Tung-Wei Hung

Silibinin inhibits the invasion and migration of renal carcinoma 786-O cells in vitro, inhibits the growth of xenografts in vivo and enhances chemosensitivity to 5-fluorouracil and paclitaxel.

Silibinin is a flavonoid antioxidant that is widely used for its anti‐hepatotoxic properties. It exerts a dose‐dependent inhibition on the invasion and migration of 786‐O renal cell carcinoma (RCC) cells in the absence of cytotoxicity. 786‐O cells were treated with silibinin at various concentrations, up to 50 µM, for a defined period and then subjected to gelatin zymography, casein zymography, and Western blot to investigate the impacts of silibinin on metalloproteinase (MMP) ‐2, ‐9, urokinase plasminogen activator (u‐PA), and MAPK pathway signaling proteins, respectively. The results showed that silibinin decreased MMP‐2, MMP‐9, u‐PA, p‐p38, and p‐Erk1/2 expressions in a concentration‐dependent manner. The reduced expressions of MMP‐2 and u‐PA, as well as inhibition of cell invasion were obtained in the cultures pre‐treated with PD98059 (Erk1/2 inhibitor) and SB203580 (p38 inhibitor). An in vivo anti‐tumor study with a nude mice xenograft model by a subcutaneous inoculation of 786‐O cells demonstrated small solid tumors after eight days following cell inoculation. There was a 70.1% reduction in tumor volume and 69.7% reduction in tumor weight by silibinin feeding on day 44, compared to those of controls. Moreover, combination treatment with silibinin and 5‐fluorouracil, paclitaxel, vinblastine, or RAD‐001 enhanced the chemosensitivity of 5‐fluorouracil and paclitaxel. In conclusion, silibinin inhibits the invasion and migration of 786‐O cells in vitro, inhibits the growth of xenografts in vivo, and enhances chemosensitivity to 5‐fluorouracil and paclitaxel.

The suppressive effect of Rho kinase inhibitor, Y-27632, on oncogenic Ras/RhoA induced invasion/migration of human bladder cancer TSGH cells.

Urothelial cell carcinoma is the most common type of malignancy found in long-term dialysis patients and kidney transplant recipients in Taiwan. Surgical specimens of tumorous and non-tumorous bladder tissues were collected from 12 patients with bladder cancer. Increased expressions of Ras, RhoA, Akt, PI-3K were demonstrated in the tumors as compared to adjacent control tissues. To understand the impact of Ras over-expression on bladder cancer progression, human bladder cancer TSGH 8301 cells were transfected with Ras DNA. The Ras-transfected cells were then treated with either a PI-3K inhibitor (wortmannin) or Rho kinase inhibitor (Y-27632) and the expressions of Ras, PI-3K, Akt, NF-kappaB, and RhoA were analyzed. Fluorescent phalloidin staining demonstrated more intense F-actin staining in the Ras over-expressed cells than in the control cells, and the intensity of F-actin was inhibited by Y-27632. A gelatin zymography study demonstrated that the MMP-2 and MMP-9 expressions of the Ras-transfected cells were enhanced, and Y-27632 treatment reduced the levels of MMP-2 and MMP-9. Similarly, a wound healing assay revealed that the ability of cell migration was markedly increased by Ras transfection and the healing rate after treatment of Y-27632 was delayed. Our results provide evidence that Ras-induced RhoA and NF-kappaB activation was involved in the invasion/migration of bladder cancer. Through Ras and/or RhoA inhibition, there might be an opportunity for new therapeutic interventions in bladder cancer.

Plasminogen activator inhibitor-1 5G/5G genotype is a protecting factor preventing posttransplant diabetes mellitus.

OBJECTIVE Plasminogen activator inhibitor 1 (PAI-1) is thought to play a role in the pathogenesis of obesity and insulin resistance. A connection between gestational diabetes mellitus and the functional -675 PAI-1 genotype has been reported. Therefore, we examined the role of the PAI-1 gene polymorphism in kidney transplant recipients. METHODS A total of 376 kidney transplant recipients were prospectively screened for posttransplant diabetes mellitus (PTDM). Eighty-one (21.5%) patients were diagnosed with PTDM and the other 295 patients were non-diabetic following kidney transplantation. DNA samples were isolated from the sera and analyzed for the functional -675 4G/5G promoter polymorphisms of the PAI-1 gene. RESULTS Kidney transplant recipients with PTDM were significantly associated with tacrolimus use (p=0.03), older age (p=0.036), and higher body mass index (p=0.001). The genotype distribution was significantly different between the patients with PTDM (genotype 4G/4G:4G/5G:5G/5G=33.3%:60.5%:6.2%) and those without PTDM (genotype 4G/4G:4G/5G:5G/5G=36.9%:44.1%:19.0%) (p=0.018). Patients with homozygosity for 5G had a significantly lower rate of PTDM (aOR, 0.286, p=0.022) and higher cumulative event-free probability of time to PTDM (log rank test, p=0.0058). CONCLUSION Homozygosity for the 5G allele of the PAI-1 gene constitutes a protecting factor for the development of PTDM. Our findings are similar to a previous study on gestational diabetes mellitus, and strongly support a possible genetic role of PAI-1 in the development of PTDM.

Community-acquired urinary tract infection in kidney transplantation: risk factors for bacteremia and recurrent infection.

BACKGROUND/PURPOSE Urinary tract infection (UTI) is the most common type of infectious complication among kidney transplant patients. However, the antibiotic susceptibility of causative microorganisms and risk factors for concomitant bacteremia and recurrent infection are rarely discussed. METHODS This was a retrospective cohort review of kidney transplant recipients who had received follow-up in the past 10 years at the Chung-Shan Medical University (Taichung, Taiwan). Only community-acquired and symptomatic UTIs were included in this study. RESULTS During the 53 ± 22 months of follow-up, 99 patients developed 167 episodes of UTI. Forty-two (25%) episodes had concomitant bacteremia. Escherichia coli was the most common causative microorganism, and strains with resistance to multiple commonly used empirical antibiotics began to emerge. The independent risk factors for UTI with concomitant bacteremia in multivariate analysis were immunosuppression with tacrolimus (adjusted odds ratio [AOR] 3.17; 95% confidence interval [CI] 1.29-7.75; P = 0.011) and baseline serum creatinine level >1.3 mg/dL before first UTI (AOR 2.55; 95% CI 1.02-6.36; P = 0.045). However, there were no factors that were significantly associated with recurrent infection. CONCLUSION From this study, we found that E coli tends to have resistance to commonly used empirical antibiotics in this modern era and that patients who use the immunosuppressant tacrolimus and have baseline serum creatinine level >1.3 mg/dL before their first UTI have a tendency to suffer from concomitant bacteremia and even sepsis.

Conversion to prolonged release tacrolimus formulation in stable kidney transplant recipients.

PRINCIPLES The once-daily tacrolimus formulation (Advagraf®), with the potential for improving medical adherence, has been advocated to improve long-term kidney allograft outcomes. However, experience with late conversion from the twice-daily tacrolimus formulation (Prograf®) to Advagraf in the daily care of stable kidney transplant recipients has been limited. METHODS The aim of this study was to observe the efficacy and safety of conversion from Prograf to Advagraf in chronic stable kidney transplant recipients in routine clinical practice. The recruited patients had postconversion follow-up at least once monthly for a total of six months, unless they had discontinued the use of Advagraf, had been lost the follow-up or had lost the graft. RESULTS The mean age of the 199 patients was 51.5 ± 10.4 years (60.8% male). The mean time from transplantation to the conversion to Advagraf was 8.3 ± 3.2 years and the mean tacrolimus trough level at conversion was 4.2 ± 1.4 ng/ml. After conversion, 147 patients (73.8 %) had a reduced trough level at one month and the mean change in trough level postconversion was -13.5%. The mean serum creatinine level between conversion and six months postconversion was not significantly different (1.12 ± 0.36 vs 1.10 ± 0.42 mg/dl). Thirty-four patients (17%) discontinued the treatment with Advagraf and two (1%) developed biopsy-proved acute rejection. CONCLUSIONS In conclusion, frequent conversion caused by a high discontinuation rate may further raise the potential risk of allograft rejection and increase unnecessary cost. In view of this, the policy of converting to Advagraf with the purpose of improving medical adherence should be individualised in routine clinical practice.

Association between interleukin 23 receptor polymorphism and kidney transplant outcomes: a 10-year Taiwan cohort study.

OBJECTIVE Interleukin 23 receptor (IL-23R) plays a role in the pathogenesis of multiple autoimmune processes. The relationship between allograft outcomes and the IL-23Rvariant genotypes has not been reported on previously. Therefore, we examined the relationship between this genetic polymorphism and kidney transplant outcomes. METHODS This is an observational cohort study and 422 renal transplant recipients (RTRs) were enrolled. Polymerase chain reaction-restriction fragment length polymorphism was used for the measurement of IL-23R genetic polymorphisms. We used a composite end-point incorporating serum creatinine (SCr) doubling, graft failure and death as the primary outcome. Secondary outcomes included biopsy-proven acute rejection (BPAR), biopsy-proven interstitial fibrosis/tubular atrophy (IF/TA) and individual primary outcome. The risks of developing primary and secondary outcomes were compared between the different IL-23R genotypes and alleles. RESULTS With a mean follow-up of 79.3±28.8 months, 26 patients in the IL-23R genotype AA group and 32 patients in the IL-23R genotype AC/CC group reached the primary outcome (p=0.061). RTRs who carried the IL-23R AC/CC genotype (aHR 1.78; 95% CI. 1.01-3.12; p=0.046) and C allele (aHR 1.48; 95% CI. 0.96-2.28; p=0.075) had a higher risk of developing primary outcome as compared to those with IL-23R AA genotype and A allele, respectively. Moreover, RTRs who carried the IL-23R AC/CC genotype and C allele had a higher risk of developing biopsy-proven IF/TA (p=0.012; p=0.012) and SCr doubling (p=0.024; p=0.042) as compared to those with IL-23R AA genotype and A allele, respectively. The risk of BPAR, graft failure and death between the IL-23R genotypes and alleles were comparable. CONCLUSION IL-23R polymorphism may have a potential immuno-modulating role in long-term allograft outcome.

Glutathione S-transferase gene polymorphisms are not major risks for susceptibility to posttransplantation diabetes mellitus in Taiwan renal transplant recipients.

Glutathione S‐transferase (GST) M1 null genotype has been reported playing a significant role in the diabetes mellitus (DM) susceptibility in Turkish population. We investigated whether the GSTM1, GSTA1, and GSTP1 gene polymorphisms are associated with posttransplantation diabetes mellitus (PTDM) in Taiwan. There were 283 renal transplant recipients (RTRs) enrolled. Polymerase chain reaction–restriction fragment length polymorphism was used for the measurement of GSTA1, M1, and P1 genetic polymorphisms. PTDM was diagnosed according to the American Diabetes Association guidelines. Eight‐five patients (30%) were diagnosed with PTDM. The averaged posttransplant follow‐up period was 77.9 ± 27.2 months. Duration from transplantat to diagnosis of PTDM ranged from 0.2 to 103.1 months (19.2 ± 26.3 months). There were significantly differences between non‐DM and PTDM groups in age (50.6 ± 11.0 vs. 54.6 ± 9.36 years, P = 0.005), BMI (22.4 ± 3.6 vs. 24.3 ± 3.8, P<0.001). The distributions of GSTA1, GSTP1, and GSTM1 genotypes alleles were not significantly different between PTDM and non‐DM group. Patients carrying the different GSTA1, GSTP1, and GSTM1 genetic and allelic polymorphisms had no differences for the development of PTDM. These overall results suggested a lack of strong association with GSTA1, GSTP1, and GSTM1 genetic polymorphisms to the susceptibility of PTDM in Taiwanese RTRs. J. Clin. Lab. Anal. 25:432–435, 2011.

Y27632 attenuates the aristolochic acid-promoted invasion and migration of human urothelial cancer TSGH cells in vitro and inhibits the growth of xenografts in vivo

BACKGROUND Aristolochic acid I (AAI) has been implicated in urothelial cell carcinoma (UCC) in humans. However, whether AAI promotes invasion/migration of UCC has not been established. METHODS A study of human UCC TSGH cells cultured with AAI was conducted. Cell viability, the effects of AAI on the activity of matrix metalloproteinase (MMP)-9, the abilities of invasion/migration and the migration-related proteins (Ras, RhoA, ROCK1, PI-3K, pAkt and nuclear factor-kappaB) of the TSGH cells were assessed. The TSGH cells were subcategorized to 1-day or 30-day AAI exposure. An in vivo study using a nude mice xenograft model was employed to test the antitumor effects of Rho kinase inhibitor or Y27632. RESULTS A time- and dose-dependent increase in both activity and messenger RNA (mRNA) level of MMP-9 were demonstrated. The mRNA level of urokinase-type plasminogen activator was increased and tissue inhibitor of metalloproteinase-1 was decreased in the cells with 30-day but not 1-day AAI exposure. A dose-dependent enhancement in wound-healing rate and cell migration was demonstrated, especially in the 30-day AAI-exposed cells. Expressions of Ras/RhoA and other migration-related proteins were increased after AAI treatment, which could be inhibited by Y27632. The in vivo results demonstrated that Y27632 was able to attenuate the speed of growth of the inoculated tumors in nude mice. CONCLUSION Clinically, the patients with prolonged AAI exposure are highly associated UCC, our results provided in vitro and in vivo evidence that prolonged AAI exposure enhances invasion and migration of human TSGH cells.

Kaempferol Inhibits the Invasion and Migration of Renal Cancer Cells through the Downregulation of AKT and FAK Pathways

Kaempferol, which is isolated from several natural plants, is a polyphenol belonging to the subgroup of flavonoids. Kaempferol exhibits various pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial, and anticancer activities. In this study, kaempferol can significantly inhibit the invasion and migration of 786-O renal cell carcinoma (RCC) without cytotoxicity. We examined the potential mechanisms underlying its anti-invasive activities on 786-O RCC cells. Western blot was performed, and the results showed that kaempferol attenuates the manifestation of metalloproteinase-2 (MMP-2) protein and activity. The inhibitive effect of kaempferol on MMP-2 may be attributed to the downregulation of phosphorylation of Akt and focal adhesion kinase (FAK). By examining the SCID mice model, we found that kaempferol can safely inhibit the metastasis of the 786-O RCC cells into the lungs by about 87.4% as compared to vehicle treated control animals. In addition, the lung tumor masses of mice pretreated with 2-10 mg/kg kaempferol were reduced about twofold to fourfold. These data suggested that kaempferol can play a promising role in tumor prevention and cancer metastasis inhibition.

Pentraxin 3 Activates JNK Signaling and Regulates the Epithelial-To-Mesenchymal Transition in Renal Fibrosis

Background/Aims: Tubulointerstitial fibrosis can lead to end-stage renal disease. Pentraxin 3 (PTX3) is an acute phase protein produced by resident and innate immunity cells. We investigated the effect of PTX3 on cultured human proximal tubular epithelial (HK-2) cells and a rat unilateral ureteral obstruction (UUO) model of renal fibrosis. Methods: Gain-of-function experiments were used to examine the effect of recombinant human PTX3 (Rh-PTX3) on HK-2 cells. Cell proliferation (MTT assay) and in vitro cell migration were measured. The levels of PTX3, p-JNK, and EMT markers were measured using immunohistochemistry, RT-PCR, and western blotting in UUO rats and HK-2 cells. Results: HK-2 cells treated with Rh PTX3 did not affect cell viability, but significantly increased cell migration. Moreover, Rh-PTX3 increased the expression of snail, slug, N-cadherin, and vimentin, decreased the expression of E-cadherin, and increased the phosphorylation of JNK. SP600126 (a specific JNK inhibitor) enhanced the effects of Rh-PTX3. Rats with UUO exhibited time-dependent increased levels of PTX3, p-JNK, and vimentin, and decreased expression of E-cadherin. Conclusions: Our results suggest that PTX3 induces cell migration via upregulation of EMT in a JNK-dependent mechanism, and highlight the role of PTX3 in the pathogenesis renal fibrosis.