François Le Loarer

Synovium CD20 expression is a potential new predictor of bone erosion progression in very-early arthritis treated by sequential DMARDs monotherapy – A pilot study from the VErA cohort

OBJECTIVE Because available biomarkers (rheumatoid factors [RF], anti-cyclic citrullinated autoantibodies [anti-CCP2], erythrocyte sedimentation rate at 1st hour [ESR]/C-reactive peptide [CRP] and bone erosions) are insufficient to predict rheumatoid arthritis (RA) structural damage, to determine whether synovium expression of greater or equal to 1 markers could constitute new prognostic factor(s). METHOD The study was conducted on 18 prospectively enrolled disease-modifying anti-rheumatic drug (DMARD)- and glucocorticoid-naïve, VErA cohort patients with very-early arthritis (median duration: 4months). Recorded at baseline were: clinical and biological (serum ESR, CRP, RF-isotypes, anti-CCP2, osteoprotegerin, receptor activator of nuclear κB-ligand [RANK-L] and cartilage oligomeric matrix protein [COMP] levels) data; synovium expression (HLA-DR, CD163, CD3, CD20, VEGF, osteoprotegerin, RANK-L, Bcl2 and global inflammation index) for a metacarpophalangeal joint-synovium biopsy. Baseline and 3-year hand-and-foot X-rays were graded with the van der Heijde-modified-Sharp score; the judgment criterion was its progression during follow-up. Pearsons product moment correlation statistics were used to test for association between paired samples. RESULTS A baseline, a significant relationship was found between erosive damage and markers of B-cell activation, notably the synovium CD20 expression (r=0.68; P=0.0001). Quantified by the modified-Sharp erosion score variation, the 3-year structural damage progression was significantly correlated with: serum levels of RF-IgG (r=0.75; P=0.0003), -IgM (r=0.69; P=0.001), anti-CCP2 (r=0.53; P=0.02) and RANK-L (r=0.61; P=0.007); synovium CD20 expression (r=0.70; P=0.001). CONCLUSION This analysis of the prognostic value of a large panel of synovium markers in a limited sample of prospectively followed, well-documented patients suggested that both synovial CD20 and serum RANK-L levels might be new predictors of structural damage progression in very-early RA.

Combined targeting of MDM2 and CDK4 is synergistic in dedifferentiated liposarcomas

PurposeMDM2 and CDK4 are frequently co-amplified in well-differentiated/dedifferentiated liposarcoma (WDLPS/DDLPS). We aimed to determine whether combined MDM2/CDK4 targeting is associated with higher antitumour activity than a single agent in preclinical models of DDLPS.Experimental designDDLPS cells were exposed to RG7388 (MDM2 antagonist) and palbociclib (CDK4 inhibitor), and apoptosis and signalling/survival pathway perturbations were monitored by flow cytometry and Western blotting. Xenograft mouse models were used to assess tumour growth and survival. Treatment efficacy was assessed by Western blotting, histopathology and tumour volume.ResultsRG7388 and palbociclib together exerted a greater antitumour effect than either drug alone, with significant differences in cell viability after a 72-h treatment with RG7388 and/or palbociclib. The combination treatment significantly increased apoptosis compared to the single agents. We then analysed the in vivo antitumour activity of RG7388 and palbociclib in a xenograft model of DDLPS. The combination regimen reduced the tumour growth rate compared with a single agent alone and significantly increased the median progression-free survival.ConclusionsOur results provide a strong rationale for evaluating the therapeutic potential of CDK4 inhibitors as potentiators of MDM2 antagonists in DDLPS and justify clinical trials in this setting.

Transcriptomic definition of molecular subgroups of small round cell sarcomas: Molecular classification of sarcoma subtypes

Sarcoma represents a highly heterogeneous group of tumours. We report here the first unbiased and systematic search for gene fusions combined with unsupervised expression analysis of a series of 184 small round cell sarcomas. Fusion genes were detected in 59% of samples, with half of them being observed recurrently. We identified biologically homogeneous groups of tumours such as the CIC‐fused (to DUX4, FOXO4 or NUTM1) and BCOR‐rearranged (BCOR–CCNB3, BCOR–MAML3, ZC3H7B–BCOR, and BCOR internal duplication) tumour groups. VGLL2‐fused tumours represented a more biologically and pathologically heterogeneous group. This study also refined the characteristics of some entities such as EWSR1–PATZ1 spindle cell sarcoma or FUS–NFATC2 bone tumours that are different from EWSR1–NFATC2 tumours and transcriptionally resemble CIC‐fused tumour entities. We also describe a completely novel group of epithelioid and spindle‐cell rhabdomyosarcomas characterized by EWSR1– or FUS–TFCP2 fusions. Finally, expression data identified some potentially new therapeutic targets or pathways. Copyright

Activity of trabectedin and the PARP inhibitor rucaparib in soft-tissue sarcomas

BackgroundTrabectedin has recently been approved in the USA and in Europe for advanced soft-tissue sarcoma patients who have been treated with anthracycline-based chemotherapy without success. The mechanism of action of trabectedin depends on the status of both the nucleotide excision repair (NER) and homologous recombination (HR) DNA repair pathways. Trabectedin results in DNA double-strand breaks. We hypothesized that PARP-1 inhibition is able to perpetuate trabectedin-induced DNA damage.MethodsWe explored the effects of combining a PARP inhibitor (rucaparib) and trabectedin in a large panel of soft-tissue sarcoma (STS) cell lines and in a mouse model of dedifferentiated liposarcoma.ResultsThe combination of rucaparib and trabectedin in vitro was synergistic, inhibited cell proliferation, induced apoptosis, and accumulated in the G2/M phase of the cell cycle with higher efficacy than either single agent alone. The combination also resulted in enhanced γH2AX intranuclear accumulation as a result of DNA damage induction. In vivo, the combination of trabectedin and rucaparib significantly enhanced progression-free survival with an increased percentage of tumor necrosis.ConclusionThe combination of PARP inhibitor and trabectedin is beneficial in pre-clinical models of soft-tissue sarcoma and deserves further exploration in the clinical setting.

Expression and role of TYRO3 and AXL as potential therapeutical targets in leiomyosarcoma

Background:Leiomyosarcoma (LMS) are 15% of adult sarcomas and remain seldom curable in metastatic phase. The TAM receptors and their ligands are overexpressed or activated in multiple malignancies, including LMS.Methods:The TAM receptor and ligand expression was evaluated in LMS cell lines and 358 sarcoma samples by either gene expression or immunohistochemistry. TYRO3 and AXL were knocked down. Crizotinib and foretinib were investigated in vitro.Results:High expression of TYRO3 and AXL was detected in LMS cell lines. TYRO3 or AXL gene knockdown reduced cell proliferation/colony formation. Crizotinib and foretinib decreased TYRO3 and AXL phosphorylation, apoptosis, G2/arrest and reduced colony formation. Immunohistochemistry performed in 107 sarcomas showed higher expression of TYRO3 and GAS6 in LMS vs other sarcomas and nuclear TYRO3 only in LMS. Microarray gene expression performed in 251 sarcomas revealed significantly higher expression of TYRO3 and GAS6 in LMS than other sarcomas. Leiomyosarcoma patients with high expression of GAS6 or PROS1 present a significantly worse PFS.Conclusions:Leiomyosarcoma patients, especially those whom develop metastasis, express higher levels of TYRO3 and GAS6. Crizotinib and foretinib showed effective antitumour activity in LMS through TYRO3 and AXL deactivation indicating that clinical trials using TYRO3 and AXL inhibitors are warranted in advanced LMS.

Small Cell Carcinoma of the Ovary, Hypercalcemic Type: Report of a Bilateral Case in a Teenager Associated with SMARCA4 Germline Mutation.

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), is a highly aggressive neoplasm that typically occurs in young females. Paraneoplastic hypercalcemia is associated in two thirds of the cases. Recent studies demonstrated that this rare tumor harbors the same molecular features of malignant rhabdoid tumor secondary to SMARCA4/BRG1 mutations. We illustrate herein a typical bilateral case of SCCOHT with comprehensive molecular characterization in a 14-year-old girl. We also discuss the value of SMARCA4 immunostaining in the diagnostic approach of undifferentiated ovarian and pelvic malignancies.

Complete response to exemestane in a patient with a desmoid tumor

Desmoid tumors are rare mesenchymal neoplasms without metastatic potential. Despite the benign nature of this condition, some patients develop disease progression despite all locoregional options for care. Aggressive forms of desmoid tumors may induce morbidity that can lead to physical impairment and mortality that is occasionally observed as a result of local infiltrative growth and tissue invasion, in particular with abdominal disease. Few therapeutic options are available for patients with recurrent/unresectable desmoid tumors. Several studies have suggested the potential benefit of antiestrogens such as tamoxifen in this setting. Here we report the first description of the efficacy of an aromatase inhibitor in a patient with a desmoid tumor.

Multiple skeletal muscle metastases revealing a cardiac intimal sarcoma

We report the case of a 59-year-old female with progressive bilateral painful swelling of the thighs. MRI revealed multiple intramuscular necrotic masses with similar morphologic patterns. Whole-body CT and 18-FDG PET-CT scans demonstrated additional hypermetabolic muscular masses and a lobulated lesion within the left atrial cavity. As biopsy of a muscular mass was compatible with a poorly differentiated sarcoma with MDM2 oncogene amplification, two diagnoses were discussed: a dedifferentiated liposarcoma with muscle and heart metastases or a primary cardiac sarcoma, mainly a cardiac intimal sarcoma, with muscular metastases, which was finally confirmed by array-comparative genomic hybridization (aCGH) in a sarcoma reference center. This case emphasizes the potential for intimal sarcoma to disseminate in skeletal muscle prior to any other organ and the need for a genomic approach in addition to classical radiopathologic analyses to distinguish primary from secondary locations facing simultaneous tumors of the heart and skeletal muscles with MDM2 amplification.

Alternative PDGFD rearrangements in dermatofibrosarcomas protuberans without PDGFB fusions

Dermatofibrosarcoma protuberans is underlined by recurrent collagen type I alpha 1 chain-platelet-derived growth factor B chain(COL1A1-PDGFB) fusions but ~ 4% of typical dermatofibrosarcoma protuberans remain negative for this translocation in routine molecular screening. We investigated a series of 21 cases not associated with the pathognomonic COL1A1-PDGFB fusion on routine fluorescence in situ hybridization (FISH) testing. All cases displayed morphological and clinical features consistent with the diagnosis of dermatofibrosarcoma protuberans. RNA-sequencing analysis was successful in 20 cases. The classical COL1A1-PDGFB fusion was present in 40% of cases (n = 8/20), and subsequently confirmed with a COL1A1 break-apart FISH probe in all but one case (n = 7/8). 55% of cases (n = 11/20) displayed novel PDGFD rearrangements; PDGFD being fused either to the 5′ part of COL6A3 (2q37.3) (n = 9/11) or EMILIN2 (18p11) (n = 2/11). All rearrangements led to in-frame fusion transcripts and were confirmed at genomic level by FISH and/or array-comparative genomic hybridization. PDGFD-rearranged dermatofibrosarcoma protuberans presented clinical outcomes similar to typical dermatofibrosarcoma protuberans. Notably, the two EMILIN2-PDGFD cases displayed fibrosarcomatous transformation and homozygous deletions of CDKN2A at genomic level. We report the first recurrent molecular variant of dermatofibrosarcoma protuberans involving PDGFD, which functionally mimic bona fide COL1A1-PDGFB fusions, leading presumably to a similar autocrine loop-stimulating PDGFRB. This study also emphasizes that COL1A1-PDGFB fusions can be cytogenetically cryptic on FISH testing in a subset of cases, thereby representing a diagnostic pitfall that pathologists should be aware of.

Clinical activity of eribulin in advanced desmoplastic small round-cell tumor

Desmoplastic small round-cell tumor is a rare but highly aggressive tumor occurring mainly in adolescents and young adults. Prolonged progression-free survival has been documented in patients who have undergone aggressive multimodality therapy - that is, multiagent intensive chemotherapy, debulking surgery, and radiation therapy. Eribulin is a microtubule-dynamics inhibitor, and it has recently been shown to be active in liposarcomas. In preclinical models, eribulin activities have also been shown to occur in Ewings sarcoma cell lines, rhabdomyosarcomas and osteosarcomas. In this study, we report three cases of male patients suffering from desmoplastic small round-cell tumor and the clinical response to eribulin in two of them.