Antiproliferative and Antimigration Activities of Fluoro-Neplanocin A via Inhibition of Histone H3 Methylation in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is among the most aggressive and potentially metastatic malignancies. Most affected patients have poor clinical outcomes due to the lack of specific molecular targets on tumor cells. The upregulated expression of disruptor of telomeric silencing 1-like (DOT1L), a histone methyltransferase specific for the histone H3 lysine 79 residue (H3K79), is strongly correlated with TNBC cell aggressiveness. Therefore, DOT1L is considered a potential molecular target in TNBC. Fluoro-neplanocin A (F-NepA), an inhibitor of S-adenosylhomocysteine hydrolase, exhibited potent antiproliferative activity against various types of cancer cells, including breast cancers. However, the molecular mechanism underlying the anticancer activity of F-NepA in TNBC cells remains to be elucidated. We determined that F-NepA exhibited a higher growth-inhibitory activity against TNBC cells relative to non-TNBC breast cancer and normal breast epithelial cells. Moreover, F-NepA effectively downregulated the level of H3K79me2 in MDA-MB-231 TNBC cells by inhibiting DOT1L activity. F-NepA also significantly inhibited TNBC cell migration and invasion. These activities of F-NepA might be associated with the upregulation of E-cadherin and downregulation of N-cadherin and Vimentin in TNBC cells. Taken together, these data highlight F-NepA as a strong potential candidate for the targeted treatment of high-DOT1L-expressing TNBC.

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Overexpression of SERPINA3 promotes tumor invasion and migration, epithelial-mesenchymal-transition in triple-negative breast cancer cells

Breast Cancer ◽

10.1007/s12282-021-01221-4 ◽

2021 ◽

Author(s):

Yingzi Zhang ◽

Jiao Tian ◽

Chi Qu ◽

Yang Peng ◽

Jinwei Lei ◽

...

Keyword(s):

Breast Cancer ◽

Cell Proliferation ◽

Cell Lines ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Epithelial Mesenchymal Transition ◽

Cell Counting ◽

Migration And Invasion ◽

Mesenchymal Transition ◽

Tnbc Cell

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.

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Phytochemicals inhibit migration of triple negative breast cancer cells by targeting kinase signaling

BMC Cancer ◽

10.1186/s12885-019-6479-2 ◽

2020 ◽

Vol 20 (1) ◽

Cited By ~ 2

Author(s):

Pradip Shahi Thakuri ◽

Megha Gupta ◽

Sunil Singh ◽

Ramila Joshi ◽

Eric Glasgow ◽

...

Keyword(s):

Breast Cancer ◽

Cell Migration ◽

Cancer Cells ◽

Protein Kinases ◽

Cell Lines ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Migration And Invasion ◽

Tnbc Cell

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.

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MicroRNA-1246 Suppresses the Metastasis of Breast Cancer Cells by Targeting the DRAK1A/PGRN Axis to Prevent the Epithelial-Mesenchymal Transition

10.21203/rs.3.rs-516130/v1 ◽

2021 ◽

Author(s):

Pan Wang ◽

Wenju Chen ◽

Yaqiong Zhang ◽

Qianyi Zhong ◽

Zhaoyun Li ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Breast Cancer Cells ◽

Triple Negative ◽

Epithelial Mesenchymal Transition ◽

Migration And Invasion ◽

Mesenchymal Transition ◽

Tnbc Cell ◽

Novel Target

Abstract Objective. Breast cancer is one of the most common malignant and highly heterogeneous tumors in women. MicroRNAs (miRNAs), such as miR-1246, play important roles in various types of malignant cancers, including triple-negative breast cancer (TNBC). However, the biological role of miR-1246 in TNBC has not yet been fully elucidated. In this study, we studied the role of miR-1246 in the occurrence and development of TNBC and its mechanism of action.Methods. Cell Counting Kit-8 (CCK-8), wound healing, and Transwell assays were performed to observe the effects of miR-1246 on TNBC cell proliferation, migration, and invasion, respectively. The expression of epithelial-mesenchymal transition (EMT) markers was detected by western blotting. Dual luciferase reporter assays were performed to determine whether DYRK1A is a novel target of miR-1246. In addition, an immunoprecipitation experiment was performed to verify the binding of DYRK1A to PGRN. Rescue experiments were performed to determine whether DYRK1A is a novel target of miR-1246 and whether miR-1246 suppresses the metastasis of breast cancer cells by targeting the DRAK1A/PGRN axis to prevent the epithelial-mesenchymal transition.Results. Our results show that miR‑1246 suppresses the proliferation, migration, and invasion of TNBC cells and that DYRK1A is a novel target of miR-1246. MiR‑1246 plays a suppressive role in the regulation of the EMT of TNBC cells by targeting DYRK1A. DYRK1A mediates the metastasis of triple-negative breast cancer via activation of the EMT. We identified PGRN as a novel DYRK1A-interacting protein. DYRK1A and PGRN act together to regulate the occurrence and development of breast cancer through miR-1246.Conclusion. miR-1246 attenuates TNBC cell invasion and the EMT by targeting the DRAK1A/PGRN axis. Our data suggest that miR‑1246 may be used to develop novel early-stage diagnostic and therapeutic strategies for TNBC.

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Co-loading of an anthracycline analogue Pirarubicin and Salinomycin in a 1:3 ratio into Quatramerbiodegradable polymeric nanoparticles synergistically inhibit growth of triple-negative breast cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.e15047 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. e15047-e15047

Author(s):

Surender Kharbanda ◽

Anees Mohammad ◽

Sachchidanand Tiwari ◽

Neha Mehrotra ◽

Sireesh Appajosyula ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Breast Cancers ◽

Mice Model ◽

Single Drug ◽

Tnbc Cell ◽

Dual Drug

e15047 Background: Triple negative breast cancer (TNBC) accounts for about 10-15% of all breast cancers and differ from other types of invasive breast cancers in that they grow and spread faster. TNBCs have limited treatment options and a worse prognosis. Therapy with anthracyclines considered to be one of the most effective agents in the treatment. Unfortunately, resistance to anthracycline therapy is very common due to drug efflux mediated by overexpression of ABC transporter. Pirarubicin (PIRA), an analogue of doxorubicin (DOX), is approved in Japan, Korea and China and is shown to be less cardiotoxic than DOX. Recent studies suggest that cancer stem cells (CSCs) play an important role in tumorigenesis and biology of TNBC. Targeting CSCs may be a promising, novel strategy for the treatment of this aggressive disease. Recent studies have shown that salinomycin (SAL) preferentially targets the viability of CSCs. Methods: SAL and PIRA were co-encapsulated in polylactic acid (PLA)-based block copolymeric nanoparticles (NPs) to efficiently co-deliver these agents to treat TNBC cells. Results: Generated SAL-PIRA co-encapsulated dual drug-loaded NPs showed an average diameter of 110 ± 7 nm, zeta potential of -12.5 mV and PDI of less than 0.25. Both of these anti-cancer agents showed slow and sustained release profile in non-physiological buffer (PBS, pH 7.4) from these dual drug-encapsulated NPs. Additionally, multiple ratios (PIRA:SAL = 3:1, 1:1, 1:3) were encapsulated to generate diverse dual drug-loaded NPs. The results demonstrate that, in contrast to 1:1 and 3:1, treatment of TNBC cells with 1:3 ratio of PIRA:SAL dual drug-loaded NPs, was associated with significant inhibition of growth in vitro in multiple TNBC cell lines. Interestingly, PIRA:SAL (1:3) was synergistic as compared to either SAL- or PIRA single drug-loaded NPs. The IC50 of PIRA and SAL in single drug-encapsulated NPs is 150 nM and 700 nM respectively in MDA-MB-468. Importantly, the IC50 of PIRA in dual drug-encapsulated NPs dropped down to 30 nM (5-fold). Similar results were obtained in SUM-149 TNBC cell line. Studies are underway to evaluate in vivo biological activity of PIRA:SAL (1:3) on tumor growth in a TNBC xenograft mice model. Conclusions: These results demonstrate that a novel dual drug-loaded NP formulation of PIRA and SAL in a unique ratio of 1:3 represents an approach for successful targeting of CSCs and bulk tumor cells in TNBC and potentially other cancer types.

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Berberine Impairs the Survival of Triple Negative Breast Cancer Cells: Cellular and Molecular Analyses

Molecules ◽

10.3390/molecules25030506 ◽

2020 ◽

Vol 25 (3) ◽

pp. 506 ◽

Cited By ~ 3

Author(s):

Lamyae El Khalki ◽

Virginie Maire ◽

Thierry Dubois ◽

Abdelmajid Zyad

Keyword(s):

Breast Cancer ◽

Cell Lines ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Breast Cancer Subtype ◽

Potential Candidate ◽

Tnbc Cell ◽

Normal Human Breast ◽

Good Potential ◽

Breast Cells

Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype. Non-available targeted therapy for TNBC represents its biggest treatment challenge. Thus, finding new promising effective drugs is urgently needed. In the present study, we investigated how berberine, a natural isoquinoline, impairs the survival of TNBC cells in both cellular and molecular levels. Our experimental model was based on the use of eight TNBC cell lines: MDA-MB-468, MDA-MB-231, HCC70, HCC38, HCC1937, HCC1143, BT-20, and BT-549. Berberine was cytotoxic against all treated TNBC cell lines. The most sensitive cell lines were HCC70 (IC50 = 0.19 µM), BT-20 (IC50 = 0.23 µM) and MDA-MB-468 (IC50 = 0.48 µM). Using flow cytometry techniques, berberine, at 0.5 and 1 µM for 120 and 144 h, not only induced cell cycle arrest, at G1 and/or G2/M phases, but it also triggered significant apoptosis. At the molecular level, these results are consistent with the expression of their related proteins using Western blot assays. Interestingly, while berberine was cytotoxic against TNBC cells, it had no effect on the viability of normal human breast cells MCF10A cultured in a 3D matrigel model. These results suggest that berberine may be a good potential candidate for TNBC drug development.

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RNA-Sequencing Reveals Heat Shock 70-kDa Protein 6 (HSPA6) as a Novel Thymoquinone-Upregulated Gene That Inhibits Growth, Migration, and Invasion of Triple-Negative Breast Cancer Cells

Frontiers in Oncology ◽

10.3389/fonc.2021.667995 ◽

2021 ◽

Vol 11 ◽

Author(s):

Shiyi Shen ◽

Chunli Wei ◽

Junjiang Fu

Keyword(s):

Breast Cancer ◽

Rna Sequencing ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Regulatory Mechanism ◽

Kegg Pathway ◽

Migration And Invasion ◽

Tnbc Cell ◽

Anti Cancer ◽

Cancer Tissues

ObjectiveBreast cancer has become the first highest incidence which surpasses lung cancer as the most commonly diagnosed cancer, and the second highest mortality among women worldwide. Thymoquinone (TQ) is a key component from black seed oil and has anti-cancer properties in a variety of tumors, including triple-negative breast cancer (TNBC).MethodsRNA-sequencing (RNA-seq) was conducted with and without TQ treatment in TNBC cell line BT-549. Gene Ontology (GO) function classification annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses for these genes were conducted. Western blot and semi-quantitative RT-PCR were used to verify the regulated gene. Functional assays by overexpression or knocking down were performed for HSPA6 and its mediator TQ for inhibiting growth, migration and invasion of TNBC cells. The regulatory mechanisms and prognosis for HSPA6 for breast cancer survival were conducted through bioinformatics and online databases.ResultsAs a result, a total of 141 downregulated and 28 upregulated genes were identified and 18 differentially expressed genes, which might be related to carcinomas, were obtained. Interestingly, GO and KEGG pathway showed their roles on anti-cancer and anti-virus. Further analysis found that the HSPA6 gene was the high significantly upregulated gene, and showed to inhibit TNBC cell growth, migration and invasion. High expression of HSPA6 was positively correlated with long overall survival (OS) in patients with breast cancer, indicating the tumor-suppressive roles for HSPA6. But DNA methylation of HSPA6 may not be the regulatory mechanism for HSPA6 mRNA upregulation in breast cancer tissues, although the mRNA levels of HSPA6 were increased in these cancer tissues compared with normal tissues. Moreover, TQ enhanced the inhibitory effect of migration and invasion when HSPA6 was overexpressed; while HSPA6 was knocked down, TQ attenuated the effects of HSPA6-promoted migration and invasion, demonstrating a partially dependent manner through HSPA6 by TQ treatment.ConclusionWe have successfully identified a novel TQ-targeted gene HSPA6, which shows the inhibitory effects on growth, migration and invasion in TNBC cells. Therefore, identification of HSPA6 not only reveals a new TQ regulatory mechanism, but also provides a novel candidate gene for clinical management and treatment of breast cancer, particularly for TNBC.

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Triptonide effectively inhibits triple-negative breast cancer metastasis through concurrent degradation of Twist1 and Notch1 oncoproteins

Breast Cancer Research ◽

10.1186/s13058-021-01488-7 ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Mengli Zhang ◽

Mei Meng ◽

Yuxi Liu ◽

Jindan Qi ◽

Zhe Zhao ◽

...

Keyword(s):

Breast Cancer ◽

Cell Migration ◽

Tumor Growth ◽

Triple Negative Breast Cancer ◽

Cancer Metastasis ◽

Triple Negative ◽

Vasculogenic Mimicry ◽

Migration And Invasion ◽

Mesenchymal Transition ◽

Tnbc Cell

Abstract Background Triple-negative breast cancer (TNBC) is highly metastatic and lethal. Due to a lack of druggable targets for this disease, there are no effective therapies in the clinic. Methods We used TNBC cells and xenografted mice as models to explore triptonide-mediated inhibition of TNBC metastasis and tumor growth. Colony formation assay was used to quantify the tumorigenesis of TNBC cells. Wound-healing and cell trans-well assays were utilized to measure cell migration and invasion. Tube formation assay was applied to access tumor cell-mediated vasculogenic mimicry. Western blot, quantitative-PCR, immunofluorescence imaging, and immunohistochemical staining were used to measure the expression levels of various tumorigenic genes in TNBC cells. Results Here, we showed that triptonide, a small molecule from the traditional Chinese medicinal herb Tripterygium wilfordii Hook F, potently inhibited TNBC cell migration, invasion, and vasculogenic mimicry, and effectively suppressed TNBC tumor growth and lung metastasis in xenografted mice with no observable toxicity. Molecular mechanistic studies revealed that triptonide strongly triggered the degradation of master epithelial-mesenchymal transition (EMT)-inducing protein Twist1 through the lysosomal system and reduced Notch1 expression and NF-κB phosphorylation, which consequently diminished the expression of pro-metastatic and angiogenic genes N-cadherin, VE-cadherin, and vascular endothelial cell growth factor receptor 2 (VEGFR2). Conclusions Triptonide effectively suppressed TNBC cell tumorigenesis, vasculogenic mimicry, and strongly inhibited the metastasis of TNBC via degradation of Twist1 and Notch1 oncoproteins, downregulation of metastatic and angiogenic gene expression, and reduction of NF-κB signaling pathway. Our findings provide a new strategy for treating highly lethal TNBC and offer a potential new drug candidate for combatting this aggressive disease.

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Optical Redox Imaging Differentiates Triple-Negative Breast Cancer Subtypes

Advances in Experimental Medicine and Biology - Oxygen Transport to Tissue XLII ◽

10.1007/978-3-030-48238-1_40 ◽

2021 ◽

pp. 253-258

Author(s):

Jinxia Jiang ◽

Min Feng ◽

Annemarie Jacob ◽

Lin Z. Li ◽

He N. Xu

Keyword(s):

Breast Cancer ◽

Cell Lines ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Treatment Options ◽

Response Patterns ◽

Breast Cancers ◽

Cancer Subtypes ◽

Mitochondrial Inhibitors ◽

Tnbc Cell

AbstractTriple-negative breast cancer (TNBC) is a highly diverse group of cancers with limited treatment options, responsible for about 15% of all breast cancers. TNBC cells differ from each other in many ways such as gene expression, metabolic activity, tumorigenicity, and invasiveness. Recently, many research and clinical efforts have focused on metabolically targeted therapy for TNBC. Metabolic characterization of TNBC cell lines can facilitate the assessment of therapeutic effects and assist in metabolic drug development. Herein, we used optical redox imaging (ORI) techniques to characterize TNBC subtypes metabolically. We found that various TNBC cell lines had differing redox statuses (levels of reduced nicotinamide adenine dinucleotide (NADH), oxidized flavin adenine dinucleotide (FAD), and the redox ratio (FAD/(NADH+FAD)). We then metabolically perturbed the cells with mitochondrial inhibitors and an uncoupler and performed ORI accordingly. As expected, we observed that these TNBC cell lines had similar response patterns to the metabolic perturbations. However, they exhibited differing redox plasticity. These results suggest that subtypes of TNBC cells are different metabolically and that ORI can serve as a sensitive technique for the metabolic profiling of TNBC cells.

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MicroRNA-1246 Suppresses the Metastasis of Breast Cancer Cells by Targeting the DYRK1A/PGRN Axis to Prevent The Epithelial-Mesenchymal Transition

10.21203/rs.3.rs-756890/v1 ◽

2021 ◽

Author(s):

Pan Wang ◽

Wenju Chen ◽

Yaqiong Zhang ◽

Qianyi Zhong ◽

Zhaoyun Li ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Breast Cancer Cells ◽

Triple Negative ◽

Epithelial Mesenchymal Transition ◽

Migration And Invasion ◽

Mesenchymal Transition ◽

Tnbc Cell ◽

Novel Target

Abstract Objective. Breast cancer is one of the most common malignant and highly heterogeneous tumors in women. MicroRNAs (miRNAs), such as miR-1246, play important roles in various types of malignant cancers, including triple-negative breast cancer (TNBC). However, the biological role of miR-1246 in TNBC has not yet been fully elucidated. In this study, we studied the role of miR-1246 in the occurrence and development of TNBC and its mechanism of action.Methods. Cell Counting Kit-8 (CCK-8), wound healing, and Transwell assays were performed to observe the effects of miR-1246 on TNBC cell proliferation, migration, and invasion, respectively. The expression of epithelial-mesenchymal transition (EMT) markers was detected by western blotting. Dual luciferase reporter assays were performed to determine whether DYRK1A is a novel target of miR-1246. In addition, an immunoprecipitation experiment was performed to verify the binding of DYRK1A to PGRN. Rescue experiments were performed to determine whether DYRK1A is a novel target of miR-1246 and whether miR-1246 suppresses the metastasis of breast cancer cells by targeting the DYRK1A/PGRN axis to prevent the epithelial-mesenchymal transition.Results. Our results show that miR‑1246 suppresses the proliferation, migration, and invasion of TNBC cells and that DYRK1A is a novel target of miR-1246. MiR‑1246 plays a suppressive role in the regulation of the EMT of TNBC cells by targeting DYRK1A. DYRK1A mediates the metastasis of triple-negative breast cancer via activation of the EMT. We identified PGRN as a novel DYRK1A-interacting protein. DYRK1A and PGRN act together to regulate the occurrence and development of breast cancer through miR-1246.Conclusion. miR-1246 attenuates TNBC cell invasion and the EMT by targeting the DYRK1A/PGRN axis. Our data suggest that miR‑1246 may be used to develop novel early-stage diagnostic and therapeutic strategies for TNBC.

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The PAD4 inhibitor GSK484 enhances the radiosensitivity of triple-negative breast cancer

Human & Experimental Toxicology ◽

10.1177/0960327120979028 ◽

2020 ◽

pp. 096032712097902

Author(s):

Lining Wei ◽

Xiangping Wang ◽

Min Luo ◽

Hongzhi Wang ◽

Hao Chen ◽

...

Keyword(s):

Breast Cancer ◽

Cell Proliferation ◽

Triple Negative Breast Cancer ◽

Protein Level ◽

Triple Negative ◽

Combined Treatment ◽

Arginine Deiminase ◽

Migration And Invasion ◽

Tnbc Cell

Triple-negative breast cancer (TNBC) accounts for approximately 10–20% of all breast cancers and is one of the leading causes of mortality among females. Radiotherapy is essential during the treatment of breast cancer. Growing evidence has indicated that peptidyl arginine deiminase-4 (PAD4) inhibitor can alleviate the development of multiple cancers, including breast cancer, through inhibiting cell proliferation. GSK484 is considered to be a highly potent PAD4-selective inhibitors. However, the potential role and mechanism of GSK484 in TNBC remain unclear. In this study, we intended to explore the effects of GSK484 on the radiosensitivity of TNBC cell lines (MDA-MB-231 and BT-549). We found that the pretreatment of GSK484 enhanced irradiation (IR)-induced inhibitory effects on cell proliferation, migration and invasion. Besides, our findings revealed that GSK484 facilitated TNBC cell apoptosis. IR treatment-induced increase of the protein level of ATG5 and ATG7, and decrease of p62 protein level were countervailed by GSK484. In addition, GSK484 enhanced DNA damage induced by IR. Moreover, in vivo experiments demonstrated that the combined treatment of IR and GSK484 showed an obvious decline of tumor growth in contrast to IR-alone or GSK484-alone treatment. Overall, GSK484 may serve as a radiosensitizer of TNBC through inhibiting IR-induced autophagy.

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