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1.  Androgen Receptor (AR) Promotes Abdominal Aortic Aneurysm (AAA) Development via Modulating Inflammatory IL1α and TGFβ1 Expression 
Hypertension  2015;66(4):881-891.
Gender difference is a risk factor for abdominal aortic aneurism formation yet the reason for male predominance remains unclear. Androgen and the androgen receptor influence the male gender difference, indicating that androgen receptor signaling may affect abdominal aortic aneurism development. Using angiotensin II induced abdominal aortic aneurism in apolipoprotein E null mouse models (82.4% abdominal aortic aneurism incidence), we found that mice lacking androgen receptor failed to develop abdominal aortic aneurism and aorta had dramatically reduced macrophages infiltration and intact elastic fibers. These findings suggested that androgen receptor expression in endothelial cells, macrophages or smooth muscle cells might play a role in abdominal aortic aneurism development. Selective knockout of androgen receptor in each of these cell types further demonstrated that mice lacking androgen receptor in macrophages (20% abdominal aortic aneurism incidence) or smooth muscle cells (12.5% abdominal aortic aneurism incidence), but not in endothelial cells (71.4% abdominal aortic aneurism incidence) had suppressed abdominal aortic aneurism development. Mechanism dissection showed that androgen receptor functioned through modulation of interleukin 1α and transforming growth factor β1 signals and by targeting androgen receptor with androgen receptor degradation enhancer ASC-J9® led to significant suppression of abdominal aortic aneurism development. These results demonstrate the underlying mechanism by which androgen receptor influences abdominal aortic aneurism development through interleukin 1α and transforming growth factor β1, and provides a potential new therapy to suppress/prevent abdominal aortic aneurism by targeting androgen receptor with ASC-J9®.
PMCID: PMC4658219  PMID: 26324502
inflammatory abdominal aortic aneurysm; interleukin 1α; TGFβ1; androgen receptor
2.  Acarbose Decreases the Rheumatoid Arthritis Risk of Diabetic Patients and Attenuates the Incidence and Severity of Collagen-induced Arthritis in Mice 
Scientific Reports  2015;5:18288.
Acarbose has been found to decrease some inflammatory parameters in diabetic patients. This study aimed to examine the influence of acarbose on rheumatoid arthritis (RA) risk in diabetes mellitus (DM) patients and on the incidence and severity of collagen-induced arthritis (CIA) in mice. In a nationwide, matched case–control study, we identified 723 incident RA cases and selected 7,230 age-, sex- and RA diagnosis date–matched controls from all newly treated DM patients. We found that use of acarbose at > 16,950 mg per year was associated with a lower RA risk (odds ratio 0.60; 95% CI, 0.41–0.89). In the CIA mouse study, acarbose was orally administered from days -7 to 38 relative to type II collagen (CII) immunization. The results revealed that acarbose at the dose of 500 mg/kg/day attenuated the incidence and severity of arthritis and the expression of proinflammatory cytokines, including TNF-α, IL-6 and IL-17 in the paw tissues. Acarbose further decreased the productions of anti-CII-IgG, IL-17 and IFN-γ by collagen-reactive lymph node cells. This work suggests that the use of acarbose decreased RA risk in DM patients and the incidence of CIA in mice. Acarbose also attenuated the severity of CIA via anti-inflammatory and immunomodulatory effects.
PMCID: PMC4683371  PMID: 26678745
3.  The Incidence and Prevalence of Common Variable Immunodeficiency Disease in Taiwan, A Population-Based Study 
PLoS ONE  2015;10(10):e0140473.
Common variable immunodeficiency (CVID) is one of the primary immunodeficiency diseases that occur in both children and adults. We present here a nationwide, population-based epidemiological study of CVID across all ages in Taiwan during 2002–2011. Using the International Classification of Diseases, Ninth Revision code 279.06, cases of CVID were identified from Taiwan's National Health Insurance Research Database from January 2002 to December 2011. Age- and sex-specific incidence and prevalence rates were calculated. A total of 47 new cases of CVID during 2002–2011 were identified. Total prevalence rose from 0.13 per 100,000 in 2002 to 0.28 per 100,000 in 2011. The annual incidence rate during 2002–2011 was 0.019 per 100,000. Cases were equally distributed between males and females and males mostly occurred in younger patients. This nationwide population-based study showed that the incidence and prevalence of CVID in Taiwan were lower than that in Western countries.
PMCID: PMC4604164  PMID: 26461272
4.  Rheumatoid Arthritis Risk Associated with Periodontitis Exposure: A Nationwide, Population-Based Cohort Study 
PLoS ONE  2015;10(10):e0139693.
The risk of periodontitis (PD) is increased in the patient group of rheumatoid arthritis (RA). RA and PD also shared some pathological mechanism. The aim of this study is to investigate the risk of RA associated with PD exposure.
Methods and Findings
This study identified 3 mutually exclusive cohorts using the 1999–2010 Taiwanese National Health Insurance Research Database (NHIRD) to investigate the association between PD and the risk of incident RA. All patients with PD in 2000 were identified from the database of all enrollees as the PD cohort. From the representative database of 1,000,000 enrollees randomly selected in 2010 (LHID2010), individuals without any periodontal disease (PO) during 1999–2010 were selected as the non-PO cohort. Individuals who were not included in the non-PO cohort and received dental scaling (DS) no more than two times per year during 1999–2010 were selected as the DS cohort from LHID2010. Using cox proportional regression analysis, hazard ratios (HRs) with 95% confidence intervals (Cis) were calculated to quantify the association between PD exposure and RA development. In the three-group comparison using the non-PO cohort as reference, we found that the risk of RA was higher in the PD and DS cohorts (HRs, 1.89 and 1.43; 95% CIs, 1.56–2.29 and 1.09–1.87, respectively). For comparisons between two cohorts, the PD cohort had a higher risk of RA than the non-PO and DS cohorts (HRs, 1.91 and 1.35; 95% CIs, 1.57–2.30 and 1.09–1.67, respectively).
PD was associated with an increased risk of RA development.
PMCID: PMC4591281  PMID: 26426533
5.  Infiltrating macrophages promote prostate tumorigenesis via modulating androgen receptor-mediated CCL4-STAT3 signaling 
Cancer research  2013;73(18):10.1158/0008-5472.CAN-12-3228.
Infiltrating macrophages are a key component of inflammation during tumorigenesis, but the direct evidence of such linkage remains unclear. We report here that persistent co-culturing of immortalized prostate epithelial cells with macrophages, without adding any carcinogens, induces prostate tumorigenesis, and that induction involves the alteration of signaling of macrophage androgen receptor (AR)-inflammatory chemokine CCL4-STAT3 activation as well as epithelial-to-mesenchymal transition (EMT) and down-regulation of p53/PTEN tumor suppressors. In vivo studies further showed that PTEN+/− mice lacking macrophage AR developed far fewer prostatic intraepithelial neoplasia (PIN) lesions, supporting an in vivo role for macrophage AR during prostate tumorigenesis. CCL4 neutralizing antibody effectively blocked macrophage-induced prostate tumorigenic signaling, and targeting AR via an AR degradation enhancer, ASC-J9®, reduced CCL4 expression and xenografted tumor growth in vivo. Importantly, CCL4 upregulation was associated with increased Snail expression and down-regulation of p53/PTEN in high-grade PIN and prostate cancer. Together, our results identify the AR-CCL4-STAT3 axis as key regulators during prostate tumor initiation and highlight the important roles of infiltrating macrophages and inflammatory cytokines for the prostate tumorigenesis.
PMCID: PMC3833080  PMID: 23878190
androgen receptor; CCL4; macrophages; epithelial-to-mesenchymal transition; prostate cancer
6.  Loss of Androgen Receptor Promotes Adipogensis but Suppresses Osteogenesis in Bone Marrow Stromal Cells 
Stem cell research  2013;11(2):938-950.
Gender differences have been described in osteoporosis with females having a higher risk of osteoporosis than males. The differentiation of bone marrow stromal cells (BMSCs) into bone or fat is a critical step for osteoporosis. Here we demonstrated that loss of the androgen receptor (AR) in BMSCs suppressed osteogenesis but promoted adipogenesis. The mechanism dissection studies revealed that AR deficiency suppressed osteogenesis-related genes to inhibit osteoblast differentiation from BMSCs. Knockout of AR promoted adipogenesis of BMSCs via Akt activation through IGFBP3-mediated IGF signaling, and the 5′ promoter assay and chromatin immunoprecipitation assays further proved that AR could modulate IGFBP3 expression at the transcriptional level. Finally, addition of IGF inhibitors successfully masked the AR deficiency-induced Akt activation, and inhibitions of Akt, IGF1, and IGF2 pathways reversed the AR depletion effects on the adipogenesis process. These results suggested that AR-mediated changes in IGFBP3 might modulate the IGF-Akt axis to regulate adipogenesis in BMSCs.
PMCID: PMC3748723  PMID: 23859805
Insulin growth factor binding protein 3; bone marrow stromal cells; adipogenesis; androgen receptor
7.  The Role of Androgen and Androgen Receptor in the Skin-Related Disorders 
Archives of dermatological research  2012;304(7):499-510.
Androgen and androgen receptor (AR) may play important roles in several skin related diseases, such as androgenetic alopecia and acne vulgaris. Current treatments for these androgen/AR-involved diseases, which target the synthesis of androgens or prevent its binding to AR, can cause significant adverse side effects. Based on the recent studies using AR knockout mice, it has been suggested that AR and androgens play distinct roles in the skin pathogenesis, and AR seems to be a better target than androgens for the treatment of these skin diseases. Here we review recent studies of androgen/AR roles in several skin-related disorders, including acne vulgaris, androgenetic alopecia, and hirsutism, as well as cutaneous wound healing.
PMCID: PMC3763909  PMID: 22829074
androgen; androgen receptor; wound healing; androgenetic alopecia; acne vulgaris; hirsutism
8.  Involvement of TLR7 MyD88-dependent signaling pathway in the pathogenesis of adult-onset Still's disease 
The objective of this study was to investigate the potential role of the Toll-like receptor 7 (TLR7) signaling pathway in the pathogenesis of adult-onset Still's disease (AOSD).
Frequencies of TLR7-expressing precursor of myeloid dendritic cells (pre-mDCs) and mDCs in 28 AOSD patients, 28 patients with systemic lupus erythematosus (SLE) and 12 healthy controls (HC) were determined by flow cytometry analysis. Transcript and protein levels of TLR7 signaling molecules in peripheral blood mononuclear cells (PBMCs) were evaluated by quantitative PCR and western blotting respectively. Serum cytokines levels were measured by ELISA.
Significantly higher median frequencies of TLR7-expressing pre-mDCs and mDCs were observed in AOSD patients (65.5% and 14.9%, respectively) and in SLE patients (60.3% and 14.4%, respectively) than in HC (42.8% and 8.8%, respectively; both P <0.001). Transcript and protein levels of TLR7-signaling molecules, including MyD88, TRAF6, IRAK4 and IFN-α, were upregulated in AOSD patients and SLE patients compared with those in HC. Disease activity scores were positively correlated with the frequencies of TLR7-expressing mDCs and expression levels of TLR7 signaling molecules in both AOSD and SLE patients. TLR7 ligand (imiquimod) stimulation of PBMCs resulted in significantly enhanced levels of interleukin (IL)-1β, IL-6, IL-18 and IFN-α in AOSD and SLE patients. Frequencies of TLR7-expressing mDCs and expression levels of TLR7 signaling molecules significantly decreased after effective therapy.
Elevated levels of TLR7 signaling molecules and their positive correlation with disease activity in AOSD patients suggest involvement of the TLR7 signaling pathway in the pathogenesis of this disease. The overexpression of TLR7 MyD88-dependent signaling molecules may be a common pathogenic mechanism for both AOSD and SLE.
PMCID: PMC3672755  PMID: 23497717
9.  New therapy targeting differential androgen receptor signaling in prostate cancer stem/progenitor vs. non-stem/progenitor cells 
The androgen deprivation therapy (ADT) to systematically suppress/reduce androgens binding to the androgen receptor (AR) has been the standard therapy for prostate cancer (PCa); yet, most of ADT eventually fails leading to the recurrence of castration resistant PCa. Here, we found that the PCa patients who received ADT had increased PCa stem/progenitor cell population. The addition of the anti-androgen, Casodex®, or AR-siRNA in various PCa cells led to increased stem/progenitor cells, whereas, in contrast, the addition of functional AR led to decreased stem/progenitor cell population but increased non-stem/progenitor cell population, suggesting that AR functions differentially in PCa stem/progenitor vs. non-stem/progenitor cells. Therefore, the current ADT might result in an undesired expansion of PCa stem/progenitor cell population, which explains why this therapy fails. Using various human PCa cell lines and three different mouse models, we concluded that targeting PCa non-stem/progenitor cells with AR degradation enhancer ASC-J9® and targeting PCa stem/progenitor cells with 5-azathioprine and γ-tocotrienol resulted in a significant suppression of the tumors at the castration resistant stage. This suggests that a combinational therapy that simultaneously targets both stem/progenitor and non-stem/progenitor cells will lead to better therapeutic efficacy and may become a new therapy to battle the PCa before and after castration resistant stages.
PMCID: PMC3570051  PMID: 22831834
prostate cancer stem cells; androgen receptor; combination therapy
10.  Germinal center kinase-like kinase (GLK/MAP4K3) expression is increased in adult-onset Still's disease and may act as an activity marker 
BMC Medicine  2012;10:84.
Germinal center kinase-like kinase (GLK, also termed MAP4K3), a member of the MAP4K family, may regulate gene transcription, apoptosis and immune inflammation in response to extracellular signals. The enhanced expression of GLK has been shown to correspond with disease severity in patients with systemic lupus erythematosus. We investigated the role of GLK in the pathogenesis of adult-onset Still's disease, which shares some similar clinical characteristics with systemic lupus erythematosus.
The frequencies of circulating GLK-expressing T-cells in 24 patients with active adult-onset Still's disease and 12 healthy controls were determined by flow cytometry analysis. The expression levels of GLK proteins and transcripts were evaluated in peripheral blood mononuclear cells by immunoblotting and quantitative PCR. Serum levels of T helper (Th)17-related cytokines, including IL-1β, IL-6, IL-17 and TNF-α, were measured by ELISA.
Significantly higher median frequencies of circulating GLK-expressing T-cells were observed in patients with adult-onset Still's disease (31.85%) than in healthy volunteers (8.93%, P <0.001). The relative expression levels of GLK proteins and transcripts were also significantly higher in patients with adult-onset Still's disease (median, 1.74 and 2.35, respectively) compared with those in healthy controls (0.66 and 0.92, respectively, both P <0.001). The disease activity scores were positively correlated with the frequencies of circulating GLK-expressing T-cells (r = 0.599, P <0.005) and the levels of GLK proteins (r = 0.435, P <0.05) or GLK transcripts (r = 0.452, P <0.05) in patients with adult-onset Still's disease. Among the examined Th17-related cytokines, elevated levels of serum IL-6 and IL-17 were positively correlated with the frequencies of circulating GLK-expressing T-cells and the levels of GLK proteins as well as transcripts in patients with adult-onset Still's disease. GLK expression levels decreased significantly after effective therapy in these patients.
Elevated expression levels of GLK and their positive correlation with disease activity in patients with adult-onset Still's disease indicate that GLK may be involved in the pathogenesis and act as a novel activity biomarker of this disease.
PMCID: PMC3424974  PMID: 22867055
Adult-onset Still's disease; GCK-like kinase (GLK, MAP4K3); mitogen-activated protein kinases (MAPKs); pathogenesis; Th17-related cytokines
11.  Loss of stromal androgen receptor leads to suppressed prostate tumourigenesis via modulation of pro-inflammatory cytokines/chemokines 
EMBO Molecular Medicine  2012;4(8):791-807.
Stromal–epithelial interaction is crucial to mediate normal prostate and prostate cancer (PCa) development. The indispensable roles of mesenchymal/stromal androgen receptor (AR) for the prostate organogenesis have been demonstrated by using tissue recombination from wild-type and testicular feminized mice. However, the stromal AR functions in the tumour microenvironment and the underlying mechanisms governing the interactions between the epithelium and stroma are not completely understood. Here, we have established the first animal model with AR deletion in stromal fibromuscular cells (dARKO, AR knockout in fibroblasts and smooth muscle cells) in the Pten+/− mouse model that can spontaneously develop prostatic intraepithelial neoplasia (PIN). We found that loss of stromal fibromuscular AR led to suppression of PIN lesion development with alleviation of epithelium proliferation and tumour-promoting microenvironments, including extracellular matrix (ECM) remodelling, immune cell infiltration and neovasculature formation due, in part, to the modulation of pro-inflammatory cytokines/chemokines. Finally, targeting stromal fibromuscular AR with the AR degradation enhancer, ASC-J9®, resulted in the reduction of PIN development/progression, which might provide a new approach to suppress PIN development.
PMCID: PMC3494077  PMID: 22745041
androgen receptor; PIN; prostate stroma; PTEN; tumour microenvironment
12.  Altered Prostate Epithelial Development and IGF-1 Signal in Mice Lacking the Androgen Receptor in Smooth Muscle Cells 
The Prostate  2010;71(5):517-524.
Androgens and the androgen receptor (AR) play critical roles in the prostate development via mesenchymal-epithelial interactions. Smooth muscle cells, differentiated from mesenchyme, are one of the basic components of the prostate stroma. However, the roles of smooth muscle AR in prostate development are still obscure.
We established the smooth muscle selective AR knockout (SM-ARKO) mouse model using the Cre-loxP system, and confirmed the AR knockout efficiency at RNA, DNA and protein levels. Then we observed the prostate morphology changes, and determined the epithelial proliferation, apoptosis, and differentiation. We also knocked down the AR in a prostate smooth muscle cell line (PS-1) to confirm the in vivo findings and to probe the mechanism.
The AR was selectively and efficiently knocked out in the anterior prostates of SM-ARKO mouse. The SM-ARKO prostates have defects with loss of infolding structures, and decrease of epithelial proliferation, but with little change of apoptosis and differentiation. The mechanism studies showed that IGF-1 expression level decreased in the SM-ARKO prostates and AR-knockdown PS-1 cells. The decreased IGF-1 expression might contribute to the defective development of SM-ARKO prostates.
The AR in smooth muscle cells plays important roles in the prostate development via the regulation of IGF-1 signal.
PMCID: PMC3037429  PMID: 20945497
stroma; transgelin; Cre-loxP; gene knockout
13.  ASC-J9 Suppresses Castration-Resistant Prostate Cancer Growth through Degradation of Full-length and Splice Variant Androgen Receptors12 
Neoplasia (New York, N.Y.)  2012;14(1):74-83.
Early studies suggested androgen receptor (AR) splice variants might contribute to the progression of prostate cancer (PCa) into castration resistance. However, the therapeutic strategy to target these AR splice variants still remains unresolved. Through tissue survey of tumors from the same patients before and after castration resistance, we found that the expression of AR3, a major AR splice variant that lacks the AR ligand-binding domain, was substantially increased after castration resistance development. The currently used antiandrogen, Casodex, showed little growth suppression in CWR22Rv1 cells. Importantly, we found that AR degradation enhancer ASC-J9 could degrade both full-length (fAR) and AR3 in CWR22Rv1 cells as well as in C4-2 and C81 cells with addition of AR3. The consequences of such degradation of both fAR and AR3 might then result in the inhibition of AR transcriptional activity and cell growth in vitro. More importantly, suppression of AR3 specifically by short-hairpin AR3 or degradation of AR3 by ASC-J9 resulted in suppression of AR transcriptional activity and cell growth in CWR22Rv1-fARKD (fAR knockdown) cells in which DHT failed to induce, suggesting the importance of targeting AR3. Finally, we demonstrated the in vivo therapeutic effects of ASC-J9 by showing the inhibition of PCa growth using the xenografted model of CWR22Rv1 cells orthotopically implanted into castrated nude mice with undetectable serum testosterone. These results suggested that targeting both fAR- and AR3-mediated PCa growth by ASC-J9 may represent the novel therapeutic approach to suppress castration-resistant PCa. Successful clinical trials targeting both fAR and AR3 may help us to battle castration-resistant PCa in the future.
PMCID: PMC3281944  PMID: 22355276
14.  Tourniquet use in total knee arthroplasty: a meta-analysis 
The use of an intraoperative tourniquet for total knee arthroplasty (TKA) is a common practice. However, the effectiveness and safety are still questionable. A systematic review was conducted to examine that whether using a tourniquet in TKA was effective without increasing the risk of complications.
A comprehensive literature search was done in PubMed Medicine, Embase, and other internet database. The review work and the following meta-analysis were processed to evaluate the role of tourniquet in TKA.
Eight randomized controlled trials and three high-quality prospective studies involving 634 knees and comparing TKA with and without the use of a tourniquet were included in this analysis. The results demonstrated that using a tourniquet could decrease the measured blood loss but could not decrease the calculated blood loss, which indicated actual blood loss. Patients managed with a tourniquet might have higher risks of thromboembolic complications. Using the tourniquet with late release after wound closure could shorten the operation time; whereas early release did not show this benefit.
The current evidence suggested that using tourniquet in TKA may save time but may not reduce the blood loss. Due to the higher risks of thromboembolic complications, we should use a tourniquet in TKA with caution.
PMCID: PMC3116117  PMID: 21161177
Tourniquet; Knee arthroplasty; Blood loss; Thromboembolism; Meta-analysis
15.  Neutropenia with impaired host defense against microbial infection in mice lacking androgen receptor 
The Journal of Experimental Medicine  2009;206(5):1181-1199.
Neutrophils, the major phagocytes that form the first line of cell-mediated defense against microbial infection, are produced in the bone marrow and released into the circulation in response to granulocyte-colony stimulating factor (G-CSF). Here, we report that androgen receptor knockout (ARKO) mice are neutropenic and susceptible to acute bacterial infection, whereas castration only results in moderate neutrophil reduction in mice and humans. Androgen supplement can restore neutrophil counts via stabilizing AR in castrated mice, but not in ARKO and testicular feminization mutant (Tfm) mice. Our results show that deletion of the AR gene does not influence myeloid lineage commitment, but significantly reduces the proliferative activity of neutrophil precursors and retards neutrophil maturation. CXCR2-dependent migration is also decreased in ARKO neutrophils as compared with wild-type controls. G-CSF is unable to delay apoptosis in ARKO neutrophils, and ARKO mice show a poor granulopoietic response to exogenous G-CSF injection. In addition, AR can restore G-CSF–dependent granulocytic differentiation upon transduction into ARKO progenitors. We further found that AR augments G-CSF signaling by activating extracellular signal-regulated kinase 1/2 and also by sustaining Stat3 activity via diminishing the inhibitory binding of PIAS3 to Stat3. Collectively, our findings demonstrate an essential role for AR in granulopoiesis and host defense against microbial infection.
PMCID: PMC2715023  PMID: 19414555
16.  Monocyte/macrophage androgen receptor suppresses cutaneous wound healing in mice by enhancing local TNF-α expression 
The Journal of Clinical Investigation  2009;119(12):3739-3751.
Cutaneous wounds heal more slowly in elderly males than in elderly females, suggesting a role for sex hormones in the healing process. Indeed, androgen/androgen receptor (AR) signaling has been shown to inhibit cutaneous wound healing. AR is expressed in several cell types in healing skin, including keratinocytes, dermal fibroblasts, and infiltrating macrophages, but the exact role of androgen/AR signaling in these different cell types remains unclear. To address this question, we generated and studied cutaneous wound healing in cell-specific AR knockout (ARKO) mice. General and myeloid-specific ARKO mice exhibited accelerated wound healing compared with WT mice, whereas keratinocyte- and fibroblast-specific ARKO mice did not. Importantly, the rate of wound healing in the general ARKO mice was dependent on AR and not serum androgen levels. Interestingly, although dispensable for wound closure, keratinocyte AR promoted re-epithelialization, while fibroblast AR suppressed it. Further analysis indicated that AR suppressed wound healing by enhancing the inflammatory response through a localized increase in TNF-α expression. Furthermore, AR enhanced local TNF-α expression via multiple mechanisms, including increasing the inflammatory monocyte population, enhancing monocyte chemotaxis by upregulating CCR2 expression, and enhancing TNF-α expression in macrophages. Finally, targeting AR by topical application of a compound (ASC-J9) that degrades AR protein resulted in accelerated healing, suggesting a potential new therapeutic approach that may lead to better treatment of wound healing.
PMCID: PMC2786793  PMID: 19907077
17.  The diverse and contrasting effects of using human prostate cancer cell lines to study androgen receptor roles in prostate cancer 
Asian Journal of Andrology  2008;11(1):39-48.
The androgen receptor (AR) plays an important role in the development and progression of prostate cancer (PCa). Androgen deprivation therapy is initially effective in blocking tumor growth, but it eventually leads to the hormone-refractory state. The detailed mechanisms of the conversion from androgen dependence to androgen independence remain unclear. Several PCa cell lines were established to study the role of AR in PCa, but the results were often inconsistent or contrasting in different cell lines, or in the same cell line grown under different conditions. The cellular and molecular alteration of epithelial cells and their microenvironments are complicated, and it is difficult to use a single cell line to address this important issue and also to study the pathophysiological effects of AR. In this paper, we summarize the different effects of AR on multiple cell lines and show the disadvantages of using a single human PCa cell line to study AR effects on PCa. We also discuss the advantages of widely used epithelium–stroma co-culture systems, xenograft mouse models, and genetically engineered PCa mouse models. The combination of in vitro cell line studies and in vivo mouse models might lead to more credible results and better strategies for the study of AR roles in PCa.
PMCID: PMC3735204  PMID: 19098932
androgen receptor; cell lines; epithelium–stroma co-culture; mouse models; prostate cancer
18.  Effects of screw eccentricity on the initial stability of the acetabular cup 
International Orthopaedics  2006;31(4):451-455.
One of the major failure modes of cementless acetabular components is the loosening of the acetabular cup, which is mostly attributable to insufficient initial stability. A hemispherical cup with a porous coating which is inserted with press-fit fixation and secured with several screws is one of the most widely used approaches. Many studies have found that bone screws are very helpful aids for cup fixation, but the optimal surgical technique for inserting screws has not been clearly reported. In this study, hemispherical cups were fixed into blocks of foam bone with zero to three screws. The effects of three types of screw eccentricity (a 1-mm offset and angular eccentricities of 15° and 25°) on the initial stability of the acetabular cup were evaluated. The experimental results indicate that increasing the number of screws enhances the cup stability in the case of ideal screwing (i.e., with no eccentricity). An angular eccentricity of 15° did not affect the cup stability for fixation with one or two screws. However, the presence of 25° of angular eccentricity significantly reduced the stability of the cup, while 1 mm of offset eccentricity produced an even greater impact.
PMCID: PMC2267626  PMID: 16947050
19.  Mini-open anterior spine surgery for anterior lumbar diseases 
European Spine Journal  2008;17(5):691-697.
Minimally invasive surgeries including endoscopic surgery and mini-open surgery are current trend of spine surgery, and its main advantages are shorter recovery time and cosmetic benefits, etc. However, mini-open surgery is easier and less technique demanding than endoscopic surgery. Besides, anterior spinal fusion is better than posterior spinal fusion while considering the physiological loading, back muscle function, etc. Therefore, we aimed to introduce the modified “mini-open anterior spine surgery” (MOASS) and to evaluate the feasibility, effectiveness and safety in the treatment of various anterior lumbar diseases with this technique. A total of 61 consecutive patients (46 female, 15 male; mean age 58.2 years) from 1997 to 2004 were included in this study, with an average follow-up of 24–52 (mean 43) months. The disease entities included vertebral fracture (20), failed back surgery (13), segmental instability or spondylolisthesis (10), infection (8), herniated disc (5), undetermined lesion for biopsy (4), and hemivertebra (1). Lesions involved 13 cases at T12–L1, 18 at L1–L2, 18 at L2–L3, 22 at L3–L4 and 11 at L4–L5 levels. All patients received a single stage anterior-only procedure for their anterior lumbar disease. We used the subjective clinical results, Oswestry disability index, fusion rate, and complications to evaluate our clinical outcome. Most patients (91.8%) were subjectively satisfied with the surgery and had good-to-excellent outcomes. Mean operation time was 85 (62–124) minutes, and mean blood loss was 136 (minimal-250) ml in the past 6 years. Hospital stay ranged from 4–26 (mean 10.6) days. Nearly all cases had improved back pain (87%), physical function (90%) and life quality (85%). Most cases (95%) achieved solid or probable solid bony fusion. There were no major complications. Therefore, MOASS is feasible, effective and safe for patients with various anterior lumbar diseases.
PMCID: PMC2367411  PMID: 18327620
Mini-open anterior spine surgery; Mini-open; Anterior lumbar interbody fusion; Techniques; Lumbar fusion; ALIF

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