Breast cancer metastases are the main reason for women ́s highest cancer mortality. Even though tumor cell dissemination via circulating tumor cells (CTC) released from the primary site is a very ineffective process, distant metastases appear in 46% of triple-negative breast cancer (TNBC) patients corresponding to the disease aggressiveness. Laboratory models for functional testing which mimic the spread of metastatic cells are needed for efficient investigation of the underlying mechanisms and therapeutic intervention. Here, we describe novel isogenic variants LMC3 and CTC3 of human TNBC cell line MDA-MB-231 that were derived by repeated injection of tumor cells into the tail vein of immunodeficient mice and subsequent selection of metastatic cells from lung metastases. These variants have increased migration potential, altered expression profiles, and elevated tumorigenic potential. Moreover, cell line CTC3 readily produces metastases in the lungs and bone marrow and detectable viable circulating tumor cells in the blood. This model enables rapid and cost-efficient strategies for biomarker exploration and novel intervention approaches to limit the CTC presence in the blood and hence tumor dissemination.

• MeSH
• biologické markery MeSH
• lidé MeSH
• metastázy nádorů MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádorové cirkulující buňky * metabolismus   MeSH
• nádory plic * sekundární   MeSH
• triple-negativní karcinom prsu * genetika   patologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Gene-directed enzyme/prodrug therapy (GDEPT) mediated by mesenchymal stromal cells (MSC) was already approved for clinical study on a progressive disease refractory to standard therapy. In this work, we examined the effect of several GDEPT approaches on chemoresistant cells. First, we derived 5-fluorouracil (5-FU)-resistant variant of human colorectal adenocarcinoma cells HT-29 designated HT-29/EGFP/FUR. Our data show that the upregulation of thymidylate synthase (TS) and downregulation of thymidine phosphorylase (TP), orotate phosphoribosyl transferase (OPRT) and dihydropyrimidine dehydrogenase (DPD) contributed to the 5-FU resistance in cancer cells. Next, we combined the MSC expressing either yeast cytosine deaminase (CD-MSC) or fusion yeast CD::uracil phosphoribosyl transferase (CD::UPRT-MSC) and prodrug 5-fluorocytosine (5-FC) in a cell-mediated GDEPT approach. Bystander cytotoxic effect in the direct co-cultures of the tumor and therapeutic cells mixed in a 5:1 ratio resulted in 55% and 70% inhibition of proliferation, respectively. However, the acquired chemoresistance to 5-FU can be overcome by introducing the prodrug-converting transgene into the tumor cells. When the transgene CD::UPRT was expressed in the chemoresistant cells (CD::UPRT-FUR), substantial suicide effect and a 90% decrease in viability was observed using non-toxic concentration of 62.5 µg/ml 5-FC. In summary, we demonstrate here that the transgene introduction circumvented 5-FU resistance in the tumor cells.

• MeSH
• fluorouracil farmakologie   terapeutické užití   MeSH
• genetická terapie metody   MeSH
• lidé MeSH
• myši SCID MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• prekurzory léčiv farmakologie   terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH