miR-486-5p inhibits cell growth of papillary thyroid carcinoma by targeting fibrillin-1

Previous studies have demonstrated that miR-486-5p functions as a tumor suppressor or oncogene in various types of cancer. In the present study, we showed that miR-486-5p was significantly down-regulated in papillary thyroid carcinoma (PTC) tissues and cell lines, whereas miR-486-5p down-regulation inhibited PTC cell proliferation and increased apoptosis. Conversely, under-expression of miR-486-5p enhanced PTC cell proliferation and decreased apoptosis. Fibrillin-1 (FBN1) was shown to be a direct target of miR-486-5p and inversely regulated by miR-486-5p. FBN1 silencing led to decreased PTC cell proliferation and enhanced apoptosis in vitro, similar to that mediated by miR-486-5p. Furthermore, miR-486-5p over-expression or FBN1 knock-down inhibited, while up-regulation of FBN1 boosted xenograft tumor formation in vivo. Our data suggest that miR-486-5p induces PTC cell growth inhibition and apoptosis by targeting and suppressing FBN1. Thus, miR-486-5p/FBN1 might provide a promising therapeutic target for PTC treatment.     

Retracted Article: miR-199a-3p knockdown inhibits dedifferentiated liposarcoma (DDLPS) cell viability and enhances apoptosis through targeting casein kinase-1 alpha (CK1α)

Dedifferentiated liposarcoma (DDLPS) is an aggressive tumor with high mortality. More insight into the biology of DDLPS tumorigenesis is needed to devise novel therapeutic approaches. Previous data showed that miRNA-199a-3p (miR-199a-3p) was strongly upregulated in DDLPS tissues. However, the biological role of miR-199a-3p in DDLPS remains unknown. In this study, we detected miR-199a-3p expression using RT-qPCR and observed that miR-199a-3p was more highly expressed in DDLPS tissues and cell lines (SW872 and LPS141). Functionally, MTT assay, flow cytometry and western blot results demonstrated that knockdown of miR-199a-3p inhibited DDLPS cell viability, enhanced apoptosis rate, and decreased expression of apoptosis-related genes Bax and cleaved caspase 3, as well as increased Bcl-2 expression in vitro. Moreover, xenograft tumors were generated and miR-199a-3p knockdown could suppress DDLPS xenograft tumor growth accompanying decreased proliferating cell nuclear antigen (PCNA) level and increased cleaved caspase 3 level in vivo. Mechanically, luciferase reporter assay and RNA immunoprecipitation (RIP) identified that CK1α was targeted and downregulated by miR-199a-3p. Expression of CK1α was lower in DDLPS tissues. Besides, there was a negative linear correlation between expressions of miR-199a-3p and CK1α in DDLPS tissues. Rescue experiments indicated that CK1α silencing could abolish the effect of miR-199a-3p knockdown on cell viability and apoptosis in DDLPS cells in vitro. In conclusion, knockdown of miR-199a-3p inhibits DDLPS cell viability and enhances apoptosis through targeting CK1α in vitro and in vivo. Our results suggest miR-199a-3p/CK1α axis may be a novel pathogen of DDLPS.

Dedifferentiated liposarcoma (DDLPS) is an aggressive tumor with high mortality.     

The microRNA-217 functions as a tumor suppressor and is frequently downregulated in human osteosarcoma

ObjectiveDysregulation of miRNA is always associated with cancer development and progression. Aberrant expression of miR-217 has been found in some types of cancer. However, its expression and function in osteosarcoma remain unclear. The aim of this study was to explore the effects of miR-217 in osteosarcoma tumorigenesis and development.MethodsThe expression level of miR-217 was quantified by real-time RT-PCR in human osteosarcoma cell lines and tissues. MTT, flow cytometric, transwell invasion and migration assays, and tumorigenicity in vivo were adopted to observe the effects of miR-217 on MG-63 cell phenotypes.ResultsMiR-217 was significantly downregulated in osteosarcoma cell lines and clinical specimens. Decreased miR-217 expression was significantly associated with large tumor size, positive distant metastasis, and advanced clinical stage. Low miR-217 expression in osteosarcoma was an independent predictor of poor survival. Overexpression of miR-217 can inhibit the proliferation, invasion, migration and promoted apoptosis of MG-63 cells in vitro and in vivo.ConclusionsThese findings indicate that miR-217 may act as a tumor suppressor in osteosarcoma and would serve as a novel therapeutic agent for miRNA-based therapy.     

Bufalin suppresses colorectal cancer cell growth through promoting autophagy in vivo and in vitro

Specific groups in Asia, including the Chinese, are more susceptible to colorectal cancer (CRC). The best strategy for anticancer drug action is to induce cancer cell apoptosis and autophagy. Bufalin is a potent inducer of apoptosis in some human cancer cell lines, but bufalin has barely been evaluated in colorectal cancer cells as a potent autophagy inducing agent. The aim of this study was to investigate the roles and interactions of bufalin in autophagy and the effects of the drug on human colorectal cancer. We applied bufalin and autophagy inhibitors (CQ and 3-MA) in LoVo cells to investigate their potential anticancer bioactivity under certain concentrations of bufalin to monitor autophagy and cell proliferation in vivo and in vitro. Bufalin induced autophagy of LoVo and inhibited proliferation of LoVo cells. Bufalin inhibited the expression of autophagy-related (ATG) proteins and tumor growth in vivo. Our studies identified that bufalin could potentially be a small molecule inhibitor for cancer therapy.

Specific groups in Asia, including the Chinese, are more susceptible to colorectal cancer (CRC).     

SNHG5 promotes proliferation and induces apoptosis in melanoma by sponging miR-155

Background: Melanoma is the most common malignancy of skin cancer. Small nucleolar RNA host gene 5 (SNHG5), a long non-coding RNA (lncRNA), has been demonstrated to be abnormally expressed in multiple malignances. However, the roles and molecular mechanisms of SNHG5 in melanoma progression have not been well identified. Methods: RT-qPCR assays were used to detect the expression patterns of SNHG5 and microRNA-155 (miR-155). Cell proliferation was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays. Cell apoptosis rate was measured by flow cytometry via double-staining of fluorescein isothiocyanate (FITC)-labeled annexin V (Annexin V-FITC) and propidium iodide (PI). The interaction between SNHG5 and miR-155 was validated using bioinformatics analysis, subcellular fraction assay, luciferase assay and RNA immunoprecipitation (RIP) assay. A mouse model of melanoma was established to further verify the effect of SNHG5 on tumor growth in vivo. Results: SNHG5 expression was upregulated in melanoma tumor tissues and cell lines. Moreover, higher SNHG5 expression was associated with advanced pathogenic status and poor prognosis. Functional analysis showed that SNHG5 knockdown suppressed proliferation and facilitated apoptosis in melanoma cells. Mechanical exploration revealed that SNHG5 acted as a molecular sponge of miR-155 in melanoma cells. Restoration experiments delineated that miR-155 down-regulation partly abrogated SNHG5-knockdown-mediated anti-proliferation and pro-apoptosis effect in melanoma cells. In vivo assays further demonstrated that SNHG5 depletion hindered tumor growth through up-regulating miR-155 expression. Conclusion: SNHG5 promoted the development of melanoma by sponging miR-155 in vitro and in vivo, implying the important implication of lncRNAs in melanoma progression and providing a potential therapeutic target for melanoma.

Melanoma is the most common malignancy of skin cancer. Small nucleolar RNA host gene 5 (SNHG5), a long non-coding RNA (lncRNA), has been demonstrated to be upregulated in tumor tissues and cells of melanoma.     

Retracted Article: SNHG3 promotes proliferation and invasion by regulating the miR-101/ZEB1 axis in breast cancer

Background: Dysregulated lncRNA expression contributes to the pathogenesis of human tumors via the lncRNAs functioning as oncogenes or tumor suppressors. Small nucleolar RNA host gene 3 (SNHG3) was demonstrated to be upregulated in breast cancer cells. However, the detailed roles and molecular mechanism of SNHG3 in breast cancer are largely unknown. Methods: The expression of SNHG3, miR-101, and zinc finger E-box-binding protein 1 (ZEB1) in breast cancer tissues and cells was detected using qRT-PCR. The effects of SNHG3 on cell proliferation and invasion were evaluated using MTT, EdU, and cell invasion assays. The protein levels of Ki-67, proliferating cell nuclear antigen (PCNA), matrix metalloproteinase MMP-2, and MMP-9 were analyzed using western blot analysis. A luciferase reporter assay and RNA immunoprecipitation (RIP) were performed to explore the interaction between SNHG3, ZEB1 and miR-101. A subcellular fractionation assay was used to detect the subcellular location of SNHG3. Xenograft tumor experiments were conducted to verify the role and mechanism of SNHG3 in breast cancer in vivo. Results: SNHG3 expression was upregulated in breast cancer tissues and correlated with poor prognosis. SNHG3 knockdown suppressed breast cancer cell proliferation and invasion, which was further demonstrated by high levels of proliferation marker proteins Ki-67/PCNA and metastasis-related proteins MMP-2/MMP-9. Additionally, SNHG3 was located in the cytoplasm of breast cancer cells. SNHG3 functioned as a molecular sponge for miR-101 in breast cancer cells. miR-101 was downregulated in breast cancer tissues and negatively correlated with SNHG3 expression. Moreover, ZEB1, a target of miR-101, was positively regulated by SNHG3 in breast cancer cells. ZEB1 mRNA expression was upregulated in breast cancer tissues and positively correlated with SNHG3 expression. Mechanistically, SNHG3 knockdown suppressed cell proliferation and invasion by upregulation of miR-101 and downregulation of ZEB1 expression in breast cancer cells in vitro and in vivo. Conclusion: SNHG3 promoted proliferation and invasion by regulating the miR-101/ZEB1 axis in breast cancer.

In the present study, we investigated the expression and functional roles of SNHG3 in breast cancer cells, as well as the underlying mechanism of SNHG3 involved in the progression of breast cancer in vitro and in vivo.     

Therapeutic Effects of MicroRNA-582-5p and -3p on the Inhibition of Bladder Cancer Progression

Many reports have indicated that the abnormal expression of microRNAs (miRNAs) is associated with the progression of disease and have identified miRNAs as attractive targets for therapeutic intervention. However, the bifunctional mechanisms of miRNA guide and passenger strands in RNA interference (RNAi) therapy have not yet been clarified. Here, we show that miRNA (miR)-582-5p and -3p, which are strongly decreased in high-grade bladder cancer clinical samples, regulate tumor progression in vitro and in vivo. Significantly, the overexpression of miR-582-5p or -3p reduced the proliferation and invasion of UM-UC-3 human bladder cancer cells. Furthermore, transurethral injections of synthetic miR-582 molecule suppressed tumor growth and metastasis in an animal model of bladder cancer. Most interestingly, our study revealed that both strands of miR-582-5p and -3p suppressed the expression of the same set of target genes such as protein geranylgeranyltransferase type I beta subunit (PGGT1B), leucine-rich repeat kinase 2 (LRRK2) and DIX domain containing 1 (DIXDC1). Knockdown of these genes using small interfering RNA (siRNA) resulted in the inhibition of cell growth and invasiveness of UM-UC-3. These findings uncover the unique regulatory pathway involving tumor suppression by both strands of a single miRNA that is a potential therapeutic target in the treatment of invasive bladder cancer.     

miR-92a/DUSP10/JNK signalling axis promotes human pancreatic cancer cells proliferation

Pancreatic cancer is one of the most common types of cancers in the whole world with a poor prognosis. Finding out how the cancer form and develop is the most important way to cure this cancer. miRNAs, 21–22 nucleotides regulatory small non-coding RNAs, have been found to be critical involved in the growth of pancreatic cancer. In this study, we found that miR-92a was up regulated in three kinds of human pancreatic cancer cell lines. There is a correlation between miR-92a and malignant degree of human pancreatic cancer cell lines. Then we found that miR-92a was essential for promoting cell proliferation in human pancreatic cancer. Inhibition of the function of miR-92a repressed the proliferation of pancreatic cancer cells. Further, we found that miR-92a enhanced the activation of JNK signalling pathway by directly targeting the JNK signalling inhibitor DUSP10. DUSP10 is responsible for miR-92a induced JNK signalling and cell proliferation. Altogether, our study showed a miR-92a/DUSP10/JNK signalling pathway that plays an important role in regulating the proliferation of pancreatic cancer cells.     

Antitumor Activity of miR-1280 in Melanoma by Regulation of Src

MicroRNAs (miRNAs) play a key role in cancer progression by coordinately repressing target genes involved in cell proliferation, migration, and invasion. miRNAs regulate gene expression by repressing translation or directing sequence-specific degradation of complementary mRNA. Here, we report that expression of miR-1280 is significantly suppressed in human melanoma specimens when compared with nevi, and in human melanoma cell lines when compared with cultured normal human melanocytes. The proto-oncogene Src was identified as a target of miR-1280 action. Levels of Src expression were significantly higher in melanoma samples and cell lines than in nevi and normal melanocytes. miR-1280 overexpression significantly suppressed the luciferase activity of reporter plasmids containing the full-length 3′ untranslated region of Src. miR-1280-mediated suppression of Src led to substantial decreases in melanoma cell proliferation, cell cycle progression, invasion, as well as induced melanoma cell apoptosis. The effects of miR-1280 overexpression on melanoma cell proliferation and growth were reversed by Src overexpression. Intratumoral delivery of miR-1280 significantly suppressed melanoma cell growth in vivo. Our results demonstrate a novel role for miR-1280 as a tumor suppressor in melanoma, identify the Src signaling pathway as a target of miR-1280 action, and suggest a potential therapeutic role for miR-1280 in melanoma.     

Retracted Article: MiR-148a agomir based targeting of c-Met and Her-3 is able to attenuate EGFR-T790M mutation driven gefitinib and erlotinib resistance in non-small cell lung cancer cells

MiR-148a inhibits NSCLC progression. Whether miR-148a would reduce EGFR tyrosine kinase inhibitor (TKI) resistance of NSCLC cells remains underexplored. In this study, 5 NSCLC patients received surgery and gefitinib treatment but developed pleural metastasis. Patients'' NSCLC adopted EGFR T790M mutation. 5 naïve and 5 gefitinib-resisting NSCLC cell lines were derived from patients primary and metastatic tumor tissues, and the 5 gefitinib-resisting NSCLC cell lines were trained with erlotinib to establish the erlotinib-resisting cell lines. MiR-148a levels in cells were analyzed by qRT-PCR. miR-148a overexpression was mimicked by agomir treatment. NSCLC cell malignancy was evaluated by cell proliferation, apoptosis, colony formation and transwell invasion assays. Protein levels of c-Met, Her-3 and IGF-1R were assessed by western blotting. miRNA-mRNA interaction was investigated by luciferase reporter assay and AGO2-RIP. Transient overexpression of MET, ERBB3 or IGF1R gene was achieved by plasmid transfection. Results showed that the MiR-148a level was decreased with the development of gefitinib and erlotinib resistance and that there was an increase in malignancy in NSCLC cells in vitro. Treatment with miR-148a agomir significantly enhanced the cytotoxicity of gefitinib and erlotinib to naïve, gefitinib-resisting and erlotinib-resisting NSCLC cells in vitro while reducing their protein levels of c-Met, Her-3 and IGF-1R, the mRNAs of which were verified as direct targets of miR-148a in NSCLC cells. Restoring c-Met or Her-3 protein levels partially reduced the gefitinib and erlotinib sensitizing effect of miR-148a agomir treatment on NSCLC cells. We concluded that MiR-148a attenuated gefitinib and erlotinib resistance in non-small cell lung cancer cells with EGFR T790M mutation by targeting c-Met and Her-3 expression.

MiR-148a inhibits NSCLC progression.     

Retracted Article: MiR-206 reduced the malignancy of hepatocellular carcinoma cells in vitro by inhibiting MET and CTNNB1 gene expressions

The anti-cancer role of miR-206 in hepatocellular carcinoma (HCC) cells has been reported, but its mechanism of action remains poorly understood. This research aimed to investigate the anti-HCC mechanism of miR-206. We analyzed 25 pairs of HCC and adjacent tissue specimens from HCC patients. Two patient-derived HCC cell lines were established. MiR-206 levels in tissue specimens and cell lines were detected by qRT-PCR. MiR-206 overexpression was mimicked by miR-206 mimic transfection. MET or CTNNB1 gene was overexpressed by transient transfection. Protein and protein phosphorylation levels of interests were assessed by western blotting. HCC cell malignancy in vitro was evaluated by cell proliferation, apoptosis, colony formation, trans-well invasion assays as well as western blotting assessing the marker proteins of epithelial or mesenchymal phenotype. We found that miR-206 level was significantly lower in HCC tissue specimens in comparison to adjacent counterparts. Two patient-derived HCC cell lines showed lower miR-206 level than L02 human hepatocytes. MiR-206 mimic transfection significantly reduced phosphorylation levels of pan-Akt Ser9, Erk1 Thr202/Tyr204 and Gsk-3beta Ser308 as well as protein levels of beta-catenin and c-Met in primary HCC cells in vitro. Luciferase reported assay and AGO2-RNA co-immunoprecipitation assays results demonstrated that miR-206 reduced MET and CTNNB1 gene expressions in HCC cells by interacting with the 3′ UTR of their mRNAs. Restoring c-Met or beta-catenin protein level by MET or CTNNB1 transient overexpression partially restored the malignancy of HCC cells in vitro. We concluded that miR-206 might inhibit HCC development by targeting MET and CTNNB1 gene expression.

The anti-cancer role of miR-206 in hepatocellular carcinoma (HCC) cells has been reported, but its mechanism of action remains poorly understood.     

KITENIN-targeting MicroRNA-124 Suppresses Colorectal Cancer Cell Motility and Tumorigenesis

MicroRNAs are increasingly implicated in the modulation of the progression of various cancers. We previously observed that KAI1 C-terminal interacting tetraspanin (KITENIN) is highly expressed in sporadic human colorectal cancer (CRC) tissues and hence the functional KITENIN complex acts to promote progression of CRC. However, it remains unknown that microRNAs target KITENIN and whether KITENIN-targeting microRNAs modulate CRC cell motility and colorectal tumorigenesis. Here, through bioinformatic analyses and functional studies, we showed that miR-124, miR-27a, and miR-30b negatively regulate KITENIN expression and suppress the migration and invasion of several CRC cell lines via modulation of KITENIN expression. Through in vitro and in vivo induction of mature microRNAs using a tetracycline-inducible system, miR-124 was found to effectively inhibit the invasion of CT-26 colon adenocarcinoma cells and tumor growth in a syngeneic mouse xenograft model. Constitutive overexpression of precursor miR-124 in CT-26 cells suppressed in vivo tumorigenicity and resulted in decreased expression of KITENIN as well as that of MYH9 and SOX9, which are targets of miR-124. Thus, our findings identify that KITENIN-targeting miR-124, miR-27a, and miR-30b function as endogenous inhibitors of CRC cell motility and demonstrate that miR-124 among KITENIN-targeting microRNAs plays a suppressor role in colorectal tumorigenesis.     

MiR-95 induces proliferation and chemo- or radioresistance through directly targeting sorting nexin1 (SNX1) in non-small cell lung cancer

MicroRNAs are emerging as a class of small regulatory RNAs whose specific roles and significant functions in the majority of carcinomas have yet to be entirely illustrated. The aim of this study is to explore the effect of miR-95 and determine whether miR-95 could be a potential therapeutic target for human non-small cell lung cancer. First of all, our study showed that miR-95 was highly expressed in both NSCLC cell lines (compared with normal cells) and tumor tissues (compared with corresponding normal tissues), whereas the protein level of SNX1 was downregulated in NSCLC cell lines. Next, we found that ectopic overexpression of miR-95 in A549 or H226 contributed to tumor growth in xenograft mouse models. In addition, the results also indicated that upregulation of miR-95 could significantly enhance the susceptibilities of NSCLC cells to chemo- or radiotherapy. Furthermore, using the luciferase reporter, we demonstrated that SNX1 is a direct target of miR-95. Meanwhile, overexpression of SNX1 could abrogate the growth of NSCLC cells induced by miR-95. Taken together, these results suggest that miR-95 functions as an oncogene role in NSCLC cells by directly targeting SNX1.     

miR-425 suppresses EMT and the development of TNBC (triple-negative breast cancer) by targeting the TGF-β 1/SMAD 3 signaling pathway

Background: EMT has a crucial effect on the progression and metastasis of tumors. This work will elucidate the role of miR-425 in EMT and the development of TNBC. Methods: The differential miRNA expression among non-tumor, para-tumor (adjacent tissue of tumor) and tumor tissues was analyzed. The luciferase activities of TGF-β1 3′UTR treated with miR-425 were determined. Then human breast cancer cell lines were treated with mimics or inhibitors of miR-425, and then the cell proliferation and migration, and invasion ability were assessed. The expression of TGF-β1 and markers of epithelial cells and mesenchymal cells were analyzed. The influences of miR-425 on the development of TNBC through inducing EMT by targeting the TGF-β1/SMAD3 signaling pathway in TNBC cell lines were investigated. Furthermore, xenograft mice were used to explore the potential roles of miR-425 on EMT and the development of TNBC in vivo. Results: Compared with non-tumor tissues, 9 miRNAs were upregulated and 3 miRNAs were down-regulated in tumor tissues. The relative expression of miR-425 in tumor tissues was obviously much lower than that in para-tumor and non-tumor tissues. MiR-425 suppressed TGF-β1 expression, and further inhibited expression of mesenchymal cell markers, while it exerted effects on cell proliferation and migration of TNBC cell lines. Moreover, the agomir of miR-425 could protect against the development process in a murine TNBC xenograft model. Conclusions: Our results demonstrated that miR-425 targets TGF-β1, and was a crucial suppressor on EMT and the development of TNBC through inhibiting the TGF-β1/SMAD3 signaling pathway. This suggests that aiming at the TGF-β1/SMAD3 signaling pathway by enhancing relative miR-425 expression, is a feasible therapy strategy for TNBC.

EMT has a crucial effect on the progression and metastasis of tumors.     

Systemic Delivery of Synthetic MicroRNA-16 Inhibits the Growth of Metastatic Prostate Tumors via Downregulation of Multiple Cell-cycle Genes

Recent reports have linked the expression of specific microRNAs (miRNAs) with tumorigenesis and metastasis. Here, we show that microRNA (miR)-16, which is expressed at lower levels in prostate cancer cells, affects the proliferation of human prostate cancer cell lines both in vitro and in vivo. Transient transfection with synthetic miR-16 significantly reduced cell proliferation of 22Rv1, Du145, PPC-1, and PC-3M-luc cells. A prostate cancer xenograft model revealed that atelocollagen could efficiently deliver synthetic miR-16 to tumor cells on bone tissues in mice when injected into tail veins. In the therapeutic bone metastasis model, injection of miR-16 with atelocollagen via tail vein significantly inhibited the growth of prostate tumors in bone. Cell model studies indicate that miR-16 likely suppresses prostate tumor growth by regulating the expression of genes such as CDK1 and CDK2 associated with cell-cycle control and cellular proliferation. There is a trend toward lower miR-16 expression in human prostate tumors versus normal prostate tissues. Thus, this study indicates the therapeutic potential of miRNA in an animal model of cancer metastasis with systemic miRNA injection and suggest that systemic delivery of miR-16 could be used to treat patients with advanced prostate cancer.     

miR-382 Inhibits Osteosarcoma Metastasis and Relapse by Targeting Y Box-Binding Protein 1

Lung metastasis and relapse in osteosarcoma (OS) patients indicate poor prognosis. Here, we identified significantly decreased expression of miR-382 in highly metastatic OS cell lines and relapsed OS samples compared to their parental cell lines and primary OS samples, respectively. In addition, our clinical data showed that the miR-382 expression level was inversely associated with relapse and positively associated with metastasis-free survival in OS patients. The overexpression of miR-382 suppressed epithelial–mesenchymal transition (EMT) and metastasis. This overexpression also decreased the cancer stem cell (CSC) population and function in OS cells. In contrast, inhibition of miR-382 stimulated EMT and metastasis and increased CSC population in OS cells. In addition, our in vivo experiments showed that the overexpression of miR-382 inhibited CSC-induced tumor formation, and the combination of miR-382 with doxorubicin prevented disease relapse in OS patients. Furthermore, we demonstrated that miR-382 exerted its tumor-suppressing potential by directly targeting Y box-binding protein 1 (YB-1) in OS. Taken together, our findings suggest that miR-382 functions as a tumor suppressor function and that the overexpression of miR-382 is a novel strategy to inhibit tumor metastasis and prevent CSC-induced relapse in OS.