boron-oxide and Neoplasms

Boron neutron capture therapy shows is a promising approach to cancer therapy, but the delivery of effective boron agents is challenging. To address the requirements for efficient boron delivery, we used a hybrid nanoparticle comprising a carborane = bearing pullulan nanogel and hydrophobized boron oxide nanoparticle (HBNGs) enabling the preparation of highly concentrated boron agents for efficient delivery. The HBNGs showed better anti-cancer effects on Colon26 cells than a clinically boron agent, L-BPA/fructose complex, by enhancing the accumulation and retention amount of the boron agent within cells in vitro. The accumulation of HBNGs in tumors, due to the enhanced permeation and retention effect, enabled the delivery of boron agents with high tumor selectivity, meeting clinical demands. Intravenous injection of boron neutron capture therapy (BNCT) using HBNGs decreased tumor volume without significant body weight loss, and no regrowth of tumor was observed three months after complete regression. The therapeutic efficacy of HBNGs was better than that of L-BPA/fructose complex. BNCT with HBNGs is a promising approach to cancer therapeutics.

Topics: Boron; Boron Compounds; Boron Neutron Capture Therapy; Fructose; Humans; Nanogels; Neoplasms

Although improvements in radiation therapy were made over the years, radioresistance is still a major challenge. Cancer cells are often deficient for DNA repair response, a feature that is currently exploited as a new anti-cancer strategy. In this context, combination of inhibitors targeting complementary pathways is of interest to sensitize cells to radiation. In this work, we used PARP (Olaparib) and RAD51 (B02) inhibitors to radiosensitize cancer cells to proton and X-ray radiation. More particularly, Olaparib and B02 were used at concentration leading to limited cytotoxic (alone or in combination) but increasing cell death when the cells were irradiated. We showed that, although at limited concentration, Olaparib and B02 were able to radiosensitize different cancer cell lines, i.e. lung and pancreatic cancer cells. Antagonistic, additive or synergistic effects were observed and correlated to cell proliferation rate. The inhibitors enhanced persistent DNA damage, delayed apoptosis, prolonged cell cycle arrest and senescence upon irradiation. These results demonstrated that radiation-induced synthetic lethality might widen the therapeutic window, hence extending the use of PARP inhibitors to patients without BRCAness.

Topics: A549 Cells; Apoptosis; Boron Compounds; Cell Cycle Checkpoints; Cell Proliferation; Cell Survival; DNA Damage; DNA Repair; Humans; Neoplasms; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Protons; Rad51 Recombinase; Radiation-Sensitizing Agents; Radiation, Ionizing; Synthetic Lethal Mutations; Time Factors