» Articles » PMID: 39034849

Tamoxifen Metabolites Treatment Promotes ERα+ Transition to Triple Negative Phenotype in Vitro, Effects of LDL in Chemoresistance

Abstract

Objective: Estrogen receptor-positive (ER+) breast cancer represents about 80% of cases, tamoxifen is the election neoadjuvant chemotherapy. However, a large percentage of patients develop chemoresistance, compromising recovery. Clinical evidence suggests that high plasmatic levels of low-density lipoproteins (LDL) could promote cancer progression. The present study analyzed the effect of LDL on the primary plasmatic active Tamoxifen's metabolites resistance acquisition, 4-hydroxytamoxifen (4OH-Tam) and 4-hydroxy-N-desmethyl-tamoxifen (endoxifen), in breast cancer ERα + cells (MCF-7).

Methods: Two resistant cellular variants, MCF-7Var-H and MCF-7Var-I, were generated by a novel strategy and their phenotype features were evaluated. Phenotypic assessment was performed by MTT assays, cytometry, immunofluorescence microscopy, zymography and protein expression analysis.

Results: MCF-7Var-H, generated only with tamoxifen metabolites, showed a critical down-regulation in hormone receptors, augmented migration capacity, metalloprotease 9 extracellular medium excretion, and a mesenchymal morphology in contrast with native MCF-7, suggesting the transition towards Triple-negative breast cancer (TNBC) phenotype. In contrast, MCF-7Var-I which was generated in a high LDL media, showed only a slight upregulation in ER and other less noticeable metabolic adaptations. Results suggest a potential role of transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in phenotypic differences observed among variants.

Conclusion: LDL high or low concentrations during Tamoxifen´s metabolites chemoresistance acquisition leads to different cellular mechanisms related to chemoresistance. A novel adaptative cellular response associated with Nrf2 activity could be implicated.

References
1.
Lu Y, Tong Y, Chen X, Shen K . Association of Biomarker Discrepancy and Treatment Decision, Disease Outcome in Recurrent/Metastatic Breast Cancer Patients. Front Oncol. 2021; 11:638619. PMC: 8283966. DOI: 10.3389/fonc.2021.638619. View

2.
Reinema F, Sweep F, Adema G, Peeters W, Martens J, Bussink J . Tamoxifen induces radioresistance through NRF2-mediated metabolic reprogramming in breast cancer. Cancer Metab. 2023; 11(1):3. PMC: 9909892. DOI: 10.1186/s40170-023-00304-4. View

3.
Lim Y, Desta Z, Flockhart D, Skaar T . Endoxifen (4-hydroxy-N-desmethyl-tamoxifen) has anti-estrogenic effects in breast cancer cells with potency similar to 4-hydroxy-tamoxifen. Cancer Chemother Pharmacol. 2005; 55(5):471-8. DOI: 10.1007/s00280-004-0926-7. View

4.
Lu C, Lo Y, Chen C, Lin C, Tsai C, Chen P . VLDL and LDL, but not HDL, promote breast cancer cell proliferation, metastasis and angiogenesis. Cancer Lett. 2016; 388:130-138. DOI: 10.1016/j.canlet.2016.11.033. View

5.
Gonzalez-Ortiz A, Galindo-Hernandez O, Hernandez-Acevedo G, Hurtado-Ureta G, Garcia-Gonzalez V . Impact of cholesterol-pathways on breast cancer development, a metabolic landscape. J Cancer. 2021; 12(14):4307-4321. PMC: 8176427. DOI: 10.7150/jca.54637. View