Identification of multiple cancer/testis antigens by allogeneic antibody screening of a melanoma cell line library

Cancer/testis (CT) antigens-immunogenic protein antigens that are expressed in testis and a proportion of diverse human cancer types-are promising targets for cancer vaccines. To identify new CT antigens, we constructed an expression cDNA library from a melanoma cell line that expresses a wide range of CT antigens and screened the library with an allogeneic melanoma patient serum known to contain antibodies against two CT antigens, MAGE-1 and NY-ESO-1. cDNA clones isolated from this library identified four CT antigen genes: MAGE-4a, NY-ESO-1, LAGE-1, and CT7. Of these four, only MAGE-4a and NY-ESO-1 proteins had been shown to be immunogenic. LAGE-1 is a member of the NY-ESO-1 gene family, and CT7 is a newly defined gene with partial sequence homology to the MAGE family at its carboxyl terminus. The predicted CT7 protein, however, contains a distinct repetitive sequence at the 5' end and is much larger than MAGE proteins. Our findings document the immunogenicity of LAGE-1 and CT7 and emphasize the power of serological analysis of cDNA expression libraries in identifying new human tumor antigens.

Genomic cloning and localization of CTAG, a gene encoding an autoimmunogenic cancer-testis antigen NY-ESO-1, to human chromosome Xq28

CTAG was initially cloned from an esophageal squamous cell carcinoma cDNA expression library by immunoscreening with autologous patient's serum. CTAG mRNA is expressed in a proportion of human cancers in a lineage-nonspecific fashion, whereas its expression in normal tissues is restricted to testis and ovary only. This expression pattern suggests that the CTAG product (NY-ESO-1) is an aberrantly activated tumor antigen and can potentially be an antigenic target for tumor vaccination. In the present study, we isolated human genomic clones of CTAG and established its genomic organization. By somatic cell hybrid studies and fluorescence in-situ hybridization, we localized this gene to chromosome Xq28, a region that also contains members of MAGE, a gene family that encodes several immunogenic tumor antigens with the characteristic cancer/testis expression pattern.

Characterization of human colon cancer antigens recognized by autologous antibodies

The screening of cDNA expression libraries derived from human tumors with autologous antibody (SEREX) has proven to be a powerful method for defining the structure of tumor antigens recognized by the humoral immune system. In the present study, 48 distinct antigens (NY-CO-1-NY-CO-48) reactive with autologous IgG were identified by SEREX analysis in 4 patients with colon cancer. Sequencing analysis showed that 17 of the cDNA clones were previously uncharacterized molecules and 31 represented known gene products. The individual cDNA clones were analyzed in the following manner: a search for mutations or other structural changes; an analysis of mRNA expression in a panel of normal tissues; and a frequency analysis of the antibody response to the expressed product in the sera of colon cancer patients and normal individuals. The initial analysis showed NY-CO-13 to be a mutated version of the p53 tumor suppressor gene. Three of the 48 antigens showed a differential pattern of mRNA expression, with NY-CO-27 (galectin-4) expressed primarily in gastrointestinal tract, and NY-CO-37 and -38 showing a pattern of tissue-specific isoforms. With regard to immunogenicity, 20 of the 48 antigens were detected by allogeneic sera; 14 of these were reactive with sera from both normal donors and cancer patients, and 6 other clones (NY-CO-8, -9, -13, -16, -20 and -38) reacted exclusively with sera from colon cancer patients (ranging from 14% to 27%). Our results on colon cancer illustrate both the complexity and the potential of the SEREX approach for analysis of the humoral immune response against human cancer.

The impact of a clinical pathway for transurethral resection of the prostate on costs and clinical outcomes

The purpose of this study was to evaluate the effects of implementing a clinical pathway for transurethral resection of the prostate on hospital costs and procedures, outcomes, and complications. Consecutive patients who underwent transurethral resection of the prostate for benign prostate hyperplasia in our hospital before (February-August 1996) and after (October 1996-March 1997) implementation of the clinical pathway were included. Statistical analyses included Student's t-test to test the impact of the clinical pathway on resource consumption and medical care processes, and multiple linear regression to control for patient characteristics such as age, severity of disease, and comorbidity. The major findings of this study were that implementation of the clinical pathway 1) decreased resource consumption and controlled medical care expenditure; 2) influenced physicians' patterns of practice and decreased the number of procedures performed; and 3) did not affect clinical outcomes or complication rates. In conclusion, our results support the hypothesis that the clinical pathway is an effective medical management tool to contain costs, which does not adversely affect quality of care. We suggest health policy makers promote clinical pathways in more hospitals to encourage appropriate resource consumption.

Prediction of right ventricular infarction from standard surface ECG in patients with inferior myocardial infarction

BACKGROUND

Patients with inferior myocardial infarction (MI) have a 45% chance of having concurrent right ventricular infarction (RVI); of these, 5-10% suffer hemodynamic collapse. Immediate correct diagnosis and appropriate management of such patients is vital. ST-segment elevation in the right precordial V4 lead (V4R) has a high diagnostic value in identifying RVI, but this determination requires additional time and cost. An attempt was made to use a collection of patients' standard surface electrocardiograms (ECG) to find any available data to detect RVI and to lead to a new way to diagnose RVI.

METHODS

Fifty patients (males/females, 44/6; mean age, 64.3 +/- 6.9 years) with acute inferior myocardial infarction were enrolled in a first group to develop new diagnostic criteria for RVI. As a first step, the ST-segment change in every standard surface ECG lead was analyzed and compared with corresponding changes in V4R. RVI was diagnosed by typical clinical symptoms (chest pain for more than 30 minutes, ST elevation > 0.1 mV and enzyme changes) accompanying ST elevation of more than 0.1 mV in V4R (by Lopez-Sendon criteria) and echocardiographic findings. RVI was diagnosed in 24 (48%) patients using ECG. The new criteria were then tested in a secondary group of 48 patients (males/females, 43/5; mean age, 65.5 +/- 7.9 years) with inferior MI.

RESULTS

Analysis of these patients found that ST depression in lead I and aVL was a specific characteristic of RVI (I + aVL > 0.2 mV). This criterion was applied to another group of patients with acute inferior MI to check the predictive value (sensitivity, 94.7%; specificity, 89.7%; positive predictive value, 85.7%; negative predictive value, 96.3%).

CONCLUSIONS

In patients with evolving inferior MI, standard surface ECG analyzed for this criterion could aid clinical recognition of concomitant RVI.

A103: An anti-melan-a monoclonal antibody for the detection of malignant melanoma in paraffin-embedded tissues

Melan-A is a previously defined, melanocyte differentiation antigen, and an anti-Melan-A murine monoclonal antibody, A103, was recently developed by our group. In this study, we evaluated A103 immunoreactivity on formalin-fixed, paraffin-embedded tissues, exploring the potential of A103 in the diagnosis of metastatic melanoma. Seventy-five metastatic melanomas, 10 primary melanomas, and 10 benign melanocytic nevi were tested. The reactivity of A103 was compared with HMB-4, an anti-gp100 antibody. Results showed that all nevi were A103 positive, and most primary melanomas were A103 and HMB45 positive. Of 75 metastatic melanomas, 61 (81%) were A103 positive, and 56 (75%) were HMB45 positive. Of 19 HMB45-negative lesions, 8 were A103 positive; of 14 A103-negative lesions, 3 were HMB45 positive. Eleven metastatic lesions, as well as 2 of 10 primary melanomas, were dual negative. These negative cases consisted mainly of the spindle cell and desmoplastic variants. Of the positive cases, A103 showed homogeneous staining in a significantly higher proportion of cases than HMB45 (72% versus 52%). In addition, focal staining with less than 5% reactive tumor cells was seen more frequently in HMB45 (12 of 56) than in A103 (5 of 61). These results indicated that A103 can be used as a first-line antibody in the diagnosis of metastatic melanoma. Our results also showed that A103 reacted with angiomyolipoma, which is known to be HMB45 positive. Of normal tissues, unexpected A103 reactivity was observed in the adrenal cortex, granulosa and theca cells of the ovary, and Leydig cells of the testis. This A103 immunoreactivity in benign and neoplastic tissues of nonmelanocytic origin, the basis of which is unclear, could also be of potential diagnostic value.

A survey of the humoral immune response of cancer patients to a panel of human tumor antigens

Evidence is growing for both humoral and cellular immune recognition of human tumor antigens. Antibodies with specificity for antigens initially recognized by cytotoxic T lymphocytes (CTLs), e.g., MAGE and tyrosinase, have been detected in melanoma patient sera, and CTLs with specificity for NY-ESO-1, a cancer-testis (CT) antigen initially identified by autologous antibody, have recently been identified. To establish a screening system for the humoral response to autoimmunogenic tumor antigens, an enzyme-linked immunosorbent assay (ELISA) was developed using recombinant NY-ESO-1, MAGE-1, MAGE-3, SSX2, Melan-A, and tyrosinase proteins. A survey of sera from 234 cancer patients showed antibodies to NY-ESO-1 in 19 patients, to MAGE-1 in 3, to MAGE-3 in 2, and to SSX2 in 1 patient. No reactivity to these antigens was found in sera from 70 normal individuals. The frequency of NY-ESO-1 antibody was 9.4% in melanoma patients and 12.5% in ovarian cancer patients. Comparison of tumor NY-ESO-1 phenotype and NY-ESO-1 antibody response in 62 stage IV melanoma patients showed that all patients with NY-ESO-1(+) antibody had NY-ESO-1(+) tumors, and no patients with NY-ESO-1(-) tumors had NY-ESO-1 antibody. As the proportion of melanomas expressing NY-ESO-1 is 20-40% and only patients with NY-ESO-1(+) tumors have antibody, this would suggest that a high percentage of patients with NY-ESO-1(+) tumors develop an antibody response to NY-ESO-1.

Improved fluorescence and dual color detection with enhanced blue and green variants of the green fluorescent protein

The green fluorescent protein (GFP) from the jellyfish Aequorea victoria is a versatile reporter protein for monitoring gene expression and protein localization in a variety of systems. Applications using GFP reporters have expanded greatly due to the availability of mutants with altered spectral properties, including several blue emission variants, all of which contain the single point mutation Tyr-66 to His in the chromophore region of the protein. However, previously described "BFP" reporters have limited utility, primarily due to relatively dim fluorescence and low expression levels attained in higher eukaryotes with such variants. To improve upon these qualities, we have combined a blue emission mutant of GFP containing four point mutations (Phe-64 to Leu, Ser-65 to Thr, Tyr-66 to His, and Tyr-145 to Phe) with a synthetic gene sequence containing codons preferentially found in highly expressed human proteins. These mutations were chosen to optimize expression of properly folded fluorescent protein in mammalian cells cultured at 37 degreesC and to maximize signal intensity. The combination of improved fluorescence and higher expression levels yield an enhanced blue fluorescent protein that provides greater sensitivity and is suitable for dual color detection with green-emitting fluorophores.

Dopamine and dobutamine have different effects on heart rate variability in patients with congestive heart failure

BACKGROUND

Autonomic dysfunction plays an important role in the pathogenesis, treatment and prognosis of congestive heart failure (CHF). Sympathomimetic amines have been widely used in the treatment of CHF, but reports on their autonomic effects in CHF are rare. This study was designed to evaluate the effects of dopamine and dobutamine on cardiac autonomic function as assessed by heart rate variability (HRV).

METHODS

Twenty patients with symptomatic CHF (systolic dysfunction) were enrolled. After recording one-hour baseline electrocardiographs (ECGs), patients were randomly selected for either dopamine (4 micrograms/kg/minute, Group A) or dobutamine (4 micrograms/kg/minute, Group B) treatment for three days. On the third day, a 24-hour ambulatory ECG was recorded and a tilt-table test was performed. Only furosemide and nitrates were allowed for adjunctive therapy. HRV was measured before and after treatment in both time and frequency domains. Frequency-domain HRV was also measured during head-up tilt.

RESULTS

After treatment, all patients improved [New York Heart Association fraction (NYHA Fc) 3.7 to 2.0]. Group A patients had higher post-treatment 24-hour HRV than those in Group B. SDNN (standard deviation of the average normal RR intervals in the entire ECG recording), SDANN (standard deviation of the average normal RR intervals for all five minute segments of an entire ECG recording) and SDNN indices in Group A were significantly higher than in Group B (90 +/- 33 ms vs 41 +/- 12 ms, 78 +/- 32 ms vs 36 +/- 11 ms, and 37 +/- 19 ms vs 16 +/- 7 ms, respectively, all p < 0.05). rMSSD (the square root of the mean of the squared differences between adjacent normal RR intervals over the entire ECG recording) and pNN50 (percentage of differences between adjacent normal RR intervals that are greater than 50 ms computed over the entire ECG recording) were also higher in Group A patients, with borderline significance. All measurements of total frequency and low-frequency and high-frequency components tended to be higher in Group A than Group B, but this was only significant for total frequency amplitude (22.9 +/- 13.4 ms vs 10.9 +/- 6.1 ms, p < 0.05). Dopamine but not dobutamine treatment seems to restore the depressed circadian change in frequency-domain HRV classically seen in patients with CHF. The HRV change during head-up tilting did not differ between the two groups. Three patients in Group B showed non-sustained ventricular tachycardia on ambulatory ECG during the treatment period.

CONCLUSIONS

Dopamine and dobutamine have comparable therapeutic effects in patients with CHF, but low-dose dopamine more favorably affects cardiac autonomic function.

Two new mutations in the 3' coding region of the glycogen debranching enzyme in a glycogen storage disease type IIIa Ashkenazi Jewish patient

Glycogen storage disease type III (GSD III) is an autosomal recessive disease caused by the deficiency of glycogen debranching enzyme (AGL). We report the finding of two new mutations in a GSD IIIa Ashkenazi Jewish patient. Both mutations are insertion of an adenine into a stretch of 8 adenines towards the 3' end of the coding region, one at position 3904 (3904insA) in exon 30, the second at position 4214 (4214insA) in exon 32. The mutations cause frameshifts and premature terminations of the glycogen debranching enzyme, the first causing a frameshift at amino acid 1304, the second causing a frameshift at amino acid 1408 of the total of 1532. These mutations demonstrate the importance of the 125 amino acids at the carboxy-terminus of the debrancher enzyme for its activity and support the suggestion that the putative glycogen binding domain is located in the carboxy-terminus of the AGL. The mutations cause distinctive single-strand conformation polymorphism (SSCP) patterns enabling easy detection.

Human lung cancer antigens recognized by autologous antibodies: definition of a novel cDNA derived from the tumor suppressor gene locus on chromosome 3p21.3

Serological analysis of a recombinant lung cancer cDNA expression library with the autologous patient serum led to the isolation of 20 clones representing 12 different genes: 4 of these were known genes, and the other 8 were previously unknown genes. Of the four known genes, aldolase A (NY-LU-1), previously shown to be overexpressed in lung cancer, was most frequently isolated. The other three genes were annexin XI, human HIV Rev-interacting protein Rip-1, and the human homologue of the ATP-binding arsA component of the bacterial arsenite transporter, all of which are known to be widely expressed in human tissues. Among the eight unknown genes, of most interest was NY-LU-12. Cloning of full-length NY-LU-12 showed that this cDNA was derived from the same gene as g16, a partially sequenced gene that mapped to the lung cancer tumor suppressor gene locus on chromosome 3p21. The reported g16 sequence, however, was significantly shorter (2433 versus 3591 bp). As a result of alternate splicing and subsequent frameshift, the reported g16 protein is 603 amino acids shorter than the NY-LU-12 product (1123 residues) at its COOH terminus and would therefore lack the epitopes recognized by the autologous serum. Analysis of the putative NY-LU-12 protein sequence predicted that it is a nuclear zinc finger protein with two RNA-binding domains, and Southern analysis showed that this gene is partially deleted in the lung cancer line NCI-H740 but not in nine other lung cancer lines. Screening of normal and cancer patient sera showed anti-NY-LU-12 seroreactivity in 2 of 21 allogeneic lung cancer patients but not in 24 patients with other tumors or in 16 sera from healthy donors. Comparison of NY-LU-12 cDNA from Lu15 tumor and normal lung tissue by DNA sequencing and/or single-strand conformation polymorphism analysis showed no evidence of mutation. Considering the high frequency of 3p21 alterations in lung cancer and the fact that the tumor suppressor gene or genes in this locus have not been identified, additional studies on the NY-LU-12 gene and its product are warranted.

Recombinant human acid alpha-glucosidase corrects acid alpha-glucosidase-deficient human fibroblasts, quail fibroblasts, and quail myoblasts

Acid alpha-glucosidase (GAA) deficiency causes Pompe disease, a lethal lysosomal glycogen storage disease for which no effective treatment currently exists. We investigated the endocytic process in deficient cells of human recombinant GAA produced in Chinese hamster ovary cells, and the potential of GAA-deficient Japanese acid maltase-deficient quail as a model for evaluating the enzyme replacement therapy for Pompe disease. After 24-h incubation with a single dose of recombinant enzyme, intracellular GAA and glycogen levels in deficient human fibroblasts were normalized, and this correction lasted for 7 d. The 110-kD precursor recombinant enzyme was processed to the 76-kD mature form within 24 h after uptake. Intracellular GAA levels in deficient quail fibroblasts and myoblasts were similarly corrected to their average normal levels within 24 h. Differences existed in the efficiency of endocytosis among subfractions of the enzyme, and among different cell types. Fractions with a larger proportion of precursor GAA were endocytosed more efficiently. Quail fibroblasts required a higher dose, 4200 nmol.h-1.mL-1 to normalize intracellular GAA levels than human fibroblasts, 1290 nmol.h-1.mL-1, whereas primary quail myoblasts required 2800 nmol.h-1.mL-1. In all three cell lines, the endocytosed enzyme localized to the lysosomes on immunofluorescence staining, and the endocytosis was inhibited by mannose 6-phosphate (Man-6-P) added to the culture medium. Despite structural differences in Man-6-P receptors between birds and mammals, these studies illustrate that Man-6-P receptor mediated endocytosis is present in quail muscle cells, and demonstrate the potential of acid maltase-deficient quail to test receptor mediated enzyme replacement therapy for Pompe disease.

Clinical and metabolic correction of pompe disease by enzyme therapy in acid maltase-deficient quail

Pompe disease is a fatal genetic muscle disorder caused by a deficiency of acid alpha-glucosidase (GAA), a glycogen degrading lysosomal enzyme. GAA-deficient (AMD) Japanese quails exhibit progressive myopathy and cannot lift their wings, fly, or right themselves from the supine position (flip test). Six 4-wk-old acid maltase-deficient quails, with the clinical symptoms listed, were intravenously injected with 14 or 4.2 mg/kg of precursor form of recombinant human GAA or buffer alone every 2-3 d for 18 d (seven injections). On day 18, both high dose-treated birds (14 mg/kg) scored positive flip tests and flapped their wings, and one bird flew up more than 100 cm. GAA activity increased in most of the tissues examined. In heart and liver, glycogen levels dropped to normal and histopathology was normal. In pectoralis muscle, morphology was essentially normal, except for increased glycogen granules. In sharp contrast, sham-treated quail muscle had markedly increased glycogen granules, multi-vesicular autophagosomes, and inter- and intrafascicular fatty infiltrations. Low dose-treated birds (4.2 mg/kg) improved less biochemically and histopathologically than high dose birds, indicating a dose-dependent response. Additional experiment with intermediate doses and extended treatment (four birds, 5.7-9 mg/kg for 45 d) halted the progression of the disease. Our data is the first to show that an exogenous protein can target to muscle and produce muscle improvement. These data also suggest enzyme replacement with recombinant human GAA is a promising therapy for human Pompe disease.

Development of Th1 and Th2 populations and the nature of immune responses to hepatitis B virus DNA vaccines can be modulated by codelivery of various cytokine genes

In this study, we provide direct evidence that the magnitude and nature of the immune response to a DNA vaccine can be differentially regulated by codelivery of various mouse cytokine genes. Mice immunized with a hepatitis B virus (HBV) DNA vaccine and the IL-12 or IFN-gamma gene exhibited a significant enhancement of Th1 cells and increased production of anti-HBV surface IgG2a Ab, as well as a marked inhibition of Th2 cells and decreased production of IgG1 Ab. In contrast, coinjection of the IL-4 gene significantly enhanced the development of specific Th2 cells and increased production of IgG1 Ab, whereas Th1 differentiation and IgG2a production were suppressed. Coinjection of the IL-2 or the granulocyte-macrophage-CSF gene enhanced the development of Th1 cells, while the development of Th2 cells was not affected, and the production of IgG1 and IgG2a Ab were both increased. The CTL activity induced by HBV DNA vaccination was most significantly enhanced by codelivery of the IL-12 or IFN-gamma gene, followed by the IL-2 or granulocyte-macrophage-CSF gene, whereas codelivery of the IL-4 gene suppressed the activity. When challenged with HBV surface Ag (HBsAg)-expressing syngeneic tumors, significant reduction of tumor growth was observed in mice that were coadministered the IL-12 gene but not the IL-4 gene. Taken together, these results demonstrate that application of a cytokine gene in a DNA vaccine formulation can influence the differentiation of Th cells as well as the nature of an immune response and may thus provide a strategy to improve its prophylactic and therapeutic efficacy.

Simultaneous humoral and cellular immune response against cancer-testis antigen NY-ESO-1: definition of human histocompatibility leukocyte antigen (HLA)-A2-binding peptide epitopes

A growing number of human tumor antigens have been described that can be recognized by cytotoxic T lymphocytes (CTLs) in a major histocompatibility complex (MHC) class I-restricted fashion. Serological screening of cDNA expression libraries, SEREX, has recently been shown to provide another route for defining immunogenic human tumor antigens. The detection of antibody responses against known CTL-defined tumor antigens, e.g., MAGE-1 and tyrosinase, raised the question whether antibody and CTL responses against a defined tumor antigen can occur simultaneously in a single patient. In this paper, we report on a melanoma patient with a high-titer antibody response against the "cancer-testis" antigen NY-ESO-1. Concurrently, a strong MHC class I-restricted CTL reactivity against the autologous NY-ESO-1-positive tumor cell line was found. A stable CTL line (NW38-IVS-1) was established from this patient that reacted with autologous melanoma cells and with allogeneic human histocompatibility leukocyte antigen (HLA)-A2(-), NY-ESO-1-positive, but not NY-ESO-1-negative, melanoma cells. Screening of NY-ESO-1 transfectants with NW38-IVS-1 revealed NY-ESO-1 as the relevant CTL target presented by HLA-A2. Computer calculation identified 26 peptides with HLA-A2-binding motifs encoded by NY-ESO-1. Of these, three peptides were efficiently recognized by NW38-IVS-1. Thus, we show that antigen-specific humoral and cellular immune responses against human tumor antigens may occur simultaneously. In addition, our analysis provides a general strategy for identifying the CTL-recognizing peptides of tumor antigens initially defined by autologous antibody.

Direct and regulated interaction of integrin alphaEbeta7 with E-cadherin

The cadherins are a family of homophilic adhesion molecules that play a vital role in the formation of cellular junctions and in tissue morphogenesis. Members of the integrin family are also involved in cell to cell adhesion, but bind heterophilically to immunoglobulin superfamily molecules such as intracellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, or mucosal addressin cell adhesion molecule (MadCAM)-1. Recently, an interaction between epithelial (E-) cadherin and the mucosal lymphocyte integrin, alphaEbeta7, has been proposed. Here, we demonstrate that a human E-cadherin-Fc fusion protein binds directly to soluble recombinant alphaEbeta7, and to alphaEbeta7 solubilized from intraepithelial T lymphocytes. Furthermore, intraepithelial lymphocytes or transfected JY' cells expressing the alphaEbeta7 integrin adhere strongly to purified E-cadherin-Fc coated on plastic, and the adhesion can be inhibited by antibodies to alphaEbeta7 or E-cadherin. The binding of alphaEbeta7 integrin to cadherins is selective since cell adhesion to P-cadherin-Fc through alphaEbeta7 requires >100-fold more fusion protein than to E-cadherin-Fc. Although the structure of the alphaE-chain is unique among integrins, the avidity of alphaEbeta7 for E-cadherin can be regulated by divalent cations or phorbol myristate acetate. Cross-linking of the T cell receptor complex on intraepithelial lymphocytes increases the avidity of alphaEbeta7 for E-cadherin, and may provide a mechanism for the adherence and activation of lymphocytes within the epithelium in the presence of specific foreign antigen. Thus, despite its dissimilarity to known integrin ligands, the specific molecular interaction demonstrated here indicates that E-cadherin is a direct counter receptor for the alphaEbeta7 integrin.

Immunoreactivity for A103, an antibody to melan-A (Mart-1), in adrenocortical and other steroid tumors

The Melan-A (MART-1) gene encodes an antigen recognized by cytotoxic T cells. It has been said to be restricted in its expression to melanocytes. However, here we report the presence of immunoreactivity for A103, an antibody to Melan-A, in five adrenocortical adenomas, 16 primary and 13 metastatic adrenocortical carcinomas, four Leydig cell tumors of the testis, and three Sertoli-Leydig cell tumors of the ovary. To evaluate the potential diagnostic role of this antibody, we studied immunoreactivity for A103 in 111 carcinomas, 40 germ cell tumors, and 33 miscellaneous nonmelanocytic epithelioid tumors. All of them were negative for A103. Our findings suggest that once melanoma is excluded, A103 can aid in the recognition of steroid hormone-producing tumors and may be particularly useful in the diagnosis of adrenocortical carcinoma. The presence of immunoreactivity for A103 practically excludes any other carcinoma that may enter into the differential diagnosis of adrenocortical tumors.

Prenatal diagnosis and carrier detection for glycogen storage disease type III using polymorphic DNA markers

Deficiency of glycogen debranching enzyme gene (AGL) causes glycogen storage disease type III (GSD-III), an autosomal recessive disease. Prenatal diagnosis and carrier detection using enzymatic methods are technically difficult and have limited ability to distinguish a carrier from an affected patient. Mutations in the AGL gene can be used for these purposes. However, the mutations identified thus far account for less than half of the total mutant alleles, and no common mutations have been detected except in North African Jews and in a rare subtype of the disease (GSD-IIIb). Our recent identification of three highly informative DNA polymorphic markers in the AGL gene allowed us to perform prenatal diagnosis and carrier detection in two GSD-III families with unknown mutations, using the polymerase chain reaction (PCR) and restriction analysis. In one family, a fetus was diagnosed to be a GSD-III carrier and his carrier status was confirmed postnatally. A newborn in the second family was postnatally diagnosed with the disease.

Quantitative analysis of antibiotics by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Comparative studies of the matrix-assisted laser desorption/ionization (MALDI) of 30 antibiotics were made using alpha-cyano-4-hydroxycinnamic acid (HCCA), 2,5-dihydroxybenzoic acid (DHB), 5,10,15,20-tetrakis(4-hydroxyphenyl)-21H,23H-porphyrin and meso-tetra(N-methyl-4-pyridyl)porphyrin matrices. Most antibiotics generated intense protonated molecules in HCCA and DHB matrices, and sodium or potassium adduct ions in porphyrin matrices. Using sulfonamide antibiotics as model compounds, DHB was found to be the most suitable matrix for quantitative analysis. Detection limits were about 1 picomole. Linear correlation (R2 > 0.97), between the sample quantity over the range 1 to 100 picomole and the signal response, was obtained when ratios of the sum of peak areas of protonated molecules and sodium adduct ions, with reference to that of a structurally analogous internal standard (acetaminophen), were measured. The precision was found to be in the range of 4 to 32% relative standard deviation, dependent on the type and concentration of the analyte. A simple acylation derivatization process was developed to confirm the presence of suspected antibiotic residues. It is demonstrated that MALDI is a viable technique for the quantitative analysis of low molecular weight antibiotics.

Molecular cloning of acid alpha-glucosidase cDNA of Japanese quail (Coturnix coturnix japonica) and the lack of its mRNA in acid maltase deficient quails

Acid alpha-glucosidase (GAA) hydrolyzes alpha-1, 4 and alpha-1, 6 glucosidic linkages of oligosaccharides and degrades glycogen in the lysosomes. The full-length GAA I cDNA, pQAM8, was isolated from a cDNA library derived from Japanese quail liver. The cDNA is 3569 base pairs long and has an open reading frame capable of coding 932 amino acids. The deduced amino acid sequence shares 52% identity with human GAA. Transfection of expression vector pETAM8 into COS-7 cells or acid maltase deficient (AMD) quail embryonic fibroblasts increased the level of GAA 20-50-fold. Compared to normal quail, the levels of GAA I mRNA were significantly reduced in the muscle, liver, heart, and brain of AMD quails, suggesting the GAA deficiency in AMD quail is due to a lack of GAA I mRNA. A second GAA II cDNA was identified after probing the cDNA library from the ovarian large follicles of quails with a PCR product derived from cultured quail skin fibroblasts. This clone having 3.1 kb insert, has GAA activity as well (3 to 10 fold increase). This cDNA, designated GAA II, predicted an 873 amino acid polypeptide showing 63% identity to human GAA and 51% identity to the GAA I. The RT-PCR analysis demonstrated that GAA II mRNAs were barely detectable in normal tissues, while they were enhanced to higher levels in AMD tissues. These results suggest that GAA II expression is up-regulated at the transcription levels, and quail GAA gene redundancy performs the same function of satisfying GAA demand at the two different phases represented by normal and AMD.

MHC class I and II expression in prostate carcinoma and modulation by interferon-alpha and -gamma

BACKGROUND

Expression of Major Histocompatibility Complex (MHC) class I and II antigens are critical for the cellular immune response. Loss of MHC expression represents one mechanism by which cancer cells escape immune recognition.

PURPOSE

To define MHC class I and II expression by prostate cancer (PCa) in vivo and in vitro and the ability to modulate MHC expression in vitro with IFN-alpha and -gamma.

METHODS

Frozen tissue sections of 25 benign prostatic hyperplasia (BPH) and 18 PCa specimens were studied by immunohistochemistry. PCa cell lines LNCaP, PC-3, and DU-145 were studied by FACS, ELISA, and cytospin. Class I was detected by monoclonal antibody (mAb) W6/32, and class II by mAb 13.17. The effects of IFN-alpha and -gamma were assessed by testing the three cell lines in the presence or absence of varying concentrations of the cytokine for varying incubation times.

RESULTS

Class I was strongly expressed by 24/25 BPH specimens; 4/18 (22%) PCa were homogeneously class I-positive, while 5/18 (28%) were heterogeneously positive and 9/18 (50%) were class I-negative. PC-3 and DU-145 expressed normal levels of class I, while LNCaP expressed only low levels. All line except LNCaP demonstrated significant up-regulation of class I with either IFN-alpha or -gamma. Class II expression was not seen in BPH epithelium nor in 17/18 PCa. Class II could be only weakly induced in the three PCa lines.

CONCLUSIONS

These findings confirm prior studies demonstrating that class I expression is commonly lost or diminished in PCa. In addition, class II up-regulation by IFN-gamma appears very limited in relation to other normal or neoplastic epithelium.

IMPLICATIONS

The present findings, taken together with previous studies, are most consistent with the expression of neoantigens by PCa, which are recognized and appropriately eliminated by the cellular immune system. This selective pressure favors outgrowth of cells which down-regulate or lose class I and/or class II expression. Understanding PCa immunobiology will help in the development of effective immunotherapy for this disease.

SSX: a multigene family with several members transcribed in normal testis and human cancer

Analysis of t(X;18) translocation in synovial sarcoma had previously led to the definition of the SSX2 gene, the fusion partner on chromosome X. Subsequent screening of testicular cDNA libraries identified 2 highly homologous genes, SSX1 and SSX3. Among these 3 genes, SSX2 has been found to be identical to HOM-MEL-40, which codes for an immunogenic tumor antigen expressed in various human cancers. SSX2 thus belongs to the family of cancer/testis (CT) antigens, i.e., immunogenic protein antigens with characteristic mRNA expression in normal testis and in cancer. To define additional CT antigens, we have immuno-screened a testicular cDNA expression library with an allogeneic serum from a melanoma patient, and both SSX2 and SSX3 were isolated. Further studies using testicular cDNA and SSX probes defined 2 new members of this gene family, SSX4 and SSX5, while a shorter cDNA variant of SSX4 was also identified. All 5 members of the SSX family shared strong sequence homology, with nucleotide homology ranging from 88 to 95% and amino acid homology ranging from 77 to 91%. Genomic cloning of a prototype SSX gene (SSX2) showed that its coding region is encoded by 6 exons, and the shortened form of SSX4 cDNA represents an alternatively spliced product lacking the 5th exon. Analysis of SSX mRNA expression by gene-specific RT-PCR confirmed that all 5 SSX genes are expressed in testis. In addition, analysis of a panel of 12 melanoma cell lines showed strong mRNA expression of either SSX1 (3/12), SSX2 (3/12), SSX4 (1/12), or SSX5 (1/12), indicating variable activation of the genes in malignant cells.

Comparison of urine collection methods for evaluating urinary nuclear matrix protein, NMP22, as a tumor marker

PURPOSE

The nuclear matrix protein, NMP22, has been shown to be a useful tumor marker for identifying patients with a high likelihood of rapid recurrence of transitional cell carcinoma of the urinary tract after surgical treatment. Currently measurement of NMP22 involves 3 urine voids collected during a 24-hour period, which are pooled and assayed as a single sample. This study was performed to determine whether any single void would yield similar results to the pooled 3-void sample.

MATERIALS AND METHODS

A total of 2,018 urine samples (3 voids per sample) was included in the study. All analyses were performed using the nonparametric Wilcoxon signed rank test for matched pairs.

RESULTS

Analysis showed that the NMP22 level of a single void collected between midnight and noon was similar to the NMP22 level of the pooled 3-void sample. Receiver operating characteristics curves of the midnight-to-noon single void and the pooled 3-void sample were similar for predicting recurrence postoperatively in patients with urinary tract transitional cell carcinoma.

CONCLUSIONS

One void collected between midnight and noon compares favorably with the current 3-void collection method for determining NMP22 levels in urine.