Regulation of Trypanosoma brucei Total and Polysomal mRNA during Development within Its Mammalian Host

This work was supported by a Wellcome Trust Programme grant to KM and by a Wellcome Trust Strategic award to the Centre for Immunity, Infection and Evolution at the University of Edinburgh. SM was supported by a studentship from the Medical Research Council, UK.The gene expression of Trypanosoma brucei has been examined extensively in the blood of mammalian hosts and in forms found in the midgut of its arthropod vector, the tsetse fly. However, trypanosomes also undergo development within the mammalian bloodstream as they progress from morphologically 'slender forms' to transmissible 'stumpy forms' through morphological intermediates. This transition is temporally progressive within the first wave of parasitaemia such that gene expression can be monitored in relatively pure slender and stumpy populations as well as during the progression between these extremes. The development also represents the progression of cells from translationally active forms adapted for proliferation in the host to translationally quiescent forms, adapted for transmission. We have used metabolic labelling to quantitate translational activity in slender forms, stumpy forms and in forms undergoing early differentiation to procyclic forms in vitro. Thereafter we have examined the cohort of total mRNAs that are enriched throughout development in the mammalian bloodstream (slender, intermediate and stumpy forms), irrespective of strain, revealing those that exhibit consistent developmental regulation rather than sample specific changes. Transcripts that cosediment with polysomes in stumpy forms and slender forms have also been enriched to identify transcripts that escape translational repression prior to transmission. Combined, the expression and polysomal association of transcripts as trypanosomes undergo development in the mammalian bloodstream have been defined, providing a resource for trypanosome researchers. This facilitates the identification of those that undergo developmental regulation in the bloodstream and therefore those likely to have a role in the survival and capacity for transmission of stumpy forms.Publisher PDFPeer reviewe

Rare Cancers in Children - The EXPeRT Initiative: A Report from the European Cooperative Study Group on Pediatric Rare Tumors.

The low incidence and the heterogeneity of very rare tumors (VRTs) demand for international cooperation. In 2008, EXPeRT (European Cooperative Study Group for Pediatric Rare Tumors) was founded by national groups from Italy, France, United Kingdom, Poland and Germany. The first aims of EXPeRT were to agree on a uniform definition of VRTs and to develop the currently most relevant scientific questions. Current initiatives include international data exchange, retrospective and prospective studies of specific entities, and the development of harmonized and internationally recognized guidelines. Moreover, EXPeRT established a network for expert consultation to assist in clinical decision in VRTs

Ovarian Sertoli Leydig cell tumours in children and adolescents: An analysis of the European Cooperative Study Group on Pediatric Rare Tumors (EXPeRT).

OBJECTIVE: To analyse ovarian Sertoli-Leydig cell tumours (SLCTs) for potential prognostic markers and their use for treatment stratification. PATIENTS: Forty-four patients were included. Patients were prospectively reported to the German MAKEI (Maligne Keimzelltumoren) studies (n=23), French TGM protocols (n=10), Italian Rare Tumour Project (TREP) registry (n=6), and the Polish Pediatric Rare Tumour Study group (n=5). Tumours were classified according to World Health Organisation (WHO) and staged according to International Federation of Gynecological Oncology (FIGO). RESULTS: Median age was 13.9 (0.5-17.4) years. All patients underwent resection by tumour enucleation (n=8), ovariectomy (n=17), adenectomy isolated (n=18) or with hysterectomy (n=1). FIGO-stage: Ia 24pts., Ic 17pts., II/III 3pts. One patient had bilateral tumours. Four patients (stage Ia: 3, stage Ic: 1) developed a metachronous contralateral tumour. Otherwise, all stage Ia patients remained in complete remission. Among 20 patients with incomplete resection or tumour spread (stage Ic-III), eight relapsed, and five patients died. Eleven patients were initially treated with two to sixcycles of cisplatin-based chemotherapy. Of these, seven patients are in continuous remission. Poor histological differentiation was associated with higher relapse rate (5/13) compared to intermediate (3/18) and high differentiation (0/4). Tumours with retiform pattern or heterologous elements showed a high relapse rate, too (5/11). After a median follow-up of 62months, event-free survival is 0.70\ub10.07, relapse-free survival 0.81\ub10.06 and overall survival 0.87\ub10.05. CONCLUSIONS: Prognosis of SLCTs is determined by stage and histopathologic differentiation. Complete resection with careful avoidance of spillage is a prerequisite of cure. The impact of chemotherapy in incompletely resected and advanced stage tumours remains to be evaluated

Comparison of outcomes based on treatment algorithms for rhabdomyosarcoma of the bladder/prostate: combined results from the Children's Oncology Group, German Cooperative Soft Tissue Sarcoma Study, Italian Cooperative Group, and International Society of Pediatric Oncology Malignant Mesenchymal Tumors Committee

he purpose of this study was to determine patient characteristics and outcomes for bladder/prostate (BP) rhabdomyosarcoma (RMS) using an international cohort of prospectively treated patients comparing different treatment algorithms. Data were collected from 379 patients (1979-1998) treated on protocol; Intergroup Rhabdomyosarcoma Study, IRS-IV (n = 239 patients), International Society of Pediatric Oncology Malignant Mesenchymal Tumors (MMT) Committee MMT-84 and -89 (n = 74), Italian Cooperative Group, RMS-79 and RMS-88 Studies (n = 37) or German Cooperative Soft Tissue Sarcoma Study CWS-91 protocols (n = 29). A total of 322 (85%) patients had localized embryonal RMS (ERMS) and 27 had metastatic disease. Thirty patients (21 local disease; 9 metastatic) had nonembryonal BP RMS. Patients with localized ERMS had large tumors (64% >5 cm) that were invasive (54%) with uninvolved regional lymph nodes (N0, 93%). The 5-year failure-free survival (FFS) was 75% and the overall survival (OS) was 84%, with 89% of deaths attributed to disease. Treatment failures were usually local disease recurrence (60%). Predictors of FFS included T-stage (invasiveness), size, and histology. FFS was decreased for patients not receiving initial radiotherapy but this did not translate into a decreased OS. The 21 patients with localized nonembryonal BP RMS had a FFS and OS of 47%. The 36 patients with metastatic disease were more likely to be older and had large tumors that were invasive with alveolar histology and regional lymph node involvement. The 5-year FFS and OS were 41 and 44%, respectively. In conclusion, the majority of BP RMS patients had localized ERMS with a resultant good prognosis using current treatment algorithms. There were differences in FFS between treatment protocols but this did not result in an altered OS

The role of adjuvant chemotherapy in children and adolescents with surgically resected, high-risk adult-type soft tissue sarcomas.

PURPOSE: This analysis evaluates whether adjuvant chemotherapy can be recommended for high-risk, surgically-resected, adult-type non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) within the new European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) protocol. The Italian and German Cooperative Groups reviewed their data-bases, analyzing patients classified as group I-II, with high-grade tumor (G3) larger than 5 cm in size. METHODS: The analysis included 36 patients, and compared the clinical features and outcome of the group of 21 patients who received chemotherapy versus the group of 15 patients treated with local therapies only. RESULTS: For the series as a whole, 5-year event-free survival (EFS), metastasis-free survival (MFS), and overall survival (OS) were 26.2%, 34.0%, and 37.5%, respectively. In patients treated with chemotherapy, MFS and OS were 49.5% and 41.5% (median time to relapse: 13 months). In patients who did not receive chemotherapy, MFS and OS were 0% and 23.8% (median time to relapse: 3 months). CONCLUSION: The role of adjuvant chemotherapy in NRSTS is still uncertain, however, the current retrospective analysis showed that: (1) despite the globally good prognosis of grossly-resected cases, patients with G3 and large-size have a high-risk of metastatic spread, and (2) MFS appears to be better in patients who had chemotherapy. Based in part on these results, and in accordance with recent suggestions coming from the literature on adult sarcomas, the EpSSG NRSTS protocol will recommend adjuvant chemotherapy in high-risk surgically-resected patients

Heat shock treatments delay the increase in wound-induced phenylalanine ammonia-lyase activity by altering its expression, not its induction in Romaine lettuce (Lactuca sativa) tissue

Wounding lettuce (Lactuca sativa L., var. Longifolia) leaves induced an eight-fold increase in the activity of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), and the subsequent accumulation of phenolic compounds and tissue browning at 10degreesC. PAL is a key enzyme in the synthesis of phenolic compounds. A PAL cDNA was previously isolated by reverse-transcription PCR using total RNA from wounded lettuce leaves. RNA gel blots showed that maximum accumulation of both PAL mRNA and PAL enzyme activity occurred 24 h after wounding. A 2-min heat shock at 45degreesC administered within 5 min of wounding delayed the wound-induced increase in PAL activity, but did not delay the increase in wound-induced PAL mRNA. Changes in the content of PAL protein were also followed by immunoblot using anti-PAL antibody raised against the bacterially expressed protein from the cDNA. Immunoblots showed that the level of PAL protein in wounded lettuce tissue was significantly reduced by the heat shock treatment. These data suggest that heat shock reduces the rise in wound-induced PAL enzyme activity by reducing the translation of wound-induced PAL mRNA, or by increasing the turnover of the induced PAL protein