Induction chemotherapy followed by chemoradiotherapy versus chemoradiotherapy alone as neoadjuvant treatment for locally recurrent rectal cancer: study protocol of a multicentre, open-label, parallel-arms, randomized controlled study (PelvEx II)

Background A resection with clear margins (R0 resection) is the most important prognostic factor in patients with locally recurrent rectal cancer (LRRC). However, this is achieved in only 60 per cent of patients. The aim of this study is to investigate whether the addition of induction chemotherapy to neoadjuvant chemo(re)irradiation improves the R0 resection rate in LRRC. Methods This multicentre, international, open-label, phase III, parallel-arms study will enrol 364 patients with resectable LRRC after previous partial or total mesorectal resection without synchronous distant metastases or recent chemo- and/or radiotherapy treatment. Patients will be randomized to receive either induction chemotherapy (three 3-week cycles of CAPOX (capecitabine, oxaliplatin), four 2-week cycles of FOLFOX (5-fluorouracil, leucovorin, oxaliplatin) or FOLFORI (5-fluorouracil, leucovorin, irinotecan)) followed by neoadjuvant chemoradiotherapy and surgery (experimental arm) or neoadjuvant chemoradiotherapy and surgery alone (control arm). Tumours will be restaged using MRI and, in the experimental arm, a further cycle of CAPOX or two cycles of FOLFOX/FOLFIRI will be administered before chemoradiotherapy in case of stable or responsive disease. The radiotherapy dose will be 25 × 2.0 Gy or 28 × 1.8 Gy in radiotherapy-naive patients, and 15 × 2.0 Gy in previously irradiated patients. The concomitant chemotherapy agent will be capecitabine administered twice daily at a dose of 825 mg/m2 on radiotherapy days. The primary endpoint of the study is the R0 resection rate. Secondary endpoints are long-term oncological outcomes, radiological and pathological response, toxicity, postoperative complications, costs, and quality of life. Discussion This trial protocol describes the PelvEx II study. PelvEx II, designed as a multicentre, open-label, phase III, parallel-arms study, is the first randomized study to compare induction chemotherapy followed by neoadjuvant chemo(re)irradiation and surgery with neoadjuvant chemo(re)irradiation and surgery alone in patients with locally recurrent rectal cancer, with the aim of improving the number of R0 resections

Furin and proprotein convertase 7 (PC7) lymphoma PC endogenously expressed in rat liver can be resolved into distinct post-Golgi compartments

The intracellular compartmentalization in rat liver of the membrane-associated convertases furin and proprotein convertase 7 (PC7)/lymphoma PC (LPC) was investigated by analytical subcellular fractionation. In control animals, both enzymes were found to localize in fractions depleted of endoplasmic reticulum, cis-Golgi and lysosomal markers, but to co-distribute with the Golgi marker galactosyltransferase and the trans-Golgi network (TGN) marker TGN38. After over-loading Golgi-derived vesicles with very-low-density lipoproteins (VLDL) by feeding rats with ethanol, the distribution of PC7/LPC was shifted markedly towards lower densities, in contrast with those of furin and the TGN marker. This provides support for the TGN localization of endogenously expressed furin and indicates that, at steady state, a considerable proportion of PC7/LPC may be associated with vesicles derived from the TGN

Notch1 Autoactivation via Transcriptional Regulation of Furin, Which Sustains Notch1 Signaling by Processing Notch1-Activating Proteases ADAM10 and Membrane Type 1 Matrix Metalloproteinase

Notch1 is an evolutionarily conserved transmembrane receptor involved in melanoma growth. Notch1 is first cleaved by furin in the Golgi apparatus to produce the biologically active heterodimer. Following ligand binding, Notch1 is cleaved at the cell mem-brane by proteases such as ADAM10 and-17 andmembrane type 1 matrix metalloproteinase (MT1-MMP), the latter of which we recently identified as a novel protease involved in Notch1 processing. The final cleavage is -secretase dependent and releases the active Notch intracellular domain (NIC). We now demonstrate that Notch1 directly regulates furin expression. Aside from acti-vating Notch1, furin cleaves and activates several proteases, includingMT1-MMP, ADAM10, and ADAM17. By chromatin im-munoprecipitation and a reporter assay, we demonstrate that Notch1 binds at position1236 of the furin promoter and drives furin expression. The Notch1-dependent enhancement of furin expression increases the activities of MT1-MMP and ADAM10 but not that of ADAM17, as demonstrated by short hairpin RNA (shRNA) knockdown of furin, and promotes the cleavage of Notch1 itself. These data highlight a novel positive-feedback loop whereby Notch1-dependent furin expression can induce Notch1 signaling by increasing Notch1 processing and by potentiating the activity of the proteases responsible for Notch1 acti-vation. This leads to Notch1 signal amplification, which can promote melanoma tumor growth and progression, as demon-strated by the inhibition of cell migration and invasion upon furin inhibition downstream of Notch1. Disruption of such feed-back signaling might represent an avenue for the treatment of melanoma. Melanoma is the deadliest form of skin cancer, causing ap-proximately 50,000 deaths a year, despite promising ne

A nonsense loss-of-function mutation in PCSK1 contributes to dominantly inherited human obesity

International audienceBackground: A significant proportion of severe familial forms of obesity remain genetically elusive. Taking advantage of our unique cohort of multigenerational obese families, we aimed to assess the contribution of rare mutations in 29 common obesity-associated genes to familial obesity, and to evaluate in these families the putative presence of nine known monogenic forms of obesity. Methods: Through next-generation sequencing, we sequenced the coding regions of 34 genes involved in polygenic and/or monogenic forms of obesity in 201 participants (75 normal weight individuals, 54 overweight individuals and 72 individuals with obesity class I, II or III) from 13 French families. In vitro functional analyses were performed to investigate the mutation PCSK1-p.Arg80* which was identified in a family. Results: A novel heterozygous nonsense variant in PCSK1 (p.Arg80*), encoding a propeptide truncated to less than two exons (out of 14), was found to co-segregate with obesity in a three-generation family. We demonstrated that this mutation inhibits PCSK1 enzyme activity and that this inhibition most likely does not involve a strong physical interaction. Furthermore, both mutations PCSK1-p.Asn180Ser and POMC-p.Phe144Leu, which had previously been reported to be associated with severe obesity, were also identified in this study, but did not co-segregate with obesity. Finally, we did not identify any rare mutations co-segregating with obesity in common obesity susceptibility genes, except for CADM2 and QPCTL, where we found two novel variants (p.Arg81His and p.Leu98Pro, respectively) in three obese individuals. Conclusions: We showed for the first time that a nonsense mutation in PCSK1 was likely to cause dominantly inherited human obesity, due to the inhibiting properties of the propeptide fragment encoded by the null allele. Furthermore, the present family sequencing design challenged the contribution of previously reported mutations to monogenic or at least severe obesity