Exosomes have emerged as a novel approach for the treatment and diagnosis of cancer after RNA content was discovered in exosomes in 2007. As important meditators of intercellular communication, exosomes have become a strong focus of investigation for researchers in the past decade, as witnessed through the exponential increase of research on exosomes. The capability of exosomes to transfer functionally active cargo highlights their importance as promising biomarkers and diagnostic molecules, as well as prospective drug delivery systems. The accessibility of exosomes in nearly all biofluids additionally alludes to its unprecedented ability in various types of cancers due to its extensive impact on tumor formation and progression. This review analyzes the role of exosomal long RNA species, which is comprised of mRNA, lncRNA, and circRNA, in tumor formation and progression, with an emphasis on their potential as future diagnostic biomarkers and treatment vectors in cancer biology. Their alignment with the development of exosomal databases is further examined in this review, in view of the accumulation of studies published on exosomes in the past decade.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0823-z) contains supplementary material, which is available to authorized users.

BackgroundThe long non-coding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) is expressed in solid malignant tumors. The aim of this systematic review and meta-analysis was to determine whether expression of the lncRNA SNHG1 was associated with prognosis in patients with malignancy.Material/MethodsA literature review from Jan 1970 to July 2018 identified publications in the English language. Databases searched included: PubMed, OVID, Web of Science, the Cochrane Database, Embase, EBSCO, Google Scholar. Systematic review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Newcastle-Ottawa Scale (NOS) assessment tool for risk of bias was used.ResultsEight publications (570 patients) and eight solid tumors were identified, including osteosarcoma, colorectal cancer, hepatocellular carcinoma, non-small cell lung cancer, esophageal cancer, ovarian cancer, glioma, and gastric cancer. Meta-analysis showed that expression of the lncRNA SNHG1 was significantly correlated with reduced overall survival (OS) (HR=1.917; 95% CI, 1.58–2.31) (P<0.001). Subgroup analysis showed that lncRNA SNHG1 expression was significantly correlated with TNM stage (OR=3.99; 95% CI, 2.48–6.43) and lymph node metastasis (OR=3.12; 95% CI, 1.95–4.98). There were no significant correlations between lncRNA SNHG1 expression and patient gender, tumor subtype, or tumor size.ConclusionsSystematic literature review and meta-analysis identified eight publications that included 570 patients with eight types of solid malignant tumor, and showed that the expression of the lncRNA SNHG1 was significantly associated with worse clinical outcome.

Chimeric antigen receptor T (CAR-T) cell therapy has exhibited a substantial clinical response in hematological malignancies, including B-cell leukemia, lymphoma, and multiple myeloma. Therefore, the feasibility of using CAR-T cells to treat solid tumors is actively evaluated. Currently, multiple basic research projects and clinical trials are being conducted to treat lung cancer with CAR-T cell therapy. Although numerous advances in CAR-T cell therapy have been made in hematological tumors, the technology still entails considerable challenges in treating lung cancer, such as on−target, of−tumor toxicity, paucity of tumor-specific antigen targets, T cell exhaustion in the tumor microenvironment, and low infiltration level of immune cells into solid tumor niches, which are even more complicated than their application in hematological tumors. Thus, progress in the scientific understanding of tumor immunology and improvements in the manufacture of cell products are advancing the clinical translation of these important cellular immunotherapies. This review focused on the latest research progress of CAR-T cell therapy in lung cancer treatment and for the first time, demonstrated the underlying challenges and future engineering strategies for the clinical application of CAR-T cell therapy against lung cancer.