Zinc protoporphyrin IX (Synonyms: ZnPPIX)

Cell lines

Human ovarian carcinoma (MDAH2774), human pancreatic adenocarcinoma (Mia PaCa2), human breast carcinoma (MDA-MB231), murine breast carcinoma (EMT6) cell lines.

Preparation Method

Tumor cells were dispensed into 96-well plates at a concentration of 5×103 cells per well and allowed to attach overnight. The following day investigated agents were added at indicated concentrations. Cells were kept in dark for 48 or 72 h. After the incubation time the cells were rinsed with PBS and stained with 0.5% crystal violet in 2% ethanol for 10 min at room temperature. Plates were washed four times with tap water and the cells were lysed with 1% SDS solution. Absorbance was measured at 595 nm using an enzyme-linked immunosorbent assay reader, equipped with a 595 nm filter.

Reaction Conditions

0-40 µM for 48, 72 hours

Applications

Incubation of C-26 cells with Zinc protoporphyrin IX for 48 or 72 h resulted in dose- and time-dependent reduction of cells in G1 phase of the cell cycle.

Animal models

Adult CD1 mice (male, 25-35 g)

Preparation Method

For assessment of antitumor activity of Zinc protoporphyrin IX in vivo, exponentially growing C-26 were harvested, re-suspended in PBS medium to the appropriate concentration, and injected at the dose of 1×105 cells per mouse into the footpad of the right hind limb of experimental mice. Tumor cell viability measured by trypan blue exclusion was always above 95%. For in vivo treatment Zinc protoporphyrin IX was dissolved in DMSO and further diluted in 0.9% NaCl to required concentrations. Final DMSO concentration was always less then 0.1%. Zinc protoporphyrin IX was distributed intraperitoneally at doses from 12.5 to 50 mg per kg of body weight or orally at doses from 11 to 22 mg per kg of body weight. Control animals received 0.1% DMSO solution in 0.9% NaCl i.p. or orally.

Dosage form

12.5 to 50 mg/kg i.p. for 7 days; 11 to 22 mg/kg oral for 7 days

Applications

HO-1 inhibitor was administered either intraperitoneally (i.p.) or per os and the tumor volume was monitored every second day, starting from day 7 after inoculation of tumor cells. Zinc protoporphyrin IX exerted dose-dependent antitumor effects manifested by the retardation of tumor growth. A statistical significance was reached on days 17 and 19 for Zinc protoporphyrin IX administered at a dose of 25 mg/kg either i.p. or orally. A stronger effect was observed when Zinc protoporphyrin IX was administered i.p. at a dose of 50 mg/kg, where a statistically significant retardation of tumor growth was observed on days 13-19, as compared with controls .

References:

[1]: Nowis D, Bugajski M, Winiarska M, et al. Zinc protoporphyrin IX, a heme oxygenase-1 inhibitor, demonstrates potent antitumor effects but is unable to potentiate antitumor effects of chemotherapeutics in mice[J]. BMC cancer, 2008, 8(1): 1-12.