º£½ÇÆƽâ°æ

BackgroundLymphatics provide a route for breast cancer cells to metastasize. Lymphatic endothelial cells (LECs), which form the structure of lymphatic vessels, play a key role in this process. Although LECs are pivotal in cancer progression, studies often rely on commercially available cell lines that may not accurately reflect the tumor microenvironment. Therefore, there is a pressing need to directly study patient-derived LECs to better understand their role in breast cancer.MethodsThis study developed a method to isolate and characterize LECs directly from human breast-to-axilla adipose tissue. We used magnetic cell separation to remove CD45?+?leukocytes and fluorescence-activated cell sorting to isolate cells expressing CD31 and podoplanin. Isolated cells were cultured under conditions promoting endothelial cell growth and were characterized through various assays assessing proliferation, tube formation, and gene expression patterns.ResultsThe sorted CD31?+?/PDPN?+?/CD45???cell populations exhibited marked increases in proliferation upon VEGF-C stimulation and formed tubule structures on BME-coated dishes, confirming their LEC properties. Notably, isolated LECs showed distinct gene expression patterns depending on the presence of lymph node metastasis and lymphatic invasion.ConclusionsThe ability to isolate and characterize patient-derived LECs from mammary adipose tissue offers new insights into the cellular mechanisms underlying breast cancer metastasis. Significant gene expression variability related to disease state highlights the potential of these cells as biomarkers and therapeutic targets. This study emphasizes the importance of using patient-derived cells to accurately assess the tumor microenvironment, potentially leading to more personalized therapeutic approaches.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13058-025-02067-w.

PurposeIsolating circulating tumour cells (CTCs) from the blood is challenging due to their low abundance and heterogeneity. Limitations of conventional CTC detection methods highlight the need for improved strategies to detect and isolate CTCs. Currently, the Food and Drug Administration (FDA)-approved CellSearch? and other RUO techniques are not available in India. Therefore, we wanted to develop a flexible CTC detection/isolation technique that addresses the limitation(s) of currently available techniques and is suitable for various downstream applications.MethodsWe developed a novel, efficient, user-friendly CTC isolation strategy combining density gradient centrifugation and immuno-magnetic hematogenous cell depletion with fluorescence-activated cell sorting (FACS)-based positive selection using multiple CTC-specific cell-surface markers. For FACS, a stringent gating strategy was optimised to exclude debris and doublets by side scatter/forward scatter (SSC/FSC) discriminator, remove dead cells by 4¡ä,6-diamidino-2-phenylindole (DAPI) staining, and eliminate non-specific fluorescence using a ¡°dump¡± channel. APC-labelled anti-CD45mAB was used to gate remaining hematogenous cells, while multiple epithelial markers (EpCAM, EGFR, and Pan-Cytokeratin) and an epithelial¨Cmesenchymal transition (EMT) marker (Vimentin) labelled with fluorescein isothiocyanate (FITC) were used to sort cancer cells. The technique was initially developed by spiking Cal 27 cancer cells into the blood of healthy donors and then validated in 95 biopsy-proven oral squamous cell carcinoma (OSCC) patients. CTCs isolated from patients were reconfirmed by Giemsa staining, immuno-staining, and whole transcriptome amplification (WTA), followed by qRT-PCR. In vitro culture and RNA sequencing (RNA-Seq) were also performed to confirm their suitability for various downstream applications.ResultsThe mean detection efficiency for the Cal 27 tongue cancer cells spiked in the whole blood of healthy donors was 32.82% ¡À 12.71%. While ~75% of our patients (71/95) had detectable CTCs, the CTC positivity was independent of the TNM staging. The isolated potential cancer cells from OSCC patients were heterogeneous in size. They expressed different CTC-specific markers in various combinations as identified by qRT-PCR after WTA in different patients. Isolated CTCs were also found to be suitable for downstream applications like short-term CTC culture and RNA-Seq.ConclusionWe developed a sensitive, specific, flexible, and affordable CTC detection/isolation technique, which is scalable to larger patient cohorts, provides a snapshot of CTC heterogeneity, isolates live CTCs ready for downstream molecular analysis, and, most importantly, is suitable for developing countries.

Pre-leukemic clones carrying DNMT3A mutations have a selective advantage and an inherent chemoresistance, however the basis for this phenotype has not been fully elucidated. Mutations affecting the gene TP53 occur in pre-leukemic hematopoietic stem/progenitor cells (preL-HSPC) and lead to chemoresistance. Many of these mutations cause a conformational change and some of them were shown to enhance self-renewal capacity of preL-HSPC. Intriguingly, a misfolded P53 was described in AML blasts that do not harbor mutations in TP53, emphasizing the dynamic equilibrium between wild-type (WT) and pseudo-mutant" conformations of P53. By combining single cell analyses and P53 conformation-specific monoclonal antibodies we studied preL-HSPC from primary human DNMT3A-mutated AML samples. We found that while leukemic blasts express mainly the WT conformation in preL-HSPC the pseudo-mutant conformation is the dominant. HSPC from non-leukemic samples expressed both conformations to a similar extent. In a mouse model we found a small subset of HSPC with a dominant pseudo-mutant P53. This subpopulation was significantly larger among DNMT3AR882H-mutated HSPC suggesting that while a pre-leukemic mutation can predispose for P53 misfolding additional factors are involved as well. Treatment with a short peptide that can shift the dynamic equilibrium favoring the WT conformation of P53 specifically eliminated preL-HSPC that had dysfunctional canonical P53 pathway activity as reflected by single cell RNA sequencing. Our observations shed light upon a possible targetable P53 dysfunction in human preL-HSPC carrying DNMT3A mutations. This opens new avenues for leukemia prevention."