[Immunohistochemistry and genotype analysis of tumors. First part: Which future for the immunochemical diagnosis of cancer?].
Immunohistochemistry (IHC) is a rapid morphological method that allows the detection of proteins involved in different mechanisms of cancer development. It is therefore a useful tool in the study of cancerogenesis. The best known example is the product of the p53 gene, a tumour suppressor gene which is altered in 50% of all human tumors. In fact, these p53 gene mutations lead to cell protein accumulation whereas the p53 product is not detectable in normal cells. This method also enables the detection of fusion proteins which result from chimeric transcript like WT1 in desmoplastic small round cell tumors, ALK in anaplastic large-cell lymphomas and FLI-1 in Ewing's sarcomas. On the contrary, gene inactivation can induce loss of immunostaining. hMLH1 and hMSH2, which are committed in DNA mismatch repair, can be altered in familial digestive carcinomas, such as hereditary non polyposis colorectal cancer. Thus IHC, which allows us to focus on the altered gene by loss of its product in tumoral cells, represents a good alternative to molecular analysis. IHC is also useful to detect the product of oncogene overexpression such as HER-2 in some breast carcinomas, which allows appropriate therapeutic protocols. Finally, IHC can be used in diagnostic, prognostic and therapeutic ends. Nevertheless, difficulties can be en- countered in the interpretation of the results. Therefore, IHC must be performed in quality control trials.
Service de Pathologie, Institut Gustave Roussy, 39 rue Camille-Desmoulins, 94800 Villejuif.
Magali
M
Svrcek
Jean-Christophe
JC
Sabourin
D005821:Genetic Techniques / Q000639:trends*; D005838:Genotype; D006801:Humans; D007150:Immunohistochemistry / Q000639:trends*; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology*; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics
D009363:Neoplasm Proteins; D011993:Recombinant Fusion Proteins