RESUMO
PURPOSE: To study the functions and underlying network of KLF14 in breast cancer invasion and tumor-associated macrophages (TAMs). METHODS: The expressions of gene or protein were assessed by qRT-PCR and western blot assays, respectively. Cell proliferation and invasion were investigated by colony formation, CCK-8 and transwell assays, respectively. Macrophage M2 polarization was identified by flow cytometry assay. The methylation level was tested by methylation Specific PCR (MSP). The molecular relationship between KLF14 and SOCS3 was validated by dual luciferase and ChIP assays. In vivo model was established to confirm effect of KLF14 on tumor growth and metastasis. RESULTS: KLF14 was downregulated in breast cancer, and its level was modified by CpG-mediated methylation. Overexpression of KLF14 significantly inhibited the proliferation and invasion of breast cancer in vitro and in vivo. Moreover, KLF14-overexpressing breast cancer cells notably reduced M2 macrophages polarization and it related promoting factor of tumor microenvironment (EGF, TGFß, MMP9 and VEGF). Mechanistically, KLF14 could positively activate SOCS3 transcription, then blocking the activation of RhoA/Rock/STAT3 signaling. Further rescue experiments identified that either SOCS3 silencing and activation of RhoA/Rock/STAT3 signaling dramatically restrained the regulatory roles of KLF14 overexpression in breast cancer invasion and M2 macrophages polarization. CONCLUSION: Collectively, KLF14 suppressed breast cancer cell invasion and M2 macrophage polarization through modulating SOCS3/RhoA/Rock/STAT3 signaling, and these findings would provide a new potential target against breast cancer.
Assuntos
Neoplasias da Mama , Fatores de Transcrição Kruppel-Like , Macrófagos , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Fatores de Transcrição Kruppel-Like/metabolismo , Ativação de Macrófagos , Macrófagos/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/farmacologia , Microambiente Tumoral , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
BACKGROUND: Ubiquitously expressed transcript (UXT) is a prefoldin-like protein. It was reported that UXT played vital role in several cancer types. However, functional role of UXT in breast cancer need further investigation. METHODS: mRNA level or protein level of were determined by qRT-PCR or western blots. Proliferation of breast cancer cells was evaluated by CCK-8 assay and EdU assay. Migrative and invasive ability of cells were determined by wound healing assay and transwell assay. Transcriptional activation of UXT was determined by dual luciferase activity. The enrichment of H3K27me3 and EZH2 on the promoter of RND3 was evaluated by ChIP assay. The methylation of RND3 promoter was determined by MSP assay. In vivo function of UXT was evaluated by xenograft model. RESULTS: Our results indicated that UXT was elevated in breast cancer and associated with poor prognosis. HOXD9 elevated expression of UXT via transcriptional activation. UXT knockdown impaired the proliferation, migration and invasion. Rescue experiments suggested that UXT promoted malignant phenotypes of breast cancer cells via epigenetically repressing RND3. Moreover, UXT promoted tumorigeneses and metastasis of breast cancer cell in vivo. CONCLUSION: Inhibition of UXT impaired proliferation and metastasis of cancer cell via promoting RND3. Moreover, UXT epigenetically repressed the expression of RND3 via recruiting EZH2 in the promoter of RND3.
