Combined high energy of extracorporeal shock wave and 5-FU effectively suppressed the proliferation and growth of tongue squamous cell carcinoma

Abstract

BackgroundWe tested the hypothesis that extracorporeal shock wave (ECSW)-assisted 5-FU therapy effectively suppressed human tongue squamous carcinoma cell line SAS (i.e., SAS cells) proliferation and tumor growth. Methods and resultsIn vitro study showed that as compared with lower ECSW energy (≤0.12 mJ/mm2), higher ECSW energy (≥0.25–035 mJ/mm2) significantly suppressed the SAS cell proliferation and upregulated tumor cell apoptosis/DNA-damage/oxidative-stress, whereas combined higher ECSW energy (0.35 mJ/mm2) and 5-FU (20uM) further significantly altered the expressions of these parameters (all p < 0.001). Adult male nude mice (NM) (n = 36) were equally categorized into group 1 (2.0 × 105 SAS cells were implanted into NM back), group 2 [SAS in NM back + stepwise-increased ECSW energy (from 0.05/0.1/0.3/to 0.5 mJ/mm2)/500 impulses which applied to the tumor at days 9/12/15/21], group 3 (SAS in NM back + 5-FU/i.p./7 mg/kg/every 3-day) and group 4 (SAS in NM back + ECSW + 5-FU) and tumors were removed from each animal by day-28. The result showed that tumor volume and tumor weight were significantly progressively reduced from group 1 to group 4 (all p < 0.0001). The protein expressions of apoptotic (mitochondrial-Bax/cleaved-caspase3/cleaved-PARP/cyclophyllin-D), autophagic (ratio of LC3B-II/LC3B-I) and oxidative-stress (NOX-1/NOX-2) biomarkers displayed an opposite pattern of tumor mass among the groups, whereas the cell-stress signaling (p-PI3K/p-Akt/p-m-TOR, and ASK1/MKK4/MKK7/p38/p-JNK/p-c-JUN), MAP kinase family members (RAS/cRAF/KRAS/BRAF/p-ERK1/2), tumor protein (p53) and cellular levels of angiogenesis/DNA-damage (α-SMA+/VEGF+/γ-H2AX+) exhibited an identical pattern of tumor mass among the groups (all p < 0.0001). ConclusionCombined high-energy ECSW and 5-FU offers an additional benefit for suppressing the cancer cell proliferation and tumor growth.