ABNORMAL EXPRESSION OF CD44 VARIANTS IN THE EXFOLIATED CELLS IN THE FECES OF PATIENTS WITH COLORECTAL-CANCER

Background & Aims: Recent investigations have shown that CD44 variant exons are frequently overexpressed in human colorectal adenocarcinoma. The aim of this study was to investigate abnormal expression of the C D44 gene in exfoliated cells from patients with colorectal cancer. Met hods: Exfoliated cells in feces from 25 patients with colorectal cance r before and after surgery and from 15 healthy volunteers were analyze d. CD44 standard, variant 6, and variant 10 messenger RNA (mRNA) expre ssions were examined in the exfoliated cells in feces by using reverse -transcription polymerase chain reaction followed by Southern hybridiz ation with exon-specific probes. Results: CD44 standard mRNA was detec ted in all samples before and after surgery and in all healthy volunte ers. CD44 variant 6 and variant 10 mRNA were detected in 17 of 25 pati ents (68%) and 15 of 25 patients (60%), respectively, in individual fe ces obtained before surgery. CD44 variant 6 mRNA and variant 10 mRNA w ere detected in postoperative samples in 3 of 25 patients (12%) and 7 of 25 patients (28%), respectively. Fifteen of 17 patients who were po sitive for CD44v6 based on preoperative fecal samples became negative after surgery (88.2%). Similarly, 12 of 15 patients who were CD44v10 p ositive in preoperative fecal samples were negative postoperatively (8 0%). Conclusions: These results suggest that analysis of CD44 variant expression in the exfoliated cells in feces can provide a noninvasive diagnostic test for colorectal cancer.