Published online Oct 28, 2013. doi: 10.3748/wjg.v19.i40.6883
Revised: August 8, 2013
Accepted: September 3, 2013
Published online: October 28, 2013
AIM: To investigate the mRNA expression of cyclooxygensae-2 (COX-2) in benign and malignant ascites, and to explore the difference in COX-2 mRNA expression among different diseases.
METHODS: A total of 36 samples were collected from the Fifth Affiliated Hospital of Sun Yat-Sen University and divided into two experimental groups: benign ascites (n = 21) and malignant ascites (n = 15). Benign ascites included cirrhotic ascites (n = 10) and tuberculous ascites (n = 5). Malignant ascites included oophoroma (n = 7), cancer of colon (n = 5), cancer of the liver (n = 6), gastric cancer (n = 2), and bladder carcinoma (n = 1). The mRNA expression of COX-2 in ascites was examined with reverse transcriptase polymerase chain reaction (RT-PCR) technology, and the positive rate of COX-2 mRNA was compared between different diseases.
RESULTS: The positive rate of COX-2 mRNA in malignant ascites was 42.9% (9/21), which was significantly higher than in benign ascites, 6.7% (1/15), difference being significant between these two groups (χ2 = 4.051, P = 0.044). The proportion of the positive rate in the malignant ascites was as follows: ovarian cancers 57.1% (4/7), colon cancer 40.0% (2/5), liver cancer 33.3% (2/6), gastric cancer 50.0% (1/2), and bladder cancer 0.00% (0/1). However, there was no significant difference in COX-2 mRNA expression among various tumors with malignant ascites (χ2 = 1.614, P = 0.806). Among the benign ascites, COX-2 mRNA levels were different between the tuberculous ascites (0/5) and cirrhotic ascites (1/10), but there was no significant difference (P = 1.000).
CONCLUSION: COX-2 mRNA, detected by RT-PCR, is useful in the differential diagnosis of benign and malignant ascites, which also has potential value in the clinical diagnosis of tumors.
Core tip: Ascites is a common symptom caused by a variety of diseases, the differential diagnosis between benign ascites and malignant ascites is one of the most important issues in clinical practice. Cytologic examinations and ascites tumor markers can provide important evidence, but their sensitivity and specificity are far from satisfactory. Our study aimed to explore the difference in cyclooxygensae-2 (COX-2) mRNA expression among different diseases. Our research suggests that COX-2mRNA can be detected by reverse transcriptase polymerase chain reaction, but there are no significant differences in the expression of COX-2 mRNA among various disease types with benign or malignant ascites.