title: Gene expression analysis of multiple gastrointestinal regions reveals activation of common cell regulatory pathways following cytotoxic chemotherapy.
abstract: Gastrointestinal mucositis involves many changes at the gene level, affecting epithelial/subepithelial interactions and leading to overt damage. The regional specificity and time course of these changes, and how they relate to subsequent mucositis development however remain unknown. The aim of this study was to determine the early time course of gene expression changes along the gastrointestinal tract of the DA rat following chemotherapy. Female DA rats were treated with a single dose of 200 mg/kg irinotecan to induce mucositis, and were killed at short intervals following treatment. Small sections of stomach, jejunum and colon were harvested for analysis of genetic profiles. RNA was hybridised to high density Affymetrix oligonucleotide microarrays. Data analysis was carried out with software package, TimeCourse, freely available through Bioconductor. As early as 1 hr following chemotherapy, expression of hundreds of genes was altered, including those for transcription factors, stress response proteins and protein turnover. These genes are involved in cell proliferation, differentiation and apoptosis along with other cellular processes. At early time points, there was a significant response involving the mitogen-activated protein kinase pathway, cell cycle regulation and cytokine receptor signalling. At later time points, changes to the complement cascade became prominent. We have shown that changes in gene expression following chemotherapy occur by 1 hr, and persist for at least 72 hr after treatment. Many of these changes are highly likely to be specifically related to the subsequent development of gastrointestinal mucositis.
authors.affiliation: Department of Medical Oncology, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia, Australia. joanne.bowen@imvs.sa.gov.au
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Bowen
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: Gibson
authors.forename: Anna
authors.initials: A
authors.lastname: Tsykin
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Stringer
authors.forename: Richard M
authors.initials: RM
authors.lastname: Logan
authors.forename: Dorothy M K
authors.initials: DM
authors.lastname: Keefe
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000009:adverse effects*; D002166:Camptothecin / Q000009:adverse effects / Q000031:analogs & derivatives*; D018797:Cell Cycle Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D003106:Colon / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000187:drug effects* / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D000077146:Irinotecan; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism; D052016:Mucositis / Q000139:chemically induced* / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D013270:Stomach / Q000187:drug effects; D013997:Time Factors; D014157:Transcription Factors / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D018797:Cell Cycle Proteins; D014157:Transcription Factors; D000077146:Irinotecan; D002166:Camptothecin