Chimeric antigen receptor-T cells targeting epithelial cell adhesion molecule antigens are effective in the treatment of colorectal cancer.

OBJECTIVE: To construct chimeric antigen receptor (CAR)-T cells targeting epithelial cell adhesion molecule (EpCAM) antigen (anti-EpCAM-CAR-T). METHODS: A third-generation CAR-T cell construct used a single-chain variable fragment derived from monoclonal antibody against human EpCAM. Peripheral blood mononuclear cells were extracted from volunteers. The proportion of cluster of differentiation 8 positive (CD8+) and CD4 + T cells was measured using flow cytometry. Western blot was used to detect the expression of EpCAM-CAR. The killing efficiency was detected using the MTT assay and transwell assay, and the secretion of killer cytokines tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) was detected using the ELISA. The inhibitory effect of EpCAM-CAR-T on colorectal cancer in vivo was detected using xenografts. RESULTS: It was found that T cells expanded greatly, and the proportion of CD3+, CD8 + and CD4 + T cells was more than 60%. Furthermore, EpCAM-CAR-T cells had a higher tumour inhibition rate in the EpCAM expression positive group than in the negative group (P < 0.05). The secretion of killer cytokines TNF-α and IFN-γ in the EpCAM expression positive cell group was higher than that in the negative group (P < 0.05). In the experimental group treated with EpCAM-CAR-T cells, the survival rate of nude mice was higher (P < 0.05), and the tumour was smaller than that in the blank and control groups (P < 0.05). The secretion of serum killer cytokines TNF-α and IFN-γ in tumour-bearing nude mice in the experimental group treated with EpCAM-CAR-T cells was higher than that in the blank and control groups (P < 0.05). CONCLUSION: This study successfully constructed EpCAM-CAR cells and found that they can target and recognise EpCAM-positive tumour cells, secrete killer cytokines TNF-α and IFN-γ and better inhibit the growth and metastasis of colorectal cancer in vitro and in vivo than unmodified T cells.

Layer-by-layer fabrication of alginate/polyethyleneimine multilayer on magnetic interface with enhanced efficiency in immuno-capturing circulating tumor cells.

BACKGROUND: The technology of capturing circulating tumor cells (CTCs) plays a crucial role in the diagnosis, evaluation of therapeutic efficacy, and prediction of prognosis in lung cancer. However, the presence of complex blood environment often results in severe nonspecific protein adsorption and interferences from blood cells, which negatively impacts the specificity of CTCs capture. There is a great need for development of novel nanomaterials for CTCs capture with prominent anti-nonspecific adsorptions from proteins or blood cells. RESULTS: We present a novel immune magnetic probe Fe3O4@(PEI/AA)4@Apt. The surface of Fe3O4 particles was modified with four layers of PEI/AA composite by layer-by-layer assembly. Furthermore, aptamers targeting epithelial marker EpCAM (SYL3C) and mesenchymal marker CSV (ZY5C) were simultaneously connected on Fe3O4@(PEI/AA)4 to improve the detection of different phenotypic CTCs and reduce false negatives. The results demonstrated that the (PEI/AA)4 coatings not only minimized non-specific protein adsorptions, but also significantly reduced the adsorption rate of red blood cells to a mere 1 %, as a result of which, the Fe3O4@(PEI/AA)4@Apt probe achieved a remarkably high capture efficiency toward CTCs (95.9 %). In the subsequent validation of clinical samples, the probe was also effective in capturing rare CTCs from lung cancer patients. SIGNIFICANCE AND NOVELTY: A (PEI/AA) polymerized composite with controllable layers was fabricated by layer-by-layer self-assembly technique, which displayed remarkable anti-nonspecific adsorption capabilities toward proteins and cells. Importantly, Fe3O4@(PEI/AA)4@Apt probe significantly improved CTCs capture purity in lung cancer patients to 89.36 %. For the first time, this study combined controllable (PEI/AA) layers with magnetic separation to innovatively build a resistant interface that significantly improves the specific capture performances of CTCs, broadening the application of this polymerized composite.

Fluorescent identification of immunomagnetically captured CTCs using triplex-aptamer-targeted dendritic SiO2@Fe3O4 nanocomposite.

The enumeration of circulating tumor cells (CTCs) in peripheral blood plays a crucial role in the early diagnosis, recurrence monitoring, and prognosis assessment of cancer patients. There is a compelling need to develop an efficient technique for the capture and identification of these rare CTCs. However, the exclusive reliance on a single criterion, such as the epithelial cell adhesion molecule (EpCAM) antibody or aptamer, for the specific recognition of epithelial CTCs is not universally suitable for clinical applications, as it usually falls short in identifying EpCAM-negative CTCs. To address this limitation, we propose a straightforward and cost-effective method involving triplex fluorescently labelled aptamers (FAM-EpCAM, Cy5-PTK7, and Texas Red-CSV) to modify Fe3O4-loaded dendritic SiO2 nanocomposite (dmSiO2@Fe3O4/Apt). This multi-recognition-based strategy not only enhanced the efficiency in capturing heterogeneous CTCs, but also facilitated the rapid and accurate identification of CTCs. The capture efficiency of heterogenous CTCs reached up to 93.33%, with a detection limit as low as 5 cells/mL. Notably, the developed dmSiO2@Fe3O4/Apt nanoprobe enabled the swift identification of captured cells in just 30 min, relying solely on the fluorescently modified aptamers, which reduced the identification time by approximately 90% compared with the conventional immunocytochemistry (ICC) technique. Finally, these nanoprobe characteristics were validated using blood samples from patients with various types of cancers.

BerEP4-Negative Basal Cell Carcinoma: An Immunophenotype Not to Forget.

ABSTRACT: Basal cell carcinoma (BCC) is the most common cancer worldwide. Although not typically metastatic, BCC can be locally destructive. BerEP4 is an antibody against CD326, an epithelial cell adhesion molecule (EpCAM) that is expressed on epithelial progenitor cells and carcinomas. BerEP4 has been reported to have a 100% positive sensitivity in basal cell carcinomas, but a much lower sensitivity for a variety of other carcinomas, including clear cell renal cell carcinoma and metastatic renal cell carcinoma. A 74-year-old woman presented with a BerEP4-negative, but anti-renal cell antibody-positive BCC, and the stark clinical implications of misdiagnosis. This case stresses the importance of considering BerEP4-negative BCC, even when other abnormal features are present.

Analysis of off-tumour toxicities of T-cell-engaging bispecific antibodies via donor-matched intestinal organoids and tumouroids.

Predicting the toxicity of cancer immunotherapies preclinically is challenging because models of tumours and healthy organs do not typically fully recapitulate the expression of relevant human antigens. Here we show that patient-derived intestinal organoids and tumouroids supplemented with immune cells can be used to study the on-target off-tumour toxicities of T-cell-engaging bispecific antibodies (TCBs), and to capture clinical toxicities not predicted by conventional tissue-based models as well as inter-patient variabilities in TCB responses. We analysed the mechanisms of T-cell-mediated damage of neoplastic and donor-matched healthy epithelia at a single-cell resolution using multiplexed immunofluorescence. We found that TCBs that target the epithelial cell-adhesion molecule led to apoptosis in healthy organoids in accordance with clinical observations, and that apoptosis is associated with T-cell activation, cytokine release and intra-epithelial T-cell infiltration. Conversely, tumour organoids were more resistant to damage, probably owing to a reduced efficiency of T-cell infiltration within the epithelium. Patient-derived intestinal organoids can aid the study of immune-epithelial interactions as well as the preclinical and clinical development of cancer immunotherapies.