Overexpressed miR-301a promotes cell proliferation and invasion by targeting RUNX3 in gastric cancer

Multifaceted role of microRNA-301a in human cancer: from biomarker potential to therapeutic targeting

With the growing data on microRNA (miRNA) expression in tissues and circulation, there is increasing evidence for the potential of microRNAs to serve as biomarkers in cancer diagnosis and prognosis, as well as novel therapeutic targets. The expression level of miRNA-301a (miR-301a) is altered in a wide range of human tumor types, and numerous studies have revealed the roles of miR-301a in tumorigenesis and tumor progression. Herein, we comprehensively summarize, compare, and contrast the research advancements on the role of miR-301a in different cancers. Differential expression patterns of miR-301a in tissues and biofluids are implicated in cancer diagnosis, treatment response, and prognosis. MiR-301a modulates the expression of multiple genes, other noncoding RNAs, and signaling cascade via direct or indirect regulation in human cancer proliferation, migration, invasion, angiogenesis, and radio- or chemotherapy resistance. Cancer cell-associated miR-301a affects the tumor microenvironment through the alteration of immune function and cancer metabolism. These findings highlight the functional roles, clinical implications, and therapeutic relevance of miR-301a in various human cancers.

The Clinical Significance of MicroRNAs in Colorectal Cancer Signaling Pathways: A Review

Colorectal carcinoma (colon and rectum) is currently considered among the most prevalent malignancies of Western societies. The pathogenesis and etiological mechanisms underlying colorectal cancer (CRC) development remain complex and heterogeneous. The homeostasis and function of normal human intestinal cells is highly regulated by microRNAs. Therefore, it is not surprising that mutations and inactivation of these molecules appear to be linked with progression of colorectal tumors. Recent studies have reported significant alterations of microRNA expression in adenomas and CRCs compared with adjacent normal tissues. This observed deviation has been proposed to correlate with the progression and survival of disease as well as with choice of optimal treatment and drug resistance. MicroRNAs can adopt either oncogenic or tumor-suppressive roles during regulation of pathways that drive carcinogenesis. Typically, oncogenic microRNAs termed oncomirs, target and silence endogenous tumor-suppressor genes. On the other hand, tumor-suppressive microRNAs are critical in downregulating genes associated with cell growth and malignant capabilities. By extensively evaluating robust studies, we have emphasized and distinguished a discrete set of microRNAs that can modulate tumor progression by silencing specific driver genes crucial in signaling pathways including Wnt/b-catenin, epidermal growth factor receptor, P53, mismatch repair DNA repair, and transforming-growth factor beta.

Micro RNAs as a Diagnostic Marker between Glioma and Primary CNS Lymphoma: A Systematic Review

Differentiating glioma from primary central nervous system lymphoma (PCNSL) can be challenging, and current diagnostic measures such as MRI and biopsy are of limited efficacy. Liquid biopsies, which detect circulating biomarkers such as microRNAs (miRs), may provide valuable insights into diagnostic biomarkers for improved discrimination. This review aimed to investigate the role of specific miRs in diagnosing and differentiating glioma from PCNSL. A systematic search was conducted of PubMed, Scopus, Web of Science, and Embase for articles on liquid biopsies as a diagnostic method for glioma and PCNSL. Sixteen dysregulated miRs were identified with significantly different levels in glioma and PCNSL, including miR-21, which was the most prominent miR with higher levels in PCNSL, followed by glioma, including glioblastoma (GBM), and control groups. The lowest levels of miR-16 and miR-205 were observed in glioma, followed by PCNSL and control groups, whereas miR-15b and miR-301 were higher in both tumor groups, with the highest levels observed in glioma patients. The levels of miR-711 were higher in glioma (including GBM) and downregulated in PCNSL compared to the control group. This review suggests that using these six circulating microRNAs as liquid biomarkers with unique changing patterns could aid in better discrimination between glioma, especially GBM, and PCNSL.

Molecular mechanisms of microRNA-301a during tumor progression and metastasis

Cancer is known as one of the leading causes of human deaths globally. Late diagnosis is considered as one of the main reasons for the high mortality rate among cancer patients. Therefore, the introduction of early diagnostic tumor markers can improve the efficiency of therapeutic modalities. MicroRNAs (miRNAs) have a key role in regulation of cell proliferation and apoptosis. MiRNAs deregulation has been frequently reported during tumor progressions. Since, miRNAs have a high stability in body fluids; they can be used as the reliable non-invasive tumor markers. Here, we discussed the role of miR-301a during tumor progressions. MiR-301a mainly functions as an oncogene via the modulation of transcription factors, autophagy, epithelial-mesenchymal transition (EMT), and signaling pathways. This review paves the way to suggest miR-301a as a non-invasive marker for the early tumor diagnosis. MiR-301a can also be suggested as an effective target in cancer therapy.

Targeting oncogenic functions of miR-301a in head and neck squamous cell carcinoma by PI3K/PTEN and MEK/ERK pathways

Treatment of head and neck squamous cell carcinomas (HNSCC), the sixth most frequent cancer worldwide, remains challenging. miRNA dysregulation is closely linked to tumorigenesis and tumor progression, thus emerging as suitable targets for cancer treatment. Transcriptomic analysis of TCGA HNSCC dataset revealed that miR-301a expression levels significantly increased in primary tumors, as compared to patient-matched normal tissue. This prompted us to investigate its pathobiological role and potential as new therapeutic target using different preclinical HNSCC models. miR-301a overexpression in HNSCC-derived cell lines led to enhanced proliferation and invasion, whereas miR-301 inhibition reduced these effects. In vivo validation was performed using an orthotopic mouse model. Results concordantly showed that the mitotic counts, the percentage of infiltration depth and Ki67 proliferative index were significantly augmented in the subgroup of mice harboring miR-301a-overexpressing tumors. Further mechanistic characterization revealed PI3K/PTEN/AKT and MEK/ERK pathways as central signaling nodes responsible for mediating the oncogenic activity of miR-301a observed in HNSCC cells. Notably, pharmacological disruption of PI3K and ERK signals with BYL-719 and PD98059, respectively, was effective to completely revert/abolish miR-301a-promoted tumor cell growth and invasion. Altogether, these findings demonstrate that miR-301a dysregulation plays an oncogenic role in HNSCC, thus emerging as a candidate therapeutic target for this disease. Importantly, available PI3K and ERK inhibitors emerge as promising anti-tumor agents to effectively target miR-301a-mediated signal circuit hampering growth-promoting and pro-invasive functions.

miR-301a Deficiency Attenuates the Macrophage Migration and Phagocytosis through YY1/CXCR4 Pathway

(1) Background: the miR-301a is well known involving the proliferation and migration of tumor cells. However, the role of miR-301a in the migration and phagocytosis of macrophages is still unclear. (2) Methods: sciatic nerve injury, liver injury models, as well as primary macrophage cultures were prepared from the miR-301a knockout (KO) and wild type (WT) mice to assess the macrophage's migration and phagocytosis capabilities. Targetscan database analysis, Western blotting, siRNA transfection, and CXCR4 inhibition or activation were performed to reveal miR301a's potential mechanism. (3) Results: the macrophage's migration and phagocytosis were significantly attenuated by the miR-301a KO both in vivo and in vitro. MiR-301a can target Yin-Yang 1 (YY1), and miR-301a KO resulted in YY1 up-regulation and CXCR4 (YY1's down-stream molecule) down-regulation. siYY1 increased the expression of CXCR4 and enhanced migration and phagocytosis in KO macrophages. Meanwhile, a CXCR4 inhibitor or agonist could attenuate or accelerate, respectively, the macrophage migration and phagocytosis. (4) Conclusions: current findings indicated that miR-301a plays important roles in a macrophage's capabilities of migration and phagocytosis through the YY1/CXCR4 pathway. Hence, miR-301a might be a promising therapeutic candidate for inflammatory diseases by adjusting macrophage bio-functions.

The miRNome of canine invasive urothelial carcinoma

Urothelial carcinoma (UC) comprises up to 2% of all naturally occurring neoplasia in dogs and can be challenging to diagnose. MicroRNAs (miRNAs) have been reported to be dysregulated in numerous diseases, including neoplasia. MiRNA expression has been evaluated in human UC, but there is limited information regarding the miRNA transcriptome of UC in dogs. Our study aimed to evaluate differential miRNA expression in bladder tissue collected from normal canine urothelium and canine invasive UC (iUC) to elucidate the dysregulated pathways in canine UC. Next-Generation RNA sequencing (RNA-Seq) was performed for dogs with UC (n = 29) and normal canine urothelium (n = 4). Raw RNA data were subjected to normalization, and pairwise comparison was performed using EdgeR with Benjamini-Hochberg FDR multiple testing correction (p < 0.05; >2-fold change) comparing tissue samples of normal urothelium to canine iUC samples. Principal component analysis and hierarchical cluster analysis were performed. MiRNA of FFPE tissue samples of separate iUC (n = 5) and normal urothelium (n = 5) were used to evaluate five miRNAs using RT-qPCR. Pathway analysis was performed utilizing miRWalk, STRING database, and Metascape utilizing KEGG pathways and GO terms databases. Twenty-eight miRNAs were differentially expressed (DE) by RNA-Seq. RT-qPCR confirmed that four miRNAs are significantly downregulated in UC compared to healthy urothelial samples (miR-105a, miR-143, miR-181a, and miR-214). Principal component analysis and hierarchical cluster analysis showed separation between miRNAs in iUC and the control group. The DE miRNAs are most often associated with gene silencing by miRNA, miRNAs in cancer, and miRNAs involved in DNA damage responses. Proteins involved include HRAS, KRAS, ARAF, RAF1, MAPK1, MAP2K1, MAPK3, FGFR3, EGFR, HBEGF, RASSF1, E2F2, E2F3, ERBB2, SRC, MMP1, and UP3KA. The differential expression of miRNAs in canine iUC compared to normal canine urothelial tissue indicates that these markers should be further evaluated for their potential role as diagnostic and therapeutic targets.

PPARGC1A affects inflammatory responses in photodynamic therapy (PDT)-treated inflammatory bowel disease (IBD)

BACKGROUND

Chronic inflammation of the gastrointestinal tract is a feature of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Targeting inflammatory signaling represents promising strategy for IBD treatment regimens.

METHODS

Dextran sulfate sodium (DSS)-induced colitis model was established in mice. Histopathological examinations were conducted by H&E staining and IHC staining. IL-1β, IL-10, and TNF-α were tested by ELISA kits. TargetScan was used to predict miRNAs that target PPARGC1A and luciferase activity assay was performed to validate the predicted binding.

RESULTS

DSS-induced acute colitis model was successfully established in mice; photodynamic therapy (PDT) treatment partially improved DSS-induced colonic damages and cell inflammation. Microarray assays and integrative bioinformatics analysis identified PPARG coactivator 1 alpha (PPARGC1A) as a significantly differentially-expressed gene in PDT-treated IBD compared with non-treated IBD. PPARGC1A expression was downregulated in IBD clinical samples, DSS-induced colitis mice colons, and DSS-stimulated colonic epithelial cells, whereas partially upregulated by PDT treatment in DSS-stimulated cells. Single DSS stimulation significantly promoted cellular inflammation; PDT partially attenuated, whereas sh-PPARGC1A transduction further enhanced DSS effects on cancer cell inflammation. In colitis mice, DSS decreased PPRA-α and PPRA-γ proteins in mice colons; the in vivo effects of DSS were partially attenuated by PDT treatment, whereas amplified by sh-PPARGC1A transduction. Upstream miR-301a-3p targeted and inhibited PPARGC1A expression.

CONCLUSIONS

Collectively, PPARGC1A, which is downregulated in DSS-induced acute colitis and DSS-stimulated colonic epithelial cells, could be upregulated by PDT treatment. PPARGC1A knockdown could attenuate PDT therapeutic effects on DSS-induced acute colitis and DSS-stimulated colonic epithelial cells.

Current and potential biomarkers in gastric cancer: a critical review of the literature

Gastric cancer is the fourth most common type of cancer worldwide and the second most lethal. Gastric cancer biomarkers can be used for diagnosis, prediction of sensitivity to treatment, and prognosis. The following search terms were applied to PubMed as of December 2020: 'gastric cancer classification', 'gastric cancer epidemiology', 'cancer metastasis' and 'gastric cancer biomarker'. Only experimental studies were reported in the 'biomarkers' section. Some biomarkers can serve as therapeutic targets for antitumoral drugs. The genes analyzed include E-cadherin, RPRM, XAF1, MINT25, TFF1, p16 and p53. The miRNAs analyzed include miR-18a, miR185-5p, miR-125b and miR-21. Some molecules were associated with metastasis of gastric cancer, specifically those involved with EMT process and tissue degradation.

MicroRNA-301a-3p promotes triple-negative breast cancer progression through downregulating MEOX2

Breast cancer is one of the most frequently diagnosed malignancies among women. Triple-negative breast cancer (TNBC) represents a significant challenge for breast oncologists, as the availability of effective therapies for this aggressive disease is limited. The molecular mechanisms underlying TNBC development are not fully understood. Previous studies have demonstrated that microRNAs (miRNAs/miRs) play important roles in the development of various types of cancer, including breast cancer; however, the role of miRNAs in TNBC remains undetermined. The results of the present study revealed that miR-301a-3p may function as an oncogenic miRNA in TNBC. Based on The Cancer Genome Atlas data, miR-301a-3p expression levels were found to be upregulated in breast cancer tissues. Reverse transcription-quantitative PCR analysis demonstrated that the expression levels of miR-301a-3p were upregulated in TNBC tissues compared with non-TNBC tissues, and in MDA-MB-231 cells compared with normal MCF-10A breast cells. miR-301a-3p mimics and inhibitors were subsequently used to overexpress and knock down miR-301a-3p expression, respectively, in MDA-MB-231 cells. Biological functional experiments demonstrated that miR-301a-3p overexpression increased the viability, and the migratory and invasive abilities of MDA-MB-231 cells. By contrast, miR-301a-3p knockdown exerted the opposite effects on MDA-MB-231 cells. Cell apoptosis was negatively regulated by miR-301a-3p. Moreover, overexpression of miR-301a-3p was found to downregulate the expression levels of mesenchyme homeobox 2 (MEOX2). The expression levels of miR-301a-3p were negatively correlated with the expression levels of MEOX2 in clinical tissue specimens from patients with TNBC. Subsequently, the knockdown of MEOX2 expression promoted the viability of MDA-MB-231 cells. In conclusion, the results of the present study suggested that miR-301a-3p may serve as an oncogenic miRNA in TNBC by regulating MEOX2 expression.

MicroRNA-301a Promotes Cell Proliferation and Resistance to Apoptosis through PTEN/PI3K/Akt Signaling Pathway in Human Ovarian Cancer

BACKGROUND

MicroRNAs are endogenous small noncoding RNAs, which play a critical role in regulating various biological and pathologic processes. Furthermore, miR-301a has been detected to be overly expressed in tumorigenic progression of ovarian cancer. However, the effects of miR-301a on ovarian cancer are still unclear.

OBJECTIVE

The objective of this study is to investigate the molecular mechanisms of miR-301a in epithelial ovarian cancer cells.

METHODS

The miR-301a expression in ovarian cancer cells was detected. Then, cell proliferation, cell cycle, and apoptosis of the miR-301a-mimic-transfected ovarian cancer cells were determined, as well as the effects of the miR-301a mimic on the PTEN/phosphoinositide 3-kinase (PI3K) signaling pathway were explored.

RESULTS

We found that the miR-301a expression levels were markedly upregulated in ovarian cancer tissues and cells, and upregulation of miR-301a-promoted cell viability and proliferation. Our results also showed that the miR-301a-mimic accelerated cell cycle progression of ovarian cancer cells by targeting the CDK4/Cyclin-D1 pathway but not the CDK2/Cyclin-E pathway. Moreover, transfection of the miR-301a mimic into ovarian cancer cells could decrease the PTEN expression while increasing the PI3K and Akt phosphorylation, as compared with the miR-301a inhibitor group and the negative control group.

CONCLUSION

Therefore, miR-301a should be an oncogene in ovarian cancer, and overexpression of miR-301a promoted proliferation of ovarian cancer cells by modulating the PTEN/PI3K/Akt signaling pathway.

miR-301a-PTEN-AKT Signaling Induces Cardiomyocyte Proliferation and Promotes Cardiac Repair Post-MI

Adult hearts are hard to recover after cardiac injury due to the limited proliferative ability of cardiomyocytes. Emerging evidence indicates the induction of cell cycle reentry of cardiomyocytes by special treatment or stimulation, which offers adult heart regenerative potential. Herein, a microRNA (miRNA) screening in cardiomyocytes identified miR-301a enriched specially in the neonatal cardiomyocytes from rats and mice. Overexpression of miR-301a in primary neonatal cardiomyocytes and H9C2 cells induced G1/S transition of the cell cycle, promoted cellular proliferation, and protected cardiomyocytes against hypoxia-induced apoptosis. Adeno-associated virus (AAV)9-mediated cardiac delivery of miR-301a to the mice model with myocardial infarction (MI) dramatically promoted cardiac repair post-MI in vivo. Phosphatase and tensin homolog (PTEN)/phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway was confirmed to mediate miR-301a-induced cell proliferation in cardiomyocytes. Loss of function of PTEN mimicked the miR-301a-induced phenotype, while gain of function of PTEN attenuated the miR-301a-induced cell proliferation in cardiomyocytes. Application of RG7440, a small molecule inhibitor of AKT, blocked the function of miR-301a in cardiomyocytes. The current study revealed a miRNA signaling in inducing the cell cycle reentry of cardiomyocytes in the injured heart, and it demonstrated the miR-301a/PTEN/AKT signaling as a potential therapeutic target to reconstitute lost cardiomyocytes in mammals.

LncRNA PCAT18/miR-301a/TP53INP1 axis is involved in gastric cancer cell viability, migration and invasion

MiR-301a is as an oncogene involved in the regulation of gastric cancer (GC) progression, but the underlying mechanism is unclear. This study was to explore the lncRNA PCAT18/miR-301a/TP53INP1 axis in regulating the GC cell proliferation and metastasis. In the present study, GC tissues and cell lines were collected for the detection of PCAT18 expression. Herein, we found that PCAT18 is significantly decreases in human GC tissues and five GC cell lines. Overexpression of PCAT18 inhibits cell viability, invasion and migration of GC cells and tumour growth of GC xenograft tumours. PCAT18 negatively regulates the expression level of miR-301a. The interaction between PCAT18 and miR-301a is confirmed by RIP and RNA pull down. MiR-301a mimic increases cell viability and promotes cell migration and invasion and reverses the inhibitory action of PCAT18. TP53INP1 expression is negatively regulated by miR-301a and TP53INP1/miR-301a is involved in GC viability, migration and invasion. The promoting of PCAT18 on TP53INP1 expression is abolished by miR-301a overexpression. In conclusion, lncRNA PCAT18 acts as a tumour suppressor for GC and lncRNA PCAT18, miR-301a and TP53INP1 comprise a signal axis in regulating GC cell proliferation, migration and invasion.

Hypoxic gastric cancer-derived exosomes promote progression and metastasis via MiR-301a-3p/PHD3/HIF-1α positive feedback loop

Hypoxic tumor microenvironment(TME) is a universal feature in solid carcinoma and is associated with unfavorable prognosis. Tumor-derived exosomes are now significantly implicating in mediating cellular communication and interactions in TME. The aim of this study was to identify exosomal miR-301a-3p involved in gastric cancer(GC) progression and metastasis. Here, we found hypoxia promote GC exosomes release and miR-301a-3p expression in an HIF-1α-dependent manner. In hypoxic TME, enriched miR-301a-3p could be transmitted between GC cells via exosomes and then contributed to inhibit HIF-1α degradation through targeting PHD3, that were capable to hydroxylate HIF-1α subunits to ubiquitinate degradation. This synergistical positive feedback loop between HIF-1α and miR-301a-3p facilitated GC proliferation, invasion, migration, and epithelial-mesenchymal transition. In clinical samples, we further discovered circulating exosomal miR-301a-3p in serum was positively related with peritoneal metastasis. Collectively, these data indicate that GC cells could generate miR-301a-3p-rich exosomes in the hypoxic TME, which then help to HIF-1α accumulation and promote GC malignant behaviors and metastasis. Exosomal miR-301a-3p/HIF-1α signaling axis may serve as a promising predictor and potential therapeutic target of GC with metastasis.

Upregulation of miRNA‑301a‑3p promotes tumor progression in gastric cancer by suppressing NKRF and activating NF‑κB signaling

MicroRNA‑301a (miRNA/miR‑301a) and nuclear factor (NF)‑κB signaling play important roles in tumor invasion, migration and progression. However, the role of miRNA‑301a‑3p in human gastric cancer (GC), and specifically in the activation of NF‑κB signaling, remains unclear. The aim of the present study was to investigate miRNA‑301a‑3p expression in GC progression and the molecular mechanisms as regards the regulation of NF‑κB signaling. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detect miRNA‑301a‑3p expression in GC and paired normal tissues. The association between the expression of miRNA‑301a‑3p and patient pathological parameters and the prognosis of GC was statistically analyzed using an in situ hybridization (ISH) assay. An MTS assay and a Transwell assay were performed to evaluate the effects of miRNA‑301a‑3p on the proliferation, invasion and migration of GC cells. RT‑qPCR and western blot analysis were used to analyze the association between miRNA‑301a‑3p and nuclear factor‑κB repressing factor (NKRF) expression and the corresponding downstream NF‑κB signaling molecules. A luciferase assay was used to verify the target effect of miRNA‑301a‑3p and NKRF. It was found that miRNA‑301a‑3p expression was significantly higher in 30 cases of primary GC compared with matched normal tissues. Additionally, the ISH assay indicated that the high expression of miRNA‑301a‑3p in GC was associated with tumor invasion depth, lymph node metastasis, lymph node invasion and tumor metastasis stage. Patients whose tumors had a higher miRNA‑301a‑3p expression level exhibited a poorer prognosis. The in vitro assay indicated that miRNA‑301a‑3p affected the proliferative and invasive ability of GC cells by targeting the expression of NKRF, which then affected NF‑κB signaling. Therefore, it was hypothesize that miRNA‑301a‑3p promotes GC progression and affects the prognosis of patients with GC by targeting NKRF, which in turn, directly influences NF‑κB activation.

Non-coding RNAs in gastric cancer

Non-coding RNAs (ncRNAs) are functional RNA molecules that play crucial regulatory roles in many fundamental biological processes. The dysregulation of ncRNAs is significantly associated with the progression of human cancers, including gastric cancer. In this review, we have summarized the oncogenic or tumor-suppressive roles and the regulatory mechanisms of lncRNAs, miRNAs, circRNAs and piRNAs, and have discussed their potential as biomarkers or therapeutic targets in gastric cancer.

MicroRNA-301a promotes pancreatic cancer invasion and metastasis through the JAK/STAT3 signaling pathway by targeting SOCS5

Pancreatic cancer is one of the most lethal digestive malignant tumors. We had previously found that microRNA-301a (miR-301a) is a oncogenic microRNA whose recognized conduce to nuclear factor-kappa B (NF-κB) activation in pancreatic cancer, yet the underlying mechanisms of miR-301a in promoting pancreatic cancer invasion and migration is obscure. In this work we found that high expression of miR-301a in human pancreatic cancer patients is related to poor survival. Overexpression of miR-301a enhances pancreatic cancer cell invasion, angiogenesis and migration, whereas inhibition of miR-301a suppresses pancreatic cancer cell invasion and reduces orthotopic pancreatic tumor growth and metastasis. Furthermore, suppressor of cytokine signaling 5 (SOCS5) is identified as a target gene of miR-301a. We found that miR-301a suppressed the expression of SOCS5 leads to janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) activation and is related to poor overall survival of pancreatic cancer patients. Taken together, our data show for the first time that the feedback loop between miR-301a and JAK/STAT3 pathway may play a significant role in pancreatic cancer invasion and metastasis. Targeting the loop may prove beneficial to prevent metastasis and provide a more effective therapeutic strategy for pancreatic cancer.

MiR-301a transcriptionally activated by HIF-2α promotes hypoxia-induced epithelial-mesenchymal transition by targeting TP63 in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is one of the deadliest cancers worldwide. PC metastasis involves a complex set of events, including epithelial-mesenchymal transition (EMT), that increase tumor cell invasiveness. Recent evidence has shown that hypoxia is a major EMT regulator in pancreatic cancer cells and facilitates metastasis; however, the mechanisms remain elusive.

AIM

To investigate the role of miR-301a in hypoxia-induced EMT in PC cells.

METHODS

Real-time PCR and Western blot analysis were used to detect the expression of miR-301a and EMT markers in PDAC cells cultured in hypoxic and normoxic conditions. Western blot analysis was used to detect the expression of EMT markers in PDAC cells with miR-301a overexpression. Wound healing assay and Transwell assay were used to detect the migration capabilities of PDAC cells with miR-301a overexpression and knockout. Luciferase assay was used to detect the miR-301a promoter and the 3' untranslated region activity of TP63. Orthotopic PC mouse models were used to study the role of miR-301a in metastasis of PDAC cells in vivo. In situ hybridization assay was used to detect the expression of miR-301a in PDAC patient samples (adjacent paratumor and paired tumor tissues).  .

RESULTS

Hypoxic environment could directly promote the EMT of PC cells. The expression level of miR-301a was increased in a HIF2α dependent manner in hypoxia-cultured CFPAC-1 and BxPC-3 cells. Overexpression of miR-301a enhanced the hypoxia-induced EMT of PC cells, while knocking out miR-301a result in the suppression of hypoxia-induced EMT. TP63 was a direct target of miR-301a and involved in the metastatic process of PC cells. Furthermore, miR-301a upregulation facilitated PDAC distant metastasis and lymph node metastasis in vivo. Additionally, miR-301a overexpression was indicative of aggressive clinicopathological behaviors and poor prognosis.

CONCLUSION

The newly identified HIF-2α-miR301a-TP63 signaling pathway may play a crucial role in hypoxia-induced EMT in PDAC cells.

MiR-301a promotes embryonic stem cell differentiation to cardiomyocytes

BACKGROUND

Cardiovascular disease is the leading cause of death worldwide. Tissue repair after pathological injury in the heart remains a major challenge due to the limited regenerative ability of cardiomyocytes in adults. Stem cell-derived cardiomyocytes provide a promising source for the cell transplantation-based treatment of injured hearts.

AIM

To explore the function and mechanisms of miR-301a in regulating cardiomyocyte differentiation of mouse embryonic stem (mES) cells, and provide experimental evidence for applying miR-301a to the cardiomyocyte differentiation induction from stem cells.

METHODS

mES cells with or without overexpression of miR-301a were applied for all functional assays. The hanging drop technique was applied to form embryoid bodies from mES cells. Cardiac markers including GATA-4, TBX5, MEF2C, and α-actinin were used to determine cardiomyocyte differentiation from mES cells.

RESULTS

High expression of miR-301a was detected in the heart from late embryonic to neonatal mice. Overexpression of miR-301a in mES cells significantly induced the expression of cardiac transcription factors, thereby promoting cardiomyocyte differentiation and beating cardiomyocyte clone formation. PTEN is a target gene of miR-301a in cardiomyocytes. PTEN-regulated PI3K-AKT-mTOR-Stat3 signaling showed involvement in regulating miR-301a-promoted cardiomyocyte differentiation from mES cells.

CONCLUSION

MiR-301a is capable of promoting embryonic stem cell differentiation to cardiomyocytes.

miR‑337‑3p inhibits gastric tumor metastasis by targeting ARHGAP10

Several microRNAs (miRNAs) are known as regulatory molecules involved in gastric tumor metastasis. The expression of miR‑337‑3p was revealed to be downregulated in metastatic gastric tumor cells. Overexpression of miR‑337‑3p in gastric cancer cells resulted in the reduction of their invasive abilities. To characterize the functions of miR‑337‑3p, miR‑337‑3p was expressed in a metastatic lymph node‑derived gastric tumor cell line, SGC‑7901. Overexpression of miR‑337‑3p reduced the viability of cells but had no effects on the cell cycle. Wound healing and Transwell migration assays revealed that miR‑337‑3p inhibited the migration capacity of cells. miR‑337‑3p was capable of binding to the 3'‑untranslated region of a cytoskeleton‑associated molecule, ARHGAP10. Overexpression of miR‑337‑3p reduced the mRNA and protein levels of ARHGAP10 and the co‑expression of ARHGAP10 and miR‑337‑3p resulted in the recovery of cell migration capacity. Furthermore, the injection of miR‑337‑3p‑overexpressing SGC‑7901 cells into an immunodeficient mouse model resulted in a decrease in tumor metastasis in the liver and lungs. The present results indicated that miR‑337‑3p regulates gastric tumor metastasis by targeting the cytoskeleton‑associated protein ARHGAP10.

Cip2a/miR-301a feedback loop promotes cell proliferation and invasion of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer subtype and lacks effective targeted therapies. Cancerous inhibitor of protein phosphatase 2A (Cip2a) is an oncogene that is known to inhibit PP2A tumor suppressor activity in human malignancies. We previously demonstrated that Cip2a is a novel target for the treatment of TNBC. However, the functional roles of Cip2a in TNBC progression are still not fully characterized. In this study, we identified that miR-301a is a novel target of Cip2a in TNBC cell lines by miRNA microarray analysis. We found that Cip2a increases E2F1 expression, which in turn transcriptional activates miR-301a by occupying the miR-301a host gene SKA2 promoter. Moreover, we found that miR-301a level is significantly increased in TNBC tissues, and up-regulation of miR-301a is responsible for Cip2a-induced cell proliferation and invasion of TNBC cells. Furthermore, miR-301a feedback promotes the expression of Cip2a via activation of ERK/CREB signaling. Together, our study suggests an auto-regulatory feedback loop between Cip2a and miR-301a and this auto-regulatory loop might play an important role in TNBC progression.

MicroRNA‑301a‑3p overexpression promotes cell invasion and proliferation by targeting runt‑related transcription factor 3 in prostate cancer

MicroRNAs (miRNAs) are known to serve a role in tumorigenic programs. The dysregulated expression of miR‑301a‑3p may affect the progression of various types of human cancer; however, the expression and the role of miR‑301a‑3p in prostate cancer are still unclear. The present study aimed to clarify the role and molecular mechanism of miR‑301a‑3p in prostate cancer. The results demonstrated that the expression of miR‑301a‑3p was significantly upregulated in human prostate cancer tissues and in several prostate cancer cell lines. In vitro overexpression of miR‑301a‑3p notably increased prostate cancer cell proliferation and invasion. Bioinformatics analysis revealed that runt‑related transcription factor 3 (RUNX3) may be a target of miR‑301a‑3p, which was confirmed by Dual‑luciferase reporter assay. Western blot analysis also demonstrated that miR‑301a‑3p regulated the protein expression levels of RUNX3. In addition, the results indicated that miR‑301a‑3p may regulate the Wnt signaling pathway, and rescue experiments indicated that RUNX3 contributed to the effects of miR‑301a‑3p on cell proliferation and invasion through Wnt signaling. In conclusion, these findings suggested that miR‑301a‑3p may promote prostate cancer cell invasion and proliferation by targeting RUNX3, and provided insight into understanding prostate cancer pathogenesis. miR‑301a‑3p may be a potential therapeutic candidate to treat prostate cancer.

Identification and validation of microRNAs and their targets expressed in osteosarcoma

Osteosarcoma (OS) is the most common type of bone cancer in children and adolescents, and has a poor prognosis. Previous studies have demonstrated that a number of microRNAs (miRNAs) were deregulated in OS, and that the expression of certain miRNAs was correlated with the stage of OS. Therefore, miRNAs may serve a role as a diagnostic and prognostic biomarker of OS. miRNA and mRNA integrated analysis of public expression profiles in the Gene Expression Omnibus database for OS was performed, and the regulated targets of miRNA in OS were predicted. Next, the regulatory network of miRNAs/genes was constructed and verified by reverse transcription-quantitative polymerase chain reaction in tissues and MG-63 cell lines. Two miRNA expression profiling studies and four eligible mRNA expression profiling studies were selected. Ten upregulated miRNAs, 5 downregulated miRNAs and 5 DGEs were identified in OS compared with normal tissues. hsa-miR-346 was inversely correlated with the target gene c-FLIP, which was consistent with the results of integrated analysis. In vitro, pre-miRNA-346 can downregulate the protein expression of c-FLIP, while not changing the mRNA level of c-FLIP. In the regulatory network, hsa-miR-346 and its target gene, c-FLIP, can be used as biomarkers for an earlier diagnosis of OS.

Runx3 expression in rectal cancer cells and its effect on cell invasion and proliferation

Effect of Runx3 gene on the cell proliferation and invasion of rectal cancer was investigated to explore potential new targets for targeted treatment of rectal cancer. The Runx3 overexpression group (OE group), blank plasmid control group, negative control and blank group of the rectal cancer HRC-9698 cell strain were set. The overexpressed Runx3 plasmid was transfected in OE group; the empty plasmid was transfected in blank plasmid control group; only liposome Lipofectamine was added to negative control group; only 1640 medium was used in blank group. RT-qPCR was used for detection of the mRNA expression of Runx3 in different groups; CCK-8 kit for detection of cell proliferation in different groups; Transwell chamber test for detection of cell strain invasion in different groups. The mRNA expression of Runx3 gene in OE group was the highest, significantly higher than that in blank plasmid control group, negative control and blank group (P<0.01). The OD values of overexpressed Runx3 at 96 h after transfection in OE group was significantly lower than each control group (P<0.01). At the same time-point, pairwise comparison in each group found that OE group was significantly lower than blank plasmid control, negative control and blank groups (all P<0.01). In the invasion experiment, the number of invasion cells in OE, blank plasmid control, negative control and blank groups were 38.63±9.33, 107.87±5.66, 110.93±4.33 and 112.86±6.66, respectively. OE group was significantly lower than each control group (P<0.01). Overexpression of Runx3 gene in vitro inhibits the cell proliferation of rectal cancer and blocks the cell invasion and metastasis. This study provides a new idea and a new molecular therapeutic target for molecular targeted therapy of rectal cancer.

miR-301a promotes lung tumorigenesis by suppressing Runx3

BACKGROUND

Our previous report demonstrated that genetic ablation of miR-301a reduces Kras-driven lung tumorigenesis in mice. However, the impact of miR-301a on host anti-tumor immunity remains unexplored. Here we assessed the underlying molecular mechanisms of miR-301a in the tumor microenvironment.

METHODS

The differentially expressed genes were identified by using deep sequencing. The immune cell counts, and cytokines expression were analyzed by realtime PCR, immunohistochemistry and flow cytometry. The role of miR-301a/Runx3 in lung tumor was evaluated on cell growth, migration and invasion. The function of miR-301a/Runx3 in regulating tumor microenvironment and tumor metastasis were evaluated in Kras transgenic mice and B16/LLC1 syngeneic xenografts tumor models.

RESULTS

In this work, we identified 1166 up-regulated and 475 down-regulated differentially expressed genes in lung tumor tissues between KrasLA2 and miR-301a-/-; KrasLA2 mice. Immune response and cell cycle were major pathways involved in the protective role of miR-301a deletion in lung tumorigenesis. Overexpression of the miR-301a target, Runx3, was an early event identified in miR-301a-/-; KrasLA2 mice compared to WT-KrasLA2 mice. We found that miR-301a deletion enhanced CD8+ T cell accumulation and IFN-γ production in the tumor microenvironment and mediated antitumor immunity. Further studies revealed that miR-301a deficiency in the tumor microenvironment effectively reduced tumor metastasis by elevating Runx3 and recruiting CD8+ T cells, whereas miR-301a knockdown in tumor cells themselves restrained cell migration by elevating Runx3 expression.

CONCLUSIONS

Our findings further underscore that miR-301a facilitates tumor microenvironment antitumor immunity by Runx3 suppression in lung tumorigenesis.

Knockdown of Urothelial Carcinoma-Associated 1 Suppressed Cell Growth and Migration Through Regulating miR-301a and CXCR4 in Osteosarcoma MHCC97 Cells

Liver cancer is one of the most common malignancies in the world and a leading cause of cancer-related mortality. Accumulating evidence has highlighted the critical role of long noncoding RNAs (lncRNAs) in various cancers. The present study aimed to explore the role of lncRNA urothelial carcinoma-associated 1 (UCA1) in cell growth and migration in MHCC97 cells and its underlying mechanism. First, we assessed the expression of UCA1 in MHCC97 and three other cell lines by RT-qPCR. Then the expression of UCA1, miR-301a, and CXCR4 in MHCC97 cells was altered by transient transfection. The effects of UCA1 and miR-301 on cell viability, migration, invasion, and apoptosis were assessed. The results revealed that UCA1 expression was relatively higher in MHCC97 cells than in MG63, hFOB1.19, and OS-732 cells. Knockdown of UCA1 reduced cell viability, inhibited migration and invasion, and promoted cell apoptosis. However, the effect of UCA1 knockdown on cell growth and migration was blocked by miR-301a overexpression, whose expression was regulated by UCA1. We also found that miR-301a positively regulated CXCR4 expression. CXCR4 inhibition reversed the effect of miR-301a overexpression on cell growth and migration. Moreover, miR-301a activated the Wnt/β-catenin and NF-κB pathways via regulating CXCR4. The present study demonstrated that UCA1 inhibition exerted an antigrowth and antimigration role in MHCC97 cells through regulating miR-301a and CXCR4 expression.

MicroRNA-301a-3p suppressed the progression of hepatocellular carcinoma via targeting VGLL4

Dysregulation of microRNAs (miRNAs) is involved in a variety of biological process including tumorigenesis. miR-301a-3p has been reported to be an onco-miRNA in various types of cancer, like breast cancer, malignant melanoma, and pancreatic cancer. However, the role of miR-301a-3p in hepatocellular carcinoma (HCC) remains largely incomplete. In the present study, we found that miR-301a-3p was upregulated in HCC tissues and cell lines, and higher miR-301a-3p expression predicted poor prognosis in HCC patients. We also demonstrated that miR-301a-3p overexpression enhanced the ability of proliferation, invasion, and chemoresistance in HCC cell lines, and conversely, silencing miR-301a-3p expression induced the opposite effects. VGLL4, as the direct target of miR-301a-3p, was predicted by bioinformatic websites and confirmed by western blot, RT-PCR, and luciferase reporter assay. Enforced VGLL4 expression rescued the effects of miR-301a-3p mimics on cell proliferation, invasion and chemoresistance. Moreover, we found miR-301a-3p modulated the transcription activity of TEADs. Collectively, our findings suggested that the miR-301a-3p-VGLL4 signaling axis might be a potential therapeutic target for HCC.

SKA2 mediates invasion and metastasis in human breast cancer via EMT

Spindle and kinetochore‑associated protein 2 (SKA2) is essential for regulating the progression of mitosis. In recent years, SKA2 upregulation has been detected in various human malignancies and the role of SKA2 in tumorigenesis has received increasing attention. However, the expression and functional significance of SKA2 in breast cancer are not completely understood. To study the effects of SKA2 on breast cancer, the expression levels of SKA2 in breast cancer tissues and cell lines were evaluated by western blotting, reverse transcription‑quantitative polymerase chain reaction and immunohistochemical staining. The results demonstrated that SKA2 expression was increased in breast cancer tissues and cells, and SKA2 overexpression was associated with clinical stage and lymph node metastasis. Functional investigations revealed that SKA2 knockdown in breast cancer cells significantly reduced migration and invasion, and resulted in the decreased expression levels of matrix metalloproteinase (MMP)2 and MMP9. Furthermore, the typical microtubule arrangement was altered in SKA2 small interfering RNA (siSKA2)‑transfected cells. Reduced levels of SKA2 also downregulated the expression of epithelial‑mesenchymal transition proteins, including fibronectin, N‑cadherin and vimentin, whereas there were no alterations in the protein expression levels of E‑cadherin. Conversely, upregulation of SKA2 decreased the expression levels of E‑cadherin, and increased N‑cadherin, fibronectin and vimentin levels. Notably, it was demonstrated that E‑cadherin was translocated from the cytoplasm to the nucleus in siSKA2‑transfected cells. These results demonstrated that SKA2 may be associated with breast cancer metastasis, and siSKA2 inhibited the invasion and metastasis of breast cancer via translocation of E‑cadherin from the cytoplasm to the nucleus.

miR-301a expression: Diagnostic and prognostic marker for prostate cancer

BACKGROUND

Prostate-specific antigen screening for prostate cancer (CaP) remains controversial. This study establishes the role of microRNA 301a (miR-301a) as a supplemental biomarker that can distinguish between patients with benign prostate hyperplasia and clinically significant CaP. We evaluate the ability of miR-301a to predict the adverse pathology of CaP.

METHODS

In the first cohort, serum and prostate tumor samples were obtained from thirteen patients with Benign prostate hyperplasia (BPH), twelve patients with Gleason 6, and sixteen patients with Gleason 7 prostate adenocarcinoma. In the second cohort, 40 prostatectomy cases were selected (BPH:12, Gleason 6:12 and Gleason 7:16). MiRNA was extracted from serum and tumor samples. Quantitative reverse transcription-polymerase chain reaction was performed for detection of miR-301a. To understand the molecular role of miR-301a, we performed cell viability, Western blots, promoter analysis, overexpression, and silencing studies in BPH and DU-145 cell lines.

RESULTS

MiR-301a demonstrated a significantly higher expression in both serum and tumor tissue in patients with CaP when compared to patients with BPH (P = 0.011 and 0.013 for serum and tissue expression, respectively). Expression of miR-301a in prostatectomy specimens correlated with increased Gleason score. We demonstrated that miR-301a inhibited the pro-apoptotic function of RUNX3, and activated ROCK1-mediated pro-survival signal in CaP. Silencing miR-301a initiated the pro-apoptotic function of RUNX3 by inhibiting ROCK1 expression in CaP cells.

CONCLUSIONS

Expression of miR-301a could be a valuable adjunct tool for stratifying patients with elevated prostate-specific antigen, as well as those diagnosed with CaP. Including the miR-301a as an additional variable in MSKCC post-prostatectomy nomogram improved its ability in facilitating clinical decision-making.

Malignant Transformation of Human Bronchial Epithelial Cells Induced by Arsenic through STAT3/miR-301a/SMAD4 Loop

Arsenic is a well-known of human carcinogen and miR-301a is an oncogenic microRNA, which links to oncogenesis, however, little is understood about its contribution to arsenic-induced cellular transformation and tumorigenesis. Here, we investigated the role of miR-301a during arsenic-induced cellular transformation and tumor formation. miR-301a was found to be upregulated during arsenic-induced BEAS-2B transformation and the overexpression of miR-301a was dependent on IL-6/STAT3 signaling. Inhibition of miR-301a leads to reduction of cell proliferation, colony formation and cell migration. By using dual luciferase assay, SMAD4 was confirmed to be a direct target of miR-301a in BEAS-2B cells and upregulation of SMAD4 is involved the restraining cell growth and migration. In addition, reducing of miR-301a expression enhances doxorubicin-induced cellular apoptosis of transformed BEAS-2B through up-regulating SMAD4. Furthermore, we demonstrated that downregulation of miR-301a in BEAS-2B attenuates tumor growth in the xenograft model by targeting SMAD4. Of note, the level of miR-301a expression correlated inversely with SMAD4 expression in clinical specimens of human lung cancer. Our findings ascertain that miR-301a is an oncogenic miRNA, which targets SMAD4 to establish an essential mechanism for arsenic-induced carcinogenesis, IL-6/STAT3/miR-301a/SMAD4 signaling pathways.

Hypoxic Tumor-Derived Exosomal miR-301a Mediates M2 Macrophage Polarization via PTEN/PI3Kγ to Promote Pancreatic Cancer Metastasis

Exosomes are emerging as important mediators of the cross-talk between tumor cells and the microenvironment. However, the mechanisms by which exosomes modulate tumor development under hypoxia in pancreatic cancer remain largely unknown. Here, we found that hypoxic exosomes derived from pancreatic cancer cells activate macrophages to the M2 phenotype in a HIF1a or HIF2a-dependent manner, which then facilitates the migration, invasion, and epithelial-mesenchymal transition of pancreatic cancer cells. Given that exosomes have been shown to transport miRNAs to alter cellular functions, we discovered that miR-301a-3p was highly expressed in hypoxic pancreatic cancer cells and enriched in hypoxic pancreatic cancer cell-derived exosomes. Circulating exosomal miR-301a-3p levels positively associated with depth of invasion, lymph node metastasis, late TNM stage, and poor prognosis of pancreatic cancer. Hypoxic exosomal miR-301a-3p induced the M2 polarization of macrophages via activation of the PTEN/PI3Kγ signaling pathway. Coculturing of pancreatic cancer cells with macrophages in which miR-301a-3p was upregulated or treated with hypoxic exosomes enhanced their metastatic capacity. Collectively, these data indicate that pancreatic cancer cells generate miR-301a-3p-rich exosomes in a hypoxic microenvironment, which then polarize macrophages to promote malignant behaviors of pancreatic cancer cells. Targeting exosomal miR-301a-3p may provide a potential diagnosis and treatment strategy for pancreatic cancer.Significance: These findings identify an exosomal miRNA critical for microenvironmental cross-talk that may prove to be a potential target for diagnosis and treatment of pancreatic cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/16/4586/F1.large.jpg Cancer Res; 78(16); 4586-98. ©2018 AACR.

miR-301a plays a pivotal role in hypoxia-induced gemcitabine resistance in pancreatic cancer

Hypoxia is a hallmark of pancreatic cancer (PC) and is associated with gemcitabine resistance. However, the mechanisms underlying hypoxia-induced gemcitabine resistance in PC remain greatly unknown. Our previous work showed that miR-301a, a hypoxia-sensitive miRNA, is involved in PC metastasis under hypoxia via regulation of its target gene P63. Here, we showed that miR-301a was upregulated in a NF-κB independent manner and promoted gemcitabine resistance under hypoxic conditions in vitro. In addition, TAp63, a member of the P63 family, reversed hypoxia-induced gemcitabine resistance by promoting degradation of HIF-1α. Furthermore, we proved that TAp63 was a functional downstream target of miR-301a and mediated the biological properties of miR-301a in PC. Taken together, these findings indicate that miR-301a exerts as a critical regulator involved in hypoxia-induced gemcitabine resistance in PC and may have potentials to be a therapeutic target for PC patients.

miR-199b-5p serves as a tumor suppressor in renal cell carcinoma

MicroRNA (miR)-199b-5p has been reported to have a critical role in various types of malignancy. However, the exact function miR-199b-5p in renal cancer remains to be fully elucidated. The present study aimed to detect the expression levels of miR-199b-5p in renal cell carcinoma (RCC) tissues and RCC cell lines, and investigated the effect of miR-199b-5p in vitro with Cell Counting Kit-8, MTT, scratch wound, Transwell and flow cytometric assays. The results demonstrated that the expression levels of miR-199b-5p were significantly downregulated in RCC tissues and cell lines compared with those in paired adjacent normal renal tissues and a reference cell line, respectively. Downregulation of miR-199b-5p by transfection with a synthetic inhibitor promoted cellular proliferation and migration, while reducing the apoptotic rate, indicating that miR-199b-5p may serve as a tumor suppressor in RCC. Further study is required to identify target genes of miR-199b-5p to elucidate the mechanisms underlying the role of miR-199b-5p in the occurrence and development of RCC.

MBD2 upregulates miR-301a-5p to induce kidney cell apoptosis during vancomycin-induced AKI

Despite DNA methylation occurred in acute kidney injury (AKI), how it influenced progression of AKI remains unclear. Methyl-CpG-binding domain protein 2 (MBD2), a protein readers of methylation, was used to analyze the impact of DNA methylation on vancomycin (VAN)-induced AKI. Here, in cultured human kidney tubular epithelial cells (HK-2), we show that knockdown of MBD2 by siRNA attenuated VAN-induced apoptosis, caspase activity, and the expression of BAX and cleaved caspase 3. Interestingly, knockdown of MBD2 by siRNA was associated with the suppression of miR-301a-5p. Mechanistic studies confirmed MBD2 binds to these methylated CpG elements of miR-301a-5p promoter, and then activates miR-301a-5p promoter by suppressing methylation. Furthermore, anti-miR-301a-5p significantly blocked VAN-induced apoptosis and caspase activity in HK-2 cells, which was accompanied by downregulation of p53, and upregulation of MITF, HDGF and MDM-4 together. The latter genes were further identified as target genes of miR-301a-5p, and silencing of MDM-4 promoted p53 accumulation. In vivo, mice with MBD2 knockout (MBD2-KO) were counteracted to VAN-induced AKI, indicated by the analysis of renal function, histology, apoptosis and inflammation. MBD2-KO also significantly suppressed the expression of miR-301a-5p, p53, BAX and cleaved caspase 3, and restored the expression of MDM-4, MITF and HDGF. Finally, in vivo inhibition of miR-301a-5p also ameliorated VAN-induced AKI. Together, these results show the novel MBD2/miR-301a-5p/MITF, HDGF and MDM-4/p53 pathway in VAN-induced AKI.

miR-130a Deregulates PTEN and Stimulates Tumor Growth

H-RasV12 oncogene has been shown to promote autophagic cell death. Here, we provide evidence of a contextual role for H-RasV12 in cell death that is varied by its effects on miR-130a. In E1A-immortalized murine embryo fibroblasts, acute expression of H-RasV12 promoted apoptosis, but not autophagic cell death. miRNA screens in this system showed that miR-130a was strongly downregulated by H-RasV12 in this model system. Enforced expression of miR-130a increased cell proliferation in part via repression of PTEN. Consistent with this effect, miR-130a overexpression in human breast cancer cells promoted Akt phosphorylation, cell survival, and tumor growth. In clinical specimens of multiple human cancers, expression of miR-130 family members correlated inversely with PTEN expression. Overall, our results defined miR-130a as an oncogenic miRNA that targets PTEN to drive malignant cell survival and tumor growth. Cancer Res; 77(22); 6168-78. ©2017 AACR.

Downregulation of microRNA-301a inhibited proliferation, migration and invasion of non-small cell lung cancer by directly targeting DLC1

Increasing evidence has indicated that the abnormal expression of microRNAs contributes to tumorigenesis and tumor development. Understanding the roles of microRNAs in non-small cell lung cancer (NSCLC) might provide valuable information for therapeutic strategies in the therapy for patients with NSCLC. In the present study, significant upregulation of microRNA (miR)-301a was observed in NSCLC tissues and cell lines compared with normal adjacent tissues and a normal human bronchial epithelial cell line. The inhibition of miR-301a suppressed proliferation, migration and invasion of NSCLC cells. Functional analyses indicated that DLC1 was a direct target of miR-301a in NSCLC. Inhibiting miR-301a expression decreased DLC1 expression at mRNA and protein levels. Moreover, DLC1 knockdown partially reversed the inhibition of proliferation, migration and invasion induced by miR-301a knockdown in NSCLC cells. Therefore, these findings may provide novel insights into the molecular mechanisms of miR-301a in proliferation, migration and invasion of NSCLC cells. The findings also indicated that miR-301a may act as a novel potential therapeutic target for patients with NSCLC.

Site-specific Hypermethylation of RUNX3 Predicts Poor Prognosis in Gastric Cancer

BACKGROUND AND AIMS

Methylation status of RUNX3 remains largely unknown in gastric cancer (GC). The aim of this study was to prognostically evaluate the methylation level of CpG sites within RUNX3 promoter region in GC.

METHODS

Using pyrosequencing, we quantitatively explored the methylation status of 8 CpG sites within RUNX3 promoter region for 76 gastric cancer and 24 normal gastric tissues. We then analyzed the association between methylation level of each CpG site and clinicopathological characteristics and outcomes in the cohort.

RESULTS

Methylation of RUNX3 promoter was significantly higher in GC than normal subjects. Overall methylation level was closely associated with tumor invasion and TNM stage. Positive associations were found between hypermethylation of the following concerned sites and variables: site -1392, -1397, -1403, -1415 and tumor invasion, as well as TNM stage; site -1392 and lymph node metastasis along with number of lymph node metastases; site -1415 and cancer recurrence; site -1403, -1415 and cancer-related deaths. In multivariate analysis, tumor invasion was correlated with sites -1392 and -1397. Lymph node metastasis was associated with site -1392. Most importantly, methylation of site -1415 was associated with poor survival by using Cox survival regression.

CONCLUSION

Analysis of RUNX3 gene promoter by quantitative pyrosequencing suggested methylation status of RUNX3 is different in normal and tumor tissues. RUNX3 methylation level is associated with GC, especially the methylation at site -1415 contributes to the poor prognosis in GC. Thus, RUNX3 methylation may serve as a valuable diagnostic and prognostic biomarker in GC.

Epigenetic modulation associated with carcinogenesis and prognosis of human gastric cancer

Gastric cancer (GC) is a leading cause of cancer-related death, particularly in Asia. Epidemiological and other clinical studies have identified an association between a number of risk factors, including Helicobacter pylori, and GC. A number of studies have also examined genetic changes associated with the development and progression of GC. When considering the clinical significance of the expression of a specific gene, its epigenetic modulation should be considered. Epigenetic modulation appears to be a primary driver of changes in gastric tissue that promotes carcinogenesis and progression of GC and other neoplasms. The role of epigenetic modulation in GC carcinogenesis and progression has been widely studied in recent years. In the present review, recent results of epigenetic modulation associated with GC and their effects on clinical outcome are examined, with particular respect to DNA methylation, histone modulation and non-coding RNA. A number of studies indicate that epigenetic changes in the expression of specific genes critically affect their clinical significance and further study may reveal epigenetic changes as the basis for targeted molecular therapy or novel biomarkers that predict GC prognosis or extension of this often fatal disease.

Epigenetic roles in the malignant transformation of gastric mucosal cells

Gastric carcinogenesis occurs when gastric epithelial cells transition through the initial, immortal, premalignant, and malignant stages of transformation. Epigenetic regulations contribute to this multistep process. Due to the critical role of epigenetic modifications , these changes are highly likely to be of clinical use in the future as new biomarkers and therapeutic targets for the early detection and treatment of cancers. Here, we summarize the recent findings on how epigenetic modifications, including DNA methylation, histone modifications, and non-coding RNAs, regulate gastric carcinogenesis, and we discuss potential new strategies for the diagnosis and treatments of gastric cancer. The strategies may be helpful in the further understanding of epigenetic regulation in human diseases.

miR-301a promotes intestinal mucosal inflammation through induction of IL-17A and TNF-α in IBD

OBJECTIVE

MicroRNA (miR)-301a is known to be involved in the tumourigenesis and pathogenesis of several autoimmune diseases, but it remains unclear whether miR-301a is associated with the pathogenesis of IBD.

METHODS

miR-301a expression was assessed in peripheral blood mononuclear cells (PBMC) and inflamed mucosa of patients with IBD by quantitative real-time-PCR. Peripheral blood CD4+ T cells were transduced with lentivirus-encoding pre-miR-301a (LV-miR-301a) or a reverse complementary sequence of miR-301a (LV-anti-miR-301a), and their differentiation and activation were investigated in vitro. Antisense miR-301a was administered into mice during trinitrobenzene sulphonic acid (TNBS)-induced colitis to determine its role in colitis.

RESULTS

miR-301a expression was significantly upregulated in PBMC and inflamed mucosa of patients with IBD compared with healthy controls. Stimulation with tumour necrosis factor-α (TNF-α) significantly enhanced miR-301a expression in IBD CD4+ T cells, which was markedly reversed by anti-TNF-α mAb (Infliximab) treatment. Transduction of LV-miR-301a into CD4+ T cells from patients with IBD promoted the Th17 cell differentiation and TNF-α production compared with the cells with expression of LV-anti-miR-301a. SNIP1 as a functional target of miR-301a was reduced in miR-301a expression but increased in LV-anti-miR-301a expression. Knockdown of SNIP1 could enhance Th17 cell differentiation. Furthermore, intracolonical administration of antisense miR-301a in TNBS-induced mouse colitis model significantly decreased numbers of interleukin (IL)-17A+ cells and amounts of pro-inflammatory cytokines (eg, IL-17A, TNF-α) in inflamed colon.

CONCLUSIONS

Our data reveal a novel mechanism in which the elevated miR-301a in PBMC and inflamed mucosa of IBD promotes Th17 cell differentiation through downregulation of SNIP1. Blockade of miR-301a in vivo may serve as a novel therapeutic approach in the treatment of IBD.

MicroRNAs serve as a bridge between oxidative stress and gastric cancer (Review)

Gastric cancer (GC) remains one of the most prevalent tumors worldwide and affects human health due to its high morbidity and mortality. Mechanisms underlying occurrence and development of GC have been widely studied. Studies have revealed reactive oxygen species (ROS) generated by cells under oxidative stress (OS) are involved in gastric tumorigenesis, and modulate expression of microRNAs (miRs). As such, miRs have been shown to be associated with OS-related GC. Given the association of OS and miRs in development of GC, this review aims to summarize the relationship between miRs and OS and their role in GC development. Serving as a link between OS and GC, miRs may offer new approaches for gaining a more in-depth understanding of mechanisms of GC and may lead to the identification of new therapeutic approaches against GC.

Comparative transcriptomic analysis reveals the oncogenic fusion protein PAX3-FOXO1 globally alters mRNA and miRNA to enhance myoblast invasion

Rhabdomyosarcoma, one of the most common childhood sarcomas, is comprised of two main subtypes, embryonal and alveolar (ARMS). ARMS, the more aggressive subtype, is primarily characterized by the t(2;13)(p35;p14) chromosomal translocation, which fuses two transcription factors, PAX3 and FOXO1 to generate the oncogenic fusion protein PAX3-FOXO1. Patients with PAX3-FOXO1-postitive tumors have a poor prognosis, in part due to the enhanced local invasive capacity of these cells, which leads to the increased metastatic potential for this tumor. Despite this knowledge, little is known about the role that the oncogenic fusion protein has in this increased invasive potential. In this report we use large-scale comparative transcriptomic analyses in physiologically relevant primary myoblasts to demonstrate that the presence of PAX3-FOXO1 is sufficient to alter the expression of 70 mRNA and 27 miRNA in a manner predicted to promote cellular invasion. In contrast the expression of PAX3 alters 60 mRNA and 23 miRNA in a manner predicted to inhibit invasion. We demonstrate that these alterations in mRNA and miRNA translate into changes in the invasive potential of primary myoblasts with PAX3-FOXO1 increasing invasion nearly 2-fold while PAX3 decreases invasion nearly 4-fold. Taken together, these results allow us to build off of previous reports and develop a more expansive molecular model by which the presence of PAX3-FOXO1 alters global gene regulatory networks to enhance the local invasiveness of cells. Further, the global nature of our observed changes highlights the fact that instead of focusing on a single-gene target, we must develop multi-faceted treatment regimens targeting multiple genes of a single oncogenic phenotype or multiple genes that target different oncogenic phenotypes for tumor progression.

MiR-301a regulates E-cadherin expression and is predictive of prostate cancer recurrence

BACKGROUND

MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression post-transcriptionally. Dysregulation of miRNA has been implicated in the development and progression of prostate cancer. Through next generation miRNA sequencing, we recently identified a panel of five miRNAs associated with prostate cancer recurrence and metastasis. Of the five miRNAs, miR-301a had the strongest association with prostate cancer recurrence. Overexpression of miR-301a in prostate cancer cells, PC3, and LNCaP resulted in increased growth both in vitro and in xenografted tumors. We therefore sought to examine its role in prostate carcinogenesis in greater detail.

METHODS

We examined the effect of miR-301a expression on biochemical recurrence and metastasis among 585 men treated with radical prostatectomy for prostate cancer. We examined the mechanism of growth deregulation by miR-301a in prostate cancer cells using analysis of the miRome of prostate cancer cell lines, quantitative PCR, and Western blotting.

RESULTS

High levels of miR-301a (above the median) were associated with an increased risk of biochemical recurrence (adjusted hazard ratio [aHR] 1.42, 95% confidence interval (CI) 1.06-1.90, P = 0.002) but not of metastasis (aHR 0.84, 95%CI 0.41-1.70, P = 0.6) after adjustment for known prognostic factors. RNA transcriptome sequencing analysis of miR-301a overexpressing prostate cancer cell lines identified the tumor suppressor p63 as a potential direct miR-301a target. Transcriptome sequencing, qPCR and Western blotting showed that miR-301a induced epithelial-mesenchymal transition (EMT) in prostate cancer cells through a pathway initiated by p63 inhibition. Luciferase assay verified p63 as a direct target of miR-301a. Loss of p63 resulted in miR-205 downregulation, releasing Zeb1 and Zeb2 from inhibition, culminating in Zeb1/Zeb2 suppression of E-cadherin. This pathway of growth alteration mediated by miR-301a upregulation was shown to be valid in prostate cancer cell lines and patient-derived tumors.

CONCLUSIONS

These data indicate that miR-301a functions as an oncogene in prostate cancer by directly targeting the p63 tumor suppressor leading to loss of E-cadherin and EMT. Hence, miR-301a may serve as a novel biomarker in prostate cancer as well as a therapeutic target for prostate cancer management. Prostate 76:869-884, 2016. © 2016 Wiley Periodicals, Inc.

Glycine confers neuroprotection through microRNA-301a/PTEN signaling

Background

Glycine is known to protect against neuronal death. However, the underlying mechanism remains to be elucidated. The microRNA-301a is involved in both biological and pathological processes. But it is not known whether microRNA-301a has a neuroprotective property. In this study, we aimed to determine whether glycine-induced neuroprotection requires microRNA-301a-dependent signaling.

Results

We provided the first evidence that glycine increased the expression of microRNA-301a in cultured rat cortical neurons and protected against cortical neuronal death through up-regulation of microRNA-301a after oxygen-glucose deprivation. MicroRNA-301a directly bound the predicted 3′UTR target sites of PTEN and reduced PTEN expression in cortical neurons. We revealed that PTEN down-regulation by microRNA-301a mediated glycine-induced neuroprotective effect following oxygen-glucose deprivation.

Conclusions

Our results suggest that 1) microRNA-301a is neuroprotective in oxygen-glucose deprivation-induced neuronal injury; 2) glycine is an upstream regulator of microRNA-301a; 3) glycine confers neuroprotection through microRNA-301a/PTEN signal pathway.

MicroRNA-301a promotes cell proliferation via PTEN targeting in Ewing's sarcoma cells

MicroRNAs (miRNAs) regulate cell proliferation and differentiation by affecting gene expression at the post-transcriptional level by binding to complementary sequences within mRNAs in cancer cells, indicating that miRNAs can function as tumor suppressors or oncogenes. Recent studies showed that dysregulation of miRNA expression was associated with increased tumorigenicity and poor prognosis in several types of cancers, including Ewing's sarcoma (ES). To explore possible oncogenic factors in ES, we conducted microarray-based investigation and profiled the changes in miRNA expression and their effects on downstream mRNAs in five ES cell lines and human mesenchymal stem cells (hMSCs). miR-301a was significantly upregulated, while the phosphatase and tensin homolog (PTEN) expression was significantly downregulated in all tested ES cells as compared to hMSCs. When anti-miR-301a was transfected into ES cell lines, PTEN expression was significantly enhanced, suggesting that PTEN might be a target of miR-301a in ES cells. The expression of protein kinase B (Akt), which is inversely correlated with PTEN expression, was significantly downregulated in anti-miR-301a-transfected cells. Additionally, the transfection of anti-miR-301a inhibited ES cell proliferation and cell cycle progression. Furthermore, downregulation of miR-301a in ES cells significantly suppressed tumor growth in vivo. Our results demonstrated the novel mechanism controlling PTEN expression via miR-301a in ES cells. Given that PTEN is a pivotal phosphatase factor that regulates cell cycle progression, apoptosis, and proliferation, these results might lead to development of new ES-related therapeutic targets.

MicroRNA-378-mediated suppression of Runx1 alleviates the aggressive phenotype of triple-negative MDA-MB-231 human breast cancer cells

The Runx1 transcription factor, known for its essential role in normal hematopoiesis, was reported in limited studies to be mutated or associated with human breast tumor tissues. Runx1 increases concomitantly with disease progression in the MMTV-PyMT transgenic mouse model of breast cancer. Compelling questions relate to mechanisms that regulate Runx1 expression in breast cancer. Here, we tested the hypothesis that dysregulation of Runx1-targeting microRNAs (miRNAs) allows for pathologic increase of Runx1 during breast cancer progression. Microarray profiling of the MMTV-PyMT model revealed significant downregulation of numerous miRNAs predicted to target Runx1. One of these, miR-378, was inversely correlated with Runx1 expression during breast cancer progression in mice and in human breast cancer cell lines MCF7 and triple-negative MDA-MB-231 that represent early- and late-stage diseases, respectively. MiR-378 is nearly absent in MDA-MB-231 cells. Luciferase reporter assays revealed that miR-378 binds the Runx1 3' untranslated region (3'UTR) and inhibits Runx1 expression. Functionally, we demonstrated that ectopic expression of miR-378 in MDA-MB-231 cells inhibited Runx1 and suppressed migration and invasion, while inhibition of miR-378 in MCF7 cells increased Runx1 levels and cell migration. Depletion of Runx1 in late-stage breast cancer cells resulted in increased expression of both the miR-378 host gene PPARGC1B and pre-miR-378, suggesting a feedback loop. Taken together, our study identifies a novel and clinically relevant mechanism for regulation of Runx1 in breast cancer that is mediated by a PPARGC1B-miR-378-Runx1 regulatory pathway. Our results highlight the translational potential of miRNA replacement therapy for inhibiting Runx1 in breast cancer.

Helicobacter pylori and microRNAs: Relation with innate immunity and progression of preneoplastic conditions

The accepted paradigm for intestinal-type gastric cancer pathogenesis is a multistep progression from chronic gastritis induced by Helicobacter pylori (H. pylori) to gastric atrophy, intestinal metaplasia, dysplasia and ultimately gastric cancer. The genetic and molecular mechanisms underlying disease progression are still not completely understood as only a fraction of colonized individuals ever develop neoplasia suggesting that bacterial, host and environmental factors are involved. MicroRNAs are noncoding RNAs that may influence H. pylori-related pathology through the regulation of the transcription and expression of various genes, playing an important role in inflammation, cell proliferation, apoptosis and differentiation. Indeed, H. pylori have been shown to modify microRNA expression in the gastric mucosa and microRNAs are involved in the immune host response to the bacteria and in the regulation of the inflammatory response. MicroRNAs have a key role in the regulation of inflammatory pathways and H. pylori may influence inflammation-mediated gastric carcinogenesis possibly through DNA methylation and epigenetic silencing of tumor suppressor microRNAs. Furthermore, microRNAs influenced by H. pylori also have been found to be involved in cell cycle regulation, apoptosis and epithelial-mesenchymal transition. Altogether, microRNAs seem to have an important role in the progression from gastritis to preneoplastic conditions and neoplastic lesions and since each microRNA can control the expression of hundreds to thousands of genes, knowledge of microRNAs target genes and their functions are of paramount importance. In this article we present a comprehensive review about the role of microRNAs in H. pylori gastric carcinogenesis, identifying the microRNAs downregulated and upregulated in the infection and clarifying their biological role in the link between immune host response, inflammation, DNA methylation and gastric carcinogenesis.

Manganese superoxide dismutase expression is negatively associated with microRNA-301a in human pancreatic ductal adenocarcinoma

Manganese superoxide dismutase (MnSOD) expression has been found to be low in human pancreatic ductal adenocarcinoma (PDAC). Previously, we have reported that microRNA-301a (miR-301a) was found being upregulated via nuclear factor-κB (NF-κB) feedback loop in human PDAC. In this study, we investigate whether the miR-301a expression level is associated with MnSOD expression in human PDAC. We established a xenograft PDAC mouse model using transfected PanC-1 cells (miR-301a antisense or scrambled control) to investigate tumor growth and the interaction between MnSOD and miR-301a. The animal study indicated that miR-301a antisense transfection could significantly decrease the growth rate of inoculated PDAC cells, and this decrease in tumor growth rate is associated with increased MnSOD expression. To evaluate the MnSOD-miR-301a correlation in human PDAC, we have analyzed a total of 60 PDAC specimens, along with 20 normal pancreatic tissue (NPT) specimens. Human specimens confirmed a significant decrease of MnSOD expression in PDAC specimens (0.88±0.38) compared with NPT control (2.45±0.76; P<0.05), whereas there was a significant increase in miR-301a levels in PDAC specimens (0.89±0.28) compared with NPT control (0.25±0.41; P<0.05). We conclude that MnSOD expression is negatively associated with miR-301a levels in PDAC tissues, and lower miR-301a levels are associated with increased MnSOD expression and inhibition of PDAC growth.