Kruppel-like factor 4 (KLF4) is required for maintenance of breast cancer stem cells and for cell migration and invasion

Abstract Purpose: TFEB is a key regulator of autophagy-lysosomal biogenesis pathways, while its dysregulation is highly prevalent in various human cancers, but the specific contribution to breast cancer remains poorly understood. The main purpose of this study is to explore the role of TFEB in breast cancer proliferation, metastasis and maintaining breast cancer stem cells (BCSCs) traits, thus uncovering its underlying mechanism.Methods: Bioinformatics, western blotting and immunohistochemical staining were applied to analyze the expression of TFEB in breast cancer. Stable down-regulation TFEB cells were established in MCF-7 and MDA-MB-231 breast cancer cell lines. MTT, clone formation, wound healing, transwell and 3D tumor invasion assays were used to evaluate the proliferation, migration and invasion ability of breast cancer cells. Mammosphere formation, immunocytochemical (ICC) staining were used to detect the effect of down-regulating TFEB on breast cancer stem cells. Results: we demonstrated that higher expression of TFEB was found in breast cancer. TFEB depletion had inhibitory effects on cellular proliferation, migration and invasion of breast cancer cells. Moreover, knockdown TFEB decreased mammosphere formation ability of BCSCs and expression of cancer stem cell markers. Autophagy-lysosomal related proteins were decreased by down regulation of TFEB. Conclusion: we uncovered a critical role of TFEB in breast cancer proliferation and metastasis, and BCSCs self-renewal and stemness. The underlying mechanisms involve in maintaining BCSCs traits, and dysregulating lysosome functions.

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Apatinib Inhibits Stem Properties and Malignant Biological Behaviors of Breast Cancer Stem Cells by Blocking Wnt/β-catenin Signal Pathway Through Down-regulating LncRNA ROR

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520621666210412103849 ◽

2021 ◽

Vol 21 ◽

Author(s):

Baohong Jiang ◽

Hongbo Zhu ◽

Liting Tang ◽

Ting Gao ◽

Yu Zhou ◽

...

Keyword(s):

Breast Cancer ◽

Stem Cells ◽

Cancer Stem Cells ◽

Magnetic Beads ◽

Signal Pathway ◽

Migration And Invasion ◽

Pcr Analysis ◽

Dependent Manner ◽

Breast Cancer Stem Cells ◽

Mesenchymal Transition

Background: Cancer stem cells could influence tumor recurrence and metastasis. Objective: To develop a new effective treatment modality targeting breast cancer stem cells (BCSCs), and to explore the role of Apatinib in BCSCs. Methods: BCSCs were isolated from MDA-MB-231 cells by immune magnetic beads method. BCSCs were treated with Apatinib, lentiviral plasmids (lncRNA ROR) and iCRT-3 (Wnt pathway inhibitors). Viability, colony numbers, sphere numbers, apoptosis, migration, invasion of BCSCs were detected by MTT, colony formation, tumor sphere, flow cytometry, wound-healing, transwell assays, respectively. The expressions of markers (ABCG2, CD44, CD90, and CD24), epithelial-mesenchymal transition (EMT)-related molecules (E-cadherin, N-cadherin, Vimentin, MMP-2, MMP-9), and Wnt/β-catenin pathway-related proteins (Wnt3a, Wnt5a, β-catenin) in breast cancer stem cells were determined by performing Western blot and qRT-PCR analysis. Results: Apatinib decreased the viability and colony numbers of BCSCs in a concentration-dependent manner, and it also reduced sphere numbers, suppressed migration, invasion and lncRNA ROR expression, and induced apoptosis of BCSCs. However, these results were partially reversed by lncRNA ROR overexpression. Apatinib suppressed stem property, EMT process and Wnt/β-catenin pathway in BCSCs, which was partially reversed by lncRNA ROR overexpression. Moreover, lncRNA ROR overexpression increased the colony and sphere numbers, and promoted the cell viability, apoptosis inhibition, migration and invasion of BCSCs, but these effects were partially reversed by iCRT-3. LncRNA ROR overexpression increased the stem property, EMT process and Wnt/β-catenin pathway, which were partially counteracted by iCRT-3. Conclusion: Apatinib inhibited stem property and malignant biological behaviors of BCSCs by blocking Wnt/β-catenin signal pathway through down-regulating lncRNA ROR.

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