Objective: To investigate the expression and relationship of receptor for activated C kinase 1 (RACK1) and clinical characteristics in esophageal squamous cell carcinoma (ESCC).
Methods: Western Blotting was conducted to detect the RACK1 expression in ESCC cell lines. Immunohistochemistry was performed to assay the expression of RACK1 and Ki67 in tumor tissues and adjacent normal epithelium from 113 ESCC patients in tissue microarray. The relationship between the RACK1 level and such clinicopathologic profiles as age, gender, location, smoking, differentiation degree and TNM (tumor, node, metastasis) stage were analyzed.
Results: The expression of RACK1 protein was significantly down-regulated in ESCC tissues as compared with the normal adjacent epithelium (χ(2) = 63.363, P < 0.01). An upregulated expression of RACK1 was observed in 72.5% (29/40) ESCC tissues of patients without a smoking history. And it was significantly higher than that in 46.6% (34/73) of patients with a smoking history (χ(2) = 7.040, P = 0.008). In addition, the rate of up-regulated of RACK1 was significantly higher in stage I and II group (63.8%, 44/69) than that in stage III group (43.2%, 19/44) (χ(2) = 4.616, P = 0.032). Moreover, the ESCC tissues with a higher Ki67 score showed a lower level of RACK1 than that with a lower Ki67 score (χ(2) = 8.261, P = 0.016).
Conclusion: The expression of RACK1 is down-regulated in ESCC tissues and associated with smoking. The expression of RACK1 was associated with smoking, TNM staging and Ki67 score of ESCC.