Upregulation of β3-Adrenergic Receptor mRNA in Human Colon Cancer: A Preliminary Study

Objective: Tumor cell proliferation and migration, as well as metastasis formation, can be affected by several neurotransmitters, which therefore seem to be involved in the most important aspects of the malignant phenotype. In particular, modified β-adrenergic functions seem to be associated with proliferative alterations of numerous cancer cell lines. Pharmacological modulation of β-adrenoceptors (β-ARs) affects tumor cell growth in several experimental systems, and inhibition of metastasis formation by β-AR antagonists in in vivo models has recently been reported. Initial epidemiological studies have provided evidence that β-blockers can reduce cancer incidence, thus suggesting a possible role also in cancer prevention. Methods: Colorectal mucosa and cancer tissue were obtained from 41 patients. Specimens were taken within 1 h after the surgical procedure and stored at –80°C until assayed. The gene expression of β1-, β2- and β3-ARs in cancer tissue and normal surrounding mucosa was measured by real-time PCRs. Results: Comparable levels of β1- and β2-AR mRNA were found to be expressed in normal mucosa and cancer tissues. A significant difference in β3-AR mRNA levels between normal mucosa and cancer tissues was found, with β3-AR mRNA expression being twice as high in cancer tissue than normal mucosa. Conclusion: The results of the present study indicate that β3-AR mRNA is upregulated in human colon cancer, thus suggesting the possible involvement of β3-AR in malignant transformation in the human colon.