title: Enhanced apoptosis of squamous cell carcinoma cells by interleukin-2-activated cytotoxic lymphocytes combined with radiation and anticancer drugs.
abstract: Induction of potent apoptosis is required in cancer therapy. We examined the combination effect of interleukin-2-activated lymphocytes (LAK cells) and anticancer drugs or gamma (gamma)-rays on the induction of apoptosis in an established oral squamous cell carcinoma cell line (OSC-3 cells). By pretreatment of OSC-3 cells with (137)Cs (5 Gy), 5-fluorouracil (5-FU) (0.5 microg/ml) or cis-dichlorodiammine-platinum (CDDP) (5 microg/ml), the activation of bid and caspase-3 by LAK cells was strongly increased and associated with an enhanced degradation of poly-(ADP-ribose) polymerase (PARP) and/or nuclear mitotic apparatus protein (NuMA) and the increased fragmentation of DNA. The LAK cell-enhanced caspase-3 activity in the pretreated OSC-3 cells was decreased to approximately 70% and 40% of the control by the addition of Z-AAD-CMK (a granzyme B inhibitor) and neutralising monoclonal antibody to Fas antigen (alphaFas-IgG), respectively. The combined treatment-induced DNA fragmentation was suppressed by approximately 20% and 30% of the control by the addition of Z-AAD-CMK and alpha Fas-IgG, respectively, in the co-culture system. While Ac-DEVD-CHO (a caspase-3 inhibitor) suppressed the DNA fragmentation levels to approximately half and this was similar to the amount of suppression that was obtained by the addition of both alpha Fas-IgG and Z-AAD-CMK. In addition, LAK cell-activated bid may have increased the intracellular reactive oxygen intermediates (ROI) level and induced a decrease of mitochondrial membrane potential. These influences by LAK cells were enhanced when OSC-3 cells were pretreated with each anticancer drug or (137)Cs. Furthermore, the increase of ROI by LAK cells was suppressed by alpha Fas-IgG and Z-AAD-CMK to approximately half the level of the control. These results indicate that anticancer drugs and gamma-rays prime squamous cell carcinoma cells to be susceptible to apoptosis by LAK cells, that LAK cell-induced apoptosis largely depends on the activation of caspase-3 by the Fas/Fas-ligand signal and granzyme B, and that LAK cells induce ROI in the target cells, which is largely mediated by Fas and granzyme B.
authors.affiliation: Department of Oral Surgery, Kochi Medical School Kohasu, Oko-cho, Nankoku-city, Kochi 783-8505, Japan. yamamott@kochi-ms.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Yoneda
authors.forename: E
authors.initials: E
authors.lastname: Ueta
authors.forename: S
authors.initials: S
authors.lastname: Doi
authors.forename: T
authors.initials: T
authors.lastname: Osaki
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy*; D020169:Caspases / Q000378:metabolism; D053938:DNA Fragmentation; D010450:Endopeptidases / Q000378:metabolism; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology / Q000627:therapeutic use*; D015979:Killer Cells, Lymphokine-Activated / Q000502:physiology*; D009062:Mouth Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy*; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D007376:Interleukin-2; D010450:Endopeptidases; D020169:Caspases