ERK inhibitors

Sorafenib (l)11 is a multikinase inhibitor marketed by Bayer and Onyx. Sorafenib blocks tyrosine kinases as well as serine/threonine kinases. Its story began in 1994 when Bayer and Onyx entered a collaboration to discover novel Raf/MEK/ERK inhibitors. They first discovered a very mildly active compound 8 (/C50 17 pM) against Rafl kinase in 1995 from screening a collection of 200,000 compounds. The optimization of its potency and its ADMET profile using medicinal chemistry and combinatorial chemistry methods led to the identification of sorafenib (1) in 1999 as a preclinical development candidate. Multiple phase I studies started in 2000, when sorafenib tosylate (19) was evaluated in patents with advanced solid tumors of different types. In December 2005, Sorafenib tosylate (19) received U.S. FDA approval for the treatment of advanced renal cell carcinoma (RCC). Two years later, it was approved for the treatment of unresectable hepatocellular carcinoma (HCC). 

Figure 2. Coronin 1C in melanoma. A) Immunohistochemical staining of the indicated tissue samples for Coronin 1C. S m sections from melanoma tumors were stained with a new Coronin 1C specific mAb (Roadcap and Bear, unpublished reagent) for 30min at 37°C with a steam heat-induced epitope retrieval, using the streptavidin/biotin method with an alkaline phosphatase label and Permanent Red (Dako) as the chromogen and then stained with hematoxylin. B) qRT-PCR analysis of the indicated melanoma cell lines treated with the Erk inhibitor U0126 or vehicle control for 24 hours.Dotted line indicates lx threshold.

In the sea urchin embryo, the ERK pathway drives PCNA activity, and ERK inhibitors switch off PCNA-driven DNA replication [1108] vide supra). In human cells, as well as in other eukaryotes, small ubiquitin-Uke modifiers (SUMO) sumoylate PCNA at multiple sites. PCNA-SUMOl fusion prevents dsDNA breaks and recombinations due replication fork collapse at stalling DN A lesion sites [ 1109]. 

Synthesis of selective and potent ERK inhibitors utilizing a protein kinase/small-molecule inhibitor complementary pair method... 

Many of these intracellular events are critical to the prohferative effects of CXCL12. For example, the CXCL12-induced effect on proliferation is dependent on calcium. Pre-treatment of pituitary adenoma cells with BAPTA-AM abohshes the CXCL12-induced increase in prohferation (Florio et al. 2006). The increase in proliferation also requires activation of Erk 1/2, as pre-treatment with PD98059, a MEK inhibitor, blocks the proliferative effect of CXCL12, and this is correlated with a decrease in Erk 1/2 phosphorylation. Similarly, the proliferative effects of... 

Figure 7.1 Major signaling pathways relevant to this chapter. Simplified schematic diagram of the major signaling pathways which impinge on mRNA translation I. The phosphatidylinositide 3-kinase (PI 3-kinase) pathway II/III. MAP kinases, especially the classical MAP kinase (ERK) pathway and the p38 MAP kinase pathway IV. The mammalian target of rapamycin (mTOR) pathway. Strictly, this diagram shows the rapamycin-sensitive events linked to mTORCl. Selected inhibitors and their sites of action are shown. A numberof components and cross-connections have been omitted for clarity.

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