LncRNA XXYLT1-AS2 promotes tumor progression via autophagy inhibition through ubiquitinated degradation of TFEB in hepatocellular carcinoma

Purpose There is compelling evidence that long-stranded non-coding RNAs (lncRNAs) play an important role in the progression of hepatocellular carcinoma (HCC). The aim of this study was to investigate the role of lncRNA XXYLT1 antisense-2 (XXYLT1-AS2) in HCC progression. Methods Real-time PCR was used to assess the levels of XXYLT1-AS2 in plasma from HCC and normal patients. Cell proliferation, apoptosis, migration, and invasion were monitored, and tumor xenografts were established to investigate the biological functions of XXYLT1-AS2 by gain-of-function and loss-of-function studies in vitro and in vivo, the expression of autophagy biomarkers and transcriptional factor EB (TFEB) was examined by immunoprecipitation, ubiquitination assays, and western blotting. Autophagy inhibitor, 3-methyladenine (3MA), and proteasome inhibitor, MG132, were used to verify the role of autophagy in HCC progression and the effect of XXYLT1-AS2 on TFEB ubiquitination, respectively. Results In this study, we identified that lncRNA XXYLT1-AS2 is highly expressed in HCC plasma and promotes tumor growth in vivo. In functional studies, it was found that silent expression of XXYLT1-AS2 inhibited HCC proliferation, migration, invasion, and activated autophagy of HCC cells, which were attenuated by autophagy inhibitor, 3MA. Mechanistically, XXYLT1-AS2 decreased the protein level of TFEB through promoting its degradation by ubiquitin proteasome pathway. Conclusion XXYLT1-AS2 plays an oncogenic role in HCC progression through inhibition of autophagy via promoting the degradation of TFEB, and thus could be a novel target for HCC treatment (AU)

Exclusive and Switchable Superoxide Radical Generation by O2-Capture-Based Electron Transfer and Supramolecular Assembly.

Type-I photosensitizers (PSs) can generate free radical anions with a broad diffusion range and powerful damage effect, rendering them highly desirable in various areas. However, it still remains a recognized challenge to develop pure Type-I PSs due to the inefficiency in producing oxygen radical anions through the collision of PSs with nearby substrates. In addition, regulating the generation of oxygen radical anions is also of great importance toward the control of photosensitizer (PS) activities on demand. Herein, a piperazine-based cationic Type-I PS (PPE-DPI) that exhibits efficient intersystem crossing and subsequently captures oxygen molecules through binding O2 to the lone pair of nitrogen in piperazine is reported. The close spatial vicinity between O2 and PPE-DPI strongly promotes the electron transfer reaction, ensuring the exclusive superoxide radical (O2 •-) generation via Type-I process. Particularly, PPE-DPI with cationic pyridine groups is able to associate with cucurbit[7]uril (CB[7]) through host-guest interactions. Thus, supramolecular assembly and disassembly are easily utilized to realize switchable O2 •- generation. This switchable Type-I PS is successfully employed in photodynamic antibacterial control.

LncRNA XXYLT1-AS2 promotes tumor progression via autophagy inhibition through ubiquitinated degradation of TFEB in hepatocellular carcinoma.

PURPOSE: There is compelling evidence that long-stranded non-coding RNAs (lncRNAs) play an important role in the progression of hepatocellular carcinoma (HCC). The aim of this study was to investigate the role of lncRNA XXYLT1 antisense-2 (XXYLT1-AS2) in HCC progression. METHODS: Real-time PCR was used to assess the levels of XXYLT1-AS2 in plasma from HCC and normal patients. Cell proliferation, apoptosis, migration, and invasion were monitored, and tumor xenografts were established to investigate the biological functions of XXYLT1-AS2 by gain-of-function and loss-of-function studies in vitro and in vivo, the expression of autophagy biomarkers and transcriptional factor EB (TFEB) was examined by immunoprecipitation, ubiquitination assays, and western blotting. Autophagy inhibitor, 3-methyladenine (3MA), and proteasome inhibitor, MG132, were used to verify the role of autophagy in HCC progression and the effect of XXYLT1-AS2 on TFEB ubiquitination, respectively. RESULTS: In this study, we identified that lncRNA XXYLT1-AS2 is highly expressed in HCC plasma and promotes tumor growth in vivo. In functional studies, it was found that silent expression of XXYLT1-AS2 inhibited HCC proliferation, migration, invasion, and activated autophagy of HCC cells, which were attenuated by autophagy inhibitor, 3MA. Mechanistically, XXYLT1-AS2 decreased the protein level of TFEB through promoting its degradation by ubiquitin proteasome pathway. CONCLUSION: XXYLT1-AS2 plays an oncogenic role in HCC progression through inhibition of autophagy via promoting the degradation of TFEB, and thus could be a novel target for HCC treatment.

The role and mechanism of HIF-1α-mediated glypican-3 secretion in hypoxia-induced tumor progression in hepatocellular carcinoma.

OBJECTIVE: To explore the expression and secretion mechanism of glypican-3 (GPC3) in hepatocellular carcinoma (HCC) cells under hypoxic conditions, and its role in tumor progression. METHODS: Huh7 cells with and without the knockdown of hypoxia-inducible factor 1-alpha (HIF-1α) were cultured under 1% O2 for varying durations to induce hypoxia. The expression levels of GPC3, HSP70, CD63, STX11 and SYT7 in the cytoplasm and exosomes of Huh7 cells were evaluated by western blotting and immunofluorescence. GPC3 protein expression was further measured in cells treated with GW4869 under hypoxic conditions. Huh7 cells and human umbilical vein endothelial cells (HUVECs) were cultured with the exosomes extracted from the control and GPC3-knockdown cells, the cell proliferation, migration, epithelial-mesenchymal transition (EMT), invasion, and in vitro angiogenesis were analyzed. Tumor xenografts were established to assess the role of GPC3-deficient exosomes in tumor growth. RESULTS: Hypoxic culture conditions downregulated GPC3, STX11 and SYT7 protein levels in the Huh7 cells and upregulated GPC3 mRNA, and also increased GPC3 protein expression in the exosomes. HIF-1α knockdown, as well as treatment with GW4869, upregulated GPC3 protein in the Huh7 cells grown under 1% O2, but downregulated exosomal GPC3. Furthermore, exosomes derived from the GPC3-knockdown cells inhibited the proliferation and migration of Huh7 cells, decreased the expression of N-cadherin, vimentin, ß-catenin, c-Myc and cyclin D1, and increased that of E-cadherin. Likewise, the GPC3-deficient exosomes also suppressed the invasion and tube formation ability of the HUVECs compared to that of control cells. Consistent with the in vitro results, the GPC3-deficient exosomes also repressed tumor growth in vivo. CONCLUSION: Hypoxia promoted secretion of exosomal GPC3 through the activation of HIF-1α. GPC3-deficient exosomes inhibited the proliferation, migration and EMT of HCC cells via the Wnt/ß-catenin signaling pathway, and suppressed the angiogenic potential of HUVECs. This provided a novel understanding of the role of exosomal GPC3 in HCC progression.

Resveratrol Inhibits Hepatocellular Carcinoma Progression through Regulating Exosome Secretion.

BACKGROUND AND OBJECTIVES: Resveratrol is a promising drug for tumor therapy, but its anti-tumor mechanism remains unclarified. The present study aimed to explore the effect of resveratrol on the secretion of exosomes and the role of resveratrol-induced exosomes in the progression of hepatocellular carcinoma. METHODS: The number and contents of exosomes induced by resveratrol were determined by nanoparticle tracking analysis and high-throughput sequencing in Huh7 cells, respectively. Expression of Rab27a was assessed by western blotting and immunofluorescence. Cell proliferation, migration and epithelial-mesenchymal transition were examined with the stimuli of resveratrol and exosomes, the activity of autophagy and wnt/ß-catenin signaling induced by resveratrol-induced exosomes and knockdown of lncRNA SNHG29 were monitored by western blotting and immunofluorescence. RESULTS: It was found that resveratrol might inhibit the exosome secretion by down-regulating the expression of Rab27a, thereby suppressing the proliferation, migration and epithelial-mesenchymal transition of Huh7 cells. Moreover, resveratrol-induced exosomes could also inhibit the malignant phenotype of Huh7 cells via inhibiting the nuclear translocation of ß-catenin and the activation of autophagy, which lncRNA SNHG29 might mediate. CONCLUSION: Resveratrol inhibits hepatocellular carcinoma progression by regulating exosome secretion and contents.

Human placental extract suppresses mast cell activation and induces mast cell apoptosis.

BACKGROUND: Human placental extract (HPE) has been documented to facilitate the healing of certain disorders including allergy. However, the effects of HPE on the functionality of mast cells, a critical cell type in allergic diseases, have not been reported. METHODS: To investigate the effects of HPE on the regulation of allergy with respect to the biological functions of mast cells, the mast cell line C57 or HMC-1 cells were treated with HPE followed by the assessment of cell proliferation, apoptosis, activation, chemotaxis and phagocytosis. Mouse peritoneal mast cells were also investigated for their responses to induction of apoptosis by HPE in vivo. Furthermore, the effect of HPE on mast cell degranulation was confirmed using the passive cutaneous anaphylaxis (PCA) assay, an acute allergy model. RESULTS: HPE was capable of suppressing mast cell proliferation and inducing mast cell apoptosis. Mast cell degranulation in response to compound 48/80- or anti-DNP IgE and DNP-mediated activation was suppressed. In addition, treatment with HPE compromised the production of cytokines by mast cells and cell chemotaxis. These observations were consistent with the dampened passive cutaneous anaphylaxis (PCA) assay following treatment with HPE. CONCLUSION: This study revealed a suppressive effect of HPE on overall mast cell activities, suggesting a potential regulatory role of HPE on the alleviation of allergic diseases through mast cells.

FcγR-dependent apoptosis regulates tissue persistence of mucosal and connective tissue mast cells.

Rodent mast cells can be divided into two major subtypes: the mucosal mast cell (MMC) and the connective tissue mast cell (CTMC). A decade-old observation revealed a longer lifespan for CTMC compared with MMC. The precise mechanisms underlying such differential tissue persistence of mast cell subsets have not been described. In this study, we have discovered that mast cells expressing only one receptor, either FcγRIIB or FcγRIIIA, underwent caspase-independent apoptosis in response to IgG immune complex treatment. Lower frequencies of CTMC in mice that lacked either FcγRIIB or FcγRIIIA compared with WT mice were recorded, especially in aged mice. We proposed that this paradigm of FcγR-mediated mast cell apoptosis could account for the more robust persistence of CTMC, which express both FcγRIIB and FcγRIIIA, than MMC, which express only FcγRIIB. Importantly, we reproduced these results using a mast cell engraftment model, which ruled out possible confounding effects of mast cell recruitment or FcγR expression by other cells on mast cell number regulation. In conclusion, our work has uncovered an FcγR-dependent mast cell number regulation paradigm that might provide a mechanistic explanation for the long-observed differential mast cell subset persistence in tissues.

A hypochlorite-activated strategy for realizing fluorescence turn-on, type I and type II ROS-combined photodynamic tumor ablation.

The combination of cancer cell-activated fluorescence and the advantages of both type I and type II photodynamic therapy (PDT) capabilities to achieve a synergistic therapeutic effect in a complex tumor environment is highly desirable. Herein, we report an approach by means of tumor intracellular hypochlorite (ClO-) to turn on fluorescence integrated with type I and II ROS generation for imaging-guided PDT. The resultant PTZSPy functions as a type II photosensitizer with mitochondria-targeting capability. In the presence of ClO-, PTZSPy is transformed into its oxidized counterpart SPTZSPy, turns on an orange-red fluorescence and triggers the type I ROS generation ability. Biological studies revealed that PTZSPy can accurately distinguishes tumor cells from normal cells, dynamically monitors the cell ablation process and be utilized for theranostics in MCF-7 tumor-bearing nude mice in vivo. This work provides an innovative strategy exploiting the highly abundant ClO- in tumor cells for the type I and II ROS two-pronged and imaging-guided PDT.

MiR-22-3p in exosomes increases the risk of heart failure after down-regulation of FURIN.

Heart failure (HF) is often the inevitable manifestation of myocardial ischemia. Hypoxia can induce cardiomyocytes to express many microRNAs (miRNAs), which are highly expressed in exosomes. In addition, miR-22-3p is a marker in heart failure. Therefore, miR-22-3p was taken as the research object to explore its role and mechanism in HF. HF differentially expressed miRNAs were screened by bioinformatic analysis. The HF rats model was constructed and identified by detecting serum brain natriuretic peptide (BNP) and ultrasound analysis [left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS)]. The extracted exosomes were identified by transmission electron microscopy, and Western blot was used to detect the expressions of Tsg101 and CD63. Quantitative real-time polymerase chain reaction detected miR-22-3p expression in serum, exosomes, and serum without exosomes, while the cardiomyocytes cytotoxicity was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and PKH26 staining. After overexpressing/silencing miR-22-3p in cells, cell viability, apoptosis, and apoptosis-associated markers were detected. Bioinformatic analysis screened the target gene of miR-22-3p, which was verified by dual-luciferase assay. Regulation of miR-22-3p on FURIN was measured by rescue tests. In vivo experiments were verified the above results. MiR-22-3p was identified as the research object. BNP was increased in the model group, while LVEF and LVFS were decreased. MiR-22-3p was overexpressed in HF-treated serum and exosomes. Normal exosomes did not affect cardiomyocyte function, while high concentrations of HF-treated exosomes were cytotoxic. By regulating apoptosis-related genes, overexpressed miR-22-3p inhibited cell activity and promoted cell apoptosis. Silenced miR-22-3p with opposite effects counteracted effects of HF-treated exosomes. FURIN, target gene of miR-22-3p, was negatively regulated by miR-22-3p, while overexpressed FURIN promoted cell activity and inhibited apoptosis. In vivo research was consistent with the results of cell experiments. By regulating FURIN, miR-22-3p in exosomes increases the risk of HF damage.

Dual-Responsive Ratiometric Fluorescent Probe for Hypochlorite and Peroxynitrite Detection and Imaging In Vitro and In Vivo.

Hypochlorite (ClO-) and peroxynitrite (ONOO-) are two crucial highly reactive oxygen/nitrogen species, which interplay with each other, and are implicated in numerous pathophysiological processes. The simultaneous detection of ClO- and ONOO- is immensely significant in evaluating the occurrence and progress of related diseases. Herein, a dual-responsive ratiometric fluorescent probe PTZ-H for the separate and simultaneous detection of ClO- and ONOO- was designed and synthesized. In this probe, the phenothiazine-based coumarin moiety was chosen as the ClO- responsive fluorescent fragment, and the precursor of 2-(benzo[d]thiazol-2-yl)aniline was employed as the sensor for ONOO-. The PTZ-H emitted red fluorescence (640 nm) can switch to green (520 nm) and turn on blue fluorescence (450 nm) in response to ClO- and ONOO-, respectively. This allowed the specific recognition and ratiometric quantification of ClO- and ONOO- with the detection limits of 17 and 21 nM, respectively. Notably, confocal laser scanning microscopy revealed that the PTZ-H probe could target-specifically image ClO- and ONOO- in living RAW 264.7 cells, zebrafish, and tissues with distinct fluorescence signals. With the aid of this single fluorescent probe, the endogenous accumulation of ClO- and ONOO- in inflammatory RAW 264.7 cells and zebrafish can be monitored through two distinct emission channels with fast responses. Moreover, the large fluorescence signal interval, high selectivity, and good biocompatibility may enable its application in deciphering the distribution and correlation of ClO- and ONOO- engaged in biological activity.

Synthesis and in vitro evaluation of novel spiroketopyrazoles as acetyl-CoA carboxylase inhibitors and potential antitumor agents.

Acetyl-CoA carboxylase (ACC) is a rate-limiting enzyme in de novo fatty acid synthesis, which plays a critical role in the growth and survival of cancer cells. In this study, a series of spiroketopyrazole derivatives bearing quinoline moieties were synthesized, and in vitro anticancer activities of these compounds as ACC inhibitors were evaluated. The biological evaluation showed that compound 7j exhibited the strongest enzyme inhibitory activity (IC50 = 1.29 nM), while compound 7m displayed the most potent anti-proliferative activity against A549, HepG2, and MDA-MB-231 cells with corresponding IC50 values of 0.55, 0.38, and 1.65 µM, respectively. The preliminary pharmacological studies confirmed that compound 7m reduced the intracellular malonyl-CoA and TG levels in a dose-dependent manner. Moreover, it could down-regulate cyclin D1 and CDK4 to disturb the cell cycle and up-regulate Bax, caspase-3, and PARP along with the suppression of Bcl-2 to induce apoptosis. Notably, the combination of 7m with doxorubicin synergistically decreased the HepG2 cell viability. These results indicated that compound 7m as a single agent, or in combination with other antitumor drugs, might be a promising therapeutic agent for the treatment of hepatocellular carcinoma.

Inhibition of acetyl-CoA carboxylase by PP-7a exerts beneficial effects on metabolic dysregulation in a mouse model of diet-induced obesity.

Acetyl-coenzyme A carboxylase (ACC) is a critical regulator of fatty acid metabolism and represents a promising therapeutic target for metabolic diseases, including obesity, type 2 diabetes and non-alcoholic fatty liver disease. Recently, a novel ACC inhibitor, PP-7a, was developed by our group by utilizing a structure-based drug design. In the present study, the pharmacological effects of PP-7a on the metabolic dysregulation in mice with high-fat diet (HFD)-induced obesity and the underlying mechanisms were investigated. The inhibitory effect on ACC activities was confirmed by assessing the level of malonyl-CoA, a product synthesized by the catalyzation of ACC. Following 16 weeks of being fed an HFD, the mice were administered PP-7a (15, 45 or 75 mg/kg) for 4 weeks. The effects of PP-7a on weight gain, glucose intolerance, hepatic lipid accumulation and the increase of serum triglyceride (TG), total cholesterol (TC) and free fatty acids (FFA) in mice were assessed. CP-640186 was used as a positive control drug and administered in the same manner as PP-7a. Chronic administration of PP-7a lowered the malonyl-CoA levels in liver and heart tissues of mice in the HFD group. In addition, HFD-induced weight gain and glucose intolerance were improved by PP-7a treatment in the mice fed the HFD. Furthermore, PP-7a suppressed hepatic lipid accumulation and the increase in TG, TC and FFA levels. Taken together, these results suggest that ACC inhibition by PP-7a may have a beneficial effect on metabolic dysregulation in obese mice.

Cobalt Chloride Induced Apoptosis by Inhibiting GPC3 Expression via the HIF-1α/c-Myc Axis in HepG2 Cells.

PURPOSE: To investigate the role of glypican-3 (GPC3) in cobalt chloride (CoCl2)-induced cell apoptosis in hepatocellular carcinoma. METHODS: HepG2 cells were treated with CoCl2 in the absence or presence of GPC3 plasmid transfection. Cell viability and apoptosis were assessed by MTT assay and flow cytometry, respectively. The expression of GPC3, hypoxia-inducible factor 1α (HIF-1α), c-myc, sp1, poly-ADP-ribose polymerase (PARP) and caspase-3 was determined by real-time PCR, Western blotting, and immunofluorescence after the cells were treated with different concentrations of CoCl2 or siRNA targeting HIF-1α. RESULTS: CoCl2 significantly inhibited the proliferation of HepG2 cells and induced apoptosis. Additionally, the expression of GPC3 mRNA and protein was decreased, and overexpression of GPC3 attenuated the tumour inhibiting effects. Further studies showed that CoCl2 increased the expression of HIF-1α while reducing the expression of sp1 and c-myc; knockdown of HIF-1α elevated the expression of GPC3, sp1, and c-myc. CONCLUSION: CoCl2 inhibited the growth of HepG2 cells through downregulation of GPC3 expression via the HIF-1α/c-myc axis.

Olmutinib (HM61713) reversed multidrug resistance by inhibiting the activity of ATP-binding cassette subfamily G member 2 in vitro and in vivo.

Overexpressing of ATP-binding cassette (ABC) transporters is the essential cause of multidrug resistance (MDR), which is a significant hurdle to the success of chemotherapy in many cancers. Therefore, inhibiting the activity of ABC transporters may be a logical approach to circumvent MDR. Olmutinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), which has been approved in South Korea for advanced EGFR T790M-positive non-small cell lung cancer (NSCLC). Here, we found that olmutinib significantly increased the sensitivity of chemotherapy drug in ABCG2-overexpressing cells. Furthermore, olmutinib could also increase the retention of doxorubicin (DOX) and rhodamine 123 (Rho 123) in ABC transporter subfamily G member 2 (ABCG2)-overexpressing cells. In addition, olmutinib was found to stimulate ATPase activity and inhibit photolabeling of ABCG2 with [125I]-iodoarylazidoprazosin (IAAP). However, olmutinib neither altered ABCG2 expression at protein and mRNA levels nor blocked EGFR, Her-2 downstream signaling of AKT and ERK. Importantly, olmutinib enhanced the efficacy of topotecan on the inhibition of S1-MI-80 cell xenograft growth. All the results suggest that olmutinib reverses ABCG2-mediated MDR by binding to ATP bind site of ABCG2 and increasing intracellular chemotherapeutic drug accumulation. Our findings encouraged to further clinical investigation on combination therapy of olmutinib with conventional chemotherapeutic drugs in ABCG2-overexpressing cancer patients.

Macrophage inhibitory cytokine-1 versus carbohydrate antigen 19-9 as a biomarker for diagnosis of pancreatic cancer: A PRISMA-compliant meta-analysis of diagnostic accuracy studies.

BACKGROUND: Because of the high malignant degree of pancreatic cancer (PC), the early diagnosis of PC is of great concern. Macrophage inhibitory cytokine-1 (MIC-1) was reported to be a potential diagnostic biomarker, but its diagnostic value is indeterminate. Therefore, we performed this meta-analysis to compare it to carbohydrate antigen 19-9 (CA19-9), the most frequently used serum biomarker in PC. MATERIAL AND METHODS: After a systematic review of the relevant studies, the pooled diagnostic indices, including sensitivity, specificity, positive/negative likelihood ratio (PLR/NLR), diagnostic odds ratio (DOR), summary receiver operating characteristic curve (sROC), and area under the SROC curve (AUC) were used to evaluate the diagnostic value of MIC-1 and CA19-9 for PC. These indices were pooled with random-effects models. We explored the heterogeneity by meta-regression. RESULTS: Fourteen studies comprising a total of 2826 subjects were included in our meta-analysis. The summary estimates for MIC-1 and CA19-9 are listed as follows: sensitivity, 80% [95% confidence interval (CI) 78-82] versus 71% (95% CI 68-73); specificity, 85% (95% CI 83-87) versus 88% (95% CI 86-90); DOR, 24.57 (95% CI 14.00-43.10) versus 17.65 (95% CI 11.65-26.76); area under sROC (AUC), 0.8945 versus 0.8322; PLR, 5.18 (95% CI 3.24-8.26) versus 5.34 (95% CI 3.78-7.54); and NLR, 0.23 (95% CI 0.19-0.29) versus 0.32 (95% CI 0.28-0.37). CONCLUSION: These data demonstrate that serum MIC-1 has a comparable diagnostic accuracy to CA19-9 for PC.

Dacomitinib potentiates the efficacy of conventional chemotherapeutic agents via inhibiting the drug efflux function of ABCG2 in vitro and in vivo.

BACKGROUND: ATP-binding cassette subfamily G member 2 (ABCG2), a member of the ABC transporter superfamily proteins, mediates multidrug resistance (MDR) by transporting substrate anticancer drugs out of cancer cells and decreasing their intracellular accumulation. MDR is a major hurdle to successful chemotherapy. A logical approach to overcome MDR is to inhibit the transporter. However, no safe and effective MDR inhibitor has been approved in the clinic. METHODS: The MTT assay was used to evaluate cell cytotoxicity and MDR reversal effect. Drug efflux and intracellular drug accumulation were measured by flow cytometry. The H460/MX20 cell xenograft model was established to evaluate the enhancement of anticancer efficacy of topotecan by dacomitinib in vivo. To ascertain the interaction of dacomitinib with the substrate binding sites of ABCG2, the competition of dacomitinib for photolabeling of ABCG2 with [125I]- iodoarylazidoprazosin (IAAP) was performed. Vanadate-sensitive ATPase activity of ABCG2 was measured in the presence of a range of different concentrations of dacomitinib to evaluate the effect of dacomitinib on ATP hydrolysis as the energy source of the transporter. A flow cytometry-based assay and western blotting were employed to study whether dacomitininb could inhibit the expression level of ABCG2. The mRNA expression levels of ABCG2 were analyzed by real-time quantitative RT-PCR. The protein expression level of AKT, ERK and their phosphorylations were detected by Western blotting. RESULTS: Here, we found that dacomitinib, an irreversible pan-ErbB tyrosine kinase inhibitor (TKI) in phase III clinical trial, could enhance the efficacy of conventional chemotherapeutic agents specifically in ABCG2-overexpressing MDR cancer cells but not in the parental sensitive cells. Dacomitinib was found to significantly increase the accumulation of ABCG2 probe substrates [doxorubicin (DOX),Rhodamine 123 (Rho 123) and Hoechst 33342] by inhibiting the transporter efflux function. Moreover, dacomitinib stimulated ABCG2 ATPase activity and competed with [125I]-IAAP photolabeling of ABCG2 in a concentration-dependent manner. However, dacomitinib did not alter ABCG2 expression at protein and mRNA levels or inhibit ErbB downstream signaling of AKT and ERK. Importantly, dacomitinib significantly enhanced the efficacy of topotecan in ABCG2-overexpressing H460/MX20 cell xenografts in nude mice without incurring additional toxicity. CONCLUSIONS: These results suggest that dacomitinib reverses ABCG2-mediated MDR by inhibiting ABCG2 efflux function and increasing intracellular accumulation of anticancer agents. Our findings advocate further clinical investigation of combinations of dacomitinib and conventional chemotherapy in cancer patients with ABCG2-overexpressing MDR tumors.

Diagnostic Value of Methylated Septin9 for Colorectal Cancer Screening: A Meta-Analysis.

BACKGROUND Septin9 is a member of GTP-binding protein family, and is used as a predictive diagnostic index. However, it has not been widely adopted due to inconsistent results reported in the literature. The present study was performed to determine the diagnostic accuracy of methylated Septin9 (mSEPT9) for colorectal cancer (CRC) and to evaluate its utility in CRC screening. MATERIAL AND METHODS After reviewing relevant studies, accuracy measures (pooled sensitivity and specificity, positive/negative likelihood ratio [PLR/NLR], and diagnostic odds ratio [DOR]) were calculated for mSEPT9 in the diagnosis of CRC. Overall test performance was summarized using summary receiver operating characteristic curve analysis. Potential between-study heterogeneity was explored by use of a meta-regression model. We divided included studies into Epi proColon test and non-Epi proColon test subgroups. We compared the effects of mSEPT9 and fecal occult blood test (FOBT) for CRC screening. RESULTS A total of 9870 subjects in 14 studies were recruited. Pooled sensitivity and specificity, PLR, NLR, DOR, and corresponding 95% confidence intervals (CI) of mSEPT9 for CRC diagnosis were 0.66 (95% CI: 0.64-0.69), 0.91 (95% CI: 0.90-0.91), 5.59 (95% CI: 4.03-7.74), 0.37 (95% CI: 0.29-0.48), and 16.79 (95% CI: 10.54-26.76), respectively. The area under the summary ROC curve (AUC) was 0.8563. The AUCs in the Epi proColon test and non-Epi proColon test for CRC diagnosis were 0.8709 and 0.7968, respectively. In head-to-head comparison, AUC of mSEPT9 and FOBT for CRC diagnosis were 0.7857 and 0.6571, respectively. CONCLUSIONS The present study demonstrates that mSEPT9 can be a good diagnostic biomarker complementary to FOBT as a screening tool for CRC.

[The Effect of TALENs-mediated Downregulation Expression of Nanog on Malignant Behavior of Cervical Cancer HeLa Cells].

OBJECTIVE: To study the effect of downregulation expression of Nanog on malignant behavior of cervical cancer HeLa cells. METHODS: Gene editing tool TALENs was employed to induce downregulation expression of Nanog, and Nanog mutation was evaluated by sequencing. RT-PCR and Western blot was used to detect the mRNA and protein expression level, respectively. Colony-formation assay, Transwell invasion assay, and chemotherapy sensibility assay was carried out to assess the capacity of colony-formation, invasion, and chemoresistance, respectively. RESULTS: TALENs successfully induced Nanog mutation and downregulated Nanog expression. Nanog mRNA and protein expression of Nanog-mutated monoclonal HeLa cells downregulated 3 times compared to thoses of wild-type HeLa cells (P < 0.05). Additionally, significant weakened abilities of colony-formation, invasion, and chemoresistance in monoclonal HeLa cells were observed when compared to those of wild-type HeLa cells (P < 0.05). CONCLUSION: Nanog mutation attenuates the malignant behavior of HeLa cells. Importantly, downregulation or silencing of Nanog is promising to be a novel strategy for the treatment of cervical carcinoma.

Functional characterization of a new non-Kunitz serine protease inhibitor from the scorpion Lychas mucronatus.

Serine protease inhibitors have been widely discovered from different animal venoms, but most of them belong to Kunitz-type toxin subfamily. Here, by screening scorpion venom gland cDNA libraries, we identified four new non-Kunitz serine protease inhibitors with a conserved Ascaris-type structural fold: Ascaris-type toxins Lychas mucronatus Ascaris-type protease inhibitor (LmAPI), Pandinus cavimanus Ascaris-type protease inhibitor (PcAPI), Pandinus cavimanus Ascaris-type protease inhibitor 2 (PcAPI-2), and Hottentotta judaicus Ascaris-type protease inhibitor (HjAPI). The detailed characterization of one Ascaris-type toxin LmAPI was further carried out, which contains 60 residues and possesses a classical Ascaris-type cysteine framework reticulated by five disulfide bridges. Enzyme and inhibitor reaction kinetics experiments showed that recombinant LmAPI inhibits the activity of chymotrypsin potently with a Ki value of 15.5 nM, but has little effect on trypsin and elastase. Bioinformatics analyses suggested that LmAPI contains unique functional residues "TQD" and might be a useful template to produce specific protease inhibitors. Our results indicated that animal venoms are a natural source of new type of protease inhibitors, which will accelerate the development of diagnostic and therapeutic agents for human diseases that target diverse proteases.