GENE-63. GENOMIC CHARACTERIZATION OF HUMAN BRAIN METASTASES IDENTIFIES NOVEL DRIVERS OF LUNG ADENOCARCINOMA PROGRESSION

Abstract Although lung adenocarcinomas frequently metastasize to the brain, treatment options for lung adenocarcinoma brain metastases are limited. We discovered novel candidate drivers of progression by using case-control analyses to compare whole-exome sequencing data from a cohort of 73 lung adenocarcinoma brain metastases to a control cohort of 503 primary lung adenocarcinomas. We identified 3 genomic regions with significantly more frequent amplifications in brain metastases compared to the control cohort: MYC (12% vs 6%), YAP1 (7% vs 0.8%) and MMP13 (10% vs 0.6%). We also identified CDKN2A/B as a region deleted at a significantly greater frequency in brain metastases compared to primary lung adenocarcinomas (27% vs 13%, respectively). We confirmed frequent amplifications of MYC and YAP1/MMP13 in an independent validation cohort of 105 lung adenocarcinoma brain metastasis samples using fluorescence in situ hybridization. We further validated that MYC, YAP1 and MMP13 can drive brain metastases in a patient-derived xenograft mouse model. We found a higher incidence of metastases to the brain in mice receiving intracardiac injections of tumor cells expressing the candidate drivers compared to tumor cells expressing LacZ as a control. These results indicate that somatic alterations can drive lung adenocarcinomas to metastasize to the brain. The candidate brain metastasis drivers that we identified may serve as therapeutic targets in patients with lung adenocarcinomas who develop this devastating complication.

Download Full-text

BSCI-11. STROMAL PLATELET DERIVED GROWTH FACTOR RECEPTOR-β (PDGFRβ) PROMOTES BREAST CANCER BRAIN METASTASIS

Neuro-Oncology Advances ◽

10.1093/noajnl/vdz014.009 ◽

2019 ◽

Vol 1 (Supplement_1) ◽

pp. i3-i3

Author(s):

Katie Thies ◽

Anisha Hammer ◽

Blake Hildreth ◽

Luke Russell ◽

Steven Sizemore ◽

...

Keyword(s):

Breast Cancer ◽

Growth Factor ◽

Brain Metastasis ◽

Brain Metastases ◽

Tumor Cells ◽

Mammary Tumor ◽

Growth Factor Receptor ◽

Platelet Derived Growth Factor ◽

Mammary Tumor Cells ◽

The Brain

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.

Download Full-text

Gene Expression Profile in Primary Tumor Is Associated with Brain-Tropism of Metastasis from Lung Adenocarcinoma

International Journal of Molecular Sciences ◽

10.3390/ijms222413374 ◽

2021 ◽

Vol 22 (24) ◽

pp. 13374

Author(s):

Yen-Yu Lin ◽

Yu-Chao Wang ◽

Da-Wei Yeh ◽

Chen-Yu Hung ◽

Yi-Chen Yeh ◽

...

Keyword(s):

Gene Expression ◽

Brain Metastasis ◽

Brain Metastases ◽

Dna Sequencing ◽

Lung Adenocarcinoma ◽

Rna Sequencing ◽

Cell Lines ◽

Differentially Expressed Genes ◽

Primary Tumor ◽

The Brain

Lung adenocarcinoma has a strong propensity to metastasize to the brain. The brain metastases are difficult to treat and can cause significant morbidity and mortality. Identifying patients with increased risk of developing brain metastasis can assist medical decision-making, facilitating a closer surveillance or justifying a preventive treatment. We analyzed 27 lung adenocarcinoma patients who received a primary lung tumor resection and developed metastases within 5 years after the surgery. Among these patients, 16 developed brain metastases and 11 developed non-brain metastases only. We performed targeted DNA sequencing, RNA sequencing and immunohistochemistry to characterize the difference between the primary tumors. We also compared our findings to the published data of brain-tropic and non-brain-tropic lung adenocarcinoma cell lines. The results demonstrated that the targeted tumor DNA sequencing did not reveal a significant difference between the groups, but the RNA sequencing identified 390 differentially expressed genes. A gene expression signature including CDKN2A could identify 100% of brain-metastasizing tumors with a 91% specificity. However, when compared to the differentially expressed genes between brain-tropic and non-brain-tropic lung cancer cell lines, a different set of genes was shared between the patient data and the cell line data, which include many genes implicated in the cancer-glia/neuron interaction. Our findings indicate that it is possible to identify lung adenocarcinoma patients at the highest risk for brain metastasis by analyzing the primary tumor. Further investigation is required to elucidate the mechanism behind these associations and to identify potential treatment targets.

Download Full-text

Irradiation-induced M1 Microglia Affect Brain Metastatic Colonization of A549 Cell Lines via miR-9/CDH1 Axis

10.21203/rs.3.rs-123435/v1 ◽

2020 ◽

Author(s):

Yu Jin ◽

Yalin Kang ◽

Wan Qin ◽

Qianxia Li ◽

Qi Mei ◽

...

Keyword(s):

Brain Metastasis ◽

Brain Metastases ◽

Tumor Cells ◽

Cell Lines ◽

A549 Cell ◽

Metastatic Tumor ◽

Qrt Pcr ◽

The Brain ◽

Mesenchymal Epithelial Transition ◽

M1 Type

Abstract Background and purpose: Brain metastasis is among the leading causes of death in patients with non-small-cell lung cancer (NSCLC). Through yet unknown mechanisms, prophylactic cranial irradiation (PCI) can significantly decrease the incidence of brain metastases. We propose that PCI probably exerts indirect anti-tumoral effects by turning cerebral “soil” unfavorable for the colonization of metastatic tumor “seeds”. This study aims to reveal how PCI regulates the brain microenvironment conducing to a reduction in brain metastases.Materials and methods: Key marks of M1/M2 microglia types and mesenchymal-to-epithelial transition (MET) were analyzed by qRT-PCR and Western Blot in vitro. The target miR-9-5p was obtained by miRNA array analysis and confirmed by qRT-PCR in microglia. miRTarBase and TargetScan were used to predict the target genes of miR-9-5p, which were assessed by luciferase activity assay. Anti-metastatic effects of irradiation on the brain were evaluated by intravital imaging using a brain metastatic NSCLC A549-f3 cell line in a nude mouse model.Results: We found the microglia can polarize into M1 type after irradiation and the irradiated microglia inhibited mesenchymal-epithelial transition of metastatic tumor cells, which decreased their adhesion and colonization capabilities in brain. We discovered up-regulated miR-9 was related with inhibition of MET process. Further overexpression/silencing experiments indicated that irradiated M1-type microglia inhibited A549 mesenchymal-epithelial transition, mediated by miR-9 up-regulation and secretion. Additionally, these results were confirmed in mice model, as low dose irradiation increased miR-9 level in the brain microenvironment and reduced brain metastases of metastatic tumor cells.Conclusions: We demonstrated that miR-9 secreted by irradiated M1-type microglia played important role in inducing A549 cell lines into mesenchymal phenotype, and further decreased their localization capabilities in brain. Our findings emphasized the modulating effect of irradiation on metastatic soil, and the cross-talk between tumor cells and the metastatic microenvironment. More importantly, our findings provided new perspectives for effective anti-metastasis therapies, especially for NSCLC patients with high risk of brain metastasis.

Download Full-text

BSCI-12. Inhibition of melanoma brain metastasis by targeting miR-146a

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab071.011 ◽

2021 ◽

Vol 3 (Supplement_3) ◽

pp. iii3-iii3

Author(s):

Jiwei Wang ◽

Emma Rigg ◽

Taral R Lunavat ◽

Wenjing Zhou ◽

Zichao Feng ◽

...

Keyword(s):

Brain Metastasis ◽

Tumor Cells ◽

Cell Lines ◽

Western Blots ◽

Cell Growth And Migration ◽

Human Astrocytes ◽

And Migration ◽

The Brain

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.

Download Full-text

Advances in radiotherapy for brain metastases

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab126 ◽

2021 ◽

Vol 3 (Supplement_5) ◽

pp. v26-v34

Author(s):

Vinai Gondi ◽

Jacquelyn Meyer ◽

Helen A Shih

Keyword(s):

Brain Metastases ◽

Management Strategy ◽

Metastatic Cancer ◽

Treatment Options ◽

Management Strategies ◽

Whole Brain Radiotherapy ◽

Brain Radiotherapy ◽

Contemporary Management ◽

The Brain ◽

Systemic Therapies

Abstract As novel systemic therapies yield improved survival in metastatic cancer patients, the frequency of brain metastases continues to increase. Over the years, management strategies have continued to evolve. Historically, stereotactic radiosurgery has been used as a boost to whole-brain radiotherapy (WBRT) but is increasingly being used as a replacement for WBRT. Given its capacity to treat both macro- and micro-metastases in the brain, WBRT has been an important management strategy for years, and recent research has identified technologic and pharmacologic approaches to delivering WBRT more safely. In this review, we outline the current landscape of radiotherapeutic treatment options and discuss approaches to integrating radiotherapy advances in the contemporary management of brain metastases.

Download Full-text

P16.08 Inhibition of melanoma brain metastasis by targeting miR-146a

Neuro-Oncology ◽

10.1093/neuonc/noab180.199 ◽

2021 ◽

Vol 23 (Supplement_2) ◽

pp. ii57-ii57

Author(s):

J Wang ◽

E K Rigg ◽

T R Lunavat ◽

W Zhou ◽

Z Feng ◽

...

Keyword(s):

Brain Metastasis ◽

Tumor Cells ◽

Cell Lines ◽

Western Blots ◽

Cell Growth And Migration ◽

Human Astrocytes ◽

And Migration ◽

The Brain

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 from 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. MATERIAL AND METHODS miRNAs in 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-146 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. CONCLUSION miR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.

Download Full-text

Molecular and cellular mechanisms underlying brain metastasis of breast cancer

Cancer and Metastasis Reviews ◽

10.1007/s10555-020-09881-y ◽

2020 ◽

Vol 39 (3) ◽

pp. 711-720 ◽

Cited By ~ 2

Author(s):

Mari Hosonaga ◽

Hideyuki Saya ◽

Yoshimi Arima

Keyword(s):

Breast Cancer ◽

Brain Metastasis ◽

Brain Metastases ◽

Cancer Cells ◽

Metastatic Cancer ◽

Breast Cancer Patients ◽

Cellular Mechanisms ◽

Her2 Positive ◽

Cells Of The Microenvironment ◽

The Brain

Abstract Metastasis of cancer cells to the brain occurs frequently in patients with certain subtypes of breast cancer. In particular, patients with HER2-positive or triple-negative breast cancer are at high risk for the development of brain metastases. Despite recent advances in the treatment of primary breast tumors, the prognosis of breast cancer patients with brain metastases remains poor. A better understanding of the molecular and cellular mechanisms underlying brain metastasis might be expected to lead to improvements in the overall survival rate for these patients. Recent studies have revealed complex interactions between metastatic cancer cells and their microenvironment in the brain. Such interactions result in the activation of various signaling pathways related to metastasis in both cancer cells and cells of the microenvironment including astrocytes and microglia. In this review, we focus on such interactions and on their role both in the metastatic process and as potential targets for therapeutic intervention.

Download Full-text

Brain metastases in patients diagnosed with a solid primary cancer during childhood: experience from a single referral cancer center

Journal of Neurosurgery Pediatrics ◽

10.3171/2014.7.peds13318 ◽

2014 ◽

Vol 14 (4) ◽

pp. 372-385 ◽

Cited By ~ 15

Author(s):

Dima Suki ◽

Rami Khoury Abdulla ◽

Minming Ding ◽

Soumen Khatua ◽

Raymond Sawaya

Keyword(s):

Brain Metastasis ◽

Brain Metastases ◽

Primary Tumor ◽

Lung Metastases ◽

Cancer Center ◽

Leptomeningeal Disease ◽

Tumor Type ◽

Primary Cancer ◽

Extracranial Metastases ◽

The Brain

Object Metastasis to the brain is frequent in adult cancer patients but rare among children. Advances in primary tumor treatment and the associated prolonged survival are said to have increased the frequency of brain metastasis in children. The authors present a series of cases of brain metastases in children diagnosed with a solid primary cancer, evaluate brain metastasis trends, and describe tumor type, patterns of occurrence, and prognosis. Methods Patients with brain metastases whose primary cancer was diagnosed during childhood were identified in the 1990–2012 Tumor Registry at The University of Texas M.D. Anderson Cancer Center. A review of their hospital records provided demographic data, history, and clinical data, including primary cancer sites, number and location of brain metastases, sites of extracranial metastases, treatments, and outcomes. Results Fifty-four pediatric patients (1.4%) had a brain metastasis from a solid primary tumor. Sarcomas were the most common (54%), followed by melanoma (15%). The patients' median ages at diagnosis of the primary cancer and the brain metastasis were 11.37 years and 15.03 years, respectively. The primary cancer was localized at diagnosis in 48% of patients and disseminated regionally in only 14%. The primary tumor and brain metastasis presented synchronously in 15% of patients, and other extracranial metastases were present when the primary cancer was diagnosed. The remaining patients were diagnosed with brain metastasis after initiation of primary cancer treatment, with a median presentation interval of 17 months after primary cancer diagnosis (range 2–77 months). At the time of diagnosis, the brain metastasis was the first site of systemic metastasis in only 4 (8%) of the 51 patients for whom data were available. Up to 70% of patients had lung metastases when brain metastases were found. Symptoms led to the brain metastasis diagnosis in 65% of cases. Brain metastases were single in 60% of cases and multiple in 35%; 6% had only leptomeningeal disease. The median Kaplan-Meier estimates of survival after diagnoses of primary cancer and brain metastasis were 29 months (95% CI 24–34 months) and 9 months (95% CI 6–11 months), respectively. Untreated patients survived for a median of 0.9 months after brain metastasis diagnosis (95% CI 0.3–1.5 months). Those receiving treatment survived for a median of 8 months after initiation of therapy (95% CI 6–11 months). Conclusions The results of this study challenge the current notion of an increased incidence of brain metastases among children with a solid primary cancer. The earlier diagnosis of the primary cancer, prior to its dissemination to distant sites (especially the brain), and initiation of presumably more effective treatments may support such an observation. However, although the actual number of cases may not be increasing, the prognosis after the diagnosis of a brain metastasis remains poor regardless of the management strategy.

Download Full-text

Brain Metastases in Soft Tissue Sarcomas: Case Report and Literature Review

Sarcoma ◽

10.1080/13577140500190921 ◽

2005 ◽

Vol 9 (3-4) ◽

pp. 147-150 ◽

Cited By ~ 6

Author(s):

Tejpal Gupta ◽

Siddhartha Laskar ◽

Sumeet Gujral ◽

Mary Ann Muckaden

Keyword(s):

Soft Tissue ◽

Brain Metastasis ◽

Brain Metastases ◽

Soft Tissue Sarcomas ◽

Whole Brain Radiotherapy ◽

Palliative Radiotherapy ◽

Adolescent Male ◽

Spindle Cell Sarcoma ◽

Solitary Brain Metastasis ◽

The Brain

Background and purpose:Brain metastasis is a relatively uncommon event in the natural history of soft tissue sarcomas. The increasing use of chemotherapy may have caused a reduction in local relapses as well as distant failures leading to an improvement in survival, thereby allowing metachronous seeding of the brain, a sanctuary site. The purpose of this report is to increase awareness amongst clinicians regarding such a possibility.Patients and methods:A review of the departmental sarcoma database following the presentation of this index case in the clinic.Results and discussion:An adolescent male who had previously been treated with surgery and radiotherapy for a spindle cell sarcoma of the left thigh developed a space-occupying lesion in the brain within 6 months of treatment of the primary tumor. He subsequently underwent resection of the presumed solitary brain metastasis followed by whole brain radiotherapy. On radiation he was detected to have pulmonary metastases too, for which he was offered palliative chemotherapy. The patient died of brain metastasis within 4 months. A review of the departmental sarcoma database, restricted to soft tissue sarcomas purely, maintained prospectively from 2000 till date, could not identify any other such case.Conclusion:Brain metastases from soft tissue sarcomas are rare. Patients with neurological symptoms, however, should be appropriately investigated. Surgical resection of brain metastasis could be considered for solitary brain metastasis in non-eloquent areas. Palliative radiotherapy is appropriate for patients with multiple brain metastases or co-existing extra-cranial disease.

Download Full-text

Metastatic Liposarcoma of the Brain with Response to Chemotherapy: Case Report

Neurosurgery ◽

10.1227/00006123-198812000-00021 ◽

1988 ◽

Vol 23 (6) ◽

pp. 777-780 ◽

Cited By ~ 18

Author(s):

Harold Haft ◽

George C. Wang

Keyword(s):

Case Report ◽

Brain Metastasis ◽

Brain Metastases ◽

Abdominal Mass ◽

Response To Chemotherapy ◽

History Of ◽

In The Beginning ◽

The Brain

Abstract Metastatic liposarcomas to the brain are rare. The authors describe a patient with a 20-year history of liposarcoma originating in the thigh and metastatic to the brain 18 years later. The brain metastasis was removed by surgery. Nine months later, the patient developed metastases to the retroperitoneum and liver. At that same time, she had recurrent brain metastasis. She was then treated with chemotherapy. The abdominal mass shrank considerably in the beginning, and the recurrent brain metastases totally disappeared. The patient eventually succumbed to widespread liposarcoma. Autopsy revealed extensive liposarcoma involving the retroperitoneum, liver, and lung, but no trace of tumor was found in the brain.

Download Full-text