Bcl-2 immunoreactivity in salivary gland neoplasms is unrelated to the expression of mRNA for natural killer cell stimulatory cytokines interleukin (IL)-2 and IL-12.
Certain cytokines are involved in the generation of natural killer (NK) cells and participate in the regulation of the proto-oncogene bcl-2. We aimed to study the mRNA expression of interleukin (IL)-2, IL-4 and IL-5, the composition of the tumour infiltrating lymphocytes (TIL), and the expression of bcl-2 in 14 benign and malignant human parotid tumours. T IL were predominantly composed of T lymphocytes and NK cells. We found evidence for the homing of T cells, and for generation of NK cells in the vicinity of the tumours. mRNA for IL-2 and IL-12, were identified but IL-4 mRNA was not found. The cytokine profiles and the composition of TIL of the two tumour categories were indistinguishable, suggesting that these host-response variables do not explain the differences in biological behaviour of these particular tumours. The results support a shift towards Th 1 (T helper 1) cells and interferon-gamma production, and that IL-12 also in vivo may play an important role in the regulatory interaction between innate resistance and adaptive immunity in tumour diseases. Most infiltrating lymphocytes showed strong expression of bcl-2; an interesting observation with regard to lymphocytic apoptosis in neoplastic diseases. The immunoreactivity for the bcl-2 protein varied considerably between and within tumours, and almost all benign tumours showed strong bcl-2 positively whereas several of the malignant tumours showed weak or absent staining. The variable expression of bcl-2 protein suggests a different susceptibility of tumour cells to apoptosis. The results also indicate that bcl-2 cannot pla a major role as protective agent in the specific apoptotic pathway induced by NK cells.
Hellquist
H B
HB
Department of Pathology II, University Hospital, Linköping, Sweden. henrik.hellquist@pat.liu.se
Karlsson
M G
MG
Viale
G
G
Karlsson
C
C
Davidsson
A
A
Dell'Orto
P
P
Olofsson
J
J
D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000235:genetics* / Q000494:pharmacology; D018664:Interleukin-12 / Q000235:genetics* / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D016131:Lymphocyte Subsets / Q000473:pathology; D016133:Polymerase Chain Reaction; D000090063:Proto-Oncogene Mas; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D012468:Salivary Gland Neoplasms / Q000378:metabolism* / Q000473:pathology
D007375:Interleukin-1; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D018664:Interleukin-12