RNF187 governs the maintenance of mouse GC-2 cell development by facilitating histone H3 ubiquitination at K57/80.

RING finger 187 (RNF187), a ubiquitin-ligating (E3) enzyme, plays a crucial role in the proliferation of cancer cells. However, it remains unclear whether RNF187 exhibits comparable functionality in the development of germline cells. To investigate the potential involvement of RNF187 in germ cell development, we conducted interference and overexpression assays using GC-2 cells, a mouse spermatocyte-derived cell line. Our findings reveal that the interaction between RNF187 and histone H3 increases the viability, proliferation, and migratory capacity of GC-2 cells. Moreover, we provide evidence demonstrating that RNF187 interacts with H3 and mediates the ubiquitination of H3 at lysine 57 (K57) or lysine 80 (K80), directly or indirectly resulting in increased cellular transcription. This is a study to report the role of RNF187 in maintaining the development of GC-2 cells by mediating histone H3 ubiquitination, thus highlighting the involvement of the K57 and K80 residues of H3 in the epistatic regulation of gene transcription. These discoveries provide a new theoretical foundation for further comprehensive investigations into the function of RNF187 in the reproductive system.

[Expression of X-linked inhibitor of apoptosis protein in Tca8113 cell and its relationship to chemoresistance].

OBJECTIVE: To explore the expression of X-linked inhibitor of apoptosis protein (XIAP) in Tca8113 cell, and to investigate its relationship to the chemoresistance. METHODS; The Tca8113 cell line was cultured by IMDM and the concentration of Pingyangmycin (PYM) added to Tca8113 cell line was increased gradually and continually, which was to induce the PYM-resistance in Tca8113 cell line. The sensitivity of Tca8113 cell to PYM and expression of XIAP were measured with methyl thiazolyl tetrazolium (MTT) chromatometry and reverse transcription-polymerase chain raction (RT-PCR). The XIAP level in the cells and its chemoresistance to PYM were analyzed by linear regression. RESULTS: The IC50 of Tca8113-1-10 group and Tca8113-10-10 group were(12.758 +/- 0.030), (18.986 +/- 0.150) microg x mL(-1) respectively. The IC50 of Tca8113-1-20 group and Tca8113-10-20 group increased to (26.302 +/- 0.072), (35.294 +/- 0.115) microg x mL(-1) respectively. There was a relation between XIAP and the drug-resistance in Tca8113 cell. CONCLUSION: XIAP may play an important role in the chemoresistance which might serve as a new therapeutic target for oral squamous cell carcinoma.

[Influential factor analysis and improvement of cultural method of oral mucosal epithelial cells].

OBJECTIVE: To analyze influential factors of cultural method of human oral mucosal epithelial cells (hOMEC)and to establish a reliable cell culture system for hOMEC. METHODS: Benzalkonium bromide and gentamicin sulfate were used to prevent microbial contamination. Separations of epithelium from underlying connective tissues with Dispase at different concentration were compared. Enzyme digestion was used to isolate cells and keratinocyte-serum free medium(K-SFM) was employed for primary culture and subculture of hOMEC. RESULTS: Microbial contamination was under control. Separation of epithelium from underlying connective tissues with 0.40% Dispase was more complete than that of 0.25% Dispase. The cells grew fast and well in vitro. CONCLUSION: The high successful culture of hOMEC and simplified procedures could be obtained with improvement of methods.

[Expression and subcellular localization of XIAP and XAF1 in human normal oral keratinocytes and Tca8113 cells].

OBJECTIVE: To clarify expression and subcellular localization of XIAP and XAF1 protein in human normal oral keratinocytes (hNOK) and Tca8113 cells human tongue carcinoma cell line. METHODS: The hNOKs and Tca8113 cells were cultured in vitro. Expression and subcellular localization of XIAP and XAF1 protein were examined by combination of indirect immunofluorescence and confocal laser scanning microscopy. RESULTS: XIAP expression was weak in the hNOKs and fluorescence staining localized chiefly in the cytoplasm and perinuclear areas. In the Tca8113 cells, high level of XIAP protein could be detected in both the cytoplasm and the nucleus. In the hNOKs, XAF1 distributed mostly in the nucleus. Homogeneous nuclear and cytoplasmic distribution of XAF1 could be visualized in the Tca8113 cells. CONCLUSIONS: In cancerization of oral mucosa, XIAP protein could play an important antiapoptotic role by overexpression, while XAF1 protein does not appear to antagonize effectively the role of XIAP.

[Expression of nuclear transcription factor kappaB in hamster buccal pouch carcinogenesis].

OBJECTIVE: To study the expression and significance of p65 which is an important subtype of nuclear transcription factor kappaB (NF-kappaB) and its inhibitory protein IkappaBalpha in malignant transformation of hamster buccal mucosa. METHODS: The animal model of malignant transformation in hamster buccal mucosa induced by DMBA (0.5%) was established. Twelve paired specimens including normal buccal mucosa, epithelial hyperplasia, epithelial dysplasia and squamous cell carcinoma (SCC) were subjected to Western blot for the analysis of p65. The expression of IkappaBalpha was observed in 22 normal buccal epithelia, 20 hyperplasia epithelia, 35 dysplasia epithelia and 23 SCC by immunohistochemical evaluation. RESULTS: In normal buccal epithelia and hyperplasia epithelia, the expression of p65 was not obvious, and there was no significant difference between them (P > 0.05). The expression of IkappaBalpha existed at large, but mostly localizing in cell cytoplasmic staining in the basal cell layer and bottom of spinocelluar layer. With the occurrence of epithelia dysplasia, the expression of p65 gradually increased, comparing with normal buccal epithelia and hyperplasia epithelia (P < 0.01). But the positive intensity of IkappaBalpha was dramatically decreased (P < 0.05). In SCC, p65 expressed at a higher level comparing with normal buccal mucosa and dysplasia (P < 0.01), while the staining of IkappaBalpha was feedbackly higher comparing with dysplasia (P < 0.01) and even with normal buccal mucosa (P < 0.01). CONCLUSION: NF-kappaB p65 is strongly activated in malignant transformation of hamster buccal mucosa. The abnormal expression of p65 and IkappaBalpha, especially the ascending expression of p65 as well as the descending expression of IkappaBalpha in dysplasia may be an early event during oral carcinogenesis, and can be used as biomarkers for supervising oral malignancy.