Zinc finger protein ZBTB17 controls cellular senescence via interacting with nuclear receptor RXRA and its downstream calcium signaling.

Cellular senescence is broadly known as a stable cell cycle arrest accompanied by a senescence-associated secretory phenotype (SASP). In the past decades, calcium signaling has emerged as a key mediator of cellular senescence. However, the transcriptional regulation of calcium signaling during cellular senescence remains partially understood. We have previously identified the nuclear receptor RXRA as a key senescence repressor through inhibiting the endoplasmic reticulum (ER) calcium release channel inositol 1,4,5-trisphosphate receptor, type 2 (ITPR2) mediated intracellular calcium signaling. Nevertheless, as a transcriptional recruiter, the mechanism by which RXRA inhibits ITPR2 during cellular senescence remains unclear. Here we identified the zinc finger protein ZBTB17 can interact with RXRA. Interestingly, knockdown of ZBTB17 induces a cascade of RXRA-dependent intracellular calcium signaling, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) accumulation, DNA damages, and ultimately cellular senescence. Moreover, the signaling and senescence phenotype induced by knocking down of ZBTB17 can also be abolished after silencing ITPR2. Altogether, our work provides a new mechanism controlling intracellular calcium signaling and cellular senescence and unveils novel insight toward the role of zinc finger proteins.

Sublobar resection versus lobectomy in the treatment of synchronous multiple primary lung cancer.

OBJECTIVE: Although synchronous multiple primary lung cancers (sMPLCs) are common in clinical practice, the choice of surgical modalities for the main lesion is still at the stage of exploration. This study is designed to analyze the prognosis of sMPLCs and single primary lung cancers with similar tumor stages and to explore whether sublobar resection has a similar prognosis as lobectomy for sMPLCs. METHODS: One-hundred forty-one cases of sMPLCs were selected, including the following: 65 cases underwent lobectomy for main lesions, and 76 cases underwent sublobar resection for main lesions. One thousand one hundred forty-four cases of single primary lung cancer were matched at 1:1 by propensity score matching. Then, the patients with sMPLCs were divided into a lobectomy group and a sublobar group according to the first tumor stage. Ninety-eight cases of patients with sMPLCs were matched. The short-term perioperative effect, 5-year disease-free survival (DFS) rate, and 5-year overall survival (OS) rate between the two groups were compared. RESULTS: There was no significant difference in OS between sMPLCs and single primary lung cancer after lobectomy (77.1% vs. 77.2%, P = 0.157) and sublobar resection (98.7% vs. 90.7%, P = 0.309). There was no significant difference in OS (86.7% vs. 83.9%, P = 0.482) or DFS (67.6 vs. 87.7%, P = 0.324) between the lobectomy group and sublobar group with sMPLCs. The sublobar resection group obtained a lower incidence of postoperative complications (40.8% vs. 16.3%, P = 0.007) and shorter postoperative hospital stay (11.22 vs. 9.27, P = 0.049). CONCLUSION: The prognosis of patients with sMPLCs generally depends on the main tumor state, which has no statistical difference regardless of sublobar resection or lobectomy, and the perioperative period of sublobar resection is safer than that of lobectomy.

Low expression of PCK2 in breast tumors contributes to better prognosis by inducing senescence of cancer cells.

Cell cycle arrest, one of the main characteristics of cellular senescence, has been described as a crucial barrier that needs to be bypassed for cancer progression. Typically, cellular senescence can be induced by multiple stresses including telomere shortening, oncogenic activation as well as therapy treatment, and contributes to the inhibition of epithelial-mesenchymal transition (EMT), tumor suppression or progression depending on the senescence-associated secretory phenotype (SASP) components. However, the mechanisms underlying cancer cell senescence remain partially understood. Here, according to METABRIC database, we identified that patients with senescent-like breast tumors show better short-term survival, lower tendency of neoplasm histological grades, lower tumor stages, and negative status of estrogen receptor (ER) and progesterone receptor (PR) compared with non-senescent ones. Interestingly, Kyoto encyclopedia of genes and genomes (KEGG) analysis identified insulin signaling was significantly repressed in senescent breast tumors. Further verification in cultured breast cancer cells indicated that phosphoenolpyruvate carboxykinase 2 (PCK2) was significantly inhibited after therapy treatment. In addition, knockdown of PCK2 induced a senescent phenotype of breast cancer cells. Moreover, comparing with the non-senescent group, the senescent breast cancers displayed lower EMT capacity both in patients and breast cancer cell lines after knocking down PCK2. In conclusion, we described for the first time that low expression level of PCK2 may contribute to better prognosis via triggering senescent phenotype and thereby inhibiting EMT capacity in breast cancers.

IL-1 signaling pathway molecules as key markers in childhood asthma.

OBJECTIVE: The prevalence of childhood asthma has been increasing in recent years. This study aims to investigate the involvement of the key molecules of IL-1 (interleukin-1) signaling pathways in pediatric patients with asthma. METHODS: Differentially expressed genes (DEGs) associated with IL-1 signaling pathways were identified with RNA-seq from peripheral blood samples collected from asthmatic or healthy children and were further verified in clinical peripheral blood samples. Cellular models and asthmatic mice were subsequently developed to validate the identified asthmatic markers. RESULTS: Among the DEGs identified by RNA-seq, eight signal transducers associated with the IL-1 signaling network, namely IL-1RN, IL-1ß, IL-1RAP, IRAK3, IL-1R1, MYD88, IRAK2, and PELI1, were found to be substantially upregulated in children with asthma. Interestingly, a significant serially increased expression of four genes (IL-1RN, IL-1RAP, IRAK3, and PELI1) was observed in healthy subjects, patients with chronic persistent asthma and patients with acute exacerbation asthma. In particular, these four genes were continuously overexpressed in recurrent patients. A significant induction of the above four genes was then observed in house dust mite (HDM)-stimulated peripheral blood mononuclear cells (PBMCs) and ovalbumin (OVA)-induced asthmatic mice. In addition, a time-dependent induction of IL-1RAP and PELI1 was also detected in HDM-treated THP-1 cells, an acute monocytic leukemia cell line. CONCLUSIONS: These results demonstrate that IL-1RN, IL-1RAP, IRAK3, and PELI1, which are signal transducers of the IL-1 signaling pathway, could serve as biomarkers for the pathogenesis of childhood asthma and for potential therapeutic targets of asthma.

DLC1 inhibits lung adenocarcinoma cell proliferation, migration and invasion via regulating MAPK signaling pathway.

Lung adenocarcinoma (LUAD), one of the most common cancers, is a major threat to people's health due to its high mortality, and the survival of most patients suffering LUAD remains poor. This study aimed to explore the mechanism of Deleted in Liver Cancer 1 (DLC1) as a tumor suppressor underlying the occurrence and progression of LUAD. As revealed by bioinformatics analysis and qRT-PCR, DLC1 was significantly down-regulated in LUAD tumor tissue and cells. A series of cellular experiments including CCK-8, wound healing and Transwell assays were performed to detect the effect of DLC1 on the biological function of LUAD cells. It was found that overexpressing DLC1 significantly inhibited LUAD cell proliferative, migratory and invasive abilities, while knockdown of DLC1 promoted these abilities. Gene Set Enrichment Analysis (GSEA) and dual-luciferase assay were used to explore the downstream signaling pathway of DLC1, finding that DLC1 could remarkably inhibit the activity of mitogen-activated protein kinase (MAPK) signaling pathway. Western blot implemented for MAPK signaling pathway-related proteins further identified that DLC1 restrained the activation of MAPK/ERK signaling pathway. Furthermore, rescue experiments suggested that DLC1 inhibited LUAD cell proliferation and invasion by suppressing the MAPK/ERK signaling pathway. Overall, our study discussed the DLC1-dependent mechanism involved in LUAD. We found that the up-regulation of DLC1 may inhibit the malignant progression of LUAD by suppressing MAPK signaling pathway, which supports the view that DLC1 may serve as a molecular target for the targeted therapy of LUAD patients.

Development of a sensitive and specific nanoparticle-assisted PCR assay for detecting HPV-16 and HPV-18 DNA.

Carcinoma precursor lesion caused by persistent infection of human papillomavirus (HPV) types 16 and 18 is known as a principal inducer of cervical cancer. Therefore, rapid and effective detection of HPV-16 and HPV-18 infection at early stage is an important strategy for preventing such disease. In this study, a novel duplex nanoparticle-assisted polymerase chain reaction (nanoPCR) assay was developed to detect both of the two genotypes simultaneously. Two pairs of primers for nanoPCR were designed based on the conserved region within the early 6 (E6) gene of HPV-16 and HPV-18, respectively. After optimizing reaction conditions, the nanoPCR assay displayed 10-fold more sensitive than that of conventional PCR and showed high specificity. The detection limit of nanoPCR was 1.7 × 101 copies/µL for HPV-16, 1.2 × 102 copies/µL for HPV-18, and no cross-reaction was detected after using other viruses or HPV subtypes as templates. Of 209 clinical samples collected from patients, as also confirmed by sequencing, the nanoPCR method gave consistent results with conventional PCR assay: 7 positives for HPV-16, 4 positives for HPV-18, and no co-infection. Here is the first report to introduce a reproducible nanoPCR assay for detecting HPV DNA with high sensitivity and specificity, which may point out a useful diagnostic tool for potential clinical application.

Comparison of immune responses induced by porcine parvovirus virus-like particles and inactivated vaccine.

Laboratory-prepared inactivated porcine parvovirus (PPV) vaccines and VP2 virus-like particles (VLPs) were utilized to immunize gilts. PPV BQ strain and SP2/0 cells were used. Hemagglutination-inhibiting (HI) antibody titers were measured in the immunized gilts and the differences in cytokine production of interferon gamma (IFN-γ, IL-2 and IL-4) were compared. CD4+ and CD8+ T cells proliferation were compared by flow cytometry. The variation between the immune response level induced by inactivated PPV vaccine and VP2 VLPs were determined. The results showed that all vaccinated gilts had HI antibody titers reaching 1:256 for at least one month post immunization and the peak level of antibody could be sustained for one month; further, PPV antibodies could be detected in the second week post immunization with VP2 VLPs. We also found that the level of cytokines (IFN-γ, IL-2 and IL-4) were all increased post immunization and continued to rise after the booster immunization; the level of increase in IFN-γ and IL-2 were significantly higher than IL-4. The flow cytometry results showed that the numbers of the CD4+ and CD8+ T cells subsets were significantly higher in the groups immunized with inactivated PPV vaccine or VP2 VLPs than those of negative control group (p<0.01); additionally, the number of CD4+ cells in the gilts that received VP2 VLP immunization was significantly higher than the inactivated vaccine group (p<0.01). In summary, the inactivated PPV vaccine and PPV VP2 VLPs were both able to induce humoral and cellular immunity, but the VP2 VLPs lead to better cellular immune responses in gilts compared to those of the inactivated vaccine..

Point-of-care multiplexed assays of nucleic acids using microcapillary-based loop-mediated isothermal amplification.

This report demonstrates a straightforward, robust, multiplexed and point-of-care microcapillary-based loop-mediated isothermal amplification (cLAMP) for assaying nucleic acids. This assay integrates capillaries (glass or plastic) to introduce and house sample/reagents, segments of water droplets to prevent contamination, pocket warmers to provide heat, and a hand-held flashlight for a visual readout of the fluorescent signal. The cLAMP system allows the simultaneous detection of two RNA targets of human immunodeficiency virus (HIV) from multiple plasma samples, and achieves a high sensitivity of two copies of standard plasmid. As few nucleic acid detection methods can be wholly independent of external power supply and equipment, our cLAMP holds great promise for point-of-care applications in resource-poor settings.

Calcium transferring from ER to mitochondria via miR-129/ITPR2 axis controls cellular senescence in vitro and in vivo.

Senescent cells are known to be accumulated in aged organisms. Although the two main characteristics, cell cycle arrest (for dividing cells) and secretion of senescence-associated secretory phenotype (SASP) factors, have been well described, the lack of sufficient senescent markers and incomplete understanding of mechanisms have limited the progress of the anti-senescence field. Calcium transferred from the endoplasmic reticulum (ER) via inositol 1, 4, 5-trisphosphate receptor type 2 (ITPR2) to mitochondria has emerged as a key player during cellular senescence and aging. However, the internal regulatory mechanisms, particularly those of endogenous molecules, remain only partially understood. Here we identified miRNA-129 (miR-129) as a direct repressor of ITPR2. Interestingly, miR-129 controlled a cascade of intracellular calcium signaling, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), DNA damage, and consequently cellular senescence through ITPR2 and mitochondrial calcium uniporter (MCU). In addition, miR-129 was repressed in different senescence models and delayed bleomycin-induced cellular senescence. Importantly, intraperitoneal injection of miR-129 partly postponed bleomycin-accelerated lung aging and natural aging markers as well as reduced immunosenescence markers in mice. Altogether, these findings demonstrated that miR-129 regulated cellular senescence and aging markers via intracellular calcium signaling by directly targeting ITPR2.

Identification of novel key markers that are induced during traumatic brain injury in mice.

Background: Traumatic brain injury (TBI) has emerged as an increasing public health problem but has not been well studied, particularly the mechanisms of brain cellular behaviors during TBI. Methods: In this study, we established an ischemia/reperfusion (I/R) brain injury mice model using transient middle cerebral artery occlusion (tMCAO) strategy. After then, RNA-sequencing of frontal lobes was performed to screen key inducers during TBI. To further verify the selected genes, we collected peripheral blood mononuclear cells (PBMCs) from TBI patients within 24 h who attended intensive care unit (ICU) in the Affiliated Hospital of Yangzhou University and analyzed the genes expression using RT-qPCR. Finally, the receiver operator characteristic (ROC) curves and co-expression with cellular senescence markers were applied to evaluate the predictive value of the genes. Results: A total of six genes were screened out from the RNA-sequencing based on their novelty in TBI and implications in apoptosis and cellular senescence signaling. RT-qPCR analysis of PBMCs from patients showed the six genes were all up-regulated during TBI after comparing with healthy volunteers who attended the hospital for physical examination. The area under ROC (AUC) curves were all >0.7, and the co-expression scores of the six genes with senescence markers were all significantly positive. We thus identified TGM1, TGM2, ATF3, RCN3, ORAI1 and ITPR3 as novel key markers that are induced during TBI, and these markers may also serve as potential predictors for the progression of TBI.

Endogenous hsa-circ_0007113 binds hsa-miR-515-5p to regulate senescence in human embryonic lung fibroblasts.

BACKGROUND: Cellular senescence can lead to many diseases. However, the roles and regulation of circular RNAs (circRNAs) in senescence are poorly understood. OBJECTIVES: To investigate the altered expression pattern and mechanism of circRNA during cellular senescence and find potential targets to prevent senescence. MATERIAL AND METHODS: The Arraystar Human circRNA Array and bioinformatics were used to profile the differentially expressed circRNAs in human embryonic lung fibroblasts (IMR-90) between young cells and senescent cells and quantification in the clinical materials. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. The miRNA targets were predicted using TargetScan and miRanda. RESULTS: A total of 113 differentially expressed circRNAs were identified, including 109 upregulated and 4 downregulated circRNAs (fold change >2 and p-value <0.05). Real-time qualitative polymerase chain reaction (qPCR) showed that the expression levels of 4 circRNA were significantly increased in senescent cells, and that of hsa_circ_0007113 was significantly decreased, consistent with the microarray. siRNA against hsa_circ_0007113 increased p21 and p53 expression levels and ß-gal staining. The hsa_circ_0007113 has a binding site for miR-515-5p, which is involved in regulating the p53/p21 signaling pathway. The expression level of hsa_circ_0007113 was also decreased in aged people. CONCLUSIONS: The study showed an altered circRNA expression pattern in cellular senescence, which might play important roles in senescence-related physiological processes. These findings provide a new direction for studying the molecular mechanism underlying senescence and a new possibility for the treatment of senescence by modulating circRNAs.

Deubiquitinase JOSD1 promotes tumor progression via stabilizing Snail in lung adenocarcinoma.

Accumulating evidence suggests that the deubiquitinase JOSD1 accounts for aggressiveness and unfavorable prognosis in multiple human cancers. But, the significance of JOSD1 in lung adenocarcinoma (LUAD) is elusive. We established that JOSD1 was aberrantly overexpressed in LUAD tissues, relative to normal tissues. Elevated JOSD1 levels in LUAD tissues positively related to advanced clinicopathological characteristics and poor overall survival (OS) in LUAD patients. Furthermore, we found that JOSD1 knockdown suppressed tumor cell proliferation and metastasis, whereas overexpression of JOSD1 led to opposite phenotypes. Mechanistically, JOSD1 stabilized Snail protein through deubiquitination, which promotes the epithelial-to-mesenchymal transition (EMT) process. Indeed, JOSD1 promoted tumor cell invasion as well as metastasis on the dependence of Snail. The protein expression analysis of LUAD tissues indicated that JOSD1 positively correlated with Snail. Moreover, JOSD1 and Snail co-overexpression had the worst prognosis in LUAD patients. Overall, these results demonstrated that JOSD1 was significantly overexpressed in LUAD and stabilized Snail via deubiquitination to promote LUAD metastasis.

UBE2L3 promotes lung adenocarcinoma invasion and metastasis through the GSK-3ß/Snail signaling pathway.

Lung cancer is the leading cause of cancer-related mortality, and the deaths are mostly attributed to distant metastasis. Previous studies have demonstrated that ubiquitin-conjugating enzyme E2 L3 (UBE2L3) mediates the progression of many human cancers. However, the roles and molecular mechanisms of UBE2L3 in invasion and metastasis of lung adenocarcinoma (LUAD) are yet to be fully understood. Here, we studied the expression pattern of UBE2L3 and demonstrated that it is dramatically up-regulated in LUAD tissues compared with the normal tissues, and its overexpression is positively correlated with lymph node metastasis. Moreover, the upregulation of UBEE2L3 in LUAD tissues is associated with shorter overall survival (OS). UBE2L3 silencing impairs the metastatic capacity of LUAD cells in vitro and in vivo, while its overexpression confers an opposite effect. In addition, our data showed that UBE2L3 promotes cancer cells epithelial-mesenchymal transition (EMT) and metastasis via the glycogen synthase kinase 3ß (GSK-3ß)/Snail axis. Besides, UBE2L3 was shown to promote ubiquitination and degradation of the GSK-3ß. Immunohistochemical analysis demonstrated that UBE2L3 expression is positively correlated with Snail, but negatively correlated with GSK-3ß and E-cadherin in LUAD tissues. Taken together, our findings demonstrated that UBE2L3 modulates metastasis of LUAD cells.

NF-κB-dependent secretome of senescent cells can trigger neuroendocrine transdifferentiation of breast cancer cells.

Cellular senescence is characterized by a stable proliferation arrest in response to stresses and the acquisition of a senescence-associated secretory phenotype, called SASP, composed of numerous factors including pro-inflammatory molecules, proteases, and growth factors. The SASP affects the environment of senescent cells, especially during aging, by inducing and modulating various phenotypes such as paracrine senescence, immune cell activity, and extracellular matrix deposition and organization, which critically impact various pathophysiological situations, including fibrosis and cancer. Here, we uncover a novel paracrine effect of the SASP: the neuroendocrine transdifferentiation (NED) of some epithelial cancer cells, evidenced both in the breast and prostate. Mechanistically, this effect is mediated by NF-κB-dependent SASP factors, and leads to an increase in intracellular Ca2+ levels. Consistently, buffering Ca2+ by overexpressing the CALB1 buffering protein partly reverts SASP-induced NED, suggesting that the SASP promotes NED through a SASP-induced Ca2+ signaling. Human breast cancer dataset analyses support that NED occurs mainly in p53 WT tumors and in older patients, in line with a role of senescent cells and its secretome, as they are increasing during aging. In conclusion, our work, uncovering SASP-induced NED in some cancer cells, paves the way for future studies aiming at better understanding the functional link between senescent cell accumulation during aging, NED and clinical patient outcome.

Baseline Serum Estradiol Level Is Associated with Acute Kidney Injury in Patients with Moderately Severe and Severe Acute Pancreatitis.

Background: Sexual dimorphism with critical diseases has been documented. However, the role of serum sex hormones for the presence of acute kidney injury (AKI) in moderately or severe acute pancreatitis (MSAP and SAP) patients remains controversial. Here we set out to evaluate whether early (first 48 h) serum estradiol level is associated with AKI in patients with MSAP and SAP. Patients and Methods. We retrospectively collected data from patients with preliminary diagnosis of MSAP and SAP from the Affiliated Hospital of Yangzhou University between January 2014 and June 2018. Serum sex hormones were extracted for further assessment within first 48 h following admission. Logistic regression analysis and the receiving operating characteristic (ROC) curve were applied to evaluate the association and correlation between serum sex hormones and AKI. Results: Data from a total of 122 patients with MSAP or SAP were enrolled in this study. There were no differences in the incidence of AKI between males and females. However, comparing with patients without AKI, those with AKI saw higher estradiol level (p ≤ 0.01) and slight higher progesterone level (p = 0.014) but similar testosterone level (p = 0.668). Interestingly, during both the manual selection and the stepwise backward logistic regression analysis, serum estradiol level was independently associated with AKI in patients with MSAP and SAP (OR 4.699, CI 1.783-12.386, and p = 0.002). Additionally, area under the curve of ROC (AUCROC) showed that serum estradiol level was a proper predictor for AKI (area under the curve 0.875). Specifically, the serum estradiol level of 223.15 pg/mL demonstrated a 92.3% sensitive and a 79.3% specificity in predicting AKI of MSAP and SAP patients, respectively. Conclusions: High baseline serum estradiol level appears to be an independent risk factor for AKI in patients with MSAP and SAP. It also tends to be an appropriate indicator for AKI.

Implication of cellular senescence in the progression of chronic kidney disease and the treatment potencies.

Chronic kidney disease (CKD) is an increasing major public health problem worldwide. And CKD shares numerous phenotypic similarities with kidney as well as systemic ageing. Cellular senescence is mainly characterized by a stable cell cycle arrest, senescence-associated secretory phenotype (SASP) and senescent cell anti-apoptotic pathways (SCAPs). Herein, the regulations and the internal mechanisms of cellular senescence will be discussed. Meanwhile, efforts are made to give a comprehensive overview of the recent advances of the implication of cellular senescence in CKD. To date, numerous studies have focused on the effects of ageing risk factors in kidney and thereby trying to interrupt the kidney ageing processes with senolytics. Interestingly, some of them showed enormous clinical application potentials. Therefore, senotherapeutics can be applied as novel potential strategies for the treatment of CKD.

MIR-301b-3p Promotes Lung Adenocarcinoma Cell Proliferation, Migration and Invasion by Targeting DLC1.

BACKGROUND: miR-301b-3p is reported in various human cancers for its abnormal expression, while the role and molecular mechanisms in lung adenocarcinoma (LUAD) remain unclear, and this is the focus of the present study. MATERIALS AND METHODS: TCGA database was consulted to know gene expression in LUAD tissue. CCK-8, colony formation assay and Transwell assay were applied to identify the role of target genes in regulating LUAD cell biological properties. Bioinformatics analysis plus dual-luciferase assay were performed to validate the potential connection between genes. RESULTS: miR-301b-3p and DLC1 were the target genes of this study and respectively differentially up-regulated and down-regulated in LUAD. Functional experiments indicated that miR-301b-3p contributed to cancer cell proliferation, migration and invasion, while this effect was reversed with overexpressed DLC1 which was identified as a direct target of and regulated by miR-301b-3p. CONCLUSIONS: Collectively, miR-301b-3p was identified to actively function on LUAD malignant progression by suppressing DLC1 expression. This discovery provides a novel therapeutic strategy for LUAD patients, which helps improve the survival of patients.

Regulation of cellular senescence by microRNAs.

Cellular senescence is mainly characterized as a stable proliferation arrest and a senescence associated secretory phenotype (SASP). Senescence is triggered by diverse stimuli such as telomere shortening, oxidative stress, oncogene activation and DNA damage, and consequently contributes to multiple physiology and pathology outcomes, including embryonic development, wound healing and tumor suppression as well as aging or age-associated diseases. Interestingly, therapeutic clearance of senescent cells in tissues has recently been demonstrated to be beneficial for extending a healthy lifespan and for improving numerous age-related disorders. However the molecular mechanisms of senescence regulation remain partially understood. Theoretically, senescence is tightly regulated by a vast number of molecules, among which the p16 and p53 pathways are the most classical. In addition, intracellular cellular calcium signaling has emerged as a key regulator of senescence. In the last few decades, a growing number of studies have demonstrated that microRNAs (miRNAs, small non-coding RNAs) are strongly implicated in controlling senescence, especially at the transcriptional and post-transcriptional levels. In this review we will discuss the involvement of miRNAs in modulating senescence through the major p16, p53, SASP and calcium signaling pathways, thus aiming to reveal the mechanisms of how miRNAs regulate cellular senescence.

POLR1B is upregulated and promotes cell proliferation in non-small cell lung cancer.

The aim of the present study was to investigate the functions of RNA polymerase I subunit B (POLR1B) in lung cancer. Reverse transcription-quantitative PCR was used to measure the mRNA expression level of POLR1B in human lung cancer cell lines including A549, NCI-H1299, NCI-H1975 and NCI-H460. A lentivirus vector transfection system was used to knockdown POLR1B in A549 cells. The Celigo Cell Counting method, MTT and colony formation assays were used to investigate the proliferation of knocking-down POLR1B in A549 cells. Flow cytometry assay was used to investigate apoptosis rates. Co-expression analysis and microarray analysis were used to identify POLR1B targets in NSCLC. The Celigo Cell Counting method, MTT and colony formation assay revealed that the proliferation rates of lung cancer cells were significantly suppressed when POLR1B was silenced by lentivirus-mediated RNA interference. In addition, knocking-down the expression of POLR1B induced lung cancer cell apoptosis, visualized via flow cytometry. Bioinformatics revealed that POLR1B regulated multiple biological processes in NSCLC, including positive regulation of glucose import, and autophagosome assembly. The present study also identified several key targets of POLR1B, including ADRA1D, NR4A1, MYC, BOP1, DKC1, RRP12, IPO4, MTHFD2, CTPS1, GARS and NOC2L. The data from the present study suggest that POLR1B is an important modulator of lung cancer cell proliferation and indicate that POLR1B may be further selected as a potential anticancer therapeutic target for human lung cancer.

Calcium signaling in brain microvascular endothelial cells and its roles in the function of the blood-brain barrier.

The blood-brain barrier (BBB) plays critical roles in maintaining the stability of the brain's internal milieu, providing nutrients for the brain, and preventing toxic materials from the blood from entering the brain. The cellular structure of the BBB is mainly composed of brain microvascular endothelial cells (BMVECs), which are surrounded by astrocytic endfeet that are connected by tight junction proteins, pericytes and astrocytes. Recently, several studies have shown that aberrant increase in intracellular calcium levels in BMVECs lead to cellular metabolic disturbances and subsequent impairment of BBB integrity. Although multiple stresses can lead to intracellular calcium accumulation, inherent protective mechanisms in affected cells are subsequently activated to maintain calcium homeostasis. However, once the increase in intracellular calcium goes beyond a certain threshold, disturbances in cellular structures, protein expression, and the BBB permeability are inevitable. Here, we review recent research on the different factors regulating intracellular calcium concentrations and the mechanisms related to how calcium signaling cascades protect the BMVECs from outside injury. We also consider the potential of calcium signaling regulators as therapeutic targets for modulating intracellular calcium homeostasis and ameliorating BBB disruption in patients with calcium-related pathologies.