Association of Tumor Suppressor Sparcl1 with Clinical Staging and Prognosis of NSCLC.

OBJECTIVE

To explore associations of tumor suppressor Sparcl1 with clinical staging and prognosis of non-small cell lung cancer (NSCLC).

METHODS

Quantitative RT-PCR and Western blot were used to measure the expression of Sparcl1 gene in NSCLC and verify the process of transfection. Expression of Sparcl1 gene in NSCLC tissues were detected by immunohistochemistry. Cell scratch test and flow cytometer were used to detect the influence on lung adenocarcinoma A549 cells' migration, apoptosis, and cell cycle causing by the overexpression of lung adenocarcinoma A549 cell and negative control group.

RESULTS

The level of Sparcl1 mRNA in the adjacent lung tissue was higher than NSCLC tissues. The level of Sparcl1 protein in the adjacent lung tissue was relatively higher than NSCLC tissues. The expression differences of Sparcl1 in NSCLC were related to clinical stages - the proportion of low expression of Sparcl1 in TNM stage (I+II) was higher than TNM stage (III+IV). Compared with patients with low expression of Sparcl1, the 5-year survival rate of patients with high expression of Sparcl1 was higher. The migration ability of A549 cell with overexpressing Sparcl1 was weaker than the negative control group. Compared with the negative control group, the number of apoptosis cells of A549 cell with overexpressing Sparcl1 were significantly increased. Compared with the negative control group, G1 stage of A549 cell with overexpressing Sparcl1was increased, but G2 and S stage were decreased.

CONCLUSIONS

The down-regulation of SPARCL1 may be related to inactivation of its tumor suppressor functions and might play an important role in the development and prognosis of NSCLC.