Abstract P5-18-01: Risk of contralateral breast cancer (CBC) in women with ductal carcinoma in situ (DCIS) with and without and synchronous lobular carcinoma in situ (LCIS)

Background: LCIS is considered a risk factor for bilateral breast cancer, but the effect of LCIS diagnosed concurrently with DCIS is not known. We sought to compare CBC and ipsilateral breast tumor recurrence (IBTR) rates in women with DCIS with and without synchronous LCIS treated with breast conserving surgery (BCS).

Methods: A prospectively maintained database of DCIS patients undergoing BCS from 2000-2011 was used to identify women with a contralateral breast at risk. Patients with synchronous ipsilateral LCIS found at core needle biopsy or surgical excision were included in the “DCIS + LCIS” group; those with contralateral or bilateral LCIS were excluded. Associations of patient, tumor, and treatment factors with CBC and IBTR were evaluated using logistic regression.

Results: Of the 1888 patients identified, 1475 (78%) had DCIS only and 413 (22%) had DCIS with synchronous LCIS. Median follow-up was 7.5 years (range 0-17 years). 305 patients had a subsequent breast event; 216 IBTR and 89 CBC.

The 5 and 10-year cumulative incidence of IBTR was similar in both groups: 6.3% and 14.4% for DCIS only, compared with 5.9% and 14.0% for DCIS + LCIS (p = 0.94), respectively. The 5 and 10-year cumulative incidence of CBC was significantly greater in the DCIS + LCIS group: 5.7% and 10.0%, compared with 2.4% and 5.0% for DCIS only (p < 0.001).

Table 1 summarizes uni-and multi-variable analyses of risk factors associated with CBC and IBTR among women with DCIS treated with BCS. After adjustment for other factors, CBC risk was more than 2-fold higher in the DCIS + LCIS group compared with the DCIS only group (HR 2.37, 95% CI 1.54-3.65, p < 0.001). There was no difference in IBTR risk based on presence of synchronous LCIS. Younger age and receipt of endocrine therapy were significantly associated with decreased risk of CBC.

Table 1:Risk factors associated with CBC and IBTR in patients with DCIS treated with BCS  Univariate Analysis Multivariate Analysis  Hazard Ratio (95% CI) Hazard Ratio (95% CI)  CBC IBTR CBC IBTRAge (continuous)1.02 (1.01-1.04) *0.99 (0.98-1.0)1.02 (1.0-1.04) *0.99 (0.97-1.0) *Presentation    Radiologic1111Clinical0.36 (0.11-1.14)1.56 (1.05-2.3) *0.41 (0.13-1.31)1.67 (1.12-2.47) *Family history    Yes1.32 (0.87-2.01)1.0 (0.76-1.32)1.33 (0.87-2.03)1.03 (0.78-1.35)Grade    Low1111Intermediate/high1.83 (1.0-3.37)1.32 (0.93-1.88)1.74 (0.92-3.29)1.62 (1.11-2.35) *Radiation    Yes1.16 (0.75-1.8)0.7 (0.54-0.92) *1.14 (0.71-1.82)0.64 (0.48-0.86) *Endocrine Therapy    Yes0.43 (0.23-0.81) *0.51 (0.35-0.74) *0.42 (0.22-0.8) *0.53 (0.36-0.77) *DCIS group    DCIS only1111DCIS + LCIS2.28 (1.49-3.5) *0.99 (0.71-1.36)2.37 (1.54-3.65) *0.99 (0.71-1.37)* p < 0.05

Conclusions: LCIS diagnosed concurrently with DCIS is not associated with IBTR, but increases the risk of CBC two-fold. Endocrine therapy should be considered both for the index DCIS and for prevention of subsequent CBC.

Citation Format: Miller ME, Muhsen S, Zabor EC, Flynn J, Olcese C, Giri D, Van Zee KJ, Pilewskie M. Risk of contralateral breast cancer (CBC) in women with ductal carcinoma in situ (DCIS) with and without and synchronous lobular carcinoma in situ (LCIS) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-01.

Unprecedented anticancer activities of organorhenium sulfonato and carboxylato complexes against hormone-dependent MCF-7 and hormone-independent triple-negative MDA-MB-231 breast cancer cells

Cisplatin and other metal-based drugs often display side effects and tumor resistance after prolonged use. Because rhenium-based anticancer complexes are often less toxic, a novel series of organorhenium complexes were synthesized of the types: XRe(CO)₃Z (X = α-diimines and Z = p-toluenesulfonate, 1-naphthalenesulfonate, 2-naphthalenesulfonate, picolinate, nicotinate, aspirinate, naproxenate, flufenamate, ibuprofenate, mefenamate, tolfenamate, N-acetyl-tryptophanate), and their biological properties were examined. Specifically, in hormone-dependent MCF-7 and hormone-independent triple-negative MDA-MB-231 breast cancer cells, the p-toluenesulfonato, 1-naphthalenesulfonato, 2-naphthalenesulfonato, picolinato, nicotinato, acetylsalicylato, flufenamato, ibuprofenato, mefenamato, and N-acetyl-tryptophanato complexes were found to be far more potent than conventional drug cisplatin. DNA-binding studies were performed in each case via UV-Vis titrations, cyclic voltammetry, gel electrophoresis, and viscosity, which suggest DNA partial intercalation interaction, and the structure-activity relationship studies suggest that the anticancer activities increase with the increasing lipophilicities of the compounds, roughly consistent with their DNA-binding activities.

Molecular Combing of λ-DNA using Self-Propelled Water Droplets on Wettability Gradient Surfaces

Surface wettability gradients were used to elongate and align double stranded λ-DNA. Gradients were prepared by vapor phase deposition of octyltrichlorosilane (C8-silane) and fluorinated octyltrichlorosilane (F-silane) precursors. Gradient formation was confirmed by water contact angle and ellipsometric film thickness measurements. Placement of a droplet of aqueous DNA solution on the hydrophobic end of each gradient led to spontaneous motion of the droplet toward the hydrophilic end and deposition of the DNA. Fluorescence imaging of surface-adsorbed YOYO-1 labeled DNA molecules revealed that they are elongated and aligned perpendicular to the droplet-surface contact line at all positions along the gradient, consistent with a dominant role played by surface tension forces in elongating the DNA. The density of adsorbed DNA was found to be greatest on the C8-silane gradient at its hydrophobic end. DNA density decreased toward the hydrophilic end, while the length of the elongated DNA was less dependent on position. The elongation of DNA molecules by spontaneous droplet motion on chemical gradient surfaces has possible applications in DNA barcoding and studies of DNA-protein interactions.

Cooperative Effects in Aligned and Opposed Multicomponent Charge Gradients Containing Strongly Acidic, Weakly Acidic, and Basic Functional Groups

Bifunctionalized surface charge gradients in which the individual component gradients either align with or oppose each other have been prepared. The multicomponent gradients contain strongly acidic, weakly acidic, and basic functionalities that cooperatively interact to define surface wettability, nanoparticle binding, and surface charge. The two-step process for gradient formation begins by modifying a siloxane coated silicon wafer in a spatially dependent fashion first with an aminoalkoxysilane and then with a mercapto-functionalized alkoxysilane. Immersion in hydrogen peroxide leads to oxidation of the surface immobilized sulfhydryl groups and subsequent protonation of the surface immobilized amines. Very different surface chemistries were obtained from gradients that either align with or oppose each other. X-ray photoelectron spectroscopy (XPS) data show that the degree of amine group protonation depends on the local concentration of sulfonate groups, which form ion pairs with the resulting ammonium ions. Contact angle measurements show that these ion pairs greatly enhance the wettability of the gradient surface. Finally, studies of colloidal gold binding show that the presence of both amine and thiol moieties enhance colloid binding, which is also influenced by surface charge. Cooperativity is also revealed in the distribution of charges on uniform samples used as models of the gradient surfaces, as evaluated via zeta potential measurements. Most significantly, the net surface charge and how it changes with distance and solution pH strongly depend on whether the gradients in amine and thiol align or oppose each other. The aligned multicomponent gradients show the most interesting behavior in that there appears to be a point at pH ∼ 6.5 where surface charge remains constant with distance. Setting the pH above or below this transition point leads to changes in the direction of charge variation along the length of the substrate.

Multiple endocrine neoplasia syndromes 1 and 2: manifestations and management in childhood and adolescence

The identification of the genetic causes of the multiple endocrine neoplasia (MEN) syndromes 1 and 2, and associated genotype-phenotype relationships, has revolutionised the clinical care of affected patients. A genetic diagnosis can be made during infancy and careful clinical surveillance, coupled with early intervention, has the potential to improve both morbidity and mortality. These developments have seen the management of patients with MEN move into the arena of paediatric medicine. In this review article, we consider the genetic causes of MEN together with the clinical manifestations and management of these syndromes.

Scientific and Regulatory Policy Committee (SRPC) Points to Consider: Histopathology Evaluation of the Pubertal Development and Thyroid Function Assay (OPPTS 890.1450, OPPTS 890.1500) in Rats to Screen for Endocrine Disruptors

The U.S. Environmental Protection Agency Endocrine Disruptor Screening Program (EDSP) is a multitiered approach to determine the potential for environmental chemicals to alter the endocrine system. The Pubertal Development and Thyroid Function in Intact Juvenile/Peripubertal Female and Male Rats (OPPTS 890.1450, 890.1500) are 2 of the 9 EDSP tier 1 test Guidelines, which assess upstream mechanistic pathways along with downstream morphological end points including histological evaluation of the kidneys, thyroid, and select male/female reproductive tissues (ovaries, uterus, testes, and epididymides). These assays are part of a battery of in vivo and in vitro screens used for initial detection of test article endocrine activity. In this Points to Consider article, we describe tissue processing, evaluation, and nomenclature to aid in standardization of assay results across laboratories. Pubertal assay end points addressed include organ weights, estrous cyclicity, clinical pathology, hormonal assays, and histological evaluation. Potential treatment-related findings that may indicate endocrine disruption are reviewed. Additional tissues that may be useful in assessment of endocrine disruption (vagina, mammary glands, and liver) are discussed. This Points to Consider article is intended to provide information for evaluating peripubertal tissues within the context of individual assay end points, the overall pubertal assay, and tier I assays of the EDSP program.

Abstract 5146: The histone demethylase KDM2A is a new promoter of tumorigenesis, drug target and negative prognostic biomarker for non-small cell lung cancer

The molecular etiology of non-small cell lung cancer (NSCLC) is heterogeneous and mostly dominated by alterations in kinase signaling pathways (i.e. KRAS, EGFR, EML4-ALK, PI3K, MEK1). Epigenetic modifiers, including histone methyltransferase and demethylases, have emerged as important regulators of oncogenic phenotypes in a small but growing number of tumor types, but the pathogenic role of histone methylation modifiers in NSCLC is largely unknown. We found that the histone H3 lysine 36 (H3K36) demethylase KDM2A is a novel oncogenic promoter of NSCLC. In our analysis KDM2A is frequently overexpressed in NSCLC cell lines and patient samples (≥14% in NSCLC tumors), and high expression levels of KDM2A correlate with poor prognosis in three independent patient populations from the USA and Asia.

KDM2A knockdown by RNAi in KDM2A overexpressing cell lines inhibits proliferation and invasiveness of NSCLC cells in vitro and in three mouse xenograft models (subcutaneous, intravenous, and orthotopic models). Consistently, KDM2A overexpression promotes these cellular characteristics in NSCLC cell lines with low endogenous KDM2A levels. Rescue experiments using KDM2A-depleted cells showed that ectopic expression of wild-type KDM2A, but not its catalytic mutant mKDM2A, restored proliferation and invasion. These results indicate that the effect of KDM2A on oncogenic phenotypes is largely dependent on its catalytic activity and validate it as drug target for development of small molecule inhibitors. Mechanistically, we uncovered, that KDM2A activates the MAPK signaling pathway (ERK1/2) by transcriptionally repressing the MAPK phosphatase DUSP3.

In summary, these novel findings indicate that KDM2A overexpression promotes NSCLC tumor growth and invasion. Our results provide new insights into how the dysregulation of an epigenetic enzyme can be coupled to activation of the ERK1/2 signaling pathway to promote NSCLC tumorigenesis and suggest that KDM2A is a promising anti-cancer therapeutic drug target for KDM2A-overexpressing NSCLC patients.

Citation Format: Klaus W. Wagner, Hunain Alam, Shilpa S. Dhar, Uma Giri, Na Li, Yongkun Wei, Tina Cascone, Dipak Giri, Jae-Hwan Kim, Yuanqing Ye, Asha Multani, Chia-Hsin Chan, Baruch Erez, Babita Saigal, Hui-Kuan Lin, Xifeng Wu, Mien-Chie Hung, John Heymach, MinGyu Lee. The histone demethylase KDM2A is a new promoter of tumorigenesis, drug target and negative prognostic biomarker for non-small cell lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5146. doi:10.1158/1538-7445.AM2014-5146

RECK controls breast cancer metastasis by modulating a convergent, STAT3-dependent neoangiogenic switch

Metastasis is the primary cause of cancer-related death in oncology patients. A comprehensive understanding of the molecular mechanisms that cancer cells usurp to promote metastatic dissemination is critical for the development and implementation of novel diagnostic and treatment strategies. Here we show that the membrane protein RECK (Reversion-inducing cysteine-rich protein with kazal motifs) controls breast cancer metastasis by modulating a novel, non-canonical and convergent signal transducer and activator of transcription factor 3 (STAT3)-dependent angiogenic program. Neoangiogenesis and STAT3 hyperactivation are known to be fundamentally important for metastasis, but the root molecular initiators of these phenotypes are poorly understood. Our study identifies loss of RECK as a critical and previously unknown trigger for these hallmarks of metastasis. Using multiple xenograft mouse models, we comprehensively show that RECK inhibits metastasis, concomitant with a suppression of neoangiogenesis at secondary sites, while leaving primary tumor growth unaffected. Further, with functional genomics and biochemical dissection we demonstrate that RECK controls this angiogenic rheostat through a novel complex with cell surface receptors to regulate STAT3 activation, cytokine signaling, and the induction of both vascular endothelial growth factor and urokinase plasminogen activator. In accordance with these findings, inhibition of STAT3 can rescue this phenotype both in vitro and in vivo. Taken together, our study uncovers, for the first time, that RECK is a novel regulator of multiple well-established and robust mediators of metastasis; thus, RECK is a keystone protein that may be exploited in a clinical setting to target metastatic disease from multiple angles.

Statistical mechanics of DNA rupture: theory and simulations

We study the effects of the shear force on the rupture mechanism on a double stranded DNA. Motivated by recent experiments, we perform the atomistic simulations with explicit solvent to obtain the distributions of extension in hydrogen and covalent bonds below the rupture force. We obtain a significant difference between the atomistic simulations and the existing results in the literature based on the coarse-grained models (theory and simulations). We discuss the possible reasons and improve the coarse-grained model by incorporating the consequences of semi-microscopic details of the nucleotides in its description. The distributions obtained by the modified model (simulations and theoretical) are qualitatively similar to the one obtained using atomistic simulations.

Anticancer Properties of Novel Rhenium Pentylcarbanato Compounds against MDA-MB-468(HTB-132) Triple Node Negative Human Breast Cancer Cell Lines

AIM

To study the efficacy of novel rhenium compounds to treat triple node negative breast cancer.

PLACE AND DURATION

Six (6) novel rhenium pentycarbanato compounds (PC1-6) were synthesized and triple node negative breast cancer cell lines HTB-132 and Balb/c mouse kidney cell lines were treated with each of them for 48 hours. The results were analyzed by a common trypan blue cell death assay system and statistically analyzed.

PLACE AND DURATION

The compounds were synthesized, analyzed and evaluated at the Department of Chemistryof Morgan State University, Baltimore, Maryland and the Pharmaceutical Sciences Department of Elizabeth City State University campus of the University of North Carolina system.

METHODOLOGY

The novel rhenium compounds were synthesized from one-pot reactions of Re₂(CO)₁₀ with the corresponding α-diimine ligands in 1-pentanol.The compounds were characterized spectroscopically. The cell lines were cultured by standard cell culture procedure and treated with each of the six compounds in DMSO for 48 hours with a negative control and a DMSO vehicular control along with a cisplatin positive control.The cytotoxicity was evaluated by standard trypan blue assay and the results were statistically analyzed.

RESULTS

The trypan blueassay reveals that these compounds have significant cytotoxicity against MDA-MB-468 (HTB-132) triple node negative breast cancer cell lines and are less nephrotoxic than cisplatin.

CONCLUSION

The novel rhenium compounds PC 1-6 can potentially find applications in the treatment of highly malignant triple node negative breast cancer.

The effect of novel rhenium compounds on lymphosarcoma, PC-3 prostate and myeloid leukemia cancer cell lines and an investigation on the DNA binding properties of one of these compounds through electronic spectroscopy

Despite the tremendous success of cisplatin and other platinum-based anticancer drugs, severe toxicity and resistance to tumors limit their applications. It is believed that the coordination (formation of covalent bond) of the metal (platinum) to the nitrogen bases of DNA cause the ruptures of the cancer as well as normal cells. A search for anticancer drugs with different modes of action resulted in the synthesis of variety of novel compounds. Many of them are in clinical trials now. Recently we synthesized a series of novel rhenium pentylcarbonato compounds (PC1-PC6). The rhenium atom in each compound is coordinated (bonded) to a planar polypyridyl aromatic ligand, thereby forcing each compound to intercalate between the DNA bases. We have investigated the DNA binding properties of one of the PC-series of compounds (PC6) using electronic spectroscopy. The UV absorption titration of PC6 with DNA shows hypochromic effect with concomitant bathochromic shift of the charge transfer band at 290 nm. These results suggest that the compound PC6 binds to DNA through intercalation. It is therefore likely that the other PC-series of compounds will behave in a similar manner. Thus it is expected that these compounds will exhibit negligible or no side effect. We have observed that the PC-series of compounds are strong cytotoxic agents against lymphosarcoma (average GI50 ≈ 2±2.6 µM), PC-3 prostate (average GI50 ≈ 3±2.8 µM) and myeloid leukemia (average GI50 ≈ 3±2.8 µM) cancer cell lines. The average GI50 values of the PC-series of compounds are 2-3 less than the corresponding GI50 values of cisplatin. Also each of the PC-series of compounds exhibits less toxicity than cisplatin in the glomerular mesangial cells.

KDM2A promotes lung tumorigenesis by epigenetically enhancing ERK1/2 signaling

Epigenetic dysregulation has emerged as a major contributor to tumorigenesis. Histone methylation is a well-established mechanism of epigenetic regulation that is dynamically modulated by histone methyltransferases and demethylases. The pathogenic role of histone methylation modifiers in non-small cell lung cancer (NSCLC), which is the leading cause of cancer deaths worldwide, remains largely unknown. Here, we found that the histone H3 lysine 36 (H3K36) demethylase KDM2A (also called FBXL11 and JHDM1A) is frequently overexpressed in NSCLC tumors and cell lines. KDM2A and its catalytic activity were required for in vitro proliferation and invasion of KDM2A-overexpressing NSCLC cells. KDM2A overexpression in NSCLC cells with low KDM2A levels increased cell proliferation and invasiveness. KDM2A knockdown abrogated tumor growth and invasive abilities of NSCLC cells in mouse xenograft models. We identified dual-specificity phosphatase 3 (DUSP3) as a key KDM2A target gene and found that DUSP3 dephosphorylates ERK1/2 in NSCLC cells. KDM2A activated ERK1/2 through epigenetic repression of DUSP3 expression via demethylation of dimethylated H3K36 at the DUSP3 locus. High KDM2A levels correlated with poor prognosis in NSCLC patients. These findings uncover an unexpected role for a histone methylation modifier in activating ERK1/2 in lung tumorigenesis and metastasis, suggesting that KDM2A may be a promising therapeutic target in NSCLC.

Single polymer gating of channels under a solvent gradient

We study the effect of a gradient of solvent quality on the coil-globule transition for a polymer in a narrow pore. A simple self-attracting, self-avoiding walk model of a polymer in solution shows that the variation in the strength of the interaction across the pore leads the system to go from one regime (good solvent) to the other (poor solvent) across the channel. This may be thought to be analogous to thermophoresis, where the polymer goes from the hot region to the cold region under the temperature gradient. The behavior of short chains is studied using exact enumeration while the behavior of long chains is studied using transfer matrix techniques. The distribution of the monomer density across the layer suggests that a gatelike effect can be created, with potential applications as a sensor.

PD10-02: Sporadic Breast Cancers Show Defects in the BRCA1-BRCA2 Pathway of Homologous Recombination in All Biomarker-Defined Sub-Types of Breast Cancer

Background: Mutation carriers of BRCA1 and BRCA2 are well known to develop early onset breast cancer, with loss of the second allele occurring in the development of the tumor. However, by array comparative genomic hybridization (aCGH) studies, some sporadic breast cancers have a similar “genetic landscape” as BRCA-mutation carriers, showing large losses and gains across the genome. We have now identified that DNA repair defects involving the BRCA1-BRCA2 pathway can occur in the absence of mutations in either gene and in the absence of a deficiency in either protein.

Methods: Fresh human breast cancer samples were irradiated, ex-vivo, to look for the ability to assemble RAD51 protein macrocomplexes or foci. Primary breast cancer specimens were obtained from consented patients with non-metastatic, invasive carcinomas following lumpectomy or mastectomy, without neoadjuvant cytotoxic or hormonal therapy. A single cell suspension was prepared from the tumor, with one half irradiated to 10Gy and the other half mock-treated. After 4h, cells were mounted, fixed on slides, and stained with anti-Rad51, anti-BRCA1, and anti-γH2AX antibodies. At least 200 nuclei were examined and scored using confocal microscopy. A failure to induce RAD51 nuclear foci by 2-fold after ionizing radiation was designated as defective in homologous recombination (HR).

Results: For the 71 patient samples analyzed, we have 14 triple-negative tumors, of which 6 are HR-defective (42.8%); for Her2-amplified tumors, we have 6/19 (31.6%) that are HR-defective and for ER+ tumors 6/38 (15.8%). The overall incidence of HR-defective tumors is 18/71 (25.3%), which is substantially higher than we would have expected.

Abstract P4-06-07: PI3K Mutations Are More Common in Low Grade DCIS

Background: DCIS is a non-obligate precursor to invasive breast cancer yet it remains difficult to predict which lesions will progress or over what time interval. Factors associated with a higher risk of progression include high histologic grade and HER2 amplification. HER2 signaling via the PI3K pathway is associated with accelerated invasiveness in laboratory models and mutations in the helical domain of PI3K have been associated with a worse prognosis in invasive cancer. We hypothesized that PI3K pathway mutations are associated with higher risk of progression in DCIS and therefore would be more common in high grade DCIS.

Methods: 195 cases of pure DCIS were identified from the MSKCC breast service database (1999-2003). All cases were reviewed by a single pathologist to assign histologic grade. Sections were obtained from archived formalin-fixed paraffin embedded (FFPE) blocks for manual microdissection to isolate pure DCIS lesions for DNA extraction. Multiplex array (Sequenom®) genotyping for PIK3CA was performed on prePCR amplified DNA. Comparisons were made between high and low grade DCIS using Fisher's exact test.

Results: Among 195 pure DCIS cases, 89 were classified as high grade and 106 as low grade. Sequenom® analysis was informative in all cases. PIK3CA mutations were identified in 4/89 (4%) cases of high grade DCIS and in 24/106 (23%) cases of low grade DCIS (p=0.000). All 4 mutations in high grade DCIS were located in the kinase domain, whereas in low grade DCIS, 9/24 (37%) mutations were in the kinase domain (H1047R) and 15/24 (67%) mutations were in the helical domain (E542K, E545K, N345K).

Conclusion: PI3K mutations were relatively uncommon in pure high grade DCIS as compared to low grade DCIS. PI3K mutations in low grade DCIS were observed in both the kinase and helical domain. These findings support the hypothesis that breast tumorigenesis differs by grade and PI3K mutations may be more prominent in low grade carcinogenesis. The significance of helical domain mutations in low grade lesions requires further investigation.

Dissociation of the E-Cadherin-Catenin-Complex (CCC) Is an Early and Progressive Event in Lobular Neoplasia

Recent data suggests that some lobular carcinoma in situ (LCIS) lesions may behave as precursors to invasive lobular carcinoma (ILC). Loss of E-cadherin (E-CD) mediated cell adhesion is characteristic of both LCIS and ILC and is reflected in the dis-cohesive appearance of the individual cells. Subsequent dissociation of the intracellular E-cadherin-catenin-complex (CCC) facilitates tumor progression, invasion and migration. Whether disruption of the CCC plays a role in the progression of select LCIS lesions to ILC remains unclear. The aim of this study was to evaluate the relation between loss of E-CD and dissociation of the CCC in pure LCIS and LCIS with concurrent ILC (LCIS w/ILC). Methods Thirty patients undergoing mastectomy for LCIS alone or LCIS w/ ILC were prospectively enrolled to an IRB-approved protocol. FFPE blocks were retrieved and sections prepared for IHC. 18 cases had LCIS w/ ILC, 12 cases had pure-LCIS. IHC was performed for ER, PR, E-CD, N-cadherin (N-CD), and α-, β- and phospho-β-catenin. ER/PR positivity was scored as any nuclear staining, and E-CD and N-CD by any membranous staining. a- and β-catenin expression was scored by site (membranous/cytoplasmic/nuclear) of staining compared to normal. Dissociation of the CCC was defined by loss of membranous α- and β-catenin expression.Results Median age at surgery was 51yrs (range 40-79); patients with pure LCIS were younger than those with LCIS w/ ILC (median 48yrs vs 57yrs, p=.0002). Among 18 cases of LCIS w/ ILC, the median tumor size was 2cm (range 1.4-5.7), 9 patients had N1 disease and 1 had M1 disease. All pure LCIS, LCIS w/ ILC and ILC lesions were ER/PR positive and E-CD negative. N-CD expression was also absent in all pure LCIS, LCIS w/ ILC and ILC lesions. Normal α-catenin membranous expression was confirmed in all normal epithelial cells but decreased with the transition from in-situ to invasive disease: pure-LCIS lesions 83%; LCIS w/ ILC 28%; ILC 0%. Loss of membranous α-catenin expression was accompanied by cytoplasmic α-catenin expression in all lesions. A similar trend of decreasing membranous staining from in-situ to invasive disease was observed for β-catenin, however in contrast to α-catenin, cytoplasmic β-catenin expression decreased from 67% in pure LCIS to 11% in LCIS w/ ILC and 6% in ILC. Active β-catenin (nuclear staining) was not seen in pure LCIS lesions and was only present in one case of LCIS w/ ILC. Inactive (phospho) β-catenin expression was present in all lesions.Conclusion Loss of E-CD expression is an early event in lobular neoplasia however subsequent dissociation of the intracellular CCC a a ppears to be a progressive process with complete dissociation occurring only in invasive lesions. This finding suggests that complete disruption of the CCC may be required to facilitate maintenance of the invasive phenotype; however, the absence of N-CD expression and predominance of inactive β-catenin in both in situ and invasive lesions suggests that alternate mechanisms are also required to mediate the pro-invasive effects of CCC dissociation. Further studies into the mechanisms of CCC dissociation and downstream events in lobular carcinoma are needed to define the role of this process in the transition from in-situ to invasive disease.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6149.

Role of pulling direction in understanding the energy landscape of proteins

Single-molecule force spectroscopy provide details of the underlying energy surfaces of proteins which are essential to the understanding of their unfolding process. Recently, it has been observed experimentally that by pulling proteins in different directions relative to their secondary structure, one can gain a better understanding of the shape of the energy landscape. We consider simple lattice models which are anisotropic in nature to study the response of a force in unfolding of a polymer. Our analytical solution of the model, supported by extensive numerical calculations, reveal that the force temperature diagrams are very different depending on the direction of the applied force. We find that either unzipping or shearing kind transitions dominate the dynamics of the unfolding process depending solely on the direction of the applied force.

Efficacy of spheroplastic and cell-wall competent vaccines for Mycobacterium avium subsp. paratuberculosis in experimentally-challenged baby goats

A Mycobacterium avium subspecies paratuberculosis (MAP) vaccine that reduced the incidence of clinical disease or reduced fecal shedding of MAP would aid control of Johne's disease (JD). The objective of the present study was to evaluate the efficacy of four MAP vaccine combinations, including cell-wall competent (CWC) alum adjuvant, CWC-QS21 adjuvant, cell-wall deficient (CWD) alum adjuvant and CWD-QS21 adjuvant vaccines. Eighty baby goats were vaccinated at 1 and 4 weeks of age with one of these vaccines or a sham control vaccine consisting of alum adjuvant. Kids were challenged orally with approximately 6.0x10(9) organisms in four divided doses of 1.5x10(9) organisms using a goat isolate of MAP. Vaccinated challenged and challenged control groups had 10 and 6 kids per group, respectively. Half of the kids within each group were necropsied at either 6 or 9 months post-challenge. Gross and microscopic lesions and relative number of acid-fast bacilli were evaluated and scored at necropsy. Results indicated all challenged kids had some lesions compatible with JD suggesting none of the vaccines prevented infection. Three vaccines (CWC-alum, CWC-QS21 and CWD-QS21) reduced lesion scores by 46-51% at 9 months. CWD-alum vaccine resulted in a more severe (+33.5%) lesion score than sham-vaccinated challenged control. Lesion scores were greater at 9 months than at 6 months post-challenge in the sham-vaccinated challenged group and CWD-alum vaccinated group, while lesion scores were generally stable with remaining vaccines. Mean fecal CFU/g were significantly different across time from challenge to 9-month necropsy (p=0.043) and the CWC-QS21 vaccine group had a marked reduction in fecal CFU/g at all time points post-challenge. A reduction in MAP CFU/g was also detected in necropsy tissues from kids given the CWC-alum, CWC-QS21 and CWD-QS21 vaccines, and increased CFU/g were detected in tissues from kids given the CWD-alum vaccine. Immunological tests evaluated included, humoral response evaluation by AGID, ELISA and Western blot, and cell mediated response by comparative PPD skin testing (M. avium, Old Johnin, M. bovis and Lot 2 Johnin PPD's), and production of MAP induced gamma-interferon. Vaccination also resulted in false-positive PPD skin test reactions for M. avium PPD, Old Johnin PPD and gamma-interferon tests. When a 2-mm cutoff above normal skin thickness was used to define positive skin test reactions, false-positive reactions for M. bovis were detected in only 2 of 32 kids given a vaccine with QS21 adjuvant.

Prostate-specific antitumor activity by probasin promoter-directed p202 expression

p202, an interferon (IFN) inducible protein, arrests cell cycle at G1 phase leading to cell growth retardation. We previously showed that ectopic expression of p202 in human prostate cancer cells renders growth inhibition and suppression of transformation phenotype in vitro. In this report, we showed that prostate cancer cells with stable expression of p202 were less tumorigenic than the parental cells. The antitumor activity of p202 was further demonstrated by an ex vivo treatment of prostate cancer cells with p202 expression vector that showed significant tumor suppression in mouse xenograft model. Importantly, to achieve a prostate-specific antitumor effect by p202, we employed a prostate-specific probasin (ARR2PB) gene promoter to direct p202 expression (ARR2PB-p202) in an androgen receptor (AR)-positive manner. The ARR2PB-p202/liposome complex was systemically administered into mice bearing orthotopic AR-positive prostate tumors. We showed that parenteral administration of an ARR2PB-p202/liposome preparation led to prostate-specific p202 expression and tumor suppression in orthotopic prostate cancer xenograft model. Furthermore, with DNA array technique, we showed that the expression of p202 was accompanied by downregulation of G2/M phase cell-cycle regulators, cyclin B, and p55cdc. Together, our results suggest that p202 suppresses prostate tumor growth, and that a prostate-specific antitumor effect can be achieved by systemic administration of liposome-mediated delivery of ARR2PB-p202.

Cellular senescence in the pathogenesis of benign prostatic hyperplasia

BACKGROUND

Senescent cells accumulate in tissues with age and show changes in protein expression that may influence the function of adjacent cells and contribute to the development of tissue pathologies associated with aging. Benign prostatic hyperplasia (BPH) is an extremely common disease of older men characterized by increased growth of prostatic epithelial and stromal cells. In BPH, there is an increased expression of Il-1alpha by prostatic epithelial cells that results in elevated expression of FGF7 by stromal cells, which in turn is strongly correlated with epithelial proliferation.

METHODS

Human BPH tissue and primary cultures of prostatic epithelial cells were analyzed by histochemical and quantitative assays for senescence-associated beta galactosidase (SA-beta gal). Il-1alpha expression was localized by immunohistochemistry and Il-1alpha tissue content determined by enzyme-linked immunoabsorption assay.

RESULTS

Expression of Il-1alpha is significantly increased in vitro when cultured prostatic epithelial cells undergo senescence. In BPH tissue a substantial population of epithelial cells express senescence-associated beta galactosidase (SA-beta gal), a marker of cellular senescence. By quantitative assay, SA-beta gal activity is correlated with both tissue levels of Il-1alpha and the severity of BPH.

CONCLUSIONS

One mechanism driving BPH in older men is the accumulation of senescent epithelial cells expressing Il-1alpha, which in turn increases FGF7 secretion and proliferation of non-senescent epithelial cells. Thus there is a mechanistic linkage between cellular senescence and one of the most common pathologies of older men.

Role of fibroblast growth factor receptor signaling in prostate cancer cell survival

BACKGROUND

Expression of fibroblast growth factors (FGFs) is increased in a substantial fraction of human prostate cancers in vivo and in prostate cancer cell lines. Altered FGF signaling can potentially have a variety of effects, including stimulating cell proliferation and inhibiting cell death. To determine the biologic significance of altered FGF signaling in human prostate cancer, we disrupted signaling by expression of a dominant-negative (DN) FGF receptor in prostate cancer cell lines.

METHODS

PC-3, LNCaP, and DU145 prostate cancer cells were stably transfected with DN FGFR constructs, and LNCaP and DU145 cells were infected with a recombinant adenovirus expressing DN FGFR-1. The effect of DN FGFR-1 expression was assessed by colony-formation assays, cell proliferation assays, flow cytometry, and cytogenetic analysis. Key regulators involved in the G(2)-to-M cell cycle transition were assessed by western blotting to examine cyclin B1 expression and by in vitro kinase assay to assess cdc2 kinase activity.

RESULTS

Stable transfection of the DN FGFR-1 construct inhibited colony formation by more than 99% in all three cell lines. Infection of LNCaP and DU145 prostate cancer cells with adenovirus expressing DN FGFR-1 led to extensive cell death within 48 hours. Flow cytometry and cytogenetic analysis revealed that the DN FGFR-1 receptor led to arrest in the G(2) phase of the cell cycle before cell death. Cyclin B1 accumulated in DN FGFR-1-infected LNCaP cells, but cdc2 kinase activity was decreased.

CONCLUSIONS

These findings reveal an unexpected dependence of prostate cancer cells on FGF receptor signal transduction to traverse the G(2)/M checkpoint. The mechanism for the G(2) arrest is not clear. Our results raise the possibility that FGF-signaling antagonists might enhance the cell death induced by other prostate cancer therapies.

Interleukin-6 is an autocrine growth factor in human prostate cancer

Prostate cancer is the most common cancer in American men and the second leading cause of cancer deaths in this group. We have found that interleukin (IL)-6 protein concentrations are increased approximately 18-fold in clinically localized prostate cancers when compared to normal prostate tissue. Normal and neoplastic prostatic epithelial cells in culture, with the exception of LNCaP cells, secrete IL-6. Addition of exogenous IL-6 to primary epithelial cells in culture or the LNCaP prostate cancer cell line leads to phosphorylation of Stat-3 and increases in net cell proliferation. The concentration of IL-6 receptor is increased eightfold in the prostate cancer tissues and is increased in the cancer cells by immunohistochemistry. The increased expression of IL-6 receptor is correlated with increased proliferation of prostate cancer cells in vivo as assessed by Ki67 immunohistochemistry. These findings strongly support the hypothesis that IL-6 acts as a significant autocrine growth factor in vivo for primary, androgen-dependent prostate cancers.

Haploinsufficiency of the Pten tumor suppressor gene promotes prostate cancer progression

The PTEN gene encodes a lipid phosphatase that negatively regulates the phosphatidylinositol 3-kinase pathway and is inactivated in a wide variety of malignant neoplasms. High rates of loss of heterozygosity are observed at the 10q23.3 region containing the human PTEN gene in prostate cancer and other human malignancies, but the demonstrated rate of biallelic inactivation of the PTEN gene by mutation or homozygous deletion is significantly lower than the rate of loss of heterozygosity. The transgenic adenocarcinoma of mouse prostate model is a well characterized animal model of prostate cancer. Analysis of prostate cancer progression in transgenic adenocarcinoma of mouse prostate mice bred to Pten(+/-) heterozygous mice, coupled with analysis of the Pten gene and protein in the resulting tumors, reveals that haploinsufficiency of the Pten gene promotes the progression of prostate cancer in this model system. This observation provides a potential explanation for the discordance in rates of loss of heterozygosity at 10q23 and biallelic PTEN inactivation observed in prostate cancer and many human malignancies.

Interleukin-8 is a paracrine inducer of fibroblast growth factor 2, a stromal and epithelial growth factor in benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is an extremely common disease of older men in which there is benign overgrowth of the prostatic transition zone, leading to obstruction of urine outflow. Fibroblast growth factor (FGF) 2, a potent growth factor for prostatic stromal and epithelial cells, is increased twofold in BPH and its concentration is correlated with stromal proliferation in this condition. Immunohistochemistry of normal and hyperplastic prostate revealed that FGF2-expressing stromal cells were present in higher numbers near the epithelial acini, implying that epithelial cells may express a factor that induces FGF2 expression by stromal cells. Conditioned medium from primary cultures of prostatic epithelial cells was capable of inducing increased expression of FGF2 by primary stromal cultures. Blocking experiments with neutralizing anti-interleukin (IL)-8 antibodies and pretreatment with lipopolysaccharide, which down-regulates the IL-8 receptor, show that this inducing activity is because of the presence of IL-8 in the epithelial-conditioned medium. Analysis of normal prostatic peripheral zone and BPH tissue by enzyme-linked immunosorbent assay reveals that IL-8 is present at increased levels in hyperplastic prostate. Therefore IL-8 produced by prostatic epithelial cells can induce FGF2, a potent stromal and epithelial growth factor, and in this manner promote the abnormal proliferation of the prostatic transition zone that is critical in the pathogenesis of BPH.

Alternative splicing of fibroblast growth factor receptors in human prostate cancer

BACKGROUND

Fibroblast growth factors (FGFs) are known to play an important role in the growth of normal prostatic epithelial cells and may promote proliferation of neoplastic prostatic epithelial cells via autocrine or paracrine mechanisms. The affinity of FGFs for FGF receptors 1-3 is critically dependent on an alternative splicing event involving the coding region for the carboxy terminal portion of the third extracellular immunoglobulin-like domain that leads to two different isoforms of each receptor (IIIb and IIIc). We therefore sought to determine whether changes in alternative splicing of FGF receptors occur in human prostate cancer.

METHODS

RNAs from normal prostate and clinically localized or metastatic prostate cancers were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) followed by digestion of products with restriction enzymes specific for each FGF receptor isoform and quantitation of the relative amounts of each isoform after electrophoresis. For FGFR-2, this was correlated with immunohistochemistry to determine the localization of the protein product.

RESULTS

FGFR-1 is expressed exclusively as the IIIc isoform in prostate cancer while FGFR-3 is expressed predominantly as the IIIb isoform, similar to the expression pattern in normal prostatic epithelial cells. In contrast, there was variable expression of the FGFR-2 IIIb and IIIc isoforms. In the majority of cases the FGFR-2 IIIb isoform was the predominant or exclusive isoform expressed, similar to normal epithelial cells, but in a subset of cases the IIIc isoform was increased, indicating a change in alternative splicing of FGFR-2 in some cases.

CONCLUSIONS

In most cases of prostate cancer there are no changes in alternative splicing of FGF receptors, but in a subgroup there is increased expression of the FGFR-2 IIIc isoform. Given that the affinity of FGFs is highly dependent on the isoform of FGF receptor expressed, this information is critical in understanding the effects of FGFs on prostate cancer cells in vivo.

Synchronous water-clear cell double parathyroid adenomas a hitherto uncharacterized entity?

Water-clear cell hyperplasia is a rare but well-documented cause of primary hyperparathyroidism. Parathyroid adenomas of the water-clear cell type are exceptionally rare, and only 2 cases have been reported. We describe a patient with synchronous water-clear cell double parathyroid adenomas, an entity that has not previously been reported. In our case, the enlarged superior parathyroid glands were completely replaced by water-clear cells, with only a minute rim of extracapsular, histologically unremarkable parathyroid tissue. The inferior parathyroid glands were grossly unremarkable, and incisional biopsy specimens were histologically normal (no foci of water-clear cells were identified). The findings in this case are most consistent with the diagnosis of double adenomas of the water-clear cell type. We acknowledge that despite molecular proof of monoclonality of the 2 lesions, it is not possible to entirely exclude the possibility that this unusual case could be due to asymmetric hyperplasia.

Are microinvasion and micrometastasis in breast cancer mountains or molehills?

BACKGROUND

The increased rate of early detection of breast cancer due to widespread mammographic screening has led to an increased incidence of in situ as well as microinvasive carcinoma. The enhanced pathological examination to which sentinel lymph nodes are subjected has led to an increased rate of detection of micrometastatic carcinoma. Despite the augmented rate of diagnoses of both diseases, the pathological diagnoses as well as clinical management of these entities continue to be controversial.

DATA SOURCES

A computerized literature search was performed on the Medline and PubMed database from 1990 to date. Relevant earlier publications were also perused. The database of the Department of Pathology at New York Presbyterian Hospital-Well Medical College of Cornell University were also accessed.

CONCLUSIONS

Based on cumulative data, patients diagnosed with either microinvasive or micrometastatic carcinoma of breast have a relatively favorable, albeit guarded, prognosis. Treatment recommendations for both of these disease entities continue to be controversial, and may remain so until additional refined clinicopathological data becomes available.

FGF-10 is expressed at low levels in the human prostate

BACKGROUND

Fibroblast growth factors (FGFs) are known to play an important role in the growth of normal prostatic epithelial cells. FGF-10 is a secreted growth factor that binds to FGF receptor-2 IIIb, which is expressed in prostatic epithelial cells and thus can potentially act as a growth factor for these cells. Prior work has indicated that FGF10 may play an important role in the development of the rat prostate, but its role in the adult human prostate is unclear.

METHODS

Expression of FGF10 in human prostate tissue and primary cultures of prostatic epithelial and stromal cells was assessed by reverse-transcriptase PCR (RT-PCR) and Northern blotting. Growth response to FGF10 was assessed by the addition of recombinant FGF-10 to primary cultures of prostatic epithelial and stromal cells.

RESULTS

FGF10 is expressed at levels detectable by RT-PCR and can act as a growth factor for prostatic epithelial cells, but is not active as a growth factor for stromal cells. However, FGF10 is expressed at extremely low levels relative to FGF7, which has a similar biological activity.

CONCLUSIONS

While FGF10 may play a role in prostatic development, it is unlikely to play a major role in prostate growth in normal or hyperplastic adult human prostate, due to its extremely low expression compared to FGF7.

Increased expression of fibroblast growth factor 6 in human prostatic intraepithelial neoplasia and prostate cancer

Fibroblast growth factors (FGFs) are known to play an important role in the growth of normal prostatic epithelial cells. In addition to their effects on proliferation, FGFs can promote cell motility, increase tumor angiogenesis, and inhibit apoptosis, all of which play an important role in tumor progression. To determine whether FGFs are overexpressed in human prostate cancers, we analyzed 26 prostate cancer RNAs by reverse transcription-PCR for expression of FGF3, FGF4, and FGF6, which cannot be detected in normal prostate tissue by this technique. Fourteen of 26 prostate cancers expressed FGF6 mRNA. No expression of FGF3 or FGF4 was detected. An ELISA of tissue extracts of normal prostate, high-grade prostatic intraepithelial neoplasia (PIN), and prostate cancer for FGF6 showed that this growth factor was undetectable in normal prostate but was present at elevated levels in 4 of 9 PIN lesions and in 15 of 24 prostate cancers. Immunohistochemical analysis with anti-FGF6 antibody revealed weak staining of prostatic basal cells in normal prostate that was markedly elevated in PIN. In the prostate cancers, the majority of cases revealed expression of FGF6 by the prostate cancer cells themselves. In two cases, expression was present in prostatic stromal cells. Exogenous FGF6 was able to stimulate proliferation of primary prostatic epithelial and stromal cells, immortalized prostatic epithelial cells, and prostate cancer cell lines in tissue culture. FGF receptor 4, which is the most potent FGF receptor for FGF6, is expressed in the human prostate in vivo and in all of the cultured cell lines. Thus, FGF6 is increased in PIN and prostate cancer and can promote the proliferation of the transformed prostatic epithelial cells via paracrine and autocrine mechanisms.

Interleukin-1alpha is a paracrine inducer of FGF7, a key epithelial growth factor in benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is an extremely common disease of older men in which there is benign overgrowth of the prostatic transition zone, leading to obstruction of urine outflow. FGF7, a potent growth factor for prostatic epithelial cells, is increased by threefold in BPH and is correlated with increased epithelial proliferation in this condition. Immunohistochemistry of normal and hyperplastic prostate revealed that FGF7-expressing fibroblastic cells were present in higher numbers near the epithelial acini, implying that epithelial cells may express a factor that induces FGF7 expression by stromal cells. Conditioned medium (CM) from primary cultures of prostatic epithelial cells was capable of inducing a two- to sixfold increase in the expression of FGF7 by primary stromal cultures. Blocking experiments with neutralizing anti-interleukin-1alpha (Il-1alpha) antibodies and IL-1Ra, an Il-1alpha receptor antagonist, show that this inducing activity was due to the presence of Il-1alpha in the epithelial CM. Analysis of normal prostatic peripheral zone and BPH tissue by enzyme-linked immunoabsorption assay reveal that Il-1alpha is present at increased levels in hyperplastic prostate and that levels of Il-1alpha correlate strongly with tissue FGF7 concentration in BPH. Therefore Il-1alpha is produced by prostatic epithelial cells and can induce FGF7, a potent epithelial growth factor, which can in turn lead to further epithelial growth and increased Il-1alpha secretion, thus establishing a double paracrine loop that is functionally equivalent to an autocrine growth loop. This double paracrine loop may play a key role in the abnormal proliferation of the transition zone, which is critical to the pathogenesis of BPH.

Microinvasive carcinoma of the breast: can it be diagnosed reliably and is it clinically significant?

Deciding whether in-situ breast carcinoma is associated with microinvasion is a common problem. Histological features resembling invasion can be simulated by in-situ carcinoma distorted by inflammatory and reparative changes. Having expended the effort to diagnose genuine microinvasion, just how useful is this diagnosis in planning further treatment and follow-up? In the following articles, Hoda et al. comment on the utility of immunohistochemistry in resolving uncertainty about the presence of microinvasion, and Ellis et al. critically appraise the definition of microinvasion and its clinical significance.

FGF7 and FGF2 are increased in benign prostatic hyperplasia and are associated with increased proliferation

PURPOSE

To determine if overexpression of FGF7 and FGF2 occurs in benign prostatic hyperplasia (BPH) and if so, whether such overexpression is correlated with increased proliferation of epithelial and/or stromal cells.

MATERIALS AND METHODS

The FGF7 and FGF2 content of protein extracts of normal peripheral zone, normal transition zone and hyperplastic prostatic tissues were determined by enzyme-linked immunoabsorption assay. Proliferation of epithelial and stromal cells was assessed by immunohistochemistry with anti-Ki67 antibodies on frozen sections of the same tissues used for protein extraction. The in vitro effects of FGF7 and FGF2 on proliferation were assessed by addition of recombinant growth factor to primary cultures of prostatic epithelial and stromal cells.

RESULTS

We have found that both FGF7 and FGF2 are overexpressed in hyperplastic prostate in comparison to normal peripheral and transition zone tissue. FGF7 is a potent mitogen for epithelial cells in culture. Consistent with these in vitro effects, quantitative analysis of cellular proliferation by Ki67 immunohistochemistry revealed a strong correlation of epithelial proliferation with FGF7 content in BPH tissue, consistent with a key role for this growth factor in driving the abnormal epithelial proliferation in BPH. FGF2 is mitogenic for stromal cells in culture and there was a weaker correlation of FGF2 content with increased stromal proliferation.

CONCLUSION

Overexpression of FGF7 and FGF2 may play an important role in the abnormal cellular proliferation seen in benign prostatic hyperplasia.

FGF9 is an autocrine and paracrine prostatic growth factor expressed by prostatic stromal cells

Polypeptide growth factors, including members of the fibroblast growth factor (FGF) family, play an important role in the growth and maintenance of the normal prostate. We have found that FGF9 is expressed at high levels in the normal peripheral and transition zone of the human prostate. Analysis of FGF9 production by primary cultures of prostatic epithelial and stromal cells has shown that FGF9 is produced and secreted by the prostatic stromal cells. Neither of these processes appears to be modulated by androgens. Production of FGF9 by stromal cells in vivo was confirmed by immunohistochemistry. FGF9 is a potent mitogen for both prostatic epithelial and stromal cells in culture and is a more potent mitogen for these cells than either FGF2 or FGF7, two other FGFs expressed in the human prostate. FGF9 is an abundant secreted growth factor that can act as both a paracrine mitogen for epithelial cells and an autocrine mitogen for stromal cells. Western blot analysis of tissue extracts from the normal and hyperplastic transition zone shows that FGF9 is present at two to threefold higher levels in the hyperplastic transition zone. Overexpression of this paracrine and autocrine growth factor may play an important role in the epithelial and stromal proliferation in benign prostatic hyperplasia.

Alterations in expression of basic fibroblast growth factor (FGF) 2 and its receptor FGFR-1 in human prostate cancer

Fibroblast growth factors (FGFs) play an important role in the growth and maintenance of the normal prostate. There is increasing evidence from both animal models and analysis of human prostate cancer cell lines that alterations of FGFs and/or FGF receptors (FGFRs) may play an important role in prostate cancer progression. To better define the role of FGF2 and FGF7 in human prostate cancer in vivo, we have quantified these two growth factors in clinically localized human prostate cancers and uninvolved prostate by ELISA and Western blotting and determined their localization by immunohistochemistry. The expression of two of the primary receptors for these growth factors, FGFR-1 and FGFR-2, were also analyzed by immunohistochemistry and Western blotting in these same samples. We have found that FGF2 is significantly increased in prostate cancers when compared with uninvolved prostate and that the FGF2 is present in the stromal fibroblasts and endothelial cells but not the cancer cells. In addition, we have observed overexpression of both FGFR-1 and FGFR-2 in the prostate cancer epithelial cells in a subset of prostate cancers and that such overexpression is correlated with poor differentiation. Thus, there is both an increase in FGF2 concentration in prostate cancers and an increased expression of a receptor capable of responding to this growth factor, establishing a potential paracrine stimulation of prostate cancer cells by the surrounding stromal cells, which may play an important role in prostate cancer progression.

Inactivation of the PTEN tumor suppressor gene is associated with increased angiogenesis in clinically localized prostate carcinoma

The PTEN tumor suppressor gene encodes a dual-specificity protein phosphatase that may play a key role in modulating integrin-mediated signals. Inactivation of the PTEN gene has been detected in a small percentage of clinically localized prostate cancers but is common in metastatic disease. It has been shown in glioblastoma cell lines that loss of chromosome 10q, where the PTEN gene is located, is associated with increased angiogenic activity in the conditioned medium attributable to downregulation of thrombospondin-1, a negative regulator of angiogenesis. Therefore, we wished to determine whether inactivation of PTEN might be associated with increased angiogenesis in prostate cancers, because increased angiogenesis in localized cancers is associated with development of metastatic disease. Angiogenesis was assessed by counting microvessels in areas of maximal neovascularization after immunostaining with anti-factor VIII-related antigen antibodies in eight cases with proven homozygous deletion of the PTEN gene and 24 control cases. There was a statistically significant correlation between PTEN inactivation and increased microvessel counts. The microvessel density was higher at all Gleason scores in the cases with PTEN inactivation compared with control cases with the same score. To determine whether the increased angiogenesis in cases with PTEN inactivation was caused by downregulation of expression of the angiogenesis inhibitor thrombospondin-1, we analyzed a subset of the cases by immunostaining with anti-thrombospondin-1 antibody. Approximately 25% of cases showed decreased staining of prostate cancer cells, but there was no correlation with PTEN inactivation. Thus, PTEN inactivation is associated with increased angiogenesis, but the increased angiogenesis is not attributable to downregulation of thrombospondin-1 expression.