Project description:Human colorectal cancer (CRC) is one of the better-understood systems for studying the genetics of cancer initiation and progression. To develop a cross-species comparison strategy for identifying CRC causative gene or genomic alterations, we performed array comparative genomic hybridization (aCGH) to investigate copy number abnormalities (CNAs), one of the most prominent lesion types reported for human CRCs, in 10 spontaneously occurring canine CRCs. The results revealed for the first time a strong degree of genetic homology between sporadic canine and human CRCs. First, we saw that between 5 and 22% of the canine genome was amplified/deleted in these tumors, and that, reminiscent of human CRCs, the total altered sequences directly correlated to the tumor’s progression stage, origin, and likely microsatellite instability status. Second, when mapping the identified CNAs onto syntenic regions of the human genome, we noted that the canine orthologs of genes participating in known human CRC pathways were recurrently disrupted, indicating that these pathways might be altered in the canine CRCs as well. Lastly, we observed a significant overlapping of CNAs between human and canine tumors, and tumors from the two species were clustered according to the tumor subtypes but not the species. Significantly, compared with the shared CNAs, we found that species-specific (especially human-specific) CNAs localize to evolutionarily unstable regions that harbor more segmental duplications and interspecies genomic rearrangement breakpoints. These findings indicate that CNAs recurrent between human and dog CRCs may have a higher probability of being cancer-causative, compared with CNAs found in one species only
Project description:Human colorectal cancer (CRC) is one of the better-understood systems for studying the genetics of cancer initiation and progression. To develop a cross-species comparison strategy for identifying CRC causative gene or genomic alterations, we performed array comparative genomic hybridization (aCGH) to investigate copy number abnormalities (CNAs), one of the most prominent lesion types reported for human CRCs, in 10 spontaneously occurring canine CRCs. The results revealed for the first time a strong degree of genetic homology between sporadic canine and human CRCs. First, we saw that between 5 and 22% of the canine genome was amplified/deleted in these tumors, and that, reminiscent of human CRCs, the total altered sequences directly correlated to the tumorâs progression stage, origin, and likely microsatellite instability status. Second, when mapping the identified CNAs onto syntenic regions of the human genome, we noted that the canine orthologs of genes participating in known human CRC pathways were recurrently disrupted, indicating that these pathways might be altered in the canine CRCs as well. Lastly, we observed a significant overlapping of CNAs between human and canine tumors, and tumors from the two species were clustered according to the tumor subtypes but not the species. Significantly, compared with the shared CNAs, we found that species-specific (especially human-specific) CNAs localize to evolutionarily unstable regions that harbor more segmental duplications and interspecies genomic rearrangement breakpoints. These findings indicate that CNAs recurrent between human and dog CRCs may have a higher probability of being cancer-causative, compared with CNAs found in one species only Comparison of human and dog colon cancer CNAs
Project description:Spontaneously occurring canine mammary cancer (MC) represents an excellent model of human breast cancer, but is greatly understudied. We performed high density arrays on 12 canine MC cases, including 7 simple carcinomas and four complex carcinomas. Simple carcinomas, which histologically match human breast carcinomas, harbor extensive genomic aberrations, many faithfully recapitulating key features of human breast cancer. Complex carcinomas, with luminal and myoepithelial cells both proliferating (which is rare in human breast cancer), appear to lack genomic abnormalities. Comparison of CNAs from canine mammary simple carcinomas and complex carcinomas
Project description:Human colorectal cancer (CRC) is one of the better-understood systems for studying the genetics of cancer initiation and progression. To develop a cross-species comparison strategy for identifying CRC causative gene or genomic alterations, we performed array comparative genomic hybridization (aCGH) to investigate copy number abnormalities (CNAs), one of the most prominent lesion types reported for human CRCs, in 10 spontaneously occurring canine CRCs. The results revealed for the first time a strong degree of genetic homology between sporadic canine and human CRCs. First, we saw that between 5% and 22% of the canine genome was amplified/deleted in these tumors, and that, reminiscent of human CRCs, the total altered sequences directly correlated to the tumor's progression stage, origin, and likely microsatellite instability status. Second, when mapping the identified CNAs onto syntenic regions of the human genome, we noted that the canine orthologs of genes participating in known human CRC pathways were recurrently disrupted, indicating that these pathways might be altered in the canine CRCs as well. Last, we observed a significant overlapping of CNAs between human and canine tumors, and tumors from the two species were clustered according to the tumor subtypes but not the species. Significantly, compared with the shared CNAs, we found that species-specific (especially human-specific) CNAs localize to evolutionarily unstable regions that harbor more segmental duplications and interspecies genomic rearrangement breakpoints. These findings indicate that CNAs recurrent between human and dog CRCs may have a higher probability of being cancer-causative, compared with CNAs found in one species only.
Project description:Abnormal function of genes is at the root of most cancers, but heritable cancer syndromes account for a very small minority of all tumors in humans and domestic animals. The majority of cancers are “sporadic,” that is, they are not heritable in the strictest sense. Instead, sporadic cancers occur due to interactions of unknown intrinsic (heritable) and environmental factors that lead to malignant transformation and uncontrolled growth. Identification of heritable risk factors in sporadic human cancers is difficult because individual genetic backgrounds are very heterogeneous. To this end, individual genetic backgrounds of purebred dogs are more homogeneous, and dog breeds show different predilection to develop specific cancers. Here, we used genomic screens based on gene expression profiling to identify sets of genes that may contribute to the development of canine hemangiosarcoma, a relatively common endothelial sarcoma. Specific genes in a single breed (Golden Retrievers) are modulated by (or with) heritable risk traits, showing functional features that appear to modulate tumor behavior. Our results suggest these methods are suitable to identify genes that will enhance our understanding of how these cancers happen, as well as possible treatment targets that will improve outcomes of both human and canine cancer patients. Keywords: Hemangiosarcoma, microarray, heritability, GSEA, canine
Project description:Abnormal function of genes is at the root of most cancers, but heritable cancer syndromes account for a very small minority of all tumors in humans and domestic animals. The majority of cancers are “sporadic,” that is, they are not heritable in the strictest sense. Instead, sporadic cancers occur due to interactions of unknown intrinsic (heritable) and environmental factors that lead to malignant transformation and uncontrolled growth. Identification of heritable risk factors in sporadic human cancers is difficult because individual genetic backgrounds are very heterogeneous. To this end, individual genetic backgrounds of purebred dogs are more homogeneous, and dog breeds show different predilection to develop specific cancers. Here, we used genomic screens based on gene expression profiling to identify sets of genes that may contribute to the development of canine hemangiosarcoma, a relatively common endothelial sarcoma. Specific genes in a single breed (Golden Retrievers) are modulated by (or with) heritable risk traits, showing functional features that appear to modulate tumor behavior. Our results suggest these methods are suitable to identify genes that will enhance our understanding of how these cancers happen, as well as possible treatment targets that will improve outcomes of both human and canine cancer patients. Keywords: Hemangiosarcoma, microarray, heritability, GSEA, canine 10 samples were analysed. 6 Golden Retrievers with hemangiosarcoma, 3 non-Golden Retrievers with hemangiosarcoma, and 1 mixed breed Golden Retriever with hemangiosarcoma. The experiment was designed to find genes associated with breed and hemangiosarcoma to asses genetic make-up on disease susceptibility and/or progression
Project description:Identification of DNA copy number imbalances in 22 spontaneous canine osteosarcoma cases using array comparative genomic hybridization (aCGH) analysis
Project description:Analysis of miRNA expression in grade 3 luminal, sporadic and BRCA1 associated basal-like breast cancers 44 primary grade III breast cancer (11 BRCA1 basal, 16 sporadic basal, 17 luminal) and 13 normal breast FFPE (formalin fixed, paraffin embedded) specimens, plus 7 controls and 5 cell lines were analysed. The aim of the study was to derive grade-specific miRNA signatures for sporadic and BRCA1 basal-like breast cancers, and to ascertain an immunohistochemical profile regulated by BRCA1 specific miRNAs for potential diagnostic uses.
Project description:We used complementary DNA (cDNA) microarrays to compare gene expression patterns in ovarian cancers associated with BRCA1 or BRCA2 mutations with gene expression patterns in sporadic epithelial ovarian cancers and to identify patterns common to both hereditary and sporadic tumors.