Interplay between MAPK/ERK signaling pathway and MicroRNAs: A crucial mechanism regulating cancer cell metabolism and tumor progression.

Mitogen-activated protein kinase (MAPK) signal transduction, as a highly conserved signaling pathway, is reported to be involved in various biological events, including metabolic reprogramming, cell proliferation, survival, and differentiation. Mutations in key molecules involved in MAPK/ERK signaling and dysregulation of this pathway are very common events in various human malignancies, which make the MAPK signaling a crucial signaling pathway participating in the regulation of glucose uptake by malignant cells and tumorigenesis. MicroRNAs (miRNAs), as small non-coding RNAs, are critical regulators of gene expression that play key roles in cancer initiation and progression. On the other hand, these small RNAs mutually regulate the MAPK signaling which is often overexpressed in the case of cancer progression; suggesting that crosstalk between miRNAs and this signaling pathway plays a pivotal role in the development of human cancers. Some miRNAs such as miR-20b, miR-34c-3p, miR-152, miR-181a, and miR-302b through inhibiting MAPK signaling, and miR-193a-3p, miR-330-3p, and miR-592 by activating this signaling pathway, play imperative roles in tumorigenesis. Therefore, in this review, we aimed to focus on the interplay between miRNAs and MAPK signaling in the various steps of tumorigenesis, including metabolic regulation, cell proliferation, apoptosis, metastasis, angiogenesis, and drug resistance.

miR-330 Regulates Colorectal Cancer Oncogenesis by Targeting BACH1.

Purpose: Based on WHO report, colorectal cancer (CRC) is the second cause of death among patients with cancer worldwide. Dysregulation of miRNAs expressions has been demonstrated in different human cancers, especially CRC. Studies have shown that miR-330 could act as both TS-miR and/or oncomiR in different types of cancers. BACH1 is also identified as a transcription factor, which is involved in ontogenesis. In this study, we evaluated the CRC suppression via silencing of BACH1 by small silencer molecule called miR-330. Methods: Firstly, we analyzed the BACH1, miR-330-3p and miR-330-5p expressions according to the colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ) project established from a patient of the colon and rectal cancer patients in The Cancer Genome Atlas (TCGA) database. The targeting of BACH1 via miR-330 in human CRC cells was evaluated by Vejnar bioinformatics methods, and confirmed by qRT-PCR and western blot analysis. Proliferation was performed by MTT assay. The MMP9, CXCR4, and VEGFR proteins were measured by western blotting. Results: The analysis of BACH1, miR-330-3p, and miR-330-5p expressions according to the COAD and READ projects showed that BACH1 was overexpressed, but miR-330-3p and miR330-5p were reduced in CRC tumors compared to normal controls. The miR-330 induction prevented proliferation of CRC cell by targeting BACH1 mRNA, which represses MMP9, C-X-C chemokine receptor type 4 (CXCR4), and vascular endothelial growth factor receptor (VEGFR) proteins expressions. Conclusion: Our results suggested that BACH1 is a potential target for miR-330 in CRC cells. The miR-330 induction inhibits CRC cells proliferation by suppressing BACH1 expression in posttranscriptional level. It was suggested that targeting of BACH1 via miRNA such as miR-330 could be a valid strategy in the field of CRC targeted therapy via modulating the oncogenic signaling pathway.

Overexpression of HMGA2 in breast cancer promotes cell proliferation, migration, invasion and stemness.

Despite improved therapeutic strategies for early-stage breast cancer, the most common cancer type in women, relapse remains common and the underlying mechanisms for this progression remain poorly understood. To gain more insight, we studied the DNA-binding protein HMGA2 in breast cancer development and stemness. We demonstrated that HMGA2 is overexpressed in breast cancer tissues at the mRNA and protein levels (P value <0.0001). HMGA2 knockdown and overexpression in breast cancer cells revealed that HMGA2 promotes cell proliferation and protects against apoptosis via the intrinsic pathway. HMGA2 knockdown also causes cell cycle arrest in G2/M phase. In addition, we found that HMGA2 increases breast cancer cell migration and invasion (P value <0.001) and promotes the acquisition of cancer stem cell features, both in vitro, in colony formation (P value <0.01) and spheroid assays, and in breast cancer tissues. Overexpression of HMGA2 in breast cancer spurs the acquisition of several hallmarks of cancer, including increased cell proliferation, migration, invasion and stemness, and decreased apoptosis. Thus, targeting HMGA2 could represent an effective strategy to block breast cancer progression.

Hyaluronic acid-decorated liposomal nanoparticles for targeted delivery of 5-fluorouracil into HT-29 colorectal cancer cells.

The use of liposomes as drug carriers improves the therapeutic efficacy of anticancer drugs, while at the same time reducing side effects. Hyaluronic acid (HA) is recognized by the CD44 receptor, which is overexpressed in many cancer cells. In this study, we developed HA-modified liposomes encapsulating 5-fluorouracil (5-FU) and tested them against a CD44 expressing colorectal cell line (HT29) and a non-CD44 expressing hepatoma cell line. The average size of 5-FU-lipo and 5-FU-lipo-HA nanoparticles were 112 ± 28 and 144 ± 77 nm, respectively. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay showed selective cancer cell death depending on the CD44 expression in a time-dependent manner. Apoptosis assays and cell-cycle analysis indicated that G0/G1 arrest occurred. The colony formation study revealed that cells treated with 5-FU-lipo and 5-FU-lipo-HA had reduced colony formation. Quantitative reverse-transcription polymerase chain reaction study showed that the oncogenic messenger RNA and microRNA levels were significantly reduced in the 5-FU-lipo-HA-treated group, while tumor suppressors were increased in that group. We suggest that optimal targeted delivery and release of 5-FU into colorectal cancer cells, renders them susceptible to apoptosis, cell-cycle arrest, and decreased colony formation.

miR-330 suppresses EMT and induces apoptosis by downregulating HMGA2 in human colorectal cancer.

MicroRNAs (miRNAs) are important molecular regulatorsof cellular signaling and behavior. They alter gene expression by targeting messenger RNAs, including those encoding transcriptional regulators, such as HMGA2. While HMGA2 is oncogenic in various tumors, miRNAs may be oncogenic or tumor suppressive. Here, we investigate the expression of HMGA2 and the miRNA miR-330 in a patient with colorectal cancer (CRC) samples and their effects on oncogenic cellular phenotypes. We found that HMGA2 expression is increased and miR-330 expression is decreased in CRCs and each predicts poor long-term patient survival. Stably increased miR-330 expression in human colorectal cancer cells (HCT116) and SW480 CRC cell lines downregulate the oncogenic expression of HMGA2, a predicted miR-330 target. Additionally, this promotes apoptosis and decreases cell migration and viability. Consistently, it also decreases protein-level expression of markers for epithelial-to-mesenchymal-transition (Snail-1, E-cadherin, and Vascular endothelial growth factor receptors) and transforming growth factor ß signaling (SMAD3), as well as phospho- Protein kinase B (AKT) and phospho-STAT3 levels. We conclude that miR-330 acts as a tumor suppressor miRNA in CRC by suppressing HMGA2 expression and reducing cell survival, proliferation, and migration. Thus, we identify miR-330 as a promising candidate for miRNA replacement therapy for patients with CRC.

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.

HMGA2 and Bach-1 cooperate to promote breast cancer cell malignancy.

During breast cancer progression, tumor cells acquire multiple malignant features. The transcription factors and cell cycle regulators high mobility group A2 (HMGA2) and BTB and CNC homology 1 (Bach-1) are overexpressed in several cancers, but the mechanistic understanding of how HMGA2 and Bach-1 promote cancer development has been limited. We found that HMGA2 and Bach-1 are overexpressed in breast cancer tissues and their expression correlates positively in tumors but not in normal tissues. Individual HMGA2 or Bach-1 knockdown downregulates expression of both proteins, suggesting a mutual stabilizing effect between the two proteins. Importantly, combined HMGA2 and Bach-1 knockdown additively decrease cell proliferation, migration, epithelial-to-mesenchymal transition, and colony formation, while promoting apoptotic cell death via upregulation of caspase-3 and caspase-9. First the first time, we show that HMGA2 and Bach-1 overexpression in tumors correlate positively and that the proteins cooperatively suppress a broad range of malignant cellular properties, such as proliferation, migration, clonogenicity, and evasion of apoptotic cell death. Thus, our observations suggest that combined targeting of HMGA2 and Bach1 may be an effective therapeutic strategy to treat breast cancer.

miR-142-3p is a tumor suppressor that inhibits estrogen receptor expression in ER-positive breast cancer.

Estrogen receptors (ERs) are involved in the development of many types of malignant tumors, in particular, breast cancer. Among others, ERs affect cell growth, proliferation, and differentiation. The microRNA (miRNA) miR-142-3p has been shown to inhibit carcinogenesis by regulating various cellular processes, including cell cycle progression, cell migration, apoptosis, and invasion. It does so via targeting molecules involved in a range of signaling pathways. We surgically collected 20 ER-positive breast cancer samples, each with matched adjacent normal breast tissue, and measured the expression of miR-142-3p via quantitative real-time polymerase chain reaction (qRT-PCR). Bioinformatics methods, luciferase reporter assay, qRT-PCR, and western blot analysis were used to assess whether miR-142-3p could target ESR1, which encodes the estrogen receptor, in ER-positive breast cancer cells and patient samples. We also restored miRNA expression and performed cell viability, cytotoxicity, and colony formation assays. Western blot analysis and qRT-PCR were used to study the expression of apoptosis and stemness markers. We found that miR-142-3p is downregulated in ER-positive breast cancers. Restoration of miR-142-3p expression in ER-positive breast cancer cells reduced cell viability, induced apoptosis via the intrinsic pathway and decreased both colony formation and the expression of stem cell markers. Bioinformatic analysis predicted miR-142-3p could bind to 3'-untranslated region ESR1 messenger RNA (mRNA). Consistently, we demonstrated that miR-142-3p reduced luciferase activity in ER-positive breast cancer cells, and decreased ESR1 expression in both mRNA and protein levels. The results revealed miR-142-3p and ESR1 expression correlated negatively in ER-positive breast cancer samples. The results suggest miR-142-3p acts as a tumor suppressor via multiple mechanisms. Thus, restoration of miR-142-3p expression, for example, via miRNA replacement therapy, may represent an effective strategy for the treatment of ER-positive breast cancer patients.

miR-142-3p as tumor suppressor miRNA in the regulation of tumorigenicity, invasion and migration of human breast cancer by targeting Bach-1 expression.

BACKGROUND: Breast cancer is the most common type of cancer among women, and despite improved treatments, it remains a major challenge. However, improved mechanistic insight may lead to novel therapeutic strategies. miR-142-3p belongs to the miR-142 family and is involved in pathogenesis and metastasis of various types of malignancies by targeting several important messenger RNAs (mRNAs) including Bach-1. This is especially true for breast cancer, where Bach-1 is involved in the metastatic spread by deregulation of metastasis-associated genes. METHODS: In this study, we collected 24 breast cancer tissues with 24 adjusted normal tissues to measure the expression levels of miR-142-3p and Bach-1 mRNA using quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and IHC. miR-142-3p targeting of Bach-1 expression in MCF-7 and MDA-MB-468 breast cancer cells was evaluated using bioinformatics, qRT-PCR and western blot analyses. The cellular proliferation, invasion, and migration were assessed by MTT, transwell matrigel and wound healing assay and the EMT-associated proteins C-X-C chemokine receptor type 4 (CXCR-4), matrix metalloproteinase-9 (MMP9), and vascular endothelial growth factor receptor (VEGFR) were analyzed by western blot analysis. Also, the expression levels of tumor suppressors including miR-330, miR-145, and miR-34a were estimated by qRT-PCR. RESULTS: Analysis of paired specimens of primary malignant and normal tissues showed that miR-142-3p was downregulated, while Bach-1 mRNA and protein both were overexpressed in the breast cancer tumors. This inverse relationship was confirmed by cell line experiments demonstrating that miR-142-3p expression reduced Bach-1 mRNA levels. Furthermore, replacement of miR-142-3p could inhibit the proliferation, invasion, and migration in breast cancer potentially by targeting of Bach-1 mRNA and subsequent inhibition of CXCR4, MMP9, and VEGFR protein expressions. In addition, induction of miR-142-3p could upregulate tumor suppressor miRNAs, including miR-330, miR-145, and miR34a. CONCLUSION: For the first time, our results revealed that miR-142-3p could target Bach-1in breast cancer cells leading to the reduction of EMT-related proteins and reduced cell proliferation, invasion, and migration. The results also demonstrated that miR-142-3p could regulate important tumor suppressor miRNAs in breast cancer cells. In conclusion, our results suggest that miR-142-3p could be a good candidate for the targeted therapy of breast cancer, especially for the invasive type.

Promising immunotherapy: Highlighting cytokine-induced killer cells.

For many years, cancer therapy has appeared to be a challenging issue for researchers and physicians. By the introduction of novel methods in immunotherapy, the prospect of cancer therapy even more explained than before. Cytokine-induced killer (CIK) cell-based immunotherapy demonstrated to have potentiality in improving clinical outcomes and relieving major side effects of standard treatment options. In addition, given the distinctive features such as high safety, low toxicity effects on healthy cells, numerous clinical trials conducted on CIK cells. Due to the shortcomings that observed in CIK cell immunotherapy alone, arising a tendency to make modifications (combined modality therapy or combination therapy) including the addition of various types of cytokines, genetic engineering, combination with immune checkpoints, and so on. In this review, we have tried to bring forth the latest immunotherapy methods and their overview. We have discussed the combination therapies with CIK cells and the conducted clinical trials. This helps the future studies to use integrated therapies with CIK cells as a promising treatment of many types of cancers.

MicroRNAs in the Diagnosis and Treatment of Cancer.

Immune cells are recruited into the tumor microenvironment and regulate anti- and pro-tumor signals. MicroRNAs (miRNAs) markedly control the immune system responses in cancer development. miRNAs that affect the immune system could be interesting targets for immunomodulation against cancer, either through the activation of effector cells or through the down-regulation of regulatory cells. Bioinformatic calculations can predict the immune system and miRNA interactions. In this review, we discuss the most recent studies about miRNA as the main regulator of recruitment and the activation of the immune system in the tumor microenvironment and finally we propose several miRNAs that could serve as therapeutic molecules in the immunotherapy of cancer.

The Different Mechanisms of Cancer Drug Resistance: A Brief Review.

Anticancer drugs resistance is a complex process that arises from altering in the drug targets. Advances in the DNA microarray, proteomics technology and the development of targeted therapies provide the new strategies to overcome the drug resistance. Although a design of the new chemotherapy agents is growing quickly, effective chemotherapy agent has not been discovered against the advanced stage of cancer (such as invasion and metastasis). The cancer cell resistance against the anticancer agents can be due to many factors such as the individual's genetic differences, especially in tumoral somatic cells. Also, the cancer drug resistance is acquired, the drug resistance can be occurred by different mechanisms, including multi-drug resistance, cell death inhibiting (apoptosis suppression), altering in the drug metabolism, epigenetic and drug targets, enhancing DNA repair and gene amplification. In this review, we outlined the mechanisms of cancer drug resistance and in following, the treatment failures by common chemotherapy agents in the different type of cancers.

Urtica dioica extract suppresses miR-21 and metastasis-related genes in breast cancer.

BACKGROUND: Breast cancer has a high prevalence among women worldwide. Tumor invasion and metastasis still remains an open issue that causes most of the therapeutic failures and remains the prime cause of patient mortality. Hence, there is an unmet need to develop the most effective therapeutic approach with the lowest side effects and highest cytotoxicity that will effectively arrest or eradicate metastasis. METHODS: An MTT assay and scratch test were used to assess the cytotoxicity and migration effects of Urtica dioica on the breast cancer cells. The QRT-PCR was used to study the expression levels of miR-21, MMP1, MMP9, MMP13, CXCR4, vimentin, and E-cadherin. RESULTS: The results of gene expression in tumoral groups confirmed the overexpression of miR-21, MMP1, MMP9, MMP13, vimentin, and CXCR4, and the lower expression of E-cadherin compared to control groups (P<0.05). Moreover, the results of the MTT assay show that Urtica dioica significantly inhibited breast cancer cell proliferation. Moreover, findings from the scratch assay exhibited the inhibitory effects of Urtica dioica on the migration of breast cancer cell lines. CONCLUSION: Urtica dioica extract could inhibit cancer cell migration by regulating miR-21, MMP1, MMP9, MMP13, vimentin, CXCR4, and E-Cadherin. Moreover, our findings demonstrated that the extract could decrease miR-21 expression, which substantially lessens the overexpressed MMP1, MMP9, MMP13, vimentin, and CXCR4 and increases E-cadherin in the tumoral group.

Toll-like receptors as a key regulator of mesenchymal stem cell function: An up-to-date review.

Understanding the role of toll-like receptors (TLRs) in the immunomodulation potential, differentiation, migration, and survival of mesenchymal stem cells (MSCs) is absolutely vital to fully exploiting their MSC-based therapeutic potential. Furthermore, through recognition of exogenous or endogenous ligands produced upon injury, TLRs have been linked to allograft rejection and maintenance of chronic inflammatory diseases, including Crohn's disease, rheumatoid arthritis. Characterizing the effect of TLRs in biological control of MSCs fate and function could improve our knowledge about the MSC-based cell therapy and immunotherapy. In this paper, we outline the impacts of TLR activation and mechanisms on MSCs immunomodulatory functions, differentiation, migration, and survivability. Moreover, we indicate that the expression patterns of TLRs in MSCs from different sources.

The Urtica dioica extract enhances sensitivity of paclitaxel drug to MDA-MB-468 breast cancer cells.

INTRODUCTION: Due to the chemo resistant nature of cancer cells and adverse effects of current therapies, researchers are looking for the most efficient therapeutic approach which has the lowest side effects and the highest toxicity on cancer cells. The aim of the present study was to investigate the synergic effect of Urtica dioica extract in combination with paclitaxel on cell death and invasion of human breast cancer MDA-MB-468 cell line. MATERIALS AND METHODS: To determine the cytotoxic effects of Urtica dioica extract with paclitaxel, MTT assay was performed. The scratch test was exploited to assess the effects of Urtica dioica, Paclitaxel alone and combination on migration of cancer cells. The expression levels of snail-1, ZEB1, ZEB2, twist, Cdc2, cyclin B1 and Wee1 genes were quantified using qRT-PCR and western blot performed for snail-1expression. The effects of plant extract, Paclitaxel alone and combination on different phases of cell cycle was analyzed using flow cytometry. RESULTS: Results of MTT assay showed that Urtica dioica significantly destroyed cancer cells. Interestingly, Concurrent use of Urtica dioica extract with paclitaxel resulted in decreased IC50 dose of paclitaxel. Moreover, findings of scratch assay exhibited the inhibitory effects of Urtica dioica, Paclitaxel alone and combination on migration of MDA-MB-468 cell line. Our findings also demonstrated that the extract substantially decreased the Snail-1 and related gene expression. Ultimately, Cell cycle arrest occurred at G2/M phase post-treatment by deregulating Cdc2 and wee1. CONCLUSIONS: Our results demonstrated that the dichloromethane extract of Urtica dioica inhibit cell growth and migration. Also, Urtica dioica extract substantially increased sensitivity of breast cancer cells to paclitaxel. Therefore, it can be used as a potential candidate for treatment of breast cancer with paclitaxel.

HMGI-C suppressing induces P53/caspase9 axis to regulate apoptosis in breast adenocarcinoma cells.

PURPOSE: The HMGI-C (high mobility group protein isoform I-C) protein is a member of the high-mobility group AT-hook (HMGA) family of small non-histone chromosomal proteins that can modulate transcription of an ample number of genes. Genome-wide studies reveal upregulation of the HMGI-C gene in many human cancers, which suggests that HMGI-C might play a critical role in the progression of various tumors. However, the exact role of HMGI-C in breast adenocarcinoma has not been made clear. METHODS: HMGI-C mRNA expression in breast cancer samples and marginal normal tissues was characterized using qRT-PCR. The cytotoxic effects of HMGI-C siRNA on breast adenocarcinoma cells were determined using MTT assay. Relative HMGI-C mRNA and protein levels were measured by quantitative real-time PCR and western blotting, respectively. Apoptosis detection was done using TUNEL and Annexin-V/PI assays, P53, caspase 3, 9, 8 and Bcl2 proteins evaluated by protein gel blot and miR34a, Let-7a genes investigates by QRT-PCR assay. Cell cycle was analyzed by flow cytometry assay using propidium iodide DNA staining. RESULTS: An overexpression of HMGA2 was revealed with highly statistically significant differences between breast cancer samples and marginal normal tissues (P < 0.0001). HMGI-C siRNA significantly reduced both mRNA and protein expression levels in a 48-hour period after transfection and in a dose-dependent manner. We observed that the knockdown of HMGI-C led to the significant induction of apoptosis via mitochondrial pathway by inducing miR34a and cell cycle arrest in MDA-MB-468 cells in vitro. CONCLUSIONS: These results propose that HMGI-C might play a critical role in the progression of breast adenocarcinoma. Here we introduced HMGI-C as a potential therapeutic target for trigger apoptosis and cell cycle arrest in human breast adenocarcinoma. Therefore HMGI-C siRNA may be an effective adjuvant in human breast adenocarcinoma.

Micro RNA 34a and Let-7a Expression in Human Breast Cancers is Associated with Apoptotic Expression Genes.

Breast cancer is the most common cause of cancer-related death among women in the whole world. MiR- 34a and let-7a are well known tumor suppressors that participate in the regulation of apoptosis, invasion and other cellular functions. In this study, expression of miR-34a, let-7a and apoptosis pathway genes such as Bcl-2, Caspase-3 and P53 were evaluated using quantitative real-time PCR in 45 paired samples of normal margin and tumor tissue collected from breast cancer patient at advanced stage (3-4). MiR-34a, let-7a, caspase-3 and P53 expression are reduced and Bcl-2 expression is increased within tumoral tissues in comparison with normal margin tissues. P53 expression directly or indirectly was correlated with miR-34a, let-7a, Bcl-2 and caspase-3 expression. In This study we found that MiR-34a and let-7a expression are reduced in the tumoral tissues. Down- regulation of these two molecules correlated with expression of genes associated with apoptosis. These results suggest that due to the correlation of miR-34a and let-7a with apoptotic and anti-apoptotic pathways these molecules could participate as regulators in advanced clinical stages of breast cancer and should be considered as markers for diagnosis, prognostic assessment and targeted therapy.