yuDetecting the percent of peripheral blood mononuclear cells displaying p-STAT-3 in malignant glioma patients.
BACKGROUND
The signal transducer and activator of transcription 3 (STAT-3) is frequently overexpressed in cancer cells, propagates tumorigenesis, and is a key regulator of immune suppression in cancer patients. The presence of phosphorylated STAT-3 (p-STAT-3) in the tumor can induce p-STAT-3 in tumor-associated immune cells that can return to the circulatory system. We hypothesized that the number of peripheral blood mononuclear cells (PBMCs) displaying p-STAT-3 would be increased in glioma patients, which would correlate with the extent of tumor-expressed p-STAT-3, and that higher p-STAT-3 levels in peripheral blood would correlate with a higher fraction of immune-suppressive regulatory T cells (Tregs).


METHODS
We measured the percentage of PBMCs displaying p-STAT-3 in 19 healthy donors and 45 patients with primary brain tumors. The level of p-STAT-3 in tumor tissue was determined by immunohistochemistry. The degree of immune suppression was determined based on the fraction of Tregs in the CD4 compartment.


RESULTS
Healthy donors had 4.8 +/- 3.6% of PBMCs that expressed p-STAT-3, while the mean proportion of PBMCs displaying p-STAT-3 in patients with GBM was 11.8 +/- 13.5% (P = 0.03). We did not observe a correlation by Spearman correlation between the degree of p-STAT-3 levels in the tumor and the percent of PBMCs displaying p-STAT-3. Furthermore, the percent of PBMCs displaying p-STAT-3 in glioma patients was not directly correlated with the fraction of Tregs in the CD4 compartment.


CONCLUSIONS
We conclude that the percent of PBMCs displaying p-STAT-3 may be increased in malignant glioma patients.
Humphries
William
W
Department of Neurosurgery, The University of Texas M, D, Anderson Cancer Center, Houston, TX, USA. humphrie@bcm.edu
Wang
Yongtao
Y
Qiao
Wei
W
Reina-Ortiz
Chantal
C
Abou-Ghazal
Mohamed K
MK
Crutcher
Lamonne M
LM
Wei
Jun
J
Kong
Ling-Yuan
LY
Sawaya
Raymond
R
Rao
Ganesh
G
Weinberg
Jeffrey
J
Prabhu
Sujit S
SS
Fuller
Gregory N
GN
Heimberger
Amy B
AB
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000097:blood* / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D005260:Female; D005910:Glioma / Q000097:blood* / Q000276:immunology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D050796:STAT3 Transcription Factor / Q000097:blood*; D016176:T-Lymphocyte Subsets / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism
D050796:STAT3 Transcription Factor