Guang-Huan Sun

Ketamine-associated bladder dysfunction

Objective:  To assess the impact of ketamine abuse on genitourinary tract dysfunction.

Monoclonal anti‐double‐stranded DNA autoantibody stimulates the expression and release of IL‐1β, IL‐6, IL‐8, IL‐10 and TNF‐α from normal human mononuclear cells involving in the lupus pathogenesis

In our previous reports, we found polyclonal anti‐double‐stranded DNA antibodies (anti‐dsDNA) purified from patients with active systemic lupus erythematosus (SLE) exerted inhibitory effect on [3H]thymidine incorporation of human mononuclear cells (MNC). However, the other immunological effects of anti‐dsDNA on the functions of MNC have not yet been reported. In this study, two monoclonal antibodies, 12B3 and 9D7, with different anti‐dsDNA activity were evaluated for their effects on the expression and release of different cytokines from human MNC. We confirmed absence of endotoxin in the two monoclonal antibody preparations and the used medium as detected by Limulus amoebocyte lysate test. The mRNA expression and release of different cytokines including interleukin (IL)‐1β, IL‐2, IL‐4, IL‐6, IL‐8, IL‐10, tumour necrosis factor‐α (TNF‐α) and interferon‐γ (IFN‐γ) were measured. We found the two monoclonal anti‐dsDNA not only dose‐responsively suppressed the phytohaemagglutinin (PHA)‐induced thymidine uptake of human MNC but stimulated the mRNA expression of IL‐1β, IL‐6 and IL‐8 in normal human MNC detected by reverse transcription–polymerase chain reaction (RT–PCR). Enzyme‐linked immunosorbent assay (ELISA) measurement of cytokines in MNC culture supernatants revealed that anti‐dsDNA enhanced IL‐1β, IL‐8, TNF‐α and IL‐10 release from resting MNC. These effects of anti‐dsDNA antibodies were not affected by polymyxin B, a potent binder and neutralizer of lipopolysaccharide (LPS). These in vitro studies suggest that anti‐dsDNA possess a dual effect on normal human MNC: (a) to enhance the release of proinflammatory cytokines (IL‐1β, IL‐8 and TNF‐α) from MNC to augment inflammatory reaction; and (b) to polarize the immune reaction towards the T helper 2 (Th2) (increased IL‐10 production) pathway. This unique effect of anti‐dsDNA may play a role in lupus pathogenesis by augmenting inflammatory reactions and autoantibody production which are commonly found in patients with active SLE.

Tumor-derived tumor necrosis factor-alpha promotes progression and epithelial-mesenchymal transition in renal cell carcinoma cells

Pro‐inflammatory cytokines and chemokines are involved in promoting tumorigenesis by facilitating tumor proliferation and metastasis. The serum levels of interleukin (IL)‐6, IL‐1β, and tumor necrosis factor‐alpha (TNF‐α) are significantly elevated in patients with renal cell carcinoma (RCC). However, the mechanisms of how these cytokines participate in the progression of RCC remains unknown. In the present study, we investigated the effects of tumor‐derived cytokines on invasion and the epithelial‐mesenchymal transition (EMT) of RCC cells. We found that expression of IL‐1β, IL‐6, TNF‐α, hypoxia‐inducible factor‐alpha (HIF‐1α), and matrix metalloproteinase‐2 (MMP2) were significantly elevated in high malignancy A498 cells compared to low malignancy 786‐O cells. The invasion ability of A498 was three‐fold higher than that of 786‐O cells. The invasiveness of 786‐O cells was markedly enhanced by adding conditioned medium derived from A498 cells. This phenomenon was significantly inhibited by immunodepletion of TNF‐α followed by MMP2, IL‐6, or IL‐1β from A498 conditioned medium. Synergistic inhibition was also noted after simultaneous immunodepletion of TNF‐α, IL‐1β, and IL‐6. RCC cell lines with higher malignancy produced more TNF‐α, which was correlated with their stronger invasive ability. The invasiveness of 786‐O cells was significantly promoted by TNF‐α in a dose‐dependent manner. Moreover, TNF‐α induced the EMT of 786‐O cells by repressing E‐cadherin, promoting vimentin expression, and activating MMP9 activity. Our findings demonstrate that pro‐inflammatory cytokines, especially TNF‐α, can enhance invasion and the EMT of renal cancer cells, which provides a therapeutic target to prevent and treat advanced RCC. (Cancer Sci 2008; 99: 905–913)

Dual Degradation of Aurora A and B Kinases by the Histone Deacetylase Inhibitor LBH589 Induces G2-M Arrest and Apoptosis of Renal Cancer Cells

Purpose: This study is aimed at investigating antineoplastic efficacy of histone deacetylase inhibitor (HDACI) LBH589 on renal cell carcinoma (RCC) and elucidating the novel molecular mechanisms involved in growth arrest and apoptosis by targeting the important nonhistone molecules. Experimental Design: We analyzed the growth-inhibitory effect of LBH589 on RCC by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in vitro and antitumor efficacy by xenograft experiments in vivo. To verify the associated molecular mechanisms involved in LBH589-mediated cell death and cell cycle progression by Western blotting and fluorescence-activated cell sorting analysis. Results: HDACI LBH589 induced degradation of both Aurora A and B kinases through a proteasome-mediated pathway by targeting HDAC3 and HDAC6. The dual degradation of Aurora A and B kinases mediated by LBH589 resulted in inducing G2-M arrest and apoptosis of renal cancer cell lines and our results also showed that LBH589 potently inhibited renal cancer cell growth in vitro and suppressed tumor formation in vivo. The Aurora A and B kinases and HDAC3 are overexpressed in the human RCC tumor tissues examined, which make them perfect targets for HDACI LBH589 treatment. Conclusions: Our in vitro and in vivo data showed that LBH589 has potent anticancer effect of renal cancer cells. LBH589 and other HDACI treatment resulted in inducing G2-M arrest and apoptosis of renal cancer cells through degradation of Aurora A and B kinases by inhibition of HDAC3 and HDAC6. The clinical efficacy of LBH589 in the treatment of patients with metastatic RCC, especially those with high Aurora kinase and HDAC expression, is worthy of further investigation.

Galectin-1 promotes lung cancer progression and chemoresistance by upregulating p38 MAPK, ERK and cyclooxygenase-2

Purpose: This study is aimed at investigating the role and novel molecular mechanisms of galectin-1 in lung cancer progression. Experimental Design: The role of galectin-1 in lung cancer progression was evaluated both in vitro and in vivo by short hairpin RNA (shRNA)-mediated knockdown of galectin-1 in lung adenocarcinoma cell lines. To explore novel molecular mechanisms underlying galectin-1–mediated tumor progression, we analyzed gene expression profiles and signaling pathways using reverse transcription PCR and Western blotting. A tissue microarray containing samples from patients with lung cancer was used to examine the expression of galectin-1 in lung cancer. Results: We found overexpression of galectin-1 in non–small cell lung cancer (NSCLC) cell lines. Suppression of endogenous galectin-1 in lung adenocarcinoma resulted in reduction of the cell migration, invasion, and anchorage-independent growth in vitro and tumor growth in mice. In particular, COX-2 was downregulated in galectin-1–knockdown cells. The decreased tumor invasion and anchorage-independent growth abilities were rescued after reexpression of COX-2 in galectin-1–knockdown cells. Furthermore, we found that TGF-β1 promoted COX-2 expression through galectin-1 interaction with Ras and subsequent activation of p38 mitogen-activated protein kinase (MAPK), extracellular signal–regulated kinase (ERK), and NF-κB pathway. Galectin-1 knockdown sensitized lung cancer cells to platinum-based chemotherapy (cisplatin). In addition, galectin-1 and COX-2 expression was correlated with the progression of lung adenocarcinoma, and high clinical relevance of both proteins was evidenced (n = 47). Conclusions: p38 MAPK, ERK, and COX-2 activation are novel mediators for the galectin-1–promoted tumor progression and chemoresistance in lung cancer. Galectin-1 may be an innovative target for combined modality therapy for lung cancer. Clin Cancer Res; 18(15); 4037–47. ©2012 AACR.

IL-27 Directly Restrains Lung Tumorigenicity by Suppressing Cyclooxygenase-2-Mediated Activities

Gene transfer of IL-27 to tumor cells has been proven to inhibit tumor growth in vivo by antiproliferation, antiangiogenesis, and stimulation of immunoprotection. To investigate the nonimmune mechanism of IL-27 that suppresses lung cancer growth, we have established a single-chain IL-27-transduced murine Lewis lung carcinoma (LLC-1) cell line (LLC-1/scIL-27) to evaluate its tumorigenic potential in vivo. Mice inoculated with LLC/scIL-27 displayed retardation of tumor growth. Production of IL-12, IFN-γ, and cytotoxic T cell activity against LLC-1 was manifest in LLC/scIL-27-injected mice. Of note, LLC-1/scIL-27 exhibited decreased expression of cyclooxygenase-2 (COX-2) and PGE2. On the cellular level, the LLC/scIL-27 transfectants had reduced malignancy, including down-regulation of vimentin expression and reduction of cellular migration and invasion. The suppression of tumorigenesis by IL-27 on lung cancer cells was further confirmed by the treatment with rIL-27 on the murine LLC-1 and human non-small cell lung carcinoma (NSCLC) cell lines. PGE2-induced vimentin expression, movement, and invasiveness were also suppressed by the treatment with rIL-27. Our data show that IL-27 not only suppresses expression of COX-2 and PGE2 but also decreases the levels of vimentin and the abilities of cellular migration and invasion. Furthermore, inoculation of LLC/scIL-27 into immunodeficient NOD/SCID mice also exhibited reduced tumor growth. Our data indicate that IL-27-induced nonimmune responses can contribute to significant antitumor effects. Taken together, the results suggest that IL-27 may serve as an effective agent for lung cancer therapy in the future.

TNF-α Induces Epithelial–Mesenchymal Transition of Renal Cell Carcinoma Cells via a GSK3β-Dependent Mechanism

TNF-α is a cytokine with antitumorigenic property. In contrast, low dose, chronic TNF-α production by tumor cells or stromal cells may promote tumor growth and metastasis. Serum levels of TNF-α are significantly elevated in renal cell carcinoma (RCC) patients. Here, we showed that TNF-α induced epithelial–mesenchymal transition (EMT) and promoted tumorigenicity of RCC by repressing E-cadherin, upregulating vimentin, activating MMP9, and invasion activities. In addition, TNF-α treatment inhibited glycogen synthase kinase 3β (GSK-3β) activity through serine-9 phosphorylation mediated by the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway in RCC cells. Inhibition of PI3K/AKT by LY294002 reactivated GSK-3β and suppressed the TNF-α–induced EMT of RCC cells. Inactivation of GSK-3β by LiCl significantly increased MMP9 activity and EMT of RCC cells. Activation of GSK-3β by transduction of constitutively active GSK-3β into RCC cells suppressed TNF-α–mediated anchorage-independent growth in soft agar and tumorigenicity in nude mice. Overexpression of a kinase-deficient GSK-3β, in contrast, potentiated EMT, anchorage-independent growth and drastically enhanced tumorigenicity in vivo. Most importantly, a 15-fold inactivation of GSK-3β activity, 3-fold decrease of E-cadherin, and 2-fold increase of vimentin were observed in human RCC tumor tissues. These results indicated that inactivation of GSK-3β plays a pivotal role in the TNF-α–mediated tumorigenesis of RCC. Mol Cancer Res; 10(8); 1109–19. ©2012 AACR.

Estrogen inhibits renal cell carcinoma cell progression through estrogen receptor-β activation.

Renal cell carcinoma (RCC) originates in the lining of the proximal convoluted tubule and accounts for approximately 3% of adult malignancies. The RCC incidence rate increases annually and is twofold higher in males than in females. Female hormones such as estrogen may play important roles during RCC carcinogenesis and result in significantly different incidence rates between males and females. In this study, we found that estrogen receptor β (ERβ) was more highly expressed in RCC cell lines (A498, RCC-1, 786-O, ACHN, and Caki-1) than in breast cancer cell lines (MCF-7 and HBL-100); however, no androgen receptor (AR) or estrogen receptor α (ERα) could be detected by western blot. In addition, proliferation of RCC cell lines was significantly decreased after estrogen (17-β-estradiol, E2) treatment. Since ERβ had been documented to be a potential tumor suppressor gene, we hypothesized that estrogen activates ERβ tumor suppressive function, which leads to different RCC incidence rates between males and females. We found that estrogen treatment inhibited cell proliferation, migration, invasion, and increased apoptosis of 786-O (high endogenous ERβ), and ERβ siRNA-induced silencing attenuated the estrogen-induced effects. Otherwise, ectopic ERβ expression in A498 (low endogenous ERβ) increased estrogen sensitivity and thus inhibited cell proliferation, migration, invasion, and increased apoptosis. Analysis of the molecular mechanisms revealed that estrogen-activated ERβ not only remarkably reduced growth hormone downstream signaling activation of the AKT, ERK, and JAK signaling pathways but also increased apoptotic cascade activation. In conclusion, this study found that estrogen-activated ERβ acts as a tumor suppressor. It may explain the different RCC incidence rates between males and females. Furthermore, it implies that ERβ may be a useful prognostic marker for RCC progression and a novel developmental direction for RCC treatment improvement.

Involvement of Purinergic Neurotransmission in Ketamine Induced Bladder Dysfunction

PURPOSE Long-term ketamine abuse in humans causes significant lower urinary tract symptoms. However, the etiology of ketamine associated cystitis is still not clear. We created a mouse model of ketamine induced lower urinary tract dysfunction to explore the pathogenesis of this condition. MATERIALS AND METHODS Female C57BL/6 mice randomly distributed into control and ketamine groups received daily intraperitoneal injection of saline and ketamine (100 mg/kg), respectively. Cystometry was done in each group at 4, 8 and 16 weeks. After sacrifice the bladders were harvested for isometric muscle tension recording and immunohistochemical examination. RESULTS After 8 weeks of treatment body weight growth was significantly decreased in ketamine treated mice. Cystometry revealed a significantly decreased intercontraction interval (mean±SEM 237±9 vs 360±20 seconds, p<0.001) and decreased bladder capacity (0.1±0.004 vs 0.13±0.006 ml, p<0.001) in ketamine vs saline injected mice. Increased adenosine triphosphate evoked detrusor contraction developed in the ketamine group. Immunohistochemical examination revealed increased P2X1 receptor expression in ketamine treated mouse bladders while M2 and M3 receptor expression was unchanged. CONCLUSIONS At 8 weeks mice treated with ketamine showed increased voiding frequency and decreased bladder capacity, the same symptoms that develop in human ketamine abusers. Enhanced noncholinergic contractions and P2X1 receptor expression in the ketamine bladder indicate that dysregulation of purinergic neurotransmission may underlie detrusor overactivity in cases of ketamine induced bladder dysfunction.

Cold-induced ependymin expression in zebrafish and carp brain: implications for cold acclimation.

Cold acclimation has been suggested to be mediated by alternations in the gene expression pattern in the cold‐adapted fish. To investigate the mechanism of cold acclimation in fish brain at the molecular level, relevant subsets of differentially expressed genes of interest were identified and cloned by the PCR‐based subtraction suppression hybridization. Characterization of the selected cold‐induced cDNA clones revealed one encoding ependymin. This gene was shown to be brain‐specific. The expression of ependymin was induced by a temperature shift from 25°C to 6°C in Cyprinus carpio or 12°C in Danio rerio. Activation of ependymin was detected 2 h after cold exposure and peaked at more than 10‐fold at 12 h. This peak level remains unchanged until the temperature returns to 25°C. Although the amount of soluble ependymin protein in brain was not changed by cold treatment, its level in the fibrous insoluble polymers increased 2‐fold after exposure to low temperature. These findings indicate that the increase in ependymin expression is an early event that may play an important role in the cold acclimation of fish.