High numbers of macrophages, especially M2-like (CD163-positive), correlate with hyaluronan accumulation and poor outcome in breast cancer.

AIMS: High amounts of tumour-associated macrophages (TAMs) and hyaluronan (HA) correlate with tumour aggressiveness in breast cancer, but the relationship between these parameters is unclear. The aim of this study was to assay the numbers of TAMs in 278 human breast cancer cases, and their correlations with HA-related factors, clinical variables, and outcome. METHODS AND RESULTS: The immunoreactivities for CD163 and CD68 were considered as indicators for M2-like and all TAMs, respectively. The numbers of TAMs were counted in at least four hot spots, and averaged to represent the numbers of TAMs in each section. In the statistical analyses, the numbers were graded as either low or high according to the median. High numbers of TAMs correlated with a high tumour HA content, HA synthases, CD44 positivity, and poor outcome. The number of CD163-positive cells represented a strong independent prognostic factor. There was also a significant correlation between obesity and a high number of CD163-positive cells. CONCLUSIONS: Concurrent increases in TAMs and HA in breast cancer indicate that the accumulation of HA facilitates macrophage infiltration and inflammatory responses during human breast cancer progression.

Hyaluronan synthases (HAS1-3) in stromal and malignant cells correlate with breast cancer grade and predict patient survival.

Accumulation of hyaluronan (HA) in pericellular stroma and carcinoma cells is predictive of unfavorable patient prognosis in many epithelial cancers. However, it is not known whether the HA originates from carcinoma or stromal cells, or whether increased expression of hyaluronan synthase proteins (HAS1-3) contributes to HA accumulation. In this study, localization and expression of HAS1-3 were evaluated immunohistochemically in 278 cases of human breast cancer, and correlated with prognostic factors and patient outcome. Both carcinoma cells and stromal cells were HAS-positive. In carcinoma cells, HAS1 and HA stainings correlated with each other, and HAS1 associated with estrogen receptor negativity, HER2 positivity, high relapse rate, and short overall survival. In stromal cells, the staining levels of all HAS isoforms correlated with the stromal HA staining, stromal cell CD44, high relapse rate, and short overall survival of the patients. In addition, expression levels of stromal HAS1 and HAS2 were related to obesity, large tumor size, lymph node positivity, and estrogen receptor negativity. Thus, stromal HAS1 and HAS3 were independent prognostic factors in the multivariate analysis. The data suggest that increased levels of HAS enzymes contribute to the accumulation of HA in breast cancer, and that HA is synthesized in carcinoma cells and stromal cells. The study also indicates that HAS enzyme levels are related to tumor aggressiveness and poor patient outcome representing potential targets for therapy.

High Numbers of CD163+ Tumor-Associated Macrophages Predict Poor Prognosis in HER2+ Breast Cancer.

Tumor-associated macrophages (TAMs) are associated with a poor outcome in breast cancer (BC), but their prognostic value in different BC subtypes has remained somewhat unclear. Here, we investigated the prognostic value of M2-like TAMs (CD163+) and all TAMs (CD68+) in a patient cohort of 278 non-metastatic BC patients, half of whom were HER2+ (n = 139). The survival endpoints investigated were overall survival (OS), breast cancer-specific survival (BCSS) and disease-free survival (DFS). In the whole patient cohort (n = 278), a high CD163+ TAM count and a high CD68+ TAM count were associated with a worse outcome (p ≤ 0.023). In HER2+ BC, a high CD163+ TAM count was an independent factor for a poor prognosis across all the investigated survival endpoints (p < 0.001). The prognostic effect was evident in both the HER2+/hormone receptor-positive (p < 0.001) and HER2+/hormone receptor-negative (p ≤ 0.012) subgroups and regardless of the provision of adjuvant trastuzumab (p ≤ 0.002). In HER2-negative BC, the CD163+ TAM count was not significantly associated with survival. These results suggest that a high CD163+ TAM count predicts an inferior outcome, especially in HER2+ BC patients, and as adjuvant trastuzumab did not overcome the poor prognostic effect, combination treatments including therapies targeting the macrophage function could represent an effective therapeutic approach in HER2+ BC.

Increased hyaluronan content and stromal cell CD44 associate with HER2 positivity and poor prognosis in human breast cancer.

Previous in vitro studies have suggested interactions between hyaluronan (HA), CD44 and HER2. We have studied the expression of HA and CD44 in a material of 278 breast cancer cases, half of which were HER2-positive. Intense stromal HA staining was associated with HER2 positivity, large tumor size, lymph node positivity, hormone receptor negativity, poor differentiation, a high body mass index, increased relapse rate and shortened overall survival. Among the 139 HER2-positive cases, the relapse rate was associated with the intensity of stromal HA staining as most of the relapses occurred in the cases with intense stromal HA staining. The presence of HA in the carcinoma cells was related to the frequency of relapses as none of the patients without HA in carcinoma cells experienced a relapse, whereas 33.3% of those with a high percentage of HA-positive carcinoma cells suffered a relapse. CD44 positivity in carcinoma cells was related to poor differentiation, postmenopausal status and triple negative breast carcinoma. CD44 positivity in stromal cells was associated with HER2 positivity, large tumor size, hormone receptor negativity, poor differentiation, increased relapse rate and shortened overall survival. The association between HER2 positivity and intense stromal HA staining indicates that HA could be one of the factors involved in the unfavorable outcome of HER2-positive patients. This study also suggests that HA in breast carcinoma cells and CD44 in stromal cells may have clinical significance.

Antieosinophilic activity of simendans.

Simendans are novel agents used in the treatment of decompensated heart failure. They sensitize troponin C to calcium and open ATP-sensitive potassium channels and have been shown to reduce cardiac myocyte apoptosis. The aim of the present study was to evaluate whether simendans reduce pulmonary eosinophilia and regulate eosinophil apoptosis. Bronchoalveolar lavage (BAL) eosinophilia was evaluated in ovalbumin-sensitized mice. Effects of simendans on apoptosis in isolated human eosinophils were assessed by relative DNA fragmentation assay, annexin V-binding, and morphological analysis. Dextrosimendan [(+)-[[4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)phenyl)hydrazono]propanedinitrile] reduced ovalbumin-induced BAL-eosinophilia in sensitized mice. Levosimendan [(-)-[[4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)phenyl]hydrazono]propanedinitrile] and dextrosimendan reversed interleukin (IL)-5-afforded survival of human eosinophils by inducing apoptosis in vitro. Even high concentrations of IL-5 were not able to overcome the effect of dextrosimendan. Dextrosimendan further enhanced spontaneous apoptosis as well as that induced by CD95 ligation, without inducing primary necrosis. Dextrosimendan-induced DNA fragmentation was shown to be dependent on caspase and c-Jun NH2-terminal kinase activation, whereas extracellular signal-regulated kinase, p38 mitogen-activated kinase, and ATP-sensitive potassium channels seemed to play no role in its actions. Taken together, our results show that simendans possess antieosinophilic activity and may be useful for the treatment of eosinophilic inflammation.