Synergistic effect of targeting dishevelled-3 and the epidermal growth factor receptor-tyrosine kinase inhibitor on mesothelioma cells in vitro

Our plain-English summary of Synergistic effect of targeting dishevelled-3 and the epidermal growth factor receptor-tyrosine kinase inhibitor on mesothelioma cells in vitro, by G. Moriyama, M. Tanigawa, K. Sakai, et al (Oncology Letters, 2018).

The study

• Authors: G. Moriyama, M. Tanigawa, K. Sakai, Y. Hirata, S. Kikuchi, Y. Saito, H. Kyoyama, K. Matsuda, M. Seike, A. Gemma, K. Uematsu
• Journal: Oncology Letters
• Published: 2018;15(1):833-838
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

It was previously revealed that Wnt signaling is activated in mesothelioma cells. Although epidermal growth factor receptor (EGFR) is expressed in mesothelioma cells, EGFR-tyrosine kinase inhibitors (TKIs) are not effective for mesothelioma treatment. However, in non-small cell lung cancer, the blocking of Wnt signaling has been identified to enhance the anticancer effect of EGFR-TKIs. To confirm the anticancer effect of blocking Wnt signaling in combination with EGFR-TKI treatment in mesothelioma, the present study evaluated the effect of simultaneous suppression of human dishevelled-3 (Dvl-3) expression with Dvl-3 small interfering RNA (siRNA) and of EGFR inhibition with gefitinib on mesothelioma cell viability. Mesothelioma cell lines with and without β-catenin gene expression were transfected with Dvl-3 siRNA and were cultured with gefitinib, and cell viability, colony formation and cell cycle analyses were performed. Dvl-3 siRNA downregulated the expression of Dvl-3 in mesothelioma cells. The combination of Dvl-3 siRNA with gefitinib acted synergistically to induce concomitant suppression of cell viability and colony formation, suggesting that inhibition of Wnt signaling by downregulating Dvl-3 with siRNA and inhibiting EGFR with gefitinib leads to significant antitumor effects.

In plain English

This was a laboratory study on three commercially obtained human mesothelioma cell lines (H28, H2452 and 211H). It did not study asbestos exposure or patients. The authors used a small interfering RNA (siRNA) to reduce a protein called dishevelled-3 (Dvl-3), part of the Wnt signaling pathway. They also treated the cells with gefitinib, a drug that blocks the epidermal growth factor receptor, at 5, 10 or 30 µM. The siRNA lowered Dvl-3 in all three cell lines. Reducing Dvl-3 alone significantly lowered the survival (viability) of H28 and 211H cells but not of H2452 cells. When cells with reduced Dvl-3 were also given gefitinib, viability was significantly lower at 5 and 10 µM in H28, at 5, 10 and 30 µM in 211H, and at 10 and 30 µM in H2452. Colony counts fell when Dvl-3 was reduced and fell further with 5 µM gefitinib. A rise in cells in the G1 phase of the cell cycle was not statistically significant. The authors concluded the combination may be useful for treating mesothelioma. They noted that the siRNA no longer worked 14 days after it was introduced.

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 (in vitro) experiment on human mesothelioma cell lines
• Who was studied: Three human mesothelioma cell lines (NCI-H28, NCI-H2452 and MSTO-211H) obtained from the American Type Culture Collection. H28 cells lack beta-catenin because of a homozygous deletion of the beta-catenin gene. No patients were studied.
• Exposure: No asbestos exposure was studied. Cells were given Dvl-3 siRNA or control siRNA, then gefitinib at 5, 10 or 30 µM, or dimethylsulfoxide (DMSO) as a control. Colony and cell cycle tests used 5 µM gefitinib.
• Main results:
  • Dvl-3 siRNA reduced Dvl-3 protein in 211H, H2452 and H28 cells at 48 hours.
  • Dvl-3 siRNA alone significantly suppressed the viability of H28 and 211H cells compared with control siRNA, but not of H2452 cells.
  • In H28 cells, 5 or 10 µM gefitinib did not suppress viability in control-siRNA cells, but significantly suppressed it in Dvl-3 siRNA cells compared with DMSO.
  • In H28 cells, 30 µM gefitinib markedly decreased viability, and this was not affected by reducing Dvl-3.
  • In 211H cells, at 5, 10 or 30 µM gefitinib, viability was significantly and synergistically suppressed in Dvl-3 siRNA cells compared with control-siRNA cells.
  • In H2452 cells, 10 and 30 µM gefitinib significantly suppressed viability of Dvl-3 siRNA cells compared with control-siRNA cells.
  • Colony counts in all three cell lines fell significantly with Dvl-3 siRNA and fell further with 5 µM gefitinib, compared with controls.
  • The share of cells in the G1 phase tended to increase further with Dvl-3 siRNA plus gefitinib in all three lines. This was not statistically significant (P greater than 0.05).
  • Reducing Dvl-3 decreased phosphorylated GSK3-beta in 211H and H2452 cells. In H28 cells, both phosphorylated and total GSK3-beta decreased.
• The authors' conclusion: The authors concluded that the results suggest blocking EGF signaling with gefitinib or other EGFR inhibitors, together with blocking Wnt signaling by suppressing Dvl-3, may be a useful combination for treating mesothelioma.
• Limitations the authors state:
  • The siRNA stopped working by 14 days after it was introduced, which was the length of the colony formation assay.
  • The 5 µM gefitinib dose used in the cell cycle analysis did not effectively inhibit cell viability 24 hours after it was added.
  • The authors state that further studies are needed to understand the mechanisms behind the results.

Topics

Medical terms in this study, explained in our Lexicon: Synergistic Effect, Tyrosine Kinase Inhibitor, Mesothelioma, EGFR, Non-Small Cell Lung Cancer.

Related studies

• Patients with peritoneal mesothelioma lack epidermal growth factor receptor tyrosine kinase mutations that would make them sensitive to tyrosine kinase inhibitors — N. Kalra, A. Ashai, et al. (2012)
• Proteoglycans in human malignant mesothelioma. Stimulation of their synthesis induced by epidermal, insulin and platelet-derived growth factors involves receptors with tyrosine kinase activity — A. Syrokou, G.N. Tzanakakis, et al. (1999)
• Different accumulation of activated extracellular signal-regulated kinases (ERK 1/2) and role in cell-cycle alterations by epidermal growth factor, hydrogen peroxide, or asbestos in pulmonary epithelial cells — S. Buder-Hoffmann, C. Palmer, et al. (2001)
• Increased epidermal growth factor-receptor protein in a human mesothelial cell line in response to long asbestos fibers — J.C. Pache, Y.M. Janssen, et al. (1998)
• Increased expression of epidermal growth factor receptor in rat pleural mesothelial cells correlates with carcinogenicity of mineral fibres — S.P. Faux, C.E. Houghton, et al. (2000)
• Autocrine stimulation of a human lung mesothelioma cell line is mediated through the transforming growth factor alpha/epidermal growth factor receptor mitogenic pathway — I.A. Mórocz, D. Schmitter, et al. (1994)

Browse more research in Oncology Letters, or return to medical research.