Open AccessConstruction of Immunoradiometric Assay for Circulating c‐ erb B‐2 Protooncogene Product in Advanced Breast Cancer Patients
Author(s) -
Hosono Makoto,
Saga Tsuneo,
Sakahara Harumi,
Kobayashi Hisataka,
Shirato Makoto,
Endo Keigo,
Yamamoto Tadashi,
Akiyama Tetsu,
Toyoshima Kumao,
Konishi Junji
Publication year - 1993
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1993.tb02848.x
Subject(s) - immunoradiometric assay , breast cancer , medicine , cancer , antibody , endocrinology , radioimmunoassay , monoclonal antibody , ovarian cancer , epitope , immunology , biology
The human c‐ erb B‐2 protooncogene product ( erb B‐2 protein) is a 185 kilodalton glycoprotein closely related to epidermal growth factor receptor protein. In this study, we measured the concentration of circulating erb B‐2 protein in cancer patients by means of a new immunoradiometric assay (IRMA). Two monoclonal antibodies (MoAbs), SV2‐61γ and 6G10, recognize erb B‐2 protein but bind to separate epitopes. SV2‐61γ was used as an immunoadsorbent and 6G10 as an 125 I‐labeled probe. A serum was considered positive for erb B‐2 protein if the percent binding exceeded the mean of the normal group by more than 3 standard deviations. Eleven of 21 patients with advanced breast cancer and 1 of 15 with advanced gastric cancer were positive. Serum erb B‐2 protein levels correlated well with the therapy and the status of the patients with breast cancer. On the contrary, all patients with advanced colon, ovarian, or pancreatic cancers, showed levels below the cut‐off value. These results suggest that circulating erb B‐2 protein can be measured using the newly constructed IRMA. Since c‐ erb B‐2 protooncogene amplification and overexpression are accepted as a good marker of aggressiveness, relapsing potency, and poor prognosis, this IRMA should be a promising tool with which to help manage breast cancer patients.