Project description:While c-Src is infrequently mutated in human cancers, it mediates oncogenic signals of many activated growth factor receptors and thus remains a key potential target of cancer therapy. However, the widespread function of Src in many cell types and processes requires evaluation of Src-targeted therapeutics within a normal developmental and immune competent environment. In an effort to direct clinical use of Src inhibitors, we tested the effectiveness of one of the four Src inhibitors in clinical testing, SKI-606 (bosutinib), in the MMTV-PyVmT transgenic mouse model of breast cancer. Tumor formation in this model is dependent on the presence of Src, but the necessity of Src kinase activity for tumor formation has not been determined. Furthermore, Src inhibitors have not been examined in an autochthonous tumor model. Here we show that oral administration of the Src inhibitor SKI-606 inhibited the phosphorylation of Src in mammary tumors, and caused a rapid decrease in the Ezh2 Polycomb group histone H3K27 methyltransferase and an increase in epithelial organization. SKI-606 prevented the appearance of palpable tumors in more than half of the animals treated from puberty and stopped tumor growth in older animals with preexisting tumors. These antitumor effects were accompanied by decreased cellular proliferation, altered tumor blood vessel organization and dramatically increased differentiation to lactational and epidermal cell fates. SKI-606 controls the development of mammary tumors in this model by inducing differentiation. Differentiation of Mammary Tumors by SKI-606 (bostutinib)
Project description:While c-Src is infrequently mutated in human cancers, it mediates oncogenic signals of many activated growth factor receptors and thus remains a key potential target of cancer therapy. However, the widespread function of Src in many cell types and processes requires evaluation of Src-targeted therapeutics within a normal developmental and immune competent environment. In an effort to direct clinical use of Src inhibitors, we tested the effectiveness of one of the four Src inhibitors in clinical testing, SKI-606 (bosutinib), in the MMTV-PyVmT transgenic mouse model of breast cancer. Tumor formation in this model is dependent on the presence of Src, but the necessity of Src kinase activity for tumor formation has not been determined. Furthermore, Src inhibitors have not been examined in an autochthonous tumor model. Here we show that oral administration of the Src inhibitor SKI-606 inhibited the phosphorylation of Src in mammary tumors, and caused a rapid decrease in the Ezh2 Polycomb group histone H3K27 methyltransferase and an increase in epithelial organization. SKI-606 prevented the appearance of palpable tumors in more than half of the animals treated from puberty and stopped tumor growth in older animals with preexisting tumors. These antitumor effects were accompanied by decreased cellular proliferation, altered tumor blood vessel organization and dramatically increased differentiation to lactational and epidermal cell fates. SKI-606 controls the development of mammary tumors in this model by inducing differentiation. Differentiation of Mammary Tumors by SKI-606 (bostutinib)
Project description:While c-Src is infrequently mutated in human cancers, it mediates oncogenic signals of many activated growth factor receptors and thus remains a key potential target of cancer therapy. However, the widespread function of Src in many cell types and processes requires evaluation of Src-targeted therapeutics within a normal developmental and immune competent environment. In an effort to direct clinical use of Src inhibitors, we tested the effectiveness of one of the four Src inhibitors in clinical testing, SKI-606 (bosutinib), in the MMTV-PyVmT transgenic mouse model of breast cancer. Tumor formation in this model is dependent on the presence of Src, but the necessity of Src kinase activity for tumor formation has not been determined. Furthermore, Src inhibitors have not been examined in an autochthonous tumor model. Here we show that oral administration of the Src inhibitor SKI-606 inhibited the phosphorylation of Src in mammary tumors, and caused a rapid decrease in the Ezh2 Polycomb group histone H3K27 methyltransferase and an increase in epithelial organization. SKI-606 prevented the appearance of palpable tumors in more than half of the animals treated from puberty and stopped tumor growth in older animals with preexisting tumors. These antitumor effects were accompanied by decreased cellular proliferation, altered tumor blood vessel organization and dramatically increased differentiation to lactational and epidermal cell fates. SKI-606 controls the development of mammary tumors in this model by inducing differentiation.
Project description:While c-Src is infrequently mutated in human cancers, it mediates oncogenic signals of many activated growth factor receptors and thus remains a key potential target of cancer therapy. However, the widespread function of Src in many cell types and processes requires evaluation of Src-targeted therapeutics within a normal developmental and immune competent environment. In an effort to direct clinical use of Src inhibitors, we tested the effectiveness of one of the four Src inhibitors in clinical testing, SKI-606 (bosutinib), in the MMTV-PyVmT transgenic mouse model of breast cancer. Tumor formation in this model is dependent on the presence of Src, but the necessity of Src kinase activity for tumor formation has not been determined. Furthermore, Src inhibitors have not been examined in an autochthonous tumor model. Here we show that oral administration of the Src inhibitor SKI-606 inhibited the phosphorylation of Src in mammary tumors, and caused a rapid decrease in the Ezh2 Polycomb group histone H3K27 methyltransferase and an increase in epithelial organization. SKI-606 prevented the appearance of palpable tumors in more than half of the animals treated from puberty and stopped tumor growth in older animals with preexisting tumors. These antitumor effects were accompanied by decreased cellular proliferation, altered tumor blood vessel organization and dramatically increased differentiation to lactational and epidermal cell fates. SKI-606 controls the development of mammary tumors in this model by inducing differentiation.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other