Chaperonin (HSP60) and annexin-2 are candidate biomarkers for non-small cell lung carcinoma

Lung cancer is responsible of 12.4% and 17.6% of all newly diagnosed cancer cases and mortality due to cancer, respectively, and 5-year survival rate despite all improved treatment options is 15%. This survival rate reaches 66% in the Stage 1 and surgically treated patients. Early diagnosis which could not be definitely and commonly achieved yet is extremely critical in obtaining high survival rate in this disease. For this reason; proteomic differences were evaluated using matrix assisted laser desorption ionization (MALDI) mass spectrometry in the subgroups of lung adenocarcinoma and squamous cell carcinoma.

Fresh tissue samples of 36 malignant cases involving 83.3% (n = 30) men and 16.7% (n = 6) women patients were distributed into 2 groups as early and end stage lung cancer and each group were composed of subgroups including 18 squamous cell carcinoma (9 early stage cases, 9 end stage cases) and 18 adenocarcinoma cases (9 early stage cases, 9 end stage cases). The fresh tissues obtained from the tumoral and matched normal sites after surgical intervention. The differences in protein expression levels were determined by comparing proteomic changes in each patient.

In the subgroups of advanced stage adenocarcinoma; tumoral tissue revealed differences in expression of 2 proteins compared with normal parenchymal tissue. Of those; difference in protein expression in heat shock protein 60 (HSP60) was found statistically significant (P = 0.0001). Subgroups of early and advanced stage squamos cell carcinoma have differed in certain 20 protein expression of normal tissue and diseased squamos cell carcinoma. Of those, increased protein expression level of only annexin-2 protein was found statistically significant (P = 0.002). No significant difference was detected in early and advanced stage protein expressions of the tumoral tissues in the subgroups of adenocarcinoma and squamous cell carcinoma.

We conclude that with respect to early diagnosis of lung cancer that HSP60 and annexin-2 proteins are the important biomarkers in the subgroups of adenocarcinoma and squamous cell carcinoma. We also consider that these 2 proteins are molecules which may provide critical contribution in evaluation of prognosis, metastatic potential, response to treatment, and in establishment of differential diagnosis between adenocarcinoma and squamous cell carcinoma.