The role of GPC5 in lung metastasis of salivary adenoid cystic carcinoma

The novel lncRNA GPC5-AS1 stabilizes GPC5 mRNA by competitively binding with miR-93/106a to suppress gastric cancer cell proliferation

Long non-coding RNAs (lncRNAs) are of importance in the genesis and progression of gastric cancer (GC). GPC5-AS1 is a novel lncRNA associated with methyl-CpG-binding protein 2 (MeCP2), identified in our previous microarray analysis; however, the role of GPC5-AS1 in GC remains unknown. In the present study, we demonstrate that GPC5-AS1 is downregulated in GC cells and tissues, and this aberrant expression is regulated by MeCP2 through CpG site binding in the promoter region. Importantly, we also demonstrate that GPC5-AS1 overexpression suppresses cell proliferation, colony formation, and cell cycle transition; induces apoptosis in vitro; and inhibits tumorigenicity in vivo. The expression of the controversial gene GPC5 was downregulated in GC tissues, and elevated GPC5 level could inhibit GC cell growth. Mechanistically, we demonstrated that GPC5-AS1 stabilizes GPC5 mRNA by acting as a molecular sponge for miR-93 and miR-106a, thereby reducing GC tumor progression. In conclusion, our results suggest that GPC5-AS1 may play a pivotal role in GC and serve as a potential diagnostic biomarker and a powerful therapeutic target for GC.

Subcellular localization of glypican-5 is associated with dynamic motility of the human mesenchymal stem cell line U3DT

Glypican-5 (GPC5) is a heparan sulfate proteoglycan (HSPG) localized to the plasma membrane. We previously reported that in the human mesenchymal stem cell line UE6E7T-3, GPC5 is overexpressed in association with transformation and promotes cell proliferation by acting as a co-receptor for Sonic hedgehog signaling. In this study, we found using immunofluorescence microscopy that in transformed cells (U3DT), GPC5 localized not only at primary cilia on the cell surface, but also at the leading edge of migrating cells, at the intercellular bridge and blebs during cytokinesis, and in extracellular vesicles. In each subcellular region, GPC5 colocalized with fibroblast growth factor receptor (FGFR) and the small GTPases Rab11 and ARF6, indicating that GPC5 is delivered to these regions by Rab11-associated recycling endosomes. These colocalizations suggest that GPC5 plays an important role in FGF2 stimulation of cell migration, which was abrogated by knockdown of GPC5. Our findings indicate that GPC5 plays a role in regulation of U3DT cell migration and provides several insights into the functions of GPC5 that could be elucidated by future studies.

Molecular principles of metastasis: a hallmark of cancer revisited

Metastasis is the hallmark of cancer that is responsible for the greatest number of cancer-related deaths. Yet, it remains poorly understood. The continuous evolution of cancer biology research and the emergence of new paradigms in the study of metastasis have revealed some of the molecular underpinnings of this dissemination process. The invading tumor cell, on its way to the target site, interacts with other proteins and cells. Recognition of these interactions improved the understanding of some of the biological principles of the metastatic cell that govern its mobility and plasticity. Communication with the tumor microenvironment allows invading cancer cells to overcome stromal challenges, settle, and colonize. These characteristics of cancer cells are driven by genetic and epigenetic modifications within the tumor cell itself and its microenvironment. Establishing the biological mechanisms of the metastatic process is crucial in finding open therapeutic windows for successful interventions. In this review, the authors explore the recent advancements in the field of metastasis and highlight the latest insights that contribute to shaping this hallmark of cancer.

MicroRNA-301b promotes the proliferation and invasion of glioma cells through enhancing activation of Wnt/β-catenin signaling via targeting Glypican-5

Accumulating evidence has suggested that Glypican-5 (GPC5) is a tumor suppressor gene in many types of cancers. However, whether GPC5 is involved in glioma remains unknown. This study was designed to explore the expression, biological function and regulatory mechanism of GPC5 in glioma. Our results demonstrated that GPC5 expression was significantly decreased in multiple glioma cell lines. Gain-of-function experiments showed that the ectopic expression of GPC5 markedly inhibited the proliferation, invasion and Wnt/β-catenin signaling of glioma cell lines. GPC5 was identified as a target gene of microRNA-301b (miR-301b). Further data showed that miR-301b expression was significantly up-regulated in glioma tissues and cell lines. In addition, miR-301b expression was inversely correlated with GPC5 expression in clinical glioma tissues. The overexpression of miR-301b promoted the proliferation, invasion and Wnt/β-catenin signaling of glioma cell lines, whereas the inhibition of miR-301b showed the opposite effect. However, the silencing of GPC5 significantly reversed the antitumor effect of miR-301b inhibition. Overall, our results revealed a tumor suppressive role of GPC5 in glioma and suggested that GPC5 expression was regulated by miR-301b. Our study indicates that the inhibition of miR-301b represses the proliferation and invasion of glioma cells by up-regulating GPC5 expression.

Role of glypicans in regulation of the tumor microenvironment and cancer progression

Glypicans are evolutionary conserved, cell surface heparan sulfate (HS) proteoglycans that are attached to the cell membrane via a glycosylphosphatidylinositol (GPI) anchor. Glypicans interact with a broad class of soluble and insoluble ligands, such as morphogens, growth factors, chemokines, receptors and components of the extracellular matrix (ECM). Such versatility comes from their ability to interact through both their HS chains and core protein. Glypicans are involved in cellular and tissue development, morphogenesis and cell motility. They exhibit differential expression in several cancers, acting as both tumor promoters and inhibitors in a cancer type-specific manner. They also influence tumor stroma by facilitating angiogenesis, ECM remodeling and alteration of immune cell functions. Glypicans have emerged as a new therapeutic moiety, whose functions can be exploited in the field of targeted therapies and precision medicine in cancer. This is demonstrated by the emergence of several anti-glypican antibody-based immunologics that have been recently developed and are being evaluated in clinical trials. This review will focus on glypican structure and function with an emphasis on their expression in various cancers. Discussion will also center on the potential of glypicans to be therapeutic targets for inhibition of cancer cell growth.

Effect of Xylosyltransferase-I Silencing on Implanting Growth of Salivary Pleomorphic Adenoma

BACKGROUND Salivary pleomorphic adenoma is one of the most common salivary gland tumors. It has a relatively high tendency to recur and a high risk of malignant transformation. The present study aimed to study the effect of XT-I gene silencing on the implanting growth of salivary pleomorphic adenoma. MATERIAL AND METHODS Primary cultures of SPA cells and fibroblasts from the same patient were assessed. The adenovirus vector Ad-shRNA-XT-I was constructed and transfected into SPA cells. The expression of XT-I gene and XT-I protein was detected by real-time PCR and Western blot. The contents of proteoglycans were detected. The SPA cells transfected with Ad-shRNA-XT-I (group SPA-XT-I) and Ad-shRNA-HK (group SPA-HK), as well as without transfection (group SPA), were implanted into ADM scaffold with fibroblasts and then transferred into 18 BALB/C-nu nude mice for 3 months. RESULTS Primary cultures showed SPA cells were positive for human CK and S-100 protein and the fibroblasts were positive for human vimentin. The expressions of XT-I gene and protein were decreased by 51% and 51.31%, respectively. The content of proteoglycans was reduced by 48.45%. The results of the implanting growth in vitro and in vivo of nude mice indicated that no tumors grew in the SPA-XT-I group, whereas SPA grew in groups SPA-HK and SPA positive for human a-SMA, S-100 protein, and calponin. CONCLUSIONS XT-I gene silencing effectively inhibited the implanting growth of SPA.

Glypican-5 suppresses Epithelial-Mesenchymal Transition of the lung adenocarcinoma by competitively binding to Wnt3a

We previously demonstrated that Glypican-5 (GPC5), one of the members of heparan sulfate proteoglycan, was a novel tumor metastasis suppressor in lung adenocarcinoma (LAC). However, it remains unclear how GPC5 suppresses lung cancer metastasis. Here, we found over-expression GPC5 induced significant Epithelial-Mesenchymal Transition (EMT) process of A549 cells in vitro. Bioinformatic analysis of RNA sequencing data indicated that GPC5 was co-expressed with EMT related markers, E-cadherin and Vimentin. Wnt/β-catenin signaling pathway was also significantly enriched after overexpressing GPC5. Further in vitro experiments demonstrated that overexpressing GPC5 could block the translocation of β-catenin from cytoplasm to nucleus and therefore inactivate the Wnt/β-catenin signaling pathway by competitively binding to Wnt3a. Subsequent rescue experiments demonstrated that GPC5-induced metastatic phenotype and EMT process suppression were significantly reversed when cells cultured in Wnt3a conditioned media. By establishing the metastatic model in severe combined immune deficiency (SCID) mice, we also demonstrated that overexpressing GPC5 suppressed LAC migration and accordingly alerted EMT related markers, which including up-regulated E-cadherin and down-regulated Vimentin in both lung and liver metastasis. Finally, clinical samples of LAC further validated that GPC5 expression was positively correlated with E-cadherin, and negatively correlated with both Twist1 and MMP2. Taken together, these data suggested that GPC5 is able to suppress the LAC metastasis by competitively binding to Wnt3a and inactivating the Wnt/β-catenin signaling pathway. Our findings expanded the role and the molecular mechanism of GPC5 on malignant bionomics of LAC.

Proteoglycans remodeling in cancer: Underlying molecular mechanisms

Extracellular matrix is a highly dynamic macromolecular network. Proteoglycans are major components of extracellular matrix playing key roles in its structural organization and cell signaling contributing to the control of numerous normal and pathological processes. As multifunctional molecules, proteoglycans participate in various cell functions during morphogenesis, wound healing, inflammation and tumorigenesis. Their interactions with matrix effectors, cell surface receptors and enzymes enable them with unique properties. In malignancy, extensive remodeling of tumor stroma is associated with marked alterations in proteoglycans' expression and structural variability. Proteoglycans exert diverse functions in tumor stroma in a cell-specific and context-specific manner and they mainly contribute to the formation of a permissive provisional matrix for tumor growth affecting tissue organization, cell-cell and cell-matrix interactions and tumor cell signaling. Proteoglycans also modulate cancer cell phenotype and properties, the development of drug resistance and tumor stroma angiogenesis. This review summarizes the proteoglycans remodeling and their novel biological roles in malignancies with particular emphasis to the underlying molecular mechanisms.

The relationship between proteoglycan inhibition via xylosyltransferase II silencing and the implantation of salivary pleomorphic adenoma

OBJECTIVE

To study the relationship between proteoglycan inhibition and the implantation of salivary pleomorphic adenoma (SPA).

METHODS

SPA fresh tissue was primitively cultured and identified. The Ad-shRNA-XT-II adenovirus vector was constructed and transfected into SPA cells to silence the XT-II gene. The expression of the XT-II gene and protein was detected using real-time PCR and Western blotting, respectively. The proteoglycan content of the cells was determined 48 h after transfection. The invasion and migration of SPA cells were observed using Matrigel invasion and wound-healing assays. Fibroblasts from the tumour capsule of the same patient were obtained, cultured and seeded onto an acellular dermal matrix (ADM) scaffold. Tumour cells were seeded onto the scaffold with the fibroblasts and then transferred to BALB/C-nu nude mice and allowed to grow in vivo for 3 months.

RESULTS

The SPA cells cultures were positive for human calponin, S-100 protein, α-SMA and CK. XT-II gene and protein expression was decreased by 42.72% and 34%, respectively. The proteoglycan content was downregulated by 41.15%. XT-II gene silencing decreased the invasion and migration abilities of SPA cells. The assessment of SPA growth in nude mice indicated an absence of tumour growth in the SPA-XT-II group (in which the XT-II gene was silenced), whereas SPA growth was observed in the other two groups (in which the XT-II gene was not silenced), and the tumour tissue was positive for the human S-100 protein, α-SMA and CK8&18.

CONCLUSION

Proteoglycan inhibition induced via XT-II gene silencing inhibited the implantation of SPA.

miR-297 acts as an oncogene by targeting GPC5 in lung adenocarcinoma

OBJECTIVES

Emerging studies have demonstrated that microRNAs (miRNAs) play crucial roles in carcinogenesis of many developing human tumours. However, the functions and mechanisms of miR-297 in lung cancer have, up to now, been largely undefined.

MATERIALS AND METHODS

Here, miR-297 expression was measured in lung adenocarcinoma tissues and cell lines, using qRT-PCR. Lung adenocarcinoma cell line was treated with an miR-297 mimic. MTT and colony analysis were performed to detect cell proliferation and colony formation. The direct target gene of miR-297 was assessed by qRT-PCR, Western blotting and luciferase assays.

RESULTS

We demonstrated that miR-297 expression was upregulated in lung adenocarcinomas compared to adjacent normal tissues. Expression of miR-297 was also upregulated in tested lung adenocarcinoma cell lines. Ectopic expression of miR-297 enhanced lung adenocarcinoma cell proliferation and colony formation. Furthermore, overexpression of miR-297 promoted cell migration and invasion. In addition, we identified Glypican-5 (GPC5) as a direct target gene of miR-297 in lung adenocarcinoma cells. Expression of GPC5 was downregulated in both lung adenocarcinoma tissues and cell lines. Moreover, expression of GPC5 was inversely associated with expression of miR-297 in lung adenocarcinoma tissues.

CONCLUSIONS

These results suggest that miR-297 acted as an oncogenic miRNA, partly by targeting GPC5, adenocarcinoma of the lung.

[Investigation of Gene Expression Profile of A549 Cells after Overexpression of GPC5 by High Throughput Transcriptome Sequencing]

背景与目的

磷脂酰肌醇蛋白聚糖-5(glypican-5, GPC5)是一个重要的抑癌基因, 然而GPC5对肺腺癌细胞增殖能力和基因表达的影响目前研究甚少。本研究拟在肺腺癌A549细胞中过表达GPC5以研究细胞增殖能力和基因表达变化情况。

方法

通过慢病毒载体构建稳定过表达GPC5的A549细胞株, 通过Cell Counter Kit 8 (CCK8)、平板克隆和EdU实验检测细胞增殖能力; 通过高通量转录组测序研究基因表达变化。

结果

相对于空白载体组, CCK8实验发现过表达GPC5可以明显抑制A549细胞的增殖速率; 平板克隆实验结果显示, 过表达GPC5之后A549细胞克隆形成能力下降(181±17 vs 278±23);EdU染色结果显示过表达GPC5后阳性染色细胞比例下降。转录组测序结果提示过表达GPC5之后, 2, 108个基因表达发生明显变化, 其中具有正性调节细胞增殖作用的基因明显下调。

结论

过表达GPC5可以明显抑制肺腺癌细A549的增殖能力, 而且过表达GPC5后具有正性调节细胞增殖作用的基因表达下调。

Low expression of endothelin receptor B (EDNRB) is related to H3K9me3 binding with the EDNRB promoter region and is associated with the clinical T tumor stage in salivary adenoid cystic carcinoma

OBJECTIVE

To investigate the endothelin receptor B (EDNRB) expression in salivary adenoid cystic carcinoma (ACC) and the mechanism of the regulation of EDNRB expression.

STUDY DESIGN

After screening, EDNRB was selected, and the expression was detected using immunohistochemistry in 33 ACC samples (including 6 clinical tumor stage 1 [T1] patients, 13 T2 patients, 9 T3 patients, and 5 T4 patients) and 20 adjacent glands. Interaction between the EDNRB promoter region and histone H3 lysine 9 trimethylation (H3K9me3) was examined using chromatin immunoprecipitation (ChIP) in combination with ChIP-polymerase chain reaction (ChIP-PCR). EDNRB expression in ACC cells treated with chaetocin was detected using quantitative real-time PCR (qRT-PCR) and Western blot tests.

RESULTS

EDNRB expression was lower in ACC than that in adjacent glands (P = .006). The expression of EDNRB in patients with advanced T stage was lower than that in patients with early T stage (P = .024). The low EDNRB gene expression group had more H3K9me3 binding regions in the gene promoter (P = .003). EDNRB gene expression significantly increased in the ACC cell lines after treatment with chaetocin. Chaetocin could reduce the interaction between the EDNRB promoter and H3K9me3.

CONCLUSIONS

H3K9me3 binding to the EDNRB promoter region could reduce the EDNRB expression. Low EDNRB expression played a role in the progression of ACC tumors.

Laryngeal adenoid cystic carcinoma: A population-based perspective

OBJECTIVES/HYPOTHESIS

Adenoid cystic carcinoma (ACC) occurs infrequently in the larynx. Consequently, no large samples describing its clinical behavior are available in the literature. Our objective was to use a nationally representative population-based resource to evaluate clinical behavior, patient demographics, and outcomes among patients diagnosed with laryngeal ACC (LACC).

STUDY DESIGN

Retrospective database analysis.

METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results database was analyzed for patients diagnosed with LACC between 1973 and 2011. Patient demographics, incidence, treatment, and survival between LACC and other laryngeal malignancies were compared.

RESULTS

Of 69 LACC patients, 63.8% were female, 78.2% Caucasian, and the median age was 54 years. LACC patients were much more likely to have subglottic lesions (44.9%) than individuals with other malignancies (1.6%). The incidence of LACC was 0.005/100,000 individuals. The majority of patients with LACC harbored T4 lesions at initial diagnosis, although 87.9% had N0 disease, and only 6.1% had distant metastasis at diagnosis. Disease-specific survival (DSS) was greater at 1 year for LACC compared to other laryngeal malignancies, but not at 5 or 10 years. Five-year DSS was greater for LACC patients who underwent surgery versus those who did not undergo surgery.

CONCLUSIONS

This analysis notes that LACC has a low incidence with no significant change in incidence over the study period. Compared to other laryngeal malignancies, LACC has a female preponderance, is much more common in the subglottis, presents at a younger age, and more often presents with T4 disease. Surgery was noted to confer a survival advantage in LACC.

LEVEL OF EVIDENCE

4.

The MicroRNA-217 Functions as a Potential Tumor Suppressor in Gastric Cancer by Targeting GPC5

Gastric cancer (GC) is one of the most common malignancies worldwide. Emerging evidence has shown that aberrant expression of microRNAs (miRNAs) plays important roles in cancer progression. However, little is known about the potential role of miR-217 in GC. In this study, we investigated the role of miR-217 on GC cell proliferation and invasion. The expression of miR-217 was down-regulated in GC cells and human GC tissues. Enforced expression of miR-217 inhibited GC cells proliferation and invasion. Moreover, Glypican-5 (GPC5), a new ocncogene, was identified as the potential target of miR-217. In addition, overexpression of miR-217 impaired GPC5-induced promotion of proliferation and invasion in GC cells. In conclusion, these findings revealed that miR-217 functioned as a tumor suppressor and inhibited the proliferation and invasion of GC cells by targeting GPC5, which might consequently serve as a therapeutic target for GC patients.

Transcriptional Dynamics of Immortalized Human Mesenchymal Stem Cells during Transformation

Comprehensive analysis of alterations in gene expression along with neoplastic transformation in human cells provides valuable information about the molecular mechanisms underlying transformation. To further address these questions, we performed whole transcriptome analysis to the human mesenchymal stem cell line, UE6E7T-3, which was immortalized with hTERT and human papillomavirus type 16 E6/E7 genes, in association with progress of transformation in these cells. At early stages of culture, UE6E7T-3 cells preferentially lost one copy of chromosome 13, as previously described; in addition, tumor suppressor genes, DNA repair genes, and apoptosis-activating genes were overexpressed. After the loss of chromosome 13, additional aneuploidy and genetic alterations that drove progressive transformation, were observed. At this stage, the cell line expressed oncogenes as well as genes related to anti-apoptotic functions, cell-cycle progression, and chromosome instability (CIN); these pro-tumorigenic changes were concomitant with a decrease in tumor suppressor gene expression. At later stages after prolong culture, the cells exhibited chromosome translocations, acquired anchorage-independent growth and tumorigenicity in nude mice, (sarcoma) and exhibited increased expression of genes encoding growth factor and DNA repair genes, and decreased expression of adhesion genes. In particular, glypican-5 (GPC5), which encodes a cell-surface proteoglycan that might be a biomarker for sarcoma, was expressed at high levels in association with transformation. Patched (Ptc1), the cell surface receptor for hedgehog (Hh) signaling, was also significantly overexpressed and co-localized with GPC5. Knockdown of GPC5 expression decreased cell proliferation, suggesting that it plays a key role in growth in U3-DT cells (transformants derived from UE6E7T-3 cells) through the Hh signaling pathway. Thus, the UE6E7T-3 cell culture model is a useful tool for assessing the functional contribution of genes showed by expression profiling to the neoplastic transformation of human fibroblasts and human mesenchymal stem cells (hMSC).