5th World Congress on Cancer Therapy
Semmelweis University, Hungary
Title: Modulated electro-hyperthermia: A local treatment may evoke distant anti-tumor response in a mice double colorectal allograft model
Biography: Tamas Vancsik
Modulated electro-hyperthermia (mEHT; tradename: oncothermia) is used as a complementary to radio- and chemotherapy. Th e electric fi eld and concomitant heat of <42oC can accumulate in malignancies due to their elevated glycolysis (Warburg eff ect) and conductivity. Previously we showed that mEHT provoke programmed cell death and infi ltration of immune cells in colorectal carcinoma xenograft s of immunocompromised mice. Here we tested if the local antitumor eff ect of mEHT aff ects a distant tumor (abscopal eff ect) using immunocompetent animals. C26 colorectal carcinoma allograft s were implanted into both femoral regions of BalbC mice. A single shot mEHT for 30 minutes was applied on the right side tumor either without or with intraperitoneal injection of a cytotoxic T cell promoting agent. Histomorphologic, immunohistochemical and TUNEL assay results were gained 12, 24, 48 and 72 hours post-treatment. mEHT caused progressive tumor cell damage compared to controls and showed elevated number of activated caspase-3, caspase-8 and TUNEL positive cells, accompanied with cytoplasmic release of chytochrome-c, but without changes in apoptosis-inducing factor (AIF), or BAX patterns. Stressassociated release of HMGB1 protein and increased numbers of CD3 positive T cells were also observed. Besides similar decay in the treated tumor, a prominent anti-tumor response was also observed in the untreated left -side tumors in animals inoculated with the fl avonoid-rich agent. In our model mEHT caused tumor destruction dominantly via caspase-dependent programmed cell death both in the treated tumors and in the untreated distant tumors when combined with a T-cell promoting agent, where the release of stress associated HMGB1 may support anti-tumor immunity.