ras p21 expression in the progression of breast cancer.

The differential expression of the ras oncogene product p21 in the primary tumor, regional nodes, and distant metastatic sites in patients with disseminated breast cancer was examined to define the biologic and clinical significance of the ras oncogene in the progression of breast cancer. The avidin-biotin peroxidase complex method was used on formalin-fixed, paraffin-embedded tissues from 16 patients with metastatic disease. The primary antibody used in this protocol was RAP-5, an anti-p21 murine monoclonal IgG2a.

Elevated ras oncogene expression correlates with lymph node metastases in breast cancer patients.

The protein product of the ras cellular oncogene(s) (p21) was assayed in primary breast carcinomas from two groups of patients who had different axillary lymph node status. Using an immunohistochemical assay, the intensity and percent of neoplastic cells demonstrating ras p21 antigen staining were significantly higher in the primary tumors from patients with lymph nodes positive (LN+) for malignancy (20 patients) compared with the lymph node negative (LNO) group (21 patients). The expression of p21 also correlated with tumor size.

Expression of ras oncogene p21 in prostate cancer.

The major neoplastic transformation-inducing genes of human solid tumors are members of the ras oncogene family. We used an immunohistochemical assay to assess expression of both the unaltered and the mutated ras oncogene protein (p21) in normal and neoplastic prostatic cells. With the concentration of monoclonal antibody used in this study, epithelial and stromal cells from subjects with normal prostates and from 19 patients with benign prostatic hyperplasia were negative for p21 antigen.

A comparison of tumor-related antigens in male and female breast cancer.

A retrospective analysis was undertaken in which 15 female and 15 male breast cancers were matched by age, stage, estrogen receptor status, and histologic type. Our protocol compares male and female breast cancers for reactivity with antibodies against tumor-associated antigens known to be present on female breast cancer cells. Formalin-fixed sections of each primary tumor were reacted in the ABC immunoperoxidase assay against antibodies B72.

ras Oncogene p21 expression is increased in premalignant lesions and high grade bladder carcinoma.

ras Oncogene p21 antigen is present in the most superficial cells of the normal bladder urothelium, as demonstrated by immunohistochemical staining. The pattern and intensity of p21 staining of cells in epithelial hyperplasia and low grade bladder carcinoma were similar to that seen in the normal urothelium. In contrast, epithelial cells in "premalignant" (dysplastic) lesions and high grade carcinomas exhibited an intense staining reaction for p21 antigen.