Influence of FOX genes on aging and aging-associated diseases. Elena Tschumak

Чтение книги онлайн.

      During these experiments, the DMEM-cultured and ATCC-derived osteosarcoma cell lines were treated with the IKK pathway inhibitor VII, the MAPK pathway inhibitor, the LY-294002 PI3K pathway inhibitor, the 117082 NF-kappa B pathway inhibitor, the Notch signalling pathway inhibitor or with the DMSO vesicle. Then the alkaline phosphatase and MTS assays were done and 405nm absorbance was measured. Other methods were RNA isolation, cDNA preparation and real-time PCR, protein isolation, immunoblotting, chromatin immunoprecipitation and flow cytometric analysis of the cell cycle distribution. The authors found a link between the 7-time increased FOXP2 expression in murine bone 48 h after treatment and the decreased growth of osteosarcoma cell lines. Unlike mesenchymal tissue osteoblasts did not require RUN involvement in FOXP2 induction. (Zhao et al., 2014) In neuroblastoma cells growth arrest was not accompanied by FOXP2 induction. Cyclin-dependent kinase inhibitors such as p21WAF1, p27KIP1, CIP1CDKN1A and CDKN1B organize CDK inhibition. These experiments also demonstrated that FOXP2 induces CDKN1A / p21 expression in osteoblasts and serves as a primary trigger for cell growth arrest. FOXP2 reduction resulted in strong CDKN1A / p21 and slight CDK4 decline and showed no effect on p53 level. Increased p53 / p21 level had no effect on FOXP-2 level. Immunoprecipitation did not show direct FOXP2 / p21 binding sites and it was demonstrated that although increased FOXP2 expression was accompanied by concomitant IL-6 expression but FOXP2 did not controls p21 expression via IL-6, p21 induction by the FOXP2 takes place indirectly. This is still to be studied. The researchers found a correlation between Lhx8 deficiency factor and FOXP2 expression. There may be a relationship between the FOXP2 and the Soxp2.

      Yan X et al. showed 2015 in „Downregulation of FOXP2 promoter human hepatocellular carcinoma cell invasion“ that FOXP2 level in human hepatocellular carcinoma cells is significantly reduced compared to adjacent non-tumor tissue. They used Western blot, transwell assays and immunohistochemistry to measure FOXP2 expression in HCC and in adjacent normal tissues of 50 patients. Their results showed that FOXP2 expression was down-regulated in HCC tumor tissue and that FOXP2-level decrease correlated with poor survival rates. FOXP2 could decrease cell invasion and affect the expression of vimentin and OXE-cadherin.

       Since the study by Schroeder and Myers (2008) has emphasized the importance of cell-specific FoxP expression it is especially important to measure it in different tissues and to take a closer look at its cell-specific interaction mechanisms. Chiu et al. (2014) described how FOXP2 inhibits the ERK / MAPK (HSPB7), NOS1, KCNJ15 and SHH pathways (PTCH1) and Vernes et al. (2011) and Ayub et al. (2013) how it influences the oncogene CDK8. FOXP2 effects Bcl-2 expression which seems to be involved in pro-caspase activation and apoptosis. (Devanna et al., 2014). Spiteri et al. (2007) described the cancer-related actin-binding protein genes TAGLN, NOS1, LBR, KCNJ15 and ANK1 as additional FOXP2 target genes. FP2 affects the proto-oncogene C-MET by binding its regulator the AP1-NFAT complex. It also affects the p53 which in turn binds to C-MMET. (Mukamel et al., 2011) (Ho and Crabtree, 2006). MAPK and TGF-β pathways are modified by lncPINT, which is also affected by the with PRC2 interacting p53.