Each cell comprising an intact, healthy, confluent epithelial layer ordinarily remains sedentary, firmly adherent to and caged by its neighbors, and thus defines an elemental constituent of a ...solid-like cellular collective 1,2. After malignant transformation, however, the cellular collective can become fluid-like and migratory, as evidenced by collective motions that arise in characteristic swirls, strands, ducts, sheets, or clusters 3,4. To transition from a solid-like to a fluid-like phase and thereafter to migrate collectively, it has been recently argued that cells comprising the disordered but confluent epithelial collective can undergo changes of cell shape so as to overcome geometric constraints attributable to the newly discovered phenomenon of cell jamming and the associated unjamming transition (UJT) 1,2,5–9. Relevance of the jamming concept to carcinoma cells lines of graded degrees of invasive potential has never been investigated, however. Using classical in vitro cultures of six breast cancer model systems, here we investigate structural and dynamical signatures of cell jamming, and the relationship between them 1,2,10,11. In order of roughly increasing invasive potential as previously reported, model systems examined included MCF10A, MCF10A.Vector; MCF10A.14-3-3ζ; MCF10.ErbB2, MCF10AT; and MCF10CA1a 12–15. Migratory speed depended on the particular cell line. Unsurprisingly, for example, the MCF10CA1a cell line exhibited much faster migratory speed relative to the others. But unexpectedly, across different cell lines higher speeds were associated with enhanced size of cooperative cell packs in a manner reminiscent of a peloton 9. Nevertheless, within each of the cell lines evaluated, cell shape and shape variability from cell-to-cell conformed with predicted structural signatures of cell layer unjamming 1. Moreover, both structure and migratory dynamics were compatible with previous theoretical descriptions of the cell jamming mechanism 2,10,11,16,17. As such, these findings demonstrate the richness of the cell jamming mechanism, which is now seen to apply across these cancer cell lines but remains poorly understood.
•In each of 6 cancer cell lines, cell shape and its variability conformed with predicted structural signatures of unjamming.•Across these different cell lines, cell shape information alone was not sufficient to predict migratory dynamics.•Across cell lines, higher speeds were associated with enhanced cooperative pack sizes in a manner reminiscent of a peloton.
Patients with smoldering multiple myeloma (SMM) are observed until progression, but early treatment may improve outcomes. We conducted a phase II trial of elotuzumab, lenalidomide, and dexamethasone ...(EloLenDex) in patients with high-risk SMM and performed single-cell RNA and T cell receptor (TCR) sequencing on 149 bone marrow (BM) and peripheral blood (PB) samples from patients and healthy donors (HDs). We find that early treatment with EloLenDex is safe and effective and provide a comprehensive characterization of alterations in immune cell composition and TCR repertoire diversity in patients. We show that the similarity of a patient’s immune cell composition to that of HDs may have prognostic relevance at diagnosis and after treatment and that the abundance of granzyme K (GZMK)+ CD8+ effector memory T (TEM) cells may be associated with treatment response. Last, we uncover similarities between immune alterations observed in the BM and PB, suggesting that PB-based immune profiling may have diagnostic and prognostic utility.
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•EloLenDex is associated with 4-year PFS of 89% in patients with high-risk SMM•Immune reactivity, post-therapy immune normalization are associated with longer PFS•Higher abundance of GZMK+ cytotoxic T cells is associated with longer PFS•Blood-based immune profiling detects immune dysregulation associated with disease
Sklavenitis-Pistofidis et al. report results of a phase II trial of EloLenDex in patients with high-risk smoldering multiple myeloma and use single-cell RNA sequencing to identify biomarkers of outcomes. They show that immune cell composition affects progression-free survival and that blood-based immune profiling can detect immune alterations observed in the bone marrow.
Patients with Smoldering Multiple Myeloma (SMM) are typically observed until progression, but early treatment of high-risk patients may improve outcomes. Clinical and genomic biomarkers can be used ...to identify SMM patients at high risk of progression, however parallel profiling of the tumor immune microenvironment (TIME) may further improve prediction models.
Here, we performed single-cell RNA-sequencing on CD138- immune cells from 40 samples of 14 patients enrolled in a Phase II trial of Elotuzumab, Lenalidomide, and Dexamethasone, in patients with high-risk SMM (E-PRISM) to develop biomarkers for optimal patient selection and monitoring of response to treatment. Specifically, we profiled 33 bone marrow (BM) samples collected at baseline (n=11), cycle 9, Day 1 (C9D1, n=13) and EOT (n=9), and 7 peripheral blood mononuclear cell (PBMC) samples collected at baseline (n=4) and C9D1 (n=3).
We found that higher abundance of mature B-cells, Th17 cells and GZMK+ T and NK cells and lower abundance of hematopoietic progenitor cells and plasmacytoid dendritic cells are associated with significantly longer progression-free survival (PFS) in SMM patients under treatment. This signal can be summarized by how normal-like the patients’ immune composition is at baseline, whereby patients whose immune composition is normal-like have significantly shorter PFS (p=0.031). This model suggests that at least some of the compositional changes observed in disease reflect the immune system’s capacity to react successfully to the immune challenge posed by the tumor, which we termed immune reactivity. Baseline immune reactivity may help to identify patients who will benefit the most from early treatment. Furthermore, we found that the expansion of tissue-resident NK cells and exhausted GZMK+ CD8+ T-cells at C9D1 of treatment is associated with significantly shorter PFS (p=0.039), suggesting that these immune biomarkers may help to monitor response to immunotherapy. Lastly, we found that patients would be classified the same way in terms of our immune biomarkers, had we assayed their peripheral blood instead of their bone marrow, suggesting that minimally invasive immune profiling for prognostication and monitoring may be feasible.
We used single-cell RNA-sequencing to profile the immune microenvironment of patients with high-risk SMM in a Phase II trial of Elotuzumab, Lenalidomide and Dexamethasone and developed immune biomarkers of response to treatment. Our study may usher in a next generation of clinical assays that assess both tumor biology and immune state, as well as common clinical biomarkers, in the marrow or blood, to accurately predict who may benefit from early treatment, monitor response and improve patient outcomes.