Heat shock protein 22 overexpression is associated with the progression and prognosis in gastric cancer

Purpose T he heat shock protein 22 (HSP22) is associated with tumor proliferation and protects tumor cell from apoptosis in many malignancies. However, the role of HSP22 in gastric cancer has not been thoroughly elucidated. The aim was to determine the relationship of HSP22 expression with clinicopathological parameters and prognosis in gastric cancer and estimate the alteration of HSP22 expression after neoadjuvant chemotherapy. Methods HSP22 and matrix metallopeptidase 9 (MMP9) antigen expressions were evaluated by immunohistochemistry in 129 gastric carcinoma samples. Univariate and multivariate analyses were performed to determine the association between HSP22 expression and prognosis. The response of HSP22 was assessed in 47 patients who received neoadjuvant chemotherapy. Results HSP22 protein expression was significantly associated with tumor size, depth invasion, lymph node metastasis and stage of disease (all P < 0.05). In univariate and multivariate analyses, HSP22 was an independent prognostic factor for both overall survival (OS) and recurrence-free survival (RFS) (P = 0.003 and P = 0.004, respectively). Furthermore, HSP22 overexpression was associated with a poor prognosis in all patients and in patients subgroups stratified by tumor size, depth invasion and lymph node metastasis. In addition, HSP22 was significantly correlated with MMP-9 among 129 gastric cancer tissues (P < 0.001). Patients who had MMP-9 overexpression had poor OS and shorter RFS. Moreover, the alteration of HSP22 was not comparable in 47 patients who underwent neoadjuvant chemotherapy. Conclusions HSP22 plays an important role on tumor aggressiveness and prognosis and may act as a promising target for prognostic prediction.