CENBIMO S.L

C-erbB2 CISH Single Stranded DNA PROBE To date, the status of HER2-neu or c-erbB2 in breast cancers has been assessed using immunohistochemistry with antibodies targeted against this oncoprotein or by assessing the amplification of the gene by CISH or FISH.

Immunohistochemistry often offers confusing results - owing to the great antigenic similarity of all of the members of the EGFR family there are cross-reactions.

On the other hand, CISH and FISH techniques to view nuclear amplification can check if this gene is amplified but there are no guaranties that the gene transcribes. This could occur for many motives for example many of the detected nuclear dots are in reality pseudogenes with the same sequence or they don’t have a promoter or other reasons.

We should take into account that only one gene copy can produce great quantities of protein. This occurs for example with the immunoglobulin genes or with the gene for serum albumin in which only one copy can produce many grams of protein daily.

There are published cases in which there has been over-expression of the c-erbB2 protein without gene amplification.

(see the article by Jose Baselga & Sandra M Swain in Nature Reviews Cancer Vol 9. Nº 7 July 2009, pg. 463:Novel anticancer targets, revisiting ERBB2 and discovering ERBB3).

HistoSonda c-erbB2 only detects the RNA transcript of the gene or the multiple c-erbB2 genes amplified and thus detects transcription.

In the preliminary studies that we have undertaken we have found a correlation of more than 98% with genetic amplification indicated by FISH.

The advantages of c-erbB2 RNA detection with HistoSonda is that it is assessed by light microscope, there is no need to count percentages, the result is yes or no, there is only 1 hour of incubation and because of this a rapid diagnosis can be obtained.