It is found out in the invention that the poly-comb
protein NSPc1 of the
neural system can highly express in the tumor
cell lines from a variety source of
neural system using the
Western blot technique, it is also found out that the expression level of NSPc1 in human gliocytoma sample is far higher than that in the
normal tissue around the
cancer and it goes up as the grading increase of the neurogliocytoma
pathology using the Real-time PCR technique. NSPc1 is found to have transcription inhibition capacity using the
fluorescence detection of reporting
gene technology, and p21Waf1 / Cip1 is found to be the target controlled
gene of NSPc1.
Promoter sequence
mutation experiments and
chromatin co-
immunoprecipitation experiments of P21Waf1 / Cip1 showed that the inhibition effect of NSPc1 on the transcription of p21Waf1 / Cip1 depends on
retinoic acid response elements (RARE). Overexpressions of
retinoic acid receptor RXRalphacan eliminate the inhibition activity of NSPc1 on p21Waf1 / Cip1
promoter. These results indicate that NSPc1 highly expressing in nerve tumor inhibits the transcription of p21Waf1 / Cip1 through interfering the controlling access of the
retinoic acid thus affects the differentiation of the
nervous system tumor. Therefore, not only can NSPc1 be used as candidate markers for grouping diagnostic of
nervous system malignant
tumor type, but also can serve as a target of
gene therapy. Meanwhile, in the invention, building the
plasmid for prokaryotic expressing of full-length
protein of NSPc1, transforming
Escherichia coli to express the corresponding
protein; After purifying the protein it can be used for the preparation of high-quality antibodies, as well as applied to the
nervous system tumor diagnosis.