Conclusion Measuring pharmacodynamic changes in CTC num bers during treatment i

Furthermore, there is a relatively large number of genes induced ARQ 197 supplier by combined E2 EGF exposure that is not induced by E2 or EGF alone. This most likely is also due to a synergistic effect of E2 and EGF because 60% of these genes are already induced by E2 or EGF alone but just below the threshold of 1. 5 fold. Conversely, there is also an antagonistic effect because some of the E2 up regulated genes are down regulated by EGF, and visa versa. In conclusion, the majority of genes are uniquely induced by either E2 or EGF and only for a limited number of genes there is an agonistic or antagonistic effect. Similar conclusions can be drawn for E2 and EGF down regulated genes. E2 and EGF induced cell signalling responsible for cell proliferation E2 and EGF induced expression of genes known to be involved in the control of cell proliferation, and these were different for E2 and EGF induced genes.<br><br> Thus, an important part of the E2 induced signalling centres around activation of RB1 E2F オーダー AZD0530 pathway that regulates the progression through the G1 phase of the mammalian cell cycle. This involves phosphorylation of RB1 by the CyclinD CdK4 6 complex. Factors activating the CyclinD CdK4 6 complex include CDC25A and MYC, and inhibitors include CDKN1A, SMAD3, TGFB members, and CDKN2B. The up and down regulation of these factors by E2 and or EGFR are presented in Additional file 8, Table S3. These data clearly show that there is a general up regulation of activating factors, and a down regulation of inhibitors of CyclinD CdK4 6 by E2.<br><br> This results in activation of E2F mediated transcription which is exemplified Alvocidib 構造 by increased transcription of E2F regulated genes such as CCNA1, CCND1, CCNE2, TK1, PCNA, DHFR, EZH2, and CDC6. At the same time, pro apoptosis factors are down regulated and anti apoptotic factors are upregulated, which contributes to cell proliferation and survival. Interestingly, also a number of oncogenes is up regulated by E2, and several tumor suppressor genes are down regulated by E2 that are not, or less, regulated by EGF. Many of these E2 induced changes in gene expression could be inhibited with TAM. On the other hand, EGF induced signalling relies more on activation of the RAS RAF MEK MAPK ELK1 and PI3K Akt pathways because phosphorylation of MAPK1 3 and Akt were greatly increased after EGF stimulation of MCF7 EGFR cells.<br><br> Consistent with this activation, transcription of FOS, EGR1 and JUNB was increased by EGF, and also up regulation of RELB, GADD45A, ETV5, ANGPTL4, and down regulation of TOB1 and PDCD4 which is part of a MAPK signature in MCF7 cells was observed. Moreover, further increase of JUN FOS signalling may occur through cooperation with Smad3 because expression of this factor is also increased several fold as is the upstream regulator of Smad signalling, TGFBR2 and its ligand TGFB2. Because the results so far had indicated that EGFR driven proliferation may be dependent on the PI3K Akt pathway and to a lesser extent on the MEK MAPK pathway, we also investigated PI3K Akt regulated gene expression. This may be accomplished via the transcription factors, CREB and NF κB.