MicroRNA-214 suppresses growth, migration and invasion through a novel target, high mobility group AT-hook 1, in human cervical and colorectal cancer cells

IKBKE promotes the ZEB2-mediated EMT process by phosphorylating HMGA1a in glioblastoma

IKBKE (Inhibitor of Nuclear Factor Kappa-B Kinase Subunit Epsilon) is an important oncogenic protein in a variety of tumors, which can promote tumor growth, proliferation, invasion and drug resistance, and plays a critical regulatory role in the occurrence and progression of malignant tumors. HMGA1a (High Mobility Group AT-hook 1a) functions as a cofactor for proper transcriptional regulation and is highly expressed in multiple types of tumors. ZEB2 (Zinc finger E-box Binding homeobox 2) exerts active functions in epithelial mesenchymal transformation (EMT). In our current study, we confirmed that IKBKE can increase the proliferation, invasion and migration of glioblastoma cells. We then found that IKBKE can phosphorylate HMGA1a at Ser 36 and/or Ser 44 sites and inhibit the degradation process of HMGA1a, and regulate the nuclear translocation of HMGA1a. Crucially, we observed that HMGA1a can regulate ZEB2 gene expression by interacting with ZEB2 promoter region. Hence, HMGA1a was found to promote the ZEB2-related metastasis. Consequently, we demonstrated that IKBKE can exert its oncogenic functions via the IKBKE/HMGA1a/ZEB2 signalling axis, and IKBKE may be a prominent biomarker for the treatment of glioblastoma in the future.

High Mobility Group A1 (HMGA1): Structure, Biological Function, and Therapeutic Potential

High mobility group A1 (HMGA1) is a nonhistone chromatin structural protein characterized by no transcriptional activity. It mainly plays a regulatory role by modifying the structure of DNA. A large number of studies have confirmed that HMGA1 regulates genes related to tumours in the reproductive system, digestive system, urinary system and haematopoietic system. HMGA1 is rare in adult cells and increases in highly proliferative cells such as embryos. After being stimulated by external factors, it will produce effects through the Wnt/β-catenin, PI3K/Akt, Hippo and MEK/ERK pathways. In addition, HMGA1 also affects the ageing, apoptosis, autophagy and chemotherapy resistance of cancer cells, which are linked to tumorigenesis. In this review, we summarize the mechanisms of HMGA1 in cancer progression and discuss the potential clinical application of targeted HMGA1 therapy, indicating that targeted HMGA1 is of great significance in the diagnosis and treatment of malignancy.

miR-214-3p Is Commonly Downregulated by EWS-FLI1 and by CD99 and Its Restoration Limits Ewing Sarcoma Aggressiveness

Simple Summary

Ewing’s sarcoma (EWS), the second most frequent primary tumor of bone in the pediatric population, is a very aggressive, undifferentiated mesenchymal malignancy with a high tendency to develop lung and/or bone metastasis. The prognosis of patients with metastasis remains dismal, and new strategies are needed to control the dissemination of EWS cells. EWS is driven by alterations induced by the EWS-FLI1 chimera which acts as an aberrant transcriptional factor that induces the complete reprograming of the gene expression. EWS cells are also characterized by high expression of CD99, a cell surface molecule that interacts with EWS-FLI1 to sustain EWS malignancy. This study shows that miR-214-3p is a common mediator of EWS-FLI1 and CD99, and we report that miR-214-3p acts as on oncosuppressor in EWS. MiR-214-3p is constitutively repressed in cell lines and clinical samples but is re-expressed after the silencing of EWS-FLI1 and/or CD99. The restoration of miR-214-3p limits EWS cell growth and migration and represses the expression of its target HMGA1, supporting the potential role of this miRNA as a marker of tumor aggressiveness.

Abstract

Ewing’s sarcoma (EWS), an aggressive pediatric bone and soft-tissue sarcoma, has a very stable genome with very few genetic alterations. Unlike in most cancers, the progression of EWS appears to depend on epigenetic alterations. EWS–FLI1 and CD99, the two hallmarks of EWS, are reported to severely impact the malignancy of EWS cells, at least partly by regulating the expression of several types of non-coding RNAs. Here, we identify miR-214-3p as a common mediator of either EWS-FLI1 or CD99 by in silico analysis. MiR-214-3p expression was lower in EWS cells and in clinical samples than in bone marrow mesenchymal stem cells, and this miRNA was barely expressed in metastatic lesions. Silencing of EWS-FLI1 or CD99 restored the expression of miR-214-3p, leading to a reduced cell growth and migration. Mechanistically, miR-214-3p restoration inhibits the expression of the high-mobility group AT-hook 1 (HMGA1) protein, a validated target of miR-214-3p and a major regulator of the transcriptional machinery. The decrease in HMGA1 expression reduced the growth and the migration of EWS cells. Taken together, our results support that the miR-214-3p is constitutively repressed by both EWS-FLI1 and CD99 because it acts as an oncosuppressor limiting the dissemination of EWS cells.

miR-142-3p simultaneously targets HMGA1, HMGA2, HMGB1, and HMGB3 and inhibits tumorigenic properties and in-vivo metastatic potential of human cervical cancer cells

AIMS

High-mobility group (HMG) proteins are oncogenic in different cancers, including cervical cancer; silencing their individual expression using sh-RNAs, siRNAs, and miRNAs has had anti-tumorigenic effects, but the consequences of their collective downregulation are not known. Since multiple gene targeting is generally very effective in cancer therapy, the present study highlighted the consequences of silencing the expression of HMGA1, A2, B1, and B3 using sh-RNAs or miR-142-3p (that can potentially target HMGA1, A2, B1, and B3) in cervical cancer cell lines.

MAIN METHODS

3' UTR luciferase reporter assays were performed to validate HMGA1, A2, B1, and B3 as targets of miR-142-3p in human cervical cancer cells. Annexin V/PI dual staining and flow cytometry analyses were used to detect apoptotic cells. miR-142-3p-mediated regulation of cell death, colony formation, migration, and invasion was investigated in human cervical cancer cells together with in vivo metastasis in zebrafish.

KEY FINDINGS

Concurrent knockdown of HMGA1, A2, B1, and B3 through their corresponding sh-RNAs inhibited cell viability and colony formation but induced apoptosis, and these effects were relatively reduced upon their individual knockdown. miR-142-3p targeted HMGA1, A2, B1, and B3 by binding to their 3'UTRs and induced apoptosis but inhibited proliferation, migration, and invasion of human cervical cancer cells. In addition, miR-142-3p expression decreased phospho-p65 and EMT-related proteins in cervical cancer cells and their in vivo metastatic potential upon implantation in zebrafish.

SIGNIFICANCE

These findings suggest that miR-142-3p acts as a tumor-suppressive miRNA by targeting HMGA1, A2, B1, and B3 and may serve as a potential therapeutic agent in human cervical cancer.

SLC7A11/ xCT is a target of miR-5096 and its restoration partially rescues miR-5096-mediated ferroptosis and anti-tumor effects in human breast cancer cells

Breast cancer cells evade cell death by overexpressing SLC7A11, which functions by transporting cystine into cells in exchange for intracellular glutamate facilitating glutathione synthesis and reducing reactive oxygen species (ROS)-mediated stress. Using an in silico approach, we predicted an miRNA (miR-5096) that can target and downregulate SLC7A11. We demonstrated SLC7A11 as a target of miR-5096 by 3'UTR luciferase assay and further validated it by identifying reduced mRNA and protein levels of SLC7A11 upon miR-5096 overexpression. miR-5096-induced ferroptotic cell death in human breast cancer cells was confirmed by concurrently increased ROS, OH^-, lipid ROS, and iron accumulation levels and decreased GSH and mitochondrial membrane potential (MitoTracker™ Orange) with mitochondrial shrinkage and partial cristae loss (observed by TEM). miR-5096 inhibited colony formation, transwell migration, and breast cancer cell invasion, whereas antimiR-5096 promoted these tumorigenic properties. Ectopic expression of SLC7A11 partly reversed miR-5096-mediated effects on cell survival, ROS, lipid peroxides, iron accumulation, GSH, hydroxyl radicals, mitochondrial membrane potential, and colony formation. miR-5096 modulated the expression of epithelial-mesenchymal transition markers in vitro and inhibited the metastatic potential of MDA-MB-231 cells in a tumor xenograft model of zebrafish larvae. Our results demonstrate that miR-5096 is a tumor-suppressive miRNA in breast cancer cells, and this paper discusses its therapeutic implications.

Knockdown of microRNA-214-3p Promotes Tumor Growth and Epithelial-Mesenchymal Transition in Prostate Cancer

Simple Summary

Prostate Cancer is the second leading cause of cancer-related deaths in the United States. In this study, we analyzed a molecule known as a microRNA, which regulates the expression of genes. microRNAs are involved in processes related to cancer onset and progression. Abnormal expression of microRNAs can promote prostate cancer. This study showed that knockdown of microRNA miR-214-3p enhanced the progression and of prostate cancer. In addition, miR-214 regulated the expression of many genes. These results are useful to better understand the function of miR-214-3p in prostate cancer and can be a useful target in the treatment of the disease.

Abstract

Abnormal expression of microRNA miR-214-3p (miR-214) is associated with multiple cancers. In this study, we assessed the effects of CRISPR/Cas9 mediated miR-214 depletion in prostate cancer (PCa) cells and the underlying mechanisms. Knockdown of miR-214 promoted PCa cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT), and increased resistance to anoikis, a key feature of PCa cells that undergo metastasis. The reintroduction of miR-214 in miR-214 knockdown cells reversed these effects and significantly suppressed cell proliferation, migration, and invasion. These in vitro studies are consistent with the role of miR-214 as a tumor suppressor. Moreover, miR-214 knockout increased tumor growth in PCa xenografts in nude mice supporting its anti-oncogenic role in PCa. Knockdown of miR-214 increased the expression of its target protein, Protein Tyrosine Kinase 6 (PTK6), a kinase shown to promote oncogenic signaling and tumorigenesis in PCa. In addition, miR-214 modulated EMT as exhibited by differential regulation of E-Cadherin, N-Cadherin, and Vimentin both in vitro and in vivo. RNA-seq analysis of miR-214 knockdown cells revealed altered gene expression related to PCa tumor growth pathways, including EMT and metastasis. Collectively, our findings reveal that miR-214 is a key regulator of PCa oncogenesis and is a potential novel therapeutic target for the treatment of the disease.

MicroRNA-214 in Health and Disease

MicroRNAs (miRNAs) are endogenously expressed, non-coding RNA molecules that mediate the post-transcriptional repression and degradation of mRNAs by targeting their 3′ untranslated region (3′-UTR). Thousands of miRNAs have been identified since their first discovery in 1993, and miR-214 was first reported to promote apoptosis in HeLa cells. Presently, miR-214 is implicated in an extensive range of conditions such as cardiovascular diseases, cancers, bone formation and cell differentiation. MiR-214 has shown pleiotropic roles in contributing to the progression of diseases such as gastric and lung cancers but may also confer cardioprotection against excessive fibrosis and oxidative damage. These contrasting functions are achieved through the diverse cast of miR-214 targets. Through silencing or overexpressing miR-214, the detrimental effects can be attenuated, and the beneficial effects promoted in order to improve health outcomes. Therefore, discovering novel miR-214 targets and understanding how miR-214 is dysregulated in human diseases may eventually lead to miRNA-based therapies. MiR-214 has also shown promise as a diagnostic biomarker in identifying breast cancer and coronary artery disease. This review provides an up-to-date discussion of miR-214 literature by describing relevant roles in health and disease, areas of disagreement, and the future direction of the field.

Increased expression of lncRNA SNHG7 promotes the cell viability, migration, and invasion in pre-eclampsia via modulating the miR-214-5p/TWIST1 axis

PURPOSE

This study is aimed to elucidate the molecular mechanism of lncRNA SNHG7 on pre-eclampsia (PE).

METHODS

The expression of SNHG7, miR-214-5p and TWIST1 in PE placental tissues was detected by qRT-PCR. The regulatory mechanism of SNHG7/miR-214-5p/TWIST1 axis on PE was determined using MTT, wound healing, transwell invasion, and western blot assays.

RESULTS

In PE pregnancies, SNHG7 and TWIST1 were decreased, while miR-214-5p was increased.The elevated miR-214-5p and decreased TWIST1 partly eliminated the promoting effects of SNHG7 up-regulation on the viability and metastasis of JEG-3 cells.

CONCLUSIONS

Up-regulated SNHG7 protects against PE through modulating the miR-214-5p/TWIST1 axi.

LncRNA TTN-AS1 acts as a tumor promoter in gallbladder carcinoma by regulating miR-107/HMGA1 axis

Background

The incidence of gallbladder carcinoma (GBM) in China has increased in recent years. Here, the functional mechanism of lncRNA TTN-AS1 in GBC was preliminary elucidated.

Methods

The expression levels of lncRNA TTN-AS1, miR-107, and HMGA1 in tissues and cell lines were assessed by RT-qPCR. Cell proliferation was measured by MTT assays. Cell invasion and migration abilities were evaluated by Transwell assays. The relationship between miR-107 and lncRNA TTN-AS1 or HMGA1 was confirmed by luciferase reporter assay.

Results

Upregulation of lncRNA TTN-AS1 and downregulation of miR-107 were detected in GBC. Furthermore, the expressions between TTN-AS1 and miR-107 were mutually inhibited in GBC. Functionally, lncRNA TTN-AS1 promoted cell viability and motility in GBC by sponging miR-107. In addition, miR-107 directly targets HMGA1. And HMGA1 can be positively regulated by lncRNA TTN-AS1 in GBC. Furthermore, HMGA1 promoted GBC progression by interacting with lncRNA TTN-AS1/miR-107 axis.

Conclusion

LncRNA TTN-AS1 acted as a tumor promoter in GBC by sponging miR-107 and upregulating HMGA1.

MicroRNA-296-5p inhibits cell proliferation by targeting HMGA1 in colorectal cancer

An increasing body of evidence indicates the involvement of microRNAs (miRNAs/miRs) in the initiation and progression of colorectal cancer (CRC). miR-296-5p was recently identified as a tumor suppressor in a variety of human cancer types; however, its function in CRC remains largely unknown. The present study demonstrated that the expression of miR-296-5p was significantly downregulated in CRC tissues and cell lines. The overexpression of miR-296-5p markedly inhibited proliferation, and induced cell cycle arrest and apoptosis in CRC cells. Bioinformatics analysis suggested that high mobility group AT-hook 1 (HMGA1) may be a target of miR-296-5p in CRC cells. Further experiments showed that miR-296-5p bound the 3'-untranslated region of HMGA1 and decreased its expression in CRC cells. HMGA1 was overexpressed in CRC tissues and was inversely correlated with the expression of miR-296-5p. The restoration of HMGA1 significantly reversed the inhibitory effect of miR-296-5p on the proliferation of CRC cells. Overall, the findings of the present study indicate that miR-296-5p suppressed the progression of CRC, at least partially via targeting HMGA1. Thus, miR-296-5p is a potential target for novel therapies in CRC.

The Role of p53 Signaling in Colorectal Cancer

The transcription factor p53 functions as a critical tumor suppressor by orchestrating a plethora of cellular responses such as DNA repair, cell cycle arrest, cellular senescence, cell death, cell differentiation, and metabolism. In unstressed cells, p53 levels are kept low due to its polyubiquitination by the E3 ubiquitin ligase MDM2. In response to various stress signals, including DNA damage and aberrant growth signals, the interaction between p53 and MDM2 is blocked and p53 becomes stabilized, allowing p53 to regulate a diverse set of cellular responses mainly through the transactivation of its target genes. The outcome of p53 activation is controlled by its dynamics, its interactions with other proteins, and post-translational modifications. Due to its involvement in several tumor-suppressing pathways, p53 function is frequently impaired in human cancers. In colorectal cancer (CRC), the TP53 gene is mutated in 43% of tumors, and the remaining tumors often have compromised p53 functioning because of alterations in the genes encoding proteins involved in p53 regulation, such as ATM (13%) or DNA-PKcs (11%). TP53 mutations in CRC are usually missense mutations that impair wild-type p53 function (loss-of-function) and that even might provide neo-morphic (gain-of-function) activities such as promoting cancer cell stemness, cell proliferation, invasion, and metastasis, thereby promoting cancer progression. Although the first compounds targeting p53 are in clinical trials, a better understanding of wild-type and mutant p53 functions will likely pave the way for novel CRC therapies.

The Role of microRNAs in Development of Colitis-Associated Colorectal Cancer

Colorectal cancer (CRC) is the third most deadly cancer worldwide, and inflammatory bowel disease (IBD) is one of the critical factors in CRC carcinogenesis. IBD is responsible for an unphysiological and sustained chronic inflammation environment favoring the transformation. MicroRNAs (miRNAs) belong to a class of highly conserved short single-stranded segments (18-25 nucleotides) non-coding RNA and have been extensively discussed in both CRC and IBD. However, the role of miRNAs in the development of colitis-associated CRC (CAC) is less clear. The aim of this review is to summarize the major upregulated (miR-18a, miR-19a, miR-21, miR-31, miR-155 and miR-214) and downregulated (miR-124, miR-193a-3p and miR-139-5p) miRNAs in CAC, and their roles in genes' expression modulation in chronic colonic-inflammation-induced carcinogenesis, including programmed cell-death pathways. These miRNAs dysregulation could be applied for early CAC diagnosis, to predict therapy efficacy and for precision treatment.

Glutathione Synthesis in Cancer Cells

Tripeptide GSH is associated not only with the control and maintenance of redox cell homeostasis, but also with the processes of detoxification, proliferation, cell differentiation, and regulation of cell death. Disruptions in GSH synthesis and changes in the GSH/GSSG ratio are common for many pathological conditions, including malignant neoplasms. Numerous data indicate the importance of GSH and the GSH/GSSG ratio in the regulation of tumor cell viability, in the initiation of tumor development, progression, and drug resistance. However, control of the mechanism of GSH synthesis in malignant tumors remains poorly understood. This review discusses the features of GSH synthesis and its regulation in tumor cells. The role of GSH in the mechanisms of apoptosis, necroptosis, ferroptosis, and autophagy is considered.

Targeting TGF-β-Mediated SMAD Signaling Pathway via Novel Recombinant Cytotoxin II: A Potent Protein from Naja naja oxiana Venom in Melanoma

Since the current treatments have not resulted in the desired outcomes for melanoma patients, there is a need to identify more effective medications. Together with other snake venom proteins, cytotoxin-II has shown promising results in tumoral cells. In this study, recombinant cytotoxin-II (rCTII) was expressed in SHuffle^® T7 Express cells, while the epitope mapping of rCTII was performed to reveal the antibody-binding regions of rCTII. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to assess the viability of SK-MEL-3 and HFF-2 cells after treating these cells with rCTII. The qRT-PCR was performed to evaluate the expression levels of matrix metallopeptidase 3 (MMP-3), SMAD2, SMAD3, caspase-8, caspase-9, and miR-214 in order to reveal the rCTII-induced signaling pathways in melanoma. Our results have shown that two regions of amino acids, 6-16 and 19-44, as predicted epitopes of this toxin, are essential for understanding the toxicity of rCTII. Treating the melanoma cells with rCTII substantially inhibited the transforming growth factor-beta (TGF-β)-SMAD signaling pathway and down-regulated the expression of MMP-3 and miR-214 as well. This cytotoxin also restored apoptosis mainly via the intrinsic pathway. The down-regulation of MMP-3 and miR-214 might be associated with the anti-metastatic property of rCTII in melanoma. The inhibitory effect of rCTII on the TGF-β signaling pathway might be associated with increased apoptosis and decreased cancer cell proliferation. It is interesting to see that the IC50 value of rCTII has been lower in the melanoma cells than non-tumoral cells, which may indicate its potential effects as a drug. In conclusion, rCTII, as a novel medication, might serve as a potent and efficient anticancer drug in melanoma.

Signaling pathways and microRNAs, the orchestrators of NANOG activity during cancer induction

Cancer stem cells (CSCs) are a small part of cancer cells inside the tumor that have similar characteristics to normal stem cells. CSCs stimulate tumor initiation and progression in a variety of cancers. Several transcription factors such as NANOG, SOX2, and OCT4 maintain the characteristics of CSCs and their upregulation is seen in many malignancies resulting in increased metastasis, invasion, and recurrence. Among these factors, NANOG plays an important role in regulating the self-renewal and pluripotency of CSCs and the clinical significance of NANOG has been suggested as a marker of CSCs in many cancers. The up and down-regulation of NANOG is associated with several important signaling pathways, including JAK/STAT, Wnt/β-catenin, Notch, TGF-β, Hedgehog, and several microRNAs (miRNAs). In this review, we will investigate the function of NANOG in CSCs and the molecular mechanism of its regulation by signaling pathways and miRNAs. We will also investigate targeting NANOG with different techniques, which is a promising treatment strategy for cancer treatment.

SRF Potentiates Colon Cancer Metastasis and Progression in a microRNA-214/PTK6-Dependent Manner

Objective

Serum response factor (SRF), a sequence-specific transcription factor, is closely related to metastasis of gastric cancer, a digestive tract cancer. Herein, we probed the effect of SRF on metastasis and progression of colon cancer (CC), another digestive tract disorder, and the detailed mechanism.

Methods

Microarray analysis was conducted on tumor and adjacent tissues to filter differentially expressed miRNA, followed by RT-qPCR validation in CC cell lines. The transcription factor and the target gene of microRNA-214 (miR-214) were predicted, and their binding relationships were tested by luciferase reporter assays and ChIP assays. Subsequently, SRF and protein tyrosine kinase 6 (PTK6) expression in CC patients and cells was evaluated by RT-qPCR, while JAK2 and STAT3 expression in cells by Western blot analysis. To further explore functions of miR-214, PTK6 and SRF on CC, CC cells were delivered with si-PTK6, miR-214 mimic and/or SRF overexpression.

Results

miR-214 expressed poorly in CC tissues and cell lines, which related to advanced TNM staging and survival. miR-214 mimic inhibited proliferation, migration, invasion, xenograft tumor growth and metastasis of CC cells. SRF, overexpressed in CC samples and cells, suppressed the transcription of miR-214. Meanwhile, SRF upregulation counteracted the inhibitory role of miR-214 mimic in CC cell growth. miR-214 negatively regulated PTK6 expression to impair the JAK2/STAT3 pathway activation, thereby halting CC cell proliferation, migration, invasion, xenograft tumor growth and metastasis.

Conclusion

Altogether, miR-214 may perform as a tumor suppressor in CC, and the SRF/miR-214/PTK6/JAK2/STAT3 axis could be applied as a biomarker and potential therapeutic target.

Long non-coding RNA LINC00460 promotes proliferation and inhibits apoptosis of cervical cancer cells by targeting microRNA-503-5p

Long non-coding RNAs are associated with the pathogenesis of cancers. Moreover, LINC00460 is involved in the development of multiple cancers. However, the function of LINC00460 in cervical cancer (CC) remains inconclusive. Herein, CC tissues and tumor-adjacent tissues were collected from patients. The effect of LINC00460 silencing in cell proliferation and apoptosis in CC was explored in vitro and in vivo. Additionally, the interaction between LINC00460 and miR-503-5p was analyzed using dual luciferase reporter assay. The expression of genes and proteins was assayed using quantitative real-time PCR, western blotting and immunohistochemistry, cell viability using MTT assay, cell cycle distribution using flow cytometry, cell apoptosis using Annexin V staining, Hoechst staining and TUNEL assay. LINC00460 levels in CC tissues were higher than tumor-adjacent tissues. LINC00460 silencing suppressed proliferation and promoted apoptosis of CC cells as evidenced by decreased cell viability, inhibited proliferation-related protein and cell cycle protein expressions and G1/S transition, increased apoptotic cells and Hoechst-positive cells, and enhanced apoptosis-related protein expressions. LINC00460 could bind to miR-503-5p and LINC00460 silencing enhanced miR-503-5p expression and inhibited its target gene expressions in CC cells. MiR-503-5p inhibition reversed LINC00460 silencing-caused inhibition of cell proliferation and miR-503-5p target gene expressions, and promotion of cell apoptosis. LINC00460 silencing also attenuated tumor growth, promoted miR-503-5p levels and cell apoptosis, and inhibited cell proliferation and miR-503-5p target gene expressions in tumor tissues. Hence, LINC00460 functioned as an oncogene in CC that affected cell proliferation and apoptosis via sponging miR-503-5p. This study provides a novel therapeutic target for CC.

circ_0084927 promotes cervical carcinogenesis by sponging miR-1179 that suppresses CDK2, a cell cycle-related gene

Background

Cervical cancer (CC) is a malignant tumor found in the lowermost part of the womb. Evolving studies on CC have reported that circRNA plays a crucial role in CC progression. In this study, we investigated the main function of a novel circRNA, circ_0084927, and its regulatory network in CC development.

Methods

qRT-PCR was applied to evaluate the expression of circ_0084927, miR-1179, and CDK2 mRNA in CC tissues and cells. Dual-luciferase reporting experiments and RNA immunoprecipitation (RIP) assay were conducted to validate the target relationship of miR-1179 with circ_0084927 and CDK2 mRNA. CCK-8 and BrdU assays were also used to evaluate CC cell proliferation. The adhesion and apoptosis phenotypes of CC cells were measured using cell–matrix adhesion and caspase 3 activation assay. Flow cytometry was also employed to detect the CC cell cycle.

Results

Our results indicated that circ_0084927 was up-regulated in CC tissues and cells. Findings also revealed that circ_0084927 silence inhibited CC cell proliferation and adhesion while facilitating apoptosis and triggering cell cycle arrest. However, miR-1179 down-regulation appeared in CC tissues. Apart from observing that circ_0084927 abolished miR-1179’s inhibitory effects on cell proliferation and adhesion, it was found that CDK2 was up-regulated in CC tissues and was instrumental in cancer promotion. Also observed was that miR-1179 directly targeted CDK2, thereby inhibiting CDK2’s promotion on the malignant phenotypes of CC cells. Lastly, results indicated that circ_0084927 revoked the inhibitory effect of miR-1179 on CDK2 by sponging miR-1179.

Conclusion

circ_0084927 promoted cervical carcinogenesis by sequestering miR-1179, which directly targeted CDK2. Our results also provided novel candidate targets for CC treatment in that it revealed the circ_0084927/miR-1179/CDK2 regulatory network that strengthened CC aggressiveness.

CREB1-induced miR-1204 promoted malignant phenotype of glioblastoma through targeting NR3C2

Background

Glioblastoma (GBM) is a subclass of brain malignancy with unsatisfactory prognosis. MicroRNAs (miRNAs) are a group of non-coding RNAs (ncRNAs) that exert key function on tumorigenesis and tumor development.

Purposes

The purpose of this work was to unravel the biological behavior and mechanism of miR-1204 in GBM.

Methods

Expressions of miR-1204, NR3C2 and CREB1 were detected by RT-qPCR and western blot. Proliferation and apoptosis of GBM cells were detected by CCK-8, colony formation, caspase-3 activity and TUNEL assays. Molecular interplays were examined by ChIP, RIP, and luciferase reporter assays.

Results

MiR-1204 level was elevated in GBM cell lines. Functionally, miR-1204 aggravated cell proliferation whereas suppressed cell apoptosis in GBM cells. Mechanistically, cAMP Responsive Element Binding Protein 1 (CREB1) bound to the promoter of miR-1204 and activated the transcription of miR-1204. Furthermore, miR-1204 targeted and inhibited Nuclear receptor subfamily 3 group C member 2 (NR3C2), a tumor suppressor gene in GBM cells. Rescue assays indicated that NR3C2 participated in the regulation of miR-1204 on the malignant phenotype of GBM cells.

Conclusions

We observed for the first time that CREB1-induced miR-1204 promoted malignant phenotype of GBM through targeting NR3C2, indicating that miR-1204 acted as a novel oncogenic miRNA in GBM.

The Repertoire of Serous Ovarian Cancer Non-genetic Heterogeneity Revealed by Single-Cell Sequencing of Normal Fallopian Tube Epithelial Cells

The inter-differentiation between cell states promotes cancer cell survival under stress and fosters non-genetic heterogeneity (NGH). NGH is, therefore, a surrogate of tumor resilience but its quantification is confounded by genetic heterogeneity. Here we show that NGH in serous ovarian cancer (SOC) can be accurately measured when informed by the molecular signatures of the normal fallopian tube epithelium (FTE) cells, the cells of origin of SOC. Surveying the transcriptomes of ∼6,000 FTE cells, predominantly from non-ovarian cancer patients, identified 6 FTE subtypes. We used subtype signatures to deconvolute SOC expression data and found substantial intra-tumor NGH. Importantly, NGH-based stratification of ∼1,700 tumors robustly correlated with survival. Our findings lay the foundation for accurate prognostic and therapeutic stratification of SOC.

High-mobility group A1 (HMGA1) gene expressions in various colorectal cancer cell lines and correlation with prognosis

BACKGROUND

The high-mobility group A1 gene (HMGA1) plays a major role in the development of malignant cancers. However, the mechanisms underlying the correlation between HMGA1 expression level and patients' overall survival rate in various malignant cancers is unclear.

METHODS

We used The Cancer Genome Atlas (TCGA) database (https://genome-cancer.ucsc.edu/) to search for mRNA expression levels of HMGA1 in tumor patients and grouped them by receiver operating characteristic (ROC) curve. This divided patients into a high expression cohort and low expression cohort, and Kaplan-Meier analysis revealed the overall survival of the cancer patients. We also used real-time quantitative PCR (qPCR) to detect the expression of HMGA1, CBX7, E-cadherin, and β-catenin gene was detected by normalized to the expression of β-actin in colorectal cancer cell lines.

RESULTS

High expression group correlated with worse survival prognosis statistically significant (P<0.05), and scatter plots showed HMGA1 high expression in the different cancers (lung cancers; lung adenocarcinoma and lung squamous cell carcinoma; stomach and colorectal cancers; liver and pancreatic cancer; kidney papillary cell carcinoma; kidney clear cell carcinoma, brain lower grade glioma; adrenocortical cancer; acute myeloid leukemia; and sarcoma; head and neck squamous cell carcinoma, cholangio and bladder urothelial cancers). Further, we also found that the mRNA expressions of HMGA1, CBX7, E-cadherin, and β-catenin genes significantly in colorectal cancer cell lines (P value: 0.0005), consistent with the results of HMGA1 in TCGA database.

CONCLUSIONS

HMGA1 is highly expressed in various cancers than normal tissues, and high expression levels of HMGA1 correlated with a worse prognosis. The gene expressions and the TCGA data clearly supports that targeting HMGA1 in the management of cancers increases the survival rate of cancer patients.

High Mobility Group A (HMGA): Chromatin Nodes Controlled by a Knotty miRNA Network

High mobility group A (HMGA) proteins are oncofoetal chromatin architectural factors that are widely involved in regulating gene expression. These proteins are unique, because they are highly expressed in embryonic and cancer cells, where they play a relevant role in cell proliferation, stemness, and the acquisition of aggressive tumour traits, i.e., motility, invasiveness, and metastatic properties. The HMGA protein expression levels and activities are controlled by a connected set of events at the transcriptional, post-transcriptional, and post-translational levels. In fact, microRNA (miRNA)-mediated RNA stability is the most-studied mechanism of HMGA protein expression modulation. In this review, we contribute to a comprehensive overview of HMGA-targeting miRNAs; we provide detailed information regarding HMGA gene structural organization and a comprehensive evaluation and description of HMGA-targeting miRNAs, while focusing on those that are widely involved in HMGA regulation; and, we aim to offer insights into HMGA-miRNA mutual cross-talk from a functional and cancer-related perspective, highlighting possible clinical implications.

HMGA Proteins in Stemness and Differentiation of Embryonic and Adult Stem Cells

HMGA1 and HMGA2 are chromatin architectural proteins that do not have transcriptional activity per se, but are able to modify chromatin structure by interacting with the transcriptional machinery and thus negatively or positively regulate the transcription of several genes. They have been extensively studied in cancer where they are often found to be overexpressed but their functions under physiologic conditions have still not been completely addressed. Hmga1 and Hmga2 are expressed during the early stages of mouse development, whereas they are not detectable in most adult tissues. Hmga overexpression or knockout studies in mouse have pointed to a key function in the development of the embryo and of various tissues. HMGA proteins are expressed in embryonic stem cells and in some adult stem cells and numerous experimental data have indicated that they play a fundamental role in the maintenance of stemness and in the regulation of differentiation. In this review, we discuss available experimental data on HMGA1 and HMGA2 functions in governing embryonic and adult stem cell fate. Moreover, based on the available evidence, we will aim to outline how HMGA expression is regulated in different contexts and how these two proteins contribute to the regulation of gene expression and chromatin architecture in stem cells.

miRNA Regulation of Glutathione Homeostasis in Cancer Initiation, Progression and Therapy Resistance

Glutathione (GSH) is the most abundant antioxidant that contributes to regulating the cellular production of Reactive Oxygen Species (ROS) which, maintained at physiological levels, can exert a function of second messengers in living organisms. In fact, it has been demonstrated that moderate amounts of ROS can activate the signaling pathways involved in cell growth and proliferation, while high levels of ROS induce DNA damage leading to cancer development. Therefore, GSH is a crucial player in the maintenance of redox homeostasis and its metabolism has a role in tumor initiation, progression, and therapy resistance. Our recent studies demonstrated that neuroblastoma cells resistant to etoposide, a common chemotherapeutic drug, show a partial monoallelic deletion of the locus coding for miRNA 15a and 16-1 leading to a loss of these miRNAs and the activation of GSH-dependent responses. Therefore, the aim of this review is to highlight the role of specific miRNAs in the modulation of intracellular GSH levels in order to take into consideration the use of modulators of miRNA expression as a useful strategy to better sensitize tumors to current therapies.

Circular RNA hsa_circ_0000515 acts as a miR-326 sponge to promote cervical cancer progression through up-regulation of ELK1

This study investigates the role of circular RNA (circRNA) hsa_circ_0000515 in cervical cancer and the underlying mechanism associated with microRNA-326 (miR-326). hsa_circ_0000515 and ETS transcription factor ELK1 (ELK1) were initially over-expressed and miR-326 was down-regulated in cervical cancer tissues and cells. Low hsa_circ_0000515 expression was found to be associated with favorable prognosis of patients with cervical cancer. A series of mimics, inhibitors, over-expression plasmids or siRNAs were introduced into cervical cancer cells to alter the expression of hsa_circ_0000515, miR-326 and ELK1. In vitro experiments exhibited that silencing of hsa_circ_0000515 or upregulation of miR-326 resulted in suppressed proliferation and invasion, along with induced apoptosis and autophagy of cervical cancer cells. Dual-luciferase reporter assay, RNA pull-down and RIP assays highlighted that hsa_circ_0000515 was able to act as a ceRNA of miR-326 to increase ELK1. Furthermore, enhancement of ELK1 expression resulted in enhanced proliferation and invasion but repressed apoptosis and autophagy of cervical cancer cells. In vivo experiments further confirmed the suppressed tumor growth by hsa_circ_0000515 silencing. Our findings demonstrated that hsa_circ_0000515 acts as a tumor promoter in cervical cancer. The study provides evidence for targeting hsa_circ_0000515 for therapeutic purposes in treating cervical cancer.

miR-214 down-regulates MKK3 and suppresses malignant phenotypes of cervical cancer cells

miRNA mediated genetic regulation is widely involved in carcinogenesis of cervical cancer. In this study, miR-214 was confirmed to directly regulate MKK3 via imperfect base-pairing to its 3'UTR, resulting down-regulation of its expression level. Compared to normal tissues, a down-regulated level of miR-214 was observed in cervical cancer, while MKK3 was up-regulated. Next, we demonstrated that over-expression of miR-214 or knockdown of MKK3 can inhibit the growth, proliferation, invasion and migration of cervical cancer in vitro and in vivo. Moreover, the effects of miR-214 in HeLa cells were rescued by the restoration of MKK3. In conclusion, our results laid new foundations for investigating the pathogenesis and diagnosis of cervical cancer.

Identification and performance evaluation of housekeeping genes for microRNA expression normalization by reverse transcription-quantitative PCR using liquid-based cervical cytology samples

Screening for cervical cancer by cytology has been effective in reducing the worldwide incidence and mortality rates of this disease. However, a number of studies have demonstrated that the sensitivity of conventional cervical cytology may be too low for detection of cervical intraepithelial neoplasias (CIN). Therefore, it is important to incorporate more sensitive molecular diagnostic tests that could substantially improve the detection rates and accuracy for identifying CIN lesions. MicroRNAs (miRNAs) are a class of small non-coding RNAs with the potential to provide robust non-invasive cancer biomarkers for detecting CIN lesions in liquid-based cervical cytology (LBC) samples. At present, there is no consensus on which are the best housekeeping genes for miRNA normalization in LBC. The present study aimed to identify housekeeping genes with consistent and reproducible performance for normalization of reverse transcription-quantitative PCR (RT-qPCR) expression analysis of miRNA using LBC samples. The present study firstly selected six potential candidate housekeeping genes based on a systematic literature evaluation. Subsequently, the expression levels of microRNAs U6, RNU-44, RNU-47, RNU-48, RNU-49 and hsa-miR-16 were measured in 40 LBC samples using RT-qPCR. The stability of each potential housekeeping gene was assessed using the NormFinder algorithm. The results revealed that U6 and RNU-49 were the most stable genes among all candidates requiring fewer amplification cycles and smaller variation across the sample set. However, RNU-44, RNU-47, RNU-48 and hsa-miR-16 stability exceeded the recommended housekeeping value suitable for normalization. The findings revealed that U6 may be a reliable housekeeping gene for normalization of miRNA RT-qPCR expression analysis using LBC samples.

Long non-coding RNA LINC01535 promotes cervical cancer progression via targeting the miR-214/EZH2 feedback loop

Long non‐coding RNAs (lncRNAs) have shown critical roles in multiple cancers via competitively binding common microRNAs. miR‐214 has been proved to play tumour suppressive roles in various cancers, including cervical cancer. In this study, we identified that lncRNA LINC01535 physically binds miR‐214, relieves the repressive roles of miR‐214 on its target EZH2, and therefore up‐regulates EZH2 protein expression. Intriguingly, we also found that EZH2 directly represses the expression of miR‐214. Thus, miR‐214 and EZH2 form double negative regulatory loop. Through up‐regulating EZH2, LINC01535 further represses miR‐214 expression. Functional experiments showed that enhanced expression of LINC01535 promotes cervical cancer cell growth, migration and invasion in vitro and cervical cancer xenograft growth in vivo. Reciprocally, LINC01535 knockdown suppresses cervical cancer cell growth, migration and invasion. Activation of the miR‐214/EZH2 regulatory loop by overexpression of miR‐214 or silencing of EZH2 reverses the roles of LINC01535 in promoting cervical canc`er cell growth, migration and invasion in vitro and cervical cancer xenograft growth in vivo. Clinically, LINC01535 is significantly up‐regulated in cervical cancer tissues and correlated with advanced clinical stage and poor prognosis. Moreover, the expression of LINC01535 is reversely associated with the expression of miR‐214 and positively associated with the expression of EZH2 in cervical cancer tissues. In conclusion, this study reveals that LINC01535 promotes cervical cancer progression via repressing the miR‐214/EZH2 regulatory loop.

MicroRNA-214 targets PTK6 to inhibit tumorigenic potential and increase drug sensitivity of prostate cancer cells

Prostate cancer is the most commonly diagnosed cancer in men with African American men disproportionally suffering from the burden of this disease. Biomarkers that could discriminate indolent from aggressive and drug resistance disease are lacking. MicroRNAs are small non-coding RNAs that affect numerous physiological and pathological processes, including cancer development and have been suggested as biomarkers and therapeutic targets. In the present study, we investigated the role of miR-214 on prostate cancer cell survival/migration/invasion, cell cycle regulation, and apoptosis. miR-214 was differentially expressed between Caucasian and African American prostate cancer cells. Importantly, miR-214 overexpression in prostate cancer cells induced apoptosis, inhibiting cell proliferation and colony forming ability. miR-214 expression in prostate cancer cells also inhibited cell migration and 3D spheroid invasion. Mechanistically, miR-214 inhibited prostate cancer cell proliferation by targeting protein tyrosine kinase 6 (PTK6). Restoration of PTK6 expression attenuated the inhibitory effect of miR-214 on cell proliferation. Moreover, simultaneous inhibition of PTK6 by ibrutinib and miR-214 significantly reduced cell proliferation/survival. Our data indicates that miR-214 could act as a tumor suppressor in prostate cancer and could potentially be utilized as a biomarker and therapeutic target.

Molecular characterization of carcinosarcomas arising in the uterus and ovaries

Gynaecological carcinosarcomas are rare biphasic tumours which are highly aggressive. We performed molecular investigations on a series of such tumours arising in the uterus (n = 16) and ovaries (n = 10) to gain more information on their mutational landscapes and the expression status of the genes HMGA1/2, FHIT, LIN28A, and MTA1, the pseudogenes HMGA1P6 and HMGA1P7, and the miRNAs known to influence expression of the above-mentioned genes. In uterine carcinosarcomas (UCS), we identified mutations in KRAS, PIK3CA, and TP53 with a frequency of 6%, 31%, and 75%, respectively, whereas in ovarian carcinosarcomas (OCS), TP53 was the only mutated gene found (30%). An inverse correlation was observed between overexpression of HMGA1/2, LIN28A, and MTA1 and downregulation of miRNAs such as let-7a, let-7d, miR26a, miR16, miR214, and miR30c in both UCS and OCS. HMGA2 was expressed in its full length in 14 UCS and 9 OCS; in the remaining tumours, it was expressed in its truncated form. Because FHIT was normally expressed while miR30c was downregulated, not both downregulated as is the case in several other carcinomas, alterations of the epithelial-mesenchymal transition through an as yet unknown mechanism seems to be a feature of carcinosarcomas.

MicroRNA‑214 suppresses the viability, migration and invasion of human colorectal carcinoma cells via targeting transglutaminase 2

Colorectal carcinoma (CRC) is a common malignancy of the digestive tract. MicroRNA (miR)-214 is considered a key hub that controls tumor networks; therefore, the effects of miR-214 on CRC were examined and its target gene was investigated in this study. The expression levels of transglutaminase 2 (TGM2) and miR-214 were detected in CRC and adjacent normal tissues by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting, and luciferase activity was analyzed by dual luciferase reporter analysis. In addition, cell viability, invasion and migration were measured by Cell Counting kit-8 and Transwell assays, respectively. The expression levels of epithelial-mesenchymal transition-related proteins, and phosphoinositide-3 kinase (PI3K)/protein kinase B (Akt) signaling-associated factors were detected using RT-qPCR and western blotting. The results demonstrated that miR-214 expression was downregulated in CRC tissue, whereas TGM2 expression was upregulated. According to TargetScan prediction, miR-214 possesses a binding site to TGM2. In addition, transfection with miR-214 mimics markedly suppressed the viability of LoVo cells. miR-214 overexpression also inhibited cell invasion and migration by increasing E-cadherin and tissue inhibitor of metalloproteinases-2 expression, and decreasing matrix metalloproteinase (MMP)-2 and MMP-9 expression. Furthermore, miR-214 downregulated phosphorylation of PI3K and Akt; however, the expression levels of total PI3K and Akt were not affected by miR-214. In conclusion, this study indicated that TGM2 was a target gene of miR-214, and a negative correlation between miR-214 and TGM2 expression was determined in CRC. Notably, miR-214 markedly suppressed the viability, invasion and migration of CRC cells, which may be associated with a downregulation in PI3K/Akt signaling. These findings suggested that miR-214 may be considered a novel target for the treatment of CRC.

MicroRNA Dysregulation in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and it can be locally invasive and metastatic to distant sites. MicroRNAs (miRNAs or miRs) are endogenous, small, non-coding RNAs of 19–25 nucleotides in length, that are involved in regulating gene expression at a post-transcriptional level. MicroRNAs have been implicated in diverse biological functions and diseases. In cancer, miRNAs can proceed either as oncogenic miRNAs (onco-miRs) or as tumor suppressor miRNAs (oncosuppressor-miRs), depending on the pathway in which they are involved. Dysregulation of miRNA expression has been shown in most of the tumors evaluated. MiRNA dysregulation is known to be involved in the development of cutaneous squamous cell carcinoma (CSCC). In this review, we focus on the recent evidence about the role of miRNAs in the development of CSCC and in the prognosis of this form of skin cancer.

GRSF1-mediated MIR-G-1 promotes malignant behavior and nuclear autophagy by directly upregulating TMED5 and LMNB1 in cervical cancer cells

Emerging evidence has revealed that miRNAs could upregulate the expression levels of target genes. However, the molecular mechanism underlying upregulation of targets mediated by miRNAs remains unclear. In this study, we found a novel miRNA named MIR-G-1 by GRSF1-RNA immunoprecipitation (RIP)-deep sequencing, which could directly target and upregulate LMNB1 and TMED5 in a GRSF1-dependent manner in cervical cancer cells. In addition, upregulated MIR-G-1 in cervical cancer promoted a malignant phenotype in vitro and in vivo. TMED5 could interact with WNT7B and thus activated the canonical WNT-CTNNB1/β-catenin signaling pathway. MIR-G-1 mediated the activation of this pathway. Furthermore, MIR-G-1 promoted serum starvation-induced nuclear macroautophagy/autophagy, and accelerated taxol (TAX)-induced DNA-damage repair in cervical cancer cells. Collectively, these findings may provide a new insight into the upregulation mechanism and nuclear autophagy mediated by miRNAs and provide a potential biomarker for cervical cancer. Abbreviations: 3'UTR: 3' untranslated region; EMSA: electrophoretic mobility shift assay; EMT: epithelial-mesenchymal transition; GRSF1: G-rich RNA sequence binding factor 1; IF: immunofluorescence; IP: immunoprecipitation; IHC: immunohistochemistry; lnc: long noncoding; miRNA:microRNA; TAX: taxol; TMED5: transmembrane p24 trafficking protein 5.

HMGA1 in cancer: Cancer classification by location

The high mobility group A1 (HMGA1) gene plays an important role in numerous malignant cancers. HMGA1 is an oncofoetal gene, and we have a certain understanding of the biological function of HMGA1 based on its activities in various neoplasms. As an architectural transcription factor, HMGA1 remodels the chromatin structure and promotes the interaction between transcriptional regulatory proteins and DNA in different cancers. Through analysis of the molecular mechanism of HMGA1 and clinical studies, emerging evidence indicates that HMGA1 promotes the occurrence and metastasis of cancer. Within a similar location or the same genetic background, the function and role of HMGA1 may have certain similarities. In this paper, to characterize HMGA1 comprehensively, research on various types of tumours is discussed to further understanding of the function and mechanism of HMGA1. The findings provide a more reliable basis for classifying HMGA1 function according to the tumour location. In this review, we summarize recent studies related to HMGA1, including its structure and oncogenic properties, its major functions in each cancer, its upstream and downstream regulation associated with the tumourigenesis and metastasis of cancer, and its potential as a biomarker for clinical diagnosis of cancer.

Epigenetic Regulation by lncRNAs: An Overview Focused on UCA1 in Colorectal Cancer

Colorectal cancers have become the second leading cause of cancer-related deaths. In particular, acquired chemoresistance and metastatic lesions occurring in colorectal cancer are a major challenge for chemotherapy treatment. Accumulating evidence shows that long non-coding (lncRNAs) are involved in the initiation, progression, and metastasis of cancer. We here discuss the epigenetic mechanisms through which lncRNAs regulate gene expression in cancer cells. In the second part of this review, we focus on the role of lncRNA Urothelial Cancer Associated 1 (UCA1) to integrate research in different types of cancer in order to decipher its putative function and mechanism of regulation in colorectal cancer cells. UCA1 is highly expressed in cancer cells and mediates transcriptional regulation on an epigenetic level through the interaction with chromatin modifiers, by direct regulation via chromatin looping and/or by sponging the action of a diversity of miRNAs. Furthermore, we discuss the role of UCA1 in the regulation of cell cycle progression and its relation to chemoresistance in colorectal cancer cells.

microRNA-214 suppresses the growth of cervical cancer cells by targeting EZH2

A number of studies have revealed the significance of microRNAs (miRs) in tumorigenesis. Cervical cancer (CC) is one of the most malignant cancer types and is associated with a poor overall survival rate. A previous study demonstrated a critical role of miR-214 in the development of multiple cancer types, but its role in CC remains elusive. In the current study, miR-214 was observed to be downregulated in CC tissues compared with the adjacent non-cancerous tissue. Overexpression of miR-214 reduced the proliferation of CC cells, whereas inhibiting its expression resulted in enhanced proliferation. Furthermore, Enhancer of zeste homolog 2 (EZH2) was demonstrated to be a direct target of miR-214 in CC. An MTT assay demonstrated that upregulating miR-214 expression or knocking down the expression of EZH2 impaired the proliferation of a CC cell line. Low expression of miR-214 was positively associated with tumor differentiation (P=0.037) and tumor stage (P=0.012). Notably, low expression of miR-214 predicted poor prognosis of patients with CC. Consequently, the results of the current study demonstrated that miR-214 functions as a tumor suppressor in CC and may be regarded as a potential therapeutic target in CC.

HMGA1 exacerbates tumor growth through regulating the cell cycle and accelerates migration/invasion via targeting miR-221/222 in cervical cancer

High-mobility group AT-hook1 (HMGA1, formerly HMG-I/Y), an architectural transcription factor, participates in a number of tumor biological processes. However, its effect on cervical cancer remains largely indistinct. In this study, we found that HMGA1 was generally overexpressed in cervical cancer tissues and was positively correlated with lymph node metastasis and advanced clinical stage. Via exogenously increasing or decreasing the expression of HMGA1, we showed that HMGA1 affected the proliferation, colony formation, migration and invasion of cervical cancer cells in vitro. Rescue experiments suggested that miR-221/222 could partly reverse HMGA1-mediated migration and invasion processes. Mechanistically, we discovered that HMGA1 accelerated the G1/S phase transition by regulating the expression of cyclin D1 and cyclin E1, which was consistent with the results of the in vivo experiment. Furthermore, we found that HMGA1 regulated the expression of the miR-221/222 cluster at the transcriptional level and that miR-221/222 targeted the 3'UTR of tissue inhibitor of metalloproteinases 3(TIMP3). We propose a fresh perspective that HMGA1 participates in the migration and invasion process via the miR-221/222-TIMP3-MMP2/MMP9 axis in cervical cancer. In summary, our study identified a critical role played by HMGA1 in the progression of cervical cancer and the potential mechanisms by which exerts its effects, suggesting that targeting HMGA1-related pathways could be conducive to the therapies for cervical cancer.

MicroRNA‑539 inhibits the proliferation and invasion of bladder cancer cells by regulating IGF‑1R

Bladder cancer is the most frequent malignancy of the urinary tract and the seventh most common cancer worldwide. The abnormal expression of microRNAs has been frequently observed in various types of human cancers, including bladder cancer. In addition, an increasing body of evidence has demonstrated that microRNAs are potential targets for cancer diagnosis, treatments and prognosis. The aim of the present study was to investigate the expression patterns and potential roles of microRNA‑539 (miR‑539) in bladder cancer and its underlying mechanism. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to detect miR‑539 expression in the bladder cancer tissues and cell lines. Following transfection, MTT and cell invasion assays were used to investigate the effects of miR‑539 overexpression or IGF1R underexpression on bladder cancer cell proliferation and invasion. Bioinformatics analysis, a luciferase reporter assay, RT‑qPCR and western blot analysis were utilized to determine the potential targets of miR‑539 in bladder cancer. The results revealed that miR‑539 levels were relatively decreased in bladder cancer tissues and cell lines when compared with those observed in the matched adjacent normal bladder tissues and normal bladder epithelial cell line. miR‑539 expression was associated with the tumor stage and lymph node metastasis of patients with bladder cancer. In addition, the expression of miR‑539 suppressed bladder cancer cell proliferation and invasion. Insulin like growth factor 1 receptor (IGF‑1R) was identified as a direct target of miR‑539, and miR‑539 was also observed to regulate the protein kinase B and extracellular signal‑regulated kinases signaling pathways. IGF‑1R was markedly upregulated in bladder cancer tissues and negatively associated with miR‑539 expression levels. Furthermore, IGF‑1R knockdown in bladder cancer cells significantly inhibited cell proliferation and invasion. To the best of our knowledge, these results demonstrated for the first time that miR‑539 may act as a tumor suppressor and serve important roles in tumorigenesis and progression of bladder cancer. Thus, miR‑539/IGF‑1R may be a potential therapeutic target for the treatment of bladder cancer.

microRNA-363-3p inhibits cell growth and invasion of non‑small cell lung cancer by targeting HMGA2

Lung cancer is the second most common cancer and is the leading cause of cancer-related death worldwide. For decades, increasing evidence revealed that microRNAs may contribute to non‑small cell lung cancer (NSCLC) carcinogenesis and progression and could provide novel therapeutic targets for treatments of patients with NSCLC. Accumulated studies indicate that microRNA (miR)‑363‑3p serves important roles in tumorigenesis and tumor development; however, the role of miR‑363‑3p in NSCLC is still unclear. The current study reported that miR‑363‑3p exhibited reduced expression in NSCLC tissues and cell lines. Reduced miR‑363‑3p expression was correlated with tumor node metastasis classification and distant metastasis of NSCLC patients. Notably, miR‑363‑3p re‑expression significantly suppressed cell proliferation and invasion of NSCLC. Furthermore, bioinformatics analysis, luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction and western blotting indicated that (high mobility group AT-hook 2) HMGA2 was a direct target gene of miR‑363‑3p. HMGA2 was increased in NSCLC tissues and inversely associated with HMGA2 expression. Moreover, HMGA2 underexpression had similar effects to miR‑363‑3p overexpression in NSCLC cells. Thus, the current study suggested that miR‑363‑3p may act as a tumor suppressor in NSCLC and that the miR‑363‑3p could be investigated as a therapeutic target for the patients with this disease.

Thyroid hormone inhibits growth of hepatoma cells through induction of miR-214

Thyroid hormone (TH) plays a role in regulating the metabolic rate, heart functions, muscle control and maintenance of bones. 3,3′5-tri-iodo-L-thyronine (T₃) displays high affinity to nuclear thyroid hormone receptors (TRs), which mediate most TH actions. Recent studies have shown hypothyroidism in patients with an increased risk of hepatocellular carcinoma (HCC). MicroRNAs (miRNAs), a class of non-protein-coding RNA, are suggested to control tumor growth by interacting with target genes. However, the clinical significance of T₃/TR-regulated miRNAs in tumors has yet to be established. In the current study, miRNA expression profile screening was performed using SYBR Green-Based qRT-PCR array in TR-overexpressing HepG2 cells. miR-214-3p, which is expressed at low levels in HCC, was stimulated upon T₃ application. The 3′UTR luciferase reporter assay confirmed that the proto-oncogene serine/threonine-protein kinase, PIM-1, is a miR-214-3p target. PIM-1 was decreased upon treatment with miR-214-3p or T₃ stimulation. PIM-1 was highly expressed in HCC, and the effect of PIM-1 on cell proliferation might be mediated by the inhibition of p21. Furthermore, the T₃-induced suppression of cell proliferation was partially rescued upon miR-214-3p knockdown. Our data demonstrate that T₃ induces miR-214-3p expression and suppresses cell proliferation through PIM-1, thus contributing to the inhibition of HCC tumor formation.

miR-214 activates TP53 but suppresses the expression of RELA, CTNNB1, and STAT3 in human cervical and colorectal cancer cells

High Mobility Group AT-hook 1 (HMGA1) was identified as a target of miR-214 in human cervical and colorectal cancers (CaCx and CRC) in a previous study. While the expression of miR-214 remains suppressed, HMGA1 behaves as a potent oncogene and plays crucial roles in several aberrant signalling pathways by interacting with intermediates like RELA, CTNNB1, STAT3, and TP53 in CaCx and CRC. Hypothetically, miR-214 should be able to regulate the stabilization of some of these intermediates through the regulation of HMGA1. This was assessed by ectopically expressing miR-214 or complementarily, by inhibiting the expression of HMGA1. In promoter luciferase assays, miR-214 inhibited NF-κB and Wnt activities but elevated TP53 activity in cancer cells. Further, miR-214 suppressed the expression of HMGA1, RELA, CTNNB1, and STAT3 while elevating TP53 levels, similar to when small interfering RNA (siRNA) against HMGA1 was used, as revealed by Western blotting. It is suggested that poor expression of miR-214, commonly reported in CaCx and CRC tissues, may not only result in the sustained expression of HMGA1 but also that of RELA, CTNNB1, and STAT3, and a congruent suppression of TP53 during cancer initiation/progression. These several states are, however, reversed when miR-214 is reintroduced and could explain the tumour suppressive functions observed in earlier studies. Further studies are, however, required to reveal how microRNA-mediated regulation of HMGA1 expression may affect individual signalling pathways in CaCx and CRC. Current results reveal that miR-214 is not only able to regulate the expression of its direct target, HMGA1, but also that of a few signalling intermediates like TP53, RELA, CTNNB1, and STAT3, with which HMGA1 interacts. These intermediates play crucial roles in signalling pathways commonly deregulated in human CaCx and CRC. Hence, it is proposed that miR-214 might act as a tumour suppressor by regulating several aberrant signalling pathways through HMGA1. This knowledge has the potential to help design novel therapeutic strategies in CaCx and CRC.

Circulating microRNA-214 and -126 as potential biomarkers for canine neoplastic disease

Circulating microRNAs in the blood may provide diagnostic and prognostic information about canine neoplastic diseases, and their profiles may be conserved between human and canine species. We performed RT-qPCR to obtain the profiles of circulating plasma microRNA-214 and -126 in total 181 cases of canine neoplastic diseases and healthy controls. MicroRNA-214 levels were high in 2 epithelial tumours (thyroid and mammary carcinomas) and 4 non-epithelial tumours (osteosarcoma, histiocytic sarcoma, chondrosarcoma, and hemangiosarcoma). In contrast, microRNA-126 levels were high in 6 epithelial tumours (mammary, hepatocellular, squamous cell, thyroid, transitional cell carcinomas, and adenocarcinoma) and 4 non-epithelial tumours (osteosarcoma, mast cell tumour, melanoma, and hemangiosarcoma). The diagnostic potential of microRNA-214 was relatively high in sarcomas, whereas that of microR-126 was high in most types of the tumours. MicroRNA-214 and -126 were prognostic predictors in 2 groups (adenocarcinoma and non-epithelial tumours except for osteosarcoma) and 3 groups (epithelial tumours, adenocarcinoma, and melanoma), respectively. Additionally, the microRNA levels did not show a strong correlation with the other clinical parameters. In conclusion, circulating microRNA-214 and -126 have the potential to be diagnostic and prognostic biomarkers for canine neoplastic diseases. Furthermore, their profiles may be key references as well for exploring novel biomarkers for human cancers.