| Neurobastoma (NB) is a common childhood malignancy thought to arise from postganglionic sympathetic nervous tissue. There is a remarkable heterogeneity of this tumor on clinical and biological feature. In some patients, the tumor may occasionally regress spontaneously, or mature into a benign ganglioneuroma, but most have a very poor prognosis and remains a particularly difficult therapeutic challenge. Studies have shown that approximately one-third of neuroblastoma express Bcl-2, which is very important in nerve system during embryonal development. Statistical analysis demonstrated that Bcl-2 expression was strongly correlated with aggressive tumor behavior and a poor prognosis. Bcl-2, which encodes a 26 KD protein, is the first oncogene that associated with apoptosis of the cell. The protein encoded by bcl-2 is a potent suppressor of apoptosis. Many studies have shown that Bcl-2 overexpression can inhibit cell apoptosis induced by hypoxia, irradiation, anti-ras antibody as well as withdraw of fetal bovine serium from the culture medium. Again, high level expressing Bcl-2 is found in more than half of all human cancers. Moreover, there is a close relationship between expressing Bcl-2 and chemoresistance as shown by clinical studies. Elevated expression of Bcl-2 is associated with shorter survival in patients with at least... |
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