miR-149 Suppresses Breast Cancer Metastasis by Blocking Paracrine Interactions with Macrophages

MiRNA affects the advancement of breast cancer by modulating the immune system's response

Breast cancer (BC), which is the most common tumor in women, has greatly endangered women's lives and health. Currently, patients with BC receive comprehensive treatments, including surgery, chemotherapy, radiotherapy, endocrine therapy, and targeted therapy. According to the latest research, the development of BC is closely related to the inflammatory immune response, and the immunogenicity of BC has steadily been recognized. As such, immunotherapy is one of the promising and anticipated forms of treatment for BC. The potential values of miRNA in the diagnosis and prognosis of BC have been established, and aberrant expression of associated miRNA can either facilitate or inhibit progression of BC. In the tumor immune microenvironment (TME), miRNAs are considered to be an essential molecular mechanism by which tumor cells interact with immunocytes and immunologic factors. Aberrant expression of miRNAs results in reprogramming of tumor cells actively, which may suppress the generation and activation of immunocytes and immunologic factors, avoid tumor cells apoptosis, and ultimately result in uncontrolled proliferation and deterioration. Therefore, through activating and regulating the immunocytes related to tumors and associated immunologic factors, miRNA can contribute to the advancement of BC. In this review, we assessed the function of miRNA and associated immune system components in regulating the advancement of BC, as well as the potential and viability of using miRNA in immunotherapy for BC.

The Pre-metastatic Niche: How Cancer Stem Cell-Derived Exosomal MicroRNA Fit into the Puzzle

Cancer metastasis is a complicated biological process that critically affects cancer progression, patient outcomes, and treatment plans. A significant step in metastasis is the formation of a pre-metastatic niche (PMN). A small subset of cells within tumors, known as cancer stem cells (CSCs), possess unique characteristics including, differentiation into different cell types within the tumor, self-renewal, and resistance to conventional therapies, that enable them to initiate tumors and drive metastasis. PMN plays an important role in preparing secondary organs for the arrival and proliferation of CSCs, thereby facilitating metastasis. CSC-derived exosomes are crucial components in the complex interplay between CSCs and the tumor microenvironment. These exosomes function as transporters of various substances that can promote cancer progression, metastasis, and modulation of pre-metastatic environments by delivering microRNA (miRNA, miR) cargo. This review aims to illustrate how exosomal miRNAs (exo-miRs) secreted by CSCs can predispose PMN and promote angiogenesis and metastasis.

Multi-miRNAs-Mediated Hepatic Lepr Axis Suppression: A Pparg-Dicer1 Pathway-Driven Mechanism in Spermatogenesis for the Intergenerational Transmission of Paternal Metabolic Syndrome

Bisphenol A (BPA) is an "environmental obesogen" and this study aims to investigate the intergenerational impacts of BPA-induced metabolic syndrome (MetS), specifically focusing on unraveling mechanisms. Exposure to BPA induces metabolic disorders in the paternal mice, which are then transmitted to offspring, leading to late-onset MetS. Mechanistically, BPA upregulates Srebf1, which in turn promotes the Pparg-dependent transcription of Dicer1 in spermatocytes, increasing the levels of multiple sperm microRNAs (miRNAs). Several of these miRNAs are highly expressed in a synchronized manner in liver of the offspring. miR149-5p, miR150-5p, and miR700-5p target a specific region in the Lepr 3'UTR, termed "SMITE" ("Several MiRNAs Targeting Elements"), to negatively regulate Lepr. These inherited anti-Lepr miRNAs, also referred to inherited anti-Lepr miRNAs (IAL-miRs), modulate hepatic steatosis, and insulin signaling through the Lepr regulatory Igfbp2, Egfr, and Ampk. Furthermore, IAL-miRs inhibit Ccnd1 not only via binding to "SMITE" but also via Lepr-Igfbp2 axis, which contribute to hepatocyte senescence. These pathological processes interact in a self-reinforcing cycle, worsening MetS in the paternal BPA-exposed offspring. The findings reveal mechanism wherein lipid metabolism reprogramming in spermatocytes-induced perturbations of sperm miRNAs, triggered by BPA, leads to intergenerational inheritance of paternal MetS through suppression of the hepatic Lepr axis in the offspring.

The Combined Impact of Curcumin: Piperine and Sorafenib on microRNAs and Different Pathways in Breast Cancer Cells

Breast cancer is the most common malignancy in the women. Chemotherapy is a crucial part of breast cancer treatment especially for advanced and metastatic forms of the disease. However, chemotherapy has limitations due to tumor heterogeneity, chemoresistance, and side effects. There is potential in combining chemotherapeutic drugs with natural items to enhance their effectiveness against cancer. In this study, we examined the synergistic effects of combining curcumin: piperine with sorafenib on the progression of breast cancer cells by altering many pathways associated with cancer and regulating the expression of numerous microRNAs. We tested the cytotoxic impact of curcumin: piperine on MCF-7 breast cancer cells using SRB assay. We analyzed the expression levels of selected microRNAs, genes, and proteins related to cancer stem cells, epithelial-mesenchymal transition, apoptosis and cell cycle progression using qPCR, ELISA and flow cytometry techniques. The findings of this study demonstrated that sorafenib and curcumin: piperine together enhances the suppression of MCF-7 cell survival. Molecular genetic analysis revealed that this combination provoked downregulation in oncomirs [miR-21 and miR-155], vimentin, Snail1, Notch, TGF-β1, Smad4, β-catenin1 and Wnt10b genes. Meanwhile, there were upregulation of tumor suppressor miRNAs [miR-28, miR-139 and miR-149] and E-cadherin gene expression level. Also, this combination resulted in a decrease of vimentin, IL-6, STAT3 and MMP-9; an increase of E-cadherin protein levels. Moreover, this combination induced apoptotic cell death and arrested cell cycles at specific phases. This study suggests that the combination of sorafenib and curcumin: piperine can combat breast cancer by modulating several microRNAs and signaling pathways involved in the development and progression of breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-024-01212-0.

3D-Printed Breast Prosthesis that Smartly Senses and Targets Breast Cancer Relapse

Breast reconstruction is essential for improving the appearance of patients after cancer surgery. Traditional breast prostheses are not appropriate for those undergoing partial resections and cannot detect and treat locoregional recurrence. Personalized shape prostheses that can smartly sense tumor relapse and deliver therapeutics are needed. A 3D-printed prosthesis that contains a therapeutic hydrogel is developed. The hydrogel, which is fabricated by crosslinking the polyvinyl alcohol with N1-(4-boronobenzyl)-N3-(4-boronophenyl)-N1, N1, N3, N3-tetramethylpropane-1,3-diaminium, is responsive to reactive oxygen species (ROS) in the tumor microenvironment. Specifically, RSL3, a ferroptosis inducer that is loaded in hydrogels, can trigger tumor ferroptosis. Intriguingly, RSL3 encapsulated in the ROS-responsive hydrogel exerts antitumor effects by increasing the numbers of tumor-infiltrated CD4+ T cells, CD8+ T cells, and M1 macrophages while reducing the number of M2 macrophages. Therefore, this new prosthesis not only allows personalized shape reconstruction, but also detects and inhibits tumor recurrence. This combination of aesthetic appearance and therapeutic function can be very beneficial for breast cancer patients undergoing surgery.

Unleashing nanotechnology to redefine tumor-associated macrophage dynamics and non-coding RNA crosstalk in breast cancer

Breast cancer is a significant global health issue. Tumor-associated macrophages (TAMs) are crucial in influencing the tumor microenvironment and the progression of the disease. TAMs exhibit remarkable plasticity in adopting distinct phenotypes ranging from pro-inflammatory and anti-tumorigenic (M1-like) to immunosuppressive and tumor-promoting (M2-like). This review elucidates the multifaceted roles of TAMs in driving breast tumor growth, angiogenesis, invasion, and metastatic dissemination. Significantly, it highlights the intricate crosstalk between TAMs and non-coding RNAs (ncRNAs), including microRNAs, long noncoding RNAs, and circular RNAs, as a crucial regulatory mechanism modulating TAM polarization and functional dynamics that present potential therapeutic targets. Nanotechnology-based strategies are explored as a promising approach to reprogramming TAMs toward an anti-tumor phenotype. Various nanoparticle delivery systems have shown potential for modulating TAM polarization and inhibiting tumor-promoting effects. Notably, nanoparticles can deliver ncRNA therapeutics to TAMs, offering unique opportunities to modulate their polarization and activity.

Role of microRNAs in triple‑negative breast cancer and new therapeutic concepts (Review)

Breast cancer has surpassed lung cancer as the most prevalent malignancy affecting women worldwide. Triple-negative breast cancer (TNBC) is the type of breast cancer with the worst prognosis. As a heterogeneous disease, TNBC has a pathogenesis that involves multiple oncogenic pathways, including involvement of gene mutations and alterations in signaling pathways. MicroRNAs (miRNAs) are small endogenous, single-stranded non-coding RNAs that bind to the 3' untranslated region of target cell mRNAs to negatively regulate the gene expression of these specific mRNAs. Therefore, miRNAs are involved in cell growth, development, division and differentiation stages. miRNAs are also involved in gene targeting in tumorigenesis, tumor growth and the regulation of metastasis, including in breast cancer. Meanwhile, miRNAs also regulate components of signaling pathways. In this review, the role of miRNAs in the TNBC signaling pathway discovered in recent years is described in detail. The new concept of bi-targeted therapy for breast cancer using miRNA and artificial intelligence is also discussed.

Identification of a glycolysis-related miRNA Signature for Predicting Breast cancer Survival

Breast cancer (BC) is a common type of cancer and has a poor prognosis. In this study, we collected the mRNA and miRNA expression profiles of BC patients were obtained from The Cancer Genome Atlas (TCGA) to explore a novel prognostic strategy for BC patients using bioinformatics tools. We found that six glycolysis-related miRNAs (GRmiRs, including hsa-mir-1247, hsa-mir148b, hsa-mir-133a-2, has-mir-1307, hsa-mir-195 and hsa-mir-1258) were correlated with prognosis of BC samples. The risk score model was established based on 6 prognosis-associated GRmiRs. The outcome of high risk group was significantly poorer. Cox regression analysis showed that risk score was an independent prognostic factor. Differentially expressed genes identified between high and low risk groups were mainly enriched in inflammation and immune-related signaling pathways. The proportion of infiltration of 12 kinds of immune cells in high and low risk groups were significantly different. Risk score was closely associated with many immune indexes. Multiple DEGRGs and miRNAs were associated with drugs. In conclusion, glycolysis-related miRNA signature effectively predicts BC prognosis.

Exploring the Relationship between MicroRNAs, Intratumoral Microbiota, and Breast Cancer Progression in Patients with and without Metastasis

Breast cancer (BC) continues to pose a significant burden on global cancer-related morbidity and mortality, primarily driven by metastasis. However, the combined influence of microRNAs (miRNAs) and intratumoral microbiota on BC metastasis remains largely unexplored. In this study, we aimed to elucidate the interplay between intratumoral microbiota composition, miRNA expression profiles, and their collective influence on metastasis development in BC patients by employing 16S rRNA sequencing and qPCR methodologies. Our findings revealed an increase in the expression of miR-149-5p, miR-20b-5p, and miR-342-5p in metastatic breast cancer (Met-BC) patients. The Met-BC patients exhibited heightened microbial richness and diversity, primarily attributed to diverse pathogenic bacteria. Taxonomic analysis identified several pathogenic and pro-inflammatory species enriched in Met-BC, contrasting with non-metastatic breast cancer (NonMet-BC) patients, which displayed an enrichment in potential probiotic and anti-inflammatory species. Notably, we identified and verified a baseline prognostic signature for metastasis in BC patients, with its clinical relevance further validated by its impact on overall survival. In conclusion, the observed disparities in miRNA expression and species-level bacterial abundance suggest their involvement in BC progression. The development of a prognostic signature holds promise for metastasis risk assessment, paving the way for personalized interventions and improved clinical outcomes in BC patients.

A novel immune‑related lncRNA as a prognostic biomarker in HER2+ breast cancer

Human epidermal growth factor receptor 2 (HER2)+ breast cancer is characterized by high malignancy and poor prognosis. Long non-coding (lnc)RNAs are crucial in breast cancer progression and prognosis, especially in tumor-associated immune processes. The present study aimed to elucidate novel lncRNAs related to immune function that could serve as biomarkers for both diagnosis and prognosis of this cancer subtype. Using data from The Cancer Genome Atlas and The Immunology Database and Analysis Portal, correlation analysis was performed to identify differentially expressed lncRNAs and immune-related genes. Through receiver operating characteristic analysis, the diagnostic value of specific lncRNAs was identified and evaluated, with a focus on their capacity to distinguish between cancerous and non-cancerous states. The present research revealed 22 differentially expressed lncRNAs and 23 differentially expressed immune-related genes, with 19 immune-related lncRNAs. A total of 13 of these lncRNAs demonstrated diagnostic relevance. In particular, it was demonstrated that the expression of lncRNA CTC-537E7.2 was significantly correlated with patient survival, suggesting its potential as a prognostic marker. Additionally, the expression of lncRNA CTC-537E7.2 was significantly correlated with clinical parameters, such as hormone receptor status and patient demographics. Moreover, it exhibited associations with four distinct immune cell types and demonstrated involvement in the Janus kinase-signal transducer and activator of transcription pathway. Further assessment by in situ hybridization confirmed the increased expression of lncRNA CTC-537E7.2 in samples from HER2+ patients, reinforcing its significance. In summary, the present study uncovered a novel prognostic biomarker for HER2+ breast cancer, thereby laying the groundwork for investigating the underlying molecular mechanisms driving the development of this subtype of breast cancer.

The Pivotal Function of SLC16A1 and SLC16A1-AS1 in Cancer Progress: Molecular Pathogenesis and Prognosis

More than 300 membranes make up the SLC family of transporters, utilizing an ion gradient or electrochemical potential difference to move their substrates across biological membranes. The SLC16 gene family contains fourteen members. Proton-linked transportation of monocarboxylates can be promoted by the transporters MCT1, which the SLC16A1 gene family encodes. Glycolysis is constitutively up-regulated in cancer cells, and the amount of lactate produced as a result is correlated with prognosis. Further speaking, SLC16A1 plays an essential role in controlling the growth and spread of tumors, according to mounting evidence. Additionally, LncRNAs are the collective term for all genes that produce RNA transcripts longer than 200 nucleotides but do not convert into proteins. It has steadily developed into a hub for research, offering an innovative approach to tumor study as technology related to molecular biology advances. The growing study has uncovered SLC16A1-AS1, an RNA that acts as an antisense to SLC16A1, which is erroneously expressed in various types of cancers. Therefore, we compiled the most recent information on the physiological functions and underlying processes of SLC16A1 and the LncRNA SLC16A1-AS1 during tumor development to explore their impact on cancer treatment and prognosis. We compiled the most recent information on the physiological functions and underlying processes of SLC16A1 and the LncRNA SLC16A1-AS1 during tumor development to explore their impact on cancer treatment and prognosis. Relevant studies were retrieved and collected through the PubMed system. After determining SLC16A1 and SLC16A1-AS1 as the research object, we found a close relationship between SLC16A1 and tumorigenesis as well as the influencing factors through the analysis of the research articles. SLC16A1 regulates lactate chemotaxis while uncovering SLC16A1- AS1 as an antisense RNA acting through multiple pathways; they affect the metabolism of tumor cells and have an impact on the prognosis of patients with various cancers.

Inhibition of inflammation and infiltration of M2 macrophages in NSCLC through the ATF3/CSF1 axis: Role of miR-27a-3p

Non-small cell lung cancer (NSCLC) imposes a significant economic burden on patients and society due to its low overall cure and survival rates. Tumour-associated macrophages (TAM) affect tumour development and may be a novel therapeutic target for cancer. We collected NSCLC and tumour-adjacent tissue samples. Compared with the tumour-adjacent tissues, the Activation Transcription Factor 3 (ATF3) and Colony Stimulating Factor 1 (CSF-1) were increased in NSCLC tissues. Levels of ATF3 and CSF-1 were identified in different cell lines (HBE, A549, SPC-A-1, NCI-H1299 and NCI-H1795). Overexpression of ATF3 in A549 cells increased the expression of CD68, CD206 and CSF-1. Moreover, levels of CD206, CD163, IL-10 and TGF-β increased when A549 cells were co-cultured with M0 macrophages under the stimulation of CSF-1. Using the starbase online software prediction and dual-luciferase assays, we identified the targeting between miR-27a-3p and ATF3. Levels of ATF3, CSF-1, CD206, CD163, IL-10 and TGF-β decreased in the miR-27a mimics, and the tumour growth was slowed in the miR-27a mimics compared with the mimics NC group. Overall, the study suggested that miR-27a-3p might inhibit the ATF3/CFS1 axis, regulate the M2 polarization of macrophages and ultimately hinder the progress of NSCLC. This research might provide a new therapeutic strategy for NSCLC.

Non-coding RNAs: a promising target for early metastasis intervention

ABSTRACT

Metastases account for the overwhelming majority of cancer-associated deaths. The dissemination of cancer cells from the primary tumor to distant organs involves a complex process known as the invasion-metastasis cascade. The underlying biological mechanisms of metastasis, however, remain largely elusive. Recently, the discovery and characterization of non-coding RNAs (ncRNAs) have revealed the diversity of their regulatory roles, especially as key contributors throughout the metastatic cascade. Here, we review recent progress in how three major types of ncRNAs (microRNAs, long non-coding RNAs, and circular RNAs) are involved in the multistep procedure of metastasis. We further examine interactions among the three ncRNAs as well as current progress in their regulatory mechanisms. We also propose the prevention of metastasis in the early stages of cancer progression and discuss current translational studies using ncRNAs as targets for metastasis diagnosis and treatments. These studies provide insights into developing more effective strategies to target metastatic relapse.

Garcinone E suppresses breast cancer growth and metastasis by modulating tumor-associated macrophages polarization via STAT6 signaling

Cancer metastasis remains the most common cause of death in breast cancer patients. Tumor-associated macrophages (TAMs) are a novel therapeutic target for the treatment of metastatic breast cancer. Despite the good anti-cancer activity of garcinone E (GE), there are no reports on its therapeutic effects on breast cancer metastasis. The objective of this study was to examine the anti-cancer effects of GE on metastatic breast cancer. RAW 264.7 and THP-1 cells were polarized to M2 macrophages by IL-4/IL-13 in vitro. A 4T1 mouse breast cancer model and the tail vein breast cancer metastasis model were used to explore the effect of GE on breast cancer growth and metastasis in vivo. In vitro studies showed that GE dose-dependently suppressed IL-4 + IL-13-induced expression of CD206 in both RAW 264.7 cells and differentiated THP-1 macrophages. However, GE did not affect the LPS + IFN-γ-induced polarization to the M1-like macrophages in vitro. GE inhibited the expression of the M2 macrophage specific genes in RAW 264.7 cells, and simultaneously impaired M2 macrophage-induced breast cancer cell proliferation and migration, and angiogenesis. In animal studies, GE significantly suppressed tumor growth, angiogenesis, and lung metastasis in 4T1 tumor-bearing mice, without causing toxicity. In both tumor and lung tissues, the proportion of M2-like TAMs was significantly decreased while the proportion of M1-like TAMs was markedly increased by GE treatment. Mechanistically, GE inhibited phosphorylation of STAT6 in vitro and in vivo. Our results demonstrate for the first time that GE suppresses breast cancer growth and pulmonary metastasis by modulating M2-like macrophage polarization through the STAT6 signaling pathway.

Tumor-associated monocytes promote mesenchymal transformation through EGFR signaling in glioma

The role of brain immune compartments in glioma evolution remains elusive. We profile immune cells in glioma microenvironment and the matched peripheral blood from 11 patients. Glioblastoma exhibits specific infiltration of blood-originated monocytes expressing epidermal growth factor receptor (EGFR) ligands EREG and AREG, coined as tumor-associated monocytes (TAMo). TAMo infiltration is mutually exclusive with EGFR alterations (p = 0.019), while co-occurring with mesenchymal subtype (p = 4.7 × 10-7) and marking worse prognosis (p = 0.004 and 0.032 in two cohorts). Evolutionary analysis of initial-recurrent glioma pairs and single-cell study of a multi-centric glioblastoma reveal association between elevated TAMo and glioma mesenchymal transformation. Further analyses identify FOSL2 as a TAMo master regulator and demonstrates that FOSL2-EREG/AREG-EGFR signaling axis promotes glioma invasion in vitro. Collectively, we identify TAMo in tumor microenvironment and reveal its driving role in activating EGFR signaling to shape glioma evolution.

Tumor cell-derived exosomes regulate macrophage polarization: Emerging directions in the study of tumor genesis and development

As an extracellular vesicle, exosomes play an important role in intercellular information transmission, delivering cargos of the parent cell, such as RNA, DNA, proteins, and lipids, activating different signaling pathways in the target cell and regulating inflammation, angiogenesis, and tumor progression. In particular, exosomes secreted by tumor cells can change the function of surrounding cells, creating a microenvironment conducive to tumor growth and metastasis. For example, after macrophages phagocytose exosomes and accept their cargos, they activate macrophage polarization-related signaling pathways and polarize macrophages into M1 or M2 types to exert antitumor or protumor functions. Currently, the study of exosomes affecting the polarization of macrophages has attracted increasing attention. Therefore, this paper reviews relevant studies in this field to better understand the mechanism of exosome-induced macrophage polarization and provide evidence for exploring novel targets for tumor therapy and new diagnostic markers in the future.

Friend and foe: the regulation network of ascites components in ovarian cancer progression

The tumor microenvironment (TME) and its complex role in cancer progression have been hotspots of cancer research in recent years. Ascites, which occurs frequently in patients with ovarian cancer especially in advanced stages, represents a unique TME. Malignant ascites contains abundant cellular and acellular components that play important roles in tumorigenesis, growth, metastasis, and chemoresistance of ovarian cancer through complex molecular mechanisms and signaling pathways. As a valuable liquid biopsy sample, ascites fluid is also of great significance for the prognostic analysis of ovarian cancer. The components of ovarian cancer ascites are generally considered to comprise tumor-promoting factors; however, in recent years studies have found that ascites also contains tumor-suppressing factors, raising new perspectives on interactions between ascites and tumors. Malignant ascites directly constitutes the ovarian cancer microenvironment, therefore, the study of its components will aid in the development of new therapeutic strategies. This article reviews the current research on tumor-promoting and tumor-suppressing factors and molecular mechanisms of their actions in ovarian cancer-derived ascites and therapeutic strategies targeting ascites, which may provide references for the development of novel therapeutic targets for ovarian cancer in the future.

Non-Coding RNAs: Foes or Friends for Targeting Tumor Microenvironment

Non-coding RNAs (ncRNAs) are a group of molecules critical for cell development and growth regulation. They are key regulators of important cellular pathways in the tumor microenvironment. To analyze ncRNAs in the tumor microenvironment, the use of RNA sequencing technology has revolutionized the field. The advancement of this technique has broadened our understanding of the molecular biology of cancer, presenting abundant possibilities for the exploration of novel biomarkers for cancer treatment. In this review, we will summarize recent achievements in understanding the complex role of ncRNA in the tumor microenvironment, we will report the latest studies on the tumor microenvironment using RNA sequencing, and we will discuss the potential use of ncRNAs as therapeutics for the treatment of cancer.

Targeting molecular cross-talk between tumor cells and tumor associated macrophage as therapeutic strategy in triple negative breast cancer

Triple-negative Breast cancer (TNBC) is a subtype of breast cancer (BC) that lacks expression for ER/PR/Her2 receptors and is associated with aggressive disease pathogenesis and the worst prognosis among other subtypes of BC. Accumulating evidence-based studies indicate the high immunogenic ability of TNBC tumors and the applicability of immunotherapeutic strategies to overcome therapy resistance and tumor recurrence in TNBC patients. However, not all TNBC patients respond equally well to current immunotherapies that mainly target the adaptive immune system for tumor rejection. Recent studies are contemplating the efficacy of tumor-associated macrophage (TAM) targeted therapies since these subpopulations of cells comprise one of the major components of tumor-infiltrating immune cells (TIIs) in the TNBC tumor microenvironment (TME) and play an essential role in priming the adaptive immune response mediators towards both antitumorigenic and pro-tumorigenic response facilitated by intercellular cross-talk between tumor cells and TAM populations present within TNBC-TME. The present review discusses these molecular mechanisms and their consequence on the progression of TNBC tumors. Also, the therapeutic strategies targeting candidate genes/pathways involved in molecular cross-talk between TAM-TNBC cells and their impact on the development and progression of TNBC tumors are also discussed.

Development of the expression and prognostic significance of m5 C-related LncRNAs in breast cancer

BACKGROUND

5-Methylcytosine (m5C) methylation is a major epigenetic RNA modification and is closely related to tumorigenesis in various cancers. This study aimed to explore the prognostic value of m5C-related lncRNAs in breast cancer.

METHODS

Clinical characteristics and RNA-seq expression data from TCGA (The Cancer Genome Atlas) were used in the study. First, we performed differentially expressed gene (DEG) analysis and constructed a PPI network for the 12 m5C regulators. Then, we identified the m5C-related LncRNAs by the "cor. test." An m5C-related lncRNA prognostic risk signature was developed using univariate Cox regression and Lasso-penalized Cox regression analyses. The model's performance was determined using Kaplan-Meier (KM) survival analysis and ROC curves. Finally, a nomogram was constructed for clinical application in evaluating patients with BRCA. We also researched the drug sensitivity of signature lncRNAs and immune cell infiltration. Finally, we validated the expression of the signature lncRNAs through qRT-PCR in a breast cancer cell line and a breast epithelial cell line.

RESULTS

Overall, we constructed an 11-lncRNA risk score signature based on the lncRNAs associated with m5C regulators. According to the median risk score, we divided BRCA patients into high- and low-risk groups. The prognostic risk signature displayed excellent accuracy and demonstrated sufficient independence from other clinical characteristics. The immune cell infiltration analysis showed that the prognostic risk signature was related to the infiltration of immune cell subtypes. Drug sensitivity proved that our prognostic risk signature potentially has therapeutic value.

CONCLUSIONS

The m5C-related lncRNA signature reliably predicted the prognosis of breast cancer patients and may provide new insight into the breast cancer tumor immune microenvironment.

LINC00543 promotes colorectal cancer metastasis by driving EMT and inducing the M2 polarization of tumor associated macrophages

BACKGROUND

The interaction between the tumor-microenvironment (TME) and the cancer cells has emerged as a key player in colorectal cancer (CRC) metastasis. A small proportion of CRC cells which undergo epithelial-mesenchymal transition (EMT) facilitate the reshaping of the TME by regulating various cellular ingredients.

METHODS

Immunohistochemical analysis, RNA immunoprecipitation (RIP), RNA Antisense Purification (RAP), dual luciferase assays were conducted to investigate the biological function and regulation of LINC00543 in CRC. A series in vitro and in vivo experiments were used to clarify the role of LINC00543 in CRC metastasis.

RESULTS

Here we found that the long non-coding RNA LINC00543, was overexpressed in colorectal cancer tissues, which correlated with advanced TNM stage and poorer prognosis of CRC patients. The overexpression of LINC00543 promoted tumorigenesis and metastasis of CRC cells by enhancing EMT and remodeling the TME. Mechanistically, LINC00543 blocked the transport of pre-miR-506-3p across the nuclear-cytoplasmic transporter XPO5, thereby reducing the production of mature miR-506-3p, resulting in the increase in the expression of FOXQ1 and induction of EMT. In addition, upregulation of FOXQ1 induced the expression of CCL2 that accelerated the recruitment of macrophages and their M2 polarization.

CONCLUSIONS

Our study showed that LINC00543 enhanced EMT of CRC cells through the pre-miR-506-3p/FOXQ1 axis. This resulted in the upregulation of CCL2, leading to macrophages recruitment and M2 polarization, and ultimately stimulating the progression of CRC.

New progress in the role of microRNAs in the diagnosis and prognosis of triple negative breast cancer

Triple negative breast cancer is distinguished by its high malignancy, aggressive invasion, rapid progression, easy recurrence, and distant metastases. Additionally, it has a poor prognosis, a high mortality, and is unresponsive to conventional endocrine and targeted therapy, making it a challenging problem for breast cancer treatment and a hotspot for scientific research. Recent research has revealed that certain miRNA can directly or indirectly affect the occurrence, progress and recurrence of TNBC. Their expression levels have a significant impact on TNBC diagnosis, treatment and prognosis. Some miRNAs can serve as biomarkers for TNBC diagnosis and prognosis. This article summarizes the progress of miRNA research in TNBC, discusses their roles in the occurrence, invasion, metastasis, prognosis, and chemotherapy of TNBC, and proposes a treatment strategy for TNBC by interfering with miRNA expression levels.

circBGN accelerates gastric cancer cell proliferation and invasion via activating IL6/STAT3 signaling pathway

Circular RNAs participate in the pathogenesis of various tumors, including gastric cancer (GC). In this study, we investigated the role of circBGN in regulating proliferation and invasion of GC cells and elucidated the mechanism. The expression of circBGN was assessed by quantitative reverse-transcription PCR and in situ hybridization. In addition, loss- and gain-of-function investigations in vitro and in vivo were performed to determine the biological functions of circBGN. Luciferase reporter assays and rescue experiments were applied to investigate the interaction between circBGN and miR-149-5p as well as the relationship between miR-149-5p and IL6. Our results showed that circBGN expression was significantly elevated in GC tissues and cells. Knockdown of circBGN dramatically suppressed GC cell proliferation and invasion in vitro. Xenograft experiments revealed that knockdown of circBGN delayed tumor growth in vivo. Furthermore, circBGN can directly bind to miR-149-5p, thereby preventing miR-149-5p from binding to its target mRNA [IL6 mRNA], thus activating IL6/STAT3 signaling pathway. Rescue assays indicated that circBGN regulates GC cell proliferation and invasion by upregulating miR-149-5p/IL6 axis output. Taken together, our investigation indicates that circBGN supports GC progression by activating IL6/STAT3 signaling pathway, thus pointing to a new possible therapeutic target in GC.

Regulation of CCL2 by EZH2 affects tumor-associated macrophages polarization and infiltration in breast cancer

Tumor associated macrophages (TAMs) play an important role in tumorigenesis, development and anti-cancer drug therapy. However, very few epigenetic compounds have been elucidated to affect tumor growth by educating TAMs in the tumor microenvironment (TME). Herein, we identified that EZH2 performs a crucial role in the regulation of TAMs infiltration and protumoral polarization by interacting with human breast cancer (BC) cells. We showed that EZH2 inhibitors-treated BC cells induced M2 macrophage polarization in vitro and in vivo, while EZH2 knockdown exhibited the opposite effect. Mechanistically, inhibition of EZH2 histone methyltransferase alone by EZH2 inhibitors in breast cancer cells could reduce the enrichment of H3K27me3 on CCL2 gene promoter, elevate CCL2 transcription and secretion, contributing to the induction of M2 macrophage polarization and recruitment in TME, which reveal a potential explanation behind the frustrating results of EZH2 inhibitors against breast cancer. On the contrary, EZH2 depletion led to DNA demethylation and subsequent upregulation of miR-124-3p level, which inhibited its target CCL2 expression in the tumor cells, causing arrest of TAMs M2 polarization. Taken together, these data suggested that EZH2 can exert opposite regulatory effects on TAMs polarization through its enzymatic or non-enzymatic activities. Our results also imply that the effect of antitumor drugs on TAMs may affect its therapeutic efficacy, and the combined application with TAMs modifiers should be warranted to achieve great clinical success.

CircMMP9 accelerates the progression of hepatocellular carcinoma through the miR-149/CCND2 axis

BACKGROUND

This study aimed to verify the hypothesis that circular RNA MMP9 (circMMP9) promotes hepatocellular carcinoma (HCC) progression through targeting miR-149 and regulating cyclin D2 (CCND2) expression.

METHODS

Expression of circMMP9, miR-149 and CCND2 was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) or protein blotting. Cell Counting Kit-8 (CCK-8) was used to evaluate cell proliferation. The HCC cell migration and invasion were evaluated using wound healing and transwell assays. The interaction among circMMP9, miR-149, and CCND2 was evaluated using luciferase, RNA-pull down, and RNA immunoprecipitation (RIP) assays, respectively. Cell apoptosis and cycle were examined by flow cytometry. A subcutaneous HCC xenograft mouse model was established for analyzing the role of circMMP9 in regulating the progression of HCC in vivo.

RESULTS

The expression of circMMP9 was elevated in HCC tissues and its high expression correlated with poor prognosis (P<0.05). Knockdown of circMMP9 restrained the proliferation, migration, and invasion of HCC cells and led to arrested cell cycle and increased apoptosis (all P<0.05). Furthermore, knockdown of circMMP9 attenuated HCC growth in vivo (P<0.05). Mechanically, circMMP9 acted as a sponge for miR-149 and enhanced CCND2 expression in HCC cells (P<0.05). Inhibition of miR-149 or overexpression of CCND2 abrogated knockdown of circMMP9-mediated alleviation of the malignant phenotypes of HCC (P<0.05).

CONCLUSIONS

For the first time, we demonstrated that circMMP9 exacerbated HCC progression through the miR-149/CCND2 axis, which suggested that circMMP9 could be potentially targeted for HCC treatment.

The circular RNA hsa_circ_0003091 regulates sepsis-induced lung injury by sponging the miR-149/Smad2 axis

Sepsis-induced acute lung injury (ALI) is a severe cause of death. Increasing evidence has identified circular RNAs (circRNAs) acting as critical regulators of human diseases. However, their expression pattern and underlying mechanisms in ALI remain unclear. Herein, we screened the circRNAs of ALI patients and constructed a lung injury murine model using lipopolysaccharides (LPS) induction. Functional analyses of targeted circRNA were performed in vivo and in vitro. Then, the downstream miRNA and mRNA of specific circRNAs were identified. Compared to healthy subjects, 35 circRNAs were upregulated and 9 circRNAs were downregulated in sepsis patients. The top 10 differentially expressed circRNAs were selected for validation and has_circ_0003091 was selected. The ALI mice presented significantly elevated has_circ_0003091 (mmu_circ_0015268). The functional analysis revealed that mmu_circ_0015268 contributed to the pulmonary injury, cell apoptosis, inflammatory responses, and endothelial activation in the ALI murine model. On the other hand, silencing mmu_circ_0015268 showed protective effects in LPS-treated mice and PMVECs. Furthermore, mmu_circ_0015268 sponged miR-149 to upregulate the expression of its target Smad2. In summary, we demonstrated that has_circ_0003091 might be a novel target for the management and treatment of sepsis-induced ALI.

Predicting lymph node metastasis and prognosis of individual cancer patients based on miRNA-mediated RNA interactions

Background

Lymph node metastasis is usually detected based on the images obtained from clinical examinations. Detecting lymph node metastasis from clinical examinations is a direct way of diagnosing metastasis, but the diagnosis is done after lymph node metastasis occurs.

Results

We developed a new method for predicting lymph node metastasis based on differential correlations of miRNA-mediated RNA interactions in cancer. The types of RNAs considered in this study include mRNAs, lncRNAs, miRNAs, and pseudogenes. We constructed cancer patient-specific networks of miRNA mediated RNA interactions and identified key miRNA–RNA pairs from the network. A prediction model using differential correlations of the miRNA–RNA pairs of a patient as features showed a much higher performance than other methods which use gene expression data. The key miRNA–RNA pairs were also powerful in predicting prognosis of an individual patient in several types of cancer.

Conclusions

Differential correlations of miRNA–RNA pairs identified from patient-specific networks of miRNA mediated RNA interactions are powerful in predicting lymph node metastasis in cancer patients. The key miRNA–RNA pairs were also powerful in predicting prognosis of an individual patient of solid cancer.

Non-coding RNAs and macrophage interaction in tumor progression

The macrophages are abundantly found in TME and their M2 polarization is in favor of tumor malignancy. On the other hand, non-coding RNAs (ncRNAs) can modulate macrophage polarization in TME to affect cancer progression. The miRNAs can dually induce/suppress M2 polarization of macrophages and by affecting various molecular pathways, they modulate tumor progression and therapy response. The lncRNAs can affect miRNAs via sponging and other molecular pathways to modulate macrophage polarization. A few experiments have also examined role of circRNAs in targeting signaling networks and affecting macrophages. The therapeutic targeting of these ncRNAs can mediate TME remodeling and affect macrophage polarization. Furthermore, exosomal ncRNAs derived from tumor cells or macrophages can modulate polarization and TME remodeling. Suppressing biogenesis and secretion of exosomes can inhibit ncRNA-mediated M2 polarization of macrophages and prevent tumor progression. The ncRNAs, especially exosomal ncRNAs can be considered as non-invasive biomarkers for tumor diagnosis.

Non-Exosomal and Exosome-Derived miRNAs as Promising Biomarkers in Canine Mammary Cancer

Canine mammary cancer (CMC), similar to human breast cancer (HBC) in many aspects, is the most common neoplasm associated with significant mortality in female dogs. Due to the limited therapy options, biomarkers are highly desirable for early clinical diagnosis or cancer progression monitoring. Since the discovery of microRNAs (miRNAs or miRs) as post-transcriptional gene regulators, they have become attractive biomarkers in oncological research. Except for intracellular miRNAs and cell-free miRNAs, exosome-derived miRNAs (exomiRs) have drawn much attention in recent years as biomarkers for cancer detection. Analysis of exosomes represents a non-invasive, pain-free, time- and money-saving alternative to conventional tissue biopsy. The purpose of this review is to provide a summary of miRNAs that come from non-exosomal sources (canine mammary tumor, mammary tumor cell lines or canine blood serum) and from exosomes as promising biomarkers of CMC based on the current literature. As is discussed, some of the miRNAs postulated as diagnostic or prognostic biomarkers in CMC were also altered in HBC (such as miR-21, miR-29b, miR-141, miR-429, miR-200c, miR-497, miR-210, miR-96, miR-18a, miR19b, miR-20b, miR-93, miR-101, miR-105a, miR-130a, miR-200c, miR-340, miR-486), which may be considered as potential disease-specific biomarkers in both CMC and HBC.

CircITGB6 promotes ovarian cancer cisplatin resistance by resetting tumor-associated macrophage polarization toward the M2 phenotype

Background

Platinum resistance is a major challenge in the clinical treatment of advanced ovarian cancer (OC). Accumulating evidence shows that the tumor-promotive M2 macrophage is linked to the limiting chemotherapy efficacy of multiple malignancies including OC. Circular RNAs (circRNAs) are a novel class of non-coding RNAs which function as the critical regulator in biological process of cancer. However, their impact on macrophage polarization and chemoresistance of OC remain unclear.

Methods

Platinum-resistant circRNAs were screened using circRNA deep sequencing and validated using in situ hybridization in OC tissues with or without platinum resistance. The role of circITGB6 in inducing cisplatin (CDDP) resistance was evaluated by clone formation, immunofluorescence and annexin V assays in vitro, and by intraperitoneal tumor model in vivo. The mechanism underlying circITGB6-mediated tumor-associated macrophage (TAM) polarization into M2 phenotype was investigated using RNA pull-down, luciferase reporter, electrophoretic mobility shift, RNA binding protein immunoprecipitation (RIP), ELISA and immunofluorescence assays.

Results

We identified that a novel circRNA, circITGB6, robustly elevated in tumor tissues and serums from patients with OC with platinum resistance, was correlated with poor prognosis. circITGB6 overexpression promoted an M2 macrophage-dependent CDDP resistance in both vivo and vitro. Mechanistic research determined that circITGB6 directly interacted with IGF2BP2 and FGF9 mRNA to form a circITGB6/IGF2BP2/FGF9 RNA–protein ternary complex in the cytoplasm, thereby stabilizing FGF9 mRNA and inducing polarization of TAMs toward M2 phenotype. Importantly, blocking M2 macrophage polarization with an antisense oligonucleotide targeting circITGB6 markedly reversed the circITGB6-induced CDDP resistance of OC in vivo.

Conclusions

This study reveals a novel mechanism for platinum resistance in OC and demonstrates that circITGB6 may serve as a potential prognostic marker and a therapeutic target for patients with OC.

Non-Coding RNAs in the Crosstalk between Breast Cancer Cells and Tumor-Associated Macrophages

Non-coding RNAs (ncRNAs) play a pivotal role in regulating the tumor microenvironment (TME) by controlling gene expression at multiple levels. In tumors, ncRNAs can mediate the crosstalk between cancer cells and other cells in the TME, such as immune cells, stromal cells, and endothelial cells, influencing tumor development and progression. Tumor-associated macrophages (TAMs) are among the most abundant inflammatory cells infiltrating solid cancers that promote tumorigenesis, and their infiltration correlates with a poor prognosis in many tumors. Cancer cells produce different ncRNAs that orchestrate TAM recruitment and polarization toward a tumor-promoting phenotype. Tumor-reprogrammed macrophages shape the TME by promoting angiogenesis and tissue remodeling, and suppressing the anti-tumor activity of adaptive immune cells. TAMs can also produce ncRNA molecules that boost cancer cell proliferation and direct their phenotype and metabolic changes facilitating cancer progression and metastasis. This review will focus on the crosstalk between cancer cells and TAMs mediated by microRNAs and long non-coding RNAs during breast cancer (BC) initiation and progression.

DNA methyltransferase 3 beta regulates promoter methylation of microRNA-149 to augment esophageal squamous cell carcinoma development through the ring finger protein 2/Wnt/β-catenin axis

Esophageal squamous cell carcinoma (ESCC) is an aggressive form of human squamous cell carcinomas with extremely aggressive pathological features. This study explores the functions of microRNA-149 (miR-149) and its interacted molecules in ESCC. The ESCC-related miRNA and messenger RNA (mRNA) datasets were applied to identify aberrantly expressed genes in ESCC. Forty-two patients with ESCC were included and their tissue samples were collected. miR-149 was poorly expressed whereas DNA methyltransferase 3 beta (DNMT3B) and ring finger protein 2 (RNF2) were abundantly expressed in ESCC tumor samples. Overexpression of miR-149 suppressed growth and invasiveness of ESCC cells in vitro and in vivo. DNMT3B bound to the promoter region of miR-149 to trigger its promoter methylation and downregulation. RNF2 mRNA was a target of miR-149. RNF2 overexpression blocked the inhibitory effect of miR-149 on ESCC cell growth. RNF2 activated the Wnt/β-catenin pathway to promote ESCC development. In conclusion, this study found that DNMT3B downregulates miR-149 level through methylation modification of the miR-149 promoter, while miR-149 suppresses RNF2 expression and inactivates the Wnt/β-catenin pathway to suppress growth of ESCC cells.

Tumor-associated macrophages: An important player in breast cancer progression

Breast cancer is the most common form of malignant tumor in females, accounting for the second highest mortality among cancer patients. In the breast tumor microenvironment, tumor-associated macrophages (TAMs) are the most abundant immune cells, which regulate the progression of breast cancer. During breast cancer tumorigenesis and progression, TAMs support breast tumor growth by promoting angiogenesis and cancer cell metastasis, inducing cancer stemness, regulating energy metabolism, and supporting immune system suppression. TAMs exhibit a high degree of cellular plasticity. Repolarizing tumor-related macrophages into M1 macrophages can promote tumor regression. This study reviews the role and mechanism of action of TAMs in the development of breast cancer and establishes TAMs as effective targets for breast cancer treatment.

Knockdown of circular RNA septin 9 inhibits the malignant progression of breast cancer by reducing the expression of solute carrier family 1 member 5 in a microRNA-149-5p-dependent manner

Breast cancer (BC) is the most frequently diagnosed cancer in women. Increasing evidence suggests that circular RNA (circRNA) exerts critical functions in BC progression. However, the roles of circRNA septin 9 (circSEPT9) in BC development and the underneath mechanism remain largely unclear so far. In this work, the RNA levels of circSEPT9, microRNA-149-5p (miR-149-5p) and solute carrier family 1 member 5 (SLC1A5) were detected by quantitative real-time polymerase chain reaction. Western blot was performed to check protein expression. Glutamine uptake, cell proliferation and cell apoptosis were investigated by glutamine uptake, cell counting kit-8, cell colony formation, 5-Ethynyl-29-deoxyuridine, flow cytometry analysis or DNA content quantitation assay. The interactions of miR-149-5p with circSEPT9 and SLC1A5 were identified by a dual-luciferase reporter assay. Mouse model assay was carried out to analyze the effect of circSEPT9 on tumor formation in vivo. Results showed that circSEPT9 and SLC1A5 expression were significantly upregulated, while miR-149-5p was downregulated in BC tissues and cells as compared with paracancerous normal breast tissues and human normal breast cells. Knockdown of circSEPT9 or SLC1A5 inhibited glutamine uptake and cell proliferation, but induced cell apoptosis in BC cells. SLC1A5 overexpression relieved circSEPT9 silencing-induced repression of BC cell malignancy. In mechanism, circSEPT9 regulated SLC1A5 expression by sponging miR-149-5p. In support, circSEPT9 knockdown led to delayed tumor tumorigenesis in vivo. In summary, these results indicates that circSEPT9 may act an oncogenic role in BC malignant progression by regulating miR-149-5p/SLC1A5 pathway, providing a novel mechanism responsible for BC development.

MicroRNAs regulating SOX2 in cancer progression and therapy response

The proliferation, metastasis and therapy response of tumour cells are tightly regulated by interaction among various signalling networks. The microRNAs (miRNAs) can bind to 3'-UTR of mRNA and down-regulate expression of target gene. The miRNAs target various molecular pathways in regulating biological events such as apoptosis, differentiation, angiogenesis and migration. The aberrant expression of miRNAs occurs in cancers and they have both tumour-suppressor and tumour-promoting functions. On the contrary, SOX proteins are capable of binding to DNA and regulating gene expression. SOX2 is a well-known member of SOX family that its overexpression in different cancers to ensure progression and stemness. The present review focuses on modulatory impact of miRNAs on SOX2 in affecting growth, migration and therapy response of cancers. The lncRNAs and circRNAs can function as upstream mediators of miRNA/SOX2 axis in cancers. In addition, NF-κB, TNF-α and SOX17 are among other molecular pathways regulating miRNA/SOX2 axis in cancer. Noteworthy, anti-cancer compounds including bufalin and ovatodiolide are suggested to regulate miRNA/SOX2 axis in cancers. The translation of current findings to clinical course can pave the way to effective treatment of cancer patients and improve their prognosis.

MiR-613 inhibits the proliferation, migration, and invasion of papillary thyroid carcinoma cells by directly targeting TAGLN2

Background

Papillary thyroid carcinoma (PTC), with a rapidly increasing incidence, is the most prevalent malignant cancer of the thyroid. However, its pathogenesis is unclear and its specific clinical indicators have not yet been identified. There is increasing evidence that microRNAs (miRNAs) play important roles in tumor occurrence and progression. Specifically, miR-613 participates in the regulation of tumor development in various cancers; however, its effects and mechanisms of action in PTC are still unclear. Therefore, in this study, we investigated the expression and function of miR-613 in PTC.

Methods

qRT-PCR was used to determine miR-613 expression in 107 pairs of PTC and adjacent-normal tissues as well as in PTC cell lines and to detect TAGLN2 mRNA expression in PTC tissues and adjacent normal tissues. Western blot analysis was performed to identify TAGLN2 and epithelial–mesenchymal transition (EMT) biomarkers. The effects of miR-613 on PTC progression were evaluated by performing MTS, wound-healing, and Transwell assays in vitro. Luciferase reporter assays were also performed to validate the target of miR-613.

Results

In PTC, miR-613 was significantly downregulated and its low expression level was associated with cervical lymph node metastasis. However, its overexpression significantly suppressed PTC cell proliferation, migration, and invasion and inhibited EMT. TAGLN2 was identified as a target of miR-613, which also significantly inhibited the expression of TAGLN2. Further, the restoration of TAGLN2 expression attenuated the inhibitory effects of miR-613 on PTC cell proliferation and metastasis.

Conclusion

Our findings demonstrated that miR-613 can suppress the progression of PTC cells by targeting TAGLN2, indicating that miR-613 plays the role of a tumor suppressor in PTC. Overall, these results suggest that the upregulation of miR-613 is a promising therapeutic strategy for PTC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02083-8.

Analysis of the signal cross talk via CCL26 in the tumor microenvironment in osteosarcoma

Interaction with surrounding healthy cells plays a major role in the growth and metastasis of osteosarcoma. In this study, we hypothesized that humoral factors, which do not require direct contact with cells, are involved in the interaction between osteosarcoma and the surrounding cells. We identified the humoral factor involved in the association between tumor cells and surrounding normal cells using a co-culture model and investigated the significance of our findings. When human osteosarcoma cells (MG63) and human mesenchymal stem cells (hMSCs) were co-cultured and comprehensively analyzed for changes in each culture group, we found that the expression of chemokine (CC motif) ligand 26 (CCL26) was significantly enhanced. We also analyzed the changes in cell proliferation in co-culture, enhanced interaction with administration of recombinant CCL26 (rCCL26), reduced interaction with administration of anti-CCL26 antibodies, changes in invasive and metastatic abilities. CCL26 levels, motility, and invasive capability increased in the co-culture group and the group with added rCCL26, compared to the corresponding values in the MG63 single culture group. In the group with added CCL26 neutralizing antibodies, CCL26 level decreased in both the single and co-culture groups, and motility and invasive ability were also reduced. In a nude mice lung metastasis model, the number of lung metastases increased in the co-culture group and the group with added rCCL26, whereas the number of tumors were suppressed in the group with added neutralizing antibodies compared to those in the MG63 alone. This study identified a possible mechanism by which osteosarcoma cells altered the properties of normal cells to favorably change the microenvironment proximal to tumors and to promote distant metastasis.

Breast Cancer Drug Resistance: Overcoming the Challenge by Capitalizing on MicroRNA and Tumor Microenvironment Interplay

The clinical management of breast cancer reaches new frontiers every day. However, the number of drug resistant cases is still high, and, currently, this constitutes one of the major challenges that cancer research has to face. For instance, 50% of women affected with HER2 positive breast cancer presents or acquires resistance to trastuzumab. Moreover, for patients affected with triple negative breast cancer, standard chemotherapy is still the fist-line therapy, and often patients become resistant to treatments. Tumor microenvironment plays a crucial role in this context. Indeed, cancer-associated stromal cells deliver oncogenic cues to the tumor and vice versa to escape exogenous insults. It is well known that microRNAs are among the molecules exploited in this aberrant crosstalk. Indeed, microRNAs play a crucial function both in the induction of pro-tumoral traits in stromal cells and in the stroma-mediated fueling of tumor aggressiveness. Here, we summarize the most recent literature regarding the involvement of miRNAs in the crosstalk between tumor and stromal cells and their capability to modulate tumor microenvironment characteristics. All up-to-date findings suggest that microRNAs in the TME could serve both to reverse malignant phenotype of stromal cells, modulating response to therapy, and as predictive/prognostic biomarkers.

Roles for growth factors and mutations in metastatic dissemination

Cancer is initiated largely by specific cohorts of genetic aberrations, which are generated by mutagens and often mimic active growth factor receptors, or downstream effectors. Once initiated cells outgrow and attract blood vessels, a multi-step process, called metastasis, disseminates cancer cells primarily through vascular routes. The major steps of the metastatic cascade comprise intravasation into blood vessels, circulation as single or collectives of cells, and eventual colonization of distant organs. Herein, we consider metastasis as a multi-step process that seized principles and molecular players employed by physiological processes, such as tissue regeneration and migration of neural crest progenitors. Our discussion contrasts the irreversible nature of mutagenesis, which establishes primary tumors, and the reversible epigenetic processes (e.g. epithelial-mesenchymal transition) underlying the establishment of micro-metastases and secondary tumors. Interestingly, analyses of sequencing data from untreated metastases inferred depletion of putative driver mutations among metastases, in line with the pivotal role played by growth factors and epigenetic processes in metastasis. Conceivably, driver mutations may not confer the same advantage in the microenvironment of the primary tumor and of the colonization site, hence phenotypic plasticity rather than rigid cellular states hardwired by mutations becomes advantageous during metastasis. We review the latest reported examples of growth factors harnessed by the metastatic cascade, with the goal of identifying opportunities for anti-metastasis interventions. In summary, because the overwhelming majority of cancer-associated deaths are caused by metastatic disease, understanding the complexity of metastasis, especially the roles played by growth factors, is vital for preventing, diagnosing and treating metastasis.

A Pan-cancer Analysis Reveals the Abnormal Expression and Drug Sensitivity of CSF1

BACKGROUND

Colony-stimulating factor-1 (CSF1) is a cytokine that is closely related to normal organ growth and development as well as tumor progression.

OBJECTIVE

We aimed to summarize and clarify the reasons for the abnormal expression of CSF1 in tumors and explore the role of CSF1 in tumor progression. Furthermore, drug response analysis may provide a reference for clinical medication.

METHODS

The expression of CSF1 was analyzed by TCGA and CCLE. Besides, cBioPortal and MethSurv databases were used to conduct mutation and DNA methylation analyses. Further, correlations between CSF1 expression and tumor stage, survival, immune infiltration, drug sensitivity and enrichment analyses were validated via UALCAN, Kaplan-Meier plotter, TIMER, CTRP and Coexperia databases.

RESULTS

CSF1 is expressed in a variety of tissues, meaningfully, it can be detected in blood. Compared with normal tissues, CSF1 expression was significantly decreased in most tumors. The missense mutation and DNA methylation of CSF1 may cause the downregulated expression. Moreover, decreased CSF1 expression was related with higher tumor stage and worse survival. Further, the promoter DNA methylation level of CSF1 was prognostically significant in most tumors. Besides, CSF1 was closely related to immune infiltration, especially macrophages. Importantly, CSF1 expression was associated with a good response to VEGFRs inhibitors, which may be due to the possible involvement of CSF1 in tumor angiogenesis and metastasis processes.

CONCLUSION

The abnormal expression of CSF1 could serve as a promising biomarker of tumor progression and prognosis in pan-cancer. Significantly, angiogenesis and metastasis inhibitors may show a good response to CSF1-related tumors.

miR-497 inhibits proliferation and invasion in triple-negative breast cancer cells via YAP1

MicroRNA (miR)-497 has been reported as a tumor suppressor in various cancer types. Nonetheless, the regulation of triple-negative breast cancer (TNBC) by miR-497 remains poorly understood. The present study aimed to investigate the potential function and mechanism of miR-497 in TNBC. A total of 36 TNBC and matched non-cancerous tissue samples were collected for analysis. Reverse transcription-quantitative PCR was performed to detect the miR-497 levels in TNBC tissue. The association between miR-497 expression, clinical characteristics and survival was then analyzed. To investigate the role of miR-497 in TNBC, MTT, colony formation, Transwell invasion, cell cycle and cell apoptosis assays were conducted following transfection of miR-497 mimics into the MDA-MB-231 and MDA-MB-468 cell lines. Luciferase reporter assays and western blot analysis were used to confirm the regulation of a putative target of miR-497. The results indicated that the expression of miR-497 was downregulated in the TNBC specimens. Further analysis demonstrated that the expression of miR-497 was downregulated in patients with advanced TNBC stages and that low miR-497 was associated with poor prognosis in patients with TNBC. Transfection of miR-497 mimics inhibited TNBC cell proliferation and increased cell apoptosis in MDA-MB-231 and MDA-MB-468 cells. Moreover, cell migration was inhibited following overexpression of miR-497, which also led to the arrest of the breast cancer cells in the G₀/G₁ phase of the cell cycle. Yes-associated protein 1 (YAP1), a critical molecule in the Hippo pathway, was identified as a target of miR-497. Notably, the protein and mRNA expression levels of YAP1 in MDA-MB-231 and MDA-MB-468 cells were downregulated following overexpression of miR-497. Overall, the findings of the present study indicated that miR-497 inhibited TNBC cell proliferation and migration and induced cell apoptosis by negatively regulating YAP1 expression. Thus, targeting miR-497 may represent a potential strategy for the treatment of TNBC.

MicroRNAs in Metastasis and the Tumour Microenvironment

Metastasis is the process whereby cancer cells migrate from the primary tumour site to colonise the surrounding or distant tissue or organ. Metastasis is the primary cause of cancer-related mortality and approximately half of all cancer patients present at diagnosis with some form of metastasis. Consequently, there is a clear need to better understand metastasis in order to develop new tools to combat this process. MicroRNAs (miRNAs) regulate gene expression and play an important role in cancer development and progression including in the metastatic process. Particularly important are the roles that miRNAs play in the interaction between tumour cells and non-tumoral cells of the tumour microenvironment (TME), a process mediated largely by circulating miRNAs contained primarily in extracellular vesicles (EVs). In this review, we outline the accumulating evidence for the importance of miRNAs in the communication between tumour cells and the cells of the TME in the context of the pre-metastatic and metastatic niche.

LncRNA SLC16A1-AS1 is Upregulated in Glioblastoma and Promotes Cancer Cell Proliferation by Regulating miR-149 Methylation

Introduction

LncRNA SLC16A1-AS1 has been characterized as a critical player in lung cancer, while its role in glioblastoma (GBM) is unknown. By analyzing the TCGA dataset, we observed the upregulation of SLC16A1-AS1 expression in GBM. Therefore, we aimed to investigate the role of SLC16A1-AS1 in this cancer.

Methods

GBM tissues and paired non-tumor tissues were collected from 62 GBM patients through biopsy. RT-qPCR was performed to determine the expression of SLC16A1-AS1 and miR-149. Linear regression was used to analyze their correlations. The relationship between SLC16A1-AS1 and miR-149 was assessed by gain and loss of function experiments. Methylation-specific PCR (MSP) and bisulfite sequencing PCR (BSP) were performed to analyze the methylation status of miR-149. Cell proliferation was evaluated by CCK-8 assay and colony formation experiments in GBM cells.

Results

We found that SLC16A1-AS1 expression was upregulated in GBM tissues, and the upregulated expression of SLC16A1-AS1 predicted poor survival of GBM patients. MiR-149 was downregulated in GBM tissues and inversely correlated with the expression of SLC16A1-AS1. In GBM cells, overexpression of SLC16A1-AS1 downregulated the expression of miR-149 and increased the methylation of miR-149 gene. In cell proliferation and colony formation assay, overexpression of SLC16A1-AS1 reduced the inhibitory effects of miR-149 on GBM cell proliferation.

Conclusion

SLC16A1-AS1 may promote GBM cell proliferation by regulating miR-149 methylation. SLC16A1-AS1 can be considered as a potential diagnostic marker in GBM.

Tumor-associated macrophages: potential therapeutic strategies and future prospects in cancer

Macrophages are the most important phagocytes in vivo. However, the tumor microenvironment can affect the function and polarization of macrophages and form tumor-associated macrophages (TAMs). Usually, the abundance of TAMs in tumors is closely associated with poor prognosis. Preclinical studies have identified important pathways regulating the infiltration and polarization of TAMs during tumor progression. Furthermore, potential therapeutic strategies targeting TAMs in tumors have been studied, including inhibition of macrophage recruitment to tumors, functional repolarization of TAMs toward an antitumor phenotype, and other therapeutic strategies that elicit macrophage-mediated extracellular phagocytosis and intracellular destruction of cancer cells. Therefore, with the increasing impact of tumor immunotherapy, new antitumor strategies to target TAMs are now being discussed.

Identification of MicroRNAs as Diagnostic Biomarkers for Breast Cancer Based on the Cancer Genome Atlas

Breast cancer is the most common cancer among women worldwide. MicroRNAs (miRNAs or miRs) play an important role in tumorigenesis, and thus, they have been identified as potential targets for translational research with diagnostic, prognostic, and therapeutic markers. This study aimed to identify differentially expressed (DE) miRNAs in breast cancer using the Cancer Genome Atlas. The miRNA profiles of 755 breast cancer tissues and 86 adjacent non-cancerous breast tissues were analyzed using Multi Experiment Viewer; miRNA–mRNA network analyses and constructed KEGG pathways with the predicted target genes were performed. The clinical relevance of miRNAs was investigated using area under the receiver operating characteristic curve (AUC) analysis, sensitivity, and specificity. The analysis identified 28 DE miRNAs in breast cancer tissues, including nine upregulated and 19 downregulated miRNAs, compared to non-cancerous breast tissues (p < 0.001). The AUC for each DE miRNA, miR-10b, miR-21, miR-96, miR-99a, miR-100, miR-125b-1, miR-125b-2, miR-139, miR-141, miR-145, miR-182, miR-183, miR-195, miR-200a, miR-337, miR-429, and let-7c, exceeded 0.9, indicating excellent diagnostic performance in breast cancer. Moreover, 1381 potential target genes were predicted using the prediction database tool, miRNet. These genes are related to PD-L1 expression and PD-1 checkpoint in cancer, MAPK signaling, apoptosis, and TNF pathways; hence, they regulate the development, progression, and immune escape of cancer. Thus, these 28 miRNAs can serve as prospective biomarkers for the diagnosis of breast cancer. Taken together, these results provide insight into the pathogenic mechanisms and potential therapies for breast cancer.

Circular PVT1 regulates cell proliferation and invasion via miR-149-5p/FOXM1 axis in ovarian cancer

Long non-coding RNA plasmacytoma variant translocation 1 (PVT1) is a dysregulated gene in malignancy and is associated with oncogenesis. In this study, we found PVT1 RNA was an ovarian specific expressing gene, and overexpressed in multiple cancer types, including ovarian cancer (OV). Higher expression levels of PVT1 are related to shorter survival time in OV patients, especially in patients with advanced stage and grade. Recent studies indicated circular PVT1 also had an important role in cancer progression, whose roles in OV remain unclear. Knockdown of circular PVT1 significantly suppressed OV cell proliferation, migration and invasion. Bioinformatics analysis demonstrated that circular PVT1 was involved in regulating angiogenesis, osteoblast differentiation, regulation of cell growth, type B pancreatic cell proliferation, negative regulation of apoptotic process, phospholipid homeostasis, regulation of neurogenesis, definitive hemopoiesis, cell migration, regulation of glucose metabolic process, central nervous system development and type 2 immune response. Our data showed miR-149-5p targeted FOXM1, which was regulated by circular PVT1. Forkhead Box M1 (FOXM1) expression in ovarian cancer exhibited high level when compared with normal tissues, and had relation with relatively poor survival. FOXM1 promoted cell viability and reduced FOXM1 could rescue circular influence of circular PVT1-caused carcinoma induction. In conclusion, circular PVT1 increased FOXM1 level via binding to miR-149-5p and thus affected ovarian cancer cell viability and migration.

Polysaccharides Derived from Saposhnikovia divaricata May Suppress Breast Cancer Through Activating Macrophages

BACKGROUND

Saposhnikovia divaricata (SD) has been used in traditional Chinese medicine to treat pain, inflammation, and arthritis. Recently, it has been reported that SD extract may inhibit tumor growth, but the mechanism involved is elusive. The aim of this study was to investigate the anti-tumor activity of polysaccharides derived from SD in breast cancer and the underlying mechanisms.

MATERIALS AND METHODS

Polysaccharides isolated from SD were analyzed using Fourier transform infrared (FT-IR) spectroscopy and gas chromatography-mass spectroscopy (GC-MS). Their effects on cell growth of U937, MCF-7, and MDA-MB-231, and tumor growth in a mouse MDA-MB 231 xenograft model were examined. Their role in U937 activation, MCF-7, and MDA-MB 231 cytokine release profiles were also tested.

RESULTS

In vitro studies showed that SD polysaccharides (SDPs) promoted U937 cell growth dose-dependently, with no obvious effect on growth of breast cancer cell lines MCF-7 and MDA-MB-231. SDP also showed an antagonistic effect against the growth inhibition of U937 by the culture supernatants of MCF-7 and MDA-MB-231, and reversed the polarization status of U937. Treatment of SCID mice bearing MDA-MB-231-derived xenograft tumors with SDP significantly reduced tumor growth. At all tested concentrations, no obvious toxic side-effects were recorded.

DISCUSSION

We tentatively concluded that SDPs potently promote the growth of U937 and activate it to inhibit the tumor growth of SCID mice bearing MDA-MB-231-derived xenograft tumors indirectly, with no obvious growth inhibition effects on MCF-7 and MDA-MB-231 in vitro. Our finding indicated that SDP could be a potential anticancer agent for breast cancer.

MicroRNA-149: A review of its role in digestive system cancers

MicroRNAs (miRNAs) are a group of highly conserved, short (18-25 nucleotide long) non-coding RNAs which play important functional roles in cellular differentiation, biological development, pathogenesis and disease susceptibility and have been linked to both tumorigenesis and the malignant progression of various cancers. miRNAs primarily exert their function through the negative regulation of their target gene's transcription via the specific recognition of their 3' untranslated region. A single miRNA can regulate multiple target genes and most miRNAs are controlled by several factors. Recent studies have shown that microRNA-149 (miR-149) plays a pivotal role in the pathogenesis of digestive system cancers and may act as a potential diagnostic marker and therapeutic target. In this review, we summarize and discuss the most recent reports describing miR-149 in digestive system cancers, including its single nucleotide polymorphisms, expression levels, target genes, drug sensitivity and clinical significance.

Emerging Cancer Epigenetic Mechanisms Regulated by All-Trans Retinoic Acid

All-trans retinoic acid (RA), which is the dietary bioactive derivative obtained from animal (retinol) and plant sources (beta-carotene), is a physiological lipid signal of both embryonic and postembryonic development. During pregnancy, either RA deficiency or an excessive RA intake is teratogenic. Too low or too high RA affects not only prenatal, but also postnatal, developmental processes such as myelopoiesis and mammary gland morphogenesis. In this review, we mostly focus on emerging RA-regulated epigenetic mechanisms involving RA receptor alpha (RARA) and Annexin A8 (ANXA8), which is a member of the Annexin family, as well as ANXA8 regulatory microRNAs (miRNAs). The first cancer showing ANXA8 upregulation was reported in acute promyelocytic leukemia (APL), which induces the differentiation arrest of promyelocytes due to defective RA signaling caused by RARA fusion genes as the PML-RARA gene. Over the years, ANXA8 has also been found to be upregulated in other cancers, even in the absence of RARA fusion genes. Mechanistic studies on human mammary cells and mammary glands of mice showed that ANXA8 upregulation is caused by genetic mutations affecting RARA functions. Although not all of the underlying mechanisms of ANXA8 upregulation have been elucidated, the interdependence of RA-RARA and ANXA8 seems to play a relevant role in some normal and tumorigenic settings.