Downregulation of long non-coding RNA TRIM52-AS1 functions as a tumor suppressor in renal cell carcinoma.

Long non-coding RNAs (lncRNAs) are important regulators of gene expression, interacting with the major pathways of cell growth, proliferation, differentiation and survival. Alterations in the function of lncRNAs promote tumor formation, progression and metastasis. The purpose of the present study was to identify novel tumor suppressor lncRNAs, and elucidate their physiological function and mechanism in renal cell carcinoma (RCC). The results of the present study revealed that the expression of the lncRNA, TRIM52­AS1, was downregulated in RCC, which was demonstrated using reverse transcription­quantitative polymerase chain reaction analysis. Furthermore, the effects of TRIM52­AS1 on proliferation, cell migration and apoptosis were analyzed using a wound scratch assay, a 3­(4,5­dimethylthiazol­2yl)­2,5­diphenyl tetrazolium bromide assay and flow cytometric analysis, respectively. The overexpression of TRIM52­AS1 using a synthesized vector significantly suppressed cell migration and proliferation, and induced apoptosis of the RCC cells in vitro, and interference of its expression led to the opposite effects. The present study was the first, to the best of our knowledge, to demonstrate that TRIM52­AS1 functions as a tumor suppressor in RCC. Further investigation is required to elucidate the molecular mechanisms underlying the effects of TRIM52-AS1 in the development of RCC.

Mutational analysis of proto-oncogene Dbl on Xq27 in testicular germ cell tumors reveals a rare SNP in a patient with bilateral undescended testis.

OBJECTIVES: An abundance of X chromosomes in testicular germ cell tumors (TGCTs), and a candidate TGCTs susceptibility gene (TGCT1) on Xq27 highlight the potential involvement of X chromosomes in TGCT pathogenesis. However, the TGCT1 on Xq27 has so far not been identified. We hypothesized that a somatic mutation of dbl oncogene on Xq27 may play a role for the development of TGCTs. METHODS: We have screened 41 TGCT tissues for dbl mutations using single-strand conformation polymorphism (SSCP) analysis. These tissues are composed of 25 seminomatous TGCTs tissues and 16 non-seminomatous TGCTs tissues, including two cases with a rhabdomyosarcoma component. RESULTS: Somatic mutations were not detected in the 25 exons of dbl in these TGCTs. However, we found a rare single nucleotide polymorphism (SNP) (T to C nucleotide change) within intron 22 in one out of the 41 TGCTs cases (2%). Furthermore, the sample with the rare SNP was identified as the sole TGCTs case associated with bilateral undescended testis in our series. CONCLUSIONS: Our results indicate that proto-oncogene dbl is not a major target for sporadic TGCTs. However, the rare SNP in dbl may affect the susceptibility to undescended testis. Determining the frequency of this SNP in patients with various types of undescended testis in different ethnic groups is a warranted study.

[Inhibitory effect of silencing STAT3 gene with short hairpin RNA mediated by polyamidoamine dendrimers on growth of prostate cancer].

OBJECTIVE: To investigate the possibility of using generation 5 polyamidoamine dendrimers (G5-PAMAM-D) as gene vector for eukaryotic expression plasmid of siRNA in prostate carcinoma in vitro and vivo. METHODS: Firstly, eukaryotic expression vector of siRNA pSilencing 4.1-EGFP-shRNA, specific for enhanced green fluorescent protein (EGFP), pSilencing 4.1-STAT3-shRNA for signal transducers and activators of transcription 3 (STAT3) was constructed. pEGFP-C1 and pSilencing 4.1-EGFP-shRNA were cotransfected into prostate cancer cells PC-3 and 22Rv1 with G5-PAPAM-D as vector, and to observe silencing of EGFP. Next, pSilencing 4.1-STAT3-shRNA was transfected into PC-3 and 22Rv1 cells by G5-PAPAM-D, Western blotting and apoptosis staining was used to detect silencing of STAT3 and growth inhibition. Thirdly, BALB/C mice subcutaneous tumor model was made with PC-3 cells. Polyplex of G5-PAMAM-D and pSilencing 4.1-STAT3-shRNA was injected intratumorally. The tumor volume was measured and recorded. RESULTS: Fluorescence detection and Western blotting analysis demonstrated that G5-PAMAM-D was able to deliver Silencing 4.1-EGFP-shRNA and pSilencing 4.1-STAT3-shRNA into the two prostate cancer cell lines, and shRNA was expressed to induce silence of EGFP and STAT3. MTT results showed that proliferation of prostate cancer cells was suppressed by G5-PAMAM-D/pSilencing 4.1-STAT3-shRNA and induced apoptosis of PC-3 cells in vitro. Human prostate cancer in mice was successfully formed by inoculation of PC-3 cells into male BABL/C mice. In G5-PAMAM-D/pSilencing 4.1-STAT3-shRNA treated group, the tumor volume was shrank remarkably at 9 days after treatment and tumor growth was retarded compared with control groups. CONCLUSION: GS-PAMAM-D nanoparticles can be used to deliver plasmid vector expressing shRNA into prostate cancer cells effectively in vitro and vivo. It appears to be a promising gene vector for RNA interference therapy in prostate cancer.