H2o2 against cancer is far from new - or a simple matter:
sciencedirect.com Dual role of hydrogen peroxide in cancer: possible relevance to cancer chemoprevention and therapy - Miguel López-Lázaro - Cancer letters 252 (1), 1-8, 2007
Accumulating evidence suggests that hydrogen peroxide (H2O2) plays an important role in cancer development. Experimental data have shown that cancer cells produce high amounts of H2O2. An increase in the cellular levels of H2O2 has been linked to several key alterations in cancer, including DNA alterations, cell proliferation, apoptosis resistance, metastasis, angiogenesis and hypoxia-inducible factor 1 (HIF-1) activation. It has also been observed that the malignant phenotype of cancer cells can be reversed just by decreasing the cellular levels of H2O2.
[[So h2o2 must be bad, right? Calm your horses.]]
On the other hand, there is evidence that H2O2 can induce apoptosis in cancer cells selectively and that the activity of several anticancer drugs commonly used in the clinic is mediated, at least in part, by H2O2. The present report discusses that the high levels of H2O2 commonly observed in cancer cells may be essential for cancer development; these high levels, however, seem almost incompatible with cell survival and may make cancer cells more susceptible to H2O2-induced cell death than normal cells. An understanding of this dual role of H2O2 in cancer might be exploited for the development of cancer chemopreventive and therapeutic strategies.
cancerres.aacrjournals.org Tumor-targeted delivery of polyethylene glycol-conjugated D-amino acid oxidase for antitumor therapy via enzymatic generation of hydrogen peroxide - Jun Fang, Tomohiro Sawa, Takaaki Akaike, Hiroshi Maeda - Cancer research 62 (11), 3138-3143, 2002
Hydrogen peroxide (H2O2) is a strong oxidant that induces apoptosis of tumor cells in vitro. Here, we investigated the antitumor activity of an H2O2-generating enzyme, d-amino acid oxidase (DAO), and its conjugate with polyethylene glycol (PEG; PEG-DAO). Compared with DAO, PEG-DAO showed improved pharmacokinetic parameters in mice after i.v. injection. PEG-DAO administered i.v. accumulated selectively in tumor tissue with insignificant accumulation in normal organs and tissues. To generate cytotoxic H2O2 at the tumor site, PEG-DAO was first administrated i.v. to tumor-bearing mice. After an adequate lag time, the substrate of DAO, d-proline, was injected i.p. This treatment resulted in significant suppression of tumor growth compared with tumor growth in control animals (not given treatment; P < 0.001). Similar treatment with native DAO showed no effect under the same conditions. Oxidative metabolites were significantly increased in solid tumors by administration of PEG-DAO followed by d-proline (P < 0.002, compared with the group receiving no treatment), as evidenced by thiobarbituric acid-reactive substance assay. This treatment did not affect results from the metabolites in the liver and kidney. These findings suggest that tumor-targeted delivery of DAO is accomplished by using pegylated enzyme and thereby taking advantage of the enhanced permeability and retention effect in solid tumor. PEG-DAO thus delivered together with d-proline produces remarkable antitumor activity via extensive generation of H2O2.
cancerres.aacrjournals.org - Tumor-targeted delivery of polyethylene glycol-conjugated D-amino acid oxidase for antitumor therapy via enzymatic generation of hydrogen peroxide - Jun Fang, Tomohiro Sawa, Takaaki Akaike, Hiroshi Maeda - Cancer research 62 (11), 3138-3143, 2002
Hydrogen peroxide (H2O2) is a strong oxidant that induces apoptosis of tumor cells in vitro. Here, we investigated the antitumor activity of an H2O2-generating enzyme, d-amino acid oxidase (DAO), and its conjugate with polyethylene glycol (PEG; PEG-DAO). Compared with DAO, PEG-DAO showed improved pharmacokinetic parameters in mice after i.v. injection. PEG-DAO administered i.v. accumulated selectively in tumor tissue with insignificant accumulation in normal organs and tissues. To generate cytotoxic H2O2 at the tumor site, PEG-DAO was first administrated i.v. to tumor-bearing mice. After an adequate lag time, the substrate of DAO, d-proline, was injected i.p. This treatment resulted in significant suppression of tumor growth compared with tumor growth in control animals (not given treatment; P < 0.001). Similar treatment with native DAO showed no effect under the same conditions. Oxidative metabolites were significantly increased in solid tumors by administration of PEG-DAO followed by d-proline (P < 0.002, compared with the group receiving no treatment), as evidenced by thiobarbituric acid-reactive substance assay. This treatment did not affect results from the metabolites in the liver and kidney. These findings suggest that tumor-targeted delivery of DAO is accomplished by using pegylated enzyme and thereby taking advantage of the enhanced permeability and retention effect in solid tumor. PEG-DAO thus delivered together with d-proline produces remarkable antitumor activity via extensive generation of H2O2.
Glucose‐Responsive Sequential Generation of Hydrogen Peroxide and Nitric Oxide for Synergistic Cancer Starving‐Like/Gas Therapy - Wenpei Fan, Nan Lu, Peng Huang, Yi Liu, Zhen Yang, Sheng Wang, Guocan Yu, Yijing Liu, Junkai Hu, Qianjun He, Junle Qu, Tianfu Wang, Xiaoyuan Chen - Angewandte Chemie International Edition 56 (5), 1229-1233, 2017
Glucose is a key energy supplier and nutrient for tumor growth. Herein, inspired by the glucose oxidase (GOx)‐assisted conversion of glucose into gluconic acid and toxic H2O2, a novel treatment paradigm of starving‐like therapy is developed for significant tumor‐killing effects, more effective than conventional starving therapy by only cutting off the energy supply. Furthermore, the generated acidic H2O2 can oxidize l‐Arginine (l‐Arg) into NO for enhanced gas therapy. By using hollow mesoporous organosilica nanoparticle (HMON) as a biocompatible/biodegradable nanocarrier for the co‐delivery of GOx and l‐Arg, a novel glucose‐responsive nanomedicine (l‐Arg‐HMON‐GOx) has been for the first time constructed for synergistic cancer starving‐like/gas therapy without the need of external excitation, which yields a remarkable H2O2–NO cooperative anticancer effect with minimal adverse effect.
Now I'll see what I can find about possible IQ boost/ reversing o2 starvation.
Edited by Seganfredo, 01 January 2020 - 06:58 PM.