Cytoplasmic HuR expression: correlation with cellular inhibitors of apoptosis protein-2 expression and clinicopathologic factors in oral squamous cell carcinoma cells.

Background: HuR expression has been noted in several cancer types, in which it may contribute to increased expression of cellular inhibitors of apoptosis protein-2 (cIAP2) observed during tumorigenesis.

Methods: To assess the correlation between cIAP2 and HuR in cases of oral squamous cell carcinoma (OSCC), the expression patterns of HuR and cIAP2 were assessed by immunohistochemical analyses of 95 treated OSCC samples.

Results: In the tumor tissues, positive cytoplasmic HuR expression was evident in 71.6% of samples and positive cIAP2 expression was noted in 95.8% of samples. Positive cytoplasmic HuR expression was significantly associated with positive cIAP2 (p < .035) and high cIAP2 expression (p < .007), as well as high grade (p < .050). The inhibition of HuR expression by small interfering RNA or leptomycin B caused a reduction in the inducibility of cIAP2 in oral cancer cells.

Conclusion: Cytoplasmic expression of HuR is associated with cIAP2 expression in OSCCs.