Pazopanib in rare histologies of metastatic soft tissue sarcoma

Establishment and characterization of the novel myxofibrosarcoma cell line, SMU-MFS

Myxofibrosarcoma (MFS) is one of the most common soft-tissue sarcomas in elderly patients. Owing to the limited efficacy of chemotherapy and radiotherapy, complete resection is the only available curative treatment. Therefore, developing novel therapies for MFS is important to improve clinical outcomes. Herein, a novel MFS cell line, namely SMU-MFS, was established to better understand the biologic characteristics of MFS and develop new therapies. A tissue sample from the surgically resected tumor tissue of a 56-year-old patient with a tumor was subjected to primary culture. The cell line was established and authenticated by assessing the short tandem repeats of DNA microsatellites. The monolayer cultures of SMU-MFS cells exhibited constant growth, spheroid formation, and invasive capacity. Furthermore, the cells exhibited low chemosensitivity to doxorubicin, eribulin, and pazopanib, which are used to inhibit metastatic progression. In addition, of the four mice inoculated with SMU-MFS cells, tumors developed in two mice after 8 weeks. Altogether, the findings of this study suggest that the SMU-MFS cell line can be a useful tool for investigating MFS development and evaluating novel therapeutic agents.

Shedding light on pancreatic metastasis of clear cell sarcoma: An exceptional journey

This editorial comments on the study by Liu et al investigating pancreatic metastasis of clear cell sarcoma (CCS) published in the World Journal of Clinical Cases. CCS is a rare and aggressive melanocytic tumor, that typically arises from tendons and aponeuroses of the limbs, and metastasizes to the lungs, bones, and brain. However, pancreatic metastasis has rarely been reported, presenting unique diagnostic and therapeutic challenges. Elucidating the clinical characteristics, imaging features, prognostic factors, and treatment outcomes of patients with pancreatic CCS metastasis is crucial. Surgery remains an effective management strategy for CCS. However, the high recurrence rate and low effectiveness of traditional adjuvant treatments necessitate a shift towards more personalized and targeted treatment plans. Research is needed to investigate and validate novel therapeutic approaches specifically tailored to the distinct genetic and molecular characteristics of rare malignancies like CCS. Additionally, the development of late metastases after a long disease-free interval is common in CCS patients. Therefore, routine postoperative surveillance for metastasis using computed tomography, magnetic resonance imaging, bone scans, and positron emission tomography scans is crucial. Moving forward, enhanced collaboration, investigation, and creative thinking among scientists, medical professionals, and legislators are essential to gain a deeper understanding of these rare presentations.

Metastatic clear cell sarcoma of the pancreas: A rare case report

BACKGROUND

Clear cell sarcoma (CCS) is a rare soft-tissue sarcoma. The most common metastatic sites for CCS are the lungs, bones and brain. CCS is highly invasive and mainly metastasizes to the lung, followed by the bone and brain; however, pancreatic metastasis is relatively rare.

CASE SUMMARY

We report on a rare case of CCS with pancreatic metastasis in a 47-year-old man. The patient had a relevant medical history 3 years ago, with abdominal pain as the main clinical manifestation. No abnormalities were observed on physical examination and the tumor was found on abdominal computed tomography. Based on the medical history and postoperative pathology, the patient was diagnosed with CCS with pancreatic metastasis. The patient was successfully treated with surgical interventions, including distal pancreatectomy and splenectomy.

CONCLUSION

This report summarizes the available treatment modalities for CCS and the importance of regular postoperative follow-up for patients with CCS.

Biology and Management of High-Grade Myxofibrosarcoma: State of the Art and Future Perspectives

Myxofibrosarcoma (MFS) is one of the most common adult soft tissue sarcomas, typically arising in the extremities. Histologically, MFS is classified into three grades: low, intermediate, and high. Histological grades correlate with distant metastases and tumor-associated mortality. The diagnosis of MFS is challenging due to a lack of well-characterized immunohistochemical markers. High-grade MFS displays highly complex karyotypes with multiple copy number alterations. Recent integrated genomic studies have shown the predominance of somatic copy number aberrations. However, the molecular pathogenesis of high-grade MFS remains poorly understood. The standard treatment for localized MFS is surgical resection. The systemic treatment options for advanced disease are limited. This review provides an updated overview of the clinical and imaging features, pathogenesis, histopathology, and treatment of high-grade MFS.

PAK1 overexpression promotes myxofibrosarcoma angiogenesis through STAT5B-mediated CSF2 transactivation: clinical and therapeutic relevance of amplification and nuclear entry

Myxofibrosarcoma is genetically complex without established nonsurgical therapies. In public datasets, PAK1 was recurrently gained with mRNA upregulation. Using myxofibrosarcoma cells, we explored the oncogenic underpinning of PAK1 with genetic manipulation and a pan-PAK inhibitor (PF3758309). Myxofibrosarcoma specimens were analyzed for the levels of PAK1, phospho-PAKT423, CSF2 and microvascular density (MVD) and those of PAK1 gene and mRNA. PAK1-expressing xenografts were assessed for the effects of PF3758309 and CSF2 silencing. Besides pro-proliferative and pro-migrator/pro-invasive attributes, PAK1 strongly enhanced angiogenesis in vitro, which, not phenocopied by PAK2-4, was identified as CSF2-mediated using antibody arrays. PAK1 underwent phosphorylation at tyrosines153,201,285 and threonine423 to facilitate nuclear entry, whereby nuclear PAK1 bound STAT5B to co-transactivate the CSF2 promoter, increasing CSF2 secretion needed for angiogenesis. Angiogenesis driven by PAK1-upregulated CSF2 was negated by CSF2 silencing, anti-CSF2, and PF3758309. Clinically, overexpressed whole-cell phospho-PAKT423, related to PAK1 amplification, was associated with increased grades, stages, and PAK1 mRNA, higher MVD, and CSF2 overexpression. Overexpressed whole-cell phospho-PAKT423 and CSF2 independently portended shorter metastasis-free survival and disease-specific survival, respectively. In vivo, both CSF2 silencing and PF3758309 suppressed PAK1-driven tumor proliferation and angiogenesis. Conclusively, the nuclear entry of overexpressed/activated PAK1 endows myxofibrosarcomas with pro-angiogenic function, highlighting the vulnerable PAK1/STAT5B/CSF2 regulatory axis.

Clear cell sarcoma: state-of-the art and perspectives

INTRODUCTION

Clear cell sarcoma (CCS) is an ultrarare soft tissue sarcoma (STS) with a poor prognosis due to its propensity to metastasize and its low chemosensitivity. The standard treatment of localized CCS consists of wide surgical excision with or without additive radiotherapy. However, unresectable CCS is generally treated with conventional systemic therapies available for treatment of STS despite the weak scientific evidence to support its use.

AREAS COVERED

In this review, we discuss the clinicopathologic characteristics of CSS, as well as the current treatment landscape and future therapeutic approaches.

EXPERT OPINION

The current treatment strategy of advanced CCSs, based on STSs regimens, shows a lack of effective options. Combination therapiesin particular, the association of immunotherapy and TKIs, represent a promising approach. Translational studies are needed in order to decipher the regulatory mechanisms involved in the oncogenesis of this ultrarare sarcoma and identify potential molecular targets.