Recombinant horseradish peroxidase variants for targeted cancer treatment

Abstract

Cancer is a major cause of death. Common chemo‐ and radiation‐therapies damage healthy tissue and cause painful side effects. The enzyme horseradish peroxidase (HRP) has been shown to activate the plant hormone indole‐3‐acetic acid (IAA) to a powerful anticancer agent in in vitro studies, but gene directed enzyme prodrug therapy (GDEPT) studies showed ambivalent results. Thus, HRP/IAA in antibody directed enzyme prodrug therapy (ADEPT) was investigated as an alternative. However, this approach has not been intensively studied, since the enzyme preparation from plant describes an undefined mixture of isoenzymes with a heterogenic glycosylation pattern incompatible with the human system. Here, we describe the recombinant production of the two HRP isoenzymes C1A and A2A in a Pichia pastoris benchmark strain and a glyco‐engineered strain with a knockout of the α‐1,6‐mannosyltransferase (OCH1) responsible for hypermannosylation. We biochemically characterized the enzyme variants, tested them with IAA and applied them on cancer cells. In the absence of H2O2, HRP C1A turned out to be highly active with IAA, independent of its surface glycosylation. Subsequent in vitro cytotoxicity studies with human T24 bladder carcinoma and MDA‐MB‐231 breast carcinoma cells underlined the applicability of recombinant HRP C1A with reduced surface glycoslyation for targeted cancer treatment. Summarizing, this is the first study describing the successful use of recombinantly produced HRP for targeted cancer treatment. Our findings might pave the way for an increased use of the powerful isoenzyme HRP C1A in cancer research in the future.

Inhibition of Horseradish Peroxidase Activity by Boroxine Derivative, Dipotassium-trioxohydroxytetrafluorotriborate K2[B3O3F4OH]

“…HRP was used for the investigation of inhibitor activity of anti-inflammatory drugs [15]. In other studies it has been found that better understanding the role of HRP and other peroxidases in this process could lead to a new targeted cancer therapy [16][17][18].…”

Clinical Pharmacy Practices in Oncology Patients Treated with Tyrosine Kinase Inhibitors

“…With respect to the interactions with herbal products (9.1% of patients) in this study, the pharmacist advised not to use these products, since literature do not provide any robust evidence to indicate the mechanism and management of those interactions. [23][24][25] A combination of chemotherapeutics and use of other medications for comorbid conditions poses a significant risk for drug interactions in cancer treatment. A broad-spectrum of adverse effects of chemotherapeutics along with potential drug interactions may lead to increased toxicity and discontinuation of effective treatments in patients.…”

Therapeutic Nanoreactors as In Vivo Nanoplatforms for Cancer Therapy

“…[12c] Nevertheless, due to the commonly low catalytic activity and stabilityo ft he activating enzymes required for EPT,v arious approaches, such as antibody-directed enzymep rodrug therapy (ADEPT), gene-directed enzyme-prodrug therapy (GDEPT), ands ubstrate-mediated enzymep rodrug therapy (SMEPT), have been developed to maintain the activity of the enzymes whilew orking in vivo. [33] In recent years, the introduction of therapeutic nanoreactors into EPT for cancer therapyw hich involves the immobilization of activating agentsi nto the matrices of synthetic nanoplatforms that can convert less or no-toxic prodrugs in situ into parentt oxic drugs, indicated great potentials over the traditional approaches in EPT,s uch as ADEPT or GDEPTwhich often suffer from the reduced catalytic activity,i mmunogenicity,a nd lack of efficiency for localized delivery duringt reatment. [10a, 31a] Amongt he unique advantages of using therapeutic nanoreactors in EPT for cancer therapy are:…”