Differential expression of Kindlin-1 and Kindlin-2 correlates with esophageal cancer progression and epidemiology.

Esophageal cancer (EC) is one of the most lethal malignancies in China, but the etiology and risk factors remain unclear. The integrin-interacting proteins Kindlin-1 and Kindlin-2 are focal adhesion molecules that activate transmembrane receptor integrins and regulate tumor cell growth, invasion, and metastasis. Here, we report that Kindlin-1 and Kindlin-2 are differentially expressed among Chinese EC patients. For this, Kindlin-1 and Kindlin-2 expression was evaluated in 220 EC patients by immunohistochemistry (IHC) and found to be correlated with the EC progression, along with a variety of epidemiologic parameters, including smoking, family EC history, and EC invasion status. Moreover, data downloaded from the Oncomine database revealed that both Kindlin-1 and Kindlin-2 were upregulated in ECs compared with normal esophageal tissues; although Kindlin-1 was highly expressed in well-differentiated tumors, whereas Kindlin-2 was more prevalent in poorly differentiated tumors. Collectively, these data suggest that Kindlin-1 may inhibit, while Kindlin-2 may promote, EC progression. This study, for the first time, linked the expression of Kindlin-1 and Kindlin-2 with EC family genetic background and living habits, which may help further our understanding of the various causes of EC.