Over-expression of COX-2 mRNA in colorectal cancer

Abstract

BackgroundCyclooxygenase-2 (COX-2, PTGS2) is an enzyme involved in the synthesis of prostaglandins and thromboxanes, which are regulators of biologic processes such as inflammation, cell proliferation and angiogenesis. COX-2 over-expression was reported in many (pre) malignant tissues, but data strongly vary and seem to depend on the methodology used.MethodsNormal colorectal mucosa and paired cancerous tissue from 60 patients with colorectal cancer was investigated for the levels of COX-2 mRNA by real-time quantitative Polymerase Chain Reaction (qPCR). COX-2 levels were expressed relative to either: tissue weight or levels of the housekeeping genes beta-2 microglobulin (B2M) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH).ResultsCOX-2 mRNA levels, normalized with respect to tissue weight or mRNA levels of the housekeeping genes B2M or GAPDH, were over-expressed in 80%, 70% and 40% of the colorectal tumor tissues, as compared to the paired adjacent normal colorectal mucosa samples, respectively. Highest mRNA COX-2 ratios tumor/normal were measured when expressed per mg tissue (mean ratio 21.6). When normalized with respect to the housekeeping genes B2M or GAPDH, mean tumor/normal ratios were 16.1 and 7.5, respectively.ConclusionExpression of COX-2 mRNA levels per mg tissue is most simple in comparison to normalization with respect to the housekeeping genes B2M or GAPDH. Levels of COX-2 mRNA are found over-expressed in almost 80% of the colorectal tumors, compared to paired adjacent normal colorectal mucosa, suggesting a role of COX-2 as a potential biomarker for cancer risk, whereas inhibitors of COX-2 could be of value in chemoprevention of colon cancer.

Tests for Serum Transglutaminase and Endomysial Antibodies Do Not Detect Most Patients With Celiac Disease and Persistent Villous Atrophy on Gluten-free Diets: a Meta-analysis

“…When comparing diagnostic accuracy for Marsh 0–1 vs Marsh 2–3 lesions, there were 9 24,25,28,29,41,44,45,47,48 eligible studies of tTG IgA (479 patients; 25% Marsh 2–3 lesions; see supplementary figure S2). Sensitivity of tTG IgA ranged from 0.16 to 0.79 and specificity ranged from 0.68 to 0.99.…”

Colorectal cancer carcinogenesis: a review of mechanisms

“…The deletion of a single allele causes 34% reduction, whereas a complete knockdown causes 86% reduction in the number of intestinal polyps in APC 716 knockout mice 65 . Increased levels of both COX-2 and prostaglandin E 2 (PGE 2 ), which is the enzymatic product of COX-2, are found in CRCs [66][67] . Another study found 51 SNPs in HPGD, SLCO2A, and ABCC4 aside from Cox-2, which code for 15-PGDH (Cox-2 antagonist), MRP4 (Cox-2 transporter), and PGT (Cox-2 transporter), respectively.…”

Down-regulation of cyclooxygenase-2 (COX-2) by cannabidiolic acid in human breast cancer cells

“…A real-time quantitative RT-PCR assay was performed with FastStart Essential DNA Green Master (Roche Applied Science, Indianapolis, IN, USA) and the LightCycler Nano (Roche Diagnostics, Mannheim, Germany). Primers for the PCR of β-actin, COX-2, and CHIP were taken from previous studies (Wu et al, 2003;Shigematsu et al, 2009;Roelofs et al, 2014). The reaction conditions for COX-2 were 95°C for 10 min, followed by 45 cycles at 95°C for 10 sec, at 58°C for 10 sec, and 72°C for 15 sec, and for CHIP were 95°C for 10 min, followed by 45 cycles at 95°C for 10 sec, at 60°C for 10 sec, and 72°C for 15 sec.…”