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A glycoprotein, BCA-225 (Mr 225,000-250,000), has been identified in cells and spent medium of clone 11 T47D breast carcinoma cells by three murine monoclonal antibodies, CU18, CU26, and CU46. The antigen was localized in paraffin sections of 167/178 (94%) Bouin's-fixed human breast carcinoma tissues and few other carcinomas (1/8 lung [squamous], 4/4 uterine cervix) in an intracellular pattern, whereas an apical or glycocalyx distribution was seen in several normal tissues, benign lesions, and malignant tumors. Although the immunocytochemical staining patterns observed with these antibodies have many similarities to those described with other previously reported monoclonal antibodies, notable differences include the lack of reactivity of CU18, CU26, and CU46 with lactating mammary gland and with gastrointestinal malignancies. BCA-225 binds to wheat germ lectin, not to concanavalin A, but monoclonal antibody binding does not appear to involve the carbohydrate component of the molecule. The frequency of the immunocytochemical detection of BCA-225 in breast carcinomas and its restricted distribution in other human tissues suggest considerable clinical potential for this antigen and its corresponding monoclonal antibodies.

Z-DNA has been detected in several pro- and eukaryotic cells and possible roles in regulating transcriptional activity and meiotic recombination proposed. The present study examined the localization of reaction product to potential Z-DNA sites in human testicular tubule epithelium from three subjects using an avidin-biotin complex (ABC)-immunoperoxidase method with a specific rabbit antibody previously shown to react with rat spermatogonial nuclei. A total of 46,626 cells were scored, of which 5656 were Sertoli cells. Eighty-six percent of spermatogonia in mitotic metaphase were found to be negative. Interphase spermatogonia identified as A dark or pale were positive in 93 and 92%, respectively, of cells, and this positivity persisted through B spermatogonia into meiosis. Of 8083 leptotene/zygotene spermatocytes, 99% were positive. Pachytene spermatocytes were 98% positive in the autosomal bivalents. First meiotic metaphase nuclei were negative (92%), as were almost all cells scored of the spermiogenic series (16,195). Nuclei of Sertoli cells had reaction product over the chromatin in 81% of 5656 cells, with no reaction product on the prominent nucleolus. The presence of potential Z-DNA sites in the genome of human spermatogenesis and Sertoli cells during known active stages of transcription (pachytene) and recombination (zygotene/pachytene) suggests a role for this conformation during these stages.