miR-9-5p Promotes β-Catenin-Activated Epithelial-To-Mesenchymal Transition of Triple-Negative Breast Cancer Via Targeting LZTS2

Author(s):  
Jie Zhang ◽  
Lina Zhang ◽  
Jianlong Wang ◽  
Jing Zhao ◽  
Xuelian Zhao ◽  
...  

Abstract Background: Leucine zipper tumor suppressor 2 (LZTS2), an emerging tumor-suppressor, is attenuated in multiple cancers including prostate, lung and colon cancer. However, its expression and upstream regulatory mechanisms in triple negative breast cancer (TNBC) still remain unknown.Materials and methods: The expression of LZTS2 in TNBC and matched para-carcinoma tissues was detected with immunohistochemistry. The correlations between LZTS2 expression and clinicopathological parameters were analyzed. Kaplan-Meier analysis was performed to determine the prognostic role of LZTS2 for TNBC patients. CCK-8, wound healing and transwell assay were used to detect the effect of LZTS2 overexpression on the proliferation, migration and invasion ability, respectively. The bioinformation algorithms were used to reveal the potential upstream regulatory miRNA. Then, dual-luciferase reporter assay was performed to confirm the regulatory effect of the chosen miRNA on the expression of LZTS2. miR-9-5p inhibitor was used to determine the effect of miR-9-5p on the subcellular localization of β-catenin. Then, western blotting was performed to reveal the effect of miR-9-5p on EMT-related proteins in TNBC cells. Xenograft tumor model was established to reveal the effect of miR-9-5p on TNBC progression in vivo.Results: Low expression of LZTS2 was observed in 62 of 95 cases of TNBC tissue. Low expression of LZTS2 was correlated with poor postoperative DFS and OS of TNBC patients. LZTS2 could inhibit the proliferation, migration and invasion ability of TNBC cells. LZTS2 could be downregulated by miR-9-5p in TNBC, and the nuclear export of β-catenin was suppressed. Consequently, miR-9-5p inhibitor downregulated E-cadherin and upregulated N-cadherin, Twist and Vimentin in TNBC cells. Xenograft tumor model showed that miR-9-5p inhibitor could upregulate the expression of LZTS2 and induce nuclear export of β-catenin in TNBC.Conclusions: miR-9-5p contributes to β-catenin-activated EMT via downregulating LZTS2, and thus promotes TNBC progression.

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Weiguang Liu ◽  
Jianjun Han ◽  
Sufang Shi ◽  
Yuna Dai ◽  
Jianchao He

Abstract Background Triple negative breast cancer (TNBC) is a breast cancer (BC) subtype that is characterized by its strong invasion and a high risk of metastasis. However, the specific mechanisms underlying these phenotypes are unclear. TUFT1 plays an important role in BC and impacts the proliferation and survival of BC cells. Recent studies have shown that TUFT1 mediates intracellular lysosome localization and vesicle transport by regulating Rab GTPase, but the relevance of this activity in TNBC is unknown. Therefore, our aim was to systematically study the role of TUFT1 in the metastasis and chemoresistance of TNBC. Methods We measured TUFT1, Rab5-GTP, and Rac1-GTP expression levels in samples of human TNBC by immunohistochemistry (IHC) and conducted univariate and multivariate analyses. shRNA-mediated knockdown and overexpression, combined with transwell assays, co-immunoprecipitation, a nude mouse xenograft tumor model, and GTP activity assays were used for further mechanistic studies. Results TUFT1 expression was positively correlated with Rab5-GTP and Rac1-GTP in the TNBC samples, and co-expression of TUFT1 and Rab5-GTP predicted poor prognosis in TNBC patients who were treated with chemotherapy. Mechanism studies showed that TUFT1 could activate Rab5 by binding to p85α, leading to activation of Rac1 through recruitment of Tiam1, and concurrent down-regulation of the NF-κB pathway and proapoptotic factors, ultimately promoting metastasis and chemoresistance in TNBC cells. Conclusions Our findings suggest that the TUFT1/Rab5/Rac1 pathway may be a potential target for the effective treatment of TNBC.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jie Sun ◽  
Xiaohua Li ◽  
Enqiao Yu ◽  
Jianxia Liu ◽  
Liang Sun ◽  
...  

Abstract Background Triple-negative breast cancer (TNBC) is a special type of breast cancer that lacks effective therapeutic targets. There is a significant need to clarify its pathogenesis, so as to bring new targeted approaches for TNBC management. Here, we identified a long-non coding RNA (lncRNA) ASMTL-AS1 that linked to TNBC development and progression. Methods Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assays were used to test gene and protein levels, respectively. The regulatory axis of miR-1228-3p/SOX17/β-catenin was determined by luciferase reporter and RNA pull-down assays. In vivo assay was conducted by using the nude mice model via subcutaneous transplantation of tumor cells. Results ASMTL-AS1 was significantly downregulated in TNBC tissues compared to normal tissues, which was closely associated with aggressive clinical features and unfavorable prognosis. Lentivirus-mediated ASMTL-AS1 overexpression evidently reduced the ability of TNBC cell colony formation, activity and invasion by more than 2.5 times. RNA pull-down and luciferase reporter assays revealed that miR-1228-3p directly bound to ASMTL-AS1, ASMTL-AS1 increased SOX17 expression via sponging and repressing miR-1228-3p. Subsequently, the upregulated SOX17 trans-suppressed β-catenin expression, resulting in the inactivation of carcinogenic Wnt/β-catenin signaling, thereby restraining TNBC cell growth and dissemination. Importantly, the xenograft tumor model showed that the ASMTL-AS1 overexpression significantly retarded tumor growth, and negatively regulated Wnt/β-catenin pathway. Conclusions Our data characterize a novel tumor suppressor in TNBC, restoration of ASMTL-AS1 may be a candidate therapeutic intervention for TNBC patients.


2021 ◽  
Author(s):  
Jie Sun ◽  
Xiaohua Li ◽  
Enqiao Yu ◽  
Jianxia Liu ◽  
Liang Sun ◽  
...  

Abstract Background: Triple-negative breast cancer (TNBC) is a special type of breast cancer that lacks effective therapeutic targets. There is a significant need to clarify its pathogenesis, so as to bring new targeted approaches for TNBC management. Here, we identified a long-non coding RNA (lncRNA) ASMTL-AS1 that linked to TNBC development and progression. Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assays were used to test gene and protein levels, respectively. The regulatory axis of miR-1228-3p/SOX17/β-catenin was determined by luciferase reporter and RNA pull-down assays. In vivo assay was conducted by using the nude mice model via subcutaneous transplantation of tumor cells.Results: ASMTL-AS1 was significantly downregulated in TNBC tissues compared to normal tissues, which was closely associated with aggressive clinical features and unfavorable prognosis. Lentivirus-mediated ASMTL-AS1 overexpression evidently inhibited TNBC cell colony formation, viability and invasion. RNA pull-down and luciferase reporter assays revealed that miR-1228-3p was the downstream target of ASMTL-AS1, ASMTL-AS1 increased SOX17 expression via sponging and repressing miR-1228-3p. Subsequently, the upregulated SOX17 trans-suppressed β-catenin expression, resulting in the inactivation of carcinogenic Wnt/β-catenin signaling, thereby restraining TNBC cell growth and dissemination. Importantly, the xenograft tumor model showed that the ASMTL-AS1/miR-1228-3p/SOX17/β-catenin regulatory axis was indeed existed in vivo.Conclusion: Our data characterize a novel tumor suppressor in TNBC, restoration of ASMTL-AS1 may be a candidate therapeutic intervention for TNBC patients.


Breast Cancer ◽  
2021 ◽  
Author(s):  
Yingzi Zhang ◽  
Jiao Tian ◽  
Chi Qu ◽  
Yang Peng ◽  
Jinwei Lei ◽  
...  

Abstract Background Recent studies have indicated that serpin peptidase inhibitor, clade A, member 3 (SERPINA3) is a potential marker associated with tumor progression, which connoted that SERPINA3 is related to malignant phenotypes in cancer. However, the biological function of SERPINA3 in breast cancer (BC) remains unclear. Methods Bioinformatics data were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Immunohistochemical staining (IHC) was conducted to determine SERPINA3 expression. With strong aggressive abilities, triple-negative breast cancer (TNBC) cell lines (MDA-MB-231, BT549 and MDA-MB-436) were obtained to examine SERPINA3 expression and functions. Wound healing and Transwell assays were performed to measure cell migration and invasion. Cell Counting Kit-8 (CCK-8) assay was conducted to detect cell proliferation abilities and cell viabilities. Results SERPINA3 was upregulated in BC tissues. Functional assays suggested that overexpression of SERPINA3 significantly promoted cell proliferation, where migration and invasion of TNBC cells were accelerated. Knockdown of SERPINA3 had the opposite effects. These results causing by overexpression of SERPINA3 were also confirmed in non-TNBC cell lines. Overexpression of SERPINA3 remarkably enhanced the epithelial–mesenchymal transition (EMT) by upregulating the EMT markers and EZH2. In addition, the overexpression of SERPINA3 reduced the sensitivity of TNBC cells to cisplatin. Conclusion SERPINA3 can regulate the migration, invasion and EMT of TNBC cells and increased expression of SERPINA3 confers resistance to cisplatin in TNBC cells. We discern it is required for the regulation of BC progression and is a critical target for the clinical treatment of BC.


BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Pradip Shahi Thakuri ◽  
Megha Gupta ◽  
Sunil Singh ◽  
Ramila Joshi ◽  
Eric Glasgow ◽  
...  

Abstract Background Cell migration and invasion are essential processes for metastatic dissemination of cancer cells. Significant progress has been made in developing new therapies against oncogenic signaling to eliminate cancer cells and shrink tumors. However, inherent heterogeneity and treatment-induced adaptation to drugs commonly enable subsets of cancer cells to survive therapy. In addition to local recurrence, these cells escape a primary tumor and migrate through the stroma to access the circulation and metastasize to different organs, leading to an incurable disease. As such, therapeutics that block migration and invasion of cancer cells may inhibit or reduce metastasis and significantly improve cancer therapy. This is particularly more important for cancers, such as triple negative breast cancer, that currently lack targeted drugs. Methods We used cell migration, 3D invasion, zebrafish metastasis model, and phosphorylation analysis of 43 protein kinases in nine triple negative breast cancer (TNBC) cell lines to study effects of fisetin and quercetin on inhibition of TNBC cell migration, invasion, and metastasis. Results Fisetin and quercetin were highly effective against migration of all nine TNBC cell lines with up to 76 and 74% inhibitory effects, respectively. In addition, treatments significantly reduced 3D invasion of highly motile TNBC cells from spheroids into a collagen matrix and their metastasis in vivo. Fisetin and quercetin commonly targeted different components and substrates of the oncogenic PI3K/AKT pathway and significantly reduced their activities. Additionally, both compounds disrupted activities of several protein kinases in MAPK and STAT pathways. We used molecular inhibitors specific to these signaling proteins to establish the migration-inhibitory role of the two phytochemicals against TNBC cells. Conclusions We established that fisetin and quercetin potently inhibit migration of metastatic TNBC cells by interfering with activities of oncogenic protein kinases in multiple pathways.


2017 ◽  
Vol 43 (4) ◽  
pp. 418-435.e13 ◽  
Author(s):  
Sameer S. Bajikar ◽  
Chun-Chao Wang ◽  
Michael A. Borten ◽  
Elizabeth J. Pereira ◽  
Kristen A. Atkins ◽  
...  

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