Loss of transgelin in breast and colon tumors and in RIE-1 cells by Ras deregulation of gene expression through Raf-independent pathways

Proteomics Investigation of the Impact of the Enterococcus faecalis Secretome on MCF-7 Tumor Cells

Breast cancer is the most prevalent form of cancer among women. The microenvironment of a cancer tumor is surrounded by various cells, including the microbiota. An imbalance between microbes and their host may contribute to the development and spread of breast cancer. Therefore, the objective of this study is to investigate the influence of Enterococcus faecalis on a breast cancer cell line (MCF-7) to mimic the luminal A subtype of breast cancer, using an untargeted proteomics approach to analyze the proteomic profiles of breast cancer cells after their treatment with E. faecalis in order to understand the microbiome and its role in the development of cancer. The breast cancer cell line MCF-7 was cultured and then treated with a 10% bacterial supernatant at two time points (24 h and 48 h) at 37 °C in a humidified incubator with 5% CO2. Proteins were then extracted and separated using two-dimensional difference (2D-DIGE) gel electrophoresis, and the statistically significant proteins (p-value < 0.05, fold change > 1.5) were identified via matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS). The protein fingerprints showed a differential protein expression pattern in the cells treated with E. faecalis for 24 and 48 h compared with the control. We found 58 statistically significant proteins changes in the MCF-7 breast cancer cells affected by E. faecalis. Kilin and transgelin were upregulated after 24 h of treatment and could be used as diagnostic and prognostic markers for breast cancer. In addition, another protein involved in the inhibition of cell proliferation was coiled-coil domain-containing protein 154. The protein markers identified in this study may serve as possible biomarkers for breast cancer progression. This promotes their future uses as important therapeutic goals in the treatment and diagnosis of cancer and increases our understanding of the breast microbiome and its role in the development of cancer.

Neutropenia in Cynomolgus Monkeys With Anti-Drug Antibodies Associated With Administration of Afucosylated Humanized Monoclonal Antibodies

Removal of the core fucose from the Fc region of humanized monoclonal antibodies (afucosylated antibodies) enhances their antibody-dependent cell cytotoxicity activities in killing cancer cells. Based on the authors' experience and literature, administrations of afucosylated antibodies have been associated with neutropenia in cynomolgus monkeys. However, in a recent general toxicology study conducted with an afucosylated antibody in cynomolgus monkeys, transient neutropenia was observed and correlated with the emergence of anti-drug antibodies (ADAs) in the affected animals. To further explore the relationship between neutropenia, afucosylated antibodies, and ADAs in cynomolgus monkeys, we performed an investigational retrospective meta-analysis of data from general toxicology studies conducted with Genentech's therapeutic antibodies administered to cynomolgus monkeys between 2005 and 2021. In this analysis, transient neutropenia strongly correlated with ADA-induced inflammation in cynomolgus monkeys administered afucosylated antibodies. This may reflect the simultaneous occurrence of two distinct processes of neutrophil elimination and utilization, thus overwhelming bone marrow reserve capacity leading to transient neutropenia. The integrated analysis of immunogenicity, and anatomic and clinical pathology results from these studies highlights the correlation of transient neutropenia in cynomolgus monkeys with ADA-related inflammation, potentially exacerbated by enhanced effector function of afucosylated antibodies.

Transgelin Inhibits the Malignant Progression of Esophageal Squamous Cell Carcinomas by Regulating Epithelial-Mesenchymal Transition

Objective

This article investigates the role of Transgelin (TAGLN) in the epithelial–mesenchymal transition (EMT) of esophageal squamous cell carcinomas (ESCC) and its possible mechanism of inhibiting the invasion of these cancers.

Methods

Tissue specimens and clinical information of patients with ESCC were collected to analyze the relationship between Transgelin expression level and prognosis of patients with ESCC. Transgelin siRNA was used to knock down Transgelin expression. The expression of Transgelin in Eca-109 and KYSE-150 cells was overexpressed by Transgelin-overexpressing plasmid. The effects of Transgelin overexpression and knockdown on the proliferation of Eca-109 and KYSE-150 cells were examined by Transwell chamber, scratch assay, and CCK-8 cell activity assay. RT-PCR and Western blot were used to detect the effect of Transgelin overexpression or knockdown on the mRNA and protein expressions of E-cadherin and Vimentin. TCGA data were used to analyze Transgelin co-expressed genes and further study the GO and KEGG enrichment analysis results under the influence of Transgelin.

Results

The expression of Transgelin was low in ESCC, and its expression level was positively correlated with the prognosis of patients with ESCC. The targeted Transgelin siRNA and Transgelin-overexpressing plasmid can effectively regulate the expression of Transgelin mRNA and protein in Eca-109 and KYSE-150 cells. After overexpression of Transgelin, the invasion and proliferation abilities of Eca-109 and KYSE-150 cells were significantly decreased compared with those of the control group (P < 0.05). However, Transgelin knockdown could promote the proliferation, migration, and invasion of ESCC cells. The overexpression of Transgelin inhibits EMT in ESCC. With the increase of Transgelin expression in Eca-109 and KYSE-150 cells, the expression of E-cadherin increased, while the expression of Vimentin decreased, and the difference was statistically significant (P < 0.05).

Conclusion

Transgelin can inhibit the malignant progression of ESCC by inhibiting the occurrence of EMT.

RETRACTED: Tumor cell-secreted exosomal miR-22-3p inhibits transgelin and induces vascular abnormalization to promote tumor budding

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the editor-in-chief. The editor-in-chief was informed of evidence for image duplication in identical or altered fashion in Figures 3A and 8D, as well as undisclosed reuse of an image in Figure 5B from a previous article in Cell Death & Disease (https://doi.org/10.1038/s41419-018-0902-5), in a PubPeer thread: https://pubpeer.com/publications/F5B591481C516F4CE42C7925AC48E9. Image analysis performed by the journal's editorial office confirmed these findings. This reuse (and in part misrepresentation) of data without appropriate attribution represents a severe abuse of the scientific publishing system.

Transgelin-2: A Double-Edged Sword in Immunity and Cancer Metastasis

Transgelin-2, a small actin-binding protein, is the only transgelin family member expressed in immune cells. In T and B lymphocytes, transgelin-2 is constitutively expressed, but in antigen-presenting cells, it is significantly upregulated upon lipopolysaccharide stimulation. Transgelin-2 acts as a molecular staple to stabilize the actin cytoskeleton, and it competes with cofilin to bind filamentous (F)-actin. This action may enable immune synapse stabilization during T-cell interaction with cognate antigen-presenting cells. Furthermore, transgelin-2 blocks Arp2/3 complex-nucleated actin branching, which is presumably related to small filopodia formation, enhanced phagocytic function, and antigen presentation. Overall, transgelin-2 is an essential part of the molecular armament required for host defense against neoplasms and infectious diseases. However, transgelin-2 acts as a double-edged sword, as its expression is also essential for a wide range of tumor development, including drug resistance and metastasis. Thus, targeting transgelin-2 can also have a therapeutic advantage for cancer treatment; selectively suppressing transgelin-2 expression may prevent multidrug resistance in cancer chemotherapy. Here, we review newly discovered molecular characteristics of transgelin-2 and discuss clinical applications for cancer and immunotherapy.

TAGLN Is Downregulated by TRAF6-Mediated Proteasomal Degradation in Prostate Cancer Cells

Transgelin (TAGLN, also named SM22) is an actin-associated protein and affects dynamics of actin filaments. Deregulation of TAGLN contributes to the development of different cancers, and it is commonly considered to be a tumor suppressor. TAGLN is usually downregulated in prostate cancer; however, the detailed functions of TAGLN in prostate cancer and how TAGLN is regulated remains unclear. In this study, we confirmed that TAGLN is downregulated in prostate cancer tissues and demonstrated that the downregulation of TAGLN occurs through proteasomal degradation. Next, we found that the expression level of TAGLN is inversely correlated with TRAF6. We screened more than 20 E2-E3 pairs by in vitro ubiquitination assay and found that the E2A-TRAF6 pair catalyzed mono ubiquitination of TAGLN. We then identified the ubiquitination sites of TAGLN to be on K89 or K108 residues and demonstrated that ubiquitination of TAGLN on K89/K108 are important for TRAF6-mediated proteasomal degradation. Furthermore, we investigated the function of TAGLN in prostate cancer cells. We found that ablation of TAGLN promoted prostate cancer cell proliferation and suppressed their migration via activation of NF-κB and Myc signaling pathways. Overall, our study provided new insights into the mechanisms underlying TAGLN expression and activity in prostate cancer. IMPLICATIONS: E3 ligase TRAF6 mediate mono-ubiquitination and degradation of TAGLN, which leads to activation of NF-κB and Myc signaling pathways in prostate cancer cells.

TAGLN and High-mobility Group AT-Hook 2 (HMGA2) Complex Regulates TGF-β-induced Colorectal Cancer Metastasis

Background

Colorectal cancer is one of the three most common cancers worldwide. Altered TGF-β signaling pathway in colorectal cancer is associated with metastasis and poor prognosis. It is also involved in epithelial-to-mesenchymal transition (EMT), which is essential in progression and metastasis. This study aims to investigate the role of transgelin (TAGLN) and high-mobility group AT-hook 2 (HMGA2) in the progression of colon cancer.

Methods

HT29 and HCT116 cells were treated with TGF-β, and the effects of inhibition of TAGLN and overexpression of HMGA2 on TGF-β treated cell on cell migration and invasion, expression of EMT markers, including E-cadherin, vimentin and fibronectin were detected as well as MMP2 and MMP9, which are critical in cancer cell metastasis. The interaction of TAGLN and HMGA2 was also investigated by using co-immunoprecipitation. The function of TAGLN in tumor metastasis and growth was investigated in vivo.

Results

We found that TGF-β could significantly promote the migration of HT29 and HCT116 cells, as well as TAGLN protein expression and nucleus translocation, while inhibition of TAGLN could effectively reverse the effects of TGF-β on HT29 and HCT116 cells, which was observed in terms of decreased cell migration and invasion. Knockdown of TAGLN could also rescue TGF-β-induced loss of E-cadherin, and decreased TGF-β-induced vimentin and fibronectin expression; the elevation of MMP9 and MMP2 was also reversed by inhibition of TAGLN. Further investigation confirmed the interaction of HMGA2 and TAGLN, as overexpression of HMGA2 restores the effects of TGF-β on HT29 cells, which were attenuated by TAGLN inhibition both in vitro and in vivo.

Conclusion

Overall, our study revealed that interaction between TAGLN and HMGA2 was involved in TGF-β-induced cell migration and promotion of colon cancer cells, suggesting that HMGA2 and TAGLN are potential molecular targets to prevent colon cancer progression.

Transgelins: Cytoskeletal Associated Proteins Implicated in the Metastasis of Colorectal Cancer

Transgelins, including transgelin-1 (T-1), transgelin-2 (T-2), and transgelin-3 (T-3), are a family of actin-binding proteins (ABPs) that can alter the structure and morphology of the cytoskeleton. These proteins function by regulating migration, proliferation and apoptosis in many different cancers. Several studies have shown that in various types of tumor cells, including colorectal cancer (CRC) cells, and in the tumor microenvironment, the expression and biological effects of transgelins are diverse and may transform during tumor progression. Previous researches have demonstrated that transgelin levels are positively correlated with metastasis in CRC, and down-regulating their expression can inhibit this process. In advanced disease, T-1 is a tumor activator with increasing expression, and T-2 expression increases with the progression of CRC. Finally, T-3 is only expressed in neurons and is not associated with CRC. This evidence suggests that T-1 and T-2 are potential biomarkers and therapeutic targets for CRC metastasis.

Proteomic Profiling of Colon Cancer Tissues: Discovery of New Candidate Biomarkers

Colon cancer is an aggressive tumor form with a poor prognosis. This study reports a comparative proteomic analysis performed by using two-dimensional differential in-gel electrophoresis (2D-DIGE) between 26 pooled colon cancer surgical tissues and adjacent non-tumoral tissues, to identify potential target proteins correlated with carcinogenesis. The DAVID functional classification tool revealed that most of the differentially regulated proteins, acting both intracellularly and extracellularly, concur across multiple cancer steps. The identified protein classes include proteins involved in cell proliferation, apoptosis, metabolic pathways, oxidative stress, cell motility, Ras signal transduction, and cytoskeleton. Interestingly, networks and pathways analysis showed that the identified proteins could be biologically inter-connected to the tumor-host microenvironment, including innate immune response, platelet and neutrophil degranulation, and hemostasis. Finally, transgelin (TAGL), here identified for the first time with four different protein species, collectively down-regulated in colon cancer tissues, emerged as a top-ranked biomarker for colorectal cancer (CRC). In conclusion, our findings revealed a different proteomic profiling in colon cancer tissues characterized by the deregulation of specific pathways involved in hallmarks of cancer. All of these proteins may represent promising novel colon cancer biomarkers and potential therapeutic targets, if validated in larger cohorts of patients.

Transgelin, a p53 and PTEN-Upregulated Gene, Inhibits the Cell Proliferation and Invasion of Human Bladder Carcinoma Cells in Vitro and in Vivo

Transgelin (TAGLN/SM22-α) is a regulator of the actin cytoskeleton, affecting the survival, migration, and apoptosis of various cancer cells divergently; however, the roles of TAGLN in bladder carcinoma cells remain inconclusive. We compared expressions of TAGLN in human bladder carcinoma cells to the normal human bladder tissues to determine the potential biological functions and regulatory mechanisms of TAGLN in bladder carcinoma cells. Results of RT-qPCR and immunoblot assays indicated that TAGLN expressions were higher in bladder smooth muscle cells, fibroblast cells, and normal epithelial cells than in carcinoma cells (RT-4, HT1376, TSGH-8301, and T24) in vitro. Besides, the results of RT-qPCR revealed that TAGLN expressions were higher in normal tissues than the paired tumor tissues. In vitro, TAGLN knockdown enhanced cell proliferation and invasion, while overexpression of TAGLN had the inverse effects in bladder carcinoma cells. Meanwhile, ectopic overexpression of TAGLN attenuated tumorigenesis in vivo. Immunofluorescence and immunoblot assays showed that TAGLN was predominantly in the cytosol and colocalized with F-actin. Ectopic overexpression of either p53 or PTEN induced TAGLN expression, while p53 knockdown downregulated TAGLN expression in bladder carcinoma cells. Our results indicate that TAGLN is a p53 and PTEN-upregulated gene, expressing higher levels in normal bladder epithelial cells than carcinoma cells. Further, TAGLN inhibited cell proliferation and invasion in vitro and blocked tumorigenesis in vivo. Collectively, it can be concluded that TAGLN is an antitumor gene in the human bladder.

Downregulation of transgelin 2 promotes breast cancer metastasis by activating the reactive oxygen species/nuclear factor‑κB signaling pathway

Transgelin 2 (TAGLN2) is a cytoskeletal protein of the calponin family. Abnormal expression of TAGLN2 was observed in various types of cancer. Our previous study reported that TAGLN2 expression was reduced in lymph node-positive breast cancer patients; however, the role of TAGLN2 in breast cancer metastasis remains unknown. In the present study, the role of TAGLN2 in breast cancer metastasis was investigated in vitro and in vivo via Transwell migration, luciferase and flow cytometry assays, and a mouse xenograft model. Proteins interacting with TAGLN2 were identified via co-immunoprecipitation assays and liquid chromatography/mass spectrometry, and the signaling pathway associated with the effects of TAGLN2 was investigated. Additionally, western blotting and reverse transcription-quantitative polymerase chain reaction were performed to further explore the potential pathway in which TAGLN2 may be involved and the mechanism underlying its effects in breast cancer metastasis. The present study reported that TAGLN2 expression was increased by 11.4-fold in patients without distant metastasis compared with those positive for distant metastasis. Knockdown of TAGLN2 resulted in increased cell migration in vitro and promoted lung metastasis in vivo. Additionally, overexpression of TAGLN2 suppressed lung metastasis in a mouse model. Peroxiredoxin 1 (PRDX1), an important reactive oxygen species (ROS) regulator, was revealed to interact with TAGLN2. In addition, mitochondrial redistribution and PRDX1 downregulation were reported following TAGLN2 silencing, which promoted ROS production and nuclear factor (NF)-κB activation in breast cancer cells. This induced the expression of metastasis-associated genes, including C-X-C chemokine receptor 4, matrix metalloproteinase (MMP)1 and MMP2. The present study proposed TAGLN2 to function as a tumor suppressor and that loss of TAGLN2 may promote the metastasis of breast cancer by activating the ROS/NF-κB signaling pathway.

Insight into the modulation of intestinal proteome of juvenile common carp (Cyprinus carpio L.) after dietary exposure to ZnO nanoparticles

ZnO nanoparticles (NPs) are widely used in industrial and consumer products. Therefore understanding their interaction with biological systems is key to their safe application. Proteomics was applied to assess the sub-lethal effects of dietary ZnO NPs on two parts of carp intestine, the intestinal folds and the muscular parts. A commercial carp feed containing 500mgkg^-1 of ZnO NPs was fed to fish for six weeks. The abundances of 32 proteins in the treated intestinal folds were significantly changed and in addition, 28 proteins were significantly changed in the muscular parts. Pathways analysis revealed downregulation of pathways attributed to protein synthesis in both parts of the treated intestine. Remodelling of actin cytoskeleton pathways were regulated positively and negatively in intestinal folds and muscular parts, respectively, albeit via different mechanisms. Apoptosis response was indicated in exposed intestinal folds, whereas elevated levels of protein associated with cancerous cell survival were observed in the muscular parts. Results showed that ZnO NPs affected the protein abundances associated with cell motility, immune system response, oxidative stress response, as well as cell metabolism. Data are available via ProteomeXchange with identifier PXD006867.

Functions of nuclear actin-binding proteins in human cancer

Nuclear actin-binding proteins (ABPs) perform distinguishable functions compared with their cytoplasmic counterparts in extensive activities of living cells. In addition to the ability to regulate actin cytoskeleton dynamics, nuclear ABPs are associated with multiple nuclear biological processes, including chromatin remodeling, gene transcriptional regulation, DNA damage response, nucleocytoplasmic trafficking and nuclear structure maintenance. The nuclear translocation of ABPs is affected by numerous intracellular or extracellular stimuli, which may lead to developmental malformation, tumor initiation, tumor progression and metastasis. Abnormal expression of certain ABPs have been reported in different types of cancer. This review focuses on the newly identified roles of nuclear ABPs in the pathological processes associated with cancer.

Elevated transgelin/TNS1 expression is a potential biomarker in human colorectal cancer

Transgelin is an actin-binding protein that regulates cell motility and other important cellular functions. Previous studies have suggested that transgelin expression is associated with cancer development and progression, but its specific role in colorectal cancer (CRC) remains controversial. We analyzed expression of transgelin and its candidate downstream target, tensin 1 (TNS1), in CRC patients using the ONCOMINE, Protein Atlas, and OncoLnc databases. Transgelin and TNS1 mRNA and protein levels were higher in CRC patients and CRC cell lines than in normal tissues and cells. Survival analyses using the OncoLnc database revealed that elevated TAGLN/TNS1 levels were associated with a poor overall survival in CRC patients. Transgelin suppression using siRNA decreased TNS1 expression in CRC cells, demonstrating that transgelin induces the TNS1 expression. Importantly, suppression of transgelin or TNS1 using siRNA decreased proliferation and invasiveness of CRC cells. These results suggest that transgelin/TNS1 signaling promotes CRC cell proliferation and invasion, and that transgelin/TNS1 expression levels could potentially serve as a prognostic and therapeutic target in CRC patients.

Mechanoregulation of SM22α/Transgelin

SM22α, also named transgelin, is an actin filament-associated protein in smooth muscle and fibroblasts. Three decades after its discovery, the biological function of SM22α remains under investigation. Here we report a novel finding that the expression and degradation of SM22α/transgelin are regulated by mechanical tension. Following a mass spectrometry identification of SM22α degradation in isolated and tension-unloaded mouse aorta, we developed specific monoclonal antibodies to study the regulation of SM22α in human fetal lung myofibroblast line MRC-5 and primary cultures of neonatal mouse skin fibroblasts. The level of SM22α is positively related to the mechanical tension in the cytoskeleton produced by the myosin II motor in response to the stiffness of the culture matrix. Quantitative reverse transcription polymerase chain reaction demonstrated that the expression of SM22α is regulated at the transcriptional level. This mechanical regulation resembles that of calponin 2, another actin filament-associated protein. Immunofluorescent staining co-localized SM22α with F-actin, myosin, and calponin 2 in mouse skin fibroblasts. The close phylogenetic relationship between SM22α and the calponin family supports that SM22α is a calponin-like regulatory protein. The level of SM22α is decreased in skin fibroblasts isolated from calponin 2 knockout mice, suggesting interrelated regulation and function of the two proteins. On the other hand, SM22α expression was maximized at a matrix stiffness higher than that for calponin 2 in the same cell type, indicating differentiated regulation and tension responsiveness. The novel mechanoregulation of SM22α/transgelin lays the groundwork for understanding its cellular functions.

Role of transgelin-2 in diabetes-associated pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with poor prognosis. Diabetes is a significant risk factor for PDAC and >50% of PDAC patients have concomitant diabetes. How diabetes influences the initiation and progression of PDAC remains elusive. Here, we show that transgelin-2 is dominantly expressed in PDAC tissues compared with adjacent normal tissues. The high level of transgelin-2 indicates poor survival of patients with PDAC. Remarkably, transgelin-2 expression is correlated with diabetic status. Hyperinsulinemia is frequently observed in type 2 diabetes. Our results indicate that upregulation of transgelin-2 is induced by insulin via sterol regulatory element-binding protein (SREBP)-1-mediated transcription in PDAC cells. Transgelin-2 is a novel target of SREBP-1. Our data support a novel mechanism in diabetes-associated PDAC by which transgelin-2 mediates proliferation of PDAC cells upon insulin stimulation. The insulin/SREBP-1/transgelin-2 network should be further explored as a diagnostic marker or a novel therapeutic target for diabetes-associated PDAC.

Proteomic identification of potential biomarkers for cervical squamous cell carcinoma and human papillomavirus infection

It is known that high-risk human papillomavirus infection is the main etiological factor in cervical carcinogenesis. However, human papillomavirus screening is not sufficient for early diagnosis. In this study, we aimed to identify potential biomarkers common to cervical carcinoma and human papillomavirus infection by proteomics for human papillomavirus-based early diagnosis and prognosis. To this end, we collected 76 cases of fresh cervical tissues and 116 cases of paraffin-embedded tissue slices, diagnosed as cervical squamous cell carcinoma, cervical intraepithelial neoplasia II-III, or normal cervix from ethnic Uighur and Han women. Human papillomavirus infection by eight oncogenic human papillomavirus types was detected in tissue DNA samples using a quantitative polymerase chain reaction. The protein profile of cervical specimens from human papillomavirus 16-positive squamous cell carcinoma and human papillomavirus-negative normal controls was analyzed by proteomics and bioinformatics. The expression of candidate proteins was further determined by quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry. We identified 67 proteins that were differentially expressed in human papillomavirus 16-positive squamous cell carcinoma compared to normal cervix. The quantitative reverse transcriptase-polymerase chain reaction analysis verified the upregulation of ASAH1, PCBP2, DDX5, MCM5, TAGLN2, hnRNPA1, ENO1, TYPH, CYC, and MCM4 in squamous cell carcinoma compared to normal cervix ( p < 0.05). In addition, the transcription of PCBP2, MCM5, hnRNPA1, TYPH, and CYC was also significantly increased in cervical intraepithelial neoplasia II-III compared to normal cervix. Immunohistochemistry staining further confirmed the overexpression of PCBP2, hnRNPA1, ASAH1, and DDX5 in squamous cell carcinoma and cervical intraepithelial neoplasia II-III compared to normal controls ( p < 0.05). Our data suggest that the expression of ASAH1, PCBP2, DDX5, and hnRNPA1, and possibly MCM4, MCM5, CYC, ENO1, and TYPH, is upregulated during cervical carcinogenesis and potentially associated with human papillomavirus infection. Further validation studies of the profile will contribute to establishing auxiliary diagnostic markers for human papillomavirus-based cancer prognosis.

Comparative proteome analysis of human esophageal cancer and adjacent normal tissues

Objective(s):

Ranking as the sixth commonest cancer, esophageal squamous cell carcinoma (ESCC) represents one of the leading causes of cancer death worldwide. One of the main reasons for the low survival of patients with esophageal cancer is its late diagnosis.

Materials and Methods:

We used proteomics approach to analyze ESCC tissues with the aim of a better understanding of the malignant mechanism and searching candidate protein biomarkers for early diagnosis of esophageal cancer. The differential protein expression between cancerous and normal esophageal tissues was investigated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Then proteins were identified by matrix-assisted laser desorption/ ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) and MASCOT web based search engine.

Results:

We reported 4 differentially expressed proteins involved in the pathological process of esophageal cancer, such as annexinA1 (ANXA1), peroxiredoxin-2 (PRDX2), transgelin (TAGLN) andactin-aortic smooth muscle (ACTA2).

Conclusion:

In this report we have introduced new potential biomarker (ACTA2). Moreover, our data confirmed some already known markers for EC in our region.

Integrated Proteomic and Transcriptomic-Based Approaches to Identifying Signature Biomarkers and Pathways for Elucidation of Daoy and UW228 Subtypes

Medulloblastoma (MB) is the most common malignant pediatric brain tumor. Patient survival has remained largely the same for the past 20 years, with therapies causing significant health, cognitive, behavioral and developmental complications for those who survive the tumor. In this study, we profiled the total transcriptome and proteome of two established MB cell lines, Daoy and UW228, using high-throughput RNA sequencing (RNA-Seq) and label-free nano-LC-MS/MS-based quantitative proteomics, coupled with advanced pathway analysis. While Daoy has been suggested to belong to the sonic hedgehog (SHH) subtype, the exact UW228 subtype is not yet clearly established. Thus, a goal of this study was to identify protein markers and pathways that would help elucidate their subtype classification. A number of differentially expressed genes and proteins, including a number of adhesion, cytoskeletal and signaling molecules, were observed between the two cell lines. While several cancer-associated genes/proteins exhibited similar expression across the two cell lines, upregulation of a number of signature proteins and enrichment of key components of SHH and WNT signaling pathways were uniquely observed in Daoy and UW228, respectively. The novel information on differentially expressed genes/proteins and enriched pathways provide insights into the biology of MB, which could help elucidate their subtype classification.

Downregulation of transgelin blocks interleukin-8 utilization and suppresses vasculogenic mimicry in breast cancer cells

Vasculogenic mimicry (VM) is a non-classical mechanism recently described in many tumors, whereby cancer cells, rather than endothelial cells, form blood vessels. Transgelin is an actin-binding protein that has been implicated in multiple stages of cancer development. In this study, we investigated the role of transgelin in VM and assessed its effect on the expression of endothelial and angiogenesis-related genes during VM in MDA-MB-231 breast cancer cells. We confirmed the ability of MDA-MB-231 cells to undergo VM through a tube formation assay. Flow cytometry analysis revealed an increase in the expression of the endothelial-related markers VE-cadherin and CD34 in cells that underwent VM, compared with those growing in a monolayer, which was confirmed by immunocytochemistry. We employed siRNA to silence transgelin, and knockdown efficiency was determined by western blot analyses. Downregulation of transgelin suppressed cell proliferation and tube formation, but increased IL-8 levels in Matrigel cultures. RT-PCR analyses revealed that the expression of IL-8, VE-cadherin, and CD34 was unaffected by transgelin knockdown, indicating that increased IL-8 expression was not due to enhanced transcriptional activity. More importantly, the inhibition of IL-8/CXCR2 signaling also resulted in suppression of VM with increased IL-8 levels, confirming that increased IL-8 levels after transgelin knockdown was due to inhibition of IL-8 uptake. Our findings indicate that transgelin regulates VM by enhancing IL uptake. These observations are relevant to the future development of efficient antivascular agents. Impact statement Vasculogenic mimicry (VM) is an angiogenic-independent mechanism of blood vessel formation whereby aggressive tumor cells undergo formation of capillary-like structures. Thus, interventions aimed at angiogenesis might not target the entire tumor vasculature. A more holistic approach is therefore needed in the development of improved antivascular agents. Transgelin, an actin-binding protein, has been associated with multiple stages of cancer development such as proliferation, migration and invasion, but little is known about its role in vasculogenic mimicry. We present here, an additional mechanism by which transgelin promotes malignancy by way of its association with the occurrence of VM. Although transgelin knockdown did not affect the transcript levels of most of the angiogenesis-related genes in this study, it was associated with the inhibition of the uptake of IL-8, accompanied by suppressed VM, indicating that transgelin is required for VM. These observations are relevant to the future development of efficient antivascular agents.

Integrated analysis of mRNA, microRNA and protein in systemic lupus erythematosus-specific induced pluripotent stem cells from urine

Background

In clinical practice, it is difficult to monitor the repeating relapse in patients who have been suffering from systemic lupus erythematosus (SLE). The underlying etiology remains largely unknown.

Methods

Aiming to understand the pathogenesis of SLE, a detailed study was conducted. Renal tubular cells–derived iPSCs were successfully obtained from the urine of SLE patients and healthy controls. With the purpose to identify simultaneous expression profiling of microRNA, mRNA and protein, Illumina HiSeq™ 2000 System and iTRAQ-coupled 2D LC-MS/MS analysis were utilized in systemic lupus erythematosus-specific induced pluripotent stem cells (SLE-iPSCs) and normal control-iPSCs (NC-iPSCs). The integration of multiple profiling datasets was realized since it could facilitate the identification of non-seed miRNA targets, as well as differentially expressed mRNAs and proteins.

Results

For this study, profiling datasets of 1099 differentially expressed mRNAs, 223 differentially expressed microRNAs and 94 differentially expressed proteins were integrated. In order to investigate the influence of miRNA on the processes of regulating mRNAs and proteins’ levels, potential targets of differentially expressed mRNAs and proteins were predicted using miRanda, TargetScan and Pictar. Multiple profiling datasets were integrated to facilitate the identification of miRNA targets, as well as differentially expressed mRNAs and proteins. Through gene ontology (GO) analysis of differentially expressed mRNAs and proteins, biological processes that drive proliferation were identified, such as mRNA processing and translation. Western blot and Q-PCR confirmed AK4 protein and mRNA up-regulation. The findings also showed that TAGLN’s protein and mRNA level were down-regulated in SLE-iPSCs, both miR-371a-5p and let-7a-5p in SLE-iPSC were down-regulated and verified using Q-PCR. The up-regulation of AK4 involved in nucleotide biosynthesis suggested a general acceleration of anabolic metabolism induced by down-regulated miR-371a-5p, which might contribute to SLE.

Conclusion

Based on high throughput analysis, integrated miRNA, mRNA, and protein expression data were generated. Differentially expressed dates were also adopted in conjunction with in-silico tools to identify potential candidates for SLE-iPSCs. Representative miRNA, mRNA and proteins were verified. It was also expected that the knowledge gained from this study can be applied to assess the usefulness of pathogenesis and novel biomarker candidates of SLE, which may develop a new way for SLE diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2809-9) contains supplementary material, which is available to authorized users.

Folic acid induces cell type-specific changes in the transcriptome of breast cancer cell lines: a proof-of-concept study

The effect of folic acid (FA) on breast cancer (BC) risk is uncertain. We hypothesised that this uncertainty may be due, in part, to differential effects of FA between BC cells with different phenotypes. To test this we investigated the effect of treatment with FA concentrations within the range of unmetabolised FA reported in humans on the expression of the transcriptome of non-transformed (MCF10A) and cancerous (MCF7 and Hs578T) BC cells. The total number of transcripts altered was: MCF10A, seventy-five (seventy up-regulated); MCF7, twenty-four (fourteen up-regulated); and Hs578T, 328 (156 up-regulated). Only the cancer-associated gene TAGLN was altered by FA in all three cell lines. In MCF10A and Hs578T cells, FA treatment decreased pathways associated with apoptosis, cell death and senescence, but increased those associated with cell proliferation. The folate transporters SLC19A1, SLC46A1 and FOLR1 were differentially expressed between cell lines tested. However, the level of expression was not altered by FA treatment. These findings suggest that physiological concentrations of FA can induce cell type-specific changes in gene regulation in a manner that is consistent with proliferative phenotype. This has implications for understanding the role of FA in BC risk. In addition, these findings support the suggestion that differences in gene expression induced by FA may involve differential activities of folate transporters. Together these findings indicate the need for further studies of the effect of FA on BC.

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.

Transgelin increases metastatic potential of colorectal cancer cells in vivo and alters expression of genes involved in cell motility

Background

Transgelin is an actin-binding protein that promotes motility in normal cells. Although the role of transgelin in cancer is controversial, a number of studies have shown that elevated levels correlate with aggressive tumor behavior, advanced stage, and poor prognosis. Here we sought to determine the role of transgelin more directly by determining whether experimental manipulation of transgelin levels in colorectal cancer (CRC) cells led to changes in metastatic potential in vivo.

Methods

Isogenic CRC cell lines that differ in transgelin expression were characterized using in vitro assays of growth and invasiveness and a mouse tail vein assay of experimental metastasis. Downstream effects of transgelin overexpression were investigated by gene expression profiling and quantitative PCR.

Results

Stable overexpression of transgelin in RKO cells, which have low endogenous levels, led to increased invasiveness, growth at low density, and growth in soft agar. Overexpression also led to an increase in the number and size of lung metastases in the mouse tail vein injection model. Similarly, attenuation of transgelin expression in HCT116 cells, which have high endogenous levels, decreased metastases in the same model. Investigation of mRNA expression patterns showed that transgelin overexpression altered the levels of approximately 250 other transcripts, with over-representation of genes that affect function of actin or other cytoskeletal proteins. Changes included increases in HOOK1, SDCCAG8, ENAH/Mena, and TNS1 and decreases in EMB, BCL11B, and PTPRD.

Conclusions

Increases or decreases in transgelin levels have reciprocal effects on tumor cell behavior, with higher expression promoting metastasis. Chronic overexpression influences steady-state levels of mRNAs for metastasis-related genes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2105-8) contains supplementary material, which is available to authorized users.

Transgelin is upregulated in stromal cells of lymph node positive breast cancer

Transgelin and transgelin-2 have been discussed as potential markers of various cancers. Here we identified increased transgelin level in lymph node positive vs. negative, low grade primary breast cancer tissues using 2-DE in the cohort of 12 patients. We further clinically validated 2-DE results in an independent cohort of 48 low grade breast cancer patients through untargeted and targeted proteomics analysis (iTRAQ-2D-LC-MS/MS, mTRAQ-SRM), at transcript level and using immunohistochemistry. Another group of 48 high grade tumors of different breast cancer subtypes was analyzed together with the low grade samples to test transgelin specificity for low grade tumors and to study transgelin relation to known molecular markers and histological features. The results confirmed transgelin connection with the lymph node metastasis. As a marker of a reactive tumor stroma, transgelin can be connected with the higher risk of metastasis development. Moreover, we observed significant down-regulation of transgelin in high vs. low grade tumors caused by decreased content of stromal cells (mainly expressing transgelin) in high grade tumor tissue. We also analyzed expression of transgelin-2 in the second cohort using proteomics and immunohistochemistry. Transgelin-2 was mainly expressed by epithelial cancer cells and its levels were increased in metastatic and poorly differentiated tumors.

BIOLOGICAL SIGNIFICANCE

Both transgelin and transgelin-2 have been previously described as potential markers of many types of cancer. We are specifying this connection to metastatic affection of lymph nodes and cell differentiation in breast cancer. In the wider context, the results of our study highlight tumor stroma as a source of cancer biomarkers and point out how measured levels of tissue markers can actually reflect cellular feature of cancer mass.

Transgelin gene is frequently downregulated by promoter DNA hypermethylation in breast cancer

Background

CpG hypermethylation in gene promoters is a frequent mechanism of tumor suppressor gene silencing in various types of cancers. It usually occurs at early steps of cancer progression and can be detected easily, giving rise to development of promising biomarkers for both detection and progression of cancer, including breast cancer. 5-aza-2′-deoxycytidine (AZA) is a DNA demethylating and anti-cancer agent resulting in induction of genes suppressed via DNA hypermethylation.

Results

Using microarray expression profiling of AZA- or DMSO-treated breast cancer and non-tumorigenic breast (NTB) cells, we identified for the first time TAGLN gene as a target of DNA hypermethylation in breast cancer. TAGLN expression was significantly and frequently downregulated via promoter DNA hypermethylation in breast cancer cells compared to NTB cells, and also in 13/21 (61.9 %) of breast tumors compared to matched normal tissues. Analyses of public microarray methylation data showed that TAGLN was also hypermethylated in 63.02 % of tumors compared to normal tissues; relapse-free survival of patients was worse with higher TAGLN methylation; and methylation levels could discriminate between tumors and healthy tissues with 83.14 % sensitivity and 100 % specificity. Additionally, qRT-PCR and immunohistochemistry experiments showed that TAGLN expression was significantly downregulated in two more independent sets of breast tumors compared to normal tissues and was lower in tumors with poor prognosis. Colony formation was increased in TAGLN silenced NTB cells, while decreased in overexpressing BC cells.

Conclusions

TAGLN gene is frequently downregulated by DNA hypermethylation, and TAGLN promoter methylation profiles could serve as a future diagnostic biomarker, with possible clinical impact regarding the prognosis in breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0138-5) contains supplementary material, which is available to authorized users.

Increased Expression of Tissue/Salivary Transgelin mRNA Predicts Poor Prognosis in Patients with Oral Squamous Cell Carcinoma (OSCC)

Background

Transgelin is supposed to be a tumor suppression gene and it is down-regulated in a variety of human cancers. However, the role of transgelin in different cancers is still very controversial. In addition, currently little information is available the relationship between transgelin and Oral Squamous Cell Carcinoma (OSCC).

Material/Methods

Western Blotting was performed to test the transgelin protein expression level in OSCC tissues and adjacent normal tissues. Real-time PCR was used to examine the expression level of transgelin mRNA in tissue, serum and saliva of OSCC patients and negative controls. The correlation between tissue and salivary transgelin mRNA expression level with a variety of clinical parameters was further studied.

Results

Transgelin protein expression was increased in OSCC patients compared with healthy individuals. Similarly, the expression level of both tissue and salivary transgelin mRNA were increased significantly in patients with OSCC in comparison with normal controls. However, little difference of serum transgelin mRNA expression was found between the OSCC patients and healthy controls. In addition, overexpression of tissue or salivary transgelin was closely associated with various clinical parameters including poorer overall survival. Furthermore, our results showed that tissue and salivary transgelin mRNA were independent prognosis factors for OSCC.

Conclusions

The expressions level of tissue mRNA and protein were increased in OSCC patients. Both tissue and salivary transgelin mRNA were closely correlated with various important clinicopathological parameters and were independent prognosis factors for OSCC, indicating they might serve promising biomarkers for OSCC.

Transgelin: a potentially useful diagnostic marker differentially expressed in triple-negative and non-triple-negative breast cancers

Triple negative (TN) (estrogen receptor [ER], progesterone receptor [PR] and HER2-) are highly aggressive, rapidly growing, hormone-unresponsive tumors diagnosed at later stage that affect younger women with shorter overall survival. Most TN tumors are of the basal type. For the remainder, identification of target markers for effective treatment strategies remains a challenge. Transgelin (TGLN) is a 22-kd actin-binding protein of the calponin family. It is one of the earliest markers of smooth muscle differentiation. TGLN has been shown to have important biologic activities including regulating muscle fiber contractility, cell migration, and tumor suppression. We examined TGLN expression in the different molecular subtypes of breast cancer. TGLN expression was examined as a function of tumor size, grade, histologic type, lymph node status, patients' age and overall survival, ER, PR, HER2, and Ki-67 in 101 tumors that included 35 luminal A, 28 luminal B, 4 HER2, and 34 TN types. TGLN positivity (defined as 2+ or 3+) was associated with more aggressive tumors (10% of grade I/II tumors were TGLN+ versus 53% of grade III tumors; P < .001), high Ki-67 count, and low ER and PR expression (P < .001) but not with tumor size, age, or lymph node metastasis. TN (n = 34) tumors were 7.7 times more likely to be TGLN+ than non-TN (n = 67) tumors (77% versus 10%, respectively; P < .001). TGLN may be an excellent diagnostic marker of TN tumors and could be useful in stratification of patients. TGLN may also prove a potential target for future treatment strategies.

TAGLN expression is upregulated in NF1-associated malignant peripheral nerve sheath tumors by hypomethylation in its promoter and subpromoter regions

Neurofibromatosis type 1 (NF1) caused by NF1 gene mutation is a commonly inherited autosomal dominant disorder. Malignant peripheral nerve sheath tumors (MPNSTs), a type of aggressive sarcoma, are a major cause of mortality in NF1 patients. The malignant transformation of benign plexiform neurofibromas (PNs) to MPNSTs is a marked peculiarity in NF1 patients, yet the pathogenesis remains poorly understood. We found that an actin-associated protein transgelin (SM22) was highly expressed in NF1-deficient MPNST tissues compared to NF1-deficient PN tissues using immunohistological staining and primary cultured MPNST cells in western blot analysis. We further found that this transgelin upregulation was caused by increased transcriptional expression of the TAGLN gene encoding transgelin. Comparison of DNA methylation values in the promoter and subpromoter regions of the TAGLN gene in three types of NF1-deficient primary-cultured cells, derived from an NF1 patient's normal phenotype, a benign PN and MPNST tissues, revealed that the TAGLN gene was hypomethylated in the MPNST cells. Next, to determine the functional role of transgelin in MPNST pathogenesis, we manipulated the TAGLN gene expression and investigated the alteration of the RAS-mitogen-activated protein kinase (MAPK) signaling pathway in the normal-phenotypic and malignant tumor cells. The downregulation of TAGLN expression in NF1-deficient MPNST tumor cells through the treatment of the small interfering RNA resulted in a decrease in the RAS activation (GTP-RAS) and the downstream ERK1/2 activation (phosphorylated ERK1/2), while the overexpression of TAGLN in normal-phenotypic NF1-deficient cells caused an increase in RAS and ERK1/2 activation. These results indicate that upregulation of transgelin caused by hypomethylation of the TAGLN gene is closely involved in tumor progression in NF1.

Identification of prosaposin and transgelin as potential biomarkers for gallbladder cancer using quantitative proteomics

Gallbladder cancer is an uncommon but lethal malignancy with particularly high incidence in Chile, India, Japan and China. There is a paucity of unbiased large-scale studies investigating molecular basis of gallbladder cancer. To systematically identify differentially regulated proteins in gallbladder cancer, iTRAQ-based quantitative proteomics of gallbladder cancer was carried out using Fourier transform high resolution mass spectrometry. Of the 2575 proteins identified, proteins upregulated in gallbladder cancer included several lysosomal proteins such as prosaposin, cathepsin Z and cathepsin H. Downregulated proteins included serine protease HTRA1 and transgelin, which have been reported to be downregulated in several other cancers. Novel biomarker candidates including prosaposin and transgelin were validated to be upregulated and downregulated, respectively, in gallbladder cancer using tissue microarrays. Our study provides the first large scale proteomic characterization of gallbladder cancer which will serve as a resource for future discovery of biomarkers for gallbladder cancer.

Transgelins, cytoskeletal proteins implicated in different aspects of cancer development

Transgelin is an abundant protein of smooth muscle cells, where its role has been primarily studied. As a protein affecting dynamics of the actin cytoskeleton via stabilization of actin filaments, transgelin is both directly and indirectly involved in many cancer-related processes such as migration, proliferation, differentiation or apoptosis. Transgelin was previously reviewed as a tumor suppressor; however, recent data based on a number of proteomics studies indicate its pro-tumorigenic role, for example, in colorectal or hepatocellular cancer. We summarize these contradictory observations in both clinical and functional proteomics projects and analyze the role of transgelin in tumors in detail. Generally, the expression and biological role of transgelin seem to differ among various types of tumor cells and stroma, and possibly change during tumor progression. We also overview the recent data on transgelin-2, a sequence homolog of transgelin, whose role in the tumor development might be contradictory to the role of transgelin.

Profiling of hepatocellular carcinoma cell cycle regulating genes targeted by calycosin

We cocultured calycosin with human hepatocellular carcinoma cell line (BEL-7402) to investigate the effect on cell proliferation. Calycosin can markedly block the cell growth in G₁ phase (P < 0.01) on the IC₅₀ concentration. There were seventeen genes involved in cell-cycle regulation showing differentially expressed in treated cells detected by gene chip. Eight genes were upregulated and nine genes were downregulated. Downregulated TFDP-1, CDKN2D, and SPK2 and upregulated CDC2 and CCNB1 might affect cell cycle of tumor cells. Furthermore, we checked the transcription pattern using 2D gel method to find different expression of proteins in human hepatocellular carcinoma cells after exposure to calycosin. Fourteen proteins were identified by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Twelve proteins expression were increased such as transgelin 2, pyridoxine 5′-phosphate, stress-induced-phosphoprotein 1, peroxiredoxin 1, endoplasmic reticulum protein 29, and phosphoglycerate mutase 1. Only thioredoxin peroxidase and high-mobility group box1 proteins' expression decreased. Both genes and proteins changes might be relate to the mechanism of antitumor effect under treatment of calycosin. In conclusion, calycosin has a potential effect to inhibit the BEL-7402 cell growth by inhibiting some oncogene expression and increasing anticancer genes expression, what is more, by blocking cell cycle.

Transgelin: an androgen-dependent protein identified in the seminal vesicles of three Saharan rodents

During the breeding season, a major androgen-dependent protein with an apparent molecular weight of 21 kDa was isolated and purified from the seminal vesicles of three Saharan rodents (MLVSP21 from Meriones libycus, MSVSP21 from Meriones shawi, and MCVSP21 from Meriones crassus). The 21-kDa protein was isolated and purified from soluble seminal vesicle proteins of homogenate by one-dimensional polyacrylamide gel electrophoresis (SDS-PAGE). Using polyclonal antibodies directed against POSVP21 (Psammomys obesus seminal vesicles protein of 21 kDa), a major androgen-dependent secretory protein from sand rat seminal vesicles, identified previously as transgelin, we showed an immunological homology with POSVP21 by immunoblotting. These three major androgen-dependent proteins with a same apparent molecular weight of 21 kDa designated as MLVSP21 (Meriones libycus seminal vesicles protein of 21 kDa), MSVSP21 (Meriones shawi seminal vesicles protein of 21 kDa), and MCVSP21 (Meriones crassus seminal vesicles protein of 21 kDa) were localized by immunohistochemistry and identified by applying a proteomic approach. Our results indicated that the isolated proteins MLSVP21, MSSVP21, and MCSVP21 seem to correspond to the same protein: the transgelin. So that transgelin can be used as a specific marker of these rodent physiological reproduction mechanisms.

Proteomic analysis of differential protein expression by brain metastases of gynecological malignancies

Brain metastases of gynecological malignancies are rare, but the incidence is increasing. Patients with brain metastases have a poor prognosis, therefore early detection and optimal management is necessary. In order to determine a new biomarker, we aimed to identify proteins that associated with brain metastases. We investigated proteins associated with brain metastases of gynecological malignancies in three patients who underwent surgical resection (stage IIb cervical cancer, stage Ib endometrial cancer, and stage IIIb ovarian cancer). Proteomic analysis was performed on formalin-fixed paraffin-embedded (FFPE) samples of the primary tumors and brain metastases, which were analyzed by liquid chromatography with tandem mass spectrometry. Thereafter, candidate proteins were identified by the Scaffold system and Mascot search program, and were analyzed using western blotting and immunohistochemistry. As a result, a total of 129 proteins were identified. In endometrial and ovarian cancers, western blotting revealed that the expression of alpha-enolase (ENO1) and triosephosphate isomerase (TPI-1) was higher and the expression of Transgelin-2 (TAGLN2) was lower in metastatic tumors than in primary tumors. On the other hand, the expression of TPI-1 and TAGLN2 was lower in metastatic tumors than in primary tumors in cervical cancer. Immunohistochemistry confirmed that ENO1 expression was elevated in the metastatic tumors compared with the primary tumors. In conclusion, the present study showed that FFPE tissue-based proteomics analysis can be powerful tool, and these findings suggested that ENO1, TPI-1, and TAGLN2 may have a role in the development and progression of brain metastasis from gynecological malignancies.

Reduced expression of SM22 is correlated with low autophagy activity in human colorectal cancer

Colorectal cancer (CRC) is a common malignancy with a high incidence and mortality rate. Recent studies have pointed to deregulation of autophagy as a novel pathogenesis of human malignancy. SM22 is considered as a tumor suppressor. The aim of the present study was to evaluate the correlation of the SM22 expression level with the autophagy activity and the clinical characteristics in human CRC tissues. The expressions of SM22 and p62, a biomarker of autophagy activity, in paired tumor and adjacent non-tumor tissues from 43 patients with colorectal cancer were detected by western blot and immunohistochemical staining, respectively. The results showed that the SM22 level decreased significantly in 81.4% CRC tissues, while the expression of p62 increased in 79.1% cases. There was a negative correlation between p62 and SM22 expressions in colorectal cancer tissues (p=0.004). Similarly, the negative correlation between SM22 and p62 was verified in human CRC cell lines. The data suggest that the autophagy activity decreased in human CRC, which was associated with reduction in SM22 expression. However, the expression of SM22 was not associated with the gender, tumor site and Duke's stage of the patients. In conclusion, our findings suggest that the disruption of SM22 may be involved in tumorigenesis in CRC. The autophagic activity may be suppressed in human CRC, and SM22 may act as a positive regulator in the processes of autophagy.

Epithelial morphogenesis of MDCK cells in three-dimensional collagen culture is modulated by interleukin-8

Epithelial morphogenesis is dependent upon a variety of factors, many of which involve complex interactions between cells and their surrounding environments. We analyzed the patterns of differential gene expression associated with Madin-Darby canine kidney (MDCK) renal epithelial cells grown within a collagen gel in three-dimensional (3D) culture compared with those grown atop a collagen gel in two-dimensional (2D) culture. Under these conditions, MDCK cells spontaneously formed either hollow spherical cysts or flat monolayer sheets, respectively. Microarray analysis of gene expression revealed a twofold or greater expression difference in 732 gene sets from MDCK cysts compared with monolayers (false discovery rate or FDR-adjusted P values <0.05). Interleukin-8 (IL-8) was reproducibly found to be among the genes whose expression was most dramatically upregulated, and this behavior was verified through real-time PCR analysis. The level of IL-8 protein expression was significantly increased in 3D MDCK cultures compared with that detected in cells in 2D culture. Hepatocyte growth factor (HGF) induces MDCK cells in 3D culture to form linear tubule-like structures. We found that HGF stimulation caused MDCK cells in 3D culture to decrease the expression of IL-8 at both the mRNA and protein levels. Furthermore, the addition of recombinant IL-8 to HGF-stimulated 3D MDCK cultures was sufficient to partially reverse the tubulogenic effects of HGF, resulting in the formation of cystic structures. These data suggest that IL-8 participates in the formation of cystic structures by MDCK cells in 3D culture and that HGF may stimulate tubulogenesis through the suppression of IL-8.

Upregulation of transgelin is an independent factor predictive of poor prognosis in patients with advanced pancreatic cancer

Transgelin is a known actin-binding protein, which plays a role in regulating the functions of smooth muscle cells or fibroblasts. Recent evidence indicates that transgelin is involved in diverse human cancers, yet its role in pancreatic cancer remains unclear. We therefore evaluated the expression characteristics and function of transgelin in pancreatic cancer. Immunohistochemical analysis of benign (n = 30 patients) and malignant (n = 114 patients) pancreatic ductal cells showed significantly higher transgelin staining in malignant cells. Lymph node metastasis (P = 0.026) and diabetes (P = 0.041) were shown to significantly correlate with transgelin protein expression. Patients with high transgelin expression showed a shorter 5-year overall survival and a lower tumor-specific survival than those with low transgelin expression. Multivariate analysis revealed that transgelin was an independent factor affecting pancreatic tumor-specific survival (P = 0.025). In vitro, RNA interference-mediated transgelin knockdown resulted in inhibition of pancreatic cancer cell proliferation, migration and invasion. Depletion of transgelin expression could suppress pancreatic tumorigenicity and tumor growth in vivo, and produce enhanced cytotoxic effects of gemcitabine on pancreatic cancer cells both in vitro and in vivo. Our results indicate that transgelin plays a promoting role in tumor progression, and appears to be a novel prognostic marker for advanced pancreatic cancer.

Identification of proteins expressed differently among surgically resected stage I lung adenocarcinomas

RATIONALE

Among patients with surgically resected stage I lung adenocarcinoma, some succumb to early recurrence, while others survive for more than 5 years. Few markers to predict prognoses in these patients have been accepted. Recent advances in proteomic methodologies offer a unique chance to identify new candidate biomarkers. The aim of this study is to find differences in protein expression in resected lung cancer tissue of stage I adenocarcinoma from patients with no recurrence for more than 5 years and from those with early recurrence.

METHODS

Lung cancer tissues were obtained from 15 patients with pathologically confirmed stage I adenocarcinoma. The patients were divided into two groups, those with recurrence within 36 months (early recurrence group, n=9) and those that were disease-free for over 5 years (disease free group, n=6). Tissue proteins were separated by a two-dimensional electrophoresis long gel system (30 × 40 cm) with set ranges (3-10 NL) and examined by nano-LC-ESI-MS/MS. Western blot assays were performed to validate these proteins.

RESULTS

Twelve protein spots were up-regulated and 8 were down-regulated in the disease-free group as compared with the recurrence group. Of the 12 up-regulated proteins, haptoglubin, tau-tubulin kinase-2 (TTBK2), thymidine phosphorylase, annexin-1, PIN1, CAPG, and SEC23 were validated by Western blot. Among the 8 down-regulated proteins, serpinB6 and trangelin-2 were validated.

CONCLUSIONS

A total of 9 differentially expressed proteins were successfully extracted, identified, and confirmed from stage I lung adenocarcinoma tissues. The increased or decreased expression of these proteins according to prognosis may be the basis for further studies of proteomics in developing prognostic biomarkers.

Gene expression signatures differentiate uterine endometrial stromal sarcoma from leiomyosarcoma

OBJECTIVE

Endometrial stromal sarcoma (ESS) and leiomyosarcoma (LMS) are the two most common uterine sarcomas, but both are rare tumors. The aim of the present study was to compare the global gene expression patterns of ESS and LMS.

METHODS

Gene expression profiles of 7 ESS and 13 LMS were analyzed using the HumanRef-8 BeadChip from Illumina. Differentially expressed candidate genes were validated using quantitative real-time PCR and immunohistochemistry.

RESULTS

Unsupervised hierarchical clustering using all 54,675 genes in the array separated ESS from LMS samples. We identified 549 unique probes that were significantly differentially expressed in the two malignancies by greater than 2-fold with 1% FDR cutoff using one-way ANOVA with Benjamini-Hochberg correction, of which 336 and 213 were overexpressed in ESS and LMS, respectively. Genes overexpressed in ESS included SLC7A10, EFNB3, CCND2, ECEL1, ITM2A, NPW, PLAG1 and GCGR. Genes overexpressed in LMS included CDKN2A, FABP3, TAGLN, JPH2, GEM, NAV2 and RAB23. The top 100 genes overexpressed in LMS included those coding for myosin light chain and caldesmon, but not the genes coding for desmin or actin. CD10 was not overexpressed in ESS. Results for selected genes were validated by quantitative real-time PCR and immunohistochemistry.

CONCLUSIONS

We present the first study in which gene expression profiling was shown to distinguish between ESS and LMS. The molecular signatures unique to each of these malignancies may aid in expanding the diagnostic battery for their differentiation, and may provide a molecular basis for prognostic studies and therapeutic target discovery.

Discovery of stage-related proteins in esophageal squamous cell carcinoma using proteomic analysis

Esophageal squamous cell carcinoma (ESCC) is the major subtype of esophageal cancers in China, and characterized with high morbidity and mortality. So far, the diagnosis of ESCC is mainly dependent on the alterations in esophageal histology, but most cases of ESCC with low stage do not display visible histological abnormalities. Therefore, a deep understanding of the mechanism of ESCC progression and seeking stage-specific molecules might improve the diagnosis and therapy for ESCC. In this study, we used proteomics to analyze ESCC tissues with classification by TNM stage, and determined the proteomic features correlated with ESCC progression (from stages I to III). Proteins that exhibited significantly different expression patterns between ESCC and corresponding normal esophageal tissues were identified using MS. The identified proteins with differentiated expression mainly fell into three protein categories (i.e. cytoskeleton system-associated proteins, metabolism enzymes, and heat shock proteins). In addition, real-time PCR highlighted some molecules that were associated with tumor stages at the mRNA level, such as enolase 1, chromosome 1 ORF 10, elastase inhibitor, α B crystalline, stress-induced phosphoprotein 1, and squamous cell carcinoma antigen 1. Altogether, these data provided further information on ESCC progression and potential drug targets for ESCC clinical therapy.

Necdin, a p53-target gene, is an inhibitor of p53-mediated growth arrest

In vitro, cellular immortalization and transformation define a model for multistep carcinogenesis and current ongoing challenges include the identification of specific molecular events associated with steps along this oncogenic pathway. Here, using NIH3T3 cells, we identified transcriptionally related events associated with the expression of Polyomavirus Large-T antigen (PyLT), a potent viral oncogene. We propose that a subset of these alterations in gene expression may be related to the early events that contribute to carcinogenesis. The proposed tumor suppressor Necdin, known to be regulated by p53, was within a group of genes that was consistently upregulated in the presence of PyLT. While Necdin is induced following p53 activation with different genotoxic stresses, Necdin induction by PyLT did not involve p53 activation or the Rb-binding site of PyLT. Necdin depletion by shRNA conferred a proliferative advantage to NIH3T3 and PyLT-expressing NIH3T3 (NIHLT) cells. In contrast, our results demonstrate that although overexpression of Necdin induced a growth arrest in NIH3T3 and NIHLT cells, a growing population rapidly emerged from these arrested cells. This population no longer showed significant proliferation defects despite high Necdin expression. Moreover, we established that Necdin is a negative regulator of p53-mediated growth arrest induced by nutlin-3, suggesting that Necdin upregulation could contribute to the bypass of a p53-response in p53 wild type tumors. To support this, we characterized Necdin expression in low malignant potential ovarian cancer (LMP) where p53 mutations rarely occur. Elevated levels of Necdin expression were observed in LMP when compared to aggressive serous ovarian cancers. We propose that in some contexts, the constitutive expression of Necdin could contribute to cancer promotion by delaying appropriate p53 responses and potentially promote genomic instability.

Quantitative histological analysis of SM22α (transgelin) in an adriamycin-induced focal segmental glomerulosclerosis model

BACKGROUND/AIMS

SM22α, transgelin, has been revealed to be specifically expressed in glomerular epithelial cells and interstitial cells, according to the nature of the renal injury. In this study, quantitative analyses of SM22α positivity were performed to investigate the pathological significance of its expression.

METHODS

Kidney samples of adriamycin nephropathy underwent immunohistochemistry with a newly established anti-SM22α monoclonal antibody. The SM22α positivity was quantified by an image analyzer. The correlation of the histological values with biochemical data was investigated statistically. Microstructural localization of SM22α was studied by immunoelectron microscopy.

RESULTS

SM22α was expressed along the dense basal microfilaments of degenerating podocytes, and diffusely in interstitial cells. Both the extent and intensity of SM22α expression in glomerular and tubulointerstitial area were correlated with the deterioration of renal function and the severity of proteinuria. Stepwise multiple linear regression analysis revealed that the extent of its positivity in glomerular or tubulointerstitial area was the determinant of the amount of proteinuria or the deterioration of creatinine clearance (Ccr), respectively. Inversely, the deterioration of Ccr was the most important predictor of SM22α expression.

CONCLUSION

SM22α expression in podocytes and interstitial cells represented the severity of proteinuria and the deterioration of renal function. SM22α expression in renal tissues might be a hallmark of kidney diseases.

Cyclin-dependent kinase-associated protein Cks2 is associated with bladder cancer progression

In this observational retrospective study, expression of possible cancer-related genes was measured in patients with a pathological diagnosis of superficial bladder cancer. Further measurements were made in those who subsequently developed muscle-invasive cancer. Seven of the 45 patients with superficial bladder cancer progressed to muscle-invasive cancer. Expression of fatty acid binding protein 5 (FABP5), poly(A) binding protein cytoplasmic 1 (PABPC1), DEAD box polypeptide 5 (DDX5), splicing factor 3b subunit 1 (SF3B1), murine mammary tumour integration site 6 (EIF3S6), tropomyosin 2β (TPM2), transgelin (TAGLN) and cyclin-dependent kinase-associated protein (Cks2) genes was measured in bladder samples using real-time reverse transcription-polymerase chain reaction. FABP5, PABPC1, DDX5, SF3B1, EIF3S6 and Cks2 expression levels were significantly increased, and TPM2 and TAGLN were significantly decreased, in superficial bladder cancer compared with normal bladder tissue. In patients who developed muscle-invasive cancer, the Cks2 gene showed significantly increased expression after, compared with before, invasion. The Cks2 gene may have potential as a biomarker for predicting superficial bladder cancer progression to muscle-invasive cancer.

TAGLN expression is deregulated in endometriosis and may be involved in cell invasion, migration, and differentiation

We found an increased expression of the TAGLN gene in endometriotic lesions compared with the eutopic endometrium of the same patients by real-time polymerase chain reaction. It is possible that this deregulation contributes to the development and maintenance of endometriosis by being involved in the pathways of organization of cytoskeletal architecture.

A novel interplay between oncogenic PFTK1 protein kinase and tumor suppressor TAGLN2 in the control of liver cancer cell motility

The PFTK1 gene encodes a cdc2-related serine/threonine protein kinase that has been shown to confer cell migratory properties in hepatocellular carcinoma (HCC). However, the prognostic value and biological mechanism by which PFTK1 promotes HCC motility remain largely unknown. Here, we showed from tissue microarray that common upregulations of PFTK1 in primary HCC tumors (n=133/180) correlated significantly with early age onset (40 years), advance tumor grading and presence of microvascular invasion (P0.05). To understand downstream phosphorylated substrate(s) of PFTK1, phospho-proteins in PFTK1 expressing and knockdown Hep3B cells were profiled by two-dimensional-polyacrylamide gel electrophoresis mass spectrometric analysis. Protein identification of differential spots revealed β-actin (ACTB) and transgelin2 (TAGLN2) as the two most profound phosphorylated changes affected by PFTK1. We verified the presence of TAGLN2 serine phosphorylation and ACTB tyrosine phosphorylation. Moreover, reduced TAGLN2 and ACTB phosphorylations in PFTK1-suppressed Hep3B corresponded to distinct actin depolymerizations and marked inhibition on cell invasion and motility. Given that TAGLN2 is a tumor suppressor whose function has been ascribed in cancer metastasis, we examined if TAGLN2 is an intermediate substrate in the biological path of PFTK1. We showed in PFTK1-suppressed cells that knockdown of TAGLN2 over-rode the inhibitory effect on cell invasion and motility, and a recovery on actin polymerization was evident. Interestingly, we also found that unphosphorylated TAGLN2 in PFTK1-suppressed cells elicited strong actin-binding ability, a mechanism that possibly halts the actin cytoskeleton dynamics. Site-directed mutagenesis of TAGLN2 suggested that PFTK1 regulates the actin-binding affinity of TAGLN2 through the S83 and S163 residues, which if mutated can significantly affect HCC cell motility. Taken together, our data propose a novel, oncogene-tumor suppressor interplay, where oncogenic PFTK1 confers HCC cell motility through inactivating the actin-binding motile suppressing function of TAGLN2 via phosphorylation.

Does TGF-β induced formation of actin stress fibres reinforce Smad dependent TGF-β signalling in the prostate?

In the normal prostate, and during early stages of prostate cancer (PCa) development, the cytokine transforming growth factor beta (TGF-β) acts as a tumour suppressor by inducing cytostasis and apoptosis. However, during tumour development these Smad signalling-dependent endpoints are lost in favour of Smad-independent tumourigenic actions of TGF-β. In this working hypothesis we present an argument for an intimate association between the TGF-β signalling pathway and the actin cytoskeleton that acts to reinforce the tumour suppressive actions of TGF-β in the normal prostate epithelial cell. The rationale is that TGF-β induces expression of the actin binding and stabilising proteins transgelin and tropomyosin. Expression of these proteins is progressively repressed during PCa development, and is inhibited by constitutive activation of the Ras/MEK/ERK pathway, also known to antagonise TGF-β tumour suppression in PCa. The subsequent de-stabilisation of the actin cytoskeleton might, therefore, result in suppression of TGF-β/Smad signalling as an intact link between cytoskeleton and TGF-β receptor/Smad complex is essential. Filamin A is a scaffold protein that provides this link for receptor associated Smads. It is required for activation of the TGF-β signal transduction pathway. Thus, actin filament disorganisation would prevent Filamin A/R-Smad mediated TGF-β signalling, a subsequent loss of tumour suppression and hence promote the progression of PCa. Furthermore, it could be one mechanism by which the switch to a TGF-β tumourigenic response occurs.