Malignant Mesenchymal Cells Research Articles

Combination screen in multi-cell type tumor spheroids reveals interaction between aryl hydrocarbon receptor antagonists and E1 ubiquitin-activating enzyme inhibitor

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that regulates genes of drug transporters and metabolic enzymes to detoxify small molecule xenobiotics. It has a complex role in cancer biology, influencing both the progression and suppression of tumors by modulating malignant properties of tumor cells and anti-tumor immunity, depending on the specific tumor type and developmental stage. This has led to the discovery and development of selective AhR modulators, including BAY 2416964 which is currently in clinical trials. To identify small molecule anticancer agents that might be combined with AhR antagonists for cancer therapy, a high-throughput combination screen was performed using multi-cell type tumor spheroids grown from malignant cells, endothelial cells, and mesenchymal stem cells. The AhR selective antagonists BAY 2416964, GNF351, and CH-223191 were tested individually and in combination with twenty-five small molecule anticancer agents. As single agents, BAY 2416964 and CH-223191 showed minimal activity, whereas GNF351 reduced the viability of some spheroid models at concentrations greater than 1 µM. The activity of most combinations aligned well with the single agent activity of the combined agent, without apparent contributions from the AhR antagonist. All three AhR antagonists sensitized tumor spheroids to TAK-243, an E1 ubiquitin-activating enzyme inhibitor. These combinations were active in spheroids containing bladder, breast, ovary, kidney, pancreas, colon, and lung tumor cell lines. The AhR antagonists also potentiated pevonedistat, a selective inhibitor of the NEDD8-activating enzyme E1 regulatory subunit, in several tumor spheroid models. In contrast, the AhR antagonists did not enhance the cytotoxicity of the proteasome inhibitor bortezomib.

PPARγ and C/EBPα enable adipocyte differentiation upon inhibition of histone methyltransferase PRC2 in malignant tumors

Loss of terminal differentiation is a hallmark of cancer and offers a potential mechanism for differentiation therapy. Polycomb Repressive Complex 2 (PRC2) serves as the methyltransferase for K27 of histone H3 that is crucial in development. While PRC2 inhibitors show promise in treating various cancers, the underlying mechanisms remain incompletely understood. Here, we demonstrated that the inhibition or depletion of PRC2 enhanced adipocyte differentiation in malignant rhabdoid tumors (MRTs) and mesenchymal stem cells (MSCs), through upregulation of PPARG and CEBPA. Mechanistically, PRC2 directly represses their transcription through H3K27 methylation, as both genes exhibit a bivalent state in MSCs. Knockout of PPARG compromised C/EBPα expression and impeded the PRC2 inhibitor-induced differentiation into adipocytes. Furthermore, the combination of the PPARγ agonist rosiglitazone and the PRC2 inhibitor MAK683 exhibited a higher inhibition on Ki67 positivity in tumor xenograft compared to MAK683 alone. High CEBPA, PLIN1 and FABP4 levels positively correlated with favorable prognosis in sarcoma patients in TCGA cohort. Together, these findings unveil an epigenetic regulatory mechanism for PPARG and highlight the essential role of PPARγ and C/EBPα in the adipocyte differentiation of MRTs and sarcomas with a potential clinical implication.

Single-cell transcriptomics reveals tumor landscape in ovarian carcinosarcoma.

The present study used single-cell RNA sequencing (scRNA-seq) to characterize the cellular composition of ovarian carcinosarcoma (OCS) and identify its molecular characteristics. scRNA-seq was performed in resected primary OCS for an in-depth analysis of tumor cells and the tumor microenvironment. Immunohistochemistry staining was used for validation. The scRNA-seq data of OCS were compared with those of high-grade serous ovarian carcinoma (HGSOC) tumors and other OCS tumors. Both malignant epithelial and malignant mesenchymal cells were observed in the OCS patient of this study. We identified four epithelial cell subclusters with different biological roles. Among them, epithelial subcluster 4 presented high levels of breast cancer type 1 susceptibility protein homolog (BRCA1) and DNA topoisomerase 2-α (TOP2A) expression and was related to drug resistance and cell cycle. We analyzed the interaction between epithelial and mesenchymal cells and found that fibroblast growth factor (FGF) and pleiotrophin (PTN) signalings were the main pathways contributing to communication between these cells. Moreover, we compared the malignant epithelial and mesenchymal cells of this OCS tumor with our previous published HGSOC scRNA-seq data and OCS data. All the epithelial subclusters in the OCS tumor could be found in the HGSOC samples. Notably, the mesenchymal subcluster C14 exhibited specific expression patterns in the OCS tumor, characterized by elevated expression of cytochrome P450 family 24 subfamily A member 1 (CYP24A1), collagen type XXIII α1 chain (COL23A1), cholecystokinin (CCK), bone morphogenetic protein 7 (BMP7), PTN, Wnt inhibitory factor 1 (WIF1), and insulin-like growth factor 2 (IGF2). Moreover, this subcluster showed distinct characteristics when compared with both another previously published OCS tumor and normal ovarian tissue. This study provides the single-cell transcriptomics signature of human OCS, which constitutes a new resource for elucidating OCS diversity.

Abstract 4608: Combinations of Cdc-like kinase (CLK) inhibitors with targeted oncology agents or standard chemotherapy in patient-derived multi-cell type tumor spheroids

Abstract The alternative splicing of mRNA precursors allows one gene the capacity to yield multiple protein isoforms, each with distinct functions. Although this intricate process is subject to stringent regulation under normal physiological conditions, aberrant alternative splicing can generate atypical proteins and contribute to various diseases, including cancer. By activating splicing factors, Cdc-like kinases (CLKs) serve as pivotal regulators of alternative splicing and are considered promising therapeutic targets for various tumors. In this study, we investigated the activity of two CLK inhibitors, cirtuvivint (SM08502) and CC-671, in combination with precision oncology agents or conventional chemotherapeutics. Thirty highly characterized patient-derived cancer cell lines were selected from the National Cancer Institute’s Patient-Derived Models Repository (https://pdmr.cancer.gov/models/database.htm). The cell lines were derived from a range of cancer types including head and neck, bladder, pancreas, endometrial, colon, and melanoma, and contained clinically relevant variants of KRAS (G12C, G12D). Multi-cell type tumor spheroids were grown from a ratio of 6:2.5:1.5 malignant cells, endothelial cells, and mesenchymal stem cells, respectively. Following three days of growth, the spheroids were treated with single agents or combinations at concentrations up to their clinical Cmax value, if reported. After seven days of continuous drug exposure, cell viability was assessed using the CellTiter-Glo 3D assay. As a single agent, cirtuvivint showed concentration-dependent activity in all spheroid types with 1 – 3 logs of cytotoxicity, whereas CC-671 did not show activity in all spheroid types and achieved no more than 1 log of cytotoxicity. Among the standard chemotherapeutic drugs, doxorubicin and SN-38 demonstrated additive and greater-than-additive cytotoxicity in various spheroid types when combined with either CLK inhibitor. Several of the targeted oncology drugs exhibited noteworthy additive and greater-than-additive cytotoxicity when combined with a CLK inhibitor. These agents included the XPO1 inhibitor, eltanexor, the MCL-1 inhibitor, tapotoclax, the α-isoform-specific PI3K inhibitor, inavolisib, and the pan-PI3K inhibitor, copanlisib. Notably, combinations of the CLK inhibitors with the KRAS G12D variant-specific inhibitor, MRTX-1133, showed selective activity against all tumor cell lines harboring this genetic variant. Interestingly, a strong antagonistic interaction between paclitaxel and CC-671 was observed in all thirty spheroid types, while no such interaction was observed with cirtuvivint. This project was funded in part with federal funds from the NCI, NIH, under contract no. HHSN261201500003I. Citation Format: Thomas Steven Dexheimer, Thomas Silvers, Nathan P. Coussens, Steven D. Gore, James H. Doroshow, Beverly A. Teicher. Combinations of Cdc-like kinase (CLK) inhibitors with targeted oncology agents or standard chemotherapy in patient-derived multi-cell type tumor spheroids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4608.

Osteosarcoma in a free-living yellow armadillo (Euphractus sexcinctus)

An adult male free-living yellow armadillo (Euphractus sexcinctus) was found by hunters and referred for clinical evaluation because of a tumour-like lesion on the carapace. The animal was lethargic and weak with severe dehydration, enophthalmos and cachexia, and was euthanized because of its very poor clinical condition. Necropsy revealed a whitish, exophytic, irregular and moist mass (7 × 6.5 × 1.5 cm) in the caudal third of the carapace. On cut section, the mass was hard, compact, irregular and whitish. Histopathology revealed a densely cellular, expansive, poorly delimited neoplasm composed of malignant mesenchymal cells arranged in islands and cords, interspersed by numerous areas of irregularly mineralized osteoid matrix. Neoplastic cells were intensely immunolabelled for vimentin. The diagnosis of a high-grade osteosarcoma of osteoblastic subtype was based on the clinical, gross, histopathological and immunohistochemical findings. This first report of an osteosarcoma in an armadillo expands the list of armadillo diseases and will assist the management of these animals by veterinarians.

SP-8356 (A Verbenone Derivative) Inhibits Proliferation, Suppresses Cell Migration and Invasion and Decreases Tumor Growth of Osteosarcoma: Role of PGC-1α/TFAM and AMPK-Activation.

Osteosarcoma (OS) is an uncommon sarcoma with osteoid formation in conjunction with malignant mesenchymal cells on histological examination. SP-8356 has been reported to exhibit anti-cancer properties in human cancers. However the impact of SP-8356 on OS is largely unknown. The metabolic pathways are coordinated by AMPactivated protein kinase (AMPK), which maintains a balance between the supply and demand of nutrients and energy. This study aimed to investigate effect of SP-8356 on proliferation and apoptosis of OS cells and tumor growth in mice. Furthermore, involvement of PGC-1α/TFAM and AMPK-activation was studied. In the experimental study, Saos-2 and MG63 cells were cultured with SP-8356 for 24 hours and analysed for cellular proliferation using MTT assay. DNA fragmentation was studied using ELISA based kit. Furthermore, transwell chambers assay was used to determine cell migration and cell invasion. Targeted protein expression levels were assessed using western blotting. For in vivo studies, mice (5-6 weeks old) were implanted with either Saos-2 or MG63 cells on dorsal surface subcutaneously and they were administered with SP-8356 (10 mg/kg) for two weeks prior to bone tumor induction. We found that SP-8356 exerted anti-proliferative effects on Saos-2 and MG63 cells. Furthermore, SP-8356 treatment significantly restricted migration and invasion of Saos-2 and MG63 cells. Compared to the control, SP-8356 significantly reduced apoptotic cell death, while it increased PGC-1α and TFAM expressions. Without affecting body weight, SP-8356 significantly reduced tumor development in mice, as compared to the control group. SP-8356 was found to inhibit proliferation, suppressed cells migration and invasion and decreased OS tumor growth. Furthermore, SP-8356 was found to act through PGC-1α/TFAM and AMPK activations. SP-8356 can be therefore used as therapeutic agent for OS treatment.

Osteosarcoma: A case report

Osteosarcoma (OS) is a primary malignant bone tumor with a worldwide incidence. OS is a rare sarcoma that has the histological findings of osteoid production in association with malignant mesenchymal cells. Osteosarcoma is the eighth-most common form of childhood cancer. The most common site of origin is the metaphyseal region of tubular long bones, with 42% occurring in the femur, followed by the tibia, and the humerus. We reported a case of osteosarcoma of the right tibia in a 12-year-old patient.

Neuroectodermal elements are part of the morphological spectrum of DICER1-associated neoplasms

Many sarcomas with DICER1 pathogenic variants (PVs) exhibit a characteristic morphology, including a subepithelial layer of malignant mesenchymal cells, areas of rhabdomyoblastic differentiation and cartilaginous and/or osseous elements. We report 5 DICER1-associated neoplasms (1 moderately to poorly differentiated Sertoli Leydig cell tumour and 4 sarcomas) containing variable amounts of neuroectodermal elements. The neoplasms predominantly involved or were in close proximity to the female genital tract (ovary, uterine corpus, abdominal and pelvic cavity) and occurred in females aged 14 months to 54 years. The neuroectodermal elements were characterised by solid and tubular/rosette-like patterns and variable immunoreactivity with SALL4 and neuroendocrine markers. In some cases, the neuroectodermal component was focal while in others it was exclusive. In one case, the focal neuroectodermal component within an ovarian Sertoli Leydig cell tumour resulted in extraovarian metastasis. In reporting these cases, we suggest that neuroectodermal elements, including pure neuroectodermal tumours, are part of the morphological spectrum of DICER1-associated neoplasms. It is important that pathologists recognize that a neuroectodermal component (often admixed with other elements) may be a feature of such neoplasms. This will facilitate appropriate tumour and/or germline testing which could lead to the identification of germline DICER1 PVs (DICER1 syndrome). Three of the patients we report were subsequently shown to have a germline DICER1 PV.

Solitary Fibrous Tumour of Liver Presenting as Doege–Potter Syndrome – A Case Report

Background: Doege–Potter syndrome is a rare syndrome which is defined as Solitary fibrous tumour (SFT) that is associated with NICTH (non-islet cell tumour hypoglycaemia). Limited case reports are available on Solitary fibrous tumour of liver presenting as Doege–Potter syndrome in published medical literature. Case report: A 60-year-old female presented with episodic weakness and incoherent behaviour since 3 months and during that episode her serum glucose were low which corrected on glucose administration and abdominal distension for 1 month. Abdominal lump was noted in right hypochondrium arising from liver. On investigation- fasting serum glucose levels, fasting insulin levels and fasting C peptide levels were low and serum IGFII levels were elevated. CT abdomen revealed heterogeneously enhancing solitary lesion of 23 x 18 x 14 cm arising from segment 5 ,6, 7, 8 of liver. AFP, CA19-9 levels were within normal range. Liver biopsy shows spindle cell tumour of fibroblastic origin. Anatomical right hepatectomy with MHV preservation was done. Postoperative course was uneventful with symptomatic improvement, serum glucose levels normalised, and patient was discharged on 8th POD. Discussion: Solitary fibrous tumours are uncommon benign or malignant mesenchymal cell tumours which originate from visceral pleura, pelvis, retroperitoneum and liver. Doege–Potter syndrome which is a rare paraneoplastic manifestation of Solitary fibrous tumour, when there is secretion of prohormone - insulin-like growth factor II (IGF-II), causing hypo insulinemic hypoglycaemia and suppressed serum insulin, C peptide and elevated IGFII/IGFI ratio . Definitive treatment is complete tumour resection.

Analysis of Extended Resection of Limb Soft Tissue Leiomyosarcoma.

Leiomyosarcoma is an uncommon soft tissue sarcoma that composed of malignant mesenchymal cells with distinct features of the smooth muscle lineage. Typically affects the uterus and gastrointestinal tract, it can rarely be seen in large blood vessels, lymphatic and glandular duts, the mesentery, the omentum, retroperitoneum, and limbs. Occurrence is particularly rare in the limb region. Retrospective study based on patient records and postoperative pathological histological features. Four patients with limb leiomyosarcoma that were operated between 2016 and 2020 were included, three of them arising in the subcutis of the thigh region and one in cubitus. Extend resection with satisfactory outcomes is reported. Pathological examination showed that masses were composed of a fascicular arrangement of hyperchromatic spindle-shaped cells, characterized by the proliferation of epithelioid cells with eosinophilic cytoplasm for epithelioid leiomyosarcoma. Leiomyosarcomas that arise in the soft tissue, although rare, should be differentiated from other lesions, such as neurilemoma, neurofibroma, liomyoma,lipomyoma, synoviosarcoma, rhabdomyosarcoma, malignant fibrous histiotoma, and malignant neurinoma.

Cell fusion enhances energy metabolism of mesenchymal tumor hybrid cells to sustain their proliferation and invasion

BackgroundCell-to-cell fusion is emerging as a key element of the metastatic process in various cancer types. We recently showed that hybrids made from the spontaneous merging of pre-malignant (IMR90 E6E7, i.e. E6E7) and malignant (IMR90 E6E7 RST, i.e. RST) mesenchymal cells recapitulate the main features of human undifferentiated pleomorphic sarcoma (UPS), with a highly rearranged genome and increased spreading capacities. To better characterize the intrinsic properties of these hybrids, we investigated here their metabolic energy profile compared to their parents.ResultsOur results unveiled that hybrids harbored a Warburg-like metabolism, like their RST counterparts. However, hybrids displayed a much greater metabolic activity, enhancing glycolysis to proliferate. Interestingly, modifying the metabolic environmental conditions through the use of 5-aminoimidazole-4-carbox-amide-1-β-D-ribofuranoside (AICAR), an activator of the 5′-adenosine monophosphate (AMP)-activated protein kinase (AMPK), specifically reduced the growth of hybrids, and also abrogated the invasive capacity of hybrids displaying enhanced glycolysis. Furthermore, AICAR efficiently blocked the tumoral features related to the aggressiveness of human UPS cell lines.ConclusionAltogether, our findings strongly suggest that hybrids rely on higher energy flux to proliferate and that a drug altering this metabolic equilibrium could impair their survival and be potentially considered as a novel therapeutic strategy.

Wilms' Tumor 1 (WT1): A Novel Immunomarker of Dermatofibrosarcoma Protuberans-An Immunohistochemical Study on a Series of 114 Cases of Bland-Looking Mesenchymal Spindle Cell Lesions of the Dermis/Subcutaneous Tissues.

Simple SummaryDermatofibrosarcoma protuberans (DFSP) is a superficial fibroblastic spindle cell sarcoma with a high rate of local recurrence (20% to 50%) but with a low metastatic potential. DFSP is characterized by COL1A1-PDGFB gene fusion and diffuse immunohistochemical expression of CD34. This immunomarker is especially useful in distinguishing DFSP from its morphological mimickers, especially when pathologists are faced with small biopsies. Apart from CD34, there are no additional diagnostic immunomarkers for DFSP, and thus, there is the need to identify more sensitive and specific markers for this sarcoma. Recently, Wilms’ tumor 1 (WT1) has been shown to be diffusely expressed in the cytoplasm of several benign and malignant mesenchymal spindle cell lesions. Based on this background, the aim of this study is to evaluate the immunohistochemical expression of WT1 protein in a series of bland-looking spindle cell lesions of the dermis/subcutis, emphasizing its potential diagnostic role in identifying DFSP among its morphological mimickers.Purpose: to investigate the immunohistochemical expression and distribution of Wilms’ tumor 1 (WT1) (transcription factor produced by the tumor suppressor gene of the same name) in a series of 114 cases of bland-looking mesenchymal spindle cell lesions of the dermis/subcutaneous tissues to establish whether this immunomarker is differentially expressed in dermatofibrosarcoma protuberans (DFSP) versus its potential morphological mimickers. Methods: This retrospective multi-centric immunohistochemical study included 57 DFSP cases, 15 dermatofibromas, 5 deep fibrous histiocytomas, 8 neurofibromas, 5 spindle cell lipomas, 8 dermal scars, 6 nodular fasciitis, 5 cutaneous leiomyomas and 5 solitary fibrous tumors. Among the 57 DFSP cases, 11 were recurrent lesions; 2 non-recurrent cases exhibited an additional “fibrosarcomatous” overgrowth and 1 recurrent and 2 primary tumors contained a minority of “giant cell fibroblastoma” components. Results: Most DFSP (95% of cases) exhibited cytoplasmic staining for WT1; 11/11 residual/recurrent tumors showed diffuse and strong WT1 cytoplasmic immunoreactivity; apart from neurofibromas, WT1 expression was lacking in all the other cases studied. Conclusions: The cytoplasmic expression of WT1 may be exploitable as a complementary diagnostic immunomarker to CD34 in confirming the diagnosis of DFSP and to better evaluate the residual/recurrent tumor component.

MiRNA-1225 Inhibits Osteosarcoma Tumor Growth and Progression by Targeting YWHAZ.

IntroductionOsteosarcoma is the most common bone tumor and is characterized by the presence of malignant mesenchymal cells produced in the bone stroma. MiRNAs are known to function as post-transcriptional negative regulators of gene expression. Emerging evidence showed that miR-1225-5P functions as a tumor suppressor in several types of cancers. The detailed mechanisms of which miR-1225-5P suppresses tumor growth are not fully understood. The objective of the present study was to test the hypothesis that miR-1225-5P inhibits osteosarcoma cell growth in vitro and tumor growth in vivo by targeting YWHAZ expression.MethodsReal-time PCR and Western blot were carried out to test the expression of miR-1225-5P and YWHAZ in osteosarcoma cell lines. Luciferase assay was used to demonstrate whether miR-1225-5P targets YWHAZ 3ʹ UTR. To assess the function of miR-1225-5P in human osteosarcoma cell lines, gain-of-function and loss-of-function of miR-1225-5P were performed by transfecting miR-1225-5P mimic or miR-1225-5P inhibitor into osteosarcoma cell lines. Furthermore, cell cycle analysis was performed to elucidate the possible mechanisms of the action of miR-1225-5P and YWHAZ in human osteosarcoma cells. The potential therapeutic effect of miR-1225-5p was tested in human osteosarcoma xenograft mouse model, by intravenous injection of miR-1225-5P into nude mice. Tumor sizes were measured and lung metastasis was counted after the mice were sacrificed.ResultsThe expression of miR-1225-5P was inversely correlated with the expression of YWHAZ in human osteosarcoma cell lines. Database search revealed that miR-1225-5P targeted YWHAZ 3ʹ UTR. Transfection of miR-1225-5P mimic downregulated YWHAZ expression, which was demonstrated by real-time PCR, Western blot and luciferase assay. Over-expression of miR-1225-5P reduced human osteosarcoma cell growth, migration and invasion by downregulating YWHAZ expression. Cell growth, migration and invasion were increased by inhibiting miR-1225-5P in human osteosarcoma cells. The inhibition of cell growth, migration and invasion was rescued by over-expression of YWHAZ in osteosarcoma cells. Cell cycle analysis revealed that miR-1225-5P inhibited G1/G0 phase exit. In vivo xenograft model demonstrated that miR-1225-5P inhibited in vivo osteosarcoma tumor growth and lung metastasis.ConclusionOur findings suggested that miR-1225-5P inhibits osteosarcoma cell growth in vitro and tumor growth in vivo by targeting YWHAZ. This study suggested that miR-1225-5P can serve as a potential therapeutic method for treating osteosarcoma.

ORAL AND MAXILLOFACIAL OSTEOSARCOMA: CASE REPORT

A 43-year-old female patient attended the oral maxillofacial and traumatology service presenting volume increase in the right hemiface with painful symptomatology. At the intraoral examination, an exophytic lesion involving the alveolar ridge and palate region was observed, extending to the right nostril. The lesion showed a partially ulcerated surface, with purulent secretion, firm consistency, and normal mucosal color. Computed tomography revealed a mixed appearance of hyperdensity and ill-defined hypodensity in the maxillary region with extension to the zygoma and the right orbit. Because of poor oral hygiene and a history of regression with antibiotic therapy, a clinical diagnosis of actinomycosis was issued, and incisional biopsy of the lesion was subsequently performed. In the microscopic analysis, proliferation of pleomorphic and atypical malignant mesenchymal cells was associated with deposition of osteoid matrix, thus confirming the histopathologic diagnosis of osteosarcoma. The patient was referred to the State Reference Center for appropriate treatment.

Metaplastic breast carcinoma: Current therapeutic approaches and novel targeted therapies.

Metaplastic breast carcinoma (MBC) is a rare subtype of invasive breast cancer consisting of various combinations of malignant epithelial and mesenchymal cells. Its aggressive growth pattern combined with its histological heterogeneity account for MBC's characteristic resistance to systemic therapies, which subsequently leads to increased risk of recurrence and breast cancer mortality compared with other invasive mammary carcinomas. The aim of this review is to discuss the current therapeutic approaches, both in loco-regional as well as in systemic management of MBC. With the accumulation of knowledge from histopathologic assessment and the increasing identification of underlying molecular aberrations, emerging, novel targeted therapies will enable physicians to implement a more individualized and efficacious therapeutic strategy, leading hopefully to an improvement in the poor prognosis of MBC.

̈Mandibular intraoseous angiosarcoma, a multidisciplinary approacḧ

Background: The angiosarcoma is a malignant mesenchymal cells tumor with a differentiation into vascular endothelium. Angiosarcoma is a rare tumor and can occur in any location of the body, being the most common sites soft tissue and skin. This pathology in the oral cavity is extremely rare, there are a few cases reported and case series described in literature.

Epigenetic alterations in mesenchymal stem cells by osteosarcoma-derived extracellular vesicles

ABSTRACTExtracellular vesicles (EVs) are central to intercellular communication and play an important role in cancer progression and development. Osteosarcoma (OS) is an aggressive bone tumour, characterized by the presence of malignant mesenchymal cells. The specific tumour-driving genetic alterations that are associated with OS development are currently poorly understood. Mesenchymal stem cells (MSCs) of osteogenic lineage have been postulated as likely candidates as the cells of origin for OS, thus indicating that MSCs and OS stroma cells may be related cell types. Therefore, this study set out to examine the EV-mediated intercellular crosstalk of MSCs and OS. MSCs and pre-osteoblasts were treated with OS-EVs at different time points, and the epigenetic signature of OS-EVs was assessed by methylation analysis of LINE-1 (long interspersed element) and tumour suppressor genes. In addition, surface markers and expression of specific genes were also evaluated. Our data indicated that OS-EVs mediated LINE-1 hypomethylation in MSCs, whereas an opposite effect was seen in pre-osteoblasts, indicating that MSCs but not pre-osteoblasts were susceptible to epigenetic transformation. Thus, OS-EVs modulated the fate of MSCs by modulating the epigenetic status, and also influenced the expression of genes related to bone microenvironment remodelling. Overall, this study provided evidence that epigenetic regulation appears to be an early event in the transformation of MSCs during the development of OS. Elucidating the mechanisms of EV-mediated communication may lead to new avenues for therapeutic exploitation.

Sarcomatoid carcinoma of the pyriform sinus: A rare malignancy in a rare location responsive to combination of chemotherapy and radiotherapy

Sarcomatoid carcinoma (SaC) is a rare variant of squamous cell carcinoma with sarcomatoid features having biphasic characteristic malignant mesenchymal spindle cell and squamous cell component comprising of dysplasia, carcinoma in situ, or invasive carcinoma. Most information about this malignant entity in the head-and-neck region has emerged from larynx and oral cavity with an incidence of 0.5%–3% and 1%, respectively, with very few cases reported in hypopharynx. We hereby report such a case in a 76-year-old male who presented with dysphagia and swelling right side neck. Clinicopathological evaluation showed a localized SaC hypopharynx. In view of old age and comorbidities of hypertension and diabetes, no surgical intervention was contemplated, and he was treated with definitive concurrent chemo-radiotherapy (CCRT). A thorough review of the literature revealed that while earlier reported cases underwent upfront surgery followed by adjuvant RT or adjuvant CCRT, we treated this case with combination of chemotherapy and RT resulting in a significant therapeutic effect.

Effects of FOSL1 silencing on osteosarcoma cell proliferation, invasion and migration through the ERK/AP-1 signaling pathway.

Osteosarcoma (OS), as the most frequent primary malignancy of bone, is characterized by the presence of malignant mesenchymal cells. In the current study, our aim was to explore the possible effects Fos-like antigen-1 (FOSL1) had on the silencing regarding OS cell proliferation, invasion, and migration through the activation of the extracellular-signal-regulated kinase (ERK)/activator protein-1 (AP-1) signaling pathway. After the collection of OS on top of already having the adjacent normal tissue samples, the protein positive expression rate of FOSL1 was then measured by implementing the use of immunohistochemistry and discovered that FOSL1 was robustly expressed in OS. Later, to better grasp the impact FOSL1 projects on OS and its underlying mechanism, we determined the OS related genes as well as the ERK/AP-1 signaling pathway related genes expression by using a reverse-transcription quantitative polymerase chain reaction and western blot assay techniques. The results of the aforementioned two experiments revealed that the FOSL1 depletion had downregulated the expression of OS related genes by simultaneously downregulating the ERK/AP-1 signaling pathway. Moreover, cell proliferation, cycle, apoptosis, invasion, and migration of FOS1 were all tested by using a cell counting kit-8 assay, flow cytometry, Transwell assay, and scratch test, and these results presented that silencing of the FOSL1 gene inhibited OS cell proliferation, invasion, and migration. Our findings revealed a novel mechanism by which FOSL1 depletion played a significantly negative role in the OS progression through the regulation of theERK/AP-1 signaling pathway. Functional suppression of FOSL1 might be a future therapeutic strategy regarding OS.

Primary Gallbladder Carcinosarcoma: A Rare Biliary Malignancy

Gallbladder cancer comprises approximately 85-90% of all biliary tract malignancies, with carcinosarcomas accounting for less than 1%. Karl Landsteiner first described sarcomatoid carcinoma in the gallbladder in 1907, with less than 100 cases reported since that time. A 49-year-old male presented with 1 month of sharp, epigastric pain. Initial labs revealed a lipase of 3785 U/l, AST 658, ALT 489, total bilirubin 2.4 mg/dl, and direct bilirubin 1.3 mg/dl. Computer tomography (CT) of abdomen and pelvis revealed intra and extra-hepatic biliary duct dilation, cholelithiasis with biliary sludge, and hyper-enhancement of the gallbladder wall. Magnetic resonance cholangiopancreatography (MRCP) revealed gallbladder wall thickening with a polyp or a large amount of gallbladder sludge. There was no definite evidence of choledocholithiasis. Patient underwent laparoscopic cholecystectomy. Pathology of the gallbladder showed a circumferential tumor at the gallbladder fundus measuring 3.2 cm with gross and microscopic invasion through the muscular wall (Figure 1). The tumor showed glandular differentiation with pleomorphic spindle cell components consistent with sarcomatoid carcinoma of the gallbladder (Figure 2). Tumor markers including AFP, Ca 19-9, and CEA were negative. He underwent further robotic-assisted liver resection with lymphadenectomy. Lymph nodes were negative for malignancy. He was evaluated by oncology and recommended adjuvant platinum based chemotherapy for six months.1243_A.tif Figure 1: Gross image of gallbladder showing a 3.2 cm, circumferential, intramural mass with associated mucosal ulceration1243_B.tif Figure 2: No Caption available.Carcinosarcoma is a rare gallbladder malignancy without clear diagnostic and treatment guidelines. Preoperative diagnosis is difficult as there are no specific radiographic findings. Histologically these tumors are characterized by malignant epithelial and mesenchymal cells, that stain positive for cytokeratin and vimentin respectively. Tumor markers are often nonspecific. Major prognostic factors may include tumor size, staging, and depth of invasion. Primary therapy is surgical resection. Some cases have reported chemotherapy regimens including a combination of 5-fluorouracil with a carboplatin. Overall prognosis is poor in locally advanced disease with a 5-year survival rate of approximately 16%. This case illustrates the importance of considering carcinosarcoma as a differential in a patient with prolonged epigastric pain with non-specific image findings. It stresses the importance of ongoing research to help define adjuvant chemotherapy or chemoradiation regimens to improve survival.