Wang D G, Johnston C F, Atkinson A B, Heaney A P, Mirakhur M, Buchanan K D
Department of Medicine, School of Clinical Medicine, Queen's University of Belfast.
J Clin Pathol. 1996 Oct;49(10):795-7. doi: 10.1136/jcp.49.10.795.
AIMS/BACKGROUND: Whereas the control of hormone secretion from pituitary adenomas has been studied in considerable detail, the molecular events underlying the development of these tumours are still poorly understood. Abnormalities of some oncogenes and tumour suppressor genes have been previously reported to occur at very low frequencies. The aim of the present study was to assess the possible expression of the bcl-2 oncoprotein and to compare it with that of c-myc in pituitary adenomas.
Monoclonal antibodies were used, along with microwave antigen retrieval and the avidin-biotin immunohistochemical method, to investigate expression of the oncoproteins bcl-2 and c-myc in 30 primary pituitary tumours from five broad diagnostic groups and in five normal pituitaries.
Bcl-2 and c-myc immunoreactivities were detected in nine (30%) and eight (27%) tumour samples, respectively. Of the nine bcl-2 and eight c-myc positive tumours, seven were positive for both oncoproteins and included one of the four corticotrophinomas studied, four of seven prolactinomas, one of two somatotrophinomas, and one of four oncocytomas. All 13 null cell adenomas studied were negative for both bcl-2 and c-myc immunoreactivities.
These results indicate that the bcl-2 and c-myc oncoproteins are expressed abnormally in over one quarter of pituitary tumours. Most these tumours co-expressed both oncoproteins. The genetic complementation of simultaneously deregulated bcl-2 and c-myc is implicated, through the regulation of apoptosis, in the pathogenesis of pituitary tumours.
目的/背景：虽然垂体腺瘤激素分泌的调控已得到相当详细的研究，但这些肿瘤发生发展的分子机制仍知之甚少。先前报道某些癌基因和肿瘤抑制基因的异常发生频率极低。本研究的目的是评估bcl-2癌蛋白的可能表达，并将其与垂体腺瘤中的c-myc表达进行比较。
使用单克隆抗体，结合微波抗原修复和抗生物素蛋白-生物素免疫组化方法，研究bcl-2和c-myc癌蛋白在来自五个广泛诊断组的30例原发性垂体肿瘤以及五个正常垂体中的表达。
分别在九个（30%）和八个（27%）肿瘤样本中检测到bcl-2和c-myc免疫反应性。在九个bcl-2阳性和八个c-myc阳性肿瘤中，七个同时表达这两种癌蛋白，包括所研究的四个促肾上腺皮质激素瘤中的一个、七个催乳素瘤中的四个、两个生长激素瘤中的一个以及四个嗜酸性细胞瘤中的一个。所研究的所有13例无功能细胞腺瘤的bcl-2和c-myc免疫反应性均为阴性。
这些结果表明，bcl-2和c-myc癌蛋白在超过四分之一的垂体肿瘤中异常表达。大多数这些肿瘤同时表达这两种癌蛋白。通过凋亡调控，同时失调的bcl-2和c-myc的基因互补作用与垂体肿瘤的发病机制有关。
