Upregulation of beta3-adrenergic receptor mRNA in human colon cancer: a preliminary study

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 beta-adrenergic functions seem to be associated with proliferative alterations of numerous cancer cell lines. Pharmacological modulation of beta-adrenoceptors (beta-ARs) affects tumor cell growth in several experimental systems, and inhibition of metastasis formation by beta-AR antagonists in in vivo models has recently been reported. Initial epidemiological studies have provided evidence that beta-blockers can reduce cancer incidence, thus suggesting a possible role also in cancer prevention.

Colorectal mucosa and cancer tissue were obtained from 41 patients. Specimens were taken within 1 h after the surgical procedure and stored at -80 degrees C until assayed. The gene expression of beta(1)-, beta(2)- and beta(3)-ARs in cancer tissue and normal surrounding mucosa was measured by real-time PCRs.

Comparable levels of beta(1)- and beta(2)-AR mRNA were found to be expressed in normal mucosa and cancer tissues. A significant difference in beta(3)-AR mRNA levels between normal mucosa and cancer tissues was found, with beta(3)-AR mRNA expression being twice as high in cancer tissue than normal mucosa.

The results of the present study indicate that beta(3)-AR mRNA is upregulated in human colon cancer, thus suggesting the possible involvement of beta(3)-AR in malignant transformation in the human colon.