CD26 is overexpressed in lung adenocarcinoma and qualifies as a therapeutic target against lung cancer

Hintergrund:

Lung cancer is the leading cause of cancer-related deaths worldwide. The immune response of this malignancy is closely associated with its prognosis.

CD26/dipeptidyl peptidase 4 (CD26) is a molecule expressed on multiple cell surfaces with an enzymatic activity degrading various inflammatory mediators. We have previously shown that the inhibition of CD26 decreases the growth of lung cancer in mice. We thus analyzed now the expression of CD26 in human lung tumors to test if this molecule has the potential as a target against lung cancer.

Material and Methode:

Tumor samples from 87 patients (non-small cell lung carcinoma, NSCLC: Adenocarcinoma, n = 51; Squamous carcinoma, n = 19) vs. other tumor types (carcinoid, small cell lung carcinoma, secondary lung cancers, n = 17) were analyzed by immunohistochemistry (IHC) and RT-PCR for the expression of CD26. Statistical analysis was performed using the student t-test for unpaired samples (Prism 5.0, GraphPad Software, San Diego, CA, USA).

Ergebnis:

The expression of CD26 in IHC was significantly increased in NSCLC when compared to normal tissue or other tumor types (p < 0.05), which was additionally confirmed RT-PCR. The expression of CD26 was significantly higher in early stages of NSCLC (I-II), both in IHC and PCR compared to later stages (III-IV) (p < 0.05). Moreover, the expression of CD26 was significantly higher in adenocarcinoma compared to squamous carcinoma.

Schlussfolgerung:

The expression CD26 in human lung adenocarcinoma was significantly higher compared to normal lung tissue or other types of cancers. These data support the hypothesis that CD26 is a putative target for lung adenocarcinoma inhibition.