Rhaponticin decreases the metastatic and angiogenic abilities of cancer cells via suppression of the HIF‑1α pathway

Rhaponticin suppresses the stemness phenotype of gastric cancer stem-like cells CD133+/CD166 + by inhibiting programmed death-ligand 1

BACKGROUND

Gastric cancer stem cells (GCSCs) are key contributors to tumorigenesis, recurrence and metastasis, complicating gastric cancer (GC) treatment. Rhaponticin (RA), a potential novel anticancer drug, has unexplored effects on GCSCs.

METHODS

GCSCs were isolated using CD133 and CD166 markers with magnetic bead separation method and then evaluated their response to the IC50 concentrations of RA (16.90 µg/mL for BGC-823 and 22.18 µg/mL for SGC-7901), and effects on cell proliferation, migration, invasion, and stemness were measured. We analyzed the GCSC-related microarray dataset GSE111556 and explored RA's role in restoring programmed cell death ligand 1 (PD-L1) function in CD133+/CD166 + cells post-PD-L1 knockdown. RA's impact on tumour growth and immune microenvironment was assessed in a xenograft mouse model.

RESULTS

The CD133+/CD166 + subpopulation exhibited stem-like characteristics, with the highest proportion in BGC-823 (38.85%) and SGC-7901 (43.81%) cells. These cells formed tumour spheres and had increased expression of stemness markers Sox2 and Oct-4 (compared to the parental cell line, P < 0.001). RA treatment showed no toxicity to normal GES-1 cells but reduced the viability of CD133+/CD166 + cells in a dose-dependent manner, with IC50 values of 16.90 µg/ml for BGC-823 and 22.18 µg/ml for SGC-7901. RA also decreased the proportion of CD133+/CD166 + cells and their stem-like properties (P < 0.001). Analysis of the GEO database identified PD-L1 as a key target gene of RA, with high expression in GC tissues. Knocking down PD-L1 in CD133+/CD166 + cells and introducing RA did not significantly change PD-L1 expression (P>0.05), suggesting RA's effect may be PD-L1 dependent. In a xenograft mouse model, the tumour size in the RA treatment group was approximately one-sixth that of the CD133+/CD166 + group (P < 0.001). Post-RA treatment, there was an elevation in the expression levels of CD4 and CD8, alongside a reduction in PD-L1 expression (P < 0.001).

CONCLUSIONS

RA suppresses GCSC stem - like phenotype by inhibiting PD - L1 and enhancing T cell tumour infiltration in the studied models. These findings suggest that RA may have potential for further exploration as a candidate for GC treatment, but extensive preclinical and clinical studies are required to determine its true therapeutic value.

Identification of PIMREG as a novel prognostic signature in breast cancer via integrated bioinformatics analysis and experimental validation

Background

Phosphatidylinositol binding clathrin assembly protein interacting mitotic regulator (PIMREG) expression is upregulated in a variety of cancers. However, its potential role in breast cancer (BC) remains uncertain.

Methods

The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were used to gather relevant information. The expression of PIMREG and its clinical implication in BC were assessed by using Wilcoxon rank-sum test. The prognostic value of PIMREG in BC was evaluated through the Cox regression model and nomogram, and visualized by Kaplan-Meier survival curves. Genes/proteins that interact with PIMREG in BC were also identified through GeneMANIA and MaxLink. Gene set enrichment analysis (GSEA) was then performed. The correlations of the immune cell infiltration and immune checkpoints with the expression of PIMREG in BC were explored via TIMER, TISIDB, and GEPIA. Potential drugs that interact with PIMREG in BC were explored via Q-omic. The siRNA transfection, CCK-8, and transwell migration assay were conducted to explore the function of PIMREG in cell proliferation and migration.

Results

PIMREG expression was significantly higher in infiltrating ductal carcinoma, estrogen receptor negative BC, and progestin receptor negative BC. High expression of PIMREG was associated with poor overall survival, disease-specific survival, and progression-free interval. A nomogram based on PIMREG was developed with a satisfactory prognostic value. PIMREG also had a high diagnostic ability, with an area under the curve of 0.940. Its correlations with several immunomodulators were also observed. Immune checkpoint CTLA-4 was significantly positively associated with PIMREG. HDAC2 was found as a potentially critical link between PIMREG and BRCA1/2. In addition, PIMREG knockdown could inhibit cell proliferation and migration in BC.

Conclusions

The high expression of PIMREG is associated with poor prognosis and immune checkpoints in BC. HDAC2 may be a critical link between PIMREG and BRCA1/2, potentially a therapeutic target.

Targeting hypoxia-inducible factors for breast cancer therapy: A narrative review

Hypoxia-inducible factors (HIFs), central regulators for cells to adapt to low cellular oxygen levels, are often overexpressed and activated in breast cancer. HIFs modulate the primary transcriptional response of downstream pathways and target genes in response to hypoxia, including glycolysis, angiogenesis and metastasis. They can promote the development of breast cancer and are associated with poor prognosis of breast cancer patients by regulating cancer processes closely related to tumor invasion, metastasis and drug resistance. Thus, specific targeting of HIFs may improve the efficiency of cancer therapy. In this review, we summarize the advances in HIF-related molecular mechanisms and clinical and preclinical studies of drugs targeting HIFs in breast cancer. Given the rapid progression in this field and nanotechnology, drug delivery systems (DDSs) for HIF targeting are increasingly being developed. Therefore, we highlight the HIF related DDS, including liposomes, polymers, metal-based or carbon-based nanoparticles.

Microvascular Experimentation in the Chick Chorioallantoic Membrane as a Model for Screening Angiogenic Agents including from Gene-Modified Cells

The chick chorioallantoic membrane (CAM) assay model of angiogenesis has been highlighted as a relatively quick, low cost and effective model for the study of pro-angiogenic and anti-angiogenic factors. The chick CAM is a highly vascularised extraembryonic membrane which functions for gas exchange, nutrient exchange and waste removal for the growing chick embryo. It is beneficial as it can function as a treatment screening tool, which bridges the gap between cell based in vitro studies and in vivo animal experimentation. In this review, we explore the benefits and drawbacks of the CAM assay to study microcirculation, by the investigation of each distinct stage of the CAM assay procedure, including cultivation techniques, treatment applications and methods of determining an angiogenic response using this assay. We detail the angiogenic effect of treatments, including drugs, metabolites, genes and cells used in conjunction with the CAM assay, while also highlighting the testing of genetically modified cells. We also present a detailed exploration of the advantages and limitations of different CAM analysis techniques, including visual assessment, histological and molecular analysis along with vascular casting methods and live blood flow observations.

Mechanism Analysis of Antiangiogenic d-Isofloridoside from Marine Edible Red algae Laurencia undulata in HUVEC and HT1080 cell

Laurencia undulata, as one of the most biologically active species in the genus Laurencia, is an edible folk herb red algae. Among them, d-isofloridoside (DIF, 940.68 Da) is isolated from Laurencia undulata, which has antioxidant and matrix metalloproteinases (MMP) inhibitory activities. However, its mechanism of action on tumor angiogenesis has not yet been reported. In this study, we have studied the mechanism of DIF on tumor metastasis and angiogenesis in HT1080 cell and human vascular endothelial cell (HUVEC). The results show that DIF can reduce the activity of MMP-2/9, and can inhibit the expression of hypoxia-inducible factor-1α (HIF-1α) by regulating the downstream PI3K/AKT and mitogen-activated protein kinases (MAPK) pathways, thereby down-regulating the production of vascular endothelial growth factor (VEGF) in CoCl₂-induced HT1080 cell. In addition, DIF can inhibit the activation of VEGF receptor (VEGFR-2), regulate downstream PI3K/AKT, MAPK, nuclear factor-kappa B (NF-κB) signal pathways, activate apoptosis, and thus down-regulate the production of platelet-derived growth factor (PDGF) in VEGF-induced HUVEC. In conclusion, our research shows that DIF has the potential to develop into a tumor-preventing functional food and tumor angiogenesis inhibitor, and it can provide theoretical guidance for the high-value comprehensive utilization of edible red algae Laurencia undulata.

Inhibitory Effects of Rhaponticin on Osteoclast Formation and Resorption by Targeting RANKL-Induced NFATc1 and ROS Activity

The extravagant osteoclast formation and resorption is the main cause of osteoporosis. Inhibiting the hyperactive osteoclastic resorption is considered as an efficient treatment for osteoporosis. Rhaponticin (RH) is a small molecule that has been reported to possess anti-inflammatory, anti-allergic, anti-fibrotic, and anti-diabetic activities. However, the influence of RH on osteoclasts differentiation and function is still unclear. To this end, an array of assays including receptor activator of nuclear factor kappa-Β (NF-κB) ligand (RANKL) induced osteoclastogenesis, tartrate-resistant acidic phosphatase (TRAcP) staining, immunofluorescence, and hydroxyapatite resorption were performed in this study. It was found that RH had significant anti-catabolic effects by inhibiting osteoclastogenesis and bone resorption without cytotoxicity. Mechanistically, the expression of NADPH oxidase 1 (Nox1) was found to be suppressed and antioxidant enzymes including catalase, superoxide dismutase 2 (SOD-2), and heme oxygenase-1(HO-1) were enhanced following RH treatment, suggesting RH exhibited antioxidant activity by reducing the generation of reactive oxygen species (ROS) as well as enhancing the depletion of ROS. In addition, MAPKs, NF-κB, and intracellular Ca2+ oscillation pathways were significantly inhibited by RH. These changes led to the deactivation of osteoclast master transcriptional factor-nuclear factor of activated T cells 1 (NFATc1), as examined by qPCR and Western blot assay, which led to the decreased expression of downstream integrin β3, c-Fos, cathepsin K, and Atp6v0d2. These results suggested that RH could effectively suppress RANKL-regulated osteoclast formation and bone resorption. Therefore, we propose that RH can represent a novel natural small molecule for the treatment of osteoporosis by inhibiting excessive osteoclast activity.

Anti-Cancer Activity of Phytochemicals Targeting Hypoxia-Inducible Factor-1 Alpha

Hypoxia-inducible factor-1 alpha (HIF-1α) is overexpressed in cancer, leading to a poor prognosis in patients. Diverse cellular factors are able to regulate HIF-1α expression in hypoxia and even in non-hypoxic conditions, affecting its progression and malignant characteristics by regulating the expression of the HIF-1α target genes that are involved in cell survival, angiogenesis, metabolism, therapeutic resistance, et cetera. Numerous studies have exhibited the anti-cancer effect of HIF-1α inhibition itself and the augmentation of anti-cancer treatment efficacy by interfering with HIF-1α-mediated signaling. The anti-cancer effect of plant-derived phytochemicals has been evaluated, and they have been found to possess significant therapeutic potentials against numerous cancer types. A better understanding of phytochemicals is indispensable for establishing advanced strategies for cancer therapy. This article reviews the anti-cancer effect of phytochemicals in connection with HIF-1α regulation.

The prognostic outcome of 'type 2 diabetes mellitus and breast cancer' association pivots on hypoxia-hyperglycemia axis

Type 2 diabetes mellitus and breast cancer are complex, chronic, heterogeneous, and multi-factorial diseases; with common risk factors including but not limited to diet, obesity, and age. They also share mutually inclusive phenotypic features such as the metabolic deregulations resulting from hyperglycemia, hypoxic conditions and hormonal imbalances. Although, the association between diabetes and cancer has long been speculated; however, the exact molecular nature of this link remains to be fully elucidated. Both the diseases are leading causes of death worldwide and a causal relationship between the two if not addressed, may translate into a major global health concern. Previous studies have hypothesized hyperglycemia, hyperinsulinemia, hormonal imbalances and chronic inflammation, as some of the possible grounds for explaining how diabetes may lead to cancer initiation, yet further research still needs to be done to validate these proposed mechanisms. At the crux of this dilemma, hyperglycemia and hypoxia are two intimately related states involving an intricate level of crosstalk and hypoxia inducible factor 1, at the center of this, plays a key role in mediating an aggressive disease state, particularly in solid tumors such as breast cancer. Subsequently, elucidating the role of HIF1 in establishing the diabetes-breast cancer link on hypoxia-hyperglycemia axis may not only provide an insight into the molecular mechanisms underlying the association but also, illuminate on the prognostic outcome of the therapeutic targeting of HIF1 signaling in diabetic patients with breast cancer or vice versa. Hence, this review highlights the critical role of HIF1 signaling in patients with both T2DM and breast cancer, potentiates its significance as a prognostic marker in comorbid patients, and further discusses the potential prognostic outcome of targeting HIF1, subsequently establishing the pressing need for HIF1 molecular profiling-based patient selection leading to more effective therapeutic strategies emerging from personalized medicine.

Rhaponticin suppresses osteosarcoma through the inhibition of PI3K-Akt-mTOR pathway

Osteosarcoma is the frequent pediatric bone cancer where pediatric osteosarcoma incidences are more than 10% within the population. Most of the patients with osteosarcoma fall within the age of 15-30 years. Therefore, in this research, we examined the anticancer effect of Rhaponticin against the human osteosarcoma (MG-63) cells. The cytotoxicity of Rhaponticin on the MC3T3-E1 and MG-63 cells was examined through the MTT assay. The intracellular ROS accumulation, cell nuclear morphological alterations, apoptotic cell death and nuclear damages, and MMP status of Rhaponticin administered MG-63 cells were inspected by fluorescent staining techniques. The cell migration was assessed through scratch assay. The mRNA expressions of PI3K-Akt-mTOR signaling proteins were studied by RT-PCR analysis. Rhaponticin showed potent cytotoxicity, substantially inhibited the MG-63 cell growth, and displayed morphological alterations. However, rhaponticin did not affect the MC3T3-E1 cell viability. Rhaponticin administered MG-63 cells demonstrated augmented intracellular ROS accretion, weakened MMP, increased nuclear damages, and increased apoptosis. Rhaponticin effectively down-regulated the PI3K-Akt-mTOR signaling cascade in the MG-63 cells. These outcomes proved that the Rhaponticin can be a hopeful chemotherapeutic agent in the future to treat human osteosarcoma.

Anticancer and immunomodulatory effect of rhaponticin on Benzo(a)Pyrene-induced lung carcinogenesis and induction of apoptosis in A549 cells

In worldwide, one of the most important cancer-related death is lung cancer. Also has the highest mortality rate between various cancer types. The count of lung cancer occurrence is increasing with an increased frequency by smoking. Proficient chemoprevention approaches are needed to prevent the occurrence of lung cancer. Therefore, the aim of this exploration is to determine the therapeutic impact on the immune modulatory effect of rhaponticin on lung tumorigenesis in vivo and in vitro cytotoxicity effect in A549 cells of human lung cancer. Lung cancer tumorigenesis in mice was challenged with benzo(a)pyrene (BaP) with 50 mg/kg bodyweight (b.wt) as oral administration for 6 weeks (two times/week). Rhaponticin were given orally 30 mg/kg b.wt (two times/week) in BaP induced mice from 12 weeks to 18 weeks. After treatment completes, the body weight was measured and then blood, lung tissue was collected for various parameters detection. The results evidenced that BaP induced mice decreased the bodyweight, increased lung weight, increased tumor markers (AHH, CEA and LDH), and increased the proinflammatory cytokines. The enzyme catalase, superoxide dismutase activity was decreased and increased lipid peroxidation in immune comprising cells compared with the control cells. Moreover, rhaponticin treatment improves in chemical assays and also the histopathological alteration of lung tissues. The present findings provide evidence about the therapeutic potentials of rhaponticin against BaP triggered lung tumorigenesis.

Role of the HIF‑1α/SDF‑1/CXCR4 signaling axis in accelerated fracture healing after craniocerebral injury

The hypoxic state of the brain tissue surrounding craniocerebral injury induces an increase in the secretion of HIF-1α during the healing process. HIF-1α can promote mesenchymal stem cell (MSC) migration to ischemic and hypoxic sites by regulating the expression levels of molecules such as stromal cell-derived factor-1 (SDF-1) in the microenvironment. Stem cells express the SDF-1 receptor C-X-C chemokine receptor type 4 (CXCR4) and serve a key role in tissue repair, as well as a number of physiological and pathological processes. The present study aimed to determine the role of HIF-1α/SDF-1/CXCR4 signaling in the process of accelerated fracture healing during craniocerebral injury. Cultured MSCs underwent HIF-1α knockdown to elucidate its effect on the proliferative ability of MSCs, and the effect of SDF-1 in MSCs was investigated. It was also determined whether HIF-1α could promote osteogenesis via SDF-1/CXCR4 signaling and recruit MSCs. The results indicated that HIF-1α knockdown suppressed MSC proliferation in vitro, and SDF-1 promoted cell migration via binding to CXCR4. Furthermore, HIF-1α knockdown inhibited MSC migration via SDF-1/CXCR4 signaling. Considering the wide distribution and diversity of roles of SDF-1 and CXCR4, the present results may form a basis for the development of novel strategies for the treatment of craniocerebral injury.

β‑elemene inhibits the generation of peritoneum effusion in pancreatic cancer via suppression of the HIF1A‑VEGFA pathway based on network pharmacology

Pancreatic cancer remains one of the most lethal types of cancer. Late-stage pancreatic cancer patients usually suffer peritoneum effusion, which severely compromises quality of life. Great efforts have been made concerning the treatment of peritoneum effusion, including treatment with β-elemene. Although peritoneal perfusion of β-elemene attenuates the progression of malignant effusion without severe adverse effects in the clinic, the underlying molecular mechanism underlying the activity of β-elemene against peritoneum effusion remains unclear. In the present study, a network pharmacology approach was undertaken to explore the mechanism of β-elemene against peritoneum effusion. Particularly, the networks of β-elemene and pancreatic cancer target genes were constructed based on the BATMAN-TCM and DigSee databases, respectively. Thirty-three genes, including hypoxia inducible factor 1 subunit α (HIF1A), were discovered in both networks. A potential interaction of β-elemene with HIF1A was revealed by molecular docking simulation and co-expression analysis of pancreatic cancer datasets from The Cancer Genome Atlas (TCGA) database. Additionally, experimental validation by MTT assay demonstrated that β-elemene suppressed proliferation of PANC-1 and BxPC3 cells and cells from peritoneum effusion in patients with pancreatic cancer. Furthermore, the protein expression levels of HIF1A and vascular endothelial growth factor A (VEGFA), as detected by western blotting, were reduced by β-elemene. Overall, this study proposes a potential molecular mechanism illustrating that β-elemene can block the HIF1A/VEGFA pathway, thereby inhibiting the generation of peritoneum effusion in pancreatic cancer based on network pharmacology analysis, and further highlights the importance of targeting the HIF1A/VEGF pathway as a therapeutic approach to treat peritoneum effusion in patients with pancreatic cancer.

Identification of hepatitis B virus and liver cancer bridge molecules based on functional module network

BACKGROUND

The potential role of chronic inflammation in the development of cancer has been widely recognized. However, there has been little research fully and thoroughly exploring the molecular link between hepatitis B virus (HBV) and hepatocellular carcinoma (HCC).

AIM

To elucidate the molecular links between HBV and HCC through analyzing the molecular processes of HBV-HCC using a multidimensional approach.

METHODS

First, maladjusted genes shared between HBV and HCC were identified by disease-related differentially expressed genes. Second, the protein-protein interaction network based on dysfunctional genes identified a series of dysfunctional modules and significant crosstalk between modules based on the hypergeometric test. In addition, key regulators were detected by pivot analysis. Finally, targeted drugs that have regulatory effects on diseases were predicted by modular methods and drug target information.

RESULTS

The study found that 67 genes continued to increase in the HBV-HCC process. Moreover, 366 overlapping genes in the module network participated in multiple functional blocks. It could be presumed that these genes and their interactions play an important role in the relationship between inflammation and cancer. Correspondingly, significant crosstalk constructed a module level bridge for HBV-HCC molecular processes. On the other hand, a series of non-coding RNAs and transcription factors that have potential pivot regulatory effects on HBV and HCC were identified. Among them, some of the regulators also had persistent disorders in the process of HBV-HCC including microRNA-192, microRNA-215, and microRNA-874, and early growth response 2, FOS, and Kruppel-like factor 4. Therefore, the study concluded that these pivots are the key bridge molecules outside the module. Last but not least, a variety of drugs that may have some potential pharmacological or toxic side effects on HBV-induced HCC were predicted, but their mechanisms still need to be further explored.

CONCLUSION

The results suggest that the persistent inflammatory environment of HBV can be utilized as an important risk factor to induce the occurrence of HCC, which is supported by molecular evidence.

Dual Effects of Chinese Herbal Medicines on Angiogenesis in Cancer and Ischemic Stroke Treatments: Role of HIF-1 Network

Hypoxia-inducible factor-1 (HIF-1)–induced angiogenesis has been involved in numerous pathological conditions, and it may be harmful or beneficial depending on the types of diseases. Exploration on angiogenesis has sparked hopes in providing novel therapeutic approaches on multiple diseases with high mortality rates, such as cancer and ischemic stroke. The HIF-1 pathway is considered to be a major regulator of angiogenesis. HIF-1 seems to be involved in the vascular formation process by synergistic correlations with other proangiogenic factors in cancer and cerebrovascular disease. The regulation of HIF-1–dependent angiogenesis is related to the modulation of HIF-1 bioactivity by regulating HIF-1α transcription or protein translation, HIF-1α DNA binding, HIF-1α and HIF-1α dimerization, and HIF-1 degradation. Traditional Chinese herbal medicines have a long history of clinical use in both cancer and stroke treatments in Asia. Growing evidence has demonstrated potential proangiogenic benefits of Chinese herbal medicines in ischemic stroke, whereas tumor angiogenesis could be inhibited by the active components in Chinese herbal medicines. The objective of this review is to provide comprehensive insight on the effects of Chinese herbal medicines on angiogenesis by regulating HIF-1 pathways in both cancer and ischemic stroke.

Arsenic Trioxide Inhibits the Metastasis of Small Cell Lung Cancer by Blocking Calcineurin-Nuclear Factor of Activated T Cells (NFAT) Signaling

BACKGROUND The inhibitory effect of arsenic trioxide (As₂O₃) on lung cancer has been reported in some preclinical studies. However, its effect on small cell lung cancer (SCLC) has been poorly explored. Calcineurin and its substrate, nuclear factor of activated T cells (NFAT), mediate the downstream signaling of VEGF, and is critical in the process endothelium activation and tumor metastasis. In this study, we aimed to evaluate whether As₂O₃ had inhibitory effects on endothelial cells activation and the metastasis of SCLC, and to explore the possible mechanisms. MATERIAL AND METHODS In vitro, human umbilical vein endothelial cells (HUVECs) were used. Cell Counting Kit-8 assay and cell migration assay were performed to determine the effect of As₂O₃ on HUVECs proliferation and migration. The level of calcineurin, NFAT, downstream factors for Down syndrome candidate region 1 (DSCR1), and the endogenous inhibitor of calcineurin, were evaluated by quantitative PCR and western blotting. In vivo, SCLC metastasis models were established by injecting NCI-H446 cells into tail veins of nude mice. Tumor-bearing mice were treated with As₂O₃ or calcineurin inhibitor for 10 days, after which tumor metastasis in target organs was evaluated. RESULTS As₂O₃ significantly inhibited the proliferation and migration of endothelial cells. Also, As₂O₃ inhibited the expression levels of calcineurin, NFAT, and the downstream target genes CXCR7 and RND1, while it upregulated the level of DSCR1. Both As₂O₃ and calcineurin inhibitor exhibited notable inhibitory effect on the metastasis of SCLC, without obvious side effects. CONCLUSIONS These findings suggested that As₂O₃ had remarkable inhibitory effects on the endothelial cell activation and SCLC metastasis, and the mechanism might be related to the blocking of calcineurin-NFAT signaling by upregulating DSCR1.

The inhibitive effect of sh-HIF1A-AS2 on the proliferation, invasion, and pathological damage of breast cancer via targeting miR-548c-3p through regulating HIF-1α/VEGF pathway in vitro and vivo

Background

Breast cancer (BC) has been the commonest malignant tumor with a low survival rate among woman. Long non-coding RNA hypoxia-inducible factor-1 alpha antisense RNA-2 (HIF1A-AS2) was correlated with various cancers.

Purpose

The study aimed to investigate the roles and related underlying molecular mechanisms of HIF1A-AS2 in BC.

Material and methods

Target relationships were speculated by Targetscan 7.0 and confirmed by dual luciferase reporter assay. Proteins levels were monitored by RT-qPCR, Western blot and immunohistochemistry assays. CCK-8 assay, SA-β-gal staining and transwell assay were used to detect proliferation, senescence and invasion, respectively. Xenograft nude mice were put into use to evaluate the tumor growth and motility.

Results

The present study exhibited that HIF1A-AS2 and hypoxia-inducible factor-1 alpha (HIF-1α) were upregulated while miR-548c-3p was downregulated in MDA-MB-231, MCF-7, ZR-75-1, and BT-549 BC cell lines. Bioinformatics analysis showed HIF1A-AS2 and HIF-1α were two targets of miR-548c-3p, and the target relationship was further confirmed by dual luciferase reporter assay. Moreover, knockdown of HIF1A-AS2 by shRNA (sh-HIF1A-AS2) markedly elevated miR-548c-3p level, and the enhanced miR-548c-3p noticeably suppressed cell proliferation, invasion, and epithelial–mesenchymal transition, and promoted senescence in vitro. In addition, overexpression of HIF-1α promoted MCF-7 cell invasion. Intriguingly, low expression of HIF1A-AS2 reduced HIF-1α level by upregulating the expression of miR-548c-3p. Furthermore, experiment in xenograft nude mice has indicated that sh-HIF1A-AS2 inhibited tumor growth and motility by targeting miR-548c-3p through regulating HIF-1α/vascular endothelial growth factor (VEGF) pathway in vivo.

Conclusion

The inhibitive effect of HIF-1α/VEGF pathway by sh-HIF1A-AS2 through targeting miR-548c-3p plays crucial regulatory roles in BC. Therefore, designing targeted drugs against HIF1A-AS2 provides a new direction for the treatment of BC.