Plasma HMGB-1 after the initial dose of epirubicin/docetaxel in cancer.

BACKGROUND: The response of breast cancer patients to neoadjuvant chemotherapy (NCT) is highly heterogeneous, and reliable predictive instruments remain to be defined. High-mobility group box-1 (HMGB-1) protein is a cell death marker, which is easily detectable in plasma. We hypothesized that the initial dose of NCT with epirubicin/docetaxel induces changes in plasma HMGB-1 which could allow for an early prediction of response to therapy. MATERIALS AND METHODS: First, we analysed whether epirubicin/docetaxel releases HMGB-1 from HCC1143 breast cancer cells in vitro. Thereafter, plasma HMGB-1 levels before and 1-4 days after the first dose of epirubicin/docetaxel-based NCT were determined in 41 breast cancer patients and correlated with pathological response to treatment. RESULTS: Treatment of HCC1143 cells with epirubicin/docetaxel resulted in a significant HMGB-1 release in vitro. In vivo, HMGB-1 levels increased significantly only in responders (pathological complete response or partial remission, n = 22) but not in nonresponders (stable or progressive disease, n = 19). CONCLUSION: Our data suggest that early dynamic changes of plasma HMGB1 could be a promising biomarker to predict the final response to NCT in breast cancer patients.

Prognostic value of HMGB1 in early breast cancer patients under neoadjuvant chemotherapy.

The response to neoadjuvant chemotherapy in breast cancer patients is usually assessed by pCR and RCB score. However, the prognostic value of these parameters is still in discussion. We showed recently that an epirubicin/docetaxel therapy is associated with an increase in the cell death marker high-mobility group box 1 protein (HMGB1) in the circulation. Here, we investigate whether this increase correlates with the long-term outcome. Thirty-six early breast cancer patients under neoadjuvant epirubicin/docetaxel combination chemotherapy were included in this study. To determine the immediate effect of this treatment on HMGB1, we collected blood samples before and 24-96 h after the initial dose. This time course was then compared to the 5-year follow-up of the patients. HMGB1 levels varied before chemotherapy between 4.1 and 11.3 ng/mL and reacted differently in response to therapy. Some patients showed an increase while others did not show any changes. Therefore, we subdivided the patient collective into two groups: patients with an at least 1.1 ng/mL increase in HMGB1 and patients with smaller changes. The disease-free survival was longer in the HMGB1 increase group (56.2 months vs. 46.6 months), but this difference did not reach significance. The overall survival (OS) was significantly better in patients with an increase in HMGB1 (log rank P = 0.021). These data suggest that an immediate increase in HMGB1 levels correlates with improved outcome in early breast cancer patients receiving neoadjuvant chemotherapy, and may be a valuable complementary biomarker for early estimation of prognosis.

Lymphocyte activation induces cell surface expression of an immunogenic vimentin isoform.

High titers of anti-vimentin antibodies after transplantation are known to be associated with poor long-term graft survival. Vimentin is an intracellular protein which is present in different isoforms in the cell. In a previous study with sera from hemodialysis patients on the kidney transplantation waiting list we could show that only a 49 kDa and a 60 kDa isoform are recognized by patients' anti-vimentin antibodies while the other isoforms remain undetected. However, it is still unclear whether antibodies against this intracellular protein can bind to intact cells. Here we show that vimentin can be present on the cell surface under certain conditions. Lymphocytes from healthy volunteers were used as a model for allogeneic cells. We could show by immunofluorescence microscopy, flow cytometry and Western blot experiments that concanavalin A (Con A) activated lymphocytes express a 49 kDa vimentin isoform on their cell surface while the 60 kDa isoform remains inaccessible from the outside. This expression is associated with an increased binding of sera from hemodialysis patients which were positive for anti-vimentin antibodies. These results suggest that cell activation enhances binding of anti-vimentin antibodies to intact cells which might contribute to chronic allograft nephropathy.

Interaction of mesalasine (5-ASA) with translational initiation factors eIF4 partially explains 5-ASA anti-inflammatory and anti-neoplastic activities.

5-Aminosalicylic acid (5-ASA or mesalazine) is widely used for treatment of inflammatory bowel disease and considered to be cancer preventive. Still, the molecular mechanisms explaining its properties remain largely unknown, partially due to the lack of instrumentarium needed to identify its array of molecular targets. Modern OMICs-based technologies utilized in this study may serve as a powerful and unbiased tool to search for such targets. Here we demonstrate that 5-ASA alters ß-catenin immunocomplex formation by changing complex binding of seven proteins including translation initiation factors eIF4b. OMICs-based cross-testing by reverse in-gel chemogenomics (utilizing 5-ASA's fluorescent properties), in-silico docking and surface plasmon resonance experiments identified binding of 5-ASA to eIF4e's cap-binding pocket, a key regulatory site for protein synthesis. In-vitro translation experiments with rabbit reticulocytes confirmed a dose-dependent inhibition of protein syntheses by 5-ASA. By using two unbiased and independent OMICs-based experimental approaches two members of the cellular translation machinery, eIF4b and IF4e, were identified as targets of 5-ASA. Inhibition of protein syntheses is a previously unrecognized property of 5-ASA that may add to its anti-inflammatory and anti-neoplastic activities.