MicroRNA-328 inhibits migration and epithelial-mesenchymal transition by targeting CD44 in nasopharyngeal carcinoma cells

MiRNA signatures in nasopharyngeal carcinoma: molecular mechanisms and therapeutic perspectives

Nasopharyngeal carcinoma (NPC) is a prevalent cancerous tumor that affects the head and neck region. Recent studies have provided compelling evidence indicating the significant involvement of microRNAs (miRNAs) in the development and progression of NPC. This review aims to present a comprehensive summary of the current knowledge regarding miRNA signatures in NPC, encompassing their expression patterns, molecular mechanisms, and potential therapeutic implications. Initially, the article outlines the aberrant expression of miRNAs in NPC and elucidates their roles in tumor initiation, invasion, and metastasis. Subsequently, the underlying molecular mechanisms of miRNA-mediated regulation of NPC-associated signaling pathways are discussed. Additionally, the review highlights the potential clinical applications of miRNAs as diagnostic and prognostic biomarkers, as well as their therapeutic potential in NPC treatment. In conclusion, this review underscores the critical involvement of miRNAs in NPC pathogenesis and underscores their promise as novel therapeutic targets for combating this devastating disease.

Diverse functions of miR-328 in the carcinogenesis

MicroRNA-328 (miR-328) is an RNA gene that is primarily associated with lung cancer, and its encoding gene is located on 16q22.1. Expression of miR-328 has been observed in lung and esophagus tissues based on RNAseq data. Although several studies have aimed at the detection of miR-328 levels in tumor tissues, there is an obvious discrepancy between the results of these studies. Even in a certain type of cancer, some studies have reported up-regulation of miR-328 in cancerous tissues versus control tissues, while others have reported its down-regulation. This discrepancy might be attributed to different stages/grades of tumor tissues or other clinical characteristics. This review article focuses on the available literature to explore the functions of miR-328 in the development of human carcinogenesis.

Capsaicin suppresses the migration and invasion of human nasopharyngeal carcinoma cells through the modulation of mTOR signaling pathway

Nasopharyngeal carcinoma (NPC), a malignancy of the nasopharynx, is prevalent in Southeast Asia and Southern China. The prognosis of NPC is poor and local recurrence and metastasis often occur. Capsaicin (tran-8-methyl-N-vanillyl-6-nonenamide), a pungent constituent of hot chili peppers, shows anti-cancer activities such as anti-proliferation and anti-metastasis. Currently, the role of capsaicin in cell metastasis of NPC is not well understood. We tested whether capsaicin has anti-metastatic activity in NPC cell lines. Capsaicin suppressed cell proliferation in dose-dependent manner. Moreover, capsaicin inhibited cell metastasis as shown by wound healing assay and decreased the expressions of MMP-2 and MMP-9. In addition, the phosphorylation of mTOR was downregulated by capsaicin. Combination of capsaicin and rapamycin (mTOR inhibitor) treatments led to increasing of anti-growth and anti-metastatic activities. Therefore, capsaicin has potential to be used as an optional therapeutic drug for treatment of NPC.

Advances in research on microRNAs related to the invasion and metastasis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), which is associated with latent Epstein-Barr virus infection in most cases, is a unique epithelial malignancy arising from the nasopharyngeal mucosal lining. Accumulating evidence provides insights into the genetic and molecular aberrations that likely drive nasopharyngeal tumor development and progression. We review recent analyses of microRNAs (miRNAs), including Epstein-Barr virus-encoded miRNAs (EBV-encoded miRNAs) and dysregulated cellular miRNAs, that may be related to the metastasis of nasopharyngeal carcinoma. The studies summarized herein have greatly expanded our knowledge of the molecular biology of NPC involving miRNAs, and they may provide new biological targets for clinical diagnosis and reveal the potential of microRNA therapeutics. However, much information remains to be uncovered.

Fatty acid β-oxidation promotes breast cancer stemness and metastasis via the miRNA-328-3p-CPT1A pathway

MicroRNAs (miRNA) have been shown to be associated with tumor diagnosis, prognosis, and therapeutic response. MiR-328-3p plays a significant role in breast cancer growth; however, its actual function and how it modulates specific biological functions is poorly understood. Here, miR-328-3p was significantly downregulated in breast cancer, especially in patients with metastasis. Mitochondrial carnitine palmitoyl transferase 1a (CPT1A) is a downstream target gene in the miR-328-3p-regulated pathway. Furthermore, the miR-328-3p/CPT1A/fatty acid β-oxidation/stemness axis was shown responsible for breast cancer metastasis. Collectively, this study revealed that miR-328-3p is a potential therapeutic target for the treatment of breast cancer patients with metastasis, and also a model for the miRNA-fatty acid β-oxidation-stemness axis, which may assist inunderstanding the cancer stem cell signaling functions of miRNA.

LncRNA LOC146880 promotes esophageal squamous cell carcinoma progression via miR-328-5p/FSCN1/MAPK axis

We investigated the role of long non-coding RNA (lncRNA) LOC146880 in esophageal squamous cell carcinoma (ESCC). LOC146880 was significantly upregulated in ESCC tissues (n = 21) and cell lines compared to the corresponding controls. Higher LOC146880 expression correlated with poorer overall survival (OS) of ESCC patients. Moreover, CREB-binding protein (CBP) and H3K27 acetylation levels were significantly higher in the LOC146880 promoter in ESCC cell lines than in the controls. LOC146880 silencing inhibited in vitro proliferation, invasion, migration, and epithelial-mesenchymal transition of ESCC cells. LOC146880 silencing also induced G1-phase cell cycle arrest and apoptosis in ESCC cells. Bioinformatics analysis, dual luciferase reporter assays, and RNA immunoprecipitation assays showed that LOC146880 regulates FSCN1 expression in ESCC cells by sponging miR-328-5p. Moreover, FSCN1 expression correlated with activation of the MAPK signaling pathway in ESCC cells and tissues. In vivo xenograft tumor volume and liver metastasis were significantly reduced in nude mice injected with LOC146880-silenced ESCC cells as compared to those injected with control shRNA-transfected ESCC cells. These findings show that the LOC146880/miR-328-5p/FSCN1/MAPK axis regulates ESCC progression in vitro and in vivo. LOC146880 is thus a promising prognostic biomarker and potential therapeutic target in ESCC.

Identification of a novel microRNA profile including miR-106b, miR-17, miR-20b, miR-18a and miR-93 in the metastasis of nasopharyngeal carcinoma

BACKGROUND

Metastasis often leads to poor prognosis in nasopharyngeal carcinoma (NPC) patients. Evidence has indicated the important roles of microRNA (miRNA) in cancer metastasis. The aim of this study was to identify and verify the key miRNAs that might be involved in the development of NPC metastasis.

METHODS

Microarray data were obtained and analyzed to screen the differentially expressed miRNAs (DEMs) between NPC tissues with metastasis and those without metastasis. The target genes of the DEMs were predicted and their functions were annotated. Then, candidate hub genes were screened out through protein-protein interaction analysis, and the key miRNAs were identified. Afterwards, the expression levels of the key miRNAs were assessed by qRT-PCR based on an in vitro model.

RESULTS

A total of 22 DEMs were screened out, and 616 target genes were predicted. Gene Ontology (GO) and pathway enrichment analysis showed that the target genes may be enriched in a diversity of GO terms and signaling pathways. Among them, eleven hub genes were identified, such as PTEN, KAT2B, CCND1, STAT3, and MAP3K5. Moreover, a five-miRNA profile (miR-106b, miR-17, miR-20b, miR-18a and miR-93) was identified and their expression levels were tested to be up-regulated in high-metastatic NPC cells relative to low-metastatic ones.

CONCLUSION

The present study revealed that five miRNAs (miR-106b, miR-17, miR-20b, miR-18a and miR-93) and several hub genes such as PTEN, KAT2B, CCND1, STAT3, and MAP3K5, might play critical roles in the development of NPC metastasis. Future investigations are needed to confirm the results.

Significance of alternative splicing in cancer cells

Objective

Alternative splicing can generate various structural and functional protein isoforms. Recently, accumulating evidence shows a relationship between alternative splicing and cancer. Cancer is a complex and chronic disease that involves malignant transformation. In this review, we consider alternative splicing events in relation to the hallmarks of cancer cells, and discuss current therapies to treat cancer-related to alternative splicing.

Data sources

Data cited in this article are from the PubMed and Embase database, primarily focusing on research published from 2000 to 2018.

Study selection

Articles were selected with the search terms “alternative splicing,” “cancer cell,” “tumor microenvironment,” and “therapy.”

Results

Alternative splicing plays an important role in tumorigenesis, development, and escape from cell death. Taking this trait of cancer cells into consideration will allow more definite diagnoses of cancer, and allow the development of more effective medicines to intervene in cancer that could focus on controlling alternative splicing or competitively binding to the final products.

Conclusions

Alternative splicing is common in cancer cells. Consideration of alternative splicing may allow different strategies for cancer therapy or the identification of novel biomarkers for cancer diagnosis.

EMT signaling: potential contribution of CRISPR/Cas gene editing

Epithelial to mesenchymal transition (EMT) is a complex plastic and reversible cellular process that has critical roles in diverse physiological and pathological phenomena. EMT is involved in embryonic development, organogenesis and tissue repair, as well as in fibrosis, cancer metastasis and drug resistance. In recent years, the ability to edit the genome using the clustered regularly interspaced palindromic repeats (CRISPR) and associated protein (Cas) system has greatly contributed to identify or validate critical genes in pathway signaling. This review delineates the complex EMT networks and discusses recent studies that have used CRISPR/Cas technology to further advance our understanding of the EMT process.

Low expression of microRNA-328 can predict sepsis and alleviate sepsis-induced cardiac dysfunction and inflammatory response

Sepsis often leads to cardiac dysfunction and inflammation. This study investigated the clinical value of microRNA-328 (miR-328) in sepsis and its role in cardiac dysfunction and inflammation caused by sepsis. The expression level of miR-328 in the serum of the subjects was detected by qRT-PCR. Receiver operating characteristic (ROC) curve measured the diagnostic value of miR-328 in sepsis. Rat sepsis model was established to detect left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), and maximal rate of increase/decrease of left ventricular pressure (±dp/dt_max). Myocardial injury markers serum cardiac troponin I (cTnI), myocardial kinase isoenzyme (CK-MB), and inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA). miR-328 expression was assessed in serum of sepsis patients and in rat models of sepsis. The AUC of ROC curve was 0.926, sensitivity 87.60%, and specificity 86.36%. Compared with the sham group, LVSP and +dp/dt_max were decreased in the rat model of sepsis. LVEDP, -dp/dt_max, cTnI, CK-MB, tumor necrosis factor-α, interleukin (IL)-6, and IL-1β were upregulated in the rat model of sepsis. The low expression of miR-328 reversed these indicators. miR-328 is a diagnostic marker for patients with sepsis, and decreasing the expression level of miR-328 can ameliorate cardiac dysfunction and cardiac inflammation in sepsis.

LINC00210 plays oncogenic roles in non-small cell lung cancer by sponging microRNA-328-5p

Long noncoding RNA (lncRNA) has an important role in regulating non-small cell lung cancer (NSCLC) progression. The present study aimed to investigate the effect of LINC00210 in NSCLC progression in order to provide a novel treatment target for patients with NSCLC. A total of 39 NSCLC patients were obtained and divided into LINC00210 high expression and low expression groups. Subsequently, the 5-year survival rate from this patient cohort was analyzed. The SK-MES-1 and A549 NSCLC and the human 16-HBE bronchial epithelial cell lines were utilized to investigate expression level of LIN00210. A549 cells were used to investigate cell proliferation, migration and invasive abilities using Cell Counting kit 8, Transwell and Matrigel assays, respectively. In addition, the luciferase reporter gene assay was performed to investigate the potential target of LINC00210. Reverse transcription-quantitative PCR was used to determine LINC00210 and microRNA (miR)-328-5p expression levels in NSCLC tissues and tumor cell lines (SK-MES-1 and A549). The results demonstrated that LINC00210 was upregulated in NSCLC tissues and cell lines compared with that in normal tissues and 16-HBE cells, and that LINC00210 expression was associated with a poor prognosis in patients with NSCLC (P<0.05). Furthermore, A549 cell transfection with small interfering (si)LINC00210#1 and siLINC00210#2 induced a significant decrease in cell proliferation, and migratory and invasive abilities compared with that in the control groups (P<0.05). In addition, miR-328-5p overexpression was stimulated by knockdown of LINC00210. Furthermore, A549 cells transfected with siLINC00210#1 and miR-328-5p inhibitor exhibited a significant increase in cell proliferation, and migratory and invasive ability compared with that in A549 cells transfected with siLINC00210#1. These findings suggest that LINC00210 may serve as an oncogenic role in NSCLC by sponging miR-328-5p.

MiR-328-3p inhibits cell proliferation and metastasis in colorectal cancer by targeting Girdin and inhibiting the PI3K/Akt signaling pathway

MiR-328-3p has been reported to be downregulated and serve as a tumor suppressor in several cancers. Previous studies only have reported the downregulation of miR-328-3p in CRC. However, the roles of miR-328-3p in CRC growth and metastasis were unknown. In this study, we demonstrated that miR-328-3p overexpression inhibited cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). The PI3K/Akt signaling pathway was also inactivated by miR-328-3p overexpression. MiR-328-3p knockdown showed the opposite effects. In addition, we confirmed that miR-328-3p directly bound to 3'UTR of Girdin and negatively regulated its expression. Girdin knockdown or treatment with PI3K inhibitor LY294002 blocked the effects of miR-328-3p inhibitor on cell proliferation, metastasis, and the PI3K/Akt signaling pathway. Moreover, pre-miR-328 decreased numbers of liver metastatic nodules, and reduced the levels of p-Akt, p-Girdin, and Girdin in metastatic tissues in liver. In conclusion, miR-328-3p may inhibit proliferation and metastasis of CRC cells by targeting Girdin and inactivating the PI3K/Akt signaling pathway. MiR-328-3p may be a novel target in cancer therapy.

miRNA-520c-3p accelerates progression of nasopharyngeal carcinoma via targeting RAB22A

Biological function of microRNA-20c-3p (miRNA-520c-3p) in the progression of nasopharyngeal carcinoma (NPC) and the potential mechanism were investigated. Relative level of miRNA-520c-3p in NPC tissues and adjacent normal tissues was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Particularly, miRNA-520c-3p level in NPC with different tumor stages and tumor sizes was examined. Subsequently, miRNA-520c-3p level in nasopharyngeal epithelial cells and NPC cells was detected. The potential influence of miRNA-520c-3p on the proliferative ability and cell cycle progression of NPC cells were evaluated through cell counting kit-8 (CCK-8) and flow cytometry. The target gene of miRNA-520c-3p was verified by dual-luciferase reporter gene assay. Regulatory role of miRNA-520c-3p/RAB22A in the malignant progression of NPC was identified. miRNA-520c-3p was downregulated in NPC tissues and cell lines. Its level was lower in NPC with worse tumor grade and larger tumor size. Overexpression of miRNA-520c-3p suppressed the proliferative ability and arrested cell cycle in G0/G1 phase. RAB22A was confirmed to be the downstream target of miRNA-520c-3p. In NPC tissues and cell lines, RAB22A remained in higher abundance relative to controls. Overexpression of RAB22A reversed the inhibitory effects of overexpressed miRNA-520c-3p on proliferative ability and cell cycle progression of NPC cells. miRNA-520c-3p is downregulated in NPC, which accelerates the malignant progression of NPC by targeting RAB22A.

Characterizing CD44 regulatory microRNAs as putative therapeutic agents in human melanoma

The multistructural and multifunctional transmembrane glycoprotein CD44 is overexpressed in many tumors of distinct origin including malignant melanoma and contributes to a poor prognosis by affecting cell proliferation, cell migration, and also the sensitivity for apoptosis induction. Previous studies reported so far 15 CD44 regulatory microRNAs (miRs) in different cell systems. Using a novel method for miR affinity purification miR-143-3p was identified as most potent binder to the 3' untranslated region (UTR) of CD44. Overexpression of miR-143-3p in melanoma cells inhibits CD44 translation, which is accompanied by a reduced proliferation, migration and enhanced daunorubicin induced apoptosis of melanoma cells in vitro. Analyses of discordant CD44 and miR-143-3p expression levels in human melanocytic nevi and dermal melanoma samples demonstrated medium to high CD44 levels with no association to tumor grading or staging. The CD44 expression correlated to PD-L1, but not to MART-1 expression in malignant melanoma. Interestingly, the CD44 expression was inversely correlated to the infiltration of pro-inflammatory immune effector cells. In conclusion, the tumor suppressive miR-143-3p was identified as the most potent CD44 inhibitory miR, which affects growth characteristics of melanoma cells suggesting the implementation of miR-143-3p as as a potential anti-CD44 therapy of malignant melanoma.

MicroRNA-154 Targets the Wnt/β-Catenin Signaling Pathway Following Injury to Human Vascular Endothelial Cells by Hydrogen Peroxide

Background

Endothelial cells are involved in vascular homeostasis, and endothelial cell dysfunction is involved in the pathogenesis of cardiovascular disease. This study aimed to investigate the effects of microRNA-154 in human umbilical vein endothelial cells (HUVECs) following injury induced by hydrogen peroxide (H₂O₂).

Material/Methods

Cell viability and apoptosis of HUVECs treated with H₂O₂ were measured. The expression of microRNA-154 was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell survival, caspase-3 activity, and the apoptosis rate were evaluated in H₂O₂-treated HUVECs cells after the upregulation and down-regulation of microRNA-154 expression. The interaction between microRNA-154 and Dickkopf WNT signaling pathway inhibitor 2 (DKK2) was predicted by bioinformatics analysis and was verified by luciferase reporter gene assay and Western blot. The effects of DKK2 short-interfering RNA (siRNA) on antioxidant injury in HUVECs cells were determined.

Results

The survival rate of HUVECs exposed to H₂O₂ was significantly reduced and the apoptosis rate was significantly increased, and H₂O₂ significantly inhibited the expression of microRNA-154 in a dose-dependent manner. Overexpression of microRNA-154 increased cell survival, reduced the activity of caspase-3, and reduced cell apoptosis. Inhibition of microRNA-154 expression decreased cell survival, increased the activity of caspase-3, and promoted cell apoptosis. Luciferase reporter gene assay and Western blot showed that microRNA-154 interacted with the Wnt pathway molecule DKK2 in HUVECS. Also, DDK2 siRNA resulted in a similar protective effect on H₂O₂-treated HUVECs as overexpression of microRNA-154.

Conclusions

Oxidative injury in HUVECs was regulated by microRNA-154 targeting the Wnt/β-catenin signaling pathway.

Strand-specific miR-28-3p and miR-28-5p have differential effects on nasopharyngeal cancer cells proliferation, apoptosis, migration and invasion

Background

MicroRNAs (miRNAs) play crucial roles in varieties of cancers, particularly in tumorigenesis, progression, and migration. Dysregulation of miR-28 was reported to occur in various types of human malignancies. In humans, two different mature miRNA sequences are excised from opposite arms of the stem-loop pre-miR-28, hsa-miR-28-3p and hsamiR-28-5p. However, the expression and distinct role of miR-28-3p and miR-28-5p in nasopharyngeal carcinoma (NPC) remain undetermined.

Methods

The expressions of miR-28-3p/-5p in human NPC tissues were tested by quantitative real-time PCR. miR-28-3p/-5p were overexpressed by mimics and silenced by inhibitors. The roles of miR-28-3p/-5p in NPC development were studied using cultured HONE-1 cells.

Results

The mRNA expression levels of miR-28-3p and -5p were significantly decreased in NPC tissues in comparison with adjacent normal tissues. Overexpression of miR-28-5p suppressed NPC cell proliferation and induced cell cycle arrest and apoptosis, while miR-28-3p promoted NPC cell migration and invasion. The miRNAs effected on different signal pathways: miR-28-5p altered expression of cyclin D1 and influenced the PI3K/AKT signaling pathway. In contrast, miR-28-3p downregulated Nm23-H1 and accelerated the process of EMT.

Conclusion

miR-28-3p and -5p were both downregulated in NPC tissues but had distinct biological effects in NPC cells. They may serve as potential prognostic markers and therapeutic targets for NPC.

microRNA-328 in exosomes derived from M2 macrophages exerts a promotive effect on the progression of pulmonary fibrosis via FAM13A in a rat model

Currently, exosome-enclosed microRNAs (miRs) in exhaled breath have potential for biomarker discovery in patients with pulmonary diseases. This study was performed to investigate the roles of M2 macrophage-derived exosomes expressing miR-328 in pulmonary fibrosis (PF). Microarray-based analysis was used to screen differentially expressed genes (DEGs) and regulatory miRs in PF. The miR-target relationship between FAM13A and miR-328 was confirmed. The expression of FAM13A and miR-328 was measured in PF rats, and gain- and loss-of-function assays were conducted to determine the regulatory effects of FAM13A and miR-328 on PF. In addition, exosomes derived from M2 macrophages were isolated and then cocultured with pulmonary interstitial fibroblasts to identify the role of these exosomes in PF. Furthermore, the effects of M2 macrophage-derived exosomes overexpressing miR-328 on pulmonary fibroblast proliferation and the progression of PF were assessed in vivo. miR-328 might perform a vital function in PF by regulating FAM13A. FAM13A expression was downregulated while miR-328 expression was upregulated in rats with PF, and a miR-target relationship between miR-328 and FAM13A was observed. Additionally, miR-328 overexpression and FAM13A silencing each were suggested to promote pulmonary interstitial fibroblast proliferation and the expression of Collagen 1A, Collagen 3A and α-SMA. Then, in vitro experiments demonstrated that M2 macrophage-derived exosomes overexpressing miR-328 contributed to enhanced pulmonary interstitial fibroblast proliferation and promoted PF. Furthermore, in vivo experiments confirmed the promotive effects of M2 macrophage-derived exosomes overexpressing miR-328 on the progression of PF. Collectively, the results showed that M2 macrophage-derived exosomes overexpressing miR-328 aggravate PF through the regulation of FAM13A.

Studies in rats suggest that microRNAs, small molecules of ribonucleic acid, released by macrophage cells of the immune system can promote pulmonary fibrosis (PF), the formation of scar tissue in lungs. Gao-Feng Zhao, Li-Hua Xing and colleagues at The First Affiliated Hospital of Zhengzhou University in China investigated the role of microRNAs in rats with a form of PF that serves as a model for the disease in humans. Their findings confirm that specific microRNAs released in tiny membrane-bound sacs called exosomes interact with and inhibit a gene whose activity is known to be disrupted in PF. The protein encoded by this gene mediates crucial molecular signaling events in lung cells. Developing drugs that interfere with the activity of the microRNAs is a potential new treatment approach for PF.

Elevated expression of microRNA-328-3p suppresses aggressive malignant behaviors via targeting matrix metalloprotease 16 in osteosarcoma

Background

A previous study indicated that microRNA(miR)-328-3p upregulation might be critical for resveratrol-mediated suppression of metastatic ability in human osteosarcoma, implying its potential role in this malignancy. However, the clinical significance and the biological functions of miR-328-3p in osteosarcoma remain unclear.

Methods

miR-328-3p expression in 88 pairs of osteosarcoma and matched non-cancerous bone tissues were detected by quantitative real-time PCR. Then, the associations of miR-328-3p expression with various clinicopathological features of osteosarcoma patients were statistically analyzed. Cell Counting Kit-8 and scratch-wound healing were performed to evaluate roles of miR-328-3p in human osteosarcoma cells. After that, luciferase reporter assay, western blot analysis and rescue assay were applied to determine the underlying molecular mechanisms of miR-328-3p in osteosarcoma cells.

Results

miR-328-3p expression in osteosarcoma tissues was significantly lower than those in non-cancerous bone tissues (P<0.001). miR-328-3p downregulation was significantly associated with advanced surgical stage, positive metastasis and recurrence (all P<0.05). Functionally, enforced expression of miR-328-3p efficiently suppressed cell proliferation and migration in vitro. Moreover, matrix metalloprotease 16 (MMP16) was identified as a direct target of miR-328-3p in osteosarcoma cells. Notably, MMP16 overexpression partially reversed the miR-328-3p-inhibited cell proliferation and migration of osteosarcoma cells.

Conclusions

Our data indicated that the aberrant expression of miR-328-3p may play a crucial role in malignant progression of human osteosarcoma. More importantly, miR-328-3p may function as a tumor suppressor inhibiting osteosarcoma cell proliferation and migration partially mediated by regulating of MMP16.

Muscleblind‑like 1 destabilizes Snail mRNA and suppresses the metastasis of colorectal cancer cells via the Snail/E‑cadherin axis

RNA-binding proteins (RBPs) play a fundamental role in the recurrence and metastasis of colorectal cancer (CRC). In this study, we identified muscleblind-like 1 (MBNL1), an RBP implicated in developmental control, as a robust suppressor of CRC cell metastasis in vitro. By using a scratch assay coupled with time-lapse live cell imaging, our findings revealed that the knockdown of MBNL1 induced epithelial-to-mesenchymal transition (EMT)-like morphological changes in the HCT-116 cells, accompanied by an enhanced cell motility, and by the downregulation of E-cadherin and the upregulation of Snail expression. By contrast, the ectopic overexpression of MBNL1 suppressed EMT, characterized by the upregulation of E-cadherin and the downregulation of Snail expression. Mechanistically, Snail rather than E-cadherin, was identified as a direct downstream target gene of MBNL1. The ectopic the overexpression of MBNL1 markedly enhanced the recruitment of Snail transcripts to processing bodies (P-bodies), leading to the increased degradation of Snail mRNA and consequent translational silencing. Furthermore, the effect of MBNL1 on CRC cell migration was confirmed in additional CRC cell lines. SW480 and HT-29 cells exhibited similar changes in migratory capacity and the expression of Snail/E-cadherin to those observed in HCT-116 cells. On the whole, this study demonstrates that MBNL1 destabilizes Snail transcripts and, in turn, suppresses the EMT of CRC cells through the Snail/E-cadherin axis in vitro. Therefore, this EMT-related MBNL1/Snail/E-cadherin axis may prove to be a novel therapeutic target for CRC metastasis.

The regulatory network of nasopharyngeal carcinoma metastasis with a focus on EBV, lncRNAs and miRNAs

Metastasis of nasopharyngeal carcinoma (NPC) remains a main cause of death for NPC patients even though great advances have been made in therapeutic approaches. An in-depth study into the molecular mechanisms of NPC metastasis will help us combat NPC. Epstein-Barr virus (EBV) infection is an evident feature of nonkeratinizing NPC and is strongly associated with tumor metastasis. Recently, long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) have become a hot topic of research due to their epigenetic regulatory roles in NPC metastasis. The EBV products, lncRNAs and miRNAs can target each other and share several common signaling pathways, which form an interconnected, complex molecular regulatory network. In this review, we discuss the features of this regulatory network and summarize the molecular mechanisms of NPC metastasis, focusing on EBV, lncRNAs and miRNAs with updated knowledge.

MiR-1284 enhances sensitivity of cervical cancer cells to cisplatin via downregulating HMGB1

BACKGROUND

Chemotherapy is one of the commonest therapeutic method for cervical cancer. There are some common chemotherapy drugs, such as cisplatin, docetaxel, paclitaxel and selenium nanoparticle. microRNAs (miRNAs) have been verified to be regulators in various human cancers. This study aims to investigate the effects of miR-1284 on the cisplatin sensitivity of cervical cancer cells.

METHODS

The levels of miR-1284 in different tissues and cell lines were detected through using qRT-PCR analysis. Kaplan Meier analysis was utilized to analyze the influence of miR-1284 expression on the overall survival rate of cervical cancer patients. The biological effects of miR-1284 on the progression and chemosensitivity of cervical cancer were tested through conducting functional assays. Mechanism investigations were used to prove the binding relation between miR-1284 and HMGB1. Rescue assays were applied to demonstrate the effects of miR-1284-HMGB1 axis on chemosensitivity of cervical cancer cells.

RESULTS

miR-1284 was down-expressed in cervical cancer tissues and cell lines. Patients with low level of miR-1284 had low overall survival rate. Upregulation of miR-1284 suppressed proliferation and invasion, while promoted apoptosis. Moreover, upregulated miR-1284 enhanced sensitivity of cervical cancer cells to cisplatin. HMGB1 was a target gene of miR-1284. HMGB1 reversed the effects of miR-1284 on the progression and chemosensitivity of cervical cancer cells.

CONCLUSION

miR-1284 enhances sensitivity of cervical cancer cells to cisplatin via targeting HMGB1.