Gene expression changes associated with malignant transformation of oral potentially malignant disorders
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ABSTRACT: A large number of oral squamous cell carcinomas (OSCCs) are believed to be preceded by oral potentially malignant disorders (OPMD) that have an increased likelihood of malignant transformation compared to clinically normal mucosa. This study was performed to identify differentially expressed genes between OPMDs that underwent malignant transformation (MT) and those that did not, termed ‘non-transforming’ (NT) cases. Total RNA was extracted from formalin-fixed paraffin-embedded tissue biopsies of 20 OPMD cases with known clinical outcomes (10 MT vs. 10 NT). Samples were assessed for quantity, quality and integrity of RNA prior to sequencing. Analysis for differential gene expression between MT and NT was performed using statistical packages in R. Genes were considered to be significantly differentially expressed if the False Discovery Rate corrected p-value was < 0.05. RNA yield was variable but RNA purity was good (A260/A280 >1.90). Analysis of RNA-Sequencing outputs revealed 41 genes (34 protein-coding; 7 non-coding) that were significantly differentially expressed between MT and NT cases. The log2 fold change for the statistically significant differentially expressed genes ranged from -2.63 to 2.48, with 23 protein-coding genes being downregulated and 11 protein-coding genes being upregulated in MT cases compared to NT cases. Several candidate genes that may play a role in malignant transformation of OPMD have been identified. Experiments to validate these candidates are underway. It is anticipated that this work will contribute to better understanding of the aetiopathogenesis of OPMD and development of novel biomarkers.
Project description:To investigate the pathogenesis of malignant phyllodes tumors of the breast, we used lncRNA+mRNA microarray expression profiling as a platform to investigate lncRNAs that play a key role in the malignant progression of phyllodes tumors of the breast.A total of 4 cases of breast fibroadenomas, 6 cases of benign phyllodes tumors and 6 cases of malignant phyllodes tumors were included. Fibroadenomas and benign phyllodes tumors were used as controls to screen out significantly differentially expressed lncrnas in malignant phyllodes tumors.
Project description:The Homeobox (HOX) family of genes encodes transcription factors involved in basic developmental processes, most notably during embryogenesis. A possible HOX gene link between development and oncogenesis has recently been described. Dysregulation of HOX genes may be an early event in malignant transformation likely to induce antibody response and thus provide a potential marker for early diagnosis of cancer. Ovarian cancer is characterized by poor early detection and serves as an excellent model system to develop potential markers for early diagnosis. In this study we begin to characterize HOX gene expression in malignant tumors of the ovary and analyze the potential role of HOX genes as biomarkers for early detection of ovarian cancer. Microarray analysis of mRNA from human ovarian tissues was performed on 65 samples of normal, benign, borderline malignant and malignant ovarian tissue. These samples were analyzed using the Affymetrix Human Genome Focus GeneChip (HG-Focus) microarray to distinguish the differential pattern of mRNA expression between the four types of samples. Real-time reverse transcription PCR was utilized to confirm up-regulation of HOX genes as determined by microarray analysis. Our results demonstrate multiple HOX genes to be up-regulated in ovarian cancer. We have shown stepped increase in HOX expression comparing normal, benign neoplastic, and malignant human ovarian tissue samples. This suggests dysregulation of HOX genes may be an early event in malignant transformation and warrants additional studies to validate HOX gene products as potential markers for early detection of ovarian cancer. Experiment Overall Design: 67 samples were analyzed. 4 groupings based on pathology (normal, benign, borderline malignant, malignant). An average of normal samples was used as controls. Cell lines were used as ovarian cancer control samples.
Project description:This SuperSeries is composed of the following subset Series: GSE38926: Patterns of aberrant DNA methylation after toxicant-induced malignant transformation (MeDIP-chip dataset 1) GSE38928: Patterns of aberrant DNA methylation after toxicant-induced malignant transformation (MeDIP-chip dataset 2) GSE38929: Patterns of aberrant DNA methylation after toxicant-induced malignant transformation (miRNA dataset) Refer to individual Series
Project description:The 5-year survival rate for patients with oral squamous cell carcinomas (SCC), including tongue SCC, has not significantly improved over the last several decades. Oral potentially malignant disorders (OPMD), including oral dysplasias, are oral epithelial disorders that can develop into oral SCCs. To identify molecular characteristics that might predict conversion of OPMDs to SCCs and guide treatment plans, we performed global transcriptomic analysis of human tongue OPMD (n=9) and tongue SCC (n=11) samples with paired normal margin tissue from patients treated at Weill Cornell Medicine. Compared to margin tissue, SCCs showed more transcript changes than OPMDs. OPMDs and SCCs shared some altered transcripts, but these changes were generally greater in SCCs than OPMDs. Both OPMDs and SCCs showed altered signaling pathways related to cell migration, basement membrane disruption, and metastasis. We suggest that OPMDs were on the path towards malignant transformation. Based in patterns of gene expression, both OPMD samples and SCC samples can be categorized into subclasses (mesenchymal, classical, basal, and atypical) similar to those seen in human head and neck SCC (HNSCC). These subclasses of OPMDs the potential to be used to stratify patient prognosis and therapeutic options for tongue OPMDs. Lastly, we developed Firth logistic regression models to classify OPMDs and SCCs using a signature gene set ELF5, RPTN, IGSF10, HTR3A, and CRMP1, and this predictive model is amenable to testing as data sets become available. We suggest that changes in these five transcripts relative to paired normal tissue could be used to predict of the likelihood of an OPMD developing into a SCC.
Project description:Oral malignancies are among the top most deadly cancers in the world. Early diagnosis of oral premalignant and malignant lesions is essential for treatment decision-making and prognosis improvement. In this study, we systematically evaluated the gene expression patterns during the pathogenesis of oral moderate dysplasia. RNA sequencing detected 21556 genes in moderate dysplasia and paired normal tissues from three patients. Hierarchical clustering analysis revealed distinct gene expression patterns between the moderate dysplasia samples. 346 differentially expressed genes that may contribute to the pathogenesis of moderate dysplasia were identified. Among these genes, ISG15 and MAGEA family showed different transcription profiles that close related with the alterations of gene expression patterns in moderate dysplasia samples and paired normal tissues. We speculated that, as the potential marker to signal the risk of malignant transformation, ISG15 and MAGEA together with their close related misexpressed genes may involve in two different pathways during the malignant conversion from oral dysplasia to oral squamous cell carcinoma.
Project description:OBJECTIVE: Although the malignant transformation of sinonasal inverted papilloma (SNIP) into squamous cell carcinomas (SCC) has been reported in the literature, the molecular mechanisms driving this transformation have not been elucidated. This study compares genome-wide DNA methylation between SNIP and SCC arising in SNIP and further validates the expression of aberrantly methylated genes. Methots:We used a comprehensive methylation profiling technique to investigate DNA methylation in CpG islands and promoters in six SNIP samples and seven SCC arising in SNIP samples. A total of 11,201 nominally differentially methylated sites were observed, between SNIP and SCC arising in SNIP. This study is the first to compare the differences in global DNA methylation between SNIP and SCC arising in SNIP.
Project description:The aim of this study was to determine how gene expression is changed after arsenite-induced malignant transformation of prostate epithelial cells. Gene expression from three distinct passages of untreated, immortal RWPE-1 cells was compared to three timepoints of arsenite-exposed RWPE-1 cells (CAsE-PE) that have undergone malignant transformation.
Project description:Gliomas are the most common primary brain tumor in humans. Low-grade gliomas (WHO grade II) invariably progress to high-grade gliomas (WHO grade III or IV). Although malignant progression may take many years, the survival rate after transformation to a high-grade glioma is poor, often only 12-15 months. In this data set, we have identified low-grade gliomas that have progressed to high-grade gliomas or high-grade gliomas that have progressed from low-grade gliomas. Some cases are matched pairs (meaning we have both the original low-grade tumor and the subsequent high-grade tumor). The samples deposited have been analyzed with bulk-RNA sequencing. They are also de-identified but are clinically annotated. When available, genetic information including IDH mutation status, 1p/19q deletion and histological subtype are also included.