miR-218 suppresses the growth of hepatocellular carcinoma by inhibiting the expression of proto-oncogene Bmi-1.

PURPOSE: To identify microRNAs (miRNAs) directly regulating the proto-oncogene Bmi-1 expression in the development of hepatocellular carcinoma (HCC) and to explore the underlying molecular mechanisms. METHODS: Four HCC cell lines, including HepG2, Bel7404, Huh7, and PLC5, the normal hepatocellular cell line MIHA, and 30 HCC biopsies were included in this study. Potential miRNAs, which interact with Bmi-1 and are involved in the development of HCC were identified through bioinformatic analyses. The expression of miRNA and Bmi-1 in HCC cell lines and HCC tissues was analyzed using fluorescence protein analysis, real-time quantitative PCR (RT-qPCR), and Western blotting. RESULTS: Bioinformatic analysis suggested that miR-218 is a potential miRNA regulating Bmi-1 expression. Fluorescence protein analysis, RT-qPCR, and Western blotting confirmed the direct interaction between miR-218 and Bmi-1. In addition, increased expression of Bmi-1 was detected in HCC cell lines and HCC tissues. In most HCC tissues, the expression of miR-218 was decreased and was associated with increased expression of Bmi-1. CONCLUSION: miR-p218 downregulates the expression of the proto-oncogene Bmi-1 in HCC, and it may be an effective target for the treatment of this disease.

MicroRNA­24­2 is associated with cell proliferation, invasion, migration and apoptosis in renal cell carcinoma.

Micro (mi)RNAs are involved in multiple cellular processes, and alterations in miRNA expression have been demonstrated to lead to tumorigenesis. Previous microarray analysis revealed that miRNA (miR)­24 was downregulated in renal cell carcinoma (RCC). Additionally, miR­24 has been identified as an oncogene and tumor suppressor in various cancers. The present study assessed the expression levels of two stem­loops of miR­24, miR­24­1 and miR­24­2, in RCC tissues and paired healthy tissues by reverse transcription­quantitative polymerase chain reaction. The results revealed that miR­24­2 was upregulated in RCC tissues and ACHN, 786­O and 769P cell lines compared with healthy tissues and HEK­293T cells, respectively, whereas miR­24­1 was almost absent in RCC and healthy kidney tissues. To investigate the role of miR­24­2 in RCC, a synthesized miR­24­2 mimic, negative control (NC), inhibitor or inhibitor NC was transfected into 786­O and ACHN RCC cells, and cell proliferation, mobility and apoptosis assays were performed. The results of the present study revealed that miR­24­2 was associated with cell proliferation, migration, invasion and apoptosis, thus demonstrating that miR­24­2 may serve a role as an oncogene in RCC. Further studies are required to investigate the signaling pathways of miR­24­2, and the potential of miR­24­2 as a therapeutic target or biomarker for the early detection of RCC.

The expression characteristics of FAM71D and its association with sperm motility.

STUDY QUESTION: What are the features of FAM71D (Family with sequence similarity 71, member D) expression and is there an association between FAM71D expression and sperm motility? SUMMARY ANSWER: FAM71D, a novel protein exclusively expressed in the testis, is located in sperm flagella and is functionally involved in sperm motility. WHAT IS KNOWN ALREADY: Some testis-specific proteins have been reported as potential diagnostic biomarkers to evaluate the spermatogenesis process and sperm quality. We have identified a novel testis-specific protein, FAM71D, through microarray data analysis, yet little is known about its expression and function. STUDY DESIGN, SIZE, DURATION: FAM71D mRNA and protein expression was quantified during mouse testis development. Its localization in germ cells was detected by dual-labeled immunostaining in testis sections and sperm smears. The clinical significance was assessed by comparing FAM71D expression in spermatozoa from normozoospermic controls and asthenozoospermic patients. PARTICIPANTS/MATERIALS, SETTING, METHODS: Testes were dissected from C57BL/6 J male mice at postnatal ages of 1, 2, 3, 4, 6, 8 weeks and 6 months, and sperm was collected from cauda epididymides of adult mice by the swim-up method. Human spermatozoa were isolated from 100 human semen samples by density gradient Percoll centrifugation. RT-qPCR and western blot were performed to semi-quantify the expression of FAM71D in mouse testis, and in the ejaculated spermatozoa of normozoospermic controls and asthenozoospermic patients. Immunofluorescence staining was used to detect the localization of FAM71D. Co-immunoprecipitation assay was performed to evaluate the interaction between FAM71D and calmodulin. An antibody blocking assay was employed to assess the role of FAM71D in sperm motility. MAIN RESULTS AND THE ROLE OF CHANCE: Our results showed that FAM71D was exclusively expressed in the testis in an age-dependent manner. FAM71D expression exhibited dynamic change in the cytoplasm of spermatids during spermiogenesis and was finally retained in sperm flagella. FAM71D could interact with calmodulin. Use of anti-FAM71D antibody on sperm significantly decreased sperm motility. Expression level of FAM71D was markedly reduced in the ejaculated spermataozoa of asthenozoospermic patients (P < 0.05), and this was correlated with sperm progressive motility (r = 0.7435, P < 0.0001). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: The sample size was limited and it is necessary to verify the correlation of FAM71D expression with sperm motility in larger cohorts. Furthermore, our results were descriptive and follow-up studies would be needed to elucidate the detailed role of FAM71D in sperm motility. WIDER IMPLICATIONS OF THE FINDINGS: This is the first systematic study to document the expression of endogenous FAM71D and a function for FAM71D in sperm motility. It provides new insights into our understanding of sperm motility regulation and causes of male infertility. STUDY FUNDING/COMPETING INTERESTS: This study was funded by the National Natural Science Foundation of China, Guangdong Natural Science Foundation and the Shenzhen Project of Science and Technology. The authors have no competing interests.

Non-Genomic Action of Androgens is Mediated by Rapid Phosphorylation and Regulation of Androgen Receptor Trafficking.

BACKGROUND: Testosterone is critical for maintaining spermatogenesis and male fertility. The accomplishment of these processes requires the synergistic actions of the classical and non-classical signaling pathways of androgens. METHODS: A murine testicular Sertoli cell line, TM4 cell was used to examine androgen actions in Sertoli cells. Western blot analysis and immunofluorescence assay were employed to study the testosterone-induced Androgen receptor (AR) translocation. Protein phosphorylation antibody array was applied to identify the phosphorylation sites under testosterone treatment, and these findings were verified by Western blot analysis. RESULTS: We found that a physiological dose of testosterone induced fast membrane association of AR. By using a phosphorylation antibody array, several phosphorylation sites, such as MEK1/2 (Ser217/221), Akt (Ser473), and Erk1/2 (Thr202/Tyr204) were rapidly phosphorylated within 5 min of testosterone treatment. Inhibition of the MEK and Akt signaling pathways prevented AR trafficking. Blocking of AR by flutamide eliminated the stimulation effect of testosterone on kinase phosphorylation. Testosterone induced kinase Src phosphorylation, and inhibition of Src restricted AR translocation to the membrane and the nucleus. CONCLUSION: Findings suggested that the membrane association of AR was mediated by the MEK and Akt phosphorylation signaling pathways, which resulted in Src activation and was initiated by testosterone binding to the membrane-localized AR. This study provides new insights into the testosterone signaling pathway in Sertoli cells, which mediate spermatogenesis. In addition, the study can be used in the diagnosis and treatment of male infertility caused by disorders in spermatogenesis.

Identification of miR­30b as an oncogene in renal cell carcinoma.

microRNAs (miRs) have been investigated as a novel class of regulators of cellular processes, including proliferation, apoptosis and metabolism. In particular, miR­30b has been demonstrated to be deregulated in certain types of cancer, including lung, colorectal and gastric cancer. Previous studies of miR­30b in renal clear cell carcinoma demonstrated that the expression level of miR­30b was associated with distant metastasis. However, the function of miR­30b in renal cell carcinoma (RCC) remained to be elucidated. In the present study, the expression of miR­30b in 31 paired RCC tissues from four cell lines (786­O, 769­P, ACHN and 293T) was detected by reverse transcription­quantitative polymerase chain reaction. In addition, the effect of miR­30b on cell proliferation in RCC cells was also determined using MTT and Cell Counting Kit­8 assay analyses. Furthermore, the function of miR­30b in cell migration and invasion was determined by wound scratch and Transwell assays. Flow cytometry was also performed to quantify the effect of miR­30b on cell apoptosis. The results of the current study indicated that miR­30b was upregulated in RCC tissues from affected cell lines when compared with adjacent normal tissues and a normal kidney cell line, which is different to the downregulation of miR­30b as observed in other types of cancer. miR­30b is associated with RCC cell proliferation, invasion, migration and apoptosis, which indicated that miR­30b acts as an oncogene in RCC. To the best of our knowledge, the present study is the first to demonstrate the upregulation of miR­30b in RCC tissues and describe miR­30b as an oncogene in RCC in the regulation of cell proliferation, migration, invasion and apoptosis. Further studies will define the target gene of miR­30b in RCC and investigate the potential role of miR­30b as a biomarker for RCC.

Identification of miR­195­3p as an oncogene in RCC.

There is increasing evidence that the deregulation of microRNAs (miRNAs; miRs) contributes to tumorigenesis. Previous studies have shown that miR­195 is downregulated in various types of cancer. The present study aimed to investigate the function and expression levels of miR­125b. Results of qPCR revealed that miR­195­3p, the mature sequence of miR­195, was upregulated in renal cell carcinoma (RCC) tissues and cell lines (786­O, 769P and ACHN). This indicated that the function and role of miR­195­3p may differ in different types of tumor. To assess the function of miR­195­3p in RCC cell lines, cell proliferation was examined using MTT and CCK­8 assays, mobility was assessed using a cell scratch assay, Transwell migration assay and invasion assay, and apoptosis was examined using flow cytometry. These assessments were also performed in cells with upregulated or downregulated miR­195­3p via transfection with synthesized miR­195­3p mimic or inhibitor. The results revealed that the overexpression of miR­195­3p promoted 786­O and ACHN RCC cell proliferation, migration and invasion, and inhibited cell apoptosis, whereas the downregulation of miR­195­3p suppressed cell proliferation, migration and invasion, and induced cell apoptosis. These results indicated that miR­195­3p was associated with the tumorigenesis of RCC, with further investigations to focus on the pathway and use of miR­195­3p as a clinical biomarker for RCC.

A nonsense mutation in Ccdc62 gene is responsible for spermiogenesis defects and male infertility in repro29/repro29 mice.

Phenotype-driven mutagenesis is an unbiased method to identify novel genes involved in spermatogenesis and other reproductive processes. Male repro29/repro29 mice generated by the Reproductive Genomics Program at the Jackson Laboratory were infertile with deformed sperm and poor motility. Using selected exonic capture and massively parallel sequencing technologies, we identified a nonsense mutation in the exon 6 of coiled-coil domain-containing 62 gene (Ccdc62), which results in a formation of a premature stop codon and a truncated protein. Among the tissues examined, CCDC62 was found to be expressed at the highest level in mouse testis by reverse transcriptase-PCR (RT-PCR) and Western blot analysis. With immunofluorescent staining, we demonstrated that CCDC62 was expressed in the cytoplasm and the developing acrosome in the spematids of mouse testis, and was specifically localized at the acrosome in mature sperm. The complementation analysis by mating repro29/+ mice with Ccdc62 -/- mice (generated by CRISPR-Cas9 strategy) further provided genetic proof that the infertility of repro29/repro29 mice was caused by Ccdc62 mutation. Finally, it was found that intracellular colocalization and interaction of CCDC62 and Golgi-associated PDZ and coiled-coil motif-containing protein may be important for acrosome formation. Taken together, this study identified a nonsense mutation in Ccdc62, which directly results in male infertility in repro29/repro29 mice.

[Expression characteristics of the Daxx gene in the mouse testis during spermatogenesis].

OBJECTIVE: To investigate the expression characteristic of the Daxx gene in the mouse testis and its role in spermatogenesis. METHODS: Real-time PCR, Western blot and immunofluorescence were used in examining the expression characteristics of DAXX in the testis tissue from wild-type, Sertoli cell-specific androgen receptor knockout (SCARKO) and androgen receptor knockout (ARKO) mice at different postnatal weeks . RESULTS: The Daxx gene was highly expressed in the testis tissue and mainly in the nuclei of the wild-type mice at 4 postnatal weeks. Compared with the wild-type, the ARKO mice showed a markedly decreased expression of DAXX (0.299±0.026), which displayed a polar distribution in the spermatogenic cells (0.853±0.058) and exhibited no significant difference in the SCARKO mice (1.000±0.015). CONCLUSIONS: The Daxx gene expression is the highest in the middle-stage development of the mouse testis, significantly decreased in ARKO mice as compared with the wild-type, and its location influenced by specific AR knockout in Sertoli cells. DAXX may be involved in the regulation of spermatogenesis in mice.

[Expression characteristics of the 1700008O03Rik gene in the mouse testis during spermatogenesis and results of bioinformatic analysis].

OBJECTIVE: To investigate the characteristics of the expression of the RIKEN cDNA 1700008O03 (1700008O03Rik) gene in the testis of the mouse from birth to sexual maturity and its potential role in regulating spermatogenesis. METHODS: Using mouse gene expression profile microarray, we screened the testis-specific gene 1700008O03Rik from the mouse. We studied the expression characteristics of the gene in the development of the mouse testis by reverse transcription PCR, quantitative real-time PCR, Western-blot, immunohistochemistry and immunofluorescence, and analyzed the structure of the 1700008O03Rik protein and its homology with other species using the bioinformatic software. RESULTS: 1700008O03Rik gene was highly expressed in the testis of the mouse, increasing in an age-dependent manner, and mainly in the endochylema of oblong spermatozoa. Bioinformatic analysis revealed a high homology of the 1700008O03Rik protein between human and mice, and phylogenetic tree analysis showed it to be highly conserved in mammalian evolution. CONCLUSIONS: 1700008O03Rik is a highly expressed gene in the mouse testis, mainly in the endochylema of oblong spermatozoa, which may be involved in the regulation of spermatogenesis in mice.

Deficiency of SPATA46, a Novel Nuclear Membrane Protein, Causes Subfertility in Male Mice.

Teratozoospermia is generally associated with clinical infertility. Despite numerous studies, the molecular mechanisms underlying male infertility are still poorly understood. In the present study, we demonstrated that deletion of Spata46, a gene encoding a novel protein of unknown function found in mouse testis, was responsible for male subfertility, and the cause of subfertility was characterized as abnormal sperm head shape and a failure of sperm-egg fusion. We also demonstrated that SPATA46 was expressed predominantly in condensed spermatids, with a highly specific localization restricted to the subacrosomal area; the protein is located at the nuclear membrane due to a transmembrane region in the N-terminus of the protein. At the subcellular level, SPATA46-deficient condensed spermatids displayed structural defects consisting of a discontinuous nuclear envelope and a cavity in the nucleus associated with an abnormal nuclear shape. Additionally, in vitro, we determined that the absence of SPATA46 led to accumulation of sperm around the perivitelline space of eggs, and the same phenomenon was also observed for natural sperm incubated with an anti-SPATA46 antibody, suggesting functional relevance of SPATA46 for sperm-egg fusion. Taken together, these results indicated that SPATA46 is a novel protein involved in reshaping of the sperm head and sperm-egg fusion.

Identification of NR0B1 as a novel androgen receptor co-repressor in mouse Sertoli cells.

Nuclear receptor subfamily 0 group B member 1 (Nr0b1) is an atypical member of the nuclear receptor family that is predominantly expressed in mouse Sertoli cells (SCs). Mutations of NR0B1 in humans cause adrenal failure and hypogonadotropic hypogonadism. The targeted mutagenesis of Nr0b1 in mice has revealed a primary gonadal defect characterized by the overexpression of aromatase and cellular obstruction of the seminiferous tubules and efferent ductules, leading to germ cell death and infertility. The transgenic expression of Nr0b1 under the control of the Müllerian-inhibiting substance promoter (MIS-Nr0b1), which is selectively expressed in SCs, improves fertility. Testicular androgen receptor (AR) was also expressed in SCs. Many genes are directly regulated by androgen and its AR, which are involved in spermatogenesis and male infertility. As the association between NR0B1 and AR remains unclear in mouse SCs, we decided to further explore the relationship between them. In the present study, we have identified NR0B1 as a novel AR co-repressor in mouse SCs. Using RT­qPCR and immunofluorescence, we determined that NR0B1 was mainly expressed in mouse SCs in an age-dependent manner from 2-8 weeks of age postnatally. The inhibition of the effects of AR on AR target genes by NR0B1, in an androgen­dependent manner, was further demonstrated by western blot analysis and RT-qPCR in TM4 cells, a mouse Sertoli cell line. Finally, in vitro luciferase and co-immunoprecipitation assays validated that NR0B1, as an AR co-repressor, significantly inhibited the transcriptional activation of its target genes. These results suggest that novel inhibitory mechanisms underlie the effects of NR0B1 in modulating androgen-dependent gene transcription in mouse SCs.

Identification and characteristics of the testes-specific gene, Ccdc38, in mice.

Distinguishing the testes-specific genes in different species may disclose key genes associated with testes-specific functions and provide sufficient information for the study and treatment of male infertility. A testes­specific gene, coiled-coil domain containing 38 (Ccdc38), was identified by screening UniGene libraries. Systematic bioinformatics analysis demonstrated that the CCDC38 protein was conserved in various mammalian species. It was determined that CCDC38 was exclusively expressed in testes and its expression increased from 2­8 weeks of age. Additional immunohistochemical analysis indicated that CCDC38 was mainly expressed in spermatogonia and spermatocytes. It is of note that, immunofluorescence and co-immunoprecipitation assays demonstrated that CCDC38 interacted with ubiquitinated histone H2A in mouse testes. Therefore, these results suggest that Ccdc38 is a testes-specific gene, which may be important for mouse spermatogenesis.

A Novel Missense Mutation in USP26 Gene Is Associated With Nonobstructive Azoospermia.

OBJECTIVE: The aim of this study was to evaluate whether ubiquitin-specific peptidase 26 (USP26) gene variations were associated with nonobstructive azoospermia (NOA). METHODS: Seven hundred and seventy-six patients diagnosed with NOA and 709 proven fertile men were included in this study. Genetic variations of infertility-related genes, including USP26, were identified by selected exonic sequencing. The effects of USP26 mutations on androgen receptor (AR) binding, ubiquitination, and transcriptional activity were detected by immunoprecipitation and luciferase assay in Hela and TM4 cells. RESULTS: Six novel missense mutations and 1 novel synonymous mutation of USP26 unique to the patients with NOA were identified. Of these missense mutations, USP26 R344W remarkably reduced the binding affinity and deubiquitinating activity of USP26 to AR, thus eliminated the inhibitory effect of USP26 on transcriptional activity of AR in Hela and TM4 cells. CONCLUSION: A novel USP26 variant p.R344W is associated with NOA probably through affecting AR function.

[Expression characteristics of the Ccdc70 gene in the mouse testis during spermatogenesis].

OBJECTIVE: To investigate the expression characteristics of the gene of coiled-coil domain-containing protein 70 (Ccdc70) in the mouse testis and its potential role in spermatogenesis. METHODS: Using expression profile microarray, we screened the mouse testis-specific gene Ccdc70, studied its expression characteristics in the mouse testis by RT-PCR, real-time PCR, Western blot and immunohistochemistry, followed by bioinformatic analysis of the Ccdc70 protein. RESULTS: The Ccdc70 gene was expressed highly in the testis but lowly in the epididymis of the mice. The Ccdc70 protein was expressed mainly in the spermatocytes and round spermatids of the testis and in the epithelial cells of the epididymis. Bioinformatic analysis showed a structural domain in the Ccdc70 protein, which was highly conserved in mammalian evolution. CONCLUSION: The Ccdc70 gene is highly expressed in the mouse testis and mainly in the spermatocytes, round spermatids, and epididymal epithelial cells, which indicates that it is involved in the regulation of spermatogenesis and epididymal sperm maturation.

Oncogenic microRNA-142-3p is associated with cellular migration, proliferation and apoptosis in renal cell carcinoma.

MicroRNAs (miRNAs/miRs) serve an important role in the regulation of carcinogenic pathways. RCC is the most prevalent kidney cancer that occurs in adults. miRNAs have gained increasing attention due to their association with RCC tumorigenesis, serving as biomarkers for early detection and progression monitoring, and as potential targets for molecular therapy. Upregulation of miRNA-142-3p has been previously identified in RCC tissues by microarray profile, however, its expression and function in RCC have not yet been validated. In the present study, quantitative polymerase chain reaction was performed to quantify the relative expression of miR-142-3p in 53 paired RCC and adjacent normal tissues. Furthermore, wound healing, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometry assays were performed to analyze the impacts of miR-142-3p on cellular migration, proliferation and apoptosis. The results demonstrated that miR-142-3p was significantly upregulated in RCC tissues compared with adjacent normal tissues. Downregulation of miR-142-3p, induced by chemically synthesized miR-142-3p inhibitor, significantly suppressed cell migration and proliferation, and promoted cell apoptosis in 786-O and ACHN cells, supporting the theory that miR-142-3p may function as an oncogene in RCC. The potential clinical significance of miR-142-3p, as a biomarker and therapeutic target, provides rationale for further investigation into the miR-142-3p-mediated molecular pathway and how it is associated with RCC development.

Identification of miR­130b as an oncogene in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common type of renal tumor, which has a poor prognosis. Improvements in understanding the underlying molecular biology of RCC has led to systemic treatments, which have markedly improved patient outcomes. Therefore, it is necessary and worthwhile to identify novel biomarkers for RCC. MicroRNAs (miRNAs) have been found to be important in a wide range of biological and pathological processes, including cell differentiation, migration, growth, proliferation, apoptosis and metabolism. Aberrant expression of miRNA­130b has previously been reported in tumors, however, its role in RCC remains to be elucidated. In the present study, the upregulation of miR­130b was observed in RCC tissues and cell lines using reverse transcription­quantitative polymerase chain reaction analysis, which was consistent with previous microRNA profiling in RCC. Furthermore, the effects of miR­130b on cell migration, proliferation and apoptosis were examined using a wound scratch assay, an MTT assay and flow cytometric analysis, respectively. The results demonstrated that the downregulation of miR­130b by a synthesized inhibitor inhibited cell migration, suppressed cell proliferation and induced RCC cell apoptosis. The present study was the first, to the best of our knowledge, to suggest that miR­130b may be a promising biomarker for diagnosis and a therapeutic target for the treatment of RCC. Further investigations are required to examine the roles and target genes of miR­130b in RCC.

Oncogenic cAMP responsive element binding protein 1 is overexpressed upon loss of tumor suppressive miR-10b-5p and miR-363-3p in renal cancer.

Renal cell carcinoma (RCC) is the most common kidney cancer in adults and has a poor prognosis. cAMP responsive element binding protein 1 (CREB1) is a proto­oncogenic transcription factor involved in malignancies of various organs. However, its functional role(s) have not yet been elucidated in RCC. We investigated the expression pattern, function and regulation of CREB1 in RCC. CREB1 was overexpressed in the RCC tissues and cell lines. Downregulation of CREB1 inhibited RCC tumorigenesis by affecting cell proliferation, migration and apoptosis. Multiple computational algorithms predicted that the 3'­untranslated region (3'­UTR) of human CREB1 mRNA is a target for miR­10b­5p and miR­363­3p. Luciferase reporter assay, qPCR and western blot analysis confirmed that miR­10b­5p and miR­363­3p bind directly to the 3'­UTR of CREB1 mRNA and inhibit mRNA and protein expression of CREB1. qPCR data also revealed a significantly lower expression of miR­10b­5p and miR­363­3p in RCC tissues. Introduction of miR­10b­5p and miR­363­3p mimics led to suppressed expression of CREB1 and inhibited cell proliferation, migration and apoptosis reduction. Taken together, we propose that CREB1 is an oncogene in RCC and that upregulation of CREB1 by loss of tumor suppressive miR­10b­5p and miR­363­3p plays an important role in the tumorigenesis of RCC.

Analysis of a four generation family reveals the widespread sequence-dependent maintenance of allelic DNA methylation in somatic and germ cells.

Differential methylation of the homologous chromosomes, a well-known mechanism leading to genomic imprinting and X-chromosome inactivation, is widely reported at the non-imprinted regions on autosomes. To evaluate the transgenerational DNA methylation patterns in human, we analyzed the DNA methylomes of somatic and germ cells in a four-generation family. We found that allelic asymmetry of DNA methylation was pervasive at the non-imprinted loci and was likely regulated by cis-acting genetic variants. We also observed that the allelic methylation patterns for the vast majority of the cis-regulated loci were shared between the somatic and germ cells from the same individual. These results demonstrated the interaction between genetic and epigenetic variations and suggested the possibility of widespread sequence-dependent transmission of DNA methylation during spermatogenesis.

MicroRNA-106b functions as an oncogene in renal cell carcinoma by affecting cell proliferation, migration and apoptosis.

Kidney cancer is the 14th most common cancer in the world and its prognosis remains poor due to difficult early detection and treatment. Therefore, the identification of biomarkers for early-stage renal cell carcinoma (RCC) is important. MicroRNA-106b (miR-106b) has been described as an oncogene in several types of human cancer. Previous microarray studies have suggested that miR-106b was significantly upregulated in RCC tissues compared with paired normal kidney tissues and may be a promising biomarker for the prediction of early metastasis following nephrectomy. The present study aimed to determine the expression and function of miR-106b in RCC. The expression of miR-106b in RCC tissues and cells, and in paired normal tissues and cells was determined by reverse transcription quantitative polymerase chain reaction, based on the previous sequencing results of miRNAs. Furthermore, a wound scratch assay, MTT assay and flow cytometry were performed to examine the functions of miR-106b on cell migration, proliferation and apoptosis. The results demonstrated that miR-106b was upregulated in RCC tissues and cell lines compared with control normal tissues and cell lines. Downregulation of miR-106b with a synthesized inhibitor suppressed cell migration and proliferation and induced renal cancer cell apoptosis, suggesting that miR-106b can be characterized as an oncogene in RCC. To the best of our knowledge, the present study was the first to reveal that miR-106b is upregulated and affects cellular migration, proliferation and apoptosis in RCC. Further studies are required to examine the role and target genes of miR-106b in RCC.

Protein Arginine Methyltransferase 6 Involved in Germ Cell Viability during Spermatogenesis and Down-Regulated by the Androgen Receptor.

Androgens and the androgen receptor (AR) are of great importance to spermatogenesis and male fertility. AR knockout (ARKO) mice display a complete insensitivity to androgens and male infertility; however, the exact molecular mechanism for this effect remains unclear. In this study, we found that the expression levels of Prmt6 mRNA and protein were significantly up-regulated in the testes of ARKO mice compared to wild type (WT) mice. PRMT6 was principally localized to the nucleus of spermatogonia and spermatocytes by immunofluorescence staining. Furthermore, luciferase assay data showed that AR together with testosterone treatment suppressed Prmt6 transcription via binding to the androgen-responsive element (ARE) of the Prmt6 promoter. Moreover, knockdown of Prmt6 suppressed germ cells migration and promoted apoptosis. In addition, both of these cellular activities could not be enhanced by testosterone treatment. Taken together, these data indicate that PRMT6, which was down-regulated by AR and influenced cell migration and apoptosis of germ cells, could play a potentially important role in spermatogenesis.