Retracted: Upregulation of microRNA-140-3p inhibits epithelial-mesenchymal transition,invasion, and metastasis of hepatocellular carcinoma through inactivation of the MAPK signaling pathway by targeting GRN

Invasion and metastasis in hepatocellular carcinoma (HCC) results in poor prognosis. Human intervention in these pathological processes may benefit the treatment of HCC. The aim of the present study is to elucidate the mechanism of miR-140-3p affecting epithelial-mesenchymal transition (EMT), invasion, and metastasis in HCC. Microarray analysis was performed for differentially expressed genes screening. The target relationship between miR-140-3p and GRN was analyzed. Small interfering RNA (siRNA) against granulin (GRN) was synthesized. EMT markers were detected, and invasion and migration were evaluated in HCC cells introduced with a miR-140-3p inhibitor or mimic, or siRNA against GRN. A mechanistic investigation was conducted for the determination of mitogen-activated protein kinase (MAPK) signaling pathway-related genes and EMT markers (E-cadherin, N-cadherin, and Vimentin). GRN was highlighted as an upregulated gene in HCC. GRN was a target gene of miR-140-3p. Elevation of miR-140-3p or inhibition of GRN restrained the EMT process and suppressed the HCC cell migration and invasion. HCC cells treated with the miR-140-3p mimic or siRNA-GRN exhibited decreased GRN expression and downregulated the expressions of the MAPK signaling pathway-related genes, N-cadherin, and Vimentin but upregulated the expression of E-cadherin. GRN silencing can reverse the activation of the MAPK signaling pathway and induction of EMT mediated by miR-140-3p inhibition. Taken together, the results show that miR-140-3p confers suppression of the MAPK signaling pathway by targeting GRN, thus inhibiting EMT, invasion, and metastasis in HCC.     

MicroRNA-506-3p initiates mesenchymal-to-epithelial transition and suppresses autophagy in osteosarcoma cells by directly targeting SPHK1

Osteosarcoma (OS) is the most common malignant bone tumor. In cancer cells, autophagy is related to epithelial-to-mesenchymal transition (EMT). Although microRNA (miR)-506-3p has been demonstrated to act as a tumor suppressor in OS, its role in regulating the EMT process and autophagy remains unknown. The results showed that miR-506-3p directly inhibited the expression of sphingosine kinase 1 (SPHK1) in 143B and SaOS-2 cells. The invasive capability of OS cells was reduced following miR-506-3p mimics transfection, and restored when SPHK1 was overexpressed simultaneously. Further, miR-506-3p mimics initiated mesenchymal-to-epithelial transition (MET) – E-cadherin expression was upregulated, whilst vimentin and fibronectin were downregulated. The basal autophagy flux (LC3II/I) was suppressed by miR-506-3p mimics. The alterations induced by miR-506-3p mimics were partly reversed by SPHK1 overexpression or treatment of rapamycin. Meanwhile, treatment of SPHK1-transfected cells with 3-methyladenine inhibited EMT. The data suggest that miR-506-3p initiates MET and suppresses autophagy in OS cells by targeting SPHK1.     

MicroRNA-409-3p inhibits migration and invasion of bladder cancer cells via targeting c-Met

There is increasing evidence suggesting that dysregulation of certain microRNAs (miRNAs) may contribute to tumor progression and metastasis. Previous studies have shown that miR-409-3p is dysregulated in some malignancies, but its role in bladder cancer is still unknown. Here, we find that miR-409-3p is down-regulated in human bladder cancer tissues and cell lines. Enforced expression of miR-409-3p in bladder cancer cells significantly reduced their migration and invasion without affecting cell viability. Bioinformatics analysis identified the pro-metastatic gene c-Met as a potential miR-409-3p target. Further studies indicated that miR-409-3p suppressed the expression of c-Met by binding to its 3′-untranslated region. Silencing of c-Met by small interfering RNAs phenocopied the effects of miR-409-3p overexpression, whereas restoration of c-Met in bladder cancer cells bladder cancer cells overexpressing miR-409-3p, partially reversed the suppressive effects of miR-409-3p. We further showed that MMP2 and MMP9 may be downstream effector proteins of miR-409-3p. These findings indicate that miR-409-3p could be a potential tumor suppressor in bladder cancer.     

MicroRNA-329-mediated PTTG1 downregulation inactivates the MAPK signaling pathway to suppress cell proliferation and tumor growth in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a severe malignancy usually producing a poor prognosis and high mortality rate. MicroRNAs (miRNAs) have been reported in association with CCA; however, the role miR-329 plays in the CCA condition still remains unclear. Therefore, this study was conducted to explore the underlying mechanism of which miR-329 is influencing the progression of CCA. This work studied the differential analysis of the expression chips of CCA obtained from the Gene Expression Omnibus database. Next, to determine both the expression and role of pituitary tumor transforming gene-1 (PTTG1) in CCA, the miRNAs regulating PTTG1 were predicted. In the CCA cells that had been intervened with miR-329 upregulation or inhibition, along with PTTG1 silencing, expression of miR-329, PTTG1, p-p38/p38, p-ERK5/ERK5, proliferating cell nuclear antigen (PCNA), Cyclin D1, Bcl-2-associated X protein (Bax), B-cell CLL/lymphoma 2 (Bcl-2), and caspase-3 were determined. The effects of both miR-329 and PTTG1 on cell proliferation, cell-cycle distribution, and apoptosis were also assayed. The miR-329 was likely to affect the CCA development through regulation of the PTTG1-mediated mitogen-activated protein kinase (MAPK) signaling pathway. The miR-329 targeted PTTG1, leading to inactivation of the MAPK signaling pathway. Upregulation of miR-329 and silencing of PTTG1 inhibited the CCA cell proliferation, induced cell-cycle arrest, and subsequently promoted apoptosis with elevations in Bax, cleaved caspase-3, and total caspase-3, but showed declines in PCNA, Cyclin D1, and Bcl-2. Moreover, miR-329 was also found to suppress the tumor growth by downregulation of PTTG1. To summarize, miR-329 inhibited the expression of PTTG1 to inactivate the MAPK signaling pathway, thus suppressing the CCA progression, thereby providing a therapeutic basis for the CCA treatment.     

MicroRNA-1296-5p suppresses the proliferation,migration, and invasion of human osteosarcoma cells by targeting NOTCH2

Osteosarcoma (OS) is a highly aggressive bone tumor with a poor prognosis. MicroRNAs are revealed to exerts essential roles in the carcinogenesis and tumor invasion of OS. But, the function of miR-1296-5p and its related mechanism in OS progression have not yet been studied. This study discovered the levels of miR-1296-5p in OS and corresponding noncancerous tissues, and we demonstrated that miR-1296-5p level was markedly downregulated in tumor specimens as compared with nontumor tissues. In addition, we discovered that miR-1296-5p was also underexpressed in OS cells compared with the hFOB1.19 osteoblast cells. Interestingly, the reduced expression of miR-1296-5p was confirmed to associated with large tumor size, advanced tumor stages, and distance metastasis, respectively. Patients with OS low-expressing miR-1296-5p showed a prominent shorter survival. In addition, gain-of-function assays verified that miR-1296-5p overexpression remarkably repressed OS cell proliferation, migration, and invasion. Conversely, depletion of miR-1296-5p facilitated the growth and mobility of OS cells. Notably, miR-1296-5p inversely modulated notch receptor 2 (NOTCH2) in OS cells. The level of NOTCH2 messenger RNA was negatively correlated with miR-1296-5p level in OS samples. NOTCH2 knockdown markedly suppressed the abilities of MG-63 cell proliferation and mobility. More importantly, the restoration of NOTCH2 prominently rescued miR-1296-5p-induced tumor-suppressive effects on MG-63 cells. In conclusion, our study identified the reduced expression of miR-1296-5p, which contributed to OS progression. miR-1296-5p might be a promising prognostic marker and therapeutic target in OS.     

Retracted: MicroRNA-204-3p represses colon cancer cells proliferation,migration, and invasion by targeting HMGA2

Colon cancer is a detrimental neoplasm of the digestive tract. MicroRNAs (miRNAs) as central regulators have been discovered in colon cancer. Nonetheless, the impact of miR-204-3p on colon cancer remains indistinct. The research attempted to uncover the impacts of miR-204-3p on colon cancer cells growth, migration, and invasion. miR-204-3p expression level in colon cancer tissues and diverse colon cancer cell lines were testified by the quantitative real-time polymerase chain reaction. Exploration of the impacts of miR-204-3p on cell growth, migration, invasion, and their associated factors through assessment of CCK-8, flow cytometry, Transwell, and western blot, respectively. High mobility group AT-hook 2 (HMGA2) expression was then detected in Caco-2 cells after miR-204-3p mimic and inhibitor transfection, additionally dual-luciferase activity was implemented to further uncover the correlation between HMGA2 and miR-204-3p. The impact of HMGA2 on Caco-2 cell growth, migration, and invasion was finally assessed. We found that repression of miR-204-3p was discovered in colon cancer tissues and HCT116, SW480, Caco-2, HT29 and SW620 cell lines. MiR-204-3p overexpression mitigated Coca-2 cell viability, facilitated apoptosis, simultaneously adjusted CyclinD1 and cleaved caspase-3 expression. Cell migration, invasion, and the associated factors were all suppressed by miR-204-3p overexpression. Reduction of HMGA2 was presented in Caco-2 cells with miR-204-3p mimic transfection, and HMGA2 was predicated to be a target gene of miR-204-3p. Besides, HMGA2 silence showed the inhibitory effect on Caco-2 cells growth, migration, and invasion. In conclusion, miR-204-3p repressed colon cancer cell growth, migration, and invasion through targeting HMGA2.     

MicroRNA-323-3p promotes myogenesis by targeting Smad2

Skeletal muscle is an important and complex organ with multiple biological functions in humans and animals. Proliferation and differentiation of myoblasts are the key steps during the development of skeletal muscle. MicroRNA (miRNA) is a class of 21-nucleotide noncoding RNAs regulating gene expression by combining with the 3′-untranslated region of target messenger RNA. Many studies in recent years have suggested that miRNAs play a critical role in myogenesis. Through high-throughput sequencing, we found that miR-323-3p showed significant changes in the longissimus dorsi muscle of Rongchang pigs in different age groups. In this study, we discovered that overexpression of miR-323-3p repressed myoblast proliferation and promoted differentiation, whereas the inhibitor of miR-323-3p displayed the opposite results. Furthermore, we predicted Smad2 as the target gene of miR-323-3p and found that miR-323-3p directly modulated the expression level of Smad2. Then luciferase reporter assays verified that Smad2 was a target gene of miR-323-3p during the differentiation of myoblasts. These findings reveal that miR-323-3p is a positive regulator of myogenesis by targeting Smad2. This provides a novel mechanism of miRNAs in myogenesis.     

miR-338-3p suppresses neuroblastoma proliferation,invasion and migration through targeting PREX2a

MicroRNAs (miRNA) can regulate cancer cell proliferation and metastasis. Here, we show that miR-338-3p is down-regulated in metastatic tumor tissues compared to primary tumors, and that that miR-338-3p can inhibit cell proliferation by inducing cell cycle arrest, as well as restrain cell migration and invasion. PREX2a is confirmed as a direct target of miR-338-3p. Knockdown of PREX2a inhibits cell proliferation, migration and invasion through the PTEN/Akt pathway. miR-338-3p-dependent inhibition of proliferation and invasion can be rescued by PREXa. Overall, this study demonstrates that miR-338-3p affects the PTEN/Akt pathway by down-regulating PREX2a. This newly identified function of miR-338-3p provides novel insights into neuroblastoma and may foster therapeutic applications.     

Cantharidin inhibits osteosarcoma proliferation and metastasis by directly targeting miR-214-3p/DKK3 axis to inactivate β-catenin nuclear translocation and LEF1 translation

Background: As the leading primary bone cancer in adolescents and children, osteosarcoma patients with metastasis show a five-year-survival-rate of 20-30%, without improvement over the past 30 years. Wnt/β-catenin is important in promoting osteosarcoma development. DKK3 is a Wnt/β-catenin antagonist and predicted to have the specific binding site in 3′-UTR with miR-214-3p.Methods: miR-214-3p and DKK3 levels were investigated in human osteosarcoma tissues and cells by RT-qPCR; the prognostic importance of DKK3 level in osteosarcoma patients was determined with Log-rank test; direct binding between DKK3 with miR-214-3p was identified with targetscan; anti-osteosarcoma mechanism of cantharidin was investigated by miR-214-3p silence/over-expression with or without cantharidin treatment, and nuclear/cytoplasmic protein assay in osteosarcoma cells.Results: Down-regulated DKK3 indicated poor prognosis of osteosarcoma patients. Up-regulated miR-214-3p promoted proliferation and migration, while suppressed apoptosis of osteosarcoma cells by increasing β-catenin nuclear translocation and LEF1 translation via degradation of DKK3. Cantharidin suppressed viabilities, migration and invasion, while promoted cell cycle arrest and apoptosis in 143B and U-2 OS cells via down-regulating miR-214-3p to up-regulate DKK3, thus inhibited p-GSK-3β expression, β-catenin nuclear translocation and LEF1 translation. Meanwhile, cantharidin inhibited tumor growth in xenograft-bearing mice with 143B cell injection in tibia.Conclusion: miR-214-3p mediated Wnt/β-catenin/LEF1 signaling activation by targeting DKK3 to promote oncogenesis of osteosarcoma; cantharidin inhibited proliferation and metastasis of osteosarcoma cells via down-regulating miR-214-3p to up-regulate DKK3 and decrease β-catenin nuclear translocation, indicating that cantharidin may be a prospective candidate for osteosarcoma treatment by targeting miR-214-3p/DKK3/β-catenin signaling.     

MicroRNA-490-3p inhibits proliferation of A549 lung cancer cells by targeting CCND1

MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate the translation of messenger RNAs by binding their 3′-untranslated region (3′UTR). In this study, we found that miR-490-3p is significantly down-regulated in A549 lung cancer cells compared with the normal bronchial epithelial cell line. To better characterize the role of miR-490-3p in A549 cells, we performed a gain-of-function analysis by transfecting the A549 cells with chemically synthesized miR-490-3P mimics. Overexpression of miR-490-3P evidently inhibits cell proliferation via G1-phase arrest. We also found that forced expression of miR-490-3P decreased both mRNA and protein levels of CCND1, which plays a key role in G1/S phase transition. In addition, the dual-luciferase reporter assays indicated that miR-490-3P directly targets CCND1 through binding its 3′UTR. These findings indicated miR-490-3P could be a potential suppressor of cellular proliferation.     

MicroRNA-129-5p inhibits 3T3-L1 preadipocyte proliferation by targeting G3BP1

MicroRNAs have been regarded to play a crucial role in the proliferation of different cell types including preadipocytes. In our study, we observed that miR-129-5p was down-regulated during 3T3-L1 preadipocyte proliferation, while the expression of G3BP1 showed a contrary tendency. 5-Ethynyl-2′-deoxyuridine (EdU) incorporation assay and flow cytometry showed that overexpression of miR-129-5p could bring about a reduction in S-phase cells and G2-phase arrest. Additional study indicated that miR-129-5p impaired cell cycle-related genes in 3T3-L1 preadipocytes. Importantly, it showed that miR-129-5p directly targeted the 3′UTR of G3BP1 and the expression of G3BP1 was inhibited by miR-129-5p mimic. Moreover, miR-129-5p mimic activated the p38 signaling pathway through up-regulating p38 and the phosphorylation level of p38. In a word, results in our study revealed that miR-129-5p suppressed preadipocyte proliferation via targeting G3BP1 and activating the p38 signaling pathway.     

MicroRNA-188-5p promotes apoptosis and inhibits cell proliferation of breast cancer cells via the MAPK signaling pathway by targeting Rap2c

Breast cancer is a common malignancy that is highly lethal with poor survival rates and immature therapeutics that urgently needs more effective and efficient therapies. MicroRNAs are intrinsically involved in different cancer remedies, but their mechanism in breast cancer has not been elucidated for prospective treatment. The function and mechanism of microRNA-188-5p (miR-188) have not been thoroughly investigated in breast cancer. In our study, we found that the expression of miR-188 in breast cancer tissues was obviously reduced. Our findings also revealed the abnormal overexpression of miR-188 in 4T1 and MCF-7 cells significantly suppressed cell proliferation and migration and also enhanced apoptosis. miR-188 induced cell cycle arrest in the G1 phase. To illuminate the molecular mechanism of miR-188, Rap2c was screened as a single target gene by bioinformatics database analysis and was further confirmed by dual-luciferase assay. Moreover, Rap2c was found to be a vital molecular switch for the mitogen-activated protein kinase signaling pathway in tumor progression by decreasing apoptosis and promoting proliferation and migration. In conclusion, our results revealed that miR-188 is a cancer progression suppressor and a promising future target for breast cancer therapy.     

Signaling pathway of MAPK/ERK in cell proliferation,differentiation, migration,senescence and apoptosis

Abstract

The generic mitogen-activated protein kinases (MAPK) signaling pathway is shared by four distinct cascades, including the extracellular signal-related kinases (ERK1/2), Jun amino-terminal kinases (JNK1/2/3), p38-MAPK and ERK5. Mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/ERK) pathway is reported to be associated with the cell proliferation, differentiation, migration, senescence and apoptosis. The literatures were searched extensively and this review was performed to review the role of MAPK/ERK signaling pathway in cell proliferation, differentiation, migration, senescence and apoptosis.     

MicroRNA-5p and -3p co-expression and cross-targeting in colon cancer cells

Background

Two mature miRNA species may be generated from the 5’ and 3’ arms of a pre-miRNA precursor. In most cases, only one species remains while the complementary species is degraded. However, co-existence of miRNA-5p and -3p species is increasingly being reported. In this work, we aimed to systematically investigate co-expression of miRNA-5p/3p in colon cancer cells in a genome-wide analysis, and to examine cross-targeting of the dysregulated miRNAs and 5p/3p species.

Results

Four colon cancer cell lines were examined relative to two normal colon tissues. Of the 1,190 miRNAs analyzed, 92 and 36 were found to be up- or down-regulated, respectively, in cancer cells. Nineteen co-expressed miRNA-5p/3p pairs were further identified suggesting frequent 5p/3p co-accumulation in colon cancer cells. Of these, 14 pairs were co-up-regulated and 3 pairs were co-down-regulated indicating concerted 5p/3p dysregulation. Nine dysregulated miRNA pairs fell into three miRNA gene families, namely let-7, mir-8/200 and mir-17, which showed frequent cross-targeting in the metastasis process. Focusing on the let-7d-5p/3p pair, the respectively targeted IGF1R and KRAS were shown to be in a reverse relationship with expression of the respective miRNA, which was confirmed in transient transfection assays using let-7d mimic or inhibitor. Targeting of KRAS by let-7d was previous reported; targeting of IGF1R by let-7d-5p was confirmed in luciferase assays in this study. The findings of let-7d-5p/3p and multiple other miRNAs targeting IGF1R, KRAS and other metastasis-related factors suggest that 5p/3p miRNAs contribute to cross-targeting of multiple cancer-associated factors and processes possibly to evade functional abolishment when any one of the crucial factors are inactivated.

Conclusions

miRNA-5p/3p species are frequently co-expressed and are coordinately regulated in colon cancer cells. In cancer cells, multiple cross-targeting by the miRNAs, including the co-existing 5p/3p species, frequently occurs in an apparent safe-proof scheme of miRNA regulation of important tumorigenesis processes. Further systematic analysis of co-existing miRNA-5p/3p pairs in clinical tissues is important in elucidating 5p/3p contributions to cancer pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-014-0095-x) contains supplementary material, which is available to authorized users.