Inhibition of tumour cell growth by hyperforin, a novel anticancer drug from St. John's wort that acts by induction of apoptosis

Hyperforin is a plant derived antibiotic from St. John's wort. Here we describe a novel activity of hyperforin, namely its ability to inhibit the growth of tumour cells by induction of apoptosis. Hyperforin inhibited the growth of various human and rat tumour cell lines in vivo, with IC(50) values between 3-15 microM. Treatment of tumour cells with hyperforin resulted in a dose-dependent generation of apoptotic oligonucleosomes, typical DNA-laddering and apoptosis-specific morphological changes. In MT-450 mammary carcinoma cells hyperforin increased the activity of caspase-9 and caspase-3, and hyperforin-mediated apoptosis was blocked by the broad-range caspase inhibitor zVAD.fmk. When added to MT-450 cells, hyperforin, but not paclitaxel, induced a rapid loss of the mitochondrial transmembrane potential Deltapsi(m), and subsequent morphological changes such as homogenization and vacuolization of mitochondria. Monitoring of Deltapsi(m) revealed that the hyperforin-mediated mitochondrial permeability transition can not be prevented by zVAD.fmk. This indicates that mitochondrial permeabilization is a cause rather than a consequence of caspase activation. Moreover, hyperforin was capable of releasing cytochrome c from isolated mitochondria. These findings suggest that hyperforin activates a mitochondria-mediated apoptosis pathway. In vivo, hyperforin inhibited the growth of autologous MT-450 breast carcinoma in immunocompetent Wistar rats to a similar extent as the cytotoxic drug paclitaxel, without any signs of acute toxicity. Owing to the combination of significant antitumour activity, low toxicity in vivo and natural abundance of the compound, hyperforin holds the promise of being an interesting novel antineoplastic agent that deserves further laboratory and in vivo exploration.     

Early cytoskeletal rearrangement during dendritic cell maturation enhances synapse formation and Ca(2+) signaling in CD8(+) T cells

The interplay between dendritic cells (DC) and T cells is a dynamic process critically depending on DC maturation. Ca(2+) influx is one of the initial events occurring during DC/T cell contacts. To determine how DC maturation influences DC/T cell contacts, time-lapse video microscopy was established using TCR-transgenic CD8(+) T cells from P14 mice. DC maturation shifted DC/T cell contacts from short-lived interactions with transient Ca(2+) influx in T cells to long-lasting interactions and sustained Ca(2+) influx of 30 min and more. Follow-up of DC/T cell interactions after 2 h using confocal microscopy revealed that long-lasting Ca(2+) responses in T cells were preferentially associated with the formation of an immunological synapse involving CD54 and H2-K(b) at the DC/T cell interface. Such synapse formation preceded MHC or B7 up-regulation, since DC developed into potent Ca(2+) stimulators 7 h after initiation of maturation. Instead, the enhanced capacity of 7 h-matured DC to induce sustained Ca(2+) responses in CD8(+) T cells is critically dependent on the polarization and rearrangement of the cytoskeleton, as shown by Clostridium difficile toxin B inhibitor experiments. These data indicate that already very early after receiving a maturation stimulus, DC display enhanced cytoskeletal activity resulting in the rapid formation of immunological synapses and effective CD8(+) T cell stimulation.     

Video assisted thoracoscopic treatment of pleuropericardial cysts

Question of the Study In this study, safety and feasibility of thoracoscopic fenestration of pleuropericardial cysts under local and general anaesthesia is evaluated. Besides, a rare case of a pleural cyst, causing a superior vena cava syndrome, is described.Materials, Patients and Methods In a retrospective study, the results of thoracoscopic treatment of pleuropericardial cysts in three patients are presented. We performed videothoracoscopic fenestration of pleuropericardial cysts. One of these was performed under local anaesthesia. The two other cases were performed under general anaesthesia. After fenestration, talc poudrage of the inner lining of the cysts was performed in one case.Results Thoracoscopic fenestration appeared to be safe and effective. No recurrence was observed. One patient was lost to follow-up.Answer to the Question Thoracoscopic fenestration of pleuropericardial cysts is safe and effective. This procedure can be performed under local anaesthesia in selected cases. The role of talc poudrage of the cysts is unclear and needs further investigation.     

IgA-lineare Dermatose im Erwachsenenalter mit klinischen Zeichen eines Stevens-Johnson-Syndroms

Immunohistologically linear IgA disease presents with unambiguous features, whereas clinical manifestations are variable. It sometimes shows similarity to other bullous dermatoses such as bullous pemphigoid and dermatitis herpetiformis. A 73 year old female patient was referred with the diagnosis of bullous pemphigoid. One day after admission clinical examination revealed the classical features of Stevens-Johnson syndrome (SJS): widespread confluent atypical target lesions, partly raised, partly flat with central blisters, and erythematous spots, but few typical targets, as well as blisters and large areas of skin detachment on her back and buttocks, accompanied by erosions of the oral and genital mucosa. Direct immunofluorescence performed on peri-lesional skin showed linear deposition of IgA along the basement membrane zone, leading to the diagnosis of linear IgA disease of adults. Our case report shows that linear IgA disease may present with the clinical pattern of SJS.     

Effects of long-term stress and recovery on the prefrontal cortex and dentate gyrus in male and female rats

Women show a higher prevalence for depression than men. However, the biological basis of gender differences in stress response and recovery still remain poorly understood. Therefore, the aim of the study was to assess the gender differences in response to acute stress, chronic stress and recovery in rats. Our results showed that stress decreased male body weight but had no effect on female rats. Open field test demonstrated behavioral changes in grooming and velocity after chronic stress and recovery. Increased activity of hypothalamic-pituitary-adrenocortical axis was reflected by adrenal hypertrophy and increase of plasma corticosterone levels except in the socially housed female rats after stress. Gender and brain region differences in response to stress and recovery were found in the expression of cAMP response element-binding protein (CREB) and phosphorylated CREB (pCREB). On the whole, expression of CREB and pCREB in male dentate gyrus (DG) and prefrontal cortex (PFC) was sensitive but in female DG and PFC it was resistant to acute and chronic stress. Interestingly, recovery restored the measured parameters to the normal level in male rats but not in female rats. In conclusion, these results suggest that male and female rats responded to stress and recovery in a different way.     

CD44 is the principal mediator of hyaluronic-acid-induced melanoma cell proliferation

Interactions of the extracellular matrix component hyaluronic acid and its cellular receptors CD44 and RHAMM/IHABP have been linked to tumor progression and metastasis formation. We investigated the expression and hyaluronic-acid-dependent functions of CD44 and RHAMM/IHABP in human melanoma. Immunohistochemistry of tumor specimens at different stages of melanoma progression revealed an increased expression of CD44 and RHAMM/IHABP. High mRNA expression of CD44 was found in three highly tumorigenic melanoma cell lines compared with less tumorigenic melanoma cells or nontransformed melanocytes. RHAMM/IHABP expression was upregulated in all cell lines analyzed but not in melanocytes. In contrast to the cell surface localization of CD44, RHAMM/IHABP was detected exclusively within the cytoplasm of melanoma cells. Binding and adhesion of melanoma cells to hyaluronic acid is mainly CD44 dependent as it was inhibited to 60%--80% by an anti-CD44 monoclonal antibody whereas anti-RHAMM/IHABP sera had no effect. Culture of melanoma cells in the presence of hyaluronic acid resulted in a dose-dependent, CD44-mediated increase of melanoma cell proliferation and enhanced release of basic fibroblast growth factor and transforming growth factor beta 1. We conclude that (i) the expression of CD44 and RHAMM/IHABP is increased during melanoma progression, (ii) CD44 is the principal hyaluronic acid surface receptor on melanoma cells, and (iii) the hyaluronic-acid-induced increase of the proliferative capacity of melanoma cells is mainly dependent on CD44--hyaluronic acid interactions.     

Gemcitabine and cisplatin as induction regimen for patients with biopsy-proven stage IIIA N2 non-small-cell lung cancer: a phase II study of the European Organization for Research and Treatment of Cancer Lung Cancer Cooperative Group (EORTC 08955).

PURPOSE: Our objective was to better define the activity/feasibility of gemcitabine/cisplatin (GC) as induction chemotherapy in patients with stage IIIA N2 non-small-cell lung cancer (NSCLC) followed by surgery or radiotherapy within a large, ongoing comparative study (EORTC 08941). PATIENTS AND METHODS: Forty-seven chemotherapy-naive patients with NSCLC, median age of 58 years, stage IIIA N2 disease, World Health Organization performance status of 0 or 1, and the ability to tolerate a pneumonectomy received gemcitabine 1,000 mg/m(2) on days 1, 8, and 15 and cisplatin 100 mg/m(2) on day 2, every 4 weeks. Patients received induction chemotherapy (three cycles) before re-evaluation and randomization to surgery or radiotherapy. RESULTS: Grade 3/4 thrombocytopenia, the main hematologic toxicity, occurred in 60% of patients but was not associated with bleeding. Full-dose gemcitabine was given in 48% of the courses. Severe nonhematologic toxicity was uncommon. Two patients with preexisting, autoimmune pulmonary fibrosis had deterioration of pulmonary function after radiotherapy. Thirty-three (70.2%; 95% confidence interval, 55.1% to 82.7%) of the 47 eligible patients had objective responses (three complete responses and 30 partial responses). Mediastinal nodes were tumor-free after induction therapy in 53% of cases. Resections were considered complete in 71% of the patients who underwent thoracotomy after induction therapy. Median survival for all recruited patients (N = 53) was 18.9 months, with an estimated 1-year survival rate of 69%. CONCLUSION: In patients with N2 stage IIIA NSCLC, GC is a highly active and well-tolerated induction regimen. GC should be explored in combination with surgery or radiotherapy in stage I and II patients.