TCR-transgenic T cells and YB-1-based oncolytic virotherapy improve survival in a preclinical Ewing sarcoma xenograft mouse model

BackgroundEwing sarcoma (EwS) is an aggressive and highly metastatic bone and soft tissue tumor in pediatric patients and young adults. Cure rates are low when patients present with metastatic or relapsed disease. Therefore, innovative therapy approaches are urgently needed. Cellular- and oncolytic virus-based immunotherapies are on the rise for solid cancers.MethodsHere, we assess the combination of EwS tumor-associated antigen CHM1319-specific TCR-transgenic CD8+ T cells and the YB-1-driven (i.e. E1A13S-deleted) oncolytic adenovirus XVir-N-31 in vitro and in a xenograft mouse model for antitumor activity and immunostimulatory properties.ResultsIn vitro both approaches specifically kill EwS cell lines in a synergistic manner over controls. This effect was confirmed in vivo, with increased survival using the combination therapy. Further in vitro analyses of immunogenic cell death and antigen presentation confirmed immunostimulatory properties of virus-infected EwS tumor cells. As dendritic cell maturation was also increased by XVir-N-31, we observed superior proliferation of CHM1319-specific TCR-transgenic CD8+ T cells only in virus-tested conditions, emphasizing the superior immune-activating potential of XVir-N-31.ConclusionOur data prove synergistic antitumor effects in vitro and superior tumor control in a preclinical xenograft setting. Combination strategies of EwS-redirected T cells and YB-1-driven virotherapy are a highly promising immunotherapeutic approach for EwS and warrant further evaluation in a clinical setting

Biallelic CACNA1A variants: Review of literature and report of a child with drug‐resistant epilepsy and developmental delay

Funder: Great Ormond Street Hospital Charity; Id: http://dx.doi.org/10.13039/501100001279Funder: NIHR Cambridge Biomedical Research Centre; Id: http://dx.doi.org/10.13039/501100018956Funder: Department of Health; Id: http://dx.doi.org/10.13039/501100003921Funder: Cambridge University Hospitals; Id: http://dx.doi.org/10.13039/501100002926Abstract: Biallelic variants in CACNA1A have previously been reported in nine individuals (four families) presenting with epilepsy and cognitive impairments of variable severity and age‐of‐onset. Here, we describe a child who presented at 6 months of age with drug‐resistant epilepsy and developmental delay. At 10 years of age, she has profound impairments in motor function and communication. MRI was initially unremarkable, but progressed to severe cerebellar atrophy by age 3 years. Next Generation Sequencing and panel analysis identified a maternally inherited truncating variant c.2042_2043delAG, p.(Gln681ArgfsTer100) and paternally inherited missense variant c.1693G>A, p.(Glu565Lys). In contrast to previously reported biallelic cases, parents carrying these monoallelic variants did not display clear signs of a CACNA1A‐associated syndrome. In conclusion, we provide further evidence that biallelic CACNA1A variants can cause a severe epileptic and developmental encephalopathy with progressive cerebellar atrophy, and highlight complexities of genetic counseling in such situations

Matrix Metalloproteinase 1 promotes tumor formation and lung metastasis in an intratibial injection osteosarcoma mouse model

Proteolytic degradation of the extracellular matrix (ECM) is an important process during tumor invasion. Matrix Metalloproteinase 1 (MMP-1) is one of the proteases that degrade collagen type I, a major component of bone ECM. In the present study, the biological relevance of MMP-1 in osteosarcoma (OS) tumor growth and metastasis was investigated in vitro and in vivo. Human OS cells in primary culture expressed MMP-1 encoding mRNA at considerably higher levels than normal human bone cells. In addition, MMP-1 mRNA and protein expression in the highly metastatic human osteosarcoma 143-B cell line was remarkably higher than in the non-metastatic parental HOS cell line. Stable shRNA-mediated downregulation of MMP-1 in 143-B cells impaired adhesion to collagen I and anchorage-independent growth, reflected by a reduced ability to grow in soft agar. Upon intratibial injection into SCID mice, 143-B cells with shRNA-downregulated MMP-1 expression formed smaller primary tumors and significantly lower numbers of lung micro- and macrometastases than control cells. Conversely, HOS cells stably overexpressing MMP-1 showed an enhanced adhesion capability to collagen I and accelerated anchorage-independent growth compared to empty vector-transduced control cells. Furthermore, and most importantly, individual MMP-1 overexpression in HOS cells enabled the formation of osteolytic primary tumors and lung metastasis while the HOS control cells did not develop any tumors or metastases after intratibial injection. The findings of the present study reveal an important role of MMP-1 in OS primary tumor and metastasis formation to the lung, the major organ of OS metastasis