Células-tronco cancerosas (CSCs) estão implicados na reincidência do tumor devido a chemoresistance. Nós otimizamos um protocolo para a seleção e expansão dos CSCs de linhas celulares de cancro do ovário. Ao tratar as células com a cisplatina quimioterapêutico e a cultura de uma célula-tronco nos meios de promoção para enriquecer culturas CSC não aderentes.
Células-tronco cancerosas (CSCS) são definidos como um subconjunto de ciclismo lento e células indiferenciadas que se dividem de forma assimétrica para gerar altamente proliferativa, invasiva e células tumorais quimiorresistentes. Portanto, CSCs são uma população de células atraente para direcionar terapeuticamente. CSCs são previstos para contribuir para um número de tipos de tumores, incluindo os do sangue, cérebro, pulmão, tracto gastrointestinal, próstata, ovário. Isolando e enriquecendo a população de células tumorais para CSCs irá permitir aos pesquisadores estudar as propriedades, genética e resposta terapêutica dos CSCs. Geramos um protocolo que enriquece reprodutível para CSCs câncer de ovário de linhas celulares de cancro do ovário (SKOV3 e OVCA429). As linhas de células são tratadas com 20 pM de cisplatina durante 3 dias. As células sobreviventes são isoladas e cultivadas em meios de células-tronco isento de soro contendo citoquinas e factores de crescimento. Nós demonstramos um enriquecimento dessas CSCs purificados por análise das células isoladas, para known marcadores de células estaminais Oct4, nanog, e Prom1 (CD133) e a expressão da superfície das células de CD177 e CD133. A exposição CSCs aumento chemoresistance. Este método de isolamento de CSCs é uma ferramenta útil para o estudo do papel das CSCs na quimiorresistência de tumor e de recaídas.
Resistance to chemotherapy is a major impediment to the treatment and cure of cancer. Ovarian cancer is the 5th leading cause of cancer-related deaths among women in the United States (American Cancer Society Facts and Figures 2013). Patients initially respond well to chemotherapy, but most patients relapse1. After relapse patients are treated with a variety of additional chemotherapy agents with very little benefit2. General properties of CSCs include unlimited proliferative capabilities, retention of an undifferentiated state, resistance to drug treatment, efficient DNA repair, and ability to generate malignant tumor cells with different phenotypes3. CSCs frequently exhibit expression of stem cell genes such as Nanog, Oct4, Sox2, Nestin, CD133, and CD117. CSCs often express elevated levels of ABCG2, and ALDH genes that may contribute to drug efflux and metabolism3,4.
The first definitive evidence for CSCs was demonstrated by isolating acute myeloid leukemia-initiating cells that were capable of self-renewal and tumor generation5. These leukemic stem cells expressed surface CD34 and generated leukemia in NOD/SCID (immunocompromised) mice5. Since then CSCs have been identified in many cancer types including leukemias/lymphomas, breast, bladder, colorectal, endometrial, sarcomas, hepatocellular carcinoma, melanomas, gliomas, ovarian, pancreatic, prostate, squamous cell carcinoma, and lung6. Therefore, being able to study this subtype of cancer cell is advantageous.
The goal of this study is to create a protocol for the selection and isolation of chemoresistant CSCs. Several methods have been reported for the isolation of CSCs from ovarian cancer cell lines. Non-adherent spheroids isolated from OVCAR-3, SKOV3, or HO8910 cultures demonstrate stem-like properties7,8. Isolation of CD133+ cells from OVCAR-3 cultures also yields CSCs. CSCs have also been selected in culture by treatment with chemotherapeutic agents. Treating tumor cell lines (OVCA433, Hey, and SKOV3 cells) with cisplatin and paclitaxel allows for the expansion and isolation of CSCs4,9. While culture of some cell types in CSC media leads to isolation of CSCs, SKOV3 cells did not survive culture in serum-free media or form sphere cells4. Therefore, treatment of cells with cisplatin and paclitaxel aided the expansion or isolation of this population4.
Using a modification of the procedure presented by Ma and colleagues4 we developed a method to isolate CSCs from the ovarian cancer cell lines. Our protocol is advantageous as it yields more viable cells while using less toxic chemotherapeutic agents. Cells are treated with cisplatin and subsequently grown in serum-free media supplemented with growth factors (stem cell media). We isolate the resulting non-adherent sphere cells and assay them for their expression of stem cell markers. This model enables the study of CSC properties and response to drug therapy.
CSCs que são resistentes à terapia pode ser responsável por recaída após o tratamento do tumor primário. Caracterização dos CSCs podem levar a melhores terapias para o câncer de ovário. Os parâmetros críticos no estabelecimento de CSCs quimiorresistentes utilizando o protocolo anteriormente referido, são cronometrar o tempo de tratamento com a quimioterapia e a concentração de quimioterapia. Ao usar o protocolo em Ma et al. verificou-se que ao fim de 7 dias de tratamento com cisplatina e paclitax…
The authors have nothing to disclose.
Serene Samyesudhas and Dr. Lynn Roy assisted in preparing samples for filming.
Name of Reagent/ Equipment | Company | Catalog Number | Comments/Description |
McCoy | Life Technologies | 16600-108 | Warm to 37C prior to use |
DMEM / F12 serum free | Life Technologies | 11320-033 | Warm to 37C prior to use |
Minimal Essential Media | Life Technologies | 42360032 | Warm to 37C prior to use |
Sodium Pyruvate | Life Technologies | 11360070 | |
Polybrene | Millipore | TR-1003-G | |
Blasticidin | Life Technologies | R21001 | |
Fetal Bovine Serum | Atlas Biologicals | F-0500-A | |
Penicillin-streptomycin | Life Technologies | 15070-063 | |
Cisplatin | Sigma-Aldrich | T7402-5MG | Caution: Toxic Use precautions |
pLenti-suCMV-Rsv | Gentarget | LVP023 | BSL2 approval needed |
Insulin | Sigma-Aldrich | I-1882 | |
Human Recombinant EGF | Cell Signaling Technology | 8916LC | |
bFGF | BD biosciences | 354060 | |
LIF | Santa Cruz | sc-4988A | |
Bovine Serum Albumin | Roche | 03 116 956 001 | |
TRIzol | Life Technologies | 15596-018 | |
High Capacity cDNA Reverse Transcription Kit | Applied Biosystems | 4368813 | |
IQ Multiplex Powermix | BioRad | 1725849 | |
Accumax | Millipore | ||
Primers | Integrated DNA Technology | individually designed and ordered (see protocol for sequnces) | |
Anti-CD133 PE | Milenyl | 130-098-826 | Primer/probe sets are light sensitive |
CD117-Biotin | Miltenly | 130-098-570 | |
AntiBiotin-FITC | Miltenly | 130-098-796 | |
Paraformaldehyde | Sigma-Aldrich | P6148-1KG | Caution: Toxic always prepare in hood and make fresh. |
Trypsin | Life Technologies | 25300062 | |
MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) | Sigma-Aldrich | 25200-072 | |
EVOS Fl Epifluorescence and Transmitted Light Microscope | Advanced Microscopy Group | ||
Biorad CFX96 C1000 System | Biorad | ||
Beckman Coulter FC500 Flow Cytometer | Beckman Coulter | ||
Spectramax 340PC384 | Molecular Devices |