Natural Resistance against H-2+ and H-2- Tumor Cells Grafted to the Brain

2015 ◽  
pp. 285-289
Author(s):  
George Klein ◽  
Klas K�rre ◽  
Hans-Gustaf Ljunggren ◽  
Toshiki Yamasaki ◽  
Claes �hl�n ◽  
...  
Author(s):  
C. N. Sun ◽  
C. Araoz ◽  
H. J. White

The ultrastructure of a cerebral primitive neuroectodermal tumor has been reported previously. In the present case, we will present some unusual previously unreported membranous structures and alterations in the cytoplasm and nucleus of the tumor cells.Specimens were cut into small pieces about 1 mm3 and immediately fixed in 4% glutaraldehyde in phosphate buffer for two hours, then post-fixed in 1% buffered osmium tetroxide for one hour. After dehydration, tissues were embedded in Epon 812. Thin sections were stained with uranyl acetate and lead citrate.In the cytoplasm of the tumor cells, we found paired cisternae (Fig. 1) and annulate lamellae (Fig. 2) noting that the annulate lamellae were sometimes associated with the outer nuclear envelope (Fig. 3). These membranous structures have been reported in other tumor cells. In our case, mitochondrial to nuclear envelope fusions were often noted (Fig. 4). Although this phenomenon was reported in an oncocytoma, their frequency in the present study is quite striking.


2021 ◽  
Vol 9 (6) ◽  
pp. e002181
Author(s):  
Erin F Simonds ◽  
Edbert D Lu ◽  
Oscar Badillo ◽  
Shokoufeh Karimi ◽  
Eric V Liu ◽  
...  

BackgroundGlioblastoma (GBM) is refractory to immune checkpoint inhibitor (ICI) therapy. We sought to determine to what extent this immune evasion is due to intrinsic properties of the tumor cells versus the specialized immune context of the brain, and if it can be reversed.MethodsWe used CyTOF mass cytometry to compare the tumor immune microenvironments (TIME) of human tumors that are generally ICI-refractory (GBM and sarcoma) or ICI-responsive (renal cell carcinoma), as well as mouse models of GBM that are ICI-responsive (GL261) or ICI-refractory (SB28). We further compared SB28 tumors grown intracerebrally versus subcutaneously to determine how tumor site affects TIME and responsiveness to dual CTLA-4/PD-1 blockade. Informed by these data, we explored rational immunotherapeutic combinations.ResultsICI-sensitivity in human and mouse tumors was associated with increased T cells and dendritic cells (DCs), and fewer myeloid cells, in particular PD-L1+ tumor-associated macrophages. The SB28 mouse model of GBM responded to ICI when grown subcutaneously but not intracerebrally, providing a system to explore mechanisms underlying ICI resistance in GBM. The response to ICI in the subcutaneous SB28 model required CD4 T cells and NK cells, but not CD8 T cells. Recombinant FLT3L expanded DCs, improved antigen-specific T cell priming, and prolonged survival of mice with intracerebral SB28 tumors, but at the cost of increased Tregs. Targeting PD-L1 also prolonged survival, especially when combined with stereotactic radiation.ConclusionsOur data suggest that a major obstacle for effective immunotherapy of GBM is poor antigen presentation in the brain, rather than intrinsic immunosuppressive properties of GBM tumor cells. Deep immune profiling identified DCs and PD-L1+ tumor-associated macrophages as promising targetable cell populations, which was confirmed using therapeutic interventions in vivo.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hideki Nagano ◽  
Tamotsu Togawa ◽  
Takeshi Watanabe ◽  
Kenji Ohnishi ◽  
Toshihisa Kimura ◽  
...  

Abstract Background Heterotopic ossification (HO) is the formation of osseous tissue outside the skeleton. HO in malignant tumors of the digestive tract is extremely rare, as is ossification in metastatic lesions from HO-negative digestive tract tumors. Regarding the pathogenesis of HO, two theories have been proposed. The first is that the osteoblastic metaplasia of tumor cells (driven by the epithelial-mesenchymal transition, EMT) results in HO, and the second is that factors secreted by cancer cells lead to the metaplasia of stromal pluripotent cells into osteoblasts. However, the osteogenic mechanisms remain unclear. Case presentation An 83-year-old Japanese woman underwent low anterior rectal resection for rectal cancer before presentation at our institution, in June 2018. The final diagnosis was stage IIB rectal adenocarcinoma (T4aN0M0). Histological examination did not reveal HO in the primary tumor. Thirteen months after the operation, a solitary metastatic lesion in the brain 20 mm in size and a solitary metastatic lesion in a right axillary lymph node 20 mm in size were diagnosed. The patient was treated with gamma-knife therapy for the brain metastasis. One month later, she was referred to our institution. She underwent lymph node resection. Histological examination revealed that most portions of the affected lymph node were occupied by metastatic tumor cells and that central necrosis and four small ossified lesions without an osteoblast-like cell rim were present in the peripheral region. Immunohistochemical analysis showed tumor cells positive for BMP-2, osteonectin, osteocalcin, AE1/AE3, TGF-β1, Gli2, Smad2/3, and CDX2 and negative for nestin, CD56, and CK7. Conclusion This is the first English case report of HO in a metachronous metastatic lymph node after the curative resection of HO-negative rectal cancer. Unlike HO lesions in past reports, the HO lesion did not show peripheral osteoblast-like cells, and the immunohistochemical findings indicated that the present case resulted from the EMT.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Alice Buonfiglioli ◽  
Dolores Hambardzumyan

AbstractGlioblastoma (GBM) is the most aggressive and deadliest of the primary brain tumors, characterized by malignant growth, invasion into the brain parenchyma, and resistance to therapy. GBM is a heterogeneous disease characterized by high degrees of both inter- and intra-tumor heterogeneity. Another layer of complexity arises from the unique brain microenvironment in which GBM develops and grows. The GBM microenvironment consists of neoplastic and non-neoplastic cells. The most abundant non-neoplastic cells are those of the innate immune system, called tumor-associated macrophages (TAMs). TAMs constitute up to 40% of the tumor mass and consist of both brain-resident microglia and bone marrow-derived myeloid cells from the periphery. Although genetically stable, TAMs can change their expression profiles based upon the signals that they receive from tumor cells; therefore, heterogeneity in GBM creates heterogeneity in TAMs. By interacting with tumor cells and with the other non-neoplastic cells in the tumor microenvironment, TAMs promote tumor progression. Here, we review the origin, heterogeneity, and functional roles of TAMs. In addition, we discuss the prospects of therapeutically targeting TAMs alone or in combination with standard or newly-emerging GBM targeting therapies.


2021 ◽  
pp. 1118-1123
Author(s):  
Kengo Setta ◽  
Takaaki Beppu ◽  
Yuichi Sato ◽  
Hiroaki Saura ◽  
Junichi Nomura ◽  
...  

Malignant lymphoma of the head rarely arises outside of the brain parenchyma as primary cranial vault lymphoma (PCVL). A case of PCVL that invaded from subcutaneous tissue into the brain, passing through the skull, and occurred after mild head trauma is reported along with a review of the literature. The patient was a 75-year-old man with decreased activity. One month before his visit to our hospital, he bruised the left frontal area of his head. Magnetic resonance imaging showed homogeneously enhanced tumors with contrast media in the subcutaneous tissue corresponding to the head impact area and the cerebral parenchyma, but no obvious abnormal findings in the skull. A biopsy with craniotomy was performed under general anesthesia. The pathological diagnosis was diffuse large B-cell lymphoma. On histological examination, tumor cells grew aggressively under the skin. Tumor cells invaded along the emissary vein into the external table without remarkable bone destruction and extended across the skull through the Haversian canals in the diploe. Tumor cells were found only at the perivascular areas in the dura mater and extended into the brain parenchyma. Considering the history of head trauma and the neuroimaging and histological findings, the PCVL in the present case arose primarily under the skin, passed though the skull and dura mater, and invaded along vessels and reached the brain.


1993 ◽  
Vol 79 (5) ◽  
pp. 729-735 ◽  
Author(s):  
David Barba ◽  
Joseph Hardin ◽  
Jasodhara Ray ◽  
Fred H. Gage

✓ Gene therapy has many potential applications in central nervous system (CNS) disorders, including the selective killing of tumor cells in the brain. A rat brain tumor model was used to test the herpes simplex virus (HSV)-thymidine kinase (TK) gene for its ability to selectively kill C6 and 9L tumor cells in the brain following systemic administration of the nucleoside analog ganciclovir. The HSV-TK gene was introduced in vitro into tumor cells (C6-TK and 9L-TK), then these modified tumor cells were evaluated for their sensitivity to cell killing by ganciclovir. In a dose-response assay, both C6-TK and 9L-TK cells were 100 times more sensitive to killing by ganciclovir (median lethal dose: C6-TK, 0.1 µg ganciclovir/ml; C6, 5.0 µg ganciclovir/ml) than unmodified wild-type tumor cells or cultured fibroblasts. In vivo studies confirmed the ability of intraperitoneal ganciclovir administration to kill established brain tumors in rats as quantified by both stereological assessment of brain tumor volumes and studies of animal survival over 90 days. Rats with brain tumors established by intracerebral injection of wild-type or HSV-TK modified tumor cells or by a combination of wild-type and HSV-TK-modified cells were studied with and without ganciclovir treatments. Stereological methods determined that ganciclovir treatment eliminated tumors composed of HSV-TK-modified cells while control tumors grew as expected (p < 0.001). In survival studies, all 10 rats with 9L-TK tumors treated with ganciclovir survived 90 days while all untreated rats died within 25 days. Curiously, tumors composed of combinations of 9L and 9L-TK cells could be eliminated by ganciclovir treatments even when only one-half of the tumor cells carried the HSV-TK gene. While not completely understood, this additional tumor cell killing appears to be both tumor selective and local in nature. It is concluded that HSV-TK gene therapy with ganciclovir treatment does selectively kill tumor cells in the brain and has many potential applications in CNS disorders, including the treatment of cancer.


Bone Research ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yao Fan ◽  
Rongrong Zha ◽  
Tomohiko Sano ◽  
Xinyu Zhao ◽  
Shengzhi Liu ◽  
...  

AbstractMechanical loading to the bone is known to be beneficial for bone homeostasis and for suppressing tumor-induced osteolysis in the loaded bone. However, whether loading to a weight-bearing hind limb can inhibit distant tumor growth in the brain is unknown. We examined the possibility of bone-to-brain mechanotransduction using a mouse model of a brain tumor by focusing on the response to Lrp5-mediated Wnt signaling and dopamine in tumor cells. The results revealed that loading the tibia with elevated levels of tyrosine hydroxylase, a rate-limiting enzyme in dopamine synthesis, markedly reduced the progression of the brain tumors. The simultaneous application of fluphenazine (FP), an antipsychotic dopamine modulator, enhanced tumor suppression. Dopamine and FP exerted antitumor effects through the dopamine receptors DRD1 and DRD2, respectively. Notably, dopamine downregulated Lrp5 via DRD1 in tumor cells. A cytokine array analysis revealed that the reduction in CCN4 was critical for loading-driven, dopamine-mediated tumor suppression. The silencing of Lrp5 reduced CCN4, and the administration of CCN4 elevated oncogenic genes such as MMP9, Runx2, and Snail. In summary, this study demonstrates that mechanical loading regulates dopaminergic signaling and remotely suppresses brain tumors by inhibiting the Lrp5-CCN4 axis via DRD1, indicating the possibility of developing an adjuvant bone-mediated loading therapy.


2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii28-ii28
Author(s):  
S Weil ◽  
E Jung ◽  
D Domínguez Azorín ◽  
J Higgins ◽  
J Reckless ◽  
...  

Abstract BACKGROUND Glioblastomas are notoriously therapy resistant tumors. As opposed to other tumor entities, no major advances in therapeutic success have been made in the past decades. This has been calling for a deeper biological understanding of the tumor, its growth and resistance patterns. We have been using a xenograft glioma model, where human glioblastoma cells are implanted under chronic cranial windows and studied longitudinally over many weeks and months using multi photon laser scanning microscopy (MPLSM). To test the effect of (new) drugs, a stable and direct delivery system avoiding the blood-brain-barrier has come into our interest. MATERIAL AND METHODS We implanted cranial windows and fluorescently labeled human glioblastoma stem-like cells into NMRI nude mice to follow up on the tumor development in our MPLSM model. After tumor establishment, an Alzet® micropump was implanted to directly deliver agents via a catheter system continuously over 28 days directly under the cranial window onto the brain surface. Using the MPLSM technique, the continuous delivery and infusion of drugs onto the brain and into the tumor was measured over many weeks in detail using MPLSM. RESULTS The establishment of the combined methods allowed reliable concurrent drug delivery over 28 days bypassing the blood-brain-barrier. Individual regions and tumor cells could be measured and followed up before, and after the beginning of the treatment, as well as after the end of the pump activity. Fluorescently labelled drugs were detectable in the MPLSM and its distribution into the brain parenchyma could be quantified. After the end of the micropump activity, further MPLSM measurements offer the possibility to observe long term effects of the applied drug on the tumor. CONCLUSION The combination of tumor observation in the MPSLM and concurrent continuous drug delivery is a feasible and reliable method for the investigation of (novel) anti-tumor agents, especially drugs that are not blood-brain-barrier penetrant. Morphological or even functional changes of individual tumor cells can be measured under and after treatment. These techniques can be used to test new drugs targeting the tumor, its tumor microtubes and tumor cells networks, and measure the effects longitudinally.


2019 ◽  
Vol 1 (Supplement_1) ◽  
pp. i3-i3
Author(s):  
Katie Thies ◽  
Anisha Hammer ◽  
Blake Hildreth ◽  
Luke Russell ◽  
Steven Sizemore ◽  
...  

Abstract Stromal platelet-derived growth factor receptor-beta (PDGFRβ) has emerged as an actionable mediator of breast tumor-stromal communication. As a receptor tyrosine kinase, PDGFRβ is activated by its ligand, PDGFB, which is released by neighboring tumor epithelium and endothelium. However, how PDGF signaling mediates breast cancer (BC) initiation, progression, and metastasis remains unclear. To evaluate PDGFRβ in this disease, we developed a mouse model of stromal-specific PDGFRβ activation using the Fsp-cre transgene previously published by our group. Mesenchymal-specific activation of PDGFRβ promotes preferential experimental brain metastasis of PDGFB-expressing mammary tumor cells when injected intravenously and accelerates intracranial tumor growth of these cells. Mammary tumor cells expressing low levels of PDGFB do not exhibit a similar increase in brain metastases in PDGFRβ mutant mice. To our knowledge, this is the first example where genetic manipulation of the stroma leads to an increased incidence of BCBM. Our pre-clinical data suggests that primary breast tumors that express high PDGFB could preferentially metastasize to the brain. To test this in patients, we analyzed PDGFB protein expression in a tissue microarray comprised of HER2-positive and triple negative BC primary tumors. While high PDGFB did not correlate with site-independent metastatic recurrence, it was prognostic of brain metastasis, mirroring our mouse data. Our findings suggest that high primary tumor PDGFB expression defines a subset of BC patients predisposed to brain metastases. These patients may benefit from therapeutic intervention of PDGFRβ signaling. To test this pre-clinically, we treated mice harboring intracranial tumors with the PDGFR-specific inhibitor, crenolanib. Excitingly, crenolanib treatment significantly inhibited the brain tumor burden in these mice. Combined, our findings (1) advocate that primary tumor expression of PDGFB is a novel prognostic biomarker for the development of BCBM and (2) support clinical trial evaluation of PDGFR inhibitors for the prevention and treatment of BCBM.


2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii3-iii3
Author(s):  
Jiwei Wang ◽  
Emma Rigg ◽  
Taral R Lunavat ◽  
Wenjing Zhou ◽  
Zichao Feng ◽  
...  

Abstract Background Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released by the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. Materials and Methods miRNAs from exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. Results miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146a in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. Conclusions MiR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.


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