Proteomic analysis and the antimetastatic effect of N-(4-methyl)phenyl-O-(4-methoxy) phenyl-thionocarbamate-induced apoptosis in human melanoma SK-MEL-28 cells.

We employed human SK-MEL-28 cells as a model system to identify cellular proteins that accompany N-(4-methyl)phenyl-O-(4-methoxy)phenyl-thionocarbamate (MMTC)-induced apoptosis based on a proteomic approach. Cell viability tests revealed that SK-MEL-28 skin cancer cells underwent more cell death than normal HaCaT cells in a dose-dependent manner after treatment with MMTC. Two-dimensional electrophoresis in conjunction with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry analysis or computer matching with a protein database further revealed that the MMTC-induced apoptosis is accompanied by increased levels of caspase-1, checkpoint suppressor-1, caspase-4, NF-kappaB inhibitor, AP-2, c-Jun-N-terminal kinase, melanoma inhibitor, granzyme K, G1/S specific cyclin D3, cystein rich protein, Ras-related protein Rab-37 or Ras-related protein Rab-13, and reduced levels of EMS (oncogene), ATP synthase, tyrosine-phosphatase, Cdc25c, 14-3-3 protein or specific structure of nuclear receptor. The migration suppressing effect of MMTC on SK-MEL-28 cell was tested. MMTC suppressed the metastasis of SK-MEL-8 cells. It was also identified that MMTC had little angiogenic effect because it did not suppress the proliferation of HUVEC cell line. These results suggest that MMTC is a novel chemotherapeutic and metastatic agents against the SK-MEL-28 human melanoma cell line.

[Cell differentiation during carcinogenesis of cervical epithelia].

BACKGROUND & OBJECTIVE: The disturbance of cell differentiation is an important characteristic of tumor, but, up to date, the researches on this aspect are not as deep as those on cell proliferation of tumor. This study was to detect the alterations of cell differentiation and relative regulating factors during the carcinogenesis of cervical epithelia. METHODS: The protein expression of keratin (KT) 10, 14, 19 and beta1-integrin and beta-catenin in 20 specimens of normal squamous epithelium (NSE), 19 specimens of dysplasia squamous epithelial hyperplasia (DSEH), 39 specimens of squamous carcinoma in situ (SCIS), and 20 specimens of invasive squamous epithelial carcinoma (ISEC) were detected by inmmunohistochemistry; the mRNA expression of of beta1-integrin and beta-catenin were detected by in situ hybridization. RESULTS: The strong positive rates of KT10 in NSE, DSEH, SCIS, and ISEC were 85.0%, 52.6%, 18.0% and 0, respectively, with a descending trend; it was significantly lower in SCIS and ISEC than in NSE and DSEH (Chi(2)=11.28, P<0.05; Chi(2)=8.53, P<0.05). The expression of KT14 and KT19 showed a heterogeneity in SCIS and ISEC: the proteins were negative in some cases, but overexpressed in other cases with positive cells moved upwards from the basal layer; positive cells scattered at the full epithelial layer of SCIS. The expression of beta1-integrin also showed a descending trend in NSE, DSEH, SCIS, and ISEC. The positive rate of beta1-integrin was significantly lower in ISEC than in NSE and DSEH (Chi(2)=7.62, P <0.05; value of exact probability=0.014, P < 0.05); the mRNA expression of beta1-integrin showed the same trend as its protein expression in the samples although the difference were not significant. The protein and mRNA expression of beta-catenin was located in nuclei or cytoplasm of SCIS and ISEC; increased positive cells moved upwards from the basal layer. CONCLUSIONS: Restraint of terminal differentiation of epithelial cells may relate to the abnormal expression of beta1-integrin and the dysfunction of Wnt signaling pathway on regulating cell differentiation during the carcinogenesis of cervical epithelia. The expression of KT10 and beta1-integrin in SCIS is not obviously different from that in ISEC.