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Aberrant deposition of the extracellular matrix (ECM) causes fibrosis and leads to ECM stiffening. This fibrotic ECM provides biological and biophysical stimulations to alter cell activity and drive progression of fibrosis. As an emerging discipline, mechanobiology aims to access the impact of both these cues on cell behavior and relates the reciprocity of mechanical and biological interactions; it incorporates concepts from different fields, like biology and physics, to help study the mechanical and biological facets of fibrosis extensively. A useful experimental platform in mechanobiology is decellularized ECM (dECM), which mimics the native microenvironment more accurately than standard 2D culture techniques as its composition includes similar ECM protein components and stiffness. dECM, therefore, generates more reliable results that better recapitulate in vivo fibrosis.

The extracellular matrix (ECM) is a protein polymer network that physically supports cells within a tissue and also acts as an important biochemical stimulus directing cell behaviors. For fibronectin, a predominant component of the ECM, these physical and biochemical activities are inextricably linked as physical forces trigger conformational changes that impact its biochemical activity. We analyzed whether oxidative post-translational modifications, specifically glutathionylation, enable fibronectin to ‘record’ physical information through stretch-dependent protein modification. Posttranslational modifications of the ECM are understudied, but represent opportunities for time- or stimuli-dependent changes in structure-function relationships that both persist over time and could have dominant impacts on cell-ECM homeostasis. We provide direct evidence that stretch-dependent glutathionylation of fibronectin irreversibly and significantly alters its mechanical properties with concomitant changes in the binding of integrin receptors and downstream cell signaling events. Stretch-dependent glutathionylation of fibronectin could have significant impact on the balance between tissue homeostasis and pathological progression, particularly in tissues and organs that are exposed to high oxidative stress, such as the lung.

Aberrant deposition of the extracellular matrix (ECM) causes fibrosis and leads to ECM stiffening. This fibrotic ECM provides biological and biophysical stimulations to alter cell activity and drive progression of fibrosis. As an emerging discipline, mechanobiology aims to access the impact of both these cues on cell behavior and relates the reciprocity of mechanical and biological interactions; it incorporates concepts from different fields, like biology and physics, to help study the mechanical and biological facets of fibrosis extensively. A useful experimental platform in mechanobiology is decellularized ECM (dECM), which mimics the native microenvironment more accurately than standard 2D culture techniques as its composition includes similar ECM protein components and stiffness. dECM, therefore, generates more reliable results that better recapitulate in vivo fibrosis.

Renal cell carcinoma (RCC) has the third highest mortality rate among urological tumors, and 20-30% of RCC patients present with metastatic RCC at the time of diagnosis. Although recent studies have indicated that estrogen receptor β (ERβ) could play promoting roles in RCC progression, the detailed mechanisms remain to be clarified. In the present study, we found that expression of ERβ, but not ERα, increases with tumor stage and grade, and also observed that modification of ERβ signals using estrogens/anti-estrogens, shRNA knockdown of ERβ and overexpression of ERβ using ectopic cDNA affects RCC cell proliferation, migration and invasion. Mechanism analysis revealed that ERβ can promote RCC cell invasion via an increase in transforming growth factor β1 (TGF-β1)/SMAD3 signals, and interrupting TGF-β1/SMAD3 signals with a TGFβR1 inhibitor can reverse/block ERβ-increased RCC cell migration. Importantly, preclinical analyses using in vivo mouse models of RCC revealed that targeting of this newly identified ERβ/TGF-β1/SMAD3 pathway with either the FDA-approved anti-estrogen ICI182,780 (Faslodex) or a selective ERβ antagonist 4-[2-phenyl-5,7 bis(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-3-yl]phenol can significantly reduce RCC tumor growth and invasion, which may be suitable as the basis for novel therapies to more effectively suppress metastatic RCC.

Recent studies indicated that the estrogen receptor beta (ERβ) could affect the progression of prostate and bladder tumors, however, its roles in the renal cell carcinoma (RCC), remain to be elucidated. Here, we provide clinical evidence that ERβ expression is correlated in a negative manner with the overall survival/disease-free survival in RCC patients. Mechanism dissection revealed that targeting ERβ with ERβ-shRNA and stimulating the transactivation of ERβ with 17β-estradiol or environmental endocrine disrupting chemicals, all resulted in altering the lncRNA HOTAIR expression. The ERβ-modulated HOTAIR is able to function via antagonizing several microRNAs, including miR-138, miR-200c, miR-204, or miR-217 to impact various oncogenes, including ADAM9, CCND2, EZH2, VEGFA, VIM, ZEB1, and ZEB2, to promote RCC proliferation and invasion. Together, the identification of the ERβ-HOTAIR axis may provide us new biomarkers and/or therapeutic targets to better suppress RCC progression in the future.

INTRODUCTION AND OBJECTIVES:Renal cell carcinoma (RCC) has the third highest mortality rate among all urological tumors, and 20-30% of RCC patients present with metastatic RCC at the time of diagno...

The extracellular matrix (ECM) microenvironment is increasingly implicated in the instruction of pathologically relevant cell behaviors, from aberrant transdifferentation to invasion and beyond. Indeed, pathologic ECMs possess a panoply of alterations that provide deleterious instructions to resident cells. Here we demonstrate the precise manner in which the ECM protein fibronectin (FN) undergoes the posttranslational modification citrullination in response to peptidyl-arginine deiminase (PAD), an enzyme associated with innate immune cell activity and implicated in systemic ECM-centric diseases, like cancer, fibrosis and rheumatoid arthritis. FN can be citrullinated in at least 24 locations, 5 of which reside in FN's primary cell-binding domain. Citrullination of FN alters integrin clustering and focal adhesion stability with a concomitant enhancement in force-triggered integrin signaling along the FAK-Src and ILK-Parvin pathways within fibroblasts. In vitro migration and in vivo wound healing studies demonstrate the ability of citrullinated FN to support a more migratory/invasive phenotype that enables more rapid wound closure. These findings highlight the potential of ECM, particularly FN, to "record" inflammatory insults via post-translational modification by inflammation-associated enzymes that are subsequently "read" by resident tissue fibroblasts, establishing a direct link between inflammation and tissue homeostasis and pathogenesis through the matrix.

Early clinical studies suggested that infiltrating mast cells could be associated with a poor outcome in bladder cancer (BCa) patients. The mechanisms of how mast cells influence the BCa progression, however, are unclear. Using the human clinical BCa sample survey and in vitro co-culture systems, we found BCa cells could recruit more mast cells than the surrounding non-malignant urothelial cells. The consequences of this better recruitment of mast cells toward BCa cells could then enhance BCa cell invasion. Mechanism dissection revealed that the enhanced BCa cell invasion could function via up-regulation of the estrogen receptor beta (ERβ) in both mast cells and BCa cells, which resulted in the increased CCL2/CCR2/EMT/MMP9 signals. Using the pre-clinical mouse BCa model, we further validated the mast cell-promoted BCa invasion. Interruption of the newly identified ERβ/CCL2/CCR2/EMT/MMP9 pathway via either ERβ-siRNA, ERβ antagonist PHTPP, or CCR2 antagonist can effectively reverse the mast cell-enhanced BCa cells invasion. Together, our finding could lead to the development of an alternative new therapeutic approach to better treat BCa metastasis.

Previous studies indicated the T cells, one of the most common types of immune cells existing in the microenvironment of renal cell carcinoma (RCC), may influence the progression of RCC. The potential linkage of T cells and the estrogen receptor beta (ERβ), a key player to impact RCC progression, however, remains unclear. Our results demonstrate that RCC cells can recruit more T cells than non-malignant kidney cells. Using an in vitro matrigel invasion system, we found infiltrating T cells could promote RCC cells invasion via increasing ERβ expression and transcriptional activity. Mechanism dissection suggested that co-culturing T cells with RCC cells released more T cell attraction factors, including IFN-γ, CCL3 and CCL5, suggesting a positive regulatory feed-back mechanism. Meanwhile, infiltrating T cells may also promote RCC cell invasion via increased ERβ and decreased DAB2IP expressions, and knocking down DAB2IP can then reverse the T cells-promoted RCC cell invasion. Together, our results suggest that infiltrating T cells may promote RCC cell invasion via increasing the RCC cell ERβ expression to inhibit the tumor suppressor DAB2IP signals. Further mechanism dissection showed that co-culturing T cells with RCC cells could produce more IGF-1 and FGF-7, which may enhance the ERβ transcriptional activity. The newly identified relationship between infiltrating T cells/ERβ/DAB2IP signals may provide a novel therapeutic target in the development of agents against RCC.

// Wenbin Song 1,2,* , Chiuan-Ren Yeh 1,* , Dalin He 2,* , Yong Wang 1 , Hongjun Xie 1,2 , See-Tong Pang 1 , Luke Sien-Shih Chang 2 , Lei Li 2 and Shuyuan Yeh 1 1 George Whipple Lab for Cancer Research, Departments of Urology and Pathology, University of Rochester Medical Center, Rochester, New York, USA 2 Sex Hormone Research Center, Department of Urology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China * These authors Contributed equally to this work Correspondence to: Lei Li, email: // Shuyuan Yeh, email: // Keywords : tumor microenvironment, RCC, Neutrophils, ERβ, VEGFa and HIF pathways Received : November 24, 2014 Accepted : April 02, 2015 Published : June 15, 2015 Abstract Neutrophils make up a significant portion of the infiltrated immune cells found in the tumor microenvironment. Here we found more infiltrated neutrophils in human renal cell carcinoma (RCC) lesions than adjacent benign areas. In vitro RCC studies showed that neutrophils (HL-60N cells) infiltrated toward RCC cells and subsequently enhanced RCC cell migration and invasion. Co-culture of RCC cells with HL-60N cells up-regulated ERβ, VEGFa and HIF2α mRNA levels. ERβ signals increased RCC cell migration via induction of the VEGFa/HIF2α pathway. Treatment of HIF inhibitor or rapamycin, or knockdown of ERβ in RCC cells reversed HL-60N-promoted RCC migration . In vivo data using orthotopically xenografted RCC mouse model confirmed that infiltrated neutrophils promoted RCC migration via modulating the expressions of ERβ, VEGFa and HIF2α signal pathways. Together, our studies revealed that neutrophils are favorably recruited to the RCC cells to promote the RCC migration and invasion. Targeting the infiltrating RCC tumor microenvironment with anti-estrogen or rapamycin may be a potential therapy to suppress RCC progression.

Squamous metaplasia (SQM) is a specific phenotype in response to oestrogen in the prostate and oestrogen receptor (ER) α is required to mediate this response. Previous studies utilizing tissue recombination with seminal vesicle (SV) mesenchyme and prostatic ductal tips from wild type and ERαKO mice suggested that both epithelial and stromal ERα are necessary for SQM. However, tissue recombination is conducted in the renal capsule of immune-deficient mice, in which the microenvironment is different from normal prostate microenvironment in the intact mice. Furthermore, whether the requirement of stromal ERα in the SV for developing SQM is the same as in the prostate is unknown. Therefore, there is a clear need to evaluate the respective roles of ERα in prostate epithelial versus stromal compartments in the intact mouse. Here we generated a mouse model that has selectively lost ERα in either stromal (FSP-ERαKO) or epithelial prostate cells (pes-ERαKO) to determine the requirements of ERα for oestrogen-stimulated prostate proliferation and SQM. Our results indicated that FSP-ERαKO prostates develop full and uniform SQM, which suggests that loss of the majority (~65%) of stromal ERα will not influence oestrogen-mediated SQM. In contrast, loss of epithelial ERα inhibits oestrogen-mediated prostate growth and SQM evidenced by decreasing cytokertin 10 positive squamous cell stratification and differentiation, by reduced ERα protein expression in SQM compared to wild type mice ERα, and by the presence of normal proliferative activities in the oestrogen-treated pes-ERαKO prostates. These in vivo results suggest that epithelial ERα is required for oestrogen-mediated proliferative response and could be an appropriate target for preventing aberrant oestrogen signalling in the prostate.

BACKGROUND. Androgens and the androgen receptor (AR) play important roles in the development of male urogenital organs. We previously found that mice with total AR knockout (ARKO) and epithelial ARKO failed to develop normal prostate with loss of differentiation. We have recently knocked out AR gene in smooth muscle cells and found the reduced luminal infolding and IGF-1 production in the mouse prostate. However, AR roles of stromal fibroblasts in prostate development remain unclear. METHODS. To further probe the stromal fibroblast AR roles in prostate development, we generated tissue-selective knockout mice with the AR gene deleted in stromal fibroblasts (FSP-ARKO). We also used primary culture stromal cells to confirm the in vivo data and investigate mechanisms related to prostate development. RESULTS. The results showed cellular alterations in the FSP-ARKO mouse prostate with decreased epithelial proliferation, increased apoptosis, and decreased collagen composition. Further mechanistic studies demonstrated that FSP-ARKO mice have defects in the expression of prostate stromal growth factors. To further confirm these in vivo findings, we prepared primary cultured mouse prostate stromal cells and found knocking down the stromal AR could result in growth retardation of prostate stromal cells and co-cultured prostate epithelial cells, as well as decrease of some stromal growth factors. CONCLUSIONS. Our FSP-ARKO mice not only provide the first in vivo evidence in Cre-loxP knockout system for the requirement of stromal fibroblast AR to maintain the normal development of the prostate, but may also suggest the selective knockdown of stromal AR might become a potential therapeutic approach to battle prostate hyperplasia and cancer. Prostate # 2011 Wiley-Liss, Inc.

Estrogen and mechanical forces are positive regulators for osteoblast proliferation and bone formation. We investigated the synergistic effect of estrogen and flow-induced shear stress on signal transduction and gene expression in human osetoblast-like MG63 cells and primary osteoblasts (HOBs) using activations of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) and expressions of c-fos and cyclooxygenase-2 (I) as readouts. Estrogen (17β-estradiol, 10 nM) and shear stress (12 dyn/cm2) alone induced transient phosphorylations of ERK and p38 MAPK in MG63 cells. Pretreating MG63 cells with 17β-estradiol for 6 hours before shearing augmented these shear-induced MAPK phosphorylations. Western blot and flow cytometric analyses showed that treating MG63 cells with 17β-estradiol for 6 hrs induced their β1-integrin expression. This estrogen-induction of β1-integrin was inhibited by pretreating the cells with a specific antagonist of estrogen receptor ICI 182,780. Both 17β-estradiol and shear stress alone induced c-fos and Cox-2 gene expressions in MG63 cells. Pretreating MG63 cells with 17β-estradiol for 6 hrs augmented the shear-induced c-fos and Cox-2 expressions. The augmented effects of 17β-estradiol on shear-induced MAPK phosphorylations and c-fos and Cox-2 expressions were inhibited by pretreating the cells with ICI 182,780 or transfecting the cells with β1-specific small interfering RNA. Similar results on the augmented effect of estrogen on shear-induced signaling and gene expression were obtained with HOBs. Our findings provide insights into the mechanism by which estrogen augments shear stress responsiveness of signal transduction and gene expression in bone cells via estrogen receptor–mediated increases in β1-integrin expression. © 2010 American Society for Bone and Mineral Research.

Cell cycle regulation by differentiation signals is critical for eukaryote development. We investigated the roles of bone morphogenetic protein (BMP)-4, an important stimulator of osteoblast differentiation and bone formation, in regulating cell cycle distribution in four osteoblast-like cell lines and mouse primary osteoblasts, and the underlying mechanisms. In all cells used, BMP-4 induced G(0)/G(1) arrest. The molecular basis of the BMP-4 effect was analyzed, and the presentation on molecular mechanism is focused on human MG63 cells. BMP-4 induced p21(CIP1) and p27(KIP1) expressions and hence cell differentiation but had no effects on the expressions of cyclins A, B1, D1, and E, cyclin-dependent protein kinase-2, -4, and -6. Using specific small interfering RNA (siRNA), we found that BMP-4-induced G(0)/G(1) arrest, and p21(CIP1) and p27(KIP1) expressions were mediated by BMP receptor type IA (BMPRIA)-specific Sma- and Mad-related protein (Smad)1/5. BMP-4 induced transient phosphorylations of ERK; transfection of MG63 cells with ERK2, but not ERK1, -specific siRNA inhibited the BMP-4-induced responses in MG63 cells. Pretreatment of MG63 cells with Arg-Gly-Asp-Ser, which blocks the cell-extracellular matrix interaction, or transfection with beta(3) integrin-specific siRNA inhibited BMP-4-induced ERK and Smad1/5 phosphorylations. BMP-4 induced transient increases in associations of beta(3)-integrin with focal adhesion kinase and Shc, the dominant-negative mutants of which inhibited BMP-4-induced ERK and Smad1/5 phosphorylations. Our results indicate that BMP-4 induces G(0)/G(1) arrest and hence differentiation in osteoblast-like cells through increased expressions of p21(CIP1) and p27(KIP1), which are mediated by BMPRIA-specific Smad1/5. The extracellular matrix/beta(3) integrin/ focal adhesion kinase/Shc/ERK2 signaling pathway is involved in these BMP-4-induced responses in osteoblast-like cells.

CAF.ERα(+) can reduce the M2 marker expressions in the co-cultured macrophages (Mφ). (A) ERα in CAF cells inhibits M2-type macrophages transformation. (B) mRNA expressions of IL-4 and IL-13 in CAF cells were assayed by qPCR. mRNA expressions of M2 markers in macrophages were assayed by qPCR. After incubating with CM collected from CAF.ERα(+) or CAFERα(-), macrophages were collected to detect M2 markers by qPCR. *, P

CM from co-cultured CAF/macrophages affects PCa invasion in the 3D culture system. The carton illustrates the experimental system. CM was collected from co-culture of CAF.ERα(+) or CAF.ERα(-) cells and RAW264.7 cells or B6 primary macrophages (Mφ) for 24 hr. The CM was then used to treat CWR22Rv-1 cells for 3 days, then seeded in 3D environment for 12 days to form inter-acinar bridges. (A) Numbers of inter-aciniar bridges were counted per field and quantifications are in right panels. (B) Laminin 5 mRNA was quantified to show the invasive potential of the PCa cells in the 3D culture environment. At Day 12, RNA was extracted from PCa cells and expression levels of laminin 5 were measured by qPCR and quantifications are shown. (C) Expression of invasion related marker, MMP9, was also demonstrated by Q-PCR in CWR22Rv-1 cells pre-inoculated with the collected CM, quantification is shown. *, P

Stromal E2/ERα signals negatively-regulate the PCa invasion. CAF.ERα(-) or ERα(+) cells were treated with vehicle, E2 (10 nM) or/and ICI182,780 (10 μM) and co-cultured with macrophages for 48 hr. CMs were collected and added to 24-well plates and the PCa cells (C4-2) were seeded into inserted transwells pre-coated with matrigel. After 48 hr of incubation, invaded PCa cells were counted and compared, and quantitation data is shown below the images.

Background Genetically engineered mouse models are essential to the investigation of the molecular mechanisms underlying human prostate pathology and the effects of therapy on the diseased prostate. Serial in vivo volumetric imaging expands the scope and accuracy of experimental investigations of models of normal prostate physiology, benign prostatic hyperplasia and prostate cancer, which are otherwise limited by the anatomy of the mouse prostate. Moreover, accurate imaging of hyperplastic and tumorigenic prostates is now recognized as essential to rigorous pre-clinical trials of new therapies. Bioluminescent imaging has been widely used to determine prostate tumor size, but is semi-quantitative at best. Magnetic resonance imaging can determine prostate volume very accurately, but is expensive and has low throughput. We therefore sought to develop and implement a high throughput, low cost, and accurate serial imaging protocol for the mouse prostate. Methods We developed a high frequency ultrasound imaging technique employing 3D reconstruction that allows rapid and precise assessment of mouse prostate volume. Wild-type mouse prostates were examined (n = 4) for reproducible baseline imaging, and treatment effects on volume were compared, and blinded data analyzed for intra- and inter-operator assessments of reproducibility by correlation and for Bland-Altman analysis. Examples of benign prostatic hyperplasia mouse model prostate (n = 2) and mouse prostate implantation of orthotopic human prostate cancer tumor and its growth (n = 6) are also demonstrated. Results Serial measurement volume of the mouse prostate revealed that high frequency ultrasound was very precise. Following endocrine manipulation, regression and regrowth of the prostate could be monitored with very low intra- and interobserver variability. This technique was also valuable to monitor the development of prostate growth in a model of benign prostatic hyperplasia. Additionally, we demonstrate accurate ultrasound image-guided implantation of orthotopic tumor xenografts and monitoring of subsequent tumor growth from ~10 to ~750 mm3 volume. Discussion High frequency ultrasound imaging allows precise determination of normal, neoplastic and hyperplastic mouse prostate. Low cost and small image size allows incorporation of this imaging modality inside clean animal facilities, and thereby imaging of immunocompromised models. 3D reconstruction for volume determination is easily mastered, and both small and large relative changes in volume are accurately visualized. Ultrasound imaging does not rely on penetration of exogenous imaging agents, and so may therefore better measure poorly vascularized or necrotic diseased tissue, relative to bioluminescent imaging (IVIS). Conclusions Our method is precise and reproducible with very low inter- and intra-observer variability. Because it is non-invasive, mouse models of prostatic disease states can be imaged serially, reducing inter-animal variability, and enhancing the power to detect small volume changes following therapeutic intervention.

Early studies found critical roles for neutrophils in renal cell carcinoma (RCC) progression. However, detailed mechanisms of how infiltrating neutrophils in the kidney tumor microenvironment impact RCC progression remain unclear. Here we found more neutrophils were infiltrated in human RCC lesions than those found in surrounding normal kidney tissues. Similarly, in vitro studies also revealed that RCC cells recruited more neutrophil HL-60N cells than normal kidney epithelial cells. Furthermore, in vitro and in vivo experiments also showed that the infiltrated neutrophils could promote RCC cell growth. Mechanism studies showed that co-culture of RCC cells with neutrophil HL-60N cells could selectively upregulate the androgen receptor (AR) signals, which might then alter the c-Myc signals. Interruption approaches using AR-siRNA to knock down AR in RCC cells blocked neutrophil-enhanced RCC cell proliferation. In vivo data using an orthotopically xenografted RCC mouse model also confirmed that infiltrated neutrophils could promote RCC proliferation via modulating the expressions of related cytokines. Together, these results conclude that infiltrated neutrophils may function through modulating the AR → c-Myc signals to promote RCC cell proliferation. Targeting this newly identified infiltrating neutrophil → AR → c-Myc signal pathway in the kidney tumor microenvironment may provide a new potential therapy to better suppress RCC progression.

A few finite element models have addressed the dynamic juxtaarticular stress transmission but none focused the investigation on the combined influence of the individual moduli of the underlying bones, including the subchondral plate, the femoral head and the femoral neck of the proximal femur. A finite element model including the acetabulum and the proximal femur was analyzed with dynamic loadings to study the effects of mechanical property changes in the underlying bones of the proximal femur on the stress distribution in the cartilage at the hip joint. We found the stress distribution was most sensitive to the subchondral plate stiffening, while the overall stiffening of the underlying bones had mild effect on the shear stress on the cartilage surface (or at the subchondral bone/cartilage interface) and on the strain energy density in the cartilage. Our results indicate that the subchondral plate plays a predominant mechanical role in the initial degeneration of the cartilage. The results may offer a mechanical explanation as to why the cartilage failure is common in patients with osteoarthritis but rare in patients with osteoporosis.

The prostate cancer (PCa) microenvironment contains active stromal cells known as cancer-associated fibroblasts (CAF) that may play important roles in influencing tumor progression. Here we studied the role of CAF estrogen receptor alpha (ERα) and found that it could protect against PCa invasion. Immunohistochemistry on prostatectomy specimens showed that PCa patients with ERα-positive stroma had a significantly lower risk for biochemical recurrence. In vitro invasion assays further confirmed that the stromal ERα was able to reduce PCa cell invasion. Dissection of the molecular mechanism revealed that the CAF ERα could function through a CAF–epithelial interaction via selectively upregulating thrombospondin 2 (Thbs2) and downregulating matrix metalloproteinase 3 (MMP3) at the protein and messenger RNA levels. Chromatin immunoprecipitation assays further showed that ERα could bind to an estrogen response element on the promoter of Thbs2. Importantly, knockdown of Thbs2 led to increased MMP3 expression and interruption of the ERα mediated invasion suppression, providing further evidence of an ERα–Thbs2–MMP3 axis in CAF. In vivo studies using athymic nude mice injected with 22Rv1 PCa epithelial cells and CAF cells ± ERα also confirmed that mice coimplanted with PCa cells and CAF ERα+ cells had less tumor foci in the pelvic lymph nodes, less metastasis, and tumors showed less angiogenesis, MMP3, and MMP9 (an MMP3 downstream target) positive staining. Together, these data suggest that CAF ERα could play protective roles in suppressing PCa metastasis. Our results may lead to developing new and alternative therapeutic approaches to battle PCa via controlling ERα signaling in CAF.

Estrogen and estrogen receptor (ER)-mediated signaling pathways play important roles in the etiology and progression of human breast, endometrial, and ovarian cancers. Attenuating ER activities by natural products and their derivatives is a relatively practical strategy to control and reduce breast, endometrial, and ovarian cancer risk. Here, we found 3-butoxy-1,8,9-trihydroxy-6H-benzofuro[3,2-c]benzopyran-6-one (BTB), a new derivative of wedelolactone, could effectively inhibit the 17-estradiol (E2)-induced ER transactivation and suppress the growth of breast cancer as well as endometrial and ovarian cancer cells. Our results indicate that 2.5 μM BTB effectively suppresses ER-positive, but not ER-negative, breast, endometrial, and ovarian cancer cells. Furthermore, our data indicate that BTB can modulate ER transactivation and suppress the expression of E2-mediated ER target genes (Cyclin D1, E2F1, and TERT) in the ER-positive MCF-7, Ishikawa, and SKOV-3 cells. Importantly, this BTB mediated inhibition of ER activity is selective since BTB does not suppress the activities of other nuclear receptors, including glucocorticoid receptor and progesterone receptor, suggesting that BTB functions as a selective ER signaling inhibitor with the potential to treat breast, endometrial, and ovarian cancers.

The prostate cancer (PCa) microenvironment contains active stromal cells known as cancer-associated fibroblasts (CAF) that may play important roles in influencing tumor progression. Here we studied the role of CAF estrogen receptor alpha (ERα) and found that it could protect against PCa invasion. Immunohistochemistry on prostatectomy specimens showed that PCa patients with ERα-positive stroma had a significantly lower risk for biochemical recurrence. In vitro invasion assays further confirmed that the stromal ERα was able to reduce PCa cell invasion. Dissection of the molecular mechanism revealed that the CAF ERα could function through a CAF-epithelial interaction via selectively upregulating thrombospondin 2 (Thbs2) and downregulating matrix metalloproteinase 3 (MMP3) at the protein and messenger RNA levels. Chromatin immunoprecipitation assays further showed that ERα could bind to an estrogen response element on the promoter of Thbs2. Importantly, knockdown of Thbs2 led to increased MMP3 expression and interruption of the ERα mediated invasion suppression, providing further evidence of an ERα-Thbs2-MMP3 axis in CAF. In vivo studies using athymic nude mice injected with CWR22Rv1 (22Rv1) PCa epithelial cells and CAF cells ± ERα also confirmed that mice coimplanted with PCa cells and CAF ERα+ cells had less tumor foci in the pelvic lymph nodes, less metastases, and tumors showed less angiogenesis, MMP3, and MMP9 (an MMP3 downstream target) positive staining. Together, these data suggest that CAF ERα could play protective roles in suppressing PCa metastasis. Our results may lead to developing new and alternative therapeutic approaches to battle PCa via controlling ERα signaling in CAF.

Estrogen signaling, through estrogen receptor (ER)α, has been shown to cause hypertrophy in the prostate. Our recent report has shown that epithelial ERα knockout (KO) will not affect the normal prostate development or homeostasis. However, it remains unclear whether ERα in different types of stromal cells has distinct roles in prostate development. This study proposed to elucidate how KO of ERα in the stromal smooth muscle or fibroblast cells may interrupt cross talk between prostate stromal and epithelial cells. Smooth muscle ERαKO (smERαKO) mice showed decreased glandular infolding with the proximal area exhibiting a significant decrease. Fibroblast ERαKO mouse prostates did not exhibit this phenotype but showed a decrease in the number of ductal tips. Additionally, the amount of collagen observed in the basement membrane was reduced in smERαKO prostates. Interestingly, these phenotypes were found to be mutually exclusive among smERαKO or fibroblast ERαKO mice. Compound KO of ERα in both fibroblast and smooth muscle showed combined phenotypes from each of the single KO. Further mechanistic studies showed that IGF-I and epidermal growth factor were down-regulated in prostate smooth muscle PS-1 cells lacking ERα. Together, our results indicate the distinct functions of fibroblast vs. smERα in prostate development.

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.

Early studies suggested that estrogen receptor alpha (ERa) is involved in estrogen-mediated imprinting effects in prostate development. We recently reported a more complete ERa knockout (KO) mouse model via mating b-actin Cre transgenic mice with floxedERamice.TheseACTB-ERaKOmale miceshowed defectsin prostatic branchingmorphogenesis, whichdemonstratesthat ERa is necessary to maintain proliferative events in the prostate. However, within which prostate cell type ERa exerts those important functions remains to be elucidated. To address this, we have bred floxed ERa mice with either fibroblast-specific protein (FSP)-Cre or probasin-Cre transgenic mice to generate a mouse model that has deleted ERa gene in either stromal fibroblast (FSP-ERaKO) or epithelial (pes-ERaKO) prostate cells. We found that circulating testosterone and fertility were not altered in FSP-ERaKO and pes-ERaKO male mice. Prostates of FSP-ERaKO mice have less branching morphogenesis compared to that of wild-type littermates. Further analyses indicated that loss of stromal ERa leads to increased stromal apoptosis, reduced expression of insulin-like growth factor-1(IGF-1) andFGF10, andincreased expression ofBMP4. Collectively, wehave establishedthefirstin vivoprostatestromal and epithelialselectiveERaKOmousemodelsandtheresultsfromthesemiceindicatedthatstromalfibroblastERaplaysimportantrolesin prostatic branching morphogenesis via a paracrine fashion. Selective deletion of the ERa gene in mouse prostate epithelial cells by probasin-Cre does not affect the regular prostate development and homeostasis. Asian Journal of Andrology (2012) 14, 546–555; doi:10.1038/aja.2011.181; published online 21 May 2012

Squamous metaplasia (SQM) is a specific phenotype in response to oestrogen in the prostate and oestrogen receptor (ER) α is required to mediate this response. Previous studies utilizing tissue recombination with seminal vesicle (SV) mesenchyme and prostatic ductal tips from wild type and ERαKO mice suggested that both epithelial and stromal ERα are necessary for SQM. However, tissue recombination is conducted in the renal capsule of immune-deficient mice, in which the microenvironment is different from normal prostate microenvironment in the intact mice. Furthermore, whether the requirement of stromal ERα in the SV for developing SQM is the same as in the prostate is unknown. Therefore, there is a clear need to evaluate the respective roles of ERα in prostate epithelial versus stromal compartments in the intact mouse. Here we generated a mouse model that has selectively lost ERα in either stromal (FSP-ERαKO) or epithelial prostate cells (pes-ERαKO) to determine the requirements of ERα for oestrogen-stimulated prostate proliferation and SQM. Our results indicated that FSP-ERαKO prostates develop full and uniform SQM, which suggests that loss of the majority (∼65%) of stromal ERα will not influence oestrogen-mediated SQM. In contrast, loss of epithelial ERα inhibits oestrogen-mediated prostate growth and SQM evidenced by decreasing cytokertin 10 positive squamous cell stratification and differentiation, by reduced ERα protein expression in SQM compared to wild type mice ERα, and by the presence of normal proliferative activities in the oestrogen-treated pes-ERαKO prostates. These in vivo results suggest that epithelial ERα is required for oestrogen-mediated proliferative response and could be an appropriate target for preventing aberrant oestrogen signalling in the prostate. Copyright  2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Squamous metaplasia (SQM) is a specific phenotype in response to oestrogen in the prostate and oestrogen receptor (ER) α is required to mediate this response. Previous studies utilizing tissue recombination with seminal vesicle (SV) mesenchyme and prostatic ductal tips from wild type and ERαKO mice suggested that both epithelial and stromal ERα are necessary for SQM. However, tissue recombination is conducted in the renal capsule of immune-deficient mice, in which the microenvironment is different from normal prostate microenvironment in the intact mice. Furthermore, whether the requirement of stromal ERα in the SV for developing SQM is the same as in the prostate is unknown. Therefore, there is a clear need to evaluate the respective roles of ERα in prostate epithelial versus stromal compartments in the intact mouse. Here we generated a mouse model that has selectively lost ERα in either stromal (FSP-ERαKO) or epithelial prostate cells (pes-ERαKO) to determine the requirements of ERα for oestrogen-stimulated prostate proliferation and SQM. Our results indicated that FSP-ERαKO prostates develop full and uniform SQM, which suggests that loss of the majority (~65%) of stromal ERα will not influence oestrogen-mediated SQM. In contrast, loss of epithelial ERα inhibits oestrogen-mediated prostate growth and SQM evidenced by decreasing cytokertin 10 positive squamous cell stratification and differentiation, by reduced ERα protein expression in SQM compared to wild type mice ERα, and by the presence of normal proliferative activities in the oestrogen-treated pes-ERαKO prostates. These in vivo results suggest that epithelial ERα is required for oestrogen-mediated proliferative response and could be an appropriate target for preventing aberrant oestrogen signalling in the prostate.

Integrins play significant roles in mechanical responses of cells on extracellular matrix (ECM). We studied the roles of integrins and ECM proteins (fibronectin [FN], type I collagen [COL1], and laminin [LM]) in shear-mediated signaling and the expression of bone formation-related genes (early growth response-1 [Egr-1], c-fos, cyclooxygenase-2 [Cox-2], and osteopontin [OPN]) in human osteosarcoma MG63 cells. MG63 cells on FN, COL1, and LM were kept as controls or subjected to shear stress (12 dynes/cm(2)), and the association of alpha(v)beta(3) and beta(1) integrins with Shc, phosphorylation of mitogen-activated protein kinases (MAPKs, i.e., extracellular signal-regulated kinase [ERK], c-jun-NH(2)-terminal kinase [JNK], and p38), and expressions of Egr-1, c-fos, Cox-2, and OPN were determined. In MG63 cells, shear stress induces sustained associations of alpha(v)beta(3) and beta(1) with Shc when seeded on FN, but sustained associations of only beta(1) with Shc when seeded on COL1/LM. Shear inductions of MAPKs and bone formation-related genes were sustained (24 h) in cells on FN, but some of these responses were transient in cells on COL1/LM. The shear activations of ERK, JNK, and p38 were mediated by integrins and Shc, and these pathways differentially modulated the downstream bone formation-related gene expression. Our findings showed that beta(1) integrin plays predominant roles for shear-induced signaling and gene expression in osteoblast-like MG63 cells on FN, COL1, and LM and that alpha(v)beta(3) also plays significant roles for such responses in cells on FN. The beta(1)/Shc association leads to the activation of ERK, which is critical for shear induction of bone formation-related genes in osteoblast-like cells.

Interstitial flow in and around tumor tissue affects the mechanical microenvironment to modulate tumor cell growth and metastasis. We investigated the roles of flow-induced shear stress in modulating cell cycle distribution in four tumor cell lines and the underlying mechanisms. In all four cell lines, incubation under static conditions for 24 or 48 h led to G 0 /G 1 arrest; in contrast, shear stress (12 dynes/cm 2 ) induced G 2 /M arrest. The molecular basis of the shear effect was analyzed, and the presentation on molecular mechanism is focused on human MG63 osteosarcoma cells. Shear stress induced increased expressions of cyclin B1 and p21 CIP1 and decreased expressions of cyclins A, D1, and E, cyclin-dependent protein kinases (Cdk)-1, -2, -4, and -6, and p27 KIP1 as well as a decrease in Cdk1 activity. Using specific antibodies and small interfering RNA, we found that the shear-induced G 2 /M arrest and corresponding changes in G 2 /M regulatory protein expression and activity were mediated by α v β 3 and β 1 integrins through bone morphogenetic protein receptor type IA-specific Smad1 and Smad5. Shear stress also down-regulated runt-related transcription factor 2 (Runx2) binding activity and osteocalcin and alkaline phosphatase expressions in MG63 cells; these responses were mediated by α v β 3 and β 1 integrins through Smad5. Our findings provide insights into the mechanism by which shear stress induces G 2 /M arrest in tumor cells and inhibits cell differentiation and demonstrate the importance of mechanical microenvironment in modulating molecular signaling, gene expression, cell cycle, and functions in tumor cells.

Co-culture of CAF ERα(+) cells and PCa cells can decrease PCa cell invasion through changing IL-6 expression. CM was collected from CAF.ERα(-) and CAF.ERα(+) cells together with or without with IL-6 neutralizing antibody (Anti IL-6) or IgG (control) into bottom wells of 24-well transwell systems. We then trypsinized and seeded CWR22Rv-1 and C4-2 cells (1x105) into matrigel-pre-coated transwells for invasion assay. Quantitation is at right.

Infiltrated Macrophages (Mφ) can affect the macrophages recruited-related gene profiles in CAF cells. CAF.ERα(-) or CAF.ERα(+) cells were co-cultured with macrophages for 2 days. We compared gene profiles of macrophages attraction related CCL5 and IL6 in CAF.ERα(+) and CAF.ERα(-) using qPCR.

Co-culture of CAF ERα(+) cells and PCa cells can decrease PCa cell invasion through changing IL-6 expression. CM was collected from CAF.ERα(-) and CAF.ERα(+) cells together with or without with IL-6 neutralizing antibody (Anti IL-6) or IgG (control) into bottom wells of 24-well transwell systems. We then trypsinized and seeded CWR22Rv-1 and C4-2 cells (1x105) into matrigel-pre-coated transwells for invasion assay. Quantitation is at right.

Infiltrated Macrophages (Mφ) can affect the macrophages recruited-related gene profiles in CAF cells. CAF.ERα(-) or CAF.ERα(+) cells were co-cultured with macrophages for 2 days. We compared gene profiles of macrophages attraction related CCL5 and IL6 in CAF.ERα(+) and CAF.ERα(-) using qPCR.