miR-425-5p Regulates Proliferation of Bovine Mammary Epithelial Cells by Targeting TOB2.

In recent years, rising temperatures have caused heat stress (HS), which has had a significant impact on livestock production and growth, presenting considerable challenges to the agricultural industry. Research has shown that miR-425-5p regulates cellular proliferation in organisms. However, the specific role of miR-425-5p in bovine mammary epithelial cells (BMECs) remains to be determined. The aim of this study was to investigate the potential of miR-425-5p in alleviating the HS-induced proliferation stagnation in BMECs. The results showed that the expression of miR-425-5p significantly decreased when BMEC were exposed to HS. However, the overexpression of miR-425-5p effectively alleviated the inhibitory effect of HS on BMEC proliferation. Furthermore, RNA sequencing analysis revealed 753 differentially expressed genes (DEGs), comprising 361 upregulated and 392 downregulated genes. Some of these genes were associated with proliferation and thermogenesis through enrichment analyses. Further experimentation revealed that TOB2, which acts as a target gene of miR-425-5p, is involved in the regulatory mechanism of BMEC proliferation. In summary, this study suggests that miR-425-5p can promote the proliferation of BMECs by regulating TOB2. The miR-425-5p/TOB2 axis may represent a potential pathway through which miR-425-5p ameliorates the proliferation stagnation of BMECs induced by HS.

Hsa_circ_0086414/transducer of ERBB2 (TOB2) axis-driven lipid elimination and tumor suppression in clear cell renal cell cancer via perilipin 3.

BACKGROUND: Renal cell cancer (RCC) is characterized by abnormal lipid accumulation. However, the specific mechanism by which such lipid deposition is eliminated remains unclear. Circular RNAs (circRNAs) widely regulate various biological processes, but the effect of circRNAs on lipid metabolism in cancers, especially clear cell renal cell carcinoma (ccRCC), remains poorly understood. METHODS: The downregulated circRNA, hsa_circ_0086414, was identified from high-throughput RNA-sequencing data of human ccRCC and pair-matched normal tissues. The target relationship between circRNA_0086414 and miR-661, and the transducer of ERBB2 (TOB2) was predicted using publicly available software programs and verified by luciferase reporter assays. The clinical prognostic value of TOB2 was evaluated by bioinformatic analysis. The expression levels of circRNA_0086414, miR-661, TOB2, and perilipin 3 (PLIN3) were measured by quantitative reverse-transcription polymerase chain reaction or western blot analysis. Cell Counting Kit-8, transwell assays, and xenograft models were employed to assess the biological behaviors of the hsa_circ_0086414/TOB2 axis. Oil Red staining and triglyceride assay was conducted to assess lipid deposition. RESULTS: Herein, we identified a downregulated circRNA, hsa_circ_0086414. Functionally, the restored hsa_circ_0086414 inhibited ccRCC proliferation, metastasis, and lipid accumulation in vitro and in vivo. Furthermore, the downregulated TOB2 predicted adverse prognosis and promoted cancer progression and lipid deposition in ccRCC. Mechanically, the binding of hsa_circ_0086414 to miR-661, as a miRNA sponge, upregulates the expression of TOB2, wielding an anti-oncogene effect. Importantly, the restored hsa_circ_0086414/TOB2 axis significantly contributed to the elimination of lipid deposition by inhibiting the lipid metabolism regulator PLIN3 in ccRCC cells. CONCLUSIONS: Our data highlight the importance of the hsa_circ_0086414/TOB2/PLIN3 axis as a tumor suppressor and lipid eliminator in ccRCC. The positive modulation of the hsa_circ_0086414/TOB2 axis might lead to the development of novel treatment strategies for ccRCC.

miR-378a-3p promotes renal cell carcinoma proliferation, migration, and invasion by targeting TOB2

Purpose Renal cell carcinoma (RCC) is one of the most common malignant tumors of the urinary system, which has high metastasis. MicroRNAs (miRNAs) have been reported to participate in RCC progression. The present study aimed to understand the biological role and mechanism of miR-378a-3p in RCC. Methods RT-qPCR assay was used to assess miR-378a-3p and transducer of ERBB2 (TOB2) expression in RCC tissues and cell lines. CCK-8, clone formation, scratch, and transwell assays were carried out to evaluate cell proliferation, migration, and invasion. Furthermore, the target genes of miR-378a-3p were predicted by the online bioinformatics databases. Dual-luciferase reporter assay was used to validate the relationship between miR-378a-3p and TOB2. Results miR-378a-3p was highly expressed in RCC tissues and RCC cell lines. Besides, miR-378a-3p accelerated the progression of RCC by mediating cell proliferation, migration and invasion. More importantly, TOB2 was confirmed as a potential target gene of miR-378a-3p. The results of loss-of-function experiments showed that inhibition of TOB2 reversed the inhibitory roles of miR-378a-3p inhibitor on RCC progression. Conclusions miR-378a-3p promoted cell proliferation, migration and invasion through regulating TOB2 in RCC, which indicated a promising target for the treatment of RCC (AU)

miR-378a-3p promotes renal cell carcinoma proliferation, migration, and invasion by targeting TOB2.

PURPOSE: Renal cell carcinoma (RCC) is one of the most common malignant tumors of the urinary system, which has high metastasis. MicroRNAs (miRNAs) have been reported to participate in RCC progression. The present study aimed to understand the biological role and mechanism of miR-378a-3p in RCC. METHODS: RT-qPCR assay was used to assess miR-378a-3p and transducer of ERBB2 (TOB2) expression in RCC tissues and cell lines. CCK-8, clone formation, scratch, and transwell assays were carried out to evaluate cell proliferation, migration, and invasion. Furthermore, the target genes of miR-378a-3p were predicted by the online bioinformatics databases. Dual-luciferase reporter assay was used to validate the relationship between miR-378a-3p and TOB2. RESULTS: miR-378a-3p was highly expressed in RCC tissues and RCC cell lines. Besides, miR-378a-3p accelerated the progression of RCC by mediating cell proliferation, migration and invasion. More importantly, TOB2 was confirmed as a potential target gene of miR-378a-3p. The results of loss-of-function experiments showed that inhibition of TOB2 reversed the inhibitory roles of miR-378a-3p inhibitor on RCC progression. CONCLUSIONS: miR-378a-3p promoted cell proliferation, migration and invasion through regulating TOB2 in RCC, which indicated a promising target for the treatment of RCC.

LncRNA AL133467. 1 Acts as the ceRNA of miR-661 to Inhibit theProliferation and Invasion of Breast Cancer Cells / 中国生物化学与分子生物学报

Long non-coding RNAs (LncRNAs) are abnormally expressed in a variety of tumors and participate in the occurrence and development of tumors. However, the expression and function of many LncRNAs in tumors have not been fully clarified. In this paper, 113 normal breast tissues and 1 109breast cancer tissues were analyzed in TCGT database. LncRNA AL133467. 1 was found to be lowly expressed in breast cancer tissues and negatively correlated with poor prognosis of breast cancer patients. The expression of AL133467. 1 in breast cancer cells was significantly lower than that in normal breast epithelial cells. We overexpressed AL133467. 1 in relatively low-expression breast cancer cells SKBR3and BT474, and cell count and plate colony-formation experiments showed that overexpression ofAL133467. 1 could significantly inhibit the proliferation and colony formation of breast cancer cells (P< 0. 01). Cell scratch and Transwell assays showed that the migration and invasion ability of breast cancer cells overexpressing AL133467. 1 was significantly reduced compared with the control group (P<0. 01). MiRDB database showed that AL133467. 1 had binding sites with miR-661. miR-661 could bind the transducer of ErbB2, 2 (ErbB2, 2, TOB2). qRT-PCR showed that miR-661 was highly expressed inbreast cancer cells and positively correlated with poor prognosis of breast cancer patients (P < 0. 001). Luciferase reporter assays showed that AL133467. 1 had specific binding to miR-661 (P < 0. 01). AL133467. 1 overexpression could inhibit the expression of miR-661 in breast cancer cells (P<0. 0001). Transfection of miR-661 mimics eliminated the inhibitory effect of overexpression of AL133467. 1 on breast cancer cells (P < 0. 001). In addition, qRT-PCR and Western blotting results showed that overexpression of AL133467. 1 up-regulated TOB2 mRNA (P < 0. 0001) and protein levels. But whenmiR-661 mimics were transfected, TOB2 mRNA (P < 0. 0001) and protein levels were significantly inhibited. In conclusion, as a competitive endogenous RNA of miR-661. AL133467. 1 promotes the expression of TOB2, thereby inhibiting the proliferation and invasion of breast cancer cells.

MiR-375 promotes human periodontal ligament stem cells proliferation and osteogenic differentiation by targeting transducer of ERBB2, 2.

BACKGROUND: MiRNAs have been demonstrated to be important regulators during osteogenic differentiation in multiple types of stem cells. In the study, the interaction between miR-375 and TOB2 was analyzed to identify their functions on the proliferation and osteogenic differentiation of hPDLSCs. METHODS: hPDLSCs were isolated from human first premolars, and hPDLSCs stably expressing and silenced miR-375 were constructed using miR-375-ago and miR-375-antago, respectively. miR-375 and RUNX2 mRNA expression levels in hPDLSCs during osteogenic differentiation were investigated using qRT-PCR. The impact of miR-375 expression on hPDLSCs proliferation and osteogenic differentiation was determined using MTT assay, ALP assay, and alizarin red S staining. The protein expression levels of COL1A1, RUNX2 and OCN were detected using Western blot. The targeting of TOB2 by miR-375 was validated using dual luciferase reporter assay. RESULTS: The expression levels of miR-375 were increased in hPDLSCs during osteogenic differentiation in a time-dependant manner, and was positively correlated with RUNX2 mRNA expression. miR-375 facilitated the proliferation and osteogenic differentiation of hPDLSCs, and promoted the protein expression levels of COL1A1, RUNX2 and OCN. Moreover, TOB2 protein expression was reduced in hPDLSCs during osteogenic differentiation in a time-dependant manner, and miR-375 directly targeted TOB2 expression. In addition, targeting TOB2 expression in hPDLSCs could rescue the suppression of cell proliferation and osteogenic differentiation by miR-375-antago. CONCLUSION: In summary, miR-375 promotes proliferation and osteogenic differentiation of hPDLSCs by targeting TOB2, which reveals a new regulatory mechanism underlying osteogenic differentiation of hPDLSCs by miR-375/TOB2 axis.

A Novel Regulatory Circuit "C/EBPα/miR-20a-5p/TOB2" Regulates Adipogenesis and Lipogenesis.

Recent studies have identified growing importance of microRNAs as key regulators of adipocyte differentiation. We have previously reported that miR-20a-5p is able to induce adipogenesis of established adipogenic cell lines and bone marrow derived mesenchymal stem cells (BMSCs). However, the molecular mechanisms by which miR-20a-5p controls adipogenesis and by which miR-20a-5p expression is regulated need to be further explored. In the current study we found that miR-20a-5p expression was induced during adipocyte differentiation from preadipocyte 3T3-L1 and was increased in epididymal white adipose tissue from either ob/ob mice or high fat diet-induced obese mice. Functional studies identified miR-20a-5p as a positive regulator of adipocyte differentiation and lipogenesis in 3T3-L1 by using either synthetic mimics to supplement miR-20a-5p, or using synthetic inhibitor or sponge lentivirus to inactivate endogenous miR-20a-5p. Luciferase activity assay revealed that TOB2 is a novel target of miR-20a-5p and functional experiment demonstrated its negative regulatory role in adipocyte differentiation. Moreover, Tob2 overexpression significantly attenuated adipocyte formation induced by miR-20a-5p supplementation. In-depth investigation of mechanisms that govern miR-20a-5p expression clarified that C/EBPα transcriptionally activated miR-20a-5p expression via binding to the promoter of miR-20a-5p. Taken together, we conclude that a novel C/EBPα/miR-20a-5p/TOB2 circuit exists and regulates adipogenesis and lipogenesis.

MiR-5100 targets TOB2 to drive epithelial-mesenchymal transition associated with activating smad2/3 in lung epithelial cells.

Idiopathic pulmonary fibrosis (IPF) is a devastating disease and the pathogenesis of IPF remains unclear. Our previous study indicated that miR-5100 promotes the proliferation and metastasis of lung epithelial cells. In this study, we investigated the effect and mechanism of miR-5100 on bleomycin (BLM)-induced mouse lung fibrosis and transforming growth factor ß (TGF-ß1) or epidermal growth factor (EGF) induced EMT-model in A549 and Beas-2B cells. The elevated level of miR-5100 was observed in both the mouse lung fibrosis tissues and EMT cell model. Furthermore, the exogenous expression of miR-5100 promoted the EMT-related changes, enhanced TGF-ß1 or EGF-induced EMT and activated the smad2/3 in lung epithelial cells, while silencing miR-5100 had the converse effects. In addition, transwell assay showed that miR-5100 can enhance cell migration. Using target prediction software and luciferase reporter assays, we identified TOB2 as a specific target of miR-5100 and miR-5100 can decrease the accumulation of endogenous TOB2 in A549 and Beas-2B cells. Moreover, the exogenous expression of TOB2 relieves the promotion of miR-5100 on EMT process and migration ability. Taken together, our results indicate that miR-5100 promotes the EMT process by targeting TOB2 associated with activating smad2/3 in lung epithlium cells. Our findings may provide novel insights into the pathogenesis of IPF.

MiR-5100 promotes osteogenic differentiation by targeting Tob2.

MicroRNAs have emerged as pivotal regulators in various physiological and pathological processes, including osteogenesis. Here we discuss the contribution of miR-5100 to osteoblast differentiation and mineralization. We found that miR-5100 was upregulated during osteoblast differentiation in ST2 and MC3T3-E1 cells. Next, we verified that miR-5100 can promote osteogenic differentiation with gain-of-function and loss-of-function experiments. Target prediction analysis and experimental validation demonstrated that Tob2, which acts as a negative regulator of osteogenesis, was negatively regulated by miR-5100. Furthermore, we confirmed that the important bone-related transcription factor osterix, which can be degraded by binding to Tob2, was influenced by miR-5100 during osteoblast differentiation. Collectively, our results revealed a new molecular mechanism that fine-tunes osteoblast differentiation through miR-5100/Tob2/osterix networks.

Upregulation of miR-362-3p Modulates Proliferation and Anchorage-Independent Growth by Directly Targeting Tob2 in Hepatocellular Carcinoma.

The dysregulation of microRNAs (miRNAs) contributes to the pathogenesis of human malignancies, and miRNA expression can be affected by genetic and epigenetic changes, such as methylation of the CpG islands of their promoters. To identify miRNAs regulated by DNA methylation, the global miRNA expression profile was analyzed in two hepatocellular carcinoma (HCC) cell lines and two normal immortalized cell lines treated with 5-Aza-2'-deoxycytidine (DAC, an inhibitor of DNA methylation) plus TSA (Trichostatin A, histone deacetylase inhibitor). Results revealed that these epigenetic drugs differentially affect miRNA expression that is dependent or independent of cell type, especially miR-362-3p. miR-362-3p expression increased while methylation of its promoter significantly decreased in human HCC cells and tissues compared with normal cells and adjacent noncancerous tissues. Ectopic expression of miR-362-3p increased proliferation and anchorage-independent soft agar growth and its expression inhibition had opposing effects that were associated with regulation of its direct target-Tob2 in HCC cells. Inhibition of Tob2 recapitulated the effects of miR-362-3p overexpression, whereas enforced Tob2 expression reversed the promoting effects of miR-362-3p. Tob2 expression was reduced in human primary HCCs compared to adjacent noncancerous tissues. Our findings suggest that dysregulation of miR-362-3p and Tob2 may contribute to HCC malignancy.

The role of microRNAs in osteoclasts and osteoporosis.

Osteoclasts are the exclusive cells of bone resorption. Abnormally activating osteoclasts can lead to low bone mineral density, which will cause osteopenia, osteoporosis, and other bone disorders. To date, the mechanism of how osteoclast precursors differentiate into mature osteoclasts remains elusive. MicroRNAs (miRNAs) are novel regulatory factors that play an important role in numerous cellular processes, including cell differentiation and apoptosis, by post-transcriptional regulation of genes. Recently, a number of studies have revealed that miRNAs participate in bone homeostasis, including osteoclastic bone resorption, which sheds light on the mechanisms underlying osteoclast differentiation. In this review, we highlight the miRNAs involved in regulating osteoclast differentiation and bone resorption, and their roles in osteoporosis.

Regulation of Btg2(/TIS21/PC3) expression via reactive oxygen species-protein kinase C-ΝFκΒ pathway under stress conditions.

Human B-cell translocation gene 2 (BTG2), an ortholog of mouse TIS21 (12-O-tetradecanoyl phorbol-13-acetate inducible sequence 21) and rat PC3 (Pheochromocytoma Cell 3), is a tumor suppressor gene that belongs to an antiproliferative gene family. Btg2 is involved in a variety of biological processes including cell growth, development, differentiation, senescence, and cell death and its expression is strongly regulated by p53. Recently, we have reported transient induction of Btg2 expression in response to oxidative damage; however, the regulatory mechanism was not explored. In the present study we revealed ΝFκΒ as the upstream mediator involved in Btg2 transcription in response to cell stress challenges such as serum deprivation and oxidative stress i.e. H2O2, TPA or doxorubicin treatments in several cell lines. We observed close interrelation between generation of reactive oxygen species (ROS), enhanced IκBα degradation, nuclear translocation of ΝFκΒ (p65/RelA) and the significant increase of Btg2 expression independent of p53 status. ChIP analysis revealed an enrichment of RelA (p65) bound to the κB response element on Btg2 promoter in response to the cell stress challenges. Employing various inhibitors led to cytoplasmic accumulation of IκBα, decreased p65 nuclear translocation along with significant reduction of Btg2 expression. Generation of ROS was the common event mediating ΝFκΒ activation and Btg2 transcription. Furthermore, PKC activation was also found to be a critical factor mediating ROS-mediated signals to NFκB pathway that culminate on Btg2 regulation, and specifically PKC-δ was responsible for this regulation under oxidative stress. However, serum deprivation-associated ROS generation bypassed PKC activation for induction of Btg2 expression via NFκB activation. The present data imply that oxidative stress upregulates Btg2 expression via ROS-PKC-ΝFκΒ cascade, independent of p53 status that in turn could be involved in mediating various biological phenotypes depending on the cellular context.

MicroRNA-322 (miR-322) and its target protein Tob2 modulate Osterix (Osx) mRNA stability.

Osteogenesis depends on a coordinated network of signals and transcription factors such as Runx2 and Osterix. Recent evidence indicates that microRNAs (miRNAs) act as important post-transcriptional regulators in a large number of processes, including osteoblast differentiation. In this study, we performed miRNA expression profiling and identified miR-322, a BMP-2-down-regulated miRNA, as a regulator of osteoblast differentiation. We report miR-322 gain- and loss-of-function experiments in C2C12 and MC3T3-E1 cells and primary cultures of murine bone marrow-derived mesenchymal stem cells. We demonstrate that overexpression of miR-322 enhances BMP-2 response, increasing the expression of Osx and other osteogenic genes. Furthermore, we identify Tob2 as a target of miR-322, and we characterize the specific Tob2 3'-UTR sequence bound by miR-322 by reporter assays. We demonstrate that Tob2 is a negative regulator of osteogenesis that binds and mediates degradation of Osx mRNA. Our results demonstrate a new molecular mechanism controlling osteogenesis through the specific miR-322/Tob2 regulation of specific target mRNAs. This regulatory circuit provides a clear example of a complex miRNA-transcription factor network for fine-tuning the osteoblast differentiation program.