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ABSTRACT: Herein, murine prostate cancer cell lines, generated via selective transduction with a single oncogene (c-Myc, Ha-Ras, and v-Src), demonstrated oncogene-specific prostate cancer molecular signatures that were recapitulated in human prostate cancer, and developed lung metastasis in immune competent mice. Interrogation of two independent retrospective cohorts of patient samples using the oncogene signature demonstrated an ability to distinguish tumor from normal prostate with a predictive value for prostate cancer of 98 - 99%. In a blinded study, the signature algorithm demonstrated independent substratification of reduced recurrence free survival by Kaplan-Meier analysis. The generation of new oncogene-specific prostate cancer cell lines that recapitulate human prostate cancer gene expression, that metastasize in immune-competent mice, are a valuable new resource for testing targeted therapy while the molecular signatures identified herein provides further value over current gene signature markers of prediction and outcome.
Cancer Research 11/2012; · 7.86 Impact Factor
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ABSTRACT: Cancer stem cells (CSCs) are a small subpopulation of cells within tumors with capabilities of self-renewal, differentiation, and tumorigenicity when transplanted into an animal host. A number of cell surface markers such as CD44, CD24, and CD133 are often used to identify and enrich CSCs. A regulatory network consisting of microRNAs and Wnt/β-catenin, Notch, and Hedgehog signaling pathways controls CSC properties. The clinical relevance of CSCs has been strengthened by emerging evidence, demonstrating that CSCs are resistant to conventional chemotherapy and radiation treatment and that CSCs are very likely to be the origin of cancer metastasis. CSCs are believed to be an important target for novel anti-cancer drug discovery. Herein we summarize the current understanding of CSCs, with a focus on the role of miRNA and epithelial-mesenchymal transition (EMT), and discuss the clinical application of targeting CSCs for cancer treatment.
The international journal of biochemistry & cell biology 09/2012; 44(12):2144-2151. · 4.89 Impact Factor
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Mathew C Casimiro,
Marco Crosariol,
Emanuele Loro,
Adam Ertel, Zuoren Yu,
William Dampier,
Elizabeth A Saria,
Alex Papanikolaou,
Timothy J Stanek,
Zhiping Li,
Chenguang Wang,
Paolo Fortina,
Sankar Addya,
Aydin Tozeren,
Erik S Knudsen,
Andrew Arnold,
Richard G Pestell
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ABSTRACT: Chromosomal instability (CIN) in tumors is characterized by chromosomal abnormalities and an altered gene expression signature; however, the mechanism of CIN is poorly understood. CCND1 (which encodes cyclin D1) is overexpressed in human malignancies and has been shown to play a direct role in transcriptional regulation. Here, we used genome-wide ChIP sequencing and found that the DNA-bound form of cyclin D1 occupied the regulatory region of genes governing chromosomal integrity and mitochondrial biogenesis. Adding cyclin D1 back to Ccnd1(-/-) mouse embryonic fibroblasts resulted in CIN gene regulatory region occupancy by the DNA-bound form of cyclin D1 and induction of CIN gene expression. Furthermore, increased chromosomal aberrations, aneuploidy, and centrosome abnormalities were observed in the cyclin D1-rescued cells by spectral karyotyping and immunofluorescence. To assess cyclin D1 effects in vivo, we generated transgenic mice with acute and continuous mammary gland-targeted cyclin D1 expression. These transgenic mice presented with increased tumor prevalence and signature CIN gene profiles. Additionally, interrogation of gene expression from 2,254 human breast tumors revealed that cyclin D1 expression correlated with CIN in luminal B breast cancer. These data suggest that cyclin D1 contributes to CIN and tumorigenesis by directly regulating a transcriptional program that governs chromosomal stability.
The Journal of clinical investigation 03/2012; 122(3):833-43. · 15.39 Impact Factor
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ABSTRACT: Small non-coding RNAs include siRNA, miRNA, piRNA and snoRNA. The involvement of miRNAs in the regulation of mammary gland tumorigenesis has been widely studied while the role for other small non-coding RNAs remains unclear. Here we summarize the involvement of miRNA in breast cancer onset and progression through regulating the cell cycle and cellular proliferation. The regulation of breast cancer stem cells and tumor regeneration by miRNA is reviewed. In addition, the emerging evidence demonstrating the involvement of piRNA and snoRNA in breast cancer is briefly described.
Journal of Mammary Gland Biology and Neoplasia 03/2012; 17(1):59-64. · 6.74 Impact Factor
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ABSTRACT: Stem cells undergo symmetric and asymmetric divisions to generate differentiated cells and more stem cells. The balance between self-renewal and differentiation of stem cells is controlled by transcription factors, epigenetic regulatory networks, and microRNAs (miRNAs). Herein the miRNA involvement in the regulation of stem cell self-renewal and differentiation is summarized. miRNA contribution to malignancy through regulating cancer stem cells is described. In addition, the reciprocal associations between miRNAs and epigenetic modifications in control of stem cell fate are discussed.
Frontiers in genetics. 01/2012; 3:191.
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ABSTRACT: microRNAs are thought to regulate tumor progression and invasion via direct interaction with target genes within cells. Here the microRNA17/20 cluster is shown to govern cellular migration and invasion of nearby cells via heterotypic secreted signals. microRNA17/20 abundance is reduced in highly invasive breast cancer cell lines and node-positive breast cancer specimens. Cell-conditioned medium from microRNA17/20-overexpressing noninvasive breast cancer cell MCF7 was sufficient to inhibit MDA-MB-231 cell migration and invasion through inhibiting secretion of a subset of cytokines, and suppressing plasminogen activation via inhibition of the secreted plasminogen activators (cytokeratin 8 and alpha-enolase). microRNA17/20 directly repressed IL-8 by targeting its 3' UTR, and inhibited cytokeratin 8 via the cell cycle control protein cyclin D1. At variance with prior studies, these results demonstrated a unique mechanism of how the altered microRNA17/20 expression regulates cellular secretion and tumor microenvironment to control migration and invasion of neighboring cells in breast cancer. These findings not only reveal an antiinvasive function of miR-17/20 in breast cancer, but also identify a heterotypic secreted signal that mediates the microRNA regulation of tumor metastasis.
Proceedings of the National Academy of Sciences 05/2010; 107(18):8231-6. · 9.68 Impact Factor
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ABSTRACT: The discovery of microRNAs as a novel class of gene expression regulators has led to a new strategy for disease diagnostics and therapeutics. Cell cycle, cell proliferation, and tumorigenesis are all regulated by microRNAs. Several general principles linking microRNAs and cancer have been recently reviewed; therefore, the current review focuses specifically on the perspective of microRNAs in control of cell cycle, stem cells, and heterotypic signaling, as well as the role of these processes in breast cancer. Altered abundance of cell cycle regulation proteins and aberrant expression of microRNAs frequently coexist in human breast cancers. Altered microRNA expression in breast cancer cell lines is associated with altered cell cycle progression and cell proliferation. Indeed, recent studies have demonstrated a causal role for microRNA in governing breast tumor suppression or collaborative oncogenesis. This review summarizes the current understanding of the role for microRNA in regulating the cell cycle and summarizes the evidence for aberrant microRNA expression in breast cancer. The new evidence for microRNA regulation by annotated genes and the involvement of microRNA in breast cancer metastasis are discussed, as is the potential for microRNA to improve breast cancer diagnosis and therapy.
American Journal Of Pathology 03/2010; 176(3):1058-64. · 4.89 Impact Factor
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Manran Liu,
Mathew C Casimiro,
Chenguang Wang,
L Andrew Shirley,
Xuanmao Jiao,
Sanjay Katiyar,
Xiaoming Ju,
Zhiping Li, Zuoren Yu,
Jie Zhou,
Michael Johnson,
Paolo Fortina,
Terry Hyslop,
Jolene J Windle,
Richard G Pestell
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ABSTRACT: p21(CIP1/WAF1) is a downstream effector of tumor suppressors and functions as a cyclin-dependent kinase inhibitor to block cellular proliferation. Breast tumors may derive from self-renewing tumor-initiating cells (BT-ICs), which contribute to tumor progression, recurrence, and therapy resistance. The role of p21(CIP1) in regulating features of tumor stem cells in vivo is unknown. Herein, deletion of p21(CIP1), which enhanced the rate of tumorigenesis induced by mammary-targeted Ha-Ras or c-Myc, enhanced gene expression profiles and immunohistochemical features of epithelial mesenchymal transition (EMT) and putative cancer stem cells in vivo. Silencing of p21(CIP1) enhanced, and expression of p21(CIP1) repressed, features of EMT in transformed immortal human MEC lines. p21(CIP1) attenuated oncogene-induced BT-IC and mammosphere formation. Thus, the in vitro cell culture assays reflect the changes observed in vivo in transgenic mice. These findings establish a link between the loss of p21(CIP1) and the acquisition of breast cancer EMT and stem cell properties in vivo.
Proceedings of the National Academy of Sciences 11/2009; 106(45):19035-9. · 9.68 Impact Factor
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Maria Genander,
Michael M Halford,
Nan-Jie Xu,
Malin Eriksson, Zuoren Yu,
Zhaozhu Qiu,
Anna Martling,
Gedas Greicius,
Sonal Thakar,
Timothy Catchpole,
Michael J Chumley,
Sofia Zdunek,
Chenguang Wang,
Torbjörn Holm,
Stephen P Goff,
Sven Pettersson,
Richard G Pestell,
Mark Henkemeyer,
Jonas Frisén
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ABSTRACT: Signaling proteins driving the proliferation of stem and progenitor cells are often encoded by proto-oncogenes. EphB receptors represent a rare exception; they promote cell proliferation in the intestinal epithelium and function as tumor suppressors by controlling cell migration and inhibiting invasive growth. We show that cell migration and proliferation are controlled independently by the receptor EphB2. EphB2 regulated cell positioning is kinase-independent and mediated via phosphatidylinositol 3-kinase, whereas EphB2 tyrosine kinase activity regulates cell proliferation through an Abl-cyclin D1 pathway. Cyclin D1 regulation becomes uncoupled from EphB signaling during the progression from adenoma to colon carcinoma in humans, allowing continued proliferation with invasive growth. The dissociation of EphB2 signaling pathways enables the selective inhibition of the mitogenic effect without affecting the tumor suppressor function and identifies a pharmacological strategy to suppress adenoma growth.
Cell 11/2009; 139(4):679-92. · 32.40 Impact Factor
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Manran Liu,
Xiaoming Ju,
Nicole E Willmarth,
Mathew C Casimiro,
John Ojeifo,
Toshiyuki Sakamaki,
Sanjay Katiyar,
Xuanmao Jiao,
Vladimir M Popov, Zuoren Yu,
Kongming Wu,
David Joyce,
Chenguang Wang,
Richard G Pestell
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ABSTRACT: The (HER2/Neu) ErbB2 oncogene is commonly overexpressed in human breast cancer and is sufficient for mammary tumorigenesis in transgenic mice. Nuclear factor (NF)-kappaB activity is increased in both human and murine breast tumors. The immune response to mammary tumorigenesis may regulate tumor progression. The role of endogenous mammary epithelial cell NF-kappaB had not previously been determined in immune-competent animals. Furthermore, the role of the NF-kappaB components, p50 and p65, in tumor growth was not known. Herein, the expression of a stabilized form of the NF-kappaB-inhibiting IkappaBalpha protein (IkappaBalphaSR) in breast tumor cell lines that express oncogenic ErbB2 inhibited DNA synthesis and growth in both two- and three-dimensional cultures. Either NF-kappaB inhibition or selective silencing of p50 or p65 led to a loss of contact-independent tumor growth in vitro. IkappaBalphaSR reversed the features of the oncogene-induced phenotype under three-dimensional growth conditions. The NF-kappaB blockade inhibited ErbB2-induced mammary tumor growth in both immune-competent and immune-deficient mice. These findings were associated with both reduced tumor microvascular density and a reduction in the amount of vascular endothelial growth factor. The expression of IkappaBalphaSR in breast cancer tumors inhibited angiogenesis. Thus, mammary epithelial cell NF-kappaB activity enhances ErbB2-mediated mammary tumorigenesis in vivo by promoting both growth and survival signaling via the promotion of tumor vasculogenesis.
American Journal Of Pathology 05/2009; 174(5):1910-20. · 4.89 Impact Factor
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Expert Review of Anti-infective Therapy 04/2009; 9(3):275-9. · 2.65 Impact Factor
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Zuoren Yu,
Chenguang Wang,
Min Wang,
Zhiping Li,
Mathew C Casimiro,
Manran Liu,
Kongming Wu,
James Whittle,
Xiaoming Ju,
Terry Hyslop,
Peter McCue,
Richard G Pestell
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ABSTRACT: Decreased expression of specific microRNAs (miRNAs) occurs in human tumors, which suggests a function for miRNAs in tumor suppression. Herein, levels of the miR-17-5p/miR-20a miRNA cluster were inversely correlated to cyclin D1 abundance in human breast tumors and cell lines. MiR-17/20 suppressed breast cancer cell proliferation and tumor colony formation by negatively regulating cyclin D1 translation via a conserved 3' untranslated region miRNA-binding site, thereby inhibiting serum-induced S phase entry. The cell cycle effect of miR-17/20 was abrogated by cyclin D1 siRNA and in cyclin D1-deficient breast cancer cells. Mammary epithelial cell-targeted cyclin D1 expression induced miR-17-5p and miR-20a expression in vivo, and cyclin D1 bound the miR-17/20 cluster promoter regulatory region. In summary, these studies identify a novel cyclin D1/miR-17/20 regulatory feedback loop through which cyclin D1 induces miR-17-5p/miR-20a. In turn, miR-17/20 limits the proliferative function of cyclin D1, thus linking expression of a specific miRNA cluster to the regulation of oncogenesis.
The Journal of Cell Biology 09/2008; 182(3):509-17. · 10.26 Impact Factor
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ABSTRACT: Translin (TSN), also known as testis-brain RNA-binding protein, is proposed to bind to breakpoint junctions at chromosomal translocations in the nucleus and to specific RNAs in the cytoplasm. In germ cells of the mouse testis, it recognizes target mRNAs transcribed by the transcription factor CREM-tau in spermatids, specific meiotically expressed mRNAs, and a noncoding RNA that encodes piRNAs. Here we show that TSN also binds to the microRNA miR-122a. MiR-122a is expressed in late-stage germ cells and is complementary to a sequence in the 3' untranslated region of the transition protein 2 mRNA. The binding of TSN to miR-122a increases its in vivo stability, suggesting an additional posttranscriptional function for TSN.
Journal of Andrology 07/2008; 29(5):572-9. · 2.97 Impact Factor
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ABSTRACT: Dishevelled (Dsh in Drosophila or DVL in mice) is a member of the highly conserved Wg/Wnt signaling pathway, which regulates important processes such as cell proliferation, polarity, and specification of cell fate. Three orthologous genes of Dishevelled (Dvl-1, Dvl-2, and Dvl-3) have been found in both humans and mice. They play pivotal roles in regulating cell morphology and a variety of changes in cell behaviors. In the present study, we show that the expression of Dvl-1 is stage-dependent during mouse spermatogenesis, although Dvl-2 and Dvl-3 show relative consistent expression. The expression of Dvl-1 mRNA first appears in pachytene spermatocytes, increases in round and elongating spermatids, and then turns to an undetectable level in mature sperm cells. Analyses of immunohistochemistry and immunofluorescence staining show that DVL-1 is present diffusely in the cytoplasm of pachytene spermatocytes and exhibits mainly a vesicular pattern and perinuclear distribution and a weak diffusely cytoplasmic signal in round and elongating spermatids. The vesicular pattern of DVL-1 has been observed by previous studies in somatic cells, and suggested to play roles in signal transduction. Immunoprecipitation experiments show that DVL-1 coimmunprecipitates with spermatogenic cells beta-actin rather than alpha-tubulin. These results indicate that DVL-1 may be involved in spermatid morphological changes during mouse spermiogenesis through mediating signal transduction and/or regulating actin cytoskeleton organization.
Molecular Reproduction and Development 07/2006; 73(6):774-83. · 2.53 Impact Factor
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Molecular Reproduction and Development - MOL REPROD DEV. 01/2006; 73(6):774-783.
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ABSTRACT: MicroRNAs play important roles in regulating development at both transcriptional and posttranscriptional levels. Here, we report 29 microRNAs from mouse testis that are differentially expressed as the prepubertal testis differentiates to the adult testis. Using computational analyses to identify potential microRNA target mRNAs, we identify several possible male germ cell target mRNAs. One highly conserved sequence in the 3'-untranslated region (UTR) of transition protein 2 (Tnp2) mRNA, a testis-specific and posttranscriptionally regulated mRNA in postmeiotic germ cells, is complementary to Mirn122a. Mirn122a is enriched in late-stage male germ cells and is predominantly on polysomes. Mirn122a, but not another noncomplementary microRNA, inhibits the activity of a luciferase reporter construct containing the 3'-UTR of Tnp2. Site-directed mutations of Mirn122a indicate that base pairing of the 5'-region of Mirn122a to its complementary site in the 3'-UTR of Tnp2 mRNA is essential for the downregulation of luciferase activity. Real-time reverse transcription-polymerase chain reaction and ribonuclease protection assays reveal that the Mirn122a-directed decrease of the Tnp2 reporter gene activity results from mRNA cleavage. We propose that specific microRNAs, such as Mirn122a, could be involved in the posttranscriptional regulation of mRNAs such as Tnp2 in the mammalian testis.
Biology of Reproduction 10/2005; 73(3):427-33. · 4.01 Impact Factor
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ABSTRACT: Spermatogenesis occurs in successive mitotic, meiotic, and post-meiotic phase, and involves a number of unique processes including meiosis and dramatic morphological changes. The unique differentiation mechanisms of spermatogenesis suggest the existence of germ-cell-specific molecules. The most straight forward strategy to elucidate differentiation mechanisms is to identify and characterize differentiation-specific molecules and their associated genes in germ cells. However, only a few genes specifically involved in spermatogenesis have been studied. In the present study, six different types of spermatogenic cells (primitive type A spermatogonia, type B spermatogonia, preleptotene spermatocytes, pachytene spermatocytes, round spermatids, and elongating spermatids) were isolated from Balb/c mice testes using velocity sedimentation and Atlas cDNA arrays containing 1,176 known mouse genes were used to determine the gene expression profiles of the spermatogenic cells. The expression of 260 genes were detected in six different stages of spermatogenic cells and a number of genes showed differential expression. The 23 differentially expressed genes were further analysed by reverse transcription polymerase chain reaction (RT-PCR) for their stage-specific and tissue-specific expression characteristics. Based on the results of RT-PCR, six genes highly express in both primitive type A and type B spermatogonia, four genes up-regulate in type B spermatogonia, two genes up-regulate in spermatocytes, two genes up-regulate in spermatids, three genes express constantly from primitive A spermatogonia to elongating spermatids, two genes express constantly from primitive A spermatogonia to round spermatids, two genes do not change in their expression during spermatogenesis, two genes can be detected highly in adult testis, but are undetectable in spermatogenic cells. The tissue-specific expression characteristics of the 23 genes showed that some of them specifically expressed in testes or other tissues. These data provide new information for further studies into spermatogenesis-related genes and may lead to the identification of genes with potential relevance to the differentiation of spermatogenic cells. In addition, some of these genes could be considered to be used as the molecular markers for different stages of spermatogenic cells.
Molecular Reproduction and Development 04/2004; 67(3):264-72. · 2.53 Impact Factor
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ABSTRACT: During spermatogenesis, diploid stem cells differentiate, undergo meiosis and spermiogenesis, and transform into haploid spermatozoa. Various factors have been demonstrated to regulate this marvelous process of differentiation, but the expression of only a few genes specifically involved in spermatogenesis has been studied. In the present study, different types of spermatogenic cells were isolated from Balb/c mice testes of different ages using the velocity sedimentation method, and we determined the expression profiles of 1176 known mouse genes in six different types of mouse spermatogenic cells (primitive type A spermatogonia, type B spermatogonia, preleptotene spermatocytes, pachytene spermatocytes, round spermatids, and elongating spermatids) using Atlas cDNA arrays. Of the 1176 genes on the Atlas Mouse 1.2 cDNA Expression Arrays, we detected 181 genes in primitive type A spermatogonia, 256 in type B spermatogonia, 221 in preleptotene spermatocytes, 160 in pachytene spermatocytes, 141 in round spermatids, and 126 in elongating spermatids. A number of genes were detected as differential expression (up-regulation or down-regulation). Fourteen of the differentially expressed genes have been further confirmed by reverse transcription-polymerase chain reaction for their expression characterizations in different types of spermatogenic cells. These results provide more information for further studies into spermatogenesis-related genes and may lead to the identification of genes with potential relevance to spermatogenesis.
Biology of Reproduction 08/2003; 69(1):37-47. · 4.01 Impact Factor
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ABSTRACT: Centrins are members of the centrosome protein family, which is highly conserved during revolution. The homologous genes of centrin in many organisms had been cloned, but the sequences of the rat centrin genes were not reported yet in GenBank. We cloned the cDNA fragments of centrin-1, -2 and -3 from the rat testis by RT-PCR, and analyzed the homology of the deduced amino acid sequences. The expression characterization of centrin genes in rat spermatogenesis was carried out by semi-quantitative RT-PCR. The results show that the homology of the corresponding centrin proteins in human, mouse and rat is high. The expression of centrin-1 is testis-specific, spermatogenic cell-specific and developmental stage-related. Centrin-1 begins to be transcribed when the meiosis occurs, and its mRNA level reaches the peak in round spermatids. Centrin-2 and centrin-3 are highly expressed in spermatogonia and their mRNA level decreases markedly when meiosis occurs. These results suggest that centrin-1 may play roles in meiosis and spermiogenesis, and centrin-2 and centrin-3 may be related to mitosis.
Science in China Series C Life Sciences 01/2003; 45(6):655-62. · 1.61 Impact Factor
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ABSTRACT: The differentiation process of round spermatids to spermatozoa during the late stage of spermatogenesis is called spermiogenesis.
To explore spermiogenesis-related genes, cDNA microarray was used to study expression patterns of 1176 genes in pachytene
spermatocytes, round spermatids and elongating spermatids of Balb/c mice. The results showed that 208 genes were detected
in all the three cell types. Most of them were down-regulated from pachytene spermatocytes to round spermatids and elongating
spermatids. However, up-regulation of 7 genes expression in round spermatids and 3 genes in elongating spermatids were found.
Expression of 7 differentially expressed genes in cDNA arrays was further confirmed by semi-quantitative RT-PCR study. The
RT-PCR results indicated that the expression of 6 genes was consistent with that in cDNA arrays, only one gene did not show
differential expression by RT-PCR. These results may provide important clues for studying of expression, regulation, and function
of spermiogenesis-related genes.
Chinese Science Bulletin 11/2002; 47(24):2075-2079. · 1.32 Impact Factor
