CGI-99 promotes breast cancer metastasis via autocrine interleukin-6 signaling

A Microfluidic 3D-Tumor-Spheroid Model for the Evaluation of Targeted Therapies from Angiogenesis-Related Cytokines at the Single Spheroid Level

Angiogenesis is a key player in drug resistance to targeted therapies for breast cancer. The average expression of angiogenesis-related cytokines is widely associated with the treatments of target therapies for a population of cells or spheroids, overlooking the distinct responses for individuals. In this work, a highly integrated microfluidic platform is developed for the generation of monodisperse multicellular tumor spheroids (MTSs), drug treatments, and the measurement of cytokines for individual MTSs in a single chip. The platform allows the correlation evaluation between cytokine secretion and drug treatment at the level of individual spheroids. For validation, quantities of six representative proangiogenic cytokines are tested against treatments with four model drugs at varying times and concentrations. By applying a linear regression model, significant correlations are established between cytokine secretion and the treated drug concentration for individual spheroids. The proposed platform provides a high-throughput method for the investigation of the molecular mechanism of the cytokine response to targeted therapies and paves the way for future drug screening using predictive regression models at the single-spheroid level.

3D Tumor-Engineered Model Replicating the Osteosarcoma Stem Cell Niche and In Vivo Tumor Complexity

Osteosarcoma, among all bone sarcomas, remains a challenge despite the unwavering efforts of medical professionals and scientists. To address this, the scientific community is actively pursuing the development of three-dimensional (3D) in vitro models to faithfully replicate the heterogeneity of osteosarcoma, thereby facilitating the reliable preclinical screening of potential therapies. In this study, we present the latest advancements in engineering an in vitro 3D osteosarcoma model comprising enriched Cancer Stem Cells (CSCs) and a hybrid hydroxyapatite-based scaffold (MgHA/CoII). The improvement of the model occurred through two primary steps: (1) serial passaging of sarcospheres as the CSCs enrichment system and (2) the optimization of the structural configuration of the niche in the scaffold. Two injection-mediated approaches of sarcosphere seeding were designed and extensively characterized in vitro and in vivo Chorioallantoic Membrane (CAM) models to explore their biological properties and tumorigenic potential. The combination of the selected enriched-CSCs and custom-made seeding into the scaffold resulted in the development of 3D osteosarcoma models exhibiting tumor-like features in vitro and tumorigenic properties in vivo. The outcomes of this study offer prospects for future endeavors involving more complex systems capable of replicating specific malignant tumor behaviors (metastatic process and drug resistance), pushing the discovery of new therapeutic strategies for clinical applications.

Obesity-associated metabolic inflammation promotes triple-negative breast cancer progression through the interleukin-6/STAT3/pentraxin 3/matrix metalloproteinase 7 axis

BACKGROUND

This study aimed to investigate the regulatory mechanism of the adipose factor interleukin (IL)-6 in promoting pentraxin 3 (PTX3) expression in triple-negative breast cancer (TNBC).

METHODS

We established an in vitro coculture model of mature adipocytes and TNBC cells using a Transwell system. Cell scratch, Transwell migration, and matrix invasion assays were used to evaluate the migration and invasion abilities of TNBC cells cocultured with adipocytes. Next, we used lentivirus-mediated functional depletion experiments to study PTX3's role in the adipocyte-dependent migration of TNBC cells.

RESULTS

After coculturing TNBC cells with adipocytes, PTX3 expression was upregulated, which accompanied enhanced cell migration and invasion. Using GEO data and RNA-seq analysis, we identified PTX3 as a key target gene influenced by the adipose TNBC microenvironment. IL-6 upregulation in the conditioned medium of mature adipocytes and in the serum of high-fat diet mice was associated with this effect, and the recombinant protein IL-6 significantly promoted the migration and invasion of TNBC cells along with the phosphorylation of intracellular STAT3 and the upregulation of PTX3. PTX3 knockdown inhibited TNBC cell migration and eliminated the enhanced migration caused by coculturing with adipocytes. Furthermore, in vivo experiments confirmed that the PTX3 knockdown reduced obesity-induced lung metastasis. Subsequent experiments with cytokines and drug inhibitors confirmed that adipocyte-derived IL-6 promoted PTX3 expression by activating the STAT3 signaling pathway. Additionally, bioinformatic analysis indicated that PTX3 promotes TNBC metastasis by regulating the matrix metalloproteinase (MMP) family.

CONCLUSION

Our study elucidated Obesity-related metabolic inflammation promotes the progression via the IL-6/STAT3/PTX3/MMP7 axis.

An update on existing therapeutic options and status of novel anti-metastatic agents in breast cancer: Elucidating the molecular mechanisms underlying the pleiotropic action of Withania somnifera (Indian ginseng) in breast cancer attenuation

Major significant advancements in pharmacology and drug technology have been made to heighten the impact of cancer therapies, improving the life expectancy of subjects diagnosed with malignancy. Statistically, 99% of breast cancers occur in women while 0.5-1% occur in men, the female gender being the strongest breast cancer risk factor. Despite several breakthroughs, breast cancer continues to have a worldwide impact and is one of the leading causes of mortality. Additionally, resistance to therapy is a crucial factor enabling cancer cell persistence and resurgence. As a result, the search and discovery of novel modulatory agents and effective therapies capable of controlling tumor progression and cancer cell proliferation is critical. Withania somnifera (L.) Dunal (WS), commonly known as Indian ginseng, has long been used traditionally for the treatment of several ailments in the Indian context. Recently, WS and its phytoconstituents have shown promising anti-breast cancer properties and, as such, can be employed as prophylactic as well as therapeutic adjuncts to the main line of breast cancer treatment. The present review is an attempt to explore and provide experimental evidences in support of the prophylactic and therapeutic potential of WS in breast cancer, along with a deeper insight into the multiple molecular mechanisms and novel targets through which it acts against breast and other hormonally-induced cancers viz. ovarian, uterine and cervical. This exploration might prove crucial in providing better understanding of breast cancer progression and metastasis and its use as an adjunct in improving disease prognosis and therapeutic outcome.

An in silico prediction of interaction models of influenza A virus PA and human C14orf166 protein from yeast-two-hybrid screening data

The human C14orf166 protein, also known as RNA transcription, translation, and transport factor, shows positive modulatory activity on the cellular RNA polymerase II enzyme. This protein is a component of the tRNA-splicing ligase complex and is involved in RNA metabolism. It also functions in the nucleo-cytoplasmic transport of RNA molecules. The C14orf166 protein has been reported to be associated with some types of cancer. It has been shown that the C14orf166 protein binds to the influenza A virus RNA polymerase PA subunit and has a stimulating effect on viral replication. In this study, candidate interactor proteins for influenza A virus PA protein were screened with a Y2H assay using HEK293 Matchmaker cDNA. The C14orf166 protein fragments in different sizes were found to interact with the PA. The three-dimensional structures of the viral PA and C14orf166 proteins interacting with the PA were generated using the I-TASSER algorithm. The interaction models between these proteins were predicted with the ClusPro protein docking algorithm and analyzed with PyMol software. The results revealed that the carboxy-terminal end of the C14orf166 protein is involved in this interaction, and it is highly possible that it binds to the carboxy-terminal of the PA protein. Although amino acid residues in the interaction area of the PA protein with the C14orf166 showed distribution from 450th to 700th position, the intense interaction region was revealed to be at amino acid positions 610-630.

Epigenetics and environment in breast cancer: New paradigms for anti-cancer therapies

Breast cancer remains the most frequently diagnosed cancer in women worldwide. Delayed presentation of the disease, late stage at diagnosis, limited therapeutic options, metastasis, and relapse are the major factors contributing to breast cancer mortality. The development and progression of breast cancer is a complex and multi-step process that incorporates an accumulation of several genetic and epigenetic alterations. External environmental factors and internal cellular microenvironmental cues influence the occurrence of these alterations that drives tumorigenesis. Here, we discuss state-of-the-art information on the epigenetics of breast cancer and how environmental risk factors orchestrate major epigenetic events, emphasizing the necessity for a multidisciplinary approach toward a better understanding of the gene-environment interactions implicated in breast cancer. Since epigenetic modifications are reversible and are susceptible to extrinsic and intrinsic stimuli, they offer potential avenues that can be targeted for designing robust breast cancer therapies.

Changes in Pulmonary Microenvironment Aids Lung Metastasis of Breast Cancer

Breast cancer has become the most common malignant disease in the world according to the International Agency for Research on Cancer (IARC), and the most critical cause of death is distant metastasis. The lung is the extremely common visceral site for breast cancer metastasis. Lung metastasis of breast cancer is not only dependent on the invasive ability of the tumor itself, but also closely relates to the pulmonary microenvironment. In the progression of breast cancer, the formation of specific microenvironment in lungs can provide suitable conditions for the metastasis of breast cancer. Pulmonary inflammatory response, angiogenesis, extracellular matrix remodeling, some chemotherapeutic agents and so on all play important roles in the formation of the pulmonary microenvironment. This review highlights recent findings regarding the alterations of pulmonary microenvironment in lung metastasis of breast cancer, with a focus on various cells and acellular components.

IL-6/JAK/STAT3 Signaling in Breast Cancer Metastasis: Biology and Treatment

Breast cancer is the most commonly diagnosed cancer in women. Metastasis is the primary cause of mortality for breast cancer patients. Multiple mechanisms underlie breast cancer metastatic dissemination, including the interleukin-6 (IL-6)-mediated signaling pathway. IL-6 is a pleiotropic cytokine that plays an important role in multiple physiological processes including cell proliferation, immune surveillance, acute inflammation, metabolism, and bone remodeling. IL-6 binds to the IL-6 receptor (IL-6Rα) which subsequently binds to the glycoprotein 130 (gp130) receptor creating a signal transducing hexameric receptor complex. Janus kinases (JAKs) are recruited and activated; activated JAKs, in turn, phosphorylate signal transducer and activator of transcription 3 (STAT3) for activation, leading to gene regulation. Constitutively active IL-6/JAK/STAT3 signaling drives cancer cell proliferation and invasiveness while suppressing apoptosis, and STAT3 enhances IL-6 signaling to promote a vicious inflammatory loop. Aberrant expression of IL-6 occurs in multiple cancer types and is associated with poor clinical prognosis and metastasis. In breast cancer, the IL-6 pathway is frequently activated, which can promote breast cancer metastasis while simultaneously suppressing the anti-tumor immune response. Given these important roles in human cancers, multiple components of the IL-6 pathway are promising targets for cancer therapeutics and are currently being evaluated preclinically and clinically for breast cancer. This review covers the current biological understanding of the IL-6 signaling pathway and its impact on breast cancer metastasis, as well as, therapeutic interventions that target components of the IL-6 pathway including: IL-6, IL-6Rα, gp130 receptor, JAKs, and STAT3.

RBMS1 promotes gastric cancer metastasis through autocrine IL-6/JAK2/STAT3 signaling

Metastasis is the most important reason for the poor prognosis of gastric cancer (GC) patients, and the mechanism urgently needs to be clarified. Here, we explored a prognostic model for the estimation of tumor-associated mortality in GC patients and revealed the RNA-binding protein RBMS1 as a candidate promoter gene for GC metastasis by analyzing GOBO and Oncomine high-throughput sequencing datasets for 408 GC patients. Additionally, RBMS1 was observed with overexpression in 85 GC patient clinical specimens by IHC staining and further be verified its role in GC metastasis via inducing EMT process both in in vitro and in vivo experiments. Moreover, we identified that IL-6 was predicted to be one of the most significant upstream cytokines in the RBMS1 overexpression gene set based on the Ingenuity Pathway Analysis (IPA) algorithm. Most importantly, we also revealed that RBMS1 could promote migration and invasion through IL6 transactivation and JAK2/STAT3 downstream signaling pathway activation by influencing histone modification in the promoter regions after binding with the transcription factor MYC in the HGC-27 and SGC-7901 GC cell lines. Hence, we shed light on the potential molecular mechanisms of RBMS1 in the promotion of GC metastasis, which suggests that RBMS1 may be a potential therapeutic target for GC patients.

Protein phosphatase 1 regulatory inhibitor subunit 14C promotes triple-negative breast cancer progression via sustaining inactive glycogen synthase kinase 3 beta

Triple-negative breast cancer (TNBC) is fast-growing and highly metastatic with the poorest prognosis among the breast cancer subtypes. Inactivation of glycogen synthase kinase 3 beta (GSK3β) plays a vital role in the aggressiveness of TNBC; however, the underlying mechanism for sustained GSK3β inhibition remains largely unknown. Here, we find that protein phosphatase 1 regulatory inhibitor subunit 14C (PPP1R14C) is upregulated in TNBC and relevant to poor prognosis in patients. Overexpression of PPP1R14C facilitates cell proliferation and the aggressive phenotype of TNBC cells, whereas the depletion of PPP1R14C elicits opposite effects. Moreover, PPP1R14C is phosphorylated and activated by protein kinase C iota (PRKCI) at Thr73. p-PPP1R14C then represses Ser/Thr protein phosphatase type 1 (PP1) to retain GSK3β phosphorylation at high levels. Furthermore, p-PPP1R14C recruits E3 ligase, TRIM25, toward the ubiquitylation and degradation of non-phosphorylated GSK3β. Importantly, the blockade of PPP1R14C phosphorylation inhibits xenograft tumorigenesis and lung metastasis of TNBC cells. These findings provide a novel mechanism for sustained GSK3β inactivation in TNBC and suggest that PPP1R14C might be a potential therapeutic target.

The IL6-like Cytokine Family: Role and Biomarker Potential in Breast Cancer

IL6-like cytokines are a family of regulators with a complex, pleiotropic role in both the healthy organism, where they regulate immunity and homeostasis, and in different diseases, including cancer. Here we summarise how these cytokines exert their effect through the shared signal transducer IL6ST (gp130) and we review the extensive evidence on the role that different members of this family play in breast cancer. Additionally, we discuss how the different cytokines, their related receptors and downstream effectors, as well as specific polymorphisms in these molecules, can serve as predictive or prognostic biomarkers with the potential for clinical application in breast cancer. Lastly, we also discuss how our increasing understanding of this complex signalling axis presents promising opportunities for the development or repurposing of therapeutic strategies against cancer and, specifically, breast neoplasms.

Targeting Histone Modifications in Breast Cancer: A Precise Weapon on the Way

Histone modifications (HMs) contribute to maintaining genomic stability, transcription, DNA repair, and modulating chromatin in cancer cells. Furthermore, HMs are dynamic and reversible processes that involve interactions between numerous enzymes and molecular components. Aberrant HMs are strongly associated with tumorigenesis and progression of breast cancer (BC), although the specific mechanisms are not completely understood. Moreover, there is no comprehensive overview of abnormal HMs in BC, and BC therapies that target HMs are still in their infancy. Therefore, this review summarizes the existing evidence regarding HMs that are involved in BC and the potential mechanisms that are related to aberrant HMs. Moreover, this review examines the currently available agents and approved drugs that have been tested in pre-clinical and clinical studies to evaluate their effects on HMs. Finally, this review covers the barriers to the clinical application of therapies that target HMs, and possible strategies that could help overcome these barriers and accelerate the use of these therapies to cure patients.

Polydatin gold nanoparticles potentiate antitumor effect of doxorubicin in Ehrlich ascites carcinoma-bearing mice

Breast cancer is a leading cause of death. Anticancer treatment such as gold nanoparticles (AuNP) seems highly promising in this regard. Therefore, this study aimed to assess the beneficial effect of doxorubicin (Dox) and polydatin (PD) AuNP in Ehrlich ascites carcinoma (EAC) and the ability of PD-AuNP to protect the heart from Dox's deteriorating effects. EAC was induced in mice. The mice were divided into nine groups: normal, EAC, PD: received PD (20 mg/kg), Dox: received Dox (2 mg/kg), PD-AuNPH: received 10 ppm AuNP of PD, PD-AuNPL: received 5 ppm AuNP of PD, Dox-AuNP: received Dox-AuNP, PD-Dox-AuNP: received PD-Dox-AuNP, AuNP: received AuNP. On the 21st day from tumor inoculation, the mice were sacrificed and tumor and heart tissues were removed. Tumor β-catenin/Cyclin D1 and p53 were assessed by immunohistochemistry. IL-6 was determined by enzyme-linked immunosorbent assay. PD-AuNP and Dox-AuNP showed a significant reduction in tumor volume and weight more than their free forms. Also, PD-AuNP and Dox-AuNP showed markedly less dense tumor cells. β-catenin and Cyclin D1 were markedly decreased and p53 was highly upregulated by PD-AuNP and Dox-AuNP. Moreover, PD-AuNP and Dox-AuNP have the ability to decrease IL-6 production. PD-AuNP protected the heart from Dox-induced severe degeneration. Therefore, PD-AuNP could be a tool to decelerate the progression of breast cancer.

Nicotine-Induced ILF2 Facilitates Nuclear mRNA Export of Pluripotency Factors to Promote Stemness and Chemoresistance in Human Esophageal Cancer

Balancing mRNA nuclear export kinetics with its nuclear decay is critical for mRNA homeostasis control. How this equilibrium is aberrantly disrupted in esophageal cancer to acquire cancer stem cell properties remains unclear. Here we find that the RNA-binding protein interleukin enhancer binding factor 2 (ILF2) is robustly upregulated by nicotine, a major chemical component of tobacco smoke, via activation of JAK2/STAT3 signaling and significantly correlates with poor prognosis in heavy-smoking patients with esophageal cancer. ILF2 bound the THO complex protein THOC4 as a regulatory cofactor to induce selective interactions with pluripotency transcription factor mRNAs to promote their assembly into export-competent messenger ribonucleoprotein complexes. ILF2 facilitated nuclear mRNA export and inhibited hMTR4-mediated exosomal degradation to promote stabilization and expression of SOX2, NANOG, and SALL4, resulting in enhanced stemness and tumor-initiating capacity of esophageal cancer cells. Importantly, inducible depletion of ILF2 significantly increased the therapeutic efficiency of cisplatin and abrogated nicotine-induced chemoresistance in vitro and in vivo. These findings reveal a novel role of ILF2 in nuclear mRNA export and maintenance of cancer stem cells and open new avenues to overcome smoking-mediated chemoresistance in esophageal cancer. SIGNIFICANCE: This study defines a previously uncharacterized role of nicotine-regulated ILF2 in facilitating nuclear mRNA export to promote cancer stemness, suggesting a potential therapeutic strategy against nicotine-induced chemoresistance in esophageal cancer.

Breast Cancer and Microcalcifications: An Osteoimmunological Disorder?

The presence of microcalcifications in the breast microenvironment, combined with the growing evidences of the possible presence of osteoblast-like or osteoclast-like cells in the breast, suggest the existence of active processes of calcification in the breast tissue during a woman’s life. Furthermore, much evidence that osteoimmunological disorders, such as osteoarthritis, rheumatoid arthritis, or periodontitis influence the risk of developing breast cancer in women exists and vice versa. Antiresorptive drugs benefits on breast cancer incidence and progression have been reported in the past decades. More recently, biological agents targeting pro-inflammatory cytokines used against rheumatoid arthritis also demonstrated benefits against breast cancer cell lines proliferation, viability, and migratory abilities, both in vitro and in vivo in xenografted mice. Hence, it is tempting to hypothesize that breast carcinogenesis should be considered as a potential osteoimmunological disorder. In this review, we compare microenvironments and molecular characteristics in the most frequent osteoimmunological disorders with major events occurring in a woman’s breast during her lifetime. We also highlight what the use of bone anabolic drugs, antiresorptive, and biological agents targeting pro-inflammatory cytokines against breast cancer can teach us.

Antimetastatic effects of calycosin on osteosarcoma and the underlying mechanism

Osteosarcoma (OS) refers to a malignant tumor with potential invasiveness and metastasis; however, the current chemotherapy of OS is lacking. Thus, the alternative drug for treating OS is urgent to explore. Calycosin (CC) is evidenced in our previous study to play the anti-OS benefits for suppressing cancer cell proliferation. Consequently, further investigation of CC-medicated anti-invasive and metastatic effects against OS is needed. In the current study, the clinical samples of OS patients were collected for biological and staining assays, such as enzyme-linked immunosorbent assay and polymerase chain reaction. Meanwhile, the cell line and tumor-bearing nude mice were employed in assessing antimetastatic effects of CC against OS through biochemical tests and immunoassays. As a result, the OS patients exhibited upregulated neoplastic expressions of matrix metalloproteinase 2 (MMP2) and proliferating cell nuclear antigen (PCNA), cellular mRNAs and proteins of inhibitor of nuclear factor kappa-B alpha (IκBα), and epithelial cell transforming sequence 2 (ECT2). In cell-line study, CC-treated human OS cells exhibited induced cell apoptosis, reduced cell proliferation, and cellular MMP2 and PCNA concentration, inhibited cell migration, lowered expressions of IκBα ECT2 mRNAs, and proteins. In tumor-bearing nude mice study, CC-treated mice resulted in the dose-dependent reductions of tumor weights and intracellular MMP2 contents. As shown in further assays, neoplastic expressions of interleukin 6 protein, IκBα, ECT2 mRNAs, and proteins were downregulated dose-dependently in CC-treated tumor-bearing mice. In conclusion, these investigative findings suggest that CC may play the potential anti-invasive benefits against OS through suppressing metastasis-associated IκBα/ECT2 molecular pathway.

Two Opposing Faces of Retinoic Acid: Induction of Stemness or Induction of Differentiation Depending on Cell-Type

Stem cells have the capacity of self-renewal and, through proliferation and differentiation, are responsible for the embryonic development, postnatal development, and the regeneration of tissues in the adult organism. Cancer stem cells, analogous to the physiological stem cells, have the capacity of self-renewal and may account for growth and recurrence of tumors. Development and regeneration of healthy tissues and tumors depend on the balance of different genomic and nongenomic signaling pathways that regulate stem cell quiescence, proliferation, and differentiation. During evolution, this balance became dependent on all-trans retinoic acid (RA), a molecule derived from the environmental factor vitamin A. Here we summarize some recent findings on the prominent role of RA on the proliferation of stem and progenitor cells, in addition to its well-known function as an inductor of cell differentiation. A better understanding of the regulatory mechanisms of stemness and cell differentiation by RA may improve the therapeutic options of this molecule in regenerative medicine and cancer.

The role of clonal communication and heterogeneity in breast cancer

Background

Cancer is a rapidly evolving, multifactorial disease that accumulates numerous genetic and epigenetic alterations. This results in molecular and phenotypic heterogeneity within the tumor, the complexity of which is further amplified through specific interactions between cancer cells. We aimed to dissect the molecular mechanisms underlying the cooperation between different clones.

Methods

We produced clonal cell lines derived from the MDA-MB-231 breast cancer cell line, using the UbC-StarTrack system, which allowed tracking of multiple clones by color: GFP C3, mKO E10 and Sapphire D7. Characterization of these clones was performed by growth rate, cell metabolic activity, wound healing, invasion assays and genetic and epigenetic arrays. Tumorigenicity was tested by orthotopic and intravenous injections. Clonal cooperation was evaluated by medium complementation, co-culture and co-injection assays.

Results

Characterization of these clones in vitro revealed clear genetic and epigenetic differences that affected growth rate, cell metabolic activity, morphology and cytokine expression among cell lines. In vivo, all clonal cell lines were able to form tumors; however, injection of an equal mix of the different clones led to tumors with very few mKO E10 cells. Additionally, the mKO E10 clonal cell line showed a significant inability to form lung metastases. These results confirm that even in stable cell lines heterogeneity is present. In vitro, the complementation of growth medium with medium or exosomes from parental or clonal cell lines increased the growth rate of the other clones. Complementation assays, co-growth and co-injection of mKO E10 and GFP C3 clonal cell lines increased the efficiency of invasion and migration.

Conclusions

These findings support a model where interplay between clones confers aggressiveness, and which may allow identification of the factors involved in cellular communication that could play a role in clonal cooperation and thus represent new targets for preventing tumor progression.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5883-y) contains supplementary material, which is available to authorized users.

Interleukin 6 signaling maintains the stem-like properties of bladder cancer stem cells

Background

The relapse and metastasis of bladder cancer are due to its strong resistance to chemotherapeutic drugs after surgery as a result of the expansion and self-renewal of cancer stem cells (CSCs). However, the molecular mechanisms underlying the biology of bladder CSCs are unknown. This study aimed to investigate the role of interleukin 6 (IL6)/IL6 receptor (IL6R) in the stem-like characteristics of bladder CSCs.

Methods

Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to detect IL6 expression in the supernatant and cells of bladder CSCs, respectively. Following that, self-renewal, stem cell-associated gene expression, invasion, metastasis, and tumorigenicity were assessed by sphere-forming assay, qRT-PCR, invasion and transwell assays, and tumor-forming experiment in NOD/SCID mice, respectively. Finally, Western blot and qRT-PCR were employed to examine the IL6 signaling pathway in regulating the stem-like properties of bladder CSCs.

Results

The spheres, originating from the bladder cancer cell lines RT4 and J82, possessed a higher expression of stem-associated genes. The expression levels of IL6 were elevated in the supernatant and cells of the bladder CSCs. IL6R was also up-regulated in the bladder CSCs. Recombinant IL6 promoted the stem-like properties of the bladder CSCs, including self-renewal, expression of stem-associated genes, invasion, migration, and tumorigenicity. Mechanistically, IL6 exerted its biological effects by binding to IL6R, which enhanced the phosphorylation of STAT3 and triggered its activation. Furthermore, these effects were alleviated by the FDA-approved drug tocilizumab.

Conclusions

Our findings demonstrate that IL6/IL6R/STAT3 maintains the stem-like properties of bladder CSCs. Furthermore, IL6R may serve as a potential therapeutic target for CSCs in bladder cancer.

Adipocyte-derived IL-6 and leptin promote breast Cancer metastasis via upregulation of Lysyl Hydroxylase-2 expression

BACKGROUND

Adipocytes make up the major component of breast tissue, accounting for 90% of stromal tissue. Thus, the crosstalk between adipocytes and breast cancer cells may play a critical role in cancer progression. Adipocyte-breast cancer interactions have been considered important for the promotion of breast cancer metastasis. However, the specific mechanisms underlying these interactions are unclear. In this study, we investigated the mechanisms of adipocyte-mediated breast cancer metastasis.

METHODS

Breast cancer cells were cocultured with mature adipocytes for migration and 3D matrix invasion assays. Next, lentivirus-mediated loss-of-function experiments were used to explore the function of lysyl hydroxylase (PLOD2) in breast cancer migration and adipocyte-dependent migration of breast cancer cells. The role of PLOD2 in breast cancer metastasis was further confirmed using orthotopic mammary fat pad xenografts in vivo. Clinical samples were used to confirm that PLOD2 expression is increased in tumor tissue and is associated with poor prognosis of breast cancer patients. Cells were treated with cytokines and pharmacological inhibitors in order to verify which adipokines were responsible for activation of PLOD2 expression and which signaling pathways were activated in vitro.

RESULTS

Gene expression profiling and Western blotting analyses revealed that PLOD2 was upregulated in breast cancer cells following coculture with adipocytes; this process was accompanied by enhanced breast cancer cell migration and invasion. Loss-of-function studies indicated that PLOD2 knockdown suppressed cell migration and disrupted the formation of actin stress fibers in breast cancer cells and abrogated the migration induced by following coculture with adipocytes. Moreover, experiments performed in orthotopic mammary fat pad xenografts showed that PLOD2 knockdown could reduce metastasis to the lung and liver. Further, high PLOD2 expression correlated with poor prognosis of breast cancer patients. Mechanistically, adipocyte-derived interleukin-6 (IL-6) and leptin may facilitate PLOD2 upregulation in breast cancer cells and promote breast cancer metastasis in tail vein metastasis assays. Further investigation revealed that adipocyte-derived IL-6 and leptin promoted PLOD2 expression through activation of the JAK/STAT3 and PI3K/AKT signaling pathways.

CONCLUSIONS

Our study reveals that adipocyte-derived IL-6 and leptin promote PLOD2 expression by activating the JAK/STAT3 and PI3K/AKT signaling pathways, thus promoting breast cancer metastasis.

The role of the interleukin (IL)-6/IL-6 receptor axis in cancer

Interleukin-6 (IL-6) is a pleiotropic cytokine that activates a classic signalling pathway upon binding to its membrane-bound receptor (IL-6R). Alternatively, IL-6 may 'trans-signal' in a manner that is facilitated by its binding to a soluble derivative of the IL-6 receptor (sIL-6R). Resultant signal transduction is, respectively, driven by the association of IL-6/IL-6R or IL-6/sIL-6R complex with the membrane-associated signal transducer, gp130 (Glycoprotein 130). Distinct JAK (Janus tyrosine kinase)/STAT (signal transducers and activators of transcription) and other signalling pathways are activated as a consequence. Of translational relevance, overexpression of IL-6 has been documented in several neoplastic disorders, including but not limited to colorectal, ovarian and breast cancer and several haematological malignancies. This review attempts to summarise our current understanding of the role of IL-6 in cancer development. In short, these studies have shown important roles for IL-6 signalling in tumour cell growth and survival, angiogenesis, immunomodulation of the tumour microenvironment, stromal cell activation, and ultimate disease progression. Given this background, we also consider the potential for therapeutic targeting of this system in cancer.

Combined Inactivation of TP53 and MIR34A Promotes Colorectal Cancer Development and Progression in Mice Via Increasing Levels of IL6R and PAI1

BACKGROUND & AIMS

Combined inactivation of the microRNA 34a gene (MIR34A, by methylation) and the TP53 gene (by mutation or deletion) is observed in 50% of colorectal tumors that progress to distant metastases. We studied mice with intestinal disruption of Mir34a and Tp53 to investigate mechanisms of colorectal carcinogenesis and identify strategies to block these processes.

METHODS

Mice with disruption of Mir34a and/or Tp53 specifically in intestinal epithelial cells (IECs) (Mir34a^ΔIEC mice, Tp53^ΔIEC mice, and Mir34a^ΔIEC/Tp53^ΔIEC mice) and controls (Mir34a^Fl/Fl/Tp53^Fl/Fl) were given azoxymethane to induce colorectal carcinogenesis. Some mice were given intraperitoneal injections of an antibody against mouse interleukin 6 receptor (IL6R), or received an inhibitor of PAI1 (tiplaxtinin) in their chow. Intestinal tissues were collected and analyzed by immunohistochemistry; gene expression profiles were analyzed by RNA sequencing. We determined the expression and localization of PAI1 in 61 human primary colon cancers and compared them to MIR34A methylation and inactivating mutations in TP53. Data on mRNA levels, methylation, and clinical features of 628 colon and rectal adenocarcinomas were obtained from The Cancer Genome Atlas portal.

RESULTS

Mir34a^ΔIEC/Tp53^ΔIEC mice developed larger and more colorectal tumors, with increased invasion of surrounding tissue and metastasis to lymph nodes, than control mice or mice with disruption of either gene alone. Cells in tumors from the Mir34a^ΔIEC/Tp53^ΔIEC mice had decreased apoptosis and increased proliferation compared to tumor cells from control mice, and expressed higher levels of genes, that regulate inflammation (including Il6r and Stat3) and epithelial-mesenchymal transition. The gene expression pattern of the tumors from Mir34a^ΔIEC/Tp53^ΔIEC mice was similar to that of human colorectal tumor consensus molecular subtype 4 (mesenchymal, invasive). We identified the Pai1 messenger RNA as a target of Mir34a; levels of PAI1 protein were increased in primary colon cancer samples, that displayed methylation of MIR34A and mutational inactivation of TP53. Administration of tiplaxtinin or anti-IL6R antibody to Mir34a^ΔIEC/Tp53^ΔIEC mice decreased proliferation of cancer cells, and reduced colorectal tumor invasion and metastasis.

CONCLUSIONS

In mice, we demonstrated that combined inactivation of Mir34a and Tp53 promotes azoxymethane-induced colorectal carcinogenesis and tumor progression and metastasis by increasing levels of IL6R and PAI1. Strategies to inhibit these processes might be developed to slow progression of colorectal cancer.

Insulin-like growth factor receptor signaling in breast tumor epithelium protects cells from endoplasmic reticulum stress and regulates the tumor microenvironment

BACKGROUND

Early analyses of human breast cancer identified high expression of the insulin-like growth factor type 1 receptor (IGF-1R) correlated with hormone receptor positive breast cancer and associated with a favorable prognosis, whereas low expression of IGF-1R correlated with triple negative breast cancer (TNBC). We previously demonstrated that the IGF-1R acts as a tumor and metastasis suppressor in the Wnt1 mouse model of TNBC. The mechanisms for how reduced IGF-1R contributes to TNBC phenotypes is unknown.

METHODS

We analyzed the METABRIC dataset to further stratify IGF-1R expression with patient survival and specific parameters of TNBC. To investigate molecular events associated with the loss of IGF-1R function in breast tumor cells, we inhibited IGF-1R in human cell lines using an IGF-1R blocking antibody and analyzed MMTV-Wnt1-mediated mouse tumors with reduced IGF-1R function through expression of a dominant-negative transgene.

RESULTS

Our analysis of the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) dataset revealed association between low IGF-1R and reduced overall patient survival. IGF-1R expression was inversely correlated with patient survival even within hormone receptor-positive breast cancers, indicating reduced overall patient survival with low IGF-1R was not due simply to low IGF-1R expression within TNBCs. Inhibiting IGF-1R in either mouse or human tumor epithelial cells increased reactive oxygen species (ROS) production and activation of the endoplasmic reticulum stress response. IGF-1R inhibition in tumor epithelial cells elevated interleukin (IL)-6 and C-C motif chemokine ligand 2 (CCL2) expression, which was reversed by ROS scavenging. Moreover, the Wnt1/dnIGF-1R primary tumors displayed a tumor-promoting immune phenotype. The increased CCL2 promoted an influx of CD11b⁺ monocytes into the primary tumor that also had increased matrix metalloproteinase (MMP)-2, MMP-3, and MMP-9 expression. Increased MMP activity in the tumor stroma was associated with enhanced matrix remodeling and collagen deposition. Further analysis of the METABRIC dataset revealed an increase in IL-6, CCL2, and MMP-9 expression in patients with low IGF-1R, consistent with our mouse tumor model and data in human breast cancer cell lines.

CONCLUSIONS

Our data support the hypothesis that reduction of IGF-1R function increases cellular stress and cytokine production to promote an aggressive tumor microenvironment through infiltration of immune cells and matrix remodeling.

Simultaneous blockade of IL-6 and CCL5 signaling for synergistic inhibition of triple-negative breast cancer growth and metastasis

Background

Metastatic triple-negative breast cancer (TNBC) is a heterogeneous and incurable disease. Numerous studies have been conducted to seek molecular targets to treat TNBC effectively, but chemotherapy is still the main choice for patients with TNBC. We have previously presented evidence of the important roles of interleukin-6 (IL-6) and chemokine (C-C motif) ligand 5 (CCL5) in TNBC tumor growth and metastasis. These experiments highlighted the importance of the crosstalk between cancer cells and stromal lymphatic endothelial cells (LECs) in tumor growth and metastasis.

Methods

We examined the viability and migration of MDA-MB-231-LN, SUM149, and SUM159 cells co-cultured with LECs when treated with maraviroc (CCR5 inhibitor) and tocilizumab (anti-IL-6 receptor antibody). To assess the anti-tumor effects of the combination of these two drugs in an athymic nude mouse model, MDA-MB-231-LN cells were implanted in the mammary fat pad and maraviroc (8 mg/kg, orally daily) and cMR16-1 (murine surrogate of the anti-IL-6R antibody, 10 mg/kg, IP, 3 days a week) were administrated for 5 weeks and effects on tumor growth and thoracic metastasis were measured.

Results

In this study, we used maraviroc and tocilizumab to confirm that IL-6 and CCL5 signaling are key pathways promoting TNBC cell proliferation and migration. Further, in a xenograft mouse model, we showed that tumor growth was dramatically inhibited by cMR16-1, the mouse version of the anti-IL6R antibody. The combination of maraviroc and cMR16-1 caused significant reduction of TNBC tumor growth compared to the single agents. Significantly, the combination of maraviroc and cMR16-1 abrogated thoracic metastasis.

Conclusion

Taken together, these findings show that IL-6 and CCL5 signaling, which promote crosstalk between TNBC and lymphatic vessels, are key enhancers of TNBC tumor growth and metastasis. Furthermore, these results demonstrate that a drug combination inhibiting these pathways may be a promising therapy for TNBC patients.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0981-3) contains supplementary material, which is available to authorized users.

Cancer/testis antigen-Plac1 promotes invasion and metastasis of breast cancer through Furin/NICD/PTEN signaling pathway

Placenta‐specific protein 1 (Plac1) is a cancer/testis antigen that plays a critical role in promoting cancer initiation and progression. However, the clinical significance and mechanism of Plac1 in cancer progression remain elusive. Here, we report that Plac1 is an important oncogenic and prognostic factor, which physically interacts with Furin to drive breast cancer invasion and metastasis. We have shown that Plac1 expression positively correlates with clinical stage, lymph node metastasis, hormone receptor status, and overall patient survival. Overexpression of Plac1 promoted invasion and metastasis of breast cancer cells in vitro and in vivo. Co‐immunoprecipitation and immunofluorescence cell staining assays revealed that interaction of Plac1 and Furin degraded Notch1 and generated Notch1 intracellular domain (NICD) that could inhibit PTEN activity. These findings are consistent with the results of microarray study in MDA‐MB‐231 cells overexpressing Plac1. A rescue study showed that inhibition of Furin and overexpression of PTEN in Plac1 overexpression cells blocked Plac1‐induced tumor cell progression. Taken together, our findings suggest that functional interaction between Plac1 and Furin enhances breast cancer invasion and metastasis and the Furin/NICD/PTEN axis may act as an important therapeutic target for breast cancer treatment.

Score for the Survival Probability in Metastasis Breast Cancer: A Nomogram-Based Risk Assessment Model

PURPOSE

Survival of metastatic breast cancer (MBC) patient remains unknown and varies greatly from person to person. Thus, we aimed to construct a nomogram to quantify the survival probability of patients with MBC.

Materials and Methods

We had included 793 MBC patients and calculated trends of case fatality rate by Kaplan-Meier method and joinpoint regression. Six hundred thirty-four patients with MBC between January 2004 and July 2011 and 159 patients with MBC between August 2011 and July 2013 were assigned to training cohort and internal validation cohort, respectively. We constructed the nomogram based on the results of univariable and multivariable Cox regression analyses in the training cohort and validated the nomogram in the validation cohort. Concordance index and calibration curves were used to assess the effectiveness of nomogram.

RESULTS

Case fatality rate of MBC was increasing (annual percentage change [APC], 21.6; 95% confidence interval [CI], 1.0 to 46.3; p < 0.05) in the first 18 months and then decreased (APC, ‒4.5; 95% CI, ‒8.2 to ‒0.7; p < 0.05). Metastasis-free interval, age, metastasis location, and hormone receptor status were independent prognostic factors and were included in the nomogram, which had a concordance index of 0.69 in the training cohort and 0.67 in the validation cohort. Calibration curves indicated good consistency between the two cohorts at 1 and 3 years.

CONCLUSION

In conclusion, the fatality risk of MBC was increasing and reached the summit between 13th and 18th month afterthe detection of MBC. We have developed and validated a nomogram to predict the 1- and 3-year survival probability in MBC.

TNFα-YAP/p65-HK2 axis mediates breast cancer cell migration

Clinical and experimental evidence indicates that macrophages could promote solid-tumor progression and metastasis. However, the mechanisms underlying this process remain unclear. Here we show that yes-associated protein 1 (YAP1), a transcriptional regulator that controls tissue growth and regeneration, has an important role in tumor necrosis factor α (TNF α)-induced breast cancer migration. Mechanistically, macrophage conditioned medium (CM) or TNFα triggers IκB kinases (IKKs)-mediated YAP phosphorylation and activation in breast cancer cells. We further found that TNFα or macrophage CM treatment increases the interaction between p65 and YAP. Chromatin immunoprecipitation (ChIP) assay shows that YAP/TEAD (TEA domain family member) and p65 proteins synergistically regulate the transcription of hexokinase 2 (HK2), a speed-limiting enzyme in glycolysis, and promotes TNFα-induced or macrophage CM-induced cell migration. Together, our findings indicate an important role of TNFα-IKK-YAP/p65-HK2 signaling axis in the process of inflammation-driven migration in breast cancer cells, which reveals a new molecular link between inflammation and breast cancer metastasis.

Insights into the Link Between Obesity and Cancer

PURPOSE OF REVIEW

Adipocytes have adapted to store energy in the form of lipid and also secrete circulating factors called adipokines that signal to other tissues to coordinate energy homeostasis. These functions are disrupted in the setting of obesity, promoting the development of diseases such as diabetes, cardiovascular disease, and cancer.

RECENT FINDINGS

Obesity is linked to an increased risk of many types of cancer and increased cancer-related mortality. The basis for the striking association between obesity and cancer is not well understood. Here, we review the cellular and molecular pathways that appear to be involved in obesity-driven cancer. We also describe possible therapeutic considerations and highlight important unanswered questions in the field.