Genome-wide characterization of 5-hydoxymethylcytosine in melanoma reveals major differences with nevus.
- 作者列表："Salgado C","Oosting J","Janssen B","Kumar R","Gruis N","van Doorn R
:Melanoma demonstrates altered patterns of DNA methylation that are associated with genetic instability and transcriptional repression of numerous genes. Active DNA demethylation is mediated by TET enzymes that catalyze conversion of 5-methylcytosine (mC) to 5-hydroxymethylcytosine (hmC). Loss of hmC occurs in melanoma and correlates with disease progression. Here we analyzed the genomic distribution of hmC along with mC in nevus and melanoma using oxidative bisulfite chemistry combined with high-density arrays. HmC was enriched relative to mC at enhancers, 5'UTR regions and CpG shores in nevus and melanoma samples, pointing to specific TET enzyme activity. The proportion of interrogated CpG sites with high hmC levels was lower in melanoma (0.54%) than in nevus (2.0%). Depletion of hmC in melanoma was evident across all chromosomes and intragenic regions, being more pronounced in metastatic than in non-metastatic tumors. The patterns of hmC distribution in melanoma samples differed significantly from those in nevus samples, exceeding differences in mC patterns. We identified specific CpG sites and regions with significantly lower hmC levels in melanoma than in nevus that might serve as diagnostic markers. Differentially hydroxymethylated regions localized to cancer-related genes, including the PTEN gene promoter, suggesting that deregulated DNA hydroxymethylation may contribute to melanoma pathogenesis.
: 黑色素瘤显示 DNA 甲基化模式改变，与遗传不稳定性和众多基因的转录抑制相关。活性 DNA 去甲基化是由催化 5-甲基胞嘧啶 (mC) 转化为 5-羟甲基胞嘧啶 (hmC) 的 TET 酶介导的。HmC 的丢失发生在黑色素瘤中，并与疾病进展相关。这里我们使用氧化亚硫酸氢盐化学结合高密度阵列分析了 hmC 与 mC 在痣和黑色素瘤中的基因组分布。HmC 相对于 mC 在色素痣和黑色素瘤样本中的增强子、 5 'utr 区域和 CpG 海岸富集，指向特定的 TET 酶活性。被询问的 CpG 位点具有高 hmC 水平的比例在黑色素瘤中 (0.54%) 低于痣 (2.0%)。黑色素瘤中 hmC 的耗竭在所有染色体和基因内区域都很明显，在转移性肿瘤中比在非转移性肿瘤中更明显。HmC 在黑色素瘤样本中的分布模式与痣样本中的分布模式显著不同，超过了 mC 模式的差异。我们确定了黑色素瘤中 hmC 水平显著低于痣的特定 CpG 位点和区域，可能作为诊断标志物。差异羟甲基化区域定位于癌症相关基因，包括 PTEN 基因启动子，提示失调的 DNA 羟甲基化可能有助于黑色素瘤发病机制。
METHODS::In colorectal cancer (CRC), hepatic arterial infusion (HAI) chemotherapy may convert primarily unresectable CRC liver metastases (CLM) into resectability, although the risk of metastatic recurrence remains high after CLM ablation. We investigated the role of antitumour immunity invoked by first-line oxaliplatin-HAI for long-term CLM outcome. In a prospective study cohort of primarily unresectable CLM, we assessed patients' fms-related tyrosine kinase 3 ligand (FLT3LG) in serum, reflecting opportune intratumoural immune activity, at baseline and following 1-3 sequences of oxaliplatin-HAI. The end points were CLM resectability and overall survival. Patients who presented an immediate twofold increment of circulating FLT3LG during the treatment and at its completion were scored as CLM resectable (16.4% with both features), were alive at final follow-up 8-12 years later. All patients experienced FLT3LG increase during the treatment course, but those who remained unresectable or had the disease converted but presented a slow and gradual FLT3LG accretion, later died of the metastatic disease. These data provide further support to our previous findings that tumour-directed immunity invoked by oxaliplatin-containing therapy predicts excellent outcome of early advanced CRC if macroscopic tumour ablation is rendered possible by the 'classic' tumour response to the cytotoxic treatment.
METHODS::Prostate cancer is one of the primary causes of death around the world. As an important drug, flutamide has been used in the clinical diagnosis of prostate cancer. However, the over dosage and improper discharge of flutamide could affect the living organism. Thus, it necessary to develop the sensor for detection of flutamide with highly sensitivity. In this paper, we report the synthesis of lanthanum cobaltite decorated halloysite nanotube (LCO/HNT) nanocomposite prepared by a facile method and evaluated for selective reduction of flutamide. The as-prepared LCO/HNT nanocomposite shows the best catalytic performance towards detection of flutamide, when compared to other bare and modified electrodes. The good electrochemical performance of the LCO/HNT nanocomposite modified electrode is ascribed to abundant active sites, large specific surface area and their synergetic effects. Furthermore, the LCO/HNT modified electrode exhibits low detection limit (0.002 μM), wide working range (0.009-145 μM) and excellent selectivity with remarkable stability. Meaningfully, the developed electrochemical sensor was applied in real environmental samples with an acceptable recovery range.
METHODS::Several studies have indicated that cancer-associated fibroblasts (CAFs) could promote cancer progression in many malignancies. However, the mechanism by which CAFs promote the growth and metastasis of lung cancer remains poorly defined. In the present study, CAFs and normal fibroblasts (NFs) were isolated from human lung cancer and adjacent tissue. The data showed that the conditional medium (CM) of CAFs could increase the proliferation, migration and invasion of lung cancer cells. Vascular cell adhesion molecule-1 (VCAM-1) showed a higher expression in CAF-CM than NF-CM, and blocking VCAM-1 in CAF-CM attenuated the proliferation and invasion of cancer cells. Further, the results showed that VCAM-1 secreted from CAFs activated AKT and MAPK signaling via receptor α4β1 integrin (very-late antigen (VLA)-4) in lung cancer cells. Moreover, CAFs promoted VCAM-1 expression and tumor growth in vivo. Additionally, bioinformatics analysis indicated a positive correlation on the CAF marker protein alpha-smooth muscle actin (α-SMA) and VCAM-1 expression, which was associated with a poor prognosis in lung cancer patients. These findings demonstrate that the VCAM-1 secreted from CAFs enhances growth and invasion by activating the AKT and MAPK signaling of lung cancer cells.