Biology subjects

Ramsamooj, S.

Publications and source records attributed to Ramsamooj, S..

3 recordsLinked to original sources

bioRxiv2025

JAK1/2 Inhibition Delays Cachexia and Improves Survival through Increased Food Intake

Lung cancer is the leading cause of cancer-related death and is frequently accompanied by reduced food intake and cachexia, a debilitating syndrome characterized by weight loss and skeletal muscle wasting. We sought to identify contributors to cachexia using a murine model of lung cancer that reproduces key features of this syndrome. A multiplex cytokine screening approach, integrated with western blot and transcriptomic analyses, identified tumor-derived inflammatory mediators and downstream signaling pathways associated with cachexia. Notably, IL-6 superfamily members were elevated in the tumor and plasma of mice and patients with cachexia. The JAK-STAT3 signaling was upregulated in liver and skeletal muscle, driving the acute phase response and impairing lipid metabolism. Pharmacologic inhibition of JAK1/2 with ruxolitinib improved body weight, fat mass, and overall survival without altering tumor burden. These effects were driven primarily by blunted hypothalamic leptin receptor signaling, which increased food intake early in the disease course. In the liver, JAK inhibition reduced STAT3 activity, restored fatty acid oxidation, and decreased the production of acute-phase proteins. These findings support JAK inhibition as a therapeutic strategy for lung cancer-associated cachexia. Statement of SignificanceCancer cachexia is a lethal complication of lung cancer that lacks effective treatment. We show that JAK inhibition by ruxolitinib restores weight, fat mass, and prolongs survival in murine models of lung cancer. These effects were independent of tumor burden, underscoring the relevance of addressing cachexia to improve survival in cancer patients and supporting clinical testing of JAK inhibition for cancer cachexia

cancer biology↗

bioRxiv2023

Restoring adiponectin via rosiglitazone ameliorates tissue wasting in mice with lung cancer.

The cancer associated cachexia syndrome (CACS) is a systemic metabolic disorder resulting in loss of body weight due to skeletal muscle and adipose tissues atrophy. CACS is particularly prominent in lung cancer patients, where it contributes to poor quality of life and excess mortality. Using the Kras/Lkb1 (KL) mouse model, we found that CACS is associated with white adipose tissue (WAT) dysfunction that directly affects skeletal muscle homeostasis. WAT transcriptomes showed evidence of reduced adipogenesis, and, in agreement, we found low levels of circulating adiponectin. To preserve adipogenesis and restore adiponectin levels, we treated mice with the PPAR-{gamma} agonist, rosiglitazone. Rosiglitazone treatment increased serum adiponectin levels, delayed weight loss, and preserved skeletal muscle and adipose tissue mass, as compared to vehicle-treated mice. The preservation of muscle mass with rosiglitazone was associated with increases in AMPK and AKT activity. Similarly, activation of the adiponectin receptors in muscle cells increased AMPK activity, anabolic signaling, and protein synthesis. Our data suggest that PPAR-{gamma} agonists may be a useful adjuvant therapy to preserve tissue mass in lung cancer. Key points- The PPAR-{gamma} agonist, rosiglitazone, restores circulating adiponectin levels in mice with lung cancer. - Rosiglitazone preserves skeletal muscle and adipose tissue mass in mice with lung cancer. - The preservation of muscle mass with rosiglitazone is associated with increases in AMPK and AKT activity. - Stimulation of adiponectin signaling increases AMPK activity, anabolic signaling, and protein synthesis in muscle cell culture.

cancer biology↗

bioRxiv2022

Epinephrine inhibits PI3K alpha via the Hippo kinases.

The phosphoinositide 3-kinase, p110, is an essential mediator of insulin signaling and glucose homeostasis. We systematically interrogated the human serine, threonine, and tyrosine kinome to search for novel regulators of p110 and found that the Hippo kinases phosphorylate and completely inhibit its activity. This inhibitory state corresponds to a conformational change of a membrane binding domain on p110, which impairs its ability to engage membranes. In human primary hepatocytes, cancer cell lines, and rodent tissues, activation of the Hippo kinases, MST1/2, using forskolin or epinephrine is associated with phosphorylation and inhibition of p110, impairment of downstream insulin signaling, and suppression of glycolysis and glycogen synthesis. These changes are abrogated when MST1/2 are genetically deleted or inhibited with small molecules. Our study reveals a novel inhibitory pathway of PI3K signaling and a previously unappreciated link between epinephrine and insulin signaling.

physiology↗