Effect of melanoma on immune function in the regional lymph node basin.
OBJECTIVE
To determine if melanoma within the tumor microenvironment will result in immunosuppression within the draining lymph node as measured by down-regulation of T-cell receptor zeta (TCR zeta) expression.


METHODS
Patients with clinical stage I to III melanoma undergoing wide local excision and sentinel lymph node biopsy or therapeutic lymph node dissection were consented to have a portion of their lymph node sampled. Lymph nodes were classified as macroscopically involved (TI), microscopically involved (MI), noninvolved with positive wide excision (NI+), or noninvolved with negative wide excision (NI-). Lymphocytes were stained using antibodies to TCR zeta and other immune cells and analyzed via flow cytometer. Reverse transcription-PCR was used to assess for mediators of immunosuppression.


RESULTS
Fifty patient lymph node samples (15 TI, 7 MI, 9 NI+, and 19 NI-) were evaluated. Increasing involvement of tumor in the lymph node was associated with decreasing TCR zeta chain expression (TI 56%, MI 76%, and NI- 89%). Differences between TI and MI (P = 0.005), TI and NI- (P = 0.0001), and MI and NI- (P = 0.019) were statistically significant. There was also a significant difference between TCR zeta chain expression of NI+ and NI- (73% versus 89%; P = 0.0016). A trend toward increased arginase expression in tumor-involved lymph nodes was detected by reverse transcription-PCR.


CONCLUSIONS
Melanoma involvement of regional nodes is associated with loss of TCR zeta expression that is inversely related to tumor burden. Residual melanoma within the wide local excision specimen is associated with TCR zeta loss in noninvolved sentinel lymph nodes, suggesting that immune modulation precedes tumor spread.
Negin
Benjamin
B
Cutaneous Oncology Program, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA.
Panka
David
D
Wang
Wei
W
Siddiqui
Mustaqueem
M
Tawa
Nicholas
N
Mullen
John
J
Tahan
Steven
S
Mandato
Lucy
L
Polivy
Adam
A
Mier
James
J
Atkins
Michael
M
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000276:immunology; D016207:Cytokines / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000276:immunology; D006801:Humans; D008198:Lymph Nodes / Q000276:immunology* / Q000473:pathology; D008213:Lymphocyte Activation; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology; D008875:Middle Aged; D009367:Neoplasm Staging; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021701:Sentinel Lymph Node Biopsy
D015703:Antigens, CD; D016207:Cytokines; D008565:Membrane Proteins; D011948:Receptors, Antigen, T-Cell; C054979:antigen T cell receptor, zeta chain