Frequent microsatellite alterations at chromosomes 9p21 and 3p14 in oral premalignant lesions and their value in cancer risk assessment.

To better understand genetic alterations in oral premalignant lesions, we examined 84 oral leukoplakia samples from 37 patients who had been enrolled in a chemoprevention trial. The samples were analyzed for two microsatellite markers located at chromosomes 9p21 and 3p14. Loss of heterozygosity (LOH) at either or both loci was identified in 19 of the 37 (51%) patients. Of these 19 patients, seven (37%) have developed head and neck squamous cell carcinoma (HNSCC) while only one of 18 (6%) of patients without LOH developed HNSCC. Our data suggest that clonal genetic alterations are common in oral premalignant lesions; that multiple genetic alterations have already occurred in oral premalignant lesions, allowing at least a focal clonal expansion; and that losses of the 9p21 and 3p14 regions may be related to early processes of tumorigenesis in HNSCC. These genetic alterations in premalignant tissues may serve as markers for cancer risk assessment.

Cytostructural localization of a tumor-associated antigen.

Tumor cell membrane glycoproteins may be involved in the induction of tumor immunity or in the escape of tumors from immunologic defense mechanisms. Forty-four benign and malignant breast lesions were examined for the presence of a carbohydrate precursor antigen (T antigen) of the human blood group system MN. T antigen was demonstrated by means of an immunohistochemical technique to detect tissue binding of peanut agglutinin, a plant lectin, with affinity for T antigen. Malignant breast lesions showed a pattern of T antigen expression different from that of benign breast tissues. A possible role for T antigen in the modulation of the immune response to breast carcinoma is suggested.

Expression of the mdr (P-glycoprotein) gene in Chinese hamster digestive tracts.

P-glycoprotein has been shown to be responsible for multidrug resistance in mammalian cells. However, its physiological roles in normal cells are not known. The gene encoding this protein has been shown to express at a relatively high level in human digestive tracts. In the present study, in situ hybridizations were employed to determine the expression of this gene in gastrointestinal tissues. Epithelial cells in the villi of small intestine, colon, and stomach were rich in the P-glycoprotein gene transcript. Observations were consistent with the idea that the P-glycoprotein plays a role in detoxification by pumping potentially harmful compounds into the lumen of digestive tracts in animals.

Distinctive protein pattern in two-dimensional electrophoretograms of cancerous prostatic tissues.

In this report, we describe methods used to analyze the protein composition of sectioned frozen prostatic tissues by two-dimensional gel electrophoresis. Our results show a high degree of homology in two-dimensional electrophoretograms of proteins extracted from frozen sections of malignant prostate glands. Such homology was not apparent in protein patterns of benign hypertrophic prostatic tissue sections. Typically, 600 discrete proteins were resolved on two-dimensional electrophoretograms and 9 proteins were present in all patterns of prostate adenocarcinomatous tissues. These nine proteins were not observed in any of the protein electrophoretograms developed from nonmalignant prostate tissue. Three proteins were found common to nonmalignant prostate glands but were not present in prostatic adenocarcinoma.

Monoclonal antibody recognizing a carcinoembryonic antigen epitope differentially expressed in human colonic carcinoma versus normal adult colon tissues.

Murine hybridomas were generated against purified carcinoembryonic antigen (CEA), and their monoclonal antibodies (MAb) were assayed for their ability to recognize specific CEA epitopes. One of the MAb, designated 7F, was found to recognize an epitope of CEA that was expressed in human colonic carcinoma tissues but not in normal colonic tissues. When extracts of 13 colonic carcinoma tissues and 9 normal colonic tissues were examined with the Western blot technique using MAb 7F, 11 colonic carcinoma tissues (85%) reacted with 7F, but none of the 9 normal colonic tissues (including many obtained from the areas adjacent to the colonic carcinomas) did. Western blot analysis indicated a Mr 180,000 band in 11 of 13 (85%) colonic carcinoma extracts. The limit of detectability of CEA was 0.5 micrograms/lane. According to immunohistochemical techniques, 16 of 18 (89%) formalin-fixed paraffin-embedded sections of colonic carcinomas reacted with MAb 7F, whereas 9 of 9 (100%) frozen sections of colonic carcinomas reacted with the antibody. Of the 32 paraffin-embedded and frozen sections of normal colonic tissues examined, none showed any reactivity with MAb 7F. MAb 7F did not react with nonspecific cross-reacting antigen either. This antibody has been examined for its usefulness in detecting CEA in suspension and has been found to work both in sandwich enzyme-linked immunosorbent assays and in sandwich radioimmune assays. The detection of CEA in colon tumors but not in normal colonic tissues may be attributed to two possible explanations. It is possible that the level of CEA expression in normal colonic tissue is below the sensitivity of the assays employed. Alternatively, MAb 7F may recognize a "specific" epitope of CEA which was found in colon tumors but not in CEA of normal colonic tissues. At the present time, it is not possible to discern between these two possibilities. Nevertheless, MAb 7F was capable of detecting the differential expression of CEA in colonic carcinomas and, therefore, may be useful for the immunodiagnosis, radioimaging, and immunotherapy of colon cancer.

Sequential loss of heterozygosity at microsatellite motifs in preinvasive and invasive head and neck squamous carcinoma.

Studies of sequential molecular alterations in noninvasive and invasive head and neck squamous carcinoma are few in number. Consequently, the genetic changes associated with the neoplastic transformation of these carcinomas have not been defined. To identify chromosomal alterations in preinvasive and invasive head and neck squamous carcinoma, we analyzed DNA from microdissected normal squamous epithelium, severe dysplasia, and invasive carcinoma samples from 20 patients for loss of heterozygosity (LOH) at microsatellite loci by multiplex PCR. Twenty-five microsatellite repeats on chromosomes 3p, 5q, 8p, 9p and 9q, 11q, 17p, 17q, and 18p and 18q regions were used. In informative cases, LOH in noninvasive lesions was observed in 9p (28%), 9q and 18q (10%), 11q and 17p (7%), and 3p and 18p (5%). A high incidence of LOH in invasive carcinoma was observed at 9p (72%), 8p (53%), 3p (47%), 9q (35%), and 11q (33%). LOH was also associated with DNA aneuploidy, high tumor stage, and poor histological differentiation. Our results indicate that: (a) the high incidence of LOH at loci on chromosomes 9p, 8p, 3p, 9q, and 11q implicate these regions in head and neck squamous carcinoma tumorigenesis; (b) 9p loci alterations are manifested in the early development of these tumors; (c) LOH is correlated with poor prognostic clinicopathological factors; and (d) LOH at 8p loci appears to be associated with the tumor's aggressive features.

Amplification and overexpression of HER-2/neu in carcinomas of the salivary gland: correlation with poor prognosis.

There are few reliable prognostic markers of biological aggressiveness for head and neck carcinomas in general. For salivary gland carcinomas, anatomic location, tumor size, histological grade, and extent of disease involvement are considered to be clinically important risk factors for recurrent disease. Molecular genetic alterations in salivary gland carcinomas have not been characterized, and tumor cell proteins have not been shown to be prognostically significant. Here a cohort of mucoepidermoid carcinomas of the major (parotid and submandibular) salivary glands are analyzed for a molecular genetic alteration, HER-2/neu gene amplification, and gene amplification and expression results are compared with long-term clinical follow-up information. Archival tissues resected from 58 patients with mucoepidermoid carcinoma of salivary glands were evaluated for HER-2/neu gene amplification by fluorescence in situ hybridization and for gene expression by immunohistochemistry in a blinded fashion. Clinical follow-up information was compared with the results of these analyses to determine whether there were significant associations. Overexpression, identified as membrane immunostaining by immunohistochemistry, was observed in 22 of 58 (38%) mucoepidermoid carcinomas. Gene amplification, characterized by fluorescence in situ hybridization, was observed in 12 (21%) cases. Eleven of the 12 cases with gene amplification were also immunostained for HER-2/neu. Both gene amplification (P = 0.0001, P < 0.0001) and immunostaining (P < 0.0001, P < 0.0001) were correlated with shorter disease-free interval and poorer overall patient survival, respectively. Multivariate analysis showed that HER-2/neu immunostaining and amplification were markers of poor prognosis independent of histopathological grade, tumor size, and involvement of regional lymph nodes. HER-2/neu is amplified and/or overexpressed in approximately one-third of mucoepidermoid carcinomas of salivary glands. Amplification and/or overexpression appears to be an independent marker of poor prognosis in mucoepidermoid carcinomas of the salivary glands as it is in carcinomas of the breast, ovary, and endometrium.

p53 and retinoid chemoprevention of oral carcinogenesis.

We studied p53 protein's pattern of expression, association with retinoid response or resistance, and modulation by retinoid intervention in oral premalignancy. These p53 analyses were included in a prospective trial of the retinoid isotretinoin (1.5 mg/kg/day for 3 months) in 40 patients (45 oral premalignant lesions). Seven nonsmoking subjects (eight oral biopsies) were included as a control. Protein levels of p53 were determined separately for the whole epithelium and the basal, parabasal, and superficial layers. A wide range of accumulated p53 protein levels occurred in 40 (89%) of 45 lesions in basal and parabasal but not superficial layers. No p53 protein was detected in any normal controls. Accumulation of p53 increased in direct association with histological grade (P = 0.0004). An inverse relationship occurred between the levels of accumulated p53 protein and response to isotretinoin (P = 0.006). High-dose isotretinoin did not modulate accumulated p53 protein expression.

Localization of chromosome 8p regions involved in early tumorigenesis of oral and laryngeal squamous carcinoma.

We analysed 30 primary invasive oral and laryngeal squamous carcinomas (SC), with concurrent dysplastic lesions, for genetic alterations at 15 microsatellite loci on the short arm of chromosome 8. Overall, loss of heterozygosity (LOH) was observed, in at least one informative locus, in 27% of the dysplastic lesions and in 67% of the invasive carcinomas. The highest frequency of allele losses in dysplasia (20% and 17%), and invasive carcinoma (40% and 48%) were detected in the same D8S298 and LPL-tet loci located on chromosomes 8p21 and 8p22 respectively. The minimal region with LOH was limited to 4.6 megaBases (mBs) at 8p22 and 7.1 mBs at 8p21. In addition, allelic losses in both dysplastic and corresponding invasive specimens were noted at the same loci in some tumors suggesting their emergence from a common preneoplastic clone. Allele losses correlated significantly with male gender, oral and laryngeal sites and high proliferative index. The data suggest that inactivation of tumor suppressor gene(s), within these loci, may constitute an early event in the evolution of oral and laryngeal SC.

Superimposed histologic and genetic mapping of chromosome 17 alterations in human urinary bladder neoplasia.

Multistep alterations of chromosome 17 in the progression of human urinary bladder neoplasia were studied by superimposed histologic and genetic mapping. The p53 gene was included in the analysis as a model tumor suppressor gene that is frequently involved in urothelial carcinogenesis. The strategy provided a systematic approach to the study of multistep genomic alterations that occur as neoplasia progresses from precursor intraurothelial conditions to invasive cancer. This was accomplished by sampling the entire mucosa of the organ and displaying microscopically identified invasive cancer and precursor conditions in the form of a histologic map. Subsequent isolation of DNA provided a set of samples in which the search for genetic alterations was performed and superimposed on the histologic map. This approach disclosed multifocal allelic losses of chromosome 17 in the early preinvasive phases of urothelial neoplasia. The alterations were predominantly confined to the p12-13, q22-11 and q24-25 regions. Mutations and allelic losses of the p53 gene were mapped to early preinvasive phases of urothelial neoplasia. The data provide detailed analysis of chromosome 17 allelic losses that occur in the development and progression of urothelial neoplasia and represent the first step for genome-wide modeling of multistep human urothelial carcinogenesis.

Superimposed histologic and genetic mapping of chromosome 9 in progression of human urinary bladder neoplasia: implications for a genetic model of multistep urothelial carcinogenesis and early detection of urinary bladder cancer.

The evolution of alterations on chromosome 9, including the putative tumor suppressor genes mapped to the 9p21-22 region (the MTS genes), was studied in relation to the progression of human urinary bladder neoplasia by using whole organ superimposed histologic and genetic mapping in cystectomy specimens and was verified in urinary bladder tumors of various pathogenetic subsets with longterm follow-up. The applicability of chromosome 9 allelic losses as non-invasive markers of urothelial neoplasia was tested on voided urine and/or bladder washings of patients with urinary bladder cancer. Although sequential multiple hits in the MTS locus were documented in the development of intraurothelial precursor lesions, the MTS genes do not seem to represent a major target for p21-23 deletions in bladder cancer. Two additional tumor suppressor genes involved in bladder neoplasia located distally and proximally to the MTS locus within p22-23 and p11-13 regions respectively were identified. Several distinct putative tumor suppressor gene loci within the q12-13, q21-22, and q34 regions were identified on the q arm. In particular, the pericentromeric q12-13 area may contain the critical tumor suppressor gene or genes for the development of early urothelial neoplasia. Allelic losses of chromosome 9 were associated with expansion of the abnormal urothelial clone which frequently involved large areas of urinary bladder mucosa. These losses could be found in a high proportion of urothelial tumors and in voided urine or bladder washing samples of nearly all patients with urinary bladder carcinoma.

Blood protein fraction comparisons of normal and schizophrenic patients.

Whole blood, plasma, or serum levels of various components were measured in fasting, drug-free control subjects and drug-free schizophrenic patients. Compared to normal controls, chronic schizophrenic patients showed increased alpha2-globulins and decreased plasma cholinesterase activity and ceruloplasmin activity, and acute schizophrenic patients showed decreased alpha2-globulins. Compared to chronic patients, acute schizophrenics showed decreased alpha2-globulins and IgA. Compared to normal controls of similar age, chronic schizophrenic patients weighed less, were shorter, and had smaller body surface area. The acute schizophrenic patients were significantly younger than the normal subjects or chronic schizophrenics but there was no difference in the other physical measurements. The present study indicates no gross disturbances in the blood variables studied. That some differences are statistically significant from controls is of scientific interest, but of no clinical value in the diagnosis of schizophrenia.

Allelic loss and replication errors at microsatellite loci on chromosome 11p in head and neck squamous carcinoma: association with aggressive biological features.

The frequent loss of heterozygosity (LOH) demonstrated at chromosome 11p regions in several sporadic malignancies has suggested the presence of tumor suppressor genes at these locations. To obtain detailed mapped incidence of the microsatellite alterations at these regions and to investigate the possible correlation between the genotype and the pathobiological characteristics of head and neck squamous carcinoma, we analyzed paired DNA samples from normal mucosa and primary tumor specimens from 56 patients with these tumors. Our results show that 50.9% of the tumors had microsatellite alterations at one or more of these loci. LOH was manifested in 45. 5% and instability in 5.5% of the tumors. 11p15 loci showed more frequent LOH (39.6%) than those of 11p13 (29.3%) and 11p11-12 (18. 8%); the D11S988 (11p15) marker showed the highest single locus incidence of LOH (29.7%). Eight tumors (22.2%) demonstrated simultaneous LOH at both the 11p15 and 11p13 regions. LOH was significantly associated with poor histological differentiation, DNA aneuploidy, and high proliferative activity in these neoplasms. Our study extends the involvement of the 11p13 and 11p15 regions to head and neck squamous tumorigenesis and indicates that the terminal loci of 11p may harbor a tumor suppressor gene(s) associated with the progression of these tumors.

Accumulation of p53 protein and retinoic acid receptor beta in retinoid chemoprevention.

Although retinoids have proven to be effective as chemopreventive agents in reversing premalignant oral lesions and preventing second primary tumors, their mechanisms of chemopreventive efficacy in clinical settings have not been established. To better define this mechanism, we studied p53 protein and retinoic acid receptor beta (RAR-beta) expression in 52 baseline biopsy samples taken from premalignant oral lesions. We then studied p53 expression in 39 matched samples and RAR-beta expression in 38 matched samples before and after treating them with isotretinoin. The study results were then compared with clinical responses. To detect p53 protein expression, 4-micrometer sections of formalin-fixed, paraffin-embedded tissue specimens were used for immunohistochemical analysis with a monoclonal anti-p53 antibody, and levels of p53 expression were recorded with a labeling index (LI). Expression of RAR-beta mRNA was determined using nonradioactive in situ hybridization, and the staining intensity of RAR-beta mRNA was semiquantitated using scores from 0 (no expression) to 3+ (highest expression). p53 protein was detected in 85% of all lesions. High p53 protein expression (LI >/= 0.2) was detected in 25% of the lesions at baseline and in 18% of the lesions after isotretinoin therapy. The clinical response was 65% for lesions having low p53 expression (LI < 0.2) and 27% for lesions having high p53 expression (P = 0.027). Expression of RAR-beta mRNA was detected in 40% of the patients at baseline and increased to 90% of the patients after isotretinoin therapy (P < 0. 001). Seventy-two percent of the patients having low p53 expression had no RAR-betamRNA expression at baseline, whereas 22% of the patients having high p53 expression had no RAR-beta expression, which suggests that patients having low p53 expression tended to lose RAR-beta mRNA expression in their tissues. Eighty-three percent of patients having low p53 expression had up-regulation of RAR-beta mRNA after isotretinoin therapy, compared with 22% of patients with high p53 expression (P = 0.003). We correlated baseline p53 protein expression with RAR-beta modulation and clinical responses to isotretinoin therapy. The patients with low p53 protein expression at baseline and up-regulation of RAR-beta after isotretinoin therapy achieved a 70% rate of major response. The patients with low p53 protein expression and either no change or down-regulation of RAR-beta or with high p53 expression and up-regulation of RAR-beta had a response rate of 50%. The patients with high p53 protein expression and either no change or down-regulation of RAR-beta had a response rate of only 14% to isotretinoin therapy. The basic mechanisms underlying the association between clinical responses and these two biomarkers need to be explored.

Retrotympanic odontoma.

The clinical and histologic features of the second reported case of retrotympanic odontoma, which clinically presented as a cholesteatoma, are described. Origin from the posterior extension of the dental lamina is postulated. The dental lamina, the thickened oral ectoderm which outlines dental structures, is incorporated subendodermally in the lateral outpouching of the first pharyngeal pouch which produces the middle ear cavity. Histologically the odontoma was "complex," containing a haphazard arrangement of cementum, dentin, dental follicle and proliferating dental lamina, without the formation of recognizable teeth.

Use of Ulex europaeus agglutinin I in the identification of lymphatic and blood vessel invasion in previously stained microscopic slides.

Lymphatic and blood vessel invasion is one of the most important diagnostic and prognostic parameters used by pathologists in the evaluation of neoplastic conditions. Although a variety of tissue artifacts can make the recognition of vascular, capillary, and lymphatic permeation by tumor cells extremely difficult, recent immunohistochemical studies have employed a variety of tissue markers that appear to have great value in establishing the diagnosis of lymphovascular involvement. In the present study, we applied an immunoperoxidase staining technique to previously stained microscopic tissue sections using Ulex europaeus agglutinin I lectin, an endothelial marker that can be used in paraffin-embedded tissues. Our results indicate that this technique can be successfully applied on microscopic slides previously stained with a variety of histochemical stains. It can also be used in those cases in which paraffin blocks are not available or the area in question is absent from the recut tissue sections.

DNA ploidy in testicular germ cell neoplasms. Histogenetic and clinical implications.

Flow cytometry was used to determine the DNA ploidy pattern of 148 testicular germ cell neoplasms (seminomas and nonseminomas in pure and mixed histologic phenotypes) and in situ carcinoma (CIS) adjacent to these tumors. The great majority (96.0%) manifested aneuploid DNA contents with minimal intratumoral heterogeneity (2.5%). The mean DNA indices (DI) of CIS (1.7 +/- 0.18), pure seminoma (1.82 +/- 0.55), and the seminoma component of mixed germ cell neoplasms (1.76 +/- 0.13) were statistically similar. The mean DI of nonseminomas pure (1.46 +/- 0.29) or as a component of mixed tumors (1.43 +/- 0.32) was significantly lower (p greater than 0.001) than those of CIS and seminomas. Our data suggest that the similarity between the DNA indices of CIS and seminomas provide evidence that both lesions constitute a temporal evolutionary step in the progression of germ cell tumors and that nonseminomas may subsequently arise from either CIS or seminoma by further loss of chromosomal DNA. These characteristic findings support the nonstochastic theory for germ cell evolution and progression and may be useful in the clinicopathologic evaluation of testicular masses.

Genotypic alterations in benign and malignant salivary gland tumors: histogenetic and clinical implications.

Loss of heterozygosity (LOH) and microsatellite instability (MI) were examined at 24 microsatellite loci in 46 primary benign and malignant salivary gland tumors. Among the 27 benign tumors, 11 (40.7%), manifested microsatellite alterations in at least one locus; of these, five (18.5%) showed LOH and four (14.8%) had microsatellite instability at two or more loci. Four of 11 pleomorphic adenomas (36.4%) had allele loss on the long arm of chromosome 8. Among the 19 malignant neoplasms examined, 10 (52.6%) and one (5.2%) had allele losses and MI, respectively, at multiple loci; three tumors showed MI at only one locus. Frequent LOH was detected at D8S166 (8q11-12), D17S799, and D17S122 (17p-17p11-2) loci, with an incidence of 40%, 37.5%, and 43%, respectively. In general, malignant neoplasms with LOH exhibited aggressive tumor characteristics. Statistically significant correlation's were found between LOH and pathologic classification (chi 2, p = 0.05), higher grade (p = 0.02), DNA aneuploidy (p = 0.005), and a proliferative index of > 6% (p = 0.005) of the malignant tumors. Carcinomas with 17p loci alterations, including two carcinomas expleomorphic adenoma with concurrent 8q LOH, showed more aggressive features. The results suggested that (a) loci on chromosome 8q may harbor a tumor suppressor gene or genes associated with the development or progression of some salivary neoplasms; (b) alterations on the short arm of chromosome 17 may represent an event related to tumor progression; and (c) tumors with LOH at multiple loci have aggressive biologic characteristics.

Molecular and biomarker analyses of salivary duct carcinomas: comparison with mammary duct carcinoma.

Salivary duct carcinoma (SDC) is a rare high-grade aggressive neoplasm that manifests close histologic features with invasive ductal carcinoma of the breast (IDC). In contrast to SDC, extensive molecular studies have been performed on IDC and led to the identification of certain biological markers. To investigate the underlying molecular and biologic characteristics of SDC, we performed molecular analyses using microsatellite markers on chromosomal arms 6q, 16q, 17p, and 17q, DNA flow cytometry and immunohistochemical staining for androgen receptor (AR) and p53 expression on 28 examples of these tumors in comparison to 24 IDC cases. Our results show that generally similar allelic alterations, elevated p53 and androgen receptor expressions, and high frequency of DNA aneuploidy are manifested in both SDCs and IDCs. Differences at certain markers on 6q, 17p and 17q chromosomal loci, however, were observed between the two entities. Certain loci on 6q were more frequently altered in SDC than IDC which loci on chromosomes 17p and q arms were more seen in IDCs than SDCs. The majority of SDCs had high AR expression while most of IDCs were AR negative. Our study indicates that: i) SDC may share some genetic alterations with IDC, ii) high AR expression in SDC may play a role in tumor progression, and iii) p53 overexpression and DNA aneuploidy in both entities reflect their aggressive behavior.

Epithelioid pleural mesotheliomas and pulmonary adenocarcinomas: a comparative DNA flow cytometric study.

The DNA flow cytometric characteristics of 23 immunohistochemically and ultrastructurally proven pleural epithelioid mesotheliomas were compared with those of 41 primary pulmonary adenocarcinomas. Multiple, separate tissue blocks were analyzed from each neoplasm to assess DNA heterogeneity. All of the pleural mesotheliomas and 80% of the pulmonary adenocarcinomas manifested a homogeneous DNA ploidy (DNA stability). A significant statistical difference in the ploidy pattern between pleural mesotheliomas and pulmonary adenocarcinomas was noted (P < .001). Mesotheliomas were mostly diploid (78%) and adenocarcinomas were preponderantly aneuploid (88%). The proliferative rate and DNA indexes of the aneuploid adenocarcinomas were significantly higher than those of pleural mesotheliomas (P < .001). There was no statistical significance between the proliferative rates of diploid mesotheliomas and those of adenocarcinomas. We conclude that the DNA flow cytometric characteristics of mesotheliomas are significantly different from those of pulmonary adenocarcinomas. The clinical implications of these findings are discussed.