High body condition score combined with a reduced lambing to ram introduction interval improves the short-term ovarian response of milking Lacaune ewes to the male effect.

The male effect is an effective natural technique to induce off-season ovulation and ultimately mating or artificial insemination in small ruminants. It constitutes an alternative to hormonal treatments in conventional breeding systems and, to shift and organise the yearly production cycle, is currently the only solution complying with European organic standards. However, its associated performances are still heterogeneous, both in terms of the global response and the extent of reproductive synchronisation of the females, due to complex interactions with environmental factors that limit its use on commercial farms. This study was carried out on a French organic farm under commercial conditions to investigate, in the field and across five consecutive years, the main parameters affecting the early ovarian response to a ram effect on Lacaune dairy ewes. While the within-year binary logistic regressions yielded contrasting results, the cross-year mixed-effect binary logistic regression models clearly showed that parameters associated with the nutritional state of the animals have a profound influence on the ovarian response of the ewes. Indeed, the probabilities of a spontaneous resumption of ovarian activity before the ram effect and of an early ovarian response to the ram effect were positively associated with the body condition score, total milk production and the age of the animals, while being negatively associated with the milk production level at the 3rd milk recording. The probabilities of a spontaneous resumption of ovarian activity before the ram effect were positively associated with the interval between lambing and the introduction of the rams. Altogether, these results indicate that the ovarian performances in response to a male effect follow a bell-curve pattern with optimal performances depending upon a complex combination between photoperiodic and nutritional cues. Regarding these latter, this study highlights the major contribution of body reserves and energy balance dynamics.

Medical students' learning processes the first time they role-play in psychiatry: A grounded theory study.

BACKGROUND: Recent changes in psychiatric care and teaching that limit patient contact for medical students can be overcome in part by simulation-based education. Understanding the learning processes of medical students involved in psychiatric simulation-based programmes could usefully inform efforts to improve this teaching. This study explored the learning processes of medical students the first time they role-play in psychiatry. METHODS: We used constructivist grounded theory to analyse semi-structured interviews of 13 purposively sampled medical students and the six psychiatrists who trained them. To improve the triangulation process, the results of this analysis were compared with those of the analyses of the role-play video and the debriefing audio-tapes. RESULTS: Five organising themes emerged: improving the students' immediate perception of patients with mental disorders; cultivating clinical reasoning; managing affect; enhancing skills and attitudes and fostering involvement in learning psychiatry. CONCLUSION: Results suggest that psychiatric role-playing can improve students' progressive understanding of psychiatry through the development of intuition and by allaying affects. Emotional elaboration and student involvement appear to be key features.

[Serious video games in pediatrics]. / Les jeux vidéo sérieux en pédiatrie.

Playing video games has been associated with several negative effects in children. However, serious games, which are video games designed for a primary purpose other than pure entertainment, should not be neglected by pediatricians. In the field of public health, some serious games are a means to decrease drug consumption and improve sexual health behavior in adolescents. In schools, serious games can be used to change students' perception of the disease of one of their classmates, or to train students on basic life support. Serious games are also used with patients: they can distract them from a painful procedure, increase their compliance to treatments, or participate in their rehabilitation. Finally, serious games allow healthcare professionals to train on the management of various medical situations without risk. For every field of application, this review presents the rationale of the use of video games, followed by concrete examples of video games and the results of their scientific evaluation.

Impact of sleep deprivation on anaesthesia residents' non-technical skills: a pilot simulation-based prospective randomized trial.

BACKGROUND: Sleep deprivation is common in anaesthesia residents, but its impact on performance remains uncertain. Non-technical skills (team working, situation awareness, decision making, and task management) are key components of quality of care in anaesthesia, particularly in crisis situations occurring in the operating room. The impact of sleep deprivation on non-technical skills is unknown. We tested the hypothesis that in anaesthesia residents sleep deprivation is associated with impaired non-technical skills. METHODS: Twenty anaesthesia residents were randomly allocated to undergo a simulation session after a night shift [sleep-deprived (SLD) group, n =10] or after a night of rest [rested (R) group, n =10] from January to March 2015. The simulated scenario was a situation of crisis management in the operating room. The primary end point was a composite score of anaesthetists' non-technical skills (ANTS) assessed by two blinded evaluators. RESULTS: Non-technical skills were significantly impaired in the SLD group [ANTS score 12.2 (interquartile range 10.5-13)] compared with the R group [14.5 (14-15), P <0.02]. This difference was mainly accounted for by a difference in the team working item. On the day of simulation, the SLD group showed increased sleepiness and decreased confidence in anaesthesia skills. CONCLUSIONS: In this randomized pilot trial, sleep deprivation was associated with impaired non-technical skills of anaesthesia residents in a simulated anaesthesia intraoperative crisis scenario. TRIAL REGISTRATION: NCT02622217.

[Learning the gynecological examination on low-fidelity simulation: Impact on the feelings of medical students]. / Apprentissage de l'examen gynécologique sur simulateur : impact sur le ressenti des étudiants en médecine.

OBJECTIVES: The use of anatomic model is particularly suitable for teaching gynecological examination. Although simulation training was proved to be effective in improving medical students' technical skills, its interest in reducing their apprehension about pelvic examination was poorly evaluated. The aim of the present study was to evaluate low-fidelity simulation sessions to reduce the discomfort and apprehension of medical students towards gynecological examination. The secondary objective was to appreciate student satisfaction with these sessions. METHODS: Descriptive analysis of simulation-based teaching of breast and pelvic examination on Ilumens platform at the university Paris 5 among 3rd and 4th year medical students. It consisted in a before/after evaluation, using an anonymous questionnaire of self-evaluation and satisfaction at the beginning and at the end of the session. RESULTS: Four hundred and thirty-two students answered both questionnaires. Seventy-two percent apprehended the pelvic examination initially and 62% were uncomfortable with the idea of performing it. Among the students who had never performed pelvic examination, more than 80% felt less uncomfortable with the idea of performing pelvic examination and were less apprehensive about it at the end of the simulation session. CONCLUSION: The benefits of low-fidelity simulation in gynecology extend to the well-being of medical students who are less apprehensive about performing gynecological examination.

Improving students' ability to perform a standardized foetal biometry plane using ultrasound simulators.

OBJECTIVE: The objective of this study is to assess progress made in the ultrasound (US) measurement of femur length (FL) by students after one hour of training on US obstetric simulators. MATERIALS AND METHODS: Medical residents and midwives registered for the 2016 French national foetal US diploma were invited to a 1-hour US training course with simulators. The time to acquire the FL plane with changing foetal presentation was prospectively measured before and after the training. Every image was recorded, and quality criteria were assessed. RESULTS: Thirty new learners trained in foetal US were evaluated. The time needed to measure the FL was significantly shorter in the post-test versus the pre-test (86s versus 125, P=0.015). The quality criteria were statistically similar before and after training regarding the angle to horizontal (10.0° versus 9.6°, P=0.84) and FL (31.3mm versus 32.0mm, P=0.15). CONCLUSION: The time needed to obtain the FL plane was reduced by 30% after a 1-hour US simulation training session.

Improving the quality of transvaginal ultrasound scan by simulation training for general practice residents.

BACKGROUND: Ultrasonography (US) is an essential tool for the diagnosis of acute gynecological conditions. General practice (GP) residents are involved in the first-line management of gynecologic emergencies. They are not familiar with US equipment. Initial training on simulators was conducted.The aim of this study was to evaluate the impact of simulation-based training on the quality of the sonographic images achieved by GP residents 2 months after the simulation training versus clinical training alone. METHODS: Young GP residents assigned to emergency gynecology departments were invited to a one-day simulation-based US training session. A prospective controlled trial aiming to assess the impact of such training on TVS (transvaginal ultrasound scan) image quality was conducted. The first group included GP residents who attended the simulation training course. The second group included GP residents who did not attend the course. Written consent to participate was obtained from all participants. Images achieved 2 months after the training were scored using standardized quality criteria and compared in both groups. The stress generated by this examination was also assessed with a simple numeric scale. RESULTS: A total of 137 residents attended the simulation training, 26 consented to participate in the controlled trial. Sonographic image quality was significantly better in the simulation group for the sagittal view of the uterus (3.6 vs 2.7, p = 0.01), for the longitudinal view of the right ovary (2.8 vs 1.4, p = 0.027), and for the Morrison space (1.7 vs 0.4, p = 0.034), but the difference was not significant for the left ovary (2.9 vs 1.7, p = 0.189). The stress generated by TVS after 2 months was not different between the groups (6.0 vs 4.8, p = 0.4). CONCLUSION: Simulation-based training improved the quality of pelvic US images in GP residents assessed after 2 months of experience in gynecology compared to clinical training alone.

[Computerized ranking test in three French universities: Staff experience and students' feedback]. / Épreuves informatisées de type ECNi: retour d'expérience sur un test multiuniversité.

BACKGROUND: The year 2016 will be pivotal for the evaluation of French medical students with the introduction of the first computerized National Ranking Test (ECNi). The SIDES, online electronic system for medical student evaluation, was created for this purpose. All the universities have already organized faculty exams but few a joint computerized ranking test at several universities simultaneously. We report our experience on the organization of a mock ECNi by universities Paris Descartes, Paris Diderot and Paris 13. METHODS: Docimological, administrative and technical working groups were created to organize this ECNi. Students in their fifth year of medical studies, who will be the first students to sit for the official ECNi in 2016, were invited to attend this mock exam that represented more than 50% of what will be proposed in 2016. A final electronic questionnaire allowed a docimological and organizational evaluation by students. An analysis of ratings and rankings and their distribution on a 1000-point scale were performed. RESULTS: Sixty-four percent of enrolled students (i.e., 654) attended the three half-day exams. No difference in total score and ranking between the three universities was observed. Students' feedback was extremely positive. Normalized over 1000 points, 99% of students were scored on 300 points only. Progressive clinical cases were the most discriminating test. CONCLUSION: The organization of a mock ECNi involving multiple universities was a docimological and technical success but required an important administrative, technical and teaching investment.

[Remote dermatological advice: a survey in three French regions]. / Avis dermatologiques à distance : une enquête interrégionale.

BACKGROUND: General practitioners and specialists often seek advice from dermatologists based on digital pictures. This time-consuming activity is currently not valued nor well-established. We therefore conducted a survey to assess the extent and nature of such requests. PATIENTS AND METHODS: A questionnaire was sent to dermatologists working either at university hospitals or in private practice in three regions of France (Loire Atlantique, Rhone Alpes and Normandy). For two months, the dermatologists completed the same questionnaire for each specialized request. The following items were recorded: status of the dermatologist asked to provide a specialized opinion, region in which the request was made, status of the requesting practitioner, mode of request, type of disease, question asked, time taken to answer the request and result of the specialized advice. RESULTS: Thirty dermatologists, including 11 in private practice, participated in this study. We identified 287 requests. The majority of these requests came from general practitioners (30%) and dermatologists working in private practice (29%). These requests were sent by e-mail using a non-secure professional e-mail address in 49% of cases or via smartphone in 29% of cases. The purpose of the requests was either diagnostic/therapeutic (36%) or solely therapeutic (39%). Relevant requests concerned dermatological manifestations in paediatric or cancer patients (23% and 21% respectively), general dermatological diseases (21%) and wound management (14%). Nearly half of the specialized advice was provided in under 5minutes, and in 60% of cases a consultation with a dermatologist was avoided. CONCLUSION: Despite the small number of physicians taking part in the study, this non-exhaustive survey confirms the usefulness of remote dermatological reviews and consultations, and identifies the main intervening physicians involved in this type of procedure. The study also raises potential medico-legal issues regarding the lack of data security covering medical information. There is thus a need for dermatologists to organize their activity in order to respond to such requests without exposing themselves to medico-legal consequences.

The effects of parity, litter size, physiological state, and milking frequency on the metabolic profile of Lacaune dairy ewes.

Effects of parity (primiparous, PRIM vs multiparous, MULT) and litter size (singletons, SING vs twins, TWIN) on metabolic profiles from 1 wk before lambing to the end of lactation were studied in 48 Lacaune dairy ewes reared in confinement during most of the year and grazed on improved pastures at the end of lactation (summer). Another group of 48 ewes was incorporated during the milking period (ie, from 1 wk after weaning), to measure the effects of milking frequency (1 vs 2 milkings per day) on intake, milk production and composition, and body energy usage. Thus, in a 2 × 2 × 2 factorial design, ewes (n = 96) were allocated to homogeneous groups according to body weight (BW) and body condition score (BCS) and were monitored from late pregnancy to late lactation as a function of parity (PRIM, n = 48; MULT, n = 48), litter size (LSi) (SING, n = 40; TWIN, n = 56) and daily milking frequency (FREQ; milked once, ONE; n = 48; or twice, TWO; n = 48). Individual BW, BCS, plasma metabolites, and metabolic hormones were measured regularly (ie, 9 consecutive sampling dates). The BW was higher in MULT but no differences because of LSi or FREQ were detected at the intra-parity group level. The BCS was higher in MULT and in ewes with SING throughout the experiment. The latter was related to the demands for body reserves mobilization, as expressed by higher nonesterified fatty acids and ß-hydroxybutyrate concentrations in ewes with TWIN from late pregnancy to weaning (35 d postpartum) in both PRIM and MULT ewes. This was consistent with higher insulin in MULT and higher triiodothyronine, leptin and insulin-like growth factor 1 in ewes with SING during this period. Differences in energy balance because of FREQ were evident after interpretation of plasma nonesterified fatty acids, glucose, insulin, and leptin concentration during the milking period. At similar feed intakes, ewes in ONE were in positive balance with regard to TWO. Overall, clear effects of parity, LSi, physiological states, and FREQ on metabolic profiles were found because of differences in nutrient partitioning when combining these experimental factors. Without considering FREQ, changes in metabolic measures in milking period were marginal compared with the periparturient adjustments performed until weaning to compensate energy deficiencies.

[CO2 laser treatment of skin cylindromas in Brooke-Spiegler syndrome]. / Traitement des cylindromes cutanés par laser CO2 dans le syndrome de Brooke-Spiegler.

BACKGROUND: Multiple skin cylindromas are of autosomal dominant transmission and may be associated with spiradenoma and trichoepithelioma. This condition is known as Brooke-Spiegler syndrome. The aim of this study is to compare surgical and laser treatment for these lesions. CASE REPORTS: Five patients from a single family (two male and three female) consulted at the dermatology department for the treatment of multiple cylindromas of the scalp. The female patients presented a more severe form that had developed into "turban tumour". All patients were initially treated by surgery. Two had undergone multiple surgical excisions alone while the others had been treated with CO2 laser. One of the female patients treated with surgery had undergone complete excision of the scalp covered by total skin graft. The three patients treated with CO2 laser were completely satisfied with their therapy, which enabled a larger number of lesions to be treated at each session. They underwent one session every three months under local anaesthesia. CONCLUSION: CO2 laser constitutes an alternative to surgery in the treatment of multiple skin cylindroma. It gives excellent cosmetic result with excellent safety and a high degree of satisfaction among treated patients. It should be proposed for patients refusing surgery or where the number of lesions enables first-line use of this approach to be envisaged.

Circannual body reserve dynamics and metabolic profile changes in Romane ewes grazing on rangelands.

Throughout an entire year, 41 Romane ewes reared in an extensive rangeland were used to investigate temporal changes in body reserves (BRs) and profiles of related metabolites and metabolic hormones. Ewes were allocated to homogeneous groups according to BW and BCS and were distributed by parity (primiparous [PRIM], n = 21; multiparous [MULT], n = 20) and litter size (LSi; lambing singletons [SING], n = 21 or TWINS, n = 20). The feeding system was based on rotational grazing of rangeland paddocks and progressive supplementation with hay, silage, and barley at late pregnancy during the winter. Individual BW, BCS, plasma NEFA, ß-hydroxybutyrate (ß-OHB), glucose, insulin, leptin, and triiodothyronine (T3) were monitored at -56, -12, 8, 49, 76, 107, 156, 195, 216, 246, and 301 d relative to lambing. The BR mobilization was observed from late pregnancy to the end of suckling and varied as a function of the ewe energy balance but also because of transitions from fertilized to native rangeland paddocks and by supplementation. Contrarily, BR accretion occurred from weaning, during the dry-off, and until the start of the next pregnancy. Lipolysis was well reflected by NEFA, ß-OHB, and T3 kinetics. Mean BW (but not mean BCS) was affected by parity (MULT > PRIM), whereas both BW and BCS were influenced by LSi (SING > TWINS) but only for MULT. The most drastic BW loss was observed during the mid-suckling period (49 d in milk [DIM]) in all ewes. The lack of effects of LSi in PRIM but not in MULT was also evident in the majority of blood plasma kinetics, which were affected (P < 0.0001) by physiological stage in all ewes. A tendency to ketosis (ß-OHB) was found in ewes nursing TWINS around lambing, irrespective of parity. Glucose concentrations were greater during suckling and dry-off, and a peak (0.96 ± 0.05 g/L) was attained at 156 DIM in MULT nursing TWINS. The highest plasma leptin concentration was observed during the start and the middle of the next pregnancy in MULT (107-216 DIM; 9.6 ± 0.44 ng/mL). In all ewes the physiological stage affected T3, which was affected by LSi just in MULT (from late pregnancy, MULT by SING > MULT by TWINS; 99.91 vs 85.52 ng/dL) and during suckling (111.7 ± 4.18 ng/dL). Lamb BW was affected at birth and weaning by parity (MULT > PRIM) and LSi (SING > TWINS). Overall, temporal changes in BR were directly affected by the transition of physiological states and feeding levels, whereas individual responses were predetermined by parity. In MULT, the reactivity and magnitude of response was influenced by LSi. The whole set of parameters allowed us to detect sensitive and critical periods throughout the entire annual cycle. We thus identified opportunities for improved nutritional management, for example, during physiological states usually underestimated such as early and mid-pregnancy. This work indicates the applicability of long-term studies about BR dynamics in ruminants as a potential component contributing to farm economic resilience.

[Transfusion for post-partum haemorrhage: what's new in 2011?]. / Hémorragie du post-partum: actualités dans la prise en charge transfusionnelle.

Post-partum haemorrhage is the first cause of maternal death in France. In addition to the treatment of the cause, its treatment consists in the association of procoagulant drugs and blood transfusion. At risk situations requiring blood transfusion are well identified. However, they are not found in one third of the actually transfused patients. Therefore, for all deliveries, the medical team should be prepared to face a post-partum haemorrhage and to transfuse. As post-partum haemorrhage onset is most frequently acute, it is rare to be able to base the transfusion decision on biological parameters such as haemoglobin concentration and / or coagulation tests. The recently defined policy of early use of fresh frozen plasma in order to better control the coagulopathy frequently associated with a large haemorrhage has not been established in obstetrical situations. However, it is recommended to apply it in large volume post-partum haemorrhage, with a fresh frozen plasma/red blood cells concentrate ratio between 1/1 and 1/2. The post-partum haemorrhage treatment may benefit from the use of drugs, the most frequently used being antifibrinolytics, such as tranexemic acid, which help to reduce the magnitude of post-partum haemorrhage. Conversely, activated factor VII use should be restricted to situations where all other conventional treatments failed, as a last attempt to avoid hysterectomy.

Restoration of the immunogenicity of cisplatin-induced cancer cell death by endoplasmic reticulum stress.

In contrast to other cytotoxic agents including anthracyclins and oxaliplatin (OXP), cisplatin (CDDP) fails to induce immunogenic tumor cell death that would allow to stimulate an anticancer immune response and hence to amplify its therapeutic efficacy. This failure to induce immunogenic cell death can be attributed to CDDP's incapacity to elicit the translocation of calreticulin (CRT) from the lumen of the endoplasmic reticulum (ER) to the cell surface. Here, we show that, in contrast to OXP, CDDP is unable to activate the protein kinase-like ER kinase (PERK)-dependent phosphorylation of the eukaryotic translation initiation factor 2α (eIF2α). Accordingly, CDDP also failed to stimulate the formation of stress granules and macroautophagy, two processes that only occur after eIF2α phosphorylation. Using a screening method that monitors the voyage of CRT from the ER lumen to the cell surface, we identified thapsigargin (THAPS), an inhibitor of the sarco/ER Ca(2+)-ATPase as a molecule that on its own does not stimulate CRT exposure, yet endows CDDP with the capacity to do so. The combination of ER stress inducers (such as THAPS or tunicamycin) and CDDP effectively induced the translocation of CRT to the plasma membrane, as well as immunogenic cell death, although ER stress or CDDP alone was insufficient to induce CRT exposure and immunogenic cell death. Altogether, our results underscore the contribution of the ER stress response to the immunogenicity of cell death.

Immunogenic death of colon cancer cells treated with oxaliplatin.

Both the pre-apoptotic exposure of calreticulin (CRT) and the post-apoptotic release of high-mobility group box 1 protein (HMGB1) are required for immunogenic cell death elicited by anthracyclins. Here, we show that both oxaliplatin (OXP) and cisplatin (CDDP) were equally efficient in triggering HMGB1 release. However, OXP, but not CDDP, stimulates pre-apoptotic CRT exposure in a series of murine and human colon cancer cell lines. Subcutaneous injection of OXP-treated colorectal cancer (CRC), CT26, cells induced an anticancer immune response that was reduced by short interfering RNA-mediated depletion of CRT or HMGB1. In contrast, CDDP-treated CT26 cells failed to induce anticancer immunity, unless recombinant CRT protein was absorbed into the cells. CT26 tumors implanted in immunocompetent mice responded to OXP treatment in vivo, and this therapeutic response was lost when CRT exposure by CT26 cells was inhibited or when CT26 cells were implanted in immunodeficient mice. The knockout of toll-like receptor 4 (TLR4), the receptor for HMGB1, also resulted in a deficient immune response against OXP-treated CT26 cells. In patients with advanced (stage IV, Duke D) CRC, who received an OXP-based chemotherapeutic regimen, the loss-of-function allele of TLR4 (Asp299Gly in linkage disequilibrium with Thr399Ile, reducing its affinity for HMGB1) was as prevalent as in the general population. However, patients carrying the TLR4 loss-of-function allele exhibited reduced progression-free and overall survival, as compared with patients carrying the normal TLR4 allele. In conclusion, OXP induces immunogenic death of CRC cells, and this effect determines its therapeutic efficacy in CRC patients.

Calreticulin exposure on malignant blasts predicts a cellular anticancer immune response in patients with acute myeloid leukemia.

Experiments performed in mice revealed that anthracyclines stimulate immunogenic cell death that is characterized by the pre-apoptotic exposure of calreticulin (CRT) on the surface of dying tumor cells. Here, we determined whether CRT exposure at the cell surface (ecto-CRT) occurs in human cancer in response to anthracyclines in vivo, focusing on acute myeloid leukemia (AML), which is currently treated with a combination of aracytine and anthracyclines. Most of the patients benefit from the induction chemotherapy but relapse within 1-12 months. In this study, we investigated ecto-CRT expression on malignant blasts before and after induction chemotherapy. We observed that leukemic cells from some patients exhibited ecto-CRT regardless of chemotherapy and that this parameter was not modulated by in vivo chemotherapy. Ecto-CRT correlated with the presence of phosphorylated eIF2α within the blasts, in line with the possibility that CRT exposure results from an endoplasmic reticulum stress response. Importantly, high levels of ecto-CRT on malignant myeloblasts positively correlated with the ability of autologous T cells to secrete interferon-γ on stimulation with blast-derived dendritic cell. We conclude that the presence of ecto-CRT on leukemia cells facilitates cellular anticancer immune responses in AML patients.

The co-translocation of ERp57 and calreticulin determines the immunogenicity of cell death.

The exposure of calreticulin (CRT) on the plasma membrane can precede anthracycline-induced apoptosis and is required for cell death to be perceived as immunogenic. Mass spectroscopy, immunofluorescence and immunoprecipitation experiments revealed that CRT co-translocates to the surface with another endoplasmic reticulum-sessile protein, the disulfide isomerase ERp57. The knockout and knockdown of CRT or ERp57 inhibited the anthracycline-induced translocation of ERp57 or CRT, respectively. CRT point mutants that fail to interact with ERp57 were unable to restore ERp57 translocation upon transfection into crt(-/-) cells, underscoring that a direct interaction between CRT and ERp57 is strictly required for their co-translocation to the surface. ERp57(low) tumor cells generated by retroviral introduction of an ERp57-specific shRNA exhibited a normal apoptotic response to anthracyclines in vitro, yet were resistant to anthracycline treatment in vivo. Moreover, ERp57(low) cancer cells (which failed to expose CRT) treated with anthracyclines were unable to elicit an anti-tumor response in conditions in which control cells were highly immunogenic. The failure of ERp57(low) cells to elicit immune responses and to respond to chemotherapy could be overcome by exogenous supply of recombinant CRT protein. These results indicate that tumors that possess an intrinsic defect in the CRT-translocating machinery become resistant to anthracycline chemotherapy due to their incapacity to elicit an anti-cancer immune response.

Reduction of endoplasmic reticulum Ca2+ levels favors plasma membrane surface exposure of calreticulin.

Some chemotherapeutic agents can elicit apoptotic cancer cell death, thereby activating an anticancer immune response that influences therapeutic outcome. We previously reported that anthracyclins are particularly efficient in inducing immunogenic cell death, correlating with the pre-apoptotic exposure of calreticulin (CRT) on the plasma membrane surface of anthracyclin-treated tumor cells. Here, we investigated the role of cellular Ca(2+) homeostasis on CRT exposure. A neuroblastoma cell line (SH-SY5Y) failed to expose CRT in response to anthracyclin treatment. This defect in CRT exposure could be overcome by the overexpression of Reticulon-1C, a manipulation that led to a decrease in the Ca(2+) concentration within the endoplasmic reticulum lumen. The combination of Reticulon-1C expression and anthracyclin treatment yielded more pronounced endoplasmic reticulum Ca(2+) depletion than either of the two manipulations alone. Chelation of intracellular (and endoplasmic reticulum) Ca(2+), targeted expression of the ligand-binding domain of the IP(3) receptor and inhibition of the sarco-endoplasmic reticulum Ca(2+)-ATPase pump reduced endoplasmic reticulum Ca(2+) load and promoted pre-apoptotic CRT exposure on the cell surface, in SH-SY5Y and HeLa cells. These results provide evidence that endoplasmic reticulum Ca(2+) levels control the exposure of CRT.