Mechanistic investigations of antitumor activity of a Rhodamine B‑oleanolic acid derivative bioconjugate

Oncol Rep. 2020 Sep;44(3):1169-1183. doi: 10.3892/or.2020.7666. Epub 2020 Jun 26.

Abstract

Cancer remains a major health problem worldwide due to its high mortality rate. New therapeutic options highlight the importance of discovering new compounds that target the tumor microenvironment, interrupt angiogenesis and act selectively. The present study assessed the antitumor effect and investigated the mechanism of action of a rhodamine B‑conjugated oleanolic acid derivative (RhodOA). Consequently, the compound was tested on different human tumor cell lines (A375 melanoma, A549 lung adenocarcinoma and MDA‑MB‑231 breast adenocarcinoma) and on a non‑tumor cell line HaCaT human keratinocyte. RhodOA produced a dose‑dependent decrease in tumor cell viability especially in the melanoma cells while affecting the keratinocytes less. In melanoma cells, RhodOA reduced cell migration and produced condensation of cell nuclei and of actin fibers. Furthermore, an impairment in melanoma cell mitochondrial function was observed, while the mitochondrial function of keratinocytes was left intact. In the in ovo chorioallantoic membrane model, RhodOA elicited antiangiogenic effect, without showing irritation effect on the membrane. The study provides information on the selective antitumor effect of the derivative and its ability to inhibit cellular respiration, therefore RhodOA can be classified as 'MITOCAN'.

MeSH terms

  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Antineoplastic Agents / therapeutic use
  • Apoptosis / drug effects
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • Drug Evaluation, Preclinical
  • Humans
  • Mitochondria / drug effects
  • Neoplasms / blood supply
  • Neoplasms / drug therapy*
  • Neoplasms / pathology
  • Neovascularization, Pathologic / drug therapy*
  • Neovascularization, Pathologic / pathology
  • Oleanolic Acid / chemistry
  • Oleanolic Acid / pharmacology*
  • Oleanolic Acid / therapeutic use
  • Rhodamines / chemistry
  • Rhodamines / pharmacology*
  • Tumor Microenvironment / drug effects

Substances

  • Antineoplastic Agents
  • Rhodamines
  • Oleanolic Acid
  • rhodamine B