Expression of survivin and its four splice variants in colorectal cancer and its clinical significances

The aim of this study was to investigate the clinical significances of the mRNA expression of survivin gene and its four splice variants in the pathogenesis of colorectal cancer (CRC). CRC samples, matched adjacent tissues, and normal tissues were collected from surgical resections of 39 patients with histologically confirmed diagnosis. The mRNA expression of survivin and its four splice variants, that is, survivin-Delta Ex3, survivin-2B, survivin-3B, and survivin-2 alpha, was detected using semiquantitative PCR and RT-PCR. Carcinoembryonic antigen (CEA) CAM5 was determined as control. The mRNA expression rates of survivin, survivin-Delta Ex3, survivin-2B, survivin-3B, surviving-2 alpha, and CEA CAM5 in CRC samples were significantly higher than those in adjacent tissues (P < 0.01) and those in normal tissues (P < 0.01). The mRNA levels of the above variants in CRC samples were also significantly higher than those in adjacent tissues (P < 0.01) and those in normal tissues (P < 0.01). The mRNA levels of survivin, survivin-2B, and survivin-2 alpha were not associated with any clinical variable of patients, while the levels of survivin-Delta Ex3 and survivin-3B were associated with lymphoid metastasis and Dukes grade (P < 0.05), and survivin-Delta Ex3 was associated with invasiveness. We concluded that mRNA expression rates and levels of survivin and its four splice variants elevated in CRC tissues, and expression levels of survivin-Delta Ex3 and survivin-3B were positively associated with tumor aggression.