Exogenous proteases confer a significant chemopreventive effect in experimental tumor models

Pancreatic Proteolytic Enzymes and Cancer: New Support for an Old Theory

In 1905, the embryologist John Beard first proposed that pancreatic proteolytic enzymes had potential as a treatment for cancer. His theories were dismissed by the medical world a decade later, but various practitioners have kept the concept alive through the publication of case reports of cancer patients treated with pancreatic proteolytic enzymes. In the last 2 decades, studies of the role of proteases in physiology have made it clear that they do more than digest food. This article reviews the history of the clinical use of pancreatic proteolytic enzymes in cancer treatment, and recent research on protease activated receptors and their role in cancer.

A natural bacterial-derived product, the metalloprotease arazyme, inhibits metastatic murine melanoma by inducing MMP-8 cross-reactive antibodies

The increased incidence, high rates of mortality and few effective means of treatment of malignant melanoma, stimulate the search for new anti-tumor agents and therapeutic targets to control this deadly metastatic disease. In the present work the antitumor effect of arazyme, a natural bacterial-derived metalloprotease secreted by Serratia proteomaculans, was investigated. Arazyme significantly reduced the number of pulmonary metastatic nodules after intravenous inoculation of B16F10 melanoma cells in syngeneic mice. In vitro, the enzyme showed a dose-dependent cytostatic effect in human and murine tumor cells, and this effect was associated to the proteolytic activity of arazyme, reducing the CD44 expression at the cell surface, and also reducing in vitro adhesion and in vitro/in vivo invasion of these cells. Arazyme treatment or immunization induced the production of protease-specific IgG that cross-reacted with melanoma MMP-8. In vitro, this antibody was cytotoxic to tumor cells, an effect increased by complement. In vivo, arazyme-specific IgG inhibited melanoma lung metastasis. We suggest that the antitumor activity of arazyme in a preclinical model may be due to a direct cytostatic activity of the protease in combination with the elicited anti-protease antibody, which cross-reacts with MMP-8 produced by tumor cells. Our results show that the bacterial metalloprotease arazyme is a promising novel antitumor chemotherapeutic agent.

Traditional Chinese Medicine Herbal Treatment May Have a Relevant Impact on the Prognosis of Patients With Stage IV Adenocarcinoma of the Lung Treated With Platinum-Based Chemotherapy or Combined Targeted Therapy and Chemotherapy

Background: Targeted therapy (TT), chemotherapy, and traditional Chinese medicine herbal treatment (TCM) can improve the prognosis of advanced pulmonary adenocarcinoma patients. Their independent prognostic value is unknown. Objective: To study whether TCM improves survival in stage IV pulmonary adenocarcinoma patients with platinum-based chemotherapy (PBT), or combined PBT and second-line TT. Methods: Retrospective analysis of 133 fully ambulant clinical outpatients treated with PBT alone or PBT with/without second-line TT, with/without TCM. Univariate (Kaplan—Meier) and multivariable (Cox model) survival analysis were performed, using disease-specific mortality as an endpoint. Results: Gender ( P = .002), TT ( P < .0001), and TCM ( P < .0001) had univariate prognostic value but not age, radiotherapy, or TCM syndrome differentiation ( P > .10). TCM herbal treatment ( P < .0001) and TT ( P = .03) had multivariable independent prognostic value. TCM-treated patients (n = 103, PBT+TT+TCM+ = 62; PBT+TT−TCM+ =41) had 88% 1-year overall survival rate with median survival time (MST) of 27 months, contrasting 27% 1-year overall survival and MST of 5.0 months for non-TCM-treated (n = 30) patients. Patients with chemotherapy/TT/TCM (PBT+TT+TCM+, n = 62), TCM without TT (PBT+TT−TCM+, n = 41), or chemotherapy only (PBT+TT−TCM−, n = 30), had 1-year survival rates of 94%, 78%, and 27% respectively; for these 3 groups, respectively, MST was not reached (MST of 30.9 months), 22.6, and 5.0 months ( P < .0001). Conclusions: TCM herbal treatment may improve survival of stage IV pulmonary adenocarcinoma patients treated with chemotherapy without or with second-line TT. This warrants formal phase 1 and 2 trials and ultimately properly designed prospective clinical validation trials with adequate methodology developed for data collection.