Spatial Metabolomics and Transcriptomics Reveal Metabolic Reprogramming and Cellular Interactions in Nasopharyngeal Carcinoma with High PD-1 Expression and Therapeutic Response

Nasopharyngeal carcinoma (NPC) is a heterogeneous cancer with variable therapeutic responses, highlighting the need to better understand the molecular factors influencing treatment outcomes. This study aims to explore spatially metabolic and gene expression alterations in NPC patients with different therapeutic responses and PD-1 expression levels. Methods: This study employs spatial metabolomics (SM) and spatial transcriptomics (ST) to investigate significant alterations in metabolic pathways and metabolites in NPC patients exhibiting therapeutic sensitivity or elevated programmed death 1 (PD-1) expression. The spatial distribution of various cell types within the TME and their complex interactions were also investigated. Identified prognostic targets were validated using public datasets from TCGA, and further substantiated by in vitro functional analyses. Results: SM analysis revealed substantial reprogramming in lipid metabolism, branched-chain amino acid (BCAA) metabolism, and glutamine metabolism, which were closely associated with therapeutic response and PD-1 expression. ST analysis highlighted the critical role of interactions between precursor T cells and malignant epithelial cells in modulating therapeutic response in NPC. Notably, six key genes involved in BCAA metabolism (IL4I1, OXCT1, BCAT2, DLD, ALDH1B1, HADH) were identified in distinguishing patients with therapeutic sensitivity from those with therapeutic resistance. Functional validation of DLD and IL4I1 revealed that gene silencing significantly inhibited NPC cell proliferation, colony formation, wound healing, and invasion. Silencing DLD or IL4I1 induced cell cycle arrest. Reduction in α-Ketomethylvaleric acid (KMV) levels was demonstrated upon IL4I1 silencing. Immunohistochemical analysis further confirmed that high expression of these six genes was significantly associated with poor prognosis in NPC patients, a trend corroborated by data from the TCGA head and neck cancer cohort. Conclusions: This study highlights the pivotal roles of key molecular players in therapeutic response in NPC, providing compelling evidence for their potential application as prognostic biomarkers and therapeutic targets, thereby contributing to precision oncology strategies aimed at improving patient outcomes.

Identifying prognostic markers in spatially heterogeneous breast cancer microenvironment

To gain deeper insights into the microenvironment of breast cancer, we utilized GeoMx Digital Spatial Profiling (DSP) technology to analyze transcripts from 107 regions of interest in 65 untreated breast cancer tissue samples. Our study revealed spatial heterogeneity in the expression of marker genes in tumor cell enriched, immune cell enriched, and normal epithelial areas. We evaluated a total of 55 prognostic markers in tumor cell enriched regions and 15 in immune cell enriched regions, identifying that tumor cell enriched regions had higher levels of follicular helper T cells, resting dendritic cells, and plasma cells than immune cell enriched regions, while the levels of resting CD4 memory in T cells and regulatory (Treg) T cells were lower. Additionally, we analyzed the heterogeneity of HLA gene families, immunological checkpoints, and metabolic genes in these areas. Through univariate Cox analysis, we identified 5 prognosis-related metabolic genes. Furthermore, we conducted immunostaining experiments, including EMILIN2, SURF4, and LYPLA1, to verify our findings. Our investigation into the spatial heterogeneity of the breast cancer tumor environment has led to the discovery of specific diagnostic and prognostic markers in breast cancer.

Diagnostic utility of PAX2 and PAX5 in distinguishing non-small cell lung cancer from small cell lung cancer

Lung cancer is the leading cause of cancer-related death in both men and women and consists of different histological types. Histopathological examination and accurate subtype diagnosis has become increasingly important in guiding patient management and, as such, is the most important currently available lung cancer "biomarker". In this study, we examined the expression of PAX2 and PAX5 by immunohistochemistry in 47 cases of lung cancer and 13 cases of pneumonia. The results demonstrated that PAX2 were detected in 82.8% (24/29) of NSCLC, 0% (0/18) of SCLC and 7.7% (1/13) of pneumonia, respectively; However, PAX5 were detected in 15/18 cases (83.3%) of SCLC, 6.8% (2/29) of NSCLC and 7.7% (1/13) of pneumonia. Further, the samples with lymphatic metastasis had remarkable higher positive PAX2 or PAX5 than that without metastases. Overall, our data indicated that PAX2 and PAX5 differentially expressed in NSCLC and SCLC. Thus, PAX2 and PAX5 are useful biomarker in the differential diagnosis of lung cancer.

Intratumoral Stenotrophomonas Maltophilia in Breast Cancer: Unraveling the Interplay with Hormone Receptors and Impact on Tumor Immunity

This study aimed to explore the impact of intratumoral microorganisms in conjunction with hormone receptors on the tumor microenvironment and their potential role in predicting patient prognosis. Significant bacterial variations were identified within ER, PR, HER2, and triple-negative breast cancer subtypes. Kaplan-Meier survival analysis was employed to identify bacteria associated with patient survival. Further, a humanized immune system mouse model bearing breast cancer xenografts was used to evaluate the effects of Stenotrophomonas maltophilia (SMA) on tumor growth and CD8+ T cell infiltration. Additional validation experiments included fluorescence in situ hybridization for SMA, CD8+ T cell chemotaxis, and intracellular cytokine detection. Lawsonella clevelandensis-A, Diaphorobacter nitroreducens, and SMA were identified as significant prognostic species. Notably, tumor-infiltrating immune cells, particularly CD8+ T cells, exhibited a positive association with the presence of SMA. Experimental validation with clinically isolated SMA further confirmed its positive correlation with CD8+ T cell activation. In vivo findings demonstrated that SMA inhibited tumor growth and promoted CD8+ T cell infiltration, highlighting the complex interactions between intratumoral microbiota and tumor immunity in breast cancer. These insights contribute to the understanding of microbial influences on the tumor microenvironment and suggest potential pathways for improving patient prognosis through microbiota modulation.

Single cell analysis unveils the commonality and heterogeneity between nasopharyngeal and oropharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) and oropharyngeal carcinoma (OPC) are subtypes of head and neck cancer with different treatment effects due to the heterogeneity of tumor microenvironments. This study was to investigate the distinctive tumor microenvironments of NPC and OPC. Analyzing single-cell data from 10 cases of each subtype, we reveal significant differences in cellular composition, with NPC microenvironment dominated by T/NK and B cells, and OPC characterized by prevalent epithelial cells and fibroblasts. Dynamic transitions of CD8 T cells are observed in both tumor types, involving shifts from naivety to cytotoxicity, proliferation, and eventual exhaustion/exhausted states. Additionally, Tregs exhibit heightened proliferative abilities in later developmental stages, concomitant with exhaustion. These highly proliferative T cells and Tregs manifest elevated glycolysis and lactate metabolism activities. Furthermore, we explore intercellular communication between glycolytic malignant epithelial cells and these proliferative T cells. These findings offer comprehensive insights into the heterogeneity of tumor microenvironments and provide a solid foundation for future therapeutic strategies and targeted interventions.