Cell Liposarcoma Research Articles

Metastatic soft tissue sarcomas (STS) in elderly patients: 18 years of monoinstitutional experience.

e22528 Background: Elderly people represent more than 50% of STS patients, but few data are available in this population and old patients in clinical studies are underrepresented or not included. Aim of this retrospective, monoinstitutional study is to describe the activity and feasibility of first and second line chemotherapy in elderly patients with metastatic STS. Methods: Patients older than 65, with metastatic STS of the scalp, trunk, girdles and extremities, treated and followed from February 1998 to December 2015 in an Italian referral Center for diagnosis and care of STS were included. Median Overall survival (OS) was the principal end point calculated from the start of chemotherapy to the last date of follow up or death. Response rate and toxicities related to type of administered chemotherapy were the secondary end points. Results: 134 patients (79 M, 55F) were considered, (65-70 y) 63%, (71- 75y) 25%, ( > 76 y)11% . STS histologies: mixoid and round cell liposarcomas (34%), leiomyosarcomas (25%), pleomorphic undifferentiated sarcomas (13%), Angiosarcoma (10%), Mixofibrosarcoma (6%), MPNST (4%), synovial sarcoma (2%), other histologies (6%). All the patients received at least one course chemotherapy (1-12). Mono CT was the preferred administered schedule (92%of cases). Median OS was 7.3 months; at the time of this analysis only 14 patients were alive (10%). In the first line therapy we recorded 1 CR, 14 PR and 43 SD. In second line therapy no CR, 4 PR, 23 SD. PR were recorded mainly in 65-70y old patients. Bad PS, low score in Comprehensive Geriatric Assesment (CGA), vulnerability, comorbidities, number of metastasis, were negative prognostic factors. No toxic death were recorded. 12% of the pts were recovered for febrile neutropenia, thrombocitopenia and mucositis . Conclusions: Our study confirms that elderly patients with metastatic STS is a difficult population to be treated. Only patients less aged, good PS, good GCA and 0-1 comorbidities can be treated with full dose of drug, generally with mono CT. Chemotherapy in elderly pts doesn’t produce a significant improvement in Median Survival and benefit observed support the routine use of citotoxic treatment in selected good performance status population.

Trabectedin and Campthotecin Synergistically Eliminate Cancer Stem Cells in Cell-of-Origin Sarcoma Models

Trabectedin has been approved for second-line treatment of soft tissue sarcomas. However, its efficacy to target sarcoma initiating cells has not been addressed yet. Here, we used pioneer models of myxoid/round cell liposarcoma (MRCLS) and undifferentiated pleomorphic sarcoma (UPS) developed from transformed human mesenchymal stromal/stem cells (MSCs) to evaluate the effect of trabectedin in the cell type responsible for initiating sarcomagenesis and their derived cancer stem cells (CSC) subpopulations. We found that low nanomolar concentrations of trabectedin efficiently inhibited the growth of sarcoma-initiating cells, induced cell cycle arrest, DNA damage and apoptosis. Interestingly, trabectedin treatment repressed the expression of multiple genes responsible for the development of the CSC phenotype, including pluripotency factors, CSC markers and related signaling pathways. Accordingly, trabectedin induced apoptosis and reduced the survival of CSC-enriched tumorsphere cultures with the same efficiency that inhibits the growth of bulk tumor population. In vivo, trabectedin significantly reduced the mitotic index of MRCLS xenografts and inhibited tumor growth at a similar extent to that observed in doxorubicin-treated tumors. Combination of trabectedin with campthotecin (CPT), a chemotherapeutic drug that shows a robust anti-tumor activity when combined with alkylating agents, resulted in a very strong synergistic inhibition of tumor cell growth and highly increased DNA damage and apoptosis induction. Importantly, the enhanced anti-tumor activity of this combination was also observed in CSC subpopulations. These data suggest that trabectedin and CPT combination may constitute a novel strategy to effectively target both the cell-of-origin and CSC subpopulations in sarcoma.

T-cell infiltration and clonality correlate with programmed cell death protein 1 and programmed death-ligand 1 expression in patients with soft tissue sarcomas.

BACKGROUNDPatients with metastatic sarcomas have poor outcomes and although the disease may be amenable to immunotherapies, information regarding the immunologic profiles of soft tissue sarcoma (STS) subtypes is limited.METHODSThe authors identified patients with the common STS subtypes: leiomyosarcoma, undifferentiated pleomorphic sarcoma (UPS), synovial sarcoma (SS), well‐differentiated/dedifferentiated liposarcoma, and myxoid/round cell liposarcoma. Gene expression, immunohistochemistry for programmed cell death protein (PD‐1) and programmed death‐ligand 1 (PD‐L1), and T‐cell receptor Vβ gene sequencing were performed on formalin‐fixed, paraffin‐embedded tumors from 81 patients. Differences in liposarcoma subsets also were evaluated.RESULTSUPS and leiomyosarcoma had high expression levels of genes related to antigen presentation and T‐cell infiltration. UPS were found to have higher levels of PD‐L1 (P≤.001) and PD‐1 (P≤.05) on immunohistochemistry and had the highest T‐cell infiltration based on T‐cell receptor sequencing, significantly more than SS, which had the lowest (P≤.05). T‐cell infiltrates in UPS also were more oligoclonal compared with SS and liposarcoma (P≤.05). A model adjusted for STS histologic subtype found that for all sarcomas, T‐cell infiltration and clonality were highly correlated with PD‐1 and PD‐L1 expression levels (P≤.01).CONCLUSIONSIn the current study, the authors provide the most detailed overview of the immune microenvironment in sarcoma subtypes to date. UPS, which is a more highly mutated STS subtype, provokes a substantial immune response, suggesting that it may be well suited to treatment with immune checkpoint inhibitors. The SS and liposarcoma subsets are less mutated but do express immunogenic self‐antigens, and therefore strategies to improve antigen presentation and T‐cell infiltration may allow for successful immunotherapy in patients with these diagnoses. Cancer 2017;123:3291‐304. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Establishing a patient-derived xenograft model of human myxoid and round-cell liposarcoma.

Myxoid and round cell liposarcoma (MRCL) is a common type of soft tissue sarcoma. The lack of patient-derived tumor xenograft models that are highly consistent with human tumors has limited the drug experiments for this disease. Hence, we aimed to develop and validate a patient-derived tumor xenograft model of MRCL. A tumor sample from a patient with MRCL was implanted subcutaneously in an immunodeficient mouse shortly after resection to establish a patient-derived tumor xenograft model. After the tumor grew, it was resected and divided into several pieces for re-implantation and tumor passage. After passage 1, 3, and 5 (i.e. P1, P3, and P5, respectively), tumor morphology and the presence of the FUS-DDIT3 gene fusion were consistent with those of the original patient tumor. Short tandem repeat analysis demonstrated consistency from P1 to P5. Whole exome sequencing also showed that P5 tumors harbored many of the same gene mutations present in the original patient tumor, one of which was a PIK3CA mutation. PF-04691502 significantly inhibited tumor growth in P5 models (tumor volumes of 492.62 ± 652.80 vs 3303.81 ± 1480.79 mm3, P < 0.001, in treated vs control tumors, respectively) after 29 days of treatment. In conclusion, we have successfully established the first patient-derived xenograft model of MRCL. In addition to surgery, PI3K/mTOR inhibitors could potentially be used for the treatment of PIK3CA-positive MRCLs.

TP53INP2-related basal autophagy is involved in the growth and malignant progression in human liposarcoma cells.

Understanding the function of autophagy may allow us to develop a promising therapeutic strategy to enhance the effects of chemotherapy and improve clinical outcomes in the treatment of cancers. Here, we studied the contribution of basal autophagy in human liposarcoma. The levels of basal autophagy were analyzed by measuring autophagy-related protein expression and autophagosome formation. TP53INP2 expression was determined by real-time PCR, western blot and tissue microarray. Genetic inhibition or overexpression of TP53INP2 was performed to examine its effects on autophagic activity and cell growth. Compared with human liposarcoma cell line SW872, low level of basal autophagy were present in SW872-S cells with high malignancy. Moreover, a decrease of TP53INP2 expression was found accompanying liposarcoma malignant progression in cell lines and primary tissues. TP53INP2 expression was required for autophagic activity in liposarcoma cells. Autophagy inhibition with chloroquine suppressed the growth of liposarcoma cells. TP53INP2-related basal autophagy rendered liposarcoma cells to be more resistant to bortezomib-induced inhibition of cell growth. The results reveal the association of TP53INP2-related basal autophagy with cell growth and malignant progression of human liposarcoma, which helps re-evaluate targeting autophagy for cancer therapy, and suggest that TP53INP2 expression might be used as a prognostic marker to predict human liposarcoma malignancies.

Do Mesenchymal Stem Cells Derived From Atypical Lipomatous Tumors Have Greater Differentiation Potency Than Cells From Normal Adipose Tissues?

The p53 protein in mesenchymal stem cells (MSCs) regulates differentiation to osteogenic or adipogenic lineage. Because p53 function is depressed in most malignancies, if MSCs in malignancy also have p53 hypofunction, differentiation therapy to osteogenic or adipogenic lineage may be an effective treatment. We therefore wished to begin to explore this idea by evaluating atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) cells, because murine double minute 2 (MDM2) gene amplification, which leads to p53 hypofunction, is found in almost all ALT/WDLs. We compared osteogenic and adipogenic differentiation potency between MSCs isolated and cultured from normal adipose tissues and ALT/WDLs from the same patients. During tumor resections in six patients with ALT/WDL, we analyzed 3 mL of tumor, and for comparison, we harvested a similar amount of normal-appearing subcutaneous adipose tissue from an area remote from the tumor for comparison. Adipogenic differentiation potency was quantitatively assessed using spectrometry after oil red O staining. Osteogenic differentiation potency was semiquantitatively assessed by measuring a specific colored area after alkaline phosphatase (ALP) and alizarin red S staining. ALP is related to preosseous cellular metabolism, and alizarin red is related to calcium deposits in cell culture. There were three observers for each assessment, and each assessment (including induced-differentiation and histologic analysis) was performed in duplicate. We then analyzed the mechanism of the difference of osteogenic differentiation potency using the MDM2-specific inhibitor Nutlin-3 at various concentrations. In terms of adipogenic differentiation potency, contrary to our expectations, more fatty acid droplets were observed in MSCs derived from normal fat than in MSCs derived from ALT/WDL, although we found no significant difference between MSCs derived from ALT/WDL and MSCs derived from normal fat; the mean differentiation potency values (normal adipose tissue versus ALT/WDL) (± SD) were 0.34 (SD, ± 0.13; 95% CI, 0.24-0.44) versus 0.25 (SD, ± 0.10; 95% CI, 0.18-0.33; p = 0.22). By contrast, we found greater osteogenic differentiation potency in MSCs derived from ALT/WDL than in MSCs derived from normal fat. The mean differentiation potency values (normal adipose tissue versus ALT/WDL) (±SD) based on ALP staining was 1.0 versus 17 (SD, ± 36; 95% CI, -2.8 to 38; p = 0.04). However, we found no differences based on alizarin red S staining; mean differentiation potency value (normal adipose tissue versus ALT/WDL) (± SD) was 1.0 versus 4.2 (SD, ± 4.8; 95% CI, 1.3-7.2; p = 0.58). The gap of osteogenic differentiation potency between MSCs from normal adipose tissue and ALT/WDL was decreased as MDM2-inhibitor Nutlin-3 concentration increased. MSCs derived from ALT/WDL had higher osteogenic differentiation potency based on ALP staining, which disappeared as Nutlin-3 concentration increased, suggesting that could be caused by amplified MDM2 in ALT/WDL. Future laboratory studies might mechanistically confirm the gene and protein expression, and based on the mechanism of the gap of differentiation potency, if p53 contrast between MSCs in tumor and normal tissue could be stimulated, less-toxic and more-effective differentiation therapy to MSCs in malignancies might be developed.

A novel long noncoding RNA PILRLS promote proliferation through TCL1A by activing MDM2 in Retroperitoneal liposarcoma.

It is becoming evident that lncRNAs may be an important class of pervasive genes involved in carcinogenesis and metastasis. However, the biological and molecular mechanisms of lncRNAs in retroperitoneal liposarcoma have never been reported. In our study, we found a novel lncRNA PILRLS (Proliferation Interacting LncRNA in Retroperitoneal Liposarcoma), which as an oncogene significantly overexpressed in retroperitoneal liposarcoma. Functions of PILRLS on tumor progression both in vitro and in vivo have verified in this study which PILRLS knockdown significantly inhibited cell proliferation and colony formation. RNA pull-down assay found PILRLS can specific binding with TCL1A which also regulate the expression level of TCL1A. Our work for the first time demonstrated PILRLS can activating the MDM2 by binding with TCL1A which suppress the P53 pathway to promote the unlimited growth of retroperitoneal Liposarcoma cells. It suggests that PILRLS may be an important targets for retroperitoneal liposarcoma therapy.

Case report on the coincidence of retroperitoneal dedifferentiated giant liposarcoma and renal papillary cell carcinoma

The most common histological type of retroperitoneal sarcomas is liposarcoma. Renal papillary cancers account for approximately 10% of all known renal cell cancers and nephrectomy is the preferred choice for the treatment in suitable cases. In this report, we presented a concurrency of giant retroperitoneal liposarcoma and renal papillary cancer in a 61-year-old male patient. He was referred to our clinic with complaints of abdominal distension and pain. Computed tomography (CT) scan, magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) revealed a giant mass filling intraabdominal and retroperitoneal space, approximately 50x30 cm in size and also a separate mass which is 6x8 cm in size in the upper pole of the left kidney. The giant mass was excised in two separate pieces. After frozen section procedure, nephrectomy was performed for mass arising from the left kidney. Histopathological analysis of the large masses, revealed dedifferentiated liposarcoma and renal papillary cellular cancer in the abdomen and left kidney, respectively. In conclusion, a second primary tumor can be seen in patients with giant retroperitoneal liposarcoma and coincidence of these tumors must be determined in the preoperative period for appropriate treatment.

Curcumin and Viscum album Extract Decrease Proliferation and Cell Viability of Soft-Tissue Sarcoma Cells: An In Vitro Analysis of Eight Cell Lines Using Real-Time Monitoring and Colorimetric Assays

ABSTRACTBackground: The cytostatic effects of the polyphenol curcumin and Viscum album extract (VAE) were assessed in soft-tissue sarcoma (STS) cells. Methods: Eight human STS cell lines were used: fibrosarcoma (HT1080), liposarcoma (SW872, T778, MLS-402), synovial sarcoma (SW982, SYO1, 1273), and malignant fibrous histiocytoma (U2197). Primary human fibroblasts served as control cells. Cell proliferation, viability, and cell index (CI) were analyzed by BrdU assay, MTT assay, and real-time cell analysis (RTCA). Results: As indicated by BrdU and MTT, curcumin significantly decreased the cell proliferation of five cell lines (HT1080, SW872, SYO1, 1273, and U2197) and the viability of two cell lines (SW872 and SW982). VAE led to significant decreases of proliferation in eight cell lines (HT1080, SW872, T778, MLS-402, SW982, SYO1, 1293, and U2197) and reduced viability in seven STS lines (HT1080, SW872, T778, MLS-402, SW982, SYO1, and 1273). As indicated by RTCA for 160 h, curcumin decreased the CI of all synovial sarcoma cell lines as well as T778 and HT1080. VAE diminished the CI in most of the synovial sarcoma (SW982, SYO1) and liposarcoma (SW872, T778) cell lines as well as HT1080. Primary fibroblasts were not affected adversely by the two compounds in RTCA. Conclusion: Curcumin and VAE can inhibit the proliferation and viability of STS cells.

A Case of Myxoid/round Cell Liposarcoma in the Thigh with Concurrent Solitary Sternal Metastasis

A Case of Myxoid/round Cell Liposarcoma in the Thigh with Concurrent Solitary Sternal Metastasis

Spindle Cell Liposarcoma – A Rare Tumour Occurring at a Rare Site?

Spindle Cell Liposarcoma – A Rare Tumour Occurring at a Rare Site?

Hypercellular round cell liposarcoma: A comprehensive cytomorphologic study and review of 8 cases.

Background:Myxoid and round cell liposarcomas (RCL) are low and high-grade counterparts of a common subtype of liposarcomas (LPS), representing a histologic continuum.Aims:The aim was to study the cytomorphology of hypercellular RCL and to look for features that differentiate RCL from other sarcomas displaying round cells with myxoid change.Materials and Methods:Eight cases of hypercellular RCL were identified retrospectively in which round cell component constituted greater than 75% of the area. Cytomorphological features were studied in detail.Results:Four cases were predominantly composed of round cells, out of which 2 were entirely composed of round cells. Myxoid metachromatic stroma was absent in 2 cases, while it was present in ample amounts in the remaining 6 cases. Spindle cells were completely absent in 5 cases and lipoblasts were observed in a single case of RCL. Plexiform vascular capillaries were seen in 4 cases. Adherence of neoplastic round cells around thin capillaries (ANAC) was observed in 7 cases.Conclusions:Plexiform capillary plexus and ANAC should be separately evaluated. The latter feature is the most consistent one, and is an important clue to the adipocytic nature of the neoplasm when hypercellular round cell areas are aspirated. Confident diagnosis of hypercellular RCL can be made on the basis of this feature. Lipoblasts, although specific, are seen in few cases. The rest of the features are nonspecific and useful only in combination.

The role of histology, grading, location of tumour and ploidy in evaluation of outcome in patients with liposarcoma.

Department of Tumour Pathology, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Kraków, Poland The review of literature indicates that several clinico-morphological factors such as location of the primary tumour as well as its size, histologic subtype, and grade or even selected molecular changes may significantly affect survival of liposarcoma (LPS) patients. Data concerning prognostic importance of DNA ploidy status in LPS cells are extremely limited and results of flow cytometry (FCM) studies have never been compiled with the current classification of malignant adipocytic tumours. Based on evaluation of material from 54 liposarcomas which was available for both histological and FCM analysis, we distinguished four prognostic groups of patients. The best prognosis was noticed for diploid and grade G1 well-differentiated or myxoid liposarcomas localised on extremities. None of the patients with lipoma-like WDLPS and myxoid liposarcoma grade 1 metastasised, while metastases were observed among patients with dedifferentiated LPS (70% of 5-year MFS) and cellular myxoid or round cell liposarcoma (20% of 5-year MFS, only). The metastasis-free survival curves for the above mentioned groups of patients differed significantly (p = 0.00001).

Anti‑proliferative activity of epigallocatechin‑3‑gallate and silibinin on soft tissue sarcoma cells.

Disseminated soft tissue sarcomas (STS) present a therapeutic dilemma. The first-line cytostatic doxorubicin demonstrates a response rate of 30% and is not suitable for elderly patients with underlying cardiac disease, due to its cardiotoxicity. Well-tolerated alternative treatment options, particularly in palliative situations, are rare. Therefore, the present study assessed the anti-proliferative effects of the natural compounds epigallocatechin-3-gallate (EGCG), silibinin and noscapine on STS cells. A total of eight different human STS cell lines were used in the study: Fibrosarcoma (HT1080), liposarcoma (SW872, T778 and MLS-402), synovial sarcoma (SW982, SYO1 and 1273) and pleomorphic sarcoma (U2197). Cell proliferation and viability were analysed by 5-bromo-2′-deoxyuridine and MTT assays and real-time cell analysis (RTCA). RTCA indicated that noscapine did not exhibit any inhibitory effects. By contrast, EGCG decreased proliferation and viability of all cell lines except for the 1273 synovial sarcoma cell line. Silibinin exhibited anti-proliferative effects on all synovial sarcoma, liposarcoma and fibrosarcoma cell lines. Liposarcoma cell lines responded particularly well to EGCG while synovial sarcoma cell lines were more sensitive to silibinin. In conclusion, the green tea polyphenol EGCG and the natural flavonoid silibinin from milk thistle suppressed the proliferation and viability of liposarcoma, synovial sarcoma and fibrosarcoma cells. These compounds are therefore potential candidates as mild therapeutic options for patients that are not suitable for doxorubicin-based chemotherapy and require palliative treatment. The findings from the present study provide evidence to support in vivo trials assessing the effect of these natural compounds on solid sarcomas.

Molecular mechanism and therapeutic implications of selinexor (KPT-330) in liposarcoma.

Exportin-1 mediates nuclear export of multiple tumor suppressor and growth regulatory proteins. Aberrant expression of exportin-1 is noted in human malignancies, resulting in cytoplasmic mislocalization of its target proteins. We investigated the efficacy of selinexor against liposarcoma cells both in vitro and in vivo. Exportin-1 was highly expressed in liposarcoma samples and cell lines as determined by immunohistochemistry, western blot, and immunofluorescence assay. Knockdown of endogenous exportin-1 inhibited proliferation of liposarcoma cells. Selinexor also significantly decreased cell proliferation as well as induced cell cycle arrest and apoptosis of liposarcoma cells. The drug also significantly decreased tumor volumes and weights of liposarcoma xenografts. Importantly, selinexor inhibited insulin-like growth factor 1 (IGF1) activation of IGF-1R/AKT pathway through upregulation of insulin-like growth factor binding protein 5 (IGFBP5). Further, overexpression and knockdown experiments showed that IGFBP5 acts as a tumor suppressor and its expression was restored upon selinexor treatment of liposarcoma cells. Selinexor decreased aurora kinase A and B levels in these cells and inhibitors of these kinases suppressed the growth of the liposarcoma cells. Overall, our study showed that selinexor treatment restored tumor suppressive function of IGFBP5 and inhibited aurora kinase A and B in liposarcoma cells supporting the usefulness of selinexor as a potential therapeutic strategy for the treatment of this cancer.

Abstract IA04: The Targeting of CDK4/6: Have we gone full circle?

Abstract Cyclin Dependent kinase 4 (CDK4) is a critical kinase that regulates the G1/S phase transition within the cell cycle. There has been a major effort to develop drugs that inhibit this kinase. The first CDK4 inhibitor to be approved is Palbociclib. It is approved in combination with letrozole for the treatment of postmenopausal women with metastatic estrogen receptor (ER)-positive breast cancer as initial endocrine-based therapy. In this study Palbociclib (Palbo) improved median progression free survival (mPFS) from 10.2 months with letrozole alone to 20.2 months with Palbo in the combination therapy [Hazard Ratio (HR) 0.488 (95% CI 0.319, 0.748)]. Response rates were 55.4% with the combination and 39.4% with letrozole alone. Palbo has been tested in other disease including dedifferentiated and well-differentiated liposarcoma where CDK4 is amplified. In this disease Palbo has been reported to increase the PFS at 12 weeks to 66% surpassing the primary end of 40% in patients who had progressed on at least one primary regimen. The major toxicity is neutropenia. Other CDK4 inhibitors are in clinical trial, including LEE001 (Novartis) and LY2835219 (Eli Lilly). These agents exhibit a somewhat different toxicity profile with neutropenia and QTc prolongation with LEE001 and gastrointestinal toxicity with LY2835219. Recently, CDK4 inhibition has been shown to induce either a reversible cell cycle arrest or an irreversible senescent state. The proteolytic turnover of MDM2 appears to be critical for cellular senescence induced by CDK4 inhibition in liposarcoma, breast, lung and glioma cell lines. MDM2 turnover depends on its E3 ligase activity and expression of ATRX. In a small series of liposarcoma patients treated with Palbo the suppression of MDM2 expression correlated with improved clinical outcome suggesting that loss of MDM2 by inhibition of CDK4 could be a predictive biomarker for improved clinical outcome with this class of drugs. Citation Format: Gary K. Schwartz. The Targeting of CDK4/6: Have we gone full circle? [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr IA04.

Efficacy of trabectedin for the treatment of liposarcoma

ABSTRACTIntroduction: Trabectedin (ET-743) is a synthetic marine derived alkylating agent, extracted originally from a Caribbean Sea sponge. It is approved for the treatment of Soft Tissue sarcomas (STS) in Europe and recently by the FDA for liposarcomas and leiomyosarcomas.Areas covered: Trabectedin has multiple mechanisms of action, including one targeting the FUS-CHOP oncogene in Myxoid/Round cell Liposarcomas. Numerous Phase I, II and III clinical trials have been conducted with Trabectedin. It has been studied as monotherapy or in combination with other chemotherapeutic agents. The recommended dose based on clinical trials is 1.5 milligrams/m2 continuous infusion over 24 hours once every 3 weeks for STS with evidence of disease control in multiple clinical trials at this dose. The most common Grade 3/4 toxicities include neutropenia and transient noncumulative elevations of ALT and AST. Steroid pretreatment has shown efficacy in reducing liver and bone marrow toxicity. In phase III testing comparing trabectedin to dacarbazine, trabectedin was associated with a significantly improved progression free survival rate in patients with advanced lipo- and leiomyosarcomas.Expert opinion: Trabectedin is an important new addition to the limited treatment options currently available for STS, especially for patients with liposarcoma that have progressed on standard chemotherapeutic regimens.

Spindle cell lipoma adherent to the digital nerve in the palm.

Dear sir, Spindle cell lipoma, a solitary, slowly growing subcutaneous tumor, mainly in the posterior neck, shoulder girdle, upper back predominantly in men in the fifth to seventh decades. It can arise in other areas of the body. Johnson et al. reported a spindle cell lipoma in the orbital region; Toker et al. reported in the breast; Suster et al. reported in the gastrointestinal tract and Eckert et al. reported in the upper arm. Spindle cell lipomas are typically placed encapsulated in sub cutis, while occasionally they are poorly demarcated and can extend in to the dermis or underlying tissues. No case of spindle cell lipoma in the palm adherent to digital nerve has been reported in the literature. Here, we present a rare case of spindle cell lipoma adherent to the digital nerve in the palm. A 43 years old male patient was admitted to our clinic for further examination of the mass occurring in his right palm 24 months ago and hypoesthesia of radial side of the third finger for 3 months. A physical examination revealed 4 cm × 3 cm subcutaneous mass in the right palmar area. Ultrasonography revealed well circumscribed and low-echo 4 cm × 3 cm mass in the subcutaneous region of the palm. Furthermore, heterogenous signal intensity on all pulse sequences was showed by magnetic resonance imaging. A fine needle biopsy reported a spindle cell lipoma. At exploration, there was a well-circumscribed mass, connected to the digital nerve. (Fig.​(Fig.1a)1a) The multi lobulated 34 mm diameter mass was yellowish-white on its cut surfaces, had a firm texture, and was clearly demarcated from the adjacent tissues by a thin fibrous capsule The patient had no recurrence in 46 months follow-up. Fig. 1 a. Peroperative view of the spindle cell lipoma and the digital nerve b. Spindle cells in non-lipogenic areas are CD34 positive. (CD34; Original magnification X200) Spindle cell lipoma is a benign tumor distinguished by the replacement of mature adipocoyte by collagen forming spindle cells. It is a mixture of short spindle cells, adipocytes, and ropey collagen bundles, sometimes with a myxoid stroma. The differential diagnosis includes dermatofibrosarcoma protuberance, angiomyofibroblastoma, nodular fasciitis and myxoid liposarcoma [1]. Lipoblasts, fat necrosis, and fat with atrophic changes are important to the differential diagnosis of liposarcoma and spindle cell lipoma. There was co-expression of CD34, bcl-2, and vimentin in the spindle cells. (Fig. 1b). Tardio also reported that co-expression of CD34 and bcl-2 was common in atypical adipocytic tumors in a recent study [2]. Spindle cell lipoma is most closely related to pleomorphic lipoma in terms of demographics and presenting location. Cytogenetically, most spindle cell and pleomorphic lipomas show common 16q or 13q abnormalities [3]. Some authors have reported on the intra dermal origin which presents with different clinical or morphological features such as, widespread anatomical distribution, female predilection and an infiltrative pattern. Also, Mounasamy et al. have reported single case of spindle cell lipoma of palm [4]. Definitive diagnosis of spindle cell lipoma is crucial to recognize that this is a benign tumor and avoid misdiagnosing the lesion as a myxoid liposarcoma. The treatment of option for spindle cell lipoma is a complete local excision and its recurrence is extremely rare.

S35 - Innovative approaches to establish and characterize primary cultures: an ex vivo 3D system and the zebrafish model

Background: Patient-derived specimens are an invaluable resource to study the heterogeneous biology and behavior of cancer cells, in particular in rare tumors as Soft Tissue Sarcomas, for which several subtypes exist, not all covered by the matched cell lines. However in vivo studies on primary cultures are often limited by the low amount of material available, while conventional in vitro systems might alter the cell features and behavior. Here we present data on primary dedifferentiated liposarcoma cells cultured on tridimensional collagen-based scaffolds and injected into the Zebrafish model as a proof of concept of the usefulness of these models in the study of patient-derived material. Methods: Primary dedifferentiated liposarcoma cells, isolated from surgical specimens, were characterized in vitro for their morphological features, sensitiveness to drugs and biomarker expression, and in vivo for their engraftment and invasiveness abilities. Cells were treated with trabectedin and with the standard combination of ifosfamide and epirubicin. Aggressiveness markers were assayed by qPCR. Cells were injected in the heart cavity of zebrafish embryos, monitoring the embryos daily. Results: The 3D culture resulted enriched in cancer cells compared to standard monolayer culture and best preserved liposarcoma-associated markers. 3D-enriched cells proved sensitive to drugs with percentages of survival not significantly different between epirubicin plus ifosfamide and trabectedin alone. Liposarcoma cells injected in the Zebrafish were capable of surviving in the heart cavity and in later stages were scattered throughout the implantation area showing local migratory and invasive abilities, and the successful engraftment of this patient-derived liposarcoma culture in this animal model. Conclusions: This work provide the proof of concept of the ability of 3D cultures to preserve the original phenotypes of ex vivo cells, and of the Zebrafish model to offer a versatile in vivo system for studies with limited material. The implementation of these models could foster translational research studies, both in terms of biomolecular analyses, drug screenings and aggressiveness assays. Finally, we demonstrated in vitro a similar efficacy of trabectidin respect to the conventional first line therapy epirubicin plus ifosfamide opening new horizons to better investigate the mechanism of action of these drugs and the treatment strategy of dedifferentiated liposarcomas.

Establishment and characterization of a new human myxoid liposarcoma cell line (DL-221) with the FUS-DDIT3 translocation

Myxoid liposarcoma has the pathognomonic fusion oncogene FUS-DDIT3 encoding a chimeric transcription factor. Metastatic risk is higher with an increased round cell component and has been linked to aberrations involving the IGFR/PI3K/AKT pathway. These molecular insights have yet to translate to targeted therapies, and the lack of experimental models is a major hindrance. We describe the initial in-depth characterization of a new cell line (DL-221) and establishment of a mouse xenograft model. The cell line DL-221 was derived from a metastatic pleural lesion showing myxoid and round cell histology. This newly established cell line was characterized for phenotypic properties and molecular cytogenetic profile, using PCR, COBRA-FISH, and western blot. Next-generation whole-exome sequencing was performed to further characterize the cell line and the parent tumor. NOD-SCID-IL2R gamma knockout mice were xenograft hosts. DL-221 cells grew an adhering monolayer and COBRA-FISH showed an aneuploid karyotype with t(12;16)(q13;p11) and several other rearrangements; RT-PCR demonstrated a FUS-DDIT3 fusion transcript type 1. Both the cell line and the original tumor harbored a TP53 compound heterozygous mutation in exon 4 and 7, and were wild-type for PIK3CA. Moreover, among the 1254 variants called by whole-exome sequencing, there was 77% concordance between the cell line and parent tumor. The recently described hotspot mutation in the TERT promoter region in myxoid liposarcomas was also found at C228T in DL-221. Xenografts suitable for additional preclinical studies were successfully established in mice after subcutaneous injection. The established DL-221 cell line is the only published available myxoid liposarcoma cell line that underwent spontaneous immortalization, without requiring SV40 transformation. The cell line and its xenograft model are unique and helpful tools to study the biology and novel potential-targeted treatment approaches for myxoid liposarcoma.