ARID1A Inactivation Increases Expression of circ0008399 and Promotes Cisplatin Resistance in Bladder Cancer.

OBJECTIVE: Cisplatin (CDDP)-based chemotherapy is a first-line, drug regimen for muscle-invasive bladder cancer (BC) and metastatic bladder cancer. Clinically, resistance to CDDP restricts the clinical benefit of some bladder cancer patients. AT-rich interaction domain 1A (ARID1A) gene mutation occurs frequently in bladder cancer; however, the role of CDDP sensitivity in BC has not been studied. METHODS: We established ARID1A knockout BC cell lines using CRISPR/Cas9 technology. IC50 determination, flow cytometry analysis of apoptosis, and tumor xenograft assays were performed to verify changes in the CDDP sensitivity of BC cells losing ARID1A. qRT-PCR, Western blotting, RNA interference, bioinformatic analysis, and ChIP-qPCR analysis were performed to further explore the potential mechanism of ARID1A inactivation in CDDP sensitivity in BC. RESULTS: It was found that ARID1A inactivation was associated with CDDP resistance in BC cells. Mechanically, loss of ARID1A promoted the expression of eukaryotic translation initiation factor 4A3 (EIF4A3) through epigenetic regulation. Increased expression of EIF4A3 promoted the expression of hsa_circ_0008399 (circ0008399), a novel circular RNA (circRNA) identified in our previous study, which, to some extent, showed that ARID1A deletion caused CDDP resistance through the inhibitory effect of circ0008399 on the apoptosis of BC cells. Importantly, EIF4A3-IN-2 specifically inhibited the activity of EIF4A3 to reduce circ0008399 production and restored the sensitivity of ARID1A inactivated BC cells to CDDP. CONCLUSION: Our research deepens the understanding of the mechanisms of CDDP resistance in BC and elucidates a potential strategy to improve the efficacy of CDDP in BC patients with ARID1A deletion through combination therapy targeting EIF4A3.

Identification of Kidney Transplant Recipients with Coronavirus Disease 2019.

Coronavirus disease 2019 (COVID-19) is a novel and lethal infectious disease, posing a threat to global health security. The number of cases has increased rapidly, but no data concerning kidney transplant (KTx) recipients infected with COVID-19 are available. To present the epidemiological, clinical, and therapeutic characteristics of KTx recipients infected with COVID-19, we report on a case series of five patients who were confirmed as having COVID-19 through nucleic acid testing (NAT) from January 1, 2020 to February 28, 2020. The most common symptoms on admission to hospital were fever (five patients, 100%), cough (five patients, 100%), myalgia or fatigue (three patients, 60%), and sputum production (three patients, 60%); serum creatinine or urea nitrogen levels were slightly higher than those before symptom onset. Four patients received a reduced dose of maintenance immunosuppressive therapy during hospitalization. As of March 4, 2020 NAT was negative for COVID-19 in three patients twice in succession, and their computed tomography scans showed improved images. Although greater patient numbers and long-term follow-up data are needed, our series demonstrates that mild COVID-19 infection in KTx recipients can be managed using symptomatic support therapy combined with adjusted maintenance immunosuppressive therapy.

Overexpression of CircRNA BCRC4 regulates cell apoptosis and MicroRNA-101/EZH2 signaling in bladder cancer.

Emerging evidence has indicated that circular RNAs (circRNAs) play pivotal roles in the regulation of cellular processes and are found to be aberrantly expressed in a variety of tumors. However, the clinical role of circRNAs in bladder cancer (BC) and the molecular mechanisms have yet to be fully understood. In this study, the clinical specimens were obtained and the expression level of a circRNA BCRC4 was detected by real-time PCR in both BC tissues and cell line. The circular RNA over-expression plasmid was constructed and transfected into BC cells and related cell line. The cell cycles and apoptosis were observed using inverted microscope and flow cytometry. Western blotting was used to compare the relative protein expression of groups with different treatments. It was found that circRNA BCRC4 expression was lower in BC tissues than in adjacent normal tissues. Furthermore, consequences of forced-expression of BCRC4 promoted apoptosis and inhibited viability of T24T and UMUC3 cells, and up-regulated BCRC4-increased miR-101 level, which suppressed EZH2 expression in both RNA and protein levels. In addition, gambogic acid (GA) is a promising natural anticancer compound for BC therapy, and GA treatment increased the BCRC4 expression in T24T and UMUC3 cells in a dose-dependent manner. Altogether, our findings suggest that BCRC4 functions as a tumor suppressor in BC, and mediates anticancer function, at least in part, by up-regulating the expression of miR-101. Targeting this newly identified circRNA may help us develop a novel strategy for treating human BC.

Overexpression of CircRNA BCRC4 Regulates Cell Apoptosis and MicroRNA-101/EZH2 Signaling in Bladder Cancer / 华中科技大学学报（医学）（英德文版）

Emerging evidence has indicated that circular RNAs (circRNAs) play pivotal roles in the regulation of cellular processes and are found to be aberrantly expressed in a variety of tumors.However,the clinical role of circRNAs in bladder cancer (BC) and the molecular mechanisms have yet to be fully understood.In this study,the clinical specimens were obtained and the expression level of a circRNA BCRC4 was detected by real-time PCR in both BC tissues and cell line.The circular RNA over-expression plasmid was constructed and transfected into BC cells and related cell line.The cell cycles and apoptosis were observed using inverted microscope and flow cytometry.Western blotting was used to compare the relative protein expression of groups with different treatments.It was found that circRNA BCRC4 expression was lower in BC tissues than in adjacent normal tissues.Furthermore,consequences of fomed-expression of BCRC4 promoted apoptosis and inhibited viability of T24T and UMUC3 cells,and up-regulated BCRC4-inereased miR-101 level,which suppressed EZH2 expression in both RNA and protein levels.In addition,gambogic acid (GA) is a promising natural anticancer compound for BC therapy,and GA treatment increased the BCRC4 expression in T24T and UMUC3 cells in a dose-dependent manner.Altogether,our findings suggest that BCRC4 functions as a tumor suppressor in BC,and mediates anticancer function,at least in part,by up-regulating the expression of miR-101.Targeting this newly identified circRNA may help us develop a novel strategy for treating human BC.

Long non-coding RNA MEG3 induces renal cell carcinoma cells apoptosis by activating the mitochondrial pathway.

This study aimed to examine the effect of long non-coding RNA (LncRNA) MEG3 on the biological behaviors of renal cell carcinoma (RCC) cells 786-0 and the possible mechanism. MEG3 expression levels were detected by RT-qPCR in tumor tissues and adjacent non-tumor tissues from 29 RCC patients and in RCC lines 786-0 and SN12 and human embryonic kidney cell line 293T. Plasmids GV144-MEG3 (MEG3 overexpression plasmid) and GV144 (control plasmid) were stably transfected into 786-0 cells by using lipofectamine 2000. Cell viabilities were determined by MTT, cell apoptosis rates by flow cytometry following PE Annexin V and 7AAD staining, apoptosis-related protein expressions by Western blotting, and Bcl-2 mRNA by RT-qPCR in the transfected cells. The results showed that MEG3 was evidently downregulated in RCC tissues (P<0.05) and RCC cell lines (P<0.05). The viabilities of 786-0 cells were decreased significantly after transfection with GV144-MEG3 for over 24 h (P<0.05). Consistently, the apoptosis rate was significantly increased in 786-0 cells transfected with GV144-MEG3 for 48 h (P<0.05). Furthermore, overexpression of MEG3 could reduce the expression of Bcl-2 and procaspase-9 proteins, enhance the expression of cleaved caspase-9 protein, and promote the release of cytochrome c protein to cytoplasm (P<0.05). Additionally, Bcl-2 mRNA level was declined by MEG3 overexpression (P<0.05). It was concluded that MEG3 induces the apoptosis of RCC cells possibly by activating the mitochondrial pathway.

[Silencing pyruvate kinase M2 sensitizes human prostate cancer PC3 cells to gambogic acid-induced apoptosis].

OBJECTIVE: To study the effect of silencing pyruvate kinase M2 (PKM2) on gambogic acid (GA)-induced apoptosis of human prostate cancer PC3 cells. METHODS: Three specific PKM2 siRNAs and one negative control siRNA (si-NC) were transfected into PC3 cells. The silencing effect of PKM2 siRNAs was determined by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot, and the effects of PKM2 siRNA on the vitality and apoptosis of GA-stimulated PC3 cells detected by MTT and AO/EB double staining, respectively. The mRNA and protein levels of c-myc and cyclin D1 were analyzed by qRT-PCR and Western blot, respectively. RESULTS: All the 3 PKM2 siRNAs effectively reduced the mRNA and protein expressions of PKM2, and PKM2 siRNA-1 exhibited the strongest silencing effect. At 24 h after transfection, the expression levels of PKM2 mRNA and protein were reduced by 70% and 85%, respectively (P < 0.05). Twenty-four hours of treatment with GA (0.5 micromol/L) following transfection with PKM2 siRNA-1 inhibited the vitality of the PC3 cells by 68%, increased their apoptosis, and significantly down-regulated the mRNA and protein levels of c-myc (50% and 35%) and cyclin D1 (60% and 20%) (P < 0.05). CONCLUSION: Inhibition of PKM2 sensitized PC3 cells to GA-induced apoptosis, suggesting that PKM2 may be a potential therapeutic target for sensitizing human prostate cancer to GA.

Gambogic acid inhibits TNF-α-induced invasion of human prostate cancer PC3 cells in vitro through PI3K/Akt and NF-κB signaling pathways.

AIM: To investigate the mechanisms underlying the inhibitory effect of gambogic acid (GA) on TNF-α-induced metastasis of human prostate cancer PC3 cells in vitro. METHODS: TNF-α-mediated migration and invasion of PC3 cells was examined using migration and invasion assays, respectively. NF-κB transcriptional activity and nuclear translocation were analyzed with luciferase reporter gene assays, immunofluorescence assays and Western blots. The ability of p65 to bind the promoter of Snail, an important mesenchymal molecular marker, was detected using a chromatin immunoprecipitation (ChIP) assay. After treatment with Snail-specific siRNA, the expression of invasiveness-associated genes was measured using quantitative real-time PCR and Western blot. RESULTS: GA significantly inhibited the viability of PC3 cells at 1-5 µmol/L, but did not produce cytotoxic effect at the concentrations below 0.5 µmol/L. GA (0.125-0.5 µmol/L) dose-dependently inhibited the migration and invasion of PC3 cells induced by TNF-α (10 ng/mL). Moreover, the TNF-α-mediated activation of phosphatidylinositol-3-OH kinase/protein kinase B (PI3K/Akt) and NF-κB pathways was suppressed by GA (0.5 µmol/L). Furthermore, this anti-invasion effect of GA was associated with regulation of Snail. Snail expression was significantly down-regulated by treatment with GA (0.5 µmol/L) in the TNF-α-stimulated PC3 cells. CONCLUSION: GA inhibits TNF-α-induced invasion of PC3 cells via inactivation of the PI3K/Akt and NF-κB signaling pathways, which may offer a novel approach for the treatment of human prostate cancer.

Evaluation of thymosin ß4 in the regulation of epithelial-mesenchymal transformation in urothelial carcinoma.

OBJECTIVES: To study the underlying alteration in the expression of epithelial markers involved in epithelial-mesenchymal transition (EMT), and elucidate the potential mechanism(s) for Tß4-induced EMT-like phenotypic changes in bladder cancer cells. MATERIALS AND METHODS: All tissue samples in this study were obtained from clinical patients of the Union Hospital of Tongji Medical College, and were confirmed by surgery and pathology. Of these, normal bladder tissues (control), primary urothelial carcinoma of different grades (Stage pTa, Stage pT3), bladder paracancerous tissues, accompanied with 2 bladder cancer cell lines (BIU-87 and T24), were divided into 6 groups. Quantitative RT-PCR, Western blotting, and immunohistochemical study of adhesion molecules Tß4, ILK, E-cadherin, and ß-catenin involved in EMT were carried out. A lentiviral gene transferring vector containing the RNA polymerase III-dependent U6 promoter to express short hairpin RNA (shRNA) directed against Tß4 was also applied. In the present study, all agents were evaluated using commercial kits. RESULTS: A strong correlation between the expression levels of Tß4, ILK, E-cadherin, and ß-catenin was found in the bladder transitional cell carcinoma (TCC) patients. In the BIU-87 and T24 bladder cancer cells overexpressing Tß4, which were accompanied by a loss of E-cadherin as well as a cytosolic accumulation of ß-catenin, up-regulation of ILK was also revealed. The inhibition of the Tß4 expression with lentiviral shRNA vector could raise EMT-like phenotypic changes, significantly depressed motility, and subsequent invasiveness of bladder cancer cells. CONCLUSIONS: Our results imply that the Tß4 is likely to play a crucial role in EMT progression, and that inhibition of the Tß4 expression or interactions with other genes should be novel therapeutic targets for bladder cancers with high invasive and metastatic potential.

Predominant enhancement of apoptosis induced by methyl jasmonate in bladder cancer cells: therapeutic effect of the Antp-conjugated Smac peptide.

Methyl jasmonate (MJ) has recently attracted attention as a promising antitumoral compound because of its highly specific proapoptotic properties in a wide range of malignancies. However, the high doses required to achieve a therapeutic benefit have limited its clinical development. Here, we hypothesize that the family of inhibitor of apoptosis proteins (IAPs) may inhibit MJ-mediated apoptosis in cancer cells. We combined MJ with the IAPs inhibitor, the second mitochondria-derived activator of caspases (Smac) peptide to treat bladder cancer cells. The results showed that the combination of MJ and Smac peptide enhanced the apoptosis-inducing effect in a synergistic manner by releasing and activating IAPs-bounding caspase-3. These findings suggest that the inhibition of IAPs could overcome the resistance of cancer cells to MJ.

Silencing USP22 by asymmetric structure of interfering RNA inhibits proliferation and induces cell cycle arrest in bladder cancer cells.

The ubiquitin specific peptidase 22 (USP22) is a positive regulator of the growth of tumors. However, little is known about the impact of USP22 knockdown on the growth of human bladder cells. In the present study, we designed a series of asymmetric interfering RNAs (aiRNAs) and compared the efficacy of aiRNA and conventional symmetric interfering RNA (siRNA) in the silencing of USP22 expression and the growth of human bladder EJ cells in vitro and in vivo. In comparison with transfection with the USP22-specific siRNA, transfection with 15/21 aiRNA was more potent in down-regulating the USP22 expression and inhibiting EJ cell proliferation in vitro. Furthermore, transfection with 15/21 aiRNA induced higher frequency of EJ cells arrested at the G0/G1 phases, but did not trigger EJ cell apoptosis. Moreover, transfection with either the siRNA or 15/21 aiRNA up-regulated the expression of p53 and p21, but down-regulated the expression of cyclin E and Mdm2 in EJ cells. The up-regulated p53 expression induced by the specific siRNA or aiRNA was abrogated by induction of Mdm2 over-expression. In addition, treatment with the specific siRNA or aiRNA inhibited the growth of implanted human bladder tumors in mice and the aiRNA had more potent anti-tumor activity in vivo. Therefore, our data suggest that knockdown of USP22 expression by the aiRNA may down-regulate the expression of Mdm2 and cyclin E, resulting in the up-regulated expression of p53 and p21 and leading to cell cycling arrest and inhibition of human bladder EJ cell proliferation. Our findings indicate that the USP22-specific aiRNA may be a novel approach for the intervention of human bladder tumors.

Stable knockdown of heparanase expression in gastric cancer cells in vitro.

AIM: To develop short hairpin RNA (shRNA) against heparanase, and to determine its effects on heparanase expression and the malignant characteristics of gastric cancer cells. METHODS: Heparanase-specific shRNA was constructed and transferred into cultured the gastric cancer cell line SGC-7901. Stable subclonal cells were screened by G418 selection. Heparanase expression was measured by reverse transcriptase-polymerase chain reaction (RT-PCR), real-time quantitative PCR and Western blotting. Cell proliferation was detected by 2-(4, 5-dimethyltriazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetry and colony formation assay. The in vitro invasiveness and metastasis of cancer cells were measured by cell adhesion assay, wound healing assay and matrigel invasion assay. The angiogenesis capabilities of cancer cells were measured by tube formation of endothelial cells. RESULTS: Stable transfection of heparanase-specific shRNA, but not of scrambled shRNA and mock vector, resulted in reduced mRNA and protein levels of heparanase. The shRNA-mediated knockdown of heparanase did not affect the cellular proliferation of SGC-7901 cells. However, the in vitro invasiveness and metastasis of cancer cells were decreased after knockdown of heparanase. Moreover, transfection of heparanase-specific shRNA decreased the in vitro angiogenesis capabilities of SGC-7901 cells. CONCLUSION: Stable knockdown of heparanase can efficiently decrease the invasiveness, metastasis and angiogenesis of human gastric cancer cells. In contrast, stable knockdown of heparanase does not affect the cell proliferation.

Expression and clinical significance of heparanase in neuroblastoma.

BACKGROUND: Previous studies indicate that heparanase (HPA), an endoglycosidase involved in tumor angiogenesis and metastasis, is up-regulated in a variety of malignancies. However, the expression of HPA in neuroblastoma (NB), one of the most common extra cranial solid tumors in children, remains unknown. This study was undertaken to explore the expression and clinical significance of HPA in NB. METHODS: Immunohistochemical staining was applied to detect the expression of HPA in 42 cases of NB. The relationships among HPA expression, international neuroblastoma staging system (INSS) stages, histopathological classification, and postoperative survival of the NB patients were analyzed. RESULTS: The expression rate of HPA in NB was 61.9% (26/42), mainly in the cytoplasm of neuroblastoma cells. The expression rates of stage 1-2, stage 3-4 and stage 4S were 35.7%, 80.0% and 62.5%, respectively. The differences between stage 1-2 and stage 3-4 were significant (P<0.01). The expression of HPA was significantly higher in the NB cases that had one of the histopathological factors: age more than 1 year (P<0.01), poorer differentiation (P<0.01), and higher mitosis karyorrhexis index (P<0.01). The survival time of HPA-negative patients was significantly longer than that of HPA-positive patients (P<0.05). CONCLUSION: Although these results indicate that heparanase might be correlated with development and progression of NB, a larger series of patients with a longer follow-up are probably needed to strengthen its role in assessment of NB prognosis.

[Cloning and expression of a novel mouse testis gene TSEG-2].

OBJECTIVE: To clone the mouse testis specific gene TSEG-2 via a bioinformatic approach. METHODS: The expressed sequence tags (EST) in the normal mouse testis were obtained from the online EST database ZooDDD. Their highly homologous EST sequences were retrieved through the dbEST database to construct contigs and spliced with the biomedical software Biolign. The corresponding exons and introns within the genome sequences were predicted with the software GeneScan. Primers were designed according to the open reading frame. RT-PCR was applied in cloning the cDNA of the novel gene from the mouse testis tissue and analyzing its expression patterns in the undescended testis and various organ tissues as well as in different developmental stages of the mouse testis. The sequencing results of TSEG-2 underwent bioinformatic analyses. RESULTS: The novel mouse testis gene TSEG-2 was successfully cloned, with full-length sequence of 451 bp. The open reading frame was 267 bp, coding a protein of 88 amino acid residues, and demonstrated to be correct by RT-PCR. The expression of TSEG-2 was high in the mouse testis, regular in the testis cDNA samples of different postnatal days, and down-regulated in the cryptorchidism model. No obvious homology with other mouse cDNA was found for TSEG-2. The GenBank accession number EU079025 was achieved. Function prediction showed that mouse TSEG-2 was probably a soluble non-secretary protein located at chromosome 15qE3, or a nucleoprotein with 2 phosphorylation sites of protein kinase C (PKC) and 1 of casein kinase II (CK2). CONCLUSION: A novel mouse testis specific gene TSEG-2 was successfully cloned, which could be down-regulated by cryptorchidism-inducible 17-beta estradiol. This has prepared the ground for further researches on the biological function and expression regulation of TSEG-2.

Enhanced expression of resistin-like molecule beta in human colon cancer and its clinical significance.

Previous studies have indicated that resistin-like molecule beta (RELM beta), an intestinal goblet cell-specific protein, is markedly increased in the intestinal tumors of min mice and over-expressed in a human colon cancer cell line. We hypothesized that RELM beta might be enhanced in human colon cancer. The aim of this study was to examine the clinical importance of RELM beta expression in colon cancer patients and to correlate its expression with various clinicopathological parameters, upstream regulatory molecule expression, tumor proliferative capacity, and patients' survival. Of the 80 colon cancer patients studied, 65 (81.25%) tested positive for RELM beta, mainly in the cytoplasm of colon mucosa. Contrasting sharply with the strongly RELM beta-positive tumors, normal colon mucous membrane was negative or weakly positive. RELM beta positivity in colon cancer was correlated with histological grade of differentiation and lymph node metastasis, but not with age, gender, tumor location and size, tumor infiltration, Dukes' stage, liver metastasis, and venous invasion. RELM beta expression was significantly correlated with the expression of transcription factor CDX-2 (P < 0.01) but not with that of proliferative index Ki-67 (P > 0.05). The mean postoperative survival time (2.76 years) of RELM beta-positive patients was significantly longer than that (1.26 years) of RELM beta-negative patients (P = 0.032). These findings support evidence of the enhanced RELM beta expression in colon cancer patients and suggest that further investigation is warranted to explore the role of RELM beta in colon cancer.

[Methyl jasmonate induces apoptosis of human neuroblastoma cell line BE(2) -C and its mechanism].

This study is to explore the inhibitory effect of methyl jasmonate on cell proliferation and expression of XIAP and survivin of human neuroblastoma cell line BE(2)-C. After cultivation of 1 - 2 mmol x L(-1) jasmonates with BE (2) -C cells for 6 - 24 h, the growth inhibiting rates of BE (2) -C cells were studied by MTT colorimetry. Cell proliferation was detected by colony formation assay. Cell cycle phases were assayed by propidium iodide staining flow cytometery. Cell apoptosis was inspected by acridine orange-ethidium bromide fluorescent staining, Hoechst 33258 fluorescent staining, and Annexin V-FITC and propidium iodide staining flow cytometry. Expressions of cyclin D1, XIAP and survivin were determined by RT-PCR and real-time RT-PCR. Methyl jasmonate inhibited the growth of BE(2)-C cells in a dose- and time-dependent manner. After addition of 1, 1.5 and 2 mmol x L(-1) of methyl jasmonate for 24 h, the inhibiting rates of cell growth reached 20.6% - 85.5% (P < 0.01), and the IC50 was 1.35 mmol x L(-1). The cell cycles were arrested at S phase. A part of cells presented the characteristic morphological changes of apoptosis. The early apoptotic rates were 13.51%, 17.32%, 24.59% (P < 0.01) and the cell death rates were 29.36% , 54.73% , 75.52% (P < 0.01), respectively. The expression of XIAP and survivin mRNA were downregulated by 18.5% - 68.9% , 22.4% - 48.7% (P < 0.05), respectively, without change in that of cyclin D1. The results indicated that methyl jasmonate could significantly inhibit the growth of BE(2) -C cells through inducing cell cycle arrest and apoptosis, downregulating the expression of XIAP and survivin might be one of its molecular mechanisms of action.

Natural jasmonates of different structures suppress the growth of human neuroblastoma cell line SH-SY5Y and its mechanisms.

AIM: Recent evidence has indicated that members of natural jasmonates, a family of plant stress hormones, exhibit anticancer activity. The current study was undertaken to investigate the effects of jasmonates on the in vitro growth of human neuroblastomas, one of the most common solid tumors in children. METHODS: Cellular proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide colorimetry and colony formation assay. Apoptosis was detected by Hoechst 33258 staining and flow cytometry. Western blotting was applied to assay gene expression. RESULTS: The administration of natural jasmonates, methyl jasmonate, cis-jasmone, and jasmonic acid to cultured neuroblastoma cell line SH-SY5Y, resulted in a decrease of cell proliferation in a doseand time-dependent manner. However, the in vitro growth of cultured human embryonic kidney (HEK) cell line HEK 293 was not affected by jasmonates. The cell cycles of jasmonate-treated SH-SY5Y cells were arrested at the G2/M phase. The incubation of SH-SY5Y cells with jasmonates resulted in characteristic changes of apoptosis. The anticancer activities of natural jasmonates on SH-SY5Y cells are as follows: methyl jasmonate>cis-jasmone>jasmonic acid. In addition, the expressions of proliferating cell nuclear antigen and N-myc were downregulated by methyl jasmonate. Moreover, methyl jasmonate decreased the expression of the Xlinked inhibitor of apoptosis protein and survivin, critical members of inhibitors of the apoptosis protein family, in SH-SY5Y cells. CONCLUSION: Jasmonates suppress the growth of human neuroblastoma cell line SH-SY5Y via inhibiting cell proliferation and inducing apoptosis, which lays the groundwork for further investigation into the anticancer activities and its mechanisms of natural jasmonates on human neuroblastomas.

Methyl jasmonate downregulates expression of proliferating cell nuclear antigen and induces apoptosis in human neuroblastoma cell lines.

Recent evidence indicates that methyl jasmonate, a plant stress hormone, exhibits anticancer activity on human cancer cells. Whether methyl jasmonate could inhibit the growth of human neuroblastoma cells still, however, remains largely unknown. In this study, administration of methyl jasmonate to cultured neuroblastoma cell lines, SK-N-SH and BE(2)-C, resulted in a decrease of cell viability in a dose-dependent and time-dependent manner as demonstrated by MTT colorimetry and colony formation assay. The results from RT-PCR indicated that the expression of proliferating cell nuclear antigen, but not of cyclin D1, was downregulated by methyl jasmonate. Accordingly, the cell cycle of methyl jasmonate-treated neuroblastoma cells was arrested at the G0/G1 phase. Moreover, incubation of SK-N-SH and BE(2)-C cells with methyl jasmonate resulted in characteristic changes of apoptosis, as demonstrated by acridine orange-ethidium bromide (AO/EB) staining, Hoechst 33258 staining and flow cytometry. Moreover, methyl jasmonate decreased the expression of the X-linked inhibitor of apoptosis protein and survivin, critical members of the inhibitors of apoptosis protein family, in neuroblastoma cells. These findings indicate that methyl jasmonate suppresses the growth of cultured human neuroblastoma cells associated with downregulation of proliferating cell nuclear antigen, and induces apoptosis accompanied by downregulation of the X-linked inhibitor of apoptosis protein and survivin, which lays the groundwork for further investigation into the mechanisms of methyl jasmonate-mediated anticancer activities.

Expression and clinical significance of stem cell marker CD133 in human neuroblastoma.

BACKGROUND: Recent evidences indicate that CD133, a kind of transmembrane protein, can be used as a marker to isolate stem cells from tumors originating from neural crest. This study was undertaken to explore the expression and clinical significance of stem cell marker CD133 in neuroblastoma (NB). METHODS: Immunohistochemical staining was used to detect the expression of CD133 in 32 patients with NB and 8 patients with ganglioneuroblastoma (GNB). The relationships were analyzed among CD133 expression, international neuroblastoma staging system (INSS) stages, pathological classification, and postoperative survival time of NB patients. RESULTS: The expression rates of CD133 in NB and GNB were 46.9% (15/32) and 37.5% (3/8) respectively, mainly in cytoplasm of neuroblastoma cells. The expression rates of stage 1-2, stage 3-4 and stage 4S were 30.7%, 57.9% and 37.5%, respectively. The differences in various stages were significant (P<0.05). The positive rate of CD133 in patients with unfavorable histology (52.4%) was significantly higher than that in patients with favorable histology (36.8%) (P=0.007). The survival time of CD133 negative patients was significantly longer than that of CD133 positive patients (P=0.026). CONCLUSIONS: CD133 which might be correlated with the development and progression of NB can serve as one of the important indicators for prognosis of NB.

[Strategies for cloning of novel genes based on EST].

Expressed sequence tags (EST) are short, randomly selected single-pass nucleotide sequence reads derived from cDNA libraries and represent a small part of a gene. Along with the development of bioinformatics and genetic localization, EST has already become a powerful tool for mapping, cloning and expression profiling of genes. Recently, because of the fast distension of EST databases, application of EST in gene mapping and cloning leads to revolutionary change in the strategies for cloning of novel genes. Despite of some insufficiencies, it has been proved that EST could promote the discovery and research of novel genes. In this article, an introduction about EST, especially EST-based strategies for cloning of novel genes will be given in details.