HER-2 neu, RMab

HER-2 neu (also known as c-erbB-2) is a member of the epidermal growth factor receptor (EGFR) family and is notable for its role in the pathogenesis of breast cancer and as a target of treatment. It is a cell membrane surface-bound tyrosine kinase and is normally involved in the signal transduction pathways leading to cell growth and differentiation. HER-2 neu is a proto-oncogene located at the long arm of human chromosome 17(17q11.2-q12).

Approximately 25-30 percent of breast cancers have an amplification of the HER-2 neu gene or overexpression of its protein product. Over-expression of this receptor in breast cancer is associated with increased disease recurrence and poorer prognosis. Because of its prognostic role as well as its ability to predict response to trastuzumab, breast tumors are routinely checked for overexpression of HER-2 neu. Overexpression also occurs in other cancers such as Osteosarcoma, ovarian cancer and stomach cancer.

HER2/neu is a rabbit monoclonal antibody derived from cell culture supernatant that is concentrated, dialyzed, filter sterilized and diluted in buffer pH 7.5, containing BSA and sodium azide as a preservative.

1. Wright C, et al. Cancer Research. 1989;49:2087-90
2. Wright C, et al. British J Cancer. 1992;65:118-121
3. Slamon DJ, et al. Science. 1987;237:177-182
4. Jacobs TW, et al. Am J Clin Pathol. 2000;113:251-258
5. Gorlick R, et al. J Clin Oncol. 1999;17(9):2781-88
6. Keshgegian AA, et al. Am J Clin Pathol. 1997;Oct;108(4):456-63

1. Cut and mount 3-4 micron formalin-fixed paraffin-embedded tissues on positive charged slides.
2. Air dry for 2 hours at 58° C.
3. Deparaffinize, dehydrate and rehydrate tissues.
4. Subject tissues to heat epitope retrieval using a suitable retrieval solution such as ImmunoDNA Retriever with Citrate (BSB 0020-BSB 0023) or EDTA (BSB 0030-BSB 0033).
5. Any of three heating methods may be used:
   • Electric Pressure Cooker
     Place standoff rack at base of pressure cooker. Add 1-2 inches of distilled water to the pressure cooker and turn heat to high, and incubate for 15 minutes. Open and immediately transfer slides to room temperature.
   • Water Bath Method
     Place tissues/slides in a pre-warmed staining dish or coplin jar containing the ImmunoDNA Retriever with Citrate or EDTA in a water bath set at 95°-99° C. Incubate for 30-60 minutes.
   • Conventional Steamer Method
     Place tissues/slides in a pre-warmed staining dish or coplin jar containing the ImmunoDNA Retriever with Citrate or EDTA in a Steamer, cover and steam for 30-60 minutes.
6. After heat treatment, transfer slides in ImmunoDNA Retriever with Citrate or EDTA to room temperature and let stand for 15-20 minutes.
7. Wash slides with IHC wash buffer or DI water.
8. Continue IHC staining protocol.