MicroRNAs (miRNAs) are small, non-coding RNA molecules that regulate gene expression post-transcriptionally. They function by binding to newly transcribed mRNAs of protein-coding genes, suppressing gene expression at the post-transcriptional level. Thus, miRNAs play a crucial role in controlling a plethora of cellular processes, making miRNAs a unique class of regulatory RNA with defined developmental roles. Thus, these small yet powerful miRNAs have garnered the attention of many researchers due to the known biological regulatory role during chronic disease onset, including cancer. Over the past decade, novel small RNA therapies have been developed and implemented successfully in the clinic to combat several chronic disorders. With respect to cancer, a number of miRNAs were demonstrated to be correlated with cancer progression and disease onset. These oncomiRs or tumor suppressors control well conserved protein signaling cascades that become dysregulated during the tumorigenic process. In particular miR-9 has garnered much attention over the past decade due to the abundance of this miRNA in certain tissues such as the brain and the epithelium. In this review, we discuss the importance of miRNAs in cancer, the biology of miR-9 in a variety of cancers, explain how the term ‘oncomiR’ or ‘tumor suppressor miR’ depends upon the cellular context of gene expression during oncogenesis, and how the abundance of certain miR-9 isoforms in the cell during the initiating tumorigenic event could influence the molecular heterogeneity of the tumor. Additionally, next-generation miRNA therapeutics offer promising strategies for cancer treatment by the precise targeting of disease-related pathways with minimal toxicity and off-target effects. These strategies can also serve as solutions in situations where chemo- and radio-resistance persists.
Medulloblastoma (MB) is one of the most prevalent forms of malignant brain cancer observed within pediatric patients and is particularly difficult to diagnose and treat due to the anatomical localization of tumors near the brainstem. Currently, there are four molecular classifications of MBL: WNT, SHH, Group 3, and Group 4 tumor subgroups. Wingless-type (WNT) mutant tumors are the least common, often caused by mutations in the CTNNB1 gene that plays a crucial role in the wingless cell signaling pathway, yet associates with the best prognosis as compared to all other MBL subtypes. Sonic hedgehog (SHH) mutant tumors arise due to continued release of Shh from purkinje cells, and an uninhibited proliferation response by granular neuronal precursors (GNPs). Group 3 and 4 MBL subgroups are still a molecularly heterogeneous class of tumors, with Group 3 MBL being highly associated with metastasis upon diagnosis, and more prevalently characterized by MYC amplification and activation. Group 4 MBL tumors comprise approximately 40% of all MBL, and remain remarkably heterogeneous with respect to somatic mutations of genes such as KDM6A, OTX2, ZMYM3, with an approximate 80% of tumors harboring chromosome 17 copy number alterations. While a majority of MBL cases cannot be linked to a single protein coding gene alteration, the role of non-coding RNAs, such as miRNAs, seems quite promising as a genetic marker to further sub-categorize MBL at the molecular level. Furthermore, miRNA-based therapy is proving to be a promising treatment to curb the growth of a number of cancer types within the clinic, with particular miRNAs under investigation including miR-34a, miR-211, and miR-584-5p. These miRNAs are known to induce cell cycle arrest in mouse models and demonstrate anti-tumorigenic properties in vitro, meriting further investigation of miRNA-based clinical trials for pediatric MBL patients.
Thyroid cancer, originating in the neck’s thyroid gland, encompasses various types. Genetic mutations, particularly in BRAF and RET genes are crucial in its development. This study investigates the association between BRAF (rs113488022) and RET (rs77709286) polymorphisms and thyroid cancer risk in the Khyber Pakhtunkhwa (KP) population. Blood samples from 100 thyroid cancer patients and 100 healthy controls were genotyped using ARMS-PCR followed by gel electrophoresis and statistical analysis. Analysis revealed a significant association between the minor allele T of BRAF (rs113488022) and thyroid cancer risk (P = 0.0001). Both genotypes of BRAF (rs113488022) showed significant associations with thyroid cancer risk (AT; P = 0.0012 and TT; P = 0.045). Conversely, the minor allele G of RET (rs77709286) exhibited a non-significant association with thyroid cancer risk (P = 0.2614), and neither genotype showed significant associations (CG; P = 0.317, GG; P = 0.651). Demographic and clinical parameters analysis using SPSS showed a non-significant association between BRAF and RET variants and age group (P = 0.878 and P = 0.536), gender (P = 0.587 and P = 0.21), tumor size (P = 0.796 and P = 0.765), or tumor localization (P = 0.689 and P = 0.727). In conclusion, this study emphasizes the significant association between BRAF polymorphism and thyroid cancer risk, while RET polymorphism showed a less pronounced impact. Further validation using larger and specific datasets is essential to establish conclusive results.
Neuroinflammation is considered a balanced inflammatory response important in the intrinsic repair process after injury or infection. Under chronic states of disease, injury, or infection, persistent neuroinflammation results in a heightened presence of cytokines, chemokines, and reactive oxygen species that result in tissue damage. In the CNS, the surrounding microglia normally contain macrophages and other innate immune cells that perform active immune surveillance. The resulting cytokines produced by these macrophages affect the growth, development, and responsiveness of the microglia present in both white and gray matter regions of the CNS. Controlling the levels of these cytokines ultimately improves neurocognitive function and results in the repair of lesions associated with neurologic disease. MicroRNAs (miRNAs) are master regulators of the genome and subsequently control the activity of inflammatory responses crucial in sustaining a robust and acute immunological response towards an acute infection while dampening pathways that result in heightened levels of cytokines and chemokines associated with chronic neuroinflammation. Numerous reports have directly implicated miRNAs in controlling the abundance and activity of interleukins, TGF-B, NF-kB, and toll-like receptor-signaling intrinsically linked with the development of neurological disorders such as Parkinson's, ALS, epilepsy, Alzheimer's, and neuromuscular degeneration. This review is focused on discussing the role miRNAs play in regulating or initiating these chronic neurological states, many of which maintain the level and/or activity of neuron-specific secondary messengers. Dysregulated miRNAs present in the microglia, astrocytes, oligodendrocytes, and epididymal cells, contribute to an overall glial-specific inflammatory niche that impacts the activity of neuronal conductivity, signaling action potentials, neurotransmitter robustness, neuron-neuron specific communication, and neuron-muscular connections. Understanding which miRNAs regulate microglial activation is a crucial step forward in developing non-coding RNA-based therapeutics to treat and potentially correct the behavioral and cognitive deficits typically found in patients suffering from chronic neuroinflammation.
Background/Aims: Diabetic nephropathy (DN) is one of the complications of diabetes mellitus (DM). This study aimed to investigate the association between genetic polymorphisms, specifically AGTR1 (rs5186) and TGF-β1 (rs1800470), and the risk of developing Diabetic nephropathy (DN) in type 2 diabetes mellitus patients, compared to those without DN and healthy controls. Methods: A case-control study was conducted on 165 diabetic patients (59 with diabetic nephropathy (DN) and 54 without DN (DM)), and 52 healthy controls (HC). The genotyping was done using amplification refractory mutation system method (ARMS-PCR). Age, gender, and duration of diabetes were matched across groups. Clinical parameters including FBS, RBS, HbA1C, creatinine, urea, SBP, DBP, total cholesterol, triglycerides, LDL, and BMI were assessed. Results: Diabetic patients with nephropathy exhibited significantly higher levels of clinical parameters compared to those without nephropathy and healthy controls. The risk allele of AGTR1 , C (p <0.0001), and risk allele containing genotypes AC (p <0.0001) and CC (p - 0.0010) were significantly higher in DN patients compared to DM and HC groups. Similarly, the TGF-β1 risk allele C (p - 0.0001), and corresponding genotypes TC (p - 0.0038) and CC (p - 0.0027) were significantly associated with increased risk of diabetic nephropathy compared to DM and HC groups. Conclusion: The data showed significant association of AGTR1 (rs5186) and TGF-β1 (rs1800470) polymorphism with an increased risk of diabetic nephropathy in type 2 diabetes mellitus patients. More investigation will be required to disseminate the results, while increasing the samples size and using whole genome sequencing.
Background Single nucleotide polymorphism (SNPs) in BRCA1 , BRCA2 and TP53 has been widely associated with breast cancer risk in different ethnicities with inconsistent results. There is no such study conducted so far in the Pashtun population of Khyber Pakhtunkhwa, Pakistan. Therefore, this study was conducted to check BRCA1 (rs1799950), BRCA2 (rs144848) and TP53 (rs1042522) polymorphism with breast cancer risk in Pashtun population of Khyber Pakhtunkhwa, Pakistan. Methods This study, consisting 140 breast cancer patients and 80 gender and age matched healthy controls were subjected to confirm BRCA1 , BRCA2 and TP53 polymorphism. Clinicopathological data and blood samples were taken from all the participants. DNA was extracted and SNPs were confirmed using T-ARMS-PCR protocol. Results Our data indicated that BRCA1 , BRCA2 , and TP53 selected SNPs risk allele and risk allele containing genotypes displayed significant association ( p < 0.05) with breast cancer risk in the Pashtun population of Khyber Pakhtunkhwa, Pakistan. Conclusion All the three selected SNPs of BRCA1 , BRCA2 and TP53 showed significant association with breast cancer risk in the Pashtun population of Khyber Pakhtunkhwa, Pakistan. However, more investigation will be required on large data sets to confirm the selected SNPs and other SNPs in the selected and other related genes with the risk of breast cancer.
Figure S5, Related to Figure 6. A, Assessment of SRC mRNA levels in MDA-MB-231 SRC-ORF, EMPTY-ORF, or parental cell lines. Data is normalized in RPL19 levels. B, Crystal violet staining assays on day 5 post-transfection confirms the ability of c-SRC to rescue miR-34a-induced anti-tumor growth. C-D, Examples of Pearson correlation analysis indicating MDA-MB-231 cells were not similar to BT-549 and MDA-MB-436 cells, and therefore were not included in the initial K-Means clustering analysis (results shown in D). E, The fold knockdown by miR-34a as compared to the miR-Scr treatments of the indicated genes in Clusters 1-3 in both BT-549 and MDA-MB-436 cells using a 2-fold change cut-off. None of the genes in Cluster 4 were downregulated by miR-34a (data not shown). F, Schematic of the KEGG pathway (hsa04510: Focal Adhesion) with miR-34a downregulated genes highlighted in red. G-H, Represents further analysis of the miR-34a gene signature in breast cancer. G, Indicates correlation analyses of miR-34a target genes in TNBC patients from Metabric data. H, Confirmation of prognostic importance of mIR-34a gene signature using a PROGgeneV2 algorithm on the TCGA data set.
Figure S3, Related to Figure 4. A, c-SRC expression in normal (HFF and MCF-10A), luminal-A (MCF-7), LAR-TNBC (MDA-MB-453), and mesenchymal-TNBC (MDA-MB-231, BT-549, and Hs578T) cell lines. Expression was normalized to GAPDH and made relative to c-SRC expression in HFF lines. B-C, Clonogenic assays in Hs578T (B), and MDA-MB-436 (C) TNBC cells after miR-34a transfection and treatment with Dasatnib (left panels) and paclitaxel (right panel) or as a control HeLa cells after dasatinib treatment (C, right panel). D-E, Assessment of miR-34a target genes in MDA-MB-231 cells after 72 hours of dasatinib treatment (D), or miR-34a levels after 72 hours paclitaxel treatment (E). F, miR-34a promoter luciferase assays in MDA-MB-31 cells after dasatinib treatment. G-H, Spearman rank correlation analysis of SRC levels in cell lines described in Figure 1A (G), and in all breast cancer samples in the Metabric dataset (H). I, Comparable decreases in phospho-Tyr416 active c-SRC, non-phospho-Tyr527 c-SRC, and total c-SRC are observed in MDA-MB-231 cells transfected with 15nM miR-34a versus miR-Scr control, as determined by Western blot analysis. J, Schematic highlighting the miR-34a-c-SRC double-negative feedback loop present in MSL TNBC cells, which can be influenced by exogenous addition of miR-34a, or by dasatinib treatment. * Indicates p<0.05, as compared to control conditions.
Figure S1, Related to Figure 1. A, miRNA microarray data of the top 50 most variant miRNAs across 17 breast cancer cell lines representing either basal/TNBC (top left blue bar) or luminal (top right red bar) breast cancer subgroups. Amongst these miRNAs, miR-34a (red asterisk) was found to be uniquely downregulated in basal lines. B-C, qPCR validation of array data in TNBC and Luminal-A cancer cell lines as compared to normal mammary epithelial lines (CRCs were cultured using the ROCK inhibitor and condition medium from the 3T3 feeder system as previously described(20)). D, Schematic of WebGestalt 2 analysis of Affymetrix microarray data across 19 cell lines. ¬¬miR-34a is one of several miRNAs with target enrichment in the TNBC overexpressed gene set. E, Results of hypergeometric analysis of miR-34a targets using a more stringent context score cutoff of -0.27. F, SRB growth assays on additional TNBC and normal cell lines.
Figure S2, Related to Figure 2. A-F, Functional characterization of miR-34a re-introduction in additional TNBC and non-TNBC cell lines by way of Matrigel-invasion (A), soft agar growth (B), and BrdU labeling (C) experiments. For BrdU assays, we observed only a 5-10% accumulation of BrdU-positive cells 4 days post-transfection. SA-β-gal assays on MDA-MB-157 (D), and BT-20 (E, left panel) TNBC cells, as compared to MCF-7 luminal-A cells (E, right panel). F, MCF-7 cells stably transfected with either a miR-34a (miR-34a SP) or a control (Empty SP) reporter/sponge construct was assayed for SA-β-gal activity. Two independent miR-34a SP pools were generated. G, Luciferase reporter assays indicative of miR-34a activity in all TNBC, luminal, and normal cell lines used in this study. H, miRNA levels in MDA-MB-231, MDA-MB-436, and BT-549 TNBC cells or BT-474 and MCF-7 Luminal-A cells 72 hours after 10nM miR-34a or miR-Scr transfection. In TNBC cells miR-34a expressing lines harbored lower levels of miR-17/92 family members as compared to miR-Scr treated lines. * Indicates p<0.05, as compared to control conditions.
Figure S4, Related to Figure 5. A-F, Further characterization of c-SRC siRNA treatments in TNBC cell lines. A, Crystal violet staining of MDA-MB-231 and Hs578T cells post 15nM si-SRC and si-Neg transfection (Day 6 images, left panel), and quantification of staining abundance is shown on right panels). B, SRB results on Hs578T cell line. C, Analysis of a second siRNA to c-SRC in MDA-MB-231 cells. SRB assays are shown in the left panel and western blot analysis confirming c-SRC knockdown (72 hour post-transfection) is shown on the right panel. D, Crystal violet staining of HFF cells. E, SA-β-gal assays in the indicated cell lines 5 days after 15nM si-SRC transfection. F, miR-34a levels 72 hours after 15nM si-SRC transfection in Hs578T cells. G, Assessment of SRC mRNA levels in the indicated cell lines 72 hours after 15nM si-SRC transfection.
MicroRNA-34 (miR-34) is one of the major families of tumor suppressor miRNAs often lost in cancers. Delivery of miR-34a mimics to affected tumors as a therapeutic strategy has been tried in pre-clinical studies and in a phase I clinical trial. One approach to increase efficacy and reduce toxicity is to rationally identify drug combinations with small molecules that synergize with miR-34a. In this study we performed a high-throughput screen of a large panel of small molecules with known biological activity and identified ouabain as a candidate small molecule that synergized with miR-34a in killing lung cancer cells. We elucidated autophagy activation as a key mechanism by which miR-34a and ouabain causes increased cytotoxicity in cells. We posit that this combinatorial approach could reduce the active dose of miR-34a needed in vivo to observe tumor shrinkage and potentiate the development of miR-34a combination therapies in the future.
The accurate inheritance of genetic material is a basic necessity in all domains of life and an unexpectedly large number of RNA processing factors are required for mitotic progression and genome stability. NRDE2 (nuclear RNAi defective-2) is an evolutionarily conserved protein originally discovered for its role in nuclear RNA interference (RNAi) and heritable gene silencing in Caenorhabditis elegans (C. elegans). The function of the human NRDE2 gene remains poorly understood. Here we show that human NRDE2 is an essential protein required for suppressing intron retention in a subset of pre-mRNAs containing short, GC-rich introns with relatively weak 5′ and 3′ splice sites. NRDE2 preferentially interacts with components of the U5 small nuclear ribonucleoprotein (snRNP), the exon junction complex, and the RNA exosome. Interestingly, NRDE2-depleted cells exhibit greatly increased levels of genomic instability and DNA damage, as well as defects in centrosome maturation and mitotic progression. We identify the essential centriolar satellite protein, CEP131, as a direct NRDE2-regulated target. NRDE2 specifically binds to and promotes the efficient splicing of CEP131 pre-mRNA, and depleting NRDE2 dramatically reduces CEP131 protein expression, contributing to impaired recruitment of critical centrosomal proteins (e.g., γ-tubulin and Aurora Kinase A) to the spindle poles during mitosis. Our work establishes a conserved role for human NRDE2 in RNA splicing, characterizes the severe genomic instability phenotypes observed upon loss of NRDE2, and highlights the direct regulation of CEP131 splicing as one of multiple mechanisms through which such phenotypes might be explained.
LncRNAs are novel noncoding RNAs involved in the epigenetic regulation of gene expression by recruiting ribonucleoprotein complexes to specific genomic loci to initiate histone methylation and/or other chromatin modifications. LncRNAs themselves function as tumor suppressors or oncogenes, depending on the gene regulatory networks they govern. We identified lnc00673 (ERRLR01) as a marker of overall survival (OS) in breast cancer patients. Specifically, ERRLR01 levels were elevated in triple-negative breast cancer (TNBC) as compared with Luminal-A, Luminal-B, and HER2 breast cancer subtypes. ERRLR01 levels were also inversely correlated with breast cancer survival across all breast cancer patients. Upon stratification, OS in ERα− tumors correlated with negative overall survival, while in ERα+ tumors, ERRLR01 correlated with positive outcomes. This suggests ERRLR01 is modulated by hormone signaling in breast cancer. Gene-network analysis revealed ERRLR01 correlated with distinct pathways including “epithelial development” and “cellular differentiation.” These data suggest ERRLR01 operates as an oncogene in TNBC, as well as a biomarker in breast cancer patients.
Obesity and weight gain are associated with comorbidities including a higher risk of tumor recurrence and cancer-related deaths among breast cancer (BC) survivors; however, the underlying mechanisms linking obesity and cancer are poorly understood. Given the lack of clinically validated BC biomarkers, obesity and weight-loss studies utilize serum biomarkers as the intermediary outcomes of tumor recurrence. Studies have indicated microRNAs (miRNA)s are reliable biomarkers for cancer. We hypothesized that miRNA expression correlates with obesity and weight loss amongst BC survivors. This would yield insight into the biological pathways by which this association occurs, enabling more precise development of therapeutics.
The Journal of Cancer Metastasis and Treatment is an open access journal focused on cancer metastasis and treatment, including the occurrence, development, progression, metastasis, and treatment of oncologic disease. It covers basic, translational and clinical research related to cancer cell biology, genomics, precision medicine, oncology internal medicine, radiotherapy and radiology, obstetrics and gynecology, pediatrics, surgery, hematology, neurooncology, etc.
Triple negative breast cancer (TNBC) has been associated with the lack of three hormone receptors; estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2). However, a host of other steroid hormone receptors such as vitamin D receptor (VDR) is present in TNBC, and the role of these hormone receptors in breast tumorigenesis is unclear. The levels of microRNAs (miRNAs) are also expressed differently than in normal mammary epithelial cells. miRNAs are regulatory RNAs involved in various cellular functions, mainly gene silencing. Here, we reviewed the literature surrounding miRNAs in breast cancer, and performed in silico analysis to determine whether there was a correlation between levels of VDR in relation to miRNAs important in breast cancer development and tumorigenesis. We identified three miRNAs of interest, specifically, miR-23, miR-124, and miR-125. Through this research we determined the possibility that these miRNAs play an important role in controlling VDR activity and by virtue the development of breast cancer.
Many RNA species have been identified as important players in the development of chronic diseases, including cancer. Over the past decade, numerous studies have highlighted how regulatory RNAs such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) play crucial roles in the development of a disease state. It is clear that the aberrant expression of miRNAs promotes tumor initiation and progression, is linked with cardiac dysfunction, allows for the improper physiological response in maintaining glucose and insulin levels, and can prevent the appropriate integration of neuronal networks, resulting in neurodegenerative disorders. Because of this, there has been a major effort to therapeutically target these noncoding RNAs. In just the past 5 years, over 100 antisense oligonucleotide-based therapies have been tested in phase I clinical trials, a quarter of which have reached phase II/III. Most notable are fomivirsen and mipomersen, which have received FDA approval to treat cytomegalovirus retinitis and high blood cholesterol, respectively. The continued improvement of innovative RNA modifications and delivery entities, such as nanoparticles, will aid in the development of future RNA-based therapeutics for a broader range of chronic diseases. Here we summarize the latest promises and challenges of targeting noncoding RNAs in disease.
ABSTRACT Triple negative breast cancer (TNBC) has been associated with the lack of three hormone receptors; estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2). However, a host of other steroid hormone receptors such as vitamin D receptor (VDR) is present in TNBC, and the role of these hormone receptors in breast tumorigenesis is unclear. The levels of microRNAs (miRNAs) are also expressed differently than in normal mammary epithelial cells. miRNAs are regulatory RNAs involved in various cellular functions, mainly gene silencing. Here, we reviewed the literature surrounding miRNAs in breast cancer, and performed in silico analysis to determine whether there was a correlation between levels of VDR in relation to miRNAs important in breast cancer development and tumorigenesis. We identified three miRNAs of interest, specifically, miR-23, miR-124, and miR-125. Through this research we determined the possibility that these miRNAs play an important role in controlling VDR activity and by virtue the development of breast cancer.