gsk525762a and Neuroendocrine-Tumors

Neuroendocrine (NE) cancers are a diverse group of neoplasms typically diagnosed and treated on the basis of their site of origin. This Perspective focuses on advances in our understanding of the tumorigenesis and treatment of poorly differentiated neuroendocrine tumors. Recent evidence from sequencing indicates that, although neuroendocrine tumors can arise de novo, they can also develop as a result of lineage plasticity in response to pressure from targeted therapies. We discuss the shared genomic alterations of these tumors independently of their site of origin, and we explore potential therapeutic strategies on the basis of recent biological findings.

Topics: Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Azepines; Benzodiazepines; Carcinogenesis; Carcinoma, Neuroendocrine; Carcinoma, Small Cell; Cell Differentiation; Cell Lineage; Cell Plasticity; Colonic Neoplasms; Disease Progression; Epigenesis, Genetic; Esophageal Neoplasms; Female; Head and Neck Neoplasms; Humans; Lung Neoplasms; Male; Molecular Targeted Therapy; Neoplasms, Glandular and Epithelial; Neuroendocrine Tumors; Ovarian Neoplasms; Prostatic Neoplasms; Proto-Oncogene Proteins c-met; Proto-Oncogene Proteins c-myc; Pyrimidines; Retinoblastoma Binding Proteins; Triazoles; Tumor Suppressor Protein p53; Ubiquitin-Protein Ligases; Urinary Bladder Neoplasms; Uterine Cervical Neoplasms

The prevalence of neuroendocrine tumors (NETs) has recently been increasing. Although various drugs such as Octreotide and its analogs show certain efficacy, NETs in many patients progress and metastasize. It is desirable to develop new interventions to improve the therapy. Here we show that human neuroendocrine tumor BON cells are resistant to several drugs commonly used for NET therapy, including Octreotide that activates somatostatin receptor-induced anti-proliferation, and Capecitabine and Temozolimide that damage DNA. In contrast, an inhibitor (IBET) to an epigenetic regulator, Brd4 that binds acetylated histones and upregulates transcription of multiple genes including protooncogene c-Myc, potently inhibited the NET cells. We found that IBET increased the protein levels of cyclin-dependent kinase (CDK) inhibitor p27

Topics: Antineoplastic Agents; Benzodiazepines; Capecitabine; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p27; Dacarbazine; Drug Resistance, Neoplasm; Epigenesis, Genetic; Humans; Neuroendocrine Tumors; Nuclear Proteins; Octreotide; Protein Stability; RNA, Messenger; S-Phase Kinase-Associated Proteins; Temozolomide; Transcription Factors; Transcriptional Activation; Ubiquitin-Protein Ligases; Ubiquitination; Up-Regulation