Dual-Drug Nanomedicine Assembly with Synergistic Anti-Aneurysmal Effects via Inflammation Suppression and Extracellular Matrix Stabilization.

Abdominal aortic aneurysm (AAA) represents a critical cardiovascular condition characterized by localized dilation of the abdominal aorta, carrying a significant risk of rupture and mortality. Current treatment options are limited, necessitating novel therapeutic approaches. This study investigates the potential of a pioneering nanodrug delivery system, RAP@PFB, in mitigating AAA progression. RAP@PFB integrates pentagalloyl glucose (PGG) and rapamycin (RAP) within a metal-organic-framework (MOF) structure through a facile assembly process, ensuring remarkable drug loading capacity and colloidal stability. The synergistic effects of PGG, a polyphenolic antioxidant, and RAP, an mTOR inhibitor, collectively regulate key players in AAA pathogenesis, such as macrophages and smooth muscle cells (SMCs). In macrophages, RAP@PFB efficiently scavenges various free radicals, suppresses inflammation, and promotes M1-to-M2 phenotype repolarization. In SMCs, it inhibits apoptosis and calcification, thereby stabilizing the extracellular matrix and reducing the risk of AAA rupture. Administered intravenously, RAP@PFB exhibits effective accumulation at the AAA site, demonstrating robust efficacy in reducing AAA progression through multiple mechanisms. Moreover, RAP@PFB demonstrates favorable biosafety profiles, supporting its potential translation into clinical applications for AAA therapy.

Discovery of indole-2-one derivatives as BRD4 (BD1) selective inhibitors.

Bromodomain protein 4 (BRD4) is a member of the BET family, and its overexpression is closely associated with the development of many tumors. Inhibition of BRD4 shows great therapeutic potential in anti-tumor, and pan-BRD4 inhibitors show adverse effects of dose limiting toxicity and thrombocytopenia in clinical trials. To improve clinical effects and reduce side effects, more efforts have focused on seeking selective inhibitors of BD1 or BD2. Herein, a series of indole-2-one derivatives were designed and synthesized through docking-guided optimization to find BRD4-BD1 selective inhibitors, and their BRD4 inhibitory and antiproliferation activities were evaluated. Among them, compound 21r had potent BRD4 inhibitory activity (the IC50 values of 41 nM and 313 nM in BD1 and BD2 domain), excellent anti-proliferation (the IC50 values of 4.64 ± 0.30 µM, 0.78 ± 0.03 µM, 5.57 ± 1.03 µM against HL-60, MV-4-11 and HT-29 cells), and displayed low toxicity against normal cell GES-1 cells. Further studies revealed that 21r inhibited proliferation by decreasing the expression of proto-oncogene c-Myc, blocking cell cycle in G0/G1 phase, and inducing apoptosis in MV-4-11 cells in a dose-dependent manner. All the results showed that compound 21r was a potent BRD4 inhibitor with BD1 selectivity, which had potential in treatment of leukemia.

Discovery of novel coumarin-based KRAS-G12C inhibitors from virtual screening and Rational structural optimization.

KRAS-G12C inhibitors has been made significant progress in the treatment of KRAS-G12C mutant cancers, but their clinical application is limited due to the adaptive resistance, motivating development of novel structural inhibitors. Herein, series of coumarin derivatives as KRAS-G12C inhibitors were found through virtual screening and rational structural optimization. Especially, K45 exhibited strong antiproliferative potency on NCI-H23 and NCI-H358 cancer cells harboring KRAS-G12C with the IC50 values of 0.77 µM and 1.50 µM, which was 15 and 11 times as potent as positive drug ARS1620, respectively. Furthermore, K45 reduced the phosphorylation of KRAS downstream effectors ERK and AKT by reducing the active form of KRAS (KRAS GTP) in NCI-H23 cells. In addition, K45 induced cell apoptosis by increasing the expression of anti-apoptotic protein BAD and BAX in NCI-H23 cells. Docking studies displayed that the 3-naphthylmethoxy moiety of K45 extended into the cryptic pocket formed by the residues Gln99 and Val9, which enhanced the interaction with the KRAS-G12C protein. These results indicated that K45 was a potent KRAS-G12C inhibitor worthy of further study.

1H-Indazoles derivatives targeting PI3K/AKT/mTOR pathway: Synthesis, anti-tumor effect and molecular mechanism.

The PI3K/AKT/mTOR signaling pathway is one of the most common abnormal activation pathways in tumor cells, and has associated with multiple functions such as tumor cell growth, proliferation, migration, invasion, and tumor angiogenesis. Here, a series of 3-amino-1H-indazole derivatives were synthesized, and their antiproliferative activities against HT-29, MCF-7, A-549, HepG2 and HGC-27 cells were evaluated. Among them, W24 exhibited the broad-spectrum antiproliferative activity against four cancer cells with IC50 values of 0.43-3.88 µM. Mechanism studies revealed that W24 inhibited proliferation by affecting the DNA synthesis, induced G2/M cell cycle arrest and apoptosis by regulating Cyclin B1, BAD and Bcl-xL, meanwhile induced the change of intracellular ROS and mitochondrial membrane potential in HGC-27 cells. Moreover, W24 inhibited the migration and invasion of HGC-27 cells by decreasing EMT pathway related proteins and reducing the mRNA expression levels of Snail, Slug and HIF-1α. Furthermore, W24 displayed low tissue toxicity profile and good pharmacokinetic properties in vivo. Therefore, 3-amino-1H-indazole derivatives might serve as a new scaffold for the development of PI3K/AKT/mTOR inhibitor and anti-gastric cancer reagent.

FOXF2 oppositely regulates stemness in luminal and basal-like breast cancer cells through the Wnt/beta-catenin pathway.

The stemness of cancer cells contributes to tumorigenesis, the heterogeneity of malignancies, cancer metastasis, and therapeutic resistance. However, the roles and regulatory mechanisms maintaining stemness among breast cancer subtypes remain elusive. Our previous studies have demonstrated that ectopic expression and dynamic alteration of the mesenchymal transcription factor forkhead box F2 (FOXF2) differentially regulates breast cancer progression and metastasis organotropism in a cell subtype-specific manner. Here, we reveal the underlying mechanism by which FOXF2 enhances stemness in luminal breast cancer cells but suppresses that in basal-like breast cancer (BLBC) cells. We show that luminal breast cancer and BLBC cells with FOXF2-regulated stemness exhibit partial mesenchymal stem cell properties that toward osteogenic differentiation and myogenic differentiation, respectively. Furthermore, we show that FOXF2 activates the Wnt signaling pathway in luminal breast cancer cells but represses this pathway in BLBC cells by recruiting nuclear receptor coactivator 3 (NCoA3) and nuclear receptor corepressor 1 (NCoR1) to the promoters of Wnt family member 2B (WNT2B) and frizzled class receptor 1 (FZD1) genes to activate and repress their transcription, respectively. We propose that targeting the Wnt signaling pathway is a promising strategy for the treatment of breast cancers with dysregulated expression of FOXF2.

Protective effect of orange essential oil on the formation of non-alcoholic fatty liver disease caused by high-fat diet.

The purpose of this study was to investigate the protective effect of sniffing orange essential oil (OEO) on the formation of non-alcoholic fatty liver disease (NAFLD) caused by a high-fat diet. The results confirmed that sniffing OEO could reduce obesity caused by a high-fat diet (HFD) by reducing the levels of triglycerides (TGs), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). In addition, the observation of liver tissue sections showed that sniffing OEO could reduce lipid accumulation in liver cells. Further analysis by western blot analysis showed that OEO treatment made the expression levels of acetyl-CoA carboxylase (ACC) and Cytochrome P450 2E1 (CYP2E1) down-regulated and the expression levels of peroxisome proliferator-activated receptor-α (PPAR-α) and carnitine palmitoyltransferase-1 (CPT-1) up-regulated. These results indicate that the treatment of sniffing OEO could enhance the antioxidant capacity of mice and reduce liver damage caused by a high-fat diet. Furthermore, sniffing OEO could inhibit lipid synthesis and oxidative stress stimulated by a high-fat diet. Overall, OEO treatment had a certain protective effect on NAFLD-related diseases caused by a high-fat diet. Therefore, aromatherapy may be introduced as a treatment of long-term chronic diseases.

FOXF2 deficiency accelerates the visceral metastasis of basal-like breast cancer by unrestrictedly increasing TGF-ß and miR-182-5p.

The mesenchymal transcription factor forkhead box F2 (FOXF2) is a critical regulator of embryogenesis and tissue homeostasis. Our previous studies demonstrated that FOXF2 is ectopically expressed in basal-like breast cancer (BLBC) cells and that FOXF2 deficiency promotes the epithelial-mesenchymal transition and aggressiveness of BLBC cells. In this study, we found that FOXF2 controls transforming growth factor-beta (TGF-ß)/SMAD signaling pathway activation through transrepression of TGF-ß-coding genes in BLBC cells. FOXF2-deficient BLBC cells adopt a myofibroblast-/cancer-associated fibroblast (CAF)-like phenotype, and tend to metastasize to visceral organs by increasing autocrine TGF-ß signaling and conferring aggressiveness to neighboring cells by increasing paracrine TGF-ß signaling. In turn, TGF-ß silences FOXF2 expression through upregulating miR-182-5p, a posttranscriptional regulator of FOXF2 and inducer of metastasis. In addition to mediating a reciprocal repression loop between FOXF2 and TGF-ß through direct transrepression by SMAD3, miR-182-5p forms a reciprocal repression loop with FOXF2 that directly transrepresses MIR182 expression. Therefore, FOXF2 deficiency accelerates the visceral metastasis of BLBC through unrestricted increases in autocrine and paracrine TGF-ß signaling, and miR-182-5p expression. Our findings provide novel mechanisms underlying the roles of TGF-ß, miR-182-5p, and FOXF2 in accelerating BLBC dissemination and metastasis, and may facilitate the development of therapeutic strategies for aggressive BLBC.

Resveratrol Attenuates Pressure Overload-Induced Cardiac Fibrosis and Diastolic Dysfunction via PTEN/AKT/Smad2/3 and NF-κB Signaling Pathways.

SCOPE: Cardiac fibrosis is a key feature of cardiac remodeling. Recently, a protective role for resveratrol (RES) in pressure-overload-induced cardiac hypertrophy and contractile dysfunction has been demonstrated. However, the effect of RES on cardiac fibrosis and diastolic function in this model remains unclear. METHODS AND RESULTS: Cardiac remodeling is induced in mice by transverse aortic constriction (TAC) for 2-4 weeks. RES is administered at dose of 5 or 50 mg kg-1  d-1 for 2 weeks. It is found that RES administration at 50 mg kg-1  d-1 significantly attenuates TAC-induced adverse cardiac systolic and diastolic function, fibrosis, inflammation, and oxidative stress via inhibiting PTEN degradation and the downstream mediators. However, RES at 5 mg kg-1  d-1 has no significant effects. RES at 50 mg kg-1  d-1 also ameliorates pre-established adverse cardiac function and remodeling induced by TAC. Treatment with PTEN inhibitor VO-OHpic (10 mg kg-1  d-1 ) for 2 weeks abolishes RES-mediated protective effects. Additionally, the effect of RES (100 µm) on inhibition of Ang II-induced fibroblast proliferation and activation in vitro is verified. CONCLUSIONS: The findings provide new evidence that RES plays a critical role in the progression of cardiac fibrosis and diastolic dysfunction, and suggest that RES may be a promising therapeutic agent for cardiac fibrosis.

FOXF2 reprograms breast cancer cells into bone metastasis seeds.

Bone metastases occur in most advanced breast cancer patients and cause serious skeletal-related complications. The mechanisms by which bone metastasis seeds develop in primary tumors and specifically colonize the bone remain to be elucidated. Here, we show that forkhead box F2 (FOXF2) functions as a master transcription factor for reprogramming cancer cells into an osteomimetic phenotype by pleiotropic transactivation of the BMP4/SMAD1 signaling pathway and bone-related genes that are expressed at early stages of bone differentiation. The epithelial-to-osteomimicry transition regulated by FOXF2 confers a tendency on cancer cells to metastasize to bone which leads to osteolytic bone lesions. The BMP antagonist Noggin significantly inhibits FOXF2-driven osteolytic bone metastasis of breast cancer cells. Thus, targeting the FOXF2-BMP/SMAD axis might be a promising therapeutic strategy to manage bone metastasis. The role of FOXF2 in transactivating bone-related genes implies a biological function of FOXF2 in regulating bone development and remodeling.

Reciprocal transrepression between FOXF2 and FOXQ1 controls basal-like breast cancer aggressiveness.

FOXF2 and FOXQ1, forkhead box transcription factor superfamily members, are encoded by neighboring genes located on human chromosome 6p25.3 and play opposite roles in epithelial-mesenchymal transition (EMT) and metastasis in basal-like breast cancer (BLBC). However, the relationship between FOXF2 and FOXQ1 in cancer remains unknown. Here, we found mutual transcriptional repression between FOXF2 and FOXQ1, and the reciprocal negative feedback loop controlled EMT, aggressiveness, and chemoresistance in BLBC cells. We further demonstrated that FOXF2 recruited nuclear receptor corepressor 1 and histone deacetylase 3 to the FOXQ1 promoter to inhibit its transcription in BLBC cells, but FOXQ1 did not exert such an effect on FOXF2. Our findings reveal novel mechanisms underlying the determination of BLBC aggressiveness and the transrepressive function of FOXF2 in a basal-like cell subtype-specific manner. Therefore, blocking the vicious cycle of the abnormal reciprocal feedback loop between FOXF2 and FOXQ1 to induce cell differentiation and restore tissue homeostasis is a promising strategy for the treatment of aggressive BLBC.-Kang, L.-J., Yu, Z.-H., Cai, J., He, R., Lu, J.-T., Hou, C., Wang, Q.-S., Li, X.-Q., Zhang, R., Feng, Y.-M. Reciprocal transrepression between FOXF2 and FOXQ1 controls basal-like breast cancer aggressiveness.

Resveratrol as a new inhibitor of immunoproteasome prevents PTEN degradation and attenuates cardiac hypertrophy after pressure overload.

Sustained cardiac hypertrophy is a major cause of heart failure (HF) and death. Recent studies have demonstrated that resveratrol (RES) exerts a protective role in hypertrophic diseases. However, the molecular mechanisms involved are not fully elucidated. In this study, cardiac hypertrophic remodeling in mice were established by pressure overload induced by transverse aortic constriction (TAC). Cardiac function was evaluated by echocardiography and invasive pressure-volume analysis. Cardiomyocyte size was detected by wheat germ agglutinin staining. The protein and gene expressions of signaling mediators and hypertrophic markers were examined. Our results showed that administration of RES significantly suppressed pressure overload-induced cardiac hypertrophy, fibrosis and apoptosis and improved in vivo heart function in mice. RES also reversed pre-established hypertrophy and restoring contractile dysfunction induced by chronic pressure overload. Moreover, RES treatment blocked TAC-induced increase of immunoproteasome activity and catalytic subunit expression (ß1i, ß2i and ß5i), which inhibited PTEN degradation thereby leading to inactivation of AKT/mTOR and activation of AMPK signals. Further, blocking PTEN by the specific inhibitor VO-Ohpic significantly attenuated RES inhibitory effect on cardiomyocyte hypertrophy in vivo and in vitro. Taken together, our data suggest that RES is a novel inhibitor of immunoproteasome activity, and may represent a promising therapeutic agent for the treatment of hypertrophic diseases.

FOXF2 deficiency permits basal-like breast cancer cells to form lymphangiogenic mimicry by enhancing the response of VEGF-C/VEGFR3 signaling pathway.

Lymphatic metastasis is the main route of breast cancer metastasis. It is known that lymphangiogenesis facilitates lymphatic metastasis through vascular endothelial growth factor-C (VEGF-C)/VEGF receptor 3 (VEGFR3) pathway-linked interactions between the tumor and its microenvironment. Here, we report a novel mechanism of lymphatic metastasis by which aggressive basal-like breast cancer (BLBC) cells form lymphatic vessel-like structures that are identified by the positive expression of lymphatic endothelial cell markers lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), podoplanin, and VEGFR3, and termed as lymphangiogenic mimicry (LM), for the first time. Our clinical evidence and experimental data in vivo and in vitro revealed that forkhead box F2 (FOXF2) deficiency promotes the lymphatic metastasis of BLBC by conferring a lymphangiogenic mimetic feature upon cancer cells through directly activating VEGFR3 transcription. The fact that FOXF2 controls the activation of the VEGF-C/VEGFR3 signaling pathway in BLBC cells provides potential molecular diagnostic and therapeutic strategies for lymphatic metastasis in BLBC patients.

Dual function of MAZ mediated by FOXF2 in basal-like breast cancer: Promotion of proliferation and suppression of progression.

Myc-associated zinc finger protein (MAZ) is a transcription factor with C2H2-type zinc-finger motifs that can bind GC-rich cis-elements. MAZ activates the transcription of some cancer-related genes and represses that of others, suggesting that changes in MAZ expression may play different roles in the development and progression of different types or subtypes of cancers depending on its target genes. However, the functions and mechanisms of MAZ in regulating the carcinogenesis and progression of breast cancer have remained unclear. In the current study, we show that MAZ performs dual function in basal-like breast cancer (BLBC): suppression of aggressiveness and promotion of proliferation. Forkhead box F2 (FOXF2) is a novel transcription target of MAZ and mediates the functions of MAZ. The MAZ mRNA level, particularly in combination with the FOXF2 mRNA level, may serve as a prognostic marker for BLBC patients. Our results indicate that the dual function of the MAZ-FOXF2 axis reflect the pleiotropic nature of multifunctional transcription factors in regulating the different stages of cancer development and progression, which could lead to the complexity of cancer diagnosis and treatment.

Breast cancer cells obtain an osteomimetic feature via epithelial-mesenchymal transition that have undergone BMP2/RUNX2 signaling pathway induction.

Bone is one of the most common organs of breast cancer metastasis. Cancer cells that mimic osteoblasts by expressing bone matrix proteins and factors have a higher likelihood of metastasizing to bone. However, the molecular mechanisms of osteomimicry formation of cancer cells remain undefined. Herein, we identified a set of bone-related genes (BRGs) that are ectopically co-expressed in primary breast cancer tissues and determined that osteomimetic feature is obtained due to the osteoblast-like transformation of epithelial breast cancer cells that have undergone epithelial-mesenchymal transition (EMT) followed by bone morphogenetic protein-2 (BMP2) stimulation. Furthermore, we demonstrated that breast cancer cells that transformed into osteoblast-like cells with high expression of BRGs showed enhanced chemotaxis, adhesion, proliferation and multidrug resistance in an osteoblast-mimic bone microenvironment in vitro. During these processes, runt-related transcription factor 2 (RUNX2) functioned as a master mediator by suppressing or activating the transcription of BRGs that underlie the dynamic antagonism between the TGF-ß/SMAD and BMP/SMAD signaling pathways in breast cancer cells. Our findings suggest a novel mechanism of osteomimicry formation that arises in primary breast tumors, which may explain the propensity of breast cancer to metastasize to the skeleton and contribute to potential strategies for predicting and targeting breast cancer bone metastasis and multidrug resistance.

RUNX2 promotes breast cancer bone metastasis by increasing integrin α5-mediated colonization.

Runt-related transcription factor 2 (RUNX2) is regarded as an important contributor to breast cancer bone metastasis. However, previous studies did not provide direct clinical evidence for a role of RUNX2 in bone-specific metastasis in breast cancer, and the mechanism of RUNX2 in cancer cell recruitment and adhesion to the bone remains unclear. In this study, we showed that RUNX2 expression is positively correlated with the risk of bone-specific metastasis in lymph node-negative breast cancer patients. Then, we identified ITGA5 as a transcriptional target of RUNX2 from multiple candidate genes encoding adhesion molecules or chemokine receptors. We further provided experimental and clinical evidence that RUNX2, in an integrin α5-dependent manner, promotes the attraction and adhesion of breast cancer cells to the bone and confers cancer cell survival and bone colonization advantages. Overall, our findings clarify an adhesion-dependent mechanism of RUNX2 for the osteotropism and bone colonization of breast cancer cells and implicate RUNX2 and integrin α5 as potential molecular markers for the prediction of bone metastasis and therapeutic targets for the treatment of breast cancer bone metastasis.

Facile one-pot synthesis of highly monodisperse nickel microspheres with raised nickel dots and their adsorption performance for heavy metal ions.

This report describes the facile solvothermal synthesis of highly monodispersed nickel microspheres with surfaces uniformly covered by nickel dots. Synthesis parameters including reaction times and reagent concentrations significantly influence the microspheric particle characteristics. The novelty of the synthetic method in this work is twofold: first, the controlled synthesis of Ni metallic microspheres using ethylene glycol as the precursor of a reductant and urea as the origin of OH(-) has never been reported. Second, there are few studies on the construction of Ni microspheres covered by uniform Ni dots using a one-step solvothermal method. Importantly, the as-prepared Ni microspheres show an improved ability to remove Cd(2+) ions even at high concentrations in water and a unique adsorption isotherm having an increasing adsorption capacity for Cd(2+) ions. The presence of Ni dots was considered to play an important role in the onset of the adsorption process. We believe that this work opens up new and possibly exciting opportunities in the field of adsorption of heavy metal ions.

FOXF2 suppresses the FOXC2-mediated epithelial-mesenchymal transition and multidrug resistance of basal-like breast cancer.

Forkhead box (FOX) F2 and FOXC2 belong to the FOX transcription factor superfamily. FOXC2 is recognized as an inducer of epithelial-mesenchymal transition (EMT), and its overexpression promotes basal-like breast cancer (BLBC) metastasis. Our previous study demonstrated that FOXF2 functions as an EMT suppressor and that FOXF2 deficiency promotes BLBC metastasis. However, the relationship between the opposite EMT-related transcription factors FOXF2 and FOXC2 remains unknown. Here, we found that FOXF2 directly targets FOXC2 to negatively regulate FOXC2 transcription in BLBC cells. Functionally, we observed that FOXC2 mediates the FOXF2-regulated EMT phenotype, aggressive behavior, and multiple chemotherapy drug resistance of BLBC cells. Additionally, we detected a significant negative correlation between the FOXF2 and FOXC2 mRNA levels in triple-negative breast cancer (TNBC) tissues. TNBC patients in the FOXF2high/FOXC2low and FOXF2low/FOXC2high groups exhibited the best and worst disease-free survival (DFS), respectively, whereas the patients in the FOXF2high/FOXC2high and FOXF2low/FOXC2low groups exhibited moderate DFS. In summary, we found that FOXF2 transcriptionally targets FOXC2 and suppresses EMT and multidrug resistance by negatively regulating the transcription of FOXC2 in BLBC cells. The combined expression levels of FOXF2 and FOXC2 mRNA might serve as an effective prognostic indicator and could guide tailored therapy for TNBC or BLBC patients.

DNA Methylation Affects the SP1-regulated Transcription of FOXF2 in Breast Cancer Cells.

FOXF2 (forkhead box F2) is a mesenchyme-specific transcription factor that plays a critical role in tissue homeostasis through the maintenance of epithelial polarity. In a previous study, we demonstrated that FOXF2 is specifically expressed in basal-like breast cancer (BLBC) cells and functions as an epithelial-mesenchymal transition suppressor. FOXF2 deficiency enhances the metastatic ability of BLBC cells through activation of the epithelial-mesenchymal transition program, but reduces cell proliferation. In this study, we demonstrate that CpG island methylation of the FOXF2 proximal promoter region is involved in the regulatory mechanism of the subtype-specific expression of FOXF2 in breast cancer cells. DNMT1, DNMT3A, and DNMT3B commonly or individually contributed to this DNA methylation in different breast cancer cells. SP1 regulated the transcriptional activity of FOXF2 through direct binding to the proximal promoter region, whereas this binding was abrogated through DNA methylation. FOXF2 mediated the SP1-regulated suppression of progression and promotion of proliferation of non-methylated BLBC cells. Thus, we conclude that the subtype-specific expression and function of FOXF2 in breast cancer cells are regulated through the combined effects of DNA methylation and SP1 transcriptional regulation.

ITGBL1 Is a Runx2 Transcriptional Target and Promotes Breast Cancer Bone Metastasis by Activating the TGFß Signaling Pathway.

Bone metastasis affects more than 70% of advanced breast cancer patients, but the molecular mechanisms of this process remain unclear. Here, we present clinical and experimental evidence to clarify the role of the integrin ß-like 1 (ITGBL1) as a key contributor to bone metastasis of breast cancer. In an in vivo model system and in vitro experiments, ITGBL1 expression promoted formation of osteomimetic breast cancers, facilitating recruitment, residence, and growth of cancer cells in bone microenvironment along with osteoclast maturation there to form osteolytic lesions. Mechanistic investigations identified the TGFß signaling pathway as a downstream effector of ITGBL1 and the transcription factor Runx2 as an upstream activator of ITGBL1 expression. In support of these findings, we also found that ITGBL1 was an essential mediator of Runx2-induced bone metastasis of breast cancer. Overall, our results illuminate how bone metastasis occurs in breast cancer, and they provide functional evidence for new candidate biomarkers and therapeutic targets to identify risk, to prevent, and to treat this dismal feature of advanced breast cancer.

FOXF2 deficiency promotes epithelial-mesenchymal transition and metastasis of basal-like breast cancer.

INTRODUCTION: Our previous clinical study demonstrated that the under-expression of FOXF2 is associated with early-onset metastasis and poor prognosis of patients with triple-negative breast cancer. In this study, we further characterized the role of FOXF2 in metastasis of basal-like breast cancer (BLBC) and underlying molecular mechanisms. METHODS: RT-qPCR, immunoblot, immunofluorescence and immunohistochemistry were performed to assess the expression of genes and proteins in cell lines and tissues. A series of in vitro and in vivo assays was performed in the cells with RNAi-mediated knockdown or overexpression to elucidate the function and transcriptional regulatory role of FOXF2 in breast cancer. RESULTS: We found that FOXF2 was specifically expressed in most basal-like breast cells. FOXF2 deficiency enhanced the metastatic ability of BLBC cells in vitro and in vivo. Additionally, FOXF2 deficiency induced the epithelial-mesenchymal transition (EMT) of basal-like breast cells. Furthermore, we identified that TWIST1 is a transcriptional target of FOXF2. TWIST1 was negatively regulated by FOXF2 and mediated the FOXF2-regulated EMT phenotype of basal-like breast cells and aggressive property of BLBC. CONCLUSIONS: FOXF2 is a novel EMT-suppressing transcription factor in BLBC. FOXF2 deficiency enhances metastatic ability of BLBC cells by activating the EMT program through upregulating the transcription of TWIST1.