Purpose: Our aim was to isolate a novel human miniantibody (scFv) that specifically targets ErbB2-positive cancer cells. ErbB2, a tyrosine kinase receptor, is overexpressed in clinically significant tumors, such as breast, ovary, and lung carcinomas. In normal tissues, it is expressed only in certain epithelial cell types. Experimental Design: A large phagemid library (Griffin. 1 library) of human scFv was used for the isolation of the ErbB2-specific scFv. A very effective strategy was developed for the isolation, consisting in a double subtractive selection, the use of two different combinations of “positive,” i.e., ErbB2-bearing, and “negative” cell lines. Results: Here we report the isolation of the first human anti-ErbB2 mini-antibody endowed with antitumor action. Both in its soluble and phage format, it binds specifically to ErbB2, inhibits its autophosphorylation, is internalized by target cells, and exerts a strong and specific antiproliferative action on ErbB2-positive target cells. A correlation was found between the extent of this antiproliferative effect and the expression levels of ErbB2 on target cells, with a strong cytotoxicity for hyper-expressing cells, such as SKBR3, in which apoptosis was evidenced. Conclusions: This scFv is a potentially effective immunoreagent for diagnostics and therapeutics of certain cancers, both as a readily diffused molecule in solid tumors and as an essential asset for the construction of fully human anticancer drugs.
A new human antitumor immunoreagent specific for ErbB2 / DE LORENZO, Claudia; Palmer, Db; Piccoli, Renata; Ritter, Ma; Dalessio, G.. - In: CLINICAL CANCER RESEARCH. - ISSN 1078-0432. - STAMPA. - 8:(2002), pp. 1710-1719.
A new human antitumor immunoreagent specific for ErbB2
DE LORENZO, CLAUDIA;PICCOLI, RENATA;
2002
Abstract
Purpose: Our aim was to isolate a novel human miniantibody (scFv) that specifically targets ErbB2-positive cancer cells. ErbB2, a tyrosine kinase receptor, is overexpressed in clinically significant tumors, such as breast, ovary, and lung carcinomas. In normal tissues, it is expressed only in certain epithelial cell types. Experimental Design: A large phagemid library (Griffin. 1 library) of human scFv was used for the isolation of the ErbB2-specific scFv. A very effective strategy was developed for the isolation, consisting in a double subtractive selection, the use of two different combinations of “positive,” i.e., ErbB2-bearing, and “negative” cell lines. Results: Here we report the isolation of the first human anti-ErbB2 mini-antibody endowed with antitumor action. Both in its soluble and phage format, it binds specifically to ErbB2, inhibits its autophosphorylation, is internalized by target cells, and exerts a strong and specific antiproliferative action on ErbB2-positive target cells. A correlation was found between the extent of this antiproliferative effect and the expression levels of ErbB2 on target cells, with a strong cytotoxicity for hyper-expressing cells, such as SKBR3, in which apoptosis was evidenced. Conclusions: This scFv is a potentially effective immunoreagent for diagnostics and therapeutics of certain cancers, both as a readily diffused molecule in solid tumors and as an essential asset for the construction of fully human anticancer drugs.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.