Amino acid transporter LAT1 is expressed on cancer cell-derived exosomes with potential as a diagnostic and prognostic biomarker

Sep 21, 2026

Uploaded by Quinn

L-type amino acid transporter 1 (LAT1; SLC7A5) is upregulated in many cancers and is linked to poor patient outcomes, yet prior evaluations relied mainly on immunohistochemistry of resected tumors or biopsies. Exosomes released by cancer cells offer a noninvasive source of diagnostic and prognostic biomarkers. This study detects LAT1 on exosomes from pancreatic cancer T3M-4 cells using western blotting, immunoprecipitation, ELISA, and immuno-transmission electron microscopy, and confirms in vivo presence using peritoneal wash from tumor-bearing mice. Results support exosomal LAT1 as a novel biomarker.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages10

Reading Time25 min

AccessFree to download

Introduction

Exosomes as noninvasive cancer biomarkers

LAT1 in cancer metabolism and prognosis

Results (Study focus)

Detection of LAT1 on cancer-cell-derived exosomes

In vivo verification and biomarker implications

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN Amino acid transporter LAT1 is expressed on cancer cellderived exosomes with potential as a diagnostic and prognostic biomarker Yumiao Liu1, Ryuichi Ohgaki1,2􀀍, Hiroki Okanishi1, Minhui Xu1 & Yoshikatsu Kanai1,2,3􀀍 L-type amino acid transporter 1 (LAT1) is upregulated in various cancers and contributes to the growth and proliferation of cancer cells. Previous clinicopathological studies have revealed associations between the high expression of LAT1 and the poor prognosis in multiple cancer types. However, in those studies, the expression of LAT1 has been evaluated solely by immunohistochemistry on resected tumors or tissue biopsies. Cancer cell-derived exosomes are attracting increasing attention as a resource of diagnostic, prognostic, and therapeutic biomarkers. In this study, we revealed the expression of LAT1 on exosomes from pancreatic cancer T3M-4 cells by western blotting, immunoprecipitation, and immuno-transmission electron microscopy. LAT1 was generally detected by western blotting and ELISA on exosomes from several pancreatic, biliary tract, and ovarian cancer cells. Notably, similar trends existed between the abundance of exosomal LAT1 and the cellular LAT1 expression levels. The expression of LAT1 on exosomes in vivo was verified using the peritoneal wash from intraperitoneal T3M-4 tumor-bearing mice. These results indicate that exosomal LAT1 released from cancer cells holds significant potential as a novel biomarker for diagnosis and prognosis. Keywords Exosome, Cancer, Biomarker, Amino acid transporter, LAT1, SLC7A5 Exosomes are small membrane vesicles produced by most eukaryotic cells1,2. Originating from multivecular bodies (MVBs), exosomes contain various cargo molecules derived from their parental cells, such as proteins, mRNAs, miRNAs, lncRNAs, lipids, and metabolites. An accumulating number of studies have demonstrated that cancer cell-derived exsosomes are involved in pathological processes both in autocrine and paracrine manners, including cancer stemness, immune escape, drug resistance, angiogenesis, and premetastatic niche formation3. Additionally, exosomes have been attracting growing interest as a resource of noninvasive cancer biomarkers, because they are secreted into body fluids, including blood, saliva, urine, milk, and ascites1,2. Many exosomal proteins have been reported and extensively studied as potential biomarkers for early cancer diagnosis, prognostic monitoring, and assessment of the treatment efficacy4,5. Cancer cells generally exhibit an increased nutrient uptake to fulfill their metabolic demands for rapid growth and proliferation. L-type amino acid transporter 1 (LAT1; SLC7A5)6, which preferentially transports large neutral amino acids, is known to be upregulated in various types of cancer cells7. Amino acids transported into cancer cells by LAT1 are not only directly utilized as building blocks for the protein synthesis, but also metabolically fuel the synthesis of macromolecules such as nucleotides, lipids, and ATP. LAT1 also contributes to the regulation of these multiple biosynthetic and metabolic processes through the uptake of leucine as an essential signaling molecule that activates of a serine-threonine kinase complex mTORC1 (mechanistic target of rapamycin complex 1)8–11. Higher expression of LAT1 is associated with the poorer prognosis of patients in multiple cancer types12, 13, including the most refractory pancreatic and biliary tract cancers14–16. Intriguingly, 1Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, Japan. 2Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka, Japan. 3Department of Metabolic Reprogramming and Signal Regulation, Premium Research Institute for Human Metaverse Medicine (WPI-PRIMe), Osaka Univer

FAQs

Why is LAT1 considered important in cancer research?

LAT1 is frequently upregulated in cancers and supports tumor growth by transporting large neutral amino acids, including signaling through leucine to activate mTORC1. Higher LAT1 expression correlates with poorer prognosis across multiple cancer types.

How did the study examine LAT1 expression on exosomes?

LAT1 on exosomes from pancreatic cancer T3M-4 cells was assessed using western blotting, immunoprecipitation, immuno-transmission electron microscopy, and ELISA.

What evidence supports exosomal LAT1 as an in vivo biomarker?

The expression of LAT1 on exosomes was verified in vivo using peritoneal wash samples from intraperitoneal T3M-4 tumor-bearing mice, demonstrating that exosomal LAT1 is detectable outside cultured cells.

Sep 21, 2026

Uploaded by Quinn