Aldehyde dehydrogenases in early stage lung cancer: nuclear expression

Aldehyde dehydrogenase enzymes are a family of intracellular enzymes that participate in cellular detoxification, differentiation and drug resistance through the oxidation of cellular aldehydes. The isoform 1 (ALDH1) has been proved useful for the identification of cancer stem cells. The ALDH1 cytoplasmatic expression has been associated with poor prognostis in several tumours, such as non-small cell lung cancer. The role of the ALDH1 nuclear expression remains unknown.

We conducted a historical cohort study in 89 patients diagnosed of stage I non-small cell lung cancer treated with surgery between 2009 and 2004 in the Thoracic Surgery Department in the Universitary Hospital Puerta de Hierro. We selected from this sample those cases with nuclear expression of the ALDH1.

Three of the 89 (3.3 %) patients showed a nuclear expression of the ALDH1. The three of them are still alive with a median time of follow up of 73 months (more than 6 years).

We have identified ALDH1 as a nuclear protein in early stage non-small cell lung cancer. It might have a function in cell cycle control, associating a better prognosis to these patients. More studies are necessary to clarify the role of nuclear expression of ALDH1.