Project description:Gene expression levels in normal tissues can differ substantially between individuals, due to inherited polymorphisms acting in cis or trans. Analysis of this variation across a population of genetically distinct individuals allows us to visualize a network of co-expressed genes under normal homeostatic conditions, and the consequences of perturbation by tissue damage or disease development. Here, we explore gene expression networks in normal adult skin from 470 genetically unique mice, and demonstrate the dependence of the architecture of signaling pathways on skin tissue location (dorsal or tail skin) and perturbation by induction of inflammation or tumorigenesis. Gene networks related to specific cell types, as well as signaling pathways including Sonic Hedgehog (Shh), Wnt, Lgr family stem cell markers, and keratins differed at these tissue sites, suggesting mechanisms for the differential susceptibility of dorsal and tail skin to development of skin diseases and tumorigenesis. The Pten tumor suppressor gene network is extensively rewired in premalignant tumors compared to normal tissue, but this response to perturbation is lost during malignant progression. We present a software package for eQTL network analysis and demonstrate how network analysis of whole tissues provides insights into interactions between cell compartments and signaling molecules. Time course analysis of replicate exposure to epidermal application of TPA
Project description:Gene expression architecture of mouse dorsal and tail skin reveals functional differences in inflammation and cancer [telogen/anagen]
Project description:Germline polymorphisms influence gene expression networks in normal mammalian tissues. Analysis of this genetic architecture can identify single genes and whole pathways that influence to complex traits including inflammation and cancer susceptibility. Changes in the genetic architecture during the development of benign and malignant tumours have not been investigated. Here, we document major changes in germline control of gene expression during skin tumour development as a consequence of cell selection, somatic genetic events, and changes in tumour microenvironment. Immune response genes such as Interleukin 18 and Granzyme E are under germline control in tumours but not in normal skin. Gene expression networks linked to tumour susceptibility and hair follicle stem cell markers in normal skin undergo significant reorganization during tumour progression. Our data highlight opposing roles of Interleukin-1 signaling networks in tumour susceptibility and tumour progression and have implications for the development of chemopreventive strategies to reduce cancer incidence. Skin tumors were induced on dorsal back skin from a Mus spretus / Mus musculus backcross ([SPRET/Ei X FVB/N] X FVB/N) mice by treatment of dorsal back skin with dimethyl benzanthracene (DMBA) and tetradecanoyl-phorbol acetate (TPA). This treatment induced multiple benign papillomas as well as malignant squamous cell carcinomas (SCC) and spindle cell carcinomas. 60 carcinomas were harvested from 55 mice; five mice provided two carcinomas each.
Project description:Gene expression levels in normal tissues can differ substantially between individuals, due to inherited polymorphisms acting in cis or trans. Analysis of this variation across a population of genetically distinct individuals allows us to visualize a network of co-expressed genes under normal homeostatic conditions, and the consequences of perturbation by tissue damage or disease development. Here, we explore gene expression networks in normal adult skin from 470 genetically unique mice, and demonstrate the dependence of the architecture of signaling pathways on skin tissue location (dorsal or tail skin) and perturbation by induction of inflammation or tumorigenesis. Gene networks related to specific cell types, as well as signaling pathways including Sonic Hedgehog (Shh), Wnt, Lgr family stem cell markers, and keratins differed at these tissue sites, suggesting mechanisms for the differential susceptibility of dorsal and tail skin to development of skin diseases and tumorigenesis. The Pten tumor suppressor gene network is extensively rewired in premalignant tumors compared to normal tissue, but this response to perturbation is lost during malignant progression. We present a software package for eQTL network analysis and demonstrate how network analysis of whole tissues provides insights into interactions between cell compartments and signaling molecules. Refer to individual Series
Project description:Germline polymorphisms influence gene expression networks in normal mammalian tissues. Analysis of this genetic architecture can identify single genes and whole pathways that influence to complex traits including inflammation and cancer susceptibility. Changes in the genetic architecture during the development of benign and malignant tumours have not been investigated. Here, we document major changes in germline control of gene expression during skin tumour development as a consequence of cell selection, somatic genetic events, and changes in tumour microenvironment. Immune response genes such as Interleukin 18 and Granzyme E are under germline control in tumours but not in normal skin. Gene expression networks linked to tumour susceptibility and hair follicle stem cell markers in normal skin undergo significant reorganization during tumour progression. Our data highlight opposing roles of Interleukin-1 signaling networks in tumour susceptibility and tumour progression and have implications for the development of chemopreventive strategies to reduce cancer incidence. Skin tumors were induced on dorsal back skin from a Mus spretus / Mus musculus backcross ([SPRET/Ei X FVB/N] X FVB/N) mice by treatment of dorsal back skin with dimethyl benzanthracene (DMBA) and tetradecanoyl-phorbol acetate (TPA). This treatment induced multiple benign papillomas as well as malignant squamous cell carcinomas (SCC) and spindle cell carcinomas. Gene expression analysis was performed on mRNA extracted from 68 papillomas: two papillomas from each of 31 FVBBX mice and a single papilloma from six additional FVBBX mice. Papillomas were harvested when mice were sacrificed due to presence of a carcinoma or termination of the experiment.
Project description:Gene expression in self-renewing epithelial tissues is controlled by cis- and trans-activating regulatory factors that mediate responses to exogenous agents capable of causing tissue damage, infection, inflammation, or tumorigenesis. We used network construction methods to analyze the genetic architecture of gene expression in normal mouse skin in a cross between tumor-susceptible Mus musculus and tumor-resistant Mus spretus. We demonstrate that gene expression motifs representing different constituent cell types within the skin such as hair follicle cells, haematopoietic cells, and melanocytes are under separate genetic control. Motifs associated with inflammation, epidermal barrier function and proliferation are differentially regulated in mice susceptible or resistant to tumor development. The intestinal stem cell marker Lgr5 is identified as a candidate master regulator of hair follicle gene expression, and the Vitamin D receptor (Vdr) links epidermal barrier function, inflammation, and tumor susceptibility. Keywords: Expression Quantitative Trait Loci A backcross was generated using male Mus spretus and female FVB/N mice; female F1 hybrids were mated with male FVB/N mice. Seventy-one backcross mice (8-12 weeks old) received a single dose of DMBA (25 µg per mouse in 200 µl acetone). Starting one week after the initiation tumors were promoted with TPA (200 µl of 10-4 M solution in acetone) twice weekly for 20 weeks. Initiation and promotion were performed on doral back skin. Normal tail skin was snap frozen when the animals were sacrificed. Tail epidermis from completely untreated Spretus, FVB, and Spretus x FVB F1 mice was also analyzed.
Project description:Papillomaviruses (PVs) are able to induce papillomas, premalignant lesions, and carcinomas in a wide variety of species. PVs are classified first based on their host and tissue tropism and then their genomic diversities. A laboratory mouse papillomavirus, MmuPV1 (formerly MusPV), naturally infects NMRI-Foxn1nu/Foxn1nu (nude; T cell deficient) mice. C57BL/6J wild-type mice were not susceptible to MmuPV1 infection; however, immunocompetent, alopecic, S/RV/Cri-ba/ba (bare) mice developed small papillomas at injection sites that regressed. NMRI-Foxn1nu and B6.Cg-Foxn1nu but not NU/J-Foxn1nu mice were susceptible to MmuPV1 infection. B6 congenic strains, but not other congenic strains carrying the same allelic mutations, that lack B- and T-cells, but not B-cells alone, were susceptible to infection, indicating that mouse strain and T-cell deficiency are critical to tumor formation. Although lesions initially observed were exophytic papillomas around the muzzle, exophytic papillomas on the tail and condylomas of the vaginal lining could be induced by experimental infections. On the dorsal skin, locally invasive, poorly differentiated tumors developed with features similar to human trichoblastomas. Transcriptome analysis revealed significant differences between the normal skin in these anatomic sites and in papillomas versus trichoblastomas. The primarily dysregulated genes involved molecular pathways associated with cancer, cellular development, cellular growth and proliferation, cell morphology, and connective tissue development and function. Surprisingly, few of the genes commonly associated with basal cell carcinoma or squamous cells carcinoma were dramatically dysregulated. To determine if there were transcriptome differences between papillomas on the tail skin compared to invasive trichoblastomas on the dorsal skin, tumors from the tail and dorsal skin from 3 B6.Cg-Foxn1nu/Foxn1nu mice and unaffected skin from the tail or contra-lateral (dorsal skin) were compared using the Affymetrix GeneChip Mouse Genome 1.0 ST Array. Concurrently, a matched study was done at the University of Louisville comparing facial (muzzle) papillomas and dorsal skin trichoblastomas to respective unaffected contralateral skin.
Project description:Gene expression levels in normal tissues can differ substantially between individuals, due to inherited polymorphisms acting in cis or trans. Analysis of this variation across a population of genetically distinct individuals allows us to visualize a network of co-expressed genes under normal homeostatic conditions, and the consequences of perturbation by tissue damage or disease development. Here, we explore gene expression networks in normal adult skin from 470 genetically unique mice, and demonstrate the dependence of the architecture of signaling pathways on skin tissue location (dorsal or tail skin) and perturbation by induction of inflammation or tumorigenesis. Gene networks related to specific cell types, as well as signaling pathways including Sonic Hedgehog (Shh), Wnt, Lgr family stem cell markers, and keratins differed at these tissue sites, suggesting mechanisms for the differential susceptibility of dorsal and tail skin to development of skin diseases and tumorigenesis. The Pten tumor suppressor gene network is extensively rewired in premalignant tumors compared to normal tissue, but this response to perturbation is lost during malignant progression. We present a software package for eQTL network analysis and demonstrate how network analysis of whole tissues provides insights into interactions between cell compartments and signaling molecules.