Analysis of the level of mRNA expression of the membrane regulators of complement, CD59, CD55 and CD46, in breast cancer

Abstract

We have examined the relative mRNA expression of the complement (C) regulatory proteins CD59, CD55 and CD46 in RNA isolated from 50 primary breast cancer specimens using a semiquantitative RT-PCR approach. Having normalized the mRNA expression levels of the C regulators relative to actin, we subsequently correlated their expression with estrogen receptor (ER) and various clinical, pathologic and biochemical features of the disease. CD59 and CD46 were detected in all clinical biopsies, while CD55 mRNA was detected in the majority of samples. The comparative levels of expression between the 3 regulators analyzed, using Spearman rank correlation test, revealed a significant association (p ‫؍‬ 0.01; r ‫؍‬ 0.36) between CD46 and CD59. CD46 exhibited the most striking pattern of association, with increased levels of expression being associated with ER-positive samples and lower levels of expression associated with a loss of differentiation and epidermal growth factor receptor positivity. Application of Spearman rank correlation test revealed CD46 expression was significantly associated with expression of ER at the level of protein (p ‫؍‬ 0.031; r ‫؍‬ 0.31) and mRNA (p < 0.001; r ‫؍‬ 0.52). CD46 expression also correlated with insulin-like growth factor receptor-positive samples using Spearman rank correlation test (p ‫؍‬ 0.016; r ‫؍‬ 0.34), but negatively associated with tumor samples either exhibiting histologic grade 3 when compared to grades 1 or 2 or displaying elevated levels of inflammatory cell infiltrate. Immunohistochemical analysis of a limited series (n ‫؍‬ 8) of paraffin-embedded breast cancers indicated that the level of CD46 protein expression directly associates with that of the mRNA and, where prominent, is localized in the tumor epithelial cell population, including at the plasma membrane. These data provide new information on expression of these important regulators in breast cancer and suggest that CD46 should be evaluated as a novel prognostic indicator.

Downregulation of human CD46 by adenovirus serotype 35 vectors

“…After infection, the cells were collected at the indicated time points and total RNA was isolated from the cells using Isogen reagent (Nippon Gene, Tokyo, Japan). First-strand cDNA templates were synthesized as previously described, 43 and the templates were subjected to PCR amplification using sets of primers for human CD46 45 and GAPDH. 46 The cycling parameters were 30 s at 941C, 30 s at 551C and 30 s at 721C for both CD46 and GAPDH.…”

p53 Regulates Cellular Resistance to Complement Lysis through Enhanced Expression of CD59

“…CReg are broadly expressed on a wide variety of tissues and cells, including epithelial, endothelial, and circulatory cells, and act as physiologic brakes to complement amplification. CD46, CD55, and CD59 are expressed on a number of solid tumors and associated cell lines, and it is apparent that the level of expression in malignant tissue is often greater than that seen in the normal surrounding tissue (7,(11)(12)(13). Consequently, the increased complement resistance conferred by these membrane-bound CReg has been proposed as a mechanism that facilitates survival of the tumor or the metastasizing tumor cell when it enters circulation (8,14,15).…”

Fiber-chimeric adenoviruses expressing fibers from serotype 16 and 50 improve gene transfer to human pancreatic adenocarcinoma

“…The high expression of this receptor may offer a growth advantage to cancer cells by protecting them from complement damage. [35][36][37][38] This increased expression on many different cancer types including pancreatic cancer renders CD46 an ideal target to obtain specific transduction of tumors. Here we showed that exchanging the fiber of Ad5 with fibers of serotype 16 and 50 indeed resulted in an enhanced gene transfer to human pancreatic adenocarcinoma cell lines.…”