Antitumor efficacy of multi-target in situ vaccinations with CpG oligodeoxynucleotides,anti-OX40,anti-PD1 antibodies,and aptamers

To overcome immune tolerance to cancer,the immune system needs to be exposed to a multi-target action intervention.Here,we investigated the activating effect of CpG oligodeoxynucleotides(ODNs),mesyl phosphoramidate CpG ODNs,anti-OX40 antibodies,and OX40 RNA aptamers on major populations of immunocompetent cells ex vivo.Comparative analysis of the antitumor effects of in situ vaccination with CpG ODNs and anti-OX40 antibodies,as well as several other combinations,such as mesyl phosphoramidate CpG ODNs and OX40 RNA aptamers,was conducted.Antibodies against programmed death 1(PD1)checkpoint inhibitors or their corresponding PD1 DNA aptamers were also added to vaccination regimens for analytical purposes.Four scenarios were considered:a weakly immunogenic Krebs-2 carcinoma grafted in CBA mice;a moderately immunogenic Lewis carcinoma grafted in C57Black/6 mice;and an immunogenic A20 B cell lymphoma or an Ehrlich carcinoma grafted in BALB/c mice.Adding anti-PD1 antibodies(CpG+αOX40+αPD1)to in situ vaccinations boosts the antitumor effect.When to be used instead of antibodies,aptamers also possess antitumor activity,although this effect was less pronounced.The strongest effect across all the tumors was observed in highly immunogenic A20 B cell lymphoma and Ehrlich carcinoma.

Efficacy of the new therapeutic approach in curing malignant neoplasms on the model of human glioblastoma

Objective:Glioma is a highly invasive tumor,frequently disposed in essential areas of the brain,which makes its surgical excision extremely difficult;meanwhile adjuvant therapy remains quite ineffective.Methods:In the current report,a new therapeutic approach in curing malignant neoplasms has been performed on the U87 human glioblastoma model.This approach,termed"Karanahan",is aimed at the eradication of cancer stem cells(CSCs),which were recently shown to be capable of internalizing fragments of extracellular double-stranded DNA.After being internalized,these fragments interfere in the process of repairing interstrand cross-links caused by exposure to appropriate cytostatics,and such an interference results either in elimination of CSCs or in the loss of their tumorigenic potency.Implementation of the approach requires a scheduled administration of cytostatic and complex composite double-stranded DNA preparation.Results:U87 cells treated in vitro in accordance with the Karanahan approach completely lost their tumorigenicity and produced no grafts upon intracerebral transplantation into immunodeficient mice.In SCID mice with developed subcutaneous grafts,the treatment resulted in reliable slowing down of tumor growth rate(P<0.05).In the experiment with intracerebral transplantation of U87 cells followed by surgical excision of the developed graft and subsequent therapeutic treatment,the Karanahan approach was shown to reliably slow down the tumor growth rate and increase the median survival of the mice twofold relative to the control.Conclusions:The effectiveness of the Karanahan approach has been demonstrated both in vitro and in vivo in treating developed subcutaneous grafts as well as orthotopic grafts after surgical excision of the tumor.