Biomedical subjects

R B Nagle

Publications and source records attributed to R B Nagle.

At least 19 recordsLinked to original sources

PubMed2001

Unique expression pattern of the alpha6beta4 integrin and laminin-5 in human prostate carcinoma.

BACKGROUND: The alpha6beta4 integrin and its ligand, laminin-5, are essential gene products for the maintenance and remodeling of a stratified epithelium. Apparent loss of polarized alpha6beta4 integrin and laminin-5 protein expression in invasive prostate cancer as compared to normal prostate glands is known to occur. It is unknown whether these alterations occur in prostatic intraepithelial neoplasia (PIN) lesions and whether this combined defect occurs in other epithelial cancers. METHODS: Human prostate tissues containing both normal, PIN, and cancerous regions and normal and cancer tissue from breast and colon were obtained at surgery and examined for beta4 integrin and laminin-5 using standard immunofluorescence staining methods. RESULTS: Both normal prostate glands and PIN lesions contain beta4 integrin and laminin-5. Prostate carcinoma was unique in that both beta4 integrin and laminin-5 expression was uniformly absent. In contrast, the beta4 integrin and its ligand, laminin-5 were detected in all of the colon carcinoma cases and in 60% of the breast carcinomas. CONCLUSIONS: The beta4 integrin and its ligand, laminin-5 are altered during the transition of PIN lesions to invasive prostate carcinoma. These data suggest the loss of these proteins during cancer progression. In both prostate and breast carcinoma, the normal expression pattern of the beta4 integrin and laminin-5 is interrupted, in contrast to the persistent beta4 integrin and laminin-5 expression detected in colon carcinoma.

Antigens, Surface↗

PubMed2001

Aberrant expression of fibroblast growth factor receptor-1 in prostate epithelial cells allows induction of promatrilysin expression by fibroblast growth factors.

Matrix metalloproteinases (MMPs) degrade extracellular matrix proteins, and there is evidence that they play a role in tumor cell growth, invasion and metastasis. Matrilysin (MMP-7) is over-expressed in prostate cancer cells and increases prostate cancer cell invasion. Prostate stromal fibroblasts secrete a factor(s), including fibroblast growth factor-1 (FGF-1), which induces promatrilysin expression in the prostate carcinoma cell line LNCaP but not in normal prostate epithelial cells (PrECs). Since FGF-1 is present in the prostate, an altered sensitivity to FGF-1 might explain the up-regulation of matrilysin expression in prostate cancer cells compared to normal prostate epithelium. FGF receptor-1 (FGFR-1) is not normally expressed by normal prostate epithelial cells; however, aberrant expression of this receptor has been reported in prostate cancer cells, including the LNCaP cell line. We hypothesized that aberrant expression of FGFR-1 in PrECs would render them sensitive to induction of promatrilysin expression by recombinant FGF-1. To test this hypothesis, we transiently transfected PrECs with an FGFR-1 expression vector, which resulted in over-expression of FGFR-1 protein in approximately 40% of cells. FGF-1 increased promatrilysin expression in FGFR-1-transfected PrECs 4-fold over mock-transfected cells, and this induction was inhibited by a specific FGFR-1 inhibitor, SU5402, and by co-expression of a dominant negative FGFR-1 protein. Our results demonstrate that aberrant FGFR-1 expression, an epigenetic phenomenon that has been associated with prostate cancer progression, allows induction of promatrilysin expression by FGF-1 in PrECs.

Dimerization↗

PubMed2000

Diagnostic frozen prostate sextant biopsies: an approach for preserving protein and RNA for additional studies.

BACKGROUND: Primary prostate cancer represents 29% of newly diagnosed visceral cancers in men. Despite this common occurrence, relatively little is known about the pathogenesis of this malignancy. High-grade prostatic intraepithelial neoplasia (HGPIN) is generally accepted as a precursor to invasive prostate carcinoma. There is a lack of adequate animal models, and the available cell culture lines are limited. Tissue from prostate needle core biopsies that have been frozen can provide adequate material for both diagnosis and research. METHODS: Transrectal sextant needle biopsies were snap-frozen, serially sectioned and alternately stained with hematoxylin-eosin or reacted with a basal cell-specific antibody. Two pathologists examined all of the sections, which were scored for the presence or absence of carcinoma and HGPIN. Portions of the remaining tissue were used for studies of protein expression and gene expression. RESULTS: The incidence of carcinoma was 39%, comparable to the mean percent positive cases reported using conventional fixation and paraffin embedding. The incidence of HGPIN was 33%, higher than previously reported. CONCLUSIONS: Prostate carcinoma can be accurately diagnosed using frozen material. The observed high frequency of HGPIN is attributed to the instability of nuclear structure in the frozen material of the atypical nuclei, resulting in inflated grading of PIN lesions. Sufficient material remained in the frozen blocks for additional studies of protein and gene expression.

Aged↗

PubMed2000

Altered surface expression and increased turnover of the alpha6beta4 integrin in an undifferentiated carcinoma.

The integrin alpha6beta4, predominantly expressed on tissues of epithelial origin, is known to be variably expressed on carcinomas. The biochemical changes resulting in altered expression during tumor progression are unknown. We have analyzed the expression of alpha6beta4 in a multi-step mouse model of skin carcinogenesis representing normal keratinocyte, benign papilloma and malignant undifferentiated carcinoma. All cell lines expressed the alpha6 integrin exclusively as the alpha6beta4 integrin heterodimer. Analysis of this integrin by flow cytometry and immunoprecipitation of surface labeled proteins revealed that the undifferentiated carcinoma cells have an approximately 75% reduction in surface expression of the integrin as compared with the keratinocyte and papilloma cell lines. The alpha6beta4 integrin which remains expressed on the carcinoma cells is diffusely distributed in the membrane and has an approximately 2.5-fold increased biological turnover as compared with normal keratinocytes. The decreased biological half-life and the loss of polarized expression of alpha6beta4 on the carcinoma cells suggests an altered functional role for the alpha6beta4 integrin on carcinoma cells during tumor progression. These factors may contribute to the known supression of hemidesmosome structures and the increased migration phenotype associated with some epithelial carcinomas.

Animals↗

PubMed2000

Prognostic factors in colorectal cancer. College of American Pathologists Consensus Statement 1999.

BACKGROUND: Under the auspices of the College of American Pathologists, the current state of knowledge regarding pathologic prognostic factors (factors linked to outcome) and predictive factors (factors predicting response to therapy) in colorectal carcinoma was evaluated. A multidisciplinary group of clinical (including the disciplines of medical oncology, surgical oncology, and radiation oncology), pathologic, and statistical experts in colorectal cancer reviewed all relevant medical literature and stratified the reported prognostic factors into categories that reflected the strength of the published evidence demonstrating their prognostic value. Accordingly, the following categories of prognostic factors were defined. Category I includes factors definitively proven to be of prognostic import based on evidence from multiple statistically robust published trials and generally used in patient management. Category IIA includes factors extensively studied biologically and/or clinically and repeatedly shown to have prognostic value for outcome and/or predictive value for therapy that is of sufficient import to be included in the pathology report but that remains to be validated in statistically robust studies. Category IIB includes factors shown to be promising in multiple studies but lacking sufficient data for inclusion in category I or IIA. Category III includes factors not yet sufficiently studied to determine their prognostic value. Category IV includes factors well studied and shown to have no prognostic significance. MATERIALS AND METHODS: The medical literature was critically reviewed, and the analysis revealed specific points of variability in approach that prevented direct comparisons among published studies and compromised the quality of the collective data. Categories of variability recognized included the following: (1) methods of analysis, (2) interpretation of findings, (3) reporting of data, and (4) statistical evaluation. Additional points of variability within these categories were defined from the collective experience of the group. Reasons for the assignment of an individual prognostic factor to category I, II, III, or IV (categories defined by the level of scientific validation) were outlined with reference to the specific types of variability associated with the supportive data. For each factor and category of variability related to that factor, detailed recommendations for improvement were made. The recommendations were based on the following aims: (1) to increase the uniformity and completeness of pathologic evaluation of tumor specimens, (2) to enhance the quality of the data needed for definitive evaluation of the prognostic value of individual prognostic factors, and (3) ultimately, to improve patient care. RESULTS AND CONCLUSIONS: Factors that were determined to merit inclusion in category I were as follows: the local extent of tumor assessed pathologically (the pT category of the TNM staging system of the American Joint Committee on Cancer and the Union Internationale Contre le Cancer [AJCC/UICC]); regional lymph node metastasis (the pN category of the TNM staging system); blood or lymphatic vessel invasion; residual tumor following surgery with curative intent (the R classification of the AJCC/UICC staging system), especially as it relates to positive surgical margins; and preoperative elevation of carcinoembryonic antigen elevation (a factor established by laboratory medicine methods rather than anatomic pathology). Factors in category IIA included the following: tumor grade, radial margin status (for resection specimens with nonperitonealized surfaces), and residual tumor in the resection specimen following neoadjuvant therapy (the ypTNM category of the TNM staging system of the AJCC/UICC). (ABSTRACT TRUNCATED)

Biomarkers, Tumor↗

PubMed1999

Promatrilysin expression is induced by fibroblast growth factors in the prostatic carcinoma cell line LNCaP but not in normal primary prostate epithelial cells.

BACKGROUND: It has been determined that prostate cancer cells overexpress the matrix metalloprotease matrilysin (MMP-7), but the factors regulating this expression have not been identified. Fibroblast growth factors (FGF), which are expressed in the prostate, might participate in paracrine regulation of matrilysin expression by prostate cancer cells. METHODS: We tested the ability of recombinant FGF proteins and prostate fibroblast-conditioned media (PFCM) to induce promatrilysin expression in the prostate carcinoma cell line, LNCaP, and in normal prostate epithelial (PrEC) cells. We also characterized prostate fibroblast FGF expression by reverse transcriptase-polymerase chain reaction (RT-PCR). An inhibitor of FGF receptor activation (SU5402) was used to determine the role of FGF proteins in the induction of promatrilysin expression by PFCM. RESULTS: Recombinant FGF-1, FGF-2, FGF-9, FGF-10, and PFCM significantly induced promatrilysin expression in LNCaP cells but not in PrEC cells. Prostate fibroblasts express mRNAs for these FGF proteins, and inhibition of LNCaP cell FGF receptors with SU5402 substantially reduced the induction of promatrilysin expression by PFCM. CONCLUSIONS: Stromally expressed FGF proteins induce promatrilysin expression in a prostate carcinoma cell, and may provide a mechanism for the overexpression of promatrilysin observed in prostate cancer.

Carcinoma↗

PubMed1999

EGF induces the expression of matrilysin in the human prostate adenocarcinoma cell line, LNCaP.

BACKGROUND: Matrix metalloproteinases (MMPs) are regulated both positively and negatively at the transcriptional level by a variety of growth factors, oncogenes, and tumor promoters. Induction of the MMP, matrilysin, by epidermal growth factor (EGF) was investigated in a human prostate cancer cell line. METHODS: Secreted protein and messenger RNA were detected using Western and Northern methods, respectively. EGF receptor antibodies were used for neutralization of the EGF receptor to determine the role of the EGF growth factor family (EGF, transforming growth factor alpha (TGFalpha), or amphiregulin) in the basal induction of matrilysin. RESULTS: EGF increased mRNA and secreted protein levels for the MMP matrilysin in LNCaP cells, in a concentration- and time-dependent manner. Transforming growth factor beta1 (TGFbeta1) had no inhibitory effect on the levels of mRNA or secreted protein induced by EGF in LNCaP cells. Decay of matrilysin mRNA after the addition of actinomycin D indicated that the half-life of matrilysin mRNA was not altered by EGF. Blocking with a neutralizing antibody to the EGF receptor did not alter the basal level of secreted matrilysin. CONCLUSIONS: Exogenously added EGF increased matrilysin mRNA, perhaps at a transcriptional level. Growth factors, other than the members of the EGF family which act through the EGF receptor, may be involved in the regulation of the basal level of secreted matrilysin in LNCaP cells. Our data with LNCaP cells suggest that paracrine regulation of matrilysin expression in human prostate carcinoma cells could be via the EGF receptor.

Adenocarcinoma↗

PubMed1999

Experimental induction of rhabdomyosarcoma in mice with fractionated doses of beta-irradiation.

Repeated doses of beta-radiation in the mouse skin model have been reported to produce carcinomas and sarcomas with equal frequency. Among sarcomas, fibrosarcomas and osteosarcomas have been the predominant reported histologies. In this report we describe the beta-radiation induction of rhabdomyosarcoma (RMS), a histology previously undescribed with tumor induction protocols using ionizing radiation in an animal model. Radiation-induced RMS is often seen as a secondary tumor following therapeutic irradiation for retinoblastoma in children. In our experiment the backs of 50 CD-1 mice were irradiated 3 times weekly for 35 weeks using a 90Sr source. The initial dose was 5.5 Gy/application, which was later reduced to 3 Gy after 15 weeks due to severe skin reactions. In all, 27 skin and subcutaneous tumors were seen and collected. Of 12 sarcomas seen, 9 had a rhabdoid histology; cell lines from 3 such tumors as well as a squamous-cell carcinoma (SCC) and a malignant fibrous histiocytoma (MFH) were established. Immunohistochemical analysis of their parent tumors showed that the rhabdoid tumors expressed desmin, which established the diagnosis of RMS. Two-dimensional gel electrophoresis and Western analysis of insoluble protein extracts confirmed that the cell lines from RMS tumors expressed desmin. A screen for molecular alterations identified a mutant p53 phenotype for RMS and MFH cell lines. These radiation-induced RMS cell lines provide a unique opportunity to study the molecular biology of this tumor in an animal model and will help provide insight into the mechanisms of radiation-induced RMS in humans.

Animals↗

PubMed1999

N-Cadherin expression in human prostate carcinoma cell lines. An epithelial-mesenchymal transformation mediating adhesion withStromal cells.

In human prostate adenocarcinoma, an association between loss of E-cadherin, increased Gleason score, and extracapsular dissemination has been observed. Further characterization of the E-cadherin/catenin phenotype of human prostate carcinoma cell lines showed loss of E-cadherin and expression of N-cadherin in poorly differentiated prostate carcinoma cell lines (PC-3N derived from PC-3, PC-3, and JCA1). We showed that N-cadherin is concentrated at sites of cell-cell contact in PC-3N cellular extensions. N-cadherin was also expressed in prostate stromal fibroblasts both in vitro and in prostate tissue. Co-cultures of prostate stromal fibroblasts and PC-3N cells showed the immunolocalization of N-cadherin in intercellular contacts. In addition, the isoform expression of the cadherin binding protein p120(ctn) differed in relation to the expression of E- versus N-cadherin by the prostate carcinoma cell lines. The p100 isoform was more highly expressed in E-cadherin-positive carcinoma cell lines, whereas p120 was predominantly expressed only in N-cadherin-positive prostate carcinoma cell lines and prostate stromal fibroblasts. The N-cadherin-positive carcinoma cell line, PC-3N, displayed aggressive invasion into the surface of the diaphragm muscle after intraperitoneal injection of SCID mice. The gain of N-cadherin and loss of E-cadherin by invasive prostate carcinoma cell lines suggests a progression from an epithelial to a mesenchymal phenotype, which may allow for their interaction with surrounding stromal fibroblasts and facilitate metastasis.

Adenocarcinoma↗

PubMed1998

Synthetic matrix metalloproteinase inhibitor, BB-94, inhibits the invasion of neoplastic human prostate cells in a mouse model.

BACKGROUND: It has been suggested that increased metalloproteinase activity is a critical event in neoplastic progression leading to the initiation of local invasion and ultimately to the dissemination of neoplastic cells. This has led to an interest in testing the ability of metalloproteinase inhibitors to prevent the progression of carcinoma in situ into invasive and, therefore, more malignant tumors. One such agent is the synthetic matrix metalloproteinase inhibitor, BB-94. METHODS: The effect of BB-94 on the intrinsic invasive potential of matrilysin-transfected Du-145 cells was evaluated by an in vitro invasion assay. In addition a diaphragm invasion model, which provides an easily oriented structure in which the earliest penetration of the basal lamina can be observed, was used to investigate the effect of BB-94 on the invasion and growth of tumors formed by these cells when injected into S.C.I.D. mice. RESULTS: The synthetic matrix metalloproteinase inhibitor, BB-94, was shown to effectively inhibit the invasion of matrigel and murine diaphragm. CONCLUSIONS: Metalloproteinase inhibitors, such as BB-94, that are able to limit tumor growth, and local invasion, may decrease the invasion of invasive carcinomas.

Adenocarcinoma↗

PubMed1998

Activation of gelatinase-tissue-inhibitors-of-metalloproteinase complexes by matrilysin.

Matrilysin, gelatinase A and gelatinase B are matrix metalloproteinases (MMPs) implicated in normal and pathological processes that require remodelling of the extracellular matrix. In human prostate tissue, matrilysin is synthesized in ducts surrounded by inflammatory cells, and focally in prostate carcinoma, but not in normal glands. Gelatinase B expression is restricted to inflammatory cells. Gelatinase A can be found in both benign and malignant prostate tissue. MMP activities are regulated by their transition from latent to activated forms, as well as by the presence of tissue inhibitors of metalloproteinases (TIMPs). We investigated whether matrilysin can activate progelatinases A and B in the presence of their bound inhibitors TIMP2 and TIMP1 respectively. Incubation of progelatinase B-TIMP1 complex with active matrilysin resulted in 78 and 68 kDa active forms, as measured by SDS-PAGE and enzyme activity assays. TIMP-free gelatinase B was also activated by matrilysin. In addition, activation of progelatinase B by matrilysin was demonstrated in the conditioned medium of phorbol ester-treated HT1080 cells, confirming the results obtained in the in vitro experiments. In contrast, matrilysin did not proteolytically cleave gelatinase A-TIMP2 complex, but led to a transient increase in gelatinolytic activity of the proenzyme. Matrilysin did not enhance the autocatalytic conversion of its own proform. The data presented here suggest that matrilysin participates in a proteolytic cascade and can activate gelatinases in the presence of TIMPs.

Collagenases↗

PubMed1998

Accuracy of prostate needle biopsy in predicting extracapsular tumor extension at radical retropubic prostatectomy: application in selecting patients for nerve-sparing surgery.

OBJECTIVES: To evaluate prostate biopsy outcomes along with other clinical parameters in an effort to define the cancer-specific safety of nerve-sparing surgery. METHODS: Sixty-six consecutive men underwent radical retropubic prostatectomy for clinically localized prostate cancer (T1c = 36, T2 = 30). Preoperative prostate needle biopsies were performed on all patients, and radical prostatectomy specimens were processed in their entirety. Our pathologic end point was capsular perforation extending entirely through the prostatic capsule. Each prostatic side was analyzed individually, for a total of 132 specimens. The specimens were further divided into four categories on the basis of biopsy grade (no cancer = 44, low = 20, moderate = 60, high = 8). Additional study variables included preoperative prostate-specific antigen (PSA) and number of positive biopsy cores. RESULTS: Overall, 40 of the 132 specimens had evidence of capsular perforation. Of the 40 capsular perforations, 39 were observed in specimens (sides) that had cancer identified on biopsy. The one specimen with capsular perforation and a negative biopsy result occurred in the setting of high-grade contralateral cancer. PSA, digital rectal examination, and number of positive biopsy cores did not reliably predict capsular perforation. CONCLUSIONS: Our findings suggest that in patients with low- and moderate-grade tumors, the neurovascular bundle can be safely preserved on the side without evidence of cancer having obtained at least three biopsy cores. No safe parameters for considering nerve-sparing surgery were observed in the small number of patients with high-grade tumors, or in any specimen with cancer present on biopsy. Other clinical parameters, such as PSA or number of positive cores, did not aid in identifying candidates for nerve-sparing surgery.

Biopsy, Needle↗

PubMed1997

Cleavage of beta 4 integrin by matrilysin.

Overexpression of the matrix metalloproteinase matrilysin and the absence of beta 4 integrin are two features characteristic of human prostate carcinoma. In the following study we demonstrate that the beta 4 integrin, but not the alpha 6 or beta 1 integrin subunits, is cleaved by matrilysin in vitro. A specific fragment of 90 kDa is generated using matrilysin, which is not observed with other proteases. Two putative cleavage sites for matrilysin within the extracellular domain of the beta 4 integrin at residues 107 (isoleucine, prior to the ligand-binding region) and 417 (leucine, prior to cysteine-rich region) are identified by sequence comparisons with known matrilysin substrates. The selective cleavage of the beta 4 integrin by matrilysin may partly explain the loss of beta 4 integrin expression in invasive prostate carcinoma.

Antigens, CD↗

PubMed1997

Interleukin-1beta secreted from monocytic cells induces the expression of matrilysin in the prostatic cell line LNCaP.

Matrilysin is a matrix metalloprotease that is overexpressed in cancer cells of epithelial origin and in normal tissues during events involving matrix remodeling such as the cycling endometrium. We previously observed that inflamed ductule and acinar epithelia in the prostate also overexpress matrilysin. The presence of infiltrating macrophages in these areas prompted us to determine if factors secreted from monocytes could induce matrilysin expression in a human prostatic cell line. Conditioned media collected from the monocyte cell line THP-1 following lipopolysaccharide treatment substantially induced matrilysin protein and mRNA expression in LNCaP prostate carcinoma cells. Matrilysin expression in LNCaP cells was also induced by recombinant interleukin (IL)-1 (50 pM), but not by equimolar concentrations of recombinant tumor necrosis factor-alpha or IL-6. The matrilysin-inducing activity of THP-1 conditioned medium was completely abrogated by preincubation with a neutralizing antibody to IL-1beta. Transient transfection analyses with a chimeric human matrilysin promoter-chloramphenicol acetyltransferase reporter construct demonstrated that IL-1beta activates transcription through the matrilysin promoter in LNCaP cells. This is the first report of matrilysin induction by an inflammatory cytokine in a cell line of epithelial origin, and the results suggest a potential mechanism for the overexpression of matrilysin in inflamed ducts and glands of the prostate.

Cell Line↗

PubMed1997

Coordinated expression of matrilysin during TPA-induced apoptosis of LNCaP cells: two parallel processes affected by TPA.

Matrix metalloproteinases (MMPs) are upregulated by growth factors and 12-O-tetradecanoyl-phorbol-13-acetate (TPA). TPA (10 nM) induced apoptosis in LNCaP cells grown in serum-free medium at high seeding density, and increased mRNA and secreted protein levels for the MMP matrilysin. While the TPA-augmented increase in matrilysin mRNA was seen at 4 h, secreted matrilysin protein levels at 8 h, TPA-induced DNA ladder formation was seen only at 10 h and the TPA-induced apoptosis was detected at 12 h. The sequence of events suggested a functional role for matrilysin in apoptosis. However, when the MMP inhibitor BB-2516 was used (25 microM, with IC50 of 20 nM for matrilysin), there was no effect of BB-2516 on TPA-induced apoptosis in LNCaP cells (P = 0.2072). This observation indicates that MMPs including matrilysin do not play a primary role in TPA-induced apoptosis in LNCaP cells. We conclude that the TPA-induced apoptosis and the regulation of matrilysin (a TPA-response element (TRE)-containing gene), are independent and parallel processes.

Apoptosis↗

PubMed1997

Diagnostic accuracy of an international static-imaging telepathology consultation service.

Static-image and dynamic- (real-time) image telepathology are competing technologies. Although some studies suggest that the diagnostic accuracy of the dynamic-image telepathology approaches the accuracy of light microscopy, few reports have documented the diagnostic accuracy of static-image telepathology as used in the setting of an actual surgical pathology consultation practice. We report the results of an analysis of 171 telepathology consultation cases submitted to the Arizona-International Telemedicine Network (AITN). Digital images were submitted by pathologists from six participating institutions in Arizona, Mexico, and China. Telepathologists could render a telepathology diagnosis (TP) or defer rendering a diagnosis to obtain additional video images, glass slides for detailed analysis, or to obtain tissue blocks for special studies such as immunohistochemistry. The telepathologists rendered diagnoses for 144 cases and deferred 27 cases. Two pathologists retrospectively evaluated-glass slides from each case and rendered a consensus glass slide (GS) "truth" diagnosis. There was 88.2% concordance between TP and GS diagnoses (127 of 144 diagnoses). Concordance of 96.5% was achieved for clinically important diagnoses (139 of 144 diagnoses). Telepathologists deferred making a diagnosis to obtain glass slides for conventional light microscopy in 14 cases (8.1%) and for results of immunohistochemistry studies in 13 cases (7.6%). Thus, correct diagnoses were rendered by static-image telepathology in 127 of 171 cases (74.3%) at the time of telepathology diagnostic sessions. Inappropriate field selection and sampling biases of referring pathologists, as well as a tendency of static-image telepathologists to underestimate the complexity of some cases, may reduce the value of consultations based on the viewing of static images.

Humans↗

PubMed1997

Differential expression of cytokeratin mRNA and protein in normal prostate, prostatic intraepithelial neoplasia, and invasive carcinoma.

The expression of cytokeratin (CK) mRNA for CK5, -8, -14, -16, and -19 was investigated in normal prostate, prostatic intraepithelial neoplasia (PIN) lesions, and invasive carcinoma using in situ hybridization. Protein localization was carried out in adjacent sections using immunohistochemistry and correlated with mRNA expression. Snap-frozen human prostate samples including 22 examples of normal glands, 20 cases of PIN lesions, and 12 cases of invasive carcinoma were examined. CK5 and -14 mRNA and protein were prominently expressed only in the basal cells of normal glands and PIN lesions. CK14 mRNA was absent in the luminal cells of the most of the PIN lesions but was seen at a low level in some PIN lesions. CK14 protein was not detected in any PIN lesion, suggesting that, if the cell that makes up the PIN lesions is derived from a basal cell, CK14 translation is depressed although a low level of CK14 mRNA may persist. CK8 mRNA and protein were constitutively expressed in all epithelia of normal and abnormal prostate tissues. CK19 mRNA and protein were persistently expressed in both basal and luminal cells of the tubular portion of normal glands as well as PIN lesions, but were expressed heterogeneously in both basal and luminal cells of normal alveoli. CK16 mRNA was expressed in a similar pattern as CK19, but CK16 protein was not detected either in normal or in abnormal prostate tissues. In conclusion, the expression of CK19 in PIN lesions is similar to its tubular expression and would support an origin of PIN lesions from this structure rather than the alveolar portion of the glands. The similar cytokeratin expression between PIN lesions and invasive carcinoma further supports the concept that PIN is a precursor lesion of invasive carcinoma.

Carcinoma↗

PubMed1996

Matrilysin expression in human prostate carcinoma.

The metalloproteinases, a multigene family of metal-requiring enzymes, have been suggested to play a role in tumor invasion and metastasis. Previously, we demonstrated that human primary prostate tumors express higher levels of matrilysin and gelatinase A mRNA than normal prostate does. In the study presented here, we used in situ hybridization and immunohistochemical staining of serial sections of paraffin-embedded primary prostate tumors to compare the sites of matrilysin and gelatinase A expression and protein localization. These results confirmed the epithelial nature of matrilysin expression and protein localization. In contrast, gelatinase A mRNA was localized to the interstitial stroma, whereas the protein was associated with the epithelial tumor cells. In situ hybridization was also used to demonstrate that gelatinase B expression was restricted to macrophages infiltrating the tumors. Proteins isolated from an additional set of frozen tumor specimens were analyzed by western blotting to determine the relative amounts of matrilysin in the active and proenzyme forms. The western analyses demonstrated that in all cases in which matrilysin was detected, at least some of the enzyme was in the active form. These results are discussed with respect to the possible role these enzymes may play in prostate tumor progression.

Amino Acid Sequence↗