Increased Expression of Phosphatidylinositol 3-Kinase p110α and Gene Amplification of PIK3CA in Nasopharyngeal Carcinoma

Abstract

Molecular alterations in PIK3CA oncogene that encodes the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K p110α) are commonly found in human cancers. In this study, we examined the expression of PI3K p110α and PIK3CA gene amplification in 74 nasopharyngeal carcinoma (NPC) cases. Immunohistochemical staining demonstrated overexpression of PI3K p110α protein in 44.6% (33/74) of NPCs and 4.8% (2/42) of the adjacent normal nasopharyngeal mucosa. Copy number of PIK3CA gene was successfully analyzed in 51 of the total NPC cases and 19 non-malignant nasopharynx tissues by quantitative real-time PCR. Using mean + 2(standard deviation) of copy numbers in the non-malignant nasopharynx tissues as a cutoff value, PIK3CA copy number gain was found in 10 of 51 (19.6%) NPC cases. High PI3K p110α expression level was correlated with increased PIK3CA copy number (Spearman's rho =0.324, P = 0.02). PI3K p110α expression and PIK3CA copy number did not associate with Akt phosphorylation, and patient and tumor variables. This study suggests that PI3K p110α overexpression, which is attributed, at least in part, to PIK3CA gene amplification, may contribute to NPC pathogenesis. However, these molecular aberrations may not be responsible for activation of Akt signaling in NPC.

Serum- and glucocorticoid-inducible kinase 3 is a potential oncogene in nasopharyngeal carcinoma

“…Following washing with PBS, the sections were stained with diaminobenzidine chromogenic solution (DAB) and counterstained with hematoxylin, differentiated using hydrochloric acid in ethanol, blued by washing with water and sealed with conventional resin. 17 The results were evaluated by the HSCORE method which included both the intensity and the distribution score of the specific staining, evaluated by two pathologists independently. 18 The distribution scores of SGK3 expression were recorded as percentages of positively stained cells in each of the four intensity categories, which were scored as 0 (no staining), 1 (weak staining), 2 (distinct staining) and 3 (strong staining).…”

Estudio de la ruta de la autofagia en carcinoma de endometrio esporádico

“…en el tejido tumoral que en el adyacente, y la expresión de la proteína se encontró más incrementada en muestras de metástasis en los nódulos linfáticos [183]. En otro estudio se encontró que en carcinoma de nasofaringe existe una sobreexpresión de la proteína PIK3CA detectada mediante inmunohistoquímica en el 44.6% de los tumores [184]. Es necesario mencionar, que en la mayoría de trabajos, la expresión de PIK3CA en muestras tumorales se estudia mediante inmunohistoquímica, por lo que los resultados podrían diferir de los encontrados mediante western blot.…”