Project description:We reported the small RNA profiles of disease free and SLCMV infected leaves of susceptible and tolerant genotypes of cassava. The sRNA data generated through high throughput small RNA sequencing revealed critical regulatory role of host and pathogen derived small RNAs during SLCMV infection.
Project description:Background: Oral squamous cell carcinoma (OSCC) is a major world health problem with over 400,000 new cases diagnosed annually. Despite advances in surgery and chemo-radiotherapy, the 5 year survival has remained roughly constant at approximately 50% for several decades. The disease is characterized by both clinical and genetic heterogeneity, so elucidating the molecular basis of this heterogeneity would have significant clinical implications. It is well recognized that OSCCs from Asia that are associated with betel quid chewing are phenotypically distinct from those from the West that are predominantly caused by smoking/drinking, but the genetic basis of these differences are largely unknown. The aim of this study is to examine the most related genetic factors, carcinogenic related pathways, and molecular processes that might be responsible for the phenotypic heterogeneity of OSCC between UK and Sri Lankan population groups. Methods: We have compared the gene expression profiles of OSCCs and normal oral mucosal tissues from both Sri Lankan and UK individuals using Affymetrix gene expression arrays. Results: The gene expression profiles of UK and Sri Lankan OSCC are similar in many respects to other oral cancer expression profiles reported in the literature and were mainly similar to each other. However, genes involved in tumor invasion, metastasis and recurrence were more obviously associated with UK tumors as opposed to those from Sri Lanka. Interestingly, Ingenuity Pathway Analysis (IPA) revealed a highly activated cell-mediated immune response in both Sri Lankan normal and tumor samples relative to UK cohorts, which may, in part, explain the less aggressive behavior of these betel quid-induced OSCCs. Conclusion: The development of OSCCs in both UK and Sri Lankan populations appears largely mediated by similar biological pathways despite the differences related to race, ethnicity, lifestyle, and/or exposure to environmental carcinogens. However, IPA revealed a highly activated M-bM-^@M-^\Cell-mediated Immune ResponseM-bM-^@M-^] in Sri Lankan normal and tumor samples relative to UK cohorts. It seems likely, therefore, that any future attempts to personalize treatment for OSCC patients will need to be different in Western and Asian countries to reflect differences in gene expression and the immune status of the patients. All biopsy specimens of OSCC and normal oral mucosa were harvested with appropriate ethical approval and informed consent of individual patients (LREC 0769). Identical protocols for tissue collection and processing were used in both countries. OSCC samples were obtained from sequential incident cases treated by a single consultant surgeon from 2001 to 2004 at University Hospital of Birmingham, NHS Foundation Trust, Birmingham, UK, and Kandy General Hospital, Kandy, Sri Lanka. A total of 21 UK and 27 Sri Lankan samples yielded RNA of sufficient quality and quantity for microarray analysis. In addition, 8 normal oral mucosa specimens (five samples from UK & three samples from Sri Lankan population) were also profiled. All normal samples were from non-smokers, who did not chew betel quid and did not consume in excess of the national recommended weekly gender allowance of alcohol. Normal samples were taken from individuals with no history of cancer and had no first degree relatives with a history of cancer.
Project description:Background: Oral squamous cell carcinoma (OSCC) is a major world health problem with over 400,000 new cases diagnosed annually. Despite advances in surgery and chemo-radiotherapy, the 5 year survival has remained roughly constant at approximately 50% for several decades. The disease is characterized by both clinical and genetic heterogeneity, so elucidating the molecular basis of this heterogeneity would have significant clinical implications. It is well recognized that OSCCs from Asia that are associated with betel quid chewing are phenotypically distinct from those from the West that are predominantly caused by smoking/drinking, but the genetic basis of these differences are largely unknown. The aim of this study is to examine the most related genetic factors, carcinogenic related pathways, and molecular processes that might be responsible for the phenotypic heterogeneity of OSCC between UK and Sri Lankan population groups. Methods: We have compared the gene expression profiles of OSCCs and normal oral mucosal tissues from both Sri Lankan and UK individuals using Affymetrix gene expression arrays. Results: The gene expression profiles of UK and Sri Lankan OSCC are similar in many respects to other oral cancer expression profiles reported in the literature and were mainly similar to each other. However, genes involved in tumor invasion, metastasis and recurrence were more obviously associated with UK tumors as opposed to those from Sri Lanka. Interestingly, Ingenuity Pathway Analysis (IPA) revealed a highly activated cell-mediated immune response in both Sri Lankan normal and tumor samples relative to UK cohorts, which may, in part, explain the less aggressive behavior of these betel quid-induced OSCCs. Conclusion: The development of OSCCs in both UK and Sri Lankan populations appears largely mediated by similar biological pathways despite the differences related to race, ethnicity, lifestyle, and/or exposure to environmental carcinogens. However, IPA revealed a highly activated “Cell-mediated Immune Response” in Sri Lankan normal and tumor samples relative to UK cohorts. It seems likely, therefore, that any future attempts to personalize treatment for OSCC patients will need to be different in Western and Asian countries to reflect differences in gene expression and the immune status of the patients.
Project description:Cassava mosaic disease caused by cassava begomoviruses is the most serious disease of cassava in Africa. However, the molecular mechanisms leading to symptom development of infected cassava plants are poorly understood. Here a high throughput digital gene expression profiling (DGE) based on Illumina Solexa sequencing technology was used to investigate the global transcriptional response of cassava to the African cassava mosaic virus infection. Results showed that 3,210 genes were differentially expressed in virus-infected cassava leaves. Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that photosynthesis related genes were most affected, which was consistent with the chlorotic symptom on the infected leaves. The upregulation of chlorophyll degradation genes, e.g. the genes encoding chlorophyllase and pheophorbide a oxygenase, as well as the downregulation of the major apoproteins genes in light harvesting complex II (LHCII) identified by the DGE analysis were confirmed by qRT-PCR. Together with the reduction of chlorophyll b content and fewer grana stacks in the infected leaf cells, this study reveals that the degradation of chlorophyll plays an important role during ACMV symptom development for the first time. Meanwhile, we believe that the non-lethal effect on photosystem is a trick for virus to avoid fierce host immune response and a result of the long-term co-evolution. This study will provide a road map for future investigations into virus symptom development. ACMV-infected cassava leaves mixture from three independent replicates were collected for RNA extractions at 20 dpi. Control samples were harvested from empty agrobacteria treated leaves incubated under the same conditions.
Project description:Cassava mosaic disease caused by cassava begomoviruses is the most serious disease of cassava in Africa. However, the molecular mechanisms leading to symptom development of infected cassava plants are poorly understood. Here a high throughput digital gene expression profiling (DGE) based on Illumina Solexa sequencing technology was used to investigate the global transcriptional response of cassava to the African cassava mosaic virus infection. Results showed that 3,210 genes were differentially expressed in virus-infected cassava leaves. Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that photosynthesis related genes were most affected, which was consistent with the chlorotic symptom on the infected leaves. The upregulation of chlorophyll degradation genes, e.g. the genes encoding chlorophyllase and pheophorbide a oxygenase, as well as the downregulation of the major apoproteins genes in light harvesting complex II (LHCII) identified by the DGE analysis were confirmed by qRT-PCR. Together with the reduction of chlorophyll b content and fewer grana stacks in the infected leaf cells, this study reveals that the degradation of chlorophyll plays an important role during ACMV symptom development for the first time. Meanwhile, we believe that the non-lethal effect on photosystem is a trick for virus to avoid fierce host immune response and a result of the long-term co-evolution. This study will provide a road map for future investigations into virus symptom development.
Project description:Analysis of transcriptional response of virus-infected cassava and identification of putative sources of resistance for cassava brown streak disease transcriptome analysis of two varieties of cassava that differ in their level of resistance to cassava brown streak virus.