Isolation of Chemoresistant Cell Subpopulations

Our plain-English summary of Isolation of Chemoresistant Cell Subpopulations, by C. Canino, M. Cioce (Methods in Molecular Biology, 2016).

The study

• Authors: C. Canino, M. Cioce
• Journal: Methods in Molecular Biology
• Published: 2016;1379:139-50
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Chemoresistance is a major challenge for cancer therapy and drives tumor relapse. The emergence, within the treated tumor mass, of specific cancer cell subpopulations endowed with high tolerance to the microenvironment stress induced by therapy is being growingly recognized as a mechanism of tumor progression. To obtain detailed information with regard to the pathways underlying survival, expansion, and microenvironmental cross talk of such chemoresistant cell subpopulations may be instrumental for cancer chemoprevention. Additionally, the obtained cell subpopulations may be used for direct screening of cancer chemopreventive compounds, in appropriate experimental settings. Here we report detailed experimental procedures that we and others have setup in order to obtain cell cultures enriched for chemoresistant cells from both malignant pleural mesothelioma specimens and primary cell cultures. We provide indications for the purification and characterization of those chemoresistant cell populations and to generally validate the obtained enriched cell populations for their chemoresistance.

In plain English

This book chapter is a laboratory methods protocol, not a study of people or of asbestos exposure. Asbestos is not discussed. The authors described step-by-step procedures that they and others had set up to grow malignant pleural mesothelioma cells. The cells came from surgical tumor specimens, from pleural effusions (fluid collected from around the lung), and from cell lines. The cultures were treated in the laboratory with the chemotherapy drugs cisplatin plus pemetrexed for 7 days, at a dose worked out beforehand for each culture. Surviving cells with high activity of an enzyme called aldehyde dehydrogenase (ALDH) were then identified and sorted. The authors reported a typical yield of about 1 million cells from a 100 mg solid specimen, and said they succeed in isolating or maintaining 70 percent of primary cultures. They stated that the procedure enriches for chemoresistant cells, citing their own and others' work. They noted several limits: large differences between patients, a test that cannot tell whether the drugs stopped cell growth or killed cells, a mixed population of ALDH-bright cells, and a drop in ALDH-bright cells within 2 weeks after sorting.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory methods protocol (book chapter) describing how to isolate, enrich and characterize chemotherapy-resistant mesothelioma cell subpopulations
• Who was studied: Malignant pleural mesothelioma cells from surgical tumor specimens, pleural effusions and cell lines. No numbers of patients, places or dates are given.
• Exposure: No asbestos exposure was studied. In the laboratory, cultures were treated with chemotherapy (cisplatin plus pemetrexed for mesothelioma) for 7 days. The dose used was the CC50, the concentration found beforehand to reduce the number of viable cells by 50 percent.
• Main results:
  • The authors reported a typical yield of 1 million cells from a 100 mg solid specimen, and 10 million cells from 30 to 50 ml of freshly collected pleural effusion.
  • The authors reported that 70 percent of their attempts to isolate and maintain primary cultures from patient samples were successful.
  • In four representative mesothelioma primary cultures, freezing medium without DMSO significantly reduced the viability of frozen cells.
• The authors' conclusion: The authors stated that the procedure enriches for chemoresistant cell subpopulations. They based this on work by themselves and others in mesothelioma, lung, breast, glioblastoma and prostate cancer.
• Limitations the authors state:
  • Results vary considerably from one patient to another.
  • The viability test cannot tell whether a treatment stopped cell growth or killed the cells.
  • The sorted ALDH-bright cells are themselves a mixed population.
  • For mesothelioma, the number of ALDH-bright cells drops significantly within the first 2 weeks of culture after sorting.
  • Mesothelioma primary cultures can be grown only for a limited time (8 to 12 weeks).

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma.

Related studies

• Putative cancer stem cells in malignant pleural mesothelioma show resistance to cisplatin and pemetrexed — L. Cortes-Dericks, G.L. Carboni, et al. (2010)
• Resistance to platinum-based chemotherapy in lung cancer cell lines — J. Chen, N. Emara, et al. (2010)
• Long-term exposure of mesothelial cells to SV40 and asbestos leads to malignant transformation and chemotherapy resistance — A.L. Cleaver, K. Bhamidipaty, et al. (2014)
• Interaction and cross-resistance of cisplatin and pemetrexed in malignant pleural mesothelioma cell lines — M. Kitazono-Saitoh, Y. Takiguchi, et al. (2012)
• Asbestos induces doxorubicin resistance in MM98 mesothelioma cells via HIF-1alpha — C. Riganti, S. Doublier, et al. (2008)
• Activation of Nrf2 pathways correlates with resistance of NSCLC cell lines to CBP501 in vitro — N. Mine, S. Yamamoto, et al. (2014)

Browse more research in Methods in Molecular Biology, or return to medical research.