Mechanisms of tumor immune escape in triple-negative breast cancers (TNBC) with and without mutated BRCA 1

Purpose

Triple negative breast cancers (TNBC) are associated with an adverse outcome, although these tumors are sensitive to chemotherapy. In part, this phenomenon could be caused by tumor immune escape. The current study investigates immunogenicity of TNBC cells in vitro and the presence of immunosuppressive factors in the tumor microenvironment (pAKT and B7H1 expression, infiltration with regulatory T cells, [Tregs]).

Methods

Natural killer (NK)-cell induced lysis was evaluated in estrogen receptor (ER) positive MCF 7 breast cancers, in MDA-MB231 and MDA-MB468 and in HCC-1937 (BRCA 1 mutated) and HCC-1806 TNBC cells. Expression of pAKT, B7H1 and infiltration with Tregs were determined by immunohistochemistry in human specimens of benign and malignant breast disease.

Results

NK-cell induced lysis was significantly increased (p < 0.05) in four TNBC cell lines compared to ER + MCF 7 cells. Fibroadenomas and mastectomy samples were not infiltrated with Tregs. Infiltration with Tregs was 0.92 ± 0.21 in ER/PR + breast cancers and significantly higher in TNBC without (2.30 ± 0.34) and also significantly higher with mutation of BRCA 1 (2.10 ± 0.34). Expression of pAKT was absent in benign controls and 1.23 ± 0.36 in ER/PR + breast cancers, 1.78 ± 0.40 in TNBC without and 2.40 ± 0.30 with mutated BRCA 1. No significant differences of B7H1 expression occurred among the breast cancer subgroups.

Conclusion

TNBC cell stimulate the NK-cell immune response significantly stronger than ER positive breast cancer cells. This could explain why infiltration with immunosuppressive Tregs is increased in human specimens of TNBC with and without mutated BRCA 1. Accordingly, immunomodulatory treatment strategies should be further explored in TNBC.     

Dislocation tendency,stabilizing effect and sintering tendency of different lumbar vertebrae cages in an in vitro experiment

For biomechanical purposes, interbody fusion cages should not dislocate, should provide high stability, and should have a low subsidence risk. Zientek (Marquardt Medzintechnik), Stryker (Stryker Implants), and Ray lumbar interbody fusion cages (Surgical Dynamics) were tested in this study. They were implanted by pairs from a posterior approach without further stabilization. In a first step, each cage design was implanted into four human L3-4 segments and extracted posteriorly under an axial preload of 200 N. In a second step, standard flexibility tests were carried out with 24 human L2-3 and L4-5 specimens in an intact condition, directly after cage implantation, and after cyclic axial compression loading (200-1000 N, 40,000 cycles, 5 Hz). In a third step, a destructive axial compression test was carried out. Maximum pullout force was highest with Ray cages (median 945 N), followed by Zientek (605 N) and Stryker cages (130 N). With all three cage designs, primary stability was higher in lateral bending and flexion than in extension and axial rotation. Implantation of Ray cages caused a decreased range of motion in all three loading directions ranging between 49% and 99%. Zientek cages only stabilized in lateral bending, flexion, and extension (45-78%) and Stryker cages in none of the three loading directions. Cyclic loading caused an increased range of motion in all cases up to 190%. Axial compression force at failure was 8413 N with Ray cages, 8359 N with Stryker cages, and 5486 N with Zientek cages. The cage design seems to influence the dislocation tendency. In this regard, threaded cages or cages with anchorage systems seem to provide more security. The stabilizing effect seems to be mainly influenced by factors such as the degree of distraction or destruction of the facet joints rather than by the cage design.     

贴报-P2临床毒理学、药理学和疗效研究

5-Flourouracil（5-FU） is one of well known anti-cancer drugs, but its toxicity in normal lymphocytes remains a major problem in chemotherapy. The eastern traditional drug, Bupleuri radix（BR）, has been used for the treatment of liver diseases and contains series of triterpene saponins.     

Hepatic zonation of the induction of cytochrome P450 IVA, peroxisomal lipid beta-oxidation enzymes and peroxisome proliferation in rats treated with dehydroepiandrosterone (DHEA). Evidence of distinct zonal and sex-specific differences

Dehydroepiandrosterone (DHEA) is an intermediate product in the synthesis of male and female sex hormones in the adrenal cortex of man. In livers of rats and mice DHEA increases the levels of cytochrome P450 IVA and peroxisomal beta-oxidation enzymes associated with peroxisome proliferation. Prolonged treatment of rats with DHEA induces liver tumors that are more frequent in females arising mainly in the periportal regions of the liver lobule (Metzger et al., Toxicol. Pathol. 23, 591-605, 1995). Because of paucity of information on hepatic zonation of peroxisomal response to DHEA and controversial reports on gender-specific differences of its effects the present study was undertaken using qualitative immunohistochemical and quantitative immunoelectron microscopical techniques in addition to Western blotting. Rats were treated for 24 weeks with 0.6% DHEA supplied with diet. Immunoblot analysis revealed marked induction of peroxisomal beta- oxidation enzymes, which by quantitative analysis was equally strong in male and female animals, whilst catalase and urate-oxidase were not increased. Cytochrome P450 IVA, in contrast, was induced significantly stronger in male than in female rats. Immunohistochemistry confirmed the induction of cytochrome P450 IVA showing a marked lobular gradient in female animals with strong induction in pericentral and almost no induction in periportal regions of the liver lobule. In male animals cytochrome P450 IVA was expressed more uniformly across the liver lobule. A similar sex specific zone-dependent response was observed for peroxisomes. DHEA induced in females a significant zonal gradient with marked peroxisome proliferation and a strong induction of peroxisomal hydratase/dehydrogenase in pericentral hepatocytes and a much smaller response in periportal regions. Livers of male animals, in contrast, showed a uniform peroxisomal proliferation to DHEA with only slight zonal differences. The striking homologies of the induction patterns of cytochrome P450 IVA and the peroxisome proliferation in both sexes support the notion of a functional relationship. In view of the almost exclusive periportal localization of DHEA-induced tumors in female rats in contrast to the pericentral localization of the peroxisomal proliferation shown by this study, it seems likely that other factors in addition to peroxisome proliferation may contribute to the hepatocarcinogenic effect of DHEA.      

Pulsatile release of catecholamines in the hypothalamus of conscious rats

Summary To investigate the patterns of catecholamine release in the brain, the hypothalamus of conscious, freely moving rats was superfused through a push-pull cannula with artificial cerebrospinal fluid and the catecholamines dopamine, noradrenaline and adrenaline were determined in the superfusate radioenzymatically. Superfusate was continuously collected in time periods of 20 min for at least 20h. Dopamine, noradrenaline and adrenaline release rates fluctuated according to an ultradian rhythm with a frequency of 1 cycle/92 min (dopamine and noradrenaline) or 99 min (adrenaline). Additionally, the three catecholamines were released according to an ultradian rhythm with the following frequencies: noradrenaline and adrenaline 1 cycle/ 12 h, dopamine 1 cycle/8 h. The release rates of dopamine and adrenaline were similar during light and dark periods, while the release rate of noradrenaline in the dark period was slightly lower than that during the light period. It is concluded that in the hypothalamus of the conscious rat the release rates of dopamine, noradrenaline and adrenaline fluctuate according to two ultradian rhythms with different frequencies.This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds zur Förderung der wissenschaftlichen ForschungParts of this work have been presented at the 29th Spring Meeting of the German Society of Pharmacology and Toxicology, 1988 and at the 12th Annual Meeting of the European Neuroscience Association, 1989Correspondence to H. Prast at the above address     

Die Strahlentherapie inguinaler Lymphfisteln nach gefäßchirurgischen Eingriffen

BACKGROUND AND PURPOSE: The formation of inguinal lymphorrhea following vascular surgery is a rare but potentially serious problem with an incidence of about 2%. There is no consensus on the most effective treatment for groin lymphorrhea. In a retrospective analysis the usefulness of irradiation in the treatment of inguinal lymph fistulas was investigated. PATIENTS AND METHODS: From 08/1997 to 12/2000, 28 patients with inguinal lymph fistulas were irradiated postoperatively (4th-19th day) with a single dose of 3 Gy up to a total dose of 9 Gy on 3 consecutive days using 120- to 300-kV photons. Three further patients received 2 x 4 Gy and 3 x 5 Gy, respectively, due to an interposed weekend. RESULTS: Secretion volume at the beginning of radiotherapy varied between 50 and 650 ml daily (mean 203 ml, median 175 ml), at the end of radiotherapy between 0 and 350 ml (mean 126 ml, median 120 ml). 3/28 lymph fistulas had resolved during radiotherapy. In 17/28 patients (60.7%) the drains could be removed within 10 days, in further 10/28 patients (35.7%) within 10-20 days after the end of radiotherapy. CONCLUSION: Overall, irradiation of inguinal lymph fistulas proved to be an effective and well-tolerated treatment, facilitating removal of fistula drains within 10-20 days (mean 10.5, median 7 days) after the completion of radiotherapy, thus appearing a good alternative to other conservative treatment modalities.     

Indoleamine 2,3-dioxygenase (IDO) expression in invasive extravillous trophoblast supports role of the enzyme for materno-fetal tolerance

It is still not understood how the fetus escapes from being attacked by the maternal immune system. Recent reports based on mouse and in vitro models have suggested that the enzyme indoleamine 2,3-dioxygenase (IDO) is important for materno-fetal tolerance. IDO activity in the human placenta is known to be high and might lead to inhibition of T-cell proliferation, thus preventing fetal tissue from rejection by the maternal immune system. In an attempt to elucidate the precise location of IDO at the feto-maternal junctional zone, we investigated human placental and decidual tissue of first and third trimester of pregnancy using an immunohistochemical approach. In placental tissues, only syncytiotrophoblast and endothelial cells showed moderate expression of IDO. This pattern was observed regardless of whether first or third trimester tissue was investigated. In early and term decidua, cells with the typical morphology of invasive extravillous trophoblast (EVT) were strongly positive for IDO. Blocking immunohistochemical experiments with cytokeratin and IDO antibodies identified invasive EVT as the location of predominant IDO expression. Since EVT are the fetal cells with the closest contact to the maternal immune system, our results suggest that it is EVT which protects the fetus from rejection by downregulating local maternal T-cell responses.