Dissecting Mitochondrial Mechanisms of Alzheimer's Disease Using Gene Dependency Network and Its Implications for Discovering Nutrients Combatting the Disease.

BACKGROUND: Alzheimer's disease (AD) is the leading cause of dementia, with its prevalence increasing as the global population ages. AD is a multifactorial and intricate neurodegenerative disease with pathological changes varying from person to person. Because the mechanism of AD is highly controversial, effective treatments remain a distant prospect. Currently, one of the most promising hypotheses posits mitochondrial dysfunction as an early event in AD diagnosis and a potential therapeutic target. OBJECTIVE: Here, we adopted a systems medicine strategy to explore the mitochondria-related mechanisms of AD. Then, its implications for discovering nutrients combatting the disease were demonstrated. METHODS: We employed conditional mutual information (CMI) to construct AD gene dependency networks. Furthermore, the GeneRank algorithm was applied to prioritize the gene importance of AD patients and identify potential anti-AD nutrients targeting crucial genes. RESULTS: The results suggested that two highly interconnected networks of mitochondrial ribosomal proteins (MRPs) play an important role in the regulation of AD pathology. The close association between mitochondrial ribosome dysfunction and AD was identified. Additionally, we proposed seven nutrients with potential preventive and ameliorative effects on AD, five of which have been supported by experimental reports. CONCLUSIONS: Our study explored the important regulatory role of MRP genes in AD, which has significant implications for AD prevention and treatment.

Discovery of extracellular vesicle-delivered miR-185-5p in the plasma of patients as an indicator for advanced adenoma and colorectal cancer.

BACKGROUND: We aimed to evaluate whether extracellular vesicles (EV)-derived microRNAs (miRNAs) can be used as biomarkers for advanced adenoma (AA) and colorectal cancer (CRC). METHODS: We detected the changes in the plasma EV-delivered miRNA profiles in healthy donor (HD), AA patient, and I-II stage CRC patient groups using miRNA deep sequencing assay. We performed the TaqMan miRNA assay using 173 plasma samples (two independent cohorts) from HDs, AA patients, and CRC patients to identify the candidate miRNA(s). The accuracy of candidate miRNA(s) in diagnosing AA and CRC was determined using the area under the receiver-operating characteristic curve (AUC) values. Logistic regression analysis was performed to evaluate the association of candidate miRNA(s) as an independent factor for the diagnosis of AA and CRC. The role of candidate miRNA(s) in the malignant progression of CRC was explored using functional assays. RESULTS: We screened and identified four prospective EV-delivered miRNAs, including miR-185-5p, which were significantly upregulated or downregulated in AA vs. HD and CRC vs. AA groups. In two independent cohorts, miR-185-5p was the best potential biomarker with the AUCs of 0.737 (Cohort I) and 0.720 (Cohort II) for AA vs. HD diagnosis, 0.887 (Cohort I) and 0.803 (Cohort II) for CRC vs. HD diagnosis, and 0.700 (Cohort I) and 0.631 (Cohort II) for CRC vs. AA diagnosis. Finally, we demonstrated that the upregulated expression of miR-185-5p promoted the malignant progression of CRC. CONCLUSION: EV-delivered miR-185-5p in the plasma of patients is a promising diagnostic biomarker for colorectal AA and CRC. Trial registration The study protocol was approved by the Ethics Committee of Changzheng Hospital, Naval Medical University, China (Ethics No. 2022SL005, Registration No. of China Clinical Trial Registration Center: ChiCTR220061592).

Cryptotanshinone Induces Necroptosis Through Ca2+ Release and ROS Production in vitro and in vivo.

BACKGROUND: Necroptosis is a type of programmed necrosis mediated by receptor-interacting protein kinases 1 and 3 (RIP1 and RIP3), which is morphologically characterized by enlarged organelles, ruptured plasma membrane, and subsequent loss of intracellular contents. Cryptotanshinone (CPT), a diterpene quinone compound extracted from the root of Salvia miltiorrhiza Bunge, has been reported to have significant anticancer activities. However, the detailed mechanism of CPT has not been clearly illustrated. OBJECTIVE: The present study aimed to explore the cell death type and mechanisms of CPT-induced in non-small cell lung cancer (NSCLC) cells. METHODS: The cytotoxicity of CPT on A549 cells was assessed by MTS assay. Ca2+ release and reactive oxygen species (ROS) generation were detected by flow cytometry. The changes in mitochondrial membrane potential (MMP) were observed through JC-1 staining. The expressions of p- RIP1, p-RIP3, p-MLKL, and MAPKs pathway proteins were analyzed by western blotting analysis. The efficacy of CPT in vivo was evaluated by the Lewis lung carcinoma (LLC) xenograft mice model. Blood samples were collected for hematology analysis. ELISA investigated the effects of CPT on tumor necrosis factor α (TNF-α). Hematoxylin and eosin staining (HE) determined the tumor tissues. Proteins' expression of tumor tissues was quantified by western blotting. RESULTS: CPT inhibited the cell viability of A549 cells in a time- and concentration-dependent manner, which was reversed by Necrostatin-1 (Nec-1). In addition, CPT treatment increased the expression of p-RIP1, p-RIP3, p-MLKL, the release of Ca2+, ROS generation, and the MAPKs pathway activated in A549 cells. Moreover, animal experiment results showed that intraperitoneal injection of CPT (15 mg/kg and 30 mg/kg) significantly inhibited tumor growth in C57BL/6 mice without affecting the bodyweight and injuring the organs. CONCLUSION: Our findings suggested that CPT-induced necroptosis via RIP1/RIP3/MLKL signaling pathway both in vitro and in vivo, indicating that CPT may be a promising agent in the treatment of NSCLC.

Rotundic acid reduces LPS-induced acute lung injury in vitro and in vivo through regulating TLR4 dimer.

Acute lung injury (ALI) is a serious clinical disease. Rotundic acid (RA), a natural ingredient isolated from Ilex rotunda Thunb, exhibits multiple pharmacological activities. However, RA's therapeutic effect and mechanism on ALI remain to be elucidated. The present study aimed to further clarify its regulating effects on inflammation in vitro and in vivo. Our results indicated that RA significantly inhibited the overproduction of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). RA decreased ROS production and calcium influx. In addition, RA inhibited the activation of PI3K, MAPK, and NF-κB pathways and enhanced the activity of nuclear factor E2-related factor 2 (Nrf2) signaling. The cellular thermal shift assay and docking results indicated that RA bind to TLR4 to block TLR4 dimerization. Furthermore, RA pretreatment effectively inhibited ear edema induced by xylene and LPS-induced endotoxin death and had a protective effect on LPS-induced ALI. Our findings collectively indicated that RA has anti-inflammatory effects, which may serve as a potential therapeutic option for pulmonary inflammation.

Nuezhenide Exerts Anti-Inflammatory Activity through the NF-κB Pathway.

BACKGROUND: Nuezhenide (NZD), an iridoid glycoside isolated from Ilex pubescens Hook. & Arn. var. kwangsiensis Hand.-Mazz., used as a traditional Chinese medicine for clearing away heat and toxic materials, displays a variety of biological activities such as anti-tumor, antioxidant, and other life-protecting activities. However, a few studies involving anti-inflammatory activity and the mechanism of NZD have also been reported. In the present study, the anti-inflammatory and antioxidative effects of NZD are illustrated. OBJECTIVE: This study aims to test the hypothesis that NZD suppresses LPS-induced inflammation by targeting the NF-κB pathway in RAW264.7 cells. METHODS: LPS-stimulated RAW264.7 cells were employed to detect the effect of NZD on the release of cytokines by ELISA. Protein expression levels of related molecular markers were quantitated by western blot analysis. The levels of ROS, NO, and Ca2+ were detected by flow cytometry. The changes in mitochondrial reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were observed and verified by fluorescence microscopy. Using immunofluorescence assay, the translocation of NF-κB/p65 from the cytoplasm into the nucleus was determined by confocal microscopy. RESULTS: NZD exhibited anti-inflammatory activity and reduced the release of inflammatory cytokines such as nitrite, TNF-α, and IL-6. NZD suppressed the expression of the phosphorylated proteins like IKKα/ß, IκBα, and p65. Besides, the flow cytometry results indicated that NZD inhibited the levels of ROS, NO, and Ca2+ in LPS-stimulated RAW264.7 cells. JC-1 assay data showed that NZD reversed LPS-induced MMP loss. Furthermore, NZD suppressed LPS-induced NF-B/p65 translocation from the cytoplasm into the nucleus. CONCLUSION: NZD exhibits anti-inflammatory effects through the NF-κB pathway on RAW264.7 cells.

Linc01094 Accelerates the Growth and Metastatic-Related Traits of Glioblastoma by Sponging miR-126-5p.

BACKGROUND: Long intergenic non-coding RNAs (lincRNAs) are associated with the progression of glioblastoma (GBM). However, how linc01094 contributes to the growth and metastatic phenotypes of GBM remains not fully studied. METHODS: The expression levels of linc01094 and miR-126-5p in GBM tissues and cell lines were analyzed using qRT-PCR. Loss-of-function experiments were performed to detect the biological activity of linc01094 in GBM. Glioblastoma tumor model was constructed to explore the impact of linc01094 on GBM cell growth in vivo. Linc01094-sponged miR-126-5p was certified by luciferase reporter assay and RNA immunoprecipitation (RIP). The protein expression of miRNA target gene, dynactin subunit 4 (DCTN4) was detected using Western blotting assay. RESULTS: Herein, we observed that the level of linc01094 was higher in GBM tissues. Silencing of linc01094 restrained the growth and invasive abilities of GBM cell. Moreover, linc01094 level was negatively associated with miR-126-5p level in GBM and linc01094 acted as a "sponge" for miR-126-5p. Reintroduction of linc01094 reversed the tumor-inhibiting effects of miR-126-5p in GBM. CONCLUSION: Altogether, linc01094 promoted the tumorigenesis and metastatic phenotypes of GBM cell by modulating of miR-1126-5p/DCTN4 signaling axis.

Procyanidin A2, a polyphenolic compound, exerts anti-inflammatory and anti-oxidative activity in lipopolysaccharide-stimulated RAW264.7 cells.

Procyandin A2 (PCA2) is a polyphenolic compound which is isolated from grape seeds. It has been reported that PCA2 exhibits antioxidative and anti-inflammatory effects, but its molecular mechanism is still poorly understood. This study tests the hypothesis that PCA2 suppresses lipopolysaccharide (LPS)-induced inflammation and oxidative stress through targeting the nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and NF-E2-related factor 2 (Nrf2) pathways in RAW264.7 cells. PCA2 (20, 40, 80 µM) exhibited no significant cytotoxicity in RAW264.7 cells and showed an inhibitory effect on an LPS-induced nitrite level. Pro-inflammatory cytokines like tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), nitric oxide (NO), and reactive oxygen species (ROS) were suppressed by PCA2 with a concentration range of 0-80 µM. The mRNA levels of TNF-α and IL-6 were inhibited by PCA2 (80 µM). The hallmark-protein expression of the NF-κB (p-IKKα/ß, p-IκBα, and p-p65) and MAPK (p-p38, p-JNK, and p-ERK) pathways were decreased by PCA2 in LPS-stimulated RAW264.7 cells. In addition, immunofluorescence results indicated that PCA2 (80 µM) promoted the translocation of NF-κB/p65 from the cytoplasm into the nucleus. PCA2 upregulated the expressions of Nrf2 and HO-1 and downregulated the expression of Keap-1. Simultaneously, PCA2 (80 µM) reversed LPS-induced Nrf2 translocation from the nucleus into the cytoplasm. Collectively, PCA2 protect cells against the damage from inflammation and oxidative injury, which suggest a potential therapeutic strategy for inflammatory and oxidative stress through targeting NF-κB, MAPK, and Nrf2 pathways in RAW264.7 cells.

PHLPP2 is regulated by competing endogenous RNA network in pathogenesis of colon cancer.

Recently, homologous pleckstrin-homology (PH)-domain leucine-rich-repeat protein phosphatases (PHLPP2) has been reported as a tumor suppressor in colon cancer. This study aimed to unravel the possible involvement of long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) regulating PHLPP2 in colon cancer. Expressions of candidate lncRNAs and miRNAs were verified by the RT-qPCR and Western blot analyses in colon cancer. The roles of candidate genes in colon cancer were investigated in HT-29 cells in vitro and in mouse tumor xenograft model in vivo. PHLPP2, a target of miR-141 and miR-424, was downregulated in colon cancer. PHLPP2 upregulation and miR-141 and miR-424 downregulation suppressed the colon cancer cell proliferation, migration, invasion, and epithelial-mesenchymal transition, and promote cell apoptosis, which also resulted in suppression of tumor metastasis and formation. Furthermore, LINC00402, LINC00461, and SFTA1P were identified as the targets of miR-141 and miR-424 and acted as competitive endogenous RNAs (ceRNAs) of PHLPP2. The upregulation of LINC00402, LINC00461, and SFTA1P was verified to enhance the suppressive effects of PHLPP2 in the pathogenesis of colon cancer. Conjointly, our results demonstrated the suppressive effects of PHLPP2 in colon cancer and proved that LINC00402, LINC00461, and SFTA1P acted as ceRNAs of PHLPP2 by competitive binding to miR-141 and miR-424.

The Role of Formyl Peptide Receptor 1 Gene Polymorphisms in Human Colorectal Cancer.

Formyl peptide receptor 1 (FPR1) belongs to G protein-coupled receptors expressed mainly in phagocytic leukocytes. The gene encoding FPR1 is highly polymorphic and related to inflammation. In this study, we investigated the single nucleotide polymorphisms (SNPs) of Fpr1 in human colorectal cancer (CRC), and analyzed the association of Fpr1 SNPs with clinicopathological parameters and some specific diagnostic markers of CRC. Although the allele and genotype frequencies of Fpr1 SNPs in CRC tissues were not significantly different from that in whole blood cells derived from healthy Chinese subjects. Significant associations were observed between genotypes of c.289C>A and distant metastasis (P=0.001), and between genotypes of c.306T>C and tumor size (P=0.016). Genotypes of c.546C>A was closer to tumor size and lymphatic invasion (P=0.012 and P=0.043, respectively). Meanwhile, genotypes of c.1037C>A was related with tumor location and differentiation (P=0.000 and P=0.005, respectively). Besides, genotypes of c.576T>C>G was related with pathological type (P=0.000). Furthermore, several Fpr1 SNP positions including c.289 (C>A) and c.576 (G>C>T) were related to the expression of P53 (P=0.004 and P=0.008, respectively), and similar results were observed between other Fpr1 SNP positions and CEA, HER2 and Ki-67 (P<0.05). Our data demonstrate that Fpr1 SNPs may play the important role in the progression and metastasis of CRC.

Cryptotanshinone from Salvia miltiorrhiza Bunge (Danshen) inhibited inflammatory responses via TLR4/MyD88 signaling pathway.

BACKGROUND: Cryptotanshinone (CPT), as a major component of Salvia miltiorrhiza Bunge (Danshen), displays many pharmacological activities including anti-inflammatory effects. However, the exact cellular and molecular mechanisms of the anti-inflammatory activities of CPT remain to be elucidated. The present study was aimed to clarify its mechanisms on lipopolysaccharide (LPS)-induced inflammatory responses in mouse macrophages, RAW264.7 cells. METHODS: In the current study, the anti-inflammatory properties of CPT were evaluated using LPS-stimulated RAW264.7 cell model. MTT assay was used to determine the viability of RAW264.7 cells. The anti-inflammatory effects of CPT were measured based on the detection of nitric oxide (NO) production (Griess and flow cytometry assay), and tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) release (ELISA). Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) enzyme expressions were also determined by western blotting. Besides, by using flow cytometry, we also evaluated the effect of CPT on LPS-induced calcium influx. Finally, the underlying anti-inflammatory mechanisms of CPT were investigated using western blotting to assess the protein levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), phosphatidylinositol 3-kinase (PI3K)/AKT, nuclear factor erythroid 2 related factor 2 (Nrf2), mitogen-activated protein kinase (MAPK), and nuclear factor-kappa B (NF-κB) pathways. RESULTS: Our data showed that CPT inhibited LPS-induced pro-inflammatory cytokine release like IL-6, and TNF-α, as well as NO production. It displayed a significant inhibitory effect on the protein expressions such as iNOS, COX-2, NF-κB pathway like inhibitor of kappa B kinase (IKK)α/ß, inhibitor of kappa B (IκB)-α and NF-κB/p65, PI3K/AKT pathway like PI3K and AKT, and MAPK pathway like c-Jun N-terminal kinase (JNK)1/2, extracellular signal-regulated kinase (ERK)1/2, and p38, in LPS-stimulated RAW264.7 macrophages. Moreover, the immunofluorescence results indicated that CPT suppressed NF-κB/p65 translocation from the cytoplasm into the nucleus. Further investigations showed that CPT treatment increased NAD(P)H quinone oxidoreductase-1 (NQO1) and heme oxygenase-1 (HO-1) expressions together with its upstream mediator, Nrf2. In addition, CPT inhibited LPS-induced toll-like receptor 4 (TLR4) and MyD88 expressions in RAW264.7 macrophages. CONCLUSIONS: Collectively, we suggested that CPT exerted significant anti-inflammatory effects via modulating TLR4-MyD88/PI3K/Nrf2 and TLR4-MyD88/NF-κB/MAPK pathways.

Diethyl Blechnic Exhibits Anti-Inflammatory and Antioxidative Activity via the TLR4/MyD88 Signaling Pathway in LPS-Stimulated RAW264.7 Cells.

Inflammation is a common pathogenesis in many diseases. Salvia miltiorrhiza Bunge (Danshen), a traditional Chinese medicine, has been considered to have good anti-inflammatory effects. In the present study, we investigated the anti-inflammatory effect of diethyl blechnic (DB), a novel compound isolated from Danshen, and its possible mechanisms in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. The results showed that DB can inhibit the LPS-induced pro-inflammatory cytokines release of prostaglandin E2 (PGE2) and mRNA expression of TNF-α, IL-6, and IL-1ß. In addition, the results of the flow cytometry assay and the fluorometric intracellular ROS kit assay indicated that DB reduced the generation of ROS in LPS-stimualted RAW264.7 cells. DB reversed the LPS-induced loss of the mitochondrial membrane potential (MMP). Furthermore, DB suppressed the LPS-stimulated increased expression of Toll-like receptor 4 (TLR4), myeloid differential protein-88 (MyD88) and phosphorylation of TAK1, PI3K, and AKT. DB promoted NF-E2-related factor 2 (Nrf2) into the nucleus, increased the expression of heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase [quinone] 1 (NQO1) and reduced the expression of Keap1. In summary, DB may inhibit LPS-induced inflammation, which mainly occurs through TLR4/MyD88 and oxidative stress signaling pathways in RAW264.7 cells.

Annexin A4-nuclear factor-κB feedback circuit regulates cell malignant behavior and tumor growth in gallbladder cancer.

Gallbladder cancer (GBC) is the most common malignant tumor of the biliary system. However, the mechanisms underlying its tumor initiation, progression, and metastasis are not yet fully understood. The annexin A4 (ANXA4) gene is highly expressed in GBC tissues and may play an important role in the initiation and progression of this disease. In this study, we examined the up-regulation of ANXA4 in human GBC tissues and cell lines. Elevated ANXA4 correlated well with invasion depth in GBC patients and predicted a poor prognosis. In vitro, GBC-SD and NOZ cells with ANXA4 knockdown demonstrated increased apoptosis and inhibited cell growth, migration, and invasion. Interactions between ANXA4 and nuclear factor-κB (NF-κB) p65 proteins were detected. In vivo, ANXA4 knockdown inhibited tumor growth of GBC cells in nude mice and down-regulated the expression of downstream factors in the NF-κB signaling pathway. Taken together, these data indicate that up-regulation of ANXA4 leads to activation of the NF-κB pathway and its target genes in a feedback regulatory mechanism via the p65 subunit, resulting in tumor growth in GBC.

Hepatocyte nuclear factor 4α suppresses the aggravation of colon carcinoma.

Hepatocyte nuclear factor 4-α (HNF4α), a nuclear receptor, is expressed at lower levels in colon carcinoma tissues than in adjacent normal tissues. However, the relation between HNF4α and colon cancer progression and the underlying molecular mechanisms remain unclear. Here, we investigated the role of HNF4α in the progression of colon carcinoma. We showed that HNF4α mRNA and protein were downregulated in colon carcinoma specimens. HNF4α expression was related to pT classification (P < 0.001), lymph node metastasis (P = 0.002), distant metastasis (P < 0.001) and clinical stage (P < 0.001) in colon carcinoma patients. Patients with low or negative HNF4α expression had worse 3-year progression-free survival (PFS, P = 0.006) and overall survival (OS, P = 0.005) than patients with high HNF4α expression. Low HNF4α expression was an independent prognostic factor for 3-year PFS (hazard ratio 2.94; 95% confidence interval 1.047-8.250; P = 0.041). Ectopic expression of HNF4α inhibited colon carcinoma cell (HT29, LoVo, and SW480) proliferation, migration, and invasion, induced G2/M phase arrest and promoted apoptosis. Ectopic expression of HNF4α upregulated E-cadherin and downregulated vimentin in vitro, and suppressed SW480 xenograft tumor growth and liver metastasis in vivo. Furthermore, HNF4α overexpression downregulated the expression of snail, slug and twist. HNF4α inhibited EMT through its effect on the Wnt/ß-catenin signaling pathway, and HNF4α downregulation may be mediated by promoter methylation in cancer tissues. Our results suggest that downregulation of HNF4α plays a critical role in the aggravation of colon carcinoma possibly by promoting EMT via the Wnt/ß-catenin signaling pathway and by affecting apoptosis and cell cycle progression.

Spatio-temporal reconstruction of air temperature maps and their application to estimate rice growing season heat accumulation using multi-temporal MODIS data.

The accumulation of thermal time usually represents the local heat resources to drive crop growth. Maps of temperature-based agro-meteorological indices are commonly generated by the spatial interpolation of data collected from meteorological stations with coarse geographic continuity. To solve the critical problems of estimating air temperature (T(a)) and filling in missing pixels due to cloudy and low-quality images in growing degree days (GDDs) calculation from remotely sensed data, a novel spatio-temporal algorithm for T(a) estimation from Terra and Aqua moderate resolution imaging spectroradiometer (MODIS) data was proposed. This is a preliminary study to calculate heat accumulation, expressed in accumulative growing degree days (AGDDs) above 10 °C, from reconstructed T(a) based on MODIS land surface temperature (LST) data. The verification results of maximum T(a), minimum T(a), GDD, and AGDD from MODIS-derived data to meteorological calculation were all satisfied with high correlations over 0.01 significant levels. Overall, MODIS-derived AGDD was slightly underestimated with almost 10% relative error. However, the feasibility of employing AGDD anomaly maps to characterize the 2001-2010 spatio-temporal variability of heat accumulation and estimating the 2011 heat accumulation distribution using only MODIS data was finally demonstrated in the current paper. Our study may supply a novel way to calculate AGDD in heat-related study concerning crop growth monitoring, agricultural climatic regionalization, and agro-meteorological disaster detection at the regional scale.

Emodin as an effective agent in targeting cancer stem-like side population cells of gallbladder carcinoma.

Side population (SP) cells are previously identified from bone marrow based on their capacity to efflux of the fluorescent dye Hoechst 33342. Recent studies demonstrate that SP cells isolated from various cancer cell lines and primary tumors possess stem-cell-like properties. Thus, targeting tumor SP cells may provide new strategies for treatment in clinic. We previously showed that 1,3,8-trihydroxy-6-methylanthraquinone (emodin), a reactive oxygen species (ROS) generator, enhanced sensitivity of gallbladder cancer SGC-996 cells to cisplatin (CDDP) via generation of ROS and downregulation of multidrug-resistance-associated protein 1 (MRP1). To determine whether emodin also acts effectively on cancer stem cells of gallbladder carcinoma, we use SP cells as a model of cancer stem-cell-like cells. Here, we found that emodin, via ROS-related mechanism and suppressing the function of ATP-binding cassette super-family G member (ABCG2), which is known to be associated with Hoechst dye efflux activity of SP cells, not only reduced the ratio, inhibited clone formation, and eliminated sphere formation of SP cells effectively, but also promoted obviously the intracellular accumulation of doxorubicin, the main substrate of the efflux pump ABCG2. In addition, emodin could sensitize CDDP, via inhibition of expression of ABCG2, to overcome chemoresistance of SP cells. Importantly, similar to the experiment in vitro, emodin/CDDP co-treatment in vivo suppressed the tumor growth derived from SP cells through downregulating ABCG2 expression. Our results suggest that emodin is an effective agent targeting cancer stem-like SP cells of gallbladder carcinoma, either alone or acts as a chemotherapy enhancer.

Characterization of cancer stem-like cells derived from a side population of a human gallbladder carcinoma cell line, SGC-996.

The cancer stem cell (CSC) hypothesis proposes that CSCs, which can renew themselves proliferate infinitely, and escape chemotherapy, become the root of recurrence and metastasis. Previous studies have verified that side population (SP) cells, characterized by their ability to efflux lipophilic substrate Hoechst 33342, to share many characteristics of CSCs in multiplying solid tumors. The purpose of this study was to sort SP cells from a human gallbladder carcinoma cell line, SGC-996 and to preliminarily identify the biological characteristics of SP cells from the cell line. Using flow cytometry we effectively sorted SP cells from the cell line SGC-996. SP cells not only displayed higher proliferative, stronger clonal-generating, more migratory and more invasive capacities, but showed stronger resistance. Furthermore, our experiments demonstrated that SP cells were more tumorigenic than non-SP counterparts in vivo. Real-time PCR analysis and immunocytochemistry showed that the expression of ATP-binding cassette subfamily G member 2 (ABCG2) was significantly higher in SP cells. Hence, these results collectively suggest that SP cells are progenitor/stem-like cells and ABCG2 might be a candidate marker for SP cells in human gallbladder cancer.

Detection of pathogen based on the catalytic growth of gold nanocrystals.

A homogenous detection of pathogen (Giardia lamblia cysts) based on the catalytic growth of gold nanoparticles (AuNPs) has been studied. In this study, centrifugal filters were employed as tools to concentrate and separate the pathogen cells, and moreover amplify the detection signal. The catalytic growth of gold nanoparticles was verified to be positively related to gold seeds concentration. On this basis, homogenous detection of the pathogenic bacteria in liquid phase was established by means of conjugating antibody to gold seeds. Under the given experimental condition, detection limit of G. lamblia cysts was determined as low as 1.088 x 10(3) cells ml(-1). The additional nonspecific binding tests were also conducted to verify the detection specificity. This sensing platform has been proved to be a sensitive, reliable and simple method for large-scale pathogen detection, and provide valuable insight for the development of gold nanocrystals based colorimetric biosensors.