TY - JOUR

T1 - Localization of thymosin ß-4 in tumors

AU - Larsson, Lars-Inge

AU - Holck, Susanne

N1 - Thymosins in Health and Disease First International Symposium

PY - 2007

Y1 - 2007

N2 - Overexpression of thymosin ß-4 has been linked to malignant progression but the localization of this polypeptide within tumor is incompletely known. We therefore examined breast cancers for thymosin ß-4 using immunofluorescence. Reactive cells were identified with monoclonal cell marker antibodies. A very heterogeneous staining pattern for thymosin ß-4 was observed. Thus, while leukocytes and macrophages showed intense reactivity for this polypeptide, cancer cells, and endothelial cells showed a much more variable reactivity. A similar heterogeneous staining was observed also in colorectal carcinomas. The degree of staining of breast cancer cells for thymosin ß-4 correlated neither to histological grade nor to endothelial cell staining. However, therewas a tendency toward correlation (P = 0.07) between staining of endothelial cells and histological grade. Treatment of cultured breast cancer cells (SK-BR-3) with 1-4 µg thymosin ß-4/mL significantly increased cell numbers, as determined by MTT-assays. These data reveal an unexpected cellular heterogeneity of thymosin ß-4 expression in breast and colonic carcinomas and suggest that local release of this polypeptide in the tumor microenvironment may modulate tumor behavior.

AB - Overexpression of thymosin ß-4 has been linked to malignant progression but the localization of this polypeptide within tumor is incompletely known. We therefore examined breast cancers for thymosin ß-4 using immunofluorescence. Reactive cells were identified with monoclonal cell marker antibodies. A very heterogeneous staining pattern for thymosin ß-4 was observed. Thus, while leukocytes and macrophages showed intense reactivity for this polypeptide, cancer cells, and endothelial cells showed a much more variable reactivity. A similar heterogeneous staining was observed also in colorectal carcinomas. The degree of staining of breast cancer cells for thymosin ß-4 correlated neither to histological grade nor to endothelial cell staining. However, therewas a tendency toward correlation (P = 0.07) between staining of endothelial cells and histological grade. Treatment of cultured breast cancer cells (SK-BR-3) with 1-4 µg thymosin ß-4/mL significantly increased cell numbers, as determined by MTT-assays. These data reveal an unexpected cellular heterogeneity of thymosin ß-4 expression in breast and colonic carcinomas and suggest that local release of this polypeptide in the tumor microenvironment may modulate tumor behavior.

KW - Former LIFE faculty

KW - thomosin ß-4

KW - cancer

KW - colorectal

KW - breast

KW - endothelial cells

KW - macrophages

U2 - 10.1196/annals.1415.005

DO - 10.1196/annals.1415.005

M3 - Journal article

C2 - 17495241

VL - 1112

SP - 317

EP - 325

JO - Annals of The Lyceum of Natural History of New York

JF - Annals of The Lyceum of Natural History of New York

SN - 0077-8923

ER -