LINC00467 Promotes Prostate Cancer Progression via M2 Macrophage Polarization and the miR-494-3p/STAT3 Axis

LncRNAs act as modulators of macrophages within the tumor microenvironment

Long non-coding RNAs (lncRNAs) have been established as pivotal players in various cellular processes, encompassing the regulation of transcription, translation and post-translational modulation of proteins, thereby influencing cellular functions. Notably, lncRNAs exert a regulatory influence on diverse biological processes, particularly in the context of tumor development. Tumor-associated macrophages (TAMs) exhibit the M2 phenotype, exerting significant impact on crucial processes such as tumor initiation, angiogenesis, metastasis and immune evasion. Elevated infiltration of TAMs into the tumor microenvironment (TME) is closely associated with a poor prognosis in various cancers. LncRNAs within TAMs play a direct role in regulating cellular processes. Functioning as integral components of tumor-derived exosomes, lncRNAs prompt the M2-like polarization of macrophages. Concurrently, reports indicate that lncRNAs in tumor cells contribute to the expression and release of molecules that modulate TAMs within the TME. These actions of lncRNAs induce the recruitment, infiltration and M2 polarization of TAMs, thereby providing critical support for tumor development. In this review, we survey recent studies elucidating the impact of lncRNAs on macrophage recruitment, polarization and function across different types of cancers.

lncRNA Biomarkers of Glioblastoma Multiforme

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.

LncRNA MALAT1/microRNA-30b axis regulates macrophage polarization and function

Macrophages (Mφ) are long-lived myeloid cells that can polarize towards the proinflammatory M1 or proresolving M2 phenotype to control diverse biological processes such as inflammation, tissue damage, and regeneration. Noncoding RNA are a class of nonprotein-coding transcriptome with numerous interdependent biological roles; however, their functional interaction in the regulation of Mφ polarization and immune responses remain unclear. Here, we show antagonistic relationship between lncRNA (MALAT1) and microRNA (miR-30b) in shaping macrophage polarization and immune functions. MALAT1 expression displays a time-dependent induction during Mφ differentiation and, upon challenge with TLR4 agonist (E. coli LPS). MALAT1 knockdown promoted the expression of M2Mφ markers without affecting M1Mφ markers, suggesting that MALAT1 favors the M1 phenotype by suppressing M2 differentiation. Compared to the control, MALAT1 knockdown resulted in reduced antigen uptake and processing, bacterial phagocytosis, and bactericidal activity, strongly supporting its critical role in regulating innate immune functions in Mφ. Consistent with this, MALAT1 knockdown showed impaired cytokine secretion upon challenge with LPS. Importantly, MALAT1 exhibit an antagonistic expression pattern with all five members of the miR-30 family during M2 Mφ differentiation. Dual-luciferase assays validated a novel sequence on MALAT1 that interacts with miR-30b, a microRNA that promotes the M2 phenotype. Phagocytosis and antigen processing assays unequivocally demonstrated that MALAT1 and miR-30b are functionally antagonistic. Concurrent MALAT1 knockdown and miR-30b overexpression exhibited the most significant attenuation in both assays. In human subjects with periodontal disease and murine model of ligature-induced periodontitis, we observed higher levels of MALAT1, M1Mφ markers and downregulation of miR-30b expression in gingival tissues suggesting a pro-inflammatory function of MALAT1 in vivo. Overall, we unraveled the role of MALAT1 in Mφ polarization and delineated the underlying mechanism of its regulation by involving MALAT-1-driven miR-30b sequestration.

LncRNA LINC01569 promotes M2 macrophage polarization to accelerate hypopharyngeal carcinoma progression through the miR-193a-5p/FADS1 signaling axis

Background: Long non-coding RNA (lncRNA) LINC01569 plays an important role in regulating the tumor microenvironment (TME) and macrophage polarization. However, whether it participates in the progression of hypopharyngeal carcinoma by regulating the TME remains unclear. Methods: An online database was used to analyze clinical data. Macrophage polarization was detected using qRT-PCR and flow cytometry. In vivo experiments were performed using tumor-bearing nude mice. A co-culture system of hypopharyngeal carcinoma cells and macrophages was used to explore the interactions between the two cell types. Results: LINC01569 enhancement was observed in hypopharyngeal carcinoma tumor-associated macrophages (TAMs). In IL4-induced M2 macrophages, the expression of LINC01569 increased, while LINC01569 expression declined significantly in LPS-induced M1 macrophages. SiRNA-mediated downregulation of LINC01569 inhibits IL4-induced M2 macrophage polarization. Using online databases and a dual-luciferase reporter, miR-193a-5p was confirmed as a potential downstream sponge of LINC01569. MiR-193a-5p expression decreased in IL4-mediated M2 macrophages, which was restored by LINC01569 downregulation. Additionally, LINC01569 inhibition-mediated blocking of M2 macrophage polarization was moderately abolished by transfection with the miR-193a-5p inhibitor. Fatty acid desaturase 1 (FADS1) was verified as a downstream target of miR-193a-5p, and LINC01569 downregulation-mediated inhibition of FADS1 was blocked by miR-193a-5p mimics. Importantly, LINC01569 downregulation-mediated decline in M2 macrophage polarization was abolished by miR-193a-5p mimics, which was further reversed by FADS1 knockdown. Implantation of a mixture of FaDu cells and IL4-induced macrophages promoted tumor growth and proliferation, which were abrogated by the knockdown of LINC01569 in macrophages. Using an in co-culture system of FaDu cells and macrophages in vitro, M2 macrophage-regulated cell growth and apoptosis of FaDu cells were found to be mediated by the LINC01569/miR-193a-5p signaling axis. Conclusion: LINC01569 is highly expressed in the TAMs of hypopharyngeal carcinoma. LINC01569 downregulation restrains macrophages from polarizing toward M2 through the miR-193a-5p/FADS1 signaling axis, thereby helping tumor cells escape inherent immune surveillance and promoting the occurrence and development of hypopharyngeal carcinoma.

The Potential Use of Exosomes in Anti-Cancer Effect Induced by Polarized Macrophages

The rapid development of aberrant cells outgrowing their normal bounds, which can subsequently infect other body parts and spread to other organs-a process known as metastasis-is one of the significant characteristics of cancer. The main reason why cancer patients die is because of widespread metastases. This abnormal cell proliferation varies in cancers of over a hundred types, and their response to treatment can vary substantially. Several anti-cancer drugs have been discovered to treat various tumors, yet they still have harmful side-effects. Finding novel, highly efficient targeted therapies based on modifications in the molecular biology of tumor cells is essential to reduce the indiscriminate destruction of healthy cells. Exosomes, an extracellular vesicle, are promising as a drug carrier for cancer therapy due to their good tolerance in the body. In addition, the tumor microenvironment is a potential target to regulate in cancer treatment. Therefore, macrophages are polarized toward M1 and M2 phenotypes, which are involved in cancer proliferation and are malignant. It is evident from recent studies that controlled macrophage polarization might contribute to cancer treatment, by the direct way of using miRNA. This review provides an insight into the potential use of exosomes to develop an 'indirect', more natural, and harmless cancer treatment through regulating macrophage polarization.

Importance of long non-coding RNAs in the pathogenesis, diagnosis, and treatment of prostate cancer

Long non-coding RNAs (lncRNAs) are regulatory transcripts with essential roles in the pathogenesis of almost all types of cancers, including prostate cancer. They can act as either oncogenic lncRNAs or tumor suppressor ones in prostate cancer. Small nucleolar RNA host genes are among the mostly assessed oncogenic lncRNAs in this cancer. PCA3 is an example of oncogenic lncRNAs that has been approved as a diagnostic marker in prostate cancer. A number of well-known oncogenic lncRNAs in other cancers such as DANCR, MALAT1, CCAT1, PVT1, TUG1 and NEAT1 have also been shown to act as oncogenes in prostate cancer. On the other hand, LINC00893, LINC01679, MIR22HG, RP1-59D14.5, MAGI2-AS3, NXTAR, FGF14-AS2 and ADAMTS9-AS1 are among lncRNAs that act as tumor suppressors in prostate cancer. LncRNAs can contribute to the pathogenesis of prostate cancer via modulation of androgen receptor (AR) signaling, ubiquitin-proteasome degradation process of AR or other important signaling pathways. The current review summarizes the role of lncRNAs in the evolution of prostate cancer with an especial focus on their importance in design of novel biomarker panels and therapeutic targets.

LncRNA MALAT1/microRNA-30b axis regulate macrophage polarization and function

Introduction

Macrophages (Mφ) can polarize towards the proinflammatory M1 or proresolving M2 phenotype to control diverse biological processes such as inflammation, and tissue regeneration. Noncoding RNAs play critical roles in numerous biological pathways; however, their functional interaction in the regulation of Mφ polarization and immune responses remain unclear.

Objectives

To examine relationship between lncRNA (MALAT1) and microRNA (miR-30b) in shaping macrophage polarization and immune functions.

Methods

Expression of MALAT1 and miR-30b was examined in differentiating M1/M2 Mφ, human and murine inflamed gingival biopsies by RT-qPCR. MALAT1 and miR-30b direct interaction was examined by dual luciferase assays. Impact of MALAT1 knockdown and miR-30b overexpression was examined on macrophage polarization markers, bacterial phagocytosis, antigen uptake/processing and cytokine profiles.

Results

MALAT1 expression displays a time-dependent induction during Mφ differentiation and, upon challenge with TLR4 agonist ( E. coli LPS). Knockdown of MALAT1 enhanced the expression of M2Mφ markers without affecting the M1Mφ markers, suggesting that MALAT1 favors the M1 phenotype by suppressing M2 polarization. MALAT1 knockdown Mφ exhibit reduced antigen uptake and processing, bacterial phagocytosis, and bactericidal activity, strongly supporting its critical role in regulating innate immune functions. Consistent with this, MALAT1 knockdown showed impaired cytokine secretion upon challenge with LPS. Importantly, MALAT1 exhibit an antagonistic expression pattern with all five members of the miR-30 family during M2Mφ differentiation. Dual-luciferase assays validated a novel sequence on MALAT1 that interacts with miR-30b, a microRNA that promotes the M2 phenotype. Phagocytosis and antigen processing assays unequivocally demonstrated that MALAT1 and miR-30b are functionally antagonistic. In human subjects with periodontal disease and murine model of ligature-induced periodontitis, we observed higher levels of MALAT1, and downregulation of miR-30b that correlates with higher M1Mφ markers expression in gingival tissues suggesting a pro-inflammatory function of MALAT1.

Conclusion

MALAT1/miR-30b antagonistic interaction shapes Mφ polarization in vitro and in inflamed gingival biopsies.

LINC00467: an oncogenic long noncoding RNA

Long non-coding RNAs (lncRNAs) have been found to play essential roles in the cell proliferation, fission and differentiation, involving various processes in humans. Recently, there is more and more interest in exploring the relationship between lncRNAs and tumors. Many latest evidences revealed that LINC00467, an oncogenic lncRNA, is highly expressed in lung cancer, gastric cancer, colorectal cancer, hepatocellular carcinoma, breast cancer, glioblastoma, head and neck squamous cell carcinoma, osteosarcoma, and other malignant tumors. Besides, LINC00467 expression was linked with proliferation, migration, invasion and apoptosis via the regulation of target genes and multiple potential pathways. We reviewed the existing data on the expression, downstream targets, molecular mechanisms, functions, relevant signaling pathways, and clinical implications of LINC00467 in various cancers. LINC00467 may serve as a novel biomarker or therapeutic target for the diagnosis and prognosis of various human tumors.

Crosstalk among long non-coding RNA, tumor-associated macrophages and small extracellular vesicles in tumorigenesis and dissemination

Long noncoding RNAs (lncRNAs), which lack protein-coding ability, can regulate cancer cell growth, proliferation, invasion, and metastasis. Tumor-associated macrophages (TAMs) are key components of the tumor microenvironment that have a significant impact on cancer progression. Small extracellular vesicles (sEV) are crucial mediators of intercellular communications. Cancer cell and macrophage-derived sEV can carry lncRNAs that influence the onset and progression of cancer. Dysregulation of lncRNAs, TAMs, and sEV is widely observed in tumors which makes them valuable targets for cancer immunotherapy. In this review, we summarize current updates on the interactions among sEV, lncRNAs, and TAMs in tumors and provide new perspectives on cancer diagnosis and treatment.

The Roles of Tumor-Associated Macrophages in Prostate Cancer

The morbidity of prostate cancer (PCa) is rising year by year, and it has become the primary cause of tumor-related mortality in males. It is widely accepted that macrophages account for 50% of the tumor mass in solid tumors and have emerged as a crucial participator in multiple stages of PCa, with the huge potential for further treatment. Oftentimes, tumor-associated macrophages (TAMs) in the tumor microenvironment (TME) behave like M2-like phenotypes that modulate malignant hallmarks of tumor lesions, ranging from tumorigenesis to metastasis. Several clinical studies indicated that mean TAM density was higher in human PCa cores versus benign prostatic hyperplasia (BPH), and increased biopsy TAM density potentially predicts worse clinicopathological characteristics as well. Therefore, TAM represents a promising target for therapeutic intervention either alone or in combination with other strategies to halt the “vicious cycle,” thus improving oncological outcomes. Herein, we mainly focus on the fundamental aspects of TAMs in prostate adenocarcinoma, while reviewing the mechanisms responsible for macrophage recruitment and polarization, which has clinical translational implications for the exploitation of potentially effective therapies against TAMs.

The Role of Long Non-Coding RNAs in Epithelial-Mesenchymal Transition-Related Signaling Pathways in Prostate Cancer

Prostate cancer (PCa) is one of the most common male malignancies with frequent remote invasion and metastasis, leading to high mortality. Epithelial-mesenchymal transition (EMT) is a fundamental process in embryonic development and plays a key role in tumor proliferation, invasion and metastasis. Numerous long non-coding RNAs (lncRNAs) could regulate the occurrence and development of EMT through various complex molecular mechanisms involving multiple signaling pathways in PCa. Given the importance of EMT and lncRNAs in the progression of tumor metastasis, we recapitulate the research progress of EMT-related signaling pathways regulated by lncRNAs in PCa, including AR signaling, STAT3 signaling, Wnt/β-catenin signaling, PTEN/PI3K/AKT signaling, TGF-β/Smad and NF-κB signaling pathways. Furthermore, we summarize four modes of how lncRNAs participate in the EMT process of PCa via regulating relevant signaling pathways.

Molecular mechanism, regulation, and therapeutic targeting of the STAT3 signaling pathway in esophageal cancer (Review)

Esophageal cancer (EC) is the seventh most common cancer globally, and the overall 5-year survival rate is only 20%. Signal transducer and activator of transcription 3 (STAT3) is aberrantly activated in EC, and its activation is associated with a poor prognosis. STAT3 can be activated by canonical pathways such as the JAK/STAT3 pathway as well as non-canonical pathways including the Wnt/STAT3 and COX2/PGE2/STAT3 pathways. Activated STAT3, present as phosphorylated STAT3 (p-STAT3), can be transported into the nucleus to regulate downstream genes, including VEGF, cyclin D1, Bcl-xL, and matrix metalloproteinases (MMPs), to promote cancer cell proliferation and induce resistance to therapy. Non-coding RNAs, including microRNAs (miRNAs/miRs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), play a vital role in regulating the STAT3 signaling pathway in EC. Several miRNAs promote or suppress the function of STAT3 in EC, while lncRNAs and circRNAs primarily promote the effects of STAT3 and the progression of cancer. Additionally, various drugs and natural compounds can target STAT3 to suppress the malignant behavior of EC cells, providing novel insights into potential EC therapies.

Long Noncoding RNA LINC00467: Role in Various Human Cancers

Intricate genetic mutations promote the progression of different cancer types. Long noncoding RNAs (lncRNAs) have been widely demonstrated to participate in the genomic activities of various human cancers. Long intergenic non-coding RNA 467 (LINC00467) is an upregulated lncRNA in diverse diseases, especially in several types of cancers. Functional experiments of LINC00467 revealed that LINC00467 overexpression enhanced cell chemoresistance, proliferation, migration, and invasion in several types of cancers. Moreover, overexpressed LINC00467 was associated with a poor clinical prognosis. The present evidence suggests that LINC00467 may serve as a promising prognostic indicator and become a novel cancer therapeutic target. In this review, we introduce the biologic functions of lncRNAs and describe the molecular mechanism and clinical significance of LINC00467 in detail.

Long intergenic non-protein-coding RNA 467 promotes tumor progression and angiogenesis via the microRNA-128-3p/vascular endothelial growth factor C axis in colorectal cancer

Long non-coding RNAs (lncRNAs) are important regulators and biomarkers of tumorigenesis and tumor metastasis. Long intergenic non-protein-coding RNA 467 (LINC00467) is associated with various cancers. However, the role and mechanism of LINC00467 in colorectal cancer (CRC) promotion are poorly understood. This study aimed to present new details of LINC00467 in the progression of CRC. Reverse transcription–polymerase chain reaction demonstrated that the expression level of LINC00467 in CRC tissues and cell lines was significantly upregulated, which was closely related to the clinical features of CRC. Cell and animal studies showed that the downregulation of LINC00467 expression in CRC cells significantly inhibited cell proliferation, metastasis, and angiogenesis. Moreover, the overexpression of LINC00467 accelerated CRC promotion. Bioinformatics analysis and luciferase reporter assay confirmed that LINC00467 binds to miR-128-3p. Rescue experiments manifested that decreased miR-128-3p level reversed CRC cell inhibition by silencing LINC00467. Furthermore, vascular endothelial growth factor C (VEGFC) was identified as a target of miR-128-3p that could reverse the inhibition of cell growth that is mediated by miR-128-3p. Altogether, our results showed that LINC00467 contributes to CRC progression and angiogenesis via the miR-128-3p/VEGFC axis. Our findings expand the understanding of the mechanisms underlying CRC and suggest potential targets for clinical strategies against CRC.

Regulatory Mechanism of lncRNAs in M1/M2 Macrophages Polarization in the Diseases of Different Etiology

Precise expression and regulation of genes in the immune system is important for organisms to produce strong immunity towards pathogens and limit autoimmunity. In recent years, an increasing number of studies has shown that long noncoding RNAs (lncRNAs) are closely related to immune function and can participate in regulating immune responses by regulating immune cell differentiation, development, and function. As immune cells, the polarization response of macrophages (Mφs) plays an important role in immune function and inflammation. LncRNAs can regulate the phenotypic polarization of Mφs to M1 or M2 through various mechanisms; promote pro-inflammatory or anti-inflammatory effects; and participate in the pathogenesis of cancers, inflammatory diseases, infections, metabolic diseases, and autoimmune diseases. In addition, it is important to explore the regulatory mechanisms of lncRNAs on the dynamic transition between different Mφs phenotypes. Thus, the regulatory role of lncRNAs in the polarization of Mφs and their mechanism are discussed in this review.

The Role of Critical N6-Methyladenosine-Related Long Non-Coding RNAs and Their Correlations with Immune Checkpoints in Renal Clear Cell Carcinoma

Purpose

This study aimed to evaluate the functions of critical N6-methyladenosine (m6A)-related long non-coding RNAs (lncRNAs) and their correlations with immunotherapeutic targets in clear cell renal cell carcinoma (ccRCC).

Methods

m6A-related lncRNAs were analyzed using the dataset from The Cancer Genome Atlas database via Pearson correlation analysis. Then, their prognostic functions in patients with ccRCC were determined via univariate Cox analysis. A prognostic m6A-related lncRNA signature (MRLS) in ccRCC was established using the least absolute shrinkage and selection operator (LASSO) Cox regression model. In addition, the correlations between these prognostic m6A-related lncRNAs with immune checkpoints were further evaluated in clinical samples.

Results

MRLS was established by the LASSO Cox regression model on the basis of seven prognostic m6A-related lncRNAs. The risk score for each patient was calculated using the MRLS model, and the patients were further stratified into high- and low-risk subgroups. The MRLS model was validated with a robust prognostic ability by the stratification analysis. On the basis of age, grade, stage, and risk score, a nomogram was developed with a strong reliability in forecasting the overall survival percentages of the patients with ccRCC. Moreover, seven prognostic m6A-related lncRNAs enrolled in the MRLS model were found to be correlated with various immunotherapeutic targets, namely, PD-1, PD-L1, CTLA4, and LAG3, and the expression levels of which in the high-risk subgroup were significantly higher than those in the low-risk subgroup. The significant correlations between LINC00342 and the aforementioned immunotherapeutic targets were also confirmed in clinical samples.

Conclusion

In this study, seven m6A-related lncRNAs were identified as potential biomarkers for forecasting the prognosis of patients with ccRCC and evaluating the efficacy of immunotherapy for these patients. Furthermore, a prognostic and predictive MRLS model with a high reliability was constructed to predict the overall survival probability of patients with ccRCC.