Gefitinib in combination with tamoxifen in patients with ovarian cancer refractory or resistant to platinum-taxane based therapy--a phase II trial of the AGO Ovarian Cancer Study Group (AGO-OVAR 2.6)

BACKGROUND: Tamoxifen and gefitinib (IRESSA) combination therapy was studied in patients with ovarian cancer refractory or resistant to platinum- and taxane-based therapy. PATIENTS AND METHODS: In this phase II study, 56 patients with epithelial ovarian carcinoma or cancer of the fallopian tube or peritoneum received oral tamoxifen 40 mg/day and gefitinib 500 mg/day until progression or unacceptable toxicity. RESULTS: Seventeen patients (mean age: 59.6 years) had previously received first-line platinum/taxane treatment only, while 39 had received 2-8 (median 2) prior chemotherapy regimens. Gefitinib dose reduction to 250 mg/day was performed in 10 patients (14.9%), predominantly due to diarrhea (6 patients [10.7%]). Trial medication was discontinued in 6 patients (10.7%) due to adverse events (AEs). The most frequent drug-related AEs were diarrhea and acne-like skin rash. There were no tumor responses, but 16 patients had stable disease. Median time-to-progression was 58 days (95% CI, 55-71 days) and median survival was 253 days (95% CI, 137-355 days). CONCLUSION: Gefitinib plus tamoxifen did not appear to be efficacious in the treatment of patients with refractory/resistant ovarian cancer. The addition of tamoxifen did not worsen the known side effects of gefitinib, or induce additional side effects.     

Intracellular calcium and sodium-lithium countertransport in type 2 diabetic patients with and without albuminuria

Increased intracellular calcium concentrations ([Ca(2+)](i)) and enhanced sodium-lithium countertransport (Na/Li CT) activities may play a role in the development of diabetic complications such as diabetic nephropathy. The present study was designed to test the hypothesis that albuminuria in patients with type 2 diabetes is associated with increased [Ca(2+)](i) in response to stimulation with platelet-activating factor (PAF) or with enhanced Na/Li CT activities. The study population comprised 203 type 2 diabetic patients. Albuminuria was defined as an albumin excretion rate exceeding 30 mg/d (117 cases). PAF-evoked rises in [Ca(2+)](i) and Na/Li CT activities were determined in Epstein-Barr-virus-immortalized lymphoblasts. Albuminuria was related to high stimulated [Ca(2+)](i) but not to high basal [Ca(2+)](i). The association was independent of age, sex and several non-diabetes related confounders, but depended on diabetes-related factors, such as the duration of diabetes. The risk of albuminuria was highest in subjects with high [Ca(2+)](i) who reported a diabetes duration of < or =10 years. There was no association between Na/Li CT activities and albuminuria. The present results support the hypothesis that albuminuria in type 2 diabetic patients is associated with a primary defect in intracellular calcium homeostasis. The association between stimulated [Ca(2+)](i) and albuminuria is most prominent in early diabetes.     

Cultivation practices and manufacturing processes to produce Hoodia gordonii extract for weight management products

Hoodia gordonii (Masson) Sweet ex Decne., is a succulent shrub, indigenous to the arid regions of southern Africa. Indigenous people have historically utilised certain species of Hoodia, including H. gordonii, as a source of food and water. Studies by the Council for Scientific and Industrial Research (CSIR, South Africa) identified that extracts of H. gordonii had appetite suppressant activity associated with specific steroid glycosides. A programme to develop weight management products based around this discovery was implemented in 1998. An agronomy programme was established which demonstrated that it was possible to cultivate this novel crop on a commercial scale (in excess of 70 ha). In parallel, a food grade manufacturing process was developed consisting of four main steps: harvesting of H. gordonii plant stems, comminution, drying under controlled conditions and extraction using food grade solvents. Appropriate Quality Control (QC) procedures were developed. The extraction process is capable of delivering a consistent composition despite natural variations in the composition of the dried H. gordonii. Specifications were developed for the resulting extract. The intended use of the standardised H. gordonii extract was as a functional food ingredient for weight management products. Other development studies on characterisation, toxicology and pharmacology are reported separately.     

Pyruvate kinase M2 is a novel diagnostic marker and predicts tumor progression in human biliary tract cancer

BACKGROUND:

The early diagnosis of biliary tract cancer (BTC) remains challenging, and there are few effective therapies. This study investigated whether the M2 isotype of pyruvate kinase (M2‐PK), which serves as the key regulator of cellular energy metabolism in proliferating cells, could play a role in the diagnosis and therapy of BTC.

METHODS:

Plasma and bile M2‐PK concentrations were measured by enzyme‐linked immunosorbent assay in 88 patients with BTC, 79 with benign biliary diseases, and 17 healthy controls. M2‐PK expression was assayed in a BTC tissue array by immunohistochemistry. The role of M2‐PK in tumor growth, invasion, and angiogenesis was evaluated in BTC cell lines by retrovirus‐mediated M2‐PK transfection and short hairpin RNA silencing techniques.

RESULTS:

Sensitivity (90.3%) and specificity (84.3%) of bile M2‐PK for malignancy were significantly higher than those for plasma M2‐PK and serum carbohydrate antigen 19‐9. M2‐PK expression was specific for cancer cells and correlated with microvessel density. M2‐PK positivity was a significant independent prognostic factor by multivariable analysis. Transfection of M2‐PK in a negatively expressed cell line (HuCCT‐1 cells) increased cell invasion, whereas silencing in an M2‐PK–positive cell line (TFK cells) decreased tumor nodule formation and cellular invasion. A significant increase in endothelial tube formation was noted when supernatants from M2‐PK–transfected cells were added to an in vitro angiogenesis assay, whereas supernatants from silenced cells negated endothelial tube formation.

CONCLUSIONS:

Bile M2‐PK is a novel tumor marker for BTC and correlates with tumor aggressiveness and poor outcome. Short hairpin RNA–mediated inhibition of M2‐PK indicates the potential of M2‐PK as a therapeutic target. Cancer 2013. © 2012 American Cancer Society.     

Cholesterol regulates melanogenesis in human epidermal melanocytes and melanoma cells

Abstract:  Cholesterol is important for membrane stability and is the key substrate for the synthesis of steroid hormones and vitamin D. Furthermore, it is a major component of the lipid barrier in the stratum corneum of the human epidermis. Considering that steroid hormone synthesis is taking place in epidermal melanocytes, we tested whether downstream oestrogen receptor/cAMP signalling via MITF/tyrosine hydroxylase/tyrosinase/pigmentation could be possibly modulated by cholesterol. For this purpose, we utilized human primary melanocyte cell cultures and human melanoma cells with different pigmentation capacity applying immunofluorescence, RT-PCR, Western blotting and determination of melanin content. Our in situ and in vitro results demonstrated that melanocytes can synthesize cholesterol via HMG-CoA reductase and transport cholesterol via LDL/Apo-B100/LDLR. Moreover, we show that cholesterol increases melanogenesis in these cells and in human melanoma cells of intermediate pigmentation (FM55) in a time- and dose-dependent manner. Cellular cholesterol levels in melanoma cells with different pigmentation patterns, epidermal melanocytes and keratinocytes do not differ except in the amelanotic (FM3) melanoma cell line. This result is in agreement with decreasing cholesterol content versus increasing pigmentation in melanosomes. Cholesterol induces cAMP in a biphasic manner i.e. after 30 min and later after 6 and 24 h, meanwhile protein expression of oestrogen receptor β, CREB, MITF, tyrosine hydroxylase and tyrosinase is induced after 72 h. Taken together, we show that human epidermal melanocytes have the capacity of cholesterol signalling via LDL/Apo-B100/LDL receptor and that cholesterol under in vitro conditions increases melanogenesis.     

Handlungsempfehlungen nach der Leitlinie Klassifikation und Diagnostik der Mikrozephalie

Monatsschrift Kinderheilkunde -     

Glucocorticoids attenuate acute graft‐versus‐host disease by suppressing the cytotoxic capacity of CD8+ T cells

Glucocorticoids (GCs) are released from the adrenal gland during inflammation and help to keep immune responses at bay. Owing to their potent anti‐inflammatory activity, GCs also play a key role in controlling acute graft‐versus‐host disease (aGvHD). Here we demonstrate that mice lacking the glucocorticoid receptor (GR) in T cells develop fulminant disease after allogeneic bone marrow transplantation. In a fully MHC‐mismatched model, transfer of GR‐deficient T cells resulted in severe aGvHD symptoms and strongly decreased survival times. Histopathological features were aggravated and infiltration of CD8⁺ T cells into the jejunum was increased when the GR was not expressed. Furthermore, serum levels of IL‐2, IFNγ, and IL‐17 were elevated and the cytotoxicity of CD8⁺ T cells was enhanced after transfer of GR‐deficient T cells. Short‐term treatment with dexamethasone reduced cytokine secretion but neither impacted disease severity nor the CTLs' cytolytic capacity. Importantly, in an aGvHD model in which disease development exclusively depends on the presence of CD8⁺ T cells in the transplant, transfer of GR‐deficient T cells aggravated clinical symptoms and reduced survival times as well. Taken together, our findings highlight that suppression of CD8⁺ T‐cell function is a crucial mechanism in the control of aGvHD by endogenous GCs. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.