RESUMO
One of the models that best explains the cellular heterogeneity observed in central nervous system (CNS) tumors is the presence of cancer stem cells (CSCs). CSCs can originate from differentiated adult cells that return to an undifferentiated stage through the mechanism known as epithelial-mesenchymal transition (EMT). In this paper, we evaluated cellular and molecular heterogeneity and the participation of the epithelial-mesenchymal transition (EMT) in glioblastoma (U-87 MG and LN-18) and neuroblastoma (KELLY and IMR-32) cell lines cultured in monolayer (2D) and neurosphere (CSC enrichment- 3D) models. For this, after treatment with cisplatin, we studied different cell subpopulations by immunophenotyping using neural stem cell/progenitor markers (ALDH, CD24, CD56, and CD133), mesenchymal stem cell markers (CD73, CD90, CD105, and CD146) and hematopoietic markers (CD14, CD19, CD34, CD45, and HLA-DR) and mRNA expression profiles of genes related to EMT, such as ZEB1, TWIST1, TGFB1, STAT3, and lncRNA HOTAIR. In addition, we evaluated the growth capacity of residual cells when treated with cisplatin using the chorioallantoic membrane (CAM) model to study disease relapse. After treatment with cisplatin, we found that the expression of STAT3 and TGFB1 genes markedly increased in the neurosphere of the IMR-32 cell line, and TWIST1 was upregulated in the neurosphere of LN-18. Only the nontreated monolayer of LN-18, KELLY, and IMR-32 amplified the lncRNA HOTAIR. The IMR-32 cell line exhibited an enrichment of CD24+/ALDH+ and this cell subset decreased after cisplatin treatment. We observed the loss of CD146+/CD73+ cell subpopulations in U-87 MG monolayer and neurosphere models, after cisplatin treatment, while in LN-18 monolayer cisplatin-treated cells, CD73+/CD90+ cell subpopulations increased. Neuroblastoma cell lines showed CD14+/HLA-DR- cell subpopulations representative of myeloid-derived suppressor cells (MDSCs). Tumors generated from residual cells, after exposure to cisplatin, grafted on CAM showed patterns of organization different from those of the controls. Thus, our findings strongly supported the idea that definitions of tumor phenotypic characteristics may help to establish better therapeutic strategies for the development of new drug targets.
Assuntos
Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Cisplatino/farmacologia , Glioblastoma/tratamento farmacológico , Neuroblastoma/tratamento farmacológico , Técnicas de Cultura de Células , Diferenciação Celular/genética , Linhagem Celular Tumoral , Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/patologia , Membrana Corioalantoide/efeitos dos fármacos , Membrana Corioalantoide/patologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Antígenos Comuns de Leucócito/genética , Células-Tronco Mesenquimais/efeitos dos fármacos , Proteínas de Neoplasias/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Neuroblastoma/genética , Neuroblastoma/patologia , Proteínas Nucleares/genética , Fator de Crescimento Transformador beta1/genética , Proteína 1 Relacionada a Twist/genéticaRESUMO
Carcinoembryonic antigen (CEA) is a glycoprotein antigen generally used for diagnosis, prognosis and treatment monitoring of several types of tumors, including colorectal cancer. Nucleic acid aptamers are DNA or RNA oligonucleotides capable of binding with high specificity and affinity to a molecular target. The aim of this study was to obtain aptamers specific to CEA for use as radiopharmaceuticals in colorectal cancer diagnosis. Five aptamers were selected through the Systematic Evolution of Ligands by EXponencial Enrichment (SELEX) and tested using T84 (CEA+) and Hela (CEA-) cells. Apta 3 and Apta 5 showed the best results presenting high specificity and affinity for T84 cells, with dissociation constants (Kd) of 60.4 ± 5.7 nM and 37.8 ± 5.8 nM, respectively. These results indicate that Apta 3 and Apta 5 are promising candidates for identifying tumor cells that overexpress CEA.
Assuntos
Aptâmeros de Nucleotídeos/química , Antígeno Carcinoembrionário/análise , Neoplasias Colorretais/diagnóstico , Compostos Radiofarmacêuticos/química , Técnica de Seleção de Aptâmeros , Humanos , Células Tumorais CultivadasRESUMO
Long circulating pH-sensitive liposomes have been shown to effectively deliver doxorubicin (DOX) to tumors and reduce its toxic effects. Folic acid receptors are upregulated in a wide variety of solid, epithelial tumors, including breast cancer. In order to improve liposomal endocytosis and antitumor activity, folic acid has been added to nanoparticles surfaces to exploit overexpression of folate receptors in tumor cells. The purpose of this study was to evaluate the antitumor activity in vitro and in vivo of long circulating pH-sensitive folate-coated DOX-loaded liposomes (SpHL-DOX-Fol) in a 4T1 breast cancer model system in vitro and in vivo. Biodistribution studies were performed and in vivo electrocardiographic parameters were evaluated. A higher tumor uptake for radiolabeled SpHL-Fol (99mTc-SpHL-Fol) 4 h after intravenous administration was observed in comparision with non-folate-coated liposomes (99mTc-SpHL). Antitumor activity showed that SpHL-DOX-Fol treatment led to a 68% growth arrest and drastically reduce pulmonary metastasis foci. Additionally, eletrocardiographic parameters analysis revealed no dispersion in the QT and QTc interval was observed in liposomal treated mice. In summary, this novel multifunctional nanoplatform deomonstrated higher tumor uptake and antitumor activity. SpHL-DOX-Fol represents a drug delivery platform to improve DOX tumor delivery and reduce dose-limiting toxicity.