Jade-1: its structure, regulation and functions in the renal cancer.

Jade-1 is originally identified by the yeast two-hybrid system as a protein partner of von Hippel-Lindau (pVHL) tumor suppressor, a well-known renal tumor suppressor. In cellular signaling pathways, many upstream Jade-1 regulators, such as pVHL, CK1α, PC1, and NPHP4, can control its activity by stabilization, phosphorylation, and nuclear translocation. Numerous downstream effectors, including ß-catenin, AKT, p21, and Bcl-2, are well modulated by Jade-1, which mainly regulates cell proliferation and apoptosis. Jade-1 is also deemed to be a candidate of transcriptional co-activator associated with histone acetyltransferase (HAT) activity. This review focuses on the anticancer role of Jade-1 in clear cell renal carcinoma and the inhibitory effect of Jade-1 on cystic renal diseases. This review aims to provide a basis of disease prevention or therapy.

RPA1 expression in esophageal carcinoma and its influence on radiosensitivity of esophageal carcinoma TE-1 cells.

AIM: To determinate the RPA1 expression in esophageal carcinoma and the paired tumor-adjacent tissue, and to explore the influence of RPA1 on radiosensitivity of esophageal carcinoma TE-1 cells. METHODS: Firstly, the RPA1 expression of 40 cases esophageal carcinoma and their adjacent tissues were detected by immunohistochemistry. Secondly, The esophageal carcinoma cell subline-radiation resistance model (TE-1R) was constructed by radiation-induction, the RPA1 expression and proliferation activity of TE-1 and TE-1R cells were detected by Western blot and MTT assay respectively. After radiation, the expression of RPA1 and cell apoptosis were detected by Western blot and FACS respectively. Cell clone formation and survival rate were detected by clonogenic assay. Thirdly, Inhibiting RPA1 expression by siRNA in TE-1 cells, the expression of RPA1 was detected by RT-PCR and Western blot, Cell proliferation inhibition ratio and cell apoptosis after radiation were detected by MTT assay and FACS respectively. RESULTS: The RPA1 expression in esophageal carcinoma was significantly higher than that in the tumor-adjacent tissues, which was associated with tumor invasion and lymph node metastasis. The RPA1 expression in TE-1R cells was higher than that in TE-1 cells, while the proliferation activity of TE-1R cells was lower than that of TE-1 cells, and the apoptosis rate of TE-1R cells after radiation was less than that of TE-1 cells. In addtion, the clone formation and survival rate of TE-1R cells were higher than that of TE-1 cells. Moreover, inhibiting RPA1 expression by siRNA-RPA1 could promoted proliferation inhibition ratio and apoptosis rate of TE-1 cells after radiation. CONCLUSION: The over-expression of RPA1 in esophageal carcinoma was related with progression and metastasis. Moreover, radiation induced the excessive expression RPA1 in TE-1 cells, and the radiosensitivity of TE-1R cells was less than that of TE-1 cells. Furthermore, inhibiting RPA1 expression could increase radiosensitivity of TE-1 cells. Overall, RPA1 could influence radiosensitivity and might be one important mechanism of radiation resistance in TE-1 cells.

Oncolytic adenovirus expressing interleukin-18 induces significant antitumor effects against melanoma in mice through inhibition of angiogenesis.

It has been shown that interleukin 18 (IL-18) exerts antitumor activity. In this study, we investigated whether oncolytic adenovirus-mediated gene transfer of IL-18 could induce strong antitumor activity. A tumor-selective replicating adenovirus expressing IL-18 (ZD55-IL-18) was constructed by insertion of an IL-18 expression cassette into the ZD55 vector, which is based on deletion of the adenoviral E1B 55-kDa gene. It has been shown that ZD55-IL-18 exerted a strong cytopathic effect and significant apoptosis in tumor cells. ZD55-IL-18 significantly decreased vascular endothelial growth factor and CD34 expression in the melanoma cells. Treatment of established tumors with ZD55-IL-18 showed much stronger antitumor activity than that induced by ZD55-EGFP (enhanced green fluorescent protein) or Ad-IL-18. These data indicated that oncolytic adenovirus expressing IL-18 could exert potential antitumor activity through inhibition of angiogenesis and offer a novel approach to melanoma therapy.

Inhibition of renal cancer cell growth in vitro and in vivo with oncolytic adenovirus armed short hairpin RNA targeting Ki-67 encoding mRNA.

RNA interference (RNAi) has been proved to be a powerful tool for gene knockdown purpose and holds great promise for the treatment of cancer. Our previous study demonstrated that the reduction of Ki-67 expression by means of chemically synthesized siRNAs and shRNAs expressed from plasmid resulted in proliferation inhibition in human renal carcinoma cells. In this study, we constructed a novel oncolytic adenovirus-based shRNA expression system, ZD55-Ki67, and explored ZD55-Ki67-mediated RNAi for Ki-67 gene silencing. Our results showed that ZD55-Ki67 could induce silencing of the Ki-67 gene effectively, allow for efficient tumor-specific viral replication and induce the apoptosis of tumor cells effectively in vitro and in nude mice. We conclude that combining shRNA gene therapy and oncolytic virotherapy can enhance antitumor efficacy as a result of synergism between CRAd oncolysis and shRNA antitumor responses.

Neuroprotection against ischemic brain injury by a small peptide inhibitor of c-Jun N-terminal kinase (JNK) via nuclear and non-nuclear pathways.

Our previous studies and the others have strongly suggested that c-Jun N-terminal kinase (JNK) signaling pathway plays a critical role in ischemic brain injury. Here we reported that Tat-JNK binding domain (JBD) of JNK-interacting protein-1 (JIP-1), a smaller 11-mer peptide corresponding to residues 153-163 of murine JIP-1 conjugated to Tat peptide, perturbed the assembly of JIP-1-JNK3 complexes, thus inhibiting the activation of JNK3 induced by ischemia/reperfusion in the vulnerable hippocampal CA1 subregion. As a result, Tat-JBD diminished the increased phosphorylation of c-Jun (a nuclear substrate of JNK) and the increased expression of Fas ligand induced by ischemia/reperfusion in the vulnerable hippocampal CA1 subregion. At the same time, through inhibiting phosphorylation of Bcl-2 (a cytosolic target of JNK) and the release of Bax from Bcl-2/Bax dimers, Tat-JBD attenuated Bax translocation to mitochondria and the release of cytochrome c induced by ischemia/reperfusion. Furthermore, the activation of caspase3 and hydrolyzation of poly-ADP-ribose-polymerase induced by brain ischemia/reperfusion were also significantly suppressed by preinfusion of the peptide Tat-JBD. Importantly, Tat-JBD showed neuroprotective effects on ischemic brain damage in vivo, and administration of the peptide after ischemia also achieved the same effects as preinfusion of the peptide did. Thus, our findings imply that Tat-JBD induced neuroprotection against ischemia/reperfusion in rat hippocampal CA1 region via inhibiting nuclear and non-nuclear pathways of JNK signaling. Taken together, these results indicate that Tat-JBD peptide provides a promising therapeutic approach for ischemic brain injury.

[Expression and purification of murine interleukin 18 in Escherichia coli and its antitumor effects].

Total RNA was extracted from murine hepatocytes, and the cDNA of interleukin 18(IL-18) was amplified by RT-PCR. The cDNA was introduced into the expression vector pJW2 and sequenced. Under heat induction, the recombinant murine IL-18(rmIL-18) was expressed in inclusion bodies in E. coli with the yield accounting for 18% of total bacteria proteins. The inclusion bodies were dissolved with 5 mol/L urea, and rmIL-18 was purified using Sephadex G-100 column chromatography. In the presence of 0.5 mg/L Con A, the purified rmIL-18 showed dose-dependent IFN-gamma-inducing activity in murine splenocytes. The purified rmIL-18 exhibited significant antitumor effects in Kunming mice challenged intraperitoneally (i.p.) with H22 hepatocarcinoma when administered 10 micrograms rmIL-18 i.p. on days 1, 4 after challenge, and the mice survived resisted the rechallenged with H22 cells.