HMGA1 regulates trabectedin sensitivity in advanced soft-tissue sarcoma (STS): A Spanish Group for Research on Sarcomas (GEIS) study.

HMGA1 is a structural epigenetic chromatin factor that has been associated with tumor progression and drug resistance. Here, we reported the prognostic/predictive value of HMGA1 for trabectedin in advanced soft-tissue sarcoma (STS) and the effect of inhibiting HMGA1 or the mTOR downstream pathway in trabectedin activity. The prognostic/predictive value of HMGA1 expression was assessed in a cohort of 301 STS patients at mRNA (n = 133) and protein level (n = 272), by HTG EdgeSeq transcriptomics and immunohistochemistry, respectively. The effect of HMGA1 silencing on trabectedin activity and gene expression profiling was measured in leiomyosarcoma cells. The effect of combining mTOR inhibitors with trabectedin was assessed on cell viability in vitro studies, whereas in vivo studies tested the activity of this combination. HMGA1 mRNA and protein expression were significantly associated with worse progression-free survival of trabectedin and worse overall survival in STS. HMGA1 silencing sensitized leiomyosarcoma cells for trabectedin treatment, reducing the spheroid area and increasing cell death. The downregulation of HGMA1 significantly decreased the enrichment of some specific gene sets, including the PI3K/AKT/mTOR pathway. The inhibition of mTOR, sensitized leiomyosarcoma cultures for trabectedin treatment, increasing cell death. In in vivo studies, the combination of rapamycin with trabectedin downregulated HMGA1 expression and stabilized tumor growth of 3-methylcholantrene-induced sarcoma-like models. HMGA1 is an adverse prognostic factor for trabectedin treatment in advanced STS. HMGA1 silencing increases trabectedin efficacy, in part by modulating the mTOR signaling pathway. Trabectedin plus mTOR inhibitors are active in preclinical models of sarcoma, downregulating HMGA1 expression levels and stabilizing tumor growth.

FOXO3a deregulation in uterine smooth muscle tumors.

OBJECTIVE: The present study aimed to investigate FOXO3a deregulation in Uterine Smooth Muscle Tumors (USMT) and its potential association with cancer development and prognosis. METHODS: The authors analyzed gene and protein expression profiles of FOXO3a in 56 uterine Leiomyosarcomas (LMS), 119 leiomyomas (comprising conventional and unusual leiomyomas), and 20 Myometrium (MM) samples. The authors used techniques such as Immunohistochemistry (IHC), FISH/CISH, and qRT-PCR for the present analyses. Additionally, the authors conducted an in-silico analysis to understand the interaction network involving FOXO3a and its correlated genes. RESULTS: This investigation revealed distinct expression patterns of the FOXO3a gene and protein, including both normal and phosphorylated forms. Expression levels were notably elevated in LMS, and Unusual Leiomyomas (ULM) compared to conventional Leiomyomas (LM) and Myometrium (MM) samples. This upregulation was significantly associated with metastasis and Overall Survival (OS) in LMS patients. Intriguingly, FOXO3a deregulation did not seem to be influenced by EGF/HER-2 signaling, as there were minimal levels of EGF and VEGF expression detected, and HER-2 and EGFR were negative in the analyzed samples. In the examination of miRNAs, the authors observed upregulation of miR-96-5p and miR-155-5p, which are known negative regulators of FOXO3a, in LMS samples. Conversely, the tumor suppressor miR-let7c-5p was downregulated. CONCLUSIONS: In summary, the outcomes of the present study suggest that the imbalance in FOXO3a within Uterine Smooth Muscle Tumors might arise from both protein phosphorylation and miRNA activity. FOXO3a could emerge as a promising therapeutic target for individuals with Unusual Leiomyomas and Leiomyosarcomas (ULM and LMS), offering novel directions for treatment strategies.

Novel MIR143HG::PLAG1 gene fusion identified in a rectal myxoid leiomyosarcoma.

Myxoid leiomyosarcoma (MLS) is a rare but well-documented tumor that often portends a poor prognosis compared to the conventional leiomyosarcoma. This rare sarcoma has been reported in the uterus, external female genitalia, soft tissue, and other locations. However, a definite rectal MLS has not been reported. Recently five cases of MLS were reported to harbor PLAG1 fusions (TRPS1::PLAG1, RAD51B::PLAG1, and TRIM13::PLAG1). In this report, we present a case of rectal MLS with a novel MIR143HG::PLAG1 fusion detected by RNA next-generation sequencing.

Molecular Heterogeneity in Leiomyosarcoma and Implications for Personalised Medicine.

OPINION STATEMENT: Leiomyosarcoma (LMS) is one of the more common subtypes of soft tissue sarcomas (STS), accounting for about 20% of cases. Differences in anatomical location, risk of recurrence and histomorphological variants contribute to the substantial clinical heterogeneity in survival outcomes and therapy responses observed in patients. There is therefore a need to move away from the current one-size-fits-all treatment approach towards a personalised strategy tailored for individual patients. Over the past decade, tissue profiling studies have revealed key genomic features and an additional layer of molecular heterogeneity among patients, with potential utility for optimal risk stratification and biomarker-matched therapies. Furthermore, recent studies investigating intratumour heterogeneity and tumour evolution patterns in LMS suggest some key features that may need to be taken into consideration when designing treatment strategies and clinical trials. Moving forward, national and international collaborative efforts to aggregate expertise, data, resources and tools are needed to achieve a step change in improving patient survival outcomes in this disease of unmet need.

Developing Novel Genomic Risk Stratification Models in Soft Tissue and Uterine Leiomyosarcoma.

PURPOSE: Leiomyosarcomas (LMS) are clinically and molecularly heterogeneous tumors. Despite recent large-scale genomic studies, current LMS risk stratification is not informed by molecular alterations. We propose a clinically applicable genomic risk stratification model. EXPERIMENTAL DESIGN: We performed comprehensive genomic profiling in a cohort of 195 soft tissue LMS (STLMS), 151 primary at presentation, and a control group of 238 uterine LMS (ULMS), 177 primary at presentation, with at least 1-year follow-up. RESULTS: In STLMS, French Federation of Cancer Centers (FNCLCC) grade but not tumor size predicted progression-free survival (PFS) or disease-specific survival (DSS). In contrast, in ULMS, tumor size, mitotic rate, and necrosis were associated with inferior PFS and DSS. In STLMS, a 3-tier genomic risk stratification performed well for DSS: high risk: co-occurrence of RB1 mutation and chr12q deletion (del12q)/ATRX mutation; intermediate risk: presence of RB1 mutation, ATRX mutation, or del12q; low risk: lack of any of these three alterations. The ability of RB1 and ATRX alterations to stratify STLMS was validated in an external AACR GENIE cohort. In ULMS, a 3-tier genomic risk stratification was significant for both PFS and DSS: high risk: concurrent TP53 mutation and chr20q amplification/ATRX mutations; intermediate risk: presence of TP53 mutation, ATRX mutation, or amp20q; low risk: lack of any of these three alterations. Longitudinal sequencing showed that most molecular alterations were early clonal events that persisted during disease progression. CONCLUSIONS: Compared with traditional clinicopathologic models, genomic risk stratification demonstrates superior prediction of clinical outcome in STLMS and is comparable in ULMS.

Uterine Leiomyosarcoma Associated With Perivascular Epithelioid Cell Tumor: A Phenomenon of Differentiation/Dedifferentiation and Evidence Suggesting Cell-of-Origin.

Perivascular epithelioid cell tumor (PEComa) is a mesenchymal tumor thought to originate from perivascular epithelioid cells (PECs). The normal counterpart to PEC, however, has not been identified in any human organ, and the debate as to whether PEComa is related to smooth muscle tumors has persisted for many years. The current series characterizes 4 cases of uterine leiomyosarcoma (LMS) coexisting with PEComas. All cases exhibited an abrupt transition from the LMS to PEComa components. The LMS component displayed typical spindled morphology and fascicular growth pattern and was diffusely positive for desmin and smooth muscle myosin heavy chain, completely negative for HMB-45 and Melan A, and either negative or had focal/weak expression of cathepsin K and GPNMB. In contrast, the PEComa tumor cells in case 1 contained glycogen or lipid-distended cytoplasm with a foamy appearance (low grade), and in cases 2, 3, and 4, they displayed a similar morphology characterized by epithelioid cells with eosinophilic and granular cytoplasm and high-grade nuclear atypia. Different from the LMS component, the epithelioid PEComa cells in all cases were focally positive for HMB-45, and diffusely immunoreactive for cathepsin K and GPNMB. Melan A was focally positive in cases 1 and 3. Loss of fumarate hydratase expression (case 1) and RB1 expression (cases 2, 3, 4) was identified in both LMS and PEComa components, indicating that they are clonally related. In addition, both components showed an identical TP53 p.R196* somatic mutation and complete loss of p53 and ATRX expression in case 2 and complete loss of p53 expression in case 3. We hypothesize that LMSs containing smooth muscle progenitor cells may give rise to divergent, lineage-specific PEComatous lesions through differentiation or dedifferentiation. While we do not dispute the recognition of PEComas as a distinct entity, we advocate the hypothesis that modified smooth muscle cells represent the origin of a subset of PEComas, and our case series provides evidence to suggest this theory.

Expanding the Spectrum of NR4A3 Fusion-Positive Gynecologic Leiomyosarcomas.

Recurrent gene fusions have been observed in epithelioid and myxoid variants of uterine leiomyosarcoma. PGR::NR4A3 fusions were recently described in a subset of epithelioid leiomyosarcomas exhibiting rhabdoid morphology. In this study, we sought to expand the clinical, morphologic, immunohistochemical, and genetic features of gynecologic leiomyosarcomas harboring NR4A3 rearrangements with PGR and novel fusion partners. We identified 9 gynecologic leiomyosarcomas harboring PGR::NR4A3, CARMN::NR4A3, ACTB::NR4A3, and possible SLCO5A1::NR4A3 fusions by targeted RNA sequencing. Tumors frequently affected premenopausal women, involving the uterine corpus, uterine cervix, or pelvis. All were similarly characterized by lobules of monomorphic epithelioid and/or spindled cells arranged in sheets, cords, trabeculae, and micro- and macrocysts associated with abundant myxoid matrix and hemorrhage, creating labyrinth-like or pulmonary edema-like architecture. Myogenic differentiation with frequent estrogen receptor and progesterone receptor staining and no CD10 expression characterized all tumors. All cases showed high NR4A3 RNA expression levels and NOR1 (NR4A3) nuclear staining similar to salivary gland acinic cell carcinomas and a subset of extraskeletal myxoid chondrosarcomas harboring NR4A3 rearrangements. NOR1 (NR4A3) immunohistochemistry may serve as a useful diagnostic marker of NR4A3 fusion-positive gynecologic leiomyosarcomas.

Uterine leiomyosarcoma cell-derived extracellular vesicles induce the formation of cancer-associated fibroblasts.

OBJECTIVE: Uterine leiomyosarcoma (ULMS) is a rare malignant tumor, which is aggressive, and has a poor prognosis even during its early stages. Extracellular vesicles (EVs) carry cargo, such as microRNAs (miRNAs), which are involved in intercellular communication in the tumor microenvironment and other processes. Because there are no studies on EV-related miRNAs in ULMS, we identified EV-related miRNAs in ULMS and examined their function. METHODS: Small EVs (sEVs) and medium/large EVs (m/lEVs) were extracted from ULMS cells by ultracentrifugation and their basic characteristics were evaluated. Then, small RNA sequencing was done to obtain EV-related miRNA profiles. Next, miRNA expression levels in sera and tissues of ULMS patients were compared with those of myoma patients. RESULTS: miR-654-3p and miR-369-3p were indicated to be highly expressed in both sera and tissues of ULMS patients. These two miRNAs are also highly expressed in ULMS cell lines and ULMS-derived EVs. Some cancer-associated fibroblast (CAF) markers were increased when fibroblasts were treated with ULMS-derived EVs. Furthermore, fibroblasts took up EVs derived from ULMS as determined by confocal laser microscopy. In addition, the transfection of the two candidate miRNAs into fibroblasts significantly increased some CAF markers, particularly ACTA2. CONCLUSION: miR-654-3p and miR-369-3p are highly expressed in ULMS-derived EVs, indicating that these EV-related miRNAs induce the formation of cancer-associated fibroblasts.

Conjunctival leiomyosarcoma: A clinico-pathological study with in deep molecular characterization.

BACKGROUND: Primary and metastatic leiomyosarcomas (LMS) involving the orbital region are well known to occur however, the conjunctiva represents an extremely rare site of occurrence. METHODS: A 97-year-old male was referred to the Ocular Oncology Unit due to a rapidly growing painful mass (16×12×20 mm) in the nasal conjunctiva of his left eye. Wide excision followed by radiotherapy was performed. RESULTS: Based on the microscopic features (hypercellular neoplasm composed of spindle cells with cigar shaped and blunt ended nuclei with brightly eosinophilic fibrillary cytoplasm) and immunohistochemical findings (positive staining for Vimentin, Desmin, Caldesmon, and SMA and negative staining for AE1/AE3, EMA, CD117, S100, MelanA, SOX10, HMB45, TLE1, CD99, EMA and AE1 / AE3) the final diagnosis of grade 2 leyomiosarcoma was rendered. Moreover, 'in deep' DNA sequencing (>500 genes analysis) revealed a neoplasm with high TMB: 64 muts/Mb and numerous VUS and several pathogenic/oncogenic molecular alterations, including CNV loss or gain in > 10 genes. At the last follow-up visit, residual disease was observed in the superior fornix, at the nasal limbus and the cornea. At the time of writing, after a follow-up of 2 month the patients is still alive without evidence of metastatic disease. CONCLUSION: An uncommon molecular finding observed in our case was the presence of TSC1 gene mutation usually associated with soft tissue and gynecological PEComas. Our finding may harbor important therapeutic implications since the inactivation of the tumor suppressor genes TSC1 and TSC2 lead to upregulation of mTOR signaling, providing the rationale for target therapy with mTOR inhibitors. Additional studies on larger series are needed to validate our findings.

Immune evasion in lung metastasis of leiomyosarcoma: upregulation of EPCAM inhibits CD8+ T cell infiltration.

BACKGROUND: Leiomyosarcomas are among the most common histological types of soft tissue sarcoma (STS), with no effective treatment available for advanced patients. Lung metastasis, the most common site of distant metastasis, is the primary prognostic factor. We analysed the immune environment targeting lung metastasis of STS to explore new targets for immunotherapy. METHODS: We analysed the immune environment of primary and lung metastases in 38 patients with STS using immunohistochemistry. Next, we performed gene expression analyses on primary and lung metastatic tissues from six patients with leiomyosarcoma. Using human leiomyosarcoma cell lines, the effects of the identified genes on immune cells were assessed in vitro. RESULTS: Immunohistochemistry showed a significant decrease in CD8+ cells in the lung metastases of leiomyosarcoma. Among the genes upregulated in lung metastases, epithelial cellular adhesion molecule (EPCAM) showed the strongest negative correlation with the number of CD8+ cells. Transwell assay results showed that the migration of CD8+ T cells was significantly increased in the conditioned media obtained after inhibition or knock down of EPCAM. CONCLUSIONS: EPCAM was upregulated in lung metastases of leiomyosarcoma, suggesting inhibition of CD8+ T cell migration. Our findings suggest that EPCAM could serve as a potential novel therapeutic target for leiomyosarcoma.

MMP14 expression and collagen remodelling support uterine leiomyosarcoma aggressiveness.

Fibrillar collagen deposition, stiffness and downstream signalling support the development of leiomyomas (LMs), common benign mesenchymal tumours of the uterus, and are associated with aggressiveness in multiple carcinomas. Compared with epithelial carcinomas, however, the impact of fibrillar collagens on malignant mesenchymal tumours, including uterine leiomyosarcoma (uLMS), remains elusive. In this study, we analyse the network morphology and density of fibrillar collagens combined with the gene expression within uLMS, LM and normal myometrium (MM). We find that, in contrast to LM, uLMS tumours present low collagen density and increased expression of collagen-remodelling genes, features associated with tumour aggressiveness. Using collagen-based 3D matrices, we show that matrix metalloproteinase-14 (MMP14), a central protein with collagen-remodelling functions that is particularly overexpressed in uLMS, supports uLMS cell proliferation. In addition, we find that, unlike MM and LM cells, uLMS proliferation and migration are less sensitive to changes in collagen substrate stiffness. We demonstrate that uLMS cell growth in low-stiffness substrates is sustained by an enhanced basal yes-associated protein 1 (YAP) activity. Altogether, our results indicate that uLMS cells acquire increased collagen remodelling capabilities and are adapted to grow and migrate in low collagen and soft microenvironments. These results further suggest that matrix remodelling and YAP are potential therapeutic targets for this deadly disease.

Uterine Leiomyosarcoma With Osteoclast-like Giant Cells: Report of 2 Cases and Review of Literature.

Leiomyosarcoma (LMS) with osteoclast-like giant cells (OLGCs) is a rare entity with only 18 reported cases thus far. It is not known whether these OLGCs are a reactive or malignant component of LMS. Herein we describe the clinical, histologic, and molecular characteristics of 2 cases of LMS with OLGCs and perform a brief literature review. In 2 of our cases, the OLGCs, marked with CD68, had a low proliferation index with Ki67 and did not show diffuse positivity for smooth muscle markers by immunohistochemistry. By next-generation sequencing, one case harbored a clinically significant TP53 mutation, which has been reported in a significant subset of conventional LMSs. In this case, based on immunohistochemistry, OLGCs showed different molecular alterations as compared with LMS. Although we did not show a distinct immunophenotype or molecular profile for LMS with OLGCs, this study provides additional data on this rare entity.

[Diagnosis of uterine sarcomas and rare uterine mesenchymal tumours with malignant potential. Guidelines of the French Sarcoma Group and Rare Gynaecological Tumours]. / Diagnostic des sarcomes utérins et tumeurs mésenchymateuses utérines rares à potentiel de malignité. Référentiels du Groupe Sarcome Français et des Tumeurs Rares Gynécologiques.

The landscape of uterine sarcomas is becoming more complex with the description of new entities associated with recurrent driver molecular alterations. Uterine sarcomas, in analogy with soft tissue sarcomas, are distinguished into complex genomic and simple genomic sarcomas. Leiomyosarcomas and undifferentiated uterine sarcomas belong to complex genomic sarcomas group. Low-grade and high-grade endometrial stromal sarcomas, other rare tumors associated with fusion transcripts (such as NTRK, PDGFB, ALK, RET ROS1) and SMARCA4-deficient uterine sarcoma are considered simple genomic sarcomas. The most common uterine sarcoma are first leiomyosarcoma and secondly endometrial stromal sarcomas. Three different histological subtypes of leiomyosarcoma (fusiform, myxoid, epithelioid) are identified, myxoid and epithelioid leiomyosarcoma being more aggressive than fusiform leiomyosarcoma. The distinction between low-grade and high-grade endometrial stromal sarcoma is primarily morphological and immunohistochemical and the detection of fusion transcripts can help the diagnosis. Uterine PEComa is a rare tumor, which is distinguished into borderline and malignant, according to a risk assessment algorithm. Embryonal rhabdomyosarcoma of the uterine cervix is more common in children but can also occur in adult women. Embryonal rhabdomyosarcoma of the uterine cervix is almost always DICER1 mutated, unlike that of the vagina which is wild-type DICER1, and adenosarcoma which can be DICER1 mutated but with less frequency. Among the emerging entities, sarcomas associated with fusion transcripts involving the NTRK, ALK, PDGFB genes benefit from targeted therapy. The integration of molecular data with histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

Establishment and characterization of NCC-LMS3-C1: a novel patient-derived cell line of leiomyosarcoma.

Leiomyosarcoma (LMS) is an aggressive mesenchymal malignancy, which originates from the smooth muscle cells or from the precursor mesenchymal stem cells that potentially differentiate into smooth muscle cells. LMS is one of the most common sarcomas. LMS has genomic instability, reflecting complex and unbalanced karyotypes, and the cytogenetic and molecular changes in LMS are not consistent. The standard treatment of the primary LMS is complete resection, and the metastasis is often observed even after curative surgery. Patient-derived cancer models are a key bioresource to develop a novel therapy, and we aimed to establish and characterize a novel cell line for LMS. We established a cell line from tumor tissues of the patient with LMS and named it NCC-LMS3-C1. We maintained NCC-LMS3-C1 cells for 12 months and passed them more than 30 times. Genome-wide copy number analysis demonstrated that NCC-LMS3-C1 cells harbored genetic abnormalities. NCC-LMS3-C1 cells exhibited aggressive phenotypes such as continuous growth, spheroid formation, and invasion in the tissue culture condition, which may reflect the clinical behaviors of LMS. We performed a drug screening using NCC-LMS3-C1 cells and found that four anti-cancer agents, such as bortezomib, dasatinib, mitoxantrone, and romidepsin, had remarkable anti-proliferative effects on NCC-LMS3-C1 cells. We conclude that NCC-LMS3-C1 cells will be a useful resource for the study of LMS.

Sex-dependent Prognosis of Patients with Advanced Soft Tissue Sarcoma.

PURPOSE: To examine whether overall survival (OS) differs for male and female patients with advanced soft-tissue sarcoma (STS). EXPERIMENTAL DESIGN: The study included patients from Kaiser Permanente Northern California and Stanford Cancer Center with grade 2 and 3 locally advanced or metastatic STS whose tumor underwent next-generation sequencing. We used Cox regression modeling to examine association of sex and OS adjusting for other important factors. RESULTS: Among 388 eligible patients, 174 had leiomyosarcoma (LMS), 136 had undifferentiated pleomorphic sarcoma (UPS), and 78 had liposarcoma. OS for male versus female patients appeared to be slightly better among the full cohort [HR = 0.89; 95% confidence interval (CI), 0.66-1.20]; this association appeared to be stronger among the subsets of patients with LMS (HR = 0.76; 95% CI, 0.39-1.49) or liposarcoma (HR = 0.74; 95% CI, 0.32-1.70). Better OS for male versus female patients was also observed among all molecular subgroups except mutRB1 and mutATRX, especially among patients whose tumor retained wtTP53 (HR = 0.73; 95% CI, 0.44-1.18), wtCDKN2A (HR = 0.85; 95% CI, 0.59-1.23), wtRB1 (HR = 0.73; 95% CI, 0.51-1.04), and among patients whose tumor had mutPTEN (HR = 0.37; 95% CI, 0.09-1.62). OS also appeared to be better for males in the MSK-IMPACT and TCGA datasets. CONCLUSIONS: A fairly consistent pattern of apparent better OS for males across histologic and molecular subgroups of STS was observed. If confirmed, our results could have implications for clinical practice for prognostic stratification and possibly treatment tailoring as well as for future clinical trials design.

Sarcomas With RAD51B Fusions Are Associated With a Heterogeneous Phenotype.

RAD51B-rearranged sarcomas are rare neoplasms that exhibit a heterogeneous morphology. To date, 6 cases have been reported, all involving the uterus, including 4 perivascular epithelioid cell tumors (PEComas) and 2 leiomyosarcomas (LMS). In this study, we describe the morphologic, immunohistochemical, and molecular features of 8 additional sarcomas with RAD51B rearrangement, including the first extrauterine example. All patients were women with a median age of 57 years at presentation. Seven tumors originated in the uterus, and one in the lower extremity soft tissue, with a median tumor size of 12 cm. Histologically, 4 tumors showed predominantly spindle cell morphology with eosinophilic fibrillary cytoplasm, with or without nuclear pleomorphism, whereas 2 tumors exhibited pleomorphic epithelioid cells, featuring clear to eosinophilic, granular cytoplasm. Two neoplasms exhibited undifferentiated cytomorphology, including one with uniform small blue round cells. All tumors showed high-grade cytologic atypia and high mitotic activity (median: 30/10 high-power fields), whereas coagulative necrosis was noted in 6 cases and lymphovascular invasion in 2. By immunohistochemistry, 2 showed myoid and melanocytic markers in keeping with PEComa, whereas 4 cases were only positive for smooth muscle markers consistent with LMS (including 3 myxoid). The remaining 2 cases had a nonspecific immunoprofile. Five cases tested by targeted RNA sequencing (Archer FusionPlex, Illumina TruSight) showed different fusion partners (HMGA2, PDDC1, and CEP170). RAD51B rearrangements were identified by FISH in the remaining 3 cases. Targeted DNA sequencing in 2 cases was negative for TSC gene alterations. Clinical outcome, available in 5 patients (median follow-up, 19 months), revealed 3 local recurrences, 2 lung metastases, and 4 deaths due to disease. Our results expand the spectrum of sarcomas with RAD51B fusions, demonstrating variable clinical presentations, morphologic spectrum, and fusion partners. These tumors have a predilection for a uterine location, with either LMS, PEComa, or undifferentiated phenotypes, and are associated with an aggressive clinical course.

A differential diagnosis between uterine leiomyoma and leiomyosarcoma using transcriptome analysis.

BACKGROUND: The objective of this study was to estimate the accuracy of transcriptome-based classifier in differential diagnosis of uterine leiomyoma and leiomyosarcoma. We manually selected 114 normal uterine tissue and 31 leiomyosarcoma samples from publicly available transcriptome data in UCSC Xena as training/validation sets. We developed pre-processing procedure and gene selection method to sensitively find genes of larger variance in leiomyosarcoma than normal uterine tissues. Through our method, 17 genes were selected to build transcriptome-based classifier. The prediction accuracies of deep feedforward neural network (DNN), support vector machine (SVM), random forest (RF), and gradient boosting (GB) models were examined. We interpret the biological functionality of selected genes via network-based analysis using GeneMANIA. To validate the performance of trained model, we additionally collected 35 clinical samples of leiomyosarcoma and leiomyoma as a test set (18 + 17 as 1st and 2nd test sets). RESULTS: We discovered genes expressed in a highly variable way in leiomyosarcoma while these genes are expressed in a conserved way in normal uterine samples. These genes were mainly associated with DNA replication. As gene selection and model training were made in leiomyosarcoma and uterine normal tissue, proving discriminant of ability between leiomyosarcoma and leiomyoma is necessary. Thus, further validation of trained model was conducted in newly collected clinical samples of leiomyosarcoma and leiomyoma. The DNN classifier performed sensitivity 0.88, 0.77 (8/9, 7/9) while the specificity 1.0 (8/8, 8/8) in two test data set supporting that the selected genes in conjunction with DNN classifier are well discriminating the difference between leiomyosarcoma and leiomyoma in clinical sample. CONCLUSION: The transcriptome-based classifier accurately distinguished uterine leiomyosarcoma from leiomyoma. Our method can be helpful in clinical practice through the biopsy of sample in advance of surgery. Identification of leiomyosarcoma let the doctor avoid of laparoscopic surgery, thus it minimizes un-wanted tumor spread.

Survivin-Sodium Iodide Symporter Reporter as a Non-Invasive Diagnostic Marker to Differentiate Uterine Leiomyosarcoma from Leiomyoma.

Leiomyosarcoma (LMS) has been challenging to diagnose because of limitations in clinical and radiographic predictors, as well as the lack of reliable serum or urinary biomarkers. Most uterine masses consist of benign leiomyoma (LM). However, it is currently a significant challenge in gynecology practice to differentiate LMS from LM. This inability poses grave consequences for patients, leading to a high number of unnecessary hysterectomies, infertility, and other major morbidities and possible mortalities. This study aimed to evaluate the use of Survivin-Sodium iodide symporter (Ad-Sur-NIS) as a reporter gene biomarker to differentiate malignant LMS from benign LM by using an F18-NaBF4 PET/CT scan. The PET/CT scan images showed a significantly increased radiotracer uptake and a decreased radiotracer decay attributable to the higher abundance of Ad-Sur-NIS in the LMS tumors compared to LM (p < 0.05). An excellent safety profile was observed, with no pathological or metabolic differences detected in Ad-Sur-NIS-treated animal versus the vehicle control. Ad-Sur-NIS as a PET scan reporter is a promising imaging biomarker that can differentiate uterine LMS from LM using F18-NaBF4 as a radiotracer. As a new diagnostic method, the F18 NaBF4 PET/CT scan can provide a much-needed tool in clinical practices to effectively triage women with suspicious uterine masses and avoid unnecessary invasive interventions.

PD-1 Inhibition in metastatic high tumour mutational burden (TMB) leiomyosarcoma with clinicopathological correlates.

Leiomyosarcoma (LMS) is a subtype of sarcoma derived from smooth muscle cells. Unfortunately, this malignancy has a high rate of metastatic disease. Palliative systemic therapy has historically relied on cytotoxic agents such as doxorubicin, which have low rates of response. Immunotherapy has not been shown to be effective for most patients with sarcoma, including those with LMS. However, this has not been well described for patients with LMS and high tumour mutational burden (TMB). Herein, we report the case of a woman in her late 50s with metastatic high TMB (>10) leiomyosarcoma treated with pembrolizumab.

Hyper-Dependence on NHEJ Enables Synergy between DNA-PK Inhibitors and Low-Dose Doxorubicin in Leiomyosarcoma.

PURPOSE: Leiomyosarcoma (LMS) is an aggressive sarcoma for which standard chemotherapies achieve response rates under 30%. There are no effective targeted therapies against LMS. Most LMS are characterized by chromosomal instability (CIN), resulting in part from TP53 and RB1 co-inactivation and DNA damage repair defects. We sought to identify therapeutic targets that could exacerbate intrinsic CIN and DNA damage in LMS, inducing lethal genotoxicity. EXPERIMENTAL DESIGN: We performed clinical targeted sequencing in 287 LMS and genome-wide loss-of-function screens in 3 patient-derived LMS cell lines, to identify LMS-specific dependencies. We validated candidate targets by biochemical and cell-response assays in vitro and in seven mouse models. RESULTS: Clinical targeted sequencing revealed a high burden of somatic copy-number alterations (median fraction of the genome altered =0.62) and demonstrated homologous recombination deficiency signatures in 35% of LMS. Genome-wide short hairpin RNA screens demonstrated PRKDC (DNA-PKcs) and RPA2 essentiality, consistent with compensatory nonhomologous end joining (NHEJ) hyper-dependence. DNA-PK inhibitor combinations with unconventionally low-dose doxorubicin had synergistic activity in LMS in vitro models. Combination therapy with peposertib and low-dose doxorubicin (standard or liposomal formulations) inhibited growth of 5 of 7 LMS mouse models without toxicity. CONCLUSIONS: Combinations of DNA-PK inhibitors with unconventionally low, sensitizing, doxorubicin dosing showed synergistic effects in LMS in vitro and in vivo models, without discernable toxicity. These findings underscore the relevance of DNA damage repair alterations in LMS pathogenesis and identify dependence on NHEJ as a clinically actionable vulnerability in LMS.