Yu-Chieh Tsai

Stopping smoking might reduce tumour recurrence in nonmuscle-invasive bladder cancer

To evaluate effects of stopping smoking on the outcome of nonmuscle‐invasive bladder cancer, as cigarette smoking is a risk factor for bladder cancer and little is known about whether stopping smoking reduces the risk of recurrence or progression.

Altered prostate epithelial development in mice lacking the androgen receptor in stromal fibroblasts.

Androgens and the androgen receptor (AR) play important roles in the development of male urogenital organs. We previously found that mice with total AR knockout (ARKO) and epithelial ARKO failed to develop normal prostate with loss of differentiation. We have recently knocked out AR gene in smooth muscle cells and found the reduced luminal infolding and IGF‐1 production in the mouse prostate. However, AR roles of stromal fibroblasts in prostate development remain unclear.

Improved local control by surgery and paclitaxel-based chemoradiation for esophageal squamous cell carcinoma: Results of a retrospective non-randomized study†

To investigate the impact of using paclitaxel in chemoradiation on locally advanced esophageal squamous cell carcinoma (SCC) treated with or without surgery.

Down-regulation of glucose-regulated protein (GRP) 78 potentiates cytotoxic effect of celecoxib in human urothelial carcinoma cells.

Celecoxib is a selective cyclooxygenase-2 (COX-2) inhibitor that has been reported to elicit anti-proliferative response in various tumors. In this study, we aim to investigate the antitumor effect of celecoxib on urothelial carcinoma (UC) cells and the role endoplasmic reticulum (ER) stress plays in celecoxib-induced cytotoxicity. The cytotoxic effects were measured by MTT assay and flow cytometry. The cell cycle progression and ER stress-associated molecules were examined by Western blot and flow cytometry. Moreover, the cytotoxic effects of celecoxib combined with glucose-regulated protein (GRP) 78 knockdown (siRNA), (−)-epigallocatechin gallate (EGCG) or MG132 were assessed. We demonstrated that celecoxib markedly reduces the cell viability and causes apoptosis in human UC cells through cell cycle G1 arrest. Celecoxib possessed the ability to activate ER stress-related chaperones (IRE-1α and GRP78), caspase-4, and CCAAT/enhancer binding protein homologous protein (CHOP), which were involved in UC cell apoptosis. Down-regulation of GRP78 by siRNA, co-treatment with EGCG (a GRP78 inhibitor) or with MG132 (a proteasome inhibitor) could enhance celecoxib-induced apoptosis. We concluded that celecoxib induces cell cycle G1 arrest, ER stress, and eventually apoptosis in human UC cells. The down-regulation of ER chaperone GRP78 by siRNA, EGCG, or proteosome inhibitor potentiated the cytotoxicity of celecoxib in UC cells. These findings provide a new treatment strategy against UC.

Retrospective Analysis of Outcome Differences in Preoperative Concurrent Chemoradiation With or Without Elective Nodal Irradiation for Esophageal Squamous Cell Carcinoma

PURPOSE To evaluate the efficacy and patterns of failure of elective nodal irradiation (ENI) in patients with esophageal squamous cell carcinoma (SCC) undergoing preoperative concurrent chemoradiation (CCRT) followed by radical surgery. METHODS AND MATERIALS We retrospectively studied 118 patients with AJCC Stage II to III esophageal SCC undergoing preoperative CCRT (median, 36 Gy), followed by radical esophagectomy. Of them, 73 patients (62%) had ENI and 45 patients (38%) had no ENI. Patients with ENI received radiotherapy to either supraclavicular (n = 54) or celiac (n = 19) lymphatics. Fifty-six patients (57%) received chemotherapy with paclitaxel plus cisplatin. The 3-year progression-free survival, overall survival, and patterns of failure were analyzed. Distant nodal recurrence was classified into M1a and M1b regions. A separate analysis using matched cases was conducted. RESULTS The median follow-up was 38 months. There were no differences in pathological complete response rate (p = 0.12), perioperative mortality rate (p = 0.48), or delayed Grade 3 or greater cardiopulmonary toxicities (p = 0.44), between the groups. More patients in the non-ENI group had M1a failure than in the ENI group, with 3-year rates of 11% and 3%, respectively (p = 0.05). However, the 3-year isolated distant nodal (M1a + M1b) failure rates were not different (ENI, 10%; non-ENI, 14%; p = 0.29). In multivariate analysis, pathological nodal status was the only independent prognostic factor associated with overall survival (hazard ratio = 1.78, p = 0.045). The 3-year overall survival and progression-free survival were 45% and 45%, respectively, in the ENI group, and 52% and 43%, respectively, in the non-ENI group (p = 0.31 and 0.89, respectively). Matched cases analysis did not show a statistical difference in outcomes between the groups. CONCLUSIONS ENI reduced the M1a failure rate but was not associated with improved outcomes in patients undergoing preoperative CCRT for esophageal SCC. Pathological nodal metastasis predicted poor outcome.

INDUCTION CISPLATIN AND FLUOROURACIL-BASED CHEMOTHERAPY FOLLOWED BY CONCURRENT CHEMORADIATION FOR MUSCLE-INVASIVE BLADDER CANCER

PURPOSE To evaluate a multimodality bladder-preserving therapy in patients with muscle-invasive bladder cancer. METHODS AND MATERIALS Patients with stages T2-4aN0M0 bladder cancer suitable for cystectomy underwent radical transurethral resection and induction chemotherapy, followed by concurrent chemoradiotherapy (CCRT). Patients with a Karnofsky performance status (KPS) <80 or age > or =70 years underwent Protocol A: induction chemotherapy with three cycles of the cisplatin and 5-fluorouracil (CF) regimen, and CCRT with six doses of weekly cisplatin and 64.8 Gy radiotherapy given with the shrinking-field technique. Patients with KPS > or =80 and age <70 years underwent Protocol B: induction chemotherapy with three cycles of weekly paclitaxel plus the CF regimen, and CCRT with six doses of weekly paclitaxel and cisplatin plus 64.8 Gy radiotherapy. Interval cystoscopy was employed after induction chemotherapy and when radiotherapy reached 43.2 Gy. Patients without a complete response (CR) were referred for salvage cystectomy. RESULTS Among 30 patients (median, 66 years) enrolled, 17 and 13 patients underwent Protocol A and B, respectively. After induction chemotherapy, 23 patients achieved CR. Five (17%) of 7 patients without CR underwent salvage cystectomy. Overall, 28 patients (93%) completed the protocol treatment. Of 22 patients who completed CCRT, 1 had recurrence with carcinoma in situ and 3 had distant metastases. After a median follow-up of 47 months, overall and progression-free survival rate for all patients were 77% and 54% at 3 years, respectively. Of 19 surviving patients, 15 (79%) retained functioning bladders. CONCLUSIONS Our protocols may be alternatives to cystectomy for selected patients who wish to preserve the bladder.

MLN4924, a novel protein neddylation inhibitor, suppresses proliferation and migration of human urothelial carcinoma: In vitro and in vivo studies

MLN4924, a small molecule inhibitor of NEDD8 activating enzyme (NAE), has been reported to elicit an anti-tumor effect on various malignancies. In this study, we investigated the anti-tumor effect of MLN4924 in human urothelial carcinoma (UC) in vitro and in vivo by using three human UC cell lines of various grading (T24, NTUB1 and RT4). The impact of MLN4924 on UC cells was determined by measuring viability (MTT), proliferation (BrdU incorporation), cell cycle progression (flow cytometry with propidium iodide staining) and apoptosis (flow cytometry with annexin V-FITC labeling). The cell cycle regulatory molecules, apoptosis-related molecules, and cell stress-related proteins were examined by Western blotting. The influence of tumor cell migration and invasion was analyzed by Transwell and wound healing assays. We also evaluated the effects of MLN4924 on tumor growth by a SCID xenograft mouse model. The data show that MLN4924 induced dose-dependent cytotoxicity, anti-proliferation, anti-migration, anti-invasion and apoptosis in human UC cells, accompanied by activations of Bad, phospho-histone H2A.X, caspase-3, 7 and PARP, decreased level of phospho-Bcl2, and caused cell cycle retardation at the G2M phase. Moreover, MLN4924 activated endoplasmic reticulum stress-related molecules (caspase-4, phospho-eIF2α, ATF-4 and CHOP) and other stress responses (JNK and c-Jun activations). Finally, we confirmed MLN4924 inhibited tumor growth in a UC xenograft mouse model with minimal general toxicity. We concluded that MLN4924 induces apoptosis and cell cycle arrest, as well as activation of cell stress responses in human UC. These findings imply MLN4924 provides a novel strategy for the treatment of UC.

Targeting epidermal growth factor receptor/human epidermal growth factor receptor 2 signalling pathway by a dual receptor tyrosine kinase inhibitor afatinib for radiosensitisation in murine bladder carcinoma.

Given the promising control of bladder cancer achieved by combined chemotherapy/radiotherapy with selective transurethral resection, obstacles remain to the treatment of unresectable bladder cancer. The aim of this study was to determine whether targeting epidermal growth factor receptor (EGFR)/human epidermal growth factor receptor 2 (HER2) can radiosensitise a murine bladder tumour (MBT-2) cell line. Cell survival, expression of signal proteins and cell cycle changes in MBT-2 cells treated in vitro and in vivo with afatinib, an irreversible EGFR/HER2 inhibitor, plus radiotherapy were investigated by colony formation assay, Western blot assay and flow cytometry, respectively. Ectopic xenografts were established by subcutaneous injection of MBT-2 cells in C3H/HeN mice. Mice were randomised into 4 groups to receive afatinib (10mg/kg/day on day 1-7) and/or radiotherapy (15Gy on day 4). Positron emission tomography (PET) on day 8 was used to evaluate the early treatment response. Afatinib (200-1000nM) increased cell killing by radiation (0-10Gy). Pre-treatment of irradiated cells with afatinib inhibited radiation-activated HER2 and EGFR phosphorylation. As compared to either treatment alone, the combination increased the level of the cleavage form of poly (ADP-ribose) polymerase, the expression of phospho-γH2AX and the percentage of cells in subG1 phase (indicating enhanced induction of apoptosis), and decreased tumour metabolism and inhibited tumour growth by 64%. Afatinib has therapeutic value as a radiosensitiser of murine bladder cancer cells. The synergism between afatinib and radiation likely enhances DNA damage, leading to increased cell apoptosis.

The Selective Inhibitory Effect of a Synthetic Tanshinone Derivative on Prostate Cancer Cells

Androgen receptor (AR) is the main therapeutic target for the treatment of prostate cancer (PCa). Anti‐androgens to reduce or prevent androgens binding to AR are widely used to suppress AR‐mediated PCa growth; however, the androgen depletion therapy (ADT) is only effective for a short period of time. Here we tested PTS33, a new sodium derivative of cryptotanshinone, which can effectively inhibit the DHT‐induced AR transactivation and PCa cell growth, and then explored the effects of PTS33 on inhibiting the expressions of AR target genes and proteins.

Down-regulation of PKCζ in renal cell carcinoma and its clinicopathological implications

BackgroundMetastatic renal cell carcinoma (RCC) is highly resistant to systemic chemotherapy. Unfortunately, nearly all patients die of the metastatic and chemoresistant RCC. Recent studies have shown the atypical PKCζ is an important regulator of tumorigenesis. However, the correlation between PKCζ expression and the clinical outcome in RCC patients is unclear. We examined the level of PKCζ expression in human RCC.MethodsPKCζ mRNA and protein expressions were examined by real-time polymerase chain reaction (PCR) and immunohistochemistry (IHC) respectively in RCC tissues of 144 patients. Cellular cytotoxicity and proliferation were assessed by MTT.ResultsPKCζ expression was significantly higher in normal than in cancerous tissues (P < 0.0001) by real-time PCR and IHC. Similarly, PKCζ expression was down-regulated in four renal cancer cell lines compared to immortalized benign renal tubular cells. Interestingly, an increase of PKCζ expression was associated with the elevated tumor grade (P = 0.04), but no such association was found in TNM stage (P = 0.13). Tumors with higher PKCζ expression were associated with tumor size (P = 0.048). Expression of higher PKCζ found a poor survival in patients with high tumor grade. Down-regulation of PKCζ showed the significant chemoresistance in RCC cell lines. Inactivation of PKCζ expression enhanced cellular resistance to cisplatin and paclitaxel, and proliferation in HK-2 cells by specific PKCζ siRNA and inhibitor.ConclusionsPKCζ expression was associated with tumorigenesis and chemoresistance in RCC.