Biology subjects

Koniaris, L. G.

Publications and source records attributed to Koniaris, L. G..

5 recordsLinked to original sources

bioRxiv2025

Pancreatic Cancer Induces Population-Specific Switching of Myosin Isoforms and Discrete Activation of Cachexia Genes in Skeletal Muscle Myocytes

Skeletal muscle loss in pancreatic cancer is a significant cause of morbidity and mortality for patients. In order to understand myocytes changes we examined myonuclei- and myofiber-specific dynamics during pancreatic cancer cachexia progression. Single-nucleus RNA-seq was used to interrogate myonuclear gene expression, and RNAscope and immunofluorescence characterized myofiber-specific changes. Bulk RNA-seq of skeletal muscle provided a whole-muscle transcriptomic profile. Cachexia induces a progressive loss of muscle differentiation factor Maf and its target Myh4, accompanied by increased expression of Myh1 and Myh2. This myofiber dedifferentiation occurs without evidence for fiber type shifting, regeneration, or proliferation. Single-nuclei analysis reveals global shifts in myofiber gene expression identity including the identification of a cachexia only myonuclear subpopulation. Cachexia gene expression was not restricted solely to this PDAC-specific myonuclear subpopulation and did not overlap with Myh1 and Myh2 expressing myonuclei early in cachexia. Altogether, PDAC cachexia elicits distinct transcriptional responses across different myonuclear populations. These results reveal population-specific heterogeneity in cachexia gene activation, rather than a uniform upregulation of cachexia mediators across muscle tissue. Our data suggest that myonuclei fate occurs prior to overt muscle wasting when cachexia gene expression only modestly overlaps with differentiation factors, with a strong association after irreversible muscle wasting. These findings explain the challenge of effectively targeting skeletal muscle wasting in cancer cachexia requires addressing the changing cell population induced through non overlapping mechanisms.

cancer biology↗

bioRxiv2025

Hepatic Yap1 activates systemic catabolism and muscle loss during organ repair: evidence for a liver-derived common mechanism with cancer cachexia.

Recovery from critical injury concomitant with restoration of functional organ mass invokes a systemic catabolic response leading to muscle and fat loss, known as cachexia. We interrogated this process using mouse models of organ repair, including liver regeneration after hepatectomy, Yap1-mediated hepatomegaly, and pneumonectomy. Both hepatectomy and Yap1 induced systemic catabolism. Muscle and adipose wasting scaled with degree of liver growth, with 10-25% reduction of muscle mass and 50-80% of fat mass. In contrast, non-regenerative lung injury did not induce tissue wasting. Liver growth elevated resting energy expenditure. Tracer studies demonstrated redistribution of muscle-derived cholesterol and amino acids to regenerating liver. Gene expression changes in livers and muscles showed high concordance between the liver growth models and cancer cachexia models, including pancreatic adenocarcinoma cachexia. We propose that cachexia is a normal and essential reparative process in organ repair and regeneration and further, that cancer cachexia is a pathological exacerbation of an adaptive process mediated by activation of Yap1 in the liver.

physiology↗

bioRxiv2020

IL-6 Trans-Signaling and Tumor-Muscle-Adipose Crosstalk Mediate Pancreatic Cancer Cachexia

Most patients with pancreatic adenocarcinoma (PDAC) suffer unintentional weight loss, or cachexia. Interleukin-6 causes cachexia in mice and associates with mortality in PDAC. Here we show that tumor cell-derived IL-6 mediates crosstalk between tumor and peripheral tissues to promote cachexia. Tumor-cell IL-6 elicits expression of IL-6 in fat and IL-6 and IL-6 receptor (IL6R) in muscle, concomitantly raising both in blood. Inflammation-induced adipose lipolysis elevates circulating fatty acids, which cooperate with IL-6 to induce skeletal muscle dysmetabolism and wasting. Thus, PDAC induces crosstalk among tumor, fat and muscle via a feed-forward, IL-6 signaling loop. Tumor talks to muscle and fat through IL-6, and muscle to fat via IL6R trans-signaling, and fat to muscle through lipids and fatty acids. Disruption of this crosstalk by depletion of tumor-derived IL-6 halved fat wasting and abolished muscle loss, supporting IL-6, IL-6R and lipids as causal nodes for tissue crosstalk in PDAC cachexia. SignificancePDAC-associated cachexia significantly increases patient morbidity and mortality. This study identifies muscle and fat crosstalk via IL6R trans-signaling in concert with muscle steatosis as a main driver of PDAC-associated cachexia.

cancer biology↗

bioRxiv2018

Identification of circulating protein biomarkers for pancreatic cancer cachexia

BackgroundOver 80% of patients with pancreatic ductal adenocarcinoma (PDAC) suffer from cachexia, characterized by severe muscle and fat loss. Although various model systems have improved our understanding of cachexia, translating the findings to human cachexia has remained a challenge. In this study, our objectives were to i) identify circulating protein biomarkers using serum for human PDAC cachexia, (ii) identify the ontological functions of the identified biomarkers and (iii) identify new pathways associated with human PDAC cachexia by performing protein co-expression analysis.\n\nMethodsSerum from 30 patients with PDAC was collected. Body composition measurements of skeletal muscle index (SMI), skeletal muscle density (SMD), total adipose index (TAI) were obtained from computed tomography scans (CT). Cancer associated weight loss (CAWL), an ordinal classification of history of weight loss and body mass index (BMI) was obtained from medical record. Serum protein profiles and concentrations were generated using SOMAscan, a quantitative aptamer-based assay. Ontological analysis of the proteins correlated with clinical variables (r[≥] 0.5 and p<0.05) was performed using DAVID Bioinformatics. Protein co-expression analysis was determined using pairwise Spearmans correlation.\n\nResultsOverall, 111 proteins of 1298 correlated with these clinical measures, 48 proteins for CAWL, 19 for SMI, 14 for SMD, and 30 for TAI. LYVE1, a homolog of CD44 implicated in tumor metastasis, was the top CAWL-associated protein (r= 0.67, p=0.0001). Other proteins such as INHBA, MSTN/GDF11, and PIK3R1 strongly correlated with CAWL. Proteins correlated with cachexia included those associated with proteolysis, acute inflammatory response, as well as B cell and T cell activation. Protein co-expression analysis identified networks such as activation of immune related pathways such as B-cell signaling, Th1 and Th2 pathways, natural killer cell signaling, IL6 signaling, and mitochondrial dysfunction.\n\nConclusionTaken together, these data both identify immune system molecules and additional secreted factors and pathways not previously associated with PDAC and confirm the activation of previously identified pathways. Identifying altered secreted factors in serum of PDAC patients may assist in developing minimally invasive laboratory tests for clinical cachexia as well as identifying new mediators.

cancer biology↗

bioRxiv2018

The systemic activin response to pancreatic cancer: Implications for effective cancer cachexia therapy

Pancreatic ductal adenocarcinoma (PDAC) is a particularly lethal malignancy with high rates of cachexia. Serum activin correlates with PDAC cachexia and mortality, while activin administration causes cachexia in mice. We studied activin in human tumors and in mice with orthotopic or genetic PDAC. Cachexia severity correlated with activin expression in tumor lines. Activins were expressed in both cancer and tumor stromal cells, but also in organs in murine PDAC cachexia. Tumor cells expressed activin-{beta}A, or Inhba, while organs expressed both activin-{beta}A and activin-{beta}B, or Inhbb. PDAC elicits activin expression; PDAC conditioned medium induced activin and atrophy of myotubes. Treatment with the activin trap, ACVR2B/Fc, reduced cachexia and prolonged survival in mice with activin-low tumors, and reduced cachexia in activin-high tumors, without affecting activin expression in organs. Mice expressing dominant negative ACVR2B in muscle were protected for weight loss but not survival. Overall our results indicate that PDAC induces a systemic activin response, leading to cachexia, and that activin targets might include organs beyond muscle. Targeting of both tumor-derived and host-derived activins could improve cachexia therapy.

cancer biology↗