RESUMEN
BACKGROUND: High-grade serous ovarian cancer (HGSOC) is the most common and lethal ovarian cancer histotype. Chromosome instability (CIN, an increased rate of chromosome gains and losses) is believed to play a fundamental role in the development and evolution of HGSOC. Importantly, overexpression of Cyclin E1 protein induces CIN, and genomic amplification of CCNE1 contributes to HGSOC pathogenesis in ~20% of patients. Cyclin E1 levels are normally regulated in a cell cycle-dependent manner by the SCF (SKP1-CUL1-FBOX) complex, an E3 ubiquitin ligase that includes the proteins SKP1 and CUL1. Conceptually, diminished SKP1 or CUL1 expression is predicted to underlie increases in Cyclin E1 levels and induce CIN. METHODS: This study employs fallopian tube secretory epithelial cell models to evaluate the impact diminished SKP1 or CUL1 expression has on Cyclin E1 and CIN in both short-term (siRNA) and long-term (CRISPR/Cas9) studies. RESULTS: Single-cell quantitative imaging microscopy approaches revealed changes in CIN-associated phenotypes and chromosome numbers and increased Cyclin E1 in response to diminished SKP1 or CUL1 expression. CONCLUSIONS: These data identify SKP1 and CUL1 as novel CIN genes in HGSOC precursor cells that may drive early aetiological events contributing to HGSOC development.
Asunto(s)
Inestabilidad Cromosómica/genética , Cistadenocarcinoma Seroso , Células Madre Neoplásicas/metabolismo , Neoplasias Ováricas , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Proteínas Cullin/genética , Proteínas Cullin/metabolismo , Ciclina E/genética , Ciclina E/metabolismo , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/patología , Femenino , Regulación Neoplásica de la Expresión Génica/fisiología , Humanos , Clasificación del Tumor , Células Madre Neoplásicas/patología , Proteínas Oncogénicas/genética , Proteínas Oncogénicas/metabolismo , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Proteínas Quinasas Asociadas a Fase-S/genética , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Células Tumorales CultivadasRESUMEN
TGFß superfamily signalling participates in normal and pathophysiologic cellular processes. Despite several reports demonstrating active TGFß superfamily signalling pathways in OvCa cell lines and primary cultures, few studies examine their functional outcome. Herein we show that primary human ovarian cancer cells possess intact autocrine BMP, TGFß and activin signalling. Blocking autocrine signalling resulted in differential cellular responses affecting cellular morphology, motility and proliferation. Additionally, BMP4-induced alterations in morphology and motility are dependent on Smad signalling. These results suggest that a balance between BMP and TGFß/activin signalling may be altered to favour BMP signalling during ovarian cancer metastatic progression.
Asunto(s)
Activinas/farmacología , Proteínas Morfogenéticas Óseas/farmacología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Factor de Crecimiento Transformador beta/farmacología , Activinas/genética , Comunicación Autocrina , Western Blotting , Proteínas Morfogenéticas Óseas/genética , Línea Celular , Forma de la Célula/efectos de los fármacos , Femenino , Expresión Génica/efectos de los fármacos , Humanos , Proteína 1 Inhibidora de la Diferenciación/genética , Proteína 1 Inhibidora de la Diferenciación/metabolismo , Datos de Secuencia Molecular , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Interferencia de ARN , Proteínas Recombinantes/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteínas Smad/genética , Proteínas Smad/metabolismo , Factores de Transcripción de la Familia Snail , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Factor de Crecimiento Transformador beta/genética , Células Tumorales CultivadasRESUMEN
The majority of ovarian cancers (OCs) arise from the ovarian surface epithelium (OSE). Proliferation of the OSE can be regulated by a number of autocrine and paracrine factors, including transforming growth factor beta (TGFbeta). Defects in the TGFbeta signaling pathway have been implicated in a number of cancers, including ovarian. We previously found that the TGFbeta signaling pathway is intact and functional in primary human OC cells, and that these cells stop growing in response to TGFbeta. Ovarian cancer cells in vivo are exposed to TGFbeta, yet continue to proliferate, therefore, mechanisms must exist to inhibit TGFbeta signaling contributing to uncontrolled cellular proliferation. Numerous signaling pathways converge with the TGFbeta pathway to modulate its effects, including signaling induced by epidermal growth factor (EGF). We hypothesized that EGF can modulate TGFbeta signaling and contribute to uncontrolled cellular proliferation of OC cells. Our results show that EGF abrogates the antiproliferative effect of TGFbeta. EGF does not modulate TGFbeta signaling by inhibiting receptor-activated Smad (R-Smad) phosphorylation or nuclear translocation. Rather, EGF decreases TGFbeta-induced mRNA expression of the cell cycle regulator, p15(INK4B), contributing to decreased sensitivity of OC cells to the antiproliferative effect of TGFbeta.
