Zhendong Yu

Identification of miR-508-3p and miR-509-3p that are associated with cell invasion and migration and involved in the apoptosis of renal cell carcinoma.

MicroRNAs (miRNAs) have emerged as powerful regulators of multiple processes linked to human cancer, including cell apoptosis, proliferation and migration, suggesting that the regulation of miRNA function could play a critical role in cancer progression. Recent studies have found that human serum/plasma contains stably expressed miRNAs. If they prove indicative of disease states, miRNAs measured from peripheral blood samples may be a source for routine clinical detection of cancer. Our studies showed that both miR-508-3p and miR-509-3p were down-regulated in renal cancer tissues. The level of miR-508-3p but not miR-509-3p in renal cell carcinoma (RCC) patient plasma demonstrated significant differences from that in control plasma. In addition, the overexpression of miR-508-3p and miR-509-3p suppressed the proliferation of RCC cells (786-0), induced cell apoptosis and inhibited cell migration in vitro. Our data demonstrated that miR-508-3p and miR-509-3p played an important role as tumor suppressor genes during tumor formation and that they may serve as novel diagnostic markers for RCC.

miR-145 functions as tumor suppressor and targets two oncogenes, ANGPT2 and NEDD9, in renal cell carcinoma.

PurposeAbnormal expression of miRNAs is closely related to a variety of human cancers. The purpose of this study is to identify new tumor suppressor miRNA and elucidate its physiological function and mechanism in renal cell carcinoma (RCC).MethodsThe expression of miR-145 in 45 RCC and adjacent normal tissues was performed by quantitative RT-PCR. Cell proliferation, migration, invasion, apoptosis and cycle assays were carried out for functional analysis after miR-145 transfection. Two target genes of miR-145 were identified by luciferase reporter assay. The altered expression of 84 epithelial to mesenchymal transition (EMT)-related genes after miR-145 transfection was detected by RT2 Profiler EMT PCR array.ResultsThe expression of miR-145 was downregulated in RCC compared to their normal adjacent tissues. Restoring miR-145 expression in RCC cell lines dramatically suppressed cell proliferation, migration and invasion, and induced cell apoptosis and G2-phase arrest. We further validated those miR-145 targets two oncogenes, ANGPT2 and NEDD9 in RCC. In addition, miR-145 was found to regulate numerous genes involved in the EMT.ConclusionsThese findings demonstrate that miR-145 functions as tumor suppressor in RCC, suggesting that miR-145 may be a potential therapeutic target for RCC.

Functional elucidation of miR-494 in the tumorigenesis of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma has very high incidence and high mortality worldwide. MiRNA is related to the tumorigenesis and metastasis of a variety of tumors. In the present study, we verify that the expression of miR-494 in NPC tissues and NPC-derived cells was down-regulated, respectively. The proliferation, colony formation, migration, and invasion of NPC-derived cells were suppressed, while the cell apoptosis was promoted, when miR-494 was over-expressed in these cells. GALNT7 and CDK16 were confirmed to be the direct targets of miR-494. These results suggested that miR-494 play an inhibitory role in the tumorigenesis of NPC.

Cluster characterization of mouse embryonic stem cell-derived pluripotent embryoid bodies in four distinct developmental stages

The formation of embryoid bodies (EBs) is the principal step in the differentiation of embryonic stem (ES) cells. In this study, the morphological characteristics and gene expression patterns of EBs related to the sequential stages of embryonic development were well defined in four distinct developmental groups over 112 days of culture: early-stage EBs groups (1-7 days of differentiation), mid-stage EBs groups (9-15 days of differentiation), maturing EBs groups (17-45 days of differentiation) and matured EBs groups (50 days of differentiation). We first determined definite histological location of apoptosis within EBs and the sequential expression of molecular markers representing stem cells (Oct4, SSEA-1, Sox-2 and AKP), germ cells (Fragilis, Dazl, c-kit, StellaR, Mvh and Stra8), ectoderm (Neurod, Nestin and Neurofilament), mesoderm (Gata-1, Flk-1 and Hbb) and endoderm (AFP and Transthyretin). Our results revealed that developing EBs possess either pluripotent stem cell or germ cell states and that three-dimensional aggregates of EBs initiate mES cell differentiation during prolonged culture in vitro. Therefore, we suggest that this EB system to some extent recapitulates the early developmental processes occurring in vivo.

Tumor suppressive microRNA-200a inhibits renal cell carcinoma development by directly targeting TGFB2

A large body of evidence indicates that microRNAs play a critical role in tumor initiation and progression by negatively regulating oncogenes or tumor suppressor genes. Here, we report that the expression of miR-200a was notably downregulated in 45 renal cell carcinoma (RCC) samples. Restoration of miR-200a suppressed cell proliferation, migration, and invasion in two RCC cell lines. Furthermore, we used an epithelial-to-mesenchymal transition PCR array to explore the putative target genes of miR-200a. By performing quantitative real-time PCR, ELISA, and luciferase reporter assays, transforming growth factor beta2 (TGFB2) was validated as a direct target gene of miR-200a. Moreover, siRNA-mediated knockdown of TGFB2 partially phenocopied the effect of miR-200a overexpression. These results suggest that miR-200a suppresses RCC development via directly targeting TGFB2, indicating that miR-200a may present a novel target for diagnostic and therapeutic strategies in RCC.

Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression.

CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

MicroRNA‑205 promotes the tumorigenesis of nasopharyngeal carcinoma through targeting tumor protein p53‑inducible nuclear protein 1

Nasopharyngeal carcinoma (NPC) is a common type of cancer in southern China, miRNAs have been shown to be involved in the tumorigenesis of multiple cancer types. The present study aimed to explore the potential role of miR-205 in NPC. Reverse transcription quantitative polymerase chain reaction was used to determine the expression levels of miR-205 in 20 fresh NPC specimens and 20 normal nasopharyngeal tissues. The function of miR-205 in the proliferation, migration, invasion and apoptosis of NPC-derived cells was detected by MTT assay, colony formation assay, wound healing assay, Transwell assay and flow cytometry. Furthermore, a target gene of miR-205 was identified using the luciferase reporter assay. The expression of miR-205 was increased in NPC tissues compared with that in normal tissues. Overexpression of miR-205 was found to promote the proliferation, migration and invasion of NPC-derived cells, while apoptosis was suppressed. Tumor protein p53-inducible nuclear protein 1 was identified as a target gene of miR-205. Overall, the present study demonstrated that miR-205 may function as an oncogene in NPC tumorigenesis.

Developmental expression of ACRV1 in humans and mice

To identify the developmental expression of the ACRV1 gene in humans and mice, testes cDNA samples were collected at different post‐natal days (days 4, 9, 18, 35, 54, and 6 months) from Balb/c mice and were hybridised to the mouse whole genome 430 2.0 Array (Affymetrix Inc.) chip. The characteristics of ACRV1 were analysed using various cellular and molecular biotechnologies. The results showed that the expression of mouse ACRV1 was not detected in mouse testes on days 4, 9, and 18 but was present on days 35, 54, and 6 months. Using RT‐PCR analysis of mouse ACRV1, we determined that mouse ACRV1 was expressed specifically in the mouse testis, and its expression began at days 35. Western blot analysis demonstrated that human ACRV1 was primarily expressed in human testes, and immunofluorescent and immunohistochemistry staining showed that human ACRV1 protein was predominantly located in round and elongated spermatids in human testes, indicating that ACRV1 may play an important role in mammalian spermatogenesis and may be a target of a contraceptive vaccine.

Expression profile of a novel germ cell-specific gene, TSCPA, in mice and human.

In order to identify novel genes involved in spermatogenesis, testis cDNA samples from Balb/C mice of different postnatal days were hybridized with the whole mouse genome Affymetrix chip to screen the testis-specific genes. The characteristics of the selected genes were analyzed by RT-PCR as well as other bioinformatic tools. A novel differentially expressed testis-specific gene (GenBank Accession No: NM_029042) in the developmental stages of testes was identified, and named TSCPA. Cellular mapping prediction of TSCPA indicated that its protein was probably expressed in nuclei, and one putative domain (aa 332–377) was anchoring domain of cAMP-dependent type II PK. The result of subcellular localization of GFP-TSCPA fusion protein in Cos-7 cells showed that TSCPA protein was expressed in nuclei. RT-PCR analysis revealed that TSCPA was expressed specifically in mouse and human testis. TSCPA gene was expressed weakly in 21-day-old mouse testis and the expression was increased gradually from 38th day to 6th month of mouse testes. No expression of hTSCPA was found in cryptorchidism and Sertoli-cell-only syndrome patients. It was concluded that the expression profile of TSCPA in human and mice indicated that TSCPA might play an important role in spermatogenesis.SummaryIn order to identify novel genes involved in spermatogenesis, testis cDNA samples from Balb/C mice of different postnatal days were hybridized with the whole mouse genome Affymetrix chip to screen the testis-specific genes. The characteristics of the selected genes were analyzed by RT-PCR as well as other bioinformatic tools. A novel differentially expressed testis-specific gene (GenBank Accession No: NM_029042) in the developmental stages of testes was identified, and named TSCPA. Cellular mapping prediction of TSCPA indicated that its protein was probably expressed in nuclei, and one putative domain (aa 332–377) was anchoring domain of cAMP-dependent type II PK. The result of subcellular localization of GFP-TSCPA fusion protein in Cos-7 cells showed that TSCPA protein was expressed in nuclei. RT-PCR analysis revealed that TSCPA was expressed specifically in mouse and human testis. TSCPA gene was expressed weakly in 21-day-old mouse testis and the expression was increased gradually from 38th day to 6th month of mouse testes. No expression of hTSCPA was found in cryptorchidism and Sertoli-cell-only syndrome patients. It was concluded that the expression profile of TSCPA in human and mice indicated that TSCPA might play an important role in spermatogenesis.