Purpose: Exosome-shuttled bioactive long non-coding RNA, as novel non-invasive biomarkers for cancer diagnosis, has received increasing attention. Here, we aimed to investigate the expression of serum exosomal long non-coding RNA pcsk2-2:1 (Exo-Lnc RNApcsk2-2:1) in patients of gastric cancer and evaluate its diagnostic value as a marker. Patients and methods: Exosomes were isolated from serum sample of gastric cancer using HiPure Exosomekits and identified via transmission electron microscopy, Western blotting, and nanoparticle tracking analysis. The total exosomal RNA was extracted and reverse transcribed to cDNA. The expression of Exo-Lnc RNA PCSK2-2:1 was detected in serum exosomes of 29 healthy people and 63 gastric cancer patients by real-time quantitative reverse transcription PCR (qRT-PCR), and the relationship between the expression level of Exo-Lnc RNA PCSK2-2:1 and clinicopathological parameters of patients was analyzed. Finally, a receiver operating characteristic curve was used to evaluate the clinical value of Exo-Lnc RNA PCSK2-2:1 as an auxiliary diagnostic marker for gastric cancer. Results: Transmission electron microscopy, nanoparticle size analysis, and Western blotting showed successful separation of serum exosomes. qRT-PCR results revealed that compared with the healthy control, Lnc RNA PCSK2-2:1 expression level in serum exosomes of gastric cancer patients was significantly downregulated (p=0.006). Moreover, the expression level of Exo-Lnc RNA PCSK2-2:1 was correlated with tumor size (p=0.0441), tumor stage (p=0.0061), and venous invasion (p=0.0367). The area under the curve of Exo-Lnc RNA PCSK2-2:1 was 0.896. At the optimal cut-off value, the diagnostic sensitivity and specificity were 84% and 86.5%, respectively. Conclusion: Our data indicate that Exo-Lnc RNA PCSK2-2:1 may perform a vital role in the progression of gastric cancer and can be used as a potential marker for the diagnosis of gastric cancer.

Up-regulation of serum ephrinA2 is common in various malignancies and has been suggested as a potential biomarker for the diagnosis and prognosis of prostate cancer (PCa). However, the type of serum ephrinA2 expressed in PCa patients remains elusive. Furthermore, the level of exosomal ephrinA2 derived from serum is increased in patients with osteoporosis, a common complication of PCa patients undergoing androgen deprivation therapy. It is unknown whether exosomes derived from PCa patient serum contains ephrinA2. In this study, we explored the ephrinA2 expression in whole serum and tissues and identified the circulating exosomal ephrinA2 as a potential biomarker for PCa. Exosomes were isolated from patient sera by differential centrifugation and the presence of ephrinA2 was confirmed via electron microscopy and western blotting. The type of ephrinA2 in serum was evaluated by western blotting. The expression of serum ephrinA2 including secreted and cleaved ephrinA2 and exosomal ephrinA2 were detected by ELISA and western blotting. Compared with benign prostatic hyperplasia (BPH) and controls, the levels of whole serum ephrinA2 and exosomal ephrinA2 were significantly higher in PCa patients. Moreover, exosomal ephrinA2 expression was positively correlated with TNM staging and Gleason score of PCa patients. The diagnostic efficiency of exosomal ephrinA2 was superior to that of whole serum ephrinA2 and serum PSA in distinguishing PCa patients from those from BPH patents. Our study indicates that exosomal ephrinA2 has high potential as a biomarker for the presence of PCa and offers a new therapeutic target for this disease.

B7-H3 is an attractive target for immunotherapy because of its high expression across multiple solid tumors, including prostate cancer, and restricted expression in normal tissues. Among various types of tumor immunotherapy, chimeric antigen receptor T (CAR-T) cell therapy has shown remarkable success in hematological tumors. However, the potency of CAR-T cell therapy in solid tumors is still limited. Here, we examined the expression of B7-H3 in prostate cancer tissues and cells and developed a second-generation CAR that specifically targets B7-H3 and CD28 as costimulatory receptor to explore its tumoricidal potential against prostate cancer in vitro and in vivo. The high expression of B7-H3 was detected on both the surface of PC3, DU145 and LNCaP cells and prostate cancer tissues. B7-H3 CAR-T cells efficiently controlled the growth of prostate cancer in an antigen-dependent manner in vitro and in vivo. Moreover, tumor cells could induce the proliferation of CAR-T cells and the release of high levels of cytokines of IFN-γ and TNF-α in vitro. Results demonstrated that B7-H3 is a potential target for prostate cancer therapy that supports the clinical development of B7-H3 specific CAR-T cells for prostate cancer.

Purpose: Exosomes participate in cellular communications by transmitting active molecules, including long noncoding RNAs (lncRNAs) and are regarded as suitable candidates for disease diagnosis. This study aimed to identify gastric cancer (GC)-specific exosomal lncRNA and investigate the potential diagnostic value of plasma exosomal lncRNA in GC. Patients and Methods: Exosomes from the culture media (CM) of four GC cells (GCCs) and human gastric epithelial cells were isolated. Exosomal RNA was extracted, and lncRNA microarray assay was performed to identify GC-specific exosomal lncRNAs. The expression levels of the candidate exosomal lncRNAs were validated in 120 subjects via quantitative reverse transcription PCR (qRT-PCR). The receiver operating characteristic (ROC) curve and area under curve were used to estimate the diagnostic capacity. We investigated the potential relationship between plasma exosomal lncRNA expression and the clinicopathological parameters of GC. Results: A total of 199 exosomal lncRNAs were expressed at considerable higher levels in GCCs than those in normal controls, among which the top 10 upregulated lncRNAs were selected for further validation in cell, CM, and plasma. qRT-PCR revealed that lnc-SLC2A12-10:1 was remarkably upregulated in exosomes derived from patients with GC and GCCs. The area under the ROC curve was 0.776, which was higher than the diagnostic accuracies of CEA, CA 19– 9, and CA72– 4. The expression level of exosomal lnc-SLC2A12-10:1 was also significantly correlated with tumor size, TNM stage, lymph node metastasis, and degree of differentiation. The postoperative expression levels of exosomal lnc-SLC2A12-10:1 were lower compared with those of preoperative levels. Conclusion: Our study suggested that exosomal lnc-SLC2A12-10:1 may be a potential noninvasive biomarker for the diagnosis and prognosis monitoring of GC. Further large-scale studies are necessary to validate its performance in GC progression.

The type I cGMP-dependent protein kinase (PKG I) is recognized as a tumor suppressor, but its role in EGFR regulated epithelial ovarian cancer (EOC) progression remains unclear. We evaluated the in vivo and in vitro effects of activated PKG I in EGF-induced EOC cell proliferation, migration, and invasion. The expressions of EGFR and PKG I were elevated, but the activated PKG I was decreased in EOC tissues of patients and cells lines. The addition of 8-Br-cGMP, a specific PKG I activator, attenuated the EGF-induced EOC cell proliferation, migration, and invasion in vitro. Similarly, activated PKG I also attenuated EOC progression in vivo using an EOC xenograft nude mouse model. The activated PKG I interacted with EGFR, causing increased threonine (693) phosphorylation and decreased tyrosine (1068) phosphorylation of EGFR, which resulted in disrupted EGFR-SOS1-Grb2 combination. Subsequently, the cytoplasmic phosphorylation of downstream proteins (c-Raf, MEK1/2, and ERK1/2) were declined, impeding the phosphorylated ERK1/2’s nucleus translocation, and this reduction of phosphorylated tyrosine (1068) EGFR and ERK1/2 were also abolished by Rp-8-Br-cGMPS. Our results suggest that the activation of PKG I attenuates EGF-induced EOC progression, and the 8-Br-cGMP-PKG I-EGFR/MEK/ERK axis might be a potential target for EOC therapy.