Single‐cell sequencing reveals the correlation of aggrephagy signaling and multiple myeloma immune microenvironment composition

Abstract Aggrephagy, a type of autophagy, degrades the aggregation of misfolded protein in cells. However, the role of aggrephagy in multiple myeloma (MM) has not been fully demonstrated. In this study, we first investigated the correlation between aggrephagy signaling, MM immune microenvironment composition and disease prognosis. Single‐cell RNA‐seq data, including the expression profiles of 12,187 single cells from seven MM bone marrow (BM) and seven healthy BM samples, were analyzed by non‐negative matrix factorization for 44 aggrephagy‐related genes. Bulk RNA‐seq cohorts from the Gene Expression Omnibus database were used to evaluate the prognostic value of aggrephagy‐related immune cell subtypes and predict immune checkpoint blockade immunotherapeutic response in MM. Compared with healthy BM, MM BM exhibited different patterns of aggrephagy‐related gene expression. In MM BM, macrophages, CD8 + T cells, B cells and natural killer cells could be grouped into four to nine aggrephagy‐related subclusters. The signature of aggrephagy signaling molecule expression in the immune cells correlates with the patient's prognosis. Our investigation provides a novel view of aggrephagy signaling in MM tumor microenvironment cells, which might be a prognostic indicator and potential target for MM treatment.