While adult pancreatic stem cells are thought not to exist, it is now appreciated that the acinar compartment harbors progenitors, including tissue-repairing facultative progenitors (FPs). Here, we study a pancreatic acinar population marked by trefoil factor 2 (Tff2) expression. Long-term lineage tracing and single-cell RNA sequencing (scRNA-seq) analysis of Tff2-DTR-CreERT2-targeted cells defines a transit-amplifying progenitor (TAP) population that contributes to normal homeostasis. Following acute and chronic injury, Tff2+ cells, distinct from FPs, undergo depopulation but are eventually replenished. At baseline, oncogenic KrasG12D-targeted Tff2+ cells are resistant to PDAC initiation. However, KrasG12D activation in Tff2+ cells leads to survival and clonal expansion following pancreatitis and a cancer stem/progenitor cell-like state. Selective ablation of Tff2+ cells prior to KrasG12D activation in Mist1+ acinar or Dclk1+ FP cells results in enhanced tumorigenesis, which can be partially rescued by adenoviral Tff2 treatment. Together, Tff2 defines a pancreatic TAP population that protects against Kras-driven carcinogenesis.
Copyright © 2023 Elsevier Inc. All rights reserved.

Here, we present a protocol for the selective differentiation of human pluripotent stem cells mimicking human developmental processes into expandable PRRX1+ limb-bud mesenchymal (ExpLBM) cells. This approach enables expansion through serial passage while maintaining capacity for chondrogenic differentiation. For complete details on the use and execution of this protocol, please refer to Yamada et al. (2021, 2022).
© 2022 The Author(s).

Stem cell-based therapies and experimental methods rely on efficient induction of human pluripotent stem cells (hPSCs). During limb development, the lateral plate mesoderm (LPM) produces limb-bud mesenchymal (LBM) cells that differentiate into osteochondroprogenitor cells and form cartilage tissues in the appendicular skeleton. Previously, we generated PRRX1-tdTomato reporter hPSCs to establish the protocol for inducing the hPSC-derived PRRX1+ LBM-like cells. However, surface antigens that assess the induction efficiency of hPSC-derived PRRX1+ LBM-like cells from LPM have not been identified. Here, we used PRRX1-tdTomato reporter hPSCs and found that high pluripotent cell density suppressed the expression of PRRX1 mRNA and tdTomato after LBM-like induction. RNA sequencing and flow cytometry suggested that PRRX1-tdTomato+ LBM-like cells are defined as CD44high CD140Bhigh CD49f-. Importantly, other hPSC lines, including four human induced pluripotent stem cell lines (414C2, 1383D2, HPS1042, HPS1043) and two human embryonic stem cell lines (SEES4, SEES7), showed the same results. Thus, an appropriate cell density of hPSCs before differentiation is a prerequisite for inducing the CD44high CD140Bhigh CD49f- PRRX1+ LBM-like cells.

Accumulating evidence indicates that the zinc-finger transcription factor ZEB1 is predominantly expressed in the stroma of several tumours. However, the role of stromal ZEB1 in tumour progression remains unexplored. In this study, while interrogating human databases, we uncover a remarkable decrease in relapse-free survival of breast cancer patients expressing high ZEB1 levels in the stroma. Using a mouse model of breast cancer, we show that ZEB1 inactivation in stromal fibroblasts suppresses tumour initiation, progression and metastasis. We associate this with reduced extracellular matrix remodeling, immune cell infiltration and decreased angiogenesis. ZEB1 deletion in stromal fibroblasts increases acetylation, expression and recruitment of p53 to FGF2/7, VEGF and IL6 promoters, thereby reducing their production and secretion into the surrounding stroma. Importantly, p53 ablation in ZEB1 stroma-deleted mammary tumours sufficiently recovers the impaired cancer growth and progression. Our findings identify the ZEB1/p53 axis as a stroma-specific signaling pathway that promotes mammary epithelial tumours.

The heterogeneous nature of cancer puts cancer stem cells (CSCs) at the beating heart of the tumour. Because of their inherent characteristics of stemness, CSCs evade putative cancer therapies, resulting in treatment resistance or tumour recurrence after a seemingly successful treatment. To prevent treatment resistance and cancer recurrence, killing the beating heart of the tumour is of utmost importance. This study therefore, sought to determine the effect of Photodynamic Therapy (PDT) in eradicating cervical cancer and cervical CSCs. Cervical CSCs were isolated from a cervical adenocarcinoma cell line, HeLa cells, and grown in liquid medium incubated at 37° C, 5% CO2 and 85% humidity. Increasing doses of AlPcSmix photosensitizer were administered to both the total cell population and the isolated CSCs, and irradiated using 673.2 nm diode laser. Post-irradiation cellular changes were observed using biochemical assays and microscopy to determine the response of both the total cell population and the CSCs. Results showed a dose-dependent response of both cell populations to treatment, by demonstration of significant morphologic changes, increased cytotoxicity, and decreased cell viability and proliferation. The study suggested that PDT using AlPcSmix is a very effective treatment method for the eradication of cervical cancer cells and cervical CSCs, in vitro.