RESUMO
BACKGROUND: Circulating tumour cells (CTCs) are mainly enriched based on the epithelial cell adhesion molecule (EpCAM). Although it was shown that an EpCAM low-expressing CTC fraction is not captured by such approaches, knowledge about its prognostic and predictive relevance and its relation to EpCAM-positive CTCs is lacking. METHODS: We developed an immunomagnetic assay to enrich CTCs from metastatic breast cancer patients EpCAM independently using antibodies against Trop-2 and CD-49f and characterised their EpCAM expression. DNA of single EpCAM high expressing and low expressing CTCs was analyzed regarding chromosomal aberrations and predictive mutations. Additionally, we compared CTC-enrichment on the CellSearch system using this antibody mix and the EpCAM based enrichment. RESULTS: Both antibodies acted synergistically in capturing CTCs. Patients with EpCAM high-expressing CTCs had a worse overall and progression-free survival. EpCAM high- and low-expressing CTCs presented similar chromosomal aberrations and mutations indicating a close evolutionary relationship. A sequential enrichment of CTCs from the EpCAM-depleted fraction yielded a population of CTCs not captured EpCAM dependently but harbouring predictive information. CONCLUSIONS: Our data indicate that EpCAM low-expressing CTCs could be used as a valuable tumour surrogate material-although they may be prognostically less relevant than EpCAM high-expressing CTCs-and have particular benefit if no CTCs are detected using EpCAM-dependent technologies.
Assuntos
Biomarcadores Tumorais , Neoplasias da Mama , Molécula de Adesão da Célula Epitelial , Células Neoplásicas Circulantes , Feminino , Humanos , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/patologia , Aberrações Cromossômicas , Molécula de Adesão da Célula Epitelial/genética , Molécula de Adesão da Célula Epitelial/metabolismo , Células Neoplásicas Circulantes/patologiaRESUMO
The hanging drop cell culture technique allows to study three-dimensional growth and differentiation of cell aggregates, that is, embryonic stem cells. Compared to standard two-dimensional monolayer cell cultivation, hanging drops allow for a better visualization and understanding of the developmental processes in vitro. Hanging drop cultivation can also be used to study biology of cancer cells three-dimensionally in vitro. This method can serve as an intermediate between the two-dimensional monolayer cell culture and in vivo models, which can be simply established in laboratories exhibiting minimum requirements of cell culture equipment. In this chapter, we describe the three-dimensional cultivation of germ cell cancer cell lines in hanging drops.
Assuntos
Técnicas de Cultura de Células , Neoplasias Embrionárias de Células Germinativas/patologia , Esferoides Celulares , Técnicas de Cultura de Células/métodos , Linhagem Celular Tumoral , HumanosRESUMO
Cisplatin resistance still remains a major obstacle in the standard chemotherapeutic approach in late-stage and metastatic testicular germ cell cancer (GCC) patients. This multifactorial and complex phenomenon arises (concomitantly) on several levels due to impaired transport, decreased adduct formation, increased DNA-repair, decreased apoptosis, or compensating pathways. Evaluation of novel therapeutic approaches and pharmacological inhibitors still remains necessary to treat cisplatin-resistant GCCs. In this chapter, we present in vitro techniques to measure cytotoxic impacts of chemotherapeutic drugs on GCC cell lines. Specifically, we will discuss the measurement of relative cell viability by XTT assay, as well as cell cycle distribution and apoptosis assay by Nicoletti- and Annexin V/PI apoptosis assay with subsequent flow cytometry, respectively, to evaluate the effects of cytotoxic treatment in GCC cell lines.
