Single-Cell Dissection Identifies METTL7B as Associated with Cell Adhesion-Mediated Tumor Invasion in Lung Adenocarcinoma and Glioblastoma

Background: Tumor invasion is the central barrier to effective immunotherapy in lung adenocarcinoma (LUAD) and glioblastoma. Cell adhesion signaling critically shapes tumor–microenvironment interactions, yet the upstream regulators coordinating these invasive programs at single-cell resolution remain incompletely understood. Methyltransferase Like protein 7B (METTL7B) has recently emerged as a candidate oncogenic regulator, but its lineage-specific functions and the potential downstream effectors are unclear. Methods: We integrated publicly available single-cell RNA sequencing datasets from LUAD and glioblastoma with The Cancer Genome Atlas (TCGA) transcriptomic analyses to resolve METTL7B-associated malignant cell states and microenvironmental interactions. Functional enrichment analyses identified invasion- and focal adhesion pathways linked to METTL7B expression. Gain- and loss-of-function experiments were conducted in LUAD and glioblastoma cell lines to validate downstream cell adhesion effectors. Spatial expression patterns were examined using immunofluorescence, and transwell assays were used to assess migratory and invasive phenotypes. Results: Single-cell analyses revealed that METTL7B was selectively enriched in malignant epithelial cells in LUAD and glioblastoma and defined a transcriptional program characterized by cell adhesion signaling. Integrin Alpha 3 (ITGA3) emerged as a conserved downstream effector of METTL7B, with progressive upregulation from minimally invasive to invasive LUAD and glioblastoma. Functional perturbation confirmed that METTL7B enhances tumor cell migration and invasion through integrin-associated pathways. Conclusions: METTL7B acts as a potential lineage-enriched regulator of invasive tumor states by activating cell adhesion signaling in LUAD and glioblastoma. These findings position METTL7B as a putative prognostic factor for strategies aimed at limiting invasion in lung cancer and glioblastoma.