The Role of microRNAs in Stemness of Cancer Stem Cells

Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in hematological diseases

The oncofetal mRNA-binding protein IGF2BP1 belongs to a conserved family of RNA-binding proteins. It primarily promotes RNA stability, regulates translation and RNA localization, and mediates gene expression through its downstream effectors. Numerous studies have demonstrated that IGF2BP1 plays crucial roles in embryogenesis and carcinogenesis. IGF2BP1-modulated cell proliferation, invasion, and chemo-resistance in solid tumors have attracted researchers' attention. Additionally, several studies have highlighted the importance of IGF2BP1 in hematologic malignancies and hematological genetic diseases, positioning it as a promising therapeutic target for hematological disorders. However, there is a lack of systematic summaries regarding the IGF2BP1 gene within the hematological field. In this review, we provide a comprehensive overview of the discovery and molecular structure of IGF2BP1, along with recent studies on its role in regulating embryogenesis. We also focus on the mechanisms by which IGF2BP1 regulates hematological malignancies through its interactions with its targeted mRNAs. Furthermore, we systematically elucidate the function and mechanism of IGF2BP1 in promoting fetal hemoglobin expression in adult hematopoietic stem/progenitor cells. Finally, we discuss the limitations and challenges of IGF2BP1 as a therapeutic target, offering insights into its prospects.

The Genes-Stemness-Secretome Interplay in Malignant Pleural Mesothelioma: Molecular Dynamics and Clinical Hints

MPM has a uniquely poor somatic mutational landscape, mainly driven by environmental selective pressure. This feature has dramatically limited the development of effective treatment. However, genomic events are known to be associated with MPM progression, and specific genetic signatures emerge from the exceptional crosstalk between neoplastic cells and matrix components, among which one main area of focus is hypoxia. Here we discuss the novel therapeutic strategies focused on the exploitation of MPM genetic asset and its interconnection with the surrounding hypoxic microenvironment as well as transcript products and microvesicles representing both an insight into the pathogenesis and promising actionable targets.

Effect of miR-302b MicroRNA Inhibition on Chicken Primordial Germ Cell Proliferation and Apoptosis Rate

The primordial germ cells (PGCs) are the precursors for both the oocytes and spermatogonia. Recently, a novel culture system was established for chicken PGCs, isolated from embryonic blood. The possibility of PGC long-term cultivation issues a new advance in germ cell preservation, biotechnology, and cell biology. We investigated the consequence of gga-miR-302b-5P (5P), gga-miR-302b-3P (3P) and dual inhibition (5P/3P) in two male and two female chicken PGC lines. In treated and control cell cultures, the cell number was calculated every four hours for three days by the XLS Imaging system. Comparing the cell number of control and treated lines on the first day, we found that male lines had a higher proliferation rate independently from the treatments. Compared to the untreated ones, the proliferation rate and the number of apoptotic cells were considerably reduced at gga-miR-302b-5P inhibition in all PGC lines on the third day of the cultivation. The control PGC lines showed a significantly higher proliferation rate than 3P inhibited lines on Day 3 in all PGC lines. Dual inhibition of gga-miR-302b mature miRNAs caused a slight reduction in proliferation rate, but the number of apoptotic cells increased dramatically. The information gathered by examining the factors affecting cell proliferation of PGCs can lead to new data in stem cell biology.

Natural Products Targeting Cancer Stem Cells for Augmenting Cancer Therapeutics

Cancer stem cells (CSC) have been identified in several types of solid tumors. In some cases, CSC may be the source of all the tumor cells, the cause of the tumor's resistance to chemotherapeutic agents, and the source of metastatic cells. Thus, a combination therapy targeting non-CSC tumor cells as well as specifically targeting CSCs holds the potential to be highly effective. Natural products (NPs) have been a historically rich source of biologically active compounds and are known for their ability to influence multiple signaling pathways simultaneously with negligible side effects. In this review, we discuss the potential of NPs in targeting multiple signaling pathways in CSC and their potential to augment the efficacy of standard cancer therapy. Specifically, we focus on the anti-CSC activities of flavonoids, FDA-approved drugs originating from natural sources. Additionally, we emphasize the potential of NPs in targeting microRNA-mediated signaling, given the roles of microRNA in the maintenance of the CSC phenotype.

Nanotechnology in Oral Cancer Prevention and Therapeutics: A Literature Review

The concept of nanotechnology revolves around the delivery of nano particle incorporated drugs which are originally engineered technology. Nanoparticles are used for targeted delivery and controlled release of a curative agents. Nanotechnology is gaining importance and is likely to be routine element of regular dental clinics. Nanomaterials are being incorporated in toothpastes, mouth rinses for improved efficiencies. It has found its use in restorative dental materials, anti-cariogenic enamel surface polishing agents, implant materials, etc. Few nanoparticles possess antimicrobial propertiesand intercepts bacterial activity. Nano dentistry is cost-effectiveness and timesaving compared to other techniques. Nano particles have also been beneficial to annihilate drug resistance, prevention of metastasis or lesion recurrence by earmarking malignant stem cells. Remarkable achievements were made in using nanoparticles for detecting and treating multiple variety of malignancies including colon cancer, prostate cancer, lung cancer, breast cancer, head and neck cancer, etc. This review was made to highlight the various clinical applications of nanotechnology in the diagnosis and curative care for oral cancer.

Microarray-based Analysis of Genes, Transcription Factors, and Epigenetic Modifications in Lung Cancer Exposed to Nitric Oxide

BACKGROUND/AIM

Nitric oxide (NO) is recognized as an important biological mediator that exerts several human physiological functions. As its nature is an aqueous soluble gas that can diffuse through cells and tissues, NO can affect cell signaling, the phenotype of cancer and modify surrounding cells. The variety of effects of NO on cancer cell biology has convinced researchers to determine the defined mechanisms of these effects and how to control this mediator for a better understanding as well as for therapeutic gain.

MATERIALS AND METHODS

We used bioinformatics and pharmacological experiments to elucidate the potential regulation and underlying mechanisms of NO in non-small a lung cancer cell model.

RESULTS

Using microarrays, we identified a total of 151 NO-regulated genes (80 up-regulated genes, 71 down-regulated genes) with a strong statistically significant difference compared to untreated controls. Among these, the genes activated by a factor of more than five times were: DCBLD2, MGC24975, RAB40AL, PER3, RCN1, MRPL51, PTTG1, KLF5, NFIX. On the other hand, the expression of RBMS2, PDP2, RBAK, ORMDL2, GRPEL2, ZNF514, MTHFD2, POLR2D, RCBTB1, JOSD1, RPS27, GPR4 genes were significantly decreased by a factor of more than five times. Bioinformatics further revealed that NO exposure of lung cancer cells resulted in a change in transcription factors (TFs) and epigenetic modifications (histone modification and miRNA). Interestingly, NO treatment was shown to potentiate cancer stem cell-related genes and transcription factors Oct4, Klf4, and Myc.

CONCLUSION

Through this comprehensive approach, the present study illustrated the scheme of how NO affects molecular events in lung cancer cells.

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.

Application of the microRNA-302/367 cluster in cancer therapy

As a novel class of noncoding RNAs, microRNAs (miRNAs) can effectively silence their target genes at the posttranscriptional level. Various biological processes, such as cell proliferation, differentiation, and motility, are regulated by miRNAs. In different diseases and different stages of disease, miRNAs have various expression patterns, which makes them candidate prognostic markers and therapeutic targets. Abnormal miRNA expression has been detected in numerous neoplastic diseases in humans, which indicates the potential role of miRNAs in tumorigenesis. Previous studies have indicated that miRNAs are involved in nearly the entire process of tumor development. MicroRNA‐302a, miR‐302b, miR‐302c, miR‐302d, and miR‐367 are members of the miR‐302/367 cluster that plays various biological roles in diverse neoplastic diseases by targeting different genes. These miRNAs have been implicated in several unique characteristics of cancer, including the evasion of growth suppressors, the sustained activation of proliferative signaling, the evasion of cell death and senescence, and the regulation of angiogenesis, invasion, and metastasis. This review provides a critical overview of miR‐302/367 cluster dysregulation and the subsequent effects in cancer and highlights the vast potential of members of this cluster as therapeutic targets and novel biomarkers.

MiR-130b/TNF-α/NF-κB/VEGFA loop inhibits prostate cancer angiogenesis

BACKGROUND

Angiogenesis is a critical biological process essential for solid cancer growth and metastasis. It has been shown that microRNAs (miRNAs) play a vital role in a variety of biological processes in cancers. However, whether miR-130b is involved in prostate cancer angiogenesis remains ill-defined.

METHODS

We performed the miRNA microarray to analyze miRNA expression in human prostate cancer specimens. In vitro gain-of-function assays and loss-of-function assays were conducted to explore the potential functions of miR-130b in human prostate cancer cells. Correlation analysis and dual-luciferase reporter assay were performed to validate whether tumor necrosis factor-α (TNF-α) was a direct target of miR-130b. The Matrigel plug and tumor vascular imaging assays were performed to confirm the anti-angiogenic activity of miR-130b in nude mice.

RESULTS

We found that miR-130b was one of the miRNAs being most significantly downregulated. Subsequently, we found that miR-130b expression was markedly downregulated in human prostate cancer cell lines. Down-regulation of miR-130b in prostate cancer cells significantly promoted the proliferation, invasion and tubule formation of human umbilical vein endothelial cells (HUVECs), while ectopic expression of miR-130b blocked prostate cancer angiogenesis in vitro and in vivo. Mechanistic analyses indicated that tumor necrosis factor-α (TNF-α) was regulated by miR-130b directly. MiR-130b attenuated nuclear factor-κB (NF-κB) signaling and its downstream gene vascular endothelial growth factor-A (VEGFA) by directly inhibiting TNF-α expression. Additionally, subsequent investigations identified that the ectopic level of VEGFA markedly abrogated the anti-angiogenic effect induced by miR-130b. Interestingly, VEGFA could in turn decrease the expression of miR-130b, thus forming a negative feedback loop that drives the angiogenesis of prostate cancer.

CONCLUSION

These findings show that miR-130b/TNF-α/NF-κB/VEGFA feedback loop is significantly correlated with angiogenesis in prostate cancer and miR-130b could be regarded as potential therapeutic target for prostate cancer anti-angiogenesis treatment.

Dysregulated MicroRNA Fingerprints and Methylation Patterns in Hepatocellular Carcinoma, Cancer Stem Cells, and Mesenchymal Stem Cells

Hepatocellular carcinoma (HCC) is one of the top causes of cancer mortality worldwide. Although HCC has been researched extensively, there is still a need for novel and effective therapeutic interventions. There is substantial evidence that initiation of carcinogenesis in liver cirrhosis, a leading cause of HCC, is mediated by cancer stem cells (CSCs). CSCs were also shown to be responsible for relapse and chemoresistance in several cancers, including HCC. MicroRNAs (miRNAs) constitute important epigenetic markers that regulate carcinogenesis by acting post-transcriptionally on mRNAs, contributing to the progression of HCC. We have previously shown that co-culture of cancer cells with mesenchymal stem cells (MSCs) could induce the reprogramming of MSCs into CSC-like cells. In this review, we evaluate the available data concerning the epigenetic regulation of miRNAs through methylation and the possible role of this regulation in stem cell and somatic reprogramming in HCC.

The Role of MicroRNAs in the Regulation of Gastric Cancer Stem Cells: A Meta-Analysis of the Current Status

Gastric cancer (GC) remains one of the major causes of cancer-related mortality worldwide. As for other types of cancers, several limitations to the success of current therapeutic GC treatments may be due to cancer drug resistance that leads to tumor recurrence and metastasis. Increasing evidence suggests that cancer stem cells (CSCs) are among the major causative factors of cancer treatment failure. The research of molecular CSC mechanisms and the regulation of their properties have been intensively studied. To date, molecular gastric cancer stem cell (GCSC) characterization remains largely incomplete. Among the GCSC-targeting approaches to overcome tumor progression, recent studies have focused their attention on microRNA (miRNA). The miRNAs are short non-coding RNAs which play an important role in the regulation of numerous cellular processes through the modulation of their target gene expression. In this review, we summarize and discuss recent findings on the role of miRNAs in GCSC regulation. In addition, we perform a meta-analysis aimed to identify novel miRNAs involved in GCSC homeostasis.

Exosomes Regulate the Transformation of Cancer Cells in Cancer Stem Cell Homeostasis

In different biological model systems, exosomes are considered mediators of cell-cell communication between different cell populations. Exosomes, as extracellular vesicles, participate in physiological and pathological processes by transmitting signaling molecules such as proteins, nucleic acids, and lipids. The tumor's microenvironment consists of many types of cells, including cancer stem cells and mesenchymal cells. It is well known that these cells communicate with each other and thereby regulate the progression of the tumor. Recent studies have provided evidence that exosomes mediate the interactions between different types of cells in the tumor microenvironment, providing further insight into how these cells interact through exosome signaling. Cancer stem cells are a small kind of heterogeneous cells that existed in tumor tissues or cancer cell lines. These cells possess a stemness phenotype with a self-renewal ability and multipotential differentiation which was considered the reason for the failure of conventional cancer therapies and tumor recurrence. However, a highly dynamic equilibrium was found between cancer stem cells and cancer cells, and this indicates that cancer stem cells are no more special target and blocking the transformation of cancer stem cells and cancer cells seem to be a more significant therapy strategy. Whether exosomes, as an information transforming carrier between cells, regulated cancer cell transformation in cancer stem cell dynamic equilibrium and targeting exosome signaling attenuated the formation of cancer stem cells and finally cure cancers is worthy of further study.

Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in cancer

The insulin-like growth factor-2 mRNA-binding protein 1 (IGF2BP1) plays essential roles in embryogenesis and carcinogenesis. IGF2BP1 serves as a post-transcriptional fine-tuner regulating the expression of some essential mRNA targets required for the control of tumor cell proliferation and growth, invasion, and chemo-resistance, associating with a poor overall survival and metastasis in various types of human cancers. Therefore, IGF2BP1 has been traditionally regarded as an oncogene and potential therapeutic target for cancers. Nevertheless, a few studies have also demonstrated its tumor-suppressive role. However, the details about the contradictory functions of IGF2BP1 are unclear. The growing numbers of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have been identified as its direct regulators, during tumor cell proliferation, growth, and invasion in multiple cancers. Thus, the mechanisms of post-transcriptional modulation of gene expression mediated by IGF2BP1, miRNAs, and lncRNAs in determining the fate of the development of tissues and organs, as well as tumorigenesis, need to be elucidated. In this review, we summarized the tissue distribution, expression, and roles of IGF2BP1 in embryogenesis and tumorigenesis, and focused on modulation of the interconnectivity between IGF2BP1 and its targeted mRNAs or non-coding RNAs (ncRNAs). The potential use of inhibitors of IGF2BP1 and its related pathways in cancer therapy was also discussed.

The mechanisms for lung cancer risk of PM2.5 : Induction of epithelial-mesenchymal transition and cancer stem cell properties in human non-small cell lung cancer cells

Fine particulate matter (PM_2.5 ) is a major component of air pollutions that are closely associated with increased risk of lung cancer. However, the role of PM_2.5 in the etiology of lung cancer is largely unknown. In this study, we performed acute (24 hours) and chronic (five passages) exposure models to investigate the carcinogenetic mechanisms of PM_2.5 by targeting the induction of epithelial-mesenchymal transition (EMT) and cancer stem cells (CSC) properties in human non-small cell lung cancer cell line A549. We found that both acute and chronic PM_2.5 exposure enhanced cell migration and invasion, decreased mRNA expression of epithelial markers and increased mRNA expression of mesenchymal markers. Chronic PM_2.5 exposure further induced notable EMT morphology and CSC properties, indicating the developing process of cell malignant behaviors from acute to chronic PM_2.5 exposure. CSC properties induced by chronic PM_2.5 exposure characterized with increased cell-surface markers (CD44, ABCG2), self-renewal genes (SOX2 and OCT4), side population cells and neoplastic capacity. Furthermore, the levels of three stemness-associated microRNAs, Let-7a, miR-16 and miR-34a, were found to be significantly downregulated by chronic PM_2.5 exposure, with microarray data analysis from TCGA database showing their lower expression in human lung adenocarcinoma tissues than that in the adjacent normal lung tissues. These data revealed that the induction of EMT and CSC properties were involved in the lung cancer risk of PM_2.5 , and implicated CSC properties and related microRNAs as possible biomarkers for carcinogenicity prediction of PM_2.5 .

Inhibition of LIN28B impairs leukemia cell growth and metabolism in acute myeloid leukemia

BACKGROUND

Current conventional chemotherapy for acute myeloid leukemia (AML) can achieve remission in over 70% of patients, but a majority of them will relapse within 5 years despite continued treatment. The relapse is postulated to be due to leukemia stem cells (LSCs), which are different from normal hematopoietic stem cells (HSCs). LIN28B is microRNA regulator and stem cell reprogramming factor. Overexpression of LIN28B has been associated with advance human malignancies and cancer stem cells (CSCs), including AML. However, the molecular mechanism by which LIN28B contributes to the development of AML remains largely elusive.

METHODS

We modulated LIN28B expression in AML and non-leukemic cells and investigated functional consequences in cell proliferation, cell cycle, and colony-forming assays. We performed a microarray-based analysis for LIN28B-silencing cells and interrogated gene expression data with different bioinformatic tools. AML mouse xenograft model was used to examine the in vivo function of LIN28B.

RESULTS

We demonstrated that targeting LIN28B in AML cells resulted in cell cycle arrest, inhibition of cell proliferation and colony formation, which was induced by de-repression of let-7a miRNA. On the other hand, overexpression of LIN28B promoted cell proliferation. Data point to a mechanism where that inhibition of LIN28B induces metabolic changes in AML cells. IGF2BP1 was confirmed to be a novel downstream target of LIN28B via let-7 miRNA in AML. Notably, ectopic expression of LIN28B increased tumorigenicity, while silencing LIN28B led to slow tumor growth in vivo.

CONCLUSIONS

In sum, these results uncover a novel mechanism of an important regulatory signaling, LIN28B/let-7/IGF2BP1, in leukemogenesis and provide a rationale to target this pathway as effective therapeutic strategy.

Cancer stem-like cell behavior in anaplastic thyroid cancer: A challenging dilemma

AIMS

Anaplastic thyroid carcinoma (ATC) is an undifferentiated tumor of the thyroid which is characterized with poor prognosis, leading to its aggressive behavior and resistance to conventional therapies. Cancer stem cells (CSCs) are tumor cells that have self-renewal and clonal tumor initiation. Like other cancers, many studies have shown that ATC also has tumor cells with properties like stem cells. To evaluate the concept of cancer stem-like cell theory of ATC, we conducted this study to emphasize both on the concept of cancer stemness origin of these cells and target them for further therapeutic purposes. In the current study, we showed that two ATC cell lines, SW1736 and C643, have subpopulations (SP) that are similar to CSCs.

MATERIALS AND METHODS

Using MACS technique, cells positive for CD133 were isolated and subsequently validated with flow cytometry. For further analysis, expression of some stemness markers was evaluated.

KEY FINDINGS

ABCG2, CD133, and Sox2 were significantly up-regulated, while Nestin was down-regulated in CD133(pos) subpopulation compared to CD133(neg) cells. In contrast to previous reports that over-expression of Nestin was considered as a marker for thyroid CSCs, we noticed that expression of Nestin was declined in stem cell-like tumor cells, derived from ATC cell lines.

SIGNIFICANCE

This study reconfirmed the concept of cancer stem-like cell identity of SW1736 and C643 cells. Indeed, the characterization of CSCs should not be merely based on surface markers. Cell origin and genetic background should be additionally considered on CSCs subpopulation of ATCs for therapeutics.

MicroRNA-129-1 acts as tumour suppressor and induces cell cycle arrest of GBM cancer cells through targeting IGF2BP3 and MAPK1

BACKGROUND

MicroRNA-129-1 (miR-129-1) seems to behave as a tumour suppressor since its decreased expression is associated with different tumours such as glioblastoma multiforme (GBM). GBM is the most common form of brain tumours originating from glial cells. The impact of miR-129-1 downregulation on GBM pathogenesis has yet to be elucidated.

METHODS

MiR-129-1 was overexpressed in GBM cells, and its effect on proliferation was investigated by cell cycle assay. MiR-129-1 predicted targets (CDK6, IGF1, HDAC2, IGF2BP3 and MAPK1) were also evaluated by western blot and luciferase assay.

RESULTS

Restoration of miR-129-1 reduced cell proliferation and induced G1 accumulation, significantly. Several functional assays confirmed IGF2BP3, MAPK1 and CDK6 as targets of miR-129-1. Despite the fact that IGF1 expression can be suppressed by miR-129-1, through 3'-untranslated region complementary sequence, we could not find any association between IGF1 expression and GBM. MiR-129-1 expression inversely correlates with CDK6, IGF2BP3 and MAPK1 in primary clinical samples.

CONCLUSION

This is the first study to propose miR129-1 as a negative regulator of IGF2BP3 and MAPK1 and also a cell cycle arrest inducer in GBM cells. Our data suggests miR-129-1 as a potential tumour suppressor and presents a rationale for the use of miR-129-1 as a novel strategy to improve treatment response in GBM.

Regulatory effect of miRNA 320a on expression of aquaporin 4 in brain tissue of epileptic rats

OBJECTIVE

To study the expression of miRNA 320a in the brain tissue of epileptic rats and analyze its effect on the expression of aquaporin 4 (AQP4).

METHODS

All rats were performed with the intraperitoneal injection of lithium chloride (3 mmol/kg) and then the intraperitoneal injection of pilocarpine (30 mg/kg) 24 h later (injected twice) to prepare the epileptic model of Wistar rats. Rats in the control group were injected with the equal volume of normal saline. According to the Racine scale, rats with over stage 3 of epilepsy were chosen and the brain tissue was separated quickly and then stored at -80 °C. The immunohistochemistry was used to detect the expression of aquaporin in the brain tissue of epileptic model and the Real-time PCR was employed to determine the difference in the expression of miRNA 320a and AQP4 in the brain tissue of rats between the epileptic model group and control group. Five 5-day neonatal Wistar rats were chosen to collect the cerebral cortex and their primary astrocytes were separated and cultured. They were transfected with miRNA mimic and imitated to the endogenous miRNA 320a to up-regulate the expression of miRNA 320a.

RESULTS

In the model group, the expression of AQP4 was significantly higher than the control group (P < 0.01). However, the expression of miRNA 320a in the model group was lower than control group (P < 0.05), which was negatively correlated to AQP4. In the primary astrocytes, the transfection of miRNA 320a mimic could significantly reduce the expression of AQP4, while its inhibitor could up-regulate the expression of AQP4, which indicated that miRNA 320a could reduce the expression of AQP4.

CONCLUSIONS

In the primary astrocytes of rats, the miRNA 320a could inhibit the expression of AQP4 and after adding the inhibitor of miRNA 320a, the expression of AQP4 was up-regulated.

MiR-371-373 cluster acts as a tumor-suppressor-miR and promotes cell cycle arrest in unrestricted somatic stem cells

Recent advances in small RNA research have implicated microRNAs (miRNAs) as important regulators of proliferation and development. The miR-371-373 cluster is prominently expressed in human embryonic stem cells (ESCs) and rapidly decreases after cell differentiation. MiR-371-373 cluster was investigated as one of the key factors of stem cell maintenance and pluripotency in unrestricted somatic stem cells (USSCs) using a lentivirus system. Gene expression showed a dual effect on proliferation, which revealed a transient cell cycle progression and consequent repression in pluripotency factors and cell cycle genes. Cell proliferation analysis with CFU, MTT, and DNA content assays further confirmed the dual effect of cluster after prolonged exposure. Analyzing the course of action, it seems that miR-371-373 cluster acts as an onco/tumor suppressor-miR. MiR371-373 cluster acts by modulating the function of these factors and limiting the excessive cell cycle propagation upon oncogenic stimuli to protect cells from replicative stress, but also activate CDK inhibitors and transcriptional repressors of the retinoblastoma family to cause cell cycle arrest. In contrast to the previous studies, we believe that miR-371-373 cluster functions as a self-renewal miRNA to induce and maintain the pluripotent state but also to potentially inhibit dysregulated proliferation through cell cycle arrest. It seems that miR-371-373 cluster presents with a dual effect in this cellular context which may possess different actions in various cells. This not only expands the basic knowledge of the cluster but may offer a great chance for therapeutic interventions.

Transcription factor decoy: a pre-transcriptional approach for gene downregulation purpose in cancer

Gene therapy as a therapeutic approach has been the dream for many scientists around the globe. Many strategies have been proposed and applied for this purpose, yet the void for a functional safe method is still apparent. Since most of the diseases are caused by undesirable upregulation (oncogenes) or downregulation (tumor suppressor genes) of genes, major gene therapy's techniques affect gene expression. Most of the methods are used in post-transcriptional level such as RNA inhibitory (RNAi) and splice-switching oligonucleotides (SSOs). RNAi blocks messenger RNA (mRNA) translation by mRNA degradation or interruption between attachments of mRNA with ribosomes' subunits. However, one of the novel methods is the usage of transcription factor targeted decoys. DNA decoys are the new generation of functional gene downregulatory oligonucleotides which compete with specific binding sites of transcription factors. Considering the exponential growth of this technique in both in vitro and in vivo studies, in this paper, we aim to line out the description, design, and application of decoys in research and therapy.

Expression pattern of key microRNAs in patients with newly diagnosed chronic myeloid leukemia in chronic phase

INTRODUCTION

Chronic myeloid leukemia (CML) is caused by reciprocal translocation in hematopoietic stem cells (HSCs). This translocation forms the BCR-ABL1 oncogene, which alters several signaling pathways that control malignancy. CML has three phases: chronic, accelerated, and blast crisis. The microRNAs (miRNAs or miRs) are noncoding RNAs that downregulate their target gene by targeting 3' UTR of mRNA or through translational inhibition. It has been shown that miRNAs regulate many biological processes, and dysregulation of these regulatory RNAs is involved in disease development, particularly in cancer. The important role of miRNAs as therapeutic agents and biomarkers has been demonstrated in CML patients at different phases of the disease.

METHODS

Stem-loop reverse transcription polymerase chain reaction was used to characterize differentially expressed miRNAs of leukocytes in the peripheral blood of 50 newly diagnosed CML patients in chronic phase.

RESULTS

Some onco-miRNAs were found to be downregulated (miR-155 and miR-106), and some tumor suppressor miRs (miR-16-1, miR-15a, miR-101, miR-568) were upregulated.

CONCLUSION

These results show that very few miRNAs alone would be good candidates for CML diagnosis independently of conflicting results, but together could be an additional tool for CML diagnosis. Moreover, miRNAs might be good candidates for prognosis prediction and CML therapy.

Expression heterogeneity research of ITGB3 and BCL-2 in lung adenocarcinoma tissue and adenocarcinoma cell line

OBJECTIVE

To analyze expression heterogeneity of Integrin beta 3 (ITGB3) and B-cell lymphoma 2 (BCL-2) in lung adenocarcinoma tissue and adenocarcinoma cell line and further provide theoretical direction for molecular biological research of lung adenocarcinoma.

METHODS

Tissue microarray was used to observe relation among expression, heterogeneitpy and clinical characteristics of ITGB3 and BCL-2 in lung cancer.

RESULTS

ITGB3 and BCL-2 increased significantly in A549 cells in CAFs group withβ-actin as control; the expression level of BCL-2 also increased in ITGB3 transfected cells with GFP plasmid transfected A549 cells as control; immunohistochemistry staining showed that positive rates of ITGB3, ITGB1 and BCL-2 in normal lung tissues were 0, the positive rates in lung adenocarcinoma were 7.04%, 84.51% and 4.23%, respectively; in the results of immunohistochemistry staining, the expression of Girdin protein in lung adenocarcinoma was homogeneous, however protein expression of ITGB3, ITGB1 and BCL-2 showed different patterns in the same location with significant heterogeneity; majority of ITGB3, ITGB1 or BCL-2 positive tissue showed heterogeneity that expression in trailing edge was higher than that of trailing edge in lung adenocarcinoma tissue, the patients with BCL-2 heterogeneity showed higher lymph node metastasis ratio and lower clinical stage (P<0.05); and the expression of ITGB3 and the clinical characteristics of patients were not significant related (P>0.05).

CONCLUSIONS

Expression of ITGB3 and BCL-2 in lung adenocarcinoma and adenocarcinoma cell line showed heterogeneity that expression in trailing edge was higher than that of trailing edge, which may play an important role in promoting tumor lymph node metastasis and vascular invasion, and provides a new research direction for exploration of lung adenocarcinoma metastasis mechanism.

Rare Cytogenetic Abnormalities and Alteration of microRNAs in Acute Myeloid Leukemia and Response to Therapy

Acute myeloid leukemia (AML) is the most common acute leukemia in adults, which is heterogeneous in terms of morphological, cytogenetic and clinical features. Cytogenetic abnormalities, including karyotype aberrations, gene mutations and gene expression abnormalities are the most important diagnostic tools in diagnosis, classification and prognosis in acute myeloid leukemias. Based on World Health Organization (WHO) classification, acute myeloid leukemias can be divided to four groups. Due to the heterogeneous nature of AML and since most therapeutic protocols in AML are based on genetic alterations, gathering further information in the field of rare disorders as well as common cytogenetic abnormalities would be helpful in determining the prognosis and treatment in this group of diseases. Recently, the role of microRNAs (miRNAs) in both normal hematopoiesis and myeloid leukemic cell differentiation in myeloid lineage has been specified. miRNAs can be used instead of genes for AML diagnosis and classification in the future, and can also play a decisive role in the evaluation of relapse as well as response to treatment in the patients. Therefore, their use in clinical trials can affect treatment protocols and play a role in therapeutic strategies for these patients. In this review, we have examined rare cytogenetic abnormalities in different groups of acute myeloid leukemias according to WHO classification, and the role of miRNA expression in classification, diagnosis and response to treatment of these disorders has also been dealt with.

Molecular basis of chronic lymphocytic leukemia diagnosis and prognosis

BACKGROUNDS

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults and is characterized by a clonal accumulation of mature apoptosis-resistant neoplastic cells. It is also a heterogeneous disease with a variable clinical outcome. Here, we present a review of currently known (epi)genetic alterations that are related to the etiology, progression and chemo-refractoriness of CLL. Relevant literature was identified through a PubMed search (1994-2014) of English-language papers using the terms CLL, signaling pathway, cytogenetic abnormality, somatic mutation, epigenetic alteration and micro-RNA.

RESULTS

CLL is characterized by the presence of gross chromosomal abnormalities, epigenetic alterations, micro-RNA expression alterations, immunoglobulin heavy chain gene mutations and other genetic lesions. The expression of unmutated immunoglobulin heavy chain variable region (IGHV) genes, ZAP-70 and CD38 proteins, the occurrence of chromosomal abnormalities such as 17p and 11q deletions and mutations of the NOTCH1, SF3B1 and BIRC3 genes have been associated with a poor prognosis. In addition, mutations in tumor suppressor genes, such as TP53 and ATM, have been associated with refractoriness to conventional chemotherapeutic agents. Micro-RNA expression alterations and aberrant methylation patterns in genes that are specifically deregulated in CLL, including the BCL-2, TCL1 and ZAP-70 genes, have also been encountered and linked to distinct clinical parameters.

CONCLUSIONS

Specific chromosomal abnormalities and gene mutations may serve as diagnostic and prognostic indicators for disease progression and survival. The identification of these anomalies by state-of-the-art molecular (cyto)genetic techniques such as fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), single nucleotide polymorphism (SNP) microarray-based genomic profiling and next-generation sequencing (NGS) can be of paramount help for the clinical management of these patients, including optimal treatment design. The efficacy of novel therapeutics should to be tested according to the presence of these molecular lesions in CLL patients.

BRAF Mutation in Hairy Cell Leukemia

BRAF is a serine/threonine kinase with a regulatory role in the mitogen-activated protein kinase (MAPK) signaling pathway. A mutation in the RAF gene, especially in BRAF protein, leads to an increased stimulation of this cascade, causing uncontrolled cell division and development of malignancy. Several mutations have been observed in the gene coding for this protein in a variety of human malignancies, including hairy cell leukemia (HCL). BRAF V600E is the most common mutation reported in exon15 of BRAF, which is observed in almost all cases of classic HCL, but it is negative in other B-cell malignancies, including the HCL variant. Therefore it can be used as a marker to differentiate between these B-cell disorders. We also discuss the interaction between miRNAs and signaling pathways, including MAPK, in HCL. When this mutation is present, the use of BRAF protein inhibitors may represent an effective treatment. In this review we have evaluated the role of the mutation of the BRAF gene in the pathogenesis and progression of HCL.

Molecular regulation of bone marrow metastasis in prostate and breast cancer

Metastasis is a multistep process, which refers to the ability to leave a primary tumor through circulation toward the distant tissue and form a secondary tumor. Bone is a common site of metastasis, in which osteolytic and osteoblastic metastasis are observed. Signaling pathways, chemokines, growth factors, adhesion molecules, and cellular interactions as well as miRNAs have been known to play an important role in the development of bone metastasis. These factors provide an appropriate environment (soil) for growth and survival of metastatic tumor cells (seed) in bone marrow microenvironment. Recognition of these factors and determination of their individual roles in the development of metastasis and disruption of cellular interactions can provide important therapeutic targets for treatment of these patients, which can also be used as prognostic and diagnostic biomarkers. Thus, in this paper, we have attempted to highlight the molecular regulation of bone marrow metastasis in prostate and breast cancers.