Genomic-guided precision therapy for soft tissue sarcoma

Establishment and characterization of NCC-SS6-C1: a novel patient-derived cell line of synovial sarcoma

Synovial sarcoma (SS) is identified as a sarcoma with monomorphic blue spindle cells that display variable epithelial differentiation and is characterized by the SS18::SSX fusion gene. SS accounts for approximately 5-10% of all soft tissue sarcomas, making it a relatively common type within this group of tumors. Since SS is generally sensitive to chemotherapy, the standard treatment for SS includes extensive surgical resection, complemented by neoadjuvant chemotherapy with several approved anticancer drugs. However, in advanced and metastatic cases, the efficacy of these drugs is limited, resulting in poor prognoses. This underscores the need for innovative therapeutic strategies. Patient-derived cancer cell lines are essential tools for basic and preclinical research, yet only four SS cell lines are publicly available. To facilitate the studies of SS, we have developed a novel SS cell line, named NCC-SS6-C1, derived from surgically excised tumor tissue of an SS patient. NCC-SS6-C1 cells preserve the SS18::SSX1 fusion gene, consistent with the genetic characteristics of the original tumor. The cells exhibit continuous proliferation, invasiveness, and the ability to form spheroids. Additionally, we confirmed that this cell line was useful for evaluating the efficacy of anticancer drugs. Our results suggest that NCC-SS6-C1 is a useful tool for basic and pre-clinical studies of SS.

Current treatment and novel insights regarding ROS1-targeted therapy in malignant tumors

BACKGROUND

The proto-oncogene ROS1 encodes an intrinsic type I membrane protein of the tyrosine kinase/insulin receptor family. ROS1 facilitates the progression of various malignancies via self-mutations or rearrangements. Studies on ROS1-directed tyrosine kinase inhibitors have been conducted, and some have been approved by the FDA for clinical use. However, the adverse effects and mechanisms of resistance associated with ROS1 inhibitors remain unknown. In addition, next-generation ROS1 inhibitors, which have the advantage of treating central nervous system metastases and alleviating endogenous drug resistance, are still in the clinical trial stage.

METHOD

In this study, we searched relevant articles reporting the mechanism and clinical application of ROS1 in recent years; systematically reviewed the biological mechanisms, diagnostic methods, and research progress on ROS1 inhibitors; and provided perspectives for the future of ROS1-targeted therapy.

RESULTS

ROS1 is most expressed in malignant tumours. Only a few ROS1 kinase inhibitors are currently approved for use in NSCLC, the efficacy of other TKIs for NSCLC and other malignancies has not been ascertained. There is no effective standard treatment for adverse events or resistance to ROS1-targeted therapy. Next-generation TKIs appear capable of overcoming resistance and delaying central nervous system metastasis, but with a greater incidence of adverse effects.

CONCLUSIONS

Further research on next-generation TKIs regarding the localization of ROS1 and its fusion partners, binding sites for targeted drugs, and coadministration with other drugs is required. The correlation between TKIs and chemotherapy or immunotherapy in clinical practice requires further study.

Organoids: opportunities and challenges of cancer therapy

Organoids are a class of multicellular structures with the capability of self-organizing and the characteristic of original tissues, they are generated from stem cells in 3D culture in vitro. Organoids can mimic the occurrence and progression of original tissues and widely used in disease models in recent years. The ability of tumor organoids to retain characteristic of original tumors make them unique for tumorigenesis and cancer therapy. However, the history of organoid development and the application of organoid technology in cancer therapy are not well understood. In this paper, we reviewed the history of organoids development, the culture methods of tumor organoids establishing and the applications of organoids in cancer research for better understanding the process of tumor development and providing better strategies for cancer therapy. The standardization of organoids cultivation facilitated the large-scale production of tumor organoids. Moreover, it was found that combination of tumor organoids and other cells such as immune cells, fibroblasts and nervous cells would better mimic the microenvironment of tumor progression. This might be important developing directions for tumor organoids in the future.

The Role of CDK Pathway Dysregulation and Its Therapeutic Potential in Soft Tissue Sarcoma

Soft tissue sarcomas (STSs) are tumors that are challenging to treat due to their pathologic and molecular heterogeneity and their tumor biology that is not yet fully understood. Recent research indicates that dysregulation of cyclin-dependent kinase (CDK) signaling pathways can be a strong driver of sarcogenesis. CDKs are enzyme forms that play a crucial role in cell-cycle control and transcription. They belong to the protein kinases group and to the serine/threonine kinases subgroup. Recently identified CDK/cyclin complexes and established CDK/cyclin complexes that regulate the cell cycle are involved in the regulation of gene expression through phosphorylation of critical components of transcription and pre-mRNA processing mechanisms. The current and continually growing body of data shows that CDKs play a decisive role in tumor development and are involved in the proliferation and growth of sarcoma cells. Since the abnormal expression or activation of large numbers of CDKs is considered to be characteristic of cancer development and progression, dysregulation of the CDK signaling pathways occurs in many subtypes of STSs. This review discusses how reversal and regulation can be achieved with new therapeutics and summarizes the current evidence from studies regarding CDK modulation for STS treatment.

Safety and efficacy of pazopanib as a second-line treatment and beyond for soft tissue sarcomas: A real-life tertiary-center experience in the MENA region

INTRODUCTION

Sarcomas are uncommon malignancies. No advances have been recently achieved despite multiple efforts. Pazopanib is a safe and effective tyrosine kinase inhibitor used in managing soft tissue sarcomas (STS) after chemotherapy failure. However, its use is limited in developing countries and no efficacy data exist from our region. We aimed to study the efficacy of pazopanib in our population, characterized by response rates of patients with chemotherapy-refractory advanced STS receiving pazopanib. Secondary endpoints included progression-free survival (PFS), overall survival (OS) and toxicity profile.

MATERIALS AND METHODS

15 patients (age≥18 year) diagnosed with advanced STS, refractory to first-line chemotherapy, receiving pazopanib as ≥second-line therapy in one tertiary center in Lebanon were included between January 1st, 2014 and October 31st, 2018. Patient and disease characteristics, disease evaluation, as well as tolerance to treatment, were extracted from charts retrospectively. Statistical analysis was done using SPSS version 24.

RESULTS

The mean age was 48.6 [19-66] years. Eleven patients (73.3%) received pazopanib in second-line, whereas four patients (26.7%) received it in third-line. Thirteen patients (86.7%) progressed, and two patients (13.3%) had stable disease. The median PFS was three months [1-19] and the mean OS was 25.4 months [17.2-33.6]. Five patients required dose-reductions due to poor tolerance.

CONCLUSION

Conclusions cannot be drawn due to small patient numbers. However, given the 3-month PFS, 13% of patients maintaining stable disease, and tolerable safety profile, it is reasonable to incorporate pazopanib in STS treatment. More focused studies with larger patient populations need to be done in Lebanon.

Targeting TJP1 attenuates cell-cell aggregation and modulates chemosensitivity against doxorubicin in leiomyosarcoma

Tight junction protein 1 (TJP1) is a membrane-associated cytosolic protein important for cell-cell communication in intercellular barriers in epithelial and non-epithelial cells. Here, we explored the functional involvement of TJP1 in non-epithelial tumors such as soft tissue sarcoma, especially in leiomyosarcoma (LMS). TJP1 expression in soft tissue sarcoma was analyzed in normal and tumor tissues as well as from public datasets such as the TCGA provisional dataset, in which TJP1 expression was compared with other subtypes such as undifferentiated sarcomas, and myxofibrosarcomas. SK-LMS-1 cell lines with reduced TJP1 expression showed attenuated anchorage-independent colony formation as well as reduced intercellular aggregation on non-coated culture plates compared with control as well as parental SK-LMS-1 cells. Transcriptome profiling following TJP1 knockdown in SK-LMS-1 cells suggested the involvement of several signaling pathways, including NF-κB pathway and growth factor receptor signaling. In addition, TJP1 downregulation induced enhanced response against anti-cancer agents, doxorubicin and gefitinib. Taken together, these results suggest that TJP1 contributes to sarcoma genesis and might be useful therapeutic target. KEY MESSAGES: • TJP1 expression at RNA level higher in tumor than in normal tissues of sarcoma. • Targeting TJP1 attenuates cell-cell aggregation and anchorage-independent growth. • Targeting TJP1 is beneficial in anti-cancer therapy in LMS.