microRNA-149 targets caspase-2 in glioma progression

Systematic assessment of prognostic molecular features across cancers

Precision oncology promises accurate prediction of disease trajectories by utilizing molecular features of tumors. We present a systematic analysis of the prognostic potential of diverse molecular features across large cancer cohorts. We find that the mRNA expression of biologically coherent sets of genes (modules) is substantially more predictive of patient survival than single-locus genomic and transcriptomic aberrations. Extending our analysis beyond existing curated gene modules, we find a large novel class of highly prognostic DNA/RNA cis-regulatory modules associated with dynamic gene expression within cancers. Remarkably, in more than 82% of cancers, modules substantially improve survival stratification compared with conventional clinical factors and prominent genomic aberrations. The prognostic potential of cancer modules generalizes to external cohorts better than conventionally used single-gene features. Finally, a machine-learning framework demonstrates the combined predictive power of multiple modules, yielding prognostic models that perform substantially better than existing histopathological and clinical factors in common use.

Unveiling caspase-2 regulation by non-coding RNAs

Non-coding RNAs (ncRNAs) are a group of RNA molecules, such as small nucleolar RNAs, circular RNAs (circRNAs), microRNAs (miRNAs) and long-noncoding RNAs (ncRNAs), that do not encode proteins. Although their biofunctions are not well-understood, many regulatory ncRNAs appear to be highly involved in regulating the transcription and translation of several genes that have essential biological roles including cell differentiation, cell death, metabolism, tumorigenesis and so on. A growing number of studies have revealed the associations between dysregulated ncRNAs and caspases involved in cell death in numerous human diseases. As one of the initiator and executor caspases, caspase-2 is the most evolutionally conserved caspase in mammals, exerting both apoptotic and non-apoptotic functions. A great deal of studies has shown the involvement of caspase-2 as a tumor suppressor in multiple oncogene-driven cancers, and yet a comprehensive understanding of its biological roles remains largely unknown. In this review, we highlight a compilation of studies focused on the interaction between caspase-2 and miRNAs/lncRNAs in the context of different diseases in order to deepen our knowledge on the regulatory biofunctions of caspase-2 and, furthermore, provide more insight into understanding the role that ncRNAs/caspase-2 axis plays in the development of human diseases.

Long non-coding RNA TPT1-AS1 sensitizes breast cancer cell to paclitaxel and inhibits cell proliferation by miR-3156-5p/caspase 2 axis

Long non-coding RNAs (lncRNAs) are key modulators during cancer progression. Application of using lncRNA expression to evaluate patient prognosis and sensitivity to treatment is highly anticipated, yet the expression and mechanism of many lncRNAs remain unknown. Herein, we projected for the investigation of TPT1-AS1 function in breast cancer. TPT1-AS1 was assessed by bioinformatic analysis of publicly available datasets and quantitative real-time PCR (qRT-PCR). Cell sensitivity to paclitaxel and cell proliferation was measured by flow cytometry and CCK-8. Interaction among TPT1-AS1, microRNA (miRNA, miR)-3156-5p and Caspase 2 (CASP2) was studied by bioinformatic analysis, qRT-PCR, western blot as well as dual luciferase reporter assay. Herein, TPT1-AS1 was significantly diminished in breast cancer from publicly available datasets and our collected samples. In breast cancer cells, TPT1-AS1 overexpression repressed cell proliferation and sensitized breast cancer cells to paclitaxel. RegRNA 2.0 predicted a potential interaction between TPT1-AS1 and miR-3156-5p which was confirmed by qRT-PCR as well as dual luciferase reporter assay. CASP2, a proapoptotic gene, was corroborated to be targeted by miR-3156-5p. Meanwhile, TPT1-AS1 upregulated CASP2 in breast cancer cells, and its biological function was reversed by CASP2 knockdown. Collectively, TPT1-AS1 diminished cell proliferation and sensitized cells to chemotherapy by sponging miR-3156-5p and upregulating CASP2, acting as a biomarker for patients with breast cancer.

MicroRNAs at the Crossroad of the Dichotomic Pathway Cell Death vs. Stemness in Neural Somatic and Cancer Stem Cells: Implications and Therapeutic Strategies

Stemness and apoptosis may highlight the dichotomy between regeneration and demise in the complex pathway proceeding from ontogenesis to the end of life. In the last few years, the concept has emerged that the same microRNAs (miRNAs) can be concurrently implicated in both apoptosis-related mechanisms and cell differentiation. Whether the differentiation process gives rise to the architecture of brain areas, any long-lasting perturbation of miRNA expression can be related to the occurrence of neurodevelopmental/neuropathological conditions. Moreover, as a consequence of neural stem cell (NSC) transformation to cancer stem cells (CSCs), the fine modulation of distinct miRNAs becomes necessary. This event implies controlling the expression of pro/anti-apoptotic target genes, which is crucial for the management of neural/neural crest-derived CSCs in brain tumors, neuroblastoma, and melanoma. From a translational point of view, the current progress on the emerging miRNA-based neuropathology therapeutic applications and antitumor strategies will be disclosed and their advantages and shortcomings discussed.

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

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

Circulating MicroRNAs as Potential Biomarkers in Glioma: A Mini-Review

Glioma comprises of a group of heterogeneous brain tumors originating from glial cells. Primary glioblastoma is among the most common glial cells that have a characteristic clinical and molecular profile. Advancement in the field of cancer research and inventions of various clinical methodologies could not improve the median survival of this deadly tumor from 12 months. The development of a non-invasive prognostic biomarker in blood would be a revolution in the diagnosis and therapeutic monitoring of this tumor. Extracellular vesicles (Evs) are released from the tumor microenvironment into the blood, which contains the genetic material that represents the genetics of tumor cells. It is also seen that these Evs contain a variety of RNA populations, including miRNAs. Several studies identified that circulating cell-free miRNAs, either free or present in Evs, could be considered as a potential biomarker in early diagnosis and prognosis of glioblastoma. Micro RNA studies in glioblastoma have found to be promising, as it reveals the biological pathway behind pathogenesis and helps in predicting the treatment targets. The literature says that various treatment methods change the type and quantity of miRNAs in biological fluids, which can be used to monitor the therapy. This review paper focuses on the role of circulating miRNAs as potential biomarkers in the diagnosis and clinical management of glioma patients.

Functional Significance of Mirna-149 in Lung Cancer: Can it be Utilized as a Potential Biomarker or a Therapeutic Target?

Accumulating evidence has documented the significance of miR-149 as a promising tumor-suppressive non-coding RNA that play critical roles in regulating genes involved in cancer growth and metastasis. Notably, the ability of miR-149 to be utilized as a potential biomarker in the diagnosis/prognosis or a therapeutic target has also been explored using various cellular and preclinical models, as well as in clinical settings of lung cancer. While the applicability of miR-149 in assessing tumor progression has been suggested, its potential in predicting treatment outcomes is needed to be verified in diverse settings of lung cancer patients. The current review presents an overview of the functional significance of miR-149 with ongoing challenges in non-small cell lung cancer.

MicroRNAs in cancer cell death pathways: Apoptosis and necroptosis

To protect tissues and the organism from disease, potentially harmful cells are removed through programmed cell death processes, including apoptosis and necroptosis. These types of cell death are critically controlled by microRNAs (miRNAs). MiRNAs are short RNA molecules that target and inhibit expression of many cellular regulators, including those controlling programmed cell death via the intrinsic (Bcl-2 and Mcl-1), extrinsic (TRAIL and Fas), p53-and endoplasmic reticulum (ER) stress-induced apoptotic pathways, as well as the necroptosis cell death pathway. In this review, we discuss the current knowledge of apoptosis and necroptosis pathways and how these are impaired in cancer cells. We focus on how miRNAs disrupt apoptosis and necroptosis, thereby critically contributing to malignancy. Understanding which and how miRNAs and their targets affect cell death pathways could open up novel therapeutic opportunities for cancer patients. Indeed, restoration of pro-apoptotic tumor suppressor miRNAs (apoptomiRs) or inhibition of oncogenic miRNAs (oncomiRs) represent strategies that are currently being trialed or are already applied as miRNA-based cancer therapies. Therefore, better understanding the cancer type-specific expression of apoptomiRs and oncomiRs and their underlying mechanisms in cell death pathways will not only advance our knowledge, but also continue to provide new opportunities to treat cancer.

Inhibition of Caspase-2 Translation by the mRNA Binding Protein HuR: A Novel Path of Therapy Resistance in Colon Carcinoma Cells?

An increased expression and cytoplasmic abundance of the ubiquitous RNA binding protein human antigen R (HuR) is critically implicated in the dysregulated control of post- transcriptional gene expression during colorectal cancer development and is frequently associated with a high grade of malignancy and therapy resistance. Regardless of the fact that HuR elicits a broad cell survival program by increasing the stability of mRNAs coding for prominent anti-apoptotic factors, recent data suggest that HuR is critically involved in the regulation of translation, particularly, in the internal ribosome entry site (IRES) controlled translation of cell death regulatory proteins. Accordingly, data from human colon carcinoma cells revealed that HuR maintains constitutively reduced protein and activity levels of caspase-2 through negative interference with IRES-mediated translation. This review covers recent advances in the understanding of mechanisms underlying HuR's modulatory activity on IRES-triggered translation. With respect to the unique regulatory features of caspase-2 and its multiple roles (e.g., in DNA-damage-induced apoptosis, cell cycle regulation and maintenance of genomic stability), the pathophysiological consequences of negative caspase-2 regulation by HuR and its impact on therapy resistance of colorectal cancers will be discussed in detail. The negative HuR-caspase-2 axis may offer a novel target for tumor sensitizing therapies.

Genetic Polymorphisms of miR-149 Associated with Susceptibility to Both Pulmonary and Extrapulmonary Tuberculosis

Background: Single nucleotide polymorphisms (SNPs) within precursor microRNAs (miRNAs) can affect the expression of the miRNAs and may be involved in the pathogenesis of pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB). Aims: We investigated the potential associations among four precursor miRNA SNPs (miR-149 A>G, C>T; miR-196a2 C>T; miR-499 C>T) and both PTB and EPTB. Methods: The study included 380 PTB patients, 242 EPTB patients, and 606 healthy control (HC) subjects from a Chinese Han population. We determined the miRNA relative expression levels from 10 HCs and 10 tuberculosis (TB) patients by quantitative PCR. Results: We found that the PTB group had a significantly lower miR-149 level (p < 0.05) versus the HCs. The allele and genotype frequencies of the miR-149 SNPs were significantly different between the TB patients and the HC group. The C allele at the rs2292832 and the A allele at the rs71428439 locus were associated with susceptibility to EPTB. The C allele of rs2292832 was associated with an increased risk of EPTB compared with that of HCs (p < 0.01), and the A allele of rs71428439 was protective against EPTB (p < 0.01) and PTB (p < 0.01). Conclusions: We identified genetic polymorphisms in miR-149 that appear to be associated with susceptibility to both PTB and EPTB within a Chinese population.

miR-149-5p inhibits cell growth by regulating TWEAK/Fn14/PI3K/AKT pathway and predicts favorable survival in human osteosarcoma

MicroRNAs (miRNAs) as small non-coding RNAs act as either tumor suppressors or oncogenes in human cancers, of which miR-149-5p (miR-149) is involved in tumor growth and metastasis, but its role and molecular mechanisms underlying osteosarcoma growth are poorly understood. The correlation of miR-149 expression with clinicopathological characteristics and prognosis in patients with sarcoma was analyzed by The Cancer Genome Atlas (TCGA) RNA-sequencing data. Osteosarcoma cell growth affected by miR-149 was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays. As a result, we found that the expression level of miR-149 was markedly downregulated in human sarcoma samples and were negatively associated with tumor size, acting as an independent prognostic factor for overall survival of the sarcoma patients. Restoration of miR-149 expression suppressed osteosarcoma cell growth, while its knockdown reversed these effects. Furthermore, we identified TNFRSF12A (TNF receptor superfamily member 12A), also called fibroblast growth factor–inducible 14 (Fn14) as a direct target of miR-149, and TNFRSF12A and its ligand TNFSF12 (TNF superfamily member 12), also called tumor necrosis factor–related weak inducer of apoptosis (TWEAK), were both negatively correlated with miR-149 expression in sarcoma samples. Knockdown of TNFRSF12A suppressed cell growth, but its overexpression weakened the antiproliferative effects of miR-149 via the PI3K/AKT (AKT serine/threonine kinase) signaling pathway. Altogether, our findings show that miR-149 functions as a tumor suppressor in osteosarcoma via inhibition of the TWEAK–Fn14 axis and represents a potential therapeutic target in patients with osteosarcoma.

miR-149-5p inhibits cell proliferation and invasion through targeting GIT1 in medullary thyroid carcinoma

Previous studies indicate that miR-149 could both inhibit and promote the development of human cancer depending on the tumor type. GIT1 was found to play an important role in regulating cell migration. However, the specific function of miR-149-5p and GIT1 in the progression of medullary thyroid carcinoma (MTC) remains unknown. The purpose of this study was to confirm the function of miR-149-5p in MTC and explore its downstream regulation. Moreover, miR-149-5p level in MTC was detected via RT-quantitative PCR (RT-qPCR). GIT1 expression levels were assessed by RT-qPCR and western blot analysis. The cell proliferation and invasion were detected through MTT or Transwell assay respectively. In addition, miR-149-5p was identified to directly target GIT1 in MTC via dual luciferase assay. The results suggested that miR-149-5p level was obviously declined in MTC. Functionally, miR-149-5p overexpression inhibited proliferation and invasion. Moreover, miR-149-5p directly targeted GIT1 and was negatively associated with its expression in MTC. Conversely, GIT1 expression was obviously increased in MTC. GIT1 overexpression partially reversed the inhibitory action of miR-149-5p in MTC. miR-149-5p suppressed the proliferation and invasion of MTC cells through targeting GIT1, which would create new therapeutic avenues for MTC treatment.

Regulation and functions of MicroRNA-149 in human cancers

MicroRNAs are small non-coding RNAs that play critical roles in the regulatory mechanisms involving cell differentiation, proliferation, apoptosis and tumorigenesis. Recent research efforts have been conducted to apply these discoveries into clinical functions, including the early diagnosis and therapeutic outcome of patients with cancer. Previous studies have shown that microRNA-149 (miR-149) is dysregulated in various human cancers and exerts its effects on tumorigenesis and tumour progression. In this review, we summarized the potential roles of miR-149 dysregulation and its target genes during tumorigenesis and clinical treatment of human cancers.

Voltage-gated potassium channel blocker 4-aminopyridine induces glioma cell apoptosis by reducing expression of microRNA-10b-5p

Accumulating evidence has demonstrated that voltage-gated potassium channels (Kv channels) were associated with regulating cell proliferation and apoptosis in tumor cells. Our previous study proved that the Kv channel blocker 4-aminopyridine (4-AP) could inhibit cell proliferation and induce apoptosis in glioma. However, the precise mechanisms were not clear yet. MicroRNAs (miRNAs) are small noncoding RNAs that act as key mediators in the progression of tumor, so the aim of this study was to investigate the role of miRNAs in the apoptosis-promoting effect of 4-AP in glioma cells. Using a microRNA array, we found that 4-AP altered the miRNA expression in glioma cells, and the down-regulation of miR-10b-5p induced by 4-AP was verified by real-time PCR. Transfection of miR-10b-5p mimic significantly inhibited 4-AP-induced caspases activation and apoptosis. Moreover, we verified that apoptosis-related molecule Apaf-1 was the direct target of miR-10b-5p. Furthermore, miR-10b-5p mimic significantly inhibited 4-AP-induced up-regulation of Apaf-1 and its downstream apoptosis-related proteins, such as cleaved caspase-3. In conclusion, Kv channel blocker 4-AP may exert its anti-tumor effect by down-regulating the expression of miR-10b-5p and then raised expression of Apaf-1 and its downstream apoptosis-related proteins. Current data provide evidence that miRNAs play important roles in Kv channels-mediated cell proliferation and apoptosis.

miR-149 in Human Cancer: A Systemic Review

MicroRNAs (miRNAs) are small noncoding RNAs that regulate post-transcriptional gene expression via binding to the 3'-untranslated region (3'-UTR) of targeted mRNAs. They are reported to play important roles in tumorigenesis and progression of various cancers. Among them, miR-149 was confirmed to be aberrantly regulated in various tumors. In this review, we provide a complex overview of miR-149, particularly summarize the critical roles of it in cancers and expect to lay the foundation for future works on this important microRNA.

Genome-wide profiling of micro-RNA expression in gefitinib-resistant human lung adenocarcinoma using microarray for the identification of miR-149-5p modulation

To understand the mechanism involved in gefitinib resistance, we established gefitinib-resistant human HCC827/GR-8-1 cell line from the parental HCC827 cell line. We compared the micro-RNA expression profiles of the HCC827 cells HCC827/GR-8-1 using Agilent micro-RNA microarrays. The micro-RNAs, such as the miR-149-5p, were up- or downregulated and associated with acquired gefitinib resistance. Quantitative real-time polymerase chain reaction was then performed to verify the expression patterns of different micro-RNAs. The result showed that miR-149-5p was upregulated in the HCC827/GR-8-1 cell line. To investigate the biological function of miR-149-5p in non-small cell lung cancer cells acquired gefitinib resistance, we examined cell proliferation using a cell counting kit-8 assay. Cell viability was evaluated after the miR-149-5p mimics, inhibitors, and negative control were separately transfected into the non-small cell lung cancer cells. The results showed that the non-small cell lung cancer cells transfected with miR-149-5p mimics exhibited reduced cell motility. The drug-sensitivity assay results revealed that the overexpression of miR-149-5p effectively evaluates the half maximal inhibitory concentration values of the cell in response to gefitinib, and the downregulation of miR-149-5p can attenuate the half maximal inhibitory concentration values of the cell lines in response to gefitinib. Furthermore, the levels of miR-149-5p in the HCC827 and HCC827/GR-8-1 cells were inversely correlated with caspase-3 expression. In conclusion, this study revealed that miR-149-5p is upregulated in the HCC827/GR-8-1 cells and involved in the acquired gefitinib resistance.

Differential Impacts of Alternative Splicing Networks on Apoptosis

Apoptosis functions as a common mechanism to eliminate unnecessary or damaged cells during cell renewal and tissue development in multicellular organisms. More than 200 proteins constitute complex networks involved in apoptotic regulation. Imbalanced expressions of apoptosis-related factors frequently lead to malignant diseases. The biological functions of several apoptotic factors are manipulated through alternative splicing mechanisms which expand gene diversity by generating discrete variants from one messenger RNA precursor. It is widely observed that alternatively-spliced variants encoded from apoptosis-related genes exhibit differential effects on apoptotic regulation. Alternative splicing events are meticulously regulated by the interplay between trans-splicing factors and cis-responsive elements surrounding the regulated exons. The major focus of this review is to highlight recent studies that illustrate the influences of alternative splicing networks on apoptotic regulation which participates in diverse cellular processes and diseases.