MM
vs. HD upregulated genes and auto-HSCT
vs. MM downregulated genes were intersected to pinpoint the potential molecular targets of residual disease clearance, yielding 640 overlapping genes (
Figure S5A) with 515 genes normalized to a healthy level in MM patients treated with high-dose melphalan following auto-HSCT (
Figure S5B). Among these genes, 25 were ER stress-related (among 258 annotated ER stress-related genes, such as
HSPA5,
ATF3,
CREBZF, and
MANF;
Figure S5C) and 14 were linked to the UPR among 113 UPR-related genes, such as
ATF3,
ATF6,
EIF4E, and
WFS1 (
Figure S3I), showing the potential roles in MM pathogenesis and potential markers for MRD. In addition, 77 genes were downregulated in MM but restored in MM patients treated with high-dose melphalan following auto-HSCT (
Figure S5D), including 41 normalized to healthy levels (
Figure S5E). The overlap with UPR genes highlighted RPS14, a ribosomal biogenesis gene, selectively re-expressed in MM patients treated with high-dose melphalan following auto-HSCT (
Figure S3J). Taken together, the findings indicated that these gene sets (
HSPA5,
ATF3,
ATF6,
WFS1, and
RPS14) reflect stress adaptation in MM plasma cells and the reversal after treatment, offering potential biomarkers for MRD monitoring and therapy. The B cell receptor (BCR) spectrum in patients after auto-HSCT was analyzed. The histogram plot showed the frequency of use of the top 20 groups in IGHV (
Figure S3K) and IGHJ (
Figure S3L). Sudha et al. recently reported the distinct immune microenvironment features of MM using scRNA-seq
8. However, we focused on the identification of the immune reconstitution and hematopoiesis restoration in the system.