Exploration of miR-34a-related key miRNAs and mRNAs in esophageal cancer via scRNA-Seq and bulk RNA-Seq, along with experimental validation

Background: As a highly invasive malignant tumor, ESCA poses a major challenge due to the limited effectiveness of existing treatments. Abnormal expression of miR-34a is closely related to tumor development. This study intends to screen miR-34a-related key microRNAs (miRNAs) and messenger RNA (mRNAs) via bulk RNA-Seq, and combine scRNA-seq to analyze key cells, providing new evidence for ESCA diagnosis and treatment.Methods: Key miRNAs were obtained through machine learning, expression level validation and other analyses. Subsequently, candidate mRNAs were obtained by intersecting mRNAs related to key miRNAs and hsa-miR-34a-5p with down-regulated differentially expressed mRNAs. Further, key mRNAs were selected using the random forest (RF) algorithm. Nomogram construction and evaluation were performed for the key mRNAs. GSEA explored the biological functions of the mRNAs. Twenty-eight immune cell types were subject to abundance measurement using immune infiltration analysis. scRNA-seq screened key cell types. The analysis of key miRNA expression appliedRT-qPCR.Results: In total, 4 key miRNAs were identified in this study. Meanwhile, 40 candidate mRNAs were obtained, with 5 key mRNAs (INPP5B, ZNF426, FOXO1, PRLR, CBX7) further identified via RF algorithm analysis. The nomogram exhibitedgood predictive ability for ESCA. GSEA revealed INPP5B was mainly enriched in pathways like the proteasome pathway. Immune infiltration analysis identified 16 differentially infiltrated cell types. scRNA-seq analysis identified T cells as key cells. Public database analysis results were in alignment with the expression trends exhibited by these key miRNAs in the ESCA group.Conclusion: Overall, hsa-miR-15a-5p, hsa-miR-181b-5p, hsa-miR-181a-5p, and hsa-miR-15a-5p were identified as key miRNAs in ESCA; INPP5B, ZNF426, FOXO1, PRLR, and CBX7 as key mRNAs. This study provides a reliable model and new insights for ESCA therapeutic research.