EGF effects in the regulation of gene transcripts identified as differentially expressed in human mammary cell lines expressing different levels of ERBB2.

A amplificação gênica mais freqüente em câncer de mama é a do oncogene ERBB-2, observada em aproximadamente 30% dos tumores de mama e que está relacionada com menor intervalo livre de doença e sobrevida total das pacientes com câncer de mama. O ERBB-2 ativa importantes vias de sinalização celular, incluindo as vias MAPK e PI3K. Utilizando PCR em tempo real analisou-se o efeito do EGF e da HRG na regulação da expressão dos genes ANP32B, MATR3, ATAD4, NDRG1, ACTN1, SPARC, TPM1 e CENPH, nas células HB4a, C5.2 e SKBr3, que expressam diferentes níveis de ERBB2. Avaliou-se também o perfil de expressão destes transcritos após a supressão do ERBB2 pela técnica de siRNA nas células C5.2. O tratamento com EGF modulou de forma diferente a expressão dos genes estudados nas células HB4a, C5.2 e SKBr3. Nas células HB4a e SKBr3 a HRG também regulou a expressão dos genes acima. Após a transfecção das células C5.2 com siERBB2 houve alteração na expressão dos genes ATAD4, NDRG1, ACTN1, SPARC, MATR3, CENPH e TPM1.The more frequent genic amplification observed in breast cancer is that of the ERBB2 oncogene, which occurs in approximately 30% of the breast cancers, and is associated with lower disease-free interval and survival of all patients with breast cancer. The ERBB-2 protein activates important cell signaling pathways such as MAPK and PI3K. Using real time PCR, it was investigated the effect of EGF and HRG on ANP32B, MATR3, ATAD4, NDRG1, ACTN1, SPARC, TPM1 and CENPH transcripts regulation in the HB4a, C5.2 and SKBr3 cell, that express different levels of ERBB2. It was also evaluated the expression profile of these transcripts in the C5.2 cell line after the suppression of ERBB2 expression by the siRNA technique. The treatments with EGF modulate differently the expression of the analysed transcripts in HB4a, C5.2 and SKBr3 cells. In HB4a and SKBr3 cells the treatments with HRG also modulate the expression of the transcripts above. The C5.2 cells transfected with siERBB2 showed alteration in the expression of ATAD4, NDRG1, ACTN1, SPARC, MATR3, CENPH and TPM1 transcripts