PhenoImager™ HT Instrument Automated Quantitative Pathology Imaging System

Chemoresistance and relapse are the leading cause of AML-related deaths. Utilizing single-cell RNA sequencing (scRNA-seq), we dissected the cellular states of bone marrow samples from primary refractory or short-term relapsed AML patients and defined the transcriptional intratumoral heterogeneity. We found that compared to proliferating stem/progenitor-like cells (PSPs), a subpopulation of quiescent stem-like cells (QSCs) were involved in the chemoresistance and poor outcomes of AML. By performing longitudinal scRNA-seq analyses, we demonstrated that PSPs were reprogrammed to obtain a QSC-like expression pattern during chemotherapy in refractory AML patients, characterized by the upregulation of CD52 and LGALS1 expression. Flow cytometric analysis further confirmed that the preexisting CD99+CD49d+CD52+Galectin-1+ (QSCs) cells at diagnosis were associated with chemoresistance, and these cells were further enriched in the residual AML cells of refractory patients. Interaction of CD52-SIGLEC10 between QSCs and monocytes may contribute to immune evading and poor outcomes. Furthermore, we identified that LGALS1 was a promising target for chemoresistant AML, and LGALS1 inhibitor could help eliminate QSCs and enhance the chemotherapy in patient-derived primary AML cells, cell lines, and AML xenograft models. Our results will facilitate a better understanding of the AML chemoresistance mechanism and the development of novel therapeutic strategies for relapsed/refractory AML patients.

ivolumab, an immune checkpoint inhibitor is the first-line therapy for platinum-resistant recurrent/metastatic head and neck cancer, and highly effective for some patients. However, no factors have been identified that could predict response or prognosis after nivolumab administration. We retrospectively investigated the association between tumor infiltrating lymphocytes (TILs) of initial pathology and prognosis in patients treated with nivolumab. Twenty-eight patients with human papilloma virus and Epstein–Barr virus unrelated head and neck squamous cell carcinoma were enrolled. CD8+cells, FoxP3+cells and FoxP3-CD4+cells in the tumoral and peritumoral stromal area and PD-L1 were measured. In result, FoxP3-CD4+TIL, FoxP3+TIL, and CD8+TIL were not correlated with survival in either intratumoral and stromal area. In univariate analysis, objective response was significant prognostic factor both in progression-free survival and overall survival (p=0.01, 0.006, respectively). PD-L1 was also significant prognostic factor both in progression-free survival and overall survival (p=0.01, 0.01, respectively). ECOG Performance status was a significant prognostic factor in overall survival (p=0.0009). In the combined analysis of stromal CD8+TIL and PD-L1, PD-L1 positive with high stromal CD8+TIL subgroups had a better prognosis than PD-L1 negative with low stromal CD8+TIL subgroups in progression-free survival (p=0.006). Although these results require a further investigation, PD-L1 and ECOG Performance status and the combination of stromal CD8+TIL and PD-L1 positivity have potential as useful prognostic markers in patients of virus unrelated head and neck squamous cell carcinoma treated with nivolumab.