Transgelin-2, a novel cancer stem cell-related biomarker, is a diagnostic and therapeutic target for biliary tract cancer.

BACKGROUND: Biliary tract cancer (BTC) is a relatively rare but aggressive gastrointestinal cancer with a high mortality rate. Cancer stem cell (CSC) populations play crucial roles in tumor biology and are responsible for the low response to anti-cancer treatment and the high recurrence rate. This study investigated the role of Transgelin-2 (TAGLN2), overexpressed in CSC in BTC cells, and analyzed its expression in patient tissues and serum to identify potential new targets for BTC. METHODS: TAGLN2 expression was suppressed by small-interfering or short hairpin RNAs, and its effects on tumor biology were assessed in several BTC cell lines. Furthermore, the effects of TAGLN2 silencing on gemcitabine-resistant BTC cells, differentially expressed genes, proteins, and sensitivity to therapeutics or radiation were assessed. TAGLN2 expression was also assessed using western blotting and immunohistochemistry in samples obtained from patients with BTC to validate its clinical application. RESULTS: Suppression of TAGLN2 in BTC cell lines decreased cell proliferation, migration, invasion, and tumor size, in addition to a reduction in CSC features, including clonogenicity, radioresistance, and chemoresistance. TAGLN2 was highly expressed in BTC tissues, especially in cancer-associated fibroblasts in the stroma. Patients with a low stromal immunohistochemical index had prolonged disease-free survival compared to those with a high stromal immunohistochemical index (11.5 vs. 7.4 months, P = 0.013). TAGLN2 expression was higher in the plasma of patients with BTC than that in those with benign diseases. TAGLN2 had a higher area under the curve (0.901) than CA19-9, a validated tumor biomarker (0.799; P < 0.001). CONCLUSION: TAGLN2 plays a critical role in promoting BTC cell growth and motility and is involved in regulating BTC stemness. Silencing TAGLN2 expression enhanced cell sensitivity to radiation and chemotherapeutic drugs. The expression of TAGLN2 in patient tissue and plasma suggests its potential to serve as a secretory biomarker for BTC. Overall, targeting TAGLN2 could be an appropriate therapeutic strategy against advanced cancer following chemotherapy failure.

Transgelin-2: Biochemical and Clinical Implications in Cancer and Asthma.

Transgelin-2 has been regarded as an actin-binding protein that induces actin gelation and regulates actin cytoskeleton. However, transgelin-2 has recently been shown to relax the myosin cytoskeleton of the airway smooth muscle cells by acting as a receptor for extracellular metallothionein-2. From a clinical perspective, these results support transgelin-2 as a promising therapeutic target for diseases such as cancer and asthma. The inhibition of transgelin-2 prevents actin gelation and thereby cancer cell proliferation, invasion, and metastasis. Conversely, the activation of transgelin-2 with specific agonists relaxes airway smooth muscles and reduces pulmonary resistance in asthma. Here, we review new studies on the biochemical properties of transgelin-2 and discuss their clinical implications for the treatment of immune, oncogenic, and respiratory disorders.

Determining the domain-level reaction-diffusion properties of an actin-binding protein transgelin-2 within cells.

Proteins in cells undergo repeated binding to other molecules, thereby reducing the apparent extent of their intracellular diffusion. While much effort has been made to analytically decouple these combined effects of pure diffusion and chemical binding, it is difficult with conventional approaches to attribute the measured quantities to the nature of specific domains of the proteins. Motivated by the common goal in cell signaling research aimed at identifying the domains responsible for particular intermolecular interactions, here we describe a framework for determining the local physicochemical properties of cellular proteins associated with immobile scaffolds. To validate this new approach, we apply it to transgelin-2, an actin-binding protein whose intracellular dynamics remains elusive. We develop a fluorescence recovery after photobleaching (FRAP)-based framework, in which comprehensive combinations of domain-deletion mutants are created, and the difference among them in FRAP response is analyzed. We demonstrate that transgelin-2 in actin stress fibers (SFs) interacts with F-actin via two separate domains, and the chemical properties are determined for the individual domains. Its pure diffusion properties independent of the association to F-actin is also obtained. Our approach will thus be useful, as presented here for transgelin-2, in addressing the signaling mechanism of cellular proteins associated with SFs.

Variations in Blood Platelet Proteome and Transcriptome Revealed Altered Expression of Transgelin-2 in Acute Coronary Syndrome Patients.

Proteomic analyses based on mass spectrometry provide a powerful tool for the simultaneous identification of proteins and their signatures. Disorders detection at the molecular level delivers an immense impact for a better understanding of the pathogenesis and etiology of various diseases. Acute coronary syndrome (ACS) refers to a group of heart diseases generally associated with rupture of an atherosclerotic plaque and partial or complete thrombotic obstruction of the blood flow in the infarct-related coronary artery. The essential role in the pathogenesis of ACS is related to the abnormal, pathological activation of blood platelets. The multifactorial and complex character of ACS indicates the need to explain the molecular mechanisms responsible for thrombosis. In our study, we performed screening and comparative analysis of platelet proteome from ACS patients and healthy donors. Two-dimensional fluorescence difference gel electrophoresis and nanoscale liquid chromatography coupled to tandem mass spectrometry showed altered expressions of six proteins (i.e., vinculin, transgelin-2, fibrinogen ß and γ chains, apolipoprotein a1, and tubulin ß), with the overlapping increased expression at the mRNA level for transgelin-2. Dysregulation in protein expression identified in our study may be associated with an increased risk of thrombotic events, correlated with a higher aggregability of blood platelets and induced shape change, thus explaining the phenomenon of the hyperreactivity of blood platelets in ACS.

Transgelin-2 contributes to proliferation and progression of hepatocellular carcinoma via regulating Annexin A2.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, but its pathogenesis is not clear. This study found that the expression of TAGLN2 mRNA and protein in HCC was higher than that in adjacent tissues. TCGA database analysis further confirmed this result, and found that the expression of TAGLN2 was positively correlated with the prognosis of HCC, suggesting that TAGLN2 may be a tumor promoter gene. Then the TAGLN2-Annexin A2 (ANXA2) interaction and NF-κB signaling pathway were further clarified during the invasion and metastasis of HCC. This mechanism provides a theoretical basis for further finding molecular targets and drug targets related to HCC metastasis.

[MicroRNA-133b suppresses cell proliferation and invasion of esophageal squamous cell carcinoma via downregulating TAGLN2 expression].

Objective: To investigate the expression of microRNA-133b (miR-133b) in esophageal squamous cell carcinoma (ESCC), and explore its effect and the underlying molecular mechanisms on cell proliferation and invasion. Methods: Real-time quantitative PCR (qPCR) was used to examine miR-133b expression in 63 ESCC tissues and paired adjacent non-cancerous tissues, several ESCC cells (Eca109, EC9706, EC1, TE1, KYSE70) and normal esophageal epithelial cell Het-1A. MiR-133b mimic, inhibitor and negative control (NC) were transfected into TE1 cells. The effect of miR-133b on cell proliferation and invasion were determined by CCK-8 and Transwell assays, respectively. Subsequently, the target gene of miR-133b was predicted by online tools TargetScan and miRDB, which was verified by dual luciferase reporter assays. Finally, Western blot was utilized to detect the effects of miR-133b overexpression on expression of target gene TAGLN2 as well as EMT-related proteins E-cadherin, N-cadherin, Snail, Slug and Vimentin. Results: Relative levels of miR-133b in ESCC tissues (0.295±0.040) were significantly lower than those in adjacent non-cancerous tissues (1.002±0.011, P<0.001). The expression of miR-133b was tightly associated with clinical staging, lymph node metastasis and prognosis. Moreover, relative levels of miR-133b in ESCC cells Eca109, EC9706, EC1, TE1 and KYSE70 (0.679±0.031, 0.391±0.008, 0.236±0.016, 0.031±0.005 and 0.099±0.020) were evidently lower than that in normal esophageal epithelial cell Het-1A (1.005±0.016, all P<0.001). In TE1 cells, miR-133b mimic significantly increased the level of miR-133b to 6.199±0.627, and suppressed cell proliferation and invasion, whereas miR-133b inhibitor obviously decreased its expression to 0.182±0.023, and promoted cell proliferation and invasion. Most notably, the relative luciferase activities of miR-133b-mimic group (0.320±0.018) in TE1 cells transfected with TAGLN-3'UTR-WT were markedly lower than that in NC group (1.010±0.036, P<0.001), whereas those in TAGLN-3'UTR-MUT transfection cells were 1.019±0.056 and 1.008±0.021, respectively, showing no significantly statistical difference (P>0.05). Furthermore, miR-133b overexpression markedly downregulated TAGLN2, N-cadherin, Snail, Slug and Vimentin levels, and increased E-cadherin expression. Conclusion: MiR-133b plays an important role in the proliferation and invasion of ESCC cells by regulating TAGLN2 expression, and it may be a potential therapeutic target for ESCC patients.

Hypoxia-inducible transgelin 2 selects epithelial-to-mesenchymal transition and γ-radiation-resistant subtypes by focal adhesion kinase-associated insulin-like growth factor 1 receptor activation in non-small-cell lung cancer cells.

Microenvironment, such as hypoxia common to cancer, plays a critical role in the epithelial-to-mesenchymal transition (EMT) program, which is a major route of cancer metastasis and confers γ-radiation resistance to cells. Herein, we showed that transgelin 2 (TAGLN2), an actin-binding protein, is significantly induced in hypoxic lung cancer cells and that Snail1 is simultaneously increased, which induces EMT by downregulating E-cadherin expression. Forced TAGLN2 expression induced severe cell death; however, a small population of cells surviving after forced TAGLN2 overexpression showed γ-radiation resistance, which might promote tumor relapse and recurrence. These surviving cells showed high metastatic activity with an increase of EMT markers including Snail1. In these cells, TAGLN2 activated the insulin-like growth factor 1 receptor ß (IGF1Rß)/PI3K/AKT pathway by recruitment of focal adhesion kinase to the IGF1R signaling complex. Activation of the IGF1Rß/PI3K/AKT pathway also induced inactivation of glycogen synthase kinase 3ß (GSK3ß), which is involved in Snail1 stabilization. Therefore, both the IGF1Rß inhibitor (AG1024) and the PI3K inhibitor (LY294002) or AKT inactivation with MK2206 lower the cellular level of Snail1. Involvement of GSK3ß was also confirmed by treatment with lithium chloride, the inducer of GSK3ß phosphorylation, or MG132, the 26S proteasomal inhibitor, which also stabilized Snail1. In conclusion, the present study provides important evidence that hypoxia-inducible TAGLN2 is involved in the selection of cancer cells with enhanced EMT properties to overcome the detrimental environment of cancer cells.

Transgelin-2: A potential oncogenic factor.

Actin-binding proteins are proteins that could bind to actin or actin fibers. As a member of actin-binding proteins, Transgelin-2 is expressed in smooth muscle cells and non-smooth muscle cells, and its gene, TAGLN2, is differently expressed in all cells and tissues. The deregulation of Transgelin-2 is considered to be correlated with progression of many kinds of diseases, especially the development of malignant tumors, such as invasion, metastasis, and resistance, yet the function and mechanism of action of Transgelin-2 remain elusive. Therefore, we reviewed the basic characteristics and function of Transgelin-2 and its biological role in various types of diseases in order to provide the theoretical basis for further research and new perspectives on cancer development.

TAGLN2, a novel regulator involved in Hepatitis B virus transcription and replication.

Hepatitis B virus (HBV) infection is one of the major health problems in the world. Transgelin-2 (TAGLN2) expression has been revealed to be significantly altered in previous studies concerning HBV-host interaction. The present study investigated TAGLN2 expression patterns in HBV related hepatocellular carcinoma (HCC) tissues and its role in HBV transcription and replication. We collected 59 HBV related HCC tissue samples, their adjacent non-tumoral tissues and 16 normal livers to make the tissue microarray. TAGLN2 protein was detected by immunohistochemistry and the transcriptional levels of TAGLN2, HBc, HBs and HBx were detected by qRT-PCR. Then we investigated the function of TAGLN2 on HBV transcription and replication in vitro by ectopic expressing or knocking down TAGLN2 in HepG2 and HepG2.2.15 cell lines. We further studied the effect of HBx on TAGLN2 expression with a Tet-on HBx expressing cell line. TAGLN2 protein expression was lower in normal livers and HBV-HCC tissues comparing to adjacent non-tumoral tissues. The transcriptional levels of TAGLN2 in HBV-HCC tissues and their adjacent tissues were positively related to that of HBc, HBs and HBx (P < 0.05). Ectopic expression of TAGLN2 in vitro could enhance HBV transcription and replication while suppressing TAGLN2 had the contrary effect. TAGLN2 could be induced by HBx in a dose-dependent manner. Our data demonstrated that TAGLN2 might be an HBx induced positive host factor involved in HBV transcription and replication and HBx related liver fibrosis and tumorigenesis.

Functional significance of transgelin-2 in uterine cervical squamous cell carcinoma.

AIM: Transgelin-2 (TAGLN2) has previously been found to be highly expressed in uterine cervical squamous cell carcinoma (SCC) tissues by proteomic analyses. The present study investigated the role of TAGLN2 in the malignant behaviors of cervical SCC cells in vitro and in vivo, and the clinical significance of TAGLN2 using immunohistochemistry for human cervical SCC tissues. METHODS: Antisense (AS) constructs of TAGLN2 cDNA (AS clones) and the empty vector (control clone) were transfected into a human uterine SCC cell line (SKG IIIa), and malignant behaviors were analyzed in vitro. In an in vivo experiment, 10(7) cells of the AS and control clones were subcutaneously inoculated into female BALB/c nude mice. In immunohistochemistry with anti-TAGLN2 antibodies for human cervical SCC, FIGO stage IA and IB (n = 75), the expression patterns of TAGLN2 were divided into two groups: weak and strong. The relation between expression pattern and prognosis was analyzed. RESULTS: Suppression of TAGLN2 inhibited cancer cell migration and secretion of matrix metalloproteinases. Tumors in the control clone group continued to grow, whereas those in the AS clone group clearly stopped growing. Six weeks after injection, the tumor size was significantly smaller in the AS clone group than in the control clone group. Immunohistochemistry revealed that the strong pattern was associated with poor overall survival compared with the weak pattern by the Kaplan-Meier method. CONCLUSION: TAGLN2 plays functional roles in the progression of cervical SCC. Suppression of TAGLN2 may be a new strategy for the treatment of cervical SCC.

Micro-simulation insights into the functional and mechanistic understanding of glycyrrhizin against asthma.

Asthma is a common chronic respiratory disease, which causes inflammation and airway stenosis, leading to dyspnea, wheezing and chest tightness. Using transgelin-2 as a target, we virtually screened the lead compound glycyrrhizin from the self-built database of anti-asthma compounds by molecular docking technology, and found that it had anti-inflammatory, anti-oxidative and anti-asthma pharmacological effects. Then, molecular dynamics simulations were used to confirm the stability of the glycyrrhizin-transgelin-2 complex from a dynamic perspective, and the hydrophilic domains of glycyrrhizin was found to have the effect of targeting transgelin-2. Due to the self-assembly properties of glycyrrhizin, we explored the formation process and mechanism of the self-assembly system using self-assembly simulations, and found that hydrogen bonding and hydrophobic interactions were the main driving forces. Because of the synergistic effect of glycyrrhizin and salbutamol in improving asthma, we revealed the mechanism through simulation, and believed that salbutamol adhered to the surface of the glycyrrhizin nano-drug delivery system through hydrogen bonding and hydrophobic interactions, using the targeting effect of the hydrophilic domains of glycyrrhizin to reach the pathological parts and play a synergistic anti-asthmatic role. Finally, we used network pharmacology to predict the molecular mechanisms of glycyrrhizin against asthma, which indicated the direction for its clinical transformation.

Discovery of zolinium TSG1180 as a novel agonist of transgelin-2 for treating asthma.

Asthma is a complex and heterogeneous respiratory disease that causes serious social and economic burdens. Current drugs such as ß2-agonists cannot fully control asthma. Our previous study found that Transgelin-2 is a potential target for treating asthmatic pulmonary resistance. Herein, we discovered a zolinium compound, TSG1180, that showed a strong interaction with Transgelin-2. The equilibrium dissociation constants (KD) of TSG1180 to Transgelin-2 were determined to be 5.363 × 10-6 and 9.81 × 10-6 M by surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). Cellular thermal shift assay (CETSA) results showed that the thermal stability of Transgelin-2 increased after coincubation of TSG1180 with lysates of airway smooth muscle cells (ASMCs). Molecular docking showed that Arg39 may be the key residue for the binding. Then, the SPR result showed that the binding affinity of TSG1180 to Transgelin-2 mutant (R39E) was decreased by 1.69-fold. Real time cell analysis (RTCA) showed that TSG1180 treatment could relax ASMCs by 19 % (P < 0.05). Once Transgelin-2 was inhibited, TSG1180 cannot induce a relaxation effect, suggesting that the relaxation effect was specifically mediated by Transgelin-2. In vivo study showed TSG1180 effectively reduced pulmonary resistance by 64 % in methacholine-induced mice model (P < 0.05). Furthermore, the phosphorylation of Ezrin at T567 was increased by 8.06-fold, the phosphorylation of ROCK at Y722 was reduced by 38 % and the phosphorylation of RhoA at S188 was increased by 52 % after TSG1180 treatment. These results suggested that TSG1180 could be a Transgelin-2 agonist for further optimization and development as an anti-asthma drug.

Molecular dynamics study on the behavior and binding mechanism of target protein Transgelin-2 with its agonist TSG12 for anti-asthma drug discovery.

Transgelin-2 (TG2) is a novel promising therapeutic target for the treatment of asthma as it plays an important role in relaxing airway smooth muscles and reducing pulmonary resistance in asthma. The compound TSG12 is the only reported TG2 agonist with in vivo anti-asthma activity. However, the dynamic behavior and ligand binding sites of TG2 and its binding mechanism with TSG12 remain unclear. In this study, we performed 12.6 µs molecular dynamics (MD) simulations for apo-TG2 and TG2-TSG12 complex, respectively. The results suggested that the apo-TG2 has 4 most populated conformations, and that its binding of the agonist could expand the conformation distribution space of the protein. The simulations revealed 3 potential binding sites in 3 most populated conformations, one of which is induced by the agonist binding. Free energy decomposition uncovered 8 important residues with contributions stronger than -1 kcal/mol. Computational alanine scanning for the important residues by 100 ns conventional MD simulation for each mutated TG2-TSG12 complexes demonstrated that E27, R49 and F52 are essential residues for the agonist binding. These results should be helpful to understand the dynamic behavior of TG2 and its binding mechanism with the agonist TSG12, which could provide some structural insights into the novel mechanism for anti-asthma drug development.

Metallothionein-2: An emerging target in inflammatory diseases and cancers.

Metallothionein-2 (MT-2) was originally discovered as a mediator of zinc homeostasis and cadmium detoxification. However, MT-2 has recently received increased attention because altered expression of MT-2 is closely related to various diseases such as asthma and cancers. Several pharmacological strategies have been developed to inhibit or modify MT-2, revealing its potential as drug target in diseases. Therefore, a better understanding of the mechanisms of MT-2 action is warranted to improve drug development for potential clinical applications. In this review, we highlight recent advances in determining the protein structure, regulation, binding partners, and new functions of MT-2 in inflammatory diseases and cancers.

TAGLN2-Regulated Trophoblast Migration, Invasion and Fusion are Impaired in Preeclampsia.

Preeclampsia (PE) is a serious disease during pregnancy that affects approximately eight million mothers and infants worldwide each year and is closely related to abnormal trophoblast function. However, research on placental trophoblast functional abnormalities is insufficient, and the etiology of PE is unclear. Here, we report that the expression of transgelin-2 (TAGLN2) was downregulated in the placenta of patients with PE. In addition, a lack of TAGLN2 significantly reduced the ability of trophoblasts to migrate, invade and fuse. A co-immunoprecipitation (Co-IP) and microscale thermophoresis analysis showed that TAGLN2 bound directly to E-cadherin. A decrease in TAGLN2 expression led to a reduction in cleavage of the E-cadherin extracellular domain, thereby regulating the function of trophoblasts. In addition, we found that a reduction in soluble E-cadherin may also have an effect on blood vessel formation in the placenta, which is necessary for normal placental development. What's more, the in vivo mouse model provided additional evidence of TAGLN2 involvement in the development of PE. By injecting pregnant mice with Ad-TAGLN2, we successfully generated a human PE-like syndrome that resulted in high blood pressure and some adverse pregnancy outcomes. Overall, the association between TAGLN2 and PE gives a new insight into PE diagnosis and treatment.

Transgelin-2 interacts with CD44 to regulate Notch1 signaling pathway and participates in colorectal cancer proliferation and migration.

The abnormal expression of transgelin-2 (TAGLN2) is related to tumor occurrence and progression. However, the underlying molecular mechanism of TAGLN2 in human colorectal cancer (CRC) is still poorly understood. Compared with adjacent tissues, TAGLN2 is overexpressed in CRC tissues. Its expression level is negatively correlated with the overall survival rate of patients with CRC. In addition, knockdown of TAGLN2 inhibited the proliferation and invasion of CRC cells. We also showed that TAGLN2 could interact with CD44 to regulate the Notch-1 signaling pathway. Our findings indicate there is increased TAGLN2 expression in CRC and that it may serve as a promising potential therapeutic target for CRC.

The Effects of a Transgelin-2 Agonist Administered at Different Times in a Mouse Model of Airway Hyperresponsiveness.

Airway hyperresponsiveness (AHR) is one of the most important features of asthma. Our previous study showed that inhaled transgelin-2 agonist, TSG12, effectively reduced pulmonary resistance in a mouse model of asthma in a dose-dependent manner. However, the optimal administration time of TSG12 to reduce AHR and the pharmacological effects are still unclear. In this study, the effects of TSG12 inhalation before and during AHR occurrence were examined. The results showed that the pulmonary resistance was reduced by 57% and the dynamic compliance was increased by 46% in the TSG12 Mch group (atomize TSG12 10 min before methacholine, p < 0.05 vs. model). The pulmonary resistance was reduced by 61% and the dynamic compliance was increased by 47% in the TSG12 + Mch group (atomize TSG12 and methacholine together, p < 0.05 vs. model). Quantitative real-time PCR showed that the gene expression levels of transgelin-2, myosin phosphatase target subunit-1, and myosin light chain were up-regulated by 6.4-, 1.9-, and 2.8-fold, respectively, in the TSG12 Mch group. The gene expression levels of transgelin-2, myosin phosphatase target subunit-1, and myosin light chain were up-regulated by 3.2-, 1.4-, and 1.9-fold, respectively, in the TSG12 + Mch group. The results suggested that TSG12 effectively reduces pulmonary resistance when TSG12 inhalation occurred both before and during AHR occurrence. Gene expression levels of transgelin-2 and myosin light chain were significantly up-regulated when TSG12 inhalation occurred before AHR occurrence. This study may provide a basis for the administration time of TSG12 for asthma treatment in the future.

TAGLN2 promotes the proliferation, invasion, migration and epithelial-mesenchymal transition of colorectal cancer cells by activating STAT3 signaling through ANXA2.

Colorectal cancer (CRC) is one of the leading causes of cancer-associated mortality worldwide and currently ranks third in the USA in terms of prevalence. Transgelin-2 (TAGLN2) was previously reported to serve as a tumor promoter in various types of cancer. The present study aimed to investigate the role of TAGLN2 in the progression of CRC and to determine the potential underlying mechanism. The expression level of TAGLN2 in CRC cells (HCT116, SNU-C1, LoVo and SW480) were first detected by reverse transcription quantitative PCR and western blotting. Following TAGLN2 knockdown through transfection with short hairpin (sh)RNAs against TAGLN2, CRC cell proliferation was determined using Cell Counting Kit-8 and 5'-ethynyl-2'-deoxyuridine assays. Cell migration and invasion were evaluated using wound healing and Transwell assays, respectively. The expression levels of matrix metalloproteinase (MMP)2, MMP9 and proteins associated with epithelial-mesenchymal transition (EMT), including N-cadherin (N-cad), vimentin, zinc finger E-box binding homeobox 2 (ZEB2) and E-cadherin (E-cad), were also evaluated by western blotting. Furthermore, following TAGLN2 overexpression and the use of signal transducer and activator of transcription 3 (STAT3) inhibitors to treat CRC cells, all the aforementioned biological parameters were evaluated. The potential relationship between annexin 2 (ANXA2) and STAT3 was confirmed by western blotting analysis. The expression level of TAGLN2 was found to be particularly high in CRC cells. Following TAGLN2 knockdown, CRC cell proliferation, migration, invasion and EMT were significantly inhibited. TAGLN2 knockdown also suppressed STAT3 phosphorylation in CRC cells. In addition, the promoting effects of TAGLN2 overexpression on the progression of CRC were reversed by STAT3 inhibitor. Furthermore, ANXA2 was positively associated with STAT3. Taken together, these findings demonstrated that TAGLN2 could promote the proliferation, invasion, migration and EMT of CRC cells by activating STAT3 and regulating ANXA2 expression. This may reveal the underlying mechanism by which TAGLN2 might regulate the progression of CRC and provide potential therapeutic targets for the treatment of CRC.

MicroRNA­133b alleviates doxorubicin­induced cardiomyocyte apoptosis and cardiac fibrosis by targeting PTBP1 and TAGLN2.

Doxorubicin is one of the most important chemotherapeutic drugs for the treatment of malignant tumors, but the cardiotoxicity of doxorubicin severely limits its clinical application. Increasing numbers of microRNAs (miRNAs/miRs) have been found to be dysregulated in doxorubicin­treated cardiomyocytes or animal hearts. The current study aimed to investigate the role of miR­133b in doxorubicin­induced cardiomyocyte injury. Doxorubicin was used to treat HL­1 cardiomyocytes to mimic cardiomyocyte injury in vitro. A mouse model of cardiac injury was generated by chronic intraperitoneal injections of doxorubicin. Masson's trichrome staining was performed on cardiac tissues to reveal cardiac fibrosis. Bioinformatics analysis and luciferase reporter assays were applied to explore the downstream targets of miR­133b. Flow cytometry and western blotting were conducted to detect cardiomyocyte apoptosis. Protein expression levels of collagen I, III and IV, and fibronectin were detected to reveal extracellular matrix deposition. The results revealed that doxorubicin decreased miR­133b expression in the treated HL­1 cardiomyocytes and mouse hearts. Overexpression of miR­133b restrained cardiomyocyte apoptosis, inhibited collagen accumulation and alleviated cardiac fibrosis in vivo. Mechanistically, polypyrimidine tract binding protein 1 (PTBP1) and transgelin 2 (TAGLN2) were confirmed to bind to miR­133b after prediction and screening. Moreover, miR­133b negatively regulated the protein expression levels of PTBP1 and TAGLN2. Finally, overexpression of PTBP1 or TAGLN2 reversed the effects of miR­133b on apoptosis and collagen accumulation. Thus, the current results indicated that miR­133b alleviated doxorubicin­induced cardiomyocyte apoptosis and cardiac fibrosis by targeting PTBP1 and TAGLN2, implying that miR­133b may be a potential biomarker for doxorubicin­induced cardiac injury.

Cell-permeable transgelin-2 as a potent therapeutic for dendritic cell-based cancer immunotherapy.

BACKGROUND: Transgelin-2 is a 22 kDa actin-binding protein that has been proposed to act as an oncogenic factor, capable of contributing to tumorigenesis in a wide range of human malignancies. However, little is known whether this tiny protein also plays an important role in immunity, thereby keeping body from the cancer development and metastasis. Here, we investigated the functions of transgelin-2 in dendritic cell (DC) immunity. Further, we investigated whether the non-viral transduction of cell-permeable transgelin-2 peptide potentially enhance DC-based cancer immunotherapy. METHODS: To understand the functions of transgelin-2 in DCs, we utilized bone marrow-derived DCs (BMDCs) purified from transgelin-2 knockout (Tagln2-/-) mice. To observe the dynamic cellular mechanism of transgelin-2, we utilized confocal microscopy and flow cytometry. To monitor DC migration and cognate T-DC interaction in vivo, we used intravital two-photon microscopy. For the solid and metastasis tumor models, OVA+ B16F10 melanoma were inoculated into the C57BL/6 mice via intravenously (i.v.) and subcutaneously (s.c.), respectively. OTI TCR T cells were used for the adoptive transfer experiments. Cell-permeable, de-ubiquitinated recombinant transgelin-2 was purified from Escherichia coli and applied for DC-based adoptive immunotherapy. RESULTS: We found that transgelin-2 is remarkably expressed in BMDCs during maturation and lipopolysaccharide activation, suggesting that this protein plays a role in DC-based immunity. Although Tagln2-/- BMDCs exhibited no changes in maturation, they showed significant defects in their abilities to home to draining lymph nodes (LNs) and prime T cells to produce antigen-specific T cell clones, and these changes were associated with a failure to suppress tumor growth and metastasis of OVA+ B16F10 melanoma cells in mice. Tagln2-/- BMDCs had defects in filopodia-like membrane protrusion and podosome formation due to the attenuation of the signals that modulate actin remodeling in vitro and formed short, unstable contacts with cognate CD4+ T cells in vivo. Strikingly, non-viral transduction of cell-permeable, de-ubiquitinated recombinant transgelin-2 potentiated DC functions to suppress tumor growth and metastasis. CONCLUSION: This work demonstrates that transgelin-2 is an essential protein for both cancer and immunity. Therefore, transgelin-2 can act as a double-edged sword depending on how we apply this protein to cancer therapy. Engineering and clinical application of this protein may unveil a new era in DC-based cancer immunotherapy. Our findings indicate that cell-permeable transgelin-2 have a potential clinical value as a cancer immunotherapy based on DCs.