Novel PD-L1- and collagen-expressing patient-derived cell line of undifferentiated pleomorphic sarcoma (JBT19) as a model for cancer immunotherapy.

Soft tissue sarcomas are aggressive mesenchymal-origin malignancies. Undifferentiated pleomorphic sarcoma (UPS) belongs to the aggressive, high-grade, and least characterized sarcoma subtype, affecting multiple tissues and metastasizing to many organs. The treatment of localized UPS includes surgery in combination with radiation therapy. Metastatic forms are treated with chemotherapy. Immunotherapy is a promising treatment modality for many cancers. However, the development of immunotherapy for UPS is limited due to its heterogeneity, antigenic landscape variation, lower infiltration with immune cells, and a limited number of established patient-derived UPS cell lines for preclinical research. In this study, we established and characterized a novel patient-derived UPS cell line, JBT19. The JBT19 cells express PD-L1 and collagen, a ligand of the immune checkpoint molecule LAIR-1. JBT19 cells can form spheroids in vitro and solid tumors in immunodeficient nude mice. We found JBT19 cells induce expansion of JBT19-reactive autologous and allogeneic NK, T, and NKT-like cells, and the reactivity of the expanded cells was associated with cytotoxic impact on JBT19 cells. The PD-1 and LAIR-1 ligand-expressing JBT19 cells show ex vivo immunogenicity and effective in vivo xenoengraftment properties that can offer a unique resource in the preclinical research developing novel immunotherapeutic interventions in the treatment of UPS.

ABCB1 Amplicon Contains Cyclic AMP Response Element-Driven TRIP6 Gene in Taxane-Resistant MCF-7 Breast Cancer Sublines.

A limited number of studies are devoted to regulating TRIP6 expression in cancer. Hence, we aimed to unveil the regulation of TRIP6 expression in MCF-7 breast cancer cells (with high TRIP6 expression) and taxane-resistant MCF-7 sublines (manifesting even higher TRIP6 expression). We found that TRIP6 transcription is regulated primarily by the cyclic AMP response element (CRE) in hypomethylated proximal promoters in both taxane-sensitive and taxane-resistant MCF-7 cells. Furthermore, in taxane-resistant MCF-7 sublines, TRIP6 co-amplification with the neighboring ABCB1 gene, as witnessed by fluorescence in situ hybridization (FISH), led to TRIP6 overexpression. Ultimately, we found high TRIP6 mRNA levels in progesterone receptor-positive breast cancer and samples resected from premenopausal women.

PMEDAP and its N6-substituted derivatives: genotoxic effect and apoptosis in in vitro conditions.

Genotoxic properties expressed as acquired chromosomal aberrations and induction of apoptosis after treatment with acyclic nucleoside phosphonates PMEG, PMEDAP and its N6-substituted derivatives Me2NEt-PMEDAP, allyl-PMEDAP, Me2-PMEDAP and cypr-PMEDAP, were studied in in vitro conditions. The genotoxic and antiproliferative effect of compounds was investigated on CCRF-CEM, HeLa S3, MRC-5 and Reh cell lines. PMEG and cypr-PMEDAP exhibit high genotoxic and cytostatic effect. PMEDAP and its N6-substituted derivatives Me2NEt-PMEDAP, allyl-PMEDAP and Me2-PMEDAP are considerably less genotoxic. Time- and dose-dependent suppression of proliferation by these nucleotide analogues is accompanied by induction of apoptosis, which is dependent on cell line type. However, an increased proliferation was observed after treatment of the cell culture with very low dose of PMEDAP. The sensitivity of cell lines to PMEDAP decreased in the order: CCRF-CEM > Reh > HeLa > MRC-5. The potential embryotoxic or teratogenic effect of PMEDAP and cypr-PMEDAP was examined in inbred rats involving the mutant allele Lx that determines the polydactyly-luxate syndrome. While the prevalent effect of cypr-PMEDAP during fetus development is embryolethality, PMEDAP did not induce any embryo-lethal or teratogenic effect.