Peroxiredoxins and Immune Infiltrations in Colon Adenocarcinoma: Their Negative Correlations and Clinical Significances, an In Silico Analysis.
Peroxiredoxins 与结肠腺癌的免疫浸润: 它们的负相关和临床意义，计算机分析。
- 作者列表："Zhang X","Gao F","Li N","Zhang J","Dai L","Yang H
:Background: Peroxiredoxins (PRDXs) were reported to be associated with inflammation response in previous studies. In colon adenocarcinoma (COAD), however, their correlations and clinical significance were unclear. Methods: The RNA-seq data of 452 COAD patients with clinical information was downloaded from The Cancer Genome Atlas (TCGA) and transcripts per million (TPM) normalized. Comparisons of relative expressions of PRDXs between COAD tumor and normal controls were applied. PRDXs dy-regulations in COAD were validated via Oncomine, Human Protein Atlas (HPA) and Gene Expression Omnibus (GEO) repository. Through Tumor Immune Estimation Resource (TIMER), the immune estimation of TCGA-COAD patients was downloaded and the dy-regulated PRDXs were analyzed for their correlations with immune infiltrations in COAD. The TCGA-COAD patients were divided into younger group (age≤65 years) and older group (age>65 years) to investigate the prognostic roles of age, TNM stage, dy-regulated PRDXs and the immune infiltrations in different age groups through Kaplan-Meier survival and Cox regression analyses. Results: Three of the PRDX members showed their expressional differences both at protein and mRNA level. PRDX2 was consistently up-regulated while PRDX6 down-regulated in COAD. PRDX1 was overexpressed (mRNA) while nuclear absent (protein) in the tumor tissues. PRDX1 overexpression and PRDX6 under-expression were also shown in the stem-like colonospheres from colon cancer cells. Via TIMER, PRDX1, PRDX2, and PRDX6 were found to be negatively correlated with the immune infiltrations in COAD. Both in the younger and older patients, TNM stage had prognostic effects on their overall survival (OS) and recurrence-free survival (RFS). CD4+ T cell had independent unfavorable effects on OS of the younger patients while age had similar effects on RFS of the older ones. CD8+ T cell was independently prognostic for RFS in the two groups. Conclusions: Late diagnosis indicated poor prognosis in COAD and dy-regulated PRDXs w might be new markers for its early diagnosis. Age was prognostic and should be considered in the treatments of the older patients. Dy-regulated PRDXs were negatively correlated with immune infiltration levels. CD4+ T cell and CD8+ T cell infiltrations were prognostic in COAD and their potential as immune targets needed further investigation.
背景: 以往的研究报道过氧化物 (PRDXs) 与炎症反应有关。然而，在结肠腺癌 (COAD) 中，它们的相关性和临床意义尚不清楚。方法: 从癌症基因组图谱 (TCGA) 中下载 452 例具有临床信息的 COAD 患者的 RNA-seq 数据，并使每百万转录本 (TPM) 标准化。比较 COAD 肿瘤与正常对照组 PRDXs 的相对表达。通过 Oncomine 、人类蛋白图谱 (HPA) 和基因表达综合 (GEO) 储存库验证 COAD 中的 PRDXs dy-调节。通过肿瘤免疫估计资源 (TIMER)，下载 TCGA-COAD 患者的免疫估计值，分析 dy 调节的 PRDXs 与 COAD 中免疫浸润的相关性。将 TCGA-COAD 患者分为青年组 (年龄 ≤ 65 岁) 和老年组 (年龄> 65 岁)，探讨年龄、 TNM 分期、通过 Kaplan-Meier 生存和 Cox 回归分析，dy 调节的 PRDXs 和不同年龄组的免疫浸润。结果: 3 个 PRDX 成员在蛋白和 mRNA 水平均表现出表达差异。PRDX2 在 COAD 中持续上调，而 PRDX6 下调。PRDX1 在肿瘤组织中过表达 (mRNA)，而核缺失 (蛋白)。PRDX1 过表达和 PRDX6 表达不足也显示在来自结肠癌细胞的茎样结肠镜球中。通过计时器，发现 PRDX1 、 PRDX2 和 PRDX6 与 COAD 中的免疫浸润呈负相关。在年轻和老年患者中，TNM 分期对其总生存期 (OS) 和无复发生存期 (RFS) 均有预后影响。CD4 + T 细胞对年轻患者的 OS 有独立的不利影响，而年龄对老年患者的 RFS 有相似的影响。CD8 + T 细胞是两组 RFS 的独立预后因素。结论: COAD 和 dy 调节 PRDXs 的晚期诊断提示预后不良，w 可能是其早期诊断的新指标。年龄是预后的，在老年患者的治疗中应该考虑。Dy 调节的 PRDXs 与免疫浸润水平呈负相关。CD4 + T 细胞和 CD8 + T 细胞浸润是 COAD 的预后因素，其作为免疫靶点的潜力需要进一步研究。
METHODS::Aims: Radiotherapy is predominantly used as one of the treatment modalities to treat local tumor in colorectal cancer (CRC). Hindrance in disease treatment can be attributed to radio-tolerance of cancer stem cells (CSCs) subsistence in the tumor. Understanding the radio-resistant property of CSCs might help in the accomplishment of targeted radiotherapy treatment and increased disease-free survival. Telomeric RAP1 contributes in modulation of various transcription factors leading to aberrant cell proliferation and tumor cell migration. Therefore, we investigated the role of RAP1 in maintaining resistance phenotype and acquired stemness in radio-resistant cells.Main Methods: Characterization of HCT116 derived radio-resistant cell (HCT116RR) was performed by cell survival and DNA damage profiling. RAP1 silenced cells were investigated for DNA damage and expression of CSC markers through western blotting and Real-time PCR post-irradiation. Molecular docking and co-immunoprecipitation study were performed to investigate RAP1 and KLF4 interaction followed by RAP1 protein status profiling in CRC patient.Key findings: We established radio-resistant cells, which showed tolerance to radiotherapy and elevated expression of CSC markers along with RAP1. RAP1 silencing showed enhanced DNA damage and reduced expression of CSC markers post-irradiation. We observed strong physical interaction between RAP1 and KLF4 protein. Furthermore, higher RAP1 expression was observed in the tumor of CRC patients. Dataset analysis also revealed that high expression of RAP1 expression is associated with poor prognosis.Significance: We conclude that higher expression ofRAP1 implicates its possible role in promoting radio-resistance in CRC cells by modulating DNA damage and CSC phenotype.
METHODS::Cancer stem-like cells are rare immortal cells within tumor, which are thought to play important roles in ionizing radiation (IR) therapy-resistance. Quercetin is a natural flavonoid with potential anti-cancer properties without significant cytotoxicity in normal tissues. In this study, we demonstrated that quercetin-IR combination treatment exhibited more dramatic anti-cancer effect than either quercetin or IR treatment alone via targeting colon cancer stem cells (CSCs) and inhibiting the Notch-1 signaling. These effects were further verified by in vivo studies which showed remarkable decrease of the CSCs markers and the expression of Notch-1 signaling proteins in human colon cancer xenografts in nude mice. Co-treatment with quercetin and low dose of radiation significantly reduced the expressions of all five proteins of γ-secretase complex in HT-29 and DLD-1 cells. In addition, ectopic expression of the Notch intracellular domain (NICD) partly reversed the inhibition effects by the combination therapy. In conclusion, our results indicated that the combination of quercetin (20 μM) and IR (5Gy) might be a promising therapeutic strategy for colon cancer treatment by targeting colon cancer stem-like cells and inhibiting the Notch-1 signaling. In future studies, we intend to further explore the potential therapeutic efficacy of the quercetin-radiation combination treatment in clinical trials.
METHODS:OBJECTIVES:Long-term prevention of metastatic disease remains a challenge in locally advanced rectal cancer, and robust pretreatment prognostic factors for metastatic progression are lacking. We hypothesized that detecting circulating tumor-specific DNA (ctDNA) based on hypermethylation of the neuropeptide Y gene (meth-ctDNA) could be a prognostic marker in the neoadjuvant setting; we examined this in a secondary, explorative analysis of a prospective trial. MATERIALS AND METHODS:Serum samples were prospectively collected in a phase III trial for locally advanced rectal cancer. Positivity for and fractional abundance of meth-ctDNA in baseline samples were estimated. Overall survival (OS) and the rate of distant metastases were compared between meth-ctDNA positive and negative patients; other prognostic factors were controlled for in multivariate Cox regression. Importance of quantitative load was examined by considering the fractional abundance of meth-ctDNA relative to total circulating DNA. RESULTS:Baseline serum samples were available for 146 patients. In total, 30 patients had presence of meth-ctDNA, with no correlation with cT (P=0.8) or cN (P=0.6) stages. Median follow-up was 10.6 years for OS and 5.1 years for freedom from distant metastases. Patients with meth-ctDNA had significantly worse 5-year OS (47% vs. 69%), even when controlling for other prognostic factors (hazard ratio=2.08; 95% confidence interval, 1.23-1.51). This seemed mainly driven by disparity in the rate of distant metastases (55% vs. 72% at 5 y, P=0.01); hazard ratio=2.20 (95% confidence interval, 1.19-4.07, P=0.01) in multivariate analysis. Increased quantitative load was highly significant for worse outcomes. CONCLUSIONS:Meth-ctDNA could be a potential prognostic marker in the neoadjuvant setting and may, if validated, identify patients at increased risk of distant metastases.