Toll-like Receptor Agonist CBLB502 Protects Against Radiation-induced Intestinal Injury in Mice.

BACKGROUND/AIM: The small intestine is one of the organs most vulnerable to ionizing radiation (IR) damage. However, methods to protect against IR-induced intestinal injury are limited. CBLB502, a Toll-like receptor 5 (TLR5) agonist from Salmonella flagellin, exerts radioprotective effects on various tissues and organs. However, the molecular mechanisms by which CBLB502 protects against IR-induced intestinal injury remain unclear. Thus, this study aimed to elucidate the mechanisms underlying IR-induced intestinal injury and the protective effects of CBLB502 against this condition in mice. MATERIALS AND METHODS: Mice were administered 0.2 mg/kg CBLB502 before IR at different doses for different time points, and then the survival rate, body weight, hemogram, and histopathology of the mice were analyzed. RESULTS: CBLB502 reduced IR-induced intestinal injury. RNA-seq analysis revealed that different doses and durations of IR induced different regulatory patterns. CBLB502 protected against intestinal injury mainly after IR by reversing the expression of IR-induced genes and regulating immune processes and metabolic pathways. CONCLUSION: This study preliminarily describes the regulatory mechanism of IR-induced intestinal injury and the potential molecular protective mechanism of CBLB502, providing a basis for identifying the functional genes and molecular mechanisms that mediate protection against IR-induced injury.

Long non­coding RNA lung cancer­associated transcript 1 regulates ferroptosis via microRNA­34a­5p­mediated GTP cyclohydrolase 1 downregulation in lung cancer cells.

Ferroptosis, a recently discovered type of programmed cell death triggered by excessive accumulation of iron­dependent lipid peroxidation, is linked to several malignancies, including non­small cell lung cancer. Long non­coding RNAs (lncRNAs) are involved in ferroptosis; however, data on their role and mechanism in cancer therapy remains limited. Therefore, the aim of the present study was to identify ferroptosis­associated mRNAs and lncRNAs in A549 lung cancer cells treated with RAS­selective lethal 3 (RSL3) and ferrostatin­1 (Fer­1) using RNA sequencing. The results demonstrated that lncRNA lung cancer­associated transcript 1 (LUCAT1) was significantly upregulated in lung adenocarcinoma and lung squamous cell carcinoma tissues. Co­expression analysis of differentially expressed mRNAs and lncRNAs suggested that LUCAT1 has a crucial role in ferroptosis. LUCAT1 expression was markedly elevated in A549 cells treated with RSL3, which was prevented by co­incubation with Fer­1. Functionally, overexpression of LUCAT1 facilitated cell proliferation and reduced the occurrence of ferroptosis induced by RSL3 and Erastin, while inhibition of LUCAT1 expression reduced cell proliferation and increased ferroptosis. Mechanistically, downregulation of LUCAT1 resulted in the downregulation of both GTP cyclohydrolase 1 (GCH1) and ferroptosis suppressor protein 1 (FSP1). Furthermore, inhibition of LUCAT1 expression upregulated microRNA (miR)­34a­5p and then downregulated GCH1. These results indicated that inhibition of LUCAT1 expression promoted ferroptosis by modulating the downregulation of GCH1, mediated by miR­34a­5p. Therefore, the combination of knocking down LUCAT1 expression with ferroptosis inducers may be a promising strategy for lung cancer treatment.

Unraveling the Role of RNase L Knockout in Alleviating Immune Response Activation in Mice Bone Marrow after Irradiation.

Ionizing radiation (IR) induces severe hematopoietic injury by causing DNA and RNA damage as well as activating the immune responses, necessitating the development of effective therapeutic strategies. Ribonuclease L (RNase L) as an innate immune response pathway is triggered by exogenous and endogenous abnormal dsRNA under viral infection and dyshomeostasis, thereby activating the immune responses. Thus, we investigated the effect of RNase L on irradiation-induced bone marrow damage using RNase L knockout (RNase L-/-) mice. Phenotypic analysis revealed that RNase L knockout mitigates irradiation-induced injury in the bone marrow. Further investigation into the mechanism of RNase L by RNA-seq, qRT-PCR, and CBA analysis demonstrated that RNase L deficiency counteracts the upregulation of genes related to immune responses induced by irradiation, including cytokines and interferon-stimulated genes. Moreover, RNase L deficiency inhibits the increased levels of immunoglobulins in serum induced by irradiation. These findings indicate that RNase L plays a role in the immune response induced by irradiation in the bone marrow. This study further enhances our understanding of the biological functions of RNase L in the immune response induced by irradiation and offers a novel approach for managing irradiation-induced bone marrow injury through the regulation of RNase L activation.

Toll-like Receptor Agonist CBLB502 Protects Against Cisplatin-induced Liver and Kidney Damage in Mice.

BACKGROUND/AIM: CBLB502, a Toll-like receptor-5 agonist derived from Salmonella flagellin, exerts protective roles against irradiation and chemical drugs in mammalian tissues and stimulates tissue regeneration. This study aimed to investigate whether CBLB502 can protect against liver and kidney damage induced by the chemotherapeutic drug cisplatin (CDDP) and the underlying mechanism of the protective effect. MATERIALS AND METHODS: Mice were pretreated with CBLB502 [0.2 mg/kg, intraperitoneal (i.p.) injection] 0.5 h prior to administration of CDDP (20 mg/kg, i.p. injection), and analyses of the liver and kidney indices, blood biochemistry, and histopathology were performed. RESULTS: Pretreatment with CBLB502 alleviated CDDP-induced liver and kidney damage. RNA sequencing and bioinformatic analysis indicated that CDDP induced a similar damage-promoting gene regulation pattern in the liver and kidney. CBLB502 protected against liver and kidney damage only after CDDP treatment primarily via different pathways. However, some CBLB502-regulated genes were common between the liver and kidney, including those involved in blood coagulation, fibrinolysis, hemostasis, apoptotic regulation, NF-kappaB signaling, and response to lipopolysaccharide, suggesting a general protective effect by CBLB502. CONCLUSION: Our data provide insights into the protective mechanism of CBLB502 against CDDP-induced tissue damage in the liver and kidney and might provide a basis for future studies on functional genes and regulatory mechanisms that mediate protection against chemoradiotherapy-induced damage.

Hydrogen peroxide and iron ions can modulate lipid peroxidation, apoptosis, and the cell cycle, but do not have a significant effect on DNA double-strand break.

Hydroxyl radical (·OH) generated by the Fenton reaction between transition metal ions and hydrogen peroxide (H2O2) can induce significant cellular damage. However, the specific mechanism of ·OH-induced cell death has not been systematically studied. In this study, we reacted FeSO4 and Fe3O4 magnetic nanoparticles with H2O2 and found that ·OH generated from the intracellular Fenton reaction can lead to significant cell death. The Fenton reaction between Fe2+ with H2O2 resulted in a shift in lipid peroxidation and cell cycle arrest. It is noteworthy that the ·OH generated from the Fenton reaction triggered severe apoptosis but did not lead to DNA double-strand breakage. Our results suggest that the Fenton reaction had acute cytotoxicity, which was primarily due to ·OH produced from the Fenton reaction inducing lipid peroxidation and apoptosis and modulating the cell cycle, but not by inducing DNA damage.

Identification of Combinations of Plasma lncRNAs and mRNAs as Potential Biomarkers for Precursor Lesions and Early Gastric Cancer.

Patients with gastric cancer (GC) are usually first diagnosed at an advanced stage due to the absence of obvious symptoms at an early GC (EGC) stage. Therefore, it is necessary to identify an effective screening method to detect precursor lesions of GC (PLGC) and EGC to increase the 5-year survival rate of patients. Cell-free RNA, as a biomarker, has shown potential in early diagnosis, personalised treatment, and prognosis of cancer. In this study, six RNAs (CEBPA-AS1, INHBA-AS1, AK001058, UCA1, PPBP, and RGS18) were analysed via real-time quantitative polymerase chain reaction (RT-qPCR) using the plasma of patients with EGC and PLGC to identify diagnostic biomarkers. The receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic accuracy. Among the six RNAs, four lncRNAs (CEBPA-AS1, INHBA-AS1, AK001058, and UCA1) were upregulated and two mRNAs (PPBP and RGS18) were downregulated in the plasma of patients with PLGC and EGC. According to the findings of the ROC analysis, the four-RNA combination of INHBA-AS1, AK001058, UCA1, and RGS18 had the highest area under the curve (AUC) value for determining risk of GC in patients with PLGC and the six-RNA combination including CEBPA-AS1, INHBA-AS1, AK001058, UCA1, PPBP, and RGS18 had the highest AUC value for determining the risk of GC in patients with EGC. The results suggest the potential usefulness of noninvasive biomarkers for the molecular diagnosis of GC at earlier stages.

Long non­coding RNA nuclear paraspeckle assembly transcript 1 regulates ionizing radiation­induced pyroptosis via microRNA­448/gasdermin E in colorectal cancer cells.

Pyroptosis is mediated by gasdermins and serves a critical role in ionizing radiation (IR)­induced damage in normal tissues, but its role in cancer radiotherapy and underlying mechanisms remains unclear. Long non­coding (lnc) RNAs serve important roles in regulating the radiosensitivity of cancer cells. The present study aimed to investigate the mechanistic involvement of lncRNAs in IR­induced pyroptosis in human colorectal cancer HCT116 cells. LncRNA, microRNA (miR)­448 and gasdermin E (GSDME) levels were evaluated using reverse transcription­quantitative polymerase chain reaction. Protein expression and activation of gasdermins were measured using western blotting. The binding association between miR­448 and GSDME was assessed using the dual­luciferase reporter assay. Pyroptosis was examined using phase­contrast microscopy, flow cytometry, Cell Counting Kit­8 assay and lactate dehydrogenase release assay. IR dose­dependently induced GSDME­mediated pyroptosis in HCT116 cells. GSDME was identified as a downstream target of miR­448. LncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) was upregulated in response to IR and enhanced GSDME expression by negatively regulating miR­448 expression. Notably, NEAT1 knockdown suppressed IR­induced pyroptosis, full­length GSDME expression and GSDME cleavage compared with that in irradiated cells. In addition, NEAT1 knockdown rescued the IR­induced decrease in cell viability in HCT116 cells. The findings of the present study indicated that lncRNA NEAT1 modulates IR­induced pyroptosis and viability in HCT116 cells via miR­448 by regulating the expression, but not activation of GSDME. The present study provides crucial mechanistic insight into the potential role of lncRNA NEAT1 in IR­induced pyroptosis.

Plasma Proteins As Biodosimetric Markers of Low-Dose Radiation in Mice.

Long-term exposures to low-dose radiation (LDR) may trigger several specific biological responses, including dysregulation of the immune and inflammatory systems. Here, we examined whether biodosimetry of LDR can be used to protect tissues from radiation or assess cancer risk. Mice were subjected to gamma-irradiation with repeated or single-dose LDR, and then the organ indices, peripheral hemogram, and blood biochemistry were analyzed. An antibody array was applied followed by enzyme-linked immunosorbent assay to evaluate the utility of multiple plasma proteins as biomarkers of repeated LDR in a murine model. LDR induced inapparent symptoms but slight variations in peripheral blood cell counts and alterations in blood biochemical indicator levels. Specific plasma proteins in the LDR groups were altered in response to a higher dose of irradiation at the same time points or a single-dose equivalent to the same total dose. Plasma levels of interleukin (IL)-5, IL-12p40, P-selectin, and serum amyloid A1 were associated with the LDR dose and thus may be useful as dosimetric predictors of LDR in mice. Estimating the levels of certain plasma proteins may yield promising biodosimetry parameters to accurately identify individuals exposed to LDR, facilitating risk assessment of long-term LDR exposure in individuals.

Genome-wide analysis of lncRNA stability in human.

Transcript stability is associated with many biological processes, and the factors affecting mRNA stability have been extensively studied. However, little is known about the features related to human long noncoding RNA (lncRNA) stability. By inhibiting transcription and collecting samples in 10 time points, genome-wide RNA-seq studies was performed in human lung adenocarcinoma cells (A549) and RNA half-life datasets were constructed. The following observations were obtained. First, the half-life distributions of both lncRNAs and messanger RNAs (mRNAs) with one exon (lnc-human1 and m-human1) were significantly different from those of both lncRNAs and mRNAs with more than one exon (lnc-human2 and m-human2). Furthermore, some factors such as full-length transcript secondary structures played a contrary role in lnc-human1 and m-human2. Second, through the half-life comparisons of nucleus- and cytoplasm-specific and common lncRNAs and mRNAs, lncRNAs (mRNAs) in the nucleus were found to be less stable than those in the cytoplasm, which was derived from transcripts themselves rather than cellular location. Third, kmers-based protein-RNA or RNA-RNA interactions promoted lncRNA stability from lnc-human1 and decreased mRNA stability from m-human2 with high probability. Finally, through applying deep learning-based regression, a non-linear relationship was found to exist between the half-lives of lncRNAs (mRNAs) and related factors. The present study established lncRNA and mRNA half-life regulation networks in the A549 cell line and shed new light on the degradation behaviors of both lncRNAs and mRNAs.

RNA Profiling Reveals a Common Mechanism of Histone Gene Downregulation and Complementary Effects for Radioprotectants in Response to Ionizing Radiation.

High-dose ionizing radiation (IR) alters the expression levels of non-coding RNAs (ncRNAs). However, the roles of ncRNAs and mRNAs in mediating radiation protection by radioprotectants remain unknown. Microarrays were used to determine microRNA (miRNA), long ncRNA (lncRNA), and mRNA expression profiles in the bone marrow of irradiated mice pretreated with amifostine, CBLB502, and nilestriol. Differentially expressed mRNAs were functionally annotated by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Some histone cluster genes were validated by real-time PCR, and the effects of radioprotectant combinations were monitored by survival analysis. We found that these radioprotectants increased the induction of lncRNAs and mRNAs. miRNA, lncRNA, and mRNA expression patterns were similar with amifostine and CBLB502, but not nilestriol. The radioprotectants exhibited mostly opposite effects against IR-induced miRNAs, lncRNAs, and mRNAs while inducing a common histone gene downregulation following IR, mainly via nucleosome assembly and related signaling pathways. Notably, the effects of nilestriol significantly complemented those of amisfostine or CBLB502; low-dose drug combinations resulted in better radioprotective effects in pretreated mice. Thus, we present histone gene downregulation by radioprotectants, together with the biological functions of miRNA, lncRNA, and mRNA, to explain the mechanism underlying radioprotection.

Plasma Proteins as Biomarkers of Mortality After Total Body Irradiation in Mice.

During large-scale acute radiation exposure, rapidly distinguishing exposed individuals from nonexposed individuals is necessary. Identifying those exposed to high and potentially lethal radiation doses, and in need of immediate treatment, is especially important. To address this and find plasma biomarkers to assess ionizing radiation-induced mortality in the early stages, mice were administered a whole-body lethal dose of γ radiation, and radiation-induced damage was evaluated. Multiple blood biomarkers were screened using an antibody array, followed by validation using enzyme-linked immunoassay. The results revealed that irradiation (IR)-induced mortality in mice and caused body weight and blood platelet losses in deceased mice compared to surviving mice. The levels of certain proteins differed after IR between these 2 groups. Specific proteins in preirradiated mice were also found to potentiate radiosensitivity. Plasma levels of interleukin (IL)-22, urokinase, resistin, and IL-6 were associated with radiation-induced mortality in irradiated mice and may be useful as potential mortality predictors. Our results suggest that estimating the levels of certain plasma proteins is a promising alternative to conventional cytogenetic biodosimetry to accurately identify individuals exposed to high radiation doses and those at risk of death due to exposure. This strategy would facilitate the rapid triage of individuals requiring immediate and intensive medical treatment.

Effect of simulated microgravity and ionizing radiation on expression profiles of miRNA, lncRNA, and mRNA in human lymphoblastoid cells.

In space, multiple unique environmental factors, particularly microgravity and space radiation, pose a constant threat to astronaut health. MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are functional RNAs that play critical roles in regulating multiple cellular processes. To gain insight into the role of non-coding RNAs in response to radiation and microgravity, we analyzed RNA expression profiles in human lymphoblastoid TK6 cells incubated for 24 h under static or rotating conditions to stimulate microgravity in space, after 2-Gy γ-ray irradiation. The expression of 14 lncRNAs and 17 mRNAs (differentially-expressed genes, DEGs) was found to be significantly downregulated under simulated microgravity conditions. In contrast, irradiation upregulated 55 lncRNAs and 56 DEGs, whereas only one lncRNA, but no DEGs, was downregulated. Furthermore, two miRNAs, 70 lncRNAs, and 87 DEGs showed significantly altered expression in response to simulated microgravity after irradiation, and these changes were independently induced by irradiation and simulated microgravity. GO enrichment and KEGG pathway analyses indicated that the associated target genes showed similar patterns to the noncoding RNAs and were suggested to be involved in the immune/inflammatory response including LPS/TLR, TNF, and NF-κB signaling pathways. However, synergistic effects on RNA expression and cellular responses were also observed with a combination of simulated microgravity and irradiation based on microarray and RT-PCR analysis. Together, our results indicate that simulated microgravity and irradiation additively alter expression patterns but synergistically modulate the expression levels of RNAs and their target genes in human lymphoblastoid cells.

RNase L facilitates the repair of DNA double-strand breaks through the nonhomologous end-joining pathway.

RNA molecules have been found to play important roles in DNA double-strand break (DSB) repair, but the exact underlying mechanism remains unclear. Here, we aimed to clarify the function of RNase L, an important ribonuclease in the immune system of vertebrates, in DSB repair. Knockdown of RNase L reduces cell survival after induction of DSBs by ionizing radiation or camptothecin and causes a significant decrease in DSB repair, as evidenced by an increase in the extent of phosphorylation of histone H2AX on Ser139 (γH2AX) and γH2AX nuclear foci formation. Thus, our findings indicate that RNase L interacts with the core factors involved in DNA end joining, such as XRCC4 and Lig4, and facilitates DSB repair through the nonhomologous end-joining pathway.

Identification of plasma RGS18 and PPBP mRNAs as potential biomarkers for gastric cancer using transcriptome arrays.

Coding and noncoding RNAs serve a crucial role in tumorigenesis. Circulating RNAs have been recognized as a novel category of biomarkers for a variety of physiological and pathological conditions. To identify plasma RNA biomarkers for gastric cancer (GC), a genome-wide transcriptome analysis using GeneChip® Human Transcriptome Array, which contains probe sets covering exons of ~67500 coding and noncoding transcripts of annotated genes, was performed to screen for the RNAs that exhibited differential expression in the plasma samples of patients with GC and controls. The expression levels of 6 candidate RNAs, including regulator of G-protein signaling 18 (RGS18), integral membrane protein 2B, pro-platelet basic protein (PPBP), nucleosome assembly protein1-like 1, n324674 and ENST00000442382 were assessed in the plasma samples of 81 patients with GC and 77 healthy participants using reverse transcription-quantitative polymerase chain reaction. Furthermore, the expression levels of RGS18 and PPBP mRNAs were indicated to be significantly differentially expressed (P<0.0001) in an independent panel of plasma samples of 36 patients with GC compared with 34 healthy participants. The potential association of RGS18 and PPBP mRNA expression levels with clinicopathological features was subsequently analyzed. Receiver operating characteristic analysis indicated that the combination of these 2 mRNAs with an area under curve <0.812 was an improved indicator for gastric cancer compared with respective individual levels. The results of the present study indicate that RGS18 and PPBP mRNA expression was significantly downregulated in the plasma of patients with GC, and the combination of these 2 mRNAs may be a useful diagnostic or prognostic marker for GC.

Transcriptional activation of miR-320a by ATF2, ELK1 and YY1 induces cancer cell apoptosis under ionizing radiation conditions.

MicroRNAs (miRNAs or miRs) play important roles in numerous cellular processes, including development, proliferation, tumorigenesis and apoptosis. It has been reported that miRNA expression is induced by ionizing radiation (IR) in cancer cells. However, the underlying molecular mechanisms are not yet fully understood. In this study, endogenous miR­320a and its primary precursor (pri­miR­320a) were assayed by reverse transcription­quantitative PCR (RT­qPCR). Luciferase activities were measured using a dual­luciferase reporter assay system. Western blot analysis was used to determine the protein expressions of upstream and downstream genes of miR­320a. Cell apoptosis was evaluated by Annexin V apoptosis assay and cell proliferation was measured using the trypan blue exclusion method. The results revealed that miR­320a expression increased linearly with the IR dose and treatment duration. Three transcription factors, activating transcription factor 2 (ATF2), ETS transcription factor (ELK1) and YY1 transcription factor (YY1), were activated by p38 mitogen­activated protein kinase (MAPK) and mitogen­activated protein kinase 8 (JNK) and by upregulated miR­320a expression under IR conditions. In addition, it was identified that X­linked inhibitor of apoptosis (XIAP) was an miR­320a target gene during the IR response. By targeting XIAP, miR­320a induced apoptosis and inhibited the proliferation of the cancer cells. On the whole, the results of this study demonstrated that miRNA­320a, regulated by the p38 MAPK/JNK pathway, enhanced the radiosensitivity of cancer cells by inhibiting XIAP and this may thus prove to be a potential therapeutic approach with which to overcome radioresistance in cancer treatment.

SERS detection of radiation injury biomarkers in mouse serum.

In a large-scale radiological catastrophe, it is expected that hundreds and thousands of people could be exposed to radiation. A rapid method is required for triage of casualties to determine proper medical treatment. In this article, mice were exposed to different radiation doses and sera of mice were investigated by surface-enhanced Raman spectroscopy (SERS) and orthogonal projections to latent structure discriminant analysis (OPLS-DA) after total body irradiation (TBI). The results of the present study indicated that differences have widened over time. The different radiation groups showed a slight overlap at 24 h and 72 h but were completely distinct at the 10th day after TBI. The SERS spectrum between the normal group and the irradiated group showed a significant difference at 24 hours. The same trend was depicted in scatting score plots. Significant differences in Raman peaks were found, such as 744 and 1495 cm-1 corresponding to riboflavin and 593 and 1204 cm-1 corresponding to l-tryptophan. The lack of riboflavin and l-tryptophan will influence metabolism levels. Above all, these results bear potential in the development of label-free and rapid tools for on-site detection and screening of irradiation injuries.

Detecting RNA-RNA interactions in E. coli using a modified CLASH method.

BACKGROUND: Bacterial small regulatory RNAs (sRNAs) play important roles in sensing environment changes through sRNA-target mRNA interactions. However, the current strategy for detecting sRNA-mRNA interactions usually combines bioinformatics prediction and experimental verification, which is hampered by low prediction accuracy and low-throughput. Additionally, among the 4736 sequenced bacterial genomes, only about 2164 sRNAs from 319 strains have been described. Furthermore, target mRNAs of only 157 sRNAs have been uncovered. Obviously, highly efficient methods were required to detect sRNA-mRNA interactions in the sequenced genomes. This study aimed to apply a modified CLASH (cross-linking, ligation and sequencing hybrids) method to detect RNA-RNA interactions in E. coli, a model bacterial organism. RESULTS: Statistically significant interactions were detected in 29 transcript pairs. To the best of our knowledge, 24 pairs were reported for the first time and were novel RNA interactions, including tRNA-tRNA, tRNA-ncRNA (non-coding RNA), tRNA-rRNA, rRNA-mRNA, rRNA-ncRNA, rRNA-rRNA, rRNA-IGT (intergenic transcript), and tRNA-IGT interactions. CONCLUSIONS: Discovery of novel RNA-RNA interactions in the present study demonstrates that RNA-RNA interactions might be far more complicated than ever expected. New methods may be required to help discover more novel RNA-RNA interactions. The present work describes a high-throughput protocol not only for discovering new RNA interactions, but also directly obtaining base-pairing sequences, which should be useful in assessing RNA structure and interactions.

Circulating plasma microRNAs as potential markers to identify EGFR mutation status and to monitor epidermal growth factor receptor-tyrosine kinase inhibitor treatment in patients with advanced non-small cell lung cancer.

We aimed to identify a panel of circulating plasma microRNAs that can predict EGFR mutation status and monitor epidermal growth factor receptor-tyrosine kinase inhibitor treatment in patients with non-small cell lung cancer. Microarrays were performed for the preliminary screening of dysregulated microRNAs in 9 EGFR mutation-positive patients versus healthy controls. MiR-107 was upregulated and miR-195 was downregulated in the exon 19 deletion versus wild-type group. The areas under the receiver operating characteristic curves for miR-107, miR-195, and a panel of these 2 microRNAs were 0.72, 0.75, and 0.74, with sensitivities and specificities of 64.7% and 76.6%, 71.8% and 69.1%, and 71.7% and 78.9%, respectively. MiR-122 was significantly upregulated in the p.L858R versus wild-type group. An area under the receiver operative characteristic curve of 0.75 suggests that miR-122 might be a specific biomarker for patients with the p.L858R mutation. In addition, dynamic changes in these 3 microRNAs were also found to correlate with responses to epidermal growth factor receptor-tyrosine kinase inhibitor treatment, indicating that circulating plasma microRNAs may represent potential biomarkers for monitoring epidermal growth factor receptor-tyrosine kinase inhibitor treatment. This study demonstrates the prospective application of circulating plasma microRNAs as potential non-invasive, convenient biomarkers for patients with EGFR-sensitive mutations.

Circulating microRNAs as novel biomarkers of ALK-positive nonsmall cell lung cancer and predictors of response to crizotinib therapy.

Circulating microRNAs are potential diagnostic and predictive biomarkers, but have not been investigated for patients with anaplastic lymphoma kinase (ALK)-positive lung cancer. In this exploratory study, we sought to identify potential plasma biomarkers for ALK-positive non-small cell lung cancer (NSCLC). A microRNA microarray was used to select ALK-related microRNAs in ALK-positive NSCLC (n = 3), ALK-negative NSCLC (n = 3), and healthy subjects (n = 3). Plasma levels of 21 microRNAs were differentially expressed for ALK-positive and ALK-negative NSCLC, including 14 down-regulated and 7 up-regulated microRNAs. We also identified 5s rRNA as the most stable endogenous control gene using geNorm and NormFinder algorithms. Candidate microRNAs in plasma from ALK-positive (n = 41) and ALK-negative NSCLC patients (n = 32) were quantified using real-time reverse transcriptase quantitative polymerase chain reaction. The expression levels of miR-28-5p, miR-362-5p, and miR-660-5p were all down-regulated in ALK-positive NSCLC, compared with ALK-negative NSCLC. The areas under the receiver operating characteristic curves of miR-28-5p, miR-362-5p, miR-660-5p, and 3-microRNAs panel were 0.873, 0.673, 0.760, and 0.876, respectively. The positive predictive values of miR-28-5p, miR-362-5p, and miR-660-5p were 96.43%, 80.77%, and 83.87%, respectively. Increased plasma levels of miR-660-5p after crizotinib treatment predicted good tumor response (p = 0.012). The pre-crizotinib levels of miR-362-5p were significantly associated with progression-free survival (p = 0.015). Thus, in this preliminary investigation, we identified a potential panel of 3 microRNAs for distinguishing between patients with ALK-positive and ALK-negative NSCLC. We also identified miR-660-5p and miR-362-5p as potential predictors for response to crizotinib treatment.

A long non-coding RNA lncRNA-PE promotes invasion and epithelial-mesenchymal transition in hepatocellular carcinoma through the miR-200a/b-ZEB1 pathway.

Long non-coding RNAs have been revealed to play important roles in the progression of hepatocellular carcinoma. However, the detailed mechanisms underlying their activities are not fully understood. Using microarray technology, a number of long non-coding RNAs were previously identified to be aberrantly expressed in hepatocellular carcinoma. In this study, one of these long non-coding RNAs, designated lncRNA-PE (lncRNA promotes epithelial-mesenchymal transition), was further explored to study its expression profile and function. A cohort of human hepatocellular carcinoma tissue samples combined with benign controls and established human hepatocellular carcinoma cell lines were examined for the expression of lncRNA-PE. The biological functions of lncRNA-PE were examined by wound-healing and Transwell assays, which revealed that lncRNA-PE promotes cell invasion and migration. By detecting the level of epithelial-mesenchymal transition markers, lncRNA-PE was revealed to promote epithelial-mesenchymal transition in hepatocellular carcinoma cells. Further study suggested that lncRNA-PE downregulated miR-200a/b by repressing the primary transcript expression, enhanced ZEB1 expression, and promoted epithelial-mesenchymal transition of hepatocellular carcinoma cells. All these data imply that lncRNA-PE might play an important role in hepatocellular carcinoma development via the miR-200a/b-ZEB1 pathway.