Long non-coding RNA MALAT1 facilitates the tumorigenesis, invasion and glycolysis of multiple myeloma via miR-1271-5p/SOX13 axis

Exosomal lncRNAs as diagnostic and therapeutic targets in multiple myeloma

Multiple Myeloma (MM) is the second most common malignancy of the hematopoietic system, accounting for approximately 10% of all hematological malignancies, and currently, there is no complete cure. Existing research indicates that exosomal long non-coding RNAs (lncRNAs) play a crucial regulatory role in the initiation and progression of tumors, involving various interactions such as lncRNA-miRNA, lncRNA-mRNA, and lncRNA-RNA binding proteins (RBP). Despite the significant clinical application potential of exosomal lncRNAs, research in this area still faces challenges due to their low abundance and technical limitations. To our knowledge, this review is the first to comprehensively integrate and elucidate the three mechanisms of action of exosomal lncRNAs in MM, and to propose potential therapeutic targets and clinical cases based on these mechanisms. We highlight the latest advancements in the potential of exosomal lncRNAs as biomarkers and therapeutic targets, offering not only a comprehensive analysis of the role of exosomal lncRNAs in MM but also new perspectives and methods for future clinical diagnosis and treatment of multiple myeloma.

Epigenetic Role of Long Non-coding RNAs in Multiple Myeloma

PURPOSE OF THE REVIEW

This review aims to explore the pivotal role of long non-coding RNAs (lncRNAs) as epigenetic regulators in the pathogenesis of multiple myeloma (MM). Additionally, we have portrayed the dual role of lncRNAs in the epigenetic landscape of MM pathobiology.

RECENT FINDINGS

In MM, lncRNAs are pivotal for proliferation, progression, and drug resistance by acting as miRNA sponges, regulating mRNA activity through microRNA recognition elements (MREs). Epigenetic modifications in lncRNAs influence gene expression, with some like MEG3, GAS5, CRNDE, and H19 showing promoter hypermethylation, while MALAT1 exhibits hypomethylation. Targeting lncRNAs using siRNA, ASO, CRISPR-Cas9, or small molecule inhibitors shows promise in preclinical studies, alongside the potential benefits of epigenetic-based therapies such as DNMTi and HDACi. Clinical trials combining epigenetic modifiers with standard chemotherapy show encouraging results, especially in relapsed/refractory MM. The key finding of the studies highlighted in the review paves the way for understanding the epigenetic role of lncRNAs in MM disease progression and biology. In addition, the novel therapeutic strategies that have shown promising results have been highlighted. The adoption of the epigenetic landscape into therapeutics in addition to existing treatment strategies may increase the efficacy of treatment approaches.

LncRNAs in modulating cancer cell resistance to paclitaxel (PTX) therapy

Paclitaxel (PTX) is widely used for treating several cancers, including breast, ovarian, lung, esophageal, gastric, pancreatic, and neck cancers. Despite its clinical utility, cancer recurrence frequently occurs in patients due to the development of resistance to PTX. Resistance mechanisms in cancer cells treated with PTX include alterations in β-tubulin, the target molecule involved in mitosis, activation of molecular pathways enabling drug efflux, and dysregulation of apoptosis-related proteins. Long non-coding RNAs (lncRNAs), which are RNA molecules longer than 200 nucleotides without protein-coding potential, serve diverse regulatory roles in cellular processes. Increasing evidence highlights the involvement of lncRNAs in cancer progression and their contribution to PTX resistance across various cancers. Consequently, lncRNAs have emerged as potential therapeutic targets for addressing drug resistance in cancer treatment. This review focuses on the current understanding of lncRNAs and their role in drug resistance mechanisms, aiming to encourage further investigation in this area. Key lncRNAs and their associated pathways linked to PTX resistance will be summarized.

Roles of noncoding RNAs in multiple myeloma

Noncoding RNAs (ncRNAs) constitute a class of nucleic acid molecules within cells that do not encode proteins but play important roles in regulating gene expression, maintaining cellular homeostasis, and mediating cell signaling. This class encompasses microRNAs (miRNAs), long noncoding RNAs (lncRNAs), transfer RNAs (tRNAs), circular RNAs (circRNAs), small interfering RNAs (siRNAs), and others. miRNAs are pivotal in the regulation of gene expression in hematologic malignancies. Aberrant expression of lncRNAs has been confirmed in cancerous tissues, implicating their involvement in carcinogenesis or tumor suppression processes. tRNAs may induce errors or disturbances in protein synthesis, thereby affecting normal cellular function and proliferation. Moreover, circRNAs influence disease progression in tumors by modulating the expression of relevant genes, and siRNAs can inhibit tumor cell proliferation, invasion, and metastasis while inducing apoptosis. This review will elucidate the biological functions of ncRNAs in multiple myeloma (MM) and explore their potential value as therapeutic targets.

Aberrant NSUN2-mediated m5C modification of exosomal LncRNA MALAT1 induced RANKL-mediated bone destruction in multiple myeloma

The impact of exosome-mediated crosstalk between multiple myeloma (MM) cells and osteoclasts (OCs) on bone lesions remains to be investigated. Here, we identified NSUN2 and YBX1-mediated m5C modifications upregulated LncRNA MALAT1 expression in MM cells, which could be transported to OCs via exosomes and promote bone lesions. Methodologically, RNA-seq was carried out to detect the cargoes of exosomes. TRAP staining and WB were used to evaluate osteoclastogenesis in vitro. Micro-CT and bone histomorphometric analyses were performed to identify bone destruction in vivo. RNA pull-down, RIP, MeRIP, and luciferase reporter assays were used to test the interactions between molecules. The clinical features of MALAT1, NSUN2 and YBX1 were verified through public datasets and clinicopathological data analyses. Mechanistically, MALAT1 was the highest expressed lncRNA in U266 exosomes and could be transported to RAW264.7 cells. MALAT1 could enhance the differentiation of RAW264.7 cells into OCs by stimulating RANKL expression and its downstream AKT and MAPKs signaling pathways via a ceRNA mechanism. Additionally, MALAT1 could be modified by NSUN2, an m5C methyltransferase, which in turn stabilized MALAT1 through the "reader" YBX1. Clinical studies indicated a notable positive correlation between MALAT1, NSUN2, YBX1 levels and bone destruction features, as well as with RANKL expression.

A comprehensive review of the PTEN/PI3K/Akt axis in multiple myeloma: From molecular interactions to potential therapeutic targets

Phosphatase and tensin homolog (PTEN), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) signaling pathways contribute to the development of several cancers, including multiple myeloma (MM). PTEN is a tumor suppressor that influences the PI3K/Akt/mTOR pathway, which in turn impacts vital cellular processes like growth, survival, and treatment resistance. The current study aims to present the role of PTEN and PI3K/Akt/mTOR signaling in the development of MM and its response to treatment. In addition, the molecular interactions in MM that underpin the PI3K/Akt/mTOR pathway and address potential implications for the development of successful treatment plans are also discussed in detail. We investigate their relationship to both upstream and downstream regulators, highlighting new developments in combined therapies that target the PTEN/PI3K/Akt axis to overcome drug resistance, including the use of PI3K and mitogen-activated protein kinase (MAPK) inhibitors. We also emphasize that PTEN/PI3K/Akt pathway elements may be used in MM diagnosis, prognosis, and therapeutic targets.

Highlighting the role of long non-coding RNA (LncRNA) in multiple myeloma (MM) pathogenesis and response to therapy

Transcripts longer than 200 nucleotides that are not translated into proteins are known as long non-coding RNAs, or lncRNAs. Now, they are becoming more significant as important regulators of gene expression, and as a result, of many biological processes in both healthy and pathological circumstances, such as blood malignancies. Through controlling alternative splicing, transcription, and translation at the post-transcriptional level, lncRNAs have an impact on the expression of genes. In multiple myeloma (MM), the majority of lncRNAs is elevated and promotes the proliferation, adhesion, drug resistance and invasion of MM cells by blocking apoptosis and altering the tumor microenvironment (TME). To control mRNA splicing, stability, and translation, they either directly attach to the target mRNA or transfer RNA-binding proteins (RBPs). By expressing certain miRNA-binding sites that function as competitive endogenous RNAs (ceRNAs), most lncRNAs mimic the actions of miRNAs. Here, we highlight lncRNAs role in the MM pathogenesis with emphasize on their capacity to control the molecular mechanisms known as "hallmarks of cancer," which permit earlier tumor initiation and progression and malignant cell transformation.

M2 Tumor-Associated Macrophages-Derived Exosomal MALAT1 Promotes Glycolysis and Gastric Cancer Progression

M2-polarized tumor-associated macrophages (M2 TAMs) promote cancer progression. Exosomes mediate cellular communication in the tumor microenvironment (TME). However, the roles of exosomes from M2 TAMs in gastric cancer progression are unclear. Herein, it is reported that M2 TAMs-derived exosomes induced aerobic glycolysis in gastric cancer cells and enhanced their proliferation, metastasis, and chemoresistance in a glycolysis-dependent manner. It is identified that MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) is enriched in M2 TAM exosomes and confirmed that MALAT1 transfer from M2 TAMs to gastric cancer cells via exosomes mediates this effect. Mechanistically, MALAT1 interacted with the δ-catenin protein and suppressed its ubiquitination and degradation by β-TRCP. In addition, MALAT1 upregulated HIF-1α expression by acting as a sponge for miR-217-5p. The activation of β-catenin and HIF-1α signaling pathways by M2 TAM exosomes collectively led to enhanced aerobic glycolysis in gastric cancer cells. Finally, a dual-targeted inhibition of MALAT1 in both gastric cancer cells and macrophages by exosome-mediated delivery of siRNA remarkably suppressed gastric cancer growth and improved chemosensitivity in mouse tumor models. Taken together, these results suggest that M2 TAMs-derived exosomes promote gastric cancer progression via MALAT1-mediated regulation of glycolysis. The findings offer a potential target for gastric cancer therapy.

Long non-coding RNA MALAT1 in hematological malignancies and its clinical applications

ABSTRACT

Metastasis-associated lung adenocarcinoma transcript 1 ( MALAT1 ) is a well-established oncogenic long non-coding RNA, the higher expression of which is strongly correlated with cancer events such as tumorigenesis, progression, metastasis, drug resistance, and treatment outcome in solid cancers. Recently, a series of studies has highlighted its potential role in hematological malignancies in terms of these events. Similar to solid cancers, MALAT1 can regulate various target genes via sponging and epigenetic mechanisms, but the miRNAs sponged by MALAT1 differ from those identified in solid cancers. In this review, we systematically describe the role and underlying mechanisms of MALAT1 in multiple types of hematological malignancies, including regulation of cell proliferation, metastasis, stress response, and glycolysis. Clinically, MALAT1 expression is related to poor treatment outcome and drug resistance, therefore exhibiting potential prognostic value in multiple myeloma, lymphoma, and leukemia. Finally, we discuss the evaluation of MALAT1 as a novel therapeutic target against cancer in preclinical studies.

The diagnostic value of serum lncRNA CATG00000112921.1 as a marker of multiple myeloma

BACKGROUND

Multiple myeloma (MM) is a malignant plasma cell disease. At present, numerous studies have shown that lncRNA plays a very important role in the occurrence, development and even drug resistance of multiple myeloma. It may become a potential diagnostic and prognostic marker of multiple myeloma and provide new ideas for targeted therapy. Based on the above research background, this study used gene chip technology to screen out the differentially expressed lncRNA in the serum of MM patients and healthy people, and verified more clinical serum samples to screen out the lncRNA with the largest difference as a biomarker for further research.

METHOD

In this research, the data of hospitalized patients diagnosed with MM and healthy people in the Affiliated Hospital of Guangdong Medical University were retrospectively collected. The lncRNA expression profile of serum samples from patients with multiple myeloma and healthy controls was analyzed by lncRNA chip technology. The serum samples were verified by real-time fluorescence quantitative PCR, and the candidate diagnostic markers were screened out. The ROC working curve was drawn to evaluate the diagnostic efficacy of the candidate markers and to determine their stability at different temperatures and time.

RESULT

A total of 44 MM patients and 37 healthy people were involved in this research. Among them, 4 patients with MM and 4 patients with HD were sent for microarray analysis. According to Fold Change ≥ 2 and P < 0.05, a total of 17 differentially expressed lncRNA molecules were screened, of which 9 were up-regulated RNA molecules and 8 were down-regulated RNA molecules. Through real-time fluorescence quantitative PCR verification, it was found that lncRNA CATG00000112921.1 was highly expressed in the healthy control group and diminished in patients with multiple myeloma, P < 0.001. The ROC curve demonstrated that the area under the curve (AUC) was 0.749, the sensitivity was 0.636, the specificity was 0.789, and the 95 % CI was 0.636-0.862 (P < 0.001). In addition, in order to verify the effects of temperature, time and repeated freezing and thawing on lncRNA, it was placed at 25°C, 4°C, -20°C, -80°C for 0 h, 24 h, 48 h, 72 h, and placed at-80°C repeated freezing and thawing 0 times, 2 times, 4 times, 8 times, and the expression level was not significantly changed.

CONCLUSION

Serum lncRNA CATG00000112921.1 may be a potential candidate diagnostic marker for multiple myeloma. The ROC curve shows that it has good diagnostic value, and its high stability at different temperatures and different times is a required condition for becoming a diagnostic marker. As far as we know, this is the first study in the world to find differential expression of lncRNA CATG00000112921.1 in peripheral serum of healthy people and newly diagnosed multiple myeloma patients. This study also highlights the application of gene chip technology in screening differentially expressed genes.

Expression Pattern and Prognostic Significance of the Long Non-Coding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 in Chronic Lymphocytic Leukemia

Dysregulated expression of the long non-coding RNA MALAT1 has been implicated in the pathogenesis and progression of a variety of cancers, including hematological malignancies, but it has been poorly investigated in chronic lymphocytic leukemia (CLL). In this study, the expression of MALAT1 was measured using a quantitative reverse-transcriptase polymerase chain reaction in the peripheral blood mononuclear cells of 114 unselected, newly diagnosed CLL patients in order to analyze its association with clinical, laboratory, and molecular patients' characteristics at diagnosis, as well as its prognostic relevance. MALAT1 was found to be upregulated in CLL patients in comparison to healthy controls, and expression levels were not related to age, leukocyte, lymphocyte and platelet count, serum β2-microglobulin, and IGHV somatic hypermutational status. On the other hand, high MALAT1 expression was associated with several favorable prognostic markers (high hemoglobin, low serum lactate dehydrogenase, earlier clinical stages, CD38-negative status), but also with unfavorable cytogenetics. Furthermore, an association between high MALAT1 levels and longer time to first treatment and overall survival in IGHV-unmutated CLL subtype was observed. In summary, our results imply that high MALAT1 expression at diagnosis may be a predictor of better prognosis and point to MALAT1 expression profiling as a candidate biomarker potentially useful in clinical practice.

Potential Clinical Role of LncRNA miR503HG in Multiple Myeloma and its Effect on the Proliferation and Adhesion of Myeloma Cells

This study mainly explored the role of lncRNA miR503HG in multiple myeloma and the potential downstream regulatory mechanism affecting disease. Real-time quantitative polymerase chain reaction was used to measure the expression levels of miR503HG and miR-103. A cell counting kit-8 assay was performed to detect cell viability. The concentrations of adhesion-related factors (MUC-1, VCAM-1, ICAM-1) were determined using enzyme-linked immunosorbent assay. The targeting relationship between miR503HG and miR-103 was detected by dual-luciferase reporter assay. The miR503HG expression in peripheral blood of multiple myeloma patients was lower than that of normal healthy individuals and associated with ISS stage and worse overall survival. miR-103 was identified as the downstream target of miR503HG. Upregulation of miR503HG could inhibit cell proliferation and adhesion of multiple myeloma cell lines, which could partially reverse the inhibition of adhesion and proliferation by high expression of miR-103. lncRNA miR503HG expression was downregulated in multiple myeloma and had potential diagnostic/prognostic value. MiR503HG exerts a molecular sponge effect on miR-103 and affects its expression, thus achieving the inhibitory effect on multiple myeloma.

The functions of long non-coding RNA (lncRNA)-MALAT-1 in the pathogenesis of renal cell carcinoma

Renal cell carcinoma (RCC), a prevalent form of renal malignancy, is distinguished by its proclivity for robust tumor proliferation and metastatic dissemination. Long non-coding RNAs (lncRNAs) have emerged as pivotal modulators of gene expression, exerting substantial influence over diverse biological processes, encompassing the intricate landscape of cancer development. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1), an exemplar among lncRNAs, has been discovered to assume functional responsibilities within the context of RCC. The conspicuous expression of MALAT-1 in RCC cells has been closely linked to the advancement of tumors and an unfavorable prognosis. Experimental evidence has demonstrated the pronounced ability of MALAT-1 to stimulate RCC cell proliferation, migration, and invasion, thereby underscoring its active participation in facilitating the metastatic cascade. Furthermore, MALAT-1 has been implicated in orchestrating angiogenesis, an indispensable process for tumor expansion and metastatic dissemination, through its regulatory influence on pro-angiogenic factor expression. MALAT-1 has also been linked to the evasion of immune surveillance in RCC, as it can regulate the expression of immune checkpoint molecules and modulate the tumor microenvironment. Hence, the potential utility of MALAT-1 as a diagnostic and prognostic biomarker in RCC emerges, warranting further investigation and validation of its clinical significance. This comprehensive review provides an overview of the diverse functional roles exhibited by MALAT-1 in RCC.

MALAT1 regulates network of microRNA-15a/16-VEGFA to promote tumorigenesis and angiogenesis in multiple myeloma

MALAT1 is one of the most hopeful members implicated in angiogenesis in a variety of non-malignant diseases. In multiple myeloma (MM), MALAT1 is recognized as the most highly expressed long non-coding RNA. However, the functional roles of MALAT1 in angiogenesis and the responsible mechanisms have not yet been explored. Herein, we discovered a novel regulatory network dependent on MALAT1 in relation to MM tumorigenesis and angiogenesis. We observed that MALAT1 was upregulated in MM and significantly associated with poor overall survival. MALAT1 knockdown suppressed MM cell proliferation and promoted apoptosis, while restricting endothelial cells angiogenesis. Moreover, MALAT1 directly targeted microRNA-15a/16, and microRNA-15a/16 suppression partly reverted the effects of MALAT1 deletion on MM cells in vitro as well as tumor growth and angiogenesis in vivo. In addition, further study indicated that MALAT1 functioned as a competing endogenous RNA for microRNA-15a/16 to regulate vascular endothelial growth factor A (VEGFA) expression. Our results suggest that MALAT1 plays an important role in the regulatory axis of microRNA-15a/16-VEGFA to promote tumorigenicity and angiogenesis in MM. Consequently, MALAT1 could serve as a novel promising biomarker and a potential antiangiogenic target against MM.

The complex nature of lncRNA-mediated chromatin dynamics in multiple myeloma

Extensive genome-wide sequencing efforts have unveiled the intricate regulatory potential of long non-protein coding RNAs (lncRNAs) within the domain of haematological malignancies. Notably, lncRNAs have been found to directly modulate chromatin architecture, thereby impacting gene expression and disease progression by interacting with DNA, RNA, and proteins in a tissue- or condition-specific manner. Furthermore, recent studies have highlighted the intricate epigenetic control of lncRNAs in cancer. Consequently, this provides a rationale to explore the possibility of therapeutically targeting lncRNAs themselves or the epigenetic mechanisms that govern their activity. Within the scope of this review, we will assess the current state of knowledge regarding the epigenetic regulation of lncRNAs and how, in turn, lncRNAs contribute to chromatin remodelling in the context of multiple myeloma.

Decoding the role of miRNAs in multiple myeloma pathogenesis: A focus on signaling pathways

Multiple myeloma (MM) is a cancer of plasma cells that has been extensively studied in recent years, with researchers increasingly focusing on the role of microRNAs (miRNAs) in regulating gene expression in MM. Several non-coding RNAs have been demonstrated to regulate MM pathogenesis signaling pathways. These pathways might regulate MM development, apoptosis, progression, and therapeutic outcomes. They are Wnt/β-catenin, PI3K/Akt/mTOR, P53 and KRAS. This review highlights the impending role of miRNAs in MM signaling and their relationship with MM therapeutic interventions.

Long non-coding RNAs modulate tumor microenvironment to promote metastasis: novel avenue for therapeutic intervention

Cancer is a devastating disease and the primary cause of morbidity and mortality worldwide, with cancer metastasis responsible for 90% of cancer-related deaths. Cancer metastasis is a multistep process characterized by spreading of cancer cells from the primary tumor and acquiring molecular and phenotypic changes that enable them to expand and colonize in distant organs. Despite recent advancements, the underlying molecular mechanism(s) of cancer metastasis is limited and requires further exploration. In addition to genetic alterations, epigenetic changes have been demonstrated to play an important role in the development of cancer metastasis. Long non-coding RNAs (lncRNAs) are considered one of the most critical epigenetic regulators. By regulating signaling pathways and acting as decoys, guides, and scaffolds, they modulate key molecules in every step of cancer metastasis such as dissemination of carcinoma cells, intravascular transit, and metastatic colonization. Gaining a good knowledge of the detailed molecular basis underlying lncRNAs regulating cancer metastasis may provide previously unknown therapeutic and diagnostic lncRNAs for patients with metastatic disease. In this review, we concentrate on the molecular mechanisms underlying lncRNAs in the regulation of cancer metastasis, the cross-talk with metabolic reprogramming, modulating cancer cell anoikis resistance, influencing metastatic microenvironment, and the interaction with pre-metastatic niche formation. In addition, we also discuss the clinical utility and therapeutic potential of lncRNAs for cancer treatment. Finally, we also represent areas for future research in this rapidly developing field.

Circ_0005615 restrains the progression of multiple myeloma through modulating miR-331-3p and IGF1R regulatory cascade

BACKGROUND

Circular RNAs are implicated in modulating the progression of various malignant tumors. However, the function and underlying mechanisms of circ_0005615 in multiple myeloma (MM) remain unclear.

METHODS

The expression levels of circ_0005615, miR-331-3p and IGF1R were tested by quantitative real-time polymerase chain reaction or western blot assay. Cell counting kit-8 and 5-ethynyl-2'-deoxyuridine (EdU) assay were performed for cell proliferation detection. Cell apoptosis and cell cycle were measured by flow cytometry. The protein expressions of Bax and Bcl-2 were detected by western blot assay. Glucose consumption, lactate production and ATP/ADP ratios were estimated to disclose cell glycolysis. The interaction relationship among miR-331-3p and circ_0005615 or IGF1R was proved by dual-luciferase reporter assay.

RESULTS

The abundance of circ_0005615 and IGF1R was increased in MM patients and cells, while the expression of miR-331-3p was decreased. Circ_0005615 inhibition retarded the proliferation and cell cycle progression, while reinforced the apoptosis of MM cells. Molecularly, circ_0005615 could sponge miR-331-3p, and the repressive trends of circ_0005615 deficiency on MM progression could be alleviated by anti-miR-331-3p introduction. Additionally, IGF1R was validated to be targeted by miR-331-3p, and IGF1R overexpression mitigated the suppressive function of miR-331-3p on MM development. Furthermore, IGF1R was mediated by circ_0005615/miR-331-3p axis in MM cells.

CONCLUSION

Circ_0005615 downregulation blocked MM development by targeting miR-331-3p/IGF1R axis.

The Role of HIF1-related Genes and Non-coding RNAs Expression in Clear Cell Renal Cell Carcinoma

BACKGROUND/AIM

Renal cell carcinoma is one of the three most common malignant urologic tumors, with clear cell renal cell carcinoma (ccRCC) representing its most common subtype. Although nephrectomy can radically cure the disease, a large percentage of patients is diagnosed when metastatic sites are present and thus alternative, pharmaceutical approaches need to be sought. Since HIF1 up-regulates the transcription of genes that range from metabolic enzymes to non-coding RNAs, and is a key molecule of ccRCC pathogenesis, this study aimed to investigate the expression ALDOA, SOX-6, and non-coding RNAs (mir-122, mir-1271, and MALAT-1) in samples from ccRCC patients.

PATIENTS AND METHODS

Tumor and adjacent normal tissue samples from 14 patients with ccRCC were harvested. Expression of ALDOA, mir-122, mir-1271, and MALAT-1 mRNA was estimated using real time PCR, whereas the expression of SOX-6 protein was investigated using immunohistochemistry.

RESULTS

Up-regulation of HIF1 was observed, accompanied with up-regulation of ALDOA, MALAT-1, and mir-122. On the contrary, the expression of mir-1271 was found to be reduced, a finding that can be attributed to a potential MALAT-1 sponge function. Furthermore, SOX-6 protein levels (a transcription factor with tumor suppressing properties) were also reduced.

CONCLUSION

The observed dysregulated expression levels highlight the importance of ALDOA, MALAT-1, mir-122, mir-1271, and SOX-6, which remain less studied than the known and well-studied HIF1 pathways of VEGF, TGF-α, and EPO. Furthermore, inhibition of the up-regulated ALDOA, mir-122, and MALAT-1 could be of therapeutic interest for selected ccRCC patients.

In silico analysis to identify miR-1271-5p/PLCB4 (phospholipase C Beta 4) axis mediated oxaliplatin resistance in metastatic colorectal cancer

Oxaliplatin (OXA) is the first-line chemotherapy drug for metastatic colorectal cancer (mCRC), and the emergence of drug resistance is a major clinical challenge. Although there have been numerous studies on OXA resistance, but its underlying molecular mechanisms are still unclear. This study aims to identify key regulatory genes and pathways associated with OXA resistance. The Gene Expression Omnibus (GEO) GSE42387 dataset containing gene expression profiles of parental and OXA-resistant LoVo cells was applied to explore potential targets. GEO2R, STRING, CytoNCA (a plug-in of Cytoscape), and DAVID were used to analyze differentially expressed genes (DEGs), protein-protein interactions (PPIs), hub genes in PPIs, and gene ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. R2 online platform was used to run a survival analysis of validated hub genes enriched in KEGG pathways. The ENCORI database predicted microRNAs for candidate genes. A survival analysis of those genes was performed, and validated using the OncoLnc database. In addition, the 'clusterProfiler' package in R was used to perform gene set enrichment analysis (GSEA). We identified 395 DEGs, among which 155 were upregulated and 240 were downregulated. In total, 95 DEGs were screened as hub genes after constructing the PPI networks. Twelve GO terms and three KEGG pathways (steroid hormone biosynthesis, malaria, and pathways in cancer) were identified as being significant in the enrichment analysis of hub genes. Twenty-one hub genes enriched in KEGG pathways were defined as key genes. Among them AKT3, phospholipase C Beta 4 (PLCB4), and TGFB1 were identified as OXA-resistance genes through the survival analysis. High expressions of AKT3 and TGFB1 were each associated with a poor prognosis, and lower expression of PLCB4 was correlated with worse survival. Further, high levels of hsa-miR-1271-5p, which potentially targets PLCB4, were associated with poor overall survival in patients with CRC. Finally, we found that PLCB4 low expression was associated with MAPK signaling pathway and VEGF signaling pathway in CRC. Our results demonstrated that hsa-miR-1271-5p/PLCB4 in the pathway in cancer could be a new potential therapeutic target for mCRC with OXA resistance.

Aberrantly expressed long noncoding RNAs as potential prognostic biomarkers in newly diagnosed multiple myeloma: A systemic review and meta-analysis

BACKGROUND

Numerous studies have manifested long noncoding RNAs (lncRNAs) as biomarkers to determine the prognosis of multiple myeloma (MM) patients. Nevertheless, the prognostic role of lncRNAs in MM is still ambiguous. Herein, we performed a meta-analysis to evaluate the predictive value of aberrantly expressed lncRNAs in MM.

METHODS

A systemic literature search was performed in PubMed, EMBASE, Cochrane, and Web of Science databases until October 9, 2021, and the protocol was registered in the PROSPERO database (CRD42021284364). Our study extracted the hazard ratios (HRs) and 95% confidence intervals (CIs) of overall survival (OS), progression-free survival (PFS), or event-free survival (EFS). Begg's and Egger's tests were employed to correct publication bias.

RESULT

Twenty-six individual studies containing 3501 MM patients were enrolled in this study. The results showed that aberrant expression of lncRNAs was associated with poor OS and PFS of MM patients. The pooled HRs for univariate OS and PFS were 1.48 (95% CI = 1.17-1.88, p < 0.001) and 1.30 (95% CI = 1.18-1.43, p < 0.001), respectively, whereas the pooled HRs for multivariate OS and PFS were 1.50 (95% CI = 1.16-1.95, p < 0.001) and 1.59 (95% CI = 1.22-2.07, p < 0.001), respectively. Subgroup analysis suggested that MALAT1, TCF7, NEAT1, and PVT1 upregulation were associated with poor OS (p < 0.05), PVT1, and TCF7 upregulation were implicated with worse PFS (p < 0.05), while only TCF7 overexpression was correlated with reduced EFS (p < 0.05). Moreover, the contour-enhanced funnel plot demonstrated the reliability of our current conclusion, which was not affected by publication bias.

CONCLUSION

Aberrantly expressed particular lncRNAs are critical prognostic indicators in long-term survival as well as promising biomarkers in progression-free status. However, different cutoff values and dissimilar methods to assess lncRNA expression among studies may lead to heterogeneity.

Role of ncRNA in multiple myeloma

Multiple myeloma (MM) remains incurable despite advances in current treatment. Patients with MM exhibit significant variations in their prognosis and survival. Recently, genetic abnormalities, such as chromosomal variations and gene mutations, have been increasingly recognized in MM. Therefore, better prognostic indicators of MM are required for the diagnosis and treatment of patients with MM. ncRNAs are non-protein-coding transcripts that regulate gene expression at the post-transcriptional level. Deregulation of ncRNAs affects cell cycle progression, cancer cell invasion and metastasis. The abnormal expression of these ncRNAs is also critical for the pathogenesis of several cancers, including MM. Hence, this review aims to discuss the recent findings on the role of regulatory ncRNAs and evaluate their potential value in MM.

Current perspectives on interethnic variability in multiple myeloma: Single cell technology, population pharmacogenetics and molecular signal transduction

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This review discusses the emerging single cell technologies and applications in Multiple myeloma (MM), population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction.

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The role(s) of epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of MM are also discussed.

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It is understood that ethnic component acts as a driver of variable response to chemotherapy in different sub-populations globally.

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This review augments our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, myeloma microenvironment at the molecular and cellular level, and developing precision medicine strategies to combat this malignancy.

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The emerging single cell technologies hold great promise for enhancing our understanding of MM tumor heterogeneity and clonal diversity.

Multiple myeloma (MM) is an aggressive cancer characterised by malignancy of the plasma cells and a rising global incidence. The gold standard for optimum response is aggressive chemotherapy followed by autologous stem cell transplantation (ASCT). However, majority of the patients are above 60 years and this presents the clinician with complications such as ineligibility for ASCT, frailty, drug-induced toxicity and differential/partial response to treatment. The latter is partly driven by heterogenous genotypes of the disease in different subpopulations. In this review, we discuss emerging single cell technologies and applications in MM, population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction, as well as the role(s) played by epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of the disease. Taken together, our discussions further our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, augment our understanding of the myeloma microenvironment at the molecular and cellular level and provide a basis for developing precision medicine strategies to combat this malignancy.

A cutting-edge immunomodulatory interlinkage between HOTAIR and MALAT1 in tumor-associated macrophages in breast cancer: A personalized immunotherapeutic approach

Breast cancer (BC) is one of the most common cancers, accounting for 2.3 million cases worldwide. BC can be molecularly subclassified into luminal A, luminal B HER2-, luminal B HER2+, HER2+, and triple-negative breast cancer (TNBC). These molecular subtypes differ in their prognosis and treatment strategies; thus, understanding the tumor microenvironment (TME) of BC could lead to new potential treatment strategies. The TME hosts a population of cells that act as antitumorigenic such as tumor-associated eosinophils or pro-tumorigenic such as cancer-associated fibroblasts (CAFs), tumor-associated neutrophils (TANs), monocytic-derived populations such as MDSCs, or most importantly "tumor-associated macrophages (TAMs)," which are derived from CD14+ monocytes. TAMs are reported to have the pro-inflammatory phenotype M1, which is found only in the very early stages of tumor and is not correlated with progression; however, the M2 phenotype is anti-inflammatory that is correlated with tumor progression and metastasis. The current study focused on controlling the anti-inflammatory activity in TAMs of hormonal, HER2+, and TNBC by epigenetic fine-tuning of two immunomodulatory proteins, namely, CD80 and mesothelin (MSLN), which are known to be overexpressed in BC with pro-tumorigenic activity. Long non-coding RNAs are crucial key players in tumor progression whether acting as oncogenic or tumor suppressors. We focused on the regulatory role of MALAT1 and HOTAIR lncRNAs and their role in controlling the tumorigenic activity of TAMs. This study observed the impact of manipulation of MALAT1 and HOTAIR on the expression of both CD80 and MSLN in TAMs of BC. Moreover, we analyzed the interlinkage between HOTAIR and MALAT1 as regulators to one another in TAMs of BC. The current study reported an upstream regulatory effect of HOTAIR on MALAT1. Moreover, our results showed a promising use of MALAT1 and HOTAIR in regulating oncogenic immune-modulatory proteins MSLN and CD80 in TAMs of HER2+ and TNBC. The downregulation of MALAT1 and HOTAIR resulted in the upregulation of CD80 and MSLN, which indicates that they might have a cell-specific activity in TAMs. These data shed light on novel key players affecting the anti-inflammatory activity of TAMs as a possible therapeutic target in HER2+ and TNBC.

FAM201A Promotes Cervical Cancer Progression and Metastasis through miR-1271-5p/Flotillin-1 Axis Targeting-Induced Wnt/β-Catenin Pathway

This study investigated the role of the family with sequence similarity 201-member A (FAM201A), as previously reported oncogenic, in cervical cancer (CC). FAM201A expression in CC was analyzed through bioinformatics analyses, and its distribution in CC tissues/cells was determined by in situ hybridization. CC cells were transfected/cotransfected with FAM201A/flotillin-1 (FLOT1) overexpression plasmids and miR-1271-5p mimics, followed by functional analysis on viability, migration and invasion. Pearson's correlation tests were performed to analyze the correlation between FAM201A and miR-1271-5p in CC tissues. The targeting relationship between miR-1271-5p and FLOT1 was confirmed by dual-luciferase reporter assay. The expressions of FAM201A, miR-1271-5p, FLOT1, matrix metalloproteinases (MMP)-9, MMP-2, E-cadherin, N-cadherin, and the Wnt/β-catenin pathway-related molecules (Wnt1, β-catenin and p-β-catenin) in CC cells or tissues were assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and/or western blot. The results showed that FAM201A was abundantly expressed and miR-1271-5p expression was downregulated in CC. FAM201A was enriched in CC cell cytoplasm and negatively correlated with miR-1271-5p in CC tissues. FAM201A overexpression enhanced the cell viability, migration, invasion, and tumorigenesis of CC in vivo and increased FLOT1 expression. These trends were all reversed by upregulating miR-1271-5p, which induced opposite effects to FAM201A overexpression. MiR-1271-5p upregulation depleted the levels of MMP-9, MMP-2, N-cadherin, and the Wnt/β-catenin pathway-related molecules and upregulated E-cadherin expression. FLOT1 was a direct target of miR-1271-5p. FLOT1 overexpression induced effects contrary to the upregulation of miR-1271-5p and abolished miR-1271-5p upregulation-induced effects in CC cells. Overall, this study showed that FAM201A promoted cervical cancer progression and metastasis by targeting the miR-1271-5p/FLOT1 axis-induced Wnt/β-catenin pathway.

Oncogenic Dysregulation of Circulating Noncoding RNAs: Novel Challenges and Opportunities in Sarcoma Diagnosis and Treatment

Simple Summary

Body fluids contain different classes of RNA molecules such as protein-coding messenger RNAs (mRNA) and noncoding RNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs). These circulating RNAs can travel naked or packed into extracellular vesicles and display valuable potential as non-invasive biomarkers of sarcoma malignancy. In this review, we summarize current knowledge on the possible functions of these circulating RNAs and discuss their possible exploitation as novel markers to improve sarcoma diagnosis and prognosis. Despite the recent advance in technological tools have improved protocols for the extraction and detection of circulating RNA, many aspects related to the biology of these molecules remain to be elucidated. In particular, the lack of standardization in the assessment of these markers makes difficult their adoption into clinical practice.

Abstract

Sarcomas comprise a heterogeneous group of rare mesenchymal malignancies. Sarcomas can be grouped into two categories characterized by different prognosis and treatment approaches: soft tissue sarcoma and primary bone sarcoma. In the last years, research on novel diagnostic, prognostic or predictive biomarkers in sarcoma management has been focused on circulating tumor-derived molecules as valuable tools. Liquid biopsies that measure various tumor components, including circulating cell-free DNA and RNA, circulating tumor cells, tumor extracellular vesicles and exosomes, are gaining attention as methods for molecular screening and early diagnosis. Compared with traditional tissue biopsies, liquid biopsies are minimally invasive and blood samples can be collected serially over time to monitor cancer progression. This review will focus on circulating noncoding RNA molecules from liquid biopsies that are dysregulated in sarcoma malignancies and discuss advantages and current limitations of their employment as biomarkers in the management of sarcomas. It will also explore their utility in the evaluation of the clinical response to treatments and of disease relapse. Moreover, it will explore state-of-the-art techniques that allow for the early detection of these circulating biomarkers. Despite the huge potential, current reports highlight poor sensitivity, specificity, and survival benefit of these methods, that are therefore still insufficient for routine screening purposes.

Metabolic cross-talk within the bone marrow milieu: focus on multiple myeloma

Cancer cells are well-known for their capacity to adapt their metabolism to their increasing energy demands which is necessary for tumor progression. This is no different for Multiple Myeloma (MM), a hematological cancer which develops in the bone marrow (BM), whereby the malignant plasma cells accumulate and impair normal BM functions. It has become clear that the hypoxic BM environment contributes to metabolic rewiring of the MM cells, including changes in metabolite levels, increased/decreased activity of metabolic enzymes and metabolic shifts. These adaptations will lead to a pro-tumoral environment stimulating MM growth and drug resistance In this review, we discuss the identified metabolic changes in MM and the BM microenvironment and summarize how these identified changes have been targeted (by inhibitors, genetic approaches or deprivation studies) in order to block MM progression and survival.

Sex-determining Region Y-box transcription factor 13 promotes breast cancer cell proliferation and glycolysis by activating the tripartite motif containing 11-mediated Wnt/β-catenin signaling pathway

Breast cancer is the most frequent cancer among women and the second highest mortality in female across the world. Recent studies have illustrated that sex-determining region Y (SRY)-box protein (SOX) family plays essential roles in regulating various cancers. Nevertheless, the detailed effects of SOX13 on breast cancer are still uncovered. In our present study, SOX13 protein level was measured by using western blot assay in tissues and cells, and the results showed that SOX13 was upregulated in breast cancer tissues and cells compared with normal samples. Moreover, silencing SOX13 inhibited breast cancer cell viability, arrested cell cycle at G1/S phase and suppressed glycolysis, while overexpression of SOX13 reversed these events. Additionally, SOX13 knockdown reduced the level of proteins related to Wnt/β-catenin signaling pathway, whereas overexpression of tripartite motif containing 11 (TRM11) efficiently attenuated the effects, indicating that SOX13 controlled Wnt/β-catenin pathway depending on TRIM11. Furthermore, the data gained from xenograft tumor model illustrated that silencing SOX13 suppressed the tumor growth in nude mice and the glycolysis of tissues. In conclusion, our investigation illustrated that SOX13 facilitated breast cancer cell proliferation and glycolysis by modulating Wnt/β-catenin signaling pathway affected via TRIM11.

The Multiple Myeloma Landscape: Epigenetics and Non-Coding RNAs

Simple Summary

Recent findings in multiple myeloma have led to therapies which have improved patient life quality and expectancy. However, frequent relapse and drug resistance emphasize the need for more efficient therapeutic approaches. The discovery of non-coding RNAs as key actors in multiple myeloma has broadened the molecular landscape of this disease, together with classical epigenetic factors such as methylation and acetylation. microRNAs and long non-coding RNAs comprise the majority of the described non-coding RNAs dysregulated in multiple myeloma, while circular RNAs are recently emerging as promising molecular targets. This review provides a comprehensive overview of the most recent knowledge on this topic and suggests new therapeutic strategies.

Abstract

Despite advances in available treatments, multiple myeloma (MM) remains an incurable disease and represents a challenge in oncohematology. New insights into epigenetic factors contributing to MM development and progression have improved the knowledge surrounding its molecular basis. Beyond classical epigenetic factors, including methylation and acetylation, recent genome analyses have unveiled the importance of non-coding RNAs in MM pathogenesis. Non-coding RNAs have become of interest, as their dysregulation opens the door to new therapeutic approaches. The discovery, in the past years, of molecular techniques, such as CRISPR-Cas, has led to innovative therapies with potential benefits to achieve a better outcome for MM patients. This review summarizes the current knowledge on epigenetics and non-coding RNAs in MM pathogenesis.

The Landscape of lncRNAs in Multiple Myeloma: Implications in the "Hallmarks of Cancer", Clinical Perspectives and Therapeutic Opportunities

Simple Summary

Multiple myeloma (MM) is an aggressive hematological neoplasia caused by the uncontrolled proliferation of aberrant plasmacells. Neoplastic transformation and progression are driven by a number of biological processes, called ‘hallmarks of cancer’, which are regulated by different molecules, including long non-coding RNAs. A deeper understanding of the mechanisms that regulate MM development and progression will help to improve patients stratification and management, and promote the identification of new therapeutic targets.

Abstract

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides that are not translated into proteins. Nowadays, lncRNAs are gaining importance as key regulators of gene expression and, consequently, of several biological functions in physiological and pathological conditions, including cancer. Here, we point out the role of lncRNAs in the pathogenesis of multiple myeloma (MM). We focus on their ability to regulate the biological processes identified as “hallmarks of cancer” that enable malignant cell transformation, early tumor onset and progression. The aberrant expression of lncRNAs in MM suggests their potential use as clinical biomarkers for diagnosis, patient stratification, and clinical management. Moreover, they represent ideal candidates for therapeutic targeting.

Effects of dietary macronutrients on the hepatic transcriptome and serum metabolome in mice

Dietary macronutrient composition influences both hepatic function and aging. Previous work suggested that longevity and hepatic gene expression levels were highly responsive to dietary protein, but almost unaffected by other macronutrients. In contrast, we found expression of 4005, 4232, and 4292 genes in the livers of mice were significantly associated with changes in dietary protein (5%–30%), fat (20%–60%), and carbohydrate (10%–75%), respectively. More genes in aging‐related pathways (notably mTOR, IGF‐1, and NF‐kappaB) had significant correlations with dietary fat intake than protein and carbohydrate intake, and the pattern of gene expression changes in relation to dietary fat intake was in the opposite direction to the effect of graded levels of caloric restriction consistent with dietary fat having a negative impact on aging. We found 732, 808, and 995 serum metabolites were significantly correlated with dietary protein (5%–30%), fat (8.3%–80%), and carbohydrate (10%–80%) contents, respectively. Metabolomics pathway analysis revealed sphingosine‐1‐phosphate signaling was the significantly affected pathway by dietary fat content which has also been identified as significant changed metabolic pathway in the previous caloric restriction study. Our results suggest dietary fat has major impact on aging‐related gene and metabolic pathways compared with other macronutrients.

Identification of Novel Prognostic Signatures for Clear Cell Renal Cell Carcinoma Based on ceRNA Network Construction and Immune Infiltration Analysis

Objective. Clear cell renal cell carcinoma (ccRCC) carries significant morbidity and mortality globally and is often resistant to conventional radiotherapy and chemotherapy. Immune checkpoint blockade (ICB) has received attention in ccRCC patients as a promising anticancer treatment. Furthermore, competitive endogenous RNA (ceRNA) networks are crucial for the occurrence and progression of various tumors. This study was aimed at identifying reliable prognostic signatures and exploring potential mechanisms between ceRNA regulation and immune cell infiltration in ccRCC patients. Methods and Results. Gene expression profiling and clinical information of ccRCC samples were obtained from The Cancer Genome Atlas (TCGA) database. Through comprehensive bioinformatic analyses, differentially expressed mRNAs (DEmRNAs; $n=131$ ), lncRNAs (DElncRNAs; $n=12$ ), and miRNAs (DEmiRNAs; $n=25$ ) were identified to establish ceRNA networks. The CIBERSORT algorithm was applied to calculate the proportion of 22 types of tumor-infiltrating immune cells (TIICs) in ccRCC tissues. Subsequently, univariate Cox, Lasso, and multivariate Cox regression analyses were employed to construct ceRNA-related and TIIC-related prognostic signatures. In addition, we explored the relationship between the crucial genes and TIICs via coexpression analysis, which revealed that the interactions between MALAT1, miR-1271-5p, KIAA1324, and follicular helper T cells might be closely correlated with the progression of ccRCC. Ultimately, we preliminarily validated that the potential MALAT1/miR-1271-5p/KIAA1324 axis was consistent with the ceRNA theory by qRT-PCR in the ccRCC cell lines. Conclusion. On the basis of the ceRNA networks and TIICs, we constructed two prognostic signatures with excellent predictive value and explored possible molecular regulatory mechanisms, which might contribute to the improvement of prognosis and individualized treatment for ccRCC patients.

The Exosomes Containing LINC00461 Originated from Multiple Myeloma Inhibit the Osteoblast Differentiation of Bone Mesenchymal Stem Cells via Sponging miR-324-3p

Multiple myeloma is one of the hematological malignancies and inhibited osteoblast differentiation of bone marrow mesenchymal stem cells (BM-MSCs) which has been proved as a major complication of the patients with multiple myeloma. However, the pathomechanism of symptom remains unclear. Besides, several studies have indicated that LINC00461 plays an important role in the progression of multiple tumors. Hence, this study attempted to reveal the role of LINC00461 in the osteoblast differentiation of MSCs. In this study, the expression level of LINC00461 in the exosomes of multiple myeloma cells was measured, and BM-MSCs were cultured with the exosomes to observe the change of cellular phenotype. Moreover, downstream target of LINC00461 was searched and verified with dual-luciferase reporter assay, and the activation of the Wnt/β-catenin pathway was also observed by Western blot. The results showed that the isolated BMSCs exhibited special biomarkers of MSCs. LINC00461 was significantly upregulated in the exosomes originated multiple myeloma cells, and increased LINC00461 significantly impeded the osteoblast differentiation of MSCs. Moreover, LINC00461 could significantly suppress the activation of the Wnt/β-catenin pathway in MSCs. In conclusion, this study suggested that LINC00461 in exosomes of multiple myeloma could reduce the activity of the Wnt/β-catenin pathway to inhibit the osteoblast differentiation of BM-MSCs via targeting miR-324-3p.

Long non-coding RNAs (lncRNAs) as prognostic and diagnostic biomarkers in multiple myeloma: A systematic review and meta-analysis

BACKGROUND

Recently, emerging studies have demonstrated the utility of particular long non-coding RNAs (lncRNAs) as useful biomarkers for the diagnosis and prognosis of multiple myeloma (MM). We systematically reviewed the literature and conducted a meta-analysis to quantify the predictive effectiveness of lncRNAs in the prognosis and diagnosis of MM.

METHODS

A systematic search was performed in PubMed, Embase, and Web of Science until March 24, 2021. A meta-analysis was conducted to explore the correlation between the expression of lncRNAs and prognostic endpoints, including overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS) or event-free survival (EFS). Moreover, the diagnostic performance of lncRNAs in MM was investigated by calculating accuracy metrics.

RESULTS

Overall, 43 studies were included in this systematic review, amongst which 36 studies assessed prognostic endpoints (including 5499 participants and 69 lncRNAs), and 11 studies evaluated diagnostic outcomes (with 1723 participants and 11 lncRNAs). The overexpression of CRNDE (hazard ratio (HR)= 1.94, 95% confidence interval (CI) 1.61, 2.34), NEAT1 (HR=1.97, 95%CI 1.36, 2.85), PVT1 (HR=1.92, 95%CI 1.25, 2.97), and TCF7 (HR=1.98, 95%CI 1.42, 2.76) was significantly associated with reduced OS. Furthermore, upregulation of PVT1 was significantly correlated with poor PFS (HR=1.86, 95%CI 1.29, 2.68). The pooled diagnostic performance of lncRNAs was as follows: sensitivity 0.78 (95%CI 0.73, 0.82), specificity 0.88 (95%CI 0.83, 0.92), and area under the curve 0.89 (95%CI 0.86, 0.92).

CONCLUSIONS

Our results revealed the potential significance of lncRNAs in MM as diagnostic and prognostic markers, which may be the future targets for individualized therapy.

Novel Insights Into MALAT1 Function as a MicroRNA Sponge in NSCLC

The long non-coding RNA metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) was initially found to be overexpressed in early non-small cell lung cancer (NSCLC). Accumulating studies have shown that MALAT1 is overexpressed in the tissue or serum of NSCLC and plays a key role in its occurrence and development. In addition, the expression level of MALAT1 is significantly related to the tumor size, stage, metastasis, and distant invasion of NSCLC. Therefore, MALAT1 could be used as a biomarker for the early diagnosis, severity assessment, or prognosis evaluation of NSCLC patients. This review describes the basic properties and biological functions of MALAT1, focuses on the specific molecular mechanism of MALAT1 as a microRNA sponge in the occurrence and development of NSCLC in recent years, and emphasizes the application and potential prospect of MALAT1 in molecular biological markers and targeted therapy of NSCLC.

miRNome Profiling Reveals Shared Features in Breast Cancer Subtypes and Highlights miRNAs That Potentially Regulate MYB and EZH2 Expression

Breast cancer (BC) has been extensively studied, as it is one of the more commonly diagnosed cancer types worldwide. The study of miRNAs has increased what is known about the complexity of pathways and signaling and has identified potential biomarkers and therapeutic targets. Thus, miRNome profiling could provide important information regarding the molecular mechanisms involved in BC. On average, more than 430 miRNAs were identified as differentially expressed between BC cell lines and normal breast HMEC cells. From these, 110 miRNAs were common to BC subtypes. The miRNome enrichment analysis and interaction maps highlighted epigenetic-related pathways shared by all BC cell lines and revealed potential miRNA targets. Quantitative evaluation of BC patient samples and GETx/TCGA-BRCA datasets confirmed MYB and EZH2 as potential targets from BC miRNome. Moreover, overall survival was impacted by EZH2 expression. The expression of 15 miRNAs, selected according to aggressiveness of BC subtypes, was confirmed in TCGA-BRCA dataset. Of these miRNAs, miRNA-mRNA interaction prediction revealed 7 novel or underexplored miRNAs in BC: miR-1271-5p, miR-130a-5p, and miR-134 as MYB regulators and miR-138-5p, miR-455-3p, miR-487a, and miR-487b as EZH2 regulators. Herein, we report a novel molecular miRNA signature for BC and identify potential miRNA/mRNAs involved in disease subtypes.

LBX2-AS1 as a Novel Diagnostic Biomarker and Therapeutic Target Facilitates Multiple Myeloma Progression by Enhancing mRNA Stability of LBX2

Objective: Multiple myeloma (MM) represents a common age-associated malignancy globally. The function and underlying mechanism of antisense lncRNA LBX2-AS1 remain ambiguous in multiple myeloma (MM). Herein, we aimed to observe the biological implication of this lncRNA in MM.

Methods: RT-qPCR was employed to examine circulating LBX2-AS1 and LBX2 in 60 paired MM and healthy subjects. Correlation between the two was analyzed by Pearson test. Under transfection with shLBX2-AS1, proliferation and apoptosis were evaluated in MM cells through CCK-8, colony formation and flow cytometry. LBX2 expression was examined in MM cells with shLBX2-AS1 or pcDNA3.1-LBX2 transfection. Following treatment with cycloheximide or actinomycin D, LBX2 expression was examined in pcDNA3.1-LBX2-transfected MM cells at different time points. Rescue assays were then presented. Finally, xenograft tumor models were established.

Results: Circulating LBX2-AS1 was up-regulated in MM patients and positively correlated to LBX2 expression. Area under the curve (AUC) of LBX2-AS1 expression was 0.7525. Its up-regulation was also found in MM cells and primarily distributed in cytoplasm. LBX2-AS1 knockdown distinctly weakened proliferative ability and induced apoptosis in MM cells. Overexpressing LBX2-AS1 markedly strengthened LBX2 expression by increasing its mRNA stability. Rescue assays showed that silencing LBX2-AS1 distinctly weakened the pcDNA3.1-LBX2-induced increase in proliferation and decrease in apoptosis for MM cells. Silencing LBX2-AS1 markedly weakened tumor growth.

Conclusion: Our data demonstrated that circulating LBX2-AS1 could be an underlying diagnostic marker in MM. Targeting LBX2-AS1 suppressed tumor progression by affecting mRNA stability of LBX2 in MM. Hence, LBX2-AS1 could be a novel therapeutic marker against MM.

Long non‑coding RNA DANCR represses the viability, migration and invasion of multiple myeloma cells by sponging miR‑135b‑5p to target KLF9

Multiple myeloma (MM) is a malignancy of plasma cells that leads to marrow failure and bone lesions. Numerous studies have verified the link between long non‑coding RNAs (lncRNAs) and MM. The present study aimed to examine the role and underlying mechanism of differentiation antagonizing non‑protein coding RNA (DANCR) in MM cells. The relative expression levels of DANCR, microRNA (miR)‑135b‑5p and Krüppel‑like factor 9 (KLF9) were examined using reverse transcription‑quantitative PCR. Cell viability was assessed using the MTT assay, while relative cell migration and invasion were evaluated using Transwell assays. Moreover, the dual‑luciferase reporter assay was used to examine the interplay between DANCR, miR‑135b‑5p and KLF9. Western blotting was performed to determine the expression level of KLF9. It was found that lncRNA DANCR and KLF9 were downregulated, while miR‑135b‑5p was upregulated in the serum of patients with MM and in MM cells compared with the controls. Overexpressing DANCR or knocking down miR‑135b‑5p reduced the viability of the MM cells, as well as restrained MM cells from migrating and invading. Furthermore, DANCR directly targeted miR‑135b‑5p and was negatively correlated with miR‑135b‑5p. It was also found that KLF9 was targeted by miR‑135b‑5p and was inversely correlated with miR‑135b‑5p expression. The impact of lncRNA DANCR‑mediated suppression on cell viability, invasion and migration was partially abolished by short hairpin RNA KLF9 or miR‑135b‑5p mimics transfection in MM cells. Thus, it was suggested that lncRNA DANCR repressed the viability, migration and invasion of MM cells by sponging miR‑135b‑5p to target KLF9.

Molecular Mechanisms of miR-1271 Dysregulation in Human Cancer

MicroRNA is a small noncoding RNA that plays a role in regulating gene expression. miR-1271 is a tumor suppressor microRNA, which is related to the biological changes of many cancers. miR-1271 is considered a biomarker with a potential prognosis and high therapeutic value in tumors. Besides, the expression of miR-1271 is also regulated by many factors. In this study, we summarize the role of miR-1271 in tumors, focusing on the molecular mechanisms of the target genes of miR-1271. Our review will provide a comprehensive understanding of miR-1271 in tumors, as well as ideas for subsequent tumor research related to miR-1271.

Metabolic Control by DNA Tumor Virus-Encoded Proteins

Viruses co-opt a multitude of host cell metabolic processes in order to meet the energy and substrate requirements for successful viral replication. However, due to their limited coding capacity, viruses must enact most, if not all, of these metabolic changes by influencing the function of available host cell regulatory proteins. Typically, certain viral proteins, some of which can function as viral oncoproteins, interact with these cellular regulatory proteins directly in order to effect changes in downstream metabolic pathways. This review highlights recent research into how four different DNA tumor viruses, namely human adenovirus, human papillomavirus, Epstein-Barr virus and Kaposi's associated-sarcoma herpesvirus, can influence host cell metabolism through their interactions with either MYC, p53 or the pRb/E2F complex. Interestingly, some of these host cell regulators can be activated or inhibited by the same virus, depending on which viral oncoprotein is interacting with the regulatory protein. This review highlights how MYC, p53 and pRb/E2F regulate host cell metabolism, followed by an outline of how each of these DNA tumor viruses control their activities. Understanding how DNA tumor viruses regulate metabolism through viral oncoproteins could assist in the discovery or repurposing of metabolic inhibitors for antiviral therapy or treatment of virus-dependent cancers.

The Role of lncRNAs in the Pathobiology and Clinical Behavior of Multiple Myeloma

Simple Summary

Multiple myeloma (MM), the second most common hematological neoplasm, is still considered an incurable disease. Long non-coding RNAs (lncRNAs), genes that do not encode proteins, participate in numerous biological processes, but their deregulation, like that of coding genes, can contribute to carcinogenesis. Increasing evidence points to the relevant role of lncRNAs in the development of human tumors, such that they emerge as attractive biomarkers and therapeutic targets for cancer treatment, including MM. Here we review the oncogenic or tumor-suppressor functions of lncRNAs in MM and provide an overview of novel therapeutic approaches based on lncRNAs that will help to improve the management of these patients.

Abstract

MM is a hematological neoplasm that is still considered an incurable disease. Besides established genetic alterations, recent studies have shown that MM pathogenesis is also characterized by epigenetic aberrations, such as the gain of de novo active chromatin marks in promoter and enhancer regions and extensive DNA hypomethylation of intergenic regions, highlighting the relevance of these non-coding genomic regions. A recent study described how long non-coding RNAs (lncRNAs) correspond to 82% of the MM transcriptome and an increasing number of studies have demonstrated the importance of deregulation of lncRNAs in MM. In this review we focus on the deregulated lncRNAs in MM, including their biological or functional mechanisms, their role as biomarkers to improve the prognosis and monitoring of MM patients, and their participation in drug resistance. Furthermore, we also discuss the evidence supporting the role of lncRNAs as therapeutic targets through different novel RNA-based strategies.

Diagnostic, prognostic, and therapeutic significance of long non-coding RNA MALAT1 in cancer

Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is a widely studied lncRNA in cancer. Although dispensable for normal physiology, MALAT1 is important for cancer-related pathways regulation. It is localized in the nuclear speckles periphery along with centrally located pre-RNA splicing factors. MALAT1 associated cancer signaling pathways include MAPK/ERK, PI3K/AKT, β-catenin/Wnt, Hippo, VEGF, YAP, etc. Molecular tools such as immunoprecipitation, RNA pull-down, reporter assay, Northern blotting, microarray, and q-RT-PCR has been used to elucidate MALAT1's function in cancer pathogenesis. MALAT1 can regulate multiple steps in the development of tumours. The diagnostic and prognostic significance of MALAT1 has been demonstrated in cancers of the breast, cervix, colorectum, gallbladder, lung, ovary, pancreas, prostate, glioma, hepatocellular carcinoma, and multiple myeloma. MALAT1 has also emerged as a novel therapeutic target for solid as well as hematological malignancies. In experimental models, siRNA and antisense oligonucleotide (ASO) based strategy has been used for targeting MALAT1. The lncRNA has also been targeted for the chemosensitization and radiosensitization of cancer cells. However, most studies have been performed in preclinical models. How the cross-talk of MALAT1 with other signaling pathways affect cancer pathogenesis is the focus of this article. The diagnostic, prognostic, and therapeutic significance of MALAT1 in multiple cancer types are discussed.

Involvement of Long Non-Coding RNAs in Glucose Metabolism in Cancer

The rapid and uncontrolled proliferation of cancer cells is supported by metabolic reprogramming. Altered glucose metabolism supports cancer growth and progression. Compared with normal cells, cancer cells show increased glucose uptake, aerobic glycolysis and lactate production. Byproducts of adjusted glucose metabolism provide additional benefits supporting hallmark capabilities of cancer cells. Long non-coding RNAs (lncRNAs) are a heterogeneous group of transcripts of more than 200 nucleotides in length. They regulate numerous cellular processes, primarily through physical interaction with other molecules. Dysregulated lncRNAs are involved in all hallmarks of cancer including metabolic alterations. They may upregulate metabolic enzymes, modulate the expression of oncogenic or tumor-suppressive genes and disturb metabolic signaling pathways favoring cancer progression. Thus, lncRNAs are not only potential clinical biomarkers for cancer diagnostics and prediction but also possible therapeutic targets. This review summarizes the lncRNAs involved in cancer glucose metabolism and highlights their underlying molecular mechanisms.

p53-targeted lncRNA ST7-AS1 acts as a tumour suppressor by interacting with PTBP1 to suppress the Wnt/β-catenin signalling pathway in glioma

Glioma is the most prevalent intracranial tumour, with considerable morbidity. Long non-coding RNAs are important in the biological processes of various cancers. However, little is known about ST7 antisense RNA 1 (ST7-AS1) and its role in glioma progression. ST7-AS1 expression was reduced in glioma tissues and cells in comparison to normal brain tissues. p53 transcriptionally targeted the ST7-AS1 promoter in U251 glioma cells. The targeting significantly inhibited cell migration, invasion, and proliferation, and promoted apoptosis. ST7-AS1 directly bound to and downregulated polypyrimidine tract-binding protein 1 (PTBP1) at the post-transcriptional level. ST7-AS1 overexpression inhibited glioma progression by suppressing Wnt/β-catenin signalling by downregulating PTBP1 expression. Additionally, p53 expression negatively correlated with PTBP1 expression. Glioma progression is regulated by a positive feedback loop involving the p53/ST7-AS1/PTBP1 axis, which might be a promising therapeutic target for glioma treatment.

LRRC75A-AS1 targets miR-199b-5p/PDCD4 axis to repress multiple myeloma

BACKGROUND

Multiple functions of miR-199b-5p in diseases have been demonstrated by existing studies. However, never has the correlation between miR-199b-5p and multiple myeloma (MM) been established.

METHODS

qRT-PCR analyzed RNA expression and western blot measured protein expression. Cell proliferation ability was tested via colony formation and EdU assays, and apoptosis was determined via TUNEL, flow cytometry and detection of apoptosis-related proteins. Position of LRRC75A antisense RNA 1 (LRRC75A-AS1) was recognized by FISH assay. RIP, RNA pull-down and luciferase reporter experiments explored the molecular interplay.

RESULTS

GEO (Gene Expression Omnibus) data revealed miR-199b-5p upregulation in MM specimens, and qRT-PCR data verified miR-199b-5p upregulation in MM cells. Inhibiting miR-199b-5p markedly impeded MM cell proliferation and stimulated apoptosis. Moreover, we demonstrated the mechanism that miR-199b-5p was decoyed by LRRC75A-AS1 and miR-199b-5p targeted programmed cell death 4 (PDCD4) to repress its expression. Further, LRRC75A-AS1 was verified to repress proliferation and prompt apoptosis in a PDCD4-dependent way in MM cells.

CONCLUSION

Our data displayed that miR-199b-5p was sequestered by LRRC75A-AS1 so that PDCD4 was released to repress MM, implying the targeting miR-199b-5p as a novel thought for improving MM therapy.

Circular RNA circ_0000043 promotes endometrial carcinoma progression by regulating miR-1271-5p/CTNND1 axis

BACKGROUND

Circular RNAs (circRNAs) are involved in a variety of biological processes, including tumorigenesis. However, the exact role and molecular mechanisms of circ_0000043 in endometrial carcinoma (EC) remain largely unknown.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to determine the expression levels of circ_0000043, microRNA-1271-5p (miR-1271-5p) and catenin delta 1 (CTNND1). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were used to measure cell proliferation, cell apoptosis and cell cycle distribution, respectively. Cell migration and invasion were assessed by transwell assay. Western blot assay was performed to examine the protein expression of matrix metalloproteinase 2 (MMP2), MMP9 and CTNND1. The interaction between miR-1271-5p and circ_0000043 or CTNND1 was predicted by starBase and confirmed by dual-luciferase reporter assay. The mice xenograft model was established to investigate the role of circ_0000043 in vivo.

RESULTS

Circ_0000043 and CTNND1 were highly expressed and miR-1271-5p was lowly expressed in EC tissues and cells. Knockdown of circ_0000043 inhibited the progression of EC by inhibiting cell proliferation, migration, invasion and tumor growth (in vivo) and promoting apoptosis. MiR-1271-5p was a direct target of circ_0000043 and its inhibition reversed the inhibitory effect of circ_0000043 knockdown on the progression of EC cells. In addition, CTNND1 was a downstream target of miR-1271-5p, and miR-1271-5p overexpression inhibited EC cell proliferation, migration and invasion and induced apoptosis by targeting CTNND1. Moreover, circ_0000043 positively regulated CTNND1 expression by sponging miR-1271-5p.

CONCLUSION

Circ_0000043 knockdown inhibited the progression of EC by regulating miR-1271-5p/CTNND1 axis, which might provide a promising circRNA-targeted therapy for EC.

LncRNA MALAT1 Regulates the Progression and Cisplatin Resistance of Ovarian Cancer Cells via Modulating miR-1271-5p/E2F5 Axis

Background

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) were reported to be related to the development of ovarian cancer (OC). In this study, the functional mechanisms of lncRNA metastasis associated with lung adenocarcinoma transcript 1 (MALAT1) and microRNA-1271-5p (miR-1271-5p) were explored in OC.

Methods

The level of MALAT1, miR-1271-5p, or E2F transcription factor 5 (E2F5) was detected by qRT-PCR. MTT assay, flow cytometry analysis and transwell migration and invasion assays were performed to determine cell proliferation, apoptosis, migration and invasion, respectively. E2F5 protein expression was detected by Western blot. The interaction between miR-1271-5p and MALAT1 or E2F transcription factor 5 (E2F5) was confirmed by the dual-luciferase reporter assay.

Results

MALAT1 and E2F5 level were increased, while miR-1271-5p level was decreased in cisplatin (DDP)-resistant OC tissues and cells. MALAT1 knockdown or miR-1271-5p upregulation decreased IC₅₀ of cisplatin, and inhibited cell proliferation, migration, invasion, and facilitated cell apoptosis in DDP-resistant OC cells. Moreover, MALAT1 sponged miR-1271-5p to upregulate E2F5 expression. Besides, MALAT1 knockdown decreased DDP resistance, inhibited cell proliferation, migration, invasion, and promoted cell apoptosis by sponging miR-1271-5p to downregulate E2F5 expression in DDP-resistant OC cell.

Conclusion

We demonstrated that MALAT1 mediated DDP-resistant OC development through miR-1271-5p/E2F5 axis, providing the theoretical basis for OC therapy.

Regulation of Glycolysis by Non-coding RNAs in Cancer: Switching on the Warburg Effect

The “Warburg effect” describes the reprogramming of glucose metabolism away from oxidative phosphorylation toward aerobic glycolysis, and it is one of the hallmarks of cancer cells. Several factors can be involved in this process, but in this review, the roles of non-coding RNAs (ncRNAs) are highlighted in several types of human cancer. ncRNAs, including microRNAs, long non-coding RNAs, and circular RNAs, can all affect metabolic enzymes and transcription factors to promote glycolysis and modulate glucose metabolism to enhance the progression of tumors. In particular, the 5′-AMP-activated protein kinase (AMPK) and the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways are associated with alterations in ncRNAs. A better understanding of the roles of ncRNAs in the Warburg effect could ultimately lead to new therapeutic approaches for suppressing cancer.

microRNA-1271-5p/TIAM1 suppresses the progression of ovarian cancer through inactivating Notch signaling pathway

Objective

Ovarian cancer (OC) has been regarded as the most malignant gynecological neoplasm and often confers grave outcomes owing to the frequent metastasis and high recurrence. A previous study has demonstrated that miR-1271-5p is implicated in OC progression, however, the possible mechanism of it remains unknown. The purpose of this investigation was to explore how miR-1271-5p regulates the progression of OC.

Methods

Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were employed to analyze the differentially expressed miRNAs or genes as well as their corresponding prognostic values. miR-1271-5p expression in OC cells was examined by qRT-PCR. Cell counting kit 8 (CCK-8), colony formation, and transwell tests were conducted to evaluate the proliferation, migration and invasion potentials. Bioinformatics prediction and luciferase activity analysis were utilized to predict and verify the target gene of miR-1271-5p. Western blot assay was carried out to measure protein expression.

Results

miR-1271-5p was significantly decreased in OC and its down-regulation was associated with the grave outcome of OC patients. Upregulation of miR-1271-5p inhibited cell viability, but miR-1271-5p knockdown promoted the proliferation of OC cells. TIAM1 was a direct target gene of miR-1271-5p and expressed in OC tissues at higher level. High expression of TIAM1 induced the poorer prognosis of patients with OC. Further functional analyses showed that the suppressive role of miR-1271-5p on OC cell malignant behaviors was overturned by the upregulation of TIAM1. The protein levels of Cyclin D1, HES1, NOTCH and NUMB were remarkably changed due to the abnormal expression of miR-1271-5p and TIAM1.

Conclusion

To sum up, miR-1271-5p inhibits proliferation, invasion and migration of OC cells by directly repressing TIAM1 to inactivate the Notch signaling pathway, which provides an alternative therapeutic candidate for the advancement of OC treatment.