Biology subjects

Madariaga, M. L. L.

Publications and source records attributed to Madariaga, M. L. L..

3 recordsLinked to original sources

bioRxiv2025

Intraoperative arteriovenous patient sampling to assess in situ non-small cell lung cancer metabolism

We performed intraoperative arteriovenous sampling in participants undergoing surgical resection for non-small cell lung cancer (NSCLC) to characterize in situ tumor metabolism, directly measuring metabolite consumption and secretion in tumor-bearing lung versus normal lung and the systemic circulation. Healthy lung tissue secreted lower levels of lactate, pyruvate, and tricarboxylic acid (TCA) intermediates and consumed less glucose compared to the systemic circulation. In contrast, tumor-bearing lung demonstrated elevated lactate secretion, along with increased efflux of succinate, fumarate, glycine, and aspartate, despite similar glucose uptake. Lactate secretion correlated with tumor PET avidity but not size, and overall metabolic profiles distinguished cancerous from normal lung tissue. These findings confirm enhanced glycolysis in NSCLC in vivo, while also revealing context-dependent patterns of TCA metabolite accumulation and amino acid secretion. Our results demonstrate the utility of intraoperative sampling to uncover metabolic features of human tumors.

cancer biology↗

bioRxiv2024

Mutability and hypermutation antagonize immunoglobulin codon optimality

The efficacy of polyclonal antibody responses is inherently linked to paratope diversity, as generated through V(D)J recombination and somatic hypermutation (SHM). These processes arose in early jawed vertebrates; however, little is known about how immunoglobulin diversity, mutability, and hypermutation have evolved in tandem with another more ubiquitous feature of protein-coding DNA - codon optimality. Here, we explore these relationships through analysis of germline IG genes, natural V(D)J repertoires, serum VH usage, and monoclonal antibody (mAb) expression, each through the lens of multiple optimality metrics. Strikingly, proteomic serum IgG sequencing showed that germline IGHV codon optimality positively correlated with VH representation after influenza vaccination, and in vitro, codon deoptimization of mAbs with synonymous amino acid sequences caused consistent expression loss. Germline V genes exhibit a range of codon optimality that is maintained by functionality, and inversely related to mutability. SHM caused a load-dependent deoptimization of IGH VDJ repertoires within human tonsils, bone marrow, and lymph nodes (including SARS-CoV-2-specific clones from mRNA vaccinees), influenza-infected mice, and zebrafish. Comparison of natural mutation profiles to true random suggests the presence of selective pressures that constrain deoptimization. These findings shed light on immunoglobulin evolution, providing unanticipated insights into the antagonistic relationship between variable region diversification, codon optimality, and antibody secretion; ultimately, the need for diversity takes precedence over that for the most efficient expression of the antibody repertoire.

immunology↗

bioRxiv2023

Metabolite profiling of human renal cell carcinoma reveals tissue-origin dominance in nutrient availability

The tumor microenvironment is a determinant of cancer progression and therapeutic efficacy, with nutrient availability playing an important role. Although it is established that the local abundance of specific nutrients defines the metabolic parameters for tumor growth, the factors guiding nutrient availability in tumor compared to normal tissue and blood remain poorly understood. To define these factors in renal cell carcinoma (RCC), we performed quantitative metabolomic and comprehensive lipidomic analyses of tumor interstitial fluid (TIF), adjacent normal kidney interstitial fluid (KIF), and plasma samples collected from patients. TIF nutrient composition closely resembles KIF, suggesting that tissue-specific factors unrelated to the presence of cancer exert a stronger influence on nutrient levels than tumor-driven alterations. Notably, select metabolite changes consistent with known features of RCC metabolism are found in RCC TIF, while glucose levels in TIF are not depleted to levels that are lower than those found in KIF. These findings inform tissue nutrient dynamics in RCC, highlighting a dominant role of non-cancer driven tissue factors in shaping nutrient availability in these tumors.

cancer biology↗