Biosimilar filgrastim treatment patterns and prevention of febrile neutropenia: a prospective multicentre study in France in patients with solid tumours (the ZOHé study).

BACKGROUND: The ZOHé study was a prospective, non-interventional, multicentre study in France to assess the use of biosimilar filgrastim Zarzio® (Sandoz filgrastim) in routine clinical practice in patients at risk of neutropenia-inducing chemotherapy (CT). METHODS: Patients ≥ 18 years undergoing CT for a malignant disease and with a first prescription for Zarzio® were enrolled in two cohorts according to tumour type: solid tumour or haematological malignancy; results from the solid tumour cohort are reported here. Analyses primarily described the prescription and use of Zarzio® in current practice, and also included identification of factors linked to prescription for primary prophylaxis and comparison of Zarzio® use in relation to European Organisation for Research and Treatment of Cancer (EORTC) guidelines. RESULTS: Responses were obtained from 125 physicians and 1179 patients with solid tumours, allowing robust statistical analysis of the data. Use of Zarzio® in clinical practice was relatively standardised and followed label indication. The patient profile was in line with EORTC guidelines for granulocyte colony-stimulating factor (G-CSF) febrile neutropenia (FN) prophylaxis, and the majority of patients had ≥ 1 EORTC factor(s) for increased risk of febrile neutropenia. Some patients (10.8%) received Zarzio® despite receiving CT regimens categorised in guidelines as low (< 10%) FN risk ('over prophylaxis'). Nearly half of patients' CT regimens did not have a recommended FN risk category. Zarzio® was commonly initiated as primary prophylaxis; initiation in Cycle ≥ 2 of the current line of CT was associated more with a history of neutropenia. The safety profile of Zarzio® was confirmed. CONCLUSIONS: Use of Zarzio® in routine clinical practice is generally in line with EORTC guidelines for prophylaxis of CT-induced neutropenia. Patient-related risk factors appear to be a stronger driver of clinicians' decision to initiate Zarzio® than CT risk category for FN. The intrinsic risk of FN associated with a specific CT protocol is often miscategorised by physicians. In contrast to earlier reports of underuse of G-CSF prophylaxis, over prophylaxis is observed in a small subgroup of patients with FN risk of < 10%.

ZOHé: A Prospective Study of the Use of Biosimilar Filgrastim Zarzio in Clinical Practice in Patients Treated With Chemotherapy for Lymphoid Malignancies.

BACKGROUND: The ZOHé study was a prospective, observational, multicenter study in France to assess use of biosimilar filgrastim Zarzio in routine clinical practice in patients undergoing neutropenia-inducing chemotherapy. PATIENTS AND METHODS: Patients ≥ 18 years undergoing chemotherapy for a malignant disease and with a first prescription for Zarzio were enrolled in 2 cohorts: solid tumor (1174 patients) or hematological malignancy (633 patients); the latter is reported here. Analyses primarily described the prescription and use of Zarzio in current practice, and included identification of factors linked to prescription for primary prophylaxis, comparison of use in relation to European Organisation for the Research and Treatment of Cancer (EORTC) guidelines, and estimation of chemotherapy dose intensity maintenance in patients given Zarzio. RESULTS: Use of Zarzio in clinical practice was relatively standardized and followed label indication in 96.7% of the analysis population (633 patients). Most patients had ≥ 2 EORTC patient-related risk factors for febrile neutropenia (FN). Chemotherapy dose intensity was maintained in 85.2% of evaluable patients and 89.6% of patients with non-Hodgkin lymphoma receiving R-CHOP (rituximab-cyclophosphamide/doxorubicin/vincristine/prednisone). The safety profile of Zarzio was confirmed. CONCLUSIONS: In routine clinical practice in France, Zarzio is mostly used as primary prophylaxis for chemotherapy-induced neutropenia in patients with hematological malignancies. Patient-related risk factors appear to have more weight in clinicians' decisions to give Zarzio than the FN risk category of the chemotherapy regimen alone in real-world practice.

Zarzio®, biosimilar of filgrastim, in prophylaxis of chemotherapy-induced neutropenia in routine practice: a French prospective multicentric study.

PURPOSE: Chemotherapy-induced neutropenia is a serious and potentially life-threatening consequence of cancer treatment. Prophylactic treatment with granulocyte-colony stimulating factor (G-CSF) decreases the incidence of febrile neutropenia, the rate of hospitalization, and the use of antibiotics in patients at risk. The aim of this study was to assess efficacy, safety, and use of Zarzio(®)-biosimilar of Neupogen(®) (G-CSF; filgrastim)-in prophylaxis of chemotherapy-induced neutropenia in current practice in cancer patients. METHODS: We conducted an observational, prospective, longitudinal, and multicentric study in France. The incidence of neutropenia was evaluated at each cycle of chemotherapy. RESULTS: One hundred eighty-four patients (women, 64.7 %; mean age, 61.7 years) with solid tumor (89.7 %; breast cancer, 50.5 %) or non-Hodgkin lymphoma (10.3 %) were included. The risk of febrile neutropenia based on chemotherapy regimen was >20 % for 32.1 % of patients. No case of febrile neutropenia was reported. Neutropenia was the cause of hospitalization and/or antibiotic therapy in 10 patients. The most frequent adverse events related to Zarzio(®) were pain, in particular bone pain. No serious adverse event related to Zarzio(®) was reported. CONCLUSION: The results obtained in real-life conditions confirm that Zarzio(®) is efficient and well tolerated in cancer patients.

Intracellular itinerary of internalised ß-secretase, BACE1, and its potential impact on ß-amyloid peptide biogenesis.

ß-Secretase (BACE1) cleavage of the amyloid precursor protein (APP) represents the initial step in the formation of the Alzheimer's disease associated amyloidogenic Aß peptide. Substantive evidence indicates that APP processing by BACE1 is dependent on intracellular sorting of this enzyme. Nonetheless, knowledge of the intracellular trafficking pathway of internalised BACE1 remains in doubt. Here we show that cell surface BACE1 is rapidly internalised by the AP2/clathrin dependent pathway in transfected cells and traffics to early endosomes and Rab11-positive, juxtanuclear recycling endosomes, with very little transported to the TGN as has been previously suggested. Moreover, BACE1 is predominantly localised to the early and recycling endosome compartments in different cell types, including neuronal cells. In contrast, the majority of internalised wild-type APP traffics to late endosomes/lysosomes. To explore the relevance of the itinerary of BACE1 on APP processing, we generated a BACE1 chimera containing the cytoplasmic tail of TGN38 (BACE/TGN38), which cycles between the cell surface and TGN in an AP2-dependent manner. Wild-type BACE1 is less efficient in Aß production than the BACE/TGN38 chimera, highlighting the relevance of the itinerary of BACE1 on APP processing. Overall the data suggests that internalised BACE1 and APP diverge at early endosomes and that Aß biogenesis is regulated in part by the recycling itinerary of BACE1.

Arl5b is a Golgi-localised small G protein involved in the regulation of retrograde transport.

Regulation of membrane transport is controlled by small G proteins, which include members of the Rab and Arf families. Whereas the role of the classic Arf family members are well characterized, many of the Arf-like proteins (Arls) remain poorly defined. Here we show that Arl5a and Arl5b are localised to the trans-Golgi in mammalian cells, and furthermore have identified a role for Arl5b in the regulation of retrograde membrane transport from endosomes to the trans-Golgi network (TGN). The constitutively active Arl5b (Q70L)-GFP mutant was localised efficiently to the Golgi in HeLa cells whereas the dominant-negative Arl5b (T30N)-GFP mutant was dispersed throughout the cytoplasm and resulted in perturbation of the Golgi apparatus. Stable HeLa cells expressing GFP-tagged Arl5b (Q70L) showed an increased rate of endosome-to-Golgi transport of the membrane cargo TGN38 compared with control HeLa cells. Depletion of Arl5b by RNAi resulted in an alteration in the intracellular distribution of mannose-6-phosphate receptor, and significantly reduced the endosome-to-TGN transport of the membrane cargo TGN38 and of Shiga toxin, but had no affect on the anterograde transport of the cargo E-cadherin. Collectively these results suggest that Arl5b is a TGN-localised small G protein that plays a key role in regulating transport along the endosome-TGN pathway.

KIF20A mRNA and its product MKlp2 are increased during hepatocyte proliferation and hepatocarcinogenesis.

Mitotic kinesin-like protein 2 (MKlp2), a microtubule-associated motor, is required during mitosis exit for the final step of cytokinesis. It also contributes to retrograde vesicular trafficking from the Golgi apparatus to the endoplasmic reticulum in interphase. The KIF20A gene encoding MKlp2 is controlled by the E2F-retinoblastoma protein-p16 pathway, and its widely expressed mRNA is found in fetal and proliferating adult tissues. The expression pattern and function of MKlp2 in the adult liver, however, have not been investigated. We report herein that MKlp2 transiently accumulates in vivo during mouse liver regeneration after partial hepatectomy and is strongly overexpressed in preneoplastic and neoplastic mouse liver. In vitro in mitogen-stimulated primary hepatocytes, MKlp2 accumulated in the nucleus during the G2 phase of the cell cycle coincident with the mitotic kinase Aurora B. Human hepatoma cell lines exhibited high levels of MKlp2; however, it was undetectable in normal human hepatocytes. RNAi-mediated MKlp2 knockdown in hepatoma cells induced polyploidization consistent with its essential function in promoting cytokinesis and inhibited cell proliferation without inducing apoptosis. KIF20A mRNA was strongly accumulated in a large series of human hepatocellular carcinomas, with the highest expression observed in tumors with genomic instability. Accumulation of MKlp2 in normal proliferating, preneoplastic, and transformed hepatocytes suggests that MKlp2 contributes to both normal and pathologic hepatocyte proliferation and is linked to tumor aggressiveness in human hepatocellular carcinomas.

Identification of an endocytosis motif in an intracellular loop of Wntless protein, essential for its recycling and the control of Wnt protein signaling.

The secretion of Wnt signaling proteins is dependent upon the transmembrane sorting receptor, Wntless (Wls), which recycles between the trans-Golgi network and the cell surface. Loss of Wls results in impairment of Wnt secretion and defects in development and homeostasis in Drosophila, Caenorhabditis elegans, and the mouse. The sorting signals for the internalization and trafficking of Wls have not been defined. Here, we demonstrate that Wls internalization requires clathrin and dynamin I, components of the clathrin-mediated endocytosis pathway. Moreover, we have identified a conserved YXXϕ endocytosis motif in the third intracellular loop of the multipass membrane protein Wls. Mutation of the tyrosine-based motif YEGL to AEGL (Y425A) resulted in the accumulation of human mutant Wls on the cell surface of transfected HeLa cells. The cell surface accumulation of Wls(AEGL) was rescued by the insertion of a classical YXXϕ motif in the cytoplasmic tail. Significantly, a Drosophila Wls(AEGL) mutant displayed a wing notch phenotype, with reduced Wnt secretion and signaling. These findings demonstrate that YXXϕ endocytosis motifs can occur in the intracellular loops of multipass membrane proteins and, moreover, provide direct evidence that the trafficking of Wls is required for efficient secretion of Wnt signaling proteins.

Rab9-dependent retrograde transport and endosomal sorting of the endopeptidase furin.

The endopeptidase furin and the trans-Golgi network protein TGN38 are membrane proteins that recycle between the TGN and plasma membrane. TGN38 is transported by a retromer-dependent pathway from early endosomes to the TGN, whereas the intracellular transport of furin is poorly defined. Here we have identified the itinerary and transport requirements of furin. Using internalisation assays, we show that furin transits the early and late endosomes en route to the TGN. The GTPase Rab9 and the TGN golgin GCC185, components of the late endosome-to-TGN pathway, were required for efficient TGN retrieval of furin. By contrast, TGN38 trafficking was independent of Rab9 and GCC185. To identify the sorting signals for the early endosome-to-TGN pathway, the trafficking of furin-TGN38 chimeras was investigated. The diversion of furin from the Rab9-dependent late-endosome-to-TGN pathway to the retromer-dependent early-endosome-to-TGN pathway required both the transmembrane domain and cytoplasmic tail of TGN38. We present evidence to suggest that the length of the transmembrane domain is a contributing factor in endosomal sorting. Overall, these data show that furin uses the Rab9-dependent pathway from late endosomes and that retrograde transport directly from early endosomes is dependent on both the transmembrane domain and the cytoplasmic tail.

MD-2 controls bacterial lipopolysaccharide hyporesponsiveness in human intestinal epithelial cells.

Intestinal epithelial cells (IEC) have adapted to the presence of commensal bacteria through a state of tolerance that involves a limited response to lipopolysaccharide (LPS). Low or absent expression of two LPS receptor molecules, the myeloid differentiation (MD)-2 receptor, and toll-like receptor (TLR)4 was suggested to underlie LPS tolerance in IEC. In the present study we performed transfections of TLR4 and MD-2 alone or combined in different IEC lines derived from intestinal cancer (Caco-2, HT-29, and SW837). We found that LPS responsiveness increased more than 100-fold when IEC were transfected with MD-2 alone, but not TLR4. The release of interleukin (IL)-8, but also the expression of cyclooxygenase (Cox-)2 and the related secretion of prostaglandin (PG)E2 were coordinately stimulated by LPS in IEC transfected with MD-2 alone. Supernatants collected from MD-2-transfected IEC supported LPS activation of naïve HT-29, providing additional support to the concept that MD-2 alone endows IEC with LPS responsiveness. LPS responsiveness detected at concentrations as low as 110 pg/ml, and maximal values obtained by 10 ng/ml were clearly beyond those evoked by classical stimuli as IL-1beta. In polarized cells, apical LPS stimulation was markedly more efficient than basolateral. Our data contradict previous opinion that both TLR4 and MD-2 limit IEC response to LPS, and emphasize the prominent role of MD-2 in intestinal immune responses to Gram-negative bacteria.

Flow cytometry to sort mammalian cells in cytokinesis.

BACKGROUND: Cell division or cytokinesis, which results from a series of events starting in metaphase, is the mechanism by which the mother cell cytoplasm is divided between the two daughter cells. Hence it is the final step of the cell division cycle. The aim of the present study was to demonstrate that mammalian cells undergoing cytokinesis can be sorted selectively by flow cytometry. MATERIALS AND METHODS: Cultures of HeLa cells were arrested in prometaphase by nocodazole, collected by mitotic shake-off and released for 90 min into fresh medium to enrich for cells undergoing cytokinesis. After ethanol fixation and DNA staining, cells were sorted based on DNA content and DNA fluorescence signal height. RESULTS: We define a cell population that transiently accumulates when synchronized cells exit mitosis before their entry into G1. We show that this population is highly enriched in cells undergoing cytokinesis. In addition, this population of cells can be sorted and analyzed by immunofluorescence and western blotting. CONCLUSIONS: This method of cell synchronization and sorting provides a simple means to isolate and biochemically analyze cells in cytokinesis, a period of the cell cycle that has been difficult to study by cell fractionation.