Aim: 

Besides their role in the electrically excitable cells, voltage-gated potassium (Kv) channels are involved in physiological mechanisms such as proliferation, activation, apoptosis, differentiation and the cell volume control. Neoplastic growth is characterised by highly proliferating cells which also undergo dedifferentiation. Kv1.3 and Kv1.5 channels play an important physiological role in immune system and muscle. These proteins are involved in cell cycle progression, cell volume and apoptosis. In addition, an impaired expression has been also found in different types of tumours such as those from breast, colon, prostate, and glioma. The aim of the present work was to study the expression of Kv1.3 and Kv1.5 in different human cancers.

Methods: 

Tissue arrays containing samples of human healthy and cancerous tissues were performed and stained against Kv1.3 and Kv1.5. In addition, protein abundance was also analyzed by western blot.

Results: 

Results show that Kv1.3 and Kv1.5 were differentially expressed in all tissues. Thus, Kv1.3 was found in leukocytes, nervous system, adipose tissue and kidney. However, Kv1.5 was mostly detected in muscle, endothelium, kidney and immune system cells. The expression of Kv1.3 and Kv1.5 channels differed between healthy tissues and tumours. While Kv1.3 did not change or was down-regulated, Kv1.5 expression was increased in some tumours (i.e. astrocytoma and squamous cell carcinoma).

Conclusion: 

Our results suggest that the expression of Kv channels is impaired during cancer progression. Therefore, Kv1.3 and Kv1.5 could be considered as potential tumoral markers and their use in anti-tumoral therapies should be contemplated.

Supported by BFU2005-00695, BFU2008-00431 and CSD2008-00005 (Ministerio de Ciencia e Innovación, Spain)