Abstract
Correlative human studies suggest that the pleiotropic cytokine IL6 contributes to the development and/or progression of prostate cancer. However, the source of IL6 production in the prostate microenvironment in patients has yet to be determined. The cellular origin of IL6 in primary and metastatic prostate cancer was examined in formalin-fixed, paraffin-embedded tissues using a highly sensitive and specific chromogenic in situ hybridization (CISH) assay that underwent extensive analytical validation. Quantitative RTPCR showed that benign prostate tissues often had higher expression of IL6 mRNA than matched tumor specimens. CISH analysis further indicated that both primary and metastatic prostate adenocarcinoma cells do not express IL6 mRNA. IL6 expression was highly heterogeneous across specimens and was nearly exclusively restricted to the prostate stromal compartment-including endothelial cells and macrophages, among other cell types. The number of IL6-expressing cells correlated positively with the presence of acute inflammation. In metastatic disease, tumor cells were negative in all lesions examined, and IL6 expression was restricted to endothelial cells within the vasculature of bone metastases. Finally, IL6 was not detected in any cells in soft tissue metastases. These data suggest that, in prostate cancer patients, paracrine rather than autocrine IL6 production is likely associated with any role for the cytokine in disease progression.
Original language | English (US) |
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Pages (from-to) | 1175-1184 |
Number of pages | 10 |
Journal | Cancer Immunology Research |
Volume | 3 |
Issue number | 10 |
DOIs | |
State | Published - Oct 2015 |
Externally published | Yes |
Bibliographical note
Funding Information:This study is also supported by NIH/NCI prostate SPORE pathology core (Award No 5P50CA058236), Prostate Cancer Biorepository Network (PCBN; Department of Defense Award No. W81XWH-10-2-0056 and W81XWH-10-2-0046), Pacific Northwest Prostate Cancer SPORE (P50CA97186), PO1 NIH grant (PO1CA085859), and Richard M. Lucas Foundation.
Publisher Copyright:
© 2015 American Association for Cancer Research.