Up-regulation of miR-210 induced by a hypoxic microenvironment promotes breast cancer stem cells metastasis, proliferation, and self-renewal by targeting E-cadherin

MicroRNA as a promising molecular biomarker in the diagnosis of breast cancer

Introduction: Breast cancer represents the most prevalent malignancy among women. Recent advancements in translational research have focused on the identification of novel biomarkers capable of providing valuable insights into patient outcomes. Furthermore, comprehensive investigations aimed at discovering novel miRNAs, unraveling their biological functions, and deciphering their target genes have significantly contributed to our understanding of the roles miRNAs play in tumorigenesis. Consequently, these investigations have facilitated the way for the development of miRNA-based approaches for breast cancer prognosis, diagnosis, and treatment. However, conducting a more extensive array of studies, particularly among diverse ethnic groups, is imperative to expand the scope of research and validate the significance of miRNAs. This study aimed to assess the expression patterns of circulating miRNAs in plasma as a prospective biomarker for breast cancer patients within a population primarily consisting of individuals from Black, Indigenous, and People of Color (BIPOC) communities. Methods: We evaluated 49 patients with breast cancer compared to 44 healthy women. Results and discussion: All miRNAs analyzed in the plasma of patients with breast cancer were downregulated. ROC curve analysis of miR-21 (AUC = 0.798, 95% CI: 0.682-0.914, p <0.0001), miR-1 (AUC = 0.742, 95% CI: 0.576-0.909, p = 0.004), miR-16 (AUC = 0.721, 95% CI: 0.581-0.861, p = 0.002) and miR-195 (AUC = 0.672, 95% CI: 0.553-0.792, p = 0.004) showed better diagnostic accuracy in discrimination of breast cancer patients in comparison with healthy women. miR-210, miR-21 showed the highest specificities values (97.3%, 94.1%, respectively). Following, miR-10b and miR-195 showed the highest sensitivity values (89.3%, and 77.8%, respectively). The panel with a combination of four miRNAs (miR-195 + miR-210 + miR-21 + miR-16) had an AUC of 0.898 (0.765-0.970), a sensitivity of 71.4%, and a specificity of 100.0%. Collectively, our results highlight the miRNA combination in panels drastically improves the results and showed high accuracy for the diagnosis of breast cancer displaying good sensitivity and specificity.

The mechanisms of tanshinone in the treatment of tumors

Tanshinone is a lipophilic compound that is present in traditional Chinese medicine and is derived from the roots of Salvia miltiorrhiza (Danshen). It has been proven to be highly effective in combating tumors in various parts of the body, including liver carcinoma, gastric cancer, ovarian cancer, cervix carcinoma, breast cancer, colon cancer, and prostate cancer. Tanshinone can efficiently prevent the reproduction of cancerous cells, induce cell death, and inhibit the spread of cancerous cells, which are mainly involved in the PI3K/Akt signaling pathway, NF-κB pathway, Bcl-2 family, Caspase cascades, MicroRNA, MAPK signaling pathway, p21, STAT3 pathway, miR30b-P53-PTPN11/SHP2 axis, β-catenin, and Skp2. However, the properties and mechanisms of tanshinone's anti-tumor effects remain unclear currently. Thus, this study aims to review the research progress on tumor prevention and mechanisms of tanshinone to gain new perspectives for further development and clinical application of tanshinone.

Hypoxia-driven ncRNAs in breast cancer

Low oxygen tension, or hypoxia is the driving force behind tumor aggressiveness, leading to therapy resistance, metastasis, and stemness in solid cancers including breast cancer, which now stands as the leading cause of cancer-related mortality in women. With the great advancements in exploring the regulatory roles of the non-coding genome in recent years, the wide spectrum of hypoxia-responsive genome is not limited to just protein-coding genes but also includes multiple types of non-coding RNAs, such as micro RNAs, long non-coding RNAs, and circular RNAs. Over the years, these hypoxia-responsive non-coding molecules have been greatly implicated in breast cancer. Hypoxia drives the expression of these non-coding RNAs as upstream modulators and downstream effectors of hypoxia inducible factor signaling in the favor of breast cancer through a myriad of molecular mechanisms. These non-coding RNAs then contribute in orchestrating aggressive hypoxic tumor environment and regulate cancer associated cellular processes such as proliferation, evasion of apoptotic death, extracellular matrix remodeling, angiogenesis, migration, invasion, epithelial-to-mesenchymal transition, metastasis, therapy resistance, stemness, and evasion of the immune system in breast cancer. In addition, the interplay between hypoxia-driven non-coding RNAs as well as feedback and feedforward loops between these ncRNAs and HIFs further contribute to breast cancer progression. Although the current clinical implications of hypoxia-driven non-coding RNAs are limited to prognostics and diagnostics in breast cancer, extensive explorations have established some of these hypoxia-driven non-coding RNAs as promising targets to treat aggressive breast cancers, and future scientific endeavors hold great promise in targeting hypoxia-driven ncRNAs at clinics to treat breast cancer and limit global cancer burden.

The Intricate Interplay between Cancer Stem Cells and Oncogenic miRNAs in Breast Cancer Progression and Metastasis

Complex signaling interactions between cancer cells and their microenvironments drive the clonal selection of cancer cells. Opposing forces of antitumor and tumorigenic potential regulate the survival of the fittest clones, while key genetic and epigenetic alterations in healthy cells force them to transform, overcome cell senescence, and proliferate in an uncontrolled manner. Both clinical samples and cancer cell lines provide researchers with an insight into the complex structure and hierarchy of cancer. Intratumor heterogeneity allows for multiple cancer cell subpopulations to simultaneously coexist within tumors. One category of these cancer cell subpopulations is cancer stem cells (CSCs), which possess stem-like characteristics and are not easily detectable. In the case of breast cancer, which is the most prevalent cancer type among females, such subpopulations of cells have been isolated and characterized via specific stem cell markers. These stem-like cells, known as breast cancer stem cells (BCSCs), have been linked to major events during tumorigenesis including invasion, metastasis and patient relapse following conventional therapies. Complex signaling circuitries seem to regulate the stemness and phenotypic plasticity of BCSCs along with their differentiation, evasion of immunosurveillance, invasiveness and metastatic potential. Within these complex circuitries, new key players begin to arise, with one of them being a category of small non-coding RNAs, known as miRNAs. Here, we review the importance of oncogenic miRNAs in the regulation of CSCs during breast cancer formation, promotion and metastasis, in order to highlight their anticipated usage as diagnostic and prognostic tools in the context of patient stratification and precision medicine.

Interactions between non-coding RNAs and HIF-1α in the context of cancer

Hypoxia-inducible factor 1α (HIF-1α) is a subunit of the HIF-1 transcription factor which is encoded by the HIF1A gene. This transcription factor is the main modulator of the cell response to hypoxia. Hypoxia-induced up-regulation of HIF-1α is involved in the pathogenesis of cancer. Recently, the interactions of several long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) with HIF-1α have been reported. These ncRNAs regulate the expression of HIF-1α through different mechanisms. The regulatory roles of ncRNAs on HIF-1α are involved in the response of cancer cells to a wide range of anticancer drugs such as sorafenib, cisplatin, propofol, doxorubicin, and paclitaxel. Therefore, identification of the complex network between ncRNAs and HIF-1α not only facilitates the design of novel therapies but also promotes the efficacy of conventional anticancer treatments. This review aims to explain the interactions between these classes of ncRNAs and HIF-1α in the context of cancer.

A novel necroptosis-associated miRNA signature predicting prognosis of endometrial cancer and correlated with immune infiltration

OBJECTIVE

Necroptosis is a form of programmed cell death identified irrelevant to caspases, which plays an important role in the tumorigenesis and development of cancer. MicroRNAs (miRNAs) are important regulators of both necroptosis and cancer.

MATERIALS AND METHODS

Expression of sixteen necroptosis-associated miRNAs were analyzed in 546 endometrial cancer (EC) tissues and 33 paracancerous samples from the Cancer Genome Atlas (TCGA). Cox regression analysis was used to evaluate the correlations between miRNAs and overall survival. MiRNAs risk score (Mrs) and nomogram were established to assess the potential value of necroptosis-related miRNAs on prognosis. Expression of miRNA-148a-3p in endometrial cancer cells and endometrial epithelial cells was detected by quantitative real-time PCR (qRT-PCR). The targets genes of miR-148a-3p were predicted using miRDB, miRTarBase and TargetScan and the prognostic-related genes were screened. Immune infiltration analysis was conducted to explore the potential mechanism of these target genes.

RESULTS

We identified fourteen differentially expressed miRNAs and selected seven miRNAs (miR-15a-5p, miR148a-3p, miR-7-5p, miR-141-3p, miR-200a-5p, miR-223-3p, miR-16-5p) for prognostic-model construction. The area under the curve (AUC) of receiver operating characteristic (ROC) curve for 1-, 2- and 5-year survival were 0.678, 0.652 and 0.656 respectively. Multivariate analysis revealed that the Mrs was an independent prognostic factor considering other risk factors (HR = 1.928, 95% CI = 1.072-3.467, P = 0.028). Among these miRNAs, miRNA-148a-3p was up-regulated in cancer tissues and cells, and Kaplan-Meier analysis showed its significance in overall survival (OS). The target genes, DNAJB4 and PRNP, were associated with poor prognosis and correlated with tumor immune infiltration.

CONCLUSIONS

Our study constructed a novel necroptosis-associated miRNAs model for prognosis prediction, and DNAJB4 and PRNP may be therapeutic targets for EC.

miR-210 Expression Is Strongly Hypoxia-Induced in Anaplastic Thyroid Cancer Cell Lines and Is Associated with Extracellular Vesicles and Argonaute-2

Hypoxia, or low oxygen tension, is frequently found in highly proliferative solid tumors such as anaplastic thyroid carcinoma (ATC) and is believed to promote resistance to chemotherapy and radiation. Identifying hypoxic cells for targeted therapy may thus be an effective approach to treating aggressive cancers. Here, we explore the potential of the well-known hypoxia-responsive microRNA (miRNA) miR-210-3p as a cellular and extracellular biological marker of hypoxia. We compare miRNA expression across several ATC and papillary thyroid cancer (PTC) cell lines. In the ATC cell line SW1736, miR-210-3p expression levels indicate hypoxia during exposure to low oxygen conditions (2% O2). Furthermore, when released by SW1736 cells into the extracellular space, miR-210-3p is associated with RNA carriers such as extracellular vesicles (EVs) and Argonaute-2 (AGO2), making it a potential extracellular marker for hypoxia.

HIF‑1α inhibits ferroptosis and promotes malignant progression in non‑small cell lung cancer by activating the Hippo‑YAP signalling pathway

Ferroptosis and hypoxia-inducible factor 1α (HIF-1α) have critical roles in human tumors. The aim of the present study was to investigate the associations between ferroptosis, HIF-1α and cell growth in non-small cell lung cancer (NSCLC) cells. The lung cancer cell lines SW900 and A549 were evaluated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to detect the expression of HIF-1α. Cell Counting Kit-8, flow cytometry and Transwell migration assays were used to measure cell viability, apoptosis and invasion, respectively. The production of reactive oxygen species (ROS) and levels of malondialdehyde (MDA), glutathione (GSH) and ferrous ion (Fe²⁺) were determined using detection kits. The expression levels of glutathione peroxidase 4 (GPX4) and Yes-associated protein 1 (YAP1) were detected using RT-qPCR and western blotting. The results showed that the expression of HIF-1α was significantly upregulated in NSCLC cells compared with normal human bronchial epithelial cells. Small interfering RNA specific to HIF-1α (si-HIF-1α) significantly decreased the proliferation and invasion of NSCLC cells and increased their apoptosis. si-HIF-1α also increased the levels of ROS, MDA and Fe²⁺ but decreased GSH and GPX4 levels in A549 cells. Additionally, si-HIF-1α increased phosphorylated (p-)YAP1 levels, suppressed GPX4 and YAP1 expression, and attenuated the YAP1 overexpression-induced changes in YAP1, p-YAP1 and GPX4 levels and cell viability. The ferroptosis antagonist ferrostatin-1 partially attenuated the effects of si-HIF-1α on the NSCLC cells, while the ferroptosis agonist erastin further inhibited NSCLC growth by blocking HIF-1α expression. In conclusion, the silencing of HIF-1α induces ferroptosis by suppressing Hippo-YAP pathway activation in NSCLC cells. The present study provides novel insights into the malignant progression of NSCLC and suggests that HIF-1α is an effective target for the treatment of NSCLC.

Drug Resistance: The Role of Exosomal miRNA in the Microenvironment of Hematopoietic Tumors

Extracellular vesicles (EVs), including exosomes, have an important role thanks to their ability to communicate and exchange information between tumor cells and the tumor microenvironment (TME), and have also been associated with communicating anti-cancer drug resistance (DR). The increase in proliferation of cancer cells alters oxygen levels, which causes hypoxia and results in a release of exosomes by the cancer cells. In this review, the results of studies examining the role of exosomal miRNA in DR, and their mechanism, are discussed in detail in hematological tumors: leukemia, lymphoma, and multiple myeloma. In conclusion, we underline the exosome's function as a possible drug delivery vehicle by understanding its cargo. Engineered exosomes can be used to be more specific for personalized therapy.

Conducive target range of breast cancer: Hypoxic tumor microenvironment

Breast cancer is a kind of malignant tumor disease that poses a serious threat to human health. Its biological characteristics of rapid proliferation and delayed angiogenesis, lead to intratumoral hypoxia as a common finding in breast cancer. HIF as a transcription factor, mediate a series of reactions in the hypoxic microenvironment, including metabolic reprogramming, tumor angiogenesis, tumor cell proliferation and metastasis and other important physiological and pathological processes, as well as gene instability under hypoxia. In addition, in the immune microenvironment of hypoxia, both innate and acquired immunity of tumor cells undergo subtle changes to support tumor and inhibit immune activity. Thus, the elucidation of tumor microenvironment hypoxia provides a promising target for the resistance and limited efficacy of current breast cancer therapies. We also summarize the hypoxic mechanisms of breast cancer treatment related drug resistance, as well as the current status and prospects of latest related drugs targeted HIF inhibitors.

Hypoxia-regulated microRNAs: the molecular drivers of tumor progression

Hypoxia is a common feature of the tumor microenvironment (TME) of nearly all solid tumors, leading to therapeutic failure. The changes in stiffness of the extracellular matrix (ECM), pH gradients, and chemical balance that contribute to multiple cancer hallmarks are closely regulated by intratumoral oxygen tension via its primary mediators, hypoxia-inducible factors (HIFs). HIFs, especially HIF-1α, influence these changes in the TME by regulating vital cancer-associated signaling pathways and cellular processes including MAPK/ERK, NF-κB, STAT3, PI3K/Akt, Wnt, p53, and glycolysis. Interestingly, research has revealed the involvement of epigenetic regulation by hypoxia-regulated microRNAs (HRMs) of downstream target genes involved in these signaling. Through literature search and analysis, we identified 48 HRMs that have a functional role in the regulation of 5 key cellular processes: proliferation, metabolism, survival, invasion and migration, and immunoregulation in various cancers in hypoxic condition. Among these HRMs, 17 were identified to be directly associated with HIFs which include miR-135b, miR-145, miR-155, miR-181a, miR-182, miR-210, miR-224, miR-301a, and miR-675-5p as oncomiRNAs, and miR-100-5p, miR-138, miR-138-5p, miR-153, miR-22, miR-338-3p, miR-519d-3p, and miR-548an as tumor suppressor miRNAs. These HRMs serve as a potential lead in the development of miRNA-based targeted therapy for advanced solid tumors. Future development of combined HIF-targeted and miRNA-targeted therapy is possible, which requires comprehensive profiling of HIFs-HRMs regulatory network, and improved formula of the delivery vehicles to enhance the therapeutic kinetics of the targeted cancer therapy (TCT) moving forward.

Three-Dimensional Organotypic Cultures Reshape the microRNAs Transcriptional Program in Breast Cancer Cells

The 3D organotypic cultures, which depend on the growth of cells over the extracellular matrix (ECM) used as a scaffold, can better mimic several characteristics of solid cancers that influence tumor biology and the response to drug therapies. Most of our current knowledge on cancer is derived from studies in 2D cultures, which lack the ECM-mediated microenvironment. Moreover, the role of miRNAs that is critical for fine-tuning of gene expression is poorly understood in 3D cultures. The aim of this study was to compare the miRNA expression profiles of breast cancer cells grown in 2D and 3D conditions. On an on-top 3D cell culture model using a basement membrane matrix enriched with laminin, collagen IV, entactin, and heparin-sulfate proteoglycans, the basal B (Hs578T) and luminal (T47D) breast cancer cells formed 3D spheroid-like stellate and rounded mass structures, respectively. Morphological changes in 3D cultures were observed as cell stretching, cell–cell, and cell–ECM interactions associated with a loss of polarity and reorganization on bulk structures. Interestingly, we found prolongations of the cytoplasmic membrane of Hs578T cells similar to tunneled nanotubes contacting between neighboring cells, suggesting the existence of cellular intercommunication processes and the possibility of fusion between spheroids. Expression profiling data revealed that 354 miRNAs were differentially expressed in 3D relative to 2D cultures in Hs578T cells. Downregulated miRNAs may contribute to a positive regulation of genes involved in hypoxia, catabolic processes, and focal adhesion, whereas overexpressed miRNAs modulate genes involved in negative regulation of the cell cycle. Target genes of the top ten modulated miRNAs were selected to construct miRNA/mRNA coregulation networks. Around 502 interactions were identified for downregulated miRNAs, including miR-935/HIF1A and miR-5189-3p/AKT that could contribute to cell migration and the response to hypoxia. Furthermore, the expression levels of miR-935 and its target HIF1A correlated with the expression found in clinical tumors and predicted poor outcomes. On the other hand, 416 interactions were identified for overexpressed miRNAs, including miR-6780b-5p/ANKRD45 and miR-7641/CDK4 that may result in cell proliferation inhibition and cell cycle arrest in quiescent layers of 3D cultures. In conclusion, 3D cultures could represent a suitable model that better resembles the miRNA transcriptional programs operating in tumors, with implications not only in the understanding of basic cancer biology in 3D microenvironments, but also in the identification of novel biomarkers of disease and potential targets for personalized therapies in cancer.

Pancreatic cancer and oligonucleotide therapy: Exploring novel therapeutic options and targeting chemoresistance

Pancreatic cancer (PC) represents a malignancy with increased mortality rate, as less than 10% of patients survive for 5 years after diagnosis. Current evolution in basic sciences has revealed promising results by decrypting genetic loci vulnerable to mutations, as potential targets of novel treatment choices. In this regard, the "Oligonucleotide therapeutics", based on synthetic nucleotides, modify the function and expression of their targets. Antisense oligonucleotides (ASOs), small interfering RNA (siRNA), microRNAs (miRNAs), aptamers, CpG oligodeoxynucleotides and decoys comprise the main representatives of this emerging technology, by regulating oncogenes' expression, restoring DNA repairment mechanisms, sensitizing cancer cells in chemotherapy, and inhibiting PC progress. A plethora of genetic treatment molecules and respective targets have been described and are currently studied, thus providing a broad range of probable pharmaceutical options. This narrative review illuminates the main parameters of genetic treatment molecules for PC and underlines their deficiencies, to clarify the upcoming future and trigger further investigation in PC management.

Deciphering a Novel Necroptosis-Related miRNA Signature for Predicting the Prognosis of Clear Cell Renal Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common histological and devastating subtype of renal cell carcinoma. Necroptosis is a form of programmed cell death that causes prominent inflammatory responses. miRNAs play a significant role in cancer progression through necroptosis. However, the prognostic value of necroptosis-related miRNAs remains ambiguous. In this study, 39 necroptosis-related miRNAs (NRMs) were extracted and 17 differentially expressed NRMs between normal and tumor samples were identified using data form The Cancer Genome Atlas (TCGA). After applying univariate Cox proportional hazard regression analysis and LASSO Cox regression model, six necroptosis-related miRNA signatures were identified in the training cohort and their expression levels were verified by qRT-PCR. Using the expression levels of these miRNAs, all patients were divided into the high- and low-risk groups. Patients in the high-risk group showed poor overall survival (P < 0.0001). Time-dependent ROC curves confirmed the good performance of our signature. The results were verified in the testing cohort and the entire TCGA cohort. Univariate and multivariate Cox regression models demonstrated that the risk score was an independent prognostic factor. Additionally, a predictive nomogram with good performance was constructed to enhance the implementation of the constructed signature in a clinical setting. We then employed miRBD, miRTarBase, and TargetScan to predict the target genes of six necroptosis-related miRNAs. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that 392 potential target genes were enriched in cell proliferation-related biological processes. Six miRNAs and 59 differentially expressed target genes were used to construct an miRNA–mRNA interaction network, and 11 hub genes were selected for survival and tumor infiltration analysis. Drug sensitivity analysis revealed potential drugs that may contribute to cancer management. Hence, necroptosis-related genes play an important role in cancer biology. We developed, for the first time, a necroptosis-related miRNA signature to predict ccRCC prognosis.

miR-210 hypoxamiR in Angiogenesis and Diabetes

Significance: microRNA-210 (miR-210) is the master hypoxia-inducible miRNA (hypoxamiR) since it has been found to be significantly upregulated under hypoxia in a wide range of cell types. Recent advances: Gene ontology analysis of its targets indicates that miR-210 modulates several aspects of cellular response to hypoxia. Due to its high pleiotropy, miR-210 not only plays a protective role by fine-tuning mitochondrial metabolism and inhibiting red-ox imbalance and apoptosis, but it can also promote cell proliferation, differentiation, and migration, substantially contributing to angiogenesis. Critical issues: As most miRNAs, modulating different gene pathways, also miR-210 can potentially lead to different and even opposite effects, depending on the physio-pathological contexts in which it acts. Future direction: The use of miRNAs as therapeutics is a fast growing field. This review aimed at highlighting the role of miR-210 in angiogenesis in the context of ischemic cardiovascular diseases and diabetes in order to clarify the molecular mechanisms underpinning miR-210 action. Particular attention will be dedicated to experimentally validated miR-210 direct targets involved in cellular processes related to angiogenesis and diabetes mellitus, such as mitochondrial metabolism, redox balance, apoptosis, migration, and adhesion. Antioxid. Redox Signal. 36, 685-706.

Tanshinone IIA attenuates the stemness of breast cancer cells via targeting the miR-125b/STARD13 axis

BACKGROUND

Tanshinone II A is an effective component extracted from Salvia miltiorrhiza and the roles of Tanshinone IIA in regulating the stemness of tumor cells remain unclear. This work aims to explore the roles and underlying mechanisms of Tanshinone IIA in breast cancer stemness.

METHODS

In vitro mammary spheroid formation, flow cytometry assay on CD24^-/CD44⁺ sub-population, ALDH activity detection, cell viability assay and western blot analysis, and in vivo tumor-initiating analysis were performed to examine the effects of Tanshinone IIA on the stemness of breast cancer cells. MiRNAs-based transcriptome sequencing and data analysis, online dataset analysis, luciferase reporter assay combined with rescuing experiments were constructed to explore the underlying mechanisms.

RESULTS

Tanshinone IIA attenuated the stemness of breast cancer cells, evident by downregulating the expression of stemness markers, hindering the capacity of spheroid formation, decreasing the CD24^-/CD44⁺ sub-population in a concentration-dependent manner and reducing the tumor-initiating ability of breast cancer cells. Additionally, Tanshinone IIA enhanced adriamycin sensitivity and attenuated adriamycin resistance of breast cancer cells. Combined with miRNAs-based transcriptome sequencing assay, it was found that Tanshinone IIA downregulated miR-125b level and upregulated its target gene STARD13 (StAR-related lipid transfer protein 13) level, thus inactivating the miR-125b/STARD13 axis, which had been previously confirmed to promote breast cancer progression. Notably, miR-125b overexpression enhanced the stemness of breast cancer cells, and miR-125b overexpression or STARD13 knockdown impaired the inhibitory effects of Tanshinone IIA on the stemness of breast cancer cells.

CONCLUSIONS

Tanshinone IIA could attenuate the stemness of breast cancer cells via targeting the miR-125b/STARD13 axis.

miR-210 Regulates Apoptotic Cell Death during Cellular Hypoxia and Reoxygenation in a Diametrically Opposite Manner

Apoptotic cell death of cardiomyocytes is a characteristic hallmark of ischemia-reperfusion (I/R) injury. The master hypoxamiR, microRNA-210 (miR-210), is considered the primary driver of the cellular response to hypoxic stress. However, to date, no consensus has emerged with regards to the polarity of the miR-210-elicited cellular response, as miR-210 has been shown to exacerbate as well as attenuate hypoxia-driven apoptotic cell death. Herein, in AC-16 cardiomyocytes subjected to hypoxia-reoxygenation (H-R) stress, we unravel novel facets of miR-210 biology and resolve the biological response mediated by miR-210 into the hypoxia and reoxygenation temporal components. Using transient overexpression and decoy/inhibition vectors to modulate miR-210 expression, we elucidated a Janus role miR-210 in the cellular response to H-R stress, wherein miR-210 mitigated the hypoxia-induced apoptotic cell death but exacerbated apoptotic cell death during cellular reoxygenation. We further delineated the underlying cellular mechanisms that confer this diametrically opposite effect of miR-210 on apoptotic cell death. Our exhaustive biochemical assays cogently demonstrate that miR-210 attenuates the hypoxia-driven intrinsic apoptosis pathway, while significantly augmenting the reoxygenation-induced caspase-8-mediated extrinsic apoptosis pathway. Our study is the first to unveil this Janus role of miR-210 and to substantiate the cellular mechanisms that underlie this functional duality.

The Expression Regulatory Network in the Lung Tissue of Tibetan Pigs Provides Insight Into Hypoxia-Sensitive Pathways in High-Altitude Hypoxia

To adapt to a low-oxygen environment, Tibetan pigs have developed a series of unique characteristics and can transport oxygen more effectively; however, the regulation of the associated processes in high-altitude animals remains elusive. We performed mRNA-seq and miRNA-seq, and we constructed coexpression regulatory networks of the lung tissues of Tibetan and Landrace pigs. HBB, AGT, COL1A2, and EPHX1 were identified as major regulators of hypoxia-induced genes that regulate blood pressure and circulation, and they were enriched in pathways related to signal transduction and angiogenesis, such as HIF-1, PI3K-Akt, mTOR, and AMPK. HBB may promote the combination of hemoglobin and oxygen as well as angiogenesis for high-altitude adaptation in Tibetan pigs. The expression of MMP2 showed a similar tendency of alveolar septum thickness among the four groups. These results indicated that MMP2 activity may lead to widening of the alveolar wall and septum, alveolar structure damage, and collapse of alveolar space with remarkable fibrosis. These findings provide a perspective on hypoxia-adaptive genes in the lungs in addition to insights into potential candidate genes in Tibetan pigs for further research in the field of high-altitude adaptation.

MicroRNAs in Molecular Classification and Pathogenesis of Breast Tumors

The current clinical practice of breast tumor classification relies on the routine immunohistochemistry-based expression analysis of hormone receptors, which is inadequate in addressing breast tumor heterogeneity and drug resistance. MicroRNA expression profiling in tumor tissue and in the circulation is an efficient alternative to intrinsic molecular subtyping that enables precise molecular classification of breast tumor variants, the prediction of tumor progression, risk stratification and also identifies critical regulators of the tumor microenvironment. This review integrates data from protein, gene and miRNA expression studies to elaborate on a unique miRNA-based 10-subtype taxonomy, which we propose as the current gold standard to allow appropriate classification and separation of breast cancer into a targetable strategy for therapy.

HIF-1α promotes the migration and invasion of cancer-associated fibroblasts by miR-210

Metastasis is the major cause of death in colorectal cancer (CRC) patients. Inhibition of metastasis will prolong the survival of patients with CRC. Cancer cells bring their own soil, cancer-associated fibroblasts (CAFs), to metastasize together, promoting the survival and colonization of circulating cancer cells. However, the mechanism by which CAFs metastasize remains unclear. In this study, CAFs were derived from adipose mesenchymal stem cells (MSCs) after co-culture with CRC cell lines. Transwell assays showed that CAFs have stronger migration and invasion abilities than MSCs. In a nude mouse subcutaneous xenograft model, CAFs metastasized from the primary tumour to the lung and promoted the formation of CRC metastases. The expression of HIF-1α was upregulated when MSCs differentiated into CAFs. Inhibition of HIF-1α expression inhibited the migration and invasion of CAFs. Western blot and ChIP assays were used to identify the genes regulated by HIF-1α. HIF-1α regulated the migration and invasion of CAFs by upregulating miR-210 transcription. Bioinformatics analysis and luciferase reporter assays revealed that miR-210 specifically targeted the 3'UTR of VMP1 and regulated its expression. Downregulation of VMP1 enhanced the migration and invasion of CAFs. In vivo, inhibition of miR-210 expression in CAFs reduced the metastasis of CAFs and tumour cells. Therefore, the HIF-1α/miR-210/VMP1 pathway might regulate the migration and invasion of CAFs in CRC. Inhibition of CAF metastasis might reduce CRC metastasis.

A Novel TCGA-Validated, MiRNA-Based Signature for Prediction of Breast Cancer Prognosis and Survival

Breast cancer (BC) is the most common cancer affecting women and the leading cause of cancer-related deaths worldwide. Compelling evidence indicates that microRNAs (miRNAs) are inextricably involved in the development of cancer. Here, we constructed a novel model, based on miRNA-seq and clinical data downloaded from The Cancer Genome Atlas (TCGA). Data from a total of 962 patients were included in this study, and the relationships among their clinicopathological features, survival, and miRNA-seq expression levels were analyzed. Hsa-miR-186 and hsa-miR-361 were identified as internal reference miRNAs and used to normalize miRNA expression data. A five-miRNA signature, constructed using univariate and multivariate Cox regression, was significantly associated with disease-specific survival (DSS) of patients with BC. Kaplan–Meier (KM) and receiver operating characteristic (ROC) analyses were conducted to confirm the clinical significance of the five-miRNA signature. Finally, a nomogram was constructed based on the five-miRNA signature to evaluate its clinical value. Cox regression analysis revealed that a five-miRNA signature was significantly associated with DSS of patients with BC. KM analysis demonstrated that the signature could efficiently distinguish high- and low-risk patients. Moreover, ROC analysis showed that the five-miRNA signature exhibited high sensitivity and specificity in predicting the prognosis of patients with BC. Patients in the high-risk subgroup who received adjuvant chemotherapy had a significantly lower incidence of mortality than those who did not. A nomogram constructed based on the five-miRNA signature was effective in predicting 5-year DSS. This study presents a novel five-miRNA signature as a reliable prognostic tool to predict DSS and provide theoretical reference significance for individualized clinical decisions for patients with BC.

Identification of cancer stemness related miRNA(s) using integrated bioinformatics analysis and in vitro validation

The stemness property of cells allows them to sustain their lineage, differentiation, proliferation, and regeneration. MicroRNAs are small non-coding RNAs known to regulate the stemness property of cells by regulating the expression of stem cell signaling pathway proteins at mRNA level. Dysregulated miRNA expression and associated stem cell signaling pathways in normal stem cells give rise to cancer stem cells. Thus, the present study was aimed to identify the miRNAs involved in the regulation of major stem cell signaling pathways. The proteins (n = 36) involved in the signaling pathways viz., Notch, Wnt, JAK-STAT, and Hedgehog which is associated with the stemness property was taken into the consideration. The miRNAs, having binding sites for the targeted protein-encoding gene were predicted using an online tool (TargetScan) and the common miRNA among the test pathways were identified using Venn diagram analysis. A total of 22 common miRNAs (including 8 non-studied miRNAs) were identified which were subjected to target predictions, KEGG pathway, and gene ontology (GO) analysis to study their potential involvement in the stemness process. Further, we studied the clinical relevance of the non-studied miRNAs by performing the survival analysis and their expression levels in clinical breast cancer patients using the TCGA database. The identified miRNAs showed overall poor survival in breast cancer patients. The miR-6844 showed significantly high expression in various clinical subgroups of invasive breast cancer patients compared with the normal samples. The expression levels of identified miRNA(s) were validated in breast normal, luminal A, triple-negative, and stem cells in vitro models using qRT-PCR analysis. Further treatment with the phytochemical showed excellent down regulation of the lead miRNA. Overall the study first time reports the association of four miRNAs (miR-6791, miR-4419a, miR-4251 and miR-6844) with breast cancer stemness.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-02994-3.

Establishment and Validation of a Prognostic Immune Signature in Neuroblastoma

BACKGROUND

Neuroblastoma (NBL) is the most common extracranial solid tumor in childhood, and patients with high-risk neuroblastoma had a relatively poor prognosis despite multimodal treatment. To improve immunotherapy efficacy in neuroblastoma, systematic profiling of the immune landscape in neuroblastoma is an urgent need.

METHODS

RNA-seq and according clinical information of neuroblastoma were downloaded from the TARGET database and GEO database (GSE62564). With an immune-related-gene set obtained from the ImmPort database, Immune-related Prognostic Gene Pairs for Neuroblastoma (IPGPN) for overall survival (OS) were established with the TARGET-NBL cohort and then verified with the GEO-NBL cohort. Immune cell infiltration analysis was subsequently performed. The integrated model was established with IPGPN and clinicopathological parameters. Immune cell infiltration was analyzed with the XCELL algorithm. Functional enrichment analysis was performed with clusterProfiler package in R.

RESULTS

Immune-related Prognostic Gene Pairs for Neuroblastoma was successfully established with seven immune-related gene pairs (IGPs) involving 13 unique genes in the training cohort. In the training cohort, IPGPN successfully stratified neuroblastoma patients into a high and low immune-risk groups with different OS (HR=3.92, P = 2 × 10^-8) and event-free survival (HR=3.66, P=2 × 10^-8). ROC curve analysis confirmed its predictive power. Consistently, high IPGPN also predicted worse OS (HR=1.84, P = .002) and EFS in validation cohort (HR=1.38, P = .06) Moreover, higher activated dendritic cells, M1 macrophage, Th1 CD4⁺, and Th2 CD4⁺ T cell enrichment were evident in low immune-risk group. Further integrating IPGPN with age and stage demonstrated improved predictive performance than IPGPN alone.

CONCLUSION

Herein, we presented an immune landscape with IPGPN for prognosis prediction in neuroblastoma, which complements the present understanding of the immune signature in neuroblastoma.

MicroRNA-9 as a paradoxical but critical regulator of cancer metastasis: Implications in personalized medicine

Metastasis, is a development of secondary tumor growths at a distance from the primary site, and closely related to poor prognosis and mortality. However, there is still no effective treatment for metastatic cancer. Therefore, there is an urgent need to find an effective therapy for cancer metastasis. Plenty of evidence indicates that miR-9 can function as a promoter or suppressor in cancer metastasis and coordinate multistep of metastatic process. In this review, we summarize the different roles of miR-9 with the corresponding molecular mechanisms in metastasis of twelve common cancers and the multiple mechanisms underlying miR-9-mediated regulation of metastasis, benefiting the further research of miR-9 and metastasis, and hoping to bridge it with clinical applications.

Non-coding RNAs in necroptosis, pyroptosis and ferroptosis in cancer metastasis

Distant metastasis is the main cause of death for cancer patients. Recently, the newly discovered programmed cell death includes necroptosis, pyroptosis, and ferroptosis, which possesses an important role in the process of tumor metastasis. At the same time, it is widely reported that non-coding RNA precisely regulates programmed death and tumor metastasis. In the present review, we summarize the function and role of necroptosis, pyrolysis, and ferroptosis involving in cancer metastasis, as well as the regulatory factors, including non-coding RNAs, of necroptosis, pyroptosis, and ferroptosis in the process of tumor metastasis.

The Impact of lncRNAs and miRNAs in Regulation of Function of Cancer Stem Cells and Progression of Cancer

Stem cells have two important features, namely the ability for self-renewal and the capacity to differentiate into some cell kinds with specialized functions. These two features are also present in cancer stem cells (CSCs). These cells have been detected in almost all kinds of cancers facilitating their tumorigenicity. Molecular cascades that control self-renewal of stem cells, namely the Wnt, Notch, and Hedgehog pathways have been suggested to influence CSCs functions as well. Moreover, non-coding RNAs can regulate function of CSCs. Function of miRNAs in the regulation of CSCs has been mostly assessed in breast cancer and hepatocellular carcinoma. miR-130a-3p, miR-600, miR-590-5p, miR-142-3p, miR-221, miR-222, miR-638, miR-375, miR-31, and miR-210 are among those regulating this feature in breast cancer. Moreover, miR-206, miR-192-5p, miR-500a-3p, miR-125, miR-125b, miR-613, miR-217, miR-194, and miR-494 regulate function of CSCs in hepatocellular carcinoma. DILC, lncTCF7, MUF, HAND2-AS1, MALAT1, DLX6-AS1, HOTAIR, and XIST are among lncRNAs that regulate function of CSCs. In the present paper, we explain the effects of these two classes of non-coding RNAs in the regulation of activity of CSCs.

Polyphenol-Enriched Blueberry Preparation Controls Breast Cancer Stem Cells by Targeting FOXO1 and miR-145

Scientific evidence supports the early deregulation of epigenetic profiles during breast carcinogenesis. Research shows that cellular transformation, carcinogenesis, and stemness maintenance are regulated by epigenetic-specific changes that involve microRNAs (miRNAs). Dietary bioactive compounds such as blueberry polyphenols may modulate susceptibility to breast cancer by the modulation of CSC survival and self-renewal pathways through the epigenetic mechanism, including the regulation of miRNA expression. Therefore, the current study aimed to assay the effect of polyphenol enriched blueberry preparation (PEBP) or non-fermented blueberry juice (NBJ) on the modulation of miRNA signature and the target proteins associated with different clinical-pathological characteristics of breast cancer such as stemness, invasion, and chemoresistance using breast cancer cell lines. To this end, 4T1 and MB-MDM-231 cell lines were exposed to NBJ or PEBP for 24 h. miRNA profiling was performed in breast cancer cell cultures, and RT-qPCR was undertaken to assay the expression of target miRNA. The expression of target proteins was examined by Western blotting. Profiling of miRNA revealed that several miRNAs associated with different clinical-pathological characteristics were differentially expressed in cells treated with PEBP. The validation study showed significant downregulation of oncogenic miR-210 expression in both 4T1 and MDA-MB-231 cells exposed to PEBP. In addition, expression of tumor suppressor miR-145 was significantly increased in both cell lines treated with PEBP. Western blot analysis showed a significant increase in the relative expression of FOXO1 in 4T1 and MDA-MB-231 cells exposed to PEBP and in MDA-MB-231 cells exposed to NBJ. Furthermore, a significant decrease was observed in the relative expression of N-RAS in 4T1 and MDA-MB-231 cells exposed to PEBP and in MDA-MB-231 cells exposed to NBJ. Our data indicate a potential chemoprevention role of PEBP through the modulation of miRNA expression, particularly miR-210 and miR-145, and protection against breast cancer development and progression. Thus, PEBP may represent a source for novel chemopreventative agents against breast cancer.

Exosome-derived miR-210 involved in resistance to osimertinib and epithelial-mesenchymal transition in EGFR mutant non-small cell lung cancer cells

Background

Osimertinib is a third‐generation epidermal growth factor receptor‐tyrosine kinase inhibitor (EGFR‐TKI) approved for the treatment of patients with EGFR‐mutant non‐small cell lung cancer (NSCLC). However, the mechanisms of acquired drug resistance to osimertinib have not as yet been clarified. Exosomes and microRNAs (miRNAs) are involved in carcinogenesis and drug resistance in human cancers.

Methods

We used previously established osimertinib‐resistant HCC827 (HCC827‐OR) and PC‐9 (PC‐9‐OR) cells. We evaluated the profiles of exosomal miRNA associated with resistance to osimertinib in EGFR‐mutant NSCLC cells.

Results

Epithelial–mesenchymal transition (EMT) phenomenon was observed in HCC827‐OR and PC‐9‐OR cells. Microarray and quantitative reverse transcription‐polymerase chain reaction analysis revealed that miR‐210‐3p was co‐upregulated in exosomes isolated from HCC827‐OR and PC‐9‐OR cells compared with those isolated from parental HCC827 and PC‐9 cells. HCC827‐OR cell‐derived exosomes induced EMT changes and resistance to osimertinib in HCC827 cells. Subsequently, the induction of miR‐210‐3p directly promoted the EMT phenomenon and resistance to osimertinib in HCC827 cells.

Conclusions

Exosomal miR‐210‐3p may play a crucial role in resistance to osimertinib in the tumor microenvironment of EGFR‐mutant NSCLC.

Signaling pathways governing breast cancer stem cells behavior

Breast cancer is the second common cancer and the leading cause of malignancy among females overall. Breast cancer stem cells (BCSCs) are a small population of breast cancer cells that play a critical role in the metastasis of breast cancer to other organs in the body. BCSCs have both self-renewal and differentiation capacities, which are thought to contribute to the aggressiveness of metastatic lesions. Therefore, targeting BCSCs can be a suitable approach for the treatment and metastasis of breast cancer. Growing evidence has indicated that the Wnt, NFκB, Notch, BMP2, STAT3, and hedgehog (Hh) signaling pathways govern epithelial-to-mesenchymal transition (EMT) activation, growth, and tumorigenesis of BCSCs in the primary regions. miRNAs as the central regulatory molecules also play critical roles in BCSC self-renewal, metastasis, and drug resistance. Hence, targeting these pathways might be a novel therapeutic approach for breast cancer diagnosis and therapy. This review discusses known signaling mechanisms involved in the stimulation or prevention of BCSC self-renewal, metastasis, and tumorigenesis.

Forecasting sensitive targets of the kynurenine pathway in pancreatic adenocarcinoma using mathematical modeling

In this study, a new mathematical model was established and validated to forecast and define sensitive targets in the kynurenine pathway (Kynp) in pancreatic adenocarcinoma (PDAC). Using the Panc-1 cell line, genetic profiles of Kynp molecules were tested. qPCR data were implemented in the algorithm programming (fmincon and lsqnonlin function) to estimate 35 parameters of Kynp variables by Matlab 2017b. All tested parameters were defined as non-negative and bounded. Then, based on experimental data, the function of the fmincon equation was employed to estimate the approximate range of each parameter. These calculations were confirmed by qPCR and Western blot. The correlation coefficient (R) between model simulation and experimental data (72 hours, in intervals of 6 hours) of every variable was >0.988. The analysis of reliability and predictive accuracy depending on qPCR and Western blot data showed high predictive accuracy of the model; R was >0.988. Using the model calculations, kynurenine (x3, a6), GPR35 (x4, a8), NF-kβp105 (x7, a16), and NF-kβp65 (x8, a18) were recognized as sensitive targets in the Kynp. These predicted targets were confirmed by testing gene and protein expression responses. Therefore, this study provides new interdisciplinary evidence for Kynp-sensitive targets in the treatment of PDAC.

Hypoxia-Driven Effects in Cancer: Characterization, Mechanisms, and Therapeutic Implications

Hypoxia, a common feature of solid tumors, greatly hinders the efficacy of conventional cancer treatments such as chemo-, radio-, and immunotherapy. The depletion of oxygen in proliferating and advanced tumors causes an array of genetic, transcriptional, and metabolic adaptations that promote survival, metastasis, and a clinically malignant phenotype. At the nexus of these interconnected pathways are hypoxia-inducible factors (HIFs) which orchestrate transcriptional responses under hypoxia. The following review summarizes current literature regarding effects of hypoxia on DNA repair, metastasis, epithelial-to-mesenchymal transition, the cancer stem cell phenotype, and therapy resistance. We also discuss mechanisms and pathways, such as HIF signaling, mitochondrial dynamics, exosomes, and the unfolded protein response, that contribute to hypoxia-induced phenotypic changes. Finally, novel therapeutics that target the hypoxic tumor microenvironment or interfere with hypoxia-induced pathways are reviewed.

MiRNA-mediated EMT and CSCs in cancer chemoresistance

Cancer stem cells (CSCs) are a small group of cancer cells, which contribute to tumorigenesis and cancer progression. Cancer cells undergoing epithelial-to-mesenchymal transition (EMT) acquire the chemoresistant ability, which is regarded as an important feature of CSCs. Thus, there emerges an opinion that the generation of CSCs is considered to be driven by EMT. In this complex process, microRNAs (miRNAs) are found to play a key role. In order to overcome the drug resistance, inhibiting EMT as well as CSCs phenotype seem feasible. Thereinto, regulating the EMT- or CSCs-associated miRNAs is a crucial approach. Herein, we conduct this review to elaborate on the complicated interplay between EMT and CSCs in cancer chemoresistance, which is modulated by miRNAs. In addition, we elucidate the therapeutic strategy to overcome drug resistance through targeting EMT and CSCs.

Noncoding RNAs in the Interplay between Tumor Cells and Cancer-Associated Fibroblasts: Signals to Catch and Targets to Hit

Simple Summary

Cancer aggressiveness is the result of a proficient bidirectional interaction between tumor and stromal cells within the tumor microenvironment, among which a major role is played by the so-called cancer-associated fibroblasts. Upon such interplay, both cancer cells and fibroblasts are reprogrammed to sustain malignancy, with changes in the repertoire of noncoding RNAs, mainly microRNAs and long noncoding RNAs. Such molecules are also exchanged between the two cell types through extracellular vesicles. In this review, we summarize the current knowledge of microRNAs and long noncoding RNAs that act intracellularly or extracellularly to sustain tumor-stroma interplay. We also provide our view regarding the possible clinical utility of such noncoding RNAs as therapeutic target/tools or biomarkers to predict patient outcome or response to specific treatments.

Abstract

Cancer development and progression are not solely cell-autonomous and genetically driven processes. Dynamic interaction of cancer cells with the surrounding microenvironment, intended as the chemical/physical conditions as well as the mixture of non-neoplastic cells of the tumor niche, drive epigenetic changes that are pivotal for the acquisition of malignant traits. Cancer-associated fibroblasts (CAF), namely fibroblasts that, corrupted by cancer cells, acquire a myofibroblast-like reactive phenotype, are able to sustain tumor features by the secretion of soluble paracrine signals and the delivery extracellular vesicles. In such diabolic liaison, a major role has been ascribed to noncoding RNAs. Defined as RNAs that are functional though not being translated into proteins, noncoding RNAs predominantly act as regulators of gene expression at both the transcriptional and post-transcriptional levels. In this review, we summarize the current knowledge of microRNAs and long noncoding RNAs that act intracellularly in either CAFs or cancer cells to sustain tumor-stroma interplay. We also report on the major role of extracellular noncoding RNAs that are bidirectionally transferred between either cell type. Upon presenting a comprehensive view of the existing literature, we provide our critical opinion regarding the possible clinical utility of tumor-stroma related noncoding RNAs as therapeutic target/tools or prognostic/predictive biomarkers.

EMT-associated microRNAs and their roles in cancer stemness and drug resistance

Epithelial‐to‐mesenchymal transition (EMT) is implicated in a wide array of malignant behaviors of cancers, including proliferation, invasion, and metastasis. Most notably, previou studies have indicated that both cancer stem‐like properties and drug resistance were associated with EMT. Furthermore, microRNAs (miRNAs) play a pivotal role in the regulation of EMT phenotype, as a result, some miRNAs impact cancer stemness and drug resistance. Therefore, understanding the relationship between EMT‐associated miRNAs and cancer stemness/drug resistance is beneficial to both basic research and clinical treatment. In this review, we preliminarily looked into the various roles that the EMT‐associated miRNAs play in the stem‐like nature of malignant cells. Then, we reviewed the interaction between EMT‐associated miRNAs and the drug‐resistant complex signaling pathways of multiple cancers including lung cancer, gastric cancer, gynecologic cancer, breast cancer, liver cancer, colorectal cancer, pancreatic cancer, esophageal cancer, and nasopharyngeal cancer. We finally discussed the relationship between EMT, cancer stemness, and drug resistance, as well as looked forward to the potential applications of miRNA therapy for malignant tumors.

Obesity, leptin, and deregulation of microRNA in lipid metabolisms: their contribution to breast cancer prognosis

Obesity and Metabolic Syndrome have been associated with cardiovascular, diabetes and cancer incidence. Obesity is a state of inflammation. There are cross-talks between adipocyte, adipokines, pro-inflammatory cytokines, insulin, leptin, and other growth factors to initiate signals for proliferation, anti-apoptosis, and angiogenesis. Those networks lead to cancer initiation, promotion, progression, and metastasis. Post menopause women with breast cancer commonly have overweight, obesity, and metabolic syndrome, which are previously reported as conditions to be associated with breast cancer prognosis. MicroRNAs (miRNAs), small non-coding RNA that regulate gene expression, are known to play important roles either in metabolic or carcinogenesis process in patients with breast cancer. Some miRNAs expressions are deregulated in persons either with obesity, breast cancer, or breast cancer with co-morbid obesity. This literature review aimed at reviewing recent publications on the role of obesity, leptin, and microRNA deregulation in adverse prognosis of breast cancer. Understanding the influence of deregulated miRNAs and their target genes in patients with breast cancer and obesity will direct more studies to explore the potential prognostic role of obesity in breast cancer from epigenetic points of view.

The role of hypoxia in the tumor microenvironment and development of cancer stem cell: a novel approach to developing treatment

Hypoxia is a common feature of solid tumors, and develops because of the rapid growth of the tumor that outstrips the oxygen supply, and impaired blood flow due to the formation of abnormal blood vessels supplying the tumor. It has been reported that tumor hypoxia can: activate angiogenesis, thereby enhancing invasiveness and risk of metastasis; increase survival of tumor, as well as suppress anti-tumor immunity and hamper the therapeutic response. Hypoxia mediates these effects by several potential mechanisms: altering gene expression, the activation of oncogenes, inactivation of suppressor genes, reducing genomic stability and clonal selection. We have reviewed the effects of hypoxia on tumor biology and the possible strategiesto manage the hypoxic tumor microenvironment (TME), highlighting the potential use of cancer stem cells in tumor treatment.

miR-210 regulates the inflammation of otitis media with effusion by inhibiting the expression of hypoxia-inducible factor (HIF)-1a

Otitis media with effusion (OME) is the major cause of hearing impairment in children. miR-210 plays a critical role in inflammatory diseases, however, its role in OME is unknown. In this study, the miR-210 level in serum and middle ear effusion of is significantly down-regulated in serum, middle ear effusion from OME patients (100 cases) compared with healthy volunteers (50 cases). The expression of miR-210 is closely related to inflammatory factors and bone conduction disorder in patients with OME. In the in vitro study，the miR-210 level is significantly reduced in culture supernatant of lipopolysaccharide (LPS) treated human middle ear epithelial cells (HMEECs). miR-210 overexpression inhibited the LPS-induced in inflammatory cytokines production, cell viability reduction and cell apoptosis. Bioinformatics and dual-luciferase reporter assay showed that HIF-1a was a target gene of miR-210. The biological effects of miR-210 on cell viability, cell apoptosis and inflammation cytokines in LPS-induced HMEECs were reversed by HIF-1a overexpression. Furthermore, phosphorylation of NF-κB p65 was significantly decreased by miR-210 mediated HIF-1a in LPS-induced HMEECs. This study suggested that miR-210 may play a role in OME. Further studies are warranted to assess miR-210 as a potential target for the diagnosis and treatment of OME.

Three dimensional engineered models to study hypoxia biology in breast cancer

Breast cancer is the second leading cause of mortality among women worldwide. Despite the available therapeutic regimes, variable treatment response is reported among different breast cancer subtypes. Recently, the effects of the tumor microenvironment on tumor progression as well as treatment responses have been widely recognized. Hypoxia and hypoxia inducible factors in the tumor microenvironment have long been known as major players in tumor progression and survival. However, the majority of our understanding of hypoxia biology has been derived from two dimensional (2D) models. Although many hypoxia-targeted therapies have elicited promising results in vitro and in vivo, these results have not been successfully translated into clinical trials. These limitations of 2D models underscore the need to develop and integrate three dimensional (3D) models that recapitulate the complex tumor-stroma interactions in vivo. This review summarizes role of hypoxia in various hallmarks of cancer progression. We then compare traditional 2D experimental systems with novel 3D tissue-engineered models giving accounts of different bioengineering platforms available to develop 3D models and how these 3D models are being exploited to understand the role of hypoxia in breast cancer progression.

miR-210 is a Serological Biomarker for Predicting Recurrence and Prognosis of Colon Carcinoma Patients with Liver Metastases After Radiofrequency Ablation Treatment

Purpose

Hepatic metastasis of colon carcinoma seriously affects the prognosis of patients, and miRNA has attracted much attention in predicting hepatic metastasis of colon carcinoma (CC). This research aimed to explore the predictive role of miR-210 in serum for recurrence and prognosis of CC patients with hepatic metastasis.

Methods

Altogether, 150 patients with liver metastases of CC (research group, RG) and 130 patients with non-metastatic of CC (control group, CG) admitted to People’s Hospital of Deyang City from March 2012 to March 2015 were obtained and their serum was collected. miR-210 in the RG and the CG, and miR-210 in the RG after radiofrequency ablation treatment were detected, the relationship between miR-210 and pathological parameters of CC patients with hepatic metastasis was analyzed, and patients in the RG were followed up for 5 years to analyze the recurrence, overall survival (OS) and disease-free survival (DFS). The area under the curve (AUC) of receiver operating characteristic curve (ROC) was applied to test the predictive value of miR-210. Cox regression was applied to analyze the independent prognostic factors of patients.

Results

miR-210 in the RG was evidently higher than that in the CG, and AUC for distinguishing hepatic metastasis of CC was 0.907. miR-210 had a close correlation with lymph node metastasis, distant metastasis and pathological differentiation. After treatment, miR-210 in the RG was evidently reduced, and the serum was higher in patients with recurrence and with poor prognosis. AUC for predicting recurrence was 0.858, and AUC for predicting poor prognosis was 0.843. High miR-210 was closely related to lower 5-year OS and DFS and is also an independent prognostic factor affecting patients’ 5-year OS.

Conclusion

miR-210 is enhanced in hepatic metastasis of CC, which is a serological biomarker for predicting recurrence and prognosis of patients with hepatic metastasis of CC after radiofrequency ablation, and has great clinical application value.

The Role of Breast Cancer Stem Cell-Related Biomarkers as Prognostic Factors

Breast cancer is one of the leading causes of cancer-related deaths in women worldwide, and its incidence is on the rise. A small fraction of cancer stem cells was identified within the tumour bulk, which are regarded as cancer-initiating cells, possess self-renewal and propagation potential, and a key driver for tumour heterogeneity and disease progression. Cancer heterogeneity reduces the overall efficacy of chemotherapy and contributes to treatment failure and relapse. The cell-surface and subcellular biomarkers related to breast cancer stem cell (BCSC) phenotypes are increasingly being recognised. These biomarkers are useful for the isolation of BCSCs and can serve as potential therapeutic targets and prognostic tools to monitor treatment responses. Recently, the role of noncoding microRNAs (miRNAs) has extensively been explored as novel biomarker molecules for breast cancer diagnosis and prognosis with high specificity and sensitivity. An in-depth understanding of the biological roles of miRNA in breast carcinogenesis provides insights into the pathways of cancer development and its utility for disease prognostication. This review gives an overview of stem cells, highlights the biomarkers expressed in BCSCs and describes their potential role as prognostic indicators.

Hypoxia-induced epithelial to mesenchymal transition in cancer

A common feature of many solid tumors is low oxygen conditions due to inadequate blood supply. Hypoxia induces hypoxia inducible factor (HIF) stabilization and downstream signaling. This signaling has pleiotropic roles in cancers, including the promotion of cellular proliferation, changes in metabolism, and induction of angiogenesis. In addition, hypoxia is becoming recognized as an important driver of epithelial-to-mesenchymal (EMT) in cancer. During EMT, epithelial cells lose their typical polarized states and transition to a more mobile mesenchymal phenotype. Hypoxia induces this transition by modulating EMT signaling pathways, inducing EMT transcription factor activity, and regulating miRNA networks. As both hypoxia and EMT modulate the tumor microenvironment (TME) and are associated with immunosuppression, we also explore how these pathways may impact response to immuno-oncology therapeutics.

Extracellular Vesicles (EVs) and Pancreatic Cancer: From the Role of EVs to the Interference with EV-Mediated Reciprocal Communication

Pancreatic cancer is malignant and the seventh leading cause of cancer-related deaths worldwide. However, chemotherapy and radiotherapy are—at most—moderately effective, indicating the need for new and different kinds of therapies to manage this disease. It has been proposed that the biologic properties of pancreatic cancer cells are finely tuned by the dynamic microenvironment, which includes extracellular matrix, cancer-associated cells, and diverse immune cells. Accumulating evidence has demonstrated that extracellular vesicles (EVs) play an essential role in communication between heterogeneous subpopulations of cells by transmitting multiplex biomolecules. EV-mediated cell–cell communication ultimately contributes to several aspects of pancreatic cancer, such as growth, angiogenesis, metastasis and therapeutic resistance. In this review, we discuss the role of extracellular vesicles and their cargo molecules in pancreatic cancer. We also present the feasibility of the inhibition of extracellular biosynthesis and their itinerary (release and uptake) for a new attractive therapeutic strategy against pancreatic cancer.

MicroRNA‑137 exerts protective effects on hypoxia‑induced cell injury by inhibiting autophagy/mitophagy and maintaining mitochondrial function in breast cancer stem‑like cells

Breast cancer stem‑like cells (BCSCs) have been identified and proven to play critical roles in tumorigenesis and progression. Hypoxia is a common pathologic feature of breast cancer and potentially, at least in part, regulates the initiation, progression, and recurrence of breast cancer. However, less is known about how hypoxia regulates BCSCs. As several well‑known microRNAs respond to hypoxia, we aimed to determine how hypoxia regulates the physiological processes of BCSCs by regulating the corresponding microRNAs. As expected, microRNA‑137 (miRNA‑137 or miR‑137) was downregulated upon hypoxic exposure, indicating that it may play critical roles in BCSCs. Introduction of miR‑137 mimics promoted cell cycle entry and inhibited hypoxia‑induced cell apoptosis as determined by cell cycle assay and apoptosis assay. By detecting mitochondrial reactive oxygen species (ROS), it was found that miR‑137 inhibited ROS accumulation induced by hypoxic exposure and thus suppressed cell apoptosis. Introduction of miR‑137 mimics under hypoxia inhibited mitophagy/autophagy by targeting FUN14 domain containing 1 (Fundc1) and thus promoted mitochondrial functions, including mitochondrial mass, ATP synthesis and mitochondrial transcriptional activity, which was similar to the effects of Fundc1 knockdown by specific siRNA. Based on these observations, we hypothesized that the survival of BCSCs under hypoxia was mediated by miR‑137 by regulating mitochondrial dysfunction. We demonstrated here that the introduction of exogenous miR‑137 promoted mitochondrial function, indicating that it may be a potential therapeutic target in BCSCs.

Crosstalk between noncoding RNAs and ferroptosis: new dawn for overcoming cancer progression

Cancer progression including proliferation, metastasis, and chemoresistance has become a serious hindrance to cancer therapy. This phenomenon mainly derives from the innate insensitive or acquired resistance of cancer cells to apoptosis. Ferroptosis is a newly discovered mechanism of programmed cell death characterized by peroxidation of the lipid membrane induced by reactive oxygen species. Ferroptosis has been confirmed to eliminate cancer cells in an apoptosis-independent manner, however, the specific regulatory mechanism of ferroptosis is still unknown. The use of ferroptosis for overcoming cancer progression is limited. Noncoding RNAs have been found to play an important roles in cancer. They regulate gene expression to affect biological processes of cancer cells such as proliferation, cell cycle, and cell death. Thus far, the functions of ncRNAs in ferroptosis of cancer cells have been examined, and the specific mechanisms by which noncoding RNAs regulate ferroptosis have been partially discovered. However, there is no summary of ferroptosis associated noncoding RNAs and their functions in different cancer types. In this review, we discuss the roles of ferroptosis-associated noncoding RNAs in detail. Moreover, future work regarding the interaction between noncoding RNAs and ferroptosis is proposed, the possible obstacles are predicted and associated solutions are put forward. This review will deepen our understanding of the relationship between noncoding RNAs and ferroptosis, and provide new insights in targeting noncoding RNAs in ferroptosis associated therapeutic strategies.

The Emerging Role of MicroRNAs in Breast Cancer

Breast cancer (BC) is the most common malignancy in women. Due to BC heterogeneity, complexity, and metastasis, many BC patients do not successfully respond to therapies. The effective management of BC depends on early diagnosis and monitoring of drug response. Therefore, identifying new biomarkers for the diagnosis, prognosis, and development of new drugs is urgently required. Dysregulation of microRNAs (miRNAs) participates in the tumorigenesis and progression of cancers, especially breast cancer (BC). Several studies demonstrated that miRNAs could perform their function as oncogenes or tumor suppressors. This review describes recent progress on the role of microRNAs in the diagnosis, prognosis, hallmark, and treatment of BC. According to a recent literature survey, miRNAs play a pivotal role in the regulation of hallmarks of cancer, such as proliferation, apoptosis, invasion, metastasis, and tumor stemness. Many miRNAs are potential biomarkers for BC for diagnosis, and some are indicators of prognosis. Moreover, circulating miRNA profiles, as minimally invasive, diagnostic, and prognostic markers, are broadly used in BC therapy, and some miRNAs are good predictors of therapeutic outcomes. Other miRNAs are involved in overcoming chemoresistance and in increasing BC drug sensitivity.

Hypoxia-responsive miR-141-3p is involved in the progression of breast cancer via mediating the HMGB1/HIF-1α signaling pathway

Background

Hypoxia‐responsive miRs have been frequently reported in the growth of various malignant tumors. The present study aimed to investigate whether hypoxia‐responsive miR‐141–3p was implicated in the pathogenesis of breast cancer via mediating the high‐mobility group box protein 1 (HMGB1)/hypoxia‐inducible factor (HIF)‐1α signaling pathway.

Materials and methods

miRs expression profiling was filtrated by miR microarray assays. Gene and protein expression levels, respectively, were examined by a quantitative reverse transcriptase‐polymerase chaion reaction and western blotting. Cell migration and invasion were analyzed using a transwell assay. Cell growth was determined using nude‐mouse transplanted tumor experiments.

Results

miR‐141–3p was observed as a hypoxia‐responsive miR in breast cancer. miR‐141–3p was down‐regulated in breast cancer specimens and could serve as an independent prognostic factor for predicting overall survival in breast cancer patients. In addition, the overexpression of miR‐141–3p could inhibit hypoxia‐induced cell migration and impede human breast cancer MDA‐MB‐231 cell growth in vivo. Mechanistically, the hypoxia‐related HMGB1/HIF‐1α signaling pathway might be a possible target of miR‐141–3p with respect to preventing the development of breast cancer.

Conclusions

Our finding provides a new mechanism by which miR‐141–3p could prevent hypoxia‐induced breast tumorigenesis via post‐transcriptional repression of the HMGB1/HIF‐1α signaling pathway.

Role of Exosomal miRNAs and the Tumor Microenvironment in Drug Resistance

Tumor microenvironment (TME) is composed of different cellular populations, such as stromal, immune, endothelial, and cancer stem cells. TME represents a key factor for tumor heterogeneity maintenance, tumor progression, and drug resistance. The transport of molecules via extracellular vesicles emerged as a key messenger in intercellular communication in the TME. Exosomes are small double-layered lipid extracellular vesicles that can carry a variety of molecules, including proteins, lipids, and nucleic acids. Exosomal miRNA released by cancer cells can mediate phenotypical changes in the cells of TME to promote tumor growth and therapy resistance, for example, fibroblast- and macrophages-induced differentiation. Cancer stem cells can transfer and enhance drug resistance in neighboring sensitive cancer cells by releasing exosomal miRNAs that target antiapoptotic and immune-suppressive pathways. Exosomes induce drug resistance by carrying ABC transporters, which export chemotherapeutic agents out of the recipient cells, thereby reducing the drug concentration to suboptimal levels. Exosome biogenesis inhibitors represent a promising adjunct therapeutic approach in cancer therapy to avoid the acquisition of a resistant phenotype. In conclusion, exosomal miRNAs play a crucial role in the TME to confer drug resistance and survivability to tumor cells, and we also highlight the need for further investigations in this promising field.

Non-coding RNAs shuttled via exosomes reshape the hypoxic tumor microenvironment

Exosomes are small extracellular vesicles secreted by almost all the cells. Molecular cargos of exosomes can partially reflect the characteristics of originating cells. Exosome-mediated cell-to-cell interactions in the microenvironment are critical in cancer progression. Hypoxia, a key pro-cancerous feature of the tumor microenvironment, alters the releasing and contents of exosomes. A growing body of evidence shows that hypoxia induces more aggressive phenotypes in cancer. Of note, non-coding RNAs shuttled in hypoxic tumor-derived exosomes have been demonstrated as fundamental molecules in regulating cancer biology and remodeling tumor microenvironment. Furthermore, these hypoxic tumor-derived exosomal non-coding RNAs can be detected in the body fluids, serving as promising diagnostic and prognostic biomarkers. The current review discusses changes in cancer behaviors regulated by exosomes-secreted non-coding RNAs under hypoxic conditions.

Lung CSC-derived exosomal miR-210-3p contributes to a pro-metastatic phenotype in lung cancer by targeting FGFRL1

Lung cancer has the highest mortality rate among human cancers, and the majority of deaths can be attributed to metastatic spread. Lung cancer stem cells (CSCs) are a component of the tumour microenvironment that contributes to this process. Exosomes are small membrane vesicles secreted by all types of cells that mediate cell interactions, including cancer metastasis. Here, we show that lung CSC-derived exosomes promote the migration and invasion of lung cancer cells, up-regulate expression levels of N-cadherin, vimentin, MMP-9 and MMP-1, and down-regulate E-cadherin expression. Moreover, we verified that these exosomes contribute to a pro-metastatic phenotype in lung cancer cells via miR-210-3p transfer. The results of bioinformatics analysis and dual-luciferase reporter assays further indicated that miR-210-3p may bind to fibroblast growth factor receptor-like 1 (FGFRL1); silencing FGFRL1 enhanced the metastatic ability of lung cancer cells, whereas overexpressing FGFRL1 suppressed metastasis. Taken together, our results provide new insights into a potential molecular mechanism whereby lung CSC-derived exosomal miR-210-3p targets FGFRL1 to promote lung cancer metastasis. FGFRL1 may be a promising therapeutic target in lung cancer.