Single-cell RNA sequencing reveals the transcriptomic landscape of kidneys in patients with ischemic acute kidney injury / 中华医学杂志(英文版)

BACKGROUND@#Ischemic acute kidney injury (AKI) is a common syndrome associated with considerable mortality and healthcare costs. Up to now, the underlying pathogenesis of ischemic AKI remains incompletely understood, and specific strategies for early diagnosis and treatment of ischemic AKI are still lacking. Here, this study aimed to define the transcriptomic landscape of AKI patients through single-cell RNA sequencing (scRNA-seq) analysis in kidneys.@*METHODS@#In this study, scRNA-seq technology was applied to kidneys from two ischemic AKI patients, and three human public scRNA-seq datasets were collected as controls. Differentially expressed genes (DEGs) and cell clusters of kidneys were determined. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, as well as the ligand-receptor interaction between cells, were performed. We also validated several DEGs expression in kidneys from human ischemic AKI and ischemia/reperfusion (I/R) injury induced AKI mice through immunohistochemistry staining.@*RESULTS@#15 distinct cell clusters were determined in kidney from subjects of ischemic AKI and control. The injured proximal tubules (PT) displayed a proapoptotic and proinflammatory phenotype. PT cells of ischemic AKI had up-regulation of novel pro-apoptotic genes including USP47 , RASSF4 , EBAG9 , IER3 , SASH1 , SEPTIN7 , and NUB1 , which have not been reported in ischemic AKI previously. Several hub genes were validated in kidneys from human AKI and renal I/R injury mice, respectively. Furthermore, PT highly expressed DEGs enriched in endoplasmic reticulum stress, autophagy, and retinoic acid-inducible gene I (RIG-I) signaling. DEGs overexpressed in other tubular cells were primarily enriched in nucleotide-binding and oligomerization domain (NOD)-like receptor signaling, estrogen signaling, interleukin (IL)-12 signaling, and IL-17 signaling. Overexpressed genes in kidney-resident immune cells including macrophages, natural killer T (NKT) cells, monocytes, and dendritic cells were associated with leukocyte activation, chemotaxis, cell adhesion, and complement activation. In addition, the ligand-receptor interactions analysis revealed prominent communications between macrophages and monocytes with other cells in the process of ischemic AKI.@*CONCLUSION@#Together, this study reveals distinct cell-specific transcriptomic atlas of kidney in ischemic AKI patients, altered signaling pathways, and potential cell-cell crosstalk in the development of AKI. These data reveal new insights into the pathogenesis and potential therapeutic strategies in ischemic AKI.

The regulatory relationship between RagA and Nprl2 in Drosophila gut development / 生物工程学报

The gastrointestinal tract is the largest digestive organ and the largest immune organ and detoxification organ, which is vital to the health of the body. Drosophila is a classic model organism, and its gut is highly similar to mammalian gut in terms of cell composition and genetic regulation, therefore can be used as a good model for studying gut development. target of rapmaycin complex 1 (TORC1) is a key factor regulating cellular metabolism. Nprl2 inhibits TORC1 activity by reducing Rag GTPase activity. Previous studies have found that nprl2 mutated Drosophila showed aging-related phenotypes such as enlarged foregastric and reduced lifespan, which were caused by over-activation of TORC1. In order to explore the role of Rag GTPase in the developmental defects of the gut of nprl2 mutated Drosophila, we used genetic hybridization combined with immunofluorescence to study the intestinal morphology and intestinal cell composition of RagA knockdown and nprl2 mutated Drosophila. The results showed that RagA knockdown alone could induce intestinal thickening and forestomach enlargement, suggesting that RagA also plays an important role in intestinal development. Knockdown of RagA rescued the phenotype of intestinal thinning and decreased secretory cells in nprl2 mutants, suggesting that Nprl2 may regulate the differentiation and morphology of intestinal cells by acting on RagA. Knockdown of RagA did not rescue the enlarged forestomach phenotype in nprl2 mutants, suggesting that Nprl2 may regulate forestomach development and intestinal digestive function through a mechanism independent of Rag GTPase.

LASS2/TMSG1 overexpression inhibits proliferation and promotes apoptosis of human lung cancer A549 cells possibly by upregulating ceramide and p38 MAPK to activate a signaling cascade / 南方医科大学学报

OBJECTIVE@#To investigate the effects of LASS2/TMSG1 gene overexpression on proliferation and apoptosis of human lung cancer A549 cells and explore the possible mechanism.@*METHODS@#We examined LASS2/TMSG1 expression level in a previously constructed A549 cell line overexpressing LASS2/TMSG1 using Western blotting. The proliferation and apoptosis of the cells were detected using colony-forming assay, CCK-8 assay, Hoechst/PI double staining and flow cytometry. Fourteen nude mice were randomized into 2 groups (n=7) to receive subcutaneous injection of A549 cells with or without LASS2/TMSG1 overexpression on the back of the neck, and the cell proliferation in vivo was observed. The expression levels of p38 MAPK protein and p-p38 MAPK protein in the xenografts were detected with Western blotting. ELISA was used to detect the levels of ceramide and p38 MAPK protein in cultured A549 cell supernatants and the xenografts in nude mice.@*RESULTS@#Compared with the negative control cells, A549 cells with LASS2/TMSG1 overexpression had significantly lowered proliferation ability in vitro with increased early apoptosis rate (P < 0.05), and showed obvious growth inhibition after inoculation in nude mice(P < 0.05). Western blotting showed that in both cultured A549 cells and the xenografts in nude mice, LASS2/TMSG1 gene overexpression significantly increased the expression levels of p38 MAPK protein and p-p38 MAPK protein (P < 0.05); the results of ELISA also revealed significantly increased levels of ceramide and p38 MAPK protein in the cell supernatant andxenografts as well (P < 0.05).@*CONCLUSION@#Overexpression of LASS2/TMSG1 gene can significantly inhibit the proliferation and promote early apoptosis of human lung cancer A549 cells both in vitro and in vivo possibly by upregulating the expressions of ceramide and p38 MAPK protein to activate a signal transduction cascade.

ZNF750 facilitates carcinogenesis via promoting the expression of long non-coding RNA CYTOR and influences pharmacotherapy response in colon adenocarcinoma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The epidermal cell differentiation regulator zinc finger protein 750 (ZNF750) is a transcription factor containing the Cys2His2 (C2H2) domain, the zinc finger structure of which is located at the N-terminal 25‍‍-‍46 amino acids of ZNF750. It can promote the expression of differentiation-related factors while inhibiting the expression of progenitor cell-related genes. ZNF750 is directly regulated by p63 (encoded by the TP63 gene, belonging to the TP53 superfamily). The Krüppel-like factor 4 (KLF4), repressor element-1 (RE-1)‍-silencing transcription factor (REST) corepressor 1 (RCOR1), lysine demethylase 1A (KDM1A), and C-terminal-binding protein 1/2 (CTBP1/2) chromatin regulators cooperate with ZNF750 to repress epidermal progenitor genes and activate the expression of epidermal terminal differentiation genes (Sen et al., 2012; Boxer et al., 2014). Besides, ZNF750 and the regulatory network composed of bone morphogenetic protein (BMP) signaling pathway, long non-coding RNAs (lncRNAs) (anti-differentiation non-coding RNA (ANCR) and tissue differentiation-inducing non-protein coding RNA (TINCR)), musculoaponeurotic fibrosarcoma oncogene (MAF)/MAF family B (MAFB), grainy head-like 3 (GRHL3), and positive regulatory domain zinc finger protein 1 (PRDM1) jointly promote epidermal cell differentiation (Sen et al., 2012).

Expression and significance of CK5/6, P63, P40, CK7, TTF-1, NapsinA, CD56, Syn and CgA in biopsy specimen of squamous cell carcinoma, adenocarcinoma and small cell lung carcinoma / Expresión y significado de CK5/6, P63, P40, CK7, TTF-1, NapsinA, CD56 Syn y CgA en muestras de biopsia de carcinoma de células escamosas, adenocarcinoma y carcinoma de células pequeñas de pulmón

Nine tumor and various potential biomarkers were measured and combined the information to diagnose disease, all patients accepted fiber bronchoscopy brush liquid based cytologyand histopathology examination in order to reliably detect lung cancer. The samples from 314 Chinese lung cancer patients were obtained and CK5/6, P63, P40, CK7, TTF-1, NapsinA CD56, Syn and CgA were measured with the immunohistochemical SP method and analyzed correlation of the expression of these markers with pathological and clinical features of squamous cell carcinoma, adenocarcinoma, and small cell lung carcinoma. Squamous cell carcinoma, adenocarcinoma and small cell carcinoma were 61 cases, 114 cases and 139 cases,CK5/6 and P63 expression were more frequent in squamous cell carcinoma, with sensitivity and specificity of 77.05 % and 96.44 %, 83.61 % and 88.93 %,and compared with adenocarcinoma and small cell carcinoma difference was statistically significant (P<0.05), The incidences of a positive P40 expression were 100 % in squamous cell carcinoma, with specificity of 98.81 %.CK7, TTF-1 and NapsinA expression were more frequent in adenocarcinoma, with sensitivity and specificity of 85.09 % and 78.69 %, 79.82 % and 93.44 %, 56.14 % and 95.08 %, and compared with squamous cell carcinoma and small cell carcinoma difference was statistically significant (P<0.05). TTF-1, Syn, CgA and CD56 expression were more frequent in adenocarcinoma, with sensitivity and specificity of 86.33 % and 93.44 %, 89.21 % and 98.36 %, 74.10 % and 100 %, 96.40 % and 96.72 %. The combined detection of CK5/6, P63 and P40 were more useful and specific in differentiating squamous cell carcinoma. CK7, TTF-1 and NapsinA were more useful and specific in differentiating lung adenocarcinoma. The impaired CD56, TTF-1, Syn and CgA reflects the progression of small cell lung cancer.

Se midieron tumores y utilizaron nueve biomarcadores potenciales y se analizó la información para diagnosticar la enfermedad. A todos los pacientes se les realizó citología en líquido con broncoscopía de fibra y examen histopatológico para detectar de manera confiable el cáncer pulmonar. Se obtuvieron muestras de 314 pacientes chinos con cáncer de pulmón y CK5 / 6, P63, P40, CK7, TTF-1, Napsina A, CD56, Syn y CgA se midieron a través de histoquímica SP y analizaron la correlación de la expresión de estos marcadores con características patológicas y clínicas de carcinoma de células escamosas, adenocarcinoma y carcinoma de células pequeñas en el cáncer de pulmón. El carcinoma de células escamosas, el adenocarcinoma y el carcinoma de células pequeñas fueron 61 casos, 114 casos y 139 casos, respectivamente, la expresión de CK5 / 6 y P63 fueron más frecuentes en el carcinoma de células escamosas, con una sensibilidad y especificidad del 77,05 % y 96,44 %, 83,61 % y 88,93 %, y en comparación con el adenocarcinoma y el carcinoma de células pequeñas, la diferencia fue estadísticamente significativa (P <0,05). La incidencia de ap la expresión positiva P40 fue del 100 % en el carcinoma de células escamosas, con una especificidad del 98,81 %. La expresión de CK7, TTF-1 y NapsinA fueron más frecuentes en el adenocarcinoma, con una sensibilidad y especificidad del 85,09 % y 78,69 %, 79,82 % y 93,44 %, 56,14 % y 95,08 %, y en comparación con el carcinoma de células escamosas y la diferencia de carcinoma de células pequeñas fue estadísticamente significativa (P <0,05) .TTF-1, Syn, CgA y la expresión de CD56 fueron más frecuentes en adenocarcinoma, con sensibilidad y especificidad de 86.33 % y 93.44 %, 89.21 % y 98.36 %, 74.10 % y 100 %, 96.40 % y 96.72 %. La detección combinada de CK5 / 6, P63 y P40 fue más útil y específica en la diferenciación del carcinoma de células escamosas. CK7, TTF-1 y NapsinA fueron más útiles y específicos para diferenciar el adenocarcinoma de pulmón. El deterioro de CD56, TTF-1, Syn y CgA refleja la progresión del cáncer de pulmón de células pequeñas.

PM

BACKGROUND@#Particulate matter (PM) < 2.5 μm (PM@*METHODS@#We obtained DNA methylation and exercise data of 496 participants (aged between 30 and 70 years) from the Taiwan Biobank (TWB) database. We also extracted PM@*RESULTS@#DLEC1 methylation and PM@*CONCLUSIONS@#We found significant positive associations between PM

MicroRNA-663 facilitates the growth, migration and invasion of ovarian cancer cell by inhibiting TUSC2

BACKGROUND: MicroRNAs (miRNAs) have emerged as the critical modulators of the tumorigenesis and tumor progression. METHODS: The levels of miR-663 in ovarian cancer cell lines and clinical tissues were detected using qRT-PCR assays. The Transwell invasion and wound healing assay were conducted to assess the roles of miR-663 in the migration and invasion of ovarian cancer cell in vitro. Rescue assays were carried out to confirm the contribution of tumor suppressor candidate 2 (TUSC2) in the aggressiveness of cancer cell which was regulated by miR-663. RESULTS: The levels of miR-663 were up-regulated in ovarian cancer tissues in comparison with the corresponding normal tissues. Up-regulation of miR-663 increased the proliferation, colony formation, migration and invasion of ovarian cancer SKOV3 cell. Additional, over-expression of miR-663 increased the tumor growth of SKOV3 in xenograft model. Bioinformatics analysis and luciferase reporter assay identified that miR-663 decreased the level of TUSC2 via binding to the 3'-UTR of TUSC2 gene. Finally, the expression of TUSC2 was inversely associated with the level of miR-663 in ovarian carcinoma tissue and over-expression of TUSC2 inhibited the migration and invasion abilities of SKOV3 that was promoted by miR-663. CONCLUSION: Altogether, these results indicate that miR-663 acts as a potential tumor-promoting miRNA through targeting TUSC2 in ovarian cancer.

Protective roles of autophagy in retinal pigment epithelium under high glucose condition via regulating PINK1/Parkin pathway and BNIP3L

BACKGROUND: Our study aimed to investigate the roles of autophagy against high glucose induced response in retinal pigment epithelium (ARPE-19 cells). METHODS: The morphological changes and reactive oxygen species (ROS) generation in ARPE-19 cells under high glucose treatment were respectively detected using the transmission electron microscopy and flow cytometry. The expression levels of Parkin, PINK1, BNIP3L, LC3-I and LC3-II in ARPE-19 cells received high glucose treatment were measured by western blot after pretreatment of carbonyl cyanide m-chlorophenylhydrazone (CCCP), 3-methyladenine (3-MA), N-acetyl cysteine (NAC) or cyclosporin A (CsA) followed by high glucose treatment. RESULTS: ARPE-19 cells subjected to high glucose stress showed an obvious reduction in the LC3-I expression and significant increase in the number of autophagosomes, in the intracellular ROS level, and in the expression levels of Parkin, PINK1, BNIP3L and LC3-II (p < 0.05). Pretreatment with CCCP significantly reduced the LC3-I expression and increased the expression levels of Parkin, PINK1, BNIP3L and LC3-II (p < 0.05). ARPE-19 cells pretreated with CsA under high glucose stress showed markedly down-regulated expressions of Parkin, PINK1 and BNIP3L compared with the cells treated with high glucose (p < 0.05). Pretreatment of ARPE-19 cells with NAC or 3-MA under high glucose stress resulted in a marked reduction in the expression levels of PINK1, BNIP3L and LC3-II (p < 0.05). Meanwhile, the expression level of Parkin in the ARPE-19 cells pretreated with NAC under high glucose stress was comparable with that in the control cells. CONCLUSION: Autophagy might have protective roles against high glucose induced injury in ARPE19 cells via regulating PINK1/Parkin pathway and BNIP3L.

miR-483-5p promotes prostate cancer cell proliferation and invasion by targeting RBM5

ABSTRACT Objective: miR-483-5p has been identified as a miRNA oncogene in certain cancers. However, its role in prostate cancer has not been sufficiently investigated. In this study, we investigated the role of miR-483-5p in prostate cancer and examined RBM5 regulation by miR-483-5p. Material and methods: Expression levels of miR-483-5p were determined by quantitative real-time PCR. The effect of miR-483-5p on proliferation was evaluated by MTT assay, cell invasion was evaluated by trans-well invasion assays, and target protein expression was determined by western blotting in LNCaP, DU-145, and PC-3 cells. Luciferase reporter plasmids were constructed to confirm the action of miR-483-5p on downstream target gene RBM5 in HEK-293T cells. Results: we observed that miR-483-5p was upregulated in prostate cancer cell lines and tissues. A miR-483-5p inhibitor inhibited prostate cancer cell growth and invasion in DU-145 and PC-3 cells. miR-483-5p directly bound to the 3' untranslated region (3'UTR) of RBM5 in HEK-293T cells. RBM5 overexpression inhibited prostate cancer cell growth and invasion in LNCaP cells. Enforced RBM5 expression alleviated miR-483-5p promotion of prostate cancer cell growth and invasion in LNCaP cells. Conclusion: The present study describes a potential mechanism underlying a miR-483-5p/RBM5 link that contributes to prostate cancer development.

Expression of merlin, NDRG2, ERBB2, and c-MYC in meningiomas: relationship with tumor grade and recurrence

Meningiomas are common, usually benign tumors of the central nervous system that have a high rate of post-surgical recurrence or regrowth. We determined expression of the proteins merlin, NDRG2, ERBB2, and c-MYC in meningiomas using immunohistochemistry and assessed relationships between protein expression and gender, age, tumor grade, and recurrence or regrowth. The study sample comprised 60 patients, (44 women and 16 men) with a mean age of 53.2±12.7 years. Tumors were classified as grade I (n=48) or grades II and III (n=12). Expression of merlin, NDRG2, ERBB2, and c-MYC was not significantly different statistically with relation to gender, age, or meningioma recurrence or regrowth. Merlin was expressed in 100% of the cases. No statistically significant difference between tumor grade and recurrence or regrowth was identified. Statistically significant differences were identified between the mean age of patients with grade I (54.83±11.60) and grades II and III (46.58±15.08) meningiomas (P=0.043), between strong c-MYC expression and grades II and III (P<0.001), and between partial surgical resection and tumor recurrence or regrowth (P<0.001). These findings reveal the lower mean age among grades II and III meningioma patients than grade I patients, the influence of the protein merlin on tumorigenesis, the association of c-MYC with aggressive meningiomas, and that partial surgical resection is associated with tumor recurrence or regrowth.

Bap1 y neoplasias melanocíticas / Bap1 and melanocytic neoplasms

El melanoma maligno cutáneo (MMC) es un cáncer genéticamente heterogéneo, en cuya patogénesis participarían varios genes. Algunos de estos activan la vía MAP kinasa (BRAF, NRAS, KIT, NF1), mientras que otros confieren una mayor susceptibilidad a melanoma familiar, como CDKN2A, CDK4, MITF y BAP1. BAP1 (BRCA1-associated-protein 1) ha sido descrito como una proteína que se une a BRCA1 para inhibir el crecimiento celular. Actualmente se sabe que es producto de un gen supresor de tumores (denominado BAP1) y que actúa como una enzima con actividad deubiquitinasa, la cual se asocia a varios complejos de proteínas, regulando diversas vías celulares relacionadas con el ciclo celular, diferenciación y muerte celular, así como también gluconeogénesis y respuesta a daño del ADN. Tanto su actividad deubiquitinasa como su localización nuclear son relevantes para su función en la supresión de tumores.

Malignant cutaneous melanoma (MMC) is a genetically heterogeneous cancer and various genes participate in its pathogenesis. Some of these genes activate the MAP kinase pathway (BRAF, NRAS, KIT, NF1) and others are related to a higher susceptibility to familial melanoma like CDKN2A, CDK4, MITF y BAP1. BAP1 (BRCA1-associated –protein 1) has been described as a BRCA1-binding protein inhibiting cell growth. This protein is a product of a gene with tumor suppressor activity, the protein being a deubiquitinase associated to multiple protein complexes regulating various cellular pathways, including the cell cycle, differentiation and cell death, as well as gluconeogenesis and DNA damage response. Both deubiquitinase activity and location to the nucleus are relevant to its tumor suppressor function.

miR-205 promotes proliferation and invasion of laryngeal squamous cell carcinoma by suppressing CDK2AP1 expression

BACKGROUND: The aberrant expression of microRNAs (miRNAs) has been found in various types of cancer. miR-205 was reported to be upregulated in laryngeal squamous cell carcinoma (LSCC) tissues, however, the mechanisms by which miR-205 functions as a regulator of LSCC are largely unknown. RESULTS: In this study, Real-time qPCR and Western blot assay showed that expression of miR-205 was upregulated and expression of cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) was downregulated in LSCC tissues. The expression levels of miR-205 were negatively related to those of CDK2AP1 in LSCC tissues and cell lines. Moreover, we found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the CDK2AP1 expression in LSCC cells. 3-(4,5-dimethylthiazal-2-yl)-2,5-diphenyl-tetrazolium bromide assays and transwell invasion assay were performed to test the proliferation and invasion of LSCC cells. Gelatin zymography was used to detect the activity of MMP2 and MMP9. CDK2AP1, c-Myc and CyclinD1 expression in cells was assessed with Western blotting. We found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the expression of CDK2AP1 in LSCC cells. In addition, miR-205 significantly induced cell proliferation and invasion by suppressing CDK2AP1 expression. Consistent with miR-205 inhibitors, overexpressed CDK2AP1 suppressed the activity of MMP2 and MMP9 and c-Myc and CyclinD1 expression in LSCC cells. CONCLUSION: These findings help us to better elucidate the molecular mechanisms of LSCC progression and provide a new theoretical basis to further investigate miR-205 as a potential biomarker and a promising approach for LSCC treatment.

Effect of a Surfactant on the Antimicrobial Activity of Sodium Hypochlorite Solutions

The objective of the present study was to evaluate the antimicrobial activity of sodium hypochlorite (NaOCl) associated with a surfactant. Seventy single-rooted extracted human teeth were inoculated with Enterococcus faecalis, and incubated for 21 days (37 °C). The groups were distributed according to the irrigation solution used during root canal preparation: 5%, 2.5% and 1% NaOCl; 5%, 2.5% and 1% Hypoclean(r), a solution containing a surfactant (cetrimide) associated with NaOCl. Three microbiological samples were collected from each tooth: S1 - before instrumentation; S2 - immediately after instrumentation; and S3 - after a seven-day period. Data were submitted to ANOVA and Tukey test with 5% significance level. The results showed that immediately after root canal preparation (S2), E. faecalis was eliminated in all the experimental groups. However, after 7 days (S3), only the groups in which Hypoclean was used, remained contamination-free, including Hypoclean associated with 1% NaOCl, while the root canals irrigated with 1% NaOCl only, presented the highest percentage of bacterial growth. In conclusion, the addition of surfactant increased the antimicrobial activity of 1% NaOCl to levels similar to 5% NaOCl.

O objetivo da presente pesquisa foi avaliar a atividade antimicrobiana de hipoclorito de sódio (NaOCl), associado a um tensoativo. Setenta dentes humanos monorradiculares extraídos foram inoculados com Enterococcus faecalis e incubados durante 21 dias (37 °C). Os grupos foram distribuídos de acordo com a solução irrigadora utilizada no preparo do canal: hipoclorito de sódio a 5%, 2,5% e 1%; Hypoclean(r) a 5%, 2,5% e 1% - uma solução contendo um surfactante (cetrimida) associado com NaOCl. Três amostras microbiológicas foram coletadas de cada dente: S1 - antes de instrumentação; S2 - imediatamente após a instrumentação; e S3 - após um período de sete dias. Os dados foram submetidos à análise de variância e teste de Tukey com 5% de nível de significância. Os resultados mostraram que imediatamente após o preparo do canal radicular (S2), o E. faecalis foi eliminado em todos os grupos experimentais. No entanto, após 7 dias (S3), apenas os grupos em que se utilizou Hypoclean permaneceram livres de contaminação, incluindo Hypoclean 1%, enquanto que os canais radiculares irrigados apenas com hipoclorito de sódio 1% apresentaram a mais elevada percentagem de crescimento bacteriano. Em conclusão, a adição de surfactante aumentou a atividade antimicrobiana de 1% de NaOCl a níveis semelhantes aos do NaOCl 5% .

Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.

AKT inhibitor suppresses hyperthermia-induced Ndrg2 phosphorylation in gastric cancer cells

Hyperthermia is one of the most effective adjuvant treatments for various cancers with few side effects. However, the underlying molecular mechanisms still are not known. N-myc downstream-regulated gene 2 (NDRG2), a tumor suppressor, has been shown to be involved in diverse cellular stresses including hypoxia, lipotoxicity, etc. In addition, Ndrg2 has been reported to be related to progression of gastric cancer. In the current study, our data showed that the apoptosis rate of MKN28 cells increased relatively rapidly to 13.4% by 24 h after treatment with hyperthermia (42°C for 1 h) compared to 5.1% in control cells (P < 0.05). Nevertheless, there was no obvious change in the expression level of total Ndrg2 during this process. Further investigation demonstrated that the relative phosphorylation levels of Ndrg2 at Ser332, Thr348 increased up to 3.2- and 1.9-fold (hyperthermia group vs control group) at 3 h in MKN28 cells, respectively (P < 0.05). We also found that heat treatment significantly increased AKT phosphorylation. AKT inhibitor VIII (10 µM) decreased the phosphorylation level of Ndrg2 induced by hyperthermia. Accordingly, the apoptosis rate rose significantly in MKN28 cells (16.4%) treated with a combination of AKT inhibitor VIII and hyperthermia compared to that (6.8%) of cells treated with hyperthermia alone (P < 0.05). Taken together, these data demonstrated that Ndrg2 phosphorylation could be induced by hyperthermia in an AKT-dependent manner in gastric cancer cells. Furthermore, AKT inhibitor VIII suppressed Ndrg2 phosphorylation and rendered gastric cancer cells susceptible to apoptosis induced by hyperthermia.

Correlation of MGMT promoter methylation status with gene and protein expression levels in glioblastoma

OBJECTIVES: 1) To correlate the methylation status of the O6-methylguanine-DNA-methyltransferase (MGMT) promoter to its gene and protein expression levels in glioblastoma and 2) to determine the most reliable method for using MGMT to predict the response to adjuvant therapy in patients with glioblastoma. BACKGROUND: The MGMT gene is epigenetically silenced by promoter hypermethylation in gliomas, and this modification has emerged as a relevant predictor of therapeutic response. METHODS: Fifty-one cases of glioblastoma were analyzed for MGMT promoter methylation by methylation-specific PCR and pyrosequencing, gene expression by real time polymerase chain reaction, and protein expression by immunohistochemistry. RESULTS: MGMT promoter methylation was found in 43.1 percent of glioblastoma by methylation-specific PCR and 38.8 percent by pyrosequencing. A low level of MGMT gene expression was correlated with positive MGMT promoter methylation (p = 0.001). However, no correlation was found between promoter methylation and MGMT protein expression (p = 0.297). The mean survival time of glioblastoma patients submitted to adjuvant therapy was significantly higher among patients with MGMT promoter methylation (log rank = 0.025 by methylation-specific PCR and 0.004 by pyrosequencing), and methylation was an independent predictive factor that was associated with improved prognosis by multivariate analysis. DISCUSSION AND CONCLUSION: MGMT promoter methylation status was a more reliable predictor of susceptibility to adjuvant therapy and prognosis of glioblastoma than were MGMT protein or gene expression levels. Methylation-specific polymerase chain reaction and pyrosequencing methods were both sensitive methods for determining MGMT promoter methylation status using DNA extracted from frozen tissue.

ATM modulates transcription in response to histone deacetylase inhibition as part of its DNA damage response

Chromatin structure has a crucial role in a diversity of physiological processes, including development, differentiation and stress responses, via regulation of transcription, DNA replication and DNA damage repair. Histone deacetylase (HDAC) inhibitors regulate chromatin structure and activate the DNA damage checkpoint pathway involving Ataxia-telangiectasia mutated (ATM). Herein, we investigated the impact of histone acetylation/deacetylation modification on the ATM-mediated transcriptional modulation to provide a better understanding of the transcriptional function of ATM. The prototype HDAC inhibitor trichostain A (TSA) reprograms expression of the myeloid cell leukemia-1 (MCL1) and Gadd45alpha genes via the ATM-mediated signal pathway. Transcription of MCL1 and Gadd45alpha is enhanced following TSA treatment in ATM+ cells, but not in isogenic ATM- or kinase-dead ATM expressing cells, in the ATM-activated E2F1 or BRCA1-dependent manner, respectively. These findings suggest that ATM and its kinase activity are essential for the TSA-induced regulation of gene expression. In summary, ATM controls the transcriptional upregulation of MCL1 and Gadd45alpha through the activation of the ATM-mediated signal pathway in response to HDAC inhibition. These findings are important in helping to design combinatory treatment schedules for anticancer radio- or chemo-therapy with HDAC inhibitors.

Low dose hyper-radiosensitivity in human lung cancer cell line A549 and its possible mechanisms / 华中科技大学学报（医学）（英德文版）

The low dose hyper-radiosensitivity (HRS) in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with (60)Co gamma-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at >0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation (P>0.05). After exposure to 0.3, 0.4 and 0.5 Gy radiation, G(2)/M phase arrest occurred 6 and 12 h after radiation (P<0.05), and the ratio of G(2)/M phase cells was decreased 24 h after radiation (P<0.05). It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.

Pure malignant myoepitheliomas of the breast: an immunohistochemical study.

Myoepithelioma of breast are extremely rare. We report two cases of pure malignant myoepithelioma of the breast, utilising light microscopic and immunohistochemical methods for diagnosis. Both the cases presented as breast lump. Hematoxylin and Eosin (H&E) stained microscopic sections revealed a predominantly spindle cell tumor. Immunohistochemical work up was done. Case number one expressed positivity for vimentin, Smooth Muscle Actin (SMA), S-100 and CD10. Case number two expressed positivity for Vimentin, CD10 and p63. This led to the diagnoses of malignant myoepithelioma in both of them. Documentation of such cases prospectively and from archival material, using immunohistochemistry, is of extreme importance to assess the prevalence, various phenotypic patterns, long-term biological behaviour and to establish management protocols for malignant myoepithelioma.