Isocitrate dehydrogenase () mutations in glioma patients confer longer survival and may guide treatment decision making. We aimed to predict the status of gliomas from MR imaging by applying a residual convolutional neural network to preoperative radiographic data. Preoperative imaging was acquired for 201 patients from the Hospital of University of Pennsylvania (HUP), 157 patients from Brigham and Women's Hospital (BWH), and 138 patients from The Cancer Imaging Archive (TCIA) and divided into training, validation, and testing sets. We trained a residual convolutional neural network for each MR sequence (FLAIR, T2, T1 precontrast, and T1 postcontrast) and built a predictive model from the outputs. To increase the size of the training set and prevent overfitting, we augmented the training set images by introducing random rotations, translations, flips, shearing, and zooming. With our neural network model, we achieved IDH prediction accuracies of 82.8% (AUC = 0.90), 83.0% (AUC = 0.93), and 85.7% (AUC = 0.94) within training, validation, and testing sets, respectively. When age at diagnosis was incorporated into the model, the training, validation, and testing accuracies increased to 87.3% (AUC = 0.93), 87.6% (AUC = 0.95), and 89.1% (AUC = 0.95), respectively. We developed a deep learning technique to noninvasively predict genotype in grade II-IV glioma using conventional MR imaging using a multi-institutional data set. .

Chimeric antigen receptors (CARs) are synthetic molecules that provide new specificities to T cells. Although successful in treatment of hematologic malignancies, CAR T cells are ineffective for solid tumors to date. We found that the cell-surface molecule c-Met was expressed in ~50% of breast tumors, prompting the construction of a CAR T cell specific for c-Met, which halted tumor growth in immune-incompetent mice with tumor xenografts. We then evaluated the safety and feasibility of treating metastatic breast cancer with intratumoral administration of mRNA-transfected c-Met-CAR T cells in a phase 0 clinical trial (NCT01837602). Introducing the CAR construct via mRNA ensured safety by limiting the non-tumor cell effects (on-target/off-tumor) of targeting c-Met. Patients with metastatic breast cancer with accessible cutaneous or lymph node metastases received a single intratumoral injection of 3 × 107 or 3 × 108 cells. CAR T mRNA was detectable in peripheral blood and in the injected tumor tissues after intratumoral injection in two and four patients, respectively. mRNA c-Met-CAR T cells cell injections were well tolerated, as none of the patients had study drug–related adverse effects greater than grade 1. Tumors treated with intratumoral injected mRNA c-Met-CAR T cells were excised and analyzed by immunohistochemistry, revealing extensive tumor necrosis at the injection site, cellular debris, loss of c-Met immunoreactivity, all surrounded by macrophages at the leading edges and within necrotic zones. We conclude that intratumoral injections of mRNA c-Met-CAR T cells are well tolerated and evoke an inflammatory response within tumors.

Overexpression of HER-2/neu (c-erbB2) is associated with increased risk of recurrent disease in ductal carcinoma in situ (DCIS) and a poorer prognosis in node-positive breast cancer. We therefore examined the early immunotherapeutic targeting of HER-2/neu in DCIS. Before surgical resection, HER-2/ neu pos DCIS patients (n = 13) received 4 weekly vaccinations of dendritic cells pulsed with HER-2/neu HLA class I and II peptides. The vaccine dendritic cells were activated in vitro with IFN-; and bacterial lipopolysaccharide to become highly polarized DC1-type dendritic cells that secrete high levels of interleukin-12p70 (IL-12p70). Intranodal delivery of dendritic cells supplied both antigenic stimulation and a synchronized preconditioned burst of IL-12p70 production directly to the anatomic site of T-cell sensitization. Before vaccination, many subjects possessed HER-2/neu-HLA-A2 tetramer-staining CD8 pos T cells that expressed low levels of CD28 and high levels of the inhibitory B7 ligand CTLA-4, but this ratio inverted after vaccination. The vaccinated subjects also showed high rates of peptide-specific sensitization for both IFN-;-secreting CD4 pos (85%) and CD8 pos (80%) T cells, with recognition of antigenically relevant breast cancer lines, accumulation of T and B lymphocytes in the breast, and induction of complement-dependent, tumor-lytic antibodies. Seven of 11 evaluable patients also showed markedly decreased HER-2/neu expression in surgical tumor specimens, often with measurable decreases in residual DCIS, suggesting an active process of ''immunoediting'' for HER-2/neuexpressing tumor cells following vaccination. DC1 vaccination strategies may therefore have potential for both the prevention and the treatment of early breast cancer. [Cancer Res 2007;67(4):1842-52]

There is enormous interest to target cancer stem cells (CSCs) for clinical treatment because these cells are highly tumorigenic and resistant to chemotherapy. Oct4 is expressed by CSC-like cells in different types of cancer. However, function of Oct4 in tumor cells is unclear. In this study, we showed that expression of Oct4 gene or transmembrane delivery of Oct4 protein promoted dedifferentiation of melanoma cells to CSC-like cells. The dedifferentiated melanoma cells showed significantly decreased expression of melanocytic markers and acquired the ability to form tumor spheroids. They showed markedly increased resistance to chemotherapeutic agents and hypoxic injury. In the subcutaneous xenograft and tail vein injection assays, these cells had significantly increased tumorigenic capacity. The dedifferentiated melanoma cells acquired features associated with CSCs such as multipotent differentiation capacity and expression of melanoma CSC markers such as ABCB5 and CD271. Mechanistically, Oct4 induced dedifferentiation was associated with increased expression of endogenous Oct4, Nanog and Klf4, and global gene expression changes that enriched for transcription factors. RNAi mediated knockdown of Oct4 in dedifferentiated cells led to diminished CSC phenotypes. Oct4 expression in melanoma was regulated by hypoxia and its expression was detected in a subpopulation of melanoma cells in clinical samples. Our data indicate that Oct4 is a positive regulator of tumor dedifferentiation. The results suggest that CSC phenotype is dynamic and may be acquired through dedifferentiation. Oct4 mediated tumor cell dedifferentiation may play an important role during tumor progression.

Although immunohistochemistry has proven to be valuable in the differentiation of epithelioid mesothelioma from pulmonary or metastatic adenocarcinoma, no single antibody has demonstrated absolute sensitivity or specificity in making this distinction. Using immunohistochemical analysis with D2-40, a recently available monoclonal antibody that has been used as a lymphatic endothelial marker, we examined 53 cases of mesothelioma, 28 cases of reactive pleura, 30 cases of pulmonary adenocarcinoma, 35 cases of renal cell carcinoma, 26 cases of ovarian serous carcinoma, 16 cases of invasive breast carcinoma, 11 cases of prostatic adenocarcinoma, and seven cases of urothelial carcinoma. In addition, immunohistochemistry using calretinin, cytokeratin 5/6, and WT1 was performed on all cases of mesothelioma, pulmonary adenocarcinoma, ovarian serous carcinoma, and renal cell carcinoma. Predominantly, membranous D2-40 immunoreactivity was present in 51 of 53 (96%) mesotheliomas, 27 of 28 (96%) cases of reactive pleura, and 17 of 26 (65%) ovarian serous carcinomas; membranous staining was not seen in any other tumors examined. Compared to other immunohistochemical markers of mesothelioma, D2-40 was as sensitive as calretinin and more sensitive than cytokeratin 5/6 and WT1. We conclude that D2-40 immunoreactivity is sensitive for cells of mesothelial origin, and may be useful in the differential diagnosis of epithelioid malignant mesothelioma vs adenocarcinoma.