I plan to study exosomal lncRNA. The lncRNA expression is lower in tumor tissue compared to normal tissue, but higher in exosomes. Is there a theory to explain this?

Exosomes are extracellular nano-sized vesicles of endocytic origin. Circulating exosomes in body fluids can interact with recipient cells by carrying various functional molecules like lncRNA, miRNA, proteins, etc., mediating intercellular communication and influencing tumor occurrence and development. LncRNAs detected in exosomes are termed exosome-derived lncRNAs. Studies have found that exosomes can transfer tumor-associated lncRNAs to tissue cells, affecting tumor biological processes, playing important roles in tumor proliferation, metastasis, invasion, drug resistance, immune regulation, and angiogenesis. Furthermore, tumor-derived exosomes have the ability to precondition distant or specific sites. Transferring lncRNAs to recipient cells at these sites can create a pre-metastatic niche suitable for tumor cell growth. Therefore, changes in the tumor microenvironment may lead to altered lncRNA content within the tumor tissue itself.