrest and apoptosis, we hypothesized that induction of GADD45a expression in Du145 cells would lead to increased sensitivity to chemotherapeutic drugs. Consistent with this hypothesis, we observed that Docetaxel treatment resulted in an increased cytotoxicity in MeCP2-ve Du145 cells that exhibit enhanced GADD45a expression as compared to the wt Du145 cells, Induction of GADD45a expression by prior treatment with DNMT inhibitor, 5-Azacytidine resulted in an enhanced cytotoxicity in wt Du145 cells and wt Du145 cells that were transfected with GADD45a expression vector exhibited an enhanced cyotoxicity to Docetaxel as compared to the mock-transfected cells. In conclusion, we show that methylation of CpG dinucleotides away from the transcriptional start site but not in the proximal promoter region correlates inversely with GADD45a expression in prostate cancer cells, cell-specific interaction of MeCP2 to the methylated GADD45a promoter, and a potential role of DNA methyltransferase inhibitors in enhancing sensitivity to cytotoxic agents through upregulation of GADD45a in prostate cancer cells.

scholarly journals UBC Mediated by SEPT6 Inhibited the Progression of Prostate Cancer

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ruochen Zhang ◽  
Yaojing Yang ◽  
Haijian Huang ◽  
Tao Li ◽  
Liefu Ye ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Pearson Correlation ◽  
Tumor Formation ◽  
Pearson Correlation Coefficient ◽  
Prostate Cancer Cells ◽  
Formation Experiment ◽  
Du145 Cells ◽  
Cancer Tissues

Background. Prostate cancer is one of the most common malignancies in men. Protein ubiquitination is an important mechanism for regulating protein activity and level in vivo. We aimed to study the mechanism of SEPT6 and UBC action in prostate cancer to identify new targets. Methods. The ubiquitin-protein and the ubiquitin coding gene UBA52, UBA80, UBB, and UBC expressions were detected in clinical tissues and cells. Overexpression and knockdown of UBC were performed in prostate cancer DU145 cells. Cell Counting Kit 8 (CCK-8) assay was performed to detect cell proliferation. Cell cycle at 24 h was detected by flow cytometry. Clonal formation assay was used to measure cell clone number. Immunofluorescence (IF) was performed to detect the colocalization of SEPT6 and UBC in prostate cancer cells. Next, we overexpressed or knocked down SEPT6 expression in DU145 cells. Pearson correlation coefficient was applied to analyze the relationship between SEPT6 and UBC in prostate cancer tissue. oe-SEPT6+oe-UBC coexpressing cells were constructed to detect the upstream and downstream relationship between SEPT6 and UBC on prostate cancer cells. The tumor formation experiment was performed to explore SEPT6/UBC effect on prostate cancer. Results. UBC was upregulated in prostate cancer tissues and cells. Overexpression of UBC promoted cell survival and proliferation. IF revealed the colocalization of SEPT6 and UBC in prostate cancer cells. UBC expression decreased after oe-SEPT6, while increased after sh-SEPT6, indicating that UBC was downstream of SEPT6. Pearson correlation coefficient analysis showed that SEPT6 was negatively correlated with UBC in prostate cancer tissues. SEPT6 as an upstream gene of UBC regulated prostate cancer cell behavior through UBC. The tumor formation experiment showed that SEPT6 could inhibit tumor growth. Conclusion. In general, SEPT6 inhibited UBC expression, thereby reducing the overall ubiquitination level, affecting the expression level of downstream cell proliferation-related genes, and then affecting the progression of prostate cancer.

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