MiR-522 contributes to cell proliferation of human glioblastoma cells by suppressing PHLPP1 expression

Previous studies have shown that microRNAs play essential roles in cancer growth and progression. Although a number of microRNAs were differentially expressed in glioblastoma (GBM). In this study, we evaluated the miR-522s role in cell proliferation in GBM. Expression of miR-522 is markedly upregulated in GBM tissues and GBM cells compared with the matched non-tumor adjacent brain tissues (TAT) and normal human astrocytes (NHAs). In functional assays, miR-522 promoted GBM cell proliferation, which could be reversed by inhibitor of miR-522. We further identified PH domain leucine-rich repeats protein phosphatase-1 (PHLPP1) as a putative target of miR-522, which is likely a main contributor to the promotion of tumor cell growth observed in our assays. Our results demonstrated that miR-522 promoted tumor cell proliferation and hence may represent a novel therapeutically relevant cellular target to treatment of GBM patients.     

miR-935 promotes gastric cancer cell proliferation by targeting SOX7

Gastric cancer is the most common cancer in the world, miRNAs have been demonstrated to play critical role in the development and progression of gastric cancer, such as miR-7, miR-217 and miR-335. Here, we found miR-935 was upregulated in gastric cancer tissues and cells. Overexpression of miR-935 promoted cell proliferation and tumorigenesis in vitro determined by MTT analysis, colony formation analysis, BrdU cell proliferation analysis and soft agar growth analysis, knockdown of miR-935 reduced these effects. Tumor suppressor sex-determining region Y-box 7 (SOX7) was the direct target of miR-935, overexpression of miR-935 inhibited SOX7 expression, but promoted the levels CCND1 and C-MYC which promotes cell proliferation and tumorigenesis, knockdown of miR-935 increased SOX7 level, and inhibited CCND1 and C-MYC expression. Synchronous knockdown of miR-935 and SOX7 promoted cell proliferation and tumorigenesis in vitro, confirming miR-935 regulated gastric cancer cell proliferation by inhibiting SOX7. In summary, we found miR-935 contributed to cell proliferation of gastric cancer through targeting SOX7.     

MiR-454 inhibited cell proliferation of human glioblastoma cells by suppressing PDK1 expression

It has been well documented that aberrant expression of microRNAs is associated with carcinogenesis of glioblastoma (GBM), however the underlying mechanisms are not clear. In this present study, we aimed to clarify the biological function of miR-454 in GBM. MiR-454 was identified to be significantly down-regulated in GBM primary tumors and cell lines. Overexpression of miR-454 in GBM cells resulted in arresting cells at G₀/G₁ phase and thus inhibiting cell proliferation. Bioinformatic analysis predicted 3-phosphoinositide-dependent protein kinase-1 (PDK1) as a target of miR-454 which acted as a tumor promoter gene. Increased miR-454 significantly repressed PDK1 expression, and then regulating cell proliferation and cell cycle regulators, down-regulation of Cyclin D1 and p-pRb and p21 was up-regulated. Taken together, our study has revealed miR-454 as a tumor suppressor in GBM.     

MiR-320d suppresses the progression of breast cancer via lncRNA HNF1A-AS1 regulation and SOX4 inhibition

MicroRNA-320d (miR-320d) is a novel cancer-related miRNA and functions as a tumor suppressor in human cancers. However, the expression pattern and function of miR-320d in breast cancer remain largely unknown. In the present study, we found that the expression level of miR-320d in breast cancer tissues and cells was significantly lower than in non-tumor tissues and MCF-10A cells. Decreased miR-320d was associated with poor overall survival in patients with breast cancer. Overexpression of miR-320d inhibited proliferation, migration, and invasion and promoted apoptosis of breast cancer cells. In addition, the long non-coding RNA, HNF1A antisense RNA 1 (HNF1A-AS1) was up-regulated in both breast cancer tissues and cell lines. HNF1A-AS1 suppressed the expression and function of miR-320d. Moreover, SRY-related HMG-box 4 (SOX4) was speculated and confirmed as a target of miR-320d. We also demonstrated that HNF1A-AS1 may function as a sponge competitive endogenous RNA for miR-320d, and thus regulate the expression of SOX4. Taken together, our study has identified a novel signaling pathway through which miR-320d exerts its anti-carcinogenic roles and suggested that the HNF1A-AS1/miR-320d/SOX4 may be a potential target for the therapy of breast cancer.

MicroRNA-320d (miR-320d) is a novel cancer-related miRNA and functions as a tumor suppressor in human cancers.     

Methylglyoxal (MGO) inhibits proliferation and induces cell death of human glioblastoma multiforme T98G and U87MG cells

Glioblastoma multiforme (GBM) is the most malignant and invasive human brain tumor and it is characterized by a poor prognosis and short survival time. Current treatment strategies for GBM using surgery, chemotherapy and/or radiotherapy are ineffective. Thus new therapeutic strategies to target GBM are urgently needed. The effect of methylglyoxal (MGO) on the cell cycle, cell death and proliferation of human GBM cells was investigated. The T98G and U87MG cell lines were cultured in modified EMEM supplemented with 10% fetal bovine serum and maintained at 37 °C in a humidified atmosphere of 5% CO₂ in air. Cells were exposed to methylglyoxal (0.025 mM) per 72 h. The influence of MGO on T98G and U87MG cell cycle, proliferation and apoptosis was evaluated as well. Cell cycle phase distribution, proliferation, apoptosis were analyzed by flow cytometry. MGO causes changes in cell cycle and induces accumulation of G1/G0-phase cells and reduced fraction of cells in S and G2/M phases. We have also observed inhibition of cell proliferation and induction of apoptosis in cancer cells. We have also revealed that MGO induces senescence of U87MG but not T98G cells, but further studies are necessary in order to clarify and check mechanism of action of methylglyoxal and it Is a positive phenomenon for the treatment of GBM.     

miR-33a promotes glioma-initiating cell self-renewal via PKA and NOTCH pathways

Glioblastoma (GBM) is the most common and lethal brain tumor in adults. Glioma-initiating cells (GICs) are stem-like cells that have been implicated in glioblastoma progression and recurrence; however, the distinct properties of GICs and non-GICs within GBM tumors are largely uncharacterized. Here, we evaluated stem cell–associated microRNA (miR) expression in GICs from GBM patients and GICs derived from xenografted human glioma cell lines and determined that miR-33a promotes GIC growth and self-renewal. Moreover, evaluation of a GBM tissue array revealed that higher miR-33a expression was associated with poor prognosis of GBM patients. Antagonizing miR-33a function in GICs reduced self-renewal and tumor progression in immune-compromised mice, whereas overexpression of miR-33a in non-GICs promoted the display of features associated with GICs. We identified the mRNAs encoding phosphodiesterase 8A (PDE8A) and UV radiation resistance–associated gene (UVRAG) as direct miR-33a targets. PDE8A and UVRAG negatively regulated the cAMP/PKA and NOTCH pathways, respectively; therefore, miR-33a–dependent reduction of these proteins promoted growth and self-renewal of GICs by enhancing PKA and NOTCH activity. Furthermore, in GBM specimens, there was an inverse correlation between the expression levels of miR-33a and PDE8A and UVRAG expression. These findings reveal a miR-33a–centered signaling network that promotes GIC maintenance and has potential as a therapeutic target for GBM treatment.     

The micro RNA hsa-miR-377-3p inhibits tumor growth in malignant melanoma

Background/Aims: Most recently, micro RNAs (miRNAs/miRs) have been suggested to play a key role in various physiological and pathological processes by regulating the expression of specific genes. The influence of miR-377-3p on multitudinous cancer cells has been investigated; however, its function in melanoma remains undiscovered. Armadillo repeat-containing protein 8 (ARMC8), a target of miR-377-3p, plays essential roles in proliferation, differentiation and apoptosis. Our research aimed to detect the specific roles of miR-377-3p in melanoma. Methods: The MiRNA and mRNA expressions were evaluated by a real-time quantitative polymerase chain reaction in the A375 and HEMa-LP cell lines. We predicted the possible interactions between microRNA and mRNAs by bioinformatics database and constructed them with the Cytoscape software. The proliferation and migration activities were investigated using a cell counting kit-8 (CCK8) and wound-healing assay. Validation of the correlation between miR-377-3p and ARMC8 was implemented by the luciferase reporter assay and PCR. Results: The expression of miR-377-3p was found to be lower in malignant melanoma cells. The upregulation of miR-377-3p inhibited the melanoma cell proliferation, migration, and ARMC8 expression. miR-377-3p was identified to bind to the 3′UTR region of ARMC8 directly; this indicated that miR-377-3p suppressed melanoma cell growth partly mediated via the ARMC8 expression. Conclusion: These findings show that miR-377-3p negatively regulates tumor growth in malignant melanoma, which may thus provide a potential biological target for melanoma treatment and subsequently lead to the development of potential treatments.

We have demonstrated that miR-377-3p inhibits melanoma cell growth by binding to the ARMC8 mRNA in the A375 cell line.     

Caprin-1 is a novel microRNA-223 target for regulating the proliferation and invasion of human breast cancer cells

MicroRNAs (miRNAs) are 21–22 nucleotides regulatory small non-coding RNAs that inhibit gene expression by binding to complementary sequences especially the 3’ untranslated region (3’UTR) of mRNA. One miRNA can target many messenger RNAs, leading to a complex metabolic network. Previous studies have shown that miRNA-223 regulates migration and invasion of tumor cells and targets cytoplasmic activation/proliferation-associated protein-1 (Caprin-1). In the present study, we detected the expression of miRNA-223 and Caprin-1 in MCF-7, T-47D and MDA-MB-231 cancer cell lines, and MCF-10A normal breast cell line, and analyzed the role of miRNA-223 in Caprin-1-induced proliferation and invasion of human breast cancer cells. We found that miRNA-223 expression levels are significantly lower in MCF-7, T-47D and MDA-MB-231 cancer cells than in MCF-10A normal breast cells, while Caprin-1 expression is higher in cancer cells than in normal breast cells. The most malignant cancer cell line MDA-MB-231 has the lowest expression of miR-223, but the highest expression of Caprin-1. Further, we found that miR-223 targets the 3’UTR of Caprin-1 miRNA and down-regulates the expression of Caprin-1. We also found that over-expression of Caprin-1 can promote the proliferation and the invasion of breast cancer cells, but miRNA-223 can inhibit the proliferation and the invasion. miRNA-223-induced inhibition can be reversed by ectopic over-expression of Caprin-1. These findings suggest that miR-223 may suppress the proliferation and invasion of cancer cells by directly targeting Caprin-1. Our study also indicates that expression levels of miR-223 and Caprin-1 can be used to predict the state of cancer in breast cancer patient.     

Reduced miR-31 and let-7 maintain the balance between differentiation and quiescence in lung cancer stem-like side population cells

Recent studies have indicated that side population (SP) cells, which are an enriched source of cancer stem cells (CSCs), drive and maintain many types of human malignancies. SP cells have distinguishing biological characteristics and are thought to contribute to metastasis, therapy resistance, and tumor recurrence. In the present study, the miRNA expression profiles of SP cells and non-SP cells were compared using miRNA array analysis. Both let-7 and miR-31 were significantly down-regulated in SP cells compared to non-SP cells. The results were confirmed by real-time PCR. Engineered repression of miR-31 caused marked repression of both lung cancer SP cell and non-SP cell growth in vitro. In contrast, engineered repression of let-7 caused marked promotion of both lung cancer SP and non-SP cells growth in vitro. Cell cycle studies further revealed that reduced miR-31 could inhibit SP cell proliferation by a cell cycle arrest in the G0/G1 phase, whereas reduced let-7 induced SP cell proliferation by accelerating G1/S phase transition. Notably, reduced miR-31 prevented SP cell differentiation, whereas reduced let-7 promoted SP cell differentiation under differentiation conditions. These findings indicate that reduced miR-31 and let-7 are involved in maintaining the balance between differentiation and quiescence in SP cells.     

MiR-1 targets PIK3CA and inhibits tumorigenic properties of A549 cells

MicroRNAs are small endogenous RNAs that play important roles in the pathogenesis of human diseases, including malignancy. MicroRNA-1 (miR-1) is downregulated in non-small cell lung cancer (NSCLC); however, the underlying mechanisms by which it suppresses tumorigenesis in NSCLC are largely unknown. We investigated whether phosphoinositide-3-kinase catalytic subunit alpha (PIK3CA) was a novel target of miR-1 in the NSCLC cell line A549, and the mechanism of miR-1 inhibition of the tumorigenic properties of A549 cells is discussed. The influence of miR-1 on A549 cells was studied by transfection with miR-1 mimics or inhibitor. MiR-1 overexpression led to downregulation of PIK3CA protein, but not mRNA by western blot and quantitative real-time PCR, respectively. The dual-luciferase reporter assay confirmed that miR-1 targeted PIK3CA directly. PIK3CA downregulation by miR-1 mimics led to a significant reduction of phosphorylated Akt and survivin protein, the downstream targets of the PI3 K/Akt pathway. Cell proliferation was studied using a cell counting kit. Migration and invasion were evaluated by Transwell and Matrigel assays, respectively. Cell cycle and apoptosis were detected by flow cytometry. The results were that miR-1 upregulation inhibited A549 cell proliferation, migration, and invasion. These findings indicate that miR-1 may play an important role in the pathogenesis of NSCLC by regulating PIK3CA through the PI3 K/Akt pathway. Increasing miR-1 expression may provide a novel approach for NSCLC treatment.     

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.     

miR-601 is a prognostic marker and suppresses cell growth and invasion by targeting PTP4A1 in breast cancer

MicroRNAs (miRNA) play important roles in the initiation and progression of breast cancer. Here, we investigated the role of miR-601 in breast cancer and found that its expression was significantly down-regulated in breast cancer tissues compared with matched adjacent non-cancerous breast tissues. Moreover, we found that down-regulation of miR-601 was closely associated with distant metastasis and poor distant metastasis-free survival in breast cancer. In addition, miR-601 levels were inversely correlated with metastatic potential of human breast cancer cell lines. Further experiments showed that ectopic overexpression of miR-601 suppressed breast cancer cell proliferation, migration and invasion, whereas miR-601 knockdown promoted breast cancer cell proliferation, migration and invasion. Furthermore, protein tyrosine phosphatase type IVA 1 (PTP4A1) was identified as a direct target of miR-601. Overexpression of miR-601 repressed PTP4A1 mRNA and protein expression. Conversely, inhibition of miR-601 increased PTP4A1 mRNA and protein expression. Taken together, our data suggest that miR-601 inhibits growth and invasion of breast cancer cells by targeting PTP4A1 and that miR-601 is a potential biomarker for prognosis and therapeutic target in breast cancer.     

Tumor suppressor miR-449a inhibits the development of gastric cancer via down-regulation of SGPL1

MicroRNAs (miRNAs) are small noncoding RNAs that are known to participate in the regulation of many physiological and pathological processes, which can indirectly influence the development of malignant behaviors. Numerous studies have demonstrated that miR-449a plays important roles in human carcinogenesis. However, its precise functional and regulatory roles remain unclear. In this study, we mainly explored the functional role of miR-449a in gastric cancer (GC). The expression levels of miR-449a in 98 cases of GC tissues and cell lines were determined by qRT-PCR. The possible mechanisms of miR-449a in GC cells were explored by fluorescence reporter assay. miR-449a expression was significantly lower in GC tissues compared to matched para-carcinoma tissues and was associated with tumor differentiation. Furthermore, in vitro knockdown of miR-449a by siRNA significantly inhibited MKN-28 cell proliferation, migration and invasion as well as tumorigenesis via inducing G0/G1 arrest of GC cells. In addition, we identified SGPL1 as a target of miR-449a and demonstrated that miR-449a regulated SGPL1 expression via binding its 3′-UTR region. The experiments indicated that miR-449a functions as a novel tumor suppressor in GC and its anti-oncogenic activity may involve its inhibition of the target gene SGPL1. These findings suggested that miR-449a may be a promising candidate for the development of antitumor drugs targeting GC.

MicroRNAs (miRNAs) are small noncoding RNAs that are known to participate in the regulation of many physiological and pathological processes, which can indirectly influence the development of malignant behaviors.     

miR-142-3p靶向Wnt/β-链蛋白通路对结直肠癌细胞增殖的影响

目的探究miR-142-3p靶向Wnt/β-链蛋白(β-catenin)通路对结直肠癌(CRC)细胞增殖的影响。方法选取2018年1月—2020年10月收治的66例CRC的肿瘤组织及其相邻正常组织。同时培养正常人结肠上皮细胞NCM460和CRC细胞系(HT29、LoVo、HCT116、Caco2、SW480细胞)。通过qRT-PCR检测CRC肿瘤组织、正常组织、正常人结肠上皮细胞与CRC细胞系中miR-142-3p表达水平;经免疫蛋白印迹法检测CRC细胞系中β-catenin表达水平;采用CCK-8法和流式细胞术检测miR-142-3p过表达后对CRC细胞增殖的影响;经免疫蛋白印迹检测过表达miR-142-3p对Wnt/β-catenin信号通路相关蛋白的影响;采用双荧光素酶报告基因检验miR-142-3p与β-catenin编码基因CTNNB1的靶向关系。结果miR-142-3p在CRC肿瘤组织和CRC细胞系中的表达显著下降(P<0.05);β-catenin在CRC细胞系中的表达显著升高(P<0.05);过表达miR-142-3p可靶向结合CTNNB1,显著抑制Caco2、LoVo和HT29细胞的增殖和Ki67+细胞比例,抑制β-catenin、c-myc和Cyclin D1的表达(P<0.05)。结论miR-142-3p可通过靶向调节β-catenin的表达,干扰Wnt/β-catenin通路,抑制CRC细胞的增殖。     

miR-370 targeted FoxM1 functions as a tumor suppressor in laryngeal squamous cell carcinoma (LSCC)

microRNAs, a family of small non-coding RNAs, involve in the pathogenesis of several types of cancers, including laryngeal squamous cell carcinoma (LSCC). MiR-370 is frequently aberrant expressed in various types of human cancer including LSCC. However, the role for miR-370 in LSCC remains elusive. Here, we demonstrate that miR-370 was down-regulated in human LSCC tissues. Furthermore, there was an inverse relationship between Forkhead Box ml (FoxM1), which was up-regulated and miR-370 expression in LSCC tissues. FoxM1 was subsequently predicted by bioinformatics and verified to be a target of miR-370 by Luciferase reporter assay. Restored expression of miR-370 in Hep2 cells significantly inhibited cell proliferation. In conclusion, our results suggest that miR-370 may function as a tumor suppressor in LSCC through downregulation of FoxM1, suggesting that miR-370 could serve as a novel potential maker for LSCC therapy.     

Aryl hydrocarbon receptor agonists induce microRNA-335 expression and inhibit lung metastasis of estrogen receptor negative breast cancer cells

The aryl hydrocarbon receptor (AHR) was initially identified as a receptor that bound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related environmental toxicants; however, there is increasing evidence that the AHR is an important new drug target for treating multiple diseases including breast cancer. Treatment of estrogen receptor (ER)-negative MDA-MB-231 and BT474 breast cancer cells with TCDD or the selective AHR modulator 6-methyl-1,3,-trichlorodibenzofuran (MCDF) inhibited breast cancer cell invasion in a Boyden chamber assay. These results were similar to those previously reported for the antimetastic microRNA-335 (miR-335). Both TCDD and MCDF induced miR-335 in MDA-MB-231 and BT474 cells and this was accompanied by downregulation of SOX4, a miR-335-regulated (inhibited) gene. The effects of TCDD and MCDF on miR-335 and SOX4 expression and interactions of miR-335 with the 3'-UTR target sequence in the SOX4 gene were all inhibited in cells transfected with an oligonucleotide (iAHR) that knocks down the AHR, thus confirming AHR-miR-335 interactions. MCDF (40 mg/kg/d) also inhibited lung metastasis of MDA-MB-231 cells in a tail vein injection model, showing that the AHR is a potential new target for treating patients with ER-negative breast cancer, a disease where treatment options and their effectiveness are limited.     

miR-892a regulated PPP2R2A expression and promoted cell proliferation of human colorectal cancer cells

Colorectal cancer (CRC) is one of the most common malignancy cancers in the world. Aberrant microRNA expression is involved in human diseases including cancer. In the present study, we investigated the miR-892a's role in CRC cell proliferation. We found that miR-892a was frequently upregulated in human colorectal cancer tissues and cell lines compared with the matched tumor adjacent tissues and normal colonic cell line FHC. Overexpression of miR-892a promoted cell proliferation and colony formation of CRC. Bioinformatics analysis further revealed PPP2R2A was identified as a potential miR-892a. Overexpression of miR-892a-in SW480 cells reduced PPP2R2A protein expression. Subsequently, data from luciferase reporter assays showed that PPP2R2A 3′-untranslated region (3′-UTR) carried the directly binding site of miR-892a. Furthermore, siRNA-mediated silencing of PPP2R2A blocked the inhibitory effect of miR-892a-in on CRC cell growth. In sum, our data provided compelling evidence that overexpression of miR-892a may provide a selective growth promotion for CRC cells by direct suppression of PPP2R2A expression.     

miRNA-192-5p在多发性骨髓瘤中的表达水平及其调控机制研究

目的 探讨miR-192-5 p在多发性骨髓瘤中的表达水平及其调控机制.方法 选取骨髓瘤细胞株U266作为研究对象,利用荧光定量PCR检测多发性骨髓瘤细胞中miR-192-5 p的表达水平;使用生物信息学网站预测miR-192-5 p潜在靶基因USP1并利用双荧光素酶报告实验验证其靶向关系;利用细胞转染实验对多发性骨髓...