ABSTRACT
BACKGROUND/AIM: This study aims to explore the expression and significance of feces cyclooxygensae-2 (COX-2) mRNA in colorectal cancer and colorectal adenomas. MATERIALS AND METHODS: The expression of feces COX-2 mRNA in colorectal cancer (n = 28), colorectal adenomas (n = 54), and normal control group (n = 11) were examined by reverse transcriptase polymerase chain reaction (RT-PCR). The positive rate of fecal occult blood test (FOBT) were detected in colorectal cancer (n = 30), colorectal adenomas (n = 56), and normal control group (n = 11); the sensitivity of the two methods was also compared. RESULTS: The positive rate of feces COX-2 mRNA in colorectal cancer was 82.1% (25/28), which was significantly higher than colorectal adenomas 59.3% (32/54), and normal tissues 18.2% (2/11), the difference being significant between the three groups (χ2= 13.842,P= 0.001). The positive rate of FOBT in colorectal cancer was 73.3% (10/30), which was significantly higher than colorectal adenomas 10.7% (6/56) and normal tissues 9.1% (1/11), the difference being significant between these three groups (χ2= 7.525,P= 0.023). There was no significant association between feces COX-2 expression and various clinical pathological features of colorectal cancer and colorectal adenomas (P > 0.05). The sensitivity of the RT-PCR method is higher than FOBT, however, the specificity of FOBT is slightly higher than RT-PCR. CONCLUSIONS: High expression of feces COX-2 mRNA in colorectal adenomas and colorectal cancer is a common event; it is an early event in the development of colorectal adenomas to colorectal cancer. Feces COX-2 mRNA has a high sensitivity for detect colorectal cancer; combination with FOBT will be the best alternative. Feces COX-2 can be potentially used in the early diagnosis and screening of colorectal cancer.
Subject(s)
Adenoma/genetics , Colorectal Neoplasms/genetics , Cyclooxygenase 2/genetics , Feces/enzymology , Adenoma/enzymology , Colorectal Neoplasms/enzymology , Early Detection of Cancer , Female , Humans , Male , Middle Aged , Reverse Transcriptase Polymerase Chain Reaction/methods , Up-RegulationABSTRACT
Deregulation of Wnt/ß-catenin signaling following inactivation of the adenomatous polyposis coli (APC) tumor suppressor gene is frequently found in colorectal cancer. We have previously shown that levels of ITF-2B, encoded by the ß-catenin target gene ITF2 that is located on the tumor suppressor gene locus 18q21, are increased in colonic adenomas with deregulated ß-catenin activity. However, during tumor progression ITF-2B levels are reduced, suggesting that ITF-2B interferes with tumor development. To investigate the role of ITF2 in intestinal tumorigenesis, we specifically inactivated Itf2 in the intestinal epithelium of Apc(Min/+) mice. We found that genetic disruption of Itf2 on the Apc(Min/+) background results in earlier death and a significant increase in tumor number and size in the small intestine. Based on these data Itf2 acts as a tumor suppressor gene of the intestinal tract that inhibits tumor initiation and growth.
Subject(s)
Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/genetics , Gene Expression Regulation, Neoplastic , Genes, APC , Intestinal Neoplasms/genetics , Intestinal Neoplasms/pathology , Intestine, Small/pathology , Animals , Gene Deletion , Intestine, Small/metabolism , Mice , Mice, Inbred C57BL , Transcription Factor 4ABSTRACT
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 (χ(2) = 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 (χ(2) = 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.
Subject(s)
Ascites/enzymology , Ascites/genetics , Biomarkers, Tumor/genetics , Cyclooxygenase 2/genetics , Neoplasms/complications , RNA, Messenger/analysis , Adult , Aged , Ascites/microbiology , Biopsy , Chi-Square Distribution , Diagnosis, Differential , Female , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Neoplastic , Humans , Liver Cirrhosis/complications , Male , Middle Aged , Predictive Value of Tests , Reverse Transcriptase Polymerase Chain Reaction , Tuberculosis/complicationsABSTRACT
OBJECTIVE: To discuss effect of ionizing radiation on transcription of colorectal cancer multidrug resistance (MDR) 1 gene of HCT-8 cells. METHODS: Total RNA was extracted by guanidine thiocyanate one-step method. Northern blot was applied to detect transcription level of MDR1 gene. The expression of P-gp protein was detected by flow cytometry. RESULTS: The expression of MDR1 of normal colorectal cancer HCT-8 cells was low. It was increased by 8.35 times under stimulus with 2 Gy. When treated with low doses in advance, high expressed MDR was decreased significantly under 0.05, 0.1 Gy, which was 69.00%, 62.89% in 2 Gy group and 5.77 times, 5.25 times in sham irradiation group. No obvious difference was detected between (0.2+2) Gy group and 2 Gy group. Compared with sham irradiation group, the percentage of P-gp positive cells after radiation of a high 2 Gy dose was increased significantly (P<0.01). When treated with high radiation dose following low radiation dose (0.05 Gy, 0.1 Gy) in advance, the percentage of P-gp positive cells were also increased significantly. The percentage of P-gp positive cells were increased obviously in 0.2 Gy and 2 Gy groups. Compared with simple high radiation 2 Gy group, the percentage of P-gp positive cells was decreased significantly (P<0.05). CONCLUSIONS: Low radiation dose can reverse multidrug resistance of colorectal cancer cells caused by high radiation dose.
