Luyan Mu

Tumor Associated with CD70 Expression is Involved in Promoting Tumor Migration and Macrophage Infiltration in GBM

Tumor migration/metastasis and immunosuppression are major obstacles in effective cancer therapy. Incidentally, these 2 hurdles usually coexist inside tumors, therefore making therapy significantly more complicated, as both oncogenic mechanisms must be addressed for successful therapeutic intervention. Our recent report highlights that the tumor expression of a TNF family member, CD70, is correlated with poor survival for primary gliomas. In this study, we investigated how CD70 expression by GBM affects the characteristics of tumor cells and the tumor microenvironment. We found that the ablation of CD70 in primary GBM decreased CD44 and SOX2 gene expression, and inhibited tumor migration, growth and the ability to attract monocyte‐derived M2 macrophages in vitro. In the tumor microenvironment, CD70 was associated with immune cell infiltrates, such as T cells; myeloid‐derived suppressor cells; and monocytes/macrophages based on the RNA‐sequencing profile. The CD163+ macrophages were far more abundant than T cells were. This overwhelming level of macrophages was identified only in GBM and not in low‐grade gliomas and normal brain specimens, implying their tumor association. CD70 was detected only on tumor cells, not on macrophages, and was highly correlated with CD163 gene expression in primary GBM. Additionally, the co‐expression of the CD70 and CD163 genes was found to correlate with decreased survival for patients with primary GBM. Together, these data suggest that CD70 expression is involved in promoting tumor aggressiveness and immunosuppression via tumor‐associated macrophage recruitment/activation. Our current efforts to target this molecule using chimeric antigen receptor T cells hold great potential for treating patients with GBM.

Identifying survival-associated modules from the dysregulated triplet network in glioblastoma multiforme

BackgroundLong noncoding RNAs (lncRNAs) can act as competitive endogenous RNAs (ceRNAs) to compete with mRNAs for binding miroRNAs (miRNAs). The dysregulated triplets, composed by mRNAs, lncRNAs, and miRNAs, contributed to the development and progression of diseases, such as cancer. However, the roles played by triplet biomarkers are not fully understand in glioblastoma multiforme (GBM) patient survival.ObjectivesHere, we constructed a differential triplet interaction network (TriNet) between GBM and normal tissues and identified GBM survival related triplets.MethodsFour significantly dysregulated modules, enriched differentially expressed molecules, were identified by integrating affinity propagation method and hypergeometric method. Furthermore, knockdown of TP73-AS1 was implemented by siRNA and the expression of RFX1 was examined in U87 cells by qRT-PCR. The apoptosis of U87 cells was investigated using MTT assay and Acridine orange/Ethidium bromide (AO/EB) assay.ResultsWe randomly split GBM samples into training and testing sets, and found that these four modules can robustly and significantly distinguish low- and high-survival patients in both two sets. By manually curated literatures for triplets mediated by core interactions, we found that members involved tumor invasion, proliferation, and migration. The dysregulated triplets may cause the poor survival of GBM patients. We finally experimentally verified that knockdown of TP73-AS1, an lncRNA of one triplet, could not only reduce the expression of RFX1, an mRNA of this triplet, but also induce apoptosis in U87 cells.ConclusionsThese results can provide further insights to understand the functions of triplet biomarkers that associated with GBM prognosis.

IDH1 R132H Mutation Is Accompanied with Malignant Progression of Paired Primary-Recurrent Astrocytic Tumours.

IDH1 R132H mutation is an important marker of survival in patients with gliomas. Although there are many changes of genes in tumour malignant progression, IDH1 R132H mutation status in glioma progression remained unclear. Here, an in-depth characterization of IDH1 R132H mutations were assessed by immunohistochemistry in 55 paired primary-recurrent astrocytomas tissues, including 5 paired primary pilocytic astrocytoma (pPA, WHO grade I), 35 paired primary low grade astrocytoma (pLGA, WHO grade II and III) and 15 paired primary high grade astrocytoma (pHGA/ Glioblastoma, WHO grade IV). Meanwhile, the DNA was isolated from paired samples, and PCR amplification was used for IDH1 exon4 sequencing. Nonparametric test, KM and Cox models were used to examine the statistical difference and survival function. We found that the percent of IDH1 R132H mutation was 68.6% (24/35) in pLGA group, but no IDH1 mutation was found in pPA and pHGA groups. Meanwhile, the results from immunohistochemistry and DNA sequencing showed that, compared with primary astrocytoma, there was no change of IDH1 status in recurrent astrocytoma whatever tumour pathological grade raise or indolent. The pPA group has the longest recurrence-free period (RFP) and overall survival (OS) in three groups (p<0.01), while the pHGA group has the shortest ones (p<0.01). In pLGA group, the IDH1 R132H mutation subgroup has longer RFP than IDH1 wild type subgroup (p<0.01), but the OS has no statistical difference between two subgroups (p>0.6). Additionally, IDH1 R132H mutation independently predicted a long RFP in patients with pLGA (HR 1.073, 95% CI 0.151-0.775, p<0.01).

CD4+ and Perivascular Foxp3+ T Cells in Glioma Correlate with Angiogenesis and Tumor Progression

Background Angiogenesis and immune cell infiltration are key features of gliomas and their manipulation of the microenvironment, but their prognostic significance remains indeterminate. We evaluate the interconnection between tumor-infiltrating lymphocyte (TIL) and tumor blood-vasculatures in the context of glioma progression. Methods Paired tumor tissues of 44 patients from three tumor-recurrent groups: diffuse astrocytomas (DA) recurred as DA, DA recurred as glioblastomas (GBM), and GBM recurred as GBM were evaluated by genetic analysis, immunohistochemistry for tumor blood vessel density, TIL subsets, and clinical outcomes. These cells were geographically divided into perivascular and intratumoral TILs. Associations were examined between these TILs, CD34+ tumor blood vessels, and clinical outcomes. To determine key changes in TIL subsets, microarray data of 15-paired tumors from patients who failed antiangiogenic therapy- bevacizumab, and 16-paired tumors from chemo-naïve recurrent GBM were also evaluated and compared. Results Upon recurrence in primary gliomas, similar kinetic changes were found between tumor blood vessels and each TIL subset in all groups, but only CD4+ including Foxp3+ TILs, positively correlated with the density of tumor blood vessels. CD4 was the predominant T cell population based on the expression of gene-transcripts in primary GBMs, and increased activated CD4+ T cells were revealed in Bevacizumab-resistant recurrent tumors (not in chemo-naïve recurrent tumors). Among these TILs, 2/3 of them were found in the perivascular niche; Foxp3+ T cells in these niches not only correlated with the tumor vessels but were also an independent predictor of shortened recurrence-free survival (RFS) (HR = 4.199, 95% CI 1.522–11.584, p = 0.006). Conclusion The minimal intratumoral T cell infiltration and low detection of CD8 transcripts expression in primary GBMs can potentially limit antitumor response. CD4+ and perivascular Foxp3+ TILs associate with tumor angiogenesis and tumor progression in glioma patients. Our results suggest that combining antiangiogenic agents with immunotherapeutic approaches may help improve the antitumor efficacy for patients with malignant gliomas.