Baiteng Zhao

cDNA microarray reveals altered cytoskeletal gene expression in space-flown leukemic T lymphocytes (Jurkat)

Cytoskeletal disruption and growth arrest consistently occur in space‐flown human acute leukemic T cells (Jurkat). Although the microtubules appear to reorganize during spaceflight, cells remain nonproliferative. To test the hypothesis that spaceflight alters cytoskeletal gene expression and may thus affect cytoskeletal function, we flew Jurkat cells on Space Transportation System (STS) 95 and compared RNA message by cDNA microarray in space‐flown vs. ground controls at 24 h (4,324 genes) and 48 h (>20,000 genes). Messages for 11 cytoskeleton‐related genes, including calponin, dynactin, tropomodulin, keratin 8, two myosins, an ankyrin EST, an actinlike protein, the cytoskeletal linker (plectin), and a centriole‐associated protein (C‐NAP1), were up‐regulated in space‐flown compared with ground control cells; gelsolin precursor was down‐regulated. Up‐regulation of plectin and C‐NAP1 message in both space‐flown cells and vibrated controls is a novel finding and implies their role in vibration damage repair. This first report of cDNA microarray screening of gene expression in space‐flown leukemic T cells also identifies differential expression of genes that regulate growth, metabolism, signal transduction, adhesion, transcription, apoptosis, and tumor suppression. Based on differential expression of cytoskeletal genes, we conclude that centriole‐centriole, membrane‐cytoskeletal, and cytoskeletal filament associations are altered in the orbital phase of spaceflight.