Prosaposin is a biomarker of mesenchymal glioblastoma and regulates mesenchymal transition through the TGF-β1/Smad signaling pathway

Mesenchymal glioblastoma (GBM) is the most aggressive subtype of GBM. Our previous study found that neurotrophic factor prosaposin (PSAP) is highly expressed and secreted in glioma and can promote the growth of glioma. The role of PSAP in mesenchymal GBM is still unclear. In this study, bioinformatic analysis, western blotting and RT-qPCR were used to detect the expression of PSAP in different GBM subtypes. Human glioma cell lines and patient-derived glioma stem cells were studied in vitro and in vivo, revealing that mesenchymal GBM expressed and secreted the highest level of PSAP among four subtypes of GBM, and PSAP could promote GBM invasion and epithelial–mesenchymal transition (EMT)-like processes in vivo and in vitro. Bioinformatic analysis and western blotting showed that PSAP mainly played a regulatory role in GBM invasion and EMT-like processes via the TGF-β1/Smad signaling pathway. In conclusion, the overexpression and secretion of PSAP may be an important factor causing the high invasiveness of mesenchymal GBM. PSAP is therefore a potential target for the treatment of mesenchymal GBM. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd     

Knockdown of long noncoding RNA SPRY4-IT1 suppresses glioma cell proliferation,metastasis and epithelial-mesenchymal transition

Long noncoding RNAs (lncRNAs), a class of ribonucleic molecules, participate in various cellular processes. They are highly expressed in several types of cancer and their expression was related to pathophysiological characteristics of tumor growth, therefore, they can be considered as a promising diagnostic tool and a convenient prognostic biomarker. SPRY4-IT1, belonging to a group of intron-retained lncRNAs, was reported to affect tumor development of many types of cancer. However, the expression and the role of SPRY4-IT1 in glioma are still unclear. Therefore, in this study, we examined for the first time the expression and role of SPRY4-IT1 in glioma cells. The results of our study showed that SPRY4-IT1 was up-regulated in human glioma tissues and cell lines. Knockdown of SPRY4-IT1 could inhibit glioma cell growth and migration. Moreover, knockdown of SPRY4-IT1 could inhibit epithelial-mesenchymal transition (EMT) phenotype in glioma cells. Based on these findings, SPRY4-IT1 may be used as a new target for diagnosis and treatment of glioma.     

Inhibitor of differentiation 4 drives brain tumor-initiating cell genesis through cyclin E and notch signaling

Cellular origins and genetic factors governing the genesis and maintenance of glioblastomas (GBM) are not well understood. Here, we report a pathogenetic role of the developmental regulator Id4 (inhibitor of differentiation 4) in GBM. In primary murine Ink4a/Arf(-/-) astrocytes, and human glioma cells, we provide evidence that enforced Id4 can drive malignant transformation by stimulating increased cyclin E to produce a hyperproliferative profile and by increased Jagged1 expression with Notch1 activation to drive astrocytes into a neural stem-like cell state. Thus, Id4 plays an integral role in the transformation of astrocytes via its combined actions on two-key cell cycle and differentiation regulatory molecules.     

Role of myeloid cells in the immunosuppressive microenvironment in gliomas

Glioma is the most common primary brain cancer, and half of patients present a diagnosis of glioblastoma (GBM), its most aggressive and lethal form. Conventional therapies, including surgery, radiotherapy, and chemotherapy, have not resulted in major ameliorations in GBM survival outcome, which remains extremely poor. Recent immunotherapy improvements for other tumors, coupled with growing knowledge of the complex interactions between malignant glioma cells and the immune system, led to an exponential increase in glioma immunotherapy research. However, immunotherapeutic strategies in GBM have not yet reached their full potential, mainly due to the limited understanding of the strong immunosuppressive microenvironment (TME) characterizing this tumor. Glioma-associated macrophages and microglia (GAMs) are key drivers of the local immunosuppression promoting tumor progression and its resistance to immunomodulating therapeutic strategies. Together with other myeloid cells, such as dendritic cells and neutrophils, GAMs actively shape glioma TME, modulate anti-tumoral immune response and support angiogenesis, tumor cell invasion and proliferation. In this review, we discuss the role of myeloid cells in the complex TME of glioma and the available clinical data on therapeutic strategies focusing on approaches that affect myeloid cells activity in GBM.     

miR-204 inhibits invasion and epithelial-mesenchymal transition by targeting FOXM1 in esophageal cancer

MicroRNAs (miRNAs), endogenous noncoding small RNAs, have been reported to play crucial roles in epithelial-mesenchymal transition (EMT) in cancers. Deregulation of microRNA-204 (miR-204) has been documented in many cancers, but its role in the development of esophageal cancer (EC) has not been studied. Here, we reported the role of miR-204 in invasion and EMT in EC. We identified an inverse correlation between miR-204 expression level and the invasion and EMT phenotype of EC cells, and up-regulation of miR-204 inhibited invasion and EMT phenotype of EC cells. Furthermore, we showed that forkhead box protein M1 (FOXM1) was a direct target gene of miR-204, and miR-204 regulated invasion and EMT in EC by acting directly on the 3’UTR of FOXM1 mRNA and suppressing its protein expression. We also explored the anti-tumor effect of miR-204, and found that overexpression of miR-204 suppressed the growth of esophageal tumors in vivo. These findings suggest that miR-204 might be a suppressor of invasion and EMT in EC, which offers a novel potential therapeutic target for EC.     

Cripto‐1 Expression in Glioblastoma Multiforme

Human glioblastoma multiforme (GBM) is an aggressive cancer with a very poor prognosis. Cripto‐1 (CR‐1) has a key regulatory role in embryogenesis, while in adult tissue re‐expression of CR‐1 has been correlated to malignant progression in solid cancers of non‐neuronal origin. As CR‐1 expression has yet to be described in cerebral cancer and CR‐1 is regulated by signaling pathways dysregulated in GBM, we aimed to investigate CR‐1 in the context of expression in GBM. The study was performed using enzyme‐linked immunosorbent assay (ELISA), Western blotting, polymerase chain reaction (PCR) and immunohistochemistry to analyze the blood and tissue from 28 GBM and 4 low‐grade glioma patients. Within the patient cohort, we found high CR‐1 protein levels in blood plasma to significantly correlate with a shorter overall survival. We identified CR‐1 in different areas of GBM tissue, including perivascular tumor cells, and in endothelial cells. Collectively, our data suggest that CR‐1 could be a prognostic biomarker for GBM with the potential of being a therapeutic target.     

High-throughput microRNAome analysis in human germ cell tumours

Testicular germ cell tumours (GCTs) of adolescents and adults can be subdivided into seminomas (referred to as dysgerminomas of the ovary) and non-seminomas, all referred to as type II GCTs. They originate from carcinoma in situ (CIS), being the malignant counterparts of primordial germ cells (PGCs)/gonocytes. The invasive components mimic embryogenesis, including the stem cell component embryonal carcinoma (EC), the somatic lineage teratoma (TE), and the extra-embryonic tissues yolk sac tumour (YST) and choriocarcinoma (CH). The other type is the so-called spermatocytic seminomas (SS, type III GCT), composed of neoplastic primary spermatocytes. We reported previously that the miRNAs hsa-miR 371-373 cluster is involved in overruling cellular senescence induced by oncogenic stress, allowing cells to become malignant. Here we report the first high-throughput screen of 156 microRNAs in a series of type II and III GCTs (n = 69, in duplicate) using a quantitative PCR-based approach. After normalization to allow inter-sample analysis, the technical replicates clustered together, and the previous hsa-miRNA 371-373 cluster finding was confirmed. Unsupervised cluster analysis demonstrated that the cell lines are different from the in vivo samples. The in vivo samples, both normal and malignant, clustered predominantly based on their maturation status. This parallels normal embryogenesis, rather than chromosomal anomalies in the tumours. miRNAs within a single cluster showed a similar expression pattern, implying common regulatory mechanisms. Normal testicular tissue expressed most discriminating miRNAs at a higher level than SE and SS. Moreover, differentiated non-seminomas showed overexpression of discriminating miRNAs. These results support the model that miRNAs are involved in regulating differentiation of stem cells, retained in GCTs.     

Knockdown of LncRNA SNHG7 inhibited epithelial-mesenchymal transition in prostate cancer though miR-324-3p/WNT2B axis in vitro

It is identified that long non-coding RNAs (lncRNAs) play important roles in cancer progression and metastasis. LncRNA SNHG7 was reported to play an oncogenic role in the progression of cancers including prostate cancer. However, its potential regulatory mechanism of endothelial-mesenchymal transition in PCa remains unclear. In this study, We found a lncRNA SNHG7 was overexpressed in PCa cell lines and tissues. LncRNA SNHG7 promotes prostate cancer migration and invasion by modulating EMT. Further study indicated that lncRNA SNHG7 acts as a sponge for miRNA-324-3p and positively regulates WNT2B by a sponge effect. Moreover, We confirmed that WNT2B, an important protein in the Wnt signal pathway, promotes the malignant phenotype of PCa cells and mediated the biological effects exerted by lncRNA SNHG7. Overall, our study suggested that lncRNA SNHG7 could promote PCa EMT via miR-324-3p and WNT2B in vitro. The lncRNA SNHG7/miR-324-3p /WNT2B axis regulatory network might provide a potential new therapeutic strategy for PCa treatment.     

构建编码基因-非编码RNA调控网络挖掘前列腺癌潜在致病因子

目的 基于前列腺癌的编码基因-非编码RNA调控网络识别潜在的生物标记物.方法 利用前列腺癌的lncRNA、miRNA和mRNA表达谱数据及它们与转录因子之间的靶向关系,构建编码基因-非编码RNA三维调控网络,挖掘ceRNA子网,识别潜在竞争性的lncRNA并筛选前列腺癌潜在的致病因子.结果 从ceRNA子网中识别出4个lncRNA竞争性的结合了5个miRNA间接调控了63个基因的表达,功能预测这些lncRNA参与了激素调节;基于网络拓扑属性,挖掘出一个包含了16个lncRNAs、2个miRNAs、4个mRNAs的生物标记物.结论 多种调控因子如TF、lncRNA、miRNA、mRNA共同作用影响前列腺癌的发生发展,其中有些lncRNA作为ceRNA来发挥基因表达调控的作用.     

Long non-coding RNAs as potential biomarkers and therapeutic targets for gliomas

Gliomas are the most malignant and common primary brain tumors, accounting for 50–60%. Despite all surgical efforts in combination with intense chemoradiotherapy, gliomas still have a dismal prognosis. The early screening and identification of patients with gliomas could improve their prognosis by allowing proactive medical treatment. Traditionally, gliomas of varying subtypes and grades are diagnosed based on histopathological features, but this can be challenging, particularly in cases that lack the typical features. Molecular expression profiles using microarray analyses have provided additional information to help distinguish between glioma subtypes, which correlate well with histological profiles. Various molecular biomarkers and therapeutic targets for gliomas are currently available, including genes and miRNAs, but all remain in preclinical studies. Certain specific lncRNAs involved in gliomas have been identified in surgical brain biopsies, which may be involved in brain development and the pathogenesis of gliomas; these can also be detected in peripheral blood. Therefore, we postulate that these specific lncRNAs may be both potential biomarkers and therapeutic targets for gliomas.     

Raddeanin A inhibited epithelial-mesenchymal transition (EMT) and angiogenesis in glioblastoma by downregulating β-catenin expression

Raddeanin A (RA), an oleanane-type triterpenoid saponin derived from Anemone raddeana Regel, has been found to suppress the viability and metastasis of several cancers, including GBM, through various signaling pathways. However, the mechanisms underlying the anti-GBM properties of RA have not been fully elucidated. Epithelial to mesenchymal transition (EMT) and angiogenesis are important for the genesis and progression of GBM. These two crucial processes can be regulated by multiple molecular, including β-catenin, which has been demonstrated to act as a pro-tumorigenic molecular. In this study, we aimed to determine whether RA could suppress EMT and angiogenesis by inhibiting the action of β-catenin in GBM. We found that RA inhibited the proliferation, invasion and migratory properties of GBM cells. RA was also found to have downregulated the expressions of β-catenin and EMT-related biomarkers (N-cadherin, vimentin, and snail). In addition, the overexpression of β-catenin reversed the therapeutic effects of RA exerted on the EMT of GBM cells. RA restricted angiogenesis, as shown by the tube formation assay and CAM assay, while it downregulated VEGF levels in HUVECs. Moreover, massive β-catenin could reverse the suppression of angiogenesis induced by RA. Finally, we demonstrated that RA inhibited tumor growth and prolonged survival time in an intracranial U87 xenograft mouse model. Similar to the results in vitro, RA downregulated the expression of β-catenin, EMT makers and VEGF, and decreased vessel density in vivo. In summary, our results demonstrated that RA repressed GBM via downregulating β-catenin-mediated EMT and angiogenesis both in vitro and in vivo.     

Inhibition of cancer stem cell-like properties and reduced chemoradioresistance of glioblastoma using microRNA145 with cationic polyurethane-short branch PEI

Glioblastomas (GBMs) are the most common primary brain tumors with poor prognosis. CD133 has been considered a putative marker of cancer stem cells (CSCs) in malignant cancers, including GBMs. MicroRNAs (miRNAs), highly conserved small RNA molecules, may target oncogenes and have potential as a therapeutic strategy against cancer. However, the role of miRNAs in GBM-associated CSCs remains mostly unclear. In this study, our miRNA/mRNA-microarray and RT-PCR analysis showed that the expression of miR145 (a tumor-suppressive miRNA) is inversely correlated with the levels of Oct4 and Sox2 in GBM-CD133⁺ cells and malignant glioma specimens. We demonstrated that miR145 negatively regulates GBM tumorigenesis by targeting Oct4 and Sox2 in GBM-CD133⁺. Using polyurethane-short branch polyethylenimine (PU-PEI) as a therapeutic-delivery vehicle, PU-PEI-mediated miR145 delivery to GBM-CD133⁺ significantly inhibited their tumorigenic and CSC-like abilities and facilitated their differentiation into CD133⁻-non-CSCs. Furthermore, PU-PEI-miR145-treated GBM-CD133⁺ effectively suppressed the expression of drug-resistance and anti-apoptotic genes and increased the sensitivity of the cells to radiation and temozolomide. Finally, the in vivo delivery of PU-PEI-miR145 alone significantly suppressed tumorigenesis with stemness, and synergistically improved the survival rate when used in combination with radiotherapy and temozolomide in orthotopic GBM-CD133⁺-transplanted immunocompromised mice. Therefore, PU-PEI-miR145 is a novel therapeutic approach for malignant brain tumors.     

Thymidylate synthase is functionally associated with ZEB1 and contributes to the epithelial‐to‐mesenchymal transition of cancer cells

Thymidylate synthase (TS) is a fundamental enzyme of nucleotide metabolism and one of the oldest anti‐cancer targets. Beginning from the analysis of gene array data from the NCI‐60 panel of cancer cell lines, we identified a significant correlation at both gene and protein level between TS and the markers of epithelial‐to‐mesenchymal transition (EMT), a developmental process that allows cancer cells to acquire features of aggressiveness, like motility and chemoresistance. TS levels were found to be significantly augmented in mesenchymal‐like compared to epithelial‐like cancer cells, to be regulated by EMT induction, and to negatively correlate with micro‐RNAs (miRNAs) usually expressed in epithelial‐like cells and known to actively suppress EMT. Transfection of EMT‐suppressing miRNAs reduced TS levels, and a specific role for miR‐375 in targeting the TS 3'‐untranslated region was identified. A particularly relevant association was found between TS and the powerful EMT driver ZEB1, the shRNA‐mediated knockdown of which up‐regulated miR‐375 and reduced TS cellular levels. The TS–ZEB1 association was confirmed in clinical specimens from lung tumours and in a genetic mouse model of pancreatic cancer with ZEB1 deletion. Interestingly, TS itself appeared to have a regulatory role in EMT in cancer cells, as TS knockdown could directly reduce the EMT phenotype, the migratory ability of cells, the expression of stem‐like markers, and chemoresistance. Taken together, these data indicate that the TS enzyme is functionally linked with EMT and cancer differentiation, with several potential translational implications. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

胶质母细胞瘤和胶质瘤干细胞

胶质母细胞瘤（GBM）是一种高度恶性、浸润性、异质性和致命性的脑肿瘤,虽然其治疗方法不断改进,但GBM患者的预后依然很差。近年来,肿瘤干细胞学说的提出为肿瘤的产生和治疗提供了新的思路。自脑肿瘤中分离出一群具有自我更新、增殖和神经分化等干细胞特性的肿瘤细胞以来,这群肿瘤干细胞使得GBM的研究也越来越广泛和深入。本文就GBM和胶质瘤干细胞的最新相关进展进行综述。     

Synergistic effect of TRAIL and irradiation in elimination of glioblastoma stem-like cells

Glioblastoma multiforme (GBM) is the most common malignancy in central nervous system. A small subpopulation of GBM cells known as GBM stem-like cells (GSLCs) were supposed to be the most malignant cells among GBM cells as they are resistant to multiple therapies including radiotherapy. In this study, we set up two GSLCs cell lines from the two parental U87 and U251 glioma cell lines, and studied the expression of apoptosis-related genes alteration in GSLCs before and after irradiation. We found that one of the receptors of TNF-related apoptosis-inducing ligand (TRAIL), DR5, was dramatically up-regulated in GSLCs after irradiation (IR). Although GSLCs are resistant to both TRAIL and radiation treatment alone, the combined treatment with TRAIL and irradiation achieved maximum killing effect of GSLCs due to inducing the expression of DR5 and inhibiting the expression of cFLIP. Therefore, TRAIL and IR combined treatment would be a simple but practical therapeutic strategy for clinical application.