Contribution of the microvessel network to the clonal and kinetic profiles of adrenal cortical proliferative lesions.

Monoclonal adrenocortical lesions have been characterized by an inverse correlation between proliferation and apoptosis, and polyclonal lesions show a direct correlation. Their relationship with the vascular pattern remains unknown in adrenocortical nodular hyperplasias (ACNHs), adenomas (ACAs), and carcinomas (ACCs). We studied 20 ACNHs, 25 ACAs, and 10 ACCs (World Health Organization classification criteria) from 55 women. The analysis included X-chromosome inactivation assay (on microdissected samples), slide and flow cytometry, and in situ end labeling. Endothelial cells were stained with anti-CD31, and the blood vessel area and density were quantified by image analysis in the same areas. Appropriate tissue controls were run in every case. Regression analyses between kinetic and vascular features were performed in both polyclonal and monoclonal lesions. Polyclonal patterns were observed in 14 of 18 informative ACNHs and 3 of 22 informative ACAs, and monoclonal patterns were seen in 4 of 18 ACNHs, 19 of 22 ACAs, and 9 of 9 ACCs. A progressive increase in microvessel area was observed in the ACNH-ACA-ACC transition but was statistically significant between benign and malignant lesions only (191.36 +/- 168.32 v 958.07 +/- 1279.86 microm(2); P < .0001). In addition, case stratification by clonal pattern showed significant differences between polyclonal and monoclonal benign lesions; 6% of polyclonal and 57% of monoclonal lesions had microvessel area >186 microm(2) (P = .0000008). Monoclonal lesions showed parallel trends (but with opposite signs) for microvessel area and density in comparison with proliferation and apoptosis, whereas polyclonal lesions showed inverse trends. In conclusion, the kinetic advantage of monoclonal adrenal cortical lesions (increased proliferation, decreased apoptosis) is maintained by parallel increases in microvessel area and density.

Germline RET 634 mutation positive MEN 2A-related C-cell hyperplasias have genetic features consistent with intraepithelial neoplasia.

C-cell hyperplasias are normally multifocal in multiple endocrine neoplasia type 2A. We compared clonality, microsatellite pattern of tumor suppressor genes, and cellular kinetics of C-cell hyperplasia foci in each thyroid lobe. We selected 11 females from multiple endocrine neoplasia type 2A kindred treated with thyroidectomy due to hypercalcitoninemia. C-cell hyperplasia foci were microdissected for DNA extraction to analyze the methylation pattern of androgen receptor alleles and microsatellite regions (TP53, RB1, WT1, and NF1). Consecutive sections were selected for MIB-1, pRB1, p53, Mdm-2, and p21WAF1 immunostaining, DNA content analysis, and in situ end labeling. Appropriate tissue controls were run. Only two patients had medullary thyroid carcinoma foci. Nine informative C-cell hyperplasia patients showed germline point mutation in RET, eight of them with the same androgen receptor allele preferentially methylated in both lobes. C-cell hyperplasia foci showed heterogeneous DNA deletions revealed by loss of heterozygosity of TP53 (12 of 20), RB1 (6 of 14), and WT1 (4 of 20) and hypodiploid G0/G1 cells (14 of 20), low cellular turnover (MIB-1 index 4.5%, in situ end labeling index 0.03%), and significantly high nuclear area to DNA index ratio. MEN 2A (germline point mutation in RET codon 634) C-cell hyperplasias are monoclonal and genetically heterogeneous and show down-regulated apoptosis, findings consistent with an intraepithelial neoplasia. Concordant X-chromosome inactivation and interstitial gene deletions suggest clone expansions of precursors occurring at a point in embryonic development before divergence of each thyroid lobe and may represent a paradigm for other germline mutations.

PCR techniques for clonality assays.

Clonal overgrowths represent the hallmark of neoplastic proliferations, and their demonstration has been proved useful clinically for the diagnosis of malignant lymphomas based on the detection of specific and dominant immunoglobulin and/or T-cell receptor gene rearrangements. Nonrandom genetic alterations can also be used to test clonal expansions and the clonal evolution of neoplasms, especially analyzing hypervariable deoxyribonucleic acid (DNA) regions from patients heterozygous for a given marker. These tests rely basically on the demonstration of loss of heterozygosity (LOH) resulting from either hemizygosity (nonrandom interstitial DNA deletions) or homozygosity of mutant alleles observed in neoplasms. LOH analyses identify clonal expansions of a tumor cell population, and point to monoclonal proliferation when multiple and consistent LOH are demonstrated. Based on the methylation-related inactivation of one X chromosome in female subjects, X-linked markers (e.g., androgen receptor gene) will provide clonality information using LOH analyses after DNA digestion with methylation-sensitive restriction endonucleases. Therefore, both non-X-linked and X-linked analyses give complementary information, related and not related to the malignant transformation pathway respectively. Applied appropriately, these tools can establish the clonal evolution of tumor cell populations (tumor heterogeneity), identify early relapses, distinguish recurrent tumors from other metachronic neoplasms, and differentiate field transformation from metastatic tumor growths in synchronic and histologically identical neoplasms.

Clonal patterns in phaeochromocytomas and MEN-2A adrenal medullary hyperplasias: histological and kinetic correlates.

The relationship among histological features, cell kinetics, and clonality has not been studied in adrenal medullary hyperplasias (AMHs) and phaeochromocytomas (PCCs). Thirty-four PCCs (23 sporadic and 11 MEN-2A (multiple endocrine neoplasia type 2A)-related tumours, the latter associated with AMH) from females were included in this study. Representative samples were histologically evaluated and microdissected to extract DNA and evaluate the methylation pattern of the androgen receptor alleles. At least two tissue samples (from the peripheral and internal zones in each tumour) were analysed with appropriate tissue controls run in every case. The same areas were selected for MIB-1 staining and in situ end labelling (ISEL). Malignant PCCs were defined by histologically confirmed distant metastases. All monoclonal AMH nodules from the same patient showed the same X-chromosome inactivated. Six sporadic PCCs revealed liver metastases (malignant PCC) and eight additional sporadic PCCs showed periadrenal infiltration (locally invasive PCC). All informative PCCs were monoclonal, except for five locally invasive PCCs and one benign PCC that revealed polyclonal patterns. Those cases also showed a fibroblastic stromal reaction with prominent blood vessels, focal smooth muscle differentiation, and significantly higher MIB-1 (126.8+/-29.9) and ISEL (50.9+/-12.8) indices. Concordant X-chromosome inactivation in nodules from a given patient suggests that MEN-2A AMH is a multifocal monoclonal condition. A subgroup of PCCs characterized by balanced methylation of androgen receptor alleles, high cellular turnover, and stromal proliferation also shows locally invasive features.

Molecular evolution and intratumor heterogeneity by topographic compartments in muscle-invasive transitional cell carcinoma of the urinary bladder.

Superficial transitional cell carcinomas (TCC) of the urinary bladder have been shown to be monoclonal. However, no combined study of clonality and tumor suppressor genes (TSG) is available to date for muscle-invasive TCC. Forty-four muscle-invasive TCC of the urinary bladder selected from women were included in this study. Tumor cells located above and below the muscularis mucosa zone were systematically microdissected and used for DNA extraction. Hha-I digested and undigested samples were used to study the methylation pattern of androgen receptor alleles and undigested samples were used for microsatellite analysis of TSG (TP53, RB1, WT1, and NF1). Both loss of heterozygosity (LOH) and single nucleotide polymorphism (SNP) analyses were performed using optimized denaturing gradient gel electrophoresis. The expression of p53, pRB, and p21WAF1 was assessed by immunohistochemistry. Appropriate controls were run in every case. All except two TCC showed a monoclonal pattern with the same allele inactivated in both compartments. Microsatellite analysis of TSG revealed the same LOH/SNP pattern in both tumor compartments in 30 cases (involving more than 1 TSG locus in 8) and genetic heterogeneity in 14 cases. From the latter group, 9 cases expressed more genetic changes in the deep compartment (involving TP53 gene in all cases, WT1 gene in 2, and NF1 in 1), whereas in 4 cases the superficial compartment showed more genetic changes (three involving NF1 and one involving both RB and TP53). No statistical difference in the immunoexpression was detected, although it tended to be higher in the superficial compartment than in the deep compartment. These concordant data in polymorphic DNA regions indicate that bladder-muscle-invasive TCC are monoclonal proliferations with homogeneous tumor cell selection. Heterogeneous tumor cell selection by topography defined two different genetic compartments: superficial, NF1-defective, and deep, TP53-defective. No differences in the immunohistochemical expression were observed, precluding a more extensive clinical application.

Clonality as expression of distinctive cell kinetics patterns in nodular hyperplasias and adenomas of the adrenal cortex.

Although histopathologic criteria for adrenal cortical nodular hyperplasias (ACNHs) and adenomas (ACAs) have been developed, their kinetics and clonality are virtually unknown. We studied 20 ACNHs and 25 ACAs (based on World Health Organization criteria) from 45 females. Representative samples were histologically evaluated, and the methylation pattern of the androgen receptor alleles was analyzed on microdissected samples. Consecutive sections were selected for slide cytometry, flow cytometry, and in situ end labeling (ISEL). Apoptosis was studied by flow cytometry (nuclear area/DNA content plotter analysis) and by ISEL. Appropriate tissue controls were run in every case. Polyclonal gel patterns were revealed in 14/18 informative ACNHs and in 3/22 informative ACAs, whereas monoclonal gel patterns were observed in 4/18 ACNHs and 19/22 ACAs. Overlapping proliferation rates (PRs) were observed in both clonal groups, and apoptosis was detected only in G(0)/G(1) cells, especially in monoclonal ACNHs (3/4; 75%) and in polyclonal ACAs (2/3; 67%). Significantly higher PRs were observed in ACNHs with polyclonal patterns and G(0)/G(1) apoptosis and in ACAs regardless of clonality pattern and presence of G(0)/G(1) apoptosis. All except one ACNH (19/20; 95%) and 15/25 ACAs (60%) showed diploid DNA content, whereas the remaining cases were hyperdiploid. A direct correlation between PR and ISEL was observed in polyclonal lesions (PR = 29.32 ISEL - 1.93), whereas the correlation was inverse for monoclonal lesions (PR = -9.13 ISEL + 21.57). We concluded that only simultaneous down-regulated apoptosis and high proliferation result in selective kinetic advantage, dominant clone expansion, and unbalanced methylation patterns of androgen receptor alleles in ACNHs and ACAs.

Analysis of clonality of atypical cutaneous lymphoid infiltrates associated with drug therapy by PCR/DGGE.

Atypical lymphocytic infiltrates that mimic cutaneous lymphoma (ie, pseudolymphoma) are often observed in skin biopsy specimens from patients with altered immune function. The latter may reflect systemic immune dysregulatory states such as collagen vascular disease or human immunodeficiency virus infection. Among the iatrogenic causes are drug therapy with agents that abrogate lymphocyte function. These drugs encompass the anticonvulsants, antidepressants, phenothiazines, calcium channel blockers, and angiotensin-converting enzyme inhibitors. The appellation of lymphomatoid hypersensitivity reaction has been applied to cases of drug-associated pseudolymphoma. Pathologically and clinically, the distinction of such cases from cutaneous lymphoma is difficult. We employed the polymerase chain reaction (PCR) on archival material of proven drug-associated lymphomatoid hypersensitivity reactions both to explore its utility as an adjunct in diagnosis and to investigate the genotypic aberrations induced by drug therapy. Formalin-fixed, paraffin-embedded biopsy specimens from seven cutaneous T-cell lymphomas (CTCL), one nodal T-cell lymphoma, two cutaneous B-cell lymphomas, three typical hypersensitivity reactions, one tonsil, and 14 lymphomatoid hypersensitivity reactions were studied. Control cases for which DNA derived from fresh tissue was used include the Jurkat T-cell tumor line, placenta, one nodal B-cell lymphoma, and one case of reactive lymph node hyperplasia. DNA was obtained and purified by standard methods, then amplified with oligonucleotide primers specific for the T-cell receptor gamma locus and the immunoglobulin heavy chain genes. T-cell amplicons were analyzed by denaturing gradient gel electrophoresis (DGGE) and B-cell amplicons by either nondenaturing polyacrylamide or agarose gel electrophoresis. The nodal and Jurkat T-cell lymphomas, six of seven CTCL, one cutaneous B-cell lymphoma, and 2 of 14 lymphomatoid hypersensitivity reactions showed dominant ("monoclonal") T-cell gene rearrangement patterns, and the remainder of cases were polyclonal. A causal relationship between drug therapy and skin eruption was ascertained in the two patients showing T-cell rearrangements, and both experienced complete and sustained lesional resolution on discontinuation of the implicated drug. The only immunoglobulin heavy chain gene rearrangements detected by PCR were in two of the three B-cell lymphomas. We conclude that PCR/DGGE is a powerful method for assaying T-cell clonality in archival tissue and can aid in the discrimination of reactive from malignant cutaneous infiltrates with appropriate clinicopathologic correlation. Recognition that a monoclonal TCRgamma rearrangement can be observed in cases of drug-associated lymphomatoid hypersensitivity may help in avoiding a misdiagnosis of malignant lymphoma.

Increased beta-catenin protein and somatic APC mutations in sporadic aggressive fibromatoses (desmoid tumors).

Sporadic aggressive fibromatosis (also called desmoid tumor) is a monoclonal proliferation of spindle (fibrocyte-like) cells that is locally invasive but does not metastasize. A similarity to abdominal fibromatoses (desmoids) in familial adenomatous polyposis and a cytogenetic study showing partial deletion of 5q in a subset of aggressive fibromatoses suggests that the adenomatous polyposis coli (APC) gene plays a role in its pathogenesis. APC helps regulate the cellular level of beta-catenin, which is a downstream mediator in Wnt (Wingless) signaling. beta-Catenin has a nuclear function (binds transcription factors) and a cell membrane function (is a component of epithelial cell adherens junctions). Six cases of aggressive fibromatosis of the extremities from patients without familial adenomatous polyposis, or a family history of colon cancer, were studied. Immunohistochemistry, using carboxy and amino terminus antibodies to APC, and DNA sequencing showed that three of the six contained an APC-truncating mutation, whereas normal tissues did not contain a mutation. Western blot and Northern dot blot showed that all six tumors had a higher level of beta-catenin protein than surrounding normal tissues, despite containing similar levels of beta-catenin mRNA. Immunohistochemistry localized beta-catenin throughout the cell in tumor tissues, although it localized more to the periphery in cells from normal tissues. Reverse transcription polymerase chain reaction showed that the tumors expressed N-cadherin but not E-cadherin (a pattern of expression of proteins making up adherens junctions similar to fibrocytes), suggesting that the specific adherens junctions present in epithelial cells are not necessary for beta-catenin function. Increased beta-catenin may cause the growth advantage of cells in this tumor through a nuclear mechanism. The increased protein level, relative to the RNA level, suggests that beta-catenin is degraded at a lower rate compared with normal tissues. In some cases, this is caused by a somatic mutation resulting in a truncated APC protein.

Bcl-2 expression and DNA fragmentation in breast carcinoma, pathologic and steroid hormone receptors correlates.

B-cell leukemia/lymphoma (bcl-2) expression can override the apoptosis development in lymphoid and hormonally regulated tissue-like breast. The presence of estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR) have revealed in breast carcinomas, but they have not been correlated to the bcl-2 protein expression and DNA fragmentation markers. We evaluated the immunohistochemical expression of bcl-2 protein and hormonal receptors (ER, PR, AR) and differentiation grade in 37 infiltrating ductal carcinomas of the breast for which frozen tissues were available for DNA extraction. The immunohistochemical reaction for bcl-2 was considered positive if more than 50% of neoplastic cells had intense cytoplasmic staining, whereas for steroid receptor evaluation Battifora's criteria were used. The DNA was extracted according to the phenol-chloroform procedure and used for bcl-2 gene rearrangement study of the major breakpoint region (Southern blot) and for membrane-based end-labeling using digoxigenin-labeled nucleotides and E. coli DNA polymerase I (Klenow fragment). The results were quantified by three different observers. Low-grade carcinomas were positive for bcl-2 protein (27/28, 96.4%) and ER (15/28, 53.6%), whereas the remaining neoplasms were negative for bcl-2 (9/9, 100.0%) and ER (8/9, 53.6%) (p < 0.001). No statistically significant differences were revealed at the bcl-2, PR and AR comparisons. The Southern blot analysis for bcl-2 major breakpoint region showed neither rearrangement nor genetic amplification (densitometric study). Only the membrane-based end-labeling of DNA fragments showed correlation with bcl-2 protein and ER expressions: all except one bcl-2-negative tumor and two bcl-2-positive tumors had positive labeling using 7 pg of DNA at dot blot analysis (p < 0.002). The bcl-2 protein expression would allow both proliferation and cell progression by blocking apoptosis in well-differentiated, ER-positive breast carcinomas. In these neoplasms, DNA fragmentation as a molecular marker of apoptosis was prevented by bcl-2 expression.

Sustained biochemical and histologic remission of primary biliary cirrhosis in response to medical treatment.

BACKGROUND: Treatment of primary biliary cirrhosis with ursodiol or colchicine may stabilize the disease or slow its rate of progression, but no reports of spontaneous or treatment-related remission have been published. OBJECTIVE: To determine whether primary biliary cirrhosis fully responds to low-dose oral methotrexate therapy. DESIGN: Prospective case study with at least 6 years of observation. SETTING: Academic medical center. PATIENTS: 5 of 19 patients with biopsy-proven precirrhotic primary biliary cirrhosis who had been ill for at least 1 year. Three of the 5 had not responded to colchicine or had responded only partially. INTERVENTION: Oral methotrexate, 15 mg/wk in divided doses. MEASUREMENTS: Symptoms, biochemical tests of liver function, and percutaneous liver biopsies. The latter were done at baseline, 1 to 2 years after initiation of methotrexate therapy, and then every 2 to 3 years during methotrexate therapy. RESULTS: All 5 patients completely responded to medical treatment. Results of biochemical tests of liver function, became normal, symptoms remitted, and serial liver biopsy specimens showed progressive histologic improvement. Biopsy specimens obtained after 5 to 12 years of treatment showed few signs of primary biliary cirrhosis and, in 3 patients, were close to normal. Five of the other 14 patients have responded biochemically and have shown histologic improvement; the other 9 have not responded to methotrexate therapy, have discontinued therapy, or have been lost to follow-up. CONCLUSION: In some patients, primary biliary cirrhosis may remit in response to methotrexate alone or in combination with colchicine or ursodiol.

Aggressive fibromatosis (desmoid tumor) is a monoclonal disorder.

Aggressive fibromatosis (also called deep fibromatosis or desmoid tumor) is a proliferation of cytologically benign-appearing fibrocytes, often resulting in significant functional loss. The nature of the lesion is controversial: some evidence suggests that it is a reactive process, whereas other evidence supports a neoplastic etiology. The pattern of X chromosome inactivation, using a technique based on polymerase chain reaction (PCR) amplification of a hypervariable CAG repeat region flanking Hhal restriction sites of the human androgen receptor gene, was determined in four cases in which cryopreserved tumor and adjacent normal tissue were available. All four tumors demonstrated a monoclonal pattern, while the adjacent normal tissues demonstrated a polyclonal pattern. This demonstrates that aggressive fibromatosis is proliferation of cells derived from a single clone with a growth advantage, and thus is likely a neoplastic process.

Molecular genetic and immunohistochemical analysis of the tumor suppressor genes Rb and p53 in palmar and aggressive fibromatosis.

This pilot project analyzed the tumor suppressor genes p53 and Rb in 13 cases of aggressive fibromatoses and six cases of palmar fibromatoses (Dupuytren contracture). Immunohistochemistry, reverse transcription polymerase chain reaction, polymerase chain reaction followed by single-strand confirmation polymorphism analysis, and Southern blot to detect gene rearrangements were used. No abnormalities were detected in p53. The aggressive fibromatoses demonstrated a lack of Rb immunohistochemical staining and decreased mRNA for Rb. No structural mutation in the coding sequence of the Rb gene was detected. The decreased level of Rb gene expression, despite a normal coding sequence, may indicate increased proliferation and may suggest potential treatment schemes.

Regulation of proliferation and platelet-derived growth factor expression in palmar fibromatosis (Dupuytren contracture) by mechanical strain.

Palmar fibromatosis (Dupuytren contracture) causes fibrosis of specific palmar fascial bands. These bands are subjected to repetitive mechanical strain in situ. Primary cell cultures were derived from (a) palmar fibromatosis from eight patients, (b) uninvolved palmar fascia (Skoog's fibers) from four of these patients, and (c) normal palmar fascia from four additional patients. The cells were plated onto collagen-coated membranes either subjected to cyclic strain (25% maximal strain at 1 Hz) or without strain. Bromodeoxyuridine incorporation showed an increase in proliferation in all cultures subjected to strain. This increase was highest for palmar fibromatosis (10 to 40% nuclear incorporation, p = 0.02). Skoog's fibers and fascia from the normal individuals showed a trend (not significant) toward increase with strain (8 to 25%, p = 0.15 for Skoog's fibers, and 8 to 15%, p = 0.45 for normal fascia). Cyclic strain increased the expression of platelet-derived growth factor-A relative to glyceraldehyde-3-phosphate dehydrogenase in palmar fibromatosis (2.2 to 3.5, p = 0.05) and Skoog's fibers (0.8 to 2.0, p = 0.04). The expression of platelet-derived growth factor-B relative to glyceraldehyde-3-phosphate dehydrogenase was enhanced by cyclic strain only in the fibromatosis tissue (0.7 to 2.1, p = 0.04). The normal fascia did not express platelet-derived growth factor. Platelet-derived growth factor neutralizing antibody decreased bromodeoxyuridine incorporation in fibromatosis cultures subjected to cyclic strain to near levels for those grown in the absence of strain (38 to 16%, p = 0.05). Conditioned medium from fibromatosis cells grown under stain showed a trend toward increased proliferation in additional fibromatosis cultures compared with conditioned medium from fibromatosis cells grown without strain (9 to 15% nuclear incorporation, p = 0.20). The observed palmar fibromatosis contracture can be partially explained on the basis of the cell's response to cyclic strain, which may be mediated by platelet-derived growth factor.

Activating mutations of Gs protein in monostotic fibrous lesions of bone.

Activating mutations of the alpha chain of the heterotrimeric signal transducer Gs disrupt the inherent guanosine triphosphatase activity of the alpha chain, stimulate adenylyl cyclase, and can result in independent cell proliferation. Such mutations are identified in a number of endocrine disorders, including McCune-Albright syndrome, which is a triad of endocrinopathy, café au lait spots, and polyostotic fibrous dysplasia. The mutation in this syndrome is a missense point mutation in exon 8 that results in the substitution of either histidine or cysteine for arginine at position 201. Monostotic fibrous dysplasia is a nonhereditary isolated bone lesion. Other isolated bone lesions that share some cytologic and clinical similarities to fibrous dysplasia are osteofibrous dysplasia and aggressive fibromatosis involving bone. Four cases of monostotic fibrous dysplasia, four cases of aggressive fibromatosis involving bone, and one case of osteofibrous dysplasia were studied to determine if a mutation was present in exon 8 of the alpha chain of Gs. A missense mutation was present in all of the fibrous dysplasias. The other fibrous lesions and uninvolved tissue did not contain a mutation. Somatic activating mutations of Gs differentiate fibrous dysplasia from the other lesions and may be responsible for the loss of control of local proliferation and growth factor expression.

The expression of platelet-derived growth-factor gene in Dupuytren contracture.

Dupuytren contracture is a disease of the palmar fascia characterized by nodular fibroblastic proliferation; its etiology and pathogenesis are poorly understood. Growth factors are polypeptides that regulate cell growth and differentiation and extracellular matrix production. Platelet-derived growth factor is known to cause fibroblastic proliferation, and it may be involved in the pathogenesis of Dupuytren contracture. The purpose of this study was to determine if the gene for the B chain of platelet-derived growth factor is expressed in Dupuytren contracture. Tissue from patients who had Dupuytren disease was examined immunohistochemically with the 5B5 antibody, which is a marker for fibroblasts. Polymerase chain reaction, gel electrophoresis, Southern blotting, and in situ hybridization were also used to study gene expression in the tissue as well as in normal fascia, A172 cells, and MRC5 cells. Total cellular RNA was extracted from tissue and cells. Polymerase chain reaction was done with oligonucleotide primers complementary to a portion of the platelet-derived growth-factor-B and platelet-derived growth-factor-receptor genes. The platelet-derived growth-factor-B gene was expressed in all six specimens from the patients who had Dupuytren contracture as well as in the A172 cells, but not in the normal fascia lata or the MRC5 cells. These results were confirmed with Southern blotting of the products of the reaction with a platelet-derived growth-factor-B probe. The gene for the platelet-derived growth-factor receptor was expressed by all tissues and cells studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet-derived growth factor in fibrous musculoskeletal disorders: a study of pathologic tissue sections and in vitro primary cell cultures.

Despite the great variability in the clinical behavior of fibrous lesions of the musculoskeletal system, they are composed of cytologically similar fibrocytes. Receptors for estrogen or progesterone, or both, are present in some of these lesions and some increase their rate of growth during periods of high levels of sex steroid hormones. The platelet-derived growth factor-B (PDGF-B) proto-oncogene encodes the B chain of PDGF, a mitogen for fibrocytes. Tissue from aggressive fibromatosis, fibrous dysplasia, plantar fibromatosis, and recurrent plantar fibromatosis was analyzed with use of the polymerase chain reaction and in situ hybridization for the expression of PDGF-B and PDGF beta receptor. Cell culture was used to determine if estrogen and progesterone stimulation modulated the expression of PDGF-B. Aggressive fibromatosis, fibrous dysplasia, and recurrent plantar fibromatosis expressed PDGF-B; plantar fibromatosis, normal plantar fascia, normal fascia lata, and mature scar did not. All of the tissues expressed PDGF beta receptor. The level of expression in aggressive fibromatosis and fibrous dysplasia was four times that in the recurrent plantar fibromatosis. Estrogen and progesterone stimulation in aggressive fibromatosis resulted in an increase in the level of expression. Therefore, the detection of PDGF-B may be an adjunct in the pathologic identification of locally invasive lesions. Its production may be a common mechanism leading to a fibroproliferative response through deregulation of the control of growth by both paracrine and autocrine mechanisms.

Molecular diagnosis of the Philadelphia chromosome translocation. A comparison of isotopic and chemiluminescent Southern blotting.

Southern blotting using radiolabeled probes is a well established technique for the detection of the Philadelphia translocation in the diagnosis of chronic myelogenous leukemia (CML). However, the use of radioisotopes in the clinical setting is often problematic. Because of this we investigated the use of a digoxigenin-labeled probe and chemiluminography in the detection of the Philadelphia translocation. In this study DNA was extracted from 19 bone marrow or blood samples from patients with CML or other malignancies and subjected to Southern blotting with a probe specific for the Philadelphia translocation, Phl/bcr3. The probe was labeled with either 32P or digoxigenin to determine the relative sensitivity and specificity of autoradiography and chemiluminography in the molecular diagnosis of the BCR/abl fusion gene. All 19 samples were tested by both methods. All blots were performed and interpreted by individuals blind to the initial patient diagnosis. In addition, 12 samples (6 positive for CML, 6 negative for CML as determined by Southern blotting with 32P-labeled probe) were subjected to triplicate Southern-blot analyses, with three separate lots of digoxigenin-labeled probe to assay batch to batch variability in the efficacy of the probe. Radiolabeled and digoxigenin-labeled probes resulted in identical diagnoses in all cases. All results obtained by molecular analysis correlated perfectly with the clinical diagnoses of the patients from whom the samples had been obtained. Reanalysis of patient samples with different batches of digoxigenin-labeled probe gave highly reproducible results. With digoxigenin-labeled probe, diagnostic results were obtained after exposure times of less than 1 h at room temperature.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular characterization of the androgen receptor gene in boys with hypospadias.

Development of male external genitalia is dependent on androgens, and karyotypic males lacking appropriate levels of androgens or functionally normal receptors may show abnormal virilization. Mutations in the androgen receptor gene cause abnormal receptor function and diverse mutations may be associated with heterogeneous clinical signs of androgen insensitivity. In this study, we have searched for the existence of androgen receptor gene mutations carried by some patients with hypospadias. Genomic DNA samples from peripheral blood leucocytes from 21 patients with different degrees of hypospadias were studied. Analysis of the androgen receptor gene was performed by exon-specific amplification using polymerase chain reaction, single strand conformation polymorphism analysis, and direct genomic sequencing. Although a silent polymorphism was identified in exon 1 of the androgen receptor gene, the majority of patients studied (20/21) did not carry androgen receptor gene mutations. One patient with severe hypospadias and bilateral cryptorchidism was found to carry a point mutation in exon 8. We conclude that mutations in the androgen receptor gene may be carried by subset of patients with genital ambiguity presenting primarily with hypospadias, but this is not the underlying cause in the majority of cases. Characterization of this genetic defect may be important for classification and subsequent conservative therapeutic approaches for these patients.

Polysialic acid of the neural cell adhesion molecule in the human thyroid: a marker for medullary thyroid carcinoma and primary C-cell hyperplasia. An immunohistochemical study on 79 thyroid lesions.

We recently reported that the gold-labeled monoclonal antibody MAb 735, reactive with a long-chain form of alpha-2,8-linked polysialic acid (polySia) found on the neural cell adhesion molecule (NCAM), is useful to immunohistochemically distinguish small-cell lung carcinomas from neuroendocrine carcinomas with higher grade of differentiation (carcinoids) and other types of lung carcinomas (Am J Pathol 1991;139:297). In this study, we tested the occurrence of polySia in various types of malignant thyroid tumors and C-cell hyperplasia to determine whether polySia is a useful adjunct for the differential diagnosis of medullary thyroid carcinoma (MTC) and other thyroid neoplasms and to distinguish primary from secondary (reactive) C-cell hyperplasia (CCH). We examined formaldehyde-fixed and paraffin-embedded sections of 79 thyroid lesions, consisting of 33 MTC (14 familial and 19 sporadic tumors), 13 follicular, 11 papillary, 16 anaplastic carcinomas, and four glands with primary and two with secondary CCH. We applied a direct and an indirect immunogold-silver technique for polySia, CT, and CEA detection, respectively. All 33 MTC showed a strong cell-surface-associated immunoreactivity for polySia, which was sensitive to endoneuraminidase digestion. The polySia immunoreactivity of nerves served as an internal control in all specimens. Immunoreactivity for CT and CEA was present in all MTC with the exception of one recurrent tumor with features of an anaplastic MTC type. All other thyroid neoplasms were nonreactive for polySia, CT, and CEA. Primary CCH associated with MTC showed a strong polySia immunostaining, which was less intense in primary CCH not combined with MTC. In normal-appearing C cells and in secondary CCH, staining for polySia was absent in the majority of cases. We conclude that polySia of NCAM is a valuable marker to distinguish medullary carcinomas from other types of thyroid carcinomas. Furthermore, it allows for the discrimination of primary from secondary C-cell hyperplasia and may be helpful to better define the normal range of C cells in unaffected members of a family with a history of multiple endocrine neoplasia (MEN)-II.