Coordinate expression of the PI3-kinase downstream effectors serum and glucocorticoid-induced kinase (SGK-1) and Akt-1 in human breast cancer.
The phosphatidylinositol 3-kinase (PI3-K) signalling pathway has been implicated in breast cancer development and resistance to therapy. Akt-1 and serum and glucocorticoid-induced kinase-1 (SGK-1) are homologous kinases which are important downstream effectors of PI3-K signalling. We sought to determine the individual expression patterns of these two kinases in order to better understand their respective roles in PI3-K signalling in breast cancer. To this end, we examined the expression of both p-Akt-1 and SGK-1 in 40 breast cancers. p-Akt-1 expression was seen in 58% of tumour samples, while SGK-1 overexpression was detected in 48%. Interestingly, a highly significant association was found between the expression of p-Akt-1 and SGK-1 (P=0.002), suggesting complementary physiological functions in PI3-K signalling. This finding is consistent with recent genetic data from Caenorhabditis elegans suggesting that both SGK-1 and Akt-1 are required for signalling downstream of insulin receptor activation.
Sahoo
Sunati
S
Department of Pathology, University of Louisville, Louisville, KY 40202, USA.
Brickley
Deanna R
DR
Kocherginsky
Masha
M
Conzen
Suzanne D
SD
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000201:enzymology*; D005260:Female; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D008875:Middle Aged; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D000099184:Serum-Glucocorticoid Regulated Kinases
D017874:Immediate-Early Proteins; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D000099184:Serum-Glucocorticoid Regulated Kinases; C494918:AKT1 protein, human