Objective To investigate the regulating effect of Notch-1 on retinal progenitor cells (RPC) differentiating into retinal ganglion cells (RGC). Methods RPC of 14-day embryonic SD rats were induced and differentiated in the culture medium with Notch-1 antisense oligonucleotides (experimental group) or missense oligonucleotides (control group) for 14 days. The condition of growth and differentiation of the cells were observed daily under the phase-contrast microscope. RGC were identified by Thy1.1 immunocytochemistry methods and the cellular number was counted. Results RPC in both of the two groups differentiated into various retinal cells, including Thy1.1-positive RGC. The percentage of RGC derived from RPC was 31.19%plusmn;6.90% in experimental group and 16.57%plusmn;4.31% in control group, and the difference was statistically significant (t=9.84，Plt;0.001). Conclusion Notch-1 may down-regulate the differentiation of RPC, and the inhibition of Notch-1 may promote RPC differentiating into RGC. (Chin J Ocul Fundus Dis, 2007, 23: 101-103)
Objective To investigate the expression and clinical significance of Notch-1 protein in papillary thyroid carcinoma (PTC) tissues and cervical lymph node metastases. Methods Immunohistochemical method was used to detect the expression of Notch-1 protein in 69 cases of PTC tissues, along with tumor adjacent tissues and 34 cases of metastatic lymph node tissues, and to analyze its role in PTC and metastatic lymph node tissue. Results Compared with PTC tissues or cervical lymph node metastases and tumor adjacent tissues, the positive rates of expression of Notch-1 protein in PTC tissues or cervical lymph node metastases were significantly lower than that in cancer adjacent tissues (P＜0.05). The expression of Notch-1 protein was correlated with the tumor size and capsule invasion of patients with PTC. Conclusions Notch-1 protein expression is decreased in PTC tissues and metastatic lymph node tissues, suggesting that the Notch-1 protein may play an important role in the development, invasion and metastasis of PTC. There is no significant difference in the positive rates of Notch-1 protein expression in PTC tissues and metastatic lymph node tissues, it's suggested that the malignant degree of cancer cells in lymph node metastasis is not significantly increased, and the biological behavior remained relatively stable.