Search tips
Search criteria

Results 1-25 (25)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
1.  Antral atrophy, intestinal metaplasia, and pre-neoplastic markers in Mexican children with Helicobacter pylori-positive and negative gastritis 
Annals of diagnostic pathology  2014;18(3):129-135.
Chronic inflammation and infection are major risk factors for gastric carcinogenesis in adults. As chronic gastritis is common in Mexican children, diagnosis of Helicobacter pylori and other causes of gastritis are critical for the identification of children who would benefit from closer surveillance. Antral biopsies from 82 Mexican children (mean age 8.3±4.8y) with chronic gastritis (36 H. pylori +, 46 H. pylori -) were examined for gastritis activity, atrophy, intestinal metaplasia, and immunohistochemical expression of gastric carcinogenesis biomarkers CDX2, ephrin type-B receptor 4, matrix metalloproteinase 3 (MMP3), macrophage migration inhibitory factor (MIF), p53, β-catenin, and E-cadherin. Atrophy was diagnosed in 7/82 (9%) and intestinal metaplasia in 5/82 (6%) by routine histology, while 6 (7%) additional children (3 H. pylori +) exhibited aberrant CDX2 expression without intestinal metaplasia. Significant positive correlations were seen between EphB4, MMP3, and MIF (p<0.0001). Atrophy and follicular pathology were more frequent in H. pylori + biopsies (p<0.0001), while intestinal metaplasia and CDX2 expression showed no significant correlation with H. pylori status. Antral biopsies demonstrating atrophy, intestinal metaplasia, and/or aberrant CDX2 expression were seen in 21.95 % (18/82) of the children, potentially identifying those who would benefit from closer surveillance and preventive dietary strategies. Biomarkers CDX2, EphB4, MMP3, and MIF may be useful in the work-up of pediatric gastritis.
PMCID: PMC4516036  PMID: 24656654
antral gastritis; biomarkers; child; Helicobacter pylori; Mexican; surveillance
2.  A Cell Of Origin gene signature indicates human bladder cancer has distinct cellular progenitors 
Stem cells (Dayton, Ohio)  2014;32(4):974-982.
There are two distinct forms of urothelial (bladder) cancer: muscle-invasive (MI) and non-muscle invasive (NMI) disease. Since it is currently believed that bladder cancer arises by transformation of urothelial cells of the basal layer, bladder cancer stem cells (CSCs) have been isolated based on expression markers found in such cells. However, these CSCs have only been identified in MI tumors raising the intriguing hypothesis that NMI tumor progenitors do not arise from the basal compartment. To test this hypothesis, we carried out genomewide expression profiling of laser capture microdissected basal and umbrella cells, the two most histologically distinct cell types in normal urothelium and developed a Cell Of Origin (COO) gene signature that distinguishes these. The COO signature was a better predictor of stage and survival than other bladder, generic or breast CSC signatures and bladder cell differentiation markers in multiple patient cohorts. To assess whether NMI and MI tumors arise from a distinct (DPC) or common (CPC) progenitor cell, we developed a novel statistical framework that predicts COO score as a function of known genetic alterations (TP53, HRAS, KDM6Aand FGFR3) that drive either MI or NMI bladder cancer and compared this to the observed COO score of the tumor. Analysis of 874 patients in 5 cohorts established the DPC model as the best fit to the available data. This observation supports distinct progenitor cells in NMI and MI tumors and provides a paradigm shift in our understanding of bladder cancer biology that has significant diagnostic and therapeutic implications.
PMCID: PMC3960367  PMID: 24357085
Bladder cancer; Cancer stem cells; Urothelial tumorigenesis; DNA microarray
3.  Paneth cell-like change in benign prostate can account for P504S (AMACR) reactivity 
Paneth cell-like neuroendocrine metaplasia of benign and cancerous prostate was described in 1992. Here, we note that P504S (AMACR), the cytoplasmic marker for prostate cancer used alone or in concert with basal cell markers, can be strongly reactive in benign prostatic acini with Paneth cell-like change.
PMCID: PMC4097236  PMID: 25031776
Paneth; prostate; P504S; AMACR
4.  A Competitive Infection Model of Hematogenously Disseminated Candidiasis in Mice Redefines the Role of Candida albicans IRS4 in Pathogenesis 
Infection and Immunity  2013;81(5):1430-1438.
Candida albicans IRS4 encodes a protein that regulates phosphatidylinositol-(4,5)-bisphosphate, which was shown to contribute to hematogenously disseminated candidiasis (DC) after several days in the standard mouse model. Our objective was to more accurately define the temporal contributions of IRS4 to pathogenesis. During competition assays in vitro, an irs4-null (Δirs4) mutant exhibited wild-type fitness. In DC experiments, mice were infected intravenously with the Δirs4 mutant, strain CAI-12 (1 × 105 CFU), or a mixture of the strains (0.5 × 105 CFU each). In single-strain infections, quantitative PCR revealed reduced Δirs4 mutant burdens within kidneys at days 1, 4, and 7 but not 6 h. In competitive infections, the Δirs4 mutant was outcompeted by CAI-12 in each mouse at ≥6 h (competitive indices, P ≤ 0.0001). At 4 and 7 days, the Δirs4 mutant burdens during competitive infections were significantly lower than those during single-strain infections (P = 0.01 and P < 0.001, respectively), suggesting increased susceptibility to inflammatory responses. Phagocytic infiltration of kidneys in response to CAI-12 or competitive infections was significantly greater than that in response to Δirs4 mutant infection at days 1 and 4 (P < 0.001), and the Δirs4 mutant was more susceptible to phagocytosis and killing by human polymorphonuclear cells (P = 0.01 and P = 0.006, respectively) and mouse macrophages in vitro (P = 0.04 and P = 0.01, respectively). Therefore, IRS4 contributes to tissue invasion at early stages of DC and mediates resistance to phagocytosis as DC progresses. Microarray analysis revealed remarkably similar gene expression by the Δirs4 mutant and reference strain CAI-12 within blood, suggesting that IRS4 is not significantly involved in the hematogenous stage of disease. A competitive DC model detects attenuated virulence that is not evident with the standard model.
PMCID: PMC3647996  PMID: 23429534
5.  Renal epithelioid angiomyolipoma with a negative premelanosome marker immunoprofile: a case report and review of the literature 
The rare variant of renal epithelioid/pleomorphic angiomyolipoma has been reported in approximately 120 cases. One of the most important characteristics to differentiate these tumors from other renal cell neoplasms is their typical reactivity to premelanosome antigens. If such a tumor does not stain for HMB-45 or Melan-A, a specific diagnosis of epithelioid pleomorphic angiomyolipoma cannot be made with certainty.
Case presentation
We present here what is, to the best of our knowledge, the first case of epithelioid/pleomorphic angiomyolipoma of the kidney in a 50-year-old Caucasian man with no history of tuberous sclerosis, and with a tumor marker profile negative for several premelanosome antigens. The tumor was composed of sheets of pleomorphic, round to polygonal epithelioid cells with prominent eosinophilic cytoplasm, large nuclei, many multinucleated, and very prominent nucleoli. There were prominent vessels and rare interspersed smooth muscle fibers, but adipocytes were not identified. A tumor marker profile showed tumor cell reactivity for CD68, calponin and focally for CD10. Intervening smooth muscle was reactive with smooth muscle actin. The tumor lacked reactivity for melanin-associated antigens HMB-45 and Melan-A, and for CD31, pan-cytokeratin (AE1/3) and desmin. Electron microscopic examination of tumor cells confirmed the presence of premelanosome-like granules.
Based on the characteristic microscopic appearance of this tumor, and its overall tumor marker profile, we concluded this was a renal epithelioid/pleomorphic angiomyolipoma with a negative premelanosome antigen phenotype.
PMCID: PMC3667146  PMID: 23628229
6.  Pathology Update for Urologists 
Prostate Cancer  2011;2011:183761.
PMCID: PMC3196914  PMID: 22096649
7.  Papillary cystadenofibroma of epididymis: a case report 
We present the first reported case of papillary cystadenofibroma of the epididymis. The tumor occurred in a 46-year-old man. The mass was 3.7 cm and included a hemorrhagic fluid-filled cyst. Microscopically, stromal-filled papillae were lined by low cuboidal to columnar epithelium. Epithelial cells were reactive for cytokeratin 7, cy-tokeratins AE1/3, and focally in the apical cytoplasm for CD10. Focal CD10 reactivity was also noted in the stroma. The lesion was negative for alpha-fetoprotein. These findings ruled out other lesions, including metastatic renal cell carcinoma.
PMCID: PMC3160614  PMID: 21904638
Papillary; cystadenofibroma; epididymis
8.  Pseudolumen Size and Perimeter in Prostate Cancer: Correlation with Patient Outcome 
Prostate Cancer  2011;2011:693853.
We demonstrated in 2011 that 61% of men with postoperative PSA failure had some cribriform pattern of prostate cancer, versus 16% of nonfailures (OR = 5.89, P < .0001). That study used digitized radical prostatectomy slides from 153 men, 76 failures (≥0.2 ng/mL) matched to 77 nonfailures. The current study's hypothesis: pseudolumen size and shape variability could stratify outcome within histologic patterns (single separate acini, separate acini with undulating lumens, fused small acini, papillary, cribriform). Pseudolumens were filled digitally on image captures from previously annotated specimens. Among all 5 patterns, pseudolumen spaces averaged smaller in failures than nonfailures. After multivariate analysis controlling for stage, age, margin, cancer amount, prostate volume, and presence of individual cells (grade 5), this retained significance only for the undulating-lumens and papillary patterns. In undulating-lumens pattern, PSA failures had smaller mean pseudolumen space sizes (P = .03) but larger perimeters (P = .04), implying more pseudolumen irregularity. In papillary pattern, the number of pseudolumen spaces was higher in failures (P = .015), space size was smaller (P = .11), perimeters were smaller (P = .04), and perimeter/size ratio was higher (P = .02). In conclusion, digitally measured pseudolumen size and shape may associate with outcome.
PMCID: PMC3200296  PMID: 22110997
9.  Frequency of Positive Surgical Margin at Prostatectomy and Its Effect on Patient Outcome 
Prostate Cancer  2011;2011:673021.
A positive surgical margin at prostatectomy is defined as tumor cells touching the inked edge of the specimen. This finding is reported in 8.8% to 42% of cases (median about 20%) in various studies. It is one of the main determinants of eventual biochemical (PSA) failure, generally associated with a doubled or tripled risk of failure. The effect of a positive margin on outcome can be modified by stage or grade and the length, number and location of positive margins, as well as by technical operative approach and duration of operator experience. This paper tabulates data from the past decade of studies on margin status.
PMCID: PMC3200270  PMID: 22110996
10.  Cell adhesion molecule CD44: its functional roles in prostate cancer 
CD44 is a cell adhesion glycoprotein that also governs cell signaling. Dysregulated CD44 expression characterizes most human cancers, including prostate cancer (PCa). PCa loses expression of CD44 standard (CD44s) that is present in benign epithelium, and overexpresses the novel splice variant (v) isoform, CD44v7-10. We studied CD44 in PCa for more than a decade, and in a series of papers, established its functional significance. Using retrovi-ral gene delivery to PC-3M PCa cells, we expressed luciferase-only, enforced CD44s re-expression as a fusion protein with luciferase at its C-terminus or as a protein separate from luciferase, or knocked down CD44v7-10 by RNAi. Invasion, migration, proliferation, soft agar colony formation, adhesion, Docetaxel sensitivity, and xenograft growth assays were carried out. Compared to luciferase-only PC-3M cells, all 3 treatments reduced invasion and migration. Growth and soft agar colony formation were reduced only by re-expression of CD44s as a separate or fusion protein but not CD44v7-10 RNAi. Hyaluronan and osteopontin binding were greatly strengthened by CD44s expression as a separate protein, but not a fusion protein. CD44v7-10 RNAi in PC-3M cells caused marked sensitization to Docetaxel; the 2 CD44s re-expression approaches caused minimal sensitization. In limited numbers of mouse subcutaneous xeno-grafts, all 3 alterations produced only nonsignificant trends toward slower growth compared with luciferase-only controls. In further work, we tested the effects of the anti-growth compound silibinin, a milk thistle derivative. Using a luciferase promoter construct to test for CD44 promoter activity, silibinin significantly and dose-dependently inhibited promoter activity at physiologic doses. Total CD44 RNA and CD44v7-10 RNA were significantly decreased; both were also decreased at the protein level. Phenyl-methylene hydantoins (PMH), guanidine alkaloids derived from Red Sea sponges, have the ability to increase cell-cell adhesion in prostate cancer cells and reduce invasion. Expression of CD44 total mRNA and CD44v7-10 were markedly decreased by PMH and its S-ethyl derivative. The oncogenic mi-croRNAs, miR-373 and miR-520c, which interact with CD44, were studied in prostate cancer cells and human tissues. We found that they bound the 3’ untranslated region of the CD44 RNA, and suppressed CD44 in prostate cancer, by preventing the translation of CD44 RNA, rather than by degrading the RNA. Thus, stable re-expression of CD44s reduces PCa growth and invasion in vitro, and possibly in vivo, suggesting CD44's potential as gene therapy. Finally, CD44v7-10 may be a target for chemosensitization, and plays a role in nutraceutical abrogation of tumor development. In vivo effects of CD44 alteration still need to be investigated by use of orthotopic or renal capsule xenografts, which confer a different stromal microenvironment than that of the subcutaneous grafts.
PMCID: PMC2981422  PMID: 21139802
CD44; prostate; splicing; standard; variant; silibinin; phenyl-methylene hydantoins; xenografts
12.  Dutasteride prevents the growth response to testosterone in benign and androgen-sensitive malignant prostate cells 
We show that the dual 5-α reductase enzyme inhibitor dutasteride prevents enhanced growth of both benign and malignant prostate cell lines, incubated with physiologic to supraphysiologic doses of testosterone. Using androgen-sensitive benign BPH-1 cells, LNCaP cancer cells, their derivative C4-2 cells, or Dunning rat cancer cells, we subjected 30,000 cells/well to concomitant treatment with 10-9, 10-8, or 10-7 M testosterone in the presence of low (0.25 μM) or high (1.0 μM) doses of dutasteride. Both low- and high-dose dutasteride abrogated testosterone-stimulated growth of all 4 cell lines. If the in vitro data mimic conditions in men undergoing testosterone replacement, concomitant dutasteride use might make testosterone safe for men with benign prostatic hypertrophy, latent prostate cancer and perhaps even aggressive prostate cancer. Testosterone might also be used to prevent the rare anti-androgen side effects of dutasteride when used for benign prostatic hypertrophy and baldness. Further clinical investigation is indicated.
PMCID: PMC2929950  PMID: 20827322
Prostate cancer; BPH; testosterone; dutasteride
13.  Stable alterations of CD44 isoform expression in prostate cancer cells decrease invasion and growth and alter ligand binding and chemosensitivity 
BMC Cancer  2010;10:16.
Dysregulated CD44 expression characterizes most human cancers, including prostate cancer (PCa). PCa loses expression of CD44 standard (CD44s) that is present in benign epithelium, and overexpresses the novel splice variant isoform, CD44v7-10.
Using retroviral gene delivery to PC-3M PCa cells, we expressed luciferase-only, enforced CD44s re-expression as a fusion protein with luciferase at its C-terminus or as a protein separate from luciferase, or knocked down CD44v7-10 by RNAi. Invasion, migration, proliferation, soft agar colony formation, adhesion, Docetaxel sensitivity, and xenograft growth assays were carried out. Expression responses of merlin, a CD44 binding partner, and growth-permissive phospho-merlin, were assessed by western blot.
Compared to luciferase-only PC-3M cells, all three treatments reduced invasion and migration. Growth and soft agar colony formation were reduced only by re-expression of CD44s as a separate or fusion protein but not CD44v7-10 RNAi. Hyaluronan and osteopontin binding were greatly strengthened by CD44s expression as a separate protein, but not a fusion protein. CD44v7-10 RNAi in PC-3M cells caused marked sensitization to Docetaxel; the two CD44s re-expression approaches caused minimal sensitization. In limited numbers of mouse subcutaneous xenografts, all three alterations produced only nonsignificant trends toward slower growth compared with luciferase-only controls. The expression of CD44s as a separate protein, but not a fusion protein, caused emergence of a strongly-expressed, hypophosphorylated species of phospho-merlin.
Stable re-expression of CD44s reduces PCa growth and invasion in vitro, and possibly in vivo, suggesting CD44 alterations have potential as gene therapy. When the C-terminus of CD44s is fused to another protein, most phenotypic effects are lessened, particularly hyaluronan adhesion. Finally, CD44v7-10, although it was not functionally significant for growth, may be a target for chemosensitization.
PMCID: PMC2820461  PMID: 20074368
14.  Phenyl-methylene hydantoins alter CD44-specific ligand binding of benign and malignant prostate cells and suppress CD44 isoform expression 
Dysregulated CD44 expression is a feature of most human cancers, including prostate cancer (PCa). PCa loses expression of CD44 standard (CD44s) which is present in benign epithelium, and overexpresses a novel splice variant isoform, CD44v7-10, specifically facilitating fibronectin binding and invasion. Naturally-occurring or synthetic phenyl-methylene hydantoin (PMH) and S-ethyl PMH (S-PMH) can reportedly augment cell-cell adhesion, and reduce invasion and growth of PCa. Benign BPH-1 and malignant PC-3M prostate cells were treated with PMH or S-PMH for 36 h and cells were harvested. Cell adhesion assays were carried out. Cancer cells’ expression of total CD44 and CD44v7-10 were tested by western blot analysis and real-time RT-PCR. Compared to BPH-1 or PC-3M cells treated with vehicle only, PMH-or S-PMH-treated benign and malignant cells had decreased adhesion to hyaluronan (p=0.001 to 0.007) and fibronectin (p<0.001 to 0.047). Both compounds decreased PCa expression of CD44 total mRNA (representing mostly CD44s, to 0.076±0.033 and 0.254±0.123 of control) and CD44v7-10 (to 0.386±0.279 and 0.115±0.037 of control). S-PMH but not PMH decreased CD44 total protein, while both decreased CD44v7-10 protein. Both hydantoins lowered β-catenin, as reported previously. Both only slightly decreased β1-integrin, the definitive receptor for fibronectin. In conclusion, the ability of PMH and S-PMH to decrease hyaluronan adhesion appears to be mediated through decreased CD44s, while the decrease in fibronectin adhesion correlates with, and may be mediated by, decreased CD44v7-10.
PMCID: PMC2826825  PMID: 20182585
Alternate splicing; CD44; hydantoin; phenyl-methylene hydantoin; prostate cancer; hyaluronan; fibronectin
15.  Protein Profiling of Isolated Leukocytes, Myofibroblasts, Epithelial, Basal, and Endothelial Cells from Normal, Hyperplastic, Cancerous, and Inflammatory Human Prostate Tissues 
Journal of Cancer  2010;1:70-79.
In situ neoplastic prostate cells are not lethal unless they become invasive and metastatic. For cells to become invasive, the prostate gland must undergo degradation of the basement membrane and disruption of the basal cell layer underneath the luminal epithelia. Although the roles of proteinases in breaking down the basement membrane have been well-studied, little is known about the factors that induce basal cell layer disruption, degeneration, and its eventual disappearance in invasive cancer. It is hypothesized that microenvironmental factors may affect the degradation of the basal cell layer, which if protected may prevent tumor progression and invasion. In this study, we have revealed differential protein expression patterns between epithelial and stromal cells isolated from different prostate pathologies and identified several important epithelial and stromal proteins that may contribute to inflammation and malignant transformation of human benign prostate tissues to cancerous tissues using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and proteomics methods. Cellular retinoic acid-binding protein 2 was downregulated in basal cells of benign prostate. Caspase-1 and interleukin-18 receptor 1 were highly expressed in leukocytes of prostate cancer. Proto-oncogene Wnt-3 was downregulated in endothelial cells of prostatitis tissue and tyrosine phosphatase non receptor type 1 was only found in normal and benign endothelial cells. Poly ADP-ribose polymerase 14 was downregulated in myofibroblasts of prostatitis tissue. Interestingly, integrin alpha-6 was upregulated in epithelial cells but not detected in myofibroblasts of prostate cancer. Further validation of these proteins may generate new strategies for the prevention of basal cell layer disruption and subsequent cancer invasion.
PMCID: PMC2938068  PMID: 20842227
Prostate cancer; tumor microenvironment; inflammation; tumorigenesis; protein biomarkers; magnetic bead cell separation
17.  Candida albicans RFX2 Encodes a DNA Binding Protein Involved in DNA Damage Responses, Morphogenesis, and Virulence▿  
Eukaryotic Cell  2009;8(4):627-639.
We previously showed that Candida albicans orf19.4590, which we have renamed RFX2, expresses a protein that is reactive with antibodies in persons with candidiasis. In this study, we demonstrate that C. albicans RFX2 shares some functional redundancy with Saccharomyces cerevisiae RFX1. Complementation of an S. cerevisiae rfx1 mutant with C. albicans RFX2 partially restored UV susceptibility and the repression of DNA damage response genes. DNA damage- and UV-induced genes RAD6 and DDR48 were derepressed in a C. albicans rfx2 null mutant strain under basal conditions, and the mutant was significantly more resistant to UV irradiation, heat shock, and ethanol than wild-type strain SC5314. The rfx2 mutant was hyperfilamentous on solid media and constitutively expressed hypha-specific genes HWP1, ALS3, HYR1, ECE1, and CEK1. The mutant also demonstrated increased invasion of solid agar and significantly increased adherence to human buccal epithelial cells. During hematogenously disseminated candidiasis, mice infected with the mutant had a significantly delayed time to death compared to the wild type. During oropharyngeal candidiasis, mice infected with the mutant had significantly lower tissue burdens in the oral cavity and esophagus at 7 days and they were less likely to develop disseminated infections because of mucosal translocation. The data demonstrate that C. albicans Rfx2p regulates DNA damage responses, morphogenesis, and virulence.
PMCID: PMC2669197  PMID: 19252121
18.  Utility of serial urinary cytology in the initial evaluation of the patient with microscopic hematuria 
BMC Urology  2009;9:12.
We determine the utility of serial urinary cytologies in patients presenting with microscopic hematuria who were evaluated with upper and lower urinary tract studies to rule out a malignancy.
Two hundred and thirty-seven patients with the diagnosis of microscopic hematuria were evaluated at an inner-city tertiary care hospital. Of these 239 patients, 182 patients had 405 cytologies obtained as part of their evaluation for hematuria. In addition, all patients had their lower urinary tract and upper tract thoroughly evaluated.
Two hundred and seventy four cytology samples were read as normal, 104 (26%) as atypia, 7 (2%) as suspicious/malignant, and 20 (5%) as unsatisfactory. Seventeen patients (9.3%) had biopsy confirmed bladder cancer. Of these 17 patients, 2 had normal cytology, 11 had atypia, and 5 had suspicious/malignant. No patient had a positive cytology and a negative biopsy. Overall the number of hematuric patients harboring bladder cancer was small (7%). Cytology #1 detected 4 cases of cancer, cytology #2 detected an additional case and cytology #3 did not detect any additional cancers.
Because of this low prevalence of bladder cancer in patients presenting with microscopic hematuria and the low sensitivity of detecting bladder cancers, the utility of urinary cytology in the initial evaluation of patients with hematuria may be minimal. The exact role of urinary cytology in the evaluation of hematuria is unknown.
PMCID: PMC2751768  PMID: 19744317
19.  Persistent Exposure to Mycoplasma Induces Malignant Transformation of Human Prostate Cells 
PLoS ONE  2009;4(9):e6872.
Recent epidemiologic, genetic, and molecular studies suggest infection and inflammation initiate certain cancers, including those of the prostate. The American Cancer Society, estimates that approximately 20% of all worldwide cancers are caused by infection. Mycoplasma, a genus of bacteria that lack a cell wall, are among the few prokaryotes that can grow in close relationship with mammalian cells, often without any apparent pathology, for extended periods of time. In this study, the capacity of Mycoplasma genitalium, a prevalent sexually transmitted infection, and Mycoplasma hyorhinis, a mycoplasma found at unusually high frequency among patients with AIDS, to induce a malignant phenotype in benign human prostate cells (BPH-1) was evaluated using a series of in vitro and in vivo assays. After 19 weeks of culture, infected BPH-1 cells achieved anchorage-independent growth and increased migration and invasion. Malignant transformation of infected BPH-1 cells was confirmed by the formation of xenograft tumors in athymic mice. Associated with these changes was an increase in karyotypic entropy, evident by the accumulation of chromosomal aberrations and polysomy. This is the first report describing the capacity of M. genitalium or M. hyorhinis infection to lead to the malignant transformation of benign human epithelial cells and may serve as a model to further study the relationship between prostatitis and prostatic carcinogenesis.
PMCID: PMC2730529  PMID: 19721714
21.  Silibinin suppresses CD44 expression in prostate cancer cells 
Prostate cancer (PCa), like most human cancers, features dysregulated CD44 expression. Expression of CD44 standard (CD44s), present in benign epithelium, is lost in PCa while pro-invasive splice variant isoform CD44v7-10 is overexpressed. The role of CD44 in silibinin's anti-growth effects was uncertain. To assess silibinin's effects on CD44 promoter activity, PC-3M PCa cells were transfected with luciferase-CD44 promoter construct 24 h prior to 25–200 μM silibinin treatment for 48 h. Also, cells' expression of CD44 RNA (by qRT-PCR) and protein (Western blot analysis) was studied. Silibinin was further tested preoperatively on a pilot cohort of 6 men with PCa compared with 7 matched placebo-treated men, with immunostaining for CD44v7-10 in their prostates. In PC-3M cells, silibinin dose-dependently inhibited CD44 promoter activity up to 87%, caused a 90% inhibition of total CD44 and 70% decrease in CD44v7-10 RNA, and at the protein level, decreased total CD44 at 100–200 μM dose and decreased CD44v7-10 after 3 days. Silibinin decreased adhesion to hyaluronan and fibronectin. Silibinin at 100–200 μM inhibited Egr-1, a regulator of CD44 promoter activity. Men treated with silibinin did not differ in tissue CD44v7-10 expression. In conclusion, CD44 inhibition is one mechanism by which silibinin reduces PCa tumorigenicity.
PMCID: PMC2776293  PMID: 19966941
Silibinin, prostatic neoplasms; CD44; plasmid; alternate splicing; adhesion
22.  Cyclophosphamide-Induced Cystitis Increases Bladder CXCR4 Expression and CXCR4-Macrophage Migration Inhibitory Factor Association 
PLoS ONE  2008;3(12):e3898.
Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine involved in cystitis and a non-cognate ligand of the chemokine receptor CXCR4 in vitro. We studied whether CXCR4-MIF associations occur in rat bladder and the effect of experimental cystitis.
Methods and Findings
Twenty male rats received saline or cyclophosphamide (40 mg/kg; i.p.; every 3rd day) to induce persistent cystitis. After eight days, urine was collected and bladders excised under anesthesia. Bladder CXCR4 and CXCR4-MIF co-localization were examined with immunhistochemistry. ELISA determined MIF and stromal derived factor-1 (SDF-1; cognate ligand for CXCR4) levels. Bladder CXCR4 expression (real-time RTC-PCR) and protein levels (Western blotting) were examined. Co-immunoprecipitations studied MIF-CXCR4 associations.Urothelial basal and intermediate (but not superficial) cells in saline-treated rats contained CXCR4, co-localized with MIF. Cyclophosphamide treatment caused: 1) significant redistribution of CXCR4 immunostaining to all urothelial layers (especially apical surface of superficial cells) and increased bladder CXCR4 expression; 2) increased urine MIF with decreased bladder MIF; 3) increased bladder SDF-1; 4) increased CXCR4-MIF associations.
These data demonstrate CXCR4-MIF associations occur in vivo in rat bladder and increase in experimental cystitis. Thus, CXCR4 represents an alternative pathway for MIF-mediated signal transduction during bladder inflammation. In the bladder, MIF may compete with SDF-1 (cognate ligand) to activate signal transduction mediated by CXCR4.
PMCID: PMC2588654  PMID: 19066630
23.  MicroRNAs 373 and 520c Are Downregulated in Prostate Cancer, Suppress CD44 Translation and Enhance Invasion of Prostate Cancer Cells in vitro 
Prostate cancer (PCa), like most human cancers, features dysregulated CD44 expression. It loses expression of CD44 standard (CD44s), present in benign epithelium, and overexpresses a less abundant splice isoform, CD44v7-10. MicroRNAs 373 and 520c putatively regulate CD44. The levels of these two microRNAs were measured in matched benign and malignant patient tissues and in prostate cell lines. The effects of their transfection on CD44 mRNA and protein were documented. Whether these miRNAs act on CD44 promoter, or its 3′ untranslated region (UTR), was studied with luciferase reporter constructs and their influences on migration and invasion were determined in PC-3M cells. miR-373 and miR-520c expression were decreased in PCa cell lines and tissues, in proportion to their decreases in total CD44 mRNA. Exogenous miR-373 caused a dose-dependent increase in total CD44 RNA, but a decrease in CD44v7-10 RNA, with an optimal dose at 6 nM. At the protein level, however, both microRNAs suppressed CD44. Both migration and invasion were stimulated by miR-373 and miR-520c. The microRNAs had no effect on the CD44 promoter, but did exhibit 3′UTR binding. In conclusion, miR-373 and miR-520c exert their effect in PCa by preventing the translation of CD44 RNA, rather than by degrading the RNA. Despite this observation, they exert pro-invasive functional effects, as previously described in breast cancer cells. Their effects are mediated by binding CD44 3′UTR.
PMCID: PMC2615593  PMID: 19158933
MicroRNA; miR-373; miR-520c; prostatic neoplasms; CD44; invasion
24.  MAP kinase pathways and calcitonin influence CD44 alternate isoform expression in prostate cancer cells 
BMC Cancer  2008;8:260.
Dysregulated expression and splicing of cell adhesion marker CD44 is found in many types of cancer. In prostate cancer (PC) specifically, the standard isoform (CD44s) has been found to be downregulated compared with benign tissue whereas predominant variant isoform CD44v7-10 is upregulated. Mitogen-activated protein kinase pathways and paracrine calcitonin are two common factors linked to dysregulated expression and splicing of CD44 in cancer. Calcitonin has been found to increase proliferation and invasion in PC acting through the protein kinase A pathway.
In androgen-independent PC with known high CD44v7-10 expression, CD44 total and CD44v7-10 RNA or protein were assessed in response to exogenous and endogenous calcitonin and to inhibitors of protein kinase A, MEK, JNK, or p38 kinase. Benign cells and calcitonin receptor-negative PC cells were also tested.
MEK or p38 but not JNK reduced CD44 total RNA by 40%–65% in cancer and benign cells. Inhibition of protein kinase A reduced CD44 total and v7-10 protein expression. In calcitonin receptor-positive cells only, calcitonin increased CD44 variant RNA and protein by 3 h and persisting to 48 h, apparently dependent on an uninhibited p38 pathway. Cells with constitutive CT expression showed an increase in CD44v7-10 mRNA but a decrease in CD44 total RNA.
The MEK pathway increases CD44 RNA, while calcitonin, acting through the protein kinase A and p38 pathway, facilitates variant splicing. These findings could be used in the formulation of therapeutic methods for PC targeting CD44 alternate splicing.
PMCID: PMC2551621  PMID: 18793421
25.  Further evidence for increased macrophage migration inhibitory factor expression in prostate cancer 
BMC Cancer  2005;5:73.
Macrophage migration inhibitory factor (MIF) is a cytokine associated with prostate cancer, based on histologic evidence and circulating (serum) levels.
Recent studies from another laboratory failed to document these results. This study's aims were to extend and confirm our previous data, as well as to define possible mechanisms for the discrepant results. Additional aims were to examine MIF expression, as well as the location of MIF's receptor, CD74, in human prostatic adenocarcinoma compared to matched benign prostate.
MIF amounts were determined in random serum samples remaining following routine PSA screening by ELISA. Native, denaturing and reducing polyacrylamide gels and Western blot analyses determined the MIF form in serum. Prostate tissue arrays were processed for MIF in situ hybridization and immunohistochemistry for MIF and CD74. MIF released into culture medium from normal epithelial, LNCaP and PC-3 cells was detected by Western blot analysis.
Median serum MIF amounts were significantly elevated in prostate cancer patients (5.87 ± 3.91 ng/ml; ± interquartile range; n = 115) compared with patients with no documented diagnosis of prostate cancer (2.19 ± 2.65 ng/ml; n = 158). ELISA diluent reagents that included bovine serum albumin (BSA) significantly reduced MIF serum detection (p < 0.01). MIF mRNA was localized to prostatic epithelium in all samples, but cancer showed statistically greater MIF expression. MIF and its receptor (CD74) were localized to prostatic epithelium. Increased secreted MIF was detected in culture medium from prostate cancer cell lines (LNCaP and PC-3).
Increased serum MIF was associated with prostate cancer. Diluent reagents that included BSA resulted in MIF serum immunoassay interference. In addition, significant amounts of complexed MIF (180 kDa under denaturing conditions by Western blot) found in the serum do not bind to the MIF capture antibody. Increased MIF mRNA expression was observed in prostatic adenocarcinoma compared to benign tissue from matched samples, supporting our earlier finding of increased MIF gene expression in prostate cancer.
PMCID: PMC1177932  PMID: 16000172

Results 1-25 (25)