RESUMO
Gastric cancer (GC) is among the most lethal human malignancies, and the leading cause of GC mortality is metastasis. However, the precise mechanism of GC metastasis remains unclear. To screen key transcriptional factors (TFs) involved in GC metastasis, we performed bioinformatics analysis of The Cancer Genome Atlas database and found that Krüppel-like factor 9 (KLF9) is a GC metastasis-associated TF. KLF9 is significantly decreased in patients with GC with distant metastasis compared with those patients without distant metastasis. Ectopic expression of KLF9 evidently inhibited the migration and invasion capabilities of GC cells. Conversely, knockdown of KLF9 endowed GC cells with stronger invasive capacity. Moreover, tail intravenous injection confirmed that KLF9 strongly inhibits the lung metastasis process of GC in vivo. Mechanistically, chromatin immunoprecipitation coupled with high-throughput sequencing data from Encyclopedia of DNA Elements revealed that KLF9 specifically binds to the promoter region of matrix metalloproteinase (MMP)28. Further quantitative real-time PCR and dual-luciferase assay indicated that KLF9 directly inhibited MMP28 transcription. Importantly, decreased invasion and metastasis capability of GC cells caused by ectopic KLF9 expression could be rescued via reinforcing MMP28 expression in vivo. Collectively, our study indicates that KLF9 significantly suppresses GC cell invasion and metastasis through inhibiting MMP28 transcription.-Li, Y., Sun, Q., Jiang, M., Li, S., Zhang, J., Xu, Z., Guo, D., Gu, T., Wang, B., Xiao, L., Zhou, T., Zhuo, W. KLF9 suppresses gastric cancer cell invasion and metastasis through transcriptional inhibition of MMP28.
Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Fatores de Transcrição Kruppel-Like/fisiologia , Metaloproteinases da Matriz Secretadas/genética , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Proteínas de Neoplasias/fisiologia , Neoplasias Gástricas/patologia , Transcrição Gênica/genética , Animais , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/genética , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Metaloproteinases da Matriz Secretadas/biossíntese , Camundongos , Camundongos SCID , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Transplante de Neoplasias , Proteínas Recombinantes/metabolismo , Organismos Livres de Patógenos Específicos , Neoplasias Gástricas/genética , TransfecçãoRESUMO
Centrosomal proteins play critical roles in ciliogenesis. Mutations in many centrosomal proteins have been documented to contribute to developmental defects and cilium-related diseases. Centrosomal protein fibroblast growth factor receptor 1 oncogene partner-related protein of 20 kDa (FOR20) is crucial for ciliogenesis in mammalian cells and the unicellular eukaryote Paramecium; however, the biologic significance of FOR20 in vertebrate development remains unclear. We cloned the zebrafish homolog of the for20 gene and found that for20 mRNA is enriched in ciliated tissues during early zebrafish development. Knockdown of for20 by morpholino oligonucleotides in zebrafish results in multiple ciliary phenotypes, including curved body, hydrocephaly, pericardial edema, kidney cysts, and left-right asymmetry defects. for20 morphants show reduced number and length of cilia in Kupffer's vesicle and pronephric ducts. High-speed video microscopy reveals that cilia in most for20 morphants are consistently paralyzed or beat arrhythmically. To confirm the ciliary phenotypes of for20 morphants, we used the CRISPR/Cas9 system to disrupt for20 gene in zebrafish. for20 mutants exhibit multiple ciliary phenotypes resembling the defects in for20 morphants. All of these phenotypes in for20 morphants and mutants are significantly reversed by exogenous expression of for20 mRNA. Taken together, these data suggest that FOR20 is required for cilium-mediated processes during zebrafish embryogenesis.-Xie, S., Jin, J., Xu, Z., Huang, Y., Zhang, W., Zhao, L., Lo, L. J., Peng, J., Liu, W., Wang, F., Shu, Q., Zhou, T. Centrosomal protein FOR20 is essential for cilia-dependent development in zebrafish embryos.
Assuntos
Centrossomo/fisiologia , Cílios/genética , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Padronização Corporal/genética , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Técnicas de Silenciamento de Genes/métodos , Morfolinos/genética , Mutação/genética , RNA Mensageiro/genéticaRESUMO
Hyperactivation of Wnt/ß-catenin signaling is one of the major causes of human colorectal cancer (CRC). A hallmark of Wnt signaling is the nuclear accumulation of ß-catenin. Although ß-catenin nuclear import and export have been widely investigated, the underlying mechanism of ß-catenin's nuclear retention remains largely unknown. Here, we report that Twa1/Gid8 is a key nuclear retention factor for ß-catenin during Wnt signaling and colorectal carcinogenesis. In the absence of Wnt, Twa1 exists together with ß-catenin in the Axin complex and undergoes ubiquitination and degradation. Upon Wnt signaling, Twa1 translocates into the nucleus, where it binds and retains ß-catenin. Depletion of Twa1 attenuates Wnt-stimulated gene expression, dorsal development of zebrafish embryos and xenograft tumor growth of CRC cells. Moreover, nuclear Twa1 is significantly upregulated in human CRC tissues, correlating with the nuclear accumulation of ß-catenin and poor prognosis. Thus, our results identify Twa1 as a previously undescribed regulator of the Wnt pathway for promoting colorectal tumorigenesis by facilitating ß-catenin nuclear retention.