Project description:We identified a novel germline mutation of the microphthalmia-associated transcription factor (MITF - E318K). This mutation was found to be present in numerous melanoma families, as well as the general population, where its association with melanoma has a significant effect. We determined the effect of the E318K mutation on global MITF target gene transcription. We developed a tetracycline-inducible system for expression of wild type MITF or the E318K variant in melanoma cell lines with constitutively low or undetectable levels of endogenous MITF (HT144 and C32). We examined whole-genome expression profiles in these cells following induction of either wild-type or E318K MITF for 48 hours. Analysis suggests that the MITF E318K mutant exhibits differential transcriptional activity against some, though not all, target genes. Expression profiling by array
Project description:We identified a novel germline mutation of the microphthalmia-associated transcription factor (MITF - E318K). This mutation was found to be present in numerous melanoma families, as well as the general population, where its association with melanoma has a significant effect. We determined the effect of the E318K mutation on global MITF target gene transcription. We developed a tetracycline-inducible system for expression of wild type MITF or the E318K variant in melanoma cell lines with constitutively low or undetectable levels of endogenous MITF (HT144 and C32). We examined whole-genome expression profiles in these cells following induction of either wild-type or E318K MITF for 48 hours. Analysis suggests that the MITF E318K mutant exhibits differential transcriptional activity against some, though not all, target genes.
Project description:So far, two genes associated with familial melanoma have been identified, accounting for a minority of genetic risk in families. Mutations in CDKN2A account for approximately 40% of familial cases, and predisposing mutations in CDK4 have been reported in a very small number of melanoma kindreds. Here we report the whole-genome sequencing of probands from several melanoma families, which we performed in order to identify other genes associated with familial melanoma. We identify one individual carrying a novel germline variant (coding DNA sequence c.G1075A; protein sequence p.E318K; rs149617956) in the melanoma-lineage-specific oncogene microphthalmia-associated transcription factor (MITF). Although the variant co-segregated with melanoma in some but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a log of odds (lod) score of 2.7 under a dominant model, indicating E318K as a possible intermediate risk variant. Consistent with this, the E318K variant was significantly associated with melanoma in a large Australian case-control sample. Likewise, it was similarly associated in an independent case-control sample from the United Kingdom. In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma, multiple primary melanomas, or both. The variant allele was also associated with increased naevus count and non-blue eye colour. Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma-predisposition gene and highlight the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.
Project description:We identified a novel germline mutation of the microphthalmia-associated transcription factor (MITF - E318K). This mutation was found to be present in numerous melanoma families, as well as the general population, where its association with melanoma has a significant effect. We determined the effect of the E318K mutation on global MITF target gene transcription. We developed a tetracycline-inducible system for expression of wild type MITF or the E318K variant in melanoma cell lines with constitutively low or undetectable levels of endogenous MITF (HT144 and C32). We examined whole-genome expression profiles in these cells following induction of either wild-type or E318K MITF for 48 hours. Analysis suggests that the MITF E318K mutant exhibits differential transcriptional activity against some, though not all, target genes. Expression profiling by array
Project description:<p>We conducted whole-genome sequencing of probands from several melanoma families, identifying one individual carrying a novel germline variant (c.G1075A, NM_000248.3; p.E318K, NP_000239.1; rs149617956) in the melanoma lineage-specific oncogene MITF. While the variant cosegregated with melanoma in some, but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a LOD score of 2.7 under a dominant model, suggesting E318K as a possible intermediate risk variant. Consistent with this, E318K was significantly associated with melanoma in a large Australian case-control sample, giving an odds ratio (OR) of 2.33, 95% CI 1.21-4.70 (case and control carrier frequency, 0.0165 and 0.0072, respectively; P=0.008). Likewise, it was similarly associated in an independent case-control sample from the United Kingdom (UK P=0.012; combined P=0.0003, OR 2.19, 95% CI 1.41-3.45). In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma (OR 2.95, 95% CI 1.23-6.92), multiple primary melanomas (OR 4.22, 95% CI 1.52-10.91), or both (OR 8.37, 95% CI 2.58-23.80). The variant allele was also associated with increased nevus count (combined P=0.002, OR 2.54, 95% CI 1.42-4.55) and non-blue eye color (combined P=0.008, OR 2.01, 95% CI 1.11-3.81). Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma predisposition gene and highlights the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.</p>
Project description:Rationale: Idiopathic interstitial pneumonia (IIP) and its’ familial variants are progressive and largely untreatable disorders with poorly understood molecular mechanisms. Both the genetics and the histologic type of IIP play a role in understanding the etiology and pathogenesis of interstitial lung disease, but transcriptional signatures of these subtypes are unknown. Objectives: To evaluate gene expression in the lung tissue from patients with usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP) that were either familial or non-familial in origin and compare them to gene expression from normal lung parenchyma. Methods: We profiled RNA from lungs of 16 patients with sporadic IIP, 10 with familial IIP, and 9 normal controls on a whole human genome oligonucleotide microarray. Results: Significant transcriptional differences exist in familial and sporadic IIPs. The genes distinguishing the genetic subtypes belong to the same functional categories as transcripts that distinguish IIP from normal samples. Relevant categories include chemokines and growth factors and their receptors, complement components, genes associated with cell proliferation and death, and genes in the Wnt pathway. Keywords: disease state analysis
Project description:Most patients with pharmacoresistant mesial temporal lobe epilepsy (MTLE) have hippocampal sclerosis on the postoperative histopathological examination. Although most patients with MTLE do not refer to a family history of the disease, familial forms of MTLE have been reported. We studied surgical specimens from patients with MTLE who had epilepsy surgery for medically intractable seizures. We assessed and compared messenger RNA (mRNA) expression profiles of the tissue lesion found in patients with familial MTLE (n = 3) and sporadic MTLE (n = 5). In addition, we used data from control hippocampi obtained from a public database (n = 7). We obtained expression profiles using the Human Genome U133 Plus 2.0 (Affymetrix) microarray platform. Overall, the molecular profile identified in familial MTLE was distinct from that found in sporadic MTLE. In the tissue of patients with familial MTLE, we found an over-representation of the biological pathways related to protein response, mRNA processing, and synaptic plasticity and function. In sporadic MTLE, the gene expression profile suggests that the inflammatory response is highly activated. We also found enrichment of gene sets involved in inflammatory cytokines and mediators and chemokine receptor pathways in both groups. However, in sporadic MTLE, we also found enrichment of epidermal growth factor signaling, prostaglandin synthesis and regulation, and microglia pathogen phagocytosis pathways. Furthermore, based on the gene expression signatures, we identified different potential compounds to treat patients with familial and sporadic MTLE. To our knowledge, this is the first study assessing the mRNA profile in surgical tissue obtained from patients with familial MTLE and comparing it with sporadic MTLE. Our results clearly show that, despite phenotypic similarities, both forms of MTLE present distinct molecular signatures, thus suggesting different underlying molecular mechanisms that may require distinct therapeutic approaches.
Project description:<p>We conducted whole-genome sequencing of probands from several melanoma families, identifying one individual carrying a novel germline variant (c.G1075A, NM_000248.3; p.E318K, NP_000239.1; rs149617956) in the melanoma lineage-specific oncogene MITF. While the variant cosegregated with melanoma in some, but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a LOD score of 2.7 under a dominant model, suggesting E318K as a possible intermediate risk variant. Consistent with this, E318K was significantly associated with melanoma in a large Australian case-control sample, giving an odds ratio (OR) of 2.33, 95% CI 1.21-4.70 (case and control carrier frequency, 0.0165 and 0.0072, respectively; P=0.008). Likewise, it was similarly associated in an independent case-control sample from the United Kingdom (UK P=0.012; combined P=0.0003, OR 2.19, 95% CI 1.41-3.45). In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma (OR 2.95, 95% CI 1.23-6.92), multiple primary melanomas (OR 4.22, 95% CI 1.52-10.91), or both (OR 8.37, 95% CI 2.58-23.80). The variant allele was also associated with increased nevus count (combined P=0.002, OR 2.54, 95% CI 1.42-4.55) and non-blue eye color (combined P=0.008, OR 2.01, 95% CI 1.11-3.81). Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma predisposition gene and highlights the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.</p>