Microarray Studies of Immune Function After Surgery

In addition to its clinical advantages over conventional open surgery, laparoscopy results in less systemic inflammation and fewer alterations in the cell-mediated immune response. In experimental models, laparotomy is associated with increased tumor growth not observed following CO₂ pneumoperitoneum, which may be related to differential effects on immune function. Experimental and clinical data have shown significant differences in levels and activity of a number of serum factors which may impact postoperative tumor growth, but the mechanisms underlying these differences are unclear. Oligonucleotide microarrays were used to survey and compare gene expression in splenic T-cells following anesthesia, CO₂ pneumoperitoneum, and laparotomy in a murine model. Significant differences in patterns of alterations in gene expression between experimental groups were identified. Microarray results with respect to several T-cell genes were reproduced at the RNA and protein level, which validated this analysis as a useful tool to uncover the molecular basis for differences in immune cell response to surgical procedures. Preliminary data in a murine oncologic model also identified differential patterns of gene expression across experimental groups. In the clinical setting, microarray analysis is currently being investigated to identify genes as potential targets for modulating the immune response to surgery and to identify genes that may prove useful as diagnostic and prognostic indicators.