Qiang-Song Tong

Downregulation of XIAP expression induces apoptosis and enhances chemotherapeutic sensitivity in human gastric cancer cells.

X-linked inhibitor of apoptosis (XIAP) is the most potent member of the inhibitor of apoptosis protein (IAP) gene family in terms of its ability to inhibit caspases and suppress apoptosis. Recent evidence has suggested that XIAP is a key determinant in chemoresistance of cancer cells. To explore a novel approach for ameliorating chemotherapy of gastric cancer, the antisense expression vector for the XIAP gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53) and MKN-28 (mutant-type p53). This transfer resulted in significant downregulation of XIAP expression, decreased in vitro cell viabilities, and induced apoptosis. In transferred cells, inactive caspase-3 precursors were cleaved into the active subunits (p20 and p17) during apoptosis induced by downregulation of XIAP. The inhibitory effects of cisplatin and mitomycin C on the growth of XIAP downregulated cancer cells were significantly enhanced. In addition, this process occurred only in wild-type p53 (MKN-45), but not in mutant-type p53 (MKN-28) gastric cancer cells. The data presented suggest that downregulation of XIAP via antisense RNA can lead to apoptosis of gastric cancer cells in vitro, correlating with cellular p53 status and activation of caspase-3. This finding could lead to a potential strategy for improving the efficiency of therapies for gastric cancer.

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

BackgroundRecent 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).MethodsImmunohistochemical 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.ResultsThe 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).ConclusionsCD133 which might be correlated with the development and progression of NB can serve as one of the important indicators for prognosis of NB.

Apoptosis-inducing effects of curcumin derivatives in human bladder cancer cells

Our aim was to prepare curcumin derivatives and study their apoptosis-inducing effects on bladder cancer cells in order to establish a basis for targeted chemotherapy of cancer. n-Maleoyl-L-valine-curcumin (NVC) and n-maleoyl-glycine-curcumin (NGC) were chemically synthesized. Intracellular esterase activity of the human bladder cancer EJ cell line and renal tubular epithelial (HKC) cells was examined by 6-carboxyfluorescein diacetate fluorometry. After incubation with NVC or NGC for 6–24u2009h, cell viability was detected by MTT colorimetry. Cell apoptosis and apoptotic rates were measured by acridine orange/ethidium bromide staining, TUNEL labeling and flow cytometry. Intracellular caspase-3 activities were determined by spectrophotometry. The esterase activity within EJ cells was 10.2-fold higher than that of HKC cells, which was abolished by bis-p-nitrophenylphosphate, an esterase inhibitor, resulting in decreases in NVC- and NGC-mediated cell viability arrest. For EJ cells, the IC50 values of NVC (20.1u2009μmol/l) and NGC (18.7u2009μmol/l) were close to curcumin (16.5u2009μmol/l). Meanwhile, their IC50 values on HKC cells were, respectively, 4.06- and 3.23-fold higher than curcumin. Moreover, NVC and NGC induced apoptosis of EJ cells by 10.13–23.36 and 12.42–28.56%, respectively. Administration of these two derivatives resulted in decreased apoptosis of HKC cells compared with curcumin. The caspase-3 activities of EJ cells, but not of HKC cells, were 5.21- and 5.63-fold enhanced by NVC and NGC, respectively. Thus, novel esterase-sensitive curcumin derivatives were synthesized, which induced extensive apoptosis of bladder cancer EJ cells, but not normal cells.

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.

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

AbstractAim: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 neuro-blastoma cell line SH-SY5Y, resulted in a decrease of cell proliferation in a dose-and 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 X-linked 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.

Nitrofen suppresses cell proliferation and promotes mitochondria-mediated apoptosis in type II pneumocytes

AbstractAim:To characterize the molecular mechanisms of nitrofen-induced pulmonary hypoplasia.Methods:After administration of nitrofen to cultured type IIA549 pneumocytes, cell proliferation and DNA synthesis were investigated by 3- (4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide colorimetry, colony formation assay, flow cytometry and [3H]-thymidine incorporation assay. Apoptosis was measured by terminal transferase-mediated dUTP nick-end-labeling, acridine orange-ethidium bromide staining and flow cytometry. Expression of proliferating cell nuclear antigen (PCNA) and apoptosis-related genes was assayed by immunofluorescence, RT-PCR and Western blot.Results:Nitrofen inhibited the cell proliferation of A549 cells in a dose- and time-dependent manner, accompanied by downregulation of PCNA. As a result, the DNA synthesis of nitrofentreated A549 cells decreased, while cell cycle was arrested at G0/G1 phase. Moreover, nitrofen induced apoptosis of A549 cells, which was not abolished by Z-Val-Ala-Asp(OCH3)- fluoromethylketone. In addition, nitrofen decreased the expression of Bcl-xL, but not of Bcl-2, Bax, and Bak, resulting in a loss of mitochondrial membrane potential and the nuclear translocation of apoptosis-inducing factor (AIF). Meanwhile, nitrofen strongly activated the p38 mitogen-activated protein kinase (p38-MAPK). Pretreatment of cells with SB203580 (5 μmol/L) blocked nitrofen-induced phosphorylation of p38-MAPK and abolished nitrofen-induced AIF translocation and apoptosis in A549 cells.Conclusion:Nitrofen suppresses the proliferation of cultured type II pneumocytes accompanied by the downregulation of PCNA, and induces mitochondria-mediated apoptosis involving the activation of p38-MAPK.

Clinical value of pelvic 3-dimensional magnetic resonance image reconstruction in anorectal malformations

OBJECTIVEnThe study aimed to build a 3-dimensional (3D) reconstruction of pelvic magnetic resonance images and evaluate the clinical value in anorectal malformations (ARMs).nnnMETHODSnMagnetic resonance imaging (MRI) examinations were performed on a 1.5-T magnet. Sagittal, coronal, and transverse turbo spin-echo T1-weighted and fast spin-echo T2-weighted images of the pelvic region were obtained in 22 children. A 3D reconstruction was made on a computer and assisted by the 3D-Doctor software (Trial Version, Able Software Corp). The level and type of ARM and the developmental state of the striated muscle complex (SMC) were analyzed with 3D reconstruction image.nnnRESULTSnThe 3D images of the pelvic were confirmed in 22 cases. Three-dimensional reconstructed images perfectly displayed the anatomical relationships of the SMC and the rectal atresia in these spaces. The 3D configuration of the SMC was different in each of the high- and low-type cases. The high-type malformation of SMCs differed particularly from the descriptions.nnnCONCLUSIONSnPelvic magnetic resonance 3D reconstructed images were able to show the dimensional anatomical relations of pelvis, bladder, urethra, rectum, and SMC. Both a 3D image and positional information with MRI offers the surgeon a simulated operative profile of the SMC superior to MRI slices alone, which will help in providing morphological data for image diagnosis and operation of the ARM.

Laparoscopy-assisted orchiopexy for recurrent undescended testes in children ☆

OBJECTIVEnReoperative orchidopexy is a technical challenge to pediatric surgeons. The laparoscopy-assisted procedure is described for securing the testis in the scrotum in patients with a past history of open orchidopexy and testes in an unsatisfactory position.nnnPATIENTS AND METHODSnThirty-one patients with 35 abnormally positioned testes (4 bilateral) were evaluated. All patients had a past history of inguinal surgery, and ages ranged between 2.5 and 13 years (mean, 5.5 years). Previous surgical procedures included 32 orchiopexies and 3 testicular detorsion of undescended testis. If needed, inguinal dissection was performed to loose the adherence between the cord and inguinal canal. Laparoscopic orchidopexy was applied to allow the testis to remain in the scrotum without tension. Patients underwent follow-up every 3 months after the operation with physical and ultrasound examinations.nnnRESULTSnTen low inguinal testes were treated directly with open inguinal redo orchidopexy, whereas laparoscopy-assisted orchidopexy was possible in 23 (92%) of the remaining 25 reoperations. In 2 (8%) of these cases, severe scarring was present between the cord and the inguinal canal impeding the laparoscopy-assisted orchidopexy. For laparoscopy-assisted procedure, the operation time was 42 to 67 minutes (mean = 52 min). After the laparoscopy-assisted reoperations, 23 (92%) testes remain within the scrotum after a mean follow-up of 22 months (range, 6-32 months).nnnCONCLUSIONnWhen feasible, laparoscopy-assisted orchiopexy is a simple and effective technique for securing testicles in reoperative orchiopexy procedures.

Nuss operation for pectus excavatum: a single-institution experience

BackgroundThe Nuss procedure for repair of pectus excavatum (PE) has been accepted worldwide because of minimal invasiveness and excellent cosmetic results. We summarized our experience with the treatment of 115 patients aged 2.7–18 years.MethodsAll the 115 patients underwent the Nuss procedure successfully from July 2003 to February 2008. They were divided into two groups: children group (below 12 years) and adolescents group (aged 12–18 years).ResultsThe rate of complications was 14.7% and 37.5% in the children and adolescents groups, respectively (P<0.05). There was significant difference in operation time, length of hospital stay, and analgesic time between the two groups (P<0.05). The initial results of Nuss procedure were excellent.ConclusionsThe Nuss procedure can be performed with excellent early results in children. We suggest that children with PE should accept the Nuss procedure as early as possible when they are over 5 years old.

Selection of optimal antisense accessible sites of uroplakin II mRNA for bladder urothelium

SummaryThe optimal antisense accessible sites (AAS) of uroplakin II (UP II) mRNA, a specific gene expressed in bladder urothelium, were selected in order to provide a novel method for targeted therapy of transitional cell carcinoma (TCC) of bladder. The 20 mer random oligonucleotide library was synthesized, hybridized with in vitro transcripted total UP II cRNA, then digested by RNase H. After primer extension and autoradiography, the AAS of UP II were selected. The RNADraw software was used to analyze and choose the AAS with obvious stem-loop structures, according to which the complementary antisense oligonucleotides (AS-ODN) were synthesized. With the AS-ODN0 designed only by RNADraw as a control, the AS-ODNs were transferred into UP II highly-expressing cell line RT4. The cellular expression of UP II mRNA was detected by RT-PCR and Western blot. Twelve AAS of UP II mRNA were selected in vitro. Four AAS with stem-loop structures were chosen, locating at 558–577, 552–571, 217–236 and 97–116 bp of UP II mRNA respectively. After transfection with the corresponding AS-ODN (AS-ODN1, AS-ODN2, AS-ODN3 and AS-ODN4) for 18 h, the UP II mRNA levels in RT4 cells were reduced by 29.3%, 82.7%, 71.3% and 70.9%, while UP II protein levels were decreased by 20.2%, 78.5%, 65.2% and 64.4% respectively, which were significantly higher than those of AS-ODN0 (14.3%, 12.1% respectively) (P<0.01). The AAS of UP II mRNA was effectively selected in vitro by random oligonucletide library/RNase H cleavage method in combination with computer software analysis, which had important reference values for further studying biological functions of UP II gene and targeted therapeutic strategy for TCC of bladder.The optimal antisense accessible sites (AAS) of uroplakin II (UP II) mRNA, a specific gene expressed in bladder urothelium, were selected in order to provide a novel method for targeted therapy of transitional cell carcinoma (TCC) of bladder. The 20 mer random oligonucleotide library was synthesized, hybridized with in vitro transcripted total UP II cRNA, then digested by RNase H. After primer extension and autoradiography, the AAS of UP II were selected. The RNADraw software was used to analyze and choose the AAS with obvious stem-loop structures, according to which the complementary antisense oligonucleotides (AS-ODN) were synthesized. With the AS-ODN0 designed only by RNADraw as a control, the AS-ODNs were transferred into UP II highly-expressing cell line RT4. The cellular expression of UP II mRNA was detected by RT-PCR and Western blot. Twelve AAS of UP II mRNA were selected in vitro. Four AAS with stem-loop structures were chosen, locating at 558–577, 552–571, 217–236 and 97–116 bp of UP II mRNA respectively. After transfection with the corresponding AS-ODN (AS-ODN1, AS-ODN2, AS-ODN3 and AS-ODN4) for 18 h, the UP II mRNA levels in RT4 cells were reduced by 29.3%, 82.7%, 71.3% and 70.9%, while UP II protein levels were decreased by 20.2%, 78.5%, 65.2% and 64.4% respectively, which were significantly higher than those of AS-ODN0 (14.3%, 12.1% respectively) (P<0.01). The AAS of UP II mRNA was effectively selected in vitro by random oligonucletide library/RNase H cleavage method in combination with computer software analysis, which had important reference values for further studying biological functions of UP II gene and targeted therapeutic strategy for TCC of bladder.