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Purpose: The increased risk of second cancer after prostate radiotherapy is a debated clinical concern. The objective of the study was to assess the risk of occurrence of second cancers after prostate radiation therapy based on the analysis the literature, and to identify potential factors explaining the discrepancies in results between studies., Materials and Methods: A review of the literature was carried out, comparing the occurrence of second cancers in patients all presenting with prostate cancer, treated or not by radiation., Results: This review included 30 studies reporting the occurrence of second cancers in 2,112,000 patients treated or monitored for localized prostate cancer, including 1,111,000 by external radiation therapy and 103,000 by brachytherapy. Regarding external radiation therapy, the average follow-up was 7.3years. The majority of studies (80%) involving external radiation therapy, compared to no external radiation therapy, showed an increased risk of second cancers with a hazard ratio ranging from 1.13 to 4.9, depending on the duration of the follow-up. The median time to the occurrence of these second cancers after external radiotherapy ranged from 4 to 6years. An increased risk of second rectal and bladder cancer was observed in 52% and 85% of the studies, respectively. Considering a censoring period of more than 10 years after irradiation, 57% and 100% of the studies found an increased risk of rectal and bladder cancer, without any impact in overall survival. Studies of brachytherapy did not show an increased risk of second cancer. However, these comparative studies, most often old and retrospective, had many methodological biases., Conclusion: Despite numerous methodological biases, prostate external radiation therapy appears associated with a moderate increase in the risk of second pelvic cancer, in particular bladder cancer, without impacting survival. Brachytherapy does not increase the risk of a second cancer., (Copyright © 2024 Société française de radiothérapie oncologique (SFRO). Published by Elsevier Masson SAS. All rights reserved.)

Purpose: Retrospective description of anatomical sites of relapse based on (18F)-choline PET-CT, (68Ga)-prostatic specific-membrane antigen PET-CT, bone scan, and prostate magnetic resonance imaging (MRI) data., Materials and Methods: From two French prospective cohorts, patients treated with exclusive radiotherapy for an intermediate-risk cancer were identified during their follow-ups. They were included if they presented a rising of the prostate-specific antigen (PSA) associated with the realization of an imaging showing the sites of recurrences., Results: Two hundred and sixty-three patients were included. After a median follow-up of 76 months (interquartile range [IQR] 67-95), 65 patients had biochemical recurrence and positive imaging. The median nadir PSA was 0.6ng/mL and the median PSA at recurrence was 3.4ng/mL. A single lesion was found in 48% of cases, 2 to 4 lesions in 43% of cases and more than 4 lesions in 9% of cases. The sites of relapse identified were prostate (37/65), prostate only (19/65), seminal vesicles (9/65) Pelvic nodes (35/65), extrapelvic nodes (15/65) and bone (13/65)., Conclusions: The majority of relapses presented as a single lesion localized in the pelvis., (Copyright © 2022. Published by Elsevier Masson SAS.)

Glioblastoma (GBM) is frequent in elderly patients, but their frailty provokes debate regarding optimal treatment in general, and the standard 6-week chemoradiation (CRT) in particular, although this is the mainstay for younger patients. All patients with newly diagnosed GBM and age ≥ 70 who were referred to our institution for 6-week CRT were reviewed from 2004 to 2018. MGMT status was not available for treatment decision at that time. The primary endpoint was overall survival (OS). Secondary outcomes were progression-free survival (PFS), early adverse neurological events without neurological progression ≤ 1 month after CRT and temozolomide hematologic toxicity assessed by CTCAE v5. 128 patients were included. The median age was 74.1 (IQR: 72-77). 15% of patients were ≥ 80 years. 62.5% and 37.5% of patients fulfilled the criteria for RPA class I-II and III-IV, respectively. 81% of patients received the entire CRT and 28% completed the maintenance temozolomide. With median follow-up of 11.7 months (IQR: 6.5-17.5), median OS was 11.7 months (CI 95%: 10-13 months). Median PFS was 9.5 months (CI 95%: 9-10.5 months). 8% of patients experienced grade ≥ 3 hematologic events. 52.5% of patients without neurological progression had early adverse neurological events. Post-operative neurological disabilities and age ≥ 80 were not associated with worsened outcomes. 6-week chemoradiation was feasible for "real-life" elderly patients diagnosed with glioblastoma, even in the case of post-operative neurological disabilities. Old does not necessarily mean worse., (© 2021. The Author(s).)

Background: Oligorecurrent pelvic nodal relapse in prostatic cancer is a challenge for regional salvage treatments. Androgen depriving therapies (ADTs) are a mainstay in metastatic prostate cancer, and salvage pelvic radiotherapy may offer long ADT-free intervals for patients harboring regional nodal relapses., Objective: To assess the efficacy of the combination of ADT and salvage radiotherapy in men with oligorecurrent pelvic node relapses of prostate cancer., Design, Setting, and Participants: We performed an open-label, phase II trial of combined high-dose intensity-modulated radiotherapy and ADT (6 mo) in oligorecurrent (five or fewer) pelvic node relapses in prostate cancer, detected by fluorocholine positron-emission tomography computed tomography imaging., Outcome Measurements and Statistical Analysis: The primary endpoint was 2-yr progression-free survival defined as two consecutive prostate-specific antigen levels above the level at inclusion and/or clinical evidence of progression as per RECIST 1.1 and/or death from any cause., Results and Limitations: Between August 2014 and July 2016, 67 patients were recruited in 15 centers. Half of the patients had received prior prostatic irradiation. The median age was 67.7 yr. After a median follow-up of 49.4 mo, 2- and 3-yr progression-free survival rates were 81% and 58%, respectively. Median progression-free survival was 45.3 mo. The median biochemical relapse-free survival (BRFS) was 25.9 mo. At 2 and 3 yr, the BRFS rates were 58% and 46%, respectively. Grade 2 + 2-yr genitourinary and gastrointestinal toxicities were 10% and 2%, respectively., Conclusions: Combined high-dose salvage pelvic radiotherapy and ADT appeared to prolong tumor control in oligorecurrent pelvic node relapses in prostate cancer with limited toxicity. After 3 yr, nearly half of patients were in complete remission. Our study showed initial evidence of benefit, but a randomized trial is required to confirm this result., Patient Summary: In this report, we looked at the outcomes of combined high-dose salvage pelvic radiotherapy and 6-mo-long hormone therapy in oligorecurrent pelvic nodal relapse in prostatic cancer. We found that 46% of patients presenting with oligorecurrent pelvic node relapses in prostate cancer were in complete remission after 3 yr following combined treatment at the cost of limited toxicity., (Copyright © 2021. Published by Elsevier B.V.)

Purpose: While there is no high-level evidence showing superiority of surgery over radiation treatment, radical prostatectomy is the most common treatment option for patients with localized, non-metastatic disease. Nearly 30% of all patients undergoing surgery will develop a biochemical recurrence in 10 years. In fact, more than 30% of contemporary patients treated with RP will harbor aggressive disease characteristics at final pathology., Material and Mehods: We conducted a review of the literature evaluating the timing of radiotherapy and the place of androgen deprivation after prostatectomie totale., Results: Four trials randomizing adjuvant radiotherapy and surveillance found an advantage in biochemical relapse-free survival in favor of immediate irradiation after radical prostatectomy, called adjuvant. However, in these studies, more than 40% of patients in the arm without adjuvant radiotherapy did not relapse at 10 years of follow-up. More recently, the question of the optimal time of this post-operative, adjuvant RT or during biological relapse has arisen through three trials (RADICALS-RT, RAVES, GETUG-AFU 17). These trials did not show a benefit for adjuvant radiotherapy in terms of event-free survival, a PSA-based endpoint, while confirming the toxicities observed during irradiation immediately after surgery. The optimal duration of hormonal therapy when associated with post-prostatectomy radiation therapy remains controversial., Conclusion: Early salvage radiotherapy is a new standard of treatment and adjuvant radiotherapy could be reserved for very selected patients. The role of hormone therapy is well defined in salvage situation, but its duration is still being studied., (Copyright © 2021 Société française de radiothérapie oncologique (SFRO). Published by Elsevier Masson SAS. All rights reserved.)

Prostate cancer recurrence in patients previously treated with radical prostatectomy and radiation therapy is challenging. Re-irradiation could be an option, but data regarding efficacy and safety are lacking. We retrospectively evaluated salvage re-irradiation for local recurrence after prostatectomy and external beam radiation therapy. We collected data from 48 patients who underwent salvage reirradiation with stereotactic radiation therapy for local prostate cancer recurrence in the prostatic bed at four French centers. Fifteen patients (31%) were on androgen deprivation therapy during stereotactic radiotherapy. Biochemical response and relapse-free survival were analyzed, and post-treatment toxicities were assessed according to the Common Terminology of Adverse Events criteria. Five patients had grade 3 late bladder toxicity (cystitis), three had grade 3 late incontinence, and one had grade 3 late chronic pain. At three months, 83% of patients had a positive biochemical response. The median follow-up was 22 months. At the end of the follow-up, 21 patients (43%) had a biochemical relapse. The median time to biologic relapse was 27 months. The biochemical relapse rates at 1 and 2 years were 80% and 52%, respectively. In conclusion, salvage re-irradiation for recurrent prostate cancer in the prostate bed may generate significant toxicity rates, and a prospective study with appropriate patient selection is needed to evaluate its effectiveness.

Background : Stereotactic body radiotherapy (SBRT) is a recognized treatment for colorectal cancer (CRC) metastases. We postulated that local responses could be improved by SBRT with a concomitant radiosensitizing agent (irinotecan). Methods : RADIOSTEREO-CAMPTO was a prospective multi-center phase 2 trial investigating SBRT (40-48 Gy in 4 fractions) for liver and/or lung inoperable CRC oligometastases (≤3), combined with two weekly intravenous infusions of 40 mg/m 2 Irinotecan. Primary outcome was the objective local response rate as per RECIST. Secondary outcomes were early and late toxicities, EORTC QLQ-C30 quality of life, local control and overall survival. Results : Forty-four patients with 51 lesions (liver = 39, lungs = 12) were included. Median age was 69 years (46-84); 37 patients (84%) had received at least two prior chemotherapy treatments. Median follow-up was 48.9 months. One patient with two lung lesions was lost during follow-up. Assuming maximum bias hypothesis, the objective local response rate in ITT was 86.3% (44/51-95% CI: [76.8-95.7]) or 82.4% (42/51-95% CI: [71.9-92.8]). The observed local response rate was 85.7% (42/49-95% CI: [75.9-95.5]). The 1 and 2-year local (distant) progression-free survivals were 84.2% (38.4%) and 67.4% (21.3%), respectively. The 1 and 2-year overall survivals were 97.5% and 75.5%. There were no severe acute or late reactions. The EORTC questionnaire scores did not significantly worsen during or after treatment. Conclusions : SBRT with irinotecan was well tolerated with promising results despite heavily pretreated patients.

Introduction : Pertuzumab, a humanized monoclonal antibody that binds the human epidermal growth factor receptor 2 (HER2), inhibits the heterodimerization of HER2 with other HER receptors. It has been approved both by the Food and Drug Administration and the European Medicine Agency in the metastatic, neoadjuvant and adjuvant setting. Areas covered : This review analyses and discusses preclinical and clinical studies of pertuzumab in breast cancer. In this article, we review the status of pertuzumab, the completed and ongoing trials, and its safety. Expert opinion : Pertuzumab is a key drug for the treatment of HER2-positive metastatic or early breast cancer. However, it is imperative to identify patients that will need dual-targeting and mechanisms of resistance. Moreover, the value of pertuzumab beyond progression needs to be evaluated.

Purpose: Limited pelvic nodal relapse of prostatic cancer is a paramount challenge for locoregional salvage treatments. Salvage whole pelvis radiation therapy as considered in the BLINDED trial is an attractive option, but there are concerns about its toxicity. This article describes early toxicity with the technique., Methods and Materials: BLINDED was a prospective multicenter phase 2 trial investigating high-dose salvage pelvic irradiation with an additional dose to the fluorocholine-based positron emission tomography-positive pelvic lymph nodes, combined with 6-month androgen blockade. The prescribed dose was 54 Gy in 1.8 Gy fractions with up to 66 Gy in 2.2 Gy fractions to the pathologic pelvic lymph nodes. Early toxicity was defined as toxicity until 1 year after radiation therapy. Patients quality of life was assessed using the European Organisation for Research and Treatment of Cancer questionnaires (QLQ-C30 and QLQ-PR25)., Results: Seventy-four patients were recruited in 15 French radiation oncology departments between August 2014 and July 2016. Seven were excluded before treatment because of violation of the inclusion criteria. The intention-to-treat analysis therefore included 67 patients. Half had received prior prostatic irradiation. Median age was 67.7 ± 6.5 years. Grade 2 acute urinary toxicity was observed in 9 of 67 patients (13.4%), and grade 2 1-year toxicity occurred in 4 of 67 patients (6%). Three patients (4.4%) had grade 3 urinary toxicity. Grade 2 acute digestive toxicity was observed in 10 of 67 patients (14.9%), and grade 2 1-year toxicity occurred in 4 of 67 patients (6%). Patients with prior prostate bed irradiation did not exhibit increased urinary or digestive toxicity. The European Organisation for Research and Treatment of Cancer questionnaire scores at 1 year did not worsen significantly., Conclusions: The acute and 1-year toxicity of the BLINDED protocol was satisfactory, even in patients with a history of prostatic irradiation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: The combination of cyclin-dependent kinases 4 and 6 (CDK 4 and 6) inhibitors with endocrine therapy represents a new standard of care for endocrine-receptor positive metastatic breast cancer. Currently, three compounds are approved. Abemaciclib is the latest CDK4/6 inhibitor approved by the US Food and Drug Administration in view of the results of the MONARCH1 and 2 trials. Area covered: In this article, we review the preclinical and clinical development of abemaciclib in advanced breast cancer, describing current therapeutic indications and open questions. Expert opinion: Results of phase III trials investigating abemaciclib in patients with endocrine-receptor positive metastatic breast cancer have shown a substantial improvement in progression-free-survival, with a safe and manageable toxicity profile. In order to better select patients who will more likely respond to CDK4/6 inhibitors, biomarkers need to be identified. To optimize CDK4/6 targeting, combination therapies are being tested in several ongoing trials.

Deregulated cell division, resulting in aberrant cell proliferation, is one of the key hallmarks of cancer. Cyclin-dependent kinases (CDKs) play a central role in cell cycle progression in cancer, and the clinical development of the CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib has changed clinical practice in the setting of endocrine-receptor positive breast cancer. Results of pivotal phase II and III trials investigating these CDK4/6 inhibitors in patients with endocrine receptor-positive, advanced breast cancer have demonstrated a significant improvement in progression-free survival, with a safe toxicity profile. No validated biomarkers of sensitivity or resistance exist at the moment. Future development of CDK4/6 inhibitors in breast cancer should focus on the identification of predictive biomarkers, the development of drug combinations to overcome resistance, and the application of CDK4/6 inhibitors to other breast cancer subtypes.

Interleukin-2, a cytokine identified as T-cell growth factor, has long been regarded as central to the development and effector activities of immune responses. Several gene knockout mouse studies and observations in humans, however, have undermined that vision, and the discovery of regulatory T cells showed that IL-2, in contrast to the accepted dogma, has the essential function of promoting (1) homeostasis and (2) the function of these T regulator cells the which, limit the action of the effector cells, in particular to prevent the autoimmune reaction drifts. This new paradigm has major implications on the use of IL-2 in therapy, and creates new strategies to manipulate the Teffectors/Tregulators balance., (© 2016 médecine/sciences – Inserm.)

Alpha-radioimmunotherapy (α-RIT) is a targeted anti-tumor therapy using usually a monoclonal antibody specific for a tumor antigen that is coupled to an α-particle emitter. α-emitters represent an ideal tool to eradicate disseminated tumors or metastases. Recent data demonstrate that ionizing radiation in addition to its direct cytotoxic ability can also induce an efficient anti-tumor immunity. This suggests that biologic effects on irradiated tissues could be used to potentiate immunotherapy efficacy and opens the way for development of new therapies combining α-RIT and different types of immunotherapy., (© 2016 médecine/sciences – Inserm.)

Background.  Buruli ulcer, caused by Mycobacterium ulcerans, is a necrotizing skin disease leading to extensive cutaneous and subcutaneous destruction and functional limitations. Spontaneous healing in the absence of medical treatment occurs in rare cases, but this has not been well described in the literature. Methods.  In a retrospective case study in an area of Benin where this disease is highly endemic, we selected 26 Buruli ulcer patients presenting features of spontaneous healing from a cohort of 545 Buruli ulcer patients treated between 2010 and 2013. Results.  The 26 patients studied had a median age of 13.5 years and were predominantly male (1.4:1). Three groups of patients were defined on the basis of their spontaneous healing characteristics. The first group (12 patients) consisted of patients with an ulcer of more than 1 year's duration showing signs of healing. The second (13 patients) group contained patients with an active Buruli ulcer lesion some distance away from a first lesion that had healed spontaneously. Finally, the third group contained a single patient displaying complete healing of lesions from a nodule, without treatment and with no relapse. Conclusions.  We defined several features of spontaneous healing in Buruli ulcer patients and highlighted the difficulties associated with diagnosis and medical management. Delays in consultation contributed to the high proportion of patients with permanent sequelae and a risk of squamous cell carcinoma. Early detection and antibiotic treatment are the best ways to reduce impairments.

Azamacrocyclic bifunctional chelating agents (BCAs) are essential for the development of radiopharmaceuticals in nuclear medicine and we wish to prove that their bioconjugation by a function present on a carbon atom of the macrocyclic skeleton is a solution of choice to maintain their in vivo inertness. Based on our very recent methodology using a bisaminal template and selective N-alkylation approach, a new synthesis of conjugable C-functionalised teta, te2a and cb-te2a has been developed. These chelators have indeed a growing interest in nuclear medicine for positron emission tomography (PET) and radioimmunotherapy (RIT) where they show in several cases better complexation properties than dota or dota-like macrocycles, especially with (64)Cu or (67)Cu radioisotopes. Chelators are bearing an isothiocyanate grafting function introduced by C-alkylation to avoid as much as possible a critical decrease of their chelating properties. The synthesis is very efficient and yields the targeted ligands, teta-Ph-NCS, te2a-Ph-NCS and cb-te2a-Ph-NCS without fastidious work-up and could be easily extended to other cyclam based-BCAs. The newly synthetised te2a-Ph-NCS has been conjugated to an anti mCD138 monoclonal antibody (mAb) to evaluate its in vivo behavior and potentiality as BCA and to explore a first attempt of PET-phenotypic imaging in multiple myeloma (MM). Mass spectrometry analysis of the immunoconjugate showed that up to 4 chelates were conjugated per 9E7.4 mAb. The radiolabeling yield and specific activity post-purification of the bioconjugate 9E7.4-CSN-Ph-te2a were 95 ± 2.8% and 188 ± 27 MBq mg(-1) respectively and the immunoreactivity of (64)Cu-9E7.4-CSN-Ph-te2a was 81 ± 7%. Animal experiments were carried out on 5T33-Luc(+) tumor bearing mice, either in subcutaneous or orthotopic. To achieve PET imaging, mice were injected with (64)Cu-9E7.4-CNS-Ph-te2a and acquisitions were conducted 2 and 20 h post-injection (PI). A millimetric bone uptake was localised in a sacroiliac of a MM orthotopic tumor. Nonspecific uptakes were observed at 2 h PI but, unlike for the tumor, a significant decrease was observed at 20 h PI which improves the contrast of the images.

Unlabelled: This study proposes liposomes as a new tool for pretargeted radioimmunotherapy (RIT) in solid tumors. Tumor pretargeting is obtained by using a bispecific monoclonal antibody [BsmAb, anti-CEA × anti-DTPA-indium complex (DTPA-In)] and pegylated radioactive liposomes containing a lipid-hapten conjugate (DSPE-PEG-DTPA-In). In this work, the immunospecificity of tumor targeting is demonstrated both in vitro by fluorescence microscopy and in vivo by biodistribution studies., Methods: Carcinoembryonic antigen (CEA)-expressing cells (LS174T) were used either in cell culture or as xenografts in nude mice. Doubly fluorescent liposomes or doubly radiolabeled liposomes were, respectively, used for in vitro and in vivo studies. In each case, a tracer of the lipid bilayer [rhodamine or indium-111 ((111)In)] and a tracer of the aqueous phase [fluorescein or iodine-125 ((125)I)] were present. The targeting of liposomes was assessed with BsmAb for active targeting or without for passive targeting., Results: Data obtained with the lipid bilayer tracer showed a fluorescent signal on cell membranes two to three times higher for active than for passive targeting. This immunospecificity was confirmed in vivo with tumor uptake of 7.5 ± 2.4% ID/g (percentage of injected dose per gram of tissue) for active targeting versus 4.5 ± 0.45% ID/g for passive targeting (p = 0.03). Regarding the aqueous phase tracer, results are slightly more contrasted. In vitro, the fluorescent tracer seems to be released in the extracellular matrix, which can be correlated with the in vivo data. Indeed, the tumor uptake of (125)I is lower than that of (111)In: 5.1 ± 2.5% ID/g for active targeting and 2.7 ± 0.6% ID/g for passive targeting, but resulted in more favorable tumor/organs ratios., Conclusion: This work demonstrated the tumor targeting immunospecificity of DSPE-PEG-DTPA-In liposomes by two different methods. This original and new approach suggests the potential of immunospecific targeting liposomes for the RIT of solid tumors.

Background: Metastatic prostate cancer remains a common cause of death in Europe, and improvements in management of the disease are urgently needed. The advent of positron-emission tomography (PET) imaging enhanced with fluorocholine has led to the identification of a new sub-group of metastatic prostate cancer patients: those with so-called oligometastatic disease. Presenting with a low burden of metastatic disease (≤5 lesions), this new sub-group lies between true metastatic prostate cancer patients for whom androgen- deprivation therapy (ADT) is the mainstay of treatment, and patients with a rising PSA, but no visible lesion on conventional imaging, in whom intermittent ADT has been shown to be no less effective than continuous ADT. One might conclude that intermittent ADT would also be the standard of care for oligometastatic prostate cancer patients, but radical strategies such as extensive lymphadenectomy or high-dose radiotherapy have been suggested as another means to delay the need for ADT, and increase its effectiveness once initiated. This study will explore the role of salvage pelvic image-guided intensity-modulated radiation therapy (IMRT) combined with ADT administered for 6 months in pelvic oligometastatic patients in prolonging the failure-free interval between two consecutive ADT courses, or even to cure selected patients with limited metastatic burden., Methods/design: We plan to assess the two year outcome in oligometastatic prostate cancer patients (1-5 pelvic oligometastases) treated concomitantly with high-dose IMRT (54 Gy, 30 fractions to the pelvis and 66 Gy, 30 fractions to the lymph nodes) and ADT for six months., Discussion: This multicenter prospective phase II study will yield new data regarding the safety and efficacy of high-dose radiotherapy combined with ADT and will provide a basis for a larger phase III study to examine the role of radiotherapy in this population currently treated only with hormone therapy., Trial Registration: NCT02274779 , date of registration: 23/10/14.

The classic model of tumor suppression implies that malignant transformation requires full "two-hit" inactivation of a tumor-suppressor gene. However, more recent work in mice has led to the proposal of a "continuum" model that involves more fluid concepts such as gene dosage-sensitivity and tissue specificity. Mutations in the tumor-suppressor gene von Hippel-Lindau (VHL) are associated with a complex spectrum of conditions. Homozygotes or compound heterozygotes for the R200W germline mutation in VHL have Chuvash polycythemia, whereas heterozygous carriers are free of disease. Individuals with classic, heterozygous VHL mutations have VHL disease and are at high risk of multiple tumors (e.g., CNS hemangioblastomas, pheochromocytoma, and renal cell carcinoma). We report here an atypical family bearing two VHL gene mutations in cis (R200W and R161Q), together with phenotypic analysis, structural modeling, functional, and transcriptomic studies of these mutants in comparison with classical mutants involved in the different VHL phenotypes. We demonstrate that the complex pattern of disease manifestations observed in VHL syndrome is perfectly correlated with a gradient of VHL protein (pVHL) dysfunction in hypoxia signaling pathways. Thus, by studying naturally occurring familial mutations, our work validates in humans the "continuum" model of tumor suppression., (©2014 American Association for Cancer Research.)

Myeloproliferative neoplasms (MPNs) are often characterized by JAK2 or calreticulin (CALR) mutations, indicating aberrant trafficking in pathogenesis. This study focuses on Mpl trafficking and Jak2 association using two model systems: human erythroleukemia cells (HEL; JAK2V617F) and K562 myeloid leukemia cells (JAK2WT). Consistent with a putative chaperone role for Jak2, Mpl and Jak2 associate on both intracellular and plasma membranes (shown by proximity ligation assay) and siRNA-mediated knockdown of Jak2 led to Mpl trapping in the endoplasmic reticulum (ER). Even in Jak2 sufficient cells, Mpl accumulates in punctate structures that partially colocalize with ER-tracker, the ER exit site marker (ERES) Sec31a, the autophagy marker LC3 and LAMP1. Mpl was fused to miniSOG, a genetically encoded tag for correlated light and electron microscopy. Results suggest that a fraction of Mpl is taken up into autophagic structures from the ER and routed to autolyososomes. Surface biotinylation shows that both immature and mature Mpl reach the cell surface; in K562 cells Mpl is also released in exosomes. Both forms rapidly internalize upon ligand addition, while recovery is primarily attributed to immature Mpl. Mpl appears to reach the plasma membrane via both conventional ER-Golgi and autolysosome secretory pathways, as well as recycling., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: This paper proposes liposomes as a potential new tool for radioimmunotherapy in solid tumours with a two step targeting system. Tumour pretargeting is obtained by using a monoclonal bispecific antibody (BsmAb, anti CEA x anti-DTPA-In) and pegylated liposomes containing lipid-hapten (DSPE-DTPA-In or DSPE-PEG-DTPA-In). To optimise at the same time in vivo behaviour and specific targeting, the study focuses on the liposome formulation in order to determine more precisely the role of pegylation on both the blood half-life and the specific recognition with the BsmAb., Methods: Different liposome formulations containing two PEG length (1000 and 2000) in varying amount (1.5-6 mol%) were prepared with DTPA directly coupled to DSPE or at the end of the PEG chain (DSPE-DTPA or DSPE-PEG-DTPA). Liposomes were immobilized on an L1 chip to measure by SPR (Surface Plasmon Resonance) the effect of pegylation on the BsmAb recognition of the DTPA-In hapten. Pharmacokinetic studies were performed in mice. Tumour targeting was studied in nude mice xenografted with human colorectal adenocarcinoma cells that express CEA, and doubly radiolabelled liposomes (with (111)In and (125)I) injected 24h after the BsmAb., Results: The best in vitro apparent dissociation constant was obtained with liposomes bearing DTPA at the end of the PEG chain (KD=6.3 nM), which showed significant specific tumour uptake after BsmAb injection (8.6 ± 2.4% ID/g at 24h versus 4.5 ± 0.5%ID/g for passive targeting, α=0.01). All tumour/organ ratios were superior to 1 at 24h for this formulation, except for the spleen., Conclusion: The feasibility of specific tumour targeting in mice with a BsmAb and radiolabelled liposomes was demonstrated and the interest of SPR to predict their targeting performance in vivo was highlighted. This original and new approach provides promising prospects for the radioimmunotherapy of solid tumours., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Endothelial cells of the microvasculature are major target of ionizing radiation, responsible of the radiation-induced vascular early dysfunctions. Molecular signaling pathways involved in endothelial responses to ionizing radiation, despite being increasingly investigated, still need precise characterization. Small GTPase RhoA and its effector ROCK are crucial signaling molecules involved in many endothelial cellular functions. Recent studies identified implication of RhoA/ROCK in radiation-induced increase in endothelial permeability but other endothelial functions altered by radiation might also require RhoA proteins. Human microvascular endothelial cells HMEC-1, either treated with Y-27632 (inhibitor of ROCK) or invalidated for RhoA by RNA interference were exposed to 15Gy. We showed a rapid radiation-induced activation of RhoA, leading to a deep reorganisation of actin cytoskeleton with rapid formation of stress fibers. Endothelial early apoptosis induced by ionizing radiation was not affected by Y-27632 pre-treatment or RhoA depletion. Endothelial adhesion to fibronectin and formation of focal adhesions increased in response to radiation in a RhoA/ROCK-dependent manner. Consistent with its pro-adhesive role, ionizing radiation also decreased endothelial cells migration and RhoA was required for this inhibition. These results highlight the role of RhoA GTPase in ionizing radiation-induced deregulation of essential endothelial functions linked to actin cytoskeleton., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Targeted PEGylated liposomes could increase the amount of drugs or radionuclides delivered to tumor cells. They show favorable stability and pharmacokinetics, but steric hindrance of the PEG chains can block the binding of the targeting moiety. Here, specific interactions between an antihapten antibody (clone 734, specific for the DTPA-indium complex) and DTPA-indium-tagged liposomes were characterized by surface plasmon resonance (SPR). Non-PEGylated liposomes fused on CM5 chips whereas PEGylated liposomes did not. By contrast, both PEGylated and non-PEGylated liposomes attached to L1 chips without fusion. SPR binding kinetics showed that, in the absence of PEG, the antibody binds the hapten at the surface of lipid bilayers with the affinity of the soluble hapten. The incorporation of PEGylated lipids hinders antibody binding to extents depending on PEGylated lipid fraction and PEG molecular weight. SPR on immobilized liposomes thus appears as a useful technique to optimize formulations of liposomes for targeted therapy.