TO THE EDlTOR

We read with great interest the systematic review "Exosomes as potential diagnosis and treatment for liver cancer" recently published in

2022; 14:334-347[1].The authors conducted a literature search to identify potential diagnostic and therapeutic markers of exosomes in liver cancer.Forty potential liver cancer biomarkers,13 potential biotherapeutics and 10 potential hepatocellular carcinoma therapeutic targets were identified,providing future directions for basic research and targeted therapy of liver cancer.

Exosomes,first discovered in 1983,are small lipid bilayer vesicles with a diameter of 40-160 nm,which are found in body fluids such as blood,urine,saliva,and cerebrospinal fluid[2].Exosomes contain many biomolecules,including membrane-bound proteins,soluble proteins,lipids,DNA,microRNAs and non-coding RNAs[3].In recent years,studies have found that exosomes are involved in intercellular communication in many physiological processes in the body,and play a crucial role in mediating tumorigenesis,development and metastasis[4-6].Tumor-derived exosomes convey tumorigenic information and contribute to the tumor microenvironment for tumor proliferation and metastasis,and are a promising biomarker for cancer therapy[2].The unique characteristics of tumor cell-derived exosomes make them potential biomarkers for early cancer diagnosis,tracking cancer patient’s response to therapy,and detecting mechanisms of resistance to therapy,and making important contributions to precise and personalized cancer therapy.

A variety of cancer cell-specific proteins,lipids,DNA,RNA and metabolites can be isolated from cancer cell-derived exosomes,which can be used as cancer biomarkers[3].Studies have reported that exosome-associated glypican-1 (GPC1) is a diagnostic biomarker for early pancreatic cancer[7].Circulating exosome-derived lncRNA-GC1 can be used as a biomarker to detect early gastric cancer and monitor disease progression[8].Tumor cell-specific molecules in exosomes can be used for early diagnosis and detection of cancer recurrence.

The Fairy loved her with all her heart, for she was at once original and gentle, and she had nearly reached the age at which the gifts were generally bestowed4

Exosomes have natural delivery capabilities as carriers for cancer therapeutics and functional RNAs[9].Compared with traditional nanomaterial carriers,exosomes have the advantages of high bioavailability,non-cytotoxicity and non-immunogenicity.Transmembrane and membrane-anchored proteins within exosomes enhance endocytosis,thereby facilitating transfer of chemotherapeutics.Studies have found that neutrophil-derived exosomes deliver chemotherapeutics across the blood-brain barrier and effectively inhibit tumor growth[10].Exosomes have the characteristics of small size,strong penetration and high biological stability.Using exosomes to deliver drugs or adding inhibitory immune checkpoints on the surface of exosomes to further enhance the anti-cancer effect is a new direction for exosomes in cancer treatment.In the future,exosome-based drug delivery systems are expected to be widely used in cancer therapy (Figure 1).

The Prince sprang to his feet, hardly able to refrain from telling her that she must be blinded by vanity to suppose she resembled the lovely portrait even in the slightest degree; and after gazing at her for an instant with icy surprise, turned and left her without another word, and in a few hours quitted the Leafy Palace altogether

All authors report no relevant conflicts of interest for this article.

Fang Z and Ding YX wrote the manuscript; Li F designed the study; and All authors have read and approve the final manuscript.

China

In conclusion,much progress has been made in the field of exosome research,but the obstacles hindering the widespread clinical application of exosomes should also be highly concerned.The great prospect of exosomes for cancer diagnosis and treatment is undeniable.

With the deepening of exosome research,a more comprehensive understanding of exosomes has been achieved,but there are still factors that restrict exosome research and clinical application.For example,the large-scale extraction,isolation and purification of exosomes are limited.At present,the exosome extraction method is mainly ultracentrifugation,but with low yield and high cost,thus it is difficult to achieve industrial production and large-scale clinical application.

It was covered, and neither the servant nor anyone else had any idea what was on it, for the King never removed the cover or partook of the dish, till he was quite alone

This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers.It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BYNC 4.0) license,which permits others to distribute,remix,adapt,build upon this work non-commercially,and license their derivative works on different terms,provided the original work is properly cited and the use is noncommercial.See: https://creativecommons.org/Licenses/by-nc/4.0/

When they heard this the brothers set to work again to earn some more money, and when they had got enough they set about building a church, which should be as large and beautiful as the palace itself

Zhen Fang 0000-0002-7073-8997; Yi-Xuan Ding 0000-0001-6752-9660; Fei Li 0000-0002-6402-6811.

Ma YJ

A

Ma YJ

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