Ratio of CD44 epithelial variant to CD44 hematopoietic variant is a useful prognostic indicator in gastric and colorectal carcinoma.
BACKGROUND
The CD44 is a cell adhesion molecule that is present as numerous isoforms created by mRNA alternative splicing. Expression of variant isoforms of CD44 is associated with tumor growth and metastasis. The aim of this study was to evaluate whether CD44 isoform expression is a prognostic factor in gastric and colorectal cancer.


METHODS
We performed a polymerase chain reaction analysis following reverse transcriptase treatment for CD44 expression in fresh surgical specimens obtained from 25 colon carcinomas and 30 gastric carcinomas and matched adjacent normal mucosa. We determined the epithelial variant/hematopoietic variant (E/H) ratio (the amount of the CD44 epithelial variant transcript relative to the CD44 hematopoietic variant transcript) in cancer tissues and examined it for correlations with clinicopathological parameters and survival rate.


RESULTS
The E/H ratio in tumor tissue was significantly higher than that in adjacent non-cancerous mucosa. In gastric and colorectal cancer tissues, there was no significant relationship between E/H ratio and clinicopathological parameters. However, patients who died due to tumor recurrence had a higher E/H ratio than surviving patients with colorectal cancer. In gastric cancer, patients with high E/H tumors had a shorter survival time than those with low E/H tumors.


CONCLUSIONS
Our results suggest that the E/H ratio is a useful indicator of prognosis in gastric and colorectal carcinoma.
Shibuya
Y
Y
First Department of Surgery, Okayama University Medical School, Japan.
Okabayashi
T
T
Oda
K
K
Tanaka
N
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D004848:Epithelium; D014644:Genetic Variation; D006413:Hematopoietic System; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis / Q000235:genetics*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology
D018960:Hyaluronan Receptors; D012333:RNA, Messenger