Membrane associated cancer-oocyte neoantigen SAS1B/ovastacin is a candidate immunotherapeutic target for uterine tumors.

The metalloproteinase SAS1B [ovastacin, ASTL, astacin-like] was immunolocalized on the oolemma of ovulated human oocytes and in normal ovaries within the pool of growing oocytes where SAS1B protein was restricted to follicular stages spanning the primary-secondary follicle transition through ovulation. Gene-specific PCR and immunohistochemical studies revealed ASTL messages and SAS1B protein in both endometrioid [74%] and malignant mixed Mullerian tumors (MMMT) [87%] of the uterus. A MMMT-derived cell line, SNU539, expressed cell surface SAS1B that, after binding polyclonal antibodies, internalized into EEA1/LAMP1-positive early and late endosomes. Treatment of SNU539 cells with anti-SAS1B polyclonal antibodies caused growth arrest in the presence of active complement. A saporin-immunotoxin directed to SAS1B induced growth arrest and cell death. The oocyte restricted expression pattern of SAS1B among adult organs, cell-surface accessibility, internalization into the endocytic pathway, and tumor cell growth arrest induced by antibody-toxin conjugates suggest therapeutic approaches that would selectively target tumors while limiting adverse drug effects in healthy cells. The SAS1B metalloproteinase is proposed as a prototype cancer-oocyte tumor surface neoantigen for development of targeted immunotherapeutics with limited on-target/off tumor effects predicted to be restricted to the population of growing oocytes.

Expression of cancer-testis antigens in endometrial carcinomas using a tissue microarray.

Cancer-testis (CT) antigens are expressed in a variety of malignant tumors, but in normal adult tissue, they are only expressed in testicular germ cells. Owing to this tumor-associated expression pattern, these antigens are of major interest as potential targets for immunotherapy and possibly for diagnostic purposes. This study was performed to analyze the expression of four CT antigens, NY-ESO-1, MAGE-A3, MAGE-A4, and CT7/MAGE-C1, in endometrial carcinoma using immunohistochemistry, and to correlate expression with histologic subtypes, grade, and expression of WT1 and p53. Formalin-fixed paraffin-embedded tissues of 130 endometrial carcinomas of the following types and grades were analyzed using a tissue microarray: 85 endometrioid carcinomas (FIGO grade 1, 39; grade 2, 11; and grade 3, 35), 18 papillary serous carcinomas, 12 clear cell carcinomas, 13 malignant mixed mullerian tumors, one mucinous adenocarcinoma, and one undifferentiated carcinoma. The following anti-CT monoclonal antibodies/antigens were studied by immunohistochemistry: monoclonal antibody ES121/NY-ESO-1, monoclonal antibody M3H67/MAGE-A3, monoclonal antibody 57B/MAGE-A4, and monoclonal antibody CT7-33/CT7. The CT expression data were compared to WT1 and p53 protein expression as analyzed in a previous study. Positive staining with anti-CT monoclonal antibodies was graded as follows: focal, <5% positive cells; 1+, 5-25% cells; 2+, 26-50% cells; 3+, 51-75%; and 4+, >75% cells. The 3+ and 4+ staining patterns were considered homogeneous patterns of potential clinical significance and were scored positive for statistical analysis. In low-grade tumors, the most immunoreactivity was seen with mAb M3H67 but little labeling was observed with the other monoclonal antibodies. In high-grade tumors, monoclonal antibodies M3H67 (25%), 57B (23%), and CT7-33 (20%) showed the highest reactivity, while ES121 showed the lowest immunoreactivity (6%). The staining pattern was mostly heterogeneous. Statistical significance was found solely for the correlation of monoclonal antibody 57B staining and p53 expression. No correlation was found for any anti-CT monoclonal antibody staining and clinical stage or for anti-CT staining and WT1 expression. CT antigens CT7, MAGE-A3 and MAGE-A4, but not NY-ESO-1, are expressed in high-grade endometrial carcinomas, and expression of MAGE-A4 is correlated with the presence of overexpressed p53.

Neuroectodermal immunophenotype in uterine malignant mullerian tumors (MMT): comparative immunohistochemical analysis with embryonal uterine development.

Multidirectional differentiation of neoplastic cells in uterine MMT is still a subject of controversy. The present study was designed to assess the immunophenotype of 15 uterine MMT paying special attention to the markers of neural (neuroendocrine) differentiation. In addition, the same immunohistochemical study was performed on 20 human fetal specimens in order to establish possible relationships between the immunophenotype of MMT and the expression of the corresponding antigens in the fetal tissues of the embryonal female genital tract. Besides the typical immunohistochemical patterns in three cases the epithelial component showed simultaneous coexpression of vimentin and desmin. EMA and cytokeratin, whereas epithelial markers were coexpressed with vimentin in the sarcomatous component of one adenosarcoma. Moreover, both components were immunoreactive to the markers of neural differentiation (PGP 9.5, GFAP, HNK-1, N-CAM, HBA71). This aberrant expression was not correlated with morphological signs of neural differentiation at either light microscopy or ultrastructural levels. Regarding the analysis of fetal tissues, both epithelial and mesenchymal elements in the fetal genital tract expressed the above-mentioned neural markers at different dates of gestation. The intensity of this expression diminishes as the fetus matures and at the end of antenatal life the immunophenotype characteristic for adult life is established. Taking into consideration the capacity of uterine tissue to reproduce embryonal phenotype during neoplastic transformation, we studied this abnormal immunoprofile and its hypothetic value for the diagnosis and prognosis of MMT.

Primary peritoneal malignant mixed Müllerian tumors. A clinicopathologic, immunohistochemical, and genetic study.

BACKGROUND: Primary peritoneal malignant mixed Müllerian tumors (MMMTs) are rarely reported in the literature. METHODS: The clinical, pathologic, and immunohistochemical features of five cases of MMMT of female peritoneum were analyzed. The tumors were also investigated for expression of hormone receptors, specific BRCA-1 mutations, and clonality. RESULTS: The patients' ages ranged from 33 to 67 years. They presented with abdominal pain or mass. One case of peritoneal MMMT was associated with a synchronous endometrial carcinoma whereas another case was detected 2 years after the diagnosis of a primary adenocarcinoma of the fallopian tube. One patient died 1 month after diagnosis whereas 2 patients died with disease within 1 year. Both carcinomatous and sarcomatous elements are present in all the tumors. Squamous differentiation was noted in two cases. Heterologous elements, including chondroid, rhabodomyoblastic, and osteoid differentiation were detected in all tumors. Immunohistochemical studies confirm the biphasic differentiation with variable demonstration of neural and smooth muscle differentiation. All five MMMTs were negative for estrogen and progestogen receptors although the related endometrial and tubal carcinomas were positive. Heteroduplex analysis used to screen for specific BRCA-1 mutations were negative in all five MMMTs. Clonality study of the two MMMTs found in association with endometrial carcinoma and tubal carcinoma was inconclusive. CONCLUSIONS: Our study confirmed that primary peritoneal MMMTs were aggressive tumors with poor prognosis. The presence of synchronous or metachronous genital carcinomas suggests multifocal tumorigenesis from tissue of same embryologic origin. The lack of hormone receptor in these tumors indicates deviation from hormonal control. Specific BRCA-1 mutations found in ovarian carcinoma in Chinese patients could not be detected in our series.

Tumor suppressor gene, cell surface adhesion molecule, and multidrug resistance in Müllerian serous carcinomas: clinical divergence without immunophenotypic differences.

OBJECTIVES: We hypothesize that differences in the expression of selected tumor suppressor genes, cell surface adhesion molecules, and multidrug resistance glycoproteins could account for some of the reported differences between uterine serous carcinoma (USC) and extrauterine serous carcinomas (ESC), including ovarian and primary peritoneal carcinoma (OSC and PSC, respectively). METHODS: We studied the expression of the following antigens in 20 USCs, 20 OSCs, and 10 PSCs: p53 and mdm-2 (tumor suppressor genes), CD44 and CD44v6 (cell surface adhesion molecules), and the p-glycoprotein (a multidrug resistance protein recognized by two antibodies, C494 and JSB1). We further studied chemotherapeutic drug resistance by examining reports prepared using the Oncotech Extreme Drug Resistance Assay from 24 of the 50 study patients. Clinical data were obtained from medical record review. RESULTS: USC, OSC, and PSC patients were similar with respect to mean age at diagnosis, mean gravidity, mean parity, personal history of breast cancer, percentage treated with chemotherapy, and survival at 3 and 5 years postdiagnosis. Significant clinical differences included a high prevalence of nulliparity in OSC (P = 0.05), a low prevalence of Caucasian race in USC (P = 0.008), a paucity of stage I patients in OSC and PSC (P = 0.03), a high prevalence of familial breast cancer in OSC (P = 0.06), and superior 2-year survival in OSC (P = 0.02). Seventy-five percent of USCs, 52% of OSCs, and 60% of PSCs expressed p53. Five percent of USCs, 19% of OSCs, and 0% of PSCs expressed mdm-2. Forty percent of USCs, 33% of OSCs, and 10% of PSCs expressed CD44. None of the USCs, OSCs, or PSCs expressed CD44v6. Sixty-one percent of USCs and OSCs and 82% of PSCs expressed C494 while 17% of USCs, 19% of OSCs, and 20% of PSCs expressed JSB1. None of these apparent differences was statistically significant. USC, OSC, and PSCs patients did not demonstrate significant differences with respect to extreme drug resistance. However, the following trends were noted (P = 0.06): more prevalent low drug resistance for cyclophosphamide in OSC compared with USC and more prevalent extreme drug resistance for etoposide in OSC compared with USC. CONCLUSIONS: Therefore, despite significant clincial differences, the USCs and ESCs in our series do not differ significantly with respect to the expression of the tumor suppressor genes, cell surface adhesion molecules, and drug resistance proteins studied. It is premature, however, to recommend that USCs and ESCs should be treated identically.

Cancer-associated retinopathy.

Patients with systemic cancer may have a variety of ocular complaints. Most commonly these are metastases or adverse effects of therapy. Paraneoplastic syndromes, like cancer-associated retinopathy, rarely cause ophthalmic symptoms. We describe a patient with a malignant mixed mullerian tumor and cancer-associated retinopathy who had circulating serum antibodies to recoverin and cells positive for recoverin in the tumor. We discuss the typical clinical symptoms as well as the pathophysiology of this uncommon disorder.

Immunophenotype of human ovarian malignancies (cystadenocarcinomata and mixed müllerian tumor) established in SCID mice.

Human ovarian malignancies from three different patients (histology: two serous cystadenocarcinomata and one mixed Müllerian tumor, homologous type) were successfully serially transplanted intraperitoneally into severe combined immunodeficient (SCID) mice where the tumor cells spread around the peritoneal cavity. If the ascites derived from cystadenocarcinoma cells engrafted in the female genital tract of the SCID mice, they formed cystic tumors resembling remarkably well the original tumors in the patients. Immunohistochemical analysis revealed that the immunophenotype of the patients' original tumor and those grown in SCID mice were similar in the case of the two cystadenocarcinomata; in addition, the marker expression in general was stable during serial transplantation. If distant metastases occurred in the lungs, they immunophenotypically resembled those grown intraperitoneally. In contrast, the cells derived from the mixed Müllerian tumor shifted during serial transplantation from a spindle cell morphology toward a morphology characterized by cuboidal cells. The transition toward a more epithelial phenotype was accompanied by a changed immunophenotype of the tumor cells which became positive for epithelial cell markers such as carcinoembryonic antigens, CA 19-9 and CA 125. Concurrently with this differentiation, the p53 immunophenotype changed from positive to negative, indicating a further mutation in the p53 gene during serial passages.