Primary Malignant Cells Research Articles

Primary malignant perivascular epithelioid cell tumors with TFE3 rearrangement of bone: a clinicopathological analysis of two cases

Primary malignant perivascular epithelioid cell tumors with TFE3 rearrangement of bone: a clinicopathological analysis of two cases

Efficacy of Pazopanib on Primary Patient-derived Undifferentiated Malignant Round Cell Sarcoma Line

Abstract Introduction: Undifferentiated round cell tumours (URCTs) are rare and less researched Ewing-like mesenchymal tumours that primarily affect bones and soft tissues. Therapeutic options for advanced URCT are limited. Pazopanib, a multi-tyrosine kinase and angiogenesis inhibitor, is currently used for managing advanced soft-tissue sarcoma. However, its efficacy in the treatment of URCT remains uncertain and has not been established. In this study, we have cultured and characterised a patient-derived URCT cell line to understand the in vitro growth properties and anti-cancer agent sensitivity. Materials and Methods: Primary cell culture was performed by mechanical and enzymatic dissociation of URCT tissue specimens to derive a cell line. Morphology, growth properties and immunological features characterised the cells. Further, the in vitro sensitivity for clinically used anti-cancer drugs was evaluated. Results: The URCT cell line was established from a high-grade round-cell tumour patient. The cells had mesenchymal morphology and showed cyclin B3 (CCNB3) positivity, which was confirmed in the tissue from the patient. The cells exhibited an anchorage-independent growth property and aggregated to form spheroids in a non-adherent in vitro system. Anti-cancer agents vincristine, doxorubicin, etoposide and pazopanib inhibited URCT cell proliferation. Pazopanib exhibited cytotoxic action in URCT cells, leading to cell death. Conclusions: This is an early report of cultured URCT cells expressing CCNB3, studied in vitro. The patient-derived model suggests the efficacy of pazopanib in URCT cells. The characterised line will be helpful to advance sarcoma studies.

Multimodal imaging in the diagnosis of bone giant cell tumors: A retrospective study

BACKGROUND Giant cell tumor of bone is a locally aggressive and rarely metastasizing tumor, and also a potential malignant tumor that may develop into a primary malignant giant cell tumor. AIM To evaluate the role of multimodal imaging in the diagnosis of giant cell tumors of bone. METHODS The data of 32 patients with giant cell tumor of bone confirmed by core-needle biopsy or surgical pathology at our hospital between March 2018 and March 2023 were retrospectively selected. All the patients with giant cell tumors of the bone were examined by X-ray, computed tomography (CT) and magnetic resonance imaging (MRI), and 7 of them were examined by positron emission tomography (PET)-CT. RESULTS X-ray imaging can provide overall information on giant cell tumor lesions. CT and MRI can reveal the characteristics of the internal structure of the tumor as well as the adjacent relationships of the tumor, and these methods have unique advantages for diagnosing tumors and determining the scope of surgery. PET-CT can detect small lesions and is highly valuable for identifying benign and malignant tumors to aid in the early diagnosis of metastasis. CONCLUSION Multimodal imaging plays an important role in the diagnosis of giant cell tumor of bone and can provide a reference for the treatment of giant cell tumors.

Evaluation of lipopolymer as therapeutic siRNA delivery agents in non-malignant and malignant primary cells.

e15189 Background: Targeting leukemia-driving oncogenes via short interfering RNA (siRNA) offers an alternative approach to leukemia treatment that can overcome the limitations of current therapies. Low molecular weight polyethyleneimine grafted with lipids (lipopolymers) have emerged as promising carriers for siRNA delivery to leukemia cells. Lipopolymers harboring select lipids were recently shown to downregulate target oncogene leading to significant anti-leukemic activity in both in vitro and in vivo cell line-based leukemia models. The goal of this study was to evaluate these lipopolymers in (i) PBMCs obtained from healthy donors to determine the potential impact on non-malignant cells, and (ii) primary leukemia patient cells to assess therapeutic efficacy. Methods: Target gene levels were determined by RT-qPCR and the effect of treatment on progenitor cells was assessed by measuring changes in colony forming ability. Results: At day 1 post-treatment, no changes in FLT3 mRNA levels were observed in all 6 PBMC samples with the 2 candidate lipopolymers (LeuFectB and LeuFectC) tested. Among 11 PBMC samples evaluated at day 2, only one sample showed a significant reduction in oncogene transcript levels on treatment with LeuFectB. The impact of lipopolymer/siRNA complex treatment on progenitor cells in the PBMC population was then assessed. Of the 7 PBMC samples tested, significant reduction in colony numbers was observed in one sample with LeuFectB and two samples with LeuFectC. On an average, the lipopolymer/siRNA complexes were well tolerated by normal healthy cells as changes observed in oncogene expression and colony forming ability were not consistent across the whole pool. Primary acute lymphoblastic leukemia (ALL) patient cells treated with complexes targeting STAT5A showed marked reduction in STAT5A transcript levels in 4 out of 7 samples with both the lipopolymers tested. The subsequent impact of STAT5A downregulation on the clonogenicity of leukemia stem cells was observed in the significant decrease in colony numbers seen in 3 samples (out of 8) with LeuFects. Additionally, combined downregulation of STAT5A and BCR-ABL genes in BCR-ABL+ ALL patient samples led to a notable decrease in cell proliferation and viability. Moreover,2 out of 3 acute myeloid leukemia (AML) patient samples harboring the FLT3-ITD mutation showed significant retardation in their colony forming ability on treatment with FLT3-targeting siRNA complexes. Collectively, the ALL and AML primary samples demonstrated promising preliminary results, suggesting a therapeutic effect on the stem cell population which is critical for mitigating relapse or prolonging remission. Conclusions: These findings provide further proof-of-concept for clinical translation of lipopolymer mediated siRNA therapy of leukemia, showing relative safety and selectivity of these lipopolymer/siRNA complexes.

Ectopic mediastinal parathyroid adenoma in association with metachronous intrathymic choriocarcinoma in an elderly woman: A co-existence never described before

Primary malignant germ cell tumors of the mediastinum are extremely rare among females. Primary choriocarcinoma of the mediastinum is a rare form of extragonadal germ cell tumor that has a poorer prognosis in comparison to other extragenital germ

Abstract 1344: Improvement of the anti-tumor activity of NK cells and the efficacy of anti-CD20 monoclonal antibodies in the therapy of B cell-derived malignancies

Abstract Resistance of tumor cells to immunotherapy with monoclonal antibodies (mAbs) often relies on the reduced level of the antigen targeted by the particular mAb. We have therefore screened for the compounds able to upregulate selected antigens on the surface of lymphoma/leukemia cells, to minimize the possibility of resistance acquired by the tumor cells. We have found that members of a specific class of antibiotics, known as cation carriers, namely salinomycin (SAL), monensin (MON), narasin, and nigericin exhibit great CD20 antigen-upregulating abilities. A variety of Burkitt’s lymphoma and diffuse large B-cell lymphoma (DLBCL) cell lines as well as patients-derived primary malignant cells, such as DLBCL and chronic lymphocytic leukemia (CLL) cells exhibited upregulation of surface CD20 upon the treatment with SAL and MON at concentrations as low as 250nM and 50 nM, respectively. As a consequence, these compounds appeared to be beneficial for the therapy of lymphoma/leukemia with anti-CD20 mAbs, both in vitro and in animal models.Moreover, the proteomics analysis revealed that besides CD20, cation carriers upregulated a number of different proteins on the surface of tumor cells, including proteins implicated in the interaction with immune cells. These included ICAM1, HLA-A/B/C, CD155, CD80, CD86 and ULBP2/5/6. Particularly important appears to be the upregulation of antigens interacting with the activating receptors on NK cells, helping them to overcome the inhibitory signals and stimulate the lysis of tumor cells. Thus, the results of proteomics analysis explained why SAL- or MON-pretreated tumor cells were efficiently eliminated by NK cells, even in the absence of therapeutic mAb. In light of our discoveries, it seems reasonable to consider the cation carriers as promising drug candidates for the improvement of NK cell anti-tumor activity and potential treatment of B-cell non-Hodgkin lymphoma patients, in combination with anti-CD20 mAbs.Funding: National Science Centre (NCN, Poland), grants 2019/35/B/NZ5/01445 and 2020/39/B/NZ6/03513. Citation Format: Abdessamad Zerrouqi, Aleksandra Zdanowicz, Anna Torun, Andrzej Ciechanowicz, Bhaskar Pradhan, Grzegorz Rymkiewicz, Dimitar Efremov, Beata Pyrzynska. Improvement of the anti-tumor activity of NK cells and the efficacy of anti-CD20 monoclonal antibodies in the therapy of B cell-derived malignancies [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 1344.

The Impact of 3D Nichoids and Matrix Stiffness on Primary Malignant Mesothelioma Cells.

Malignant mesothelioma is a type of cancer that affects the mesothelium. It is an aggressive and deadly form of cancer that is often caused by exposure to asbestos. At the molecular level, it is characterized by a low number of genetic mutations and high heterogeneity among patients. In this work, we analyzed the plasticity of gene expression of primary mesothelial cancer cells by comparing their properties on 2D versus 3D surfaces. First, we derived from primary human samples four independent primary cancer cells. Then, we used Nichoids, which are micro-engineered 3D substrates, as three-dimensional structures. Nichoids limit the dimension of adhering cells during expansion by counteracting cell migration between adjacent units of a substrate with their microarchitecture. Tumor cells grow effectively on Nichoids, where they show enhanced proliferation. We performed RNAseq analyses on all the samples and compared the gene expression pattern of Nichoid-grown tumor cells to that of cells grown in a 2D culture. The PCA analysis showed that 3D samples were more transcriptionally similar compared to the 2D ones. The 3D Nichoids induced a transcriptional remodeling that affected mainly genes involved in extracellular matrix assembly. Among these genes responsible for collagen formation, COL1A1 and COL5A1 exhibited elevated expression, suggesting changes in matrix stiffness. Overall, our data show that primary mesothelioma cells can be effectively expanded in Nichoids and that 3D growth affects the cells' tensegrity or the mechanical stability of their structure.

Endolysosomal two-pore channel 2 plays opposing roles in primary and metastatic malignant melanoma cells.

The ion channel two-pore channel 2 (TPC2), localised on the membranes of acidic organelles such as endo-lysosomes and melanosomes, has been shown to play a role in pathologies including cancer, and it is differently expressed in primary versus metastatic melanoma cells. Whether TPC2 plays a pro- or anti-oncogenic role in different tumour conditions is a relevant open question which we have explored in melanoma at different stages of tumour progression. The behaviour of primary melanoma cell line B16F0 and its metastatic subline B16F10 were compared in response to TPC2 modulation by silencing (by small interfering RNA), knock-out (by CRISPR/Cas9) and overexpression (by mCherry-TPC2 transfected plasmid). TPC2 silencing increased cell migration, epithelial-to-mesenchymal transitionand autophagy in the metastatic samples, but abated them in the silenced primary ones. Interestingly, while TPC2 inactivation failed to affect markers of proliferation in both samples, it strongly enhanced the migratory behaviour of the metastatic cells, again suggesting that in the more aggressive phenotype TPC2 plays a specific antimetastatic role. In line with this, overexpression of TPC2 in B16F10 cells resulted in phenotype rescue, that is, a decrease in migratory ability, thus collectively resuming traits of the B16F0 primary cell line. Our research shows a novel role of TPC2 in melanoma cells that is intriguingly different in initial versus late stages of cancer progression.

Altered O-linked glycosylation in benign and malignant meningiomas.

Changes in protein glycosylation have been reported in various diseases, including cancer; however, the consequences of altered glycosylation in meningiomas remains undefined. We established two benign meningioma cell lines-SUT-MG12 and SUT-MG14, WHO grade I-and demonstrated the glycan and glycosyltransferase profiles of the mucin-type O-linked glycosylation in the primary benign meningioma cells compared with two malignant meningioma cell lines-HKBMM and IOMM-Lee, WHO grade III. Changes in O-linked glycosylation profiles in malignant meningiomas were proposed. Primary culture technique, morphological analysis, and immunocytochemistry were used to establish and characterize two benign meningioma cell lines. The glycan profiles of the primary benign and malignant meningiomas cell lines were then analyzed using lectin cytochemistry. The gene expression of O-linked glycosyltransferases, mucins, sialyltransferases, and fucosyltransferases were analyzed in benign and malignant meningioma using the GEO database (GEO series GSE16581) and quantitative-PCR (qPCR). Lectin cytochemistry revealed that the terminal galactose (Gal) and N-acetyl galactosamine (GalNAc) were highly expressed in primary benign meningioma cells (WHO grade I) compared to malignant meningioma cell lines (WHO grade III). The expression profile of mucin types O-glycosyltransferases in meningiomas were observed through the GEO database and gene expression experiment in meningioma cell lines. In the GEO database, C1GALT1-specific chaperone (COSMC) and mucin 1 (MUC1) were significantly increased in malignant meningiomas (Grade II and III) compared with benign meningiomas (Grade I). Meanwhile, in the cell lines, Core 2 β1,6-N-acetylglucosaminyltransferase-2 (C2GNT2) was highly expressed in malignant meningiomas. We then investigated the complex mucin-type O-glycans structures by determination of sialyltransferases and fucosyltransferases. We found ST3 β-galactoside α-2,3-sialyltransferase 4 (ST3GAL4) was significantly decreased in the GEO database, while ST3GAL1, ST3GAL3, α1,3 fucosyltransferases 1 and 8 (FUT1 and FUT8) were highly expressed in malignant meningioma cell lines-(HKBMM)-compared to primary benign meningioma cells-(SUT-MG12 and SUT-MG14). Our findings are the first to demonstrate the potential glycosylation changes in the O-linked glycans of malignant meningiomas compared with benign meningiomas, which may play an essential role in the progression, tumorigenesis, and malignancy of meningiomas.

Patient-Derived Xenograft Models in Cancer Research: Methodology, Applications, and Future Prospects.

Patient-derived xenografts (PDXs) have emerged as a pivotal tool in translational cancer research, addressing limitations of traditional methods and facilitating improved therapeutic interventions. These models involve engrafting human primary malignant cells or tissues into immunodeficient mice, allowing for the investigation of cancer mechanobiology, validation of therapeutic targets, and preclinical assessment of treatment strategies. This chapter provides an overview of PDXs methodology and their applications in both basic cancer research and preclinical studies. Despite current limitations, ongoing advancements in humanized xenochimeric models and autologous immune cell engraftment hold promise for enhancing PDX model accuracy and relevance. As PDX models continue to refine and extend their applications, they are poised to play a pivotal role in shaping the future of translational cancer research.

Elevated Serum Gastrin Is Associated with Melanoma Progression: Putative Role in Increased Migration and Invasion of Melanoma Cells

Micro-environmental factors, including stromal and immune cells, cytokines, and circulating hormones are well recognized to determine cancer progression. Melanoma cell growth was recently shown to be suppressed by cholecystokinin/gastrin (CCK) receptor antagonists, and our preliminary data suggested that melanoma patients with Helicobacter gastritis (which is associated with elevated serum gastrin) might have an increased risk of cancer progression. Therefore, in the present study, we examined how gastrin may act on melanoma cells. In 89 melanoma patients, we found a statistically significant association between circulating gastrin concentrations and melanoma thickness and metastasis, which are known risk factors of melanoma progression and prognosis. Immunocytochemistry using a validated antibody confirmed weak to moderate CCK2R expression in both primary malignant melanoma cells and the melanoma cell lines SK-MEL-2 and G361. Furthermore, among the 219 tumors in the Skin Cutaneous Melanoma TCGA Pan-Cancer dataset showing gastrin receptor (CCKBR) expression, significantly higher CCKBR mRNA levels were linked to stage III–IV than stage I–II melanomas. In both cell lines, gastrin increased intracellular calcium levels and stimulated cell migration and invasion through mechanisms inhibited by a CCK2 receptor antagonist. Proteomic studies identified increased MMP-2 and reduced TIMP-3 levels in response to gastrin that were likely to contribute to the increased migration of both cell lines. However, the effects of gastrin on tumor cell invasion were relatively weak in the presence of the extracellular matrix. Nevertheless, dermal fibroblasts/myofibroblasts, known also to express CCK2R, increased gastrin-induced cancer cell invasion. Our data suggest that in a subset of melanoma patients, an elevated serum gastrin concentration is a risk factor for melanoma tumor progression, and that gastrin may act on both melanoma and adjacent stromal cells through CCK2 receptors to promote mechanisms of tumor migration and invasion.

CD70/CD27 Signaling Promotes Expansion of Clonal Plasma Cells in Multiple Myeloma and Is a Promising Therapeutic Target in Advanced Disease

Introduction: Multiple Myeloma (MM) is a hematological malignancy characterized by the clonal expansion of malignant plasma cells within the bone marrow (BM). In the last decade, substantial advances in the treatment of MM patients have been made resulting in improved progression-free and overall survival rates. However, to date, MM remains incurable. CD70 and CD27 belong to the TNF receptor family. CD70 is the only known ligand for its receptor CD27. Physiologically, the CD70/CD27 interaction is involved in the regulation of immune cell expansion. However, numerous solid and hematological cancer types overexpress CD70. Aside, CD70 and CD27 co-expression has been described on leukemic stem cells (LSC) in acute myeloid leukemia patients where an autonomous signaling activation drives LSC self-renewal and expansion. While CD70/CD27 signaling plays a key role in the differentiation process of B lymphocytes into plasma cells, only little is known about its impact on myelomagenesis and MM progression. In this study, we analyzed the role of CD70/CD27 signaling in the pathogenesis of MM and studied the possibility to target CD70 by monoclonal antibodies to treat the disease. Materials and Methods: We evaluated CD70 and CD27 gene expression levels and its correlations with overall survival (OS), MM progression and high-risk molecular alterations using different databases (CoMMpass IA15, GSE6477). CD70 and CD27 protein expression patterns were analyzed in a newly established MM tissue microarray (TMA) and a collection of matched BM samples from initial and advanced disease stages (in collaboration with the Institutes of Pathology in Bern, Basel and Tübingen). To assess the functional role of CD70/CD27 signaling on MM initiation and expansion, we generated CD70 knock-out MM cell lines and newly established patient-derived xenografts (PDX) using CRISPR/Cas9 genome editing. CD70-expressing MM cell lines or patient-derived myeloma cells were grown in NOD/SCID (NSG) mice. Moreover, different monoclonal antibodies (Abs) and Ab-derivates were tested including a CD70 blocking antibody (αCD70) and an antibody-dependent cell-mediated cytotoxicity (ADCC) optimized antibody (cusatuzumab, ArgenX) that activates FcγR-expressing effector cells to assess the therapeutic potential of targeting CD70 in MM. Results: High CD70 gene expression levels correlate with increased MKI67 gene expression and elevated lactate dehydrogenase serum levels indicating a more rapid proliferation of CD70-expressing myeloma cells. In addition, high CD70 expression in MM patients correlated with shorter OS. Longitudinal analyses of CD70 gene expression in the precursor stages monoclonal gammopathy of undetermined significance and smoldering myeloma as well as MM and relapsed MM stages showed highest CD70 gene expression levels in relapsed MM patients. Assessment of the molecular background further revealed increased frequencies of the prognostically unfavorable genomic translocations t(4;14) and t(14;16), as well as gain/amplification of the chromosomal region 1q21 (1q+) in CD70 high expressing MM patients. In line with our previous findings, a TMA analysis of over 200 MM core biopsies as well as a longitudinal analysis of matched biopsies from patients at initial diagnosis and MM relapse indicated that CD70 was overexpressed in advanced disease. Functionally, we found that CD70/CD27 signaling promotes plasma cell survival inducing the expansion of MM cell lines and primary malignant plasma cells. CD70 blockade (αCD70) or CD70 knock-out (CD70 KO) resulted in a significant inhibition or complete abrogation of growth of a CD70-expressing MM patient-derived xenograft (PDX) (EMM01 CD70+) compared to controls (Figure 1). Interestingly, in vivo limiting dilution assays revealed that CD70+CD27+ double-positive myeloma subpopulations showed significantly higher cancer stem cell frequencies compared to CD70 negative fractions suggesting that CD70 expression might be related to an immature or stem-cell like phenotype. The ADCC-optimized CD70 specific antibody custatuzumab efficiently eliminated CD70-expressing MM cells in the presence of PBMC-derived natural killer (NK) cells in vitro and in a PDX model in vivo. Conclusion: Our results indicate that CD70-expressing MM cells have a stem-cell like phenotype and propagate the disease. Targeting CD70 is a promising new therapy especially in advanced disease.

Preclinical and Clinical Evidence for Erythroid-Stimulating Activity of RVU120 CDK8/19 Inhibitor in AML and MDS

Introduction: RVU120 is an orally bioavailable small molecule inhibitor targeting mediator complex kinases CDK8 and its paralog CDK19. Preclinical results indicated that treatment with RVU120 could reduce the viability of AML cells, in particular those positive for NPM1 and DNMT3A mutations. Further studies also indicated that RVU120 induces erythroid differentiation of malignant stem cells isolated from AML and MDS patients, likely by the induction of STAT5-GATA1-dependent transcription. The first signs of clinical efficacy have been observed in the ongoing Phase 1 dose escalation study of RVU120 in AML and HR-MDS patients. The presented work provides the preclinical rationale and growing clinical evidence that in addition to previously reported blast reduction, RVU120 has also strong erythropoiesis stimulating activity that may be useful as a potential therapeutic strategy for MDS. Methods: RVU120-induced erythroid differentiation was studied in primary malignant stem cells from MDS patients and in a stem cell model derived from cord blood cells transformed by TLS-ERG fusion. Erythroid differentiation was tracked by flow cytometry, chromatin status, and transcriptomic changes using RNAseq, ATACseq and ChIPseq. CLI120-001 study (NCT04021368) is a phase 1 dose escalation study of RVU120 in patients with relapsed/refractory AML and HR-MDS which is currently ongoing. Flow cytometry for erythroid differentiation markers, NGS myeloid panel and bulk RNAseq were performed in all patients enrolled after September 2021. Results: At the time of the abstract submission, within 24 evaluable patients' erythroid improvement was reported in 1 patient with HR-MDS, 3 patients with AML MRC, and 1 patient with AML secondary to MF. Interestingly, in these cases, erythroid improvement was observed independently of significant blast reduction, at doses from 25 mg to 135 mg every other day in 3 weeks cycles. Transient induction of erythroid differentiation markers CD71 and/or CD235a was confirmed in 3 additional transfusion-dependent patients treated with RVU120. Bulk RNA-seq confirmed broad transcriptomic changes in BM of selected patients after treatment compared to the pre-dose baseline levels. Robust induction of genes involved in erythroblast differentiation and hemoglobin metabolism genes was confirmed in 2 AML-MRC and 2 AML patients. These changes correlated with the repression of major pro-inflammatory pathways, including hallmark interferon gamma and TNF/NFKB response genes and repression of TGFβ pathway genes. Molecular and flow cytometry changes observed in patients were consistent with the erythroid commitment and sequential induction of erythroid differentiation markers in cultured CD34+ malignant stem cells isolated from MDS and AML-MRC patients treated with RVU120 and other chemically non-related CDK8 inhibitors. Conclusions: The presented results provide clinical and preclinical evidence for RVU120 as a candidate for a novel erythroid stimulating agent. Treatment with RVU120 could be a promising addition to the current treatment options for patients with lower-risk MDS who are transfusion-dependent and failing first-line therapies.

The Surprising Effect of Silicone Shells on the Growth of Primary Benign and Malignant Cells

The Surprising Effect of Silicone Shells on the Growth of Primary Benign and Malignant Cells

Clinicopathological features of primary malignant perivascular epithelioid cell tumors of ureter: Histologic-radiologic correlation

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor that is mainly seen in middle-aged women. PEComa originating in the ureter is extremely rare it is unclear whether they display typical clinical and radiographic features seen elsewhere. Herein, we report findings from 2 cases of primary PEComa of the ureter that we classified as malignant. Case 1: A 45-year-old woman was admitted to the hospital with intermittent distension in her waist. After appropriate imaging, the right ureter and right kidney were excised under general anesthesia. The tumor measured 1.4 cm. Microscopically, the tumor displayed infiltrative growth, >2 mitoses per 10 high power fields (HPF), necrosis, and lympho-vascular invasion. Case 2: A 30-year-old woman was admitted to the hospital due to hematuria 20 days duration. The left ureter and left kidney were ultimately excised under general anesthesia. The tumor measured 2 cm. Microscopically, the tumor showed infiltrative growth and >2 mitoses/10 HPF. Our cases were diagnosed as malignant PEComa. No disease recurrence was observed in either of the two patients during the postoperative follow-up period. Malignant primary ureteral PEComa is very rare. The clinical manifestations are not specific, and it is usually misdiagnosed as a malignant neoplasm on imaging. Therefore, its diagnosis requires pathological examination and immunohistochemical analysis of the sampled or resected tumor. Treatment requires a complete surgical resection and regular clinical follow-up.

Breast metastatic tumors in lung can be substituted by lung-derived malignant cells transformed by alternative splicing H19 lncRNA

Metastasis accounts for most cancer-associated deaths; yet, this complex process remains poorly understood, particularly the relationship between distant metastasis and primary site-derived cells. Here, we modified the classical MMTV–PyMT breast carcinoma model to trace the fate of mammary-derived carcinoma cells. We show that within the lung, when the metastatic breast carcinoma cells are conditionally depleted, transformed lung epithelial cells generate new metastases. Metastatic breast carcinoma cells transmit H19 long noncoding (lnc) RNA to lung epithelial cells through exosomes. SF3B1 bearing mutations at arginine-625 alternatively splices H19 lncRNA in lung epithelial cells, which selectively acts like a molecular sponge to sequester let-7a and induces Myc upregulation. Under the conditional elimination of primary site-derived breast carcinoma cells, lung malignant cells expressing the mutated SF3B1 splice variant dominate the newly created tumors. Our study suggests that these new carcinoma cells originating from within the colonized organ can replace the primary site-derived malignant cells whenever their expansion is abrogated using an inducible diphtheria toxin receptor in our designed system. These findings should call for a better understanding of metastatic tumors with the specific origin during cancer metastasis.

Upregulated Expression of ErbB1 in Diffuse Large B-Cell Lymphoma as a Predictor of Poor Overall Survival Outcome.

We examined the transcript-level expression of ErbB family protein tyrosine kinases, including ERBB1, in primary malignant lymphoma cells from 498 adult patients with diffuse large B-cell lymphoma (DLBCL). ERBB1 expression in DLBCL cells was significantly higher than in normal B-lineage lymphoid cells. An upregulated expression of ERBB1 mRNA in DLBCL cells was correlated with an amplified expression of mRNAs for transcription factors that recognized ERBB1 gene promoter sites. Notably, amplified ERBB1 expression in DLBCL and its subtypes were associated with significantly worse overall survival (OS). Our results encourage the further evaluation of the prognostic significance of high-level ERBB1 mRNA expression and the clinical potential of ERBB1-targeting therapeutics as personalized medicines in high-risk DLBCL.

Effects of pharmacological primary cilium disturbance in the context of in vitro 2D and 3D malignant pleura mesothelioma

IntroductionPrimary cilium (PC) is a single non-motile antenna-like organelle composed of a microtubule core axon originating from the mother centriole of the centrosome. The PC is universal in all mammalian cells and protrudes to the extracellular environment receiving mechanochemical cues that it transmits in the cell. Aim: To investigate the role of PC in mesothelial malignancy in the context of two-dimensional (2D) and three-dimensional (3D) phenotypes. Materials and methodsThe effect of pharmacological deciliation [using ammonium sulphate (AS) or chloral hydrate (CH)] and PC elongation [using lithium chloride (LC)] on cell viability, adhesion, and migration (2D cultures) as well as in mesothelial sphere formation, spheroid invasion and collagen gel contraction (3D cultures) was investigated in benign mesothelial MeT-5A cells and in malignant pleural mesothelioma (MPM) cell lines, M14K (epithelioid) and MSTO (biphasic), and primary malignant pleural mesothelioma cells (pMPM). ResultsPharmacological deciliation or elongation of the PC significantly affected cell viability, adhesion, migration, spheroid formation, spheroid invasion and collagen gel contraction in MeT-5A, M14K, MSTO cell lines and in pMPM cells compared to controls (no drug treatment). ConclusionsOur findings indicate a pivotal role of the PC in functional phenotypes of benign mesothelial cells and MPM cells.

PRIMITIVE MALIGNANT GERM CELL TUMORS OF THE OVARY: ABOUT 11 CASES AND LITERATURE REVIEW

Malignant germ cell tumors of the ovary are rare entities. They mainly affect young patients and can threaten the functional prognosis.
 We carried out a retrospective study of 11 cases of primary malignant germ cell tumors of the ovary, diagnosed at the paraclinical training and research unit in Pathological Anatomy and Cytology of the CHU/JRA, within a period of 10 years, from January 2010 to December 2019. The ages of these patients varied from 2 to 63 years old with an average of 30,5 years old. In the majority of cases (7 cases), radical treatement was achieved. The guiding clinical information was in all cases an abdominopelvic mass. The right side was the most affected (6/11) and one case was bilateral. The most common histological type was dysgerminoma (4/11).

Long-Term Cultured Human Glioblastoma Multiforme Cells Demonstrate Increased Radiosensitivity and Senescence-Associated Secretory Phenotype in Response to Irradiation.

The overall effect of senescence on cancer progression and cancer cell resistance to X-ray radiation (IR) is still not fully understood and remains controversial. How to induce tumor cell senescence and which senescent cell characteristics will ensure the safest therapeutic strategy for cancer treatment are under extensive investigation. While the evidence for passage number-related effects on malignant primary cells or cell lines is compelling, much less is known about how the changes affect safety and Senescence-Associated Secretory Phenotype (SASP), both of which are needed for the senescence cell-based vaccine to be effective against cancer. The present study aimed to investigate the effects of repeated passaging on the biological (self-renewal capacity and radioresistance) and functional (senescence) characteristics of the different populations of short- and long-term passaging glioblastoma multiforme (GBM) cells responding to senescence-inducing DNA-damaging IR stress. For this purpose, we compared radiobiological effects of X-ray exposure on two isogenic human U87 cell lines: U87L, minimally cultured cells (<15 passages after obtaining from the ATCC) and U87H, long-term cultured cells (>3 years of continuous culturing after obtaining from the ATCC). U87L cells displayed IR dose-related changes in the signs of IR stress-induced premature senescence. These included an increase in the proportion of senescence-associated β-galactosidase (SA-β-Gal)-positive cells, and concomitant decrease in the proportion of Ki67-positive cells and metabolically active cells. However, reproductive survival of irradiated short-term cultured U87L cells was higher compared to long-term cultured U87H cells, as the clonogenic activity results demonstrated. In contrast, the irradiated long-term cultured U87H cells possessed dose-related increases in the proportion of multinucleated giant cancer cells (MGCCs), while demonstrating higher radiosensitivity (lower self-renewal) and a significantly reduced fraction of DNA-replicating cells compared to short-term cultured U87L cells. Conditioned culture medium from U87H cells induced a significant rise of SA-β-Gal staining in U87L cells in a paracrine manner suggesting inherent SASP. Our data suggested that low-dose irradiated long-term cultured GBM cells might be a safer candidate for a recently proposed senescence cell-based vaccine against cancer.