ANXA9 facilitates S100A4 and promotes breast cancer progression through modulating STAT3 pathway.

Breast cancer has the highest global incidence and mortality rates among all cancer types. Abnormal expression of the Annexin family has been observed in different malignant tumors, including upregulated ANXA9 in breast cancer. We found highly expressed ANXA9 in metastatic breast cancer tissues, which is correlated with breast cancer progression. In vitro, the functional experiments indicated ANXA9 influenced breast cancer proliferation, motility, invasion, and apoptosis; in vivo, downregulation of ANXA9 suppressed breast cancer xenograft tumor growth and lung metastasis. Mechanically, on one side, we found that ANXA9 could mediate S100A4 and therefore regulate AKT/mTOR/STAT3 pathway to participate p53/Bcl-2 apoptosis; on the other side, we found ANXA9 transferred S100A4 from cells into the tumor microenvironment and mediated the excretion of cytokines IL-6, IL-8, CCL2, and CCL5 to participate angiogenesis via self- phosphorylation at site Ser2 and site Thr69. Our findings demonstrate significant involvement of ANXA9 in promoting breast cancer progression, thereby suggesting that therapeutic intervention via targeting ANXA9 may be effective in treating metastatic breast cancer.

Urolithin A inhibits breast cancer progression via activating TFEB-mediated mitophagy in tumor macrophages.

INTRODUCTION: Urolithin A (UA) is a naturally occurring compound that is converted from ellagitannin-like precursors in pomegranates and nuts by intestinal flora. Previous studies have found that UA exerts tumor-suppressive effects through antitumor cell proliferation and promotion of memory T-cell expansion, but its role in tumor-associated macrophages remains unknown. OBJECTIVES: Our study aims to reveal how UA affects tumor macrophages and tumor cells to inhibit breast cancer progression. METHODS: Observe the effect of UA treatment on breast cancer progression though in vivo and in vitro experiments. Western blot and PCR assays were performed to discover that UA affects tumor macrophage autophagy and inflammation. Co-ip and Molecular docking were used to explore specific molecular mechanisms. RESULTS: We observed that UA treatment could simultaneously inhibit harmful inflammatory factors, especially for InterleuKin-6 (IL-6) and tumor necrosis factor α (TNF-α), in both breast cancer cells and tumor-associated macrophages, thereby improving the tumor microenvironment and delaying tumor progression. Mechanistically, UA induced the key regulator of autophagy, transcription factor EB (TFEB), into the nucleus in a partially mTOR-dependent manner and inhibited the ubiquitination degradation of TFEB, which facilitated the clearance of damaged mitochondria via the mitophagy-lysosomal pathway in macrophages under tumor supernatant stress, and reduced the deleterious inflammatory factors induced by the release of nucleic acid from damaged mitochondria. Molecular docking and experimental studies suggest that UA block the recognition of TFEB by 1433 and induce TFEB nuclear localization. Notably, UA treatment demonstrated inhibitory effects on tumor progression in multiple breast cancer models. CONCLUSION: Our study elucidated the anti-breast cancer effect of UA from the perspective of tumor-associated macrophages. Specifically, TFEB is a crucial downstream target in macrophages.

K48-linked deubiquitination of VGLL4 by USP15 enhances the efficacy of tumor immunotherapy in triple-negative breast cancer.

Immunotherapy based on PD-1/PD-L1 antagonists has been demonstrated to be efficacious in inducing tumor remission in patients with triple-negative breast cancer (TNBC). However, tumor immune evasion caused by the PD-1/PD-L1 pathway inhibits the immunotherapeutic effect of PD-1/PD-L1 inhibitors against TNBC. Therefore, identifying potential targets for blocking the PD-1/PD-L1 pathway is a compelling strategy for TNBC treatment. Here, we discovered that VGLL4 could inhibit PD-L1 transcription by suppressing STAT3 activation, thereby enhancing the efficacy of anti-PD-1 antibody immunotherapy in TNBC. Low expression of USP15, a deubiquitinating enzyme of VGLL4, was associated with reduced CD8+ T cell infiltration and poor prognosis in TNBC patients. USP15 was found to inhibit PD-L1 transcription, leading to increased CD8+ T cell infiltration and thus enhancing the efficacy of TNBC immunotherapy. Furthermore, SART3 regulated VGLL4 stability and PD-L1 transcription by influencing the nuclear translocation of USP15. In conclusion, our study provides new insights into the biological regulation of PD-L1, identifies a previously unrecognized regulator of this critical immune checkpoint, and highlights potential therapeutic targets for overcoming immune evasion in TNBC.

LINC01572 promotes triple-negative breast cancer progression through EIF4A3-mediated ß-catenin mRNA nuclear exportation.

Long noncoding RNAs have been reported to be involved in the development of breast cancer. LINC01572 was previously reported to promote the development of various tumors. However, the potential biological function of LINC01572 in breast cancer remains largely unknown. R language was used to perform bioinformatic analysis of The Cancer Genome Atlas data. The expression level of RNAs was examined by RT-qPCR. The effect of knocking down or overexpression LINC01572 in triple-negative breast cancer (TNBC) cell lines was evaluated by detecting cell proliferation, migrant action. RNA immunoprecipitation assay and RNA pull-down assay were performed to explore the regulatory relationship between LINC01572, EIF4A3, and ß-catenin. Bioinformatics analysis identifies LINC01572 as an oncogene of breast cancer. LINC01572 is over-expressed in TNBC tissues and cell lines, correlated with poor clinical prognosis in BC patients. Cell function studies confirmed that LINC01572 facilitated the proliferation and migration of TNBC cells in both vivo and vitro. Mechanistically, ß-catenin mRNA and EIF4A3 combine spatially to form a complex, LINC01572 helps transport this complex from the nucleus to the cytoplasm, thereby facilitating the translation of ß-catenin. Our findings confirm that LINC01572 acts as a tumor promoter and may act as a biomarker in TNBC. In addition, novel molecular regulatory relationships involving LINC01572/EIF4A3/ß-catenin are critical to the development of TNBC, which led to a new understanding of the mechanisms of TNBC progression and shows a new target for precision treatment for TNBC.

miR-186-ANXA9 signaling inhibits tumorigenesis in breast cancer.

Breast cancer (BC) ranks as the highest incidence among cancer types in women all over the world. MicroRNAs (miRNAs) are a class of short endogenous non-coding RNA in cells mostly functioning to silence the target mRNAs. In the current study, a miRNA screening analysis identified miR-186-5p to be downregulated in human breast cancer tumors. Functional studies in vitro demonstrated that overexpression of miR-186-5p inhibited cellular proliferation and induced cell apoptosis in multiple breast cancer cell lines including MDA-MB-231, MCF-7, and BT549 cells. Transplantation of the miR-186-5p-overexpressing MDA-MB-231 cells into nude mice significantly inhibited mammary tumor growth in vivo. Sequence blast analysis predicted annexin A9 (ANXA9) as a target gene of miR-186-5p, which was validated by luciferase reporter assay, QRT-PCR analysis, and western blot. Additional gene expression analysis of clinical tumor samples indicated a negative correlation between miR-186-5p and ANXA9 in human breast cancer. Knockdown of ANXA9 mimicked the phenotype of miR-186-5p overexpression. Reintroduction of ANXA9 back rescued the miR-186-5p-induced cell apoptosis. In addition, miR-186-5p decreased the expression of Bcl-2 and increased the expression of p53, suggesting a mechanism regulating miR-186-5p-induced cellular apoptosis. In summary, our study is the first to demonstrate miR-186-5p-ANXA9 signaling in suppressing human breast cancer. It provided a potential therapeutic target in breast cancer.

DNMT3a-dermatopontin axis suppresses breast cancer malignancy via inactivating YAP.

Breast cancer (BC) is the most common malignant tumor in women worldwide, and its recurrence and metastasis negatively affect patient prognosis. However, the mechanisms underlying its tumorigenesis and progression remain unclear. Recently, the influence of dermatopontin (DPT), which is an extracellular matrix protein, has been proposed in the development of cancer. Here we found that DNMT3a-mediated DPT, promoter hypermethylation results in the downregulation of DPT expression in breast cancer and its low expression correlated with poor prognosis. Notably, DPT directly interacted with YAP to promote YAP Ser127 phosphorylation, and restricted the translocation of endogenous YAP from the cytoplasm to the nucleus, thereby suppressing malignant phenotypes in BC cells. In addition, Ectopic YAP overexpression reversed the inhibitory effects of DPT on BC growth and metastasis. Our study showed the critical role of DPT in regulating BC progression, making it easier to explore the clinical potential of modulating DPT/YAP activity in BC targeted therapies.

Circular RNA_0006014 promotes breast cancer progression through sponging miR-885-3p to regulate NTRK2 and PIK3/AKT pathway.

Breast cancer is the most common cancer in women worldwide. Numerous reports have demonstrated that circRNAs play an essential role in regulating the biological characteristics of breast cancer. However, there are currently no reports regarding the role of hsa_circ_0006014 in breast cancer. In this study, qRT-PCR was used to detect the expression of hsa_circ_0006014 and related genes. MTT, colony formation and Transwell assays were used to explore the potential biological functions of hsa_circ_0006014 in breast cancer cells. Western blotting was used to explore the potential molecular mechanisms involving hsa_circ_0006014. In vivo experiments were used to evaluate the influence of hsa_circ_0006014 on animal tumors. In this study, we found higher expression of hsa_circ_0006014 in breast tumor samples than in matched adjacent normal samples, and its expression was positively correlated with histological grade (grade iii). Phenotypically, hsa_circ_0006014 promoted the proliferation of MDA-MB-231 and MCF-7 breast cancer cells. Mechanistically, there were confirmed binding sites between hsa_circ_0006014 and miR-885-3p, and hsa_circ_0006014 promoted breast cancer cell proliferation partially by sponging miR-885-3p and influenced CDK2/CCNE1 and CDK4/6/CCND1. Furthermore, we found that hsa_circ_0006014 regulated NTRK2 through miR-885-3p to modulate the PIK3/AKT signaling pathway. Our results demonstrated that hsa_circ_0006014 promotes breast cancer progression by sponging miR-885-3p to regulate the NTRK2/PIK3CA/AKT axis.

Circular RNA circRPPH1 promotes breast cancer progression via circRPPH1-miR-512-5p-STAT1 axis.

Breast cancer (BC) is one of the most fatal diseases among women all over the world. Non-coding RNAs including circular RNAs (circRNAs) have been reported to be involved in different aspects during tumorigenesis and progression. In this study, we aimed to explore the biological functions and underlying mechanism of circRPPH1 in BC. Candidate circRNAs were screened in dataset GSE101123 from Gene Expression Omnibus (GEO) database and a differentially expressed circRNA, circRPPH1, was discovered in BC. CircRPPH1 expression was higher in the cancerous tissue compared to paired adjacent tissue. Further in vitro and in vivo experiments indicated that circRPPH1 acted as an oncogene in BC. In addition, circRPPH1 was mainly localized in cytoplasm and played the role of miR-512-5p sponge. By sequestering miR-512-5p from the 3'-UTR of STAT1, circRPPH1 inhibited the suppressive role of miR-512-5p, stabilized STAT1 mRNA in BC and finally affected BC progression. In conclusion, these findings indicated that circRPPH1 acted as an oncogene and regulated BC progression via circRPPH1-miR-512-5p-STAT1 axis, which might provide a potential therapeutic target for BC treatment.

MIR22HG inhibits breast cancer progression by stabilizing LATS2 tumor suppressor.

The long noncoding RNA called MIR22 host gene (MIR22HG) was previously identified as a tumor suppressor in several cancers. However, the biological function of MIR22HG in breast cancer remains unknown. In this study, we aimed to determine the function and molecular mechanism of MIR22HG in breast cancer progression using transcriptomics and biotechnological techniques. Our results showed that MIR22HG expression was lower in the cancerous tissues than in the paired adjacent normal breast tissues. Additionally, MIR22HG was found to be mainly located in the cytoplasm and acted as a miR-629-5p sponge. Notably, MIR22HG stabilized the expression of large tumor suppressor 2 (LATS2), which promoted the LATS2-dependent phosphorylation of YAP1 and suppressed the expression of its downstream target oncogenes, thereby inhibiting the proliferation and migration of breast cancer cells. Therefore, our findings reveal the MIR22HG-dependent inhibition of breast cancer cell proliferation and migration via the miR-629-5p/LATS2 pathway, providing new insights and identifying novel therapeutic targets for breast cancer treatment.

KIF23 promotes triple negative breast cancer through activating epithelial-mesenchymal transition.

BACKGROUND: KIF23 is a member of kinesin family, recent researches indicate KIF23 plays an important role in the proliferation and migration of malignant cancer cells. While the function and specific molecule mechanism of KIF23 in triple negative breast cancer remains unclear. METHODS: QRT-PCR and immunohistochemistry were conducted to analyze expression of KIF23 in triple negative breast cancer tissues and paired paracancer tissues. CCK-8 assay, colony formation assay, wound healing assay and transwell assay were applied for exploring phenotype changing of triple negative breast cancer cell lines MDA-MB-231 and BT549 after siRNA-induced knockdown of KIF23. Several bioinformatic databases were used for predicting miRNAs that combing with KIF23 mRNA and verified by dual luciferase reporter assay. Western blot assay was performed to explore downstream signaling pathway of KIF23. RESULTS: KIF23 was overexpressed in triple negative breast cancer, knockdown of KIF23 by siRNA inhibited proliferation and migration of TNBC cell lines MDA-MB-231 and BT549. Mechanistically, knockdown of KIF23 resulted in the suppression of Epithelial-Mesenchymal Transition. Meanwhile, miR-195-5p was downregulated in TNBC, and dual luciferase reporter assay indicated miR-195-5p could combine with 3'UTR of KIF23 thus promoting degradation of KIF23. CONCLUSIONS: KIF23 is a potential oncogene in triple negative breast cancer, miR-195-5p could combine with 3'UTR of KIF23. Our study reveals a new sight into triple negative breast cancer.

The Role of miR-640: A Potential Suppressor in Breast Cancer via Wnt7b/ß-catenin Signaling Pathway.

In this study, we demonstrated that miR-640 is significantly downregulated in breast cancer (BC) tissues and cell lines. Overexpression of miR-640 inhibited the proliferation and migration of BC in vitro and in vivo, while depletion of miR-640 exhibited the opposite effect. Importantly, miR-640 could directly target Wnt7b, thereby regulating Wnt/ß-catenin signaling pathway in BC. In conclusion, miR-640/Wnt7b suppresses BC cells tumorigenesis via Wnt/ß-catenin signaling pathway, which might be novel targets for BC targeted therapy.

Hsa_circ_0053063 inhibits breast cancer cell proliferation via hsa_circ_0053063/hsa-miR-330-3p/PDCD4 axis.

Breast cancer (BC) is one of the most common malignancies and its mortality is the highest among females. Circular RNAs (circRNAs), a novel group of non-coding RNAs, play an important regulatory role in angiogenesis and cancer progression. Hsa_circ_0053063 is a circRNA generated from several exons of HADHA. The potential role of hsa_circ_0053063 in BC remains unknown and needs to be explored. Hsa_circ_0053063 was mainly located in the cytoplasm and activated in BC tissues and cell lines. The binding position between hsa_circ_0053063 and miR-330-3p was confirmed by luciferase reporter assay. Moreover, hsa_circ_0053063 inhibited cell viability, proliferation, and progression of BC through the negative regulation of miR-330-3p. Programmed cell death 4 (PDCD4) is a direct target of miR-330-3p. Besides, the over-expression of miR-330-3p promoted cell progression by directly targeting and regulating PDCD4. Mechanistically, hsa_circ_0053063 activated PDCD4 by targeting miR-330-3p to inhibit BC progression. In conclusion, hsa_circ_0053063 inhibits breast cancer cell proliferation via hsa_circ_0053063/hsa-miR-330-3p/PDCD4 axis, which may provide a new therapeutic target for BC patients.

Hsa_circ_0005273 facilitates breast cancer tumorigenesis by regulating YAP1-hippo signaling pathway.

BACKGROUND: Circular RNAs (circRNAs), a novel class of endogenous RNAs, have shown to participate in the development of breast cancer (BC). Hsa_circ_0005273 is a circRNA generated from several exons of PTK2. However, the potential functional role of hsa_circ_0005273 in BC remains largely unknown. Here we aim to evaluate the role of hsa_circ_0005273 in BC. METHODS: The expression level of hsa_circ_0005273 and miR-200a-3p were examined by RT-qPCR in BC tissues and cell lines. The effect of knocking down hsa_circ_0005273 in BC cell lines were evaluated by examinations of cell proliferation, migration and cell cycle. In addition, xenografts experiment in nude mice were performed to evaluate the effect of hsa_circ_0005273 in BC. RNA immunoprecipitation assay, RNA probe pull-down assay, luciferase reporter assay and fluorescence in situ hybridization were conducted to confirm the relationship between hsa_circ_0005273, miR-200a-3p and YAP1. RESULTS: Hsa_circ_0005273 is over-expressed in BC tissues and cell lines, whereas miR-200a-3p expression is repressed. Depletion of hsa_circ_0005273 inhibited the progression of BC cells in vitro and in vivo, while overexpression of hsa_circ_0005273 exhibited the opposite effect. Importantly, hsa_circ_0005273 upregulated YAP1 expression and inactivated Hippo pathway via sponging miR-200a-3p to promote BC progression. CONCLUSIONS: Hsa_circ_0005273 regulates the miR-200a-3p/YAP1 axis and inactivates Hippo signaling pathway to promote BC progression, which may become a potential biomarker and therapeutic target.