lithium-chloride and Prostatic-Neoplasms

von Willebrand factor C and EGF domain‑containing protein (URG11), a cell growth regulator, is involved in the progression of a variety of types of cancer, including prostate cancer (Pca). However, the functions of the URG11 gene in Pca cells require in‑depth investigation. The mRNA and protein levels of URG11 were measured by reverse transcription quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. Cell Counting kit‑8 (CCK‑8), wound‑healing and Transwell assays were used to detect cell viability, migration and invasion, respectively. Apoptosis and cell cycle analyses were performed using flow cytometry. The mRNA and protein expression levels of epithelial (E)‑cadherin, vimentin, α‑smooth muscle actin (α‑SMA), cyclin D1 and MYC proto‑oncogene protein (c‑Myc) were analyzed by RT‑qPCR and western blot analysis. In the present study, the mRNA and protein levels of URG11 were markedly upregulated in Pca cell lines compared with those in the normal prostate epithelial cell line. With functional experiments, the cell viability, migration and invasion of Pca cells were markedly promoted by URG11 overexpression. The cell cycle was effectively induced by URG11 and apoptosis was inhibited by the overexpression of URG11. Concomitantly, the epithelial marker E‑cadherin was downregulated, and the mesenchymal markers vimentin and α‑SMA were upregulated following URG11 overexpression. By contrast, genetic knockout of URG11 elicited the opposite effects. The present study also identified that the downstream effector genes of the Wnt/β‑catenin signal pathway, cyclin D1 and c‑Myc, were increased following the overexpression of endogenous URG11, which are known to regulate cell proliferation. In addition, the Wnt/β‑catenin inhibitor FH535 ameliorated the promotive effects of URG11 on LNCaP cells viability, migration and invasion, and the Wnt/β‑catenin agonist LiCl reversed the inhibitory effects of siURG11 in LNCaP cells on cell viability, migration and invasion. The present study demonstrated that URG11 served an oncogenic role in the development of Pca cells and provided evidence that URG11 has potential as a novel therapeutic target in Pca.

Topics: Actins; Apoptosis; Cadherins; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Cyclin D1; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; Lithium Chloride; Male; Neoplasm Invasiveness; Prostatic Neoplasms; Proto-Oncogene Proteins c-myc; RNA, Small Interfering; Sulfonamides; Trans-Activators; Vimentin

Prostate cancer is a major health threat for men. Thiazolidenediones (TZDs) are synthetic ligands of the peroxisome proliferator-activated receptor γ (PPARγ), and previous studies have shown that TZDs induce apoptosis of prostate cancer cells independently of PPARγ activation. However, the exact mechanism of these effects remains unknown. Our objective was to investigate the effects of TZDs on apoptosis and on the serine/threonine kinase pathway, Akt, and glycogen synthase kinase 3β (GSK3β).. LNCaP cells, a type of prostate cancer cells (derived from left supraclavicular lymph node of human prostrate carcinoma), were cultured in DMEM medium, and cell viability was evaluated with a colorimetric assay using MTT level. The total and phosphorylated protein level of Akt and GSK3β were detected by Western blotting.. The apoptosis-inducing effect of TZDs on prostate cancer cells involves the inhibition of Akt phosphorylation. Furthermore, TZDs induce inactivation of GSK3β, a multifunctional kinase that mediates essential events promoting prostate cancer development and acquisition of androgen independence. In addition, the GSK3β inhibitor lithium chloride sensitizes prostate cancer cells to TZDs cytotoxicity.. Our data suggest that modulation of Akt-GSK3β pathway is involved in the cell death pathway engaged by TZDs in prostate cancer cells. This reveals another possible mechanism of TZDs on apoptosis in prostate cancer. Inhibition of the Akt-GSK3β cascade may be a useful approach in prostate cancer.

Topics: Apoptosis; Blotting, Western; Cell Line, Tumor; Cell Survival; Colorimetry; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Lithium Chloride; Male; Phosphorylation; Prostatic Neoplasms; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; Thiazolidinediones

To assess the effects of LiCl on prostate cancer growth and to explore the underlying mechanisms.. Effects of LiCl on cell growth in vitro and in vivo were determined by cell counting and xenografts of prostate cancer cells. Alterations in cell proliferation and the expression of DNA replication-related protein were determined by MTT assay, BrdU incorporation and Western blot.. Compared to PBS control group, the number of prostate cancer cells (PC-3) were lower treated with 10 mmol/L LiCl, the number was 1.9×10(5), 4.8×10(5) and the difference was significant (P < 0.05). The inhibition rate of cellular proliferation were 50%, 95% and 98%, respectively, in LiCl group, NaCl and KCl control group, the difference was significant (P < 0.05). The A-Value of BrdU incorporation was 1.5, 1.3 treated with 10 mmol/L, 30 mmol/L LiCl, while the A-value of BrdU incorporation was 4 in PBS control group, the difference was significant (P < 0.05). On the protein level, LiCl downregulates expression of cdc 6, cyclins A and cyclins E, and cdc 25C, and upregulates expression of the CDK inhibitor p21(CIP1). The mean volume and weight of xenograft tumor were 50 mm(3) and 296 mg after LiCl intraperitoneal injection, But PBS control group were 180 mm(3) and 957 mg, the difference was significant (P < 0.05).. LiCl disrupts DNA replication and suppresses tumor growth of prostate cancer cells in vitro and in vivo.

Topics: Animals; Antineoplastic Agents; cdc25 Phosphatases; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cyclin A; Cyclin E; Cyclin-Dependent Kinase Inhibitor p21; DNA Replication; Humans; Lithium Chloride; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Nuclear Proteins; Prostatic Neoplasms; Tumor Burden

Glycogen synthase kinase 3 (GSK-3) has been regarded as a potential therapeutic target for multiple human cancers. We previously reported that suppression of GSK-3 activity with lithium chloride (LiCl) or small chemical inhibitors impaired cellular DNA synthesis and reduced cell proliferation in prostate cancer cells. Therefore, in this study, we extended this in vitro findings to in vivo settings in order to establish a proof of concept that inhibition of GSK-3 activity is feasible in suppressing tumor growth of prostate cancer in vivo.. In this study, we used three GSK-3 inhibitors, LiCl, TDZD-8, and L803-mts, which are structurally unrelated and non-ATP competitive. Human prostate cancer cell lines PC-3 and C4-2 were used for nude mouse xenograft models. The autochthonous transgenic prostate cancer TRAMP mice were used for testing GSK-3 inhibitor's effect on tumor development. Anti-Ki-67 and BrdU immunohistochemistry was used to determine cell proliferation. The pE2F-TA-LUC (E2F-LUC) luciferase reporter assay and gene specific small interferencing RNA technique were used to examine C/EBP involvement in GSK-3 inhibitor-induced E2F-1 suppression.. Using mouse xenograft models, we demonstrated that LiCl and TDZD-8 significantly suppressed tumor development and growth of subcutaneous xenografts derived from human prostate cancer cells. Similarly, in the TRAMP mice, TDZD-8 and L803-mts reduced the incidence and tumor burden in the prostate lobes. Consistent with our previous in vitro findings, GSK-3 inhibitors significantly reduced BrdU incorporation and Ki67-positive cells in xenograft tumors and mouse cancerous prostates compared to the control. Further analysis revealed that following GSK-3 inhibition, C/EBPα, a negative cell cycle regulator, was remarkably accumulated in xenograft tumors or in cultured prostate cancer cells. Meanwhile, knocking down C/EBPα expression abolished GSK-3 inhibition-induced suppression of E2F1 transactivation, suggesting that C/EBPα accumulation is involved in GSK-3 inhibition-induced anti-tumor effect.. Taken together, these results suggest that GSK-3 inhibition has the potential as a therapeutic strategy for prostate cancer intervention, although further pre-clinical and clinical testing are desirable.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; CCAAT-Enhancer-Binding Protein-alpha; Cell Line, Tumor; Cell Proliferation; Glycogen Synthase Kinase 3; Humans; Lithium Chloride; Male; Mice; Mice, Inbred C57BL; Mice, Nude; Mice, Transgenic; Oligopeptides; Prostatic Neoplasms; RNA, Small Interfering; Thiadiazoles

Prostate cancer is a major health threat for American men. Therefore, the development of effective therapeutic options is an urgent issue for prostate cancer treatment. In this study, we evaluated the effect of glycogen synthase kinase-3beta (GSK-3beta) suppression on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in human prostate cancer cell lines. In the presence of lithium chloride (LiCl) or SB216763, the GSK-3beta inhibitors, TRAIL-induced cell death was dramatically enhanced, and the enhanced cell death was an augmented apoptotic response evidenced by increased Annexin V labeling and caspase-3 activation. GSK-3beta gene silencing mediated by a small interference RNA (siRNA) duplex also sensitized the cells to TRAIL, confirming the specificity of GSK-3beta suppression. Importantly, TRAIL stimulation increased GSK-3beta tyrosine phosphorylation at Y216, suggesting that GSK-3beta is activated by TRAIL. Furthermore, TRAIL sensitization was associated with increased proteolytic procession of caspase-8 and its downstream target BID, and z-IETD-FMK, the inhibitor specific to active caspase-8 totally blocked LiCl-induced TRAIL sensitization. Finally, Trichodion, a potent nuclear factor-kappaB (NF-kappaB) inhibitor, could not affect LiCl-induced TRAIL sensitization, although GSK-3beta inhibitors significantly blocked TRAIL-reduced NF-kappaB activity in prostate cancer cells. These results indicate that GSK-3beta suppression sensitizes prostate cancer cells to TRAIL-induced apoptosis that is dependent on caspase-8 activities but independent of NF-kappaB activation, and suggest that a mechanism involving GSK-3beta activation may be responsible for TRAIL resistance in prostate cancer cells.

Topics: Apoptosis; Apoptosis Regulatory Proteins; Caspase 8; Caspases; Cell Line, Tumor; Drug Resistance, Neoplasm; Gene Silencing; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Lithium Chloride; Male; Membrane Glycoproteins; NF-kappa B; Prostatic Neoplasms; Pyrones; RNA, Small Interfering; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha