Heat shock enhances the susceptibility of tumor cells to lysis by lymphokine-activated killer cells.
OBJECTIVE
To determine whether heat-treated thyroid cancer cells augment the susceptibility of target cells to lysis by autologous lymphokine-activated killer cells.


METHODS
Peripheral blood lymphocytes from patients with thyroid cancer were incubated with recombinant interleukin 2 (100 U/mL) for 7 days, and thyroid cancer cells obtained from surgical specimens were heated at 44 degrees C for 20 minutes and incubated at 37 degrees C for 18 hours before performing the radioactive chromium Cr 51 release assay.


RESULTS
The susceptibility of heat-treated thyroid cancer cells to lysis by autologous and allogeneic lymphokine-activated killer cells was significantly greater than that of untreated tumor cells. The mechanism of enhanced susceptibility was unclear. However, the effect depended on de novo protein synthesis, because inhibition of RNA synthesis by dactinomycin completely abolished the heat-enhanced susceptibility of tumor cells.


CONCLUSIONS
Immunotherapy combined with hyperthermia may be useful in management of thyroid cancer.
Fujieda
S
S
Department of Oto-Rhino-Laryngology, Fukui, Medical School, Japan.
Noda
I
I
Saito
H
H
Hoshino
T
T
Yagita
M
M
D000231:Adenocarcinoma, Papillary / Q000503:physiopathology / Q000628:therapy*; D003609:Dactinomycin / Q000494:pharmacology; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D015979:Killer Cells, Lymphokine-Activated; D012334:RNA, Neoplasm / Q000187:drug effects; D013964:Thyroid Neoplasms / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology; D014415:Tunicamycin / Q000494:pharmacology
D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D012334:RNA, Neoplasm; D014409:Tumor Necrosis Factor-alpha; D014415:Tunicamycin; D003609:Dactinomycin