Marein, a novel natural product for restoring chemo-sensitivity to cancer cells through competitive inhibition of ABCG2 function.

The pivotal roles of ATP-binding cassette (ABC) transporters in drug resistance have been widely appreciated. Here we report that marein, a natural product from Coreopsis tinctoria Nutt, is a potent chemo-sensitizer in drug resistant cancer cells overexpressing ABCG2 transporter. We demonstrate that marein can competitively inhibit efflux activity of ABCG2 protein and increase the intracellular accumulation of the chemotherapeutic drugs that belong to substrate of this transporter. We further show that marein can bind to the conserved amino acid residue F439 of ABCG2, a critical site for drug-substrate interaction. Moreover, marein can significantly sensitize the ABCG2-expressing tumor cells to chemotherapeutic drugs such as topotecan, mitoxantrone, and olaparib. This study reveals a novel role and mechanism of marein in modulating drug resistance, and may have important implications in treatment of cancers that are resistant to chemotherapeutic drugs that belong to the substrates of ABCG2 transporters.

circRNA_SLC8A1 promotes the survival of mycobacterium tuberculosis in macrophages by upregulating expression of autophagy-related protein SQSTM1/p62 to activate the NF-κB pathway.

Macrophages act as the first immune defense line of the host against Mycobacterium tuberculosis (Mtb). A previous study showed that circRNA_SLC8A1 was significantly upregulated in Mtb-infected macrophages, but its regulatory mechanism in anti-tuberculosis infection is unclear. Therefore, this study aimed to investigate the role of circRNA_SLC8A1 in the anti-tuberculosis activity of macrophages. We showed that circRNA_SLC8A1 was upregulated in tuberculosis patients. Moreover, the binding sites of miR-20b-5p on circRNA_SLC8A1 and Sequestosome 1 (SQSTM1/p62) mRNA were predicted by StarBase and verified by the double luciferase reporter gene assay. Next, we found that miR-20b-5p expression was decreased, while SQSTM1 protein expression was increased in a time- and dose-dependent manner in the human macrophage U937 in response to Mtb infection. Furthermore, circRNA_SLC8A1 overexpression vector (circRNA_SLC8A1) or shRNA (sh-circRNA_SLC8A1) and/or miR-20b-5p mimic or inhibitor and/or SQSTM1 overexpression vector (SQSTM1) or small interfering RNA (si-SQSTM1) or its corresponding control were transfected into Mtb-infected macrophages. Results showed that overexpression of circRNA_SLC8A1 or miR-20b-5p inhibitor promoted the secretion of pro-inflammatory factors IL-1ß, IL-6, and TNF-α, increased Nitric Oxide (NO) content and inducible nitric oxide synthase (iNOS) expression, inhibited Reactive oxygen species (ROS) production. Cleaved-caspase-3 protein expression, and cell apoptosis, and promoted Mtb survival. Silencing SQSTM1 inhibited secretion of pro-inflammatory factors and activation of the NF-κB pathway. Overexpression of miR-20b-5p blocked the promoting of circ-SLC8A1 on SQSTM1 protein expression. In summary, circRNA_SLC8A1 sponged miR-20b-5p to upregulate SQSTM1/p62 expression and promoted Mtb survival in macrophages through the NF-κB signaling pathway.

Mechanistic insights of NAC1 nuclear export and its role in ovarian cancer resistance to docetaxel.

In this study, we uncovered the nuclear export of nucleus accumbens-associated protein-1 (NAC1) as a novel mechanism involved in ovarian cancer resistance to taxanes, the chemotherapeutic drugs commonly used in treatment of this malignancy. We showed that NAC1, a nuclear factor of the BTB/POZ gene family, has a nuclear export signal (NES) at the N terminus (aa 17-28), and this NES critically contributes to the NAC1 nuclear-cytoplasmic shuttling when tumor cells were treated with docetaxel. Mechanistically, the nuclear-exported NAC1 bound to cullin3 (Cul3) and Cyclin B1 via its BTB and BOZ domains respectively, and the cyto-NAC1-Cul3 E3 ubiquitin ligase complex promotes the ubiquitination and degradation of Cyclin B1, thereby facilitating mitotic exit and leading to cellular resistance to docetaxel. We also showed in in vitro and in vivo experiments that TP-CH-1178, a membrane-permeable polypeptide against the NAC1 NES motif, blocked the nuclear export of NAC1, interfered with the degradation of Cyclin B1 and sensitized ovarian cancer cells to docetaxel. This study not only reveals a novel mechanism by which the NAC1 nuclear export is regulated and Cyclin B1 degradation and mitotic exit are impacted by the NAC1-Cul3 complex, but also provides the nuclear-export pathway of NAC1 as a potential target for modulating taxanes resistance in ovarian cancer and other malignancies.

Identification of HAGHL as a novel metabolic oncogene regulating human colorectal cancer progression.

PURPOSE: Cancer development remains the most challenging obstacle in colorectal cancer (CRC) treatment. The current study aims to identify and demonstrate novel oncogenes for CRC. METHODS: The CRC data of the Cancer Genome Atlas database and the Gene Expression Omnibus database were subjected to bioinformatics analysis to identify the novel potential diagnostic and prognostic biomarkers for CRC. Immunohistochemical assay, western blot, and quantitative PCR (qPCR) were used to analyze hydroxyacylglutathione hydrolase-like (HAGHL) gene expression in CRC tissues and cultured CRC cells. D-Lactate colorimetric assay was applied to determine concentration of D-lactate in supernatants from CRC tissues and cell culture medium. Cell counting kit-8 (CCK-8) assay, flow cytometry, tumor xenografts experiment, and TUNEL staining analysis were performed to evaluate the function of HAGHL in CRC. RESULTS: We comprehensively analyzed the CRC data of the Cancer Genome Atlas database and the Gene Expression Omnibus database, and identified several novel potential diagnostic and prognostic biomarkers for CRC, including HAGHL, DNTTIP1, DHX34, and AP1S3. The expression of HAGHL, the strongest oncogenic activity gene, is positively related to D-lactate levels in CRC tissues and negatively associated with patient prognosis. HAGHL downregulation suppressed the production of D-lactate and induced apoptosis, resulting in inhibition of cell proliferation in vitro. In vivo experiment showed that knockdown of HAGHL induced cell apoptosis and inhibited tumor growth. CONCLUSION: These findings suggest that HAGHL acts as a novel metabolic oncogene and demonstrate the underlying mechanism by which HAGHL regulates CRC progression, highlighting its utility as a diagnostic and prognostic factor and as a potential therapeutic target for the treatment of CRC.

MicroRNA-20a-3p regulates the host immune response to facilitate the mycobacterium tuberculosis infection by targeting IKKß/NF-κB pathway.

BACKGROUND: Mycobacterium tuberculosis (M.tb) has evolved to utilize different mechanisms to evade the host immune response. Several microRNAs (miRNAs) have been found to regulate innate immune response in M.tb replication and infection, but the roles and detailed molecular mechanisms of miRNAs in M.tb infection remain to be clarified. METHODS: Previously published dataset GSE94007 from GEO database was used for screening differential-expressed miRNAs, and a significant up-regulated miR-20a-3p was chosen for further investigation. Cells were transfected with miR-20a-3p mimics, inhibitors, IKKß siRNA, or their controls to verify the role of miR-20a-3p and IKKß in M.tb infection and host immune response. IL-ß, IL-6 and TNF-α contents in supernatant were measured by ELISA kits. The expression level of IKKß/NF-κB pathway were also detected by western blot. RESULTS: We found that miR-20a-3p was dose-and time-dependently increased during M.tb infection. Subsequently, our results demonstrated that upregulation of miR-20a-3p promoted intracellular growth of bacterial, and suppressed the release of proinflammatory cytokines in both M.tb-infected RAW264.7 and BMDM cells, while downregulation of miR-20a-3p had an opposite effect. Moreover, miR-20a-3p suppressed the activity of NF-κB pathway by directly targeting IKKß, resulting in the suppression of pro-inflammatory cytokines, attenuation of immune response and promotion of M.tb survival. CONCLUSION: Our findings uncover a role of miR-20a-3p and its target IKKß in regulating M.tb induced immune responses and provide a better understanding of pathogenesis of M.tb infection.

Design and implementation of an Omaha System-based integrated nursing management model for patients with newly-diagnosed diabetes.

AIMS: The aim of the present paper was to establish and implement an integrated nursing management model for patients with newly-diagnosed type 2 diabetes mellitus (T2DM) based on the Omaha System and to explore its impact on blood glucose levels, quality of life, and diabetes knowledge in these patients. METHODS: A non-randomized concurrent controlled trial was designed and the study was conducted in a hospital on the east coast of China between September 2013 and November 2015. We screened for patients with newly-diagnosed T2DM in 12 clinics of 3 comprehensive hospitals. A total of 367 patients with newly-diagnosed T2DM were assigned into two groups. In the intervention group, patients received routine outpatient care plus integrated nursing management; in the control group, only routine outpatient care was given. Changes in blood glucose levels, quality of life, and diabetes knowledge in both groups before the intervention and 6 months after the intervention were observed and compared. RESULTS: At the 6months, blood glucose levels, quality of life, and diabetes knowledge in the intervention group were significantly superior to those in the control group (all P<0.01). CONCLUSIONS: The integrated nursing management model was able to improve patients' glucose levels, quality of life, and diabetes knowledge.

The relationship among resilience, rumination and posttraumatic growth in hemodialysis patients in North China.

Research has indicated that clinical serious disease may lead to posttraumatic growth (PTG). However, little is known about PTG among hemodialysis (HD) patients. The study examined the relationship among resilience, rumination and PTG among Chinese HD patients. 196 HD patients were recruited from a tertiary hospital in a Northern city of China between 1 June 2015 and 30 May 2016. Patients were surveyed using the Posttraumatic Growth Inventory-Chinese version, Connor-Davidson Resilience Scale, and Chinese Event Related Rumination Inventory. Correlation analyses showed that resilience was most highly positively correlated with PTG (r = .70, p < .001), deliberate rumination moderately correlated to PTG (r = .50, p < .001), and intrusive rumination was lower negatively related to PTG (r = -.26, p < .001). Regression analyses showed that age, gender, duration of dialysis, resilience and deliberate rumination had significant associations with PTG (ß = -.31, p ＜ .0001; ß = -.14, p = .002; ß = .10, p = .032; ß = .44, p < .001; ß = .20, p < .001). They together explained 65% of the total variance in PTG (F [8,195] = 46.74, p < .001). However, intrusive rumination was not associated with PTG (p > .05). The results suggested that resilience and deliberate rumination may be instrumental for PTG improvement.

Confrontation as a Mediator between Sense of Coherence and Self-management Behaviors among Elderly Patients with Coronary Heart Disease in North China.

PURPOSE: Self-management is critical to improve health outcomes of elderly patients with coronary heart disease (CHD). Sense of coherence (SOC) is found to be linked with self-management behaviors. However, their deeper relationship is not clear. The purposes of this study were to investigate the association between SOC and self-management behaviors among elderly CHD patients in China, and whether confrontation mediates this association. METHODS: A cross-sectional design was used. A total of 275 elderly patients with CHD recruited from the cardiology department in a general hospital in North China were surveyed from October 2015 to April 2016. SOC, confrontation, and self-management behaviors were measured using the Chinese version of the SOC scale, subscale of Medical Coping Modes Questionnaire-Confrontation, and the CHD self-management scale, respectively. Correlation analysis and path analysis were conducted to analyze the data. RESULTS: The mean (±standard deviation) scores of SOC, confrontation, and self-management behaviors were 62.20 (±9.61), 19.55 (±3.15), and 76.17 (±10.63), respectively. Correlation analysis showed that SOC, confrontation, and self-management behaviors were significantly correlated with each other. Path analysis indicated that SOC exerted a direct effect on self-management behaviors, whereas could affect self-management indirectly via confrontation. Bootstrap test result showed that confrontation played a mediating role (ß = .20, p < .001) in the relationship between SOC and self-management behaviors. CONCLUSION: SOC was related to self-management behaviors, whereas confrontation mediated the effect of SOC on self-management behaviors. In practice, the role of confrontation coping should be valued when developing strategies to strengthen SOC and to improve self-management practice among elderly CHD patients.

A simple, rapid and economic method for detecting multidrug-resistant tuberculosis

OBJECTIVE: To evaluate multiplex allele specific polymerase chain reaction as a rapid molecular tool for detecting multidrug-resistant tuberculosis. METHODS: Based on drug susceptibility testing, 103 isolates were multidrug-resistant tuberculosis and 45 isolates were sensitive to isonicotinylhydrazine and rifampin. Primers were designed to target five mutations hotspots that confer resistance to the first-line drugs isoniazid and rifampin, and multiplex allele specific polymerase chain reaction was performed. Whole-genome sequencing confirmed drug resistance mutations identified by multiplex allele specific polymerase chain reaction. RESULTS: DNA sequencing revealed that 68.9% of multidrug-resistant strains have point mutations at codon 315 of the katG gene, 19.8% within the mabA-inhA promoter, and 98.0% at three hotspots within rpoB. Multiplex allele specific polymerase chain reaction detected each of these five mutations, yielding 82.3% sensitivity and 100% specificity for isoniazid resistance, and 97.9% sensitivity and 100% specificity for rifampin resistance as compared to drug susceptibility testing. CONCLUSIONS: The results show that multiplex allele specific polymerase chain reaction is an inexpensive and practical method for rapid detection of multidrug-resistant tuberculosis in developing countries.

Clinical value of a whole blood interferon-γ release assay for the diagnosis of Mycobacterium tuberculosis infection during antitubercular treatment.

The aim of this study was to evaluate the sensitivity and specificity of a whole blood interferon-γ release assay, the QuantiFERON®-TB Gold In-Tube (QFT-GIT) test, in the diagnosis of Mycobacterium tuberculosis (MTB) infection, and to assess its monitoring role during antitubercular treatment. In total, 20 patients received the QFT test, along with other commonly-used tests, prior to, and following, 2- and 6-month courses of antitubercular treatment; the results were compared and statistically analyzed. The rate of positive results for tuberculosis (TB) was 95% for the QFT test, which was significantly higher compared with those for the purified protein derivative (PPD; 55%) and the antitubercular antibody tests (15%), as well as the acid-fast bacilli smear (20%) and cultures for TB (20%; P<0.05 for all). The sensitivity and specificity of the QFT test were 96 and 93.8%, respectively. The positive result rate obtained with the QFT test was significantly higher in the TB group compared with that in the non-TB group (6.3%; P<0.05). Moreover, the positive result rate obtained with the QFT test was significantly lower in the 6-month-treated group compared with that in the 2-month group (P<0.05). In conclusion, the QFT test is a sensitive and specific method for rapidly diagnosing MTB infection, and has an improved practical clinical value in evaluating antitubercular therapies compared with that of the PPD test.

A simple, rapid and economic method for detecting multidrug-resistant tuberculosis.

OBJECTIVE: To evaluate multiplex allele specific polymerase chain reaction as a rapid molecular tool for detecting multidrug-resistant tuberculosis. METHODS: Based on drug susceptibility testing, 103 isolates were multidrug-resistant tuberculosis and 45 isolates were sensitive to isonicotinylhydrazine and rifampin. Primers were designed to target five mutations hotspots that confer resistance to the first-line drugs isoniazid and rifampin, and multiplex allele specific polymerase chain reaction was performed. Whole-genome sequencing confirmed drug resistance mutations identified by multiplex allele specific polymerase chain reaction. RESULTS: DNA sequencing revealed that 68.9% of multidrug-resistant strains have point mutations at codon 315 of the katG gene, 19.8% within the mabA-inhA promoter, and 98.0% at three hotspots within rpoB. Multiplex allele specific polymerase chain reaction detected each of these five mutations, yielding 82.3% sensitivity and 100% specificity for isoniazid resistance, and 97.9% sensitivity and 100% specificity for rifampin resistance as compared to drug susceptibility testing. CONCLUSIONS: The results show that multiplex allele specific polymerase chain reaction is an inexpensive and practical method for rapid detection of multidrug-resistant tuberculosis in developing countries.

Upregulation of HO-1 is accompanied by activation of p38MAPK and mTOR in human oesophageal squamous carcinoma cells.

Induction of HO-1 protein can have both beneficial and detrimental effects for cells, including regulating proliferation and apoptosis of several tumours. We have investigated the regulation of HO-1, p38MAPK and mTOR in the context of proliferation, cell cycle events and apoptosis of oesophageal squamous cell carcinoma cells. Real-time PCR and Western blots were used to determine the expression levels of HO-1, p38MAPK, p-p38MAPK and p-mTOR. MTT assays were used to measure proliferation, FACS for cell cycle events and Annexin V staining for apoptosis. Proliferation of Eca109 cells was inhibited and apoptosis was induced in the presence of p38MAPK inhibitor (SB203580) and mTOR inhibitor (Rapamycin, RAPA). HO-1 expression was downregulated in cells treated with SB203580 and RAPA. HO-1 overexpression inhibited apoptosis and induced G2/M arrest in SB203580 and RAPA-treated cells. HO-1 expression was upregulated in the presence of ethanol, and was accompanied by activation of p38MAPK and mTOR. However, ethanol-treated cells exposed to HO-1 inhibitor showed no effect on p38MAPK and mTOR activation. The data suggest that ethanol-induced upregulation of HO-1 in oesophageal squamous cell carcinoma is accompanied by the activation of the p38MAPK and mTOR pathways.

Invasion inhibition by a MEK inhibitor correlates with the actin-based cytoskeleton in lung cancer A549 cells.

Metastasis remains the primary cause of lung cancer. The molecules involved in metastasis may be candidates for new targets in the therapy of lung cancer. The MEK/ERK signaling pathway has been highlighted in a number of studies on invasiveness and metastasis. In this paper, we show that the MEK inhibitor U0126 induces flattened morphology, remodels the actin-based cytoskeleton, and potently inhibits chemotaxis and Matrigel invasion in the human lung cancer A549 cell line. Furthermore, downregulation of ERK by small interfering RNA significantly inhibits the invasion of A549 cells and induces stress fiber formation. Taken together, our findings provide the first evidence that the inhibition of invasion of lung cancer A549 cells by inhibiting MEK/ERK signaling activity is associated with remodeling of the actin cytoskeleton, suggesting a novel link between MEK/ERK signaling-mediated cell invasion and the actin-based cytoskeleton.