Unraveling Novel Strategies in Mesothelioma Treatments Using a Newly Synthetized Platinum(IV) Compound

Our plain-English summary of Unraveling Novel Strategies in Mesothelioma Treatments Using a Newly Synthetized Platinum(IV) Compound, by C. Favaron, L. Gaiaschi, C. Casali, et al (Pharmaceutics, 2024).

The study

• Authors: C. Favaron, L. Gaiaschi, C. Casali, F. De Luca, F. Gola, M. Cavallo, V. Ramundo, E. Aldieri, G. Milanesi, S.D. Visonà, M. Ravera, M.G. Bottone
• Journal: Pharmaceutics
• Published: 2024;16(8)
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant mesothelioma is a rare tumor associated with asbestos exposure. Mesothelioma carcinogenesis is related to enhanced reactive oxygen species (ROS) production and iron overload. Despite the recent advances in biomedical sciences, to date the only available treatments include surgery in a small fraction of patients and platinum-based chemotherapy in combination with pemetrexed. In this view, the purpose of this study was to evaluate the therapeutic potential of the newly synthetized platinum prodrug Pt(IV)Ac-POA compared to cisplatin (CDDP) on human biphasic mesothelioma cell line MSTO-211H using different complementary techniques, such as flow-cytometry, transmission electron microscopy (TEM), and immunocytochemistry. Healthy mesothelial cell lines Met-5A were also employed to assess the cytotoxicity of the above-mentioned compounds. Our in vitro results showed that Pt(IV)Ac-POA significantly interfere with iron metabolisms and more importantly is able to trigger cell death, through different pathways, including ferroptosis, necroptosis, and apoptosis, in neoplastic cells. On the other hand, CDDP triggers mainly apoptotic and necrotic cell death. In conclusion, Pt(IV)Ac-POA may represent a new promising pharmacological agent in the treatment of malignant mesothelioma.

In plain English

This was a laboratory study on cells grown in dishes. No people or animals were studied, and asbestos exposure was not examined. The authors compared cisplatin, a standard mesothelioma chemotherapy drug, with a newly made platinum compound called Pt(IV)Ac-POA. Both were tested at 10 µM for 12 and 48 hours on a human biphasic mesothelioma cell line (MSTO-211H) and a healthy human mesothelial cell line (Met-5A). In the mesothelioma cells, the share of dividing (Ki-67-positive) cells fell after 48 hours of cisplatin and after 12 and 48 hours of Pt(IV)Ac-POA. Histone acetylation was stronger with Pt(IV)Ac-POA than with cisplatin. Under the electron microscope, cisplatin-treated cells showed necrosis and apoptosis. Pt(IV)Ac-POA-treated cells showed apoptosis and necroptosis and, at 48 hours, features the authors identified as ferroptosis, an iron-linked form of cell death. After 48 hours of either drug, more mesothelioma cells than healthy cells were positive for an apoptosis marker. The authors concluded that Pt(IV)Ac-POA "may represent a new promising pharmacological agent" for malignant mesothelioma. They called for further studies, including in other cell lines and in vivo models.

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 human cell lines comparing a new platinum(IV) prodrug with cisplatin
• Who was studied: Two human cell lines: the biphasic mesothelioma cell line MSTO-211H and the healthy mesothelial cell line Met-5A. No human subjects or animals.
• Exposure: Drug treatment, not asbestos: cisplatin (CDDP) or Pt(IV)Ac-POA, each at 10 µM, as continuous treatment for 12 h and 48 h
• Main results:
  • In MSTO-211H mesothelioma cells, Ki-67-positive (dividing) cells were significantly lower than control after 48 h of cisplatin and after 12 and 48 h of Pt(IV)Ac-POA (p < 0.0001 for each)
  • In mesothelioma cells, a sub-G1 peak in the cell-cycle analysis appeared only after Pt(IV)Ac-POA treatment
  • In mesothelioma cells, histone H3 acetylation was significantly stronger after Pt(IV)Ac-POA than after cisplatin (p < 0.0001)
  • By electron microscopy of mesothelioma cells, cisplatin produced necrosis and apoptosis, while Pt(IV)Ac-POA produced apoptosis and necroptosis
  • After 48 h of Pt(IV)Ac-POA, mesothelioma cells with features of ferroptosis were seen
  • GPX4, a ferroptosis-related marker, decreased significantly after 12 and 48 h of Pt(IV)Ac-POA in both cell lines
  • FTH1 (ferritin heavy chain) expression was altered in all cisplatin- and Pt(IV)Ac-POA-treated cells (p < 0.0001), which the authors took as a sign of disturbed iron metabolism
  • The percentage of cleaved caspase-3-positive (apoptotic) cells after 48 h of either drug was significantly higher in mesothelioma cells than in healthy Met-5A cells
  • In mesothelioma cells, the necroptosis marker RIP1 was significantly increased with both drugs (p < 0.0001). MLKL was significantly increased only after 48 h of Pt(IV)Ac-POA (p < 0.0001).
• The authors' conclusion: The authors concluded that Pt(IV)Ac-POA may represent a new promising pharmacological agent in the treatment of malignant mesothelioma. In the discussion they suggested it selectively kills mesothelioma cells.
• Limitations the authors state:
  • The authors stated that further studies are needed on the compound's mechanisms, including its histone deacetylase inhibitor activity and its interplay with pemetrexed
  • The authors stated that the results should be confirmed in cell lines mutated or silenced for BAP1, NF2 and CDKN2A and in in vivo models, including to assess short- and long-term side effects

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Asbestos Exposure, Carcinogenesis, Reactive Oxygen Species (ROS), Chemotherapy, Pemetrexed (Alimta), Cisplatin, Biphasic Mesothelioma.

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