Terminal differentiation into adipocyte and growth inhibition by PPARγ activation in human A549 lung adenocarcinoma cells

Marine polychaete Namalycastis sp. extracts enhance proliferation and regeneration of mice 3T3 fibroblast and MCR-5 human fibroblast cells

The Nereidid worm is a marine polychaete commonly found near the Nipa palm (Nypa fructicans) along the mangrove estuary. Recently, many usages have been documented for this polychaete family. Nevertheless, the true potentials of these marine worms, especially Namalycastis sp., from the medical perspective are still unknown. The current study investigated the cytotoxicity effect of Namalycastis sp. crude extracts on mice 3T3 fibroblast cells and human lung MRC-5 fibroblast cells. Thirteen concentrations (2, 4, 8, 16, 31, 63 µg/mL and 0.1, 0.3, 0.5, 1, 2, 4, 8 mg/mL) of the extracts were used as a treatment for 24 h, and cell viability was measured via the MTT assay. None of the 13 concentrations of Namalycastis sp. crude extracts showed cytotoxicity effects on the cell types investigated. However, based on the live images captured by the IncuCyte™ imaging system, the cells treated with Namalycastis sp. crude extracts showed an increased proliferation and growth rate in less than 10 h Furthermore, the extract concentration of 8 µg/mL induced the highest cell proliferation rate whereas 8 mg/mL led to the lowest cell proliferation rate following the treatment. Overall, Namalycastis sp. crude extracts were non-toxic on mice and human cells within the tested concentrations set. Still, it increased cell viability and proliferation compared with the control. This finding could pave the way for an alternative therapeutic strategy to treat debilitating disorders such as ageing, cardiovascular diseases, and neurodegenerative diseases.

[Evaluation of Solubility and Membrane Permeability of Middle-Molecule Compounds Using Artificial Membranes and Living Cells]

In contrast to small molecules, middle molecules present a promising therapeutic modality owing to their elevated specificity, minimal adverse effects, capacity to target protein-protein interactions, and, unlike antibody-based drugs, their suitability for oral administration and intracellular target engagement. Post-oral administration, the paramount considerations encompass solubility and membrane permeability during the initial phase until the drug attains systemic circulation. Furthermore, penetration of the cell membrane is essential to accessing intracellular targets. We evaluated the solubility and membrane permeability of 965 compounds sourced from middle molecule libraries affiliated with Hokkaido University, Kitasato University, and the University of Tokyo. To gauge membrane permeability, we employed both the parallel artificial membrane permeability assay (PAMPA) and Caco-2 cell monolayers. Notably, while membrane permeability in Caco-2 cells exhibited an approximate threefold increase in comparison to PAMPA measurements, certain compounds demonstrated permeability levels less than one-third of those observed in Caco-2 cells. Recognizing the potential involvement of efflux transporters expressed in Caco-2 cells in these variations, we conducted additional assessments involving directional transport in the presence of a transporter inhibitor. Our findings suggest that nearly 80% of these compounds serve as substrates for efflux transporters. Considering the relevance of intracellular targets, we shifted our focus from membrane permeation to intracellular uptake, conducting simulations tailored to assess cellular uptake.

Immortalization of primary marmoset skin fibroblasts by CRISPR-Cas9-mediated gene targeting

Immortalized cell lines can be used for diverse in vitro experiments, providing invaluable data before conducting in vivo studies Callithrix jacchus, the common marmoset, is a non-human primate model utilized for studying various human diseases. However, only a few immortalized marmoset cell lines are currently available. In the present study, we reveal that CRISPR-Cas9-mediated targeting of the p53 gene or CDKN2A locus is an effective means for immortalizing primary marmoset skin fibroblasts. In addition to frameshift mutations that result in premature stop codons, in-frame mutations potentially destroying the DNA-binding motif of p53 are frequently detected in immortalized cells. Like Cdkn2a-deficient mouse cells, CDKN2A-deficient marmoset cells express wild-type p53 proteins normally respond to genotoxic stresses, including adriamycin and etoposide. Taken together, these findings indicate that Cas9- mediated gene targeting of the p53 gene or CDKN2A locus is an effective tool for establishing immortalized marmoset cell lines with defined genetic alterations.

Modulating cell differentiation in cancer models

Cancer has been traditionally viewed as a disease characterised by excessive and uncontrolled proliferation, leading to the development of cytotoxic therapies against highly proliferating malignant cells. However, tumours frequently relapse due to the presence of slow-cycling cancer stem cells eluding chemo and radiotherapy. Since these malignant stem cells are largely undifferentiated, inducing their lineage commitment has been proposed as a potential intervention strategy to deplete tumours from their most resistant components. Pro-differentiation approaches have thus far yielded clinical success in the reversion of acute promyelocytic leukaemia (APL), and new developments are fast widening their therapeutic applicability to solid carcinomas. Recent advances in cancer differentiation discussed here highlight the potential and outstanding challenges of differentiation-based approaches.