The monoclonal antibody 7E12H12 can differentiate primary adenocarcinoma of the bladder and prostate

mAb Das-1 recognizes 3'-Sulfated Lewis A/C, which is aberrantly expressed during metaplastic and oncogenic transformation of several gastrointestinal Epithelia

INTRODUCTION

Multiple previous studies have shown the monoclonal antibody Das-1 (formerly called 7E12H12) is specifically reactive towards metaplastic and carcinomatous lesions in multiple organs of the gastrointestinal system (e.g. Barrett's esophagus, intestinal-type metaplasia of the stomach, gastric adenocarcinoma, high-grade pancreatic intraepithelial neoplasm, and pancreatic ductal adenocarcinoma) as well as in other organs (bladder and lung carcinomas). Beyond being a useful biomarker in tissue, mAb Das-1 has recently proven to be more accurate than current paradigms for identifying cysts harboring advanced neoplasia. Though this antibody has been used extensively for clinical, basic science, and translational applications for decades, its epitope has remained elusive.

METHODS

In this study, we chemically deglycosylated a standard source of antigen, which resulted in near complete loss of the signal as measured by western blot analysis. The epitope recognized by mAb Das-1 was determined by affinity to a comprehensive glycan array and validated by inhibition of a direct ELISA.

RESULTS

The epitope recognized by mAb Das-1 is 3'-Sulfo-Lewis A/C (3'-Sulfo-LeA/C). 3'-Sulfo-LeA/C is broadly reexpressed across numerous GI epithelia and elsewhere during metaplastic and carcinomatous transformation.

DISCUSSION

3'-Sulfo-LeA/C is a clinically important antigen that can be detected both intracellularly in tissue using immunohistochemistry and extracellularly in cyst fluid and serum by ELISA. The results open new avenues for tumorigenic risk stratification of various gastrointestinal lesions.

mAb Das-1 is specific for high-risk and malignant intraductal papillary mucinous neoplasm (IPMN)

OBJECTIVE

Intraductal papillary mucinous neoplasm (IPMN) consists of four epithelial subtypes that correlate with histological grades and risks for malignant transformation. mAb Das-1 is a monoclonal antibody against a colonic epithelial phenotype that is reactive to premalignant conditions of the upper GI tract. We sought to assess the ability of mAb Das-1 to identify IPMN with high risk of malignant transformation.

DESIGN

mAb Das-1 reactivity was evaluated in 94 patients with IPMNs by immunohistochemistry. Lesional fluid from 38 separate patients with IPMN (n=27), low-grade non-mucinous cystic neoplasms (n=7) and pseudocysts (n=4) was analysed by ELISA and western blot.

RESULTS

Immunohistochemistry-Normal pancreatic ducts were non-reactive and low-grade gastric-type IPMN (IPMN-G) (1/17) and intermediate-grade IPMN-G (1/23) were minimally reactive with mAb Das-1. In contrast, mAb Das-1 reactivity was significantly higher in high-risk/malignant lesions (p<0.0001) including: intestinal-type IPMN with intermediate-grade dysplasia (9/10); high-grade dysplasia of gastric (4/7), intestinal (12/12), oncocytic (2/2) and pancreatobiliary types (2/2); and invasive tubular (8/12), colloid (7/7) and oncocytic (2/2) carcinoma. The sensitivity and specificity of mAb Das-1 for high-risk/malignant IPMNs were 85% and 95%, respectively. Lesional fluid-Samples from low- and intermediate-grade IPMN-G (n=9), and other low-grade/benign non-mucinous lesions demonstrated little reactivity with mAb Das-1. Conversely, cyst fluid from high-risk/malignant IPMNs (n=18) expressed significantly higher reactivity (p<0.0001). The sensitivity and specificity of mAbDas-1 in detecting high-risk/malignant IPMNs were 89% and 100%, respectively.

CONCLUSIONS

mAb Das-1 reacts with high specificity to tissue and cyst fluid from high-risk/malignant IPMNs and thus may help in preoperative clinical risk stratification.

Preparation and in-vitro bioactivity of a novel superantigen conjugate targeting bladder carcinoma

Objectives

Superantigens have shown potent effects against bladder tumours by inducing Vβ-specific T-lymphocyte proliferation and massive cytokine release but therapeutic benefit is compromised by cytotoxicity towards non-malignant cells and hypotoxicity to major histocompability complex (MHC) II-negative tumour cells. We are therefore interested in a conjugate preparation of a monoclonal antibody (MAb)—superantigens conjugate for which these drawbacks would be resolved.

Methods

The Fab fragment of the anti-bladder carcinoma MAb BDI-1 was conjugated to one member of the staphylococcal enterotoxin A (SEA) superantigen using the chemical conjugating reagent, N-succinimidyl 3-(2-pyridyldithio) propionate.

Results

After HPLC purification through a Superdex-200 gel column, another peak with a molecular mass of 250 KDa was observed before Fab and SEA were eluted. Indirect immunocytochemical analysis and immunofluorescence tests showed that the cell membranes of most human bladder cancer cells were positively stained only by the conjugate, confirming the ability of the conjugate to target human bladder carcinoma. Peripheral blood mononuclear cell proliferation and cytokine release were similar with the conjugate and SEA. Cytotoxicity targeting in MHC II-negative bladder cancer cell lines, evaluated by flow cytometry, showed significant differences between the conjugate and SEA, whereas there was no difference in the Lovo colon cancer cell line.

Conclusions

These findings indicate the conjugate of SEA protein and BDI-1 Fab fragment was prepared successfully and targeted bladder carcinoma in vitro.

Repeated exposure to acid and bile selectively induces colonic phenotype expression in a heterogeneous Barrett's epithelial cell line

Barrett's epithelium is a precancerous, specialized columnar metaplasia in the distal esophagus. We demonstrate the changes in cellular phenotype in a non-neoplastic Barrett's cell line (BAR-T), following exposure to acid and bile salt, the two important components of gastroesophageal refluxate. Cell phenotypes in BAR-T cell line were quantified by fluorescence-activated cell sorting (FACS) using monoclonal antibodies against markers: cytokeratin 8/18 (CK8/18) for columnar, CK4 for squamous, mAbDas-1 for colonic epithelial cell phenotype and p75NTR for esophageal progenitors. Cells were exposed for 5 min each day to 200 microM glycochenodeoxycholic acid at pH 4, pH 6 and pH 7.4 or only to acid (pH 4) for up to 6 weeks. The BAR-T cell line comprised 35+/-5.2% CK8/18, 32+/-3.5% mAbDas-1, 9.5+/-3% CK4 and 4+/-2.5% p75NTR-positive cells. Single exposure to acid and or bile did not change cell phenotypes. However, chronic treatment for at least 2 weeks significantly enhanced (P<0.05) the expression of colonic phenotype and CK8/18-positive cells, as evidenced by FACS analysis. Bile salt at pH 4 and bile salt followed by acid (pH 4) in succession were the strongest stimulators (P<0.01) for induction of colonic phenotype cells. Squamous (CK4(+)) phenotype did not change by the treatments. Cox-2 expression was induced after acute treatment and increased to twofold during chronic treatment, particularly in response to acidic pH. We conclude that BAR-T cells can be utilized as an 'in vitro' model to study the effect of environmental factors and their influence on the cellular phenotype and molecular changes in the pathogenesis of esophageal cancer.

The atypical urothelial cancer patient: management of bladder cancers of non-transitional cell histology and cancers of the ureters and renal pelvis

Non-transitional cell neoplasms of the bladder and upper tract transitional cell carcinomas (ureter and renal pelvis) represent only a small fraction of urothelial carcinomas. Clinicians faced with the rare case are always confronted with management dilemmas complicated by the scarcity of published experience to guide decisions. The current review brings together the best of the limited published data in an attempt to provide some reasonable context to help in the management of these difficult neoplasms.

Expression of Das-1 in primary lung adenocarcinomas represents reactivation of an oncofetal pulmonary antigen

OBJECTIVE

The monoclonal antibody (mAb) designated as mAb Das-1 was generated against a colonic epithelial protein. It reacts with bronchiolar epithelium and submucosal glands and weakly with alveolar lining cells of fetal lung. Adult alveolar epithelium is, however, nonreactive for mAb Das-1. The present study was designed to evaluate the immunoexpression of Das-1 and to correlate it with the histomorphology of primary lung adenocarcinomas and intestinal metaplasia.

METHODS

Eighty-four cases of primary lung adenocarcinomas were reviewed and categorized according to histologic grade and subtype. Immunohistochemical staining with mAb Das-1 was performed with normal colon as control.

RESULTS

Expression of Das-1 in the submucosal bronchial glands also served as internal control. Strong and diffuse staining was seen in 33 of the 84 cases of adenocarcinomas (39%).

CONCLUSIONS

Expression of Das-1 was seen in primary lung adenocarcinomas even though adult alveolar epithelium is negative. Staining with mAb Das-1 was seen regardless of the grade or histological subtype of the lung adenocarcinomas. As most primary lung adenocarcinomas are not of bronchial gland origin, expression of Das-1 represents activation of oncofetal antigens.

Skene's Gland Adenocarcinoma Resembling Prostatic Adenocarcinoma

An 88-year-old woman presented with gross hematuria and a 3-cm periurethral mass. Biopsy revealed an adenocarcinoma resembling prostatic adenocarcinoma; the tumor cells were positive for keratin and prostate-specific antigen. The serum level of prostate-specific antigen was elevated; the carcinoembryonic antigen and CA-125 serum levels were normal. One year after external beam radiotherapy, the patient is without evidence of disease. This is the sixth case of a urethral prostatic-type adenocarcinoma, tumors that are most likely of Skene's gland origin.

Villous adenoma of the urinary tract: a lesion frequently associated with malignancy

Villous adenomas arising in the urinary tract are rare. We identified 18 cases of villous adenomas of the bladder, urachus, and prostatic urethra. Patients ranged in age from 53 to 93 years with an average age of 69.6 years and a male preponderance of 67%. In six cases (33%), the lesion was pure villous adenoma. In three cases (17%), there was villous adenoma with in situ adenocarcinoma. In six cases (33%) there was villous adenoma with in situ and infiltrating adenocarcinoma. One case (6%) had villous adenomas with in situ (noninvasive) papillary urothelial carcinoma. One case (6%) had villous adenomas with in situ adenocarcinoma and in situ papillary (noninvasive) and infiltrating urothelial carcinoma. The remaining case (6%) had villous adenoma with in situ and infiltrating adenocarcinoma and in situ (noninvasive) papillary and infiltrating urothelial carcinoma. Clinical outcome was available in eight of the cases, with a mean follow-up of 4.6 years. No evidence of recurrence was found in two patients with pure villous adenoma or in two patients with villous adenoma and only in situ adenocarcinoma, all of whom were treated by nonradical excision. However, two of three cases with infiltrating cancer developed distant metastases despite radical surgery; the remaining patient was disease-free 11 years after transurethral resection. The case with villous adenoma and in situ urothelial carcinoma progressed to sarcomatoid urothelial carcinoma following partial cystectomy. Eight of 10 villous adenomas cases studied expressed the epitope for mAbDas1, found on colonic epithelium and primary adenocarcinomas of the bladder and urachus but not on normal or neoplastic urothelium. This study expands the spectrum of histologic features accompanying villous adenomas of the urinary tract. Coexisting infiltrating adenocarcinoma is often present, necessitating thorough sampling of any lesion diagnosed by biopsy as villous adenoma. Pure villous adenoma and those well-sampled lesions also containing in situ adenocarcinoma portend a favorable prognosis, even without radical treatment. Coexisting in situ or infiltrating carcinoma suggests a more aggressive course. Histologically, immunohistochemically, and prognostically, these lesions appear analogous to their counterparts in the intestine.

An antigen reacting with das-1 monoclonal antibody is ontogenically regulated in diverse organs including liver and indicates sharing of developmental mechanisms among cell lineages

The monoclonal antibody designated mAb Das-1, which was generated against a colon epithelial protein, reacts with the normal biliary epithelium and keratinocytes, which are among targets of tissue injury in ulcerative colitis. Moreover, mAb Das-1 reacts with abnormal cells in Barrett's esophagus and chronic cystitis profunda, as well as so-called 'oval cells' in the adult liver, which are considered oncogenic progenitor cells. To establish ontogenic regulation of mAb Das-1 reactivity, we studied 7- to 24-week-old human fetuses by immunohistochemistry. In liver, mAb Das-1 reactivity was further correlated with glycogen, dipeptidyl peptidase IV, glucose-6-phosphatase and gamma-glutamyl transpeptidase expression. mAb Das-1 reacted with cells in organs arising from the pharyngeal cleft (thymus), primitive gut (oral cavity, pharynx, lung, esophagus, stomach, biliary tree, pancreas, liver, colon), ureteric bud (renal tubules, collecting duct), mesonephros (kidney, testis), mesoderm (muscle) and elsewhere (skin, adrenal cortex). In distinction from the adult liver, mAb Das-1 staining was more pronounced in hepatoblasts compared with biliary cells. In adult tissues, however, mAb Das-1 reactivity was restricted to the colon, biliary epithelium, keratinocytes, and ciliary body. These data indicated that the mAb Das-1 recognized epitopes in fetal cells of diverse ectodermal, mesodermal and endodermal origin, compatible with sharing of lineage mechanisms in tissues. Reactivation of mAb Das-1 staining in epithelial precancerous conditions, including carcinomas arising in these organs, is compatible with oncofetal regulation of the antigen, which will facilitate analysis of cell subpopulations during organ development, regeneration and oncogenesis.

FEMALE URETHRAL ADENOCARCINOMA: IMMUNOHISTOCHEMICAL EVIDENCE OF MORE THAN 1 TISSUE OF ORIGIN

PURPOSE

Urethral adenocarcinoma is a rare malignancy whose origin remains controversial. The monoclonal antibody mAbDas1 (formerly 7E12H12) was developed against a unique colonic epithelial epitope and is reactive in areas of intestinal metaplasia. Recently the antibody was shown to react in cystitis glandularis as well as adenocarcinoma of the bladder, suggesting that cystitis glandularis may be the precursor of bladder adenocarcinoma. We examined urethral adenocarcinomas and benign urethral specimens using mAbDas1 to determine whether it could provide insight into their histogenesis.

MATERIALS AND METHODS

Archival tissue from 12 cases of primary female urethral adenocarcinoma and urethral specimens of inflamed urethral mucosa, urethritis glandularis and transitional cell carcinoma was studied. Immunohistochemical analysis of formalin fixed, paraffin embedded archival tissue was done using the monoclonal antibody mAbDas1. Tumors were also evaluated with a prostate specific antigen (PSA) polyclonal antibody as previous studies have noted PSA reactivity in these tumors.

RESULTS

Of the 12 cases 9 were columnar/mucinous adenocarcinoma, 2 clear cell adenocarcinoma and 1 a cribriform pattern resembling adenocarcinoma of the prostate. All columnar/mucinous adenocarcinomas reacted positively (6 strongly and 3 focally) with the mAbDas1 antibody but did not react with the PSA antibody. The tumor with a cribriform pattern reacted strongly with PSA but did not react with mAbDas1. The 2 clear cell adenocarcinomas did not react with either antibody. The benign urethral specimens demonstrated strong reactivity to the mAbDas1 antibody in areas of urethritis glandularis but normal and inflamed urethral mucosa and transitional cell carcinoma did not react.

CONCLUSIONS

Primary adenocarcinoma of the female urethra arises from more than 1 tissue of origin. Columnar/mucinous adenocarcinomas of the female urethra and urethritis glandularis demonstrate consistent reactivity with the mAbDas1 antibody, suggesting that these tumors arise from glandular metaplasia analogous to the potential histogenesis previously demonstrated in the bladder. PSA reactivity occurred in 1 tumor with a cribriform pattern and likely represents origin from Skene's glands. Clear cell adenocarcinomas did not react with either antibody, suggesting a third possible pathway in the development of this rare subset of adenocarcinomas.