SYNERGISTIC ANTI-TUMOUR EFFECT OF DOXORUBICIN-HYDROCHLORIDE WITH CRM197, AN INHIBITOR OF HB-EGF, IN SQUAMOUS-CELL CARCINOMA

Recent studies have shown that cross reacting material (CRM197), a nontoxic variant of diphtheria toxin, may play an important role in treating cancers with poor prognoses. Doxorubicin-hydrochloride (DOX) is an antineoplastic prescription medicine for the treatment of certain types of cancer. Considering that CRM197 is a known carrier in targeted delivery, CRM197-DOX complexes might be a step towards targeted therapy and reduced overall toxicity. Aim. This study aims to explore the potential to inhibit the growth of tumour cells. To achieve that goal, we evaluated the usage of CRM197-DOX complexes in squamous carcinoma cell line A431 and compared it with the effect on other immortalised cell lines. The methods used in this research include derivation and purification of recombinant CRM197 through immobilized-metal affinity chromatography and electrophoresis in a denaturing polyacrylamide gel. DOX-loaded CRM197 complexes were formed by the addition of a 5 μM solution of doxorubicin to 0.5 μg of protein with further dialysis in PBS. The cell viability assay was conducted using free CRM197 at different concentrations, DOX, CRM197 with DOX, as well as DOX-loaded CRM197. DOX-loaded CRM197 along with CRM197 with the addition of DOX showed significant differences in cell viability compared to control wells. CRM197- Results. DOX complexes have an evident inhibitory effect on epidermoid carcinoma cell growth and can be used as treatment against epithelial tumours, with CRM197 as a promising carrier for targeted drug delivery. Conclusions. CRM197-DOX complexes show evident inhibition of epidermoid carcinoma cell growth and can be used as treatment against epithelial tumours, especially those overexpressing the proHB-EGF and its receptors, EGFR1 and EGFR4, with CRM197 as a promising carrier for targeted drug delivery.