Pancreatic cancer is one of the most fatal types of
cancer in developed countries. Most patients have locally advanced or metastatic cancerous lesions when they are diagnosed, due to the progressive, invasive and metastatic capacity of this disease to liver, lymph nodes and distant organs during early stages. Although the only curative
therapy is complete surgical resection, the disease has usually already progressed by the time of diagnosis, and the majority of patients have metastatic disease. Therefore, palliative
chemotherapy remains the only
therapy for patients with progressive disease.
Gemcitabine has been used for
pancreatic cancer as the most effective anticancer
drug. However, there are many cases resistant to
gemcitabine. Thus, a better understanding of the molecular mechanisms of resistance to
gemcitabine is essential to allow it to be used more effectively. Our previous proteomic studies demonstrated that the expression of
heat-shock protein 27 (HSP27) was increased in
gemcitabine-resistant
pancreatic cancer cells and this might play a role in determining the sensitivity of
pancreatic cancer to
gemcitabine. Increased HSP27 expression in
tumor specimens was related to resistance to
gemcitabine and a shorter survival period in patients with
pancreatic cancer. Furthermore, it has been shown that treatment strategies combining the HSP inhibitor
KNK437 or
interferon-γ (IFN-γ) with
gemcitabine, were effective in
gemcitabine-resistant
pancreatic cancer cells in vitro. Furthermore, combined
therapy of
gemcitabine with IFN-γ of
gemcitabine-resistant
pancreatic cancer-bearing nude mice showed synergistic
therapeutic effects on
gemcitabine-resistant
pancreatic cancer bearers. In this review, we summarize the current understanding of HSP27 and its role in
gemcitabine resistance.