Cancer-Associated Fibroblasts Regulate Kinase Activity in Mesothelioma Cell Lines via Paracrine Signaling and Thereby Dictate Cell Faith and Behavior

Our plain-English summary of Cancer-Associated Fibroblasts Regulate Kinase Activity in Mesothelioma Cell Lines via Paracrine Signaling and Thereby Dictate Cell Faith and Behavior, by A. Mathilakathu, M. Wessolly, E. Mairinger, et al (International Journal of Molecular Sciences, 2022).

The study

• Authors: A. Mathilakathu, M. Wessolly, E. Mairinger, H. Uebner, D. Kreidt, L. Brcic, J. Steinborn, K. Greimelmaier, J. Wohlschlaeger, K.W. Schmid, F.D. Mairinger, S. Borchert
• Journal: International Journal of Molecular Sciences
• Published: 2022;23(6)
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Malignant pleural mesothelioma (MPM) has an infaust prognosis due to resistance to systemic treatment with platin-analoga. MPM cells modulate the immune response to their benefit. They release proinflammatory cytokines, such as TGF-ß, awakening resting fibrocytes that switch their phenotype into activated fibroblasts. Signaling interactions between cancer cells and cancer-associated fibroblasts (CAFs) play an integral part in tumor progression. This study aimed to investigate the role CAFs play in MPM progression, analyzing the impact this complex, symbiotic interaction has on kinase-related cell signaling in vitro.

Methods: We simulated paracrine signaling in vitro by treating MPM cell lines with conditioned medium (CM) from fibroblasts (FB) and vice versa. NCI-H2052, MSTO-211H, and NCI-H2452 cell lines representing the three mayor MPM subtypes, while embryonal myofibroblast cell lines, IMR-90 and MRC-5, provide a CAFs-like phenotype. Subsequently, differences in proliferation rates, migratory behavior, apoptosis, necrosis, and viability were used as covariates for data analysis. Kinase activity of treated samples and corresponding controls were then analyzed using the PamStation12 platform (PamGene); Results: Treatment with myofibroblast-derived CM revealed significant changes in phosphorylation patterns in MPM cell lines. The observed effect differs strongly between the analyzed MPM cell lines and depends on the origin of CM. Overall, a much stronger effect was observed using CM derived from IMR-90 than MRC-5. The phosphorylation changes mainly affected the MAPK signaling pathway.; Conclusions: The factors secreted by myofibroblasts in fibroblasts CM significantly influence the phosphorylation of kinases, mainly affecting the MAPK signaling cascade in tested MPM cell lines. Our in vitro results indicate promising therapeutic effects by the use of MEK or ERK inhibitors and might have synergistic effects in combination with cisplatin-based treatment, improving clinical outcomes for MPM patients.

In plain English

This was a laboratory study of cell lines, not patients, and it did not test asbestos. The authors treated three malignant pleural mesothelioma (MPM) cell lines (epithelioid NCI-H2052, biphasic MSTO-211H and sarcomatoid NCI-H2452) with growth medium conditioned by two embryonal myofibroblast cell lines, IMR-90 and MRC-5. These were chosen to resemble cancer-associated fibroblasts. The authors then measured kinase activity (protein phosphorylation), viability, apoptosis and migration. Phosphorylation of GSK3B and MK12 increased significantly, two- to threefold from baseline. Effects differed between cell lines and were much stronger with IMR-90 medium. Kinase activity increased in NCI-H2052 and MSTO-211H cells and decreased in NCI-H2452 cells. Changes in specific phosphorylation sites were associated with viability, apoptosis and migration. Pathway analysis showed enrichment of several pathways, including MAPK signaling (p = 0.003). The authors concluded that fibroblast-secreted factors mainly affected MAPK signaling and that MEK or ERK inhibitors could be potential therapies. They stated that further studies of MEK inhibitors were underway. As limits, they named the lack of non-tumor cells and the use of myofibroblasts that already expressed FAP.

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: In vitro laboratory experiment on cell lines (simulated paracrine signaling using conditioned medium)
• Who was studied: Three commercial human malignant pleural mesothelioma cell lines: NCI-H2052 (epithelioid), MSTO-211H (biphasic) and NCI-H2452 (sarcomatoid). Experiments were run in technical triplicate and set up independently twice. No patients were studied.
• Exposure: No asbestos exposure was studied. MPM cells were treated for 24 hours with medium conditioned for 48 hours by the embryonal myofibroblast cell lines IMR-90 or MRC-5. Controls received medium conditioned by the MPM cell line itself.
• Main results:
  • In the search for changes in phosphorylation pattern after treatment with fibroblast-conditioned medium, GSK3B and MK12 showed significant upregulation of two- to threefold from baseline (GSK3B: p = 0.036, MK12: p = 0.044).
  • The effect was much stronger with conditioned medium from IMR-90 than from MRC-5.
  • Kinase activity was activated in NCI-H2052 and MSTO-211H cells and inhibited in NCI-H2452 cells.
  • Enhanced phosphorylation of RON, MAPK3, CD3Z, EGFR, GSK3B and JAK1 was significantly associated with increased viability in each treated cell line, compared with control medium.
  • 39 phosphosites were associated with significantly elevated apoptosis. Decreased phosphorylation of EPB42, STK6 and CREB was associated with increased apoptosis.
  • Decreased phosphorylation of CDK4 was significantly associated with increased migration of MPM cells treated with fibroblast-conditioned medium (p = 0.034).
  • Gene set enrichment analysis found the MAPK signaling pathway enriched in treated MPM cell lines (p = 0.003, normalized enrichment score 1.89), among other pathways.
  • In relation to apoptosis, the MAPK signaling pathway was enriched (p = 0.003, normalized enrichment score 1.96).
• The authors' conclusion: The authors concluded that factors secreted by fibroblasts significantly influenced kinase phosphorylation, mainly in the MAPK signaling cascade, in the MPM cell lines tested. They suggested that MEK or ERK inhibitors could be potent therapeutic agents, possibly in combination with cisplatin. This suggestion was not tested in this study.
• Limitations the authors state:
  • The study had no non-tumor (benign) control cells and used myofibroblasts that already expressed FAP.

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: Fibroblast, Mesothelioma, Pleural Mesothelioma, Prognosis, Cytokine, Apoptosis, Necrosis, Synergistic Effect.

Related studies

• Cancer-Associated Fibroblasts Influence Survival in Pleural Mesothelioma: Digital Gene Expression Analysis and Supervised Machine Learning Model — S. Borchert, A. Mathilakathu, et al. (2023)
• Screening of Pleural Mesothelioma Cell Lines for Kinase Activity May Identify New Mechanisms of Therapy Resistance in Patients Receiving Platin-Based Chemotherapy — S. Borchert, P.M. Suckrau, et al. (2019)
• Extracellular Vesicles Isolated from Malignant Mesothelioma Cancer-Associated Fibroblasts Induce Pro-Oncogenic Changes in Healthy Mesothelial Cells — T. Chernova, S. Grosso, et al. (2022)
• Fibroblast-like cells in mesothelioma can derive from tumor cells — J.M. Garcia-Manteiga, E. Rrapaj, et al. (2026)
• BAG3 induces α-SMA expression in human fibroblasts and its over-expression correlates with poorer survival in fibrotic cancer patients — M. De Marco, N. Del Papa, et al. (2022)
• Crosstalk with lung fibroblasts shapes the growth and therapeutic response of mesothelioma cells — Y. Chrisochoidou, R. Roy, et al. (2023)

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