Inhibition of the Interleukin-11-STAT3 Axis Attenuates Hypoxia-Induced Migration and Invasion in MDA-MB-231 Breast Cancer Cells

Potential therapeutic targets of the JAK2/STAT3 signaling pathway in triple-negative breast cancer

Triple-negative breast cancer (TNBC) poses a significant clinical challenge due to its propensity for metastasis and poor prognosis. TNBC evades the body's immune system recognition and attack through various mechanisms, including the Janus Kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. This pathway, characterized by heightened activity in numerous solid tumors, exhibits pronounced activation in specific TNBC subtypes. Consequently, targeting the JAK2/STAT3 signaling pathway emerges as a promising and precise therapeutic strategy for TNBC. The signal transduction cascade of the JAK2/STAT3 pathway predominantly involves receptor tyrosine kinases, the tyrosine kinase JAK2, and the transcription factor STAT3. Ongoing preclinical studies and clinical research are actively investigating this pathway as a potential therapeutic target for TNBC treatment. This article comprehensively reviews preclinical and clinical investigations into TNBC treatment by targeting the JAK2/STAT3 signaling pathway using small molecule compounds. The review explores the role of the JAK2/STAT3 pathway in TNBC therapeutics, evaluating the benefits and limitations of active inhibitors and proteolysis-targeting chimeras in TNBC treatment. The aim is to facilitate the development of novel small-molecule compounds that target TNBC effectively. Ultimately, this work seeks to contribute to enhancing therapeutic efficacy for patients with TNBC.

Interleukin-11/IL-11 Receptor Promotes Glioblastoma Cell Proliferation, Epithelial-Mesenchymal Transition, and Invasion

Glioblastoma is highly proliferative and invasive. However, the regulatory cytokine networks that promote glioblastoma cell proliferation and invasion into other areas of the brain are not fully defined. In the present study, we define a critical role for the IL-11/IL-11Rα signalling axis in glioblastoma proliferation, epithelial to mesenchymal transition, and invasion. We identified enhanced IL-11/IL-11Rα expression correlated with reduced overall survival in glioblastoma patients using TCGA datasets. Proteomic analysis of glioblastoma cell lines overexpressing IL-11Rα displayed a proteome that favoured enhanced proliferation and invasion. These cells also displayed greater proliferation and migration, while the knockdown of IL-11Rα reversed these tumourigenic characteristics. In addition, these IL-11Rα overexpressing cells displayed enhanced invasion in transwell invasion assays and in 3D spheroid invasion assays, while knockdown of IL-11Rα resulted in reduced invasion. Furthermore, IL-11Rα-overexpressing cells displayed a more mesenchymal-like phenotype compared to parental cells and expressed greater levels of the mesenchymal marker Vimentin. Overall, our study identified that the IL-11/IL-11Rα pathway promotes glioblastoma cell proliferation, EMT, and invasion.

Tumor-derived cell-free DNA and circulating tumor cells: partners or rivals in metastasis formation?

The origin of metastases is a topic that has sparked controversy. Despite recent advancements, metastatic disease continues to pose challenges. The first admitted model of how metastases develop revolves around cells breaking away from the primary tumor, known as circulating tumor cells (CTCs). These cells survive while circulating through the bloodstream and subsequently establish themselves in secondary organs, a process often referred to as the "metastatic cascade". This intricate and dynamic process involves various steps, but all the mechanisms behind metastatic dissemination are not yet comprehensively elucidated. The "seed and soil" theory has shed light on the phenomenon of metastatic organotropism and the existence of pre-metastatic niches. It is now established that these niches can be primed by factors secreted by the primary tumor before the arrival of CTCs. In particular, exosomes have been identified as important contributors to this priming. Another concept then emerged, i.e. the "genometastasis" theory, which challenged all other postulates. It emphasizes the intriguing but promising role of cell-free DNA (cfDNA) in metastasis formation through oncogenic formation of recipient cells. However, it cannot be ruled out that all these theories are intertwined. This review outlines the primary theories regarding the metastases formation that involve CTCs, and depicts cfDNA, a potential second player in the metastasis formation. We discuss the potential interrelationships between CTCs and cfDNA, and propose both in vitro and in vivo experimental strategies to explore all plausible theories.

STAT3 Signaling in Breast Cancer: Multicellular Actions and Therapeutic Potential

Simple Summary

Many signaling pathways are overactive in breast cancer, and among them is the STAT3 signaling pathway. STAT3 is activated by secreted factors within the breast tumor, many of which are elevated and correlate to advanced disease and poor survival outcomes. This review examines how STAT3 signaling is activated in breast cancer by the proinflammatory, gp130 cytokines, interleukins 6 and 11. We evaluate how this signaling cascade functions in the various cells of the tumor microenvironment to drive disease progression and metastasis. We discuss how our understanding of these processes may lead to the development of novel therapeutics to tackle advanced disease.

Abstract

Interleukin (IL)-6 family cytokines, such as IL-6 and IL-11, are defined by the shared use of the gp130 receptor for the downstream activation of STAT3 signaling and the activation of genes which contribute to the “hallmarks of cancer”, including proliferation, survival, invasion and metastasis. Increased expression of these cytokines, or the ligand-specific receptors IL-6R and IL-11RA, in breast tumors positively correlate to disease progression and poorer patient outcome. In this review, we examine evidence from pre-clinical studies that correlate enhanced IL-6 and IL-11 mediated gp130/STAT3 signaling to the progression of breast cancer. Key processes by which the IL-6 family cytokines contribute to the heterogeneous nature of breast cancer, immune evasion and metastatic potential, are discussed. We examine the latest research into the therapeutic targeting of IL-6 family cytokines that inhibit STAT3 transcriptional activity as a potential breast cancer treatment, including current clinical trials. The importance of the IL-6 family of cytokines in cellular processes that promote the development and progression of breast cancer warrants further understanding of the molecular basis for its actions to help guide the development of future therapeutic targets.

Interleukin 11 (IL-11): Role(s) in Breast Cancer Bone Metastases

Bone metastases represent the main problem related to the progression of breast cancer, as they are the main cause of death for these patients. Unfortunately, to date, bone metastases are incurable and represent the main challenge for the researcher. Chemokines and cytokines affect different stages of the metastatic process, and in bone metastases, interleukin (IL) -6, IL-8, IL-1β, and IL-11 participate in the interaction between cancer cells and bone cells. This review focuses on IL-11, a pleiotropic cytokine that, in addition to its well-known effects on several tissues, also mediates certain signals in cancer cells. In particular, as IL-11 works on bone remodeling, it plays a relevant role in the osteolytic vicious cycle of bone resorption and tumour growth, which characterizes bone metastasis. IL-11 appears as a candidate for anti-metastatic therapy. Even if different therapeutic approaches have considered IL-11 and the downstream-activated gp130 signaling pathways activated downstream of gp130, further studies are needed to decipher the contribution of the different cytokines and their mechanisms of action in breast cancer progression to define therapeutic strategies.

Targeting TRAF3IP2, Compared to Rab27, is More Effective in Suppressing the Development and Metastasis of Breast Cancer

Here we investigated the roles of Rab27a, a player in exosome release, and TRAF3IP2, an inflammatory mediator, in development and metastasis of breast cancer (BC) in vivo. Knockdown (KD) of Rab27a (MDA_KDRab27a) or TRAF3IP2 (MDA_KDTRAF3IP2) in triple negative MDA-MB231 cells reduced tumor growth by 70-97% compared to wild-type tumors (MDA_w). While metastasis was detected in MDA_w-injected animals, none was detected in MDA_KDRab27a- or MDA_KDTRAF3IP2-injected animals. Interestingly, micrometastasis was detected only in the MDA_KDRab27a-injected group. In addition to inhibiting tumor growth and metastasis, silencing TRAF3IP2 disrupted inter-cellular inflammatory mediator-mediated communication with mesenchymal stem cells (MSCs) injected into contralateral mammary gland, evidenced by the lack of tumor growth at MSC-injected site. Of translational significance, treatment of pre-formed MDA_w-tumors with a lentiviral-TRAF3IP2-shRNA not only regressed their size, but also prevented metastasis. These results demonstrate that while silencing Rab27a and TRAF3IP2 each inhibited tumor growth and metastasis, silencing TRAF3IP2 is more effective; targeting TRAF3IP2 inhibited tumor formation, regressed preformed tumors, and prevented both macro- and micrometastasis. Silencing TRAF3IP2 also blocked interaction between tumor cells and MSCs injected into the contralateral gland, as evidenced by the lack of tumor formation on MSCs injected site. These results identify TRAF3IP2 as a novel therapeutic target in BC.

Activation of STAT-3 signalling by RECK downregulation via ROS is involved in the 27-hydroxycholesterol-induced invasion in breast cancer cells

Breast cancer is an important and common tumour among women worldwide. We previously showed that 27-hydroxycholesterol (27HC) promoted the invasion and migration of breast cancer cells and activated signal transducer and activator of transcription 3 (STAT-3) signalling through reactive oxygen species (ROS). However, the regulation of STAT-3 signalling by ROS needs to be further explored. Here, we showed that 27HC caused the accumulation of cellular ROS, which upregulated matrix metalloproteinase 9 (MMP9) and increased the invasive ability of MCF7 and T47D cells. 27HC decreased the protein and mRNA levels of reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) in a time- and dose-dependent manner in MCF7 and T47D cells. RECK downregulation was mediated by 27HC-induced DNA methylation via ROS in MCF7 cells. RECK knockdown increased the activity and mRNA levels of MMP9, and promoted the invasion of MCF7 cells. We also found RECK knockdown upregulated the level of p-STAT-3 in MCF7 cells. Furthermore, overexpression of RECK attenuated 27HC-induced invasion in MCF7 cells. RECK overexpression also inhibited p-STAT-3 upregulation induced by 27HC. Collectively, the results showed that DNA methylation induced by 27HC via ROS downregulated RECK, thereby activating the STAT-3 signalling pathway. RECK could serve as a novel target mediating the effect of 27HC on breast cancer.

Role of Matrix Metalloproteinases in Angiogenesis and Cancer

During angiogenesis, new vessels emerge from existing endothelial lined vessels to promote the degradation of the vascular basement membrane and remodel the extracellular matrix (ECM), followed by endothelial cell migration, and proliferation and the new generation of matrix components. Matrix metalloproteinases (MMPs) participate in the disruption, tumor neovascularization, and subsequent metastasis while tissue inhibitors of metalloproteinases (TIMPs) downregulate the activity of these MMPs. Then, the angiogenic response can be directly or indirectly mediated by MMPs through the modulation of the balance between pro- and anti-angiogenic factors. This review analyzes recent knowledge on MMPs and their participation in angiogenesis.

miR-204-5p regulates cell proliferation, invasion, and apoptosis by targeting IL-11 in esophageal squamous cell carcinoma

Esophageal cancer (EC) is the world's eighth most common malignant neoplasm and is ranked as the sixth leading cause of death related to cancer. Aberrant microRNA (miRNA) expression has been reported to be associated with esophageal squamous cell carcinoma. However, the molecular mechanism of miR-204-5p in esophageal squamous cell carcinoma (ESCC) is not clear. Therefore, the aim of this study was to investigate the potential role of miR-204-5p in ESCC. In the present study, we found that miR-204-5p could affect ESCC proliferation, invasion, apoptosis, and cell cycle in cell and mouse models. A dual-luciferase reporter assay showed that miR-204-5p expression was negatively correlated with interleukin-11 (IL-11) expression. IL-11 overexpression reversed the suppressive effects of miR-204-5p in the cell lines. These results indicated that miR-204-5p functions as a tumor suppressor by directly targeting IL-11 in ESCC.

Tumor Cell Invasion Induced by Radiation in Balb/C Mouse is Prevented by the Cox-2 Inhibitor NS-398

Radiation stimulates the expression of inflammatory mediators known to increase cancer cell invasion. Therefore, it is important to determine whether anti-inflammatory drugs can prevent this adverse effect of radiation. Since cyclooxygenase-2 (COX-2) is a central player in the inflammatory response, we performed studies to determine whether the COX-2 inhibitor NS-398 can reduce the radiation enhancement of cancer cell invasion. Thighs of Balb/c mice treated with NS-398 were irradiated with either daily fractions of 7.5 Gy for five consecutive days or a single 30 Gy dose prior to subcutaneous injection of nonirradiated MC7-L1 mammary cancer cells. Five weeks later, tumor invasion, blood vessel permeability and interstitial volumes were assessed using magnetic resonance imaging (MRI). Matrix metalloproteinase-2 (MMP-2) was measured in tissues by zymography at 21 days postirradiation. Cancer cell invasion in the mouse thighs was increased by 12-fold after fractionated irradiations (5 × 7.5 Gy) and by 17-fold after a single 30 Gy dose of radiation. This stimulation of cancer cell invasion was accompanied by a significant increase in the interstitial volume and a higher level of the protease MMP-2. NS-398 treatment largely prevented the stimulation of cancer cell invasion, which was associated with a reduction in interstitial volume in the irradiated thighs and a complete suppression of MMP-2 stimulation. In conclusion, this animal model using MC7-L1 cells demonstrates that radiation-induced cancer cell invasion can be largely prevented with the COX-2 inhibitor NS-398.

27-Hydroxycholesterol induces invasion and migration of breast cancer cells by increasing MMP9 and generating EMT through activation of STAT-3

Breast carcinoma plays a vital role in the reasons of global women's death. ER-related invasion and migration play an important part in the development and prognosis of breast cancer. Here, we found that 27-Hydroxycholesterol (27HC) could induce epithelial-mesenchymal transition (EMT) and increase the expression of the matrix metalloproteinase 9 (MMP9) at mRNA level and the active form. Meanwhile, interestingly, we found 27HC activated signal transducer and activator of transcription 3 (STAT-3) in ER positive cells except activation of ER signaling. Furthermore, inhibition of STAT-3 by siRNA attenuated the 27HC-induced improvement of MMP9 and decreased the invasion and migration ability in MCF7 and T47D cells. In addition, 27HC could also promote MMP9, vimentin and active STAT-3 in the ER negative cells MDA-MB-231. All these results not only raise a mechanism whereby 27HC enhances the invasion and metastasis, but also is helpful to realize 27HC as a potential endogenous detrimental factor in breast tumor patients.

Constitutive activation of STAT3 in breast cancer cells: A review

Signal transducer and activator of transcription 3 (STAT3) is constitutively activated in numerous cancer types, including more than 40% of breast cancers. In contrast to tight regulation of STAT3 as a latent transcription factor in normal cells, its signaling in breast cancer oncogenesis is multifaceted. Signaling through the IL-6/JAK/STAT3 pathway initiated by the binding of IL-6 family of cytokines (i.e., IL-6 and IL-11) to their receptors have been implicated in breast cancer development. Receptors with intrinsic kinase activity such as EGFR and VEGFR directly or indirectly induce STAT3 activation in various breast cancer types. Aberrant STAT3 signaling promotes breast tumor progression through deregulation of the expression of downstream target genes which control proliferation (Bcl-2, Bcl-xL, Survivin, Cyclin D1, c-Myc and Mcl-1), angiogenesis (Hif1α and VEGF) and epithelial-mesenchymal transition (Vimentin, TWIST, MMP-9 and MMP-7). These multiple modes of STAT3 regulation therefore make it a central linking point for a multitude of signaling processes. Extensive efforts to target STAT3 activation in breast cancer had no remarkable success in the past because the highly interconnected nature of STAT3 signaling introduces lack of selectivity in pathway identification for STAT3 targeted molecular therapies or because its role in tumorigenesis may not be as critical as it was thought. This review provides a full spectrum of STAT3's involvement in breast cancer by consolidating the knowledge about its role in breast cancer development at multiple levels: its differential regulation by different receptor signaling pathways, its downstream target genes, and modification of its transcriptional activity by its coregulatory transcription factors.

Sevoflurane suppresses hypoxia-induced growth and metastasis of lung cancer cells via inhibiting hypoxia-inducible factor-1α

PURPOSE

Hypoxia promotes the progression of lung cancer cells. Unfortunately, anesthetic technique might aggravate hypoxia of lung cancer cells. Sevoflurane is a commonly used anesthetic. Its effect on hypoxia-induced aggressiveness of lung cancer cells remains unknown. The aim of the study is to investigate the effects of sevoflurane on hypoxia-induced growth and metastasis of lung cancer cells. As hypoxia-inducible factor-1α (HIF-1α) plays a pivotal role in mediating the adaptation and tolerance of cancer cells under hypoxic microenvironment, the role of HIF-1α in the effect of sevoflurane on hypoxia-induced growth and metastasis has also been elucidated.

METHODS

A549 cells were treated with normoxia, hypoxia, co-treatment of sevoflurane and hypoxia, and dimethyloxaloylglycine (DMOG, a HIF-1α agonist) for 4 h, respectively. MTT assay and colony formation assay were used to evaluate cell growth. Transwell assay was performed to detect invasion and migration ability. The protein level of HIF-1α, X-linked inhibitor of apoptosis protein (XIAP), survivin, fascin, heparanase (HPA), and p38 MAPK were determined by Western blotting.

RESULTS

Hypoxia enhanced proliferation and metastatic potential of cells. Sevoflurane could suppress hypoxia-induced growth and metastasis ability of cells. Furthermore, HIF-1α, XIAP, survivin, fascin and HPA were down-regulated significantly by the co-treatment of sevoflurane and hypoxia as compared to hypoxia treatment. DMOG abolished the inhibiting effects of sevoflurane on hypoxia-induced growth and metastasis ability of cells. In addition, sevoflurane partly reversed the increase of p38 MAPK activity that was induced by hypoxia.

CONCLUSIONS

Sevoflurane could suppress hypoxia-induced growth and metastasis of lung cancer cells, which might be associated with modulating HIF-1α and its down-stream genes. Moreover, p38 MAPK signaling pathway was involved in the regulation of HIF-1α by sevoflurane.

WITHDRAWN: Hypoxia-induced STAT3 contributes to chemoresistance and epithelial-mesenchymal transition in prostate cancer cells

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