Retracted: Downregulation of microRNA-1469 promotes the development of breast cancer via targeting HOXA1 and activating PTEN/PI3K/AKT and Wnt/β-catenin pathways

Breast cancer (BC) is a common malignancy which is the most frequently diagnosed cancer in women all over the worldwide. This study aimed to investigate the roles of miR-1469 in the development of BC, as well as its regulatory mechanism. The expression levels of miR-1469 in BC tissues, serum, and cell lines were determined. Effects of overexpression of miR-1469 on MCF7 cell viability, colony-forming ability, apoptosis, migration, and invasion were then investigated. Furthermore, the potential target of miR-1469 in MCF7 cells was explored. Besides, the association between miR-1469, PTEN/PI3K/AKT, and Wnt/β-catenin pathways was elucidated. Notably, confirmatory experiments by downregulation of miR-1469 in SK-BR-3 cells were further performed. The miR-1469 expression was significantly downregulated in BC tissues, serum, and cell lines. The overexpression of miR-1469 significantly inhibited the proliferation, arrested cell-cycle at G2/M phase, increased apoptosis, suppressed migration, and invasion of MCF-7 cells. In addition, HOXA1 was verified as a direct target of miR-1469, and the effects of overexpression of miR-1469 on the malignant behaviors of MCF7 cells were significantly counteracted by overexpression of HOXA1 concurrently. Furthermore, the overexpression of miR-1469 suppressed the activation of PTEN/PI3K/AKT and Wnt/β-catenin pathways, which was reversed overexpression of HOXA1 concurrently. Besides, confirmatory experiments showed that the inhibition of miR-1469 promoted the malignant behaviors of SK-BR-3 cells, which was inversed after miR-1469 inhibition and HOXA1 knockdown at the same time. Our findings reveal that downregulation of miR-1469 may promote the development of BC by targeting HOXA1 and activating PTEN/PI3K/AKT and Wnt/β-catenin pathways. MiR-1469 may serve as a promising target for BC therapy.     

TGF-β regulates β-catenin signaling and osteoblast differentiation in human mesenchymal stem cells

Human adult bone marrow-derived skeletal stem cells a.k.a mesenchymal stem cells (hMSCs) have been shown to be precursors of several different cellular lineages, including osteoblast, chondrocyte, myoblast, adipocyte, and fibroblast. Several studies have shown that cooperation between transforming growth factor β (TGF-β) and Wnt/β-catenin signaling pathways plays a role in controlling certain developmental events and diseases. Our previous data showed that agents like TGF-β, cooperation with Wnt signaling, promote chondrocyte differentiation at the expense of adipocyte differentiation in hMSCs. In this study, we tested mechanisms by which TGF-β activation of β-catenin signaling pathway and whether these pathways interact during osteoblast differentiation of hMSCs. With selective small chemical kinase inhibitors, we demonstrated that TGF-β1 requires TGF-β type I receptor ALK-5, Smad3, phosphoinositide 3-kinases (PI3K), and protein kinase A (PKA) to stabilize β-catenin, and needs ALK-5, PKA, and JNK to inhibit osteoblastogenesis in hMSCs. Knockdown of β-catenin with siRNA stimulated alkaline phosphatase activity and antagonized the inhibitory effects of TGF-β1 on bone sialoprotein (BSP) expression, suggested that TGF-β1 cooperated with β-catenin signaling in inhibitory of osteoblastogenesis in hMSCs. In summary, TGF-β1 activates β-catenin signaling pathway via ALK-5, Smad3, PKA, and PI3K pathways, and modulates osteoblastogenesis via ALK5, PKA, and JNK pathways in hMSCs; the interaction between TGF-β and β-catenin signaling supports the view that β-catenin signaling is a mediator of TGF-β's effects on osteoblast differentiation of hMSCs.     

miR-186 modulates hepatocellular carcinoma cell proliferation and mobility via targeting MCRS1-mediated Wnt/β-catenin signaling

Previous studies have revealed that miR-186 is involved in the pathogenesis of many malignancies. However, the role of miR-186 in hepatocellular carcinoma (HCC) carcinogenesis and its detailed mechanism are poorly understood. This study was to investigate the function of miR-186 in modulating HCC cell proliferation, cell cycle, migration, and invasion. We found that miR-186 was decreased in HCC tissues and cell lines. Loss-of-function experiments showed that reduction of miR-186 dramatically enhanced tumor cell proliferation and metastasis. Besides, miR-186 also participated in the modulation of the cell cycle. In addition, luciferase reporter assays and Western blot analysis showed that MCRS1 was a novel target of miR-186 in HCC cells. Notably, upregulation of miR-186 suppressed the nuclear β-catenin accumulation and blocked the activation of Wnt/β-catenin signaling in HCC cells. Forced MCRS1 expression abrogated the inhibitory effect of miR-186 on cell growth, metastasis and Wnt/β-catenin signaling in HCC cells. Our findings may provide new insight into the pathogenesis of HCC and miR-186/ MCRS1 might function as new therapeutic targets for HCC.     

microRNA-485-5p inhibits the progression of hepatocellular carcinoma through blocking the WBP2/Wnt signaling pathway

microRNA-485-5p (miR-485-5p) has been shown to act as a tumor-suppressor gene in some cancers, such as ovarian epithelial tumors and oral tongue squamous cell carcinoma. However, with regard to the anti-tumor role of miR-485-5p in hepatocellular carcinoma (HCC), evidence is unexpectedly limited. In the present study, we investigated the expression and the role of miR-485-5p in the progression of HCC. Microarray analysis revealed that miR-485-5p was downregulated and WBP2 was upregulated in HCC, which was consistent with RT-qPCR and immunohistochemistry assays in the HCC tissues we collected. A negative correlation between the expression of miR-485-5p and WBP2 was also found in HCC tissues. It was predicted and confirmed that miR-485-5p could bind to WW domain binding protein 2 (WBP2) through in silico analysis of genetic sequences and an in vitro dual-luciferase reporter gene assay. Next, gain- or loss-of-function studies were applied in the HCC cell line (Huh7) to examine the effects of miR-485-5p and WBP2 on HCC cell behavior. The effects of miR-485-5p and WBP2 on the Wnt/β-catenin signaling pathway were determined by TOP/FOP flash luciferase assays. miR-485-5p was shown to downregulate WBP2 and block the Wnt/β-catenin signaling pathway. As expected, elevated miR-485-5p levels and inhibition of WBP2 protein expression exerted inhibitory effects on HCC cell proliferation, migration and invasion and, induced apoptosis. In vivo experiments were finally conducted, which confirmed that upregulation of miR-485-5p or depletion of WBP2 attenuated tumor growth. Collectively, our results suggest miR-485-5p can downregulate WBP2 to inhibit the development of HCC by the blockade of the Wnt/β-catenin signaling, providing a novel molecular target for HCC treatment.     

Epiregulin promotes growth and metastasis of gastric cancer via the ERK/JNK/p38 signaling pathway

Epiregulin (EREG) is a ligand of the epidermal growth factor receptor. It belongs to the ErbB family of ligands found overexpressed in various cancers such as colon cancer and lung carcinoma and is likely to play diverse oncogenic roles in several other cancer types. However, little is known about the mechanisms of EREG in the pathogenesis of gastric cancer (GC). The present study was undertaken to investigate whether EREG influences the development and progression in GC. The results revealed that EREG was found to be overexpressed in human GC cells lines. Moreover, EREG induced cell migration, invasion, and proliferation, and inhibited apoptosis in vitro. The study also found that EREG depletion inhibited tumor growth in vivo. Our findings indicated that EREG activated the ERK/JNK/p38 signaling pathway and PI3K/Akt signaling pathways to promote GC malignant progression. Overall, this study suggests that EREG may promote GC development and progression through the ERK/JNK/p38 and PI3K/Akt signaling pathways, which may improve our understanding of the molecular mechanism of EREG in GC. Thus, EREG may be a potential target for GC treatment.     

miR-155-5p modulates malignant behaviors of hepatocellular carcinoma by directly targeting CTHRC1 and indirectly regulating GSK-3β-involved Wnt/β-catenin signaling

Background

Hepatocellular carcinoma (HCC) remains one of the most lethal cancers. MicroRNA-155 (miR-155) and collagen triple helix repeat containing 1 (CTHRC1) were found to be involved in hepatocarcinogenesis, but their detailed functions in HCC are unclear. Here, we aimed to investigate the underlying role of miR-155-5p and CTHRC1 in HCC.

Methods

miR-155-5p and CTHRC1 expression levels were detected by qRT-PCR, IHC and WB in HCC patients and cell lines. Dual-luciferase assay, qRT-PCR and WB were used to validate the target interaction between miR-155-5p and CTHRC1. Biological behaviors, including apoptosis, cell cycle progression, and cell proliferation, invasion and migration, were measured by flow cytometry, CCK-8 assay and Transwell tests. A xenograft model was established to examine the effects of miR-155-5p and CTHRC1 on tumor formation. WB was finally utilized to identify the role of GSK-3β-involved Wnt/β-catenin signaling in HCC growth and metastasis.

Results

Our results showed that miR-155-5p and CTHRC1 were down-regulated and up-regulated, respectively, in HCC patients and cell lines. Dual-luciferase assay verified that CTHRC1 was the direct target of miR-155-5p. Moreover, elevated miR-155-5p expression promoted apoptosis but suppressed cell cycle progression and cell proliferation, invasion and migration in vitro and facilitated tumor formation in vivo; elevated CTHRC1 expression abolished these biological effects. Additionally, miR-155-5p overexpression increased metastasis- and anti-apoptosis-related protein expression and decreased pro-apoptosis-related protein expression, while forced CTHRC1 expression conserved the expression of these proteins.

Conclusion

Altogether, our data suggested that miR-155-5p modulated the malignant behaviors of HCC by targeting CTHRC1 and regulating GSK-3β-involved Wnt/β-catenin signaling; thereby, miR-155-5p and CTHRC1 might be promising therapeutic targets for HCC patients.

     

Exosomes miR-15a promotes nucleus pulposus-mesenchymal stem cells chondrogenic differentiation by targeting MMP-3

The physiology of the nucleus pulposus (NP) in intervertebral disc degeneration (IVD) has been studied widely. However, interactions involving nucleus pulposus -mesenchymal stem cells (NP-MSCs) are less understood. MicroRNA 15a (miR-15a) is known to target and modulate genes involved in cellular proliferation and apoptosis. This study aimed to understand the interactions and impact of miR-15a and NP-MSCs on chondrogenic differentiation and IVD degeneration. Exosomes secreted by NP cells were purified by differential centrifugation and identified by transmission electron microscopy and exosomal markers. Further, by co-culture these exosomes were re-introduced into the NP-MSC cells, which were confirmed by fluorescence confocal microscopy. NP-MSCs treated with exo-miR-15a increases aggrecan and collagen II mRNA and protein levels while decreasing mRNA and protein levels of ADAMTS4/5 and MMP-3/-13. Toluidine blue staining confirmed that chondrogenic differentiation was increased in NP-MSCs treated with exo-miR-15a. NP-MSCs treated with exo-anti-miR-15a inhibit aggrecan and collagen II expression while increasing ADAMTS4/5 and MMP-3/-13 expression and decreasing chondrogenic differentiation. Dual-luciferase reporter assays revealed that miR-15a directly targets MMP-3 and downregulates its expression. Overexpression of miR-15a increased proliferation and colony formation, whereas combinatorial overexpression with MMP3, suppressed miR-15a's effects. This was also evident through the decreased phosphorylation of PI3K and Akt, upregulation of Wnt3a and β-catenin in the presence of miR-15a, but overexpression of MMP3 indicated an opposite effect. Overall, these data demonstrate that exo-miR-15a promotes NP-MSCs chondrogenic differentiation by downregulating MMP-3 through PI3K/Akt and Wnt3a/β-catenin axis.     

Differential effects of Akt pathway inhibitors on IL-1β-induced protein phosphorylation in human fibroblast-like synoviocytes

Context: Interleukin (IL)-1β activates various signal transduction pathways including p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and Akt in human fibroblast-like synoviocytes (HFLS).

Objective: We investigated the effects of an Akt inhibitor, a phosphatidylinositol 3-kinase (PI3K) inhibitor, and Akt RNAi knockdown on IL-1β-induced protein phosphorylation in HFLS to clarify the role of the PI3K/Akt signaling pathway in the phosphorylation of the inhibitor of κB (IκB)α and heat shock protein 27 (HSP27).

Materials and methods: A multiplex suspension array system was used for the detection of phosphorylated proteins.

Results: IL-1β induced biphasic phosphorylation of IκBα, with the first phase occurring 10?min after IL-1β stimulation, and this was augmented by treatment with Akt inhibitor IV. However, this phenomenon was not observed after treatment with LY-294002, a PI3K inhibitor. Furthermore, Akt inhibitor IV suppressed ERK2 phosphorylation, whereas LY-294002 and Akt RNAi had no effect. In contrast, Akt inhibitor IV, LY-294002, and Akt RNAi augmented HSP27 phosphorylation.

Discussion and conclusions: Modulation of different stages of the PI3K/Akt pathway may differentially affect the phosphorylation of IκBα and HSP27 in HFLS.     

Prevention of TGF-β-induced apoptosis by interlukin-4 through Akt activation and p70S6K survival signaling pathways

In this study, we demonstrate that interleukin-4 (IL-4) protects human hepatocellular carcinoma (HCC) cell line Hep3B from apoptosis induced by transforming growth factor-β (TGF-β). Further investigation of IL-4-transduced signaling pathways revealed that both insulin response substrate 1 and 2 (IRS-1/-2) and extracellular signal-regulated kinase (ERK) pathways were activated after IL-4 stimulation. The IRS-1/-2 activation was accompanied by the activation of phosphotidylinositol-3-kinase (PI3K), leading to Akt and p70 ribosomal protein S6 kinase (p70S6K). Interestingly, a protein kinase C (PKC) inhibitor, Gö6976, inhibited the phosphorylation of Akt, suggesting that the Akt activation was PKC-dependent. Using specific inhibitors for PI3K or ERK, we demonstrated that the PI3K pathway, but not the ERK pathway, was required for protection. The constitutively active form of PI3K almost completely rescued TGF-β-induced apoptosis, further supporting the importance of the PI3K pathway in the protective effect of IL-4. Furthermore, a dominant negative Akt and/or Gö6976 only partially blocked the anti-apoptotic effect of IL-4. Similarly, rapamycin, which interrupted the activation of p70S6K, also only partially blocked the protective effect of IL-4. However, in the presence of both rapamycin and dominant negative Akt with or without Gö6976, IL-4 almost completely lost the anti-apoptotic effect, suggesting that both Akt and p70S6K pathways were required for the protective effect of IL-4 against TGF-β-induced apoptosis.     

肝细胞癌中抑癌基因的发现与研究进展

肝细胞癌（HCC）的发病率高、治疗效果差。HCC的发病机制复杂,主要有2类：肝炎、酒精、黄曲霉素、代谢紊乱引起的肝损伤,进而导致的肝硬化;致癌基因和抑癌基因的突变或对应染色体区域的扩增或缺失。细胞内一些信号通路参与了HCC的发生发展,包括RAF／MEK／ERK、P13K／AKT／mTOR、WNT/β-catenin、胰岛素样生长因子、肝细胞生长因子／c-MET、生长因子调节的血管新生等6类信号通路。抑癌基因通过调节信号通路而调节细胞增殖、细胞周期、细胞凋亡等对肿瘤的发生、发展起重要作用的过程。我们简要概述HCC相关的肿瘤抑制分子及其所在的信号通路及作用的分子机制。     

MiR-145 reduces the activity of PI3K/Akt and MAPK signaling pathways and inhibits adipogenesis in bovine preadipocytes

Adipose tissue is the largest metabolic organ because of adipogenesis controlled by numerous miRNAs. MiR-145 is classified into the same cluster with famous miR-143. However, few studies have investigated the role of miR-145 in adipogenesis. In the current study, we observed that the expression of miR-145 was downregulated during bovine adipogenesis in vivo and in vitro. The results of RNA-Seq analysis showed that miR-145 mainly disturb the PI3K/Akt and MAPK signaling pathways in bovine preadipocytes. MiR-145 inhibited bovine preadipocyte differentiation and downregulated phosphorylation level of Akt and ERK1/2 proteins. Furthermore, insulin, as a powerful inducer initiating adipogenesis and an activator of the PI3K/Akt and MAPK signaling pathways, was able to rescue the downregulation of Akt and ERK1/2 phosphorylation levels caused by miR-145. Taken together, our findings suggest that miR-145 is a potent inhibitor of adipogenesis that may function by reducing the activity of PI3K/Akt and MAPK signaling pathways.     

表没食子儿茶素没食子酸酯对细胞信号转导通路的影响

表没食子儿茶素没食子酸酯（epigallocatechin-3-gallate,EGCG）是绿茶中含量最丰富的儿茶素,具有抗氧化、抗炎、抗动脉粥样硬化、抗癌等多种作用。研究发现EGCG通过多条细胞信号转导通路发挥作用。本文简要综述EGCG对MAPK、NF-κB、PI3K/Akt、JAK/STAT、TGF-β/Smad、Wnt/β-catenin等多条信号转导通路的影响。     

Retracted:Propofol exerts anticancer activity on hepatocellular carcinoma cells by raising lncRNA DGCR5

Hepatocellular carcinoma is one of the most fatal cancers worldwide. Propofol is an intravenous anesthetic extensively used in clinical. Herein, we tested the anticancer activity of propofol on hepatocellular carcinoma, along with the internal molecular mechanism related to lncRNA DiGeorge syndrome critical region gene 5 (DGCR5). Followed by propofol stimulation, hepatocellular carcinoma Huh-7 and HepG2 cell viability, proliferation, migration, invasion, and apoptosis were tested, respectively. Then, DGCR5 expression levels in hepatocellular carcinoma tissues and cells were measured. sh-DGCR5 was transfected to silence DGCR5 expression. Subsequently, the influence of DGCR5 silence on propofol caused Huh-7 and HepG2 cell viability loss, proliferation inhibition, migration and invasion suppression, apoptosis induction, as well as Raf1/ERK1/2 and Wnt/β-catenin pathways inactivation were assessed, respectively. We discovered that propofol declined Huh-7 and HepG2 cell viability, proliferation, migration and invasion, but increased cell apoptosis. DGCR5 had a relatively lower expression level in hepatocellular carcinoma tissues and cells. Propofol elevated DGCR5 expression in Huh-7 and HepG2 cells. Increased expression of DGCR5 was connected with the anticancer activity of propofol on Huh-7 and HepG2 cells. Besides, propofol repressed Raf1/ERK1/2 and Wnt/β-catenin pathways through elevating DGCR5 expression. In conclusion, the anticancer activity of propofol on hepatocellular carcinoma was verified in this study. Propofol repressed hepatocellular carcinoma Huh-7 and HepG2 cell growth and metastasis at least by elevating DGCR5 and hereafter inactivating Raf1/ERK1/2 and Wnt/β-catenin pathways.     

miR-612 suppresses the stemness of liver cancer via Wnt/β-catenin signaling

Previous research showed that microRNA-612 (miR-612) has inhibitory effects on cell proliferation, migration, invasion, and metastasis of hepatocellular carcinoma (HCC). AKT2 was confirmed to be a direct target of miR-612, through which the epithelial–mesenchymal transition (EMT) and metastasis of HCC were inhibited. Our present findings reveal that miR-612 is able to suppress the stemness of HCC by reducing the number and size of tumorspheres as well as clone formation in soft agar, and to relieve drug resistance to cisplatin and 5-fluorouracil. In addition, miR-612 hampered the capacity of tumorigenesis in NOD/SCID mice and redistributed the tumor invasive frontier of miR-612-modulating cells. Finally, our findings suggest that Wnt/β-catenin signaling is required in the regulation of EMT-associated stem cell-like traits by miR-612.     

调控肿瘤上皮–间质转化及肿瘤干细胞样特性的信号通路串话

上皮–间质转化（epithelial-mesenchymal transition,EMT）是上皮来源肿瘤细胞获得侵袭和转移能力的重要生物学过程。肿瘤干细胞样细胞（cancer stem-like cells,CSLCs）在肿瘤发生、侵袭、转移和复发中亦起着关键作用。近年发现,EMT与肿瘤干细胞样特性获得存在密切关联,二者通过TGF-β、Wnt/β-catenin、Notch、Hedgehog、FGF、PI3k/Akt等多种信号通路及通路间的信号串话而交互作用,共同影响着肿瘤发生、侵袭及转移,了解调控EMT/CSLCs关键信号分子的功能及相互作用对于肿瘤靶向治疗具有重要意义。