The expression of alpha B‐crystallin in epithelial tumours: A useful tumour marker?

Abstract

Alpha B-crystallin is a lens protein showing homology with small heat-shock proteins. We have previously demonstrated its expression in non-lenticular normal and diseased human tissues by immunostaining with a polyclonal antibody. In view of the expression seen in normal renal tubular epithelium, we have assessed the immunoreactivity of a variety of epithelial tumours, to determine the usefulness of alpha B-crystallin as a specific renal tumour marker. Carcinomas arising from tissues which normally express alpha B-crystallin, such as colo-rectal and thyroid carcinomas, showed a varying pattern and degree of immunoreactivity. The most consistently positive tumours, however, with typically strong cytoplasmic and cell membrane staining, were renal cell carcinomas, 90 per cent of which showed positive immunoreactivity. This pattern of staining, while not absolutely specific, is a useful aid to the diagnosis of renal carcinoma. When a metastic deposit or a small biopsy is being assessed, anti-alpha B-crystallin may be included in a panel of antibodies, the pattern of staining of which may direct the search for the primary site of the tumour.

Differential expression of alphaB-crystallin and Hsp27-1 in anaplastic thyroid carcinomas because of tumor-specific alphaB-crystallin gene (CRYAB) silencing

“…Numerous epithelial tumors exhibited alphaB-crystallin expression, and alphaB-crystallin was even discussed as potential tumor marker (Pinder et al 1994;Chelouche-Lev et al 2004). In this context, earlier observations of strong expression of p29, which is used synonymously to Hsp27-1 in papillary thyroid carcinomas, and its correlation with distinct clinical attributes seems of special interest (Akslen and Varhaug 1995).…”

“…In addition, alphaB-crystallin is expressed in many nonlenticular tissues including heart, brain, skeletal muscles, skin, lung, and to a lower extent in the kidney and thyroid gland (Dubin et al 1989;Iwaki et al 1990;Klemenz et al 1993). AlphaB-crystallin expression has also been demonstrated to varying extent in numerous epithelial tumors (Pinder et al 1994). Similarly, Hsp27-1 expression was found in various benign and malignant tissues, eg, in retinal neurons (Whitlock et al 2005a(Whitlock et al , 2005b, in reproductive tissues (White et al 2005), in normal and neoplastic renal tissue (Neuhofer et al 2005;Tremolada et al 2005), and in malignant thyroid tissue (Akslen and Varhaug 1995).…”

Using a Xenograft Model of Human Breast Cancer Metastasis to Find Genes Associated with Clinically Aggressive Disease

“…Few reports have documented expression of the small HSP aB-crystallin in breast cancer (45). This protein is thought to share chaperone functions of HSPs and may prevent apoptosis by binding to and preventing activation of caspase-3 (46,47).…”

Heat Shock Proteins 27 and 70: Anti-Apoptotic Proteins with Tumorigenic Properties

“…119,120 Overexpression of the small heat shock protein a B crystallin has been observed in glial tumors such as astrocytoma, glioblastoma and oligodendroglioma, 121 and in renal carcinoma tumors. 122 The molecular basis for overexpression of HSPs in tumors is not completely understood. In some tumors, it may be explained by a suboptimal cellular environment, for instance due to hypoxia or nutrient stress.…”