Project description:Purpose: Serum markers that enable diagnosis in the early stage of lung cancer have not been discovered. We have developed a LC-MRM-MS assay for the identification of potential early marker proteins for lung adenocarcinoma.
Experimental design: LC-MRM-MS assay was used for measuring the level of 35 candidate peptides in plasma from 102 lung adenocarcinoma patients (including n=50, 16, 24, and 12 in stage I, II, III, and IV, respectively.) and 84 healthy controls. Stable isotope labeled standard peptides were synthesized to accurately measure the amount of these proteins.
Results: Seven proteins were found to be able to distinguish stage I patients from controls. These proteins were combined in to a protein marker panel which improved the sensitivity to discriminate stage I patients from controls and resulted in a high classification performance with cross-validated area under the curve=0.76. Besides, we found that low expression of eukaryotic initiation factor 4A-I and high expression of lumican showed significantly poor prognosis in overall survival (p=0.012 and 0.0074, respectively), which may be used as prognostic biomarkers for lung cancer.
Conclusion and clinical relevance: Proteins highlighted here may be used for early detection of lung adenocarcinoma or therapeutics development after validation in a larger cohort.
Project description:Genome wide DNA methylation profiling of Stage I Lung Adenocarcinoma and non-tumor adjacent tissues. The Illumina Infinium 27k Human DNA methylation Beadchip was used to obtain DNA methylation profiles across approximately 27,000 CpGs. Samples included tumor and adjacent non-tumor tissues excised from a cohort of 35 patients with Stage I Lung Adenocarcinoma. Candidate prognostic biomarkers were validated by pyrosequencing in independent cohorts.
Project description:To test the hypothesis that the propensity for silencing of tumor suppressor genes in the respiratory epithelium of chronic smokers by promoter hypermethylation is influenced by sequence variations that modify the activity of genes and microRNAÕs that directly or indirectly influence de novo methylation and chromatin remodeling.
Project description:Proteomic analyses identify dysregulated proteins and pathways between low-risk and high-risk subtype of early-stage lung adenocarcinoma and their prognostic impacts.Sample labels: A,low-risk tumor;B,low-risk normal;C,high-risk tumor;D,high-risk normal.
Project description:Lung cancer remains the leading cause of cancer-related death due to poor treatment responses and resistance arising from tumor heterogeneity. Here we show that adverse prognosis associated with epigenetic silencing of the tumour suppressor RASSF1A is due to increased deposition of extracellular matrix (ECM), tumour stiffness and metastatic dissemination in vitro and in vivo. We find that lung cancer cells with RASSF1A promoter methylation display constitutive nuclear YAP1 and expression of collagen prolylhydroxylase (P4HA2) which increases collagen deposition. Furthermore, we identify that elevated collagen creates a stiff-ECM which in turn triggers cancer stem-like programming and metastatic dissemination in vivo. Re-expression of RASSF1A or inhibition of P4HA2 activity reverse these effects and increase markers of lung differentiation (TTF-1, Mucin5B). Our study identifies RASSF1A as a clinical biomarker associated with mechanical properties of ECM which increases levels of cancer stemness and risk of metastatic progression in lung adenocarcinoma. Moreover, we highlight P4HA2 as a potential target for uncoupling ECM signals that support cancer stemness.
Project description:Lung cancer is the leading cause of cancer death worldwide and adenocarcinoma is its most common histological subtype. Clinical and molecular evidence indicates that lung adenocarcinoma is a heterogeneous disease, which has important implications for treatment. Here we performed genome-scale DNA methylation profiling using the Illumina Infinium HumanMethylation27 platform on 59 matched lung adenocarcinoma/non-tumor lung samples, with genome-scale verification on an independent set of tissues. We identified 766 genes showing altered DNA methylation between tumors and non-tumor lung. By integrating DNA methylation and mRNA expression data, we identified 164 hypermethylated genes showing concurrent downregulation, and 57 hypomethylated genes showing increased expression. Integrated pathways analysis indicates that these genes are involved in cell differentiation, epithelial to mesenchymal transition, RAS and WNT signaling pathways and cell cycle regulation, among others. Comparison of DNA methylation profiles between lung adenocarcinomas of current and never-smokers showed modest differences, identifying only LGALS4 as significantly hypermethylated and downregulated in smokers. LGALS4, encoding a galactoside-binding protein involved in cell-cell and cell-matrix interactions, was recently shown to be a tumor-suppressor in colorectal cancer. Unsupervised analysis of the DNA methylation data identified two tumor subgroups, one of which showed increased DNA methylation and was significantly associated with KRAS mutation and to a lesser extent, with smoking. Our analysis lays the groundwork for further molecular studies of lung adenocarcinoma by providing new candidate DNA methylation biomarkers for early detection, identifying novel molecular alterations potentially involved in lung adenocarcinoma development/progression, and describing an epigenetic subgroup of lung adenocarcinoma associated with KRAS mutation. 59 lung adenocarcinoma and 59 adjacent non-tumor lung tissue were macrodissected, bisulfite treated and analyzed on the Illumina Infinium HumanMethylation27K BeadChip
Project description:CpG hypermethylation in gene promoters is a frequent mechanism of tumor suppressor gene silencing in various types of cancers. 5-aza-2'-deoxycytidine (AZA) is a DNA demethylating and anti-cancer agent resulting in induction of genes suppressed via DNA hypermethylation. Using microarray expression profiling of AZA or DMSO treated and untreated breast cancer (MCF7 and MDA-MB-231) and non-tumorigenic breast (NTB) cells, we aim to identify candidate genes that are downregulated via promoter hypermethylation in breast cancer.
Project description:Promoter region hypermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many types of human cancers. Functional epigenetic studies, in which gene expression is induced by treatment with demethylating agents, may identify novel genes with tumour-specific methylation. We used high-density gene expression microarrays in a functional epigenetic study of 11 renal cell carcinoma (RCC) cell lines. Twenty eight genes were then selected for analysis of promoter methylation status in cell lines and primary RCC. Eight genes (BNC1, PDLIM4/RIL, REPRIMORPRM, CST6, SFRP1, GREM1, COL14A1 and COL15A1) demonstrated frequent (>30% of RCC tested) tumour-specific promoter region methylation. Hypermethylation was associated with transcriptional silencing. Re-expression of BNC1, CST6, RPRM, and SFRP1 suppressed the growth of RCC cell lines. Whereas, RNAi-knock-down of BNC1, SFRP1 and COL14A1 increased the growth potential of RCC cell lines. Methylation of BNC1 or COL14A1 was associated with a poorer prognosis independent of tumour size, stage or grade. The identification of these epigenetically inactivated candidate RCC tumour suppressor genes can provide insights into renal tumourigenesis and a basis for developing novel therapies and biomarkers for prognosis and detection. We used expression microarrays to identified genes that were frequently methylated and silenced in RCC by determining the globlal expression patterns of RCC-derived cell lines following de-methylation by treatment with 5-Aza-2'-deoxycytidine.
Project description:Lung adenocarcinoma is the most common histological subtype of lung cancer. Although early-stage LUAD (esLUAD) patients have much better prognosis than patients with advanced disease, among early stage patients treated primarily with surgery, some of early stage patients will develop metastasis with overall 5 year survival for stage 1 and 2 non-small cell lung cancer of 70% and 35%, respectively. Within lung adenocarcinoma, histology is heterogenous and associated with tumor invasion and clinical outcomes. Invasiveness is one of cancer hallmarks and is directly related with metastatic potential and clinical outcomes of the tumor. In this study, we characterize invasiveness mechanisms in esLUAD by analyzing gene expression of a novel cohort of 53 histologically heterogenous esLUAD samples.
Project description:Promoter region hypermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many types of human cancers. Functional epigenetic studies, in which gene expression is induced by treatment with demethylating agents, may identify novel genes with tumour-specific methylation. We used high-density gene expression microarrays in a functional epigenetic study of 11 renal cell carcinoma (RCC) cell lines. Twenty eight genes were then selected for analysis of promoter methylation status in cell lines and primary RCC. Eight genes (BNC1, PDLIM4/RIL, REPRIMORPRM, CST6, SFRP1, GREM1, COL14A1 and COL15A1) demonstrated frequent (>30% of RCC tested) tumour-specific promoter region methylation. Hypermethylation was associated with transcriptional silencing. Re-expression of BNC1, CST6, RPRM, and SFRP1 suppressed the growth of RCC cell lines. Whereas, RNAi-knock-down of BNC1, SFRP1 and COL14A1 increased the growth potential of RCC cell lines. Methylation of BNC1 or COL14A1 was associated with a poorer prognosis independent of tumour size, stage or grade. The identification of these epigenetically inactivated candidate RCC tumour suppressor genes can provide insights into renal tumourigenesis and a basis for developing novel therapies and biomarkers for prognosis and detection.