Project description:Metastatic medullary thyroid cancer (MTC) is a currently incurable disease. FDA approved therapies that target RET, a commonly mutated receptor tyrosine kinase in MTC, and other receptor tyrosine kinases, do not result in complete responses and acquired resistance is universal due to “gatekeeper” mutation in Ret or overactivation of alternative signaling pathways. Based on data from human MTCs and a number of murine models, the CDK/RB cell cycle pathway is a potential alternative target for MTC. The objective of this study was to determine if CDKs represent therapeutic targets for MTC and to define mechanisms of activity. We demonstrate that targeting the CDK/RB pathway with Palbociclib (CDK4/6 inhibitor) is not cytotoxic to MTC cells but that Dinaciclib (CDK1/2/5/9 inhibitor) remarkably reduced cell viability and proliferation at low doses in two MTC cell lines accompanied by loss of CDK9 and RET protein and mRNA levels. In human tumors, CDK9 protein was highly expressed and array CGH demonstrated copy number gain in 11/30 analyzed tumors. RNA sequencing demonstrated that RNA polymerase II-dependent transcription was markedly reduced by Dinaciclib, consistent with transcriptional mode of action. Subsequent studies using the CDK7 inhibitor, THZ1, demonstrated high potency vs. the MTC cell lines and marked loss of RET mRNA and protein. In silico analysis, and CHIP-Sequencing using H3K27Ac antibody confirmed that RET is associated with a super-enhancer in RET-mutated MTC cells. In summary, this study reveals a novel mechanism of RET transcription regulation that represents a potentially translatable finding for new therapeutic approaches for RET-mutated MTC.
Project description:Metastatic medullary thyroid cancer (MTC) is a currently incurable disease. FDA approved therapies that target RET, a commonly mutated receptor tyrosine kinase in MTC, and other receptor tyrosine kinases, do not result in complete responses and acquired resistance is universal due to “gatekeeper” mutation in Ret or overactivation of alternative signaling pathways. Based on data from human MTCs and a number of murine models, the CDK/RB cell cycle pathway is a potential alternative target for MTC. The objective of this study was to determine if CDKs represent therapeutic targets for MTC and to define mechanisms of activity. We demonstrate that targeting the CDK/RB pathway with Palbociclib (CDK4/6 inhibitor) is not cytotoxic to MTC cells but that Dinaciclib (CDK1/2/5/9 inhibitor) remarkably reduced cell viability and proliferation at low doses in two MTC cell lines accompanied by loss of CDK9 and RET protein and mRNA levels. In human tumors, CDK9 protein was highly expressed and array CGH demonstrated copy number gain in 11/30 analyzed tumors. RNA sequencing demonstrated that RNA polymerase II-dependent transcription was markedly reduced by Dinaciclib, consistent with transcriptional mode of action. Subsequent studies using the CDK7 inhibitor, THZ1, demonstrated high potency vs. the MTC cell lines and marked loss of RET mRNA and protein. In silico analysis, and CHIP-Sequencing using H3K27Ac antibody confirmed that RET is associated with a super-enhancer in RET-mutated MTC cells. In summary, this study reveals a novel mechanism of RET transcription regulation that represents a potentially translatable finding for new therapeutic approaches for RET-mutated MTC.
Project description:To identify a microRNA profile of human medullary thyroid cancer (MTC), we performed a miRNA microarray analysis exploiting 8 primary tumours and 9 paired neck nodes metastases in comparison with 3 non-neoplastic thyroid tissues.
Project description:Medullary thyroid cancer (MTC) accounts for less than 5% of all thyroid cancers, and it is a rare neuroendocrine tumor which derives from calcitonin-secreting thyroid C cells.Given the underlying mechanism involved in MTC remain unclear, the development and the specific pathways of MTC require further investigation.here we employed the application of TMT6plex-based LC-MS/MS to identify and analyze the novel differentially-expressed proteins(DEPs) from MTC patients, To our best knowledge, it is the first study to comprehensively investigate the molecular mechanisms of MTC by proteomics technology from Chinese MTC patients’ tissues, and these DEPs identified in our study will provide a better understanding of the underlying pathophysiology of MTC, as well as may provide potential therapeutic targets for patients with MTC.
Project description:We report gene expression profiling in a series of 17 human medullary thyroid cancer (MTC) tissues, including 8 primary tumors and 9 patient paired neck nodes metastases, in comparison with 3 non-neoplastic thyroid tissues. For the same series we have previously reported miRNA expression profiles (GSE97070 series).