Therapeutic vulnerability of an in vivo model of alveolar soft part sarcoma (ASPS) to antiangiogenic therapy

ASPSCR1::TFE3 orchestrates the angiogenic program of alveolar soft part sarcoma

Alveolar soft part sarcoma (ASPS) is a soft part malignancy affecting adolescents and young adults. ASPS is characterized by a highly integrated vascular network, and its high metastatic potential indicates the importance of ASPS's prominent angiogenic activity. Here, we find that the expression of ASPSCR1::TFE3, the fusion transcription factor causatively associated with ASPS, is dispensable for in vitro tumor maintenance; however, it is required for in vivo tumor development via angiogenesis. ASPSCR1::TFE3 is frequently associated with super-enhancers (SEs) upon its DNA binding, and the loss of its expression induces SE-distribution dynamic modification related to genes belonging to the angiogenesis pathway. Using epigenomic CRISPR/dCas9 screening, we identify Pdgfb, Rab27a, Sytl2, and Vwf as critical targets associated with reduced enhancer activities due to the ASPSCR1::TFE3 loss. Upregulation of Rab27a and Sytl2 promotes angiogenic factor-trafficking to facilitate ASPS vascular network construction. ASPSCR1::TFE3 thus orchestrates higher ordered angiogenesis via modulating the SE activity.

Establishment and characterization of NCC-ASPS1-C1: a novel patient-derived cell line of alveolar soft-part sarcoma

Alveolar soft-part sarcoma is a mesenchymal malignancy characterized by the rearrangement of ASPSCR1 and TFE3 and a histologically distinctive pseudoalveolar pattern. Although alveolar soft-part sarcoma takes an indolent course, its long-term prognosis is poor because of late distant metastases. Currently, curative treatments have not been found for alveolar soft-part sarcoma, and hence, a novel therapeutic strategy has long been required. Patient-derived cell lines comprise an important tool for basic and preclinical research. However, few cell lines from alveolar soft-part sarcoma have been reported in the literature because it is an extremely rare malignancy, accounting for less than 1% of all soft-tissue sarcomas. This study aimed to establish a novel alveolar soft-part sarcoma cell line. Using surgically-resected tumor tissue of alveolar soft-part sarcoma, we successfully established a cell line and named it NCC-ASPS1-C1. The NCC-ASPS1-C1 cells harbored an ASPSCR1-TFE3 fusion gene and exhibited slow growth, and spheroid formation. On the other hand, NCC-ASPS1-C1 did not show the capability of invasion. We screened the antiproliferative effects of 195 anticancer agents, including Food and Drug Administration-approved anticancer drugs. We found that the MET inhibitor tivantinib and multi-kinase inhibitor orantinib inhibited the proliferation of NCC-ASPS1-C1 cells. The clinical utility and molecular mechanisms of antitumor effects of these drugs are worth investigating in the further studies, and NCC-ASPS1-C1 cells will be a useful tool for the in vitro study of alveolar soft-part sarcoma.

The efficacy and safety of apatinib in metastatic alveolar soft part sarcoma: a case series of six patients in one institution

Background: Evidence suggests that advanced or metastatic alveolar soft part sarcoma (ASPS) with high metastatic potential is chemo-resistant. However, the benefits of tyrosine kinase inhibitors have been demonstrated for the treatment of ASPS.

Purpose: This study aimed to investigate the efficacy and safety of apatinib, aspecific VEGFR-2 inhibitor, in ASPS patients. This retrospective analysis involved six patients with metastatic ASPS not amenable to curative treatment.

Patients and methods: Apatinib was administered at a dose of 500mg per day. Tumor responses were assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) guidelines. Survival analysis was performed using the Kaplan–Meier test, and a safety profile was recorded.

Results: The mean age of patients was 26.5 (range, 17–32) years. The median progression-free survival (PFS) was 18.53 months (95% CI, 12.23-NE). However, median overall survival (OS) has not been reached. Twenty-four month PFS and OS rates were 50.0% and 100.0%, respectively. One patient achieved a complete response, and the remaining patients achieved partial responses, with an objective response rate of 100%. Median follow-up was 20.6 (range, 12.43–34.13) months. The most common adverse events included gastrointestinal discomfort (4/6[66.7%]), hair hypopigmentation (4/6[66.7%]) and hand-foot skin reaction (3/6[50.0%]).

Conclusion: Apatinib shows beneficial activity in metastatic ASPS patients, and further studies are warranted with more cases and longer follow-up periods to fully characterize clinical efficacy and safety of apatinib in ASPS.

Hypoxia induces TFE3 expression in head and neck squamous cell carcinoma

To assess the role of transcription factor μE3 (TFE3) in the tumorigenesis of head and neck squamous cell carcinoma (HNSCC), human HNSCC tissue arrays were investigated for TFE3 expression. Human HNSCC tissues with neoadjuvant inductive chemotherapey (docetaxel, cisplatin and fluorouracil, TPF) and mice HNSCC tissues from transgenic mice model were evaluated for TFE3 expression and the hypoxia pathway. The roles of EGF/EGFR mediated hypoxia in TFE3 nuclear expression were analyzed in vitro and in vivo. TFE3 expression was higher in human HNSCC tissues compared with that in normal oral mucosa. Moreover, high TFE3 expression was related to HIF-1α, PAI-1, and EGFR, which demonstrated the activation of the hypoxia pathway in HNSCC tissues. Furthermore, elevated TFE3 expression was observed in HNSCC after cisplatin-based chemotherapy, and high TFE3 expression may indicate poor response to TPF inductive chemotherapy. Furthermore, similar changes with increased TFE3 were observed in HNSCC of the transgenic mouse HNSCC model. Hypoxic culture in the human HNSCC cell line increased TFE3 expression, which promoted cell survival under hypoxia. EGFR inhibiton by cetuximab could attenuate hypoxia-induced TFE3 in the HNSCC cell line and transgenic mouse HNSCC model. These findings indicated that TFE3 was an important hypoxia-induced transcriptional factor in HNSCC. TFE3 could be regarded as a durgable therapeutic oncotarget by EGFR inhibition.

Identification of target genes of cediranib in alveolar soft part sarcoma using a gene microarray

The aim of the present study was to identify the target genes of cediranib and the associated signaling pathways in alveolar soft part sarcoma (ASPS). A microarray dataset (GSE32569) was obtained from the Gene Expression Omnibus database. The R software package was used for data normalization and screening of differentially expressed genes (DEGs). The Database for Annotation, Visualization and Integrated Discovery was used to perform Gene Ontology analysis. Gene Set Enrichment Analysis was performed to obtain the up- and downregulated pathways in ASPS. The Distant Regulatory Elements of co-regulated genes database was used to identify the transcription factors (TFs) that were enriched in the signaling pathways. A protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins database and was visualized using Cytoscape software. A total of 71 DEGs, including 59 upregulated genes and 12 downregulated genes, were identified. Gene sets associated with ASPS were enriched primarily in four signaling pathways: The phenylalanine metabolism pathway, the mitogen-activated protein kinase (MAPK) signaling pathway, the taste transduction pathway and the intestinal immune network for the production of immunoglobulin A. Furthermore, 107 TFs were identified to be enriched in the MAPK signaling pathway. Certain genes, including those coding for Fms-like tyrosine kinase 1, kinase insert domain receptor, E-selectin and platelet-derived growth factor receptor D, that were associated with other genes in the PPI network, were identified. The present study identified certain potential target genes and the associated signaling pathways of cediranib action in ASPS, which may be helpful in understanding the efficacy of cediranib and the development of new targets for cediranib.

Gene-edited pseudogene resurrection corrects p47phox-deficient chronic granulomatous disease

Pseudogenes are duplicated genes with mutations rendering them nonfunctional. For single-gene disorders with homologous pseudogenes, the pseudogene might be a target for genetic correction. Autosomal-recessive p47phox-deficient chronic granulomatous disease (p47-CGD) is a life-threatening immune deficiency caused by mutations in NCF1, a gene with 2 pseudogenes, NCF1B and NCF1C. The most common NCF1 mutation, a GT deletion (ΔGT) at the start of exon 2 (>90% of alleles), is constitutive to NCF1B and NCF1C. NCF1 ΔGT results in premature termination, undetectable protein expression, and defective production of antimicrobial superoxide in neutrophils. We examined strategies for p47-CGD gene correction using engineered zinc-finger nucleases targeting the exon 2 ΔGT in induced pluripotent stem cells or CD34+ hematopoietic stem cells derived from p47-CGD patients. Correction of ΔGT in NCF1 pseudogenes restores oxidase function in p47-CGD, providing the first demonstration that targeted restoration of pseudogene function can correct a monogenic disorder.

Targeted antiangiogenic agents in combination with cytotoxic chemotherapy in preclinical and clinical studies in sarcoma

Sarcomas are a heterogeneous group of mesenchymal malignancies. In recent years, studies have demonstrated that inhibition of angiogenic pathways or disruption of established vasculature can attenuate the growth of sarcomas. However, when used as monotherapy in the clinical setting, these targeted antiangiogenic agents have only provided modest survival benefits in some sarcoma subtypes, and have not been efficacious in others. Preclinical and early clinical data suggest that the addition of conventional chemotherapy to antiangiogenic agents may lead to more effective therapies for patients with these tumors. In the current review, the authors summarize the available evidence and possible mechanisms supporting this approach.

Sarcoma Cell Line Screen of Oncology Drugs and Investigational Agents Identifies Patterns Associated with Gene and microRNA Expression

The diversity in sarcoma phenotype and genotype make treatment of this family of diseases exceptionally challenging. Sixty-three human adult and pediatric sarcoma lines were screened with 100 FDA-approved oncology agents and 345 investigational agents. The investigational agents' library enabled comparison of several compounds targeting the same molecular entity allowing comparison of target specificity and heterogeneity of cell line response. Gene expression was derived from exon array data and microRNA expression was derived from direct digital detection assays. The compounds were screened against each cell line at nine concentrations in triplicate with an exposure time of 96 hours using Alamar blue as the endpoint. Results are presented for inhibitors of the following targets: aurora kinase, IGF-1R, MEK, BET bromodomain, and PARP1. Chemical structures, IC50 heat maps, concentration response curves, gene expression, and miR expression heat maps are presented for selected examples. In addition, two cases of exceptional responders are presented. The drug and compound response, gene expression, and microRNA expression data are publicly available at http://sarcoma.cancer.gov. These data provide a unique resource to the cancer research community.

Modeling alveolar soft part sarcomagenesis in the mouse: a role for lactate in the tumor microenvironment

Alveolar soft part sarcoma (ASPS), a deadly soft tissue malignancy with a predilection for adolescents and young adults, associates consistently with t(X;17) translocations that generate the fusion gene ASPSCR1-TFE3. We proved the oncogenic capacity of this fusion gene by driving sarcomagenesis in mice from conditional ASPSCR1-TFE3 expression. The completely penetrant tumors were indistinguishable from human ASPS by histology and gene expression. They formed preferentially in the anatomic environment highest in lactate, the cranial vault, expressed high levels of lactate importers, harbored abundant mitochondria, metabolized lactate as a metabolic substrate, and responded to the administration of exogenous lactate with tumor cell proliferation and angiogenesis. These data demonstrate lactate's role as a driver of alveolar soft part sarcomagenesis.

Genetics of rare mesenchymal tumors: implications for targeted treatment in DFSP, ASPS, CCS, GCTB and PEComa

Soft tissue and bone sarcomas comprise a heterogeneous group of mesenchymal tumors that include roughly 130 distinct diagnostic entities. Many of them are exceptionally rare, with only few cases diagnosed worldwide each year. Development of novel targeted treatment in this group of tumors is of special importance since many sarcoma subtypes are resistant to conventional chemotherapy and the effective therapeutic options are limited. In this review we aim to discuss the molecular implications for targeted therapy in selected rare soft tissue and bone sarcoma subtypes, including dermatofibrosarcoma protuberans (DFSP), alveolar soft part sarcoma (ASPS), clear cell sarcoma (CCS), giant cell tumor of bone (GCTB) and perivascular epithelioid cell neoplasms (PEComas). This article is part of a Directed Issue entitled: Rare cancers.

Alveolar soft-part sarcoma in the sacrum: a case report and review of the literature

Alveolar soft part sarcoma (ASPS) is a rare disease of the soft tissue. Although the disease is rare, it is refractory to chemotherapy and radiation. En bloc surgical resection offers the best chance of cure. In this article we report the case of a 28-year-old woman who presented with buttock and leg pain, bowel, bladder and gait impairment and a large mass in the sacrum. Following surgical excision, the lesion was proven to be ASPS. On pathology, the mass was TFE3 (transcription factor E3) positive, indicating the presence of the ASPL-TFE3 (novel gene-transcription factor) translocation. Following surgery, the patient had improvement in her pain and ambulation; however, she refused adjuvant therapy to pursue hospice care and succumbed to her disease 2 years after surgery. On a review of the literature, it was found that ASPS of the bone constitutes a rare and formidable subset of this disease. Further, metastases related to ASPS are common in the lungs, liver, brain, and lymph nodes. The degree of dissemination is a predictor of outcome, with 5-year survival of 81-88% in patients with local disease and only 20-46% in patients with metastatic disease at the time of presentation. Brain metastases at the time of presentation portend the worst prognosis.

A new clinical manifestation for cheek alveolar soft-part sarcoma: a case report and review of the literature

Alveolar soft part sarcoma (ASPS) is a rare, histologically distinct, soft tissue malignancy with nonspecific clinical features usually described as a nonulcerated, painless, expanding mass. It has a pseudoalveolar appearance with clustered polygonal cells lacking central cohesion. It accounts for approximately 0.5 to 1% of all soft tissue sarcomas. It has a strong predilection for adolescents and young adults 15 to 35 years old, with a female predominance. In general, ASPS grows slowly, with a predilection for the trunk and extremities and rarely in the head and neck region. A literature review found only 11 cases of cheek ASPS that have been reported since 1952. This report describes the case of an unusually rapidly growing mass in the cheek of a 36-year-old woman. The superficial location of the mass led to early detection and treatment.

Effect of bevacizumab on angiogenesis and growth of canine osteosarcoma cells xenografted in athymic mice

Objective-To investigate the effects of bevacizumab, a human monoclonal antibody against vascular endothelial growth factor, on the angiogenesis and growth of canine osteosarcoma cells xenografted in mice. Animals-27 athymic nude mice. Procedures-To each mouse, highly metastasizing parent osteosarcoma cells of canine origin were injected into the left gastrocnemius muscle. Each mouse was then randomly allocated to 1 of 3 treatment groups: high-dose bevacizumab (4 mg/kg, IP), low-dose bevacizumab (2 mg/kg, IP), or control (no treatment). Tumor growth (the number of days required for the tumor to grow from 8 to 13 mm), vasculature, histomorphology, necrosis, and pulmonary metastasis were evaluated. Results-Mice in the high-dose bevacizumab group had significantly delayed tumor growth (mean ± SD, 13.4 ± 3.8 days; range, 9 to 21 days), compared with that for mice in the low-dose bevacizumab group (mean ± SD, 9.4 ± 1.5 days; range, 7 to 11 days) or control group (mean ± SD, 7. 2 ± 1.5 days; range, 4 to 9 days). Mice in the low-dose bevacizumab group also had significantly delayed tumor growth, compared with that for mice in the control group. Conclusions and Clinical Relevance-Results indicated that bevacizumab inhibited growth of canine osteosarcoma cells xenografted in mice, which suggested that vascular endothelial growth factor inhibitors may be clinically useful for the treatment of osteosarcoma in dogs. Impact for Human Medicine-Canine osteosarcoma is used as a research model for human osteosarcoma; therefore, bevacizumab may be clinically beneficial for the treatment of osteosarcoma in humans.

Alveolar Soft Part Sarcoma-A Histological Surprise in a Male Patient who was Suspected to have Breast Cancer

Alveolar Soft Part Sarcoma (ASPS) is a very rare type of soft tissue sarcoma. Its cell of origin is unclear. It usually presents in the second to fourth decade of life. The most common reported sites of ASPS are the lower extremities, the head and the neck. Because of the rarity of this disease, there is no standard treatment plan. Surgical excision with negative margins is considered as the treatment of choice. We are reporting a rare presentation of ASPS as a male breast lump.

Molecular targeted therapies in non-GIST soft tissue sarcomas: what the radiologist needs to know

Non-gastrointestinal stromal soft tissue sarcomas are uncommon neoplasms that have a dismal prognosis due to a high incidence of metastases and a poor response to conventional chemotherapy. The identification of characteristic genetic alterations in several of these tumors has opened the window for molecular targeted therapies in patients who have failed conventional chemotherapy. Imaging plays a critical role in assessing the response to these novel therapeutic agents. Just like the response of gastrointestinal stromal tumors to imatinib, the response of non-gastrointestinal stromal soft tissue sarcomas to molecular targeted drugs is better evaluated on imaging by alternate tumor response criteria such as the Choi criteria. In addition, these drugs are associated with distinct class-specific drug toxicities that can come to attention for the first time on imaging. The purpose of this article is to provide a primer for the radiologist on the various molecular targeted therapies in advanced/metastatic non-gastrointestinal stromal soft tissue sarcomas with emphasis on the role of imaging in assessing treatment response and complications.

Bioinformatic analysis of patient-derived ASPS gene expressions and ASPL-TFE3 fusion transcript levels identify potential therapeutic targets

Gene expression data, collected from ASPS tumors of seven different patients and from one immortalized ASPS cell line (ASPS-1), was analyzed jointly with patient ASPL-TFE3 (t(X;17)(p11;q25)) fusion transcript data to identify disease-specific pathways and their component genes. Data analysis of the pooled patient and ASPS-1 gene expression data, using conventional clustering methods, revealed a relatively small set of pathways and genes characterizing the biology of ASPS. These results could be largely recapitulated using only the gene expression data collected from patient tumor samples. The concordance between expression measures derived from ASPS-1 and both pooled and individual patient tumor data provided a rationale for extending the analysis to include patient ASPL-TFE3 fusion transcript data. A novel linear model was exploited to link gene expressions to fusion transcript data and used to identify a small set of ASPS-specific pathways and their gene expression. Cellular pathways that appear aberrantly regulated in response to the t(X;17)(p11;q25) translocation include the cell cycle and cell adhesion. The identification of pathways and gene subsets characteristic of ASPS support current therapeutic strategies that target the FLT1 and MET, while also proposing additional targeting of genes found in pathways involved in the cell cycle (CHK1), cell adhesion (ARHGD1A), cell division (CDC6), control of meiosis (RAD51L3) and mitosis (BIRC5), and chemokine-related protein tyrosine kinase activity (CCL4).

Gemcitabine, docetaxel, and bevacizumab in relapsed and refractory pediatric sarcomas

BACKGROUND

The outcome for patients with relapsed and refractory pediatric sarcomas remains dismal. Novel agents are needed to improve overall survival in these patients.

OBSERVATIONS

We present 3 patients with relapsed/refractory sarcomas treated with gemcitabine, docetaxel, and bevacizumab in 3-week cycles. The combination was well tolerated with minimal toxicity. Two patients had a partial response and the third patient had stable disease for >6 months.

CONCLUSIONS

These results are limited by small patient numbers but this strategy should be evaluated in prospective clinical trials.

Targeted therapies in sarcomas: challenging the challenge

Sarcomas are a heterogeneous group of mesenchymal malignancies that very often lead to death. Nowadays, chemotherapy is the only available treatment for most sarcomas but there are few active drugs and clinical results still remain very poor. Thus, there is an imperious need to find new therapeutic alternatives in order to improve sarcoma patient's outcome. During the last years, there have been described a number of new molecular pathways that have allowed us to know more about cancer biology and tumorigenesis. Sarcomas are one of the tumors in which more advances have been made. Identification of specific chromosomal translocations, some important pathways characterization such as mTOR pathway or the insulin-like growth factor pathway, the stunning development in angiogenesis knowledge, and brand new agents like viruses have lead to the development of new therapeutic options with promising results. This paper makes an exhaustive review of preclinical and clinical evidence of the most recent targeted therapies in sarcomas and provides a future view of treatments that may lead to improve prognosis of patients affected with this disease.

Alveolar soft part sarcoma: a single-center 26-patient case series and review of the literature

Background. Alveolar soft part sarcoma (ASPS) is a rare tumor, and little information is available regarding its clinical features and appropriate treatments. Methods. A retrospective review of 26 consecutive ASPS patients (12 male, 14 female; mean age of 27 years) treated at our institution over 30 years (mean followup; 71 months) was performed. Results. The primary tumor developed in the lower extremity (12), trunk (8), and upper extremity (6), with an average size of 7.2 cm (range, 2–14 cm). The AJCC stage at presentation was IIA (7), III (3), and IV (16). Surgical excision was performed in 20 patients (R0 18, R1 plus radiotherapy 2) without local recurrence. Six patients (stage IIA 3/7, stage III 3/3) later developed metastases after an average period of 28.7 months. The median survival of the 26 patients was 90 months, with overall 5/10-year survival rates of 64%/48%. AJCC stage and tumor size were significant prognostic factors. Significant palliation and slowing of metastasis progression were achieved with gamma knife radiotherapy. Nine patients receiving chemotherapy showed no objective response. Conclusions. ASPS is indolent but has a high propensity for metastasis. Early diagnosis and complete excision of the small primary tumor are essential in the treatment of ASPS.

Alveolar soft part sarcomas: molecular pathogenesis and implications for novel targeted therapies

Alveolar soft part sarcoma (ASPS) is a very rare soft tissue sarcoma which arises primarily in children and young adults. Despite its unique histology and well-characterized genetic translocation, many questions remain regarding the pathogenesis and treatment of this tumor type. Though collective clinical experience with this tumor type spans more than 60 years, there has been little progress made in treating this uncommon but frequently fatal disease. This paper focuses on the available data regarding its molecular pathogenesis and insights into targeted therapeutics as well as the results of clinical trials performed to date to hopefully improve the outcome of patients with this rare malignancy.

ASPS-1, a novel cell line manifesting key features of alveolar soft part sarcoma

In vitro growth of alveolar soft part sarcoma (ASPS) and establishment of an ASPS cell line, ASPS-1, are described in this study. Using a recently developed xenograft model of ASPS derived from a lymph node metastasis, organoid nests consisting of 15 to 25 ASPS cells were isolated from ASPS xenograft tumors by capture on 70 μm filters and plated in vitro. After attachment to the substratum, these nests deposited small aggregates of ASPS cells. These cells grew slowly and were expanded over a period of 3 years and have maintained characteristics consistent with those of both the original ASPS tumor from the patient and the xenograft tumor including (1) presence of the alveolar soft part locus-transcription factor E3 type 1 fusion transcript and nuclear expression of the alveolar soft part locus-transcription factor E3 type 1 fusion protein; (2) maintenance of the t(X;17)(p11;q25) translocation characteristic of ASPS; and (3) expression of upregulated ASPS transcripts involved in angiogenesis (ANGPTL2, HIF-1-α, MDK, c-MET, VEGF, and TIMP-2), cell proliferation (PRL, PCSK1), metastasis (ADAM9), as well as the transcription factor BHLHB3 and the muscle-specific transcripts TRIM63 and ITGβ1BP3. This ASPS cell line forms colonies in soft agar and retains the ability to produce highly vascularized ASPS tumors in NOD.SCID/NCr mice. Immunohistochemistry of selected ASPS markers on these tumors indicated similarity to those of the original patient tumor as well as to the xenografted ASPS tumor. We anticipate that this ASPS cell line will accelerate investigations into the biology of ASPS including identification of new therapeutic approaches for treatment of this slow growing soft tissue sarcoma.

Targeted therapies: the rare cancer paradigm

This review analyzes the state of the art of targeted therapies for several tumors, starting from the paradigmatic example of Imatinib treatment in chronic myelogenous leukemia (CML). We discuss how rare tumors can be models for various mechanisms of receptor tyrosine kinase (RTK) activation, and provide the opportunity to develop new therapies also for more common cancer types. We discuss the activation of the downstream RTK effectors as further targets for therapies in colorectal cancer. Finally, we highlight how a novel multidimensional approach which adds an in silico dimension to the in vitro and in vivo approach, can predict clinical results.