Identification of microRNA biomarkers for response of advanced soft tissue sarcomas to eribulin: Translational results of the EORTC 62052 trial

BACKGROUND

Recent phase II and III clinical trials demonstrated anti-tumour activity of eribulin, a tubulin-interacting cytotoxic agent, in patients with metastatic soft tissue sarcoma (STS). In this exploratory study, we aimed to identify putative microRNA biomarkers that associate with eribulin sensitivity or resistance in STS.

MATERIALS AND METHODS

Archival tumour tissue from primary tumours or metastatic lesions was collected prior to eribulin treatment, from 65 consenting patients involved in the EORTC trial 62052. This phase II study (ClinicalTrials.gov identifier NCT00413192) included multiple subtypes of STS. Tissue was available from 21 leiomyosarcomas, 14 adipocytic sarcomas, 9 synovial sarcomas and 21 other sarcoma histotypes. Total RNA was isolated from formalin-fixed, paraffin-embedded tumour samples and analysed using Taqman^® Low Density Arrays to determine microRNA expression profiles. The expression of a total of 756 microRNAs was assessed. Progression-free survival at week 12 (RECIST 1.0) measured as a binary variable, was the primary end-point of the clinical trial and used as a primary response measure for correlative studies. Seventeen of 53 (32.1%) evaluable patients in the analysed subset had non-progressive disease at week 12 and were defined as responders.

RESULTS

The expression of 26 individual microRNAs (p < 0.05) differed significantly between non-responders and responders. Additional microRNAs of potential relevance were identified when considering the different histological subgroups.

CONCLUSIONS

The expression level of particular microRNAs in STS tissue samples may predict response to eribulin. Further validation studies as well as a preclinical assessment of the underlying molecular mechanisms are required.

Familial autoinflammation with neutrophilic dermatosis reveals a regulatory mechanism of pyrin activation

Pyrin responds to pathogen signals and loss of cellular homeostasis by forming an inflammasome complex that drives the cleavage and secretion of interleukin-1β (IL-1β). Mutations in the B30.2/SPRY domain cause pathogen-independent activation of pyrin and are responsible for the autoinflammatory disease familial Mediterranean fever (FMF). We studied a family with a dominantly inherited autoinflammatory disease, distinct from FMF, characterized by childhood-onset recurrent episodes of neutrophilic dermatosis, fever, elevated acute-phase reactants, arthralgia, and myalgia/myositis. The disease was caused by a mutation in MEFV, the gene encoding pyrin (S242R). The mutation results in the loss of a 14-3-3 binding motif at phosphorylated S242, which was not perturbed by FMF mutations in the B30.2/SPRY domain. However, loss of both S242 phosphorylation and 14-3-3 binding was observed for bacterial effectors that activate the pyrin inflammasome, such as Clostridium difficile toxin B (TcdB). The S242R mutation thus recapitulated the effect of pathogen sensing, triggering inflammasome activation and IL-1β production. Successful therapy targeting IL-1β has been initiated in one patient, resolving pyrin-associated autoinflammation with neutrophilic dermatosis. This disease provides evidence that a guard-like mechanism of pyrin regulation, originally identified for Nod-like receptors in plant innate immunity, also exists in humans.

Epithelioid Hemangioma of Bone: A Potentially Metastasizing Tumor?

The case of a 15-year-old boy with a severe swelling of the 2nd toe in the left foot and a large swelling of the left inguinofemoral region is described. Histologic examination of the foot lesion showed a typical epithelioid hemangioma of bone that extended into the soft tissues, with a secondary location in the groin, suggestive of lymph node involvement. Subsequently, imaging also revealed swelling of iliac and para-aortic lymph nodes, which probably indicates further lymph node spread.. Besides the fact that epithelioid hemangioma of the toe has not been reported yet, our case showed a noncontinuous localization, most likely in draining lymph nodes. This finding suggests metastatic disease, an event that is extremely rare for epithelioid hemangioma. As such, epithelioid hemangioma might be comparable to another benign vascular tumor, the retiform hemangioendothelioma, which occasionally metastasizes to the lymph nodes without systemic spread.

Cytokeratin-Positive Meningeal Peripheral PNET/Ewing's Sarcoma of the Cervical Spinal Cord: Diagnostic Value of Genetic Analysis

Peripheral primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES) of the central nervous system is extremely rare and should be differentiated from central PNET and other small blue round cell tumors. We describe a case of a meningeal peripheral PNET/ES of the spinal cord in an 11 -year-old boy. Immunohistochemically, the small blue round cell tumor showed expression of epithelial markers and of CD99, thus posing an important differential diagnostic problem with a poorly differentiated synovial sarcoma. Fluorescence in situ hybridization revealed rearrangement of the EWS gene, as seen in peripheral PNET/ES. Peripheral PNET/ES does occur in the central nervous system, but its diagnosis can be extremely difficult on morphologic and immunohistochemical grounds alone. Genetic analysis plays a key role in its distinction from other small blue round cell tumors.

Abstract 5197: Patient-derived xenograft (PDX) models of soft tissue sarcoma (STS): a preclinical platform for early drug testing

Background: STS constitutes a rare and very heterogeneous family of mesenchymal tumors. The limited treatment options available for advanced STS underline the need for reliable preclinical models to test novel therapeutic strategies.

Methods: A panel of patient-derived xenografts (PDX) was established by subcutaneous implantation of fresh, surgically resected tumor specimens in immunodeficient athymic nude NMRI mice. Once tumor growth was observed, pieces of tumor were re-transplanted to next generations of mice. At each passage tumor fragments were collected for histolopathological and molecular characterization. A model was considered established after observing stable histological and molecular features for at least two passages. To evaluate the stability of the genomic profile we performed low-coverage whole-genome sequencing on DNA isolated from tumors obtained from at least two passages. In addition RNA-seq was used to better characterize the mutational profile of the ex-mouse tumors.

Results: Until now 139 STS samples from consenting patients treated at the University Hospitals, Leuven, Belgium, have been transplanted. Twenty six well-characterized, stable STS PDX models have been established, maintaining the histopathological and molecular features of the original tumor. Seventeen models, analyzed with low-coverage DNA sequencing, showed a stable genomic profile in at least two different tumor passages. At this point the panel includes models of gastrointestinal stromal tumor (6 models), myxofibrosarcoma (5), dedifferentiated liposarcoma (3), malignant peripheral nerve sheath tumor (3), synovial sarcoma (2), leiomyosarcoma (3) epithelioid haemangioendothelioma (1), mesenchymal chondrosarcoma (1) and undifferentiated high grade sarcoma (2). Some of these models have already been successfully used for in vivo testing of novel agents, including both targeted and cytotoxic (pro-)drugs, and results served as a rationale for at least four prospective clinical trials. In addition 22 other xenografts are still in early stages of engraftment, not yet fulfilling our criteria of an “established model”.

Conclusion: Our panel of mesenchymal PDX models is characterized by stable histological and molecular features. These clinically well-annotated models can contribute to reliable preclinical studies for new anticancer treatments for STS. The availability of unique, rare STS xenografts also allows to study the biology of these diseases. The platform is made available to collaborators from academia and industry.

Citation Format: Agnieszka Wozniak, Jasmien Cornillie, Yemarshet K. Gebreyohannes, Bram Boeckx, Haifu Li, Thomas Van Looy, Giuseppe Floris, Jasmien Wellens, Lise Vreys, Daphne Hompes, Marguerite Stas, Friedl Sinnaeve, Diether Lambrechts, Maria Debiec-Rychter, Raf Sciot, Patrick Schoffski. Patient-derived xenograft (PDX) models of soft tissue sarcoma (STS): a preclinical platform for early drug testing. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5197.

Cladophialophora bantiana osteomyelitis in a renal transplant patient

Cladophialophora bantiana is a neurotropic dematiaceous fungus which rarely causes disseminated disease. We report a case of proven C. bantiana osteomyelitis in a renal transplant recipient, complicated with probable cerebral disease. Stable disease was reached after combined antifungal therapies, immune enhancement and amputation of the infected lower limb.

Recurrent MALAT1-GLI1 oncogenic fusion and GLI1 up-regulation define a subset of plexiform fibromyxoma

Plexiform fibromyxomas are rare neoplasms, being officially recognized as a distinct entity among benign mesenchymal gastric tumours in the 2010 WHO Classification of Tumours of the Digestive System. Characteristically, these tumours have a multinodular/plexiform growth pattern, and histologically contain variably cellular areas of bland myofibroblastic-type spindle cells embedded in an abundant myxoid matrix, rich in capillary-type vessels. As yet, the molecular and/or genetic features of these tumours are unknown. Here we describe a recurrent translocation, t(11;12)(q11;q13), involving the long non-coding gene metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and the gene glioma-associated oncogene homologue 1 (GLI1) in a subgroup of these tumours. The presence of the fusion transcript in our index case was confirmed using polymerase chain reaction (PCR) on genomic DNA, followed by Sanger sequencing. We showed that the truncated GLI1 protein is overexpressed and retains its capacity to transcriptionally activate its target genes. A specific FISH assay was developed to detect the novel MALAT1-GLI1 translocation in formalin-fixed, paraffin-embedded (FFPE) material. This resulted in the identification of two additional cases with this fusion and two cases with polysomy of the GLI1 gene. Finally, immunohistochemistry revealed that the GLI1 protein is exclusively overexpressed in those cases that harbour GLI1/12q13 genomic alterations. In conclusion, overexpression of GLI1 through a recurrent MALAT1-GLI1 translocation or GLI1 up-regulation delineates a pathogenically distinct subgroup of plexiform fibromyxomas with activation of the Sonic Hedgehog signalling pathway. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Pulmonary metastasis of a meningioma presenting as a solitary pulmonary nodule: 2 case reports

Distant metastases of meningioma are rare, especially in grade 1 meningiomas. In a recent literature review, only 115 cases were found. In almost all published cases, the meningioma was treated several years before the metastasis was diagnosed. The lungs are the most frequent site of metastasis. We describe two patients treated for meningioma (one case grade 1, the other grade 3) who were referred to the Respiratory Oncology Unit because of the incidental finding of a pulmonary nodule on routine chest radiography. Both had undergone several neurosurgical procedures but the last operation was more than 7 years before in both cases. Positron emission tomography scan was suggestive of a malignant lung tumour. The lesions were surgically removed. Pathology confirmed meningioma in both cases with the same WHO grade, immunohistochemical and genetic profiles as the original meningioma. Both patients recovered well from thoracic surgery. The patient with grade 3 meningioma died three years later from intracranial recurrence. When a patient previously treated for meningioma develops a nodular lung lesion, metastasis of the meningioma should be in the differential diagnosis list. Because of the occurrence of distant metastasis even in grade I meningiomas, we suggest that the grading system should take into account genetic changes in the meningioma. Chromosome 1p and 14q losses possibly explain the aggressive behaviour of the grade 1 meningioma.

Abstract 5353: Efficacy of an innovative, enzyme-activated doxorubicin prodrug in patient-derived dedifferentiated liposarcoma and synovial sarcoma xenograft models

Background and objective: Dedifferentiated liposarcoma (DDLPS) and synovial sarcoma (SynSa) are aggressive malignant tumors of mesenchymal origin. Prognosis of advanced disease is poor with low response rates to first-line single agent doxorubicin (doxo) treatment, which is regarded as standard of care in metastatic disease. We evaluated the efficacy of PhAc-ALGP-doxorubicin (ALGP-doxo), a prodrug which is metabolized to doxo by peptidases present in the tumor microenvironment and/or tumor cells, in one SynSa and two DDLPS patient-derived xenografts.

Methods: NMRI mice (n = 24) were transplanted subcutaneously on both flanks with human DDLPS (models UZLX-STS3 and UZLX-STS5) or SynSa (UZLX-STS7). Mice were randomized to three treatment groups: control (vehicle), doxo (0.03 mmol/kg for UZLX-STS3; 0.04 mmol/kg for UZLX-STS5 and UZLX-STS7) or ALGP-doxo (1.2 mmol/kg). Treatments were administered using intraperitoneal osmotic pumps, continuously releasing drugs for 7 days. Afterwards, half of mice from each group were sacrificed and tumors were collected. Remaining mice were monitored for another 14 days and tumors were collected on day 21. Treatment efficacy was assessed by tumor volume, hematoxylin and eosin (H&E) staining, immunohistochemistry for proliferation [phospho-histone H3 (pHH3), Ki-67] and apoptosis [cleaved caspase 3 (CC3)] and by Western blotting (WB). Statistical analysis was performed with Wilcoxon and Mann-Withney U-test, defining p&lt;0.05 as statistically significant.

Results: While the tumor volume in the control and doxo group increased steadily, in UZLX-STS3 and UZLX-STS5 ALGP-doxo caused tumor volume stabilization. Moreover, in UZLX-STS7 the average relative tumor volume decreased to 60.1% on day 7 and to 4.6% on day 21 under ALGP-doxo treatment. Long-lasting therapeutic effects of ALGP-doxo even after treatment withdrawal were observed in all three models tested. Compared to the control and doxo group, ALGP-doxo induced a significant decrease in proliferation and a significant increase in apoptotic activity on day 7 in all three models. It was also observed on day 21 in UZLX-STS3 and UZLX-STS5, while in UZLX-STS7 tumor tissue was replaced by fibroblasts. WB with tumor samples collected on day 7 showed expression of cleaved PARP in ALGP-doxo treated samples of UZLX-STS7, but not in the control or doxo group, and decreased pHH3 levels in the ALGP-doxo treated tumors of UZLX-STS5 and UZLX-STS7.

Conclusion: ALGP-doxo shows considerably higher anti-tumor activity than doxo in patient-derived DDLPS and SynSa xenografts. The delivery of a 30-40 fold higher dose of ALGP-doxo than doxo is tolerated without significant side effects, while comparable dose of doxo is lethal. The prodrug and its activation by the tumor or the microenvironment warrants further testing in anthracycline-sensitive and -resistant preclinical models of human malignancies.

Citation Format: Jasmien Cornillie, Agnieszka Wozniak, Lise Vreys, Haifu Li, Thomas Van Looy, Jasmien Wellens, Ulla Vanleeuw, André Trouet, Peter Pokreisz, Daphne Hompes, Maria Debiec-Rychter, Raf Sciot, Patrick Schöffski. Efficacy of an innovative, enzyme-activated doxorubicin prodrug in patient-derived dedifferentiated liposarcoma and synovial sarcoma xenograft models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5353. doi:10.1158/1538-7445.AM2015-5353

Abstract 1461: A panel of patient derived gastrointestinal stromal tumors (GIST) xenograft models for in vivo preclinical drug testing

Objective: Most GIST are dependent on the KIT/PDGFRA signaling pathway and therefore can be treated with specific tyrosine kinase inhibitors (TKI). With time GIST develop resistance to TKI. We need reliable models which can be used for preclinical drug testing.

Methods: Patient-derived xenografts were established in nu/nu NMRI mice by subcutaneous implantation of fresh, surgically resected tumor specimens from consenting patients with GIST treated at the University Hospitals Leuven. Once tumor growth was observed, pieces of tumor were re-transplanted to next generations of mice. At each passage tumor fragments were collected for histological and molecular characterization. A model was considered to be established after observing stable histological and molecular features for at least two passages.

Results: At present we have access to five successfully established GIST models, with different KIT mutations and different sensitivity to standard TKI (Table).

Untreated tumors from subsequent passages show morphological and immunohistochemical features resembling the original patient biopsy, verifying the stability of GIST xenografts growth. KIT mutational status has also been confirmed in samples obtained from all models. These models are used for pre-clinical testing of new therapeutic approaches, and current results served as a rationale for at least four prospective clinical trials. If needed, we parallel our patient-derived models with in vitro or in vivo studies using one of the few established GIST cell lines.

Conclusion: Our established GIST xenografts maintain the histological and molecular characteristics of the original patient sample and are a very useful and reliable preclinical platform for testing the new targeted approaches in GIST. The platform is available for collaboration with academic and commercial partners (contact patrick.schoffski@uzleuven.be).

The overview of patients-derived GIST xenograftsModel*KIT mutationIn vivo efficacy [% of relative tumor volume after three weeks]PrimarySecondaryImatinib (50mg/kg, BID)Sunitinib (40mg/kg, QD)UZLX-GIST1p.V560Dn/a2020UZLX-GIST2p.A502_Y503dupn/a17080UZLX-GIST3p.W557_V559delinsFn/a2525UZLX-GIST4p.K558_G565delinsRn/a4520UZLX-GIST9p.P577delp.W557LfsX5, p.D820G250170*models which showed tumor growth for at least two passages; n/a-not applicable

Citation Format: Agnieszka Wozniak, Thomas Van Looy, Giuseppe Floris, Yemarshet K. Gebreyohannes, Jasmien Wellens, Haifu Li, Jasmien Cornillie, Ulla Vanleeuw, Daphne Hompes, Marguerite Stas, Maria Debiec-Rychter, Raf Sciot, Patrick Schoffski. A panel of patient derived gastrointestinal stromal tumors (GIST) xenograft models for in vivo preclinical drug testing. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1461. doi:10.1158/1538-7445.AM2015-1461

Abstract 774: Cabozantinib, a multi-target receptor tyrosine kinase inhibitor, decreases tumor growth and angiogenesis in a patient-derived dedifferentiated liposarcoma xenograft

Background: Upregulation of receptor tyrosine kinase signaling pathways, including vascular endothelial growth factor receptor (VEGFR) and MET (also known as hepatocyte growth factor receptor), is found in different subtypes of soft tissue sarcoma. Cabozantinib (CABO) is a multi-target inhibitor of receptor tyrosine kinases including VEGFR, MET, RET, and KIT. We aimed to evaluate the anti-angiogenic and anti-tumor effect of CABO alone and in combination with the standard-of-care cytotoxic agent doxorubicin (DOX) in a patient-derived xenograft model of dedifferentiated liposarcoma (DDLPS).

Methods: NMRI nu/nu mice were bilaterally transplanted with human UZLX-STS3 DDLPS tumors, a model originating from a patient with DDLPS. Twenty eight tumor-bearing mice were assigned to 4 groups and treated for three weeks with either vehicle (control), DOX (i.p., 1.2mg/kg/twice per week), CABO (p.o., 30mg/kg/QD) or CABO+DOX (same dose/schedule as for the single agents). Tumor volume was measured three times a week. Mitotic and apoptotic activity were assessed on hematoxylin and eosin (H&E) staining and with phospho-histone H3 (pHH3) and cleaved-caspase 3 (CC3) immunostainings. Microvascular density (MVD) was evaluated by counting CD34 positive vessels. Statistics were calculated using the Mann-Whitney U pairs tests. p &lt; 0.05 was considered as statistically significant.

Results: A significant delay in tumor growth was observed in CABO and CABO+DOX treated groups as compared to controls (p&lt;0.05) or DOX single agent (p&lt;0.05). Both CABO and CABO+DOX reduced the mitotic activity in comparison with control (38% and 66% decrease, respectively, p&lt;0.005). CABO+DOX showed better antimitotic activity than either single agent DOX or CABO (p&lt;0.005 for both). The CABO-based treatments induced higher apoptotic activity as compared to control (2.1 fold in CABO and 2.4 fold in CABO+DOX, p&lt;0.005). Results were confirmed by pHH3 and CC3 stainings. Furthermore, significantly decreased MVD was observed in the CABO and the combination treated tumors as compared to control (64% and 67% decrease, respectively, p&lt;0.005) and as compared to DOX alone (57% and 61% decrease, respectively, p&lt;0.005).

Conclusions: CABO has anti-tumor activity in the UZLX-STS3 DDLPS xenograft model by inhibiting proliferation, inducing apoptosis and suppressing angiogenesis. These in vivo results support ongoing and planned clinical trials with cabozantinib in mesenchymal malignancies.

Citation Format: Haifu Li, Agnieszka Wozniak, Karel Van Den Bossche, Thomas Van Looy, Jasmien Wellens, Daphne Hompes, Dana Aftab, Maria Debiec-Rychter, Raf Sciot, Patrick Schöffski. Cabozantinib, a multi-target receptor tyrosine kinase inhibitor, decreases tumor growth and angiogenesis in a patient-derived dedifferentiated liposarcoma xenograft. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 774. doi:10.1158/1538-7445.AM2015-774