The RING domain in the anti-apoptotic protein XIAP stabilizes c-Myc protein and preserves anchorage-independent growth of bladder cancer cells.

X-linked inhibitor of apoptosis protein (XIAP) suppresses apoptosis and plays key roles in the development, growth, migration, and invasion of cancer cells. Therefore, XIAP has recently attracted much attention as a potential antineoplastic therapeutic target, requiring elucidation of the molecular mechanisms underlying its biological activities. Here, using shRNA-mediated gene silencing, immunoblotting, quantitative RT-PCR, anchorage-independent growth assay, and invasive assay, we found that XIAP's RING domain, but not its BIR domain, is crucial for XIAP-mediated up-regulation of c-Myc protein expression in human bladder cancer (BC) cells. Mechanistically, we observed that the RING domain stabilizes c-Myc by inhibiting its phosphorylation at Thr-58 and that this inhibition is due to activated ERK1/2-mediated phosphorylation of glycogen synthase kinase-3ß (GSK-3ß) at Ser-9. Functional studies further revealed that c-Myc protein promotes anchorage-independent growth and invasion stimulated by the XIAP RING domain in human BC cells. Collectively, the findings in our study uncover that the RING domain of XIAP supports c-Myc protein stability, providing insight into the molecular mechanism and role of c-Myc overexpression in cancer progression. Our observations support the notion of targeting XIAP's RING domain and c-Myc in cancer therapy.

CircHIPK3 sponges miR-558 to suppress heparanase expression in bladder cancer cells.

Increasing evidences suggest that circular RNAs (circRNAs) exert crucial functions in regulating gene expression. In this study, we perform RNA-seq and identify 6,154 distinct circRNAs from human bladder cancer and normal bladder tissues. We find that hundreds of circRNAs are significantly dysregulated in human bladder cancer tissues. We further show that circHIPK3, also named bladder cancer-related circular RNA-2 (BCRC-2), is significantly down-regulated in bladder cancer tissues and cell lines, and negatively correlates with bladder cancer grade, invasion as well as lymph node metastasis, respectively. Over-expression of circHIPK3 effectively inhibits migration, invasion, and angiogenesis of bladder cancer cells in vitro and suppresses bladder cancer growth and metastasis in vivo Mechanistic studies reveal that circHIPK3 contains two critical binding sites for the microRNA miR-558 and can abundantly sponge miR-558 to suppress the expression of heparanase (HPSE). Taken together, our findings provide evidence that circRNAs act as "microRNA sponges", and suggest a new therapeutic target for the treatment of bladder cancer.

Circular RNA BCRC-3 suppresses bladder cancer proliferation through miR-182-5p/p27 axis.

BACKGROUND: Circular RNAs (circRNAs) are a new member of noncoding RNAs (ncRNAs) that have recently been described as key regulators of gene expression. Our previous study had identified the negative correlation between circHIPK3 and bladder cancer grade, invasion, as well as lymph node metastasis. However, the roles of circRNAs in cellular proliferation in bladder cancer remain largely unknown. METHODS: We had analyzed circRNA high-throughout sequencing from human tissues and determined bladder cancer related circRNA-3 (BCRC-3, GenBank: KU921434.1) as a new candidate circRNA derived from PSMD1 gene. The expression levels of circRNAs, mRNAs and miRNAs in human tissues and cells were detected by quantitative real-time PCR (qRT-PCR). The effects of BCRC-3 on cancer cells were explored by transfecting with plasmids in vitro and in vivo. RNA pull down assay, luciferase reporter assay and fluorescence in situ hybridization were applied to verify the interaction between BCRC-3 and microRNAs. Anticancer effects of methyl jasmonate (MJ) were measured by flow cytometry assay, western blot and qRT-PCR. RESULTS: BCRC-3 was lowly expressed in bladder cancer tissues and cell lines. Proliferation of BC cells was suppressed by ectopic expression of BCRC-3 in vitro and in vivo. Mechanistically, overexpression of BCRC-3 induced the expression of cyclin-dependent kinase inhibitor 1B (p27). Importantly, BCRC-3 could directly interact with miR-182-5p, and subsequently act as a miRNA sponge to promote the miR-182-5p-targeted 3'UTR activity of p27. Furthermore, MJ significantly increased the expression of BCRC-3, resulting in an obvious up-regulation of p27. CONCLUSIONS: BCRC-3 functions as a tumor inhibitor to suppress BC cell proliferation through miR-182-5p/p27 axis, which would be a novel target for BC therapy.

NR4A1 is Involved in Fibrogenesis in Ovarian Endometriosis.

BACKGROUND/AIMS: Excess fibrosis may lead to chronic pain, scarring, and infertility as endometriosis develops and progresses. The pathogenesis of endometriosis has been linked to transforming growth factor-ß (TGF-ß), the most potent promoter of fibrosis. METHODS: Levels of NR4A1 and P-NR4A1 protein in human endometrial and endometriotic tissue were assessed by western blotting and immunohistochemistry. The expression levels of fibrotic markers in stromal cells were evaluated by real-time PCR. The degree of fibrosis in mouse endometriotic lesions was detected by Masson trichrome and Sirius red staining. RESULTS: The level of phosphorylated-NR4A1 was higher in ovarian endometriotic tissue than in normal endometrium, and long-term TGF-ß1 stimulation phosphorylated NR4A1 in an AKT-dependent manner and then promoted the expression of fibrotic markers. Furthermore, inhibition of NR4A1 in stromal cells increased the TGF-ß1-dependent elevated expression of fibrotic markers, and loss of NR4A1 stimulated fibrogenesis in mice with endometriosis. Additionally, Cytosporone B (Csn-B), an NR4A1 agonist, effectively decreased the TGF-ß1-dependent elevated expression of fibrotic markers in vitro and significantly inhibited fibrogenesis in vivo. CONCLUSION: NR4A1 can regulate fibrosis in endometriosis and may serve as a new target for the treatment of endometriosis.

Inhibition of BRD4 Suppresses Cell Proliferation and Induces Apoptosis in Renal Cell Carcinoma.

BACKGROUND/AIMS: Renal cell carcinoma (RCC) remains an intractable genitourinary malignancy. Resistance to chemotherapy or targeted therapies in RCC is presumably due to the complicated underlying molecular mechanisms and insufficient understanding. The aim of this research was to assess the expression and role of bromodomain-4 protein (BRD4) in RCC and evaluate the effects of BRD4 inhibitor JQ1 for RCC treatment. METHODS: BRD4 expressionlevels were assessed by qRT-PCR and western blot in RCC tissues and cells. The effects of BRD4 knockdown or JQ1 on RCC cells were assessed by MTT assay and flow cytometry. The effects of in vivo treatment were evaluated through xenograft experiments. RESULTS: BRD4 is significantly overexpressed in RCC, and is related to tumor stage and lymph node metastasis. Inhibition of BRD4 suppressed RCC cell proliferation, induced cell apoptosis in vitro and repressed tumor growth in vivo. Inhibition of BRD4 decreased BCL2 and C-MYC expression while increased BAX and cleaved caspase3 expression, and strikingly diminished the recruitment of BRD4 to BCL2 promoter. CONCLUSIONS: Our research reveals that BRD4 probably play a critical role in RCC progression, and is a new promising target for pharmacological treatment directed against this intractable disease.

Long Non-Coding RNA MEG3 Inhibits Cell Proliferation and Induces Apoptosis in Prostate Cancer.

BACKGROUND/AIMS: Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes, such as cell growth, apoptosis and migration. Although downregulation of lncRNA maternally expressed gene 3 (MEG3) has been identified in several cancers, little is known about its role in prostate cancer progression. The aim of this study was to detect MEG3 expression in clinical prostate cancer tissues, investigate its biological functions in the development of prostate cancer and the underlying mechanism. METHODS: MEG3 expression levels were detected by qRT-PCR in both tumor tissues and adjacent non-tumor tissues from 21 prostate cancer patients. The effects of MEG3 on PC3 and DU145 cells were assessed by MTT assay, colony formation assay, western blot and flow cytometry. Transfected PC3 cells were transplanted into nude mice, and the tumor growth curves were determined. RESULTS: MEG3 decreased significantly in prostate cancer tissues relative to adjacent normal tissues. MEG3 inhibited intrinsic cell survival pathway in vitro and in vivo by reducing the protein expression of Bcl-2, enhancing Bax and activating caspase 3. We further demonstrated that MEG3 inhibited the expression of cell cycle regulatory protein Cyclin D1 and induced cell cycle arrest in G0/G1 phase. CONCLUSIONS: Our study presents an important role of MEG3 in the molecular etiology of prostate cancer and implicates the potential application of MEG3 in prostate cancer therapy.

Stabilization of Snail by HIF-1α and TNF-α is required for hypoxia-induced invasion in prostate cancer PC3 cells.

Hypoxia has been involved in the development of tumor by regulating the expression of invasiveness-associated genes. However, the specific function of hypoxia in cancer cell invasion is still unclear. The aim of the present study was to determine the role of hypoxia in invasion of prostate cancer PC3 cells and to investigate the underlying mechanisms. We found that hypoxia significantly increased the invasive activity of PC3 cells, via up-regulation of the expression of hypoxia inducible factor 1α (HIF-1α) and the autocrine production of tumor necrosis factor α (TNF-α). More important, TNF-α cooperated with HIF-1α in promoting stabilization of Snail, a transcriptional repressor of E-cadherin expression, which lead to the up-regulation of invasiveness-associated genes MMP-9, fibronectin and vimentin. Snail silencing by specific siRNA significantly inhibited hypoxia-induced invasion of PC3 cells, indicating an essential role of Snail in conferring the malignant phenotype to cancer cells under hypoxic conditions. In conclusion, our data demonstrate that hypoxia promoted the invasiveness of prostate cancer PC3 cells via HIF-1α- and TNF-α-induced stabilization of Snail, suggesting a signaling mechanism involving HIF-1α/TNF-α/Snail that mediates invasiveness hypoxic tumor cells in the absence of neoangiogenesis.

Over-expression of testis-specific expressed gene 1 attenuates the proliferation and induces apoptosis of GC-1spg cells.

The effects of over-expression of testis-specific expressed gene 1 (TSEG-1) on the viability and apoptosis of cultured spermatogonial GC-1spg cells were investigated, and the immortal spermatogonial cell line GC-1spg (CRL-2053™) was obtained as the cell model in order to explore the function of TSEG-1. We transfected the eukaryotic vector of TSEG-1, named as pEGFP-TSEG-1 into cultured spermatogonial GC-1spg cells. Over-expression of TSEG-1 inhibited the proliferation of GC-1spg cells, and arrested cell cycle slightly at G0/G1 phase. Transfection of TSEG-1 attenuated the transcript levels of Ki-67, PCNA and cyclin D1. In addition, over-expression of TSEG-1 induced early and late apoptosis, and reduced the mitochondrial membrane potential of GC-1spg cells. Moreover, transfection of TSEG-1 significantly enhanced the ratio of Bax/Bcl-2 and transcript levels of caspase 9, and decreased the expression of Fas and caspase 8 in GC-1spg cells. These results indicated over-expression of TSEG-1 suppresses the proliferation and induces the apoptosis of GC-1spg cells, which establishes a basis for further study on the function of TSEG-1.

[MiR-124 suppresses the proliferation of human prostate cancer PC3 cells by targeting PKM2].

OBJECTIVE: To explore the mechanism of miR-124 inhibiting the proliferative activity of prostate cancer PC3 cells. METHODS: Luciferase reporter gene assay was used to examine the specific binding ability of miR-124 to PKM2 mRNA 3'-UTR. After miR-124 was transfected mimic to PC3 cells, the expression levels of PKM2 mRNA and protein were detected by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot, respectively. The effects of miR-124 mimic and PKM2 siRNA on the proliferative activity of the PC3 cells were determined by MTT assay. RESULTS: The expressions of PKM2 mRNA and protein were upregulated (5.12 +/- 0.35) times and (4.05 +/- 0.20) times respectively in the PC3 cells as compared with those in the RWPE-1 cells (P < 0.05). Luciferase reporter gene assay demonstrated that miR-124 targeted PKM2 3'-UTR. At 24 hours after transfection with miR-124 mimic, the PKM2 protein expression in the PC3 cells was downregulated (0.16 +/- 0.04) times (P < 0.05), while the PKM2 mRNA level was not changed significantly (P > 0.05), as compared with the control group. MTT assay showed that both miRNA-124 mimic and PKM2 siRNA could inhibit the proliferation of the PC3 cells, but the former exhibited a greater inhibitory effect than the latter. After transfection with miR-124 mimic and PKM2 siRNA, the cell growth rates were (66.20 +/- 5.10)% vs (82.10 +/- 6.35)% at 24 hours (P < 0.05) and (49.34 +/- 2.37)% vs (70.10 +/- 5.80)% at 48 hours (P < 0.05). CONCLUSION: miR-124 can suppress the proliferation of PC3 cells by regulating the PKM2 gene.

Exendin-4 ameliorates renal ischemia-reperfusion injury in the rat.

BACKGROUND: Glucagon-like peptide-1 receptor (GLP-1R) activation exerts protective effects against reactive oxygen species by inducing the oxidative defense gene heme oxygenase-1 (HO-1), and provides protection in mice against transient focal cerebral ischemia and ischemia-reperfusion injury in the rat heart. GLP-1R is also expressed in the kidney, but it is unknown whether GLP-1R activation is able to protect against ischemia-reperfusion injury in the rat kidney. MATERIALS AND METHODS: We used a rat model of renal ischemia-reperfusion injury. The rats were pretreated with the GLP-1R agonist, exendin-4 before reperfusion. We used real-time polymerase chain reaction to evaluate expression of the oxidative defense gene HO-1 and Western blot analysis for HO-1 and GLP-1R. Renal function was assessed at baseline and 24 and 72 h after reperfusion. The kidneys were processed for histologic and morphometric analysis, caspase-3, and ED1 immunohistochemistry at 72 h. The degree of apoptosis of the renal tubular cells was determined using terminal deoxynucleotidyl transferase deoxyuridine triphosphate-biotin nick end labeling assays. RESULTS: Exendin-4 pretreatment resulted in GLP-1R activation and upregulation of HO-1. Preconditional activation of GLP-1R significantly improved the serum creatinine levels compared with vehicle (P < 0.05). Furthermore, tissue injury, caspase-3 and ED1 expression, and apoptosis were less severe, as quantified by application of a standardized histologic scoring system in a blinded manner. CONCLUSIONS: These results have demonstrated that preconditional activation of the GLP-1R with exendin-4 in the kidney significantly protected against ischemia-reperfusion injury in rats by increasing HO-1 expression.

[Application of one-stop diagnosis and treatment plan in percutaneous nephrolithotomy for patients with complex renal calculi].

OBJECTIVE: To evaluate the safety and efficacy of preoperative computed tomography urography (CTU) three-dimensional reconstruction, intraoperative radiology and ultrasound guidance followed by percutaneous nephrolithotomy (PCNL) in the treatment of complex renal calculi. METHODS: We summarized the clinical data of 210 patients with complex renal calculi treated at our hospital from December 2008 to December 2011 in this retrospective study. In the one-stop diagnosis and treatment group (n = 119), the optimal puncture approach was designed according to CTU imaging and three-dimensional reconstruction. Percutaneous track was established by ultrasound and radiology guided puncture. PCNL was performed with EMS system. The control group (n = 91) underwent PCNL without radiological guidance. The success rate of puncture, mean accessing time, mean operative duration, intraoperative volume of blood loss and stone-free rate after one operative session were observed. Post-operative follow-ups were conducted until June 2012. RESULTS: Compared to the control group, the one-stop diagnosis and treatment group showed a higher success rate of puncture [98.3% (117/119) vs 92.3% (84/91), P = 0.037], a shorter operative duration [97.8 ± 13.20 vs 110.0 ± 14.73 min, P = 0.043] and a higher stone-free rate after one operative session [92.4% (110/119) vs 83.5% (76/91), P = 0.037]. No significant difference was detected in the mean accessing time[15.3 ± 3.7 vs 13.9 ± 3.9 min, P = 0.398] or intraoperative volume of blood loss [195.8 ± 84.15 vs 263.3 ± 82.06 ml, P = 0.059]. No severe complications occurred. No recurrence of calculi was noted during the follow-up period. CONCLUSION: One-stop diagnosis and treatment plan (CTU 3-D reconstruction plus radiology, ultrasound guidance followed by PCNL) may identify the puncture path, improve the successful rate of puncture and stone-free rates and reduce the complications of PCNL.

[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.

Emergency treatment of testicular torsion and postoperative follow-up: a 71 case report.

This study presented our experience in the treatment of testicular torsion, which may help achieve early diagnosis and improve therapeutic effects. A retrospective analysis was conducted in 71 patients with testicular torsion who were treated in our hospital from October 2007 to April 2011. The age of the patients ranged from 16 days to 34 years. All the patients had unilateral testicular torsion, which took place on the left side in 43 cases and on the right side in 28 cases. The course of the disease varied between three hours to 30 days. Post-operative follow-up was conducted until October 2011. Items examined included signs and symptoms at their first clinical visit, ultrasound findings, treatment in emergency surgery, and post-operative follow-up. In this study, the 71 patients were diagnosed with testicular torsion by color Doppler sonography, 7 had testicular fixation, 63 patients received orchiectomy, while 1 patient did not undergo surgery due to pressure from family members. Post-operative follow-up showed that the one patient's testicle, which had been reserved, atrophied, while all the other survived. No recurrence was found during the follow-up visits. It is concluded that an early diagnosis and surgery is important in improving the survival rate of testicular torsion, and the diagnosis and treatment by the first attending clinician is of critical importance.

Effect of Smac on TRAIL-induced apoptosis of prostate cancer cell line PC-3 and the molecular mechanism.

The effect of Smac gene on the TRAIL-induced apoptosis of the prostate cancer cell line PC-3 and the molecular mechanism were investigated. The Smac gene was transfected into PC-3 cells under the induction of liposome. The intrinsic Smac gene expression was detected by Western blotting. After treatment with TRAIL as an apoptosis inducer, in vitro cell growth activity was assayed by MTT colorimetry. The apoptosis rate of PC-3 cells was determined by annexin V-FITC and propidium iodide staining flow cytometry. The expression of cellular XIAP and caspase-3 genes was examined by Western blotting. Smac-transfected cells (PC-3/Smac group) had significantly increased Smac protein level as compared with PC-3 controls (P<0.01). After induction with 100-200 ng/mL TRAIL for 12-36 h, cellular proliferation rate in PC-3/Smac group was significantly lower than in PC-3 controls (P<0.05). After induction with 100 ng/mL TRAIL for 24 h, the apoptosis rate in PC-3/Smac group was significantly enhanced as compared with that of PC-3 controls (P<0.05). Accordingly, the XIAP expression level was down-regulated significantly (P<0.05) and caspase-3 subunit P20 was up-regulated significantly (P<0.05). It is suggested that the over-expression of cellular Smac can inhibit inhibitor of apoptosis proteins (IAPs), enhance caspases activity and the apoptosis rate of PC-3 cells induced by TRAIL, which may provide a useful experimental basis for prostate cancer therapy.

Experience in management of Fournier's gangrene: a report of 24 cases.

Fournier's gangrene (FG) is an extremely aggressive and rapidly progressive polymicrobial soft tissue infection of the perineum, anal area or genitalial regions with a high mortality rate. The objectives of this study were to share our experience with the management of this serious infectious disease over the last 15 years. This retrospective study examined 24 patients diagnosed as having FG who were admitted to our hospital between March 1996 and December 2011. The gender, age, etiology, predisposing factors, laboratory findings, treatment modality, hospitalization time and spread of gangrene of the subjects were all recorded and analyzed. The results showed that the mean age of the patients was 48.33 years, the male-to-female ratio was 5:1 and the mortality rate was 20.8% (5/24). The most common predisposing factor was diabetes mellitus in 10 patients (41.6%), followed by alcohol abuse, obesity, neoplasms and immunosuppression. The most common etiology was peri-anal and peri-rectal abscesses (45.8%), followed by lesions of urogenital origin (33.3%) and cutaneous (8.3%) origin. No local pathologies could be identified in 3 (12.5%) patients. The most commonly isolated microorganisms were Escherichia coli (62.5%), followed by Enterococcus, Pseudomonas aeruginosa and Staphylococcus aureus. The median admission Fournier's gangrene severity index (FGSI) score for survivors was 5.63±1.89 against 13.6±3.64 for non-survivors which was designed for predicting the disease severity in the series. Early diagnosis and immediate extensive surgical debridement were significant prognostic factors in the management of Fournier gangrene. Individualized reconstructive modalities for wound coverage were useful in that they repaired the tissue defect and improved the quality of life. We are led to conclude that Fournier's gangrene is a severe condition with a high mortality. The Fournier's gangrene severity index (FGSI) score at admission serves as a good predictor for the disease severity. Early diagnosis, surgical debridement and aggressive fluid therapy are significant prognostic factors in the management of Fournier gangrene. Individualized reconstructive surgery modalities for wound coverage are useful to correct the tissue defect and improve the quality of life.

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.

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.

TSEG-1, a novel member of histone H2A variants, participates in spermatogenesis via promoting apoptosis of spermatogenic cells.

A novel variant of histone H2A, named as testis specific expressed gene 1 (TSEG-1, approved symbol: H2afb1), was identified from adult mouse testis. The TSEG-1 gene is 610-bp in length and consists of one exon. TSEG-1 transcript was robustly and exclusively expressed in adult mouse testis, mainly in spermatocytes. In developmental testis, the TSEG-1 transcript was robustly expressed since postnatal day (P) 21, peaked at P30, and gradually decreased in the testis of aging mouse. The surgical cryptorchidism mouse model showed an increase in the TSEG-1 expression, accompanied by enhanced apoptosis of spermatogenic cells. The EGFP-tagged TSEG-1 protein is located in the nuclei of cultured spermatocytes (GC-2spd cells). Transfection of TSEG-1 into GC-2spd cells resulted in suppressed cell viabilities, increased apoptosis, and decreased mitochondrial membrane potential. Intratesticular injection of TSEG-1 resulted in increased apoptosis of spermatogenic cells in vivo. These results suggest that TSEG-1 may participate in the spermatogenesis via regulating the apoptosis of spermatogenic cells.