Background: Fatty acid metabolism (FAM), as a hallmark of caner, plays important roles in tumor initiation and carcinogenesis. However, the significance of fatty acid metabolism-related genes in colon adenocarcinoma (COAD) are largely unknown. Methods: RNA sequencing data and clinical information were downloaded from the Cancer Genome Atlas (TCGA) cohort. Univariate and multivariate Cox regression analyses were utilized to construct a fatty acid metabolism-related gene signature. Kaplan-Meier survival and receiver operating characteristic (ROC) analyses were used to verify the performance of this signature. GEO datasets were applied to validate the signature. Maftools package was utilized to analyze the mutation profiles of this signature. Correlation between the risk signature and stemness scores was compared by RNA stemness score (RNAss). Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene set variation analysis (GSVA) were performed to explore the potential functions and signaling pathways. Immune landscape of the signature was explored by analyzing different immune cells infiltration, immune functions and microsatellite instability. A nomogram was constructed by combining the risk signature and multiple clinical factors. Expression levels and prognostic values of the risk genes were revealed in the cancer genome atlas and GEO databases. Moreover, the expression the risk genes were measured in cell lines using real time quantitative PCR (qRT-PCR). Results: Eight fatty acid metabolism-related genes (CD36, ENO3, MORC2, PTGR1, SUCLG2, ELOVL3, ELOVL6 and CPT2) were used to construct a risk signature. This signature demonstrated better prognostic value than other clinicopathological parameters, with AUC value was 0.734 according to the cancer genome atlas database. There was negative correlation between the riskscore and RNA stemness score. The patients in the high-risk group demonstrated higher infiltration of M0 macrophages, and less infiltration of activated CD4 memory T cells and Eosinophils. There were more MSI patients in the high-risk group than those in the low-risk group (38% vs. 30%). The risk scores of patients in the MSI group were slightly higher than those in the microsatellite stability group. Gene ontology, kyoto encyclopedia of genes and genomes and gene set variation analysis enrichment analyses showed that several metabolism-related functions and signaling pathways were enriched. A nomogram showed good predictive capability of the signature. Moreover, qRT-PCR revealed upregulated expression of ENO3, MORC2, SUCLG2 and ELOVL6, and downregulated expression of CPT2 in all examined colon adenocarcinoma cell lines. Conclusion: This study provided novel insights into a fatty acid metabolism-related signature in the prognosis an immune landscape of colon adenocarcinoma patients.
Objective To explore the correlation between the change of hypoxic in microenvironment and the genesis of circulating tumor cells (CTCs) in gastric adenocarcinoma.Methods After human gastric adenocarcinomn BGC-823 cells treated with different concentration of CoCl2 (0,100,200,300,400 μmol/L)for four hours,the expression levels of hypoxia inducible factor 1 alpha (HIF-1α)were detected by Western blot to select the optimal concentration.A total of 40 BALB/c mice were divided into two equal groups,named hypoxic group and normoxic group.Optimal concentration of CoCl2 treated BGC-823 gastric cancer cells and non hypoxic induced BGC 823 gastric cancer cells were injected through the tail vein.After three days blood samples were collected through the angular vein.CTCs were enriched by density gradient centrifugation,identified with cytokeratin19 (CK19) antibody marker by cell immunofluorescence and cell number was counted.Statistical significace test were performed by analysis of variance and Dunnett-T test.Results The expression of HIF-1α reached a maximun of 1.40±-0.16 when BGC-823 cells were treated with 200 μmol/L CoCl2 for four hours.The number of CTCs in hypoxic group was higher than that of normoxic group ((4.70± 1.72)/high power field (HPF) vs (1.15±0.56)/HPF,Z=-4.824,P＜0.01).Conclusion Hypoxic microenvironment might promote the genesis of CTC in gastric adenocarcinoma.
Key words:
Hypoxia-inducible factor 1; Stomach neoplasms; Adenocarcinoma; Circulating tumor cells; Neoplasm metastasis
Lymphoma is a malignant disease of the hematopoietic system that typically affects B cells.The up-regulation of miR-148b is associated with radiosensitization in B-cell lymphoma (BCL).This study aimed to explore the role of miR-148b in regulating the radiosensitivity of BCL cells and to investigate the underlying mechanism.miR-148b directly targeted Bcl-w, decreased the cell viability and colony formation, while promoted apoptosis, in irradiated BCL cells.These changes were accompanied by decreased mitochondrial membrane potential, release of cytochrome C, increased levels of the cleaved caspase 9 and caspase 3, and increased expression of other proteins related to the mitochondrial apoptosis pathway.These effects of miR-148b were effectively inhibited by Bcl-w.In addition, miR-148b inhibited the growth of tumors in nude mice implanted with xenografts of irradiated Raji cells.In patients with BCL, levels of miR-148b were downregulated, while levels of Bcl-w were upregulated; a significant negative correlation between levels of miR-148b and Bcl-w was confirmed.Taken together, these experiments showed that miR-148b promoted radiation-induced apoptosis in BCL cells by targeting anti-apoptotic Bcl-w.miR-148b might be used as a marker to predict the radiosensitivity of BCL.
e14572 Background: Mammography screening for breast cancer results in large number of impalpable lesions without clear determination of the malignancy. Analysis of breast cancer related gene mutations in blood circulating tumor DNA (ctDNA) may provide clarification. This analysis aims to provide insights into the feasibility of the approach. Methods: The clinical trial was conducted at top tier teaching hospitals in China to recruit patients with breast diseases for surgery. Eligible patients were consented and the breast lesions were pathologically diagnosed. Peripheral blood was collected prior to surgical resection. For breast cancer patients, samples of resected tissue were also collected. The samples were analyzed using our proprietary NGS technique called systematic error correction sequencing (Sec-Seq) (detailed in Abstract ##e23057, ASCO 2018). Results: In total, 69 patients with breast lesions (57 malignant and 12 benign) were included in this analysis. Tumor gDNA and plasma ctDNA were analyzed by deep NGS sequencing using a panel of 62 breast cancer-associated genes. The average sequencing depth is 35000. After deduplication, the average number of unique reads is 1500. Detection limit for mutant allele frequency was set at 0.2% for ctDNA and 1% for tumor tissue. For ctDNA mutation detection, 2 out of 12 patients with benign diseases were found with mutations while 10 out of 55 breast cancer patients had no mutations, resulting in an overall sensitivity of 82% and specificity of 83%. By cancer stage, the two Stage 0 (carcinoma in situ) patients had no mutation, and the range of mutations detected is between 53% to 75% from Stage I to III. The tumor tissue samples have higher rate of mutations (only 2 cancer patients, 1 Stage 0 and 1 Stage 2, had no mutations). 15% patients have at least one common mutation detected in both the tumor tissue and ctDNA, and 27% patients have mutations in the same genes in the two matching samples. The concordance increases as the clinical stage advances. The most commonly mutated genes are previously reported breast cancer drivers of PIK3CA (79% of tumor and 18% of ctDNA samples), TP53 (56% and 39%), and BRCA1 (6% and 15%). Conclusions: In this hypothesis generating analysis, we showed the feasibility of plasma ctDNA sequencing for gene mutation detection in early stage breast cancer and differentiation from the benign breast diseases. Although with limited number of samples, the data encourage further improvement of the gene panel and the validation of ctDNA assay as a non-invasive approach to the cancer screening. Clinical trial information: ChiCTR1800017345.
TIF1γ (transcription intermediary factor 1 gamma), which belongs to transcription intermediary factor 1 family, is an inhibitor of the TGF-β/Smad signaling pathway and could inhibit the signal transduction mediated by TGF-β. The deficiency of TIF1γ expression in a variety of tumor cells suggests that TIF1γ may play as a tumor suppressor gene in cancer development. The aim of this study is to confirm the relationship between TIF1γ and non-small cell lung cancer (NSCLC) through exploring the expression of TIF1γ in NSCLC cells and tissues, and investigate the regulation mechanism of TIF1γ expression in NSCLC cells.Thirteen NSCLC and the paired corresponding para-cancerous lung tissue samples and three cell lines (a normal bronchial epithelial cell line HBE and two NSCLC cell lines A549 and 95C) were selected. The quantitative real-time PCR and Western blotting were used to determine the expression of TIF1γ, and ImageJ was used to evaluate the relative expression of TIF1γ. Direct sequencing was performed to detect mutations within the promoter region of the TIF1γ gene and then Bisulfite-sequencing PCR (BSP) and cloning sequencing were carried out to test the methylation status of the promoter region of TIF1γ gene in the selected cell lines.Both mRNA and protein expression of TIF1γ were found significantly decreased in A549 and 95C compared with those in HBE (P<0.05). And in 9 pairs (69.2%) of tissues among the 13 pairs, the mRNA expression of TIF1γ gene was lower in the cancer tissues than that in the paired paracancerous lung tissues (P<0.05). No abnormal mutation was found in the -287 to -5 region of the promoter of TIF1γ gene in the three cell lines. Moreover, five CpG sites (including -214 bp,-128 bp,-124 bp, -65 bp and -55 bp) were detected in the promoter of TIF1γ gene by using BSP, and the methylation profiles in these CpG sites showed similar pattern between NSCLC cells and HBE cells.TIF1γ may play a tumor suppressor role in the progression of NSCLC. No mutation was found in the -287- -5 region of the promoter of TIF1γ gene in a normal bronchial epithelial cell line and two NSCLC cell lines. But there are five CpG sites which can be methylated located in this region.背景与目的 TIF1γ（transcription intermediary factor 1 gamma）属于转录中介因子1家族的成员，可干扰TGF-β/Smad信号通路，抑制TGF-β介导的信号传导，且TIF1γ在多种肿瘤细胞的表达减弱或缺失表明TIF1γ在癌症的发生发展过程中起到抑癌的作用。本研究旨在探索TIF1γ在非小细胞肺癌（non-small cell lung cancer, NSCLC）细胞与组织中的表达差异以确定TIF1γ与肺癌发生关系以及肺癌细胞中TIF1γ表达调控的潜在机制。方法 选取13例NSCLC患者癌组织以及对应的癌旁组织样本，培养正常支气管上皮细胞HBE和NSCLC细胞株：A549和95C。运用Real-time PCR和Western blot检测细胞与组织中TIF1γ基因的表达，并用ImageJ灰度扫描软件计算TIF1γ的相对表达量。通过DNA测序的方法检测TIF1γ基因启动子区域突变情况，并采用Bisulfite-sequencing PCR（BSP）克隆测序方法检测TIF1γ基因启动子区域甲基化情况。结果 相对于HBE，TIF1γ mRNA和蛋白在A549和95C中明显下调（P<0.05），13对组织样本中，9个（69.2%）癌旁组织样本里TIF1γ mRNA的表达量高于癌组织样本（P<0.05）。突变检测表明TIF1γ基因启动子区-287﹣-5在细胞株中没有突变发生。经BSP克隆测序方法分析发现在TIF1γ基因启动子-287﹣-5区域里存在5个可被甲基化的CpG位点（-214、-128、-124、-65和-55）。但这些CpG位点的甲基化频率在NSCLC细胞株中相比HBE没有明显差异。结论 TIF1γ在NSCLC的发生中可能起抑癌的作用，TIF1γ基因启动子区域-287﹣-5在正常细胞和NSCLC细胞中都没有发生突变，但在-287﹣-5区域中存在5个可被甲基化的CpG位点。
Summary Long noncoding RNAs (lncRNAs) represent a key class of cellular regulators, involved in the modulation and control of multiple biological processes. Distinct classes of lncRNAs are now known to be induced by host cytokines following viral infections. Current evidence demonstrates that lncRNAs play essential roles at the host‐pathogen interface regulating viral infections by either innate immune responses at various levels including activation of pathogen recognition receptors or by epigenetic, transcriptional, and posttranscriptional effects. We review the newly described mechanisms underlying the interactions between lncRNAs, cytokines, and metabolites differentially expressed following viral infections; we highlight the regulatory networks of host antiviral responses and emphasize the need for interdisciplinary research between lncRNA biology and immunology to deepen understanding of viral pathogenesis.
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