A preliminary study on the MATP gene knockout in a mouse melanoma cell line using CRISPR-Cas9 system / 中国比较医学杂志

Objective To knockout the MATP gene of mouse melanoma cell line B16F10 using CRISPR/Cas9 system,and to lay foundation for the functional study of MATP gene.Methods Specific primers of MATP were designed according to the report in http://crispr.mit.edu/ website.The primers were linked to pCAS9/gRNA1 vector.Then the positive vector was transfected into mouse melanoma B16F10 cells,and monoclonal cell lines were obtained by the infinite dilution method.After the genomes of different monoclonal cell lines were extracted and sequenced,the cell lines with MATP gene cleavage were screened,and the expression of MATP in these cell lines was verified by Western-blot analysis.Results Three MATP gene knockout cell lines were successfully obtained.The western-blot results showed that the cell lines did not express MATP protein.Conclusions The knockout of MATP gene in B16F10 cell line can be successfully achieved using the pCAS9/gRNA1 vector.

Cytotoxic effects of local anesthesia through lidocaine/ropivacaine on human melanoma cell lines / Efeitos citotóxicos de anestesia local com lidocaína/ropivacaína em linhagens celulares de melanoma humano

Abstract Background: Local anesthetics (LAs) are generally considered as safe, but cytotoxicity has been reported for several local anesthetics used in humans, which is not well investigated. In the present study, the cytotoxicity of lidocaine, ropivacaine and the combination of lidocaine and ropivacaine were evaluated on human melanoma cell lines. Melphalan, a nitrogen mustard alkylating agent, was used as a control agent for comparison of cytotoxic activity. Methods: Melanoma cell lines, A375 and Hs294T, were exposed to 1 h to different concentrations of above agents. Cell-viability after exposure was determined by flow cytometry. Results: Investigated LAs showed detrimental cytotoxicity on studied melanoma cell lines in time- (p < 0.001), concentration- (p < 0.001), and agent dependant. In both A375 and Hs294T cell lines, minimum cell viability rates were found after 72 h of exposure to these agents. Lidocaine 2% caused a reduction of vital cells to 10% ± 2% and 14% ± 2% in A375 and Hs294T, respectively after 72 h of exposure. Ropivacaine 0.75% after 72 h reduced viable cells to 15% ± 3% and 25% ± 3% in A375 and Hs294T, respectively. Minimum cell viability after 72 h exposure to the combination was 10% ± 2% and 18% ± 2% in A375 and Hs294T, respectively. Minimum cell viability after 72 h exposure to melphalan was 8% ± 1% and 12% ± 2%, in A375 and Hs294T, respectively. Conclusion: LAs have cytotoxic activity on human melanoma cell lines in a time-, concentration- and agent-dependant manner. Apoptosis in the cell lines was mediated through activity of caspases-3 and caspases-8.

Resumo Justificativa: Os anestésicos locais (ALs) são geralmente considerados como seguros, mas citotoxicidade foi relatada em vários anestésicos locais usados em seres humanos, a qual não é bem investigada. No presente estudo, a citotoxicidade de lidocaína e ropivacaína e da combinação de lidocaína e ropivacaína foi avaliada em linhagens celulares de melanoma humano. Melfalano, um agente alquilante de mostarda nitrogenada, foi usado como um agente de controle para a comparação da atividade citotóxica. Métodos: Linhagens celulares de melanoma, A375 e Hs294T foram expostas por uma hora a concentrações diferentes dos agentes mencionados acima. A viabilidade celular após a exposição foi determinada por citometria de fluxo. Resultados: Os ALs investigados mostraram citotoxicidade prejudicial nas linhagens celulares de melanoma estudadas dependente do tempo (p < 0,001), da concentração (p < 0,001) e do agente. Em ambas as linhagens de células A375 e Hs294T, níveis mínimos de viabilidade celular foram encontrados após 72 horas de exposição a esses agentes. Lidocaína a 2% provocou uma redução das células vitais para 10% ± 2% e 14% ± 2% em A375 e Hs294T, respectivamente, após 72 horas de exposição. Ropivacaína a 0,75% após 72 horas reduziu as células viáveis para 15% ± 3% e 25% ± 3%, em A375 e Hs294T, respectivamente. A viabilidade celular mínima após exposição de 72 horas para a combinação foi de 10% ± 2% e 18% ± 2% em A375 e Hs294T, respectivamente. A viabilidade celular mínima após exposição de 72 horas ao melfalano foi de 8% ± 1% e 12 ± 2, em A375 e Hs294T, respectivamente. Conclusão: Os ALs têm atividade citotóxica em linhagens de celulares de melanoma humano de modo dependente do tempo, da concentração e do agente. A apoptose nas linhagens celulares foi mediada por meio da atividade das caspases-3 e caspases-8.

Molecular analysis of HLA-DR gene expression induced by IFN-gamma in malignant melanoma cell lines

Human leukocyte antigen (HLA) class II molecules are polymorphic cell surface glycoproteins that are crucial for the cellular interaction in immune response. The expression of class II molecules is regulated in a tissue-specific and cytokine-inducible manner, and is mainly restricted to the antigen presenting cells. However, some tumor cells also express class II molecules, and in some class-II-negative tumor cells, class II expression is inducible by interferon (IFN)-gamma. However, their expression varies, even though the tumor cells originate from the same histological origin; some tumor cells show strong expression, others show weak or no expression. To determine whether this differential expression of class II molecules on tumor cells is transcriptionally regulated, FACS analysis and Northern hybridization were performed using a panel of melanoma cell lines, IGR3, Malme-3M, SK-Mel-24, and SK-Mel-28 to analyze the cell surface expression and mRNA transcription rate of HLA-DR before and after treatment with IFN-gamma. FACS analysis showed that before IFN-gamma treatment, IGR3 and Malme-3M cells barely expressed HLA-DR. On the contrary, almost all of the SK-Mel-24 cells (> 90%) and a relatively high rate (> 50%) of SK-Mel-28 cells expressed HLA-DR. After IFN-gamma treatment, HLA-DR expression was induced in Malme-3M cells and SK-Mel-28 cells which displayed elevated levels of HLA-DR expression in a time-dependent manner. However, IGR3 cells never responded to IFN-gamma. Northern analysis showed that treatment with IFN-gamma led to the steady-state mRNA augmentation of the HLA-DR gene in Malme-3M and SK-Mel-28, whereas in IGR3, IFN-gamma did not augment the transcriptional rate of the HLA-DR gene. To further clarify this differential modulation, sequencing analysis of PCR product of the HLA-DR proximal promoter region was done, since the transcription rate of the class II gene is controlled by the well-conserved proximal promoter region. Six independent clones from PCR products of the HLA-DRA proximal promoter region and 16 clones from PCR products of the HLA-DRB proximal promoter region were isolated from the above cell lines and sequenced. Comparison of the nucleotide sequences of all 6 clones of DRA promoter showed that the sequences are extremely similar in both regulatory sequences and their intervening sequences. Sixteen clones of HLA-DRB promoter showed sequence variations such as substitution and insertion/deletion, and these 16 clones could be further grouped into 6 homologues with sequence homology. These data established that the melanoma cell lines studied here showed a differential susceptibility to IFN-gamma on the modulation of HLA-DR molecules, that this modulation is transcriptionally regulated, and that the difference in promoter activity by sequence variation might contribute to such a differential transcriptional regulation at the promoter level.

Expression of Heat Shock Protein 70 Family in Melanocytes / 대한피부과학회지

BACKGROUND: When cells or organisms are exposed to environmental stresses, they respond by synthesizing a characteristic group of proteins called heat shock proteins(HSP) or stress proteins. In a variety of HSP, the so-called HSP 70 family is the most prominent, conserved, and best characterized. The HSP 70 family is required for survival of cells during and after thermal stress. OBJECTIVE: The purpose of this study is to investigate if the cultured human melanocytes and rnelanotic malignant melanoma cell lines(SK 30) expressed HSP 70 family unstressed, after heat shock and ultraviolet exposure. METHODS: Protein was isolated from melanocytes and SK 30. Western blotting was done for identification of the HSP 70 family. RESULTS: HSP 70 family expression could be detected in the unstressed cultured human melanocytes and SK 30(malignant melanoma cell lines). HSP 70 family expression inereased in the melanocytes and SK 30 after heat shock. Irradiation of the melanocytes with UVA resulted in a decrease in expression of HSP 70 family after 32, 48 J/cm compared with 4, l6 J/cm. Irradiation of the melanocytes with UVA + B resulted in a dose-dependent increase in expression of HSP 70 family but a decrease in expression of HSP 70 family after 80mJ/cm. Irradiation of SK 30 with UVA resulted in a dose-dependent decrease in expression of the HSP 70 family. CONCLUSION: HSP 70 family expression was detected even unstressed. This high base line HSP 70 family expression may suggest that melanocytes have ability to protect from environmental stresses like keratinocytes.

Expression of Heat Shock Protein 70 Family in Melanocytes / 대한피부과학회지

BACKGROUND: When cells or organisms are exposed to environmental stresses, they respond by synthesizing a characteristic group of proteins called heat shock proteins(HSP) or stress proteins. In a variety of HSP, the so-called HSP 70 family is the most prominent, conserved, and best characterized. The HSP 70 family is required for survival of cells during and after thermal stress. OBJECTIVE: The purpose of this study is to investigate if the cultured human melanocytes and rnelanotic malignant melanoma cell lines(SK 30) expressed HSP 70 family unstressed, after heat shock and ultraviolet exposure. METHODS: Protein was isolated from melanocytes and SK 30. Western blotting was done for identification of the HSP 70 family. RESULTS: HSP 70 family expression could be detected in the unstressed cultured human melanocytes and SK 30(malignant melanoma cell lines). HSP 70 family expression inereased in the melanocytes and SK 30 after heat shock. Irradiation of the melanocytes with UVA resulted in a decrease in expression of HSP 70 family after 32, 48 J/cm compared with 4, l6 J/cm. Irradiation of the melanocytes with UVA + B resulted in a dose-dependent increase in expression of HSP 70 family but a decrease in expression of HSP 70 family after 80mJ/cm. Irradiation of SK 30 with UVA resulted in a dose-dependent decrease in expression of the HSP 70 family. CONCLUSION: HSP 70 family expression was detected even unstressed. This high base line HSP 70 family expression may suggest that melanocytes have ability to protect from environmental stresses like keratinocytes.

Induction of ICAM-1 and HLA-DR expression by IFN-gamma in malignant melanoma cell lines

Two human malignant melanoma cell lines, Malme-3M and SK-Mel-28, were analyzed for their ability to induce the expression of intercellular adhesion molecule 1 (ICAM-1) and human leukocyte antigen (HLA)-DR molecules on their cell surfaces as well as at the transcriptional level before and after treatment with interferon (IFN)-gamma. Both cell lines demonstrated a high percentage(> 99%) of ICAM-1 expression regardless of IFN-gamma treatment. Before IFN-gamma treatment, Malme-3M cells barely expressed HLA-DR molecules ( 50%) of HLA-DR expression. Both cell lines displayed elevated levels of HLA-DR expression in a time dependent manner after IFN-gamma treatment. However, these two cell lines have been shown to respond differentially to IFN-gamma. The molecular mechanism underlying such a differential behavior was investigated, and HLA-DR gene regulation was studied at the transcriptional level. Treatment with IFN-gamma led to the steady-state mRNA augmentation of the HLR-DR gene. The HLA-DRA mRNA augmentation was similar in both cell lines, whereas in Malme-3M, IFN-gamma did not augment the rate of transcription of the HLA-DRB gene as much as in SK-Mel-28. Data from this study established the fact that the melanoma cell lines displayed a differential susceptibility to IFN-gamma on the modulation of HLA-DR molecules, and this modulation was transcriptionally regulated.