MicroRNA-185 suppresses growth and invasion of colon cancer cells through inhibition of the hypoxia-inducible factor-2α pathway in vitro and in vivo

MicroRNA-185-5p: a marker of brain-sparing in foetuses with late-onset growth restriction

To compare the expression of microRNA-185-5p (miR-185-5p) in normal foetuses and in foetuses with late-onset growth restriction (FGR) and to determine the factors influencing this expression. In a prospective study, 40 foetuses (22 of them with late-onset FGR and 18 with normal growth) were scanned with Doppler ultrasound after week 35 and followed until birth. Subsequently, blood samples from umbilical cords were collected after delivery to evaluate the expression of miR-185-5p using real-time qPCR. Finally, multivariable regression analysis was applied to determine the clinical and ultrasonographic factors influencing miR-185-5p expression in both normal and late-onset FGR foetuses. In comparison with normal foetuses, late-onset FGR foetuses expressed upregulation of miR-185-5p (2.26 ± 1.30 versus 1.27 ± 1.03 2^-ddCt, P = 0.011). Multivariable regression analysis confirmed that cerebroplacental ratio (P < 0.05) was the only determinant of this overexpression. FGR foetuses overexpress miR-185-5p in relation to brain-sparing. Future studies will be needed to investigate the role of miR-185 in the management of late-onset FGR.

The miR-28-5p-CAMTA2 axis regulates colon cancer progression via Wnt/β-catenin signaling

BACKGROUND

Colon cancer is the third most commonly diagnosed cancer with high morbidity and mortality. Calmodulin-binding transcription activator 2 (CAMTA2) belongs to the calmodulin-binding transcription activator protein family. The functional role of CAMTA2 in colon cancer development remains unclear. Our research found out that CAMTA2 was high-level expressed in colon cancer, and the upregulated CAMTA2 expression was markedly correlated with poor survival. Functional experiments showed that knockdown of CAMTA2 repressed colon cancer cell proliferation/migration in vitro and attenuated proliferation in vivo. In additional, CAMTA2 expression was controlled by miR-28-5p via posttranscriptional regulation and miR-28-5p expression was reversely correlated with CAMTA2 expression in colon cancer. Moreover, enforced miR-28-5p expression downregulated the expression of CAMTA2 significantly and the restoration of CAMTA2 expression abolished the inhibitory effect of miR-28-5p on colon cancer cell proliferation and metastasis. Mechanistically, overexpression of miR-28-5p suppressed Wnt/β-catenin signaling and the inhibitory could be partly abolished by overexpression of CAMTA2. In summary, our findings reveal that miR-28-5p/CAMTA2 axis plays a critical role in human colon cancer, which might be a promising diagnosis and therapeutic target for colon cancer treatment.

MicroRNAs Targeting HIF-2α, VEGFR1 and/or VEGFR2 as Potential Predictive Biomarkers for VEGFR Tyrosine Kinase and HIF-2α Inhibitors in Metastatic Clear-Cell Renal Cell Carcinoma

Metastatic clear-cell renal cell carcinoma (m-ccRCC) is characterized by increased hypoxia-induced factor (HIF)-2α and vascular endothelial growth factor receptor (VEGFR)-dependent angiogenesis through loss of function of the von Hippel-Lindau protein. VEGFR tyrosine kinase inhibitors (VEGFR-TKIs) are a cornerstone of m-ccRCC treatment, and new treatments targeting HIF-2α are currently under investigation. However, predictive biomarkers for these treatments are lacking. In this retrospective cohort study including 109 patients treated with VEGFR-targeted therapies as first-line treatment, we aimed to study the possible predictive function of microRNAs (miRNAs) targeting HIF-2α, VEGFR1 and VEGFR2. We selected miRNAs inversely correlated with HIF-2α, VEGFR1 and/or VEGFR2 expression and with predicted target sites in the respective genes and subsequently studied their impact on therapeutic outcomes. We identified four miRNAs (miR-34c-5p, miR-221-3p, miR-222-3p and miR-3529-3p) inversely correlated with VEGFR1 and/or VEGFR2 expression and associated with tumor shrinkage and progression-free survival (PFS) upon treatment with VEGFR-TKIs, highlighting the potential predictive value of these miRNAs. Moreover, we identified three miRNAs (miR-185-5p, miR-223-3p and miR-3529-3p) inversely correlated with HIF-2α expression and associated with tumor shrinkage and PFS upon treatment with VEGFR-TKIs. These three miRNAs can have a predictive value not only upon treatment with VEGFR-TKIs but possibly also upon treatment with the upcoming HIF-2α inhibitor belzutifan.

MiR-185-3p mimic promotes the chemosensitivity of CRC cells via AQP5

BACKGROUND

Studies showed that microRNAs (miRNAs) are important regulators in drug resistance. The current study investigated the role of miR-185-3p and its predicted target gene AQP5 in 5-FU-insensitive colorectal cancer (CRC) cells.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) and Spearman's correlation analysis were conducted to determine the correlation of expression levels of miR-185-3p and AQP5 from CRC tissues. HCT-116 and HCT-8 cells were treated by gradient concentration of 5-FU to construct 5-FU-resistant CRC model. The inhibition and viability of 5-FU-resistant cells were detected by MTT assay, and cell migration and invasion ability were determined by wound healing and transwell assay. The expressions of miR-185-3p and AQP5 were measured by qRT-PCR. StarBase and dual-luciferase reporter assay were used to predict and confirm the interaction between miR-185-3p and AQP5. Further experiments were performed to explore the function of miR-185-3p in 5-FU-resistant cells through regulating aquaporin-5 (AQP5). The levels of EMT-associated markers and AQP5 were determined by conducting Western Blot and qRT-PCR.

RESULTS

We found that 5-FU-resistant CRC cells showed a lower inhibition rate, and higher migration and invasion abilities. MiR-185-3p was low-expressed in CRC tissues and 5-FU-resistance cells, and it targeted and regulated the expression of AQP5, which was found up-regulated in CRC and 5-FU-resistance CRC cells (r = -0.29, P < .05). Furthermore, miR-185-3p mimic enhanced the chemo-sensitivity of 5-FU-resistant cells, while overexpressed AQP5 reversed such an effect produced by miR-185-3p mimic.

CONCLUSION

MiR-185-3p mimic enhances the chemosensitivity of CRC cells via AQP5. Our research provides a potential therapeutic target for 5-FU-resistant CRC cells.

Circular RNA derived from TIMP2 functions as a competitive endogenous RNA and regulates intervertebral disc degeneration by targeting miR‑185‑5p and matrix metalloproteinase 2

Intervertebral disc degeneration (IDD) is an important cause of lower back pain, although the underlying mechanisms remain poorly understood. The present study aimed to examine the role of a circular RNA derived from tissue inhibitor of metallopeptidases 2 (circ-TIMP2) in degenerative nucleus pulposus (NP) tissues, and to validate its function in cultured human NP cells. Overexpression of miR-185-5p in NP cells markedly inhibited the enhanced extracellular matrix (ECM) catabolism induced by tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) treatment. Bioinformatics analysis demonstrated that matrix metalloproteinase 2 (MMP2) was a potential target of miR-185-5p. MMP2 protein expression levels were increased following treatment with TNF-α and IL-1β in NP cells compared with those in untreated cells, and this effect was attenuated by transfection with miR-185-5p. Compared with normal NP tissues, IDD samples exhibited higher circ-TIMP2 expression levels. In addition, overexpres-sion of circ-TIMP2 promoted ECM catabolism and suppressed ECM anabolism. Furthermore, circ-TIMP2 sequestered miR-185-5p, which may potentially upregulate the target genes associated with ECM degradation. In conclusion, the results of the present study revealed that circ-TIMP2 promoted TNF-α- and IL-1β-induced NP cell imbalance between ECM anabolism and catabolism via miR-185-5p-MMP2 signaling. These findings provide a potential therapeutic option for the treatment of IDD.

Long non coding RNA UCA1 contributes to the autophagy and survival of colorectal cancer cells via sponging miR-185-5p to up-regulate the WISP2/β-catenin pathway

The estimated number of new cases of colorectal cancer (CRC) will increase to 140 250 in 2018 worldwide. The long non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has recently been shown to be dysregulated in CRC, which plays an important role in the progression of CRC. However, the biological role and the underling mechanism of UCA1 in the carcinogenesis of CRC remain unclear. Herein, we found that UCA1 was aberrantly upregulated in two CRC cell lines (SW620 and HT29) compared to colorectal cell CCD-18Co. UCA1 knockdown inhibited the apoptosis, growth and autophagy of CRC cell lines in vitro. Furthermore, UCA1 could act as an endogenous sponge by directly interacting with miR-185-5p and downregulation miR-185-5p expression. In addition, UCA1 could reverse the inhibitory effect of miR-185-5p on the growth and autophagy of CRC cells, which might be involved in the derepression of member 1 (WNT1)-inducible signaling pathway protein 2 (WISP2, a target gene of miR-185-5p) expression and the activation of the WISP2/β-catenin signaling pathway. In vivo, the present study elucidates a novel UCA1-miR-185-5p-WISP2-Wnt/β-catenin axis in CRC, which may help us to understand the pathogenesis and the feasibility of lncRNA-directed diagnosis and therapy of CRC.

The estimated number of new cases of colorectal cancer (CRC) will increase to 140 250 in 2018 worldwide.

miR-185 inhibits cell migration and invasion of hepatocellular carcinoma through CDC42

Hepatocellular carcinoma (HCC) is a primary liver cancer with high incidence and mortality. miR-185, a microRNA with appriximately 22-28 nucleotides, was reported to be involved in many cancers. The potential mechanism of miR-185 on HCC through cell division cycle 42 (CDC42) was investigated. RT-qPCR was used to measure the RNA level of miR-185 and CDC42 in HCC tissues and cells. The dual luciferase reporter assay was used to verify whether CDC42 was a target gene for miR-185. Transwell assay was employed to detect the ability of migration and invasion to change miR-185. miR-185 expression was low in HCC and negatively correlated with CDC42. miR-185 inhibited HCC migration, invasion and miR-185 low expression predicted poor prognosis. CDC42 was predicted to be a target gene for miR-185, and regulated by miR-185. miR-185 suspressed the ability of cell migration and invasion through CDC42 in HCC. In conclusion, miR-185 suspressed migration and invasion of HCC cells by directly targeting CDC42. It is suggested that miR-185/CDC42 axis may present a novel target for HCC treatment.

miRNA-185 serves as a prognostic factor and suppresses migration and invasion through Wnt1 in colon cancer

Colon cancer is one of the deadliest cancers worldwide; abnormal microRNA expression is common during colon cancer development. The aim of the present study was to elucidate the role played by miR-185 in this context. We used quantitative real-time PCR (qRT-PCR) to measure miR-185 expression levels in colon cancer cell lines. The effects of miR-185 on colon cancer cell proliferation and invasion were assessed using the MTT, colony-forming, wound-healing, and transwell assays. A luciferase activity assay was used to confirm the target of miR-185. Our data showed that miR-185 was significantly down-regulated in colon cancer cells and colonic cancer tissues compared with NCM460 normal colonic epithelial cells and adjacent normal tissues. A functional analysis revealed that ectopic expression of miR-185 significantly inhibited colon cancer cell proliferation, colony formation, migration, and invasion. In addition, western blot, qRT-PCR, and luciferase assays confirmed in colon cancer cells that Wnt1 was a downstream target of miR-185, in turn suppressing β-catenin-mediated signaling. In conclusion, we found that miR-185 inhibits colon cancer cell proliferation and invasion by targeting Wnt1, and that it serves as a tumor suppressor, indicating that the modulation of miR-185 levels may potentially be therapeutic in colon cancer patients.

miR-185 and miR-29a are similarly expressed in the bronchoalveolar lavage cells in IPF and lung cancer but common targets DNMT1 and COL1A1 show disease specific patterns

Idiopathic pulmonary fibrosis (IPF) and lung cancer (LC) constitute two progressively devastating lung diseases with common risk factors including aging and smoking. There is an increasing interest in the investigation of common pathogenic mechanisms between IPF and LC with therapeutic implications. Several oncomirs, microRNAs associated with malignancy, are also linked with IPF. miR-29a and miR-185 downregulation is probably involved both in carcinogenesis and fibrogenesis. We have previously observed miR-29a and miR-185 downregulation in IPF cells from bronchoalveolar lavage (BAL) and in this study we investigated their expression in LC BAL cells. Common targets of miR-29a and miR-185 such as DNA methyltransferase (DNMT)1, DNMT3b, COL1A1, AKT1 and AKT2 were measured. Potential correlations with pulmonary function tests, smoking status and endobronchial findings were investigated. Similar levels of miR-29a and miR-185 were detected in IPF and LC while their common targets AKT1 and DNMT3b were not found to differ, suggesting potential pathogenetic similarities at the level of key epigenetic regulators. By conrast, COL1A1 mRNA levels were increased in IPF suggesting a disease-specific mRNA signature. Notably, DNMT1 was downregulated in the LC group and its expression was further reduced in the presence of increasing malignant burden as it was implied by the endobronchial findings.

Involvement of Non-coding RNAs in the Signaling Pathways of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common diagnosed cancers worldwide. The metastasis and development of resistance to anti-cancer treatment are major challenges in the treatment of CRC. Understanding mechanisms underpinning the pathogenesis is therefore critical in developing novel agents for CRC treatments. A large number of evidence has demonstrated that non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs have functional roles in both the physiological and pathological processes by regulating the expression of their target genes. These molecules are engaged in the pathobiology of neoplastic diseases and are targets for the diagnosis, prognosis and therapy of a variety of cancers, including CRC. In this regard, ncRNAs have emerged as one of the hallmarks of CRC pathogenesis and they also play key roles in metastasis, drug resistance and the stemness of CRC stem cell by regulating various signaling networks. Therefore, a better understanding the ncRNAs involved in the signaling pathways of CRC may lead to the development of novel strategy for diagnosis, prognosis and treatment of CRC. In this chapter, we summarize the latest findings on ncRNAs, with a focus on miRNAs and lncRNAs involving in signaling networks and in the regulation of pathogenic signaling pathways in CRC.

A functional variant in GREM1 confers risk for colorectal cancer by disrupting a hsa-miR-185-3p binding site

The transforming growth factor beta (TGF-β) pathway has been implicated in carcinogenesis of intestinal canal. Except for common variants indentified by genome-wide association studies, variants with lower frequency can also explain a part of the disease heritability, especially those in gene regulatory regions. In this study, we searched for colorectal cancer (CRC) related functional low-frequency variants (minor allele frequency 1-5%) in untranslated regions (UTR) involved in the TGF-β signaling using a next-generation sequencing based approach. A case-control study including 1,841 CRC cases and 1,837 controls was performed to identify CRC associated variants and biological experiments were applied to further explore the potential functions of the significant variants. Three low-frequency UTR variants were selected as our candidates and subsequent association analyses showed that a low-frequency variant rs12915554 in the 3’ UTR of GREM1 was significantly associated with CRC risk (Additive model: OR=1.43, 95%CI: 1.04-1.95, P=0.026). Functional annotations suggested that rs12915554 variation increased the expression of GREM1 by perturbing a hsa-miR-185-3p binding site. Moreover, higher expression level of GREM1 was investigated in colon tumor tissues compared with adjacent normal tissues using TCGA data. In conclusion, low-frequency UTR variant rs12915554 in the gene GREM1 was in relation to CRC susceptibility in a Chinese population and this variation might promote CRC development through enhancing GREM1 expression in a miRNA-mediated posttranscriptional manner.

miR-185 enhances the inhibition of proliferation and migration induced by ionizing radiation in melanoma

Melanoma is an aggressive malignancy that is increasingly common and exhibits a poor patient survival rate. Radiotherapy is the primary option for patients with melanoma, particularly those who are not candidates for surgery; however, the therapeutic effect is limited due to the relative radioresistance of melanoma to ionizing radiation (IR). It has been reported that microRNAs (miRNAs) serve a vital role in determining the radiosensitivity of tumors; however, little is known concerning the radiosensitization of melanoma using miRNA. In the present study, the radiosensitization effect of miRNA 185 (miR-185), which has been demonstrated to reduce renal cancer radioresistance, was investigated in B16 cells, a skin melanoma cell line derived from C57/BL mice, was investigated. Cell proliferation and scratch wound healing assays were used to determine the proliferative and migratory abilities of B16 cells. Annexin V/propidium iodide double staining was used to determine the apoptosis induced by IR. A tumor formation assay was performed to determine the radiosensitization effect of miR-185 on melanoma cells in vivo. Proliferation marker protein Ki-67, and hematoxylin and eosin staining were used to assess the proliferative activity and histological changes, respectively. The results of the present study demonstrated that miR-185 suppresses cellular proliferation and migration, and enhances IR-induced apoptosis, and the inhibition of proliferation and migration, in vitro and in vivo, which provides an insight into understanding the radiosensitization of melanoma using miRNA.

MiR-625-3p promotes cell migration and invasion via inhibition of SCAI in colorectal carcinoma cells

MicroRNAs (miRNAs) play a critical role in controlling tumor invasion and metastasis via regulating the expression of a variety of targets, which act as oncogenes or tumor suppressor genes. Abnormally expressed miR-625-3p has been observed in several types of human cancers. However, the molecular mechanisms of miR-625-3p-mediated tumorigenesis are largely elusive. Therefore, the aim of this study was to evaluate the biological function and molecular insight on miR-625-3p-induced oncogenesis in colorectal carcinoma (CRC). The effects of miR-625-3p in cell migration and invasion were analyzed by wound healing assay and transwell assay, respectively. In addition, the expression of miR-625-3p and its targets was detected in five human CRC cell lines. In the present study, we found that overexpression of miR-625-3p promoted migration and invasion in SW480 cells, whereas downregulation of miR-625-3p inhibited cell motility in SW620 cells. More importantly, we observed potential binding sites for miR-625-3p in the 3′-untranslated region of suppressor of cancer cell invasion (SCAI). Notably, we identified that overexpression of miR-625-3p inhibited the expression of SCAI, while depletion of miR-625-3p increased SCAI level, suggesting that SCAI could be a target of miR-625-3p. Additionally, we revealed that miR-625-3p exerts its oncogenic functions through regulation of SCAI/E-cadherin/MMP-9 pathways. Our findings indicate the pivotal role of miR-625-3p in invasion that warrants further exploration whether targeting miR-625-3p could be a promising approach for the treatment of CRC.

Verification of microRNA expression in human endometrial adenocarcinoma

BACKGROUND

MicroRNAs are small non-coding RNAs that have been implicated in tumor initiation and progression. In a previous study we identified 138 miRNAs as differentially expressed in endometrial adenocarcinoma compared to normal tissues. One of these miRNAs was miRNA-34a, which regulates several genes involved in the Notch pathway, which is frequently altered in endometrial cancer. The aims of this study were to verify the differential expression of a subset of miRNAs and to scrutinize the regulatory role of mir-34a on the target genes NOTCH1 and DLL1.

METHODS

Twenty-five miRNAs that were previously identified as differentially expressed were subjected to further analysis using qPCR. To investigate the regulation of NOTCH1 and DLL1 by mir-34a, we designed gain- and loss-of-function experiments in Ishikawa and HEK293 cell lines by transfection with a synthetic mir-34a mimic and a mir-34a inhibitor.

RESULTS

Of the 25 validated miRNAs, seven were down-regulated and 18 were up-regulated compared to normal endometrium, which was fully consistent with our previous findings. In addition, the up-regulation of mir-34a led to a significant decrease in mRNA levels of NOTCH1 and DLL1, while down-regulation led to a significant increase in mRNA levels of these two genes.

CONCLUSIONS

We verified both up-regulated and down-regulated miRNAs in the tumor samples, indicating various roles of microRNAs during tumor development. Mir-34a functions as a regulator by decreasing the expression of NOTCH1 and DLL1. Our study is the first to identify a correlation between mir-34a and its target genes NOTCH1 and DLL1 in endometrial adenocarcinoma.

The tumour hypoxia induced non-coding transcriptome

Recent investigations have highlighted the importance of the non-coding genome in regions of hypoxia in tumours. Such regions are frequently found in solid tumours, and are associated with worse patient survival and therapy resistance. Hypoxia stabilises the transcription factors, hypoxia inducible factors (HIF1α and HIF2α) which coordinate transcriptomic changes that occur in hypoxia. The changes in gene expression induced by HIF1α and HIF2α contribute to many of the hallmarks of cancer phenotypes and enable tumour growth, survival and invasion in the hypoxic tumour microenvironment. Non-coding RNAs, in particular microRNAs (miRNAs), which regulate mRNA stability and translation, and long-non-coding RNAs (lncRNAs), which have diverse functions including chromatin modification and transcriptional regulation, are also important in enabling the key hypoxia regulated processes. They have roles in the regulation of metabolism, angiogenesis, autophagy, invasion and metastasis in the hypoxic microenvironment. Furthermore, HIF1α and HIF2α expression and stabilisation are also regulated by both miRNAs and lncRNAs. Here we review the recent developments in the expression, regulation and functions of miRNAs, lncRNAs and other non-coding RNA classes in tumour hypoxia.

Differential effect of psoralidin in enhancing apoptosis of colon cancer cells via nuclear factor-κB and B-cell lymphoma-2/B-cell lymphoma-2-associated X protein signaling pathways

Worldwide, colon cancer is the third most common cancer in terms of incidence, following lung and breast cancer. Resistance to psoralidin frequently occurs following its use as an anticancer treatment. However, the mechanisms underlying the effects of psoralidin on colon cancer, remain to be elucidated. Hence, the present study investigated the anticancer effects and potential mechanism of action of psoralidin on SW480 human colon cancer cells. In the present study, an MTT assay was performed to measure the viability of SW480 cells. Additionally, an Annexin V-fluorescein isothiocyanate/propidium iodide apoptosis detection kit, DAPI staining assay and caspase-3 colorimetric assay kits were used to analyze the cellular apoptosis of SW480 cells. The nuclear factor-κB (NF-κB) p65 activity and B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated X protein (Bax) protein expression of SW480 cells was detected using NF-κB colorimetric assay kits and western blot analysis, respectively. Bcl-2 inhibitor ABT-737 was added to SW480 cells and the subsequent effects and mechanism of action of psoralidin on SW480 colon cancer cells was studied. In the present study, psoralidin reduced SW480 cell viability and enhanced the cellular apoptosis of SW480 cells in a dose-dependent manner. Caspase-3 activity of SW480 cells was increased following treatment with psoralidin. Additionally, psoralidin was able to reduce the NF-κB p65 activity of SW480 cells. Furthermore, psoralidin was able to reduce Bcl-2 protein expression and increase Bax protein expression in SW480 cells. Notably, Bcl-2 inhibitor was observed to enhance the effects of psoralidin on SW480 cells. The results of the present study suggest that psoralidin may be a candidate drug for the treatment of colon cancer by inhibition of the NF-κB and Bcl-2/Bax signaling pathways.

DBD-F induces apoptosis in gastric cancer-derived cells through suppressing HIF2α expression

PURPOSE

Gastric cancer is the third leading cause of cancer-related death in China. Accumulating evidence indicates that HIF2α may affect the aggressiveness of gastric cancer. It has also been found that HIF2α C-terminal PAS domains can form complexes with inactive benzoxadiazole antagonists. Here, the anti-tumor effect of 4-(N,Ndimethylaminosulphonyl)-7-fluoro-1,2,3-benzoxadiazole (DBD-F) on human gastric cancer cells was examined using both in vitro and in vivo assays.

METHODS AND RESULTS

We found that DBD-F can induce apoptosis and inhibit the mobility of MKN28 and MKN45 gastric cancer-derived cells in vitro. We also found that DBD-F can suppress tumor growth in established gastric cancer-derived xenograft models in vivo. Finally, we found that DBD-F can inhibit HIF2α expression in gastric cancer-derived cells.

CONCLUSIONS

From our findings we conclude that DBD-F (i) is cytotoxic to gastric cancer-derived cells and (ii) can induce apoptosis in these cells via the MEK/ERK signaling pathway. In addition, our findings strongly indicate that DBD-F can inhibit HIF2α expression by affecting the phosphorylation status of MEK/ERK in gastric cancer-derived cells.

MicroRNA-338 inhibits migration and proliferation by targeting hypoxia-induced factor 1α in nasopharyngeal carcinoma

Nasopharyngeal cancer (NPC) is an endemic type of head and neck cancer with a high rate of cervical lymph node metastasis. An increasing number of studies have shown that microRNAs (miRNAs) play a key role in the development and progression of NPC. miR-338-3p has been demonstrated as an anti-oncogene in different solid tumors. The aim of the present study was to investigate the potential role of miR‑338-3p in the development and progression of NPC. Compared with normal samples, our data showed that miR-338-3p were downregulated in NPC tissues and cells. The luciferase assay demonstrated that HIF-1α was a direct target of miR-338-3p. We also found that miR-338-3p regulated the expression levels of HIF-1α, respectively. Overexpression of miR-338-3p in NPC cells significantly inhibited cell proliferation, and migration. Conversely, miR-338-3p knockdown in cells with lower endogenous expression levels significantly reduced antitumor behavior. Furthermore, enforced expression of miR-338-3p led to a decline in ERK phosphorylation as well as inhibited the hypoxia induced epithelial to mesenchymal transition. Cells pre-transfected with miR-338-3p can overcome hypoxia-mediated cisplatin resistance. Taken together, we found that miR-338-3p directly targeted HIF-1α, and we provide insight into NPC initiation and progression, possibly representing a novel therapeutic target.

miR-330-3p controls cell proliferation by targeting early growth response 2 in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is one of the most common lung cancers, and microRNAs (miRNAs) have been reported to play essential roles in NSCLC. Recent studies have indicated that miR-330-3p expression is up-regulated in NSCLC samples and in tissues of NSCLC brain metastasis. In this study, up-regulation of miR-330-3p expression was confirmed in NSCLC and 20 NSCLC patient samples. Furthermore, miR-330-3p was over-expressed in NSCLC cell lines A549 and H23, and the promotive function of miR-330-3p was investigated in regulating NSCLC cell proliferation and cell cycle distribution. To identify potential target genes of miR-330-3p in NSCLC, the miRNA target prediction databases were used. Luciferase activity assay and real-time RT-PCR analysis confirmed that miR-330-3p is negatively correlated with the expression of early growth response 2 (EGR2). Moreover, it was also found that EGR2 mRNA contains two potential binding sites for miR-330-3p. Knock-down of EGR2 with siRNA was demonstrated to have a similar effect as the over-expression of miR-330-3p in NSCLC cell lines. Taken together, our results show that EGR2 is a target of miR-330-3p.

MicroRNAs as Regulator of Signaling Networks in Metastatic Colon Cancer

MicroRNAs (miRNAs) are a class of small, noncoding RNA molecules capable of regulating gene expression translationally and/or transcriptionally. A large number of evidence have demonstrated that miRNAs have a functional role in both physiological and pathological processes by regulating the expression of their target genes. Recently, the functionalities of miRNAs in the initiation, progression, angiogenesis, metastasis, and chemoresistance of tumors have gained increasing attentions. Particularly, the alteration of miRNA profiles has been correlated with the transformation and metastasis of various cancers, including colon cancer. This paper reports the latest findings on miRNAs involved in different signaling networks leading to colon cancer metastasis, mainly focusing on miRNA profiling and their roles in PTEN/PI3K, EGFR, TGFβ, and p53 signaling pathways of metastatic colon cancer. The potential of miRNAs used as biomarkers in the diagnosis, prognosis, and therapeutic targets in colon cancer is also discussed.