Whereas maintenance of hematopoietic stem cells (HSCs) is a requisite for life, uncontrolled expansion of HSCs might enhance the propensity for leukemic transformation. Accordingly, HSC numbers are tightly regulated. The identification of physical cellular HSC niches has underscored the importance of extrinsic regulators of HSC homeostasis.
View Article and Find Full Text PDFInhibition of mutant B-Raf signaling, through either direct inhibition of the enzyme or inhibition of MEK, the direct substrate of Raf, has been demonstrated preclinically to inhibit tumor growth. Very recently, treatment of B-Raf mutant melanoma patients with a selective B-Raf inhibitor has resulted in promising preliminary evidence of antitumor activity. This article describes the design and optimization of tetrahydronaphthalene-derived compounds as potent inhibitors of the Raf pathway in vitro and in vivo.
View Article and Find Full Text PDFThe mitotic kinase Aurora A is an important therapeutic target for cancer therapy. This study evaluated new mechanism-based pharmacodynamic biomarkers in cancer patients in two phase I studies of MLN8054, a small-molecule inhibitor of Aurora A kinase. Patients with advanced solid tumors received MLN8054 orally for 7 consecutive days in escalating dose cohorts, with skin and tumor biopsies obtained before and after dosing.
View Article and Find Full Text PDFThe formation of a lumen in three-dimensional mammary epithelial acinar structures in vitro involves selective apoptosis of centrally localized cells that lack matrix attachment. Similarly, apoptosis is induced by forced detachment of mammary epithelial cells from matrix, a process referred to as anoikis. Through microarray analysis, we found that mRNA levels of the proapoptotic BH3-only protein Bmf are up-regulated during both anoikis and acinar morphogenesis.
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