The CD151-midkine pathway regulates the immune microenvironment in inflammatory breast cancer.

The immune microenvironment in inflammatory breast cancer (IBC) is poorly characterised, and molecular and cellular pathways that control accumulation of various immune cells in IBC tissues remain largely unknown. Here, we discovered a novel pathway linking the expression of the tetraspanin protein CD151 in tumour cells with increased accumulation of macrophages in cancerous tissues. It is notable that elevated expression of CD151 and a higher number of tumour-infiltrating macrophages correlated with better patient responses to chemotherapy. Accordingly, CD151-expressing IBC xenografts were characterised by the increased infiltration of macrophages. In vitro migration experiments demonstrated that CD151 stimulates the chemoattractive potential of IBC cells for monocytes via mechanisms involving midkine (a heparin-binding growth factor), integrin α6ß1, and production of extracellular vesicles (EVs). Profiling of chemokines secreted by IBC cells demonstrated that CD151 increases production of midkine. Purified midkine specifically stimulated migration of monocytes, but not other immune cells. Further experiments demonstrated that the chemoattractive potential of IBC-derived EVs is blocked by anti-midkine antibodies. These results demonstrate for the first time that changes in the expression of a tetraspanin protein by tumour cells can affect the formation of the immune microenvironment by modulating recruitment of effector cells to cancerous tissues. Therefore, a CD151-midkine pathway can be considered as a novel target for controlled changes of the immune landscape in IBC. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Sphingosine kinase-1 predicts overall survival outcomes in non-small cell lung cancer patients treated with carboplatin and navelbine.

Sphingosine 1-phosphate (S1P) is a bioactive lipid metabolite associated with cancer cell proliferation, survival, migration and regulation of tumor angiogenesis in various cellular and animal models. Sphingosine kinase-1 (SphK1) and S1P lyase are the main enzymes that respectively control the synthesis and degradation of S1P. The present study analyzed the prognostic and predictive value of SphK1 and S1P lyase expression in patients with non-small cell lung cancer (NSCLC), treated with either surgery alone or in combination with adjuvant carboplatin and navelbine. Formalin-fixed, paraffin-embedded tissue samples from 176 patients with NSCLC were stained immunohistochemically using antibodies against SphK1 and S1P lyase, and their expression was correlated with all available clinicopathological factors. Increased expression of SphK1 was significantly associated with shorter overall and disease free survival in patients treated with adjuvant platinum-based chemotherapy. No prognostic relevance for S1P lyase expression was observed. Collectively, the results suggest that the immunohistochemical detection of SphK1 may be a promising predictive marker in NSCLC patients treated with adjuvant platinum-based chemotherapy.

Collagen triple helix repeat containing 1 protein, periostin and versican in primary and metastatic breast cancer: an immunohistochemical study.

BACKGROUND: Collagen triple helix repeat containing 1 (CTHRC1) affects Wnt signalling, collagen deposition and bone formation. It is an extracellular matrix protein which is also abnormally expressed in the tumour microenvironment. CTHRC1 has not been studied in breast cancer by immunohistochemistry. AIMS: To examine expression of CTHRC1 together with periostin and versican in breast cancer patients and investigate its association with clinicopathological characteristics. METHODS: The formalin-fixed paraffin-embedded tissues of 173 invasive carcinomas (classified into WHO histotypes and luminal, triple negative and Her2 subtypes), as well as normal tissues, precursor lesions and metastatic lymph nodes were stained by relevant antibodies, assessed semiquantitatively by histoscore and statistically evaluated. RESULTS: Expression of CTHRC1, versican and periostin was significantly higher in breast cancer than in normal tissue or precursor lesions. CTHRC1 stromal expression was enhanced in triple negative cases and also in patients with bone metastasis. Periostin expression was high in primary tumours, in particular triple negative ones, and also in their lymph node metastases. Cox regression analysis showed that in patients with high periostin, the risk of bone metastases increased with increased CTHRC1 expression. CONCLUSIONS: CTHRC1 and periostin play important roles in breast cancer progression. These preliminary results show that combined evaluation of CTHRC1 and periostin could serve as a potential marker for breast cancer bone metastasis; the other observations contribute to the description of the tumour microenvironment, with implications for lymph node and bone metastasis.