同源异型框基因Rhox5对前列腺癌细胞增殖和凋亡的影响及其作用机制探讨
|
摘要
Rhox5是Rhox同源异型框基因簇中的主要成员,其在胚胎发育、生殖系统的发育、精子的形成和成熟过程中发挥着重要作用。有研究表明,Rhox5在多种肿瘤细胞中存在异常表达,但其具体功能和作用机制仍不清楚。实验室前期工作利用酵母双杂交技术发现Rhox5与前列腺癌相关蛋白PSAP存在相互作用。这提示,Rhox5可能在前列腺癌的发展进程中扮演着某种角色。基于此,本课题首次将Rhox5与前列腺癌关联,研究Rhox5对前列腺癌细胞增殖和凋亡的影响,并初步探讨其可能的作用机制。
首先,我们采用RT-PCR和Western Blot的方法确认Rhox5在前列腺癌细胞TRAMP-C2中的表达。然后,通过荧光筛选和Western Blot筛选得到靶向Rhox5的有效siRNA序列,并以此为基础构建Rhox5的shRNA真核表达载体,建立Rhox5稳定沉默前列腺癌细胞系。然后,我们采用MTT法检测稳定细胞系的增殖以及P13K特异性抑制剂LY294002预处理后细胞的增殖情况；用Annexin V/PI双染法流式细胞仪检测无血清诱导条件下的细胞凋亡情况；并用Western Blot检测稳定细胞系中Akt的磷酸化水平。结果发现,与对照组相比,稳定沉默Rhox5的前列腺癌细胞增殖明显加快(p<0.01),而LY294002预处理后则较对照组无明显差异；此外,稳定沉默Rhox5的前列腺癌细胞的凋亡率明显降低(p<0.05),Akt磷酸化水平明显升高。这些结果表明,Rhox5可以抑制前列腺癌细胞增殖并促进其凋亡,而这可能是通过PI3K/Akt信号通路进行调控的。
为进一步探讨Rhox5功能发挥的作用机制,我们用Co-IP的方法研究了Rhox5与PSAP在前列腺癌细胞中的内源性相互作用,并用Western Blot检测了稳定前列腺癌细胞系培养上清中PSAP的表达以及PSAP对PI3K/Akt信号通路的活化作用。结果发现,Rhox5在前列腺癌细胞中可以与PSAP内源性相互作用；Rhox5的沉默上调了培养上清中PSAP的表达；此外,PSAP还被证实可以在鼠前列腺癌细胞中激活PI3K/Akt信号通路。这些结果提示,Rhox5可能通过与PSAP结合抑制PSAP的胞外分泌,从而抑制由PSAP诱导的PI3K/Akt信号通路的活化,进而抑制前列腺癌细胞的增殖、促进其凋亡。但这尚需进一步实验验证。
综上所述,本研究首次发现了Rhox5在前列腺癌细胞中的表达,并发现Rhox5能够抑制前列腺癌细胞增殖并促进其凋亡,而这可能是通过PI3K/Akt信号通路进行调控的。此外,本研究还发现Rhox5在前列腺癌细胞中可以与PSAP内源性相互作用,且Rhox5影响PSAP在细胞培养上清中的表达,从而提出Rhox5可能通过与PSAP结合抑制PSAP的胞外分泌而实现对前列腺癌细胞的增殖抑制和凋亡促进作用。
Rhox5 is the founding member of Rhox homeobox gene cluster, and it plays important roles in embryonic development, reproductive development and spermatogenesis. Although studies have indicated that Rhox5 is aberrantly expressed in multiple tumor cells, its function and mechanism are still unclear. Our lab previously found the interaction between Rhox5 and PSAP, a prostate cancer related protein, by yeast-two hybrid method, which suggests that Rhox5 may play a role in prostate cancer development. Hence, for the first time we associate Rhox5 with prostate cancer, to study its influence on proliferation and apoptosis of prostate cancer cells and primitively explore its potential mechanism.
We first identified the expression of Rhox5 in prostate cancer cell line TRAMP-C2 by RT-PCR and Western Blot. Then, we obtained effective siRNA against Rhox5 by fluorescence screening and Western Blot screening, based on which we then constructed a eukaryotic shRNA expression vector of Rhox5 and established a stable Rhox5-silencing prostate cancer cell line. The proliferation of stable cell lines with/without LY294002 pretreatment was detected by MTT assay; apoptosis induced by serum starvation was detected by Annexin V/PI double staining-FCM method; phosphorylation level of Akt was dectected by Western Blot analysis. Our results show that the proliferation of Rhox5-silencing prostate cancer cells was significantly increased as compared to control (p<0.01), while LY294002 pretreatment abrogated this difference; in addition, the apoptosis rate of Rhox5-silencing prostate cancer cells was obviously reduced (p<0.01), and the phosphorylation level of Akt was increased. These results suggest that Rhox5 can inhibit the proliferation of prostate cancer cells and promote their apoptosis, which might be mediated via PI3K/Akt pathway.
In order to explore the mechanism that Rhox5 functions, we studied the endogenous interaction between Rhox5 and PSAP in prostate cancer cells by coimmunoprecipitation, and we detected the expression of PSAP in the culture media of stable prostate cancer cell lines and confirmed the activity of PSAP on PI3K/Akt pathway. Our results show that Rhox5 can endogenously interact with PSAP in prostate cancer cells and Rhox5 silencing upregulates the expression of PSAP in the culture media. Besides, we have confirmed that PSAP can activate PI3K/Akt pathway in mouse prostate cancer cells. All these results together suggest that Rhox5 may inhibit the secretion of PSAP by binding to it, which inhibits the PSAP-induced activation of PI3K/Akt pathway and further inhibits the proliferation and promotes apoptosis of prostate cancer cells. However, further experiments are needed to confirm this hypothesis.
In conclusion, our study for the first time has found the expression of Rhox5 in prostate cancer cells and the ability of Rhox5 to inhibit the proliferation and promote apoptosis of prostate cancer cells, which might be regulated via PI3K/Akt pathway. In addition, we have found that Rhox5 can endogenously interact with PSAP in prostate cancer cells and that Rhox5 affects the expression of PSAP in the culture medium. Therefore, we propose that Rhox5 may inhibit proliferation and promote apoptosis of prostate cancer cells by binding to PSAP and inhibiting its secretion.
首先,我们采用RT-PCR和Western Blot的方法确认Rhox5在前列腺癌细胞TRAMP-C2中的表达。然后,通过荧光筛选和Western Blot筛选得到靶向Rhox5的有效siRNA序列,并以此为基础构建Rhox5的shRNA真核表达载体,建立Rhox5稳定沉默前列腺癌细胞系。然后,我们采用MTT法检测稳定细胞系的增殖以及P13K特异性抑制剂LY294002预处理后细胞的增殖情况；用Annexin V/PI双染法流式细胞仪检测无血清诱导条件下的细胞凋亡情况；并用Western Blot检测稳定细胞系中Akt的磷酸化水平。结果发现,与对照组相比,稳定沉默Rhox5的前列腺癌细胞增殖明显加快(p<0.01),而LY294002预处理后则较对照组无明显差异；此外,稳定沉默Rhox5的前列腺癌细胞的凋亡率明显降低(p<0.05),Akt磷酸化水平明显升高。这些结果表明,Rhox5可以抑制前列腺癌细胞增殖并促进其凋亡,而这可能是通过PI3K/Akt信号通路进行调控的。
为进一步探讨Rhox5功能发挥的作用机制,我们用Co-IP的方法研究了Rhox5与PSAP在前列腺癌细胞中的内源性相互作用,并用Western Blot检测了稳定前列腺癌细胞系培养上清中PSAP的表达以及PSAP对PI3K/Akt信号通路的活化作用。结果发现,Rhox5在前列腺癌细胞中可以与PSAP内源性相互作用；Rhox5的沉默上调了培养上清中PSAP的表达；此外,PSAP还被证实可以在鼠前列腺癌细胞中激活PI3K/Akt信号通路。这些结果提示,Rhox5可能通过与PSAP结合抑制PSAP的胞外分泌,从而抑制由PSAP诱导的PI3K/Akt信号通路的活化,进而抑制前列腺癌细胞的增殖、促进其凋亡。但这尚需进一步实验验证。
综上所述,本研究首次发现了Rhox5在前列腺癌细胞中的表达,并发现Rhox5能够抑制前列腺癌细胞增殖并促进其凋亡,而这可能是通过PI3K/Akt信号通路进行调控的。此外,本研究还发现Rhox5在前列腺癌细胞中可以与PSAP内源性相互作用,且Rhox5影响PSAP在细胞培养上清中的表达,从而提出Rhox5可能通过与PSAP结合抑制PSAP的胞外分泌而实现对前列腺癌细胞的增殖抑制和凋亡促进作用。
Rhox5 is the founding member of Rhox homeobox gene cluster, and it plays important roles in embryonic development, reproductive development and spermatogenesis. Although studies have indicated that Rhox5 is aberrantly expressed in multiple tumor cells, its function and mechanism are still unclear. Our lab previously found the interaction between Rhox5 and PSAP, a prostate cancer related protein, by yeast-two hybrid method, which suggests that Rhox5 may play a role in prostate cancer development. Hence, for the first time we associate Rhox5 with prostate cancer, to study its influence on proliferation and apoptosis of prostate cancer cells and primitively explore its potential mechanism.
We first identified the expression of Rhox5 in prostate cancer cell line TRAMP-C2 by RT-PCR and Western Blot. Then, we obtained effective siRNA against Rhox5 by fluorescence screening and Western Blot screening, based on which we then constructed a eukaryotic shRNA expression vector of Rhox5 and established a stable Rhox5-silencing prostate cancer cell line. The proliferation of stable cell lines with/without LY294002 pretreatment was detected by MTT assay; apoptosis induced by serum starvation was detected by Annexin V/PI double staining-FCM method; phosphorylation level of Akt was dectected by Western Blot analysis. Our results show that the proliferation of Rhox5-silencing prostate cancer cells was significantly increased as compared to control (p<0.01), while LY294002 pretreatment abrogated this difference; in addition, the apoptosis rate of Rhox5-silencing prostate cancer cells was obviously reduced (p<0.01), and the phosphorylation level of Akt was increased. These results suggest that Rhox5 can inhibit the proliferation of prostate cancer cells and promote their apoptosis, which might be mediated via PI3K/Akt pathway.
In order to explore the mechanism that Rhox5 functions, we studied the endogenous interaction between Rhox5 and PSAP in prostate cancer cells by coimmunoprecipitation, and we detected the expression of PSAP in the culture media of stable prostate cancer cell lines and confirmed the activity of PSAP on PI3K/Akt pathway. Our results show that Rhox5 can endogenously interact with PSAP in prostate cancer cells and Rhox5 silencing upregulates the expression of PSAP in the culture media. Besides, we have confirmed that PSAP can activate PI3K/Akt pathway in mouse prostate cancer cells. All these results together suggest that Rhox5 may inhibit the secretion of PSAP by binding to it, which inhibits the PSAP-induced activation of PI3K/Akt pathway and further inhibits the proliferation and promotes apoptosis of prostate cancer cells. However, further experiments are needed to confirm this hypothesis.
In conclusion, our study for the first time has found the expression of Rhox5 in prostate cancer cells and the ability of Rhox5 to inhibit the proliferation and promote apoptosis of prostate cancer cells, which might be regulated via PI3K/Akt pathway. In addition, we have found that Rhox5 can endogenously interact with PSAP in prostate cancer cells and that Rhox5 affects the expression of PSAP in the culture medium. Therefore, we propose that Rhox5 may inhibit proliferation and promote apoptosis of prostate cancer cells by binding to PSAP and inhibiting its secretion.
引文
[1]McGinnis W, Levine M S, Hafen E, et al. A conserved DNA sequence in homoeotic genes of the Drosophila Antennapedia and bithorax complexes[J]. Nature,1984,308 (5958),428-33.
[2]Otting G, Qian Y Q, Billeter M, et al. Protein-DNA contacts in the structure of a homeodomain-DNA complex determined by nuclear magnetic resonance spectroscopy in solution[J]. The EMBO journal,1990,9 (10),3085-92.
[3]McGinnis W and Krumlauf R. Homeobox genes and axial patterning[J]. Cell, 1992,68 (2),283-302.
[4]Boncinelli E, Mallamaci A, and Lavorgna G. Vertebrate homeobox genes[J]. Genetica,1994,94 (2-3),127-40.
[5]Cillo C, Cantile M, Faiella A, et al. Homeobox genes in normal and malignant cells[J]. Journal of cellular physiology,2001,188 (2),161-9.
[6]Pattyn A, Goridis C, and Brunet J F. Specification of the central noradrenergic phenotype by the homeobox gene Phox2b[J]. Molecular and cellular neurosciences,2000,15 (3),235-43.
[7]Magli M C, Barba P, Celetti A, et al. Coordinate regulation of HOX genes in human hematopoietic cells[J]. Proceedings of the National Academy of Sciences of the United States of America,1991,88 (14),6348-52.
[8]Srebrow A, Friedmann Y, Ravanpay A, et al. Expression of Hoxa-1 and Hoxb-7 is regulated by extracellular matrix-dependent signals in mammary epithelial cells [J]. Journal of cellular biochemistry,1998,69 (4),377-91.
[9]Celetti A, Barba P, Cillo C, et al. Characteristic patterns of HOX gene expression in different types of human leukemia[J]. International journal of cancer,1993,53 (2),237-44.
[10]Iida S, Rao P H, Nallasivam P, et al. The t(9;14)(p13;q32) chromosomal translocation associated with lymphoplasmacytoid lymphoma involves the PAX-5
gene[J]. Blood,1996,88 (11),4110-7.
[11]De Vita G, Barba P, Odartchenko N, et al. Expression of homeobox-containing genes in primary and metastatic colorectal cancer[J]. Eur J Cancer,1993,29A(6), 887-93.
[12]Banerjee-Basu S and Baxevanis AD. Molecular evolution of the homeodomain family of transcription factors[J]. Nucleic Acids Res,2001,29 (15),3258-69.
[13]Hogeveen K N and Sassone-Corsi P. Homeobox galore:when reproduction goes RHOX and roll[J]. Cell,2005,120 (3),287-8.
[14]Wang X and Zhang J. Remarkable expansions of an X-linked reproductive homeobox gene cluster in rodent evolution[J]. Genomics,2006,88 (1),34-43.
[15]Maclean J A,2nd, Chen M A, Wayne C M, et al. Rhox:a new homeobox gene cluster[J]. Cell,2005,120(3),369-82.
[16]Geserick C, Weiss B, Schleuning W D, et al. OTEX, an androgen-regulated human member of the paired-like class of homeobox genes [J]. The Biochemical journal,2002,366 (Pt 1),367-75.
[17]Wayne C M, MacLean J A, Cornwall G, et al. Two novel human X-linked homeobox genes, hPEPPl and hPEPP2, selectively expressed in the testis[J]. Gene, 2002,301 (1-2),1-11.
[18]Wilkinson M F, Kleeman J, Richards J, et al. A novel oncofetal gene is expressed in a stage-specific manner in murine embryonic development[J]. Developmental Biology,1990,141,451-55.
[19]Maiti S, Doskow J, Li S, et al. The Pem homeobox gene. Androgen-dependent and-independent promoters and tissue-specific alternative RNA splicing [J]. J Biol Chem,1996,271 (29),17536-46.
[20]Shanker S, Hu Z, and Wilkinson M F. Epigenetic regulation and downstream targets of the Rhox5 homeobox gene[J]. Int JAndrol,2008,31 (5),462-70.
[21]Rao M K, Maiti S, Ananthaswamy H N, et al. A highly active homeobox gene promoter regulated by Ets and Spl family members in normal granulosa cells and diverse tumor cell types[J]. J Biol Chem,2002,277 (29),26036-45.
[22]Bhardwaj A, Rao M K, Kaur R et al. GATA factors and androgen receptor collaborate to transcriptionally activate the Rhox5 homeobox gene in Sertoli cells[J]. Mol Cell Biol,2008,28 (7),2138-53.
[23]Rao M K, Wayne C M, Meistrich M L, et al. Pem homeobox gene promoter sequences that direct transcription in a Sertoli cell-specific, stage-specific, and androgen-dependent manner in the testis in vivo[J]. Molecular endocrinology (Baltimore, Md,2003,17 (2),223-33.
[24]Sutton K A, Maiti S, Tribley W A, et al. Androgen regulation of the Pem homeodomain gene in mice and rat Sertoli and epididymal cells[J]. Journal of andrology,1998,19 (1),21-30.
[25]Lindsey J S and Wilkinson M F. An androgen-regulated homeobox gene expressed in rat testis and epididymis[J]. Biol Reprod,1996,55 (5),975-83.
[26]Pitman J L, Lin T P, Kleeman J E, et al. Normal reproductive and macrophage function in Pem homeobox gene-deficient mice[J]. Dev Biol,1998,202 (2), 196-214.
[27]Hu Z Y, MacLean J A, Bhardwaj A, et al. Regulation and function of the Rhox5[J]. Ann Ny Acad Sci,2007,1120,72-83.
[28]Hu Z, Shanker S, MacLean J A, et al. The RHOX5 homeodomain protein mediates transcriptional repression of the netrin-1 receptor gene Unc5c[J]. J Biol Chem,2008,283 (7),3866-76.
[29]Guo F, Huang X, Li S, et al. Identification of prosaposin as a novel interaction partner for Rhox5[J]. Journal of genetics and genomics=Yi chuan xue bao,2007, 34 (5),392-9.
[30]Koochekpour S, Zhuang Y J, Beroukhim R, et al. Amplification and overexpression of prosaposin in prostate cancer[J]. Genes, chromosomes & cancer, 2005,44 (4),351-64.
[31]Koochekpour S, Sartor O, Hiraiwa M, et al. Saposin C stimulates growth and invasion, activates p42/44 and SAPK/JNK signaling pathways of MAPK and upregulates uPA/uPAR expression in prostate cancer and stromal cells[J]. Asian J Androl,2005,7 (2),147-58.
[32]Hu S, Delorme N, Liu Z, et al. Prosaposin down-modulation decreases metastatic prostate cancer cell adhesion, migration, and invasion[J]. Molecular cancer,2010, 9,30.
[33]Hennessy B T, Smith D L, Ram P T, et al. Exploiting the PI3K/AKT pathway for cancer drug discovery[J]. Nature reviews,2005,4 (12),988-1004.
[34]Engelman J A, Luo J, and Cantley L C. The evolution of phosphatidylinositol 3-kinases as regulators of growth and metabolism[J]. Nat Rev Genet,2006,7 (8), 606-19.
[35]Lefrancois S, Zeng J B, Hassan A J, et al. The lysosomal trafficking of sphingolipid activator proteins (SAPs) is mediated by sortilin[J]. Embo J,2003,22 (24),6430-37.
[36]Igdoura S A, Rasky A, and Morales C R. Trafficking of sulfated glycoprotein-1 (prosaposin) to lysosomes or to the extracellular space in rat Sertoli cells[J]. Cell Tissue Res,1996,283 (3),385-94.
[37]Kishimoto Y, Hiraiwa M, and O'Brien J S. Saposins:structure, function, distribution, and molecular genetics[J]. JLipid Res,1992,33 (9),1255-67.
[38]Hiraiwa M, Campana W M, Mizisin A P, et al. Prosaposin:a myelinotrophic protein that promotes expression of myelin constituents and is secreted after nerve injury[J]. Glia,1999,26 (4),353-60.
[39]Amann R P, Seidel G E, Jr., and Brink Z A. Exposure of thawed frozen bull sperm to a synthetic peptide before artificial insemination increases fertility[J]. J Androl, 1999,20(1),42-6.
[40]Sano A, Matsuda S, Wen T C, et al. Protection by prosaposin against ischemia-induced learning disability and neuronal loss[J]. Biochem Biophys Res Commun,1994,204 (2),994-1000.
[41]Kotani Y, Matsuda S, Wen T C, et al. A hydrophilic peptide comprising 18 amino acid residues of the prosaposin sequence has neurotrophic activity in vitro and in vivo[J]. JNeurochem,1996,66 (5),2197-200.
[42]Wang D, Luo W L, Zhou C Y, et al. Altered prosaposin expression in the rat facial nerve nucleus following facial nerve transection and repair [J]. Neural Regen Res, 2009,4 (3),230-35.
[43]Mizisin A P, Steinhardt R C, O'Brien J S, et al. TX14(A), a prosaposin-derived peptide, reverses established nerve disorders in Streptozotocin-diabetic rats and prevents them in galactose-fed rats[J]. J Neuropath Exp Neur,2001,60 (10), 953-60.
[44]Morita F, Wen T C, Tanaka J, et al. Protective effect of a prosaposin-derived, 18-mer peptide on slowly progressive neuronal degeneration after brief ischemia[J]. J Cerebr Blood F Met,2001,21 (11),1295-302.
[45]Lee T J, Sartor O, Luftig R B, et al. Saposin C promotes survival and prevents apoptosis via PI3K/Akt-dependent pathway in prostate cancer cells[J]. Molecular cancer,2004,3,31.
[46]MacLean J A, Hu Z Y, Bhardwaj A, et al. Rhox5 regulates key regulators of metabolism during testis development.[J]. Biol Reprod,2006,84-85.
[47]Jemal A, Siegel R, Ward E, et al. Cancer statistics,2008 [J]. CA:a cancer journal for clinicians,2008,58 (2),71-96.
[48]Gu F. Epidemiological survey of benign prostatic hyperplasia and prostatic cancer in China[J]. Chinese medical journal,2000,113 (4),299-302.
[49]Katso R, Okkenhaug K, Ahmadi K, et al. Cellular function of phosphoinositide 3-kinases:implications for development, homeostasis, and cancer[J]. Annual review of cell and developmental biology,2001,17,615-75.
[50]Vivanco I and Sawyers C L. The phosphatidylinositol 3-Kinase AKT pathway in human cancer[J]. Nat Rev Cancer,2002,2 (7),489-501.
[2]Otting G, Qian Y Q, Billeter M, et al. Protein-DNA contacts in the structure of a homeodomain-DNA complex determined by nuclear magnetic resonance spectroscopy in solution[J]. The EMBO journal,1990,9 (10),3085-92.
[3]McGinnis W and Krumlauf R. Homeobox genes and axial patterning[J]. Cell, 1992,68 (2),283-302.
[4]Boncinelli E, Mallamaci A, and Lavorgna G. Vertebrate homeobox genes[J]. Genetica,1994,94 (2-3),127-40.
[5]Cillo C, Cantile M, Faiella A, et al. Homeobox genes in normal and malignant cells[J]. Journal of cellular physiology,2001,188 (2),161-9.
[6]Pattyn A, Goridis C, and Brunet J F. Specification of the central noradrenergic phenotype by the homeobox gene Phox2b[J]. Molecular and cellular neurosciences,2000,15 (3),235-43.
[7]Magli M C, Barba P, Celetti A, et al. Coordinate regulation of HOX genes in human hematopoietic cells[J]. Proceedings of the National Academy of Sciences of the United States of America,1991,88 (14),6348-52.
[8]Srebrow A, Friedmann Y, Ravanpay A, et al. Expression of Hoxa-1 and Hoxb-7 is regulated by extracellular matrix-dependent signals in mammary epithelial cells [J]. Journal of cellular biochemistry,1998,69 (4),377-91.
[9]Celetti A, Barba P, Cillo C, et al. Characteristic patterns of HOX gene expression in different types of human leukemia[J]. International journal of cancer,1993,53 (2),237-44.
[10]Iida S, Rao P H, Nallasivam P, et al. The t(9;14)(p13;q32) chromosomal translocation associated with lymphoplasmacytoid lymphoma involves the PAX-5
gene[J]. Blood,1996,88 (11),4110-7.
[11]De Vita G, Barba P, Odartchenko N, et al. Expression of homeobox-containing genes in primary and metastatic colorectal cancer[J]. Eur J Cancer,1993,29A(6), 887-93.
[12]Banerjee-Basu S and Baxevanis AD. Molecular evolution of the homeodomain family of transcription factors[J]. Nucleic Acids Res,2001,29 (15),3258-69.
[13]Hogeveen K N and Sassone-Corsi P. Homeobox galore:when reproduction goes RHOX and roll[J]. Cell,2005,120 (3),287-8.
[14]Wang X and Zhang J. Remarkable expansions of an X-linked reproductive homeobox gene cluster in rodent evolution[J]. Genomics,2006,88 (1),34-43.
[15]Maclean J A,2nd, Chen M A, Wayne C M, et al. Rhox:a new homeobox gene cluster[J]. Cell,2005,120(3),369-82.
[16]Geserick C, Weiss B, Schleuning W D, et al. OTEX, an androgen-regulated human member of the paired-like class of homeobox genes [J]. The Biochemical journal,2002,366 (Pt 1),367-75.
[17]Wayne C M, MacLean J A, Cornwall G, et al. Two novel human X-linked homeobox genes, hPEPPl and hPEPP2, selectively expressed in the testis[J]. Gene, 2002,301 (1-2),1-11.
[18]Wilkinson M F, Kleeman J, Richards J, et al. A novel oncofetal gene is expressed in a stage-specific manner in murine embryonic development[J]. Developmental Biology,1990,141,451-55.
[19]Maiti S, Doskow J, Li S, et al. The Pem homeobox gene. Androgen-dependent and-independent promoters and tissue-specific alternative RNA splicing [J]. J Biol Chem,1996,271 (29),17536-46.
[20]Shanker S, Hu Z, and Wilkinson M F. Epigenetic regulation and downstream targets of the Rhox5 homeobox gene[J]. Int JAndrol,2008,31 (5),462-70.
[21]Rao M K, Maiti S, Ananthaswamy H N, et al. A highly active homeobox gene promoter regulated by Ets and Spl family members in normal granulosa cells and diverse tumor cell types[J]. J Biol Chem,2002,277 (29),26036-45.
[22]Bhardwaj A, Rao M K, Kaur R et al. GATA factors and androgen receptor collaborate to transcriptionally activate the Rhox5 homeobox gene in Sertoli cells[J]. Mol Cell Biol,2008,28 (7),2138-53.
[23]Rao M K, Wayne C M, Meistrich M L, et al. Pem homeobox gene promoter sequences that direct transcription in a Sertoli cell-specific, stage-specific, and androgen-dependent manner in the testis in vivo[J]. Molecular endocrinology (Baltimore, Md,2003,17 (2),223-33.
[24]Sutton K A, Maiti S, Tribley W A, et al. Androgen regulation of the Pem homeodomain gene in mice and rat Sertoli and epididymal cells[J]. Journal of andrology,1998,19 (1),21-30.
[25]Lindsey J S and Wilkinson M F. An androgen-regulated homeobox gene expressed in rat testis and epididymis[J]. Biol Reprod,1996,55 (5),975-83.
[26]Pitman J L, Lin T P, Kleeman J E, et al. Normal reproductive and macrophage function in Pem homeobox gene-deficient mice[J]. Dev Biol,1998,202 (2), 196-214.
[27]Hu Z Y, MacLean J A, Bhardwaj A, et al. Regulation and function of the Rhox5[J]. Ann Ny Acad Sci,2007,1120,72-83.
[28]Hu Z, Shanker S, MacLean J A, et al. The RHOX5 homeodomain protein mediates transcriptional repression of the netrin-1 receptor gene Unc5c[J]. J Biol Chem,2008,283 (7),3866-76.
[29]Guo F, Huang X, Li S, et al. Identification of prosaposin as a novel interaction partner for Rhox5[J]. Journal of genetics and genomics=Yi chuan xue bao,2007, 34 (5),392-9.
[30]Koochekpour S, Zhuang Y J, Beroukhim R, et al. Amplification and overexpression of prosaposin in prostate cancer[J]. Genes, chromosomes & cancer, 2005,44 (4),351-64.
[31]Koochekpour S, Sartor O, Hiraiwa M, et al. Saposin C stimulates growth and invasion, activates p42/44 and SAPK/JNK signaling pathways of MAPK and upregulates uPA/uPAR expression in prostate cancer and stromal cells[J]. Asian J Androl,2005,7 (2),147-58.
[32]Hu S, Delorme N, Liu Z, et al. Prosaposin down-modulation decreases metastatic prostate cancer cell adhesion, migration, and invasion[J]. Molecular cancer,2010, 9,30.
[33]Hennessy B T, Smith D L, Ram P T, et al. Exploiting the PI3K/AKT pathway for cancer drug discovery[J]. Nature reviews,2005,4 (12),988-1004.
[34]Engelman J A, Luo J, and Cantley L C. The evolution of phosphatidylinositol 3-kinases as regulators of growth and metabolism[J]. Nat Rev Genet,2006,7 (8), 606-19.
[35]Lefrancois S, Zeng J B, Hassan A J, et al. The lysosomal trafficking of sphingolipid activator proteins (SAPs) is mediated by sortilin[J]. Embo J,2003,22 (24),6430-37.
[36]Igdoura S A, Rasky A, and Morales C R. Trafficking of sulfated glycoprotein-1 (prosaposin) to lysosomes or to the extracellular space in rat Sertoli cells[J]. Cell Tissue Res,1996,283 (3),385-94.
[37]Kishimoto Y, Hiraiwa M, and O'Brien J S. Saposins:structure, function, distribution, and molecular genetics[J]. JLipid Res,1992,33 (9),1255-67.
[38]Hiraiwa M, Campana W M, Mizisin A P, et al. Prosaposin:a myelinotrophic protein that promotes expression of myelin constituents and is secreted after nerve injury[J]. Glia,1999,26 (4),353-60.
[39]Amann R P, Seidel G E, Jr., and Brink Z A. Exposure of thawed frozen bull sperm to a synthetic peptide before artificial insemination increases fertility[J]. J Androl, 1999,20(1),42-6.
[40]Sano A, Matsuda S, Wen T C, et al. Protection by prosaposin against ischemia-induced learning disability and neuronal loss[J]. Biochem Biophys Res Commun,1994,204 (2),994-1000.
[41]Kotani Y, Matsuda S, Wen T C, et al. A hydrophilic peptide comprising 18 amino acid residues of the prosaposin sequence has neurotrophic activity in vitro and in vivo[J]. JNeurochem,1996,66 (5),2197-200.
[42]Wang D, Luo W L, Zhou C Y, et al. Altered prosaposin expression in the rat facial nerve nucleus following facial nerve transection and repair [J]. Neural Regen Res, 2009,4 (3),230-35.
[43]Mizisin A P, Steinhardt R C, O'Brien J S, et al. TX14(A), a prosaposin-derived peptide, reverses established nerve disorders in Streptozotocin-diabetic rats and prevents them in galactose-fed rats[J]. J Neuropath Exp Neur,2001,60 (10), 953-60.
[44]Morita F, Wen T C, Tanaka J, et al. Protective effect of a prosaposin-derived, 18-mer peptide on slowly progressive neuronal degeneration after brief ischemia[J]. J Cerebr Blood F Met,2001,21 (11),1295-302.
[45]Lee T J, Sartor O, Luftig R B, et al. Saposin C promotes survival and prevents apoptosis via PI3K/Akt-dependent pathway in prostate cancer cells[J]. Molecular cancer,2004,3,31.
[46]MacLean J A, Hu Z Y, Bhardwaj A, et al. Rhox5 regulates key regulators of metabolism during testis development.[J]. Biol Reprod,2006,84-85.
[47]Jemal A, Siegel R, Ward E, et al. Cancer statistics,2008 [J]. CA:a cancer journal for clinicians,2008,58 (2),71-96.
[48]Gu F. Epidemiological survey of benign prostatic hyperplasia and prostatic cancer in China[J]. Chinese medical journal,2000,113 (4),299-302.
[49]Katso R, Okkenhaug K, Ahmadi K, et al. Cellular function of phosphoinositide 3-kinases:implications for development, homeostasis, and cancer[J]. Annual review of cell and developmental biology,2001,17,615-75.
[50]Vivanco I and Sawyers C L. The phosphatidylinositol 3-Kinase AKT pathway in human cancer[J]. Nat Rev Cancer,2002,2 (7),489-501.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |