Asch H L, Eliacin E, Fanning T G, Connolly J L, Bratthauer G, Asch B B
Department of Experimental Pathology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
Oncol Res. 1996;8(6):239-47.
Human LINE-1 (L1Hs) retrotransposons can act as insertional mutagens and are expressed in a variety of tumors, including breast cancer. The purpose of the present study was to examine expression of the p40 protein encoded by the first open reading frame of a L1Hs element in normal human breast tissue of patients without malignant breast disease and in nontumor breast tissue adjacent to cancer and to compare it to expression in breast carcinomas. An antiserum specific for the L1Hs p40 protein was used to analyze its expression in 5 reduction mammoplasties, 16 primary breast cancers, 1 lymph node metastasis and 13 non-malignant breast tissues adjacent to matched primaries by western blotting and/or immunocytochemistry. The immunoreactive band observed on westerns consistently had a M(r) of approximately 46 kDa. Westerns detected some p40 protein expression in all malignant and nonmalignant tissues examined, although 4 of 5 reduction mammoplasties had very low or trace levels as compared with tumors. Nonmalignant breast tissues adjacent to cancers showed significant western band reactivity, and all 15 tumors were positive. Immunocytochemistry revealed staining specificity of the antibody for epithelial cells. Of 12 invasive carcinomas examined, 100% were positive for the p40 protein, whereas one reduction with benign proliferative disease was very weakly reactive, two histologically normal reductions were negative, and 4 of 6 nonmalignant tissues adjacent to cancers were negative. Our data indicated that expression of the L1Hs p40 protein was often elevated in tumor cells of human breast cancers compared to epithelium of normal mammary gland.
人类LINE-1（L1Hs）逆转座子可作为插入诱变剂，并在包括乳腺癌在内的多种肿瘤中表达。本研究的目的是检测L1Hs元件第一个开放阅读框编码的p40蛋白在无乳腺恶性疾病患者的正常人类乳腺组织以及癌旁非肿瘤性乳腺组织中的表达，并将其与乳腺癌中的表达进行比较。使用针对L1Hs p40蛋白的抗血清，通过蛋白质印迹法和/或免疫细胞化学分析其在5例缩乳术标本、16例原发性乳腺癌、1例淋巴结转移灶以及13例与相应原发性肿瘤匹配的非恶性乳腺组织中的表达。蛋白质印迹法检测到的免疫反应条带的分子量（M(r)）始终约为46 kDa。蛋白质印迹法在所有检测的恶性和非恶性组织中均检测到一些p40蛋白表达，尽管5例缩乳术标本中有4例与肿瘤相比表达水平非常低或呈痕量。癌旁非恶性乳腺组织显示出明显的蛋白质印迹条带反应性，所有15例肿瘤均为阳性。免疫细胞化学显示该抗体对上皮细胞具有染色特异性。在12例浸润性癌中，100%的p40蛋白呈阳性，而1例伴有良性增生性疾病的缩乳术标本反应非常弱，2例组织学正常的缩乳术标本为阴性，6例癌旁非恶性组织中有4例为阴性。我们的数据表明，与正常乳腺上皮相比，人类乳腺癌肿瘤细胞中L1Hs p40蛋白的表达通常升高。
