Assessing metabolic activity of cells

The EZ4U (easy for you) colorimetric assay from Biomedica (cat. no. BI-5000) is a modified MTT assay for assessing cell metabolic activity.

Assessing metabolic activity of cells

Our EZ4U cell proliferation assay was highlighted in a recent study that investigated the development of novel chemosensitizers targeting therapy-resistant cancer stem cells (CSCs). The study offers an understanding of the structural criteria necessary for optimizing telmisartan, an angiotensin II receptor blocker, and its derivatives as non-toxic chemosensitizers. Furthermore, the findings indicate that these derivatives could be utilized to target and eliminate the cancer stem cell (CSC) population in chronic myeloid leukemia (CML), as well as the therapy-resistant CSCs in solid tumors like ovarian, prostate, lung, and breast cancers.

Learn more: Eradication of Therapy-Resistant Cancer Stem Cells by Novel Telmisartan Derivatives. Schoepf Anna M. et al., J Med Chem. 2025; 68(1):287-306.

Abstract

The present structure-activity relationship study investigates the development of novel chemosensitizers targeting therapy-resistant cancer stem cells (CSCs). We used 4′-((2-propyl-1H-benzo[d]imidazole-1-yl)methyl)-[1,1′-biphenyl]-2-carboxylic acid, derived from the angiotensin II type 1 receptor blocker telmisartan, as a lead structure, demonstrating that the biphenyl moiety is essential for chemosensitizing activity. Introducing a methyl carboxylate or carboxamide instead of the COOH-group significantly enhanced this effect, leading to the development of highly potent compounds. These novel, noncytotoxic chemosensitizers effectively target CSCs and overcome drug resistance by interfering with CSC persistence mechanisms─hyperactivated STAT5 signaling and increased drug transporter activity─with demonstrated efficacy in leukemia, ovarian, and prostate cancers. The carboxamide of telmisartan (telmi-amide, 7c) significantly reduced tumor growth in an imatinib-resistant leukemia xenograft model, both as monotherapy and combined with imatinib, showing promising oral bioavailability and tolerability. In summary, telmisartan derivatives act as effective chemosensitizers and offer an innovative strategy for targeting CSCs in various malignant diseases.

Determination of Metabolic Activity

Brief: ”COS-7 (2 × 10³ cells per well), IGROV-1 SP (2.5 × 10³ cells per well), A2780 V SP (1.5 × 10³ cells per well), PC3-DR (4 × 10³ cells per well), and DU145-DR (3 × 10³ cells per well) cells were seeded in 96-well plates in triplicates and after 24 h, the compounds were added at the respective concentrations. The cells were incubated at 37 °C in a humidified atmosphere (5% CO₂/95% air) for 72 h. A modified MTT colorimetric assay (EZ4U kit, Biomedica) was used to determine the metabolic activity of the tested cells, according to the manufacturer’s instructions. Absorbance was measured and the optical density of the respective FCS-containing medium and of the substrate was subtracted to exclude nonspecific staining. Metabolic activity in the absence of the compounds (CTR, DMSO) was set to 100% as reference. The results of the compounds in all assays are represented by the mean values + SEM of ≥3 independent experiments with three replicates each.”

Assessing metabolic activity of cells:

EZ4U – Cell Proliferation & Cytotoxicity Assay (cat.no. BI-5000)

-Non-radioactive & non-toxic assay

-Reliable & Sensitive

-Convenient single-step incubation  – for use on living cells

-Widely cited in more than 290 publications

 

BROCHURE – EZ4U cell proliferation and cytotoxicity assay