Mitochondria-Targeting Molecule Weakens Stem-Like Traits and Boosts Cisplatin Response in Lung Cancer Cell Model

A laboratory study on lung cancer-derived stem-like cells reports that a mitochondria-targeting molecule called PNA-TPP disrupted mitochondrial function in these cells and appeared to make them more vulnerable to the chemotherapy drug cisplatin. The work, published in BMC Molecular and Cell Biology, was carried out entirely in A549-derived stem-like spheres, a cell culture model derived from a human non-small cell lung cancer cell line, and its findings should not be read as evidence of benefit in patients.

Cisplatin resistance remains a major obstacle in treating non-small cell lung cancer, and lung cancer stem-like cells are thought to be closely linked to drug tolerance. The research team set out to test whether PNA-TPP, a peptide nucleic acid conjugated with triphenylphosphonium, could alter the response of these stem-like spheres to cisplatin, and whether any such effect was connected to Drp1, or dynamin-related protein 1, a protein involved in mitochondrial dynamics.

Methodologically, the researchers established the stem-like spheres from A549 cells using single-cell cloning and serum-free suspension culture. PNA-TPP was designed to target the mitochondrial DNA D-loop region and was applied at a concentration of 10 nanomoles per millilitre for 24 hours. The team then measured cell viability, colony formation, sphere formation, apoptosis, migration and invasion using CCK-8, colony formation, sphere formation, Annexin V-FITC/PI flow cytometry, wound healing and Transwell assays, respectively.

To probe mitochondrial function, the researchers assessed mitochondrial membrane potential with JC-1 staining, reactive oxygen species with DCFH-DA flow cytometry combined with DHE fluorescence staining, and ATP levels with an ELISA. Drp1 mRNA expression was examined by quantitative reverse transcription PCR, while Drp1 protein levels in the mitochondrial fraction were assessed by Western blotting. Drp1 overexpression and shRNA-mediated knockdown were used to evaluate the protein’s involvement in the observed effects.

The results showed that PNA-TPP increased Drp1 mRNA expression and the amount of Drp1 protein found in the mitochondrial fraction. At the same time, the treatment reduced mitochondrial membrane potential and ATP levels, and increased reactive oxygen species levels. The treated spheres also showed reduced sphere-forming ability and lower expression of the stemness-associated transcription factors OCT4, SOX2 and NANOG, suggesting that the mitochondrial perturbation was accompanied by a weakening of the cells’ stem-like phenotypes.

When the researchers combined PNA-TPP pretreatment with cisplatin, the outcome differed from cisplatin treatment alone. The combination produced lower cell viability, reduced colony formation, and diminished migration and invasion, together with increased apoptosis and a higher cleaved caspase-9 to total caspase-9 ratio, a marker pointing towards mitochondrial involvement in the apoptotic response.

The experiments manipulating Drp1 provided further mechanistic detail. Drp1 overexpression partly mimicked the effects of PNA-TPP treatment, while Drp1 knockdown partially restored mitochondrial membrane potential and the stemness-related phenotypes after PNA-TPP treatment. The authors interpret this pattern as indicating that the effects were Drp1-related, although the manipulation produced only partial changes, suggesting other pathways may also contribute.

It is important to note the scope of these findings. The study was conducted in a single cell line-derived model, without a clinical trial component, and the clinical trial number is listed as not applicable. The reported association between PNA-TPP, Drp1-related mitochondrial dysfunction and enhanced cisplatin response applies to A549-derived stem-like spheres under the specific conditions tested, and the article is currently shared as an accepted manuscript subject to further edits before the final version of record.

Nevertheless, the work adds to a body of research exploring how mitochondrial dysfunction in cancer stem-like cells might influence drug tolerance. By targeting the mitochondrial DNA D-loop region and observing downstream changes in Drp1 localisation, membrane potential, ATP and reactive oxygen species, the study offers a detailed in vitro characterisation of how one such approach altered stemness markers and cisplatin responsiveness in this lung cancer cell model.

Subject of Research: Mitochondria-targeting PNA-TPP effects on stem-like lung cancer cell spheres and cisplatin response

Article Title: PNA-TPP treatment is associated with Drp1-related mitochondrial dysfunction and an enhanced response to cisplatin in A549-derived stem-like spheres

Article References: Xie, L., Cheng, Y., Zhu, G., Zhang, X., & Ye, X. (2026). PNA-TPP treatment is associated with Drp1-related mitochondrial dysfunction and an enhanced response to cisplatin in A549-derived stem-like spheres. BMC Molecular and Cell Biology. https://doi.org/10.1186/s12860-026-00603-w

Image Credits: AI Generated

DOI: 10.1186/s12860-026-00603-w

Keywords: PNA-TPP, Drp1, mitochondrial dysfunction, cisplatin, lung cancer stem-like cells, A549 spheres, non-small cell lung cancer, mitochondrial membrane potential, reactive oxygen species, stemness, OCT4, drug tolerance