Brusatol Inhibits Proliferation and Metastasis of Colorectal Cancer by Targeting and Reversing the RhoA/ROCK1 Pathway.

Brusatol (BRU) is an important compound extracted from Brucea javanica oil, whose pharmacological effects are able to induce a series of biological effects, including inhibition of tumor cell growth, anti-inflammatory, antiviral, and antitumor. Currently, there are so few studies about the brusatol effects on colorectal cancer that its anticancer mechanism has not been clearly defined. In this study, we made an in-depth investigation into the brusatol effect towards the proliferation and metastasis of colon cancer and the possible mechanism. The inhibitory effect of BRU on the proliferation of colorectal cancer cells was unveiled via CCK-8 method and colony formation assay, while the inhibitory effect of BRU on migration and invasion of colorectal cancer cells was revealed by scratch assay and transwell assay. In addition, Western blot results also revealed that BRU inhibited not only the expressions of RhoA and ROCK1 but also the protein expressions of EMT-related markers e-cadherin, N-cadherin, Vimentin, MMP2, and MMP9 in colon cancer cells. Through the xenotransplantation model, our in vivo experiment further verified the antitumor effect of BRU on colon cancer cells in vitro, and the results were consistent with the protein expression trend. In conclusion, BRU may inhibit the proliferation and metastasis of colorectal cancer by influencing EMT through RhoA/ROCK1 pathway.

Overexpression of ABCB4 contributes to acquired doxorubicin resistance in breast cancer cells in vitro.

PURPOSE: Doxorubicin is one of the most active agents in the first-line therapy for metastatic breast cancer, but its utility is partially limited by the frequent emergence of doxorubicin resistance. In this study, we aimed to investigate the role of ATP-binding cassette sub-family B, member 4 (ABCB4) in acquired doxorubicin resistance in breast cancer cells, as well as its potential mechanism. METHODS: In doxorubicin-sensitive and -resistant breast cancer cell lines MCF-7 and MDA-MB-231, the expression levels of ABCB4 were detected using real-time quantitative PCR and Western blot analysis, the DNA methylation and histone acetylation status of ABCB4 gene were investigated by bisulfite-sequencing PCR (BSP) and chromatin immunoprecipitation (ChIP) assays, and the doxorubicin sensitivity and intracellular doxorubicin accumulation were observed using cell cytotoxicity assay and flow cytometry. In Madin-Darby Canine Kidney (MDCKII) cells, In vitro transport assay was used to assess the ABCB4-mediated transport of doxorubicin. RESULTS: ABCB4 was overexpressed in doxorubicin-resistant breast cancer cells compared to their doxorubicin-sensitive counterparts, which was associated with reduced DNA methylation as well as increased histone acetylation at the ABCB4 promoter. ABCB4 could actively pump doxorubicin out of the cells, and knockdown of ABCB4 increased doxorubicin sensitivity and intracellular accumulation in doxorubicin-resistant breast cancer cells. CONCLUSIONS: Our results indicate that ABCB4 is overexpressed in breast cancer cells with acquired doxorubicin resistance, which could be attributed, at least partially, to the epigenetic modifications of ABCB4 gene. ABCB4 mediates the efflux transport of doxorubicin, and contributes to the acquired resistance of doxorubicin in breast cancer cells.

[Effect of the heat shock protein 27 on NOS expression of spinal cord anterior hornmotoneurons after brachial plexus avulsion].

AIM: To observe the effect of heat shock protein 27 (Hsp27) on nitric oxide synthase (NOS) of spinal cord anterior horn after brachial plexus roots avulsion. METHODS: Sixty male adult Wistar rats were divided into control and experiment groups at random. The experiment group subjected to heat shock under 45 degrees C for 15 min, and maintained under 42 degrees C for 20 min subsequently. After recovering 24 h under the room temperature, the nerves of brachial plexus were avulsion with microhemostatic forcep. In a span from 12 h to 7 d, these animals were killed at different time. But the control group only received the surgery of the nerve roots of brachial plexus avulsion. The freeze sections of spinal cord were stained by NADPH-d histochemistry, HSP27 immunohistochemical. RESULTS: (1) In experiment group, the motoneuron began to express NOS abundantly at 12 h after avulsion (A=0.13625). Then the NOS-positive neurons declined quickly, but in control group, the motoneuron began to express NOS at the 5th day after lesion. (2) Hsp27 begin to show the peak at 1 d in experiment and control groups, but the experiment group were more strong than the control group. CONCLUSION: Hsp27 inhibited NOS of motoneuron after avulsion and brought into full play the cytoprotection.

[Detection of Skp2 and p27kip1 expression in human renal cell carcinoma using tissue chip technique].

OBJECTIVE: To detect the expression of skp2 and p27kip1 in human renal cell carcinoma (RCC) using tissue chip technique, and evaluate the relationship between the proteins and the biological behavior of RCC. METHODS: Tissue chip technique and immunohistochemical SP method was used to detect the expression of skp2 and p27kip1 in normal and tumor tissues. RESULTS: The positivity rate of Skp2 in RCC was significantly higher than that in normal renal tissues (P=0.025). The positivity rate of Skp2 expression in RCC was significantly correlated to poor differentiation of the tumor (P=0.002), and was not associated with the patients gender, age, tumor size, lymph node metastasis and stages of RCC (P>0.05). The positivity rate of p27kip1 in RCC was significantly lower than that in normal renal tissues (P=0.007). The positivity rate of p27kip1 expression was inversely correlated to the malignancy and stage of RCC (P<0.05), but not with the patients' age, gender, lymph node metastasis and tumor size (P>0.05). An inverse correlation was noted between Skp2 and p27kip1 expressions (r= -0.273, P=0.014). CONCLUSION: Overexpression of Skp2 protein may lead to decreased p27kip1 level in RCC, indicating its involvement in the carcinogenesis and development of RCC.

[Cytotoxic effect of oncolytic virus combined with mitomycin against human bladder cancer cells in vitro and in vivo].

OBJECTIVE: To evaluate the effect of combined use of oncolytic virus and the chemotherapeutic agents mitomycin (MMC) in growth inhibition of human bladder cancer cell line T-24 in vitro. METHODS: Human bladder cancer cell line T-24 was infected with oncolytic virus (ONYX-015) of different multiplicity of infection, or treated with MMC in addition to ONYX-015. The changes in the cell growth, morphology, and apoptosis of cultured T-24 cells were observed by means of cell counting and fluorescence microscopy after the treatments. The effects of the treatment protocols were also tested in nude mouse model of implanted subcutaneous tumor. RESULTS: Combined use of ONYX-015 and MMC produced substantially stronger cytotoxic effect against T-24 cells than exclusive use of ONYX-015. In in vivo experiments, combination of oncolytic virus and MMC resulted in much more significant tumor growth inhibition than either of the agents used alone. Obvious T-24 cell apoptosis could be observed in response to combined ONYX-105 and MMC treatment and exclusive ONYX-105 treatment. CONCLUSIONS: ONYX-015 combined with MMC can produce significant cytotoxicity against T-24 cells and enhance therapeutic efficacy against bladder carcinoma.

[Expression of TFAR19(PDCD5) in normal human kidney, renal clear cell carcinoma, normal human bladder and bladder carcinoma].

OBJECTIVE: To detect the expression of apoptosis gene PDCD5 in tissues of normal human kidney, renal clear cell carcinoma, normal bladder and bladder carcinoma, and explore the role of PDCD5 gene in renal clear cell carcinoma and bladder carcinoma. METHODS: Indirect immunohistochemistry was employed to detect PDCD5 expression in 63 kidney specimens and 42 bladder specimens. Positive expression rates and intensity of PDCD5 protein expression in the kidney tissue were investigated microscopically and by computerized image analysis. Positive expression rate in the bladder tissue was investigated by microscopic observation. RESULTS: The results of immunohistochemical staining showed PDCD5 protein overexpression in the renal tubule of normal human kidney tissues and downregulation with the stage increase of renal clear cell carcinoma. PDCD5 protein expression showed statistical significance in tissues of normal kidney and renal clear cell carcinoma in all stages. No obvious PDCD5 expression was detected in the tissues of normal human bladder and bladder carcinoma. CONCLUSION: PDCD5 is an important apoptosis-regulating factor in the occurrence of renal clear cell carcinoma, and its expression is extremely low in tissues of normal human bladder and bladder carcinoma.

[Whole-body fluorescent imaging of the growth and metastasis of GFP-expressing bladder tumors].

OBJECTIVE: To label a human bladder cancer cell line and establish a novel human bladder cancer mouse model. METHODS: T-24 cells, a human bladder transitional cell carcinoma cell line, were transfected with GFP plasmid to screen stable GFP-expressing clones. The latter were implanted into the wall of the bladder or the subcutaneous tissue of the neck of nude mice. The growth, invasion, and metastasis of the implanted tumor were observed and evaluated with whole-body optical imaging system. The findings were compared with those of HE staining on routine paraffin sections. RESULTS: GFP-labeled tumor cells displayed green fluorescence under fluorescent microscopy and showed stable GFP expression in vitro and in vivo. One week after in situ transplantation of 5 x 10(5) T24 cells, the new bladder cancer was observed and evaluated under whole-body optical imaging system. Two weeks later, the new bladder tumor could be palpated, and 4 weeks later, metastasis to regional drainage lymph nodes in the pelvic and retroperitoneal lymph nodes occurred. The growth and metastasis of the implant bladder tumor were easily observed and accurately evaluated by fluorescent microscope. CONCLUSION: GFP-labeled tumor cells display green fluorescence under fluorescent microscopy and show stable GFP expression. GFP-labeled T-24 cells and the novel human bladder cancer model described hereby provide a simple and reliable means for studying human bladder cancer in vivo.