[MHC-class I expression on prostate carcinoma and modulation by IFN-gamma].
OBJECTIVE
In this study, we investigated MHC-class I expression on both prostate cancer and normal prostate and compared those data with the number of CD8+ lymphocyte. Secondary, we investigated effect of IFN-gamma to the MHC-class I expression on prostate carcinoma.


METHODS
Twenty cryo-preserved benign prostate samples (Seven normal prostates and five benign prostatic hypertrophy samples.) and fifteen prostate carcinoma samples were used for immunohistochemistry of CD8 and MHC-class I. Eleven fresh single cell suspensions of prostate carcinoma were used for IFN-gamma study. After 24 hours IFN-gamma stimulation, MHC-I expression was measured by FACs analysis.


RESULTS
Interestingly, significant correlation was observed between MHC-class I expression and the CD8+ lymphocyte infiltrate (r = 0.705, P < 0.0001). After 24 hrs IFN-gamma stimulation, MHC-class I expression was up-regulated in all samples (p < 0.05).


CONCLUSIONS
Reduced expression of MHC-class I was thought as one of the factor which is related to the reduced degree of TILs (tumor infiltratig lymphocytes) in prostate cancer. IFN-gamma which is secreted mainly from CTL (cytotoxic T lymphocyte) might increase the degree of TIL through up-regulated MHC-class I.
Naoe
Michio
M
Department of Pathology, Duke University Medical Center, Durham, North Carolina, USA, Department of Urology, Showa University, School of Medicine, Tokyo, Japan.
Marumoto
Yoshiko
Y
Aoki
Keiichiro
K
Fukagai
Takashi
T
Ogawa
Yoshio
Y
Ishizaki
Ryoutaro
R
Nakagami
Yoshizo
Y
Yoshida
Hideki
H
Ballo
Michel
M
D000368:Aged; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D002452:Cell Count; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D006801:Humans; D007371:Interferon-gamma / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000276:immunology / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology
D015395:Histocompatibility Antigens Class I; D007371:Interferon-gamma