BACKGROUND & AIMS: Metallothionein-3 (hMT3) is a structurally unique member of the metallothioneins family of low-mass cysteine-rich proteins. hMT3 has poorly characterized functions, and its importance for hepatocellular carcinoma (HCC) cells has not yet been elucidated. Therefore, we investigated the molecular mechanisms driven by hMT3 with a special emphasis on susceptibility to sorafenib. METHODS: Intrinsically sorafenib-resistant (BCLC-3) and sensitive (Huh7) cells with or without up-regulated hMT3 were examined using cDNA microarray and methods aimed at mitochondrial flux, oxidative status, cell death, and cell cycle. In addition, in ovo/ex ovo chick chorioallantoic membrane (CAM) assays were conducted to determine a role of hMT3 in resistance to sorafenib and associated cancer hallmarks, such as angiogenesis and metastastic spread. Molecular aspects of hMT3-mediated induction of sorafenib-resistant phenotype were delineated using mass-spectrometry-based proteomics. RESULTS: The phenotype of sensitive HCC cells can be remodeled into sorafenib-resistant one via up-regulation of hMT3. hMT3 has a profound effect on mitochondrial respiration, glycolysis, and redox homeostasis. Proteomic analyses revealed a number of hMT3-affected biological pathways, including exocytosis, glycolysis, apoptosis, angiogenesis, and cellular stress, which drive resistance to sorafenib. CONCLUSIONS: hMT3 acts as a multifunctional driver capable of inducing sorafenib-resistant phenotype of HCC cells. Our data suggest that hMT3 and related pathways could serve as possible druggable targets to improve therapeutic outcomes in patients with sorafenib-resistant HCC.

• Keywords
• Hepatocellular carcinoma, Metallothionein-3, Resistance, Sorafenib,
• Publication type
• Journal Article MeSH

The efficiency of cisplatin (CDDP) is significantly hindered by the development of resistance during the treatment course. To gain a detailed understanding of the molecular mechanisms underlying the development of cisplatin resistance, we comparatively analyzed established a CDDP-resistant neuroblastoma cell line (UKF-NB-4CDDP) and its susceptible parental cells (UKF-NB-4). We verified increased chemoresistance of UKF-NB-4CDDP cells by analyzing the viability, induction of apoptosis and clonal efficiency. To shed more light on this phenomenon, we employed custom cDNA microarray (containing 2234 probes) to perform parallel transcriptomic profiling of RNA and identified that 139 genes were significantly up-regulated due to CDDP chemoresistance. The analyses of molecular pathways indicated that the top up-regulation scoring functions were response to stress, abiotic stimulus, regulation of metabolic process, apoptotic processes, regulation of cell proliferation, DNA repair or regulation of catalytic activity, which was also evidenced by analysis of molecular functions revealing up-regulation of genes encoding several proteins with a wide-spectrum of enzymatic activities. Functional analysis using lysosomotropic agents chloroquine and bafilomycin A1 validated their potential to re-sensitize UKF-NB-4CDDP cells to CDDP. Taken together, the identification of alterations in specific genes and pathways that contribute to CDDP chemoresistance may potentially lead to a renewed interest in the development of novel rational therapeutics and prognostic biomarkers for the management of CDDP-resistant neuroblastoma.

• Keywords
• chemoresistance, cisplatin, lysosomes, microarray, neuroblastoma, transport,
• MeSH
• Clone Cells MeSH
• Drug Resistance, Neoplasm drug effects   genetics   MeSH
• Chloroquine pharmacology   MeSH
• Cisplatin pharmacology   therapeutic use   MeSH
• Gene Ontology MeSH
• Gene Regulatory Networks drug effects   MeSH
• Humans MeSH
• Lysosomes drug effects   metabolism   MeSH
• Macrolides pharmacology   MeSH
• Cell Line, Tumor MeSH
• Neuroblastoma drug therapy   genetics   pathology   MeSH
• Gene Expression Regulation, Neoplastic drug effects   MeSH
• Transcriptome drug effects   genetics   MeSH
• Cell Shape drug effects   MeSH
• Up-Regulation drug effects   genetics   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• bafilomycin A1 MeSH Browser
• Chloroquine MeSH
• Cisplatin MeSH
• Macrolides MeSH

Doxorubicin (DOX) is one of the most frequently used anticancer drugs in breast cancer treatment. However, clinical applications of DOX are restricted, largely due to the fact that its action disturbs the pro/antioxidant balance in both cancerous and non-cancerous cells. The aim of this study was to investigate the influence of fullerene (C60) in cell treatment by DOX on the proliferation of human breast cancer cells (MCF-7), concentration of metallothionein (MT) and superoxide dismutase (SOD), and SOD activity in these cells. The use of C60 in complexes with DOX causes a change in the level of cell proliferation of about 5% more than when caused by DOX alone (from 60⁻65% to 70%). The use of C60 as a DOX nanotransporter reduced the MT level increase induced by DOX. C60 alone caused an increase of SOD1 concentration. On the other hand, it led to a decrease of SOD activity. C60 in complex with DOX caused a decrease of the DOX-induced SOD activity level. Exposure of MCF-7 cells to DOX-C60 complexes results in a decrease in viable cells and may become a new therapeutic approach to breast cancer. The effects of C60 in complexes with DOX on MCF-7 cells included a decreased enzymatic (SOD activity) and nonenzymatic (MT) antioxidant status, thus indicating their prooxidant role in MCF-7 cells.

• Keywords
• breast tumors, doxorubicin, drug delivery systems, fullerene, nanoparticles, metallothionein, superoxide dismutase,
• MeSH
• Doxorubicin pharmacology   MeSH
• Fullerenes chemistry   MeSH
• Humans MeSH
• Metallothionein metabolism   MeSH
• MCF-7 Cells MeSH
• Nanoparticles chemistry   MeSH
• Cell Proliferation drug effects   MeSH
• Antineoplastic Agents pharmacology   MeSH
• Superoxide Dismutase-1 metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Doxorubicin MeSH
• Fullerenes MeSH
• Metallothionein MeSH
• Antineoplastic Agents MeSH
• SOD1 protein, human MeSH Browser
• Superoxide Dismutase-1 MeSH