Expression of Leukemia/Lymphoma Related Factor (LRF) in Human Breast Carcinoma and Comparison with other Cancers

Abstract

Leukemia/lymphoma‐related factor (LRF), a member of the POK family, has a vital function in cellular transformation. Apart from its role in lymphomas, very little is known about its expression in most solid tumors, including breast carcinoma. In this study, LRF mRNA transcripts and protein expression was quantified in benign and malignant breast, colon, liver, lung, renal, and mesothelioma tissues by performing RT‐PCR, Western blot, immunohistochemistry, and immunocytochemistry. All malignant breast tissues expressed significantly more LRF mRNA transcripts and protein than the benign breast tissues. LRF was expressed more strongly in fibroadenoma, invasive lobular carcinoma and ductal carcinoma in situ than in other breast diseases. The ducts in ductal hyperplasia tissues of the breast were weakly positive. In general, a significantly higher expression of LRF was seen in malignant tissue than in the corresponding benign or normal tissue. LRF expression in the carcinoma of the colon, liver, and lung was higher than in the corresponding normal or benign tissues. A strong expression of LRF was observed in normal prostate but not in prostate cancer. These data suggest that LRF could be a marker for malignancy or proliferation of the cancers.(Supported by the Claire Booth Luce Fellowship to A.A.)