SEC61G assists EGFR-amplified glioblastoma to evade immune elimination.

Amplification of chromosome 7p11 (7p11) is the most common alteration in primary glioblastoma (GBM), resulting in gains of epidermal growth factor receptor (EGFR) copy number in 50 to 60% of GBM tumors. However, treatment strategies targeting EGFR have thus far failed in clinical trials, and the underlying mechanism remains largely unclear. We here demonstrate that EGFR amplification at the 7p11 locus frequently encompasses its neighboring genes and identifies SEC61G as a critical regulator facilitating GBM immune evasion and tumor growth. We found that SEC61G is always coamplified with EGFR and is highly expressed in GBM. As an essential subunit of the SEC61 translocon complex, SEC61G promotes translocation of newly translated immune checkpoint ligands (ICLs, including PD-L1, PVR, and PD-L2) into the endoplasmic reticulum and promotes their glycosylation, stabilization, and membrane presentation. Depletion of SEC61G promotes the infiltration and cytolytic activity of CD8+ T cells and thus inhibits GBM occurrence. Further, SEC61G inhibition augments the therapeutic efficiency of EGFR tyrosine kinase inhibitors in mice. Our study demonstrates a critical role of SEC61G in GBM immune evasion, which provides a compelling rationale for combination therapy of EGFR-amplified GBMs.

MiR-744 Functions as an Oncogene Through Direct Binding to c-Fos Promoter and Facilitates Non-small Cell Lung Cancer Progression.

Metastasis is the leading cause of death in non-small cell lung cancer (NSCLC) patients. Previously, we reported that miR-744 exerted proto-oncogenic function in nasopharyngeal carcinoma, but the role of miR-744 during NSCLC development has not been established. We focused on the function and molecular mechanism of miR-744 in NSCLC. The clinical cohort data from TCGA were analyzed for the correlation of miR-744 and outcomes in NSCLC patients. Gain- and loss-of-function experiment was performed by transfection with miR-744 agomir or antagomir in NSCLC cell lines. The expression of mRNA and protein were analyzed by qPCR assays and Western blotting respectively. Cellular proliferation, migration, and invasion were analyzed by CCK8 assays, wound healing, and transwell assays, respectively. Promoter activities and gene transcription were analyzed by luciferase reporter assays. Xenograft model was applied for in vivo study. High miR-744 expression correlated with lymph node metastasis and poor prognosis in NSCLC patient. MiR-744 aggravated the growth, invasion, and metastasis of NSCLC cells eventually induced the malignant phenotype and promotes radio/chemoresistance in vitro. The -1195 to -1227 and -298 to -323 bp upstream of c-FOS gene was observed to bind with miR-744. Lastly, miR-744 acted as a tumor promoter in lung cancer growth and metastasis in vivo. Taken together, our results indicated that miR-744 up-regulated c-Fos by binding with its promoter contributed to development of NSCLC cells malignant phenotype. Our findings highlight the potential value of miR-744, which may serve as a possible therapeutic target for NSCLC.

Induction of H2AX phosphorylation in tumor cells by gossypol acetic acid is mediated by phosphatidylinositol 3-kinase (PI3K) family.

BACKGROUND: H2AX is phosphorylated (γH2AX) by members of the phosphatidylinositol 3-kinase (PI3K) family, including Ataxia telangiectasia-mutated (ATM), ATM- and Rad3-related (ATR) and DNA-PK in response to DNA damage. Our study shows that gossypol acetic acid (GAA) alone can induce γH2AX in Human mucoepidermoid carcinoma cell line (MEC-1) in vitro. Thus, we further examined the possible mechanisms of GAA to induce γH2AX in tumor cells. MATERIALS AND METHODS: The PI3K inhibitors caffeine and wortmannin were used in an effort to identify the kinase(s) responsible for GAA -induced γH2AX in MEC-1 cells. DNA dependent protein kinase (DNA-PK) - proficient and -deficient cells, human glioma cell lines M059K and M059J, were also used to evaluate the kinases responsible for GAA induced H2AX phosphorylation. γH2AX expression was detected by immunofluorescent microscopy. Flow cytometry assay was used to assay γH2AX and cell cycle. RESULTS: GAA induced H2AX phosphorylation in a cell cycle-dependent manner and a significant G0/G1 phase arrest in MEC-1 cells was shown. Caffeine and wortmannin significantly inhibited GAA-induced H2AX phosphorylation in MEC-1 cells. GAA induced H2AX phosphorylation in M059K, but not in M059J. Taken together, these data suggested that GAA treatment alone could induce H2AX phosphorylation in a cell cycle dependent manner in MEC-1 and M059K, but not in M059J cells. A significant G0/G1 phase arrest was shown in MEC-1. CONCLUSIONS: The member of PI3K family, DNA-PK, ATM and ATR are involved in the H2AX phosphorylation of MEC-1 cells.

Targeting the HSP47-collagen axis inhibits brain metastasis by reversing M2 microglial polarization and restoring anti-tumor immunity.

Brain metastases (BrMs) are the leading cause of death in patients with solid cancers. BrMs exhibit a highly immunosuppressive milieu and poor response to immunotherapies; however, the underlying mechanism remains largely unclear. Here, we show that upregulation of HSP47 in tumor cells drives metastatic colonization and outgrowth in the brain by creating an immunosuppressive microenvironment. HSP47-mediated collagen deposition in the metastatic niche promotes microglial polarization to the M2 phenotype via the α2ß1 integrin/nuclear factor κB pathway, which upregulates the anti-inflammatory cytokines and represses CD8+ T cell anti-tumor responses. Depletion of microglia reverses HSP47-induced inactivation of CD8+ T cells and abolishes BrM. Col003, an inhibitor disrupting HSP47-collagen association restores an anti-tumor immunity and enhances the efficacy of anti-PD-L1 immunotherapy in BrM-bearing mice. Our study supports that HSP47 is a critical determinant of M2 microglial polarization and immunosuppression and that blocking the HSP47-collagen axis represents a promising therapeutic strategy against brain metastatic tumors.

FBXO7 Confers Mesenchymal Properties and Chemoresistance in Glioblastoma by Controlling Rbfox2-Mediated Alternative Splicing.

Mesenchymal glioblastoma (GBM) is highly resistant to radio-and chemotherapy and correlates with worse survival outcomes in GBM patients; however, the underlying mechanism determining the mesenchymal phenotype remains largely unclear. Herein, it is revealed that FBXO7, a substrate-recognition component of the SCF complex implicated in the pathogenesis of Parkinson's disease, confers mesenchymal properties and chemoresistance in GBM by controlling Rbfox2-mediated alternative splicing. Specifically, FBXO7 ubiquitinates Rbfox2 Lys249 through K63-linked ubiquitin chains upon arginine dimethylation at Arg341 and Arg441 by PRMT5, leading to Rbfox2 stabilization. FBXO7 controls Rbfox2-mediated splicing of mesenchymal genes, including FoxM1, Mta1, and Postn. FBXO7-induced exon Va inclusion of FoxM1 promotes FoxM1 phosphorylation by MEK1 and nuclear translocation, thereby upregulates CD44, CD9, and ID1 levels, resulting in GBM stem cell self-renewal and mesenchymal transformation. Moreover, FBXO7 is stabilized by temozolomide, and FBXO7 depletion sensitizes tumor xenografts in mice to chemotherapy. The findings demonstrate that the FBXO7-Rbfox2 axis-mediated splicing contributes to mesenchymal transformation and tumorigenesis, and targeting FBXO7 represents a potential strategy for GBM treatment.

Changes in T Lymphocyte Subsets in Different Tumors Before and After Radiotherapy: A Meta-analysis.

Purpose: Radiation therapy (RT) induces an immune response, but the relationship of this response with tumor type is not fully understood. This meta-analysis further elucidated this relationship by analyzing the changes in T lymphocyte subsets in different tumors before and after radiotherapy. Methods: We searched English-language electronic databases including PubMed, EMBASE, and the Cochrane Library to collect studies on the changes in peripheral blood CD3+ T lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes before and after radiotherapy in tumor patients from January 2015 to April 2021. The quality of the included literature was evaluated using the NOS scale provided by the Cochrane Collaboration, and statistical software RevMan 5.4 was used to analyze the included literature. P<0.05 was considered to indicate statistical significance. Results: A total of 19 studies in 16 articles involving 877 tumor patients were included. All data were collected within 1 month before or after radiotherapy. Meta-analysis showed that numbers of CD3+ T lymphocytes (SMD: -0.40; 95% CI [-0.75, -0.04]; p = 0.03) and CD4+ T lymphocytes (SMD: -0.43; 95% CI: [-0.85, -0.02]; p = 0.04) were significantly reduced after radiotherapy compared with before treatment, but there was no statistically significant difference for CD8+ T lymphocytes (SMD: 0.33; 95% CI: [-0.88, 0.74]; p = 0.12). Subgroup analysis showed that peripheral blood T lymphocytes decreased in head and neck cancer. However, in prostate cancer and breast cancer, there was no significant change in peripheral blood. 1 month after radiotherapy, it has a potential proliferation and activation effect on lymphocytes in esophageal cancer and lung cancer. The results showed that CD8+T lymphocytes increased in peripheral blood after SBRT. Radiotherapy alone reduced CD3+ T lymphocyte numbers. Conclusions: Within 1 month of radiotherapy, patients have obvious immunological changes, which can cause apoptosis and reduction of T lymphocytes, and affect the balance of peripheral blood immune cells. The degree of immune response induced by radiotherapy differed between tumor types.

Circulating miRNAs in Serum as Biomarkers for Early Diagnosis of Non-small Cell Lung Cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) accounts for about 85% of lung cancers. This study aimed to discover the potential miRNA biomarkers for early detection of NSCLC. METHODS: Total circulating miRNAs were extracted from six patients and six volunteers and run on the miRNA chip. The differentially expressed miRNAs acquired by data mining were intersected with chip results, and qRT-PCR were carried out. Then the differentially miRNAs were validated by using a validation cohort (120 participants). ROC curves were established to evaluate the diagnostic efficacy of the differentially circulating miRNAs. The target genes of the differential miRNAs were identified using the miRTarBase database, and follow-up GO and KEGG enrichment analysis were conducted. RESULTS: We identified 577 miRNA which screened according to the criteria (fold change > 2 and p value < 0.05). Among them, seven circulating miRNAs passed additional filtering based on data mining. These miRNAs were further validated in the training and validation cohort. miR-492, miR-590-3p, and miR-631 were differentially expressed in the patients' serum, and the area under the ROC curve (AUC) values of these miRNAs were 0.789, 0.792, and 0.711, respectively. When using them as a combination to discriminate healthy volunteers from patients, the AUC reached 0.828 (95% CI, 0.750-0.905, p = 0.000) with a sensitivity of 86.7% and specificity of 71.7%. The follow-up enrichment analysis showed that target genes of three miRNA were associated with tumorigenesis and progression, such as cell cycle and P53 signaling pathway. CONCLUSIONS: The combination of miR-492, miR-590-3p, and miR-631 can be utilized to distinguish healthy individuals and early-stage NSCLC patients. IMPACT: The combination of miR-492, miR-590-3p, and miR-631 might be a promising serum biomarker in patients for the early diagnosis of NSCLC.

Construction of Radiation Surviving/Resistant Lung Cancer Cell Lines with Equidifferent Gradient Dose Irradiation.

Radiotherapy plays an increasingly crucial role in the treatment of non-small cell lung cancer (NSCLC). Local tumor recurrence and tumor progression caused by intratumoral heterogeneity induced radiotherapy resistance remain the primary causes of radiotherapy failure. However, the lack of a suitable cell line model has hampered the exploration of the dynamic mechanisms of radiation resistance. We established 3 groups of equidifferent gradient dose irradiation surviving/resistant human lung cancer cell lines based on A549, H520, and H460 cells with clinical conventional fractionated radiotherapy (CFRT) (2 Gy × 20 F, 2 Gy × 30 F, and 2 Gy × 40 F). The radiosensitivity of the cells was detected by clone formation assay, EDU cell proliferation assay, neutral comet assay, and γ-H2AX immunofluorescence staining. The radiosensitivity and proliferation viability were increased in a received dose-dependent manner. Compared with parental cells, DNA double-strand breaks (DSBs) in cell lines that received higher-dose irradiation were significantly reduced. We successfully constructed equidifferent gradient dose irradiation surviving/resistant NSCLC cell lines whose radiation surviving and resistant abilities were increased in a received dose-dependent manner. This preclinical cell model could be used to dynamically observe and detect the radiation surviving/resistant biomarkers during radiotherapy stress, elucidate the mechanism of radiation resistance.

Prognostic factors of oligometastatic non-small cell lung cancer: a meta-analysis.

BACKGROUND: The prognostic factors of oligometastatic non-small cell lung cancer (NSCLC) are uncertain. We performed a meta-analysis to assess the prognostic factors of oligometastatic NSCLC patients who are most likely to achieve long-term survival. METHODS: We searched PubMed, EMBASE, the Cochrane to identify eligible articles and performed the meta-analysis of all randomized controlled trials (RCTs) and retrospective comparative studies revealing the prognostic factors of oligometastatic NSCLC. The primary endpoint of interest was overall survival (OS). RESULTS: We analyzed data from twenty-four eligible studies, including data from 1,935 patients with oligometastatic NSCLC. In the univariate analysis, we found no significant difference in OS of prognostic factors including age [hazard ratios (HRs) 1.02, 95% CI: 0.80-1.31, P=0.86], smoking status (HR 1.08, 95% CI: 0.80-1.46, P=0.62), type of metastases (HR 1.61, 95% CI: 0.86-3.03, P=0.14), but significantly positive prognoses containing female (HR 1.21, 95% CI: 1.02-1.45, P=0.03), (y)pN0 stage (HR 1.82, 95% CI: 1.40-2.36, P<0.00001), adenocarcinoma (HR 1.44, 95% CI: 1.10-1.88, P=0.008). In the multivariate analysis, patients with (y)pN0 stage had an obvious survival benefit compared with (y)pN1 (HR 1.63, 95% CI: 1.27-2.10, P=0.001), but no significant survival in contrast with (y)pN2 (HR 2.01, 95% CI: 0.80-5.03, P=0.14). In subgroup analyses, neither thoracic stage (HR 2.06, 95% CI: 1.52-2.78, P=0.55), (y)pT-stage of primary lung cancer (HR 1.38, 95% CI: 0.86-2.21, P=0.14) nor tumorous histology (HR 2.99, 95% CI: 2.10-4.28, P=0.91) and oligometastatic number (HR 1.25, 95% CI: 0.97-1.62, P=0.98) were significantly different in OS. However, patients with aggressive thoracic treatment (ATT) had improved survival (HR 0.56, 95% CI: 0.37-0.83, P=0.001), and notably, different strategies of ATT received by oligometastatic NSCLC patients might significantly influence survival (HR 0.54, 95% CI: 0.36-0.82, P<0.00001). CONCLUSIONS: Overall, factors including age, smoking status, type of metastasis were not associated with long-term survival of oligometastatic NSCLC patients. However, our finding suggests that aggressive therapies in the primary lung cancer, as well as female, (y)pT-stage, absence of nodal diseases, adenocarcinoma histology have been clarified as positive prognosis. Further studies of prospective study for these patients are warranted.

Expression of the γ-phosphorylated histone H2AX in gastric carcinoma and gastric precancerous lesions.

The histone γH2AX is a marker of activated DNA damage that is overexpressed in various cancers and corresponding precursor lesions, indicating that γH2AX is a component in oncogenic transformation. The present study aimed to determine whether the immunohistochemical expression of γH2AX is involved in the progression between superficial gastritis (n=20), atrophic gastritis (n=24) and gastric carcinoma (n=79). There was no increase in γH2AX expression between superficial and atrophic gastritis, but there was a significant increase in γH2AX expression between these two conditions and gastric carcinoma (χ2=68.712; P<0.001). The expression of γH2AX in moderately-differentiated gastric adenocarcinoma (n=49) was evidently higher compared with poorly-differentiated gastric adenocarcinoma (n=26; χ2=14.241; P<0.01). Staining for γH2AX did not reveal a significant association between the expression of the histone and patient age, depth of invasion, lymph node metastasis or the tumor-node-metastasis stage of the gastric carcinoma. Overall, the present study demonstrated that enhanced γH2AX expression may be closely associated with gastric carcinoma, but is less likely to be involved in the genesis of gastric carcinoma.