Immunohistochemical Techniques for Phosphoproteins.

The use of immunohistochemical techniques to study the patterns of protein phosphorylation has revolutionized the study of signaling pathways. This technique allows detecting the phosphorylated state of signaling proteins in formalin-fixed and paraffin-embedded tissue sections by using phosphospecific antibodies. This chapter describes in detail the immunohistocshemical protocols from which the study of phosphoproteins in tissue sections can be approached.

Dysregulated expression of the key effectors of the mammalian target of rapamycin signalling pathway in cutaneous papillomas of dogs.

Cutaneous papillomas (CP) are one of the most common skin neoplasms in dogs. Different murine models have shown that persistent activation of the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway has a central role in the development and progression of CP. The purpose of this study were to evaluate the immunohistochemical expression pattern of two key molecules involved in the PI3K/Akt/mTOR signalling pathway, pAktSer473 , and pS6Ser235/236 , on 36 canine specimens of CP using a tissue microarray. The results show that the PI3K/Akt/mTOR signalling pathway is persistently activated in CP of dogs, pointing to this pathway as a potential therapeutic target.