Chemoresistance of PRAME-expressing melanoma cell can be resolved with help of bortezomib

Background. PRAME gene spontaneous expression is frequently observed in a cancer cell. The protein encoded by this gene increases  the viability of tumour cell. NF-κB signalling pathway takes part in PRAME upregulation. It proposes, that stress conditions may increase the expression level of PRAME in the tumour cell and increase cell’s viability after it. We hypothesized that this phenomenon determines chemoresistance of PRAME-expressing cell, which can be overcome by NF-κB inhibitors, such as bortezomib.

Materials and methods. We incubated A875 melanoma cells with cisplatin, bortezomib and dexamethasone, as well as with a mixture  of cisplatin with bortezomib and cisplatin with dexamethasone within 24 hours. To assess the cytotoxicity of these combinations MTT-test was used. For evaluation of PRAME expression level, real-time polymerase chain reaction was used. All data were analyzed with Wilcoxon test for coupled samples.

Results. It was found that cisplatin and dexamethasone increased an expression level of PRAME compared to control (p <0.03). The addition of dexamethasone to cisplatin reduced cytotoxic effect of cisplatin. Bortezomib has a cytotoxic effect, but it did not increase the activity  of PRAME gene (p = 0.12). PRAME gene activity in cells incubated with a mixture of cisplatin and bortezomib was observed at a lower level in comparison with cells incubated with cisplatin (p = 0.0277).

Conclusion. The results of experiments show that an increase of PRAME expression level reduces the sensitivity of melanoma cells to the cytotoxic effect of cisplatin. PRAME activity increases under stress conditions. Using of bortezomib can inhibit the growth of PRAME expression and makes the tumour cell more vulnerable to cytotoxic agents. On the other hand, dexamethasone may increase a resistance  of PRAME-expressing cell to cytotoxic effects.

1. Epping M.T., Wang L., Plumb J.A. et al. A functional genetic screen identifies reti-^ noic acid signaling as a target of histone deacetylase inhibitors. Proc Natl Acad Sci USA 2007;104(45):17777—82. DOI: 10.1073/pnas.0702518104. PMID: 17968018.

2. Passeron T., Valencia J.C., Namiki T. et al. Upregulation of SOX9 inhibits the growth of human and mouse melanomas and restores their sensitivity to retinoic acid. J Clin Invest 2009;119(4):954—63. DOI: 10.1172/JCI34015. PMID: 19273910.

3. Oehler V.G., Guthrie K.A., Cummings C.L. et al. The preferentially expressed antigen in melanoma (PRAME) inhibits myeloid differentiation in normal hematopoietic and leukemic progenitor cells. Blood 2009;114(15):3299—308. DOI: 10.1182/blood-2008-07-170282. PMID: 19625708.

4. Kim H.L., Seo Y.R. Molecular and genomic approach for understanding the gene-environment interaction between Nrf2 deficiency and carcinogenic nickelinduced DNA damage. Oncol Rep 2012;28(6):1959—67. DOI: 10.3892/or.2012.2057. PMID: 23023193.

5. Zhang W., Chi K., Zhang Y et al. Correlation between preferentially expressed antigen of melanoma and tumour necrosis factor-related apoptosis-inducing ligand gene expression in different types of leukaemia patients. Acta Haematol 2013;130(4): 297-304. DOI: 10.1159/000351166. PMID: 24008770.

6. Yao J., Caballero O.L., Yung W.K. et al. Tumor subtype-specific cancer-testis antigens as potential biomarkers and immuno-therapeutic targets for cancers. Cancer Immunol Res 2014;2(4):371-9. DOI: 10.1158/2326-6066.CIR-13-0088. PMID: 24764584.

7. Wadelin F.R., Fulton J., Collins H.M. et al. PRAME is a golgi-targeted protein that associates with the Elongin BC complex and is upregulated by interferon-gamma and bacterial PAMPs. PLoS One 2013;8(2):e58052. DOI: 10.1371/journal.pone.0058052. PMID: 23460923.

8. Bhattacharyya S., Ratajczak C.K., Vogt S.K. et al. TAK1 targeting by glucocorticoids determines JNK and IkappaB regulation in Toll-like receptor-stimulated macrophages. Blood 2010;115(10): 1921-31. DOI: 10.1182/blood-2009-06-224782. PMID: 20065289.

9. Qin Y., Lu J., Bao L. et al. Bortezomib improves progression-free survival in multiple myeloma patients overexpressing preferentially expressed antigen of melanoma. Chin Med J (Engl) 2014;127(9):1666-71. PMID: 24791872.

10. Chen D., Frezza M., Schmitt S. et al. Bortezomib as the first proteasome inhibitor anticancer drug: current status and future perspectives. Curr Cancer Drug Targets 2011;11(3):239—53. PMID: 21247388.

11. Ikeda H., Lethe B., Lehmann F. et al. Characterization of an antigen that is recognized on a melanoma showing partial HLA loss by CTL expressing an NK inhibitory receptor. Immunity 1997;6(2): 199—208. PMID: 9047241.