PDZ-LIM domain–containing protein 2 (PDLIM2) was evaluated as a prognostic biomarker in lung adenocarcinoma (LUAD) across a large clinical cohort and in preclinical models. The clinical analysis incorporated next-generation sequencing and PD-L1 immunohistochemistry on tumor samples from 15,765 patients. High PDLIM2 expression was substantially more common in primary or local biopsy specimens than in metastatic samples (73.1% vs 53.0%; p < 0.001), indicating differential expression by sampling site.
High PDLIM2 status was associated with improved overall survival: median survival was 24.1 months for PDLIM2-high tumors versus 18.1 months for others (p < 0.001; HR = 0.84). In multivariate analysis PDLIM2 retained independent prognostic significance (HR = 0.88, 95% CI 0.83–0.93). These clinical associations support consideration of PDLIM2 as a prognostic marker in LUAD, although the authors note that its predictive role for treatment benefit requires further study.
Tumors with high PDLIM2 expression exhibited a distinct genomic profile. Specifically, PDLIM2-high tumors had lower mutation frequencies in several tumor suppressor or chromatin-regulating genes, including RB1, TP53, SMARCA4, STK11, and KEAP1 (all p < 0.01). Conversely, EGFR mutations were more frequent in PDLIM2-high tumors (p < 0.01). These associations suggest PDLIM2 expression correlates with particular mutation patterns in LUAD, though the dataset and analysis details beyond the reported associations were not provided in the source.
High PDLIM2 expression was linked with markers of an immune-receptive tumor microenvironment. PDLIM2-high tumors demonstrated increased immune cell infiltration, higher T cell–inflamed gene expression scores, and greater tumor PD-L1 positivity (all p < 0.008). Together, these findings indicate that PDLIM2 expression is associated with an inflamed, potentially more immunotherapy-responsive tumor milieu.
Beyond overall survival, the study reported that high PDLIM2 expression associated with longer duration on pembrolizumab, particularly when combined with platinum-based chemotherapy (p = 0.012; HR = 0.867). This observation links PDLIM2 to longer clinical benefit on at least one PD-1–directed therapy in the analyzed cohort, though the source emphasizes that the predictive value for treatment selection needs further validation and prospective study.
The therapeutic potential of restoring PDLIM2 was tested in syngeneic LUAD mouse models using intravenous delivery of plasmid DNA complexed in nanoparticles (referred to as nanoPDLIM2). When administered alongside chemoimmunotherapy, nanoPDLIM2 improved median overall survival compared with chemoimmunotherapy alone in two LUAD models. Reported median survival values were 10–12.5 days with nanoPDLIM2 plus chemoimmunotherapy versus 8–9 days with chemoimmunotherapy alone (N = 8; p = 0.0001 and 0.0003). These preclinical results indicate that PDLIM2 restoration can enhance the efficacy of combined chemotherapy and immune checkpoint blockade in the models tested.
PDLIM2 functions as a tumor suppressor through several mechanisms described in prior work and referenced by the authors. A key mechanism is negative regulation of the NF-κB and STAT3 signaling pathways, accomplished in part by intranuclear sequestration and proteasomal degradation of transcriptional subunits such as NF-κB p65. Suppression of these pathways can reduce pro-inflammatory and pro-survival signaling that supports tumor cell growth, migration, and invasion. The source also notes epigenetic repression of PDLIM2 in multiple cancers and that restoring PDLIM2 expression—either by nanoparticle delivery of exogenous PDLIM2 (nanoPDLIM2) or pharmacologic induction of endogenous PDLIM2—sensitizes tumors to chemotherapy and immunotherapy in preclinical models.
The combined clinical and preclinical findings position PDLIM2 as a promising prognostic biomarker for LUAD and a candidate therapeutic target to potentiate chemoimmunotherapy. Clinically, PDLIM2-high tumors were more immune-receptive and associated with longer survival and longer time on pembrolizumab, particularly with platinum-based regimens. Preclinically, nanoparticle-mediated PDLIM2 restoration enhanced survival when added to chemoimmunotherapy.
However, the article indicates that further evaluation is required to define PDLIM2’s predictive utility for selecting patients for specific therapies and to translate nanoPDLIM2 approaches into clinical testing. Details on patient selection criteria, full molecular analyses, safety, dosing regimens, and longer-term outcomes for the preclinical interventions were not reported in the provided source text. Prospective clinical studies and more comprehensive mechanistic analyses will be needed to validate PDLIM2 as a clinical biomarker and to advance PDLIM2-targeted therapies toward human trials.
In summary, the presented data support PDLIM2 as a prognostic marker linked to immune-receptive LUAD and demonstrate that restoring PDLIM2 can enhance chemoimmunotherapy efficacy in mouse models, while underscoring the need for further clinical validation and mechanistic investigation.