Roles Of ERK1/2 Signal Transduction Pathway In Glucocorticoid Antitumor Effects To Prostate Cancer

Background: Prostate cancer is a common noncutaneous cancer in men. The incidence of this disease is increasing in recent years in Chinese people. When prostate cancers first occur, they are dependent on androgens for growth and can be treated successfully with androgen ablation therapy. However, after prolonged antiandrogen therapy for about 3 years, the cancer eventually acquires the ability to proliferate and refractory to hormonal therapy. Few therapies have been proven definitively to prolong survival of patients with hormone refractory prostate cancer. Glucocorticoids are regulatory molecules that control metabolism, development, inflammation, cell growth, proliferation, and differentiation. Before, during, and after chemotherapy of cancers, glucocorticoids are given to reduce acute toxicity, particularly hyperemesis, and to protect normal tissue of cancer patients against the long-term effects of genotoxic drugs. Moreover, glucocorticoids have direct antitumor effects and are used in the therapeutic induction of apoptotic cell death in malignant lymphoid cells. For solid tumors such as lung cancer, breast cancer, hepatomas, glucocorticoids can also suppress cancer cell proliferation and induce cell differentiation. Glucocorticoids have been used in the treatment of advanced prostate cancer due to their overall palliative effect. Several recent studies of glucocorticoids therapy shew serum prostate-specific antigen levels declined more than 50% in 20%—61% of patients with hormone refractory prostate cancer. This indicates...