Enhanced expression of the mesenchymal marker, vimentin, in hyperplastic versus normal human prostatic epithelium

Intrinsic and extrinsic factors causing hyperplasia of the prostate

Prostatic hyperplasia is very common in elderly men and is a typical disease that reduces quality of life. Histologically, hyperplasia of the prostate gland causes obstruction at the bladder outlet, resulting in symptoms such as a weak urine stream. Various factors have been considered to cause histological enlargement of the prostate, but the underlying cause is still unknown. The factors that cause prostate hyperplasia can be broadly classified into intrinsic and extrinsic ones. Extrinsic factors include things that we directly come into contact with such as bacteria and food. On the other hand, intrinsic factors are those that cause changes in functions originally provided in the body due to some cause, including extrinsic factors, such as chronic inflammation and an imbalance of sex hormones. A large number of reports have been made to date regarding the etiology of prostatic hyperplasia, although they have not yet clarified the fundamental cause(s). The various factors currently known should be outlined for future research. Should it be possible to prevent this highly prevalent prostatic hyperplasia which is mainly cause of dcreasing quality of life, there is no doubt that it would be a huge contribution to humanity.

Development and dysfunction of structural cells in eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a disorder characterized by dysfunction and chronic local inflammation of the esophagus. The incidence and prevalence of EoE are increasing worldwide. The mechanisms responsible are poorly understood, and effective treatment options are limited. From the lumen outward, the esophagus comprises stratified squamous epithelium, lamina propria, and muscle. The tissue-specific nature of EoE strongly suggests that structural cells in the esophagus are involved in the EoE diathesis. Epithelial basal cell hyperplasia and dilated intercellular spaces are cardinal features of EoE. Some patients with EoE develop lamina propria fibrosis, strictures, or esophageal muscle dysmotility. Clinical symptoms of EoE are only weakly correlated with peak eosinophil count, implying that other cell types contribute to EoE pathogenesis. Epithelial, endothelial, muscle, and fibroblast cells can each initiate inflammation and repair, regulate tissue resident immune cells, recruit peripheral leukocytes, and tailor adaptive immune cell responses. A better understanding of how structural cells maintain tissue homeostasis, respond to cell-intrinsic and cell-extrinsic stressors, and exacerbate and/or resolve inflammatory responses in the esophagus is needed. This knowledge will facilitate the development of more efficacious treatment strategies for EoE that can restore homeostasis of both hematopoietic and structural elements in the esophagus.

The Effects of Caloric Restriction on Inflammatory Targets in the Prostates of Aged Rats

Numerous animal models have demonstrated that caloric restriction (CR) is an excellent tool to delay aging and increase the quality of life, likely because it counteracts age-induced oxidative stress and inflammation. The aging process can affect the prostate in three ways: the onset of benign prostatic hyperplasia, prostatitis, and prostate cancer. In this study, we used 14 aged male Sprague Dawley rats, which were allocated into two groups, at the age of 18 months old. One group was fed ad libitum (a normal diet (ND)), and the other group followed a caloric restriction diet with a 60% decrease in intake. The rats were sacrificed at the age of 24 months. By immunohistochemical (IHC) and Western blot (WB) analyses, we studied the variations between the two groups in immune inflammation and fibrosis-related markers in aged prostate tissues. Morphological examinations showed lower levels of prostatic hyperplasia and fibrosis in the CR rats vs. the ND rats. The IHC results revealed that the prostates of the CR rats exhibited a lower immune proinflammatory infiltrate level and a reduced expression of the NLRP3 inflammasome pathway, together with significantly reduced expressions of mesenchymal markers and the profibrotic factor TGFβ1. Finally, by WB analysis, we observed a reduced expression of ERα, which is notoriously implicated in prostate stromal proliferation, and increased expressions of SOD1 and Hsp70, both exerting protective effects against oxidative stress. Overall, these data suggest that CR brings potential benefits to prostatic tissues as it reduces the physiological immune-inflammatory processes and the tissue remodeling caused by aging.

Ruyong formula improves thymus function of CUMS-stimulated breast cancer mice

ETHNOPHARMACOLOGICAL RELEVANCE

Ruyong Formula (RYF) is a famous Chinese herbal formula composed of 10 traditional Chinese herbs. It has been used as a therapeutic agent for breast cancer patients with depressive symptoms in China. However, its underlying pharmacological mechanism remains unclear.

AIM OF THE STUDY

This study aimed to explore the mechanism of RYF on the changes of thymus immune function in breast cancer body under mood disorders such as depression/anxiety.

MATERIALS AND METHODS

The chronic unpredictable mild stress (CUMS) was used to stimulate 4T1 breast cancer mice. The behavioral changes, 5-hydroxytryptamine (5-HT) level in brain, cytokeratin 5 (CK5) and 8 (CK8) expression in thymus, the proportion of T cell subsets, the thymic output, phenotypic changes of thymus epithelial cells (TECs), the expression levels of immune-related factors and downstream proteins of TSLP were analyzed after RYF treatment.

RESULTS

In CUMS stimulated group, the level of 5-HT in brain was significantly increased after RYF treatment. The output function of the thymus was improved, and the number of TECs in the medulla (CK5+), the proportion of CD3+CD4-CD8- (Double negative) and CD3+CD4+CD8+ (Double positive) T cells were all increased. The mRNA level of TSLP in mouse thymus was significantly decreased, but increased for IL-7. The protein levels of TSLP and Vimentin were decreased, but increased for p-STAT3, p-JAK2, E-cadherin, and p-PI3K p55 in vivo. In vitro study was showed the levels of Snail 1, Zeb 1 and Smad increased significantly in TGF-β1 group, and RYF could reverse their expression.

CONCLUSIONS

RYF could restore the structure and function of the thymus in depressed breast cancer mice by reversing the phenotypic changes of TECs and activating the JAK2/STAT3/PI3K pathway.

The Emerging Role of Cell Adhesion Molecules on Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is a common disease in elderly men. It is characterized by prostatic enlargement and urethral compression and often causes lower urinary tract symptoms (LUTs) such as urinary frequency, urgency, and nocturia. Existing studies have shown that the pathological process of prostate hyperplasia is mainly related to the imbalance of cell proliferation and apoptosis, inflammation, epithelial-mesenchymal transition (EMT), and growth factors. However, the exact molecular mechanisms remain incompletely elucidated. Cell adhesion molecules (CAMs) are a group of cell surface proteins that mediate cell-cell adhesion and cell migration. Modulating adhesion molecule expression can regulate cell proliferation, apoptosis, EMT, and fibrotic processes, engaged in the development of prostatic hyperplasia. In this review, we went over the important roles and molecular mechanisms of cell adhesion molecules (mainly integrins and cadherins) in both physiological and pathological processes. We also analyzed the mechanisms of CAMs in prostate hyperplasia and explored the potential value of targeting CAMs as a therapeutic strategy for BPH.

Changes in the Expression and Functional Activities of C-X-C Motif Chemokine Ligand 13 (CXCL13) in Hyperplastic Prostate

BACKGROUND

C-X-C motif chemokine ligand 13 (CXCL13), a member of the CXC subtype in chemokine superfamily, affects numerous biological processes of various types of cells and the progress of a great number of clinical diseases. The purpose of the current study was to reveal the internal mechanism between CXCL13 and benign prostatic hyperplasia (BPH).

METHODS

Human serum, prostate tissues and human prostate cell lines (BPH-1, WPMY-1) were utilized. The effect of recombinant human CXCL13 (rHuCXCL13) protein and the influences of the knockdown/overexpression of CXCL13 on two cell lines were studied. Rescue experiments by anti-CXCR5 were also conducted. In vivo, rHuCXCL13 was injected into the ventral prostate of rats. Additionally, a tissue microarray of hyperplastic prostate tissues was constructed to analyze the correlations between CXCL13 and clinical parameters.

RESULTS

CXCL13 was highly expressed in the prostate tissues and upregulated in the BPH group. It was observed that CXCL13 modulated cell proliferation, apoptosis, and the epithelial-mesenchymal transition (EMT) through CXCR5 via AKT and the ERK1/2 pathway in BPH-1, while it contributed to inflammation and fibrosis through CXCR5 via the STAT3 pathway in WPMY-1. In vivo, rHuCXCL13 induced the development of rat BPH. Additionally, CXCL13 was positively correlated with the prostate volume and total prostate specific antigen.

CONCLUSIONS

Our novel data demonstrated that CXCL13 modulated cell proliferation, cell cycle, the EMT of epithelial cells, and induced the fibrosis of prostatic stromal cells via a variety of inflammatory factors, suggesting that CXCL13 might be rediscovered as a potential therapeutic target for the treatment of BPH.

The Role of Heat Shock Protein 70 Subfamily in the Hyperplastic Prostate: From Molecular Mechanisms to Therapeutic Opportunities

Benign prostatic hyperplasia (BPH) is one of the most common causes of lower urinary tract symptoms (LUTS) in men, which is characterized by a noncancerous enlargement of the prostate. BPH troubles the vast majority of aging men worldwide; however, the pathogenetic factors of BPH have not been completely identified. The heat shock protein 70 (HSP70) subfamily, which mainly includes HSP70, glucose-regulated protein 78 (GRP78) and GRP75, plays a crucial role in maintaining cellular homeostasis. HSP70s are overexpressed in the course of BPH and involved in a variety of biological processes, such as cell survival and proliferation, cell apoptosis, epithelial/mesenchymal transition (EMT) and fibrosis, contributing to the development and progress of prostate diseases. These chaperone proteins also participate in oxidative stress, a cellular stress response that takes place under stress conditions. In addition, HSP70s can bind to the androgen receptor (AR) and act as a regulator of AR activity. This interaction of HSP70s with AR provides insight into the importance of the HSP70 chaperone family in BPH pathogenesis. In this review, we discuss the function of the HSP70 family in prostate glands and the role of HSP70s in the course of BPH. We also review the potential applications of HSP70s as biomarkers of prostate diseases for targeted therapies.

Upregulated bone morphogenetic protein 5 enhances proliferation and epithelial-mesenchymal transition process in benign prostatic hyperplasia via BMP/Smad signaling pathway

BACKGROUND

Benign prostatic hyperplasia (BPH) is one of the most common illnesses in aging men. Recent studies found that bone morphogenetic protein 5 (BMP5) is upregulated in BPH tissues, however, the role of BMP5 in the development of BPH has not been examined. The current study aims to elucidate the potential roles of BMP5 and related signaling pathways in BPH.

METHODS

Human prostate cell lines (BPH-1, WPMY-1) and human/rat hyperplastic prostate tissues were utilized. Western blot, quantitative real-time polymerase chain reaction, immunofluorescent staining, and immunohistochemical staining were performed. BMP5-silenced and -overexpressed cell models were generated and then cell cycle progression, apoptosis, and proliferation were determined. The epithelial-mesenchymal transition (EMT) was also quantitated. And rescue experiments by BMP/Smad signaling pathway agonist or antagonist were accomplished. Moreover, BPH-related tissue microarray analysis was performed and associations between clinical parameters and expression of BMP5 were analyzed.

RESULTS

Our study demonstrated that BMP5 was upregulated in human and rat hyperplastic tissues and localized both in the epithelial and stromal compartments of the prostate tissues. E-cadherin was downregulated in hyperplastic tissues, while N-cadherin and vimentin were upregulated. Overexpression of BMP5 enhanced cell proliferation and the EMT process via phosphorylation of Smad1/5/8, while knockdown of BMP5 induced cell cycle arrest at G0/G1 phase and blocked the EMT process. Moreover, a BMP/Smad signaling pathway agonist and antagonist reversed the effects of BMP5 silencing and overexpression, respectively. In addition, BMP5 expression positively correlated with prostate volume and total prostate-specific antigen.

CONCLUSION

Our novel data suggest that BMP5 modulated cell proliferation and the EMT process through the BMP/Smad signaling pathway which could contribute to the development of BPH. However, further studies are required to determine the exact mechanism. Our study also indicated that BMP/Smad signaling may be rediscovered as a promising new therapeutic target for the treatment of BPH.

miR-300 promotes proliferation and EMT-mediated colorectal cancer migration and invasion by targeting p53

p53 mutations in tumors can induce the loss of wild-type tumor-suppressing p53 function, which results in the increase in proliferation, migration and invasion ability in cancer cells. Studies have shown that the expression of p53 is regulated by several microRNAs (miRNAs). In the present study, we found that miR-300 and p53 were significantly increased in colorectal cancer (CRC) tissues when compared with levels noted in adjacent colorectal tissues. Both miR-300 and p53 were significantly correlated with lymphatic metastasis and TNM stage. Both miR-300 and p53 promoted CRC cell (SW480 and HT29) proliferation, migration, and invasion, respectively, in vitro. In addition, we found that miR-300 is a direct positive regulator of p53 through binding to the binding site in the 3'UTR of the p53 gene in human CRC cells. Moreover, both miR-300 and p53 induced CRC cell epithelial‑mesenchymal transition (EMT) respectively. Taken together, we demonstrated that miR-300 promoted proliferation and EMT-mediated CRC migration and invasion by targeting p53. These findings provide a new theoretical basis and potential therapeutic targets, and thus lays the foundation for exploring the pathogenesis of CRC.

Morphological and immunohistochemical identification of epithelial-to-mesenchymal transition in clinical prostate cancer

Epithelial-to-mesenchymal transition (EMT) is a process known to be associated with aggressive tumor behavior, metastasis and treatment resistance. It is characterized by coincidental upregulation of mesenchymal markers such as vimentin, fibronectin and N-cadherin concurrent with E-cadherin downregulation. Studies on EMT are generally performed in cell lines and mouse models, while the histopathological and phenotypical properties in clinical prostate cancer (PCa) are still unclear.

The objective of this study was to identify EMT in PCa patients. We demonstrated that N-cadherin, vimentin and fibronectin were generally not co-expressed in corresponding tumor regions. Immunofluorescent double stainings confirmed that co-expression of mesenchymal markers was uncommon, as we found no prostate cancer cells that co-expressed N-cadherin with fibronectin and only rare (<1%) cells that co-expressed N-cadherin with vimentin. Downregulation of E-cadherin was demonstrated in all N-cadherin positive tumor cells, but not in vimentin or fibronectin positive tumor cells. We further analyzed N-cadherin expression in morphologically distinct PCa growth patterns in a radical prostatectomy cohort (n = 77) and found that N-cadherin is preferentially expressed in ill-defined Gleason grade 4 PCa. In conclusion, we demonstrate that N-cadherin is the most reliable marker for EMT in clinical PCa and is preferentially expressed in ill-defined Gleason grade 4 growth pattern.

Validating antimetastatic effects of natural products in an engineered microfluidic platform mimicking tumor microenvironment

Development of new, antimetastatic drugs from natural products has been substantially constrained by the lack of a reliable in vitro screening system. Such a system should ideally mimic the native, three-dimensional (3D) tumor microenvironment involving different cell types and allow quantitative analysis of cell behavior critical for metastasis. These requirements are largely unmet in the current model systems, leading to poor predictability of the in vitro collected data for in vivo trials, as well as prevailing inconsistency among different in vitro tests. In the present study, we report application of a 3D, microfluidic device for validation of the antimetastatic effects of 12 natural compounds. This system supports co-culture of endothelial and cancer cells in their native 3D morphology as in the tumor microenvironment and provides real-time monitoring of the cells treated with each compound. We found that three compounds, namely sanguinarine, nitidine, and resveratrol, exhibited significant antimetastatic or antiangiogenic effects. Each compound was further examined for its respective activity with separate conventional biological assays, and the outcomes were in agreement with the findings collected from the microfluidic system. In summary, we recommend use of this biomimetic model system as a new engineering tool for high-throughput evaluation of more diverse natural compounds with varying anticancer potentials.

Relationship between STAT3 protein expression and epithelial-mesenchymal transition in esophageal squamous cell carcinoma

AIM: To investigate the expression of signal transducer and activator of transcription 3 (STAT3) and phosphorylated STAT3 (p-STAT3) in esophageal squamous cell carcinoma (ESCC) and analyze their relationship with epithelial-mesenchymal transition and tumor infiltration and metastasis.

METHODS: Immunohistochemistry was used to determine the expression of STAT3, p-STAT3, E-cadherin and vimentin in 80 ESCC specimens and matched adjacent non-cancerous tissue specimens.

RESULTS: The positive rates of STAT3, p-STAT3, E-cadherin and vimentin in ESCC tissue were significantly different from those in adjacent non-cancerous tissue (87.5% vs 70.0%, 72.5% vs 28.8%, 37.5% vs 78.8% and 48.8% vs 0%, respectively; all P < 0.01). The expression of STAT3 and p-STAT3 was negatively correlated with E-cadherin expression (r = -0.410 and -0.506, respectively; both P = 0.000) but positively with vimentin expression (r = 0.293 and 0.321, respectively; P = 0.008 and 0.004, respectively) in ESCC tissue. The expression of STAT3 and p-STAT3 was significantly associated with depth of tumor invasion (both P < 0.05).

CONCLUSION: Overexpression of STAT3 protein may be involved in EMT and tumor invasion and metastasis in ESCC.

Transcriptome profiles of carcinoma-in-situ and invasive non-small cell lung cancer as revealed by SAGE

Background

Non-small cell lung cancer (NSCLC) presents as a progressive disease spanning precancerous, preinvasive, locally invasive, and metastatic lesions. Identification of biological pathways reflective of these progressive stages, and aberrantly expressed genes associated with these pathways, would conceivably enhance therapeutic approaches to this devastating disease.

Methodology/Principal Findings

Through the construction and analysis of SAGE libraries, we have determined transcriptome profiles for preinvasive carcinoma-in-situ (CIS) and invasive squamous cell carcinoma (SCC) of the lung, and compared these with expression profiles generated from both bronchial epithelium, and precancerous metaplastic and dysplastic lesions using Ingenuity Pathway Analysis. Expression of genes associated with epidermal development, and loss of expression of genes associated with mucociliary biology, are predominant features of CIS, largely shared with precancerous lesions. Additionally, expression of genes associated with xenobiotic metabolism/detoxification is a notable feature of CIS, and is largely maintained in invasive cancer. Genes related to tissue fibrosis and acute phase immune response are characteristic of the invasive SCC phenotype. Moreover, the data presented here suggests that tissue remodeling/fibrosis is initiated at the early stages of CIS. Additionally, this study indicates that alteration in copy-number status represents a plausible mechanism for differential gene expression in CIS and invasive SCC.

Conclusions/Significance

This study is the first report of large-scale expression profiling of CIS of the lung. Unbiased expression profiling of these preinvasive and invasive lesions provides a platform for further investigations into the molecular genetic events relevant to early stages of squamous NSCLC development. Additionally, up-regulated genes detected at extreme differences between CIS and invasive cancer may have potential to serve as biomarkers for early detection.

Correlation between Tiam1 expression and epithelial-mesenchymal transition in human colorectal cancer cell lines

AIM: To explore the correlation between Tiam1 (T-lymphoma invasion and metastasis-inducing protein 1) expression and epithelial-mesenchymal transition (EMT) in six colorectal cancer cell lines with different metastatic potential.

METHODS: The expression of Tiam1, E-cadherin and vimentin mRNAs in six human colorectal cancer cell lines was detected by real-time reverse transcription-polymerase chain reaction (RT-PCR). The expression of Tiam1, E-cadherin and vimentin proteins in LoVo and HT29 cells was detected by immunohistochemistry. The cytoskeleton of LoVo and HT29 cells was observed by Coomassie brilliant blue staining.

RESULTS: The expression levels of Tiam1, E-cadherin and vimentin mRNAs in SW620, SW480/M5, HT29, LoVo and LS174T cells were significantly different from those in SW480 cells (Tiam1: 0.51, 7.67, 0.00, 0.36 and 0.06 vs 1.00; E-cadherin: 3.18, 2.27, 5.92, 0.00 and 0.61 vs 1.00; vimentin: 6.08, 0.02, 0.35, 11.72 and 0.00 vs 1.00; all P < 0.05). E-cadherin protein was moderately expressed in the cytoplasm of HT29 cells, while Tiam1 and vimentin proteins were not detectable in HT29 cells. Tiam1 and vimentin proteins were moderately and strongly expressed in the nuclei of LoVo cells, respectively, while E-cadherin protein was undetectable in LoVo cells. HT29 cells had more surface projections, and less cytoskeletal structures and spot-like actin bodies than LoVo cells.

CONCLUSION: Tiam1 promotes the metastasis of colorectal carcinoma possibly by inducing EMT.

Differential protein mapping of ovarian serous adenocarcinomas: identification of potential markers for distinct tumor stage

Ovarian serous carcinomas (OSCs) comprise over half of all ovarian carcinomas and account for the majority of ovarian cancer-related deaths. We used a 2-dimensional liquid-based protein mapping strategy to characterize global protein expression patterns in 19 OSC tumor samples from 15 different patients to facilitate molecular classification of tumor stage. Protein expression profiles were produced, using pI-based separation in the first dimension and hydrophobicity-based separation in the second dimension, over a pH range of 4.0-7.0. Hierarchical clustering was applied to protein maps to indicate the tumor interrelationships. The 19 tumor samples could be classified into two different groups, one group associated with low stage (Stage 1) tumors and the other group associated with high stage (Stages 3/4) tumors. Proteins that were differentially expressed in different groups were selected for identification by LTQ-ESI-MS/MS. Fourteen of the selected proteins were overexpressed in the low stage tumors; 46 of the proteins were overexpressed in the high stage tumors. These proteins are known to play an important role in cellular functions such as glycolysis, protein biosynthesis, and cytoskeleton rearrangement and may serve as markers associated with different stages of OSCs. To further confirm the stage-dependent protein identifications, Lamin A/C and Vimentin expression in ovarian serous carcinomas was assessed by immunohistochemistry using ovarian tumor tissue microarrays for 66 samples.

A role for epithelial-mesenchymal transition in the etiology of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is usually described as a pathological proliferation of prostatic fibroblasts/myofibroblasts and epithelial cells. In the present study of BPH samples, we have made a morphological and immunohistochemical study of BPH prostatic sections using markers of proliferation, apoptosis, hormone receptors, and TGF-beta signaling. We found no evidence of proliferation in the stroma but in the epithelium of some ducts; 0.7% of the basal and 0.4% of luminal cells were positive for Ki67 and PCNA. Androgen receptor and estrogen receptor beta (ERbeta)1 and ERbetacx were abundant in both stromal and epithelial compartments but cells expressing ERalpha were very rare. What was very common in all BPH samples was the following: (i) regions of the ductal epithelium where the epithelial cells did not express E-cadherin, had lost their polarization, and become spindle shaped (the nuclei of these cells were strongly positive for pSmad 3 and Snail); and (ii) regions where the walls of the blood vessels were extremely thick and there was loss of endothelial layer. Loss of E-cadherin, increased pSmad 3, and high expression of Snail are all characteristic of epithelial-mesenchymal transition (EMT). We conclude that BPH is not a disease of prostatic stromal proliferation but rather of accumulation of mesenchymal-like cells derived from the prostatic epithelium and the endothelium. TGF-beta is thought to play a key role in EMT. Our data suggests that TGF-beta/Smad should be considered as targets for treatment of BPH.

Stromal growth and epithelial cell proliferation in ventral prostates of liver X receptor knockout mice

With specific liver X receptor alpha and beta (LXRalpha and LXRbeta) antibodies, we found that LXRalpha is strongly expressed in the luminal and basal cells of prostatic epithelium. The ventral prostates (VP) of LXRalpha(-/-) mice are characterized by the presence of smooth-muscle actin-positive stromal overgrowth around the prostatic ducts and by numerous fibrous nodules pushing into the ducts and causing obstruction, so that most of the ducts were extremely dilated. BrdU labeling and Ki67 staining revealed epithelial and stromal proliferation in the fibrous nodules. However, the dense stroma surrounding the ducts was not positive for proliferation markers. There was no detectable difference between WT and LXRalpha(-/-) mice VP in the expression of the androgen receptor, but there was an increase in nuclear expression of Snail and Smad 2/3, indicating enhanced TGF-beta signaling. Upon treatment of WT mice for 3 months with the LXR agonist T2320 or for 3 weeks with beta-sitosterol, LXRalpha was downregulated, and a VP phenotype similar to that of LXRalpha(-/-) mice resulted. We conclude that in rodents, LXRalpha seems to control VP stromal growth and that LXRalpha(-/-) mice may be a useful model to study prostatic stromal hyperplasia. Because LXRalpha is expressed in the epithelium, the excessive stromal growth in LXRalpha(-/-) mice indicates that LXRalpha is essential for epithelial stromal communication.

Effect of Genistein on epithelial-mesenchymal transdifferentiation induced by transforming growth factor-β1 in human pancreatic cancer cell line Panc-1

AIM: To investigate the effect of Genistein on epithelial-mesenchymal transdifferentiation (EMT) induced by transforming growth factor-β1 (TGF-βl) in human pancreatic cancer cell line Panc-1, and to explore the mechanism of Genistein inhibiting invasion of Panc-1 cells.

METHODS: Panc-1 cells were treated with TGF-β1 and Genistein (0, 1, 25, 50 μmol/L), and those treated with PSB served as controls. Transwell chamber assay was performed to determine the invasion ability change of Panc-1 cells. Reverse transcription-polymerase chain reaction (RT-PCR) was used to estimate the mRNA expression of vimentin and E-cadherin. Western bloting assay was used to measure the protein expression of E-cadherin. Cell structure was observed by microscopy.

RESULTS: TGF-βl obviously promoted EMT and invasion abilibty of Panc-1 cells. Not only the invasion ability but also EMT induced by TGF-βl were significantly inhibited by Genistein in a dose-dependent manner. The number of Panc-1 cells was larger in 0 μmol/L Genistein group than that in the control group (99.16 ± 11.30 vs 65.46 ± 8.99, P < 0.05). Genistein at concentraion of 50 μmol/L down-regulated the mRNA expression of vimentin and up-regulated the mRNA and protein expression of E-cadherin. The characteristic morphology of EMT was reversed.

CONCLUSION: Genistein can inhibit TGF-β1-induced invasion of Panc-1 cells remarkably, which may be one of its anti-invasion mechanisms.

MOLECULAR AND CELLULAR PATHOGENESIS OF BENIGN PROSTATIC HYPERPLASIA

PURPOSE

Symptomatic benign prostatic hyperplasia (BPH) is one of the most common ailments seen by the urologist. Significant advances have occurred in medical and surgical therapy, and in the understanding of the biology of this disease. However, the basic science literature is often conflicting and confusing, without a unified voice. We report the current state of knowledge of the molecular and cellular basis of BPH.

MATERIALS AND METHODS

We compiled and interpreted basic science studies relevant to BPH pathogenesis.

RESULTS

Cellular alterations that include changes in proliferation, differentiation, apoptosis and senescence in the epithelium and stroma are implicated in BPH pathogenesis. Molecular analyses have yielded numerous candidate genes important in disease progression. Differential expression of cytokines and growth factors in BPH tissue suggests roles for inflammation and hypoxia. Through the use of cell culture models the complex regulatory mechanisms of growth control in BPH are becoming defined.

CONCLUSIONS

The scientific endeavor has resulted in great strides in our understanding of BPH on a molecular and cellular level. It is hopeful that basic science and translational research will improve treatment and prevention strategies for this common disease of elderly men.

Enhanced expression of vimentin in motile prostate cell lines and in poorly differentiated and metastatic prostate carcinoma

BACKGROUND

The metastatic potential of a series of prostate cell lines was analysed by measuring motility and invasiveness, and further correlated to the expression of epithelial differentiation markers.

METHODS

Invasion and motility were measured using in vitro assays. Immunohistochemistry of cell lines and tissues was used to identify expression of cytokeratins 8 and 1, 5, 10, 14, vimentin, prostate specific antigen, prostate specific membrane antigen, androgen receptor, desmoglein, E-cadherin, beta1 integrin, CD44, hmet, vinculin and actin.

RESULTS

Expression of vimentin was the only marker to correlate with motility, no markers correlated to invasion. Lower vimentin expression was observed in cells with low motility (PNT2-C2) and high expression in cells with high motility (P4E6, PNT1a, PC-3). Vimentin expression was not detected in well differentiated tumours, moderately differentiated tumours contained vimentin positive cells (1/9 bone scan negative, 2/5 bone scan positive), but the majority of poorly differentiated cancers (4/11 bone scan negative, 9/14 bone scan positive) and bone metastases (7/8) had high vimentin expression in tumour cells.

CONCLUSIONS

Motile prostate cancer cell lines express vimentin. In tissue sections, the presence of vimentin positive tumour cells correlated positively to poorly differentiated cancers and the presence of bone metastases.

Molecular characterization of prostate hyperplasia in prolactin-transgenic mice by using cDNA representational difference analysis

BACKGROUND

Transgenic mice overexpressing the rat prolactin (PRL) gene develop a dramatic enlargement of the prostate gland. The objective of this study was to characterize the molecular mechanisms in the prostate of importance for the prostate hyperplasia seen in these transgenic mice.

METHODS

cDNA representational difference analysis (cDNA RDA) was used to isolate differentially expressed transcripts in the prostate hyperplasia of the transgenic mice compared with wildtype littermates. Furthermore, cDNA microarray analysis was used to verify the RDA output.

RESULTS

Here we report 10 transcripts, some of them described to be involved in proliferation and apoptosis, which are differentially expressed in the enlarged transgenic prostates compared with controls.

CONCLUSION

The identified differentially expressed transcripts presented herein supports molecular similarities between the prostate hyperplasia of PRL-transgenic mice and human BPH that may contribute to explain the molecular basis of prostate hyperplasia.

Gene expression signature of benign prostatic hyperplasia revealed by cDNA microarray analysis

BACKGROUND

Despite the high prevalence of benign prostatic hyperplasia (BPH) in the aging male, little is known regarding the etiology of this disease. A better understanding of the molecular etiology of BPH would be facilitated by a comprehensive analysis of gene expression patterns that are characteristic of benign growth in the prostate gland. Since genes differentially expressed between BPH and normal prostate tissues are likely to reflect underlying pathogenic mechanisms involved in the development of BPH, we performed comparative gene expression analysis using cDNA microarray technology to identify candidate genes associated with BPH.

METHODS

Total RNA was extracted from a set of 9 BPH specimens from men with extensive hyperplasia and a set of 12 histologically normal prostate tissues excised from radical prostatectomy specimens. Each of these 21 RNA samples was labeled with Cy3 in a reverse transcription reaction and cohybridized with a Cy5 labeled common reference sample to a cDNA microarray containing 6,500 human genes. Normalized fluorescent intensity ratios from each hybridization experiment were extracted to represent the relative mRNA abundance for each gene in each sample. Weighted gene and random permutation analyses were performed to generate a subset of genes with statistically significant differences in expression between BPH and normal prostate tissues. Semi-quantitative PCR analysis was performed to validate differential expression.

RESULTS

A subset of 76 genes involved in a wide range of cellular functions was identified to be differentially expressed between BPH and normal prostate tissues. Semi-quantitative PCR was performed on 10 genes and 8 were validated. Genes consistently upregulated in BPH when compared to normal prostate tissues included: a restricted set of growth factors and their binding proteins (e.g. IGF-1 and -2, TGF-beta3, BMP5, latent TGF-beta binding protein 1 and -2); hydrolases, proteases, and protease inhibitors (e.g. neuropathy target esterase, MMP2, alpha-2-macroglobulin); stress response enzymes (e.g. COX2, GSTM5); and extracellular matrix molecules (e.g. laminin alpha 4 and beta 1, chondroitin sulfate proteoglycan 2, lumican). Genes consistently expressing less mRNA in BPH than in normal prostate tissues were less commonly observed and included the transcription factor KLF4, thrombospondin 4, nitric oxide synthase 2A, transglutaminase 3, and gastrin releasing peptide.

CONCLUSIONS

We identified a diverse set of genes that are potentially related to benign prostatic hyperplasia, including genes both previously implicated in BPH pathogenesis as well as others not previously linked to this disease. Further targeted validation and investigations of these genes at the DNA, mRNA, and protein levels are warranted to determine the clinical relevance and possible therapeutic utility of these genes.

Prostate epithelial cell lines form spheroids with evidence of glandular differentiation in three-dimensional Matrigel cultures

Normal (PNT2-C2) and metastatic (PC-3) prostate cell lines were grown in Matrigel to observe the effects on morphology and phenotype in comparison to monolayer culture. In monolayer cultures, PNT2-C2 showed typical round/cuboidal epithelial morphology, with tight cell associations, whereas in Matrigel they formed smooth spheroids, tightly packed with cells. In both monolayer and Matrigel, PNT2-C2 had a differentiated luminal epithelial phenotype with high expression of cytokeratin 8, prostate specific antigen (PSA), prostate specific membrane antigen (PSMA), E-cadherin and desmoglein. In contrast, PC-3 cells possessed an epithelial/mesenchyme morphology in monolayer with loose cell to cell contact and pseudopodial extensions. Immunohistochemical phenotyping indicated the cells were undifferentiated, expressing high levels of vimentin, beta1 integrin, CD44 and low expression of cytokeratin 8. In Matrigel they formed smooth and irregular spheroids, which had a lumen surrounded by a single cell layer. Matrigel also influenced the expression of PSA, PSMA and CD44. These results indicate that Matrigel culture can induce morphological differentiation of prostate cancer cells which initially had a basal phenotype.

Phenotypic and genotypic characterization of commonly used human prostatic cell lines

OBJECTIVE

To investigate and catalogue systematically the phenotypic and genotypic characteristics of the commonly used prostatic cell lines using immunocytochemistry and polymerase chain reaction (PCR) of hypervariable sequences within the genome to provide a 'fingerprint' characteristic of each cell line. Materials and methods Malignant (LNCaP, LNCaP-r, PC-3, DU-145) and benign immortalized prostatic cell lines (PNT-1A, PNT-1B, BPH-1) were grown on four-well slides, fixed and subjected to indirect streptavidin-biotin immunocytochemistry. Twenty-three antibodies were used in the following groups: cytoskeletal elements: cytokeratins (CK)-5, -7, -8, -14 (two), -16, -18, -19 (three), -20, vimentin and desmin; MUC1 (three); cell adhesion molecules (E-cadherin, alpha-beta-and gamma-catenin); and prostatic associated proteins: prostate specific antigen (PSA), prostatic acid phosphatase (PAP) and androgen receptor (AR). For the PCR, genomic DNA was extracted from the cell lines and from SKOV3 and MCF7 (positive controls). PCR was performed on three variable regions which were then sequenced: AR exon 1 (CAG repeat polymorphism), and two areas of microsatellite instability (MSI): AR exon 8 and hypoxanthine-guanine phosphoribosyl transferase (HPRT) exon 3.

RESULTS

All cell lines were CK-8/18 positive and most also expressed CK-7 and -19. Heterogeneous CK-20 expression was detected for the first time in prostatic cell lines. All lines were positive for vimentin and negative for desmin. MUC1 was expressed in one malignant (DU-145) and all immortalized cell lines. E-cadherin expression was low or absent in three lines: PNT1A, 1B and PC-3. Only PC-3 failed to express alpha-catenin; beta- and gamma-catenin were expressed by all lines. PSA, PAP and AR were only expressed by LNCaP and LNCaP-r. On PCR, the CAG repeat lengths in exon 1 of the AR ranged from 19 to 27. Three pairs of cell lines had the same exon 1 CAG repeat length: LNCaP/PC-3 (26 repeats), BPH-1/DU-145 (19 repeats) and PNT1 A/1B (20 repeats). Exon 8 sequences were identical except for LNCaP, which showed a single base mutation, and HPRT exon 3 sequences were all identical. There was no evidence of generalized MSI in any of the cell lines examined.

CONCLUSIONS

The cell lines studied fell into three broad groups according to their phenotypic characteristics: (i) prostatic marker positive (LNCaP and LNCaP-r); (ii) high expression of most antigens (DU-145, PC-3 and BPH-1); and (iii) low or absent expression of most antigens (PNT1 A and 1B). Each of the cell lines derived from PC could be identified on the basis of exon 1 and 8 AR sequence variability. DU145 and BPH-1 had identical profiles of the three areas studied, but these cell lines are easily distinguished by their different phenotypic characteristics. PNT1A and 1B had identical genetic and similar phenotypic profiles, which is unsurprising given that they are subclones derived from the same parental line. Even so, these were separable on the basis of CK-19 immunostaining. Using a combination of geno- and phenotypic markers it was possible to derive a 'fingerprint' for each of the cell lines assessed, which will allow meaningful comparison between similar cell lines held in other laboratories.

Modulation of the malignant phenotype of human prostate cancer cells by N-(4-hydroxyphenyl)retinamide (4-HPR)

A long latent period of 20 to 30 years may be involved in the multistep process of carcinogenesis represented by prostatic intraepithelial neoplasia (PIN) in the prostate. It is, therefore, possible that progression to a malignant state could be blocked or reversed during this time. Retinoids not only have the ability to block steps in the process of carcinogenesis but they may also modulate or reverse some malignant characteristics of cancer cells. This study focuses on the ability of N-(4-hydroxyphenyl)-retinamide (4-HPR), a synthetic retinoid, to reverse malignant characteristics towards a normal phenotype, using the human prostate carcinoma cell line DU-145. These malignant characteristics include abnormal cell proliferation, intermediate filament expression, motility, invasion, and cell survival. Results show that 1 microM and 10 microM 4-HPR caused 31% and 96% inhibition of growth, while all-trains retinoic acid (ATRA) produced similar effects at 10 and 100 microM, making 4-HPR ten times more effective than ATRA. While DU-145 cells show strong immunostaining for vimentin, treatment with 1 microM 4-HPR for eight days caused a marked decrease in vimentin staining. This was accompanied by a change from an elongated to an epithelial cell morphology. Densitometric analysis of Western blots for vimentin showed a 53% decrease in vimentin expression in 1 microM 4-HPR treated cells. Concomitant with the decrease in vimentin expression, cell motility and invasive ability also decreased by 32% and 52%, respectively. Growth inhibition was accompanied by DNA fragmentation and apoptosis. Exposure of cells to 1 microM 4-HPR caused a marked upregulation of nuclear retinoid receptors RARalpha and a detectable expression of RARgamma. These results suggest that inhibition of growth and vimentin expression, and induction of apoptosis by 4-HPR in prostate cancer cells may occur via a receptor-mediated mechanism involving transrepression of AP-1 by retinoid receptors. We propose that vimentin may serve as a useful intermediate marker for early detection of prostate cancer in biopsy specimens and that 4-HPR may be effective in blocking several steps in prostate carcinogenesis as well as the progression of PIN to invasive carcinoma.

New concepts in tissue specificity for prostate cancer and benign prostatic hyperplasia

Of the hundreds of species of mammals, all of which have prostate glands, only humans and dogs are known to suffer from benign prostatic hyperplasia (BPH) and prostate carcinoma. In humans, prostate carcinoma is common, yet carcinomas of other sex accessory tissues are rare. In addition, different anatomic regions within the prostate gland have very different rates of BPH and carcinoma. In this article, we explore ideas and potential mechanisms relating to these paradoxical findings that may help explain the species, organ, and zone specificity of BPH and prostate cancer. We present an evolutionary argument that attempts to relate a high-fat diet, with its potential for generating oxidative DNA damage, to the species selectivity of prostate cancer. In addition, we outline an argument based on our preliminary studies indicating that chronic inflammation and the associated increase in cell turnover in the setting of increased oxidative stress may help to account for the organ selectivity of genitourinary carcinomas.

Stem cell features of benign and malignant prostate epithelial cells

PURPOSE

We present a new hypothesis suggesting that the different malignant potential of benign prostatic hyperplasia (BPH) and high grade prostatic intraepithelial neoplasia may be explained by distinct alterations in stem cell-like properties.

MATERIALS AND METHODS

We used our results and the recent literature to develop this hypothesis in the context of an updated prostate stem cell model.

RESULTS

While high grade prostatic intraepithelial neoplasia is a likely precursor lesion to many prostatic adenocarcinomas, BPH rarely if ever progresses directly to carcinoma. Prostate epithelium contains basal and secretory compartments. Secretory cells appear to differentiate from basal cells. Thus, prostatic stem cells most likely reside in the basal compartment. In BPH there is a slight increase in epithelial proliferation, yet most replicating epithelial cells within BPH maintain their normal restriction to the basal compartment. In high grade prostatic intraepithelial neoplasia there is a marked increase in cell proliferation. In contrast to BPH, the majority of proliferating cells in high grade prostatic intraepithelial neoplasia reside in the secretory compartment. The biological significance of this topographic infidelity of proliferation in high grade prostatic intraepithelial neoplasia remains unclear but may relate mechanistically to down regulation of the cyclin dependent kinase inhibitor, p27kip1. Normal basal cells express GSTP1, an enzyme that inactivates reactive electrophiles and organic hydroperoxides, and that may protect cells from deoxyribonucleic acid damaging agents. In contrast, normal secretory cells and high grade prostatic intraepithelial neoplasia cells do not express this enzyme.

CONCLUSIONS

We propose that topographic infidelity of proliferation produces a population of secretory cells replicating in the absence of key genome protective mechanisms, thus setting the stage for an accumulation of genomic alterations and instability in high grade prostatic intraepithelial neoplasia. This action occurs along with activation of telomerase, resulting in an immortal clone capable of developing into invasive carcinoma. The model predicts that genome protection remains intact in BPH, minimizing its malignant potential.