RESUMO
Triple-negative breast cancer (TNBC) is a highly metastatic and deadly disease. TNBC tumors lack estrogen receptor (ERα), progesterone receptor (PR), and HER2 (ErbB2) and exhibit increased glutamine metabolism, a requirement for tumor growth. The G protein-coupled kisspeptin receptor (KISS1R) is highly expressed in patient TNBC tumors and promotes malignant transformation of breast epithelial cells. This study found that TNBC patients displayed elevated plasma kisspeptin levels compared with healthy subjects. It also provides the first evidence that in addition to promoting tumor growth and metastasis in vivo, KISS1R-induced glutamine dependence of tumors. In addition, tracer-based metabolomics analyses revealed that KISS1R promoted glutaminolysis and nucleotide biosynthesis by increasing c-Myc and glutaminase levels, key regulators of glutamine metabolism. Overall, this study establishes KISS1R as a novel regulator of TNBC metabolism and metastasis, suggesting that targeting KISS1R could have therapeutic potential in the treatment of TNBC.
Assuntos
Carcinogênese/metabolismo , Reprogramação Celular , Metabolismo Energético , Receptores de Kisspeptina-1/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Adulto , Idoso , Animais , Carcinogênese/genética , Carcinogênese/patologia , Estudos de Casos e Controles , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Glutaminase/genética , Glutaminase/metabolismo , Glutamina/metabolismo , Humanos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Invasividade Neoplásica , Nucleotídeos/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptores de Kisspeptina-1/genética , Transdução de Sinais , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Carga Tumoral , Adulto JovemRESUMO
Kisspeptins (KPs), peptide products of the kisspeptin-1 (KISS1) gene, are the endogenous ligands for the KISS1 receptor, KISS1R, which is a G protein-coupled receptor. In many human tumors, KISS1 functions as a metastasis-suppressor gene and KISS1/KISS1R signaling has antimetastatic and tumor-suppressor roles. On the contrary, emerging evidence indicates that the KP/KISS1R pathway plays detrimental roles in triple negative breast cancer (TNBC), the most difficult type of breast cancer to treat. TNBC patients initially respond to chemotherapy, but tumors acquire drug resistance and many patients relapse and die of metastases within a few years. In this review, we summarize recent developments in the understanding of the mechanisms by which KP/KISS1R signaling plays an adverse role in TNBC. This includes focusing on how KISS1R signaling regulates the cell cytoskeleton to induce tumor invadopodia formation and how KISS1R communicates with growth factor receptors such as the epidermal growth factor receptor, the receptor tyrosine kinase AXL, and transforming growth factor-ß to promote cell invasion, metastasis, and drug resistance.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Kisspeptinas/fisiologia , Recidiva Local de Neoplasia/genética , Receptores de Kisspeptina-1/fisiologia , Animais , Feminino , Humanos , Kisspeptinas/genética , Metástase Neoplásica , Receptores de Kisspeptina-1/genética , Transdução de Sinais/genéticaRESUMO
Breast cancer is a leading cause of cancer mortality. In particular, triple negative breast cancer (TNBC) comprise a heterogeneous group of basal-like tumors lacking estrogen receptor (ERα), progesterone receptor (PR) and HER2 (ErbB2). TNBC represents 15-20% of all breast cancers and occurs frequently in women under 50 years of age. Unfortunately, these patients lack targeted therapy, are typically high grade and metastatic at time of diagnosis. The mechanisms regulating metastasis remain poorly understood. We have previously shown that the kisspeptin receptor, KISS1R stimulates invasiveness of TNBC cells. In this report, we demonstrate that KISS1R signals via the secreted extracellular matrix protein, fibulin-3, to regulate TNBC invasion. We found that the fibulin-3 gene is amplified in TNBC primary tumors and that plasma fibulin-3 levels are elevated in TNBC patients compared to healthy subjects. In this study, we show that KISS1R activation increases fibulin-3 expression and secretion. We show that fibulin-3 regulates TNBC metastasis in a mouse experimental metastasis xenograft model and signals downstream of KISS1R to stimulate TNBC invasion, by activating matrix metalloproteinase 9 (MMP-9) and the MAPK pathway. These results identify fibulin-3 as a new downstream mediator of KISS1R signaling and as a potential biomarker for TNBC progression and metastasis, thus revealing KISS1R and fibulin-3 as novel drug targets in TNBC.
RESUMO
Increasing evidence indicates that epigenetic changes regulate cell genesis. Here, we ask about neural precursors, focusing on CREB binding protein (CBP), a histone acetyltransferase that, when haploinsufficient, causes Rubinstein-Taybi syndrome (RTS), a genetic disorder with cognitive dysfunction. We show that neonatal cbp(+/-) mice are behaviorally impaired, displaying perturbed vocalization behavior. cbp haploinsufficiency or genetic knockdown with siRNAs inhibited differentiation of embryonic cortical precursors into all three neural lineages, coincident with decreased CBP binding and histone acetylation at promoters of neuronal and glial genes. Inhibition of histone deacetylation rescued these deficits. Moreover, CBP phosphorylation by atypical protein kinase C zeta was necessary for histone acetylation at neural gene promoters and appropriate differentiation. These data support a model in which environmental cues regulate CBP activity and histone acetylation to control neural precursor competency to differentiate, and indicate that cbp haploinsufficiency disrupts this mechanism, thereby likely causing cognitive dysfunction in RTS.