Serum-derived piR-hsa-164586 of extracellular vesicles as a novel biomarker for early diagnosis of non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a major cause of death in those with malignant tumors. To achieve the early diagnosis of NSCLC, we investigated serum-derived Piwi-interacting RNA (piRNA) of extracellular vesicles to filter diagnostic biomarkers for NSCLC. High-throughput sequencing from cancerous tissues and adjacent noncancerous tissues in patients with NSCLC was first applied to recognize candidate piRNAs as diagnostic biomarkers. These screened piRNAs were further validated in 115 patients (including 95 cases in stage I) and 47 healthy individuals using quantitative real-time PCR (qRT-PCR). We showed that piR-hsa-164586 was significantly upregulated compared with paracancerous tissues and extracellular vesicles from the serum samples of healthy individuals. Moreover, the area under the curve (AUC) value of piR-hsa-164586 was 0.623 and 0.624 to distinguish patients with all stages or stage I of NSCLC, respectively, from healthy individuals. The diagnostic performance of piR-hsa-164586 was greatly improved compared with the cytokeratin-19-fragment (CYFRA21-1). Additionally, piR-hs-164586 was associated with the clinical characteristics of patients with NSCLC. Its expression was associated with the age and TNM stage of patients with NSCLC, indicating that it can serve as an effective and promising biomarker for the early diagnosis of NSCLC.

Relationship between Patients' Baseline Characteristics and Survival Benefits in Immunotherapy-Treated Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis.

Background: The difference of patients' baseline characteristics such as sex, age, Eastern Cooperative Oncology Group performance status (ECOG PS), and smoking status may influence the immune response. However, little is known about whether these factors affect the efficacy of immune checkpoint inhibitors (ICIs) in patients with advanced non-small-cell lung cancer (NSCLC). Therefore, we performed this systematic review and meta-analysis to investigate the relationship between patients' baseline characteristics and survival benefits in immunotherapy-treated NSCLC. Materials and Methods: We performed a systematic search of PubMed, the Cochrane Library, and Embase for randomized controlled trials (RCTs) of NSCLC immunotherapy. We also searched abstracts and presentations from the proceedings of the American Society of Clinical Oncology and the European Society of Medical Oncology to identify unpublished studies. These studies have available data based on patients' baseline characteristics (such as sex, age, ECOG PS, and smoking status). We take the hazard ratios (HRs) and 95% confidence intervals (CIs) of overall survival (OS) as the effect index and use the random effect model to pool the results. Results: We included 18 phase II/III RCTs with a total of 14,189 participants. The benefits of ICIs were found for both male (pooled OS-HR 0.77, 95% CI 0.72-0.82, P < 0.05) and female patients (pooled OS-HR 0.77, 95% CI 0.67-0.87, P < 0.05); for both younger (<65 y: pooled OS-HR 0.74, 95% CI 0.68-0.81, P < 0.05) and older patients (≥65 y: pooled OS-HR 0.80, 95% CI 0.75-0.86, P < 0.05); and for both patients with ECOG PS = 0 (pooled OS-HR 0.77, 95% CI 0.71-0.84, P < 0.05) and ECOG PS ≥ 1 (pooled OS-HR 0.76, 95% CI 0.70-0.82, P < 0.05). Moreover, there was no significant difference in the efficacy of ICIs among different sex (P value for interaction = 0.955), age (P value for interaction = 0.17), or ECOG PS (P value for interaction = 0.765). However, in patients with different smoking status, the application of ICIs significantly prolonged the OS of smokers (pooled OS-HR 0.77, 95% CI 0.71-0.83, P < 0.05) but could not significantly improve the OS of never smokers (pooled OS-HR 0.85, 95% CI 0.70-1.03, P > 0.05). Conclusions: ICIs could significantly improve prognosis in patients with advanced NSCLC, regardless of sex, age, or ECOG PS. But among patients with different smoking status, the survival benefits of never smokers treated with ICIs were no better than that of controls. The impact of these factors on immunotherapy should be considered in the future clinical practice and guidelines.

piR-hsa-211106 Inhibits the Progression of Lung Adenocarcinoma Through Pyruvate Carboxylase and Enhances Chemotherapy Sensitivity.

Although the importance of PIWI-interacting RNAs (piRNAs) in cancer has recently been recognized, studies on the role and functional mechanism of piRNAs in lung adenocarcinoma (LUAD) development and progression are limited. In this study, we identified 10 differently expressed piRNAs in LUAD tissues compared to normal tissues, among which, piR-hsa-211106 expression levels were downregulated in LUAD tissues and cell lines. Furthermore, the effects of piR-hsa-211106 on the malignant phenotypes and chemosensitivity of LUAD cells were detected by gain- and loss-of-function analyses in vitro and in vivo, which showed that piR-hsa-211106 inhibited LUAD cell proliferation, tumor growth, and migration, but promoted apoptosis. Moreover, our finding indicated that piR-hsa-211106 is a potential therapeutic target that synergistically imparts anticancer effects with a chemotherapeutic agent for LUAD-cisplatin. Further mechanistic investigation indicated that piR-hsa-211106 could bind to pyruvate carboxylase (PC) by RNA pull down and RNA immunoprecipitation assays and inhibited PC mRNA and protein expression. Our study demonstrates that piR-hsa-211106 inhibits LUAD progression by hindering the expression and function of PC and enhances chemotherapy sensitivity, suggesting that piR-hsa-211106 is a novel diagnostic and therapeutic target for LUAD.

Circular RNA circ-PTEN elevates PTEN inhibiting the proliferation of non-small cell lung cancer cells.

Phosphatase and tensin homolog (PTEN) is a well-known tumor suppressor in various cancer types, including non-small cell lung cancer (NSCLC). Circular RNA (circRNA) has recently been proven to be strongly linked with cancer progression. Here, we aimed to investigate the biological relevance and clinical significance of circRNA derived from PTEN in NSCLC. We found that circ-PTEN (hsa_circ_0094342) was significantly decreased in NSCLC tissues and serum, which was attributed to the upregulation of RNA-binding protein DHX9. Low circ-PTEN was linked with malignant clinical features and poor outcome. Exogenous expression of circ-PTEN markedly inhibited NSCLC cell proliferation in vitro as well as retarded tumor growth in vivo. Circ-PTEN increased the expression of its host gene PTEN via acting as a sponge for miR-155 and miR-330-3p, leading to the inactivation of the carcinogenic PI3K/AKT signaling pathway. The xenograft tumor model also indicated the existence of circ-PTEN/miR-155/miR-330-3p/PTEN regulatory axis in vivo. Our data for the first time demonstrate that circ-PTEN functions as a tumor-inhibiting circRNA in NSCLC through post-transcriptionally regulating PTEN, hinting a promising diagnostic/prognostic biomarker as well as therapeutic target for NSCLC patients.

Exosomal circRNAs as novel cancer biomarkers: Challenges and opportunities.

Identifying high specificity and sensitivity biomarkers has always been the focus of research in the field of non-invasive cancer diagnosis. Exosomes are extracellular vesicles with a lipid bilayer membrane that can be released by all types of cells, which contain a variety of proteins, lipids, and a variety of non-coding RNAs. Increasing research has shown that the lipid bilayer can effectively protect the nucleic acid in exosomes. In cancers, tumor cell-derived exosomal circRNAs can act on target cells or organs through the transport of exosomes, and then participate in the regulation of tumor development and metastasis. Since exosomes exist in various body fluids and circRNAs in exosomes exhibit high stability, exosomal circRNAs have the potential as biomarkers for early and minimally invasive cancer diagnosis and prognosis judgment. In this review, we summarized circRNAs and their biological roles in cancers, with the emerging value biomarkers in cancer diagnosis, disease judgment, and prognosis observation. In addition, we briefly compared the advantages of exosomal circRNAs as biomarkers and the current obstacles in the exosome isolation technology, shed light to the future development of this technology.

Tandem stents thrombectomy as a rescue treatment for refractory large vessel occlusions.

BACKGROUND: Mechanical thrombectomy with a stent retriever (SR) and/or aspiration is the 'gold standard' for the treatment of acute ischemic stroke due to large vessel occlusion (LVO). However, sometimes clots may not be retrievable with a single SR alone or combined with aspiration. OBJECTIVE: To assess the safety and efficacy of a novel tandem stents thrombectomy (TST) technique as a rescue treatment for acute LVO that is refractory to conventional attempts. METHODS: All patients treated with the TST technique as rescue treatment after failure of conventional attempts were retrospectively reviewed. The postprocedural angiographic and clinical outcome, including modified Thrombolysis in Cerebral infarction (mTICI) grade, National Institutes of Health Stroke Scale (NIHSS) score, and modified Rankin Scale (mRS) score, was assessed. RESULTS: Nine patients (mean age, 65.2 years; median NIHSS score 18) with middle cerebral artery M1 segment (n=6) and terminal internal carotid artery (n=3) occlusions were included in the study. The TST technique was performed as a rescue treatment after unsuccessful stent thrombectomy alone (four cases) and stent thrombectomy plus aspiration (five cases). Successful recanalization (mTICI 2b/3) was achieved in all patients. No procedure-related complications occurred except reversible vasospasms were observed in three patients and one patient developed hemorrhage transformation after the procedure, but was asymptomatic. Three patients had good clinical outcome (mRS score 0-2 at 90 days). Two patients (22.2%) died. CONCLUSIONS: The TST technique seems to be a safe and effective rescue treatment for acute LVO that is refractory to conventional attempts.

Circular RNA circ-SLC7A6 acts as a tumor suppressor in non-small cell lung cancer through abundantly sponging miR-21.

Circular RNA (circRNA) is currently considered to be a key regulatory molecule in cancer biology. In the present study, we aimed to explore the functional and clinical roles of circ-SLC7A6 (a circRNA derived from SLC7A6 gene) in non-small cell lung cancer (NSCLC). Circ-SLC7A6 was significantly downregulated in NSCLC tissues in comparison to para-carcinoma tissues. Low circ-SLC7A6 was closely associated with larger tumor size, lymph node metastasis, advanced clinical stage and adverse outcome. Exogenous expression of circ-SLC7A6 evidently inhibited the proliferation and invasion of NSCLC cells. Further investigations revealed that miR-21 was the direct functional target of circ-SLC7A6, in which circ-SLC7A6 abundantly sponged miR-21 and elevated a cohort of tumor suppressors, thus inhibiting NSCLC progression. Interestingly, QKI, elevated by circ-SLC7A6, could directly bind to the introns flanking circ-SLC7A6 to facilitate circ-SLC7A6 production. Importantly, in vivo xenograft tumor experiments showed that reintroduction of circ-SLC7A6 retarded tumor growth as well as decreased lung metastatic nodules. Overall, our study demonstrates that circ-SLC7A6 is a novel tumor suppressor in NSCLC, targeting circ-SLC7A6/miR-21 axis may be a promising treatment for NSCLC patients.

Expression and Effects of Long Non-Coding RNA, LINC01124, in Non-Small Cell Lung Cancer.

OBJECTIVE: To investigate the expression and evaluate the clinical significance of long non-coding RNA, LINC01124, in non-small cell lung cancer (NSCLC) and to study its influence in this tumor. METHODS: Hundred specimens of NSCLC tissues and normal lung tissues after surgery were collected. The qRT-PCR for LINC01124 expression was performed on cancerous and normal lung tissues. The correlations between the expression of LINC01124 and pathological characteristics were analyzed. PcDNA-LINC01124 was transfected to upregulate LINC01124 expression in NSCLC cells, and the transfection efficiency was evaluated by the qRT-PCR. CCK8 assay, wound-healing assay, and the Transwell assay were performed to evaluate the effect of ectopic LINC01124 expression on proliferation, migration, and invasive of NSCLC cells. RESULTS: The expression level of LINC01124 was downregulated in tumor tissues when compared with the paired normal lung tissues (P<0.05). The expression of LINC01124 was associated with patients' age and distant metastasis (P<0.05). Enforced expression of LINC01124 significantly inhibited the proliferation, migration, and invasive ability of NSCLC cells. CONCLUSION: The expression of LINC01124 was decreased in patients with NSCLC of older age and with those having distant metastasis. LINC01124 may inhibit cell proliferation, migration, and invasive ability.

RNA sequencing reveals the role of splicing polymorphisms in regulating human gene expression.

Expression levels of many human genes are under the genetic control of expression quantitative trait loci (eQTLs). Despite technological advances, the precise molecular mechanisms underlying most eQTLs remain elusive. Here, we use deep mRNA sequencing of two CEU individuals to investigate those mechanisms, with particular focus on the role of splicing control loci (sQTLs). We identify a large number of genes that are differentially spliced between the two samples and associate many of those differences with nearby single nucleotide polymorphisms (SNPs). Subsequently, we investigate the potential effect of splicing SNPs on eQTL control in general. We find a significant enrichment of alternative splicing (AS) events within a set of highly confident eQTL targets discovered in previous studies, suggesting a role of AS in regulating overall gene expression levels. Next, we demonstrate high correlation between the levels of mature (exonic) and unprocessed (intronic) RNA, implying that ∼75% of eQTL target variance can be explained by control at the level of transcription, but that the remaining 25% may be regulated co- or post-transcriptionally. We focus on eQTL targets with discordant mRNA and pre-mRNA expression patterns and use four examples: USMG5, MMAB, MRPL43, and OAS1, to dissect the exact downstream effects of the associated genetic variants.