ABCG2 is a potential prognostic marker of overall survival in patients with clear cell renal cell carcinoma.

BACKGROUND: ATP-binding cassette sub-family G member 2 (ABCG2) is a semi-transport protein that plays a major role in multidrug resistance. We aimed to evaluate the prognostic significance of ABCG2 expression in patients with clear cell renal cell carcinoma. METHODS: From 2008 to 2013, 120 patients with clear cell kidney cancer underwent surgery with paraffin-embedded specimens and necessary clinical information available. Immunohistochemistry staining was performed to grade the expression of ABCG2 as ABCG2(-): less than 10% of tumor cells stained; ABCG2(+): weak membrane staining; and ABCG2(++): moderate or strong membrane staining. The overall survival was analyzed using Kaplan-Meier method. Multivariable Cox regression evaluated the independent predictors for overall survival. RESULTS: ABCG2(-) was diagnosed in 57 (48%) patients, ABCG2(+) in 52 (43%) patients, and ABCG2 (++) in 11(9.2%) patients. ABCG2 expression significantly correlated with the five-year survival (p < 0.001) and distant metastasis (p = 0.001). In the multivariable analysis, besides Fuhrman grade, the ABCG2 expression was an independent prognostic marker for overall survival (p < 0.001) when incorporating other relevant tumor and clinical parameters (HR = 3.84, 95% CI: 1.92-7.70). CONCLUSION: The current data suggests that ABCG2 may serve as a prognostic marker for overall survival in patients with clear cell renal cell carcinoma. Further studies with large cohorts of patients will be essential for validating these findings and defining the clinical utility of ABCG2 in the patient population.

Design and validation of a novel hydraulic hybrid vehicle with wheel motors.

With strong demands of energy-saving and environment-friendly vehicles, hydraulic hybrid powertrain is a suitable solution for urban transportation. This article proposes a novel hydraulic hybrid vehicle with wheel motors to improve vehicle power performance and fuel economy. A forward-looking simulation model of the vehicle is built. System parameters are determined according to the power performance demands. A smaller engine is chosen, the peak power of which is reduced by 11.96%. The simulation model is calibrated and verified by experimental tests on the designed test bench. Parameterized simulation results indicate that the acceleration time 0-100 km/h of the designed vehicle is decreased by 36.3% from 19.63 to 12.5 s compared with the conventional vehicle. The maximum vehicle speed is 140 km/h, and the maximum gradeability is 29%. When the engine works in economy mode, fuel consumption is decreased by 35.59% from 15 to 9.66 L per 100 km on the Urban Dynamometer Driving Schedule cycle compared with the conventional vehicle.

Fbxw7 regulates renal cell carcinoma migration and invasion via suppression of the epithelial-mesenchymal transition.

F-box and WD repeat domain containing 7 (Fbxw7) is an F-box protein that belongs to the SKP1-CUL1-F-box protein E3 ligase complex and is responsible for transferring the ubiquitin molecule to the substrate, which results in its recognition and subsequent degradation by proteasomes. Furthermore, it can identify a network of signaling proteins that function in cell growth, diversion and apoptosis. In the present study, Fbxw7 was downregulated in renal cell carcinoma (RCC) tissues compared with the adjacent non-tumor tissues and its expression was significantly associated with the tumor-node-metastasis stage, lymph node metastasis and distant metastasis in patients with RCC. Furthermore, multivariate Cox regression analyses indicated that Fbxw7 expression was an independent factor for the prediction of the overall survival of patients with RCC. A functional study demonstrated that downregulation of Fbxw7 facilitated tumor cell migration and invasion via the epithelial-mesenchymal transition (EMT). Therefore, the results of the current study indicted that Fbxw7 is an anti-oncogene that serves a notable function in RCC development by suppressing RCC metastasis and the EMT, indicating the potential therapeutic value of Fbxw7 in inhibiting metastasis in RCC.

Tip60 is associated with resistance to X-ray irradiation in prostate cancer.

Tip60, an oncogene, accelerates cell growth by regulating androgen receptor translocation into the nucleus in prostate cancer. However, the mechanism of Tip60 in the response of prostate cancer to radiotherapy, and radioresistance, has not been studied. Using human prostate cancer samples and two human prostate cancer cell lines (LNCaP and DU145), Tip60 protein expression and the acetylation of ataxia telangiectasia mutant (ATM) were analysed by western blotting and immunoprecipitation. Tip60 was downregulated with small interfering RNA. Cells were irradiated using X-rays at 0.25 Gy·min-1. Cell viability was assessed by the MTT assay. The expression of Tip60 protein was increased in radioresistant prostate cancer tissues in comparison with radiosensitive tissues, which was also confirmed in both irradiated DU145 and LNCaP cells. Furthermore, the acetylation of ATM was also upregulated in a time-dependent manner after irradiation of both DU145 and LNCaP cells. Additionally, depletion of Tip60 decreased the survival of LNCaP and DU145 cells by inducing apoptosis, reduced the acetylation of ATM and decreased the expression of phosphorylated ATM, Chk2 and cdc25A in both DU145 and LNCaP cells after X-ray irradiation. The results of this study demonstrated that the expression of Tip60 may be related to the radioresistance of prostate cancer and could serve as a promising predictive factor for prostate cancer patients receiving radiotherapy.

LDHA promotes tumor metastasis by facilitating epithelial­mesenchymal transition in renal cell carcinoma.

Previous studies have indicated that high expression of lactate dehydrogenase A (LDHA) exists in many human cancers. Recently, several reports showed that silencing or inhibition of LDHA could suppress metastasis of human cancer including renal cell carcinoma (RCC). However, the mechanism remains unknown. The role of LDHA in RCC migration and invasion was investigated using immunohistochemistry, western blotting, Transwell and scratch assays, and in vivo experiment. The influence of LDHA on the Warburg effect was also investigated by LDHA activity and lactate production assay. LDHA was overexpressed in RCC tissues and predicted a worse survival following renal resection. Correlation analysis demonstrated that LDHA was negatively correlated with E­cadherin and positively with N­cadherin. Experimentally, both in vivo and in vitro experiments found downregulation of LDHA suppressed RCC cells migration and invasion by inhibiting EMT. In addition, results indicated LDHA could promote the Warburg effect. Further research presented that the LDHA inhibitor, oxamate, suppressed tumor metastasis by inhibiting LDHA activity and EMT. These results demonstrated that LDHA mediates tumor metastasis by promoting EMT in RCC, suggesting that LDHA could be a promising therapeutic target for RCC therapy.

Clear cell changes in mucinous tubular and spindle cell carcinoma: cytoplasmic pallor/clearing within tubules, vacuoles or hybrid conventional clear cell carcinoma of kidney?

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare and recently recognized subtype of renal cell carcinoma (RCC). Apart from the classic morphology comprising conventional three components, there exist a large number of non-classic morphological variants of MTSCC, which make it necessity to differentiate from other RCC. Herein, we report two non-classic morphological variants of MTSCC. Case 1, a 85 years old man, showed numerous vacuoles among inherent components and cytoplasmic pallor/clearing within tubules mimicking conventional clear cell RCC with a 8.5 years follow-up, while Case 2 indicated a "mucin-poor" MTSCC associated with simultaneous conventional clear cell RCC at her age of 73 years. Until now Case 1 carries the longest disease-free survival reported in literature since MTSCC was defined and ranks the oldest since reported in literature, while Case 2 is the first report of "mucin-poor" MTSCC associated with simultaneous conventional clear cell RCC. Now, since no biomarkers or imagining tools but pathological examination can confirm the diagnosis of MTSCC, the management is always following the guideline of RCC in clinical practice. Generally, most reports consider it as a good prognosis disease, but sarcomatoid variant, even classic subtype can progress rapidly to life-threatening disease.

Prognostic factors for overall survival with targeted therapy in Chinese patients with metastatic renal cell carcinoma.

INTRODUCTON: We wanted to identify the prognostic factors for overall survival (OS) in Chinese patients with metastatic renal cell carcinoma (mRCC) treated with first-line targeted therapy (sorafenib or sunitinib). METHODS: We retrospectively reviewed clinical data from 119 mRCC patients administered sorafenib or sunitinib at the Ruijin Hospital since 2007. OS rates were calculated by the Kaplan-Meier method. Each variable was investigated univariately and then multivariately using a stepwise algorithm. A multivariate Cox regression model analyzed baseline variables for prognostic significance. RESULTS: The mean patient age was 57 ± 12 years; 37 patients (31%) received sorafenib and 82 (69%) received sunitinib. The mean OS was 22.7 ± 15.6 months (range: 2.8- 68.7). OS rates at year 1, 3 and 5 were 74%, 57%, and 36%, respectively. Univariate analysis identified significant negative prognostic factors (p < 0.05) as Eastern Cooperative Oncology Group (ECOG) performance status ≥2, symptoms, no prior nephrectomy, microscopic necrosis, ≥2 metastatic sites, presence of liver, bone, or pancreas metastasis, hemoglobin less than the lower limit of normal(female <115 g/L, male <130 g/L), and serum alkaline phosphatase greater than the upper limit of normal (126 IU/L) at baseline, as well as a relative dose intensity of targeting agents in the first month (1M-RDI) of <50%. Multivariate analysis of OS identified 4 independent predictors: no symptoms, no bone or pancreas metastasis, and 1M-RDI of targeting agents (≥50%). CONCLUSIONS: With targeted therapy, there is some change in the prognostic factors for mRCC and target drug therapies (1M-RDI ≥50%) play an important role in the prognosis of mRCC. Continued progress in the identification of patient-specific prognostic factors for mRCC will require further advances in the understanding of tumour biology.

[Single-chain urokinase-type plasminogen activator (scu-PA) purification by immuno-affinity chromatography].

The only difference of primary structure between single-chain prourokinase (pro-UK or scu-PA) and two-chain urokinase (UK or tcu-PA) is the cleavage of a single peptide bond (Lys158-Ile159) and transform scu-PA into its active two-chain form. A 13-peptide (Thr-Leu-Arg-Pro-Arg-Phe-Lys-Ile-Ile-Gly-Gly-Glu-Cys), which spans the cleavage peptide bond, was synthesized and linked to KLH (Keyhole limpet hemocyanin). The Balb/c mice were immunized by the conjugated protein with proper adjuvant. According to the Kohler and Milstein's methods, a hybridoma cell line G7 secreting monoclonal antibody specific for scu-PA was obtained. The anti-scu-PA McAb, purified from the supernatant of porous microcarrier hybridoma cell culture, was conjugated to CNBr-activated Sepharose 4B to prepare an immuno-affinity chromatography column. The u-PA was purified only by this affinity column from the supernatant of cultivating the u-PA-producing recombinant CHO cell, the u-PA recovery ratio is 90.4%, the purification factor was about 50, with the specific activity of 1.2 x 10(5) IU/mg, the scu-PA ratio in the u-PA product was 96.3%. Compared to immuno-affinity chromatography, the 3-step process for purifying u-PA (cation-exchange column, gel filtration column and benzamidine affinity column) has a u-PA recovery ratio of about 65%, with a specific activity of 1.0 x 10(5) IU/mg, and an scu-PA ratio of about 90%. These results showed that immuno-affinity chromatography is simple to recover u-PA and effective to separate scu-PA from tcu-PA.