{"id":1297,"date":"2026-01-24T08:35:20","date_gmt":"2026-01-24T08:35:20","guid":{"rendered":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/2026\/01\/24\/implication-of-mtor-in-camp-dependent-mitogenesis-in-thyroid-cells\/"},"modified":"2026-01-24T08:35:20","modified_gmt":"2026-01-24T08:35:20","slug":"implication-of-mtor-in-camp-dependent-mitogenesis-in-thyroid-cells","status":"publish","type":"post","link":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/2026\/01\/24\/implication-of-mtor-in-camp-dependent-mitogenesis-in-thyroid-cells\/","title":{"rendered":"IMPLICATION OF MTOR IN CAMP-DEPENDENT MITOGENESIS IN THYROID CELLS"},"content":{"rendered":"<div class=\"article-authors\">Blancquaert S.<sup>1<\/sup>, Wang L.<sup>2<\/sup>, Paternot S.<sup>1<\/sup>, Harris Th.<sup>2<\/sup>, Roger P.P.<sup>1<\/sup><\/div>\n<div class=\"article-institutes\"><sup>1<\/sup>IRIBHM, ULB, Campus Erasme, Brussels, Belgium, <sup>2<\/sup>University of Virginia, Department of Pharmacology, USA<\/div>\n<div class=\"article-abstract\">\n<h2>Abstract<\/h2>\n<p>In epithelial thyroid cells, phosphorylation of p70 S6K1 is the earliest convergence point between the distinct (co)mitogenic pathways. Whereas the general consensus is that p70 S6K1 phosphorylation is induced by the PI3K\/PKB\/Tuberin\/Rheb\/mTOR or the PKC\/MAPK\/mTOR pathways, in thyrocytes phosphorylation of p70 S6K1 is stimulated by TSH through cyclic AMP and PKA activation. The mechanism remains unknown. In this study the rat thyroid PCCl3 cell line was used to compare the PKB-dependent and -independent pathways that activate p70 S6K1 (respectively stimulated by insulin and by TSH or forskolin). We also investigated the effect of the mTOR\/p70 S6K1 pathway on cell cycle progression, which is inhibited by rapamycin, a specific mTOR inhibitor. TSH and forskolin, as well as insulin, stimulated the phosphorylations of p70 S6K1, S6 and 4E-BP1, and rapamycin antagonized these stimulations. Both treatments also stimulate the activity of immunoprecipitated Raptor-mTOR complex (TORC1). TORC1 activation is thus the earliest point of convergence for the different (co)mitogenic pathways in thyroid epithelial cells. Insulin treatment stimulated the phosphorylations of PKB (T308), as well as PKB-dependent phosphorylations of PRAS40 (T426) and tuberin (T1462), which leads to the activation of TORC1. TSH and forskolin did not induce these phosphorylations, which implies that TSH and insulin activateTORC1 through distinct mechanisms. Treatment by insulin and even more by TSH + insulin stimulated the accumulation of cyclin D3 and cyclin D3-CDK4 complexes, as well as their activity (phosphorylation of the oncosuppressor pRb). Rapamycin prevented these stimulations and the activation of CDK4. Moreover rapamycin inhibited the activating phosphorylation of CDK4 within residual cyclin D3-CDK4 complexes. This could be a new mechanism by which mTOR can regulate cell cycle progression during G1 phase.<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Blancquaert S.1, Wang L.2, Paternot S.1, Harris Th.2, Roger P.P.1 1IRIBHM, ULB, Campus Erasme, Brussels, Belgium, 2University of Virginia, Department of Pharmacology, USA Abstract In epithelial thyroid cells, phosphorylation of p70 S6K1 is the earliest convergence point between the distinct (co)mitogenic pathways. Whereas the general consensus is that p70 S6K1 phosphorylation is induced by the <a class=\"read-more\" href=\"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/2026\/01\/24\/implication-of-mtor-in-camp-dependent-mitogenesis-in-thyroid-cells\/\">Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[45,2,9],"tags":[],"class_list":["post-1297","post","type-post","status-publish","format-standard","hentry","category-volume-7-issue-3","category-journal-articles","category-volume-7"],"_links":{"self":[{"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/posts\/1297","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/comments?post=1297"}],"version-history":[{"count":0,"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/posts\/1297\/revisions"}],"wp:attachment":[{"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/media?parent=1297"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/categories?post=1297"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/peaceful-mccarthy.213-158-90-25.plesk.page\/index.php\/wp-json\/wp\/v2\/tags?post=1297"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}