[Nucleolar localization of human acetyltransferase-like protein and its expression in tumors].

OBJECTIVE: To confirm the nucleolar localization of telomerase-regulation associated protein-human N-acetyltransferase-like protein (hALP) and its associated functions. METHODS: Immunofluoresent staining and immunoelectron microscopy were used to detect the distribution of hALP in HeLa and Saos2 cells, and the co-localization of hALP and rDNA was analyzed by fluorescence in situ hybridization and immunofluoresence. RNAi was performed to further verify the nucleolar localization of hALP. A series of eukaryotic expression plasmids carrying various portions of hALP sequence were constructed and transiently transfected to HeLa and Saos2 cells. The expression of hALP in tumor tissues was stained by immunohistochemistry. RESULTS: hALP distributed predominantly in the nucleoli of HeLa and Saos2 cells, and colocalized with rDNA. Granular component was the precise distribution of hALP in the nucleolus under electron microscope. Nucleolar signals for hALP reduced significantly in cells transfected with hALP siRNA. The carboxy terminus of hALP including residues 549-834 was necessary for its nucleolar localization. hALP could be detected in the nucleoli of many kinds of tumor cells, including leiomyosarcoma, primitive neuroectodermal tumor, neuroblastoma, melanoma, prostatic cancer, and clear cell renal carcinoma. CONCLUSION: hALP is a nucleolar protein, and the nucleolar localization is mediated by its carboxy terminal domain, and hALP could be detected in the nucleoli of many tumor tissues, which is worthy of further investigation.

[Expression of TEIF protein in soft tissue tumors and its significance].

OBJECTIVE: To evaluate the expression of TEIF protein in human tumors of soft tissue and its significance. METHODS: Anti-TEIF polyclonal antibody was generated by immunization of E.coli expressed His-TEIF protein. The expression of TEIF in 166 cases of sarcomas and 28 case benign tumors or tumor-like lesions of soft tissue arranged in tissue chip was analyzed by immunohistochemistry. RESULTS: Polyclonal antibody obtained from immunized rabbit was verified in Western blot to prove its specific reactivity with native TEIF protein. The immunohistochemical staining of TEIF showed that about 58% (97/166) of sarcomas were positive and significantly different from that of benign tumors or tumor-like lesions (11%, 3/28). The positive staining was predominantly in synovial sarcoma 94% (16/17), primitive neuroectodermal tumor (PNET) 91% (21/23), both of which were significantly higher than 43% (6/14) of dermatofibrosarcoma protuberans, 38% (6/16) of myxofibrosarcoma, 36% (8/22) of malignant peripheral nerve sheath tumor, 32% (6/19) of liposarcoma, (P < 0.05, respectively), but not higher than 75% (15/20) of malignant fibrous histiocytoma, 70% (7/10) of rhabdomyosarcoma or 64% (9/14) of leiomyosarcoma. Meanwhile, strong positive staining of TEIF (>or= 2+) was frequently observed in PNET (83%, 19/23) and synovial sarcoma (76%, 13/17). With respect to FNCLCC grading, 19 cases of grade I sarcoma TEIF was 32% (6/19) and strong positive was 11% (2/19), 44 cases of grade II sarcoma was 48% (21/44) and 32% (14/44), and 70 of grade III was 84% (59/70) and 70% (49/70). The rate of either positive or strong positive in grade III sarcoma was significantly different from that of either grade I or II (P < 0.05), but no difference between the latter two groups (P > 0.05). CONCLUSIONS: TEIF protein could be detected in large part of soft tissue sarcomas, and it not only over-expressed in most of PNET, synovial sarcomas, but also correlated with histological grading.