1.Single-cell RNA sequencing reveals the transcriptomic landscape of kidneys in patients with ischemic acute kidney injury.
Rong TANG ; Peng JIN ; Chanjuan SHEN ; Wei LIN ; Leilin YU ; Xueling HU ; Ting MENG ; Linlin ZHANG ; Ling PENG ; Xiangcheng XIAO ; Peter EGGENHUIZEN ; Joshua D OOI ; Xueqin WU ; Xiang DING ; Yong ZHONG
Chinese Medical Journal 2023;136(10):1177-1187
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.
Humans
;
Mice
;
Animals
;
Transcriptome/genetics*
;
Ligands
;
Kidney/metabolism*
;
Acute Kidney Injury/metabolism*
;
Ischemia/metabolism*
;
Reperfusion Injury/metabolism*
;
Sequence Analysis, RNA
;
Adaptor Proteins, Signal Transducing/metabolism*
;
Tumor Suppressor Proteins/metabolism*
2.Impact of LDB3 gene polymorphisms on clinical presentation and implantable cardioverter defibrillator (ICD) implantation in Chinese patients with idiopathic dilated cardiomyopathy.
Dong-Fei WANG ; Jia-Lan LYU ; Juan FANG ; Jian CHEN ; Wan-Wan CHEN ; Jia-Qi HUANG ; Shu-Dong XIA ; Jian-Mei JIN ; Fang-Hong DONG ; Hong-Qiang CHENG ; Ying-Ke XU ; Xiao-Gang GUO
Journal of Zhejiang University. Science. B 2019;20(9):766-775
OBJECTIVE:
Mutations in LIM domain binding 3 (LDB3) gene cause idiopathic dilated cardiomyopathy (IDCM), a structural heart disease with a complicated genetic background. However, the association of polymorphisms in the LDB3 gene with susceptibility to IDCM in Chinese populations remains unexplored as dose the impact on clinical presentation.
METHODS:
We sequenced all exons and the adjacent part of introns of the LDB3 gene in 159 Chinese Han IDCM patients and 247 healthy controls. Then we detected the distribution of polymorphisms in the LDB3 gene in all participants and assessed their associations with risk of IDCM. Additionally, we conducted a stratified genotype-phenotype correlation analysis.
RESULTS:
The A allele of rs4468255 was significantly associated with IDCM (P<0.01). The rs4468255, rs11812601, rs56165849, and rs3740346 were also associated with diastolic blood pressure (DBP) and left ventricular ejection fraction (LVEF) (P<0.05). Notably, a higher frequency of rs4468255 polymorphism was observed in implantable cardioverter defibrillator (ICD) recipients under a recessive model (P<0.01), whereas the significant association disappeared after adjusting for potential confounders. However, in the dominant model, notable correlations could only be observed after adjusting for multi parameters.
CONCLUSIONS
The rs4468255 was significantly correlated with IDCM of Chinese Han population. A allele of rs4468255 is higher in IDCM patients with ICD implantation, suggesting the influence of genetic background in the generation of this response. In addition, rs11812601, rs56165849, and rs3740346 in LDB3 show association with brain natriuretic peptide, DBP, and LVEF levels in patients with IDCM but did not show any association with IDCM susceptibility.
Adaptor Proteins, Signal Transducing/genetics*
;
Adult
;
Aged
;
Alleles
;
Asian People
;
Cardiomyopathy, Dilated/surgery*
;
China/epidemiology*
;
Defibrillators, Implantable
;
Exons
;
Female
;
Genetic Association Studies
;
Genetic Predisposition to Disease
;
Genotype
;
Humans
;
LIM Domain Proteins/genetics*
;
Linkage Disequilibrium
;
Male
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Middle Aged
;
Mutation
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Polymorphism, Genetic
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Sequence Analysis, DNA
3.Investigation of PRAM1 Expression Features and Their Clinical Significance in AML via Gene Expression Microarray Database.
Na LV ; Kun QIAN ; Jing LIU ; Li-Li WANG ; Yong-Hui LI ; Li YU
Journal of Experimental Hematology 2018;26(2):368-374
OBJECTIVETo study the clinical phenotype and its prognostic value of PRAM1 in patients with acute myeloid leukemia(AML).
METHODSBased on the gene expression microarray platform of 486 AML cases, the PRAM1 expression phenotypes were summarized in all of AML subtypes. The PRAM1 expression features were explored in every differentiation stage of hematocytes through normal human stem cell chips and bone marrow gene expression microarray. The clinical drugs which could up-regulate PRAM1 expression in AML cell lines should be found out.
RESULTSThe PRAM1 expression was the richest in the inv(16) AML and the lowest in the t(15;17)M3, almost the same in the other subtypes of AML. By the classification of molecular abnormalities, PRAM1 expression was more in the panel of CN-AML with CEBPAdm than the other two panels. Interestingly, high/low expression of PRAM1 could be re-classified in the CN-AML, and the EFS is statistically significant. It was proven again that PRAM1 is more expressed in the mature granulocytes. Finally, it was confirmed that decitabine and the chidamide could up-regulate PRAM1 expression in AML cell lines, and chidamide effect is better.
CONCLUSIONPRAM1 expression is the lowest in t(15;17) M3 and the highest in inv(16) AML. The high expression of PRAM1 is a sign for favorable prognosis in the CN-AML. PRAM1 is more expressed in mature granulocytes, chidamide can up-regulate PRAM1 expression in AML cell lines.
Adaptor Proteins, Signal Transducing ; Bone Marrow ; Gene Expression ; Humans ; Leukemia, Myeloid, Acute ; Microarray Analysis ; Prognosis
4.Resolvin D1 Protects Lipopolysaccharide-induced Acute Kidney Injury by Down-regulating Nuclear Factor-kappa B Signal and Inhibiting Apoptosis.
Yu-Liang ZHAO ; Ling ZHANG ; Ying-Ying YANG ; Yi TANG ; Jiao-Jiao ZHOU ; Yu-Ying FENG ; Tian-Lei CUI ; Fang LIU ; Ping FU ;
Chinese Medical Journal 2016;129(9):1100-1107
BACKGROUNDResolvin D1 (RvD1) is a newly found anti-inflammatory bioactive compound derived from polyunsaturated fatty acids. The current study aimed to explore the protective effect of RvD1 on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and its possible mechanism.
METHODSBoth in vivo and in vitro studies were conducted. Male BALB/c mice were randomly divided into control group (saline), LPS group (LPS 5 mg/kg), RvD1 group (RvD1 5 μg/kg + LPS 5 mg/kg), and blockage group (Boc-MLP 5 μg/kg + RvD1 5 μg/kg + LPS 5 mg/kg). Boc-MLP is a RvD1 receptor blocker. The mice were intraperitoneally injected with these drugs and recorded for general condition for 48 h, while the blood and kidneys were harvested at 2, 6, 12, 24, and 48 h time points, respectively (n = 6 in each group at each time point). Human proximal tubule epithelial cells (HK-2) were randomly divided into control group (medium only), LPS group (LPS 5 μg/ml), RvD1 group (RvD1 10 ng/ml + LPS 5 μg/ml), and blockage group (Boc-MLP 10 ng/ml + RvD1 10 ng/ml + LPS 5 μg/ml). The cells were harvested for RNA at 2, 4, 6, 12, and 24 h time points, respectively (n = 6 in each group at each time point). Blood creatinine was tested by using an Abbott i-STAT portable blood gas analyzer. Tumor necrosis factor-α (TNF-α) level was detected by ELISA. Kidney pathology was observed under hematoxylin and eosin (HE) staining and transmission electron microscope (TEM). We hired immune-histological staining, Western blotting, and fluorescence quantitative polymerase chain reaction to detect the expression of RvD1 receptor ALX, nuclear factor-kappa B (NF-κB) signaling pathway as well as caspase-3. Kidney apoptosis was evaluated by TUNEL staining.
RESULTSRvD1 receptor ALX was detected on renal tubular epithelials. Kaplan-Meier analysis indicated that RvD1 improved 48 h animal survival (80%) compared with LPS group (40%) and RvD1 blockage group (60%), while RvD1 also ameliorated kidney pathological injury in HE staining and TEM scan. After LPS stimulation, the mRNA expression of toll-like receptor 4, myeloid differentiation factor 88, and TNF-α in both mice kidneys and HK-2 cells were all up-regulated, while RvD1 substantially inhibited the up-regulation of these genes. Western blotting showed that the phosphorylated-IκB/IκB ratio in LPS group was significantly higher than that in the control group, which was inhibited in the RvD1 group. RvD1 could inhibit the up-regulation of cleaved-caspase-3 protein stimulated by LPS, which was prohibited in RvD1 blockage group. RvD1 group also had a lower proportion of apoptotic nuclei in mice kidney by TUNEL staining compared with LPS group.
CONCLUSIONIn LPS-induced AKI, RvD1 could decrease TNF-α level, ameliorate kidney pathological injury, protect kidney function, and improve animal survival by down-regulating NF-κB inflammatory signal as well as inhibiting renal cell apoptosis.
Acute Kidney Injury ; chemically induced ; prevention & control ; Adaptor Proteins, Signal Transducing ; analysis ; Animals ; Apoptosis ; drug effects ; Docosahexaenoic Acids ; pharmacology ; Down-Regulation ; Kidney ; drug effects ; pathology ; Lipopolysaccharides ; pharmacology ; Male ; Mice ; Mice, Inbred BALB C ; NF-kappa B ; antagonists & inhibitors ; Tumor Necrosis Factor-alpha ; analysis
5.Expression of Wif-1 and β-catenin in the Wnt pathway in childhood acute lympho-blastic leukemia.
Ji-Zhao GAO ; Ji-Ou ZHAO ; Ying TAN
Chinese Journal of Contemporary Pediatrics 2016;18(9):835-839
OBJECTIVETo investigate the expression and possible roles of Wnt inhibitory factor-1 (Wif-1) and β-catenin in the Wnt pathway in childhood acute lymphoblastic leukemia (ALL).
METHODSThe clinical data of 35 children who had newly-diagnosed ALL and achieved complete remission on day 33 of remission induction therapy were retrospectively reviewed. The children before treatment were considered as the incipient group, and those who achieved complete remission on day 33 were considered as the remission group. Fifteen children with non-malignant hematologic diseases were enrolled as the control group. RT-PCR was used to measure the mRNA expression of Wif-1 and β-catenin. ELISA was used to measure the protein expression of Wif-1.
RESULTSCompared with the control and remission groups, the incipient group had significantly lower mRNA and protein expression of Wif-1 and significantly higher mRNA expression of β-catenin (P<0.05). In the incipient and remission groups, high-risk children showed significantly higher mRNA expression of β-catenin and significantly lower mRNA and protein expression of Wif-1 than the medium- and low-risk children (P<0.05). In the incipient and remission group, the children with T-cell acute lymphoblastic leukemia showed significantly higher mRNA expression of β-catenin and significantly lower mRNA and protein expression of Wif-1 compared with those with B-lineage acute lymphoblastic leukemia (P<0.05). In each group, there was a negative correlation between the mRNA expression of Wif-1 and β-catenin (P<0.05).
CONCLUSIONSReduced expression of Wif-1 and increased expression of β-catenin may be involved in the pathogenesis of childhood ALL, and the degree of reduction in Wif-1 and/or increase in β-catenin may be related to prognosis.
Adaptor Proteins, Signal Transducing ; genetics ; physiology ; Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; etiology ; physiopathology ; RNA, Messenger ; analysis ; Repressor Proteins ; genetics ; physiology ; Wnt Signaling Pathway ; physiology ; beta Catenin ; genetics ; physiology
6.Analysis of the relationship of DNA mismatch repair with clinicopathologic features and prognosis of colon cancer.
Qiong QIN ; Jianming YING ; Ning LYU ; Lei GUO ; Wenxue ZHI ; Aiping ZHOU ; Jinwan WANG
Chinese Journal of Oncology 2015;37(8):591-596
OBJECTIVETo explore the relationship between DNA mismatch repair (MMR) and clinicopathologic features and prognosis in patients with stages II and III colon cancers.
METHODSThe clinical and pathological data of 440 patients with stage II/III colon cancer after radical resection were retrospectively reviewed and analyzed. Immunohistochemical staining was used to assess the expression of MMR proteins (MLH1, MSH2, MSH6 and PMS2), and the correlation between DNA MMR and clinicopathological features and prognosis of colon cancers was analyzed.
RESULTSOf the 440 tumor samples tested for DNA mismatch repair status, 90 (20.5%) demonstrated defective DNA mismatch repair and 350 (79.5%) had proficient DNA mismatch repair. Defective DNA mismatch repair (dMMR) was associated with young patients (≤ 60), proximal colon cancer, stage II, poorly differentiated adenocarcinoma and mucinous adenocarcinoma (P<0.05 for all). Among the 440 patients, 126 (28.6%) cases had recurrence or metastasis and 93 (21.1%) died during the median follow-up of 61.0 months. The five-year disease-free survival (DFS) rate was 82.2% among the patients with tumor exhibiting dMMR, significantly higher than that in patients with tumors exhibiting pMMR (68.9%, P=0.02). The univariate and mutlivariate analyses showed that the MMR status is an independent factor affecting 5-year disease-free survival and overall survival (OS) in colon cancer patients (P<0.05 for both).
CONCLUSIONSDefective DNA mismatch repair (dMMR) is associated with patients with proximal colon cancer, stage II and poorly defferentiated adenocarcinoma and mucinous adenocarcinoma. The prognosis for patients with dMMR is better than those with pMMR. dMMR may be a useful biomarker for the prognosis of colon cancer.
Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma ; genetics ; metabolism ; mortality ; pathology ; Adenocarcinoma, Mucinous ; genetics ; metabolism ; mortality ; pathology ; Adenosine Triphosphatases ; metabolism ; Age Factors ; Analysis of Variance ; Colonic Neoplasms ; genetics ; metabolism ; mortality ; pathology ; DNA Mismatch Repair ; DNA Repair Enzymes ; metabolism ; DNA-Binding Proteins ; metabolism ; Disease-Free Survival ; Humans ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Neoplasm Recurrence, Local ; Nuclear Proteins ; metabolism ; Prognosis ; Retrospective Studies ; Survival Rate
7.Characterization of the osteogenic potential of mesenchymal stem cells from human periodontal ligament based on cell surface markers.
Ruth ALVAREZ ; Hye-Lim LEE ; Cun-Yu WANG ; Christine HONG
International Journal of Oral Science 2015;7(4):213-219
Mesenchymal stem cell (MSC)-mediated therapy has been shown to be clinically effective in regenerating tissue defects. For improved regenerative therapy, it is critical to isolate homogenous populations of MSCs with high capacity to differentiate into appropriate tissues. The utilization of stem cell surface antigens provides a means to identify MSCs from various tissues. However, few surface markers that consistently isolate highly regenerative MSCs have been validated, making it challenging for routine clinical applications and making it all the more imperative to identify reliable surface markers. In this study, we used three surface marker combinations: CD51/CD140α, CD271, and STRO-1/CD146 for the isolation of homogenous populations of dental mesenchymal stem cells (DMSCs) from heterogeneous periodontal ligament cells (PDLCs). Fluorescence-activated cell sorting analysis revealed that 24% of PDLCs were CD51(+)/CD140α(+), 0.8% were CD271(+), and 2.4% were STRO-1(+)/CD146(+). Sorted cell populations were further assessed for their multipotent properties by inducing osteogenic and chondrogenic differentiation. All three subsets of isolated DMSCs exhibited differentiation capacity into osteogenic and chondrogenic lineages but with varying degrees. CD271(+) DMSCs demonstrated the greatest osteogenic potential with strong induction of osteogenic markers such as DLX5, RUNX2, and BGLAP. Our study provides evidence that surface marker combinations used in this study are sufficient markers for the isolation of DMSCs from PDLCs. These results provide important insight into using specific surface markers for identifying homogenous populations of DMSCs for their improved utilization in regenerative medicine.
Adaptor Proteins, Signal Transducing
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analysis
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Adult
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Aggrecans
;
analysis
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Antigens, CD
;
analysis
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Antigens, Surface
;
analysis
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CD146 Antigen
;
analysis
;
Cell Differentiation
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physiology
;
Cell Lineage
;
Cell Separation
;
methods
;
Cells, Cultured
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Chondrogenesis
;
physiology
;
Collagen Type II
;
analysis
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Core Binding Factor Alpha 1 Subunit
;
analysis
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Flow Cytometry
;
methods
;
Homeodomain Proteins
;
analysis
;
Humans
;
Integrin alphaV
;
analysis
;
Mesenchymal Stromal Cells
;
cytology
;
physiology
;
Multipotent Stem Cells
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cytology
;
physiology
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Nerve Tissue Proteins
;
analysis
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Osteogenesis
;
physiology
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Periodontal Ligament
;
cytology
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Receptor, Platelet-Derived Growth Factor alpha
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analysis
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Receptors, Nerve Growth Factor
;
analysis
;
SOX9 Transcription Factor
;
analysis
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Time Factors
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Transcription Factors
;
analysis
8.Differential gene expression profiling for identification of potential pathogenic genes and pathways in carotid unstable plaques.
Wenqing NAI ; Hao LIU ; Yuanyuan WANG ; Lanlan SHAN ; You FU ; Hongyuan WU ; Yan DING ; Shunzhi CHEN ; Zhengjun LIU ; Jie CHEN ; Meng DAI
Journal of Southern Medical University 2015;35(5):738-742
OBJECTIVETo explore the molecular mechanism in the formation of unstable plaques.
METHODSThe cDNA microarray E-MTAB-2055 was downloaded from ArrayExpress database to screen the differentially expressed genes in 24 ruptured plaques against 24 stable plaques. Functional enrichment analysis was conducted to define the biological processes and pathways involved in disease progression. The protein-protein interaction network was constructed to identify the risk modules with close interactions. Five pairs of carotid specimens were used to validate 3 differentially expressed genes of the risk modules by real-time PCR.
RESULTSA total of 439 genes showed differential expression in our analysis, including 232 up-regulated and 207 down-regulated genes according to the data filter criteria. Immune-related biological processes and pathways were greatly enriched. The protein-protein interaction network and module analysis suggested that TYROBP, VCL and CXCR4 might play critical roles in the development of unstable plaques, and differential expressions of CXCR4 and TYROBP in carotid plaques were confirmed by real-time PCR.
CONCLUSIONOur study shows the differential gene expression profile, potential biological processes and signaling pathways involved in the process of plaque rupture. TYROBP may be a new candidate disease gene in the pathogenesis of unstable plaques.
Adaptor Proteins, Signal Transducing ; genetics ; Disease Progression ; Down-Regulation ; Gene Expression Profiling ; Humans ; Membrane Proteins ; genetics ; Oligonucleotide Array Sequence Analysis ; Plaque, Atherosclerotic ; genetics ; Protein Interaction Maps ; Real-Time Polymerase Chain Reaction ; Receptors, CXCR4 ; genetics ; Transcriptome ; Up-Regulation ; Vinculin ; genetics
9.Effect of topotecan on retinocytoma cell apoptosis and expression of Livin and PTEN.
Meng ZHANG ; Bao-En SHAN ; Nai-Fen YUAN ; Wei LIU
Chinese Medical Journal 2013;126(2):340-344
BACKGROUNDRetinocytoma (RB) is a very common intraocular malignant tumor during infancy. Chemotherapy has gradually been used as the first-line treatment for intraocular RB in recent years. In this study, Livin and PTEN expressions were observed in the RB tissue, along with the growth-inhibiting and apoptosis-induced effects of topotecan (TPT) on RB HXO-Rb44 cell strain. This study aimed to investigate the antigrowth effects of TPT on RB cell strain HXO-Rb44.
METHODSMax-Vision(TM) rapid immunohistochemistry was adopted to detect Livin and PTEN expressions in the normal retina and in RB, and their relationship with RB clinicopathologic features was analyzed. Human RB cell strain HXO-Rb44 was cultivated and passaged. MTT method was used to measure the survival rates of HXO-Rb44 cell strains under various TPT concentrations. IC50 values were calculated. Flow cytometry was used to detect the effects of various TPT concentrations on HXO-Rb44 cell apoptosis. Western blotting was used to detect the differences of Livin and PTEN protein expressions during cell apoptosis.
RESULTSThe positive expressions of Livin and PTEN in the RB group were obviously different from those in the normal control group. In RB tissue, Livin expression was relevant to PTEN expression. TPT could significantly induce the occurrence of cell apoptosis and had a dependent relationship with drug concentration. Livin and PTEN expression levels varied with the extension of the effect time of TPT based on Western blotting analysis.
CONCLUSIONSLivin and PTEN have high and low expression levels in the RB tissue, respectively. Both of them have key roles in RB occurrence and development. TPT could induce human RB cell strain HXO-Rb44 cell apoptosis, and its mechanism is associated with the inhibition of Livin and PTEN expressions.
Adaptor Proteins, Signal Transducing ; analysis ; Apoptosis ; drug effects ; Cell Line, Tumor ; Child ; Child, Preschool ; Dose-Response Relationship, Drug ; Female ; Humans ; Infant ; Inhibitor of Apoptosis Proteins ; analysis ; Male ; Neoplasm Proteins ; analysis ; PTEN Phosphohydrolase ; analysis ; Retinal Neoplasms ; drug therapy ; pathology ; Retinoblastoma ; drug therapy ; pathology ; Topoisomerase I Inhibitors ; pharmacology ; Topotecan ; pharmacology
10.Immunophenotypes and gene mutations in colorectal precancerous lesions and adenocarcinoma.
Wen-ting HUANG ; Tian QIU ; Yun LING ; Su-sheng SHI ; Lei GUO ; Bo ZHENG ; Ning LÜ ; Jian-ming YING
Chinese Journal of Pathology 2013;42(10):655-659
OBJECTIVETo analyze immunophenotypes and gene mutations of colorectal precancerous lesions and adenocarcinoma, and to compare the difference of carcinogenetic mechanisms between the two precancerous lesions.
METHODSFifty-three cases of colorectal serrated lesions including 30 hyperplastic polyps, 20 sessile serrated adenomas (SSA) and 3 mixed polyps were collected from January 2006 to June 2012.Forty-five cases of traditional adenomas and 50 cases of colorectal adenocarcinomas were also recruited. Thirty hyperplastic polyps, 20 cases of SSA, 3 mixed polyps and 45 traditional adenomas were investigated by immunohistochemistry for the expression of DNA mismatch repair (MMR) proteins (MLH1, MSH2 and MSH6) and DNA methyltransferase MGMT. Mutations of KRAS, BRAF and PIK3CA genes in 10 cases of SSAs, 10 traditional adenomas, 1 mixed polyps and 50 colorectal adenocarcinomas were analyzed by PCR followed by direct Sanger sequencing.
RESULTS(1) Only 3 cases of hyperplastic polyps lost MLH1 expression, and none of SSAs or traditional adenomas showed loss of MLH1. The negative expression rates of MSH2, MSH6 and MGMT in hyperplastic polyps and SSA were significantly higher than those of traditional adenomas. (2) KRAS mutation was found in 5/10 cases of SSAs, 5/10 traditional adenomas and 1/1 mixed polyps. (3) Colorectal adenocarcinomas harbored the mutations of KRAS (48%, 24/50), BRAF (6%, 3/50) and PIK3CA (4%, 2/50).
CONCLUSIONSImmunophenotypic and gene mutation profiles are different between colorectal serrated lesion and traditional adenoma. Alterations of MMR and MGMT expression play important roles in the pathogenesis of "serrated neoplasm". KRAS mutation is a significant genetic change in the early phase of colorectal carcinogenesis.
Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma ; genetics ; metabolism ; Adenoma ; genetics ; metabolism ; Aged ; Class I Phosphatidylinositol 3-Kinases ; Colonic Polyps ; genetics ; metabolism ; Colorectal Neoplasms ; genetics ; metabolism ; DNA Mismatch Repair ; DNA Modification Methylases ; metabolism ; DNA Repair Enzymes ; metabolism ; DNA, Neoplasm ; metabolism ; DNA-Binding Proteins ; metabolism ; Female ; Humans ; Hyperplasia ; Immunophenotyping ; Male ; Middle Aged ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Nuclear Proteins ; metabolism ; Phosphatidylinositol 3-Kinases ; genetics ; Point Mutation ; Precancerous Conditions ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; Proto-Oncogene Proteins B-raf ; genetics ; Proto-Oncogene Proteins p21(ras) ; Sequence Analysis, DNA ; Tumor Suppressor Proteins ; metabolism ; ras Proteins ; genetics

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