Metastatic Progression of Osteosarcomas: A Review of Current Knowledge of Environmental versus Oncogenic Drivers

Metastases of osteosarcomas are heterogeneous. They may grow simultaneously with the primary tumor, during treatment or shortly after, or a long time after the end of the treatment. They occur mainly in lungs but also in bone and various soft tissues. They can have the same histology as the primary tumor or show a shift towards a different differentiation path. However, the metastatic capacities of osteosarcoma cells can be predicted by gene and microRNA signatures. Despite the identification of numerous metastasis-promoting/predicting factors, there is no efficient therapeutic strategy to reduce the number of patients developing a metastatic disease or to cure these metastatic patients, except surgery. Indeed, these patients are generally resistant to the classical chemo- and to immuno-therapy. Hence, the knowledge of specific mechanisms should be extended to reveal novel therapeutic approaches. Recent studies that used DNA and RNA sequencing technologies highlighted complex relations between primary and secondary tumors. The reported results also supported a hierarchical organization of the tumor cell clones, suggesting that cancer stem cells are involved. Because of their chemoresistance, their plasticity, and their ability to modulate the immune environment, the osteosarcoma stem cells could be important players in the metastatic process.

High Plus Low Dose Radiation Strategy in Combination with TIGIT and PD1 Blockade to Promote Systemic Antitumor Responses

Tumors deploy various immune-evasion mechanisms that create a suppressive environment and render effector T-cells exhausted and inactive. Therefore, a rational utilization of checkpoint inhibitors may alleviate exhaustion and may partially restore antitumor functions. However, in high-tumor-burden models, the checkpoint blockade fails to maintain optimal efficacy, and other interventions are necessary to overcome the inhibitory tumor stroma. One such strategy is the use of radiotherapy to reset the tumor microenvironment and maximize systemic antitumor outcomes. In this study, we propose the use of anti-PD1 and anti-TIGIT checkpoint inhibitors in conjunction with our novel RadScopal technique to battle highly metastatic lung adenocarcinoma tumors, bilaterally established in 129Sv/Ev mice, to mimic high-tumor-burden settings. The RadScopal approach is comprised of high-dose radiation directed at primary tumors with low-dose radiation delivered to secondary tumors to improve the outcomes of systemic immunotherapy. Indeed, the triple therapy with RadScopal + anti-TIGIT + anti-PD1 was able to prolong the survival of treated mice and halted the growth of both primary and secondary tumors. Lung metastasis counts were also significantly reduced. In addition, the low-dose radiation component reduced TIGIT receptor (PVR) expression by tumor-associated macrophages and dendritic cells in secondary tumors. Finally, low-dose radiation within triple therapy decreased the percentages of TIGIT+ exhausted T-cells and TIGIT+ regulatory T-cells. Together, our translational approach provides a new treatment alternative for cases refractory to other checkpoints and may bring immunotherapy into a new realm of systemic disease control.

Thyroid Cancer In Children: A Multicenter International Study Highlighting Clinical Features And Surgical Outcomes Of Primary And Secondary Tumors

Background: Thyroid gland malignancy is rare in pediatrics (0.7% of tumors); only 1.8% are observed in patients < 20 yrs with a higher prevalence recorded in females and adolescents. Risk factors include genetic syndromes - MEN disorders, autoimmune disease and ionizing radiation exposure. Radiotherapy is also linked with increased risk of secondary thyroid cancers. The present study describes the clinical features and surgical outcomes of primary and secondary thyroid tumors. Methods: Institutional data was collected on pediatric patients with thyroid cancer during 2000 - 2020 from 8 International Surgical Oncology centers. Statistical analysis was performed using GraphPad Prism. Results: Of 255 cases of thyroid cancer, only 13 (5.1%) were secondary tumors. Primary thyroid malignancies were more likely to be multifocal in origin (odds ratio [OR] 1.993, 95% confidence interval [CI] 0.7466-5.132, p 0.2323), had bilateral glandular location (OR 2.847, 95% CI 0.6835-12.68, p 0.2648) and proved metastatic at 1st diagnosis (OR 1.259, 95% CI 0.3267-5.696 p>0.999). Secondary tumors showed a higher incidence of disease relapse (OR 1.556, 95% CI 0.4579-5.57, p 0.4525) and surgical morbidity (OR 2.042, 95% CI 0.7917-5.221, p 0.1614) including hypoparathyroidism and recurrent laryngeal nerve injury. Overall survival (OS) was 99% at 1 year and 97% after 10 years. No EFS differences were evident with primary vs. secondary tumors (Chi square 0.7307, p 0.39026). Conclusions: This multicenter study demonstrates excellent survival for pediatric thyroid malignancy. Secondary tumors exhibit greater disease relapse (15.8% vs 10.5%) and a higher incidence of surgical related complications (36.8% vs 22.2%).

Mapping pediatric brain tumors to their origins in the developing cerebellum

Understanding the cellular origins of childhood brain tumors is key for discovering novel tumor-specific therapeutic targets. Previous strategies mapping cellular origins typically involved comparing human tumors to murine embryonal tissues, a potentially imperfect approach due to spatio-temporal gene expression differences between species. Here we use an unprecedented single-nucleus atlas of the developing human cerebellum (Sepp, Leiss, et al) and extensive bulk and single-cell transcriptome tumor data to map their cellular origins with focus on three most common pediatric brain tumors - pilocytic astrocytoma, ependymoma, and medulloblastoma. Using custom bioinformatics approaches, we postulate the astroglial and glial lineages as the origins for posterior fossa ependymomas and radiation-induced gliomas (secondary tumors after medulloblastoma treatment), respectively. Moreover, we confirm that SHH, Group3 and Group4 medulloblastomas stem from granule cell/unipolar brush cell lineages, whereas we propose pilocytic astrocytoma to originate from the oligodendrocyte lineage. We also identify genes shared between the cerebellar lineage of origin and corresponding tumors, and genes that are tumor specific; both gene sets represent promising therapeutic targets. As a common feature among most cerebellar tumors, we observed compositional heterogeneity in terms of similarity to normal cells, suggesting that tumors arise from or differentiate into multiple points along the cerebellar "lineage of origin".

A radioenhancing nanoparticle mediated immunoradiation improves survival and generates long-term antitumor immune memory in an anti-PD1-resistant murine lung cancer model

Background Combining radiotherapy with PD1 blockade has had impressive antitumor effects in preclinical models of metastatic lung cancer, although anti-PD1 resistance remains problematic. Here, we report results from a triple-combination therapy in which NBTXR3, a clinically approved nanoparticle radioenhancer, is combined with high-dose radiation (HDXRT) to a primary tumor plus low-dose radiation (LDXRT) to a secondary tumor along with checkpoint blockade in a mouse model of anti-PD1-resistant metastatic lung cancer. Methods Mice were inoculated with 344SQR cells in the right legs on day 0 (primary tumor) and the left legs on day 3 (secondary tumor). Immune checkpoint inhibitors (ICIs), including anti-PD1 (200 μg) and anti-CTLA4 (100 μg) were given intraperitoneally. Primary tumors were injected with NBTXR3 on day 6 and irradiated with 12-Gy (HDXRT) on days 7, 8, and 9; secondary tumors were irradiated with 1-Gy (LDXRT) on days 12 and 13. The survivor mice at day 178 were rechallenged with 344SQR cells and tumor growth monitored thereafter. Results NBTXR3 + HDXRT + LDXRT + ICIs had significant antitumor effects against both primary and secondary tumors, improving the survival rate from 0 to 50%. Immune profiling of the secondary tumors revealed that NBTXR3 + HDXRT + LDXRT increased CD8 T-cell infiltration and decreased the number of regulatory T (Treg) cells. Finally, none of the re-challenged mice developed tumors, and they had higher percentages of CD4 memory T cells and CD4 and CD8 T cells in both blood and spleen relative to untreated mice. Conclusions NBTXR3 nanoparticle in combination with radioimmunotherapy significantly improves anti-PD1 resistant lung tumor control via promoting antitumor immune response. Graphical Abstract

Cluster size distribution of cells disseminating from a primary tumor

The first stage of the metastatic cascade often involves motile cells emerging from a primary tumor either as single cells or as clusters. These cells enter the circulation, transit to other parts of the body and finally are responsible for growth of secondary tumors in distant organs. The mode of dissemination is believed to depend on the EMT nature (epithelial, hybrid or mesenchymal) of the cells. Here, we calculate the cluster size distribution of these migrating cells, using a mechanistic computational model, in presence of different degree of EMT-ness of the cells; EMT is treated as given rise to changes in their active motile forces (μ) and cell-medium surface tension (Γ). We find that, for (μ > μmin, Γ > 1), when the cells are hybrid in nature, the mean cluster size, N ¯ ∼ Γ 2 . 0 / μ 2 . 8, where μmin increases with increase in Γ. For Γ ≤ 0, N ¯ = 1, the cells behave as completely mesenchymal. In presence of spectrum of hybrid states with different degree of EMT-ness (motility) in primary tumor, the cells which are relatively more mesenchymal (higher μ) in nature, form larger clusters, whereas the smaller clusters are relatively more epithelial (lower μ). Moreover, the heterogeneity in μ is comparatively higher for smaller clusters with respect to that for larger clusters. We also observe that more extended cell shapes promote the formation of smaller clusters. Overall, this study establishes a framework which connects the nature and size of migrating clusters disseminating from a primary tumor with the phenotypic composition of the tumor, and can lead to the better understanding of metastasis.

Relapse Analysis and Resistance Mutations of PML-Rara Fusion Gene in Acute Promyelocytic Leukemia Patients Treated with All-Trans Retinoic Acid and Arsenic

The clinical manifestations, management, and prognosis of acute promyelocytic leukemia (APL) are distinctive in acute myeloid leukemia (AML). Administration of all-trans retinoic acid (ATRA) and arsenic agents have greatly improved the outcome of APL from the most lethal to the most curable subtype AML. Unfortunately, relapse is still observed. And in the case of combined medication with ATRA and arsenic, the resistance mutation spectrum of PML-RARA is far from being revealed. We retrospectively analyzed 40 APL patients that admitted to our hospital from Jan. 2013 to Jul. 2020. There were 21 males and 19 females, aged 6-65 years (median age 31.5), and follow-up time was 3-210 months (median time 58.85 months). There were 3 cases that developed secondary tumors, although APL remission has been achieved. One developed refractory AML with KMT2A-MLLT3 fusion during the consolidation treatment one year after the diagnosis of APL. One case relapsed with APL 5 years after the initial diagnosis, and she developed refractory AML with RUNX1-MECOM fusion 3.5 years more after enduring multiple relapses and treatment courses. Another case developed AML-M2 3.5 years after the initial diagnosis of APL, and achieved sustained remission again through allogeneic hematopoietic stem cell transplantation (allo-HSCT). A total of 8 cases came to our hospital at the initial onset of APL, and 1 came during remission. All these cases got sustained remission through combined triple therapy (ATRA, arsenic, and chemotherapy), with the follow-up time of 3 to 37 months (median 20.5 months). No PML-RARA resistant mutation was detected in these 9 cases. A total of 28 cases came to our hospital after APL relapse. The time from APL onset to the first relapse was 9-189 months (median 34 months). PML-RARA resistance mutations were detected in 9 cases, including 8 cases that carry single RARA mutations each, and 1 case that relapsed with multiple extramedullary infiltrations carry quadruple mutations (PML S214L-A216T and RARA R276W-H298N) (Figure 1a and b). A total of 4 cases underwent allo-HSCT after APL relapse. One of them relapsed 6 months after allo-HSCT, and the other 3 got sustained remission with the follow-up time of 47, 39, and 52 months, respectively. There were 2 cases relapsed after maintaining sustained remission for more than 5 years. One was a 58-year-old male who achieved sustained remission after 2.5 years of combined triple therapy. However, APL recurred 16 years after the primary diagnosis. He achieved remission again and now underwent the consolidation course of combined triple therapy. Another was a 23-year-old male who achieved sustained remission after combined arsenic and chemotherapy, but APL relapsed 75 months after the primary diagnosis. He was resistant to combined triple therapy and achieved remission through allo-HSCT. We failed to retrieve archived specimens at the first onset of APL for genomic variation comparison with the second onset. Therefore, we could not determine whether these two cases were relapsed from the original APL or developed another APL. Although we have achieved a high remission rate and long-term survival for APL through combined triple therapy, relapse and secondary tumors still occur in some cases. Especially for cases that endure heavy treatment, genomic toxicity may promote the oncogenesis of secondary tumors. Also, APL may recur over 5 years after the primary diagnosis and sustained remission. Whether there were inherited predisposing factors in these cases is worthy of further investigation. The incidence of PML and RARA resistant mutations in cases resistance for ATRA and arsenic is not very high. This may be related to the combination use of chemotherapeutic drugs and suggests underlying resistance mechanisms. Although both ATRA and arsenic were used in most cases, the incidence of ATRA resistance mutations is significantly higher than that of arsenic, which might attribute to the sparse interaction sites of arsenic and PML. A better combination strategy of arsenic, ATRA, with or without chemotherapy is worthy of further investigation to reduce the incidence of secondary tumors and relapse. Adhering to a systematically planed treatment course is essential for acquiring rapid remission and reduction of relapse. Treatment compliance should be paid attention to guaranteed, especially during the oral administration courses outside the hospital. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

New Insight to Overcome Tumor Resistance: An Overview from Cellular to Clinical Therapies

Disease relapse caused by drug resistance still represents a major clinical hurdle in cancer treatments. Tumor cells may take advantage of different intracellular and genetic systems attenuating the drug effects. Resistant cells or minimal residual disease (MRD) cells have strong clinical relevance, as they might give rise to secondary tumors when the therapy is concluded. Thus, MRDs are crucial therapeutic targets in order to prevent tumor relapse. Therefore, several groups aim at understanding how MRDs are orginated, characterizing their molecular features, and eradicating them. In this review, we will describe MRD from a genetic, evolutionary, and molecular point of view. Moreover, we will focus on the new in vitro, in vivo, preclinical, and clinical studies that aim at eradicating tumor resistance.

Functionalized Nanoparticles Targeting Tumor-Associated Macrophages as Cancer Therapy

The tumor microenvironment (TME) plays a central role in regulating antitumor immune responses. As an important part of the TME, alternatively activated type 2 (M2) macrophages drive the development of primary and secondary tumors by promoting tumor cell proliferation, tumor angiogenesis, extracellular matrix remodeling and overall immunosuppression. Immunotherapy approaches targeting tumor-associated macrophages (TAMs) in order to reduce the immunosuppressive state in the TME have received great attention. Although these methods hold great potential for the treatment of several cancers, they also face some limitations, such as the fast degradation rate of drugs and drug-induced cytotoxicity of organs and tissues. Nanomedicine formulations that prevent TAM signaling and recruitment to the TME or deplete M2 TAMs to reduce tumor growth and metastasis represent encouraging novel strategies in cancer therapy. They allow the specific delivery of antitumor drugs to the tumor area, thereby reducing side effects associated with systemic application. In this review, we give an overview of TAM biology and the current state of nanomedicines that target M2 macrophages in the course of cancer immunotherapy, with a specific focus on nanoparticles (NPs). We summarize how different types of NPs target M2 TAMs, and how the physicochemical properties of NPs (size, shape, charge and targeting ligands) influence NP uptake by TAMs in vitro and in vivo in the TME. Furthermore, we provide a comparative analysis of passive and active NP-based TAM-targeting strategies and discuss their therapeutic potential.

The Effects of Administrated Dexamethasone on Neurologic Assessment in Neuro-oncology Scale in Patients with Intracranial Tumors

BACKGROUND: In intracranial tumors, glucocorticoids are the main therapy to treat peritumoral edema. Neurologic Assessment in Neuro-Oncology (NANO) score is an instrument that can assess neurological function objectively and practically in patients with intracranial tumors. AIM: This study aims to determine the effect of dexamethasone administration on the NANO score of intracranial tumor patients. METHODS: This study was a pre-experimental study with a pre and post-test design at the H. Adam Malik General Hospital in Medan from March to September 2020. The study population was intracranial tumor patients. The research subject were 37 subjects taken consecutively. Treated with dexamethasone injection, then examined the NANO score before and after receiving dexamethasone injection on days 1, 2, and 3. Statistical analysis with Friedman test. RESULTS: Based on the demographic characteristics of the research subjects, the mean age was 53.29 ± 8.5 years. Most of the research subjects were male (54.1%) while female (45.9%). Most types of intracranial tumors were secondary tumors (59.5%) while primary tumors (40.5%). The significant effect of dexamethasone on NANO score in patients with intracranial tumors (p < 0.001). CONCLUSION: There is an effect of dexamethasone on the NANO score of patients with intracranial tumors.