[Significance of caveolin-1 protein detected by quantum dots technique in human lung cancer invasiveness and metastasis.].

OBJECTIVE

Fluorescent semiconductor nanocrystals [also known as quantum dots (QDs)] are nanometer-sized light-emitting particles and are emerging as a new class of fluorescent probes for cancer detection, due to their unique optical and electronic properties. The aim of this study was to investigate the expression of caveolin-1 (Cav-1), extracellular matrix metalloproteinase inducer (CD(147)/EMMPRIN), matrix metalloproteinase-2 (MMP-2) proteins in the human lung cancer tissue microarray (TMA) by QDs immunofluorescence histochemistry (QDs-IHC) and therefore to evaluate the relationship between Cav-1 protein and lung cancer invasiveness and metastasis.

METHODS

QDs-IHC combined with TMA were used to detect the expression of Cav-1, CD(147) and MMP-2 proteins in 70 cases of human lung cancers and 5 cases of noncancerous lung tissues.

RESULTS

The average immunofluorescence intensity of Cav-1 protein in the lung cancer group was 55 +/- 23, significantly lower than that in the control group (80 +/- 4, t = 2.461, P = 0.016). The expression of Cav-1 was not associated with the age and the gender of the patients, nor with the histology type of lung cancer (P > 0.05). The average immunofluorescence intensity of Cav-1 protein was associated significantly with TNM staging (t = 2.466, P = 0.016) and lymph node metastasis (t = 2.972, P = 0.004). A negative correlation was observed between Cav-1 and CD(147) protein expression (r = -0.331, P = 0.005), but no correlation was observed between Cav-1 and MMP-2 protein expression (P = 0.193).

CONCLUSIONS

QDs-IHC could accurately and quantitatively detect different protein location in lung cancer TMA. A close relationship was detected between Cav-1 protein and the development of lung cancer. High expression of Cav-1 may be involved in invasiveness and metastasis of lung cancer, possibly through the regulation of CD(147) rather than MMP-2 activition.