Hesperetin promotes bladder cancer cells death via the PI3K/AKT pathway by network pharmacology and molecular docking.

Patients with bladder cancer (BLCA) still show high recurrence after surgery and chemotherapy. Hesperetin (HE), as a natural compound, has attracted researchers' attention due to its low toxicity and easy access. However, the inhibitory effect of HE on BLCA remains unknown. The hub genes and enrichment pathways regulated by HE in the treatment of BLCA were predicted by network pharmacology. The molecular docking of HE and hub proteins was visualized. Colony and CCK8 assays were used to test cell proliferation, and BLCA migration was confirmed by transwell and wound healing assays. In addition, the occurrence of apoptosis and ferroptosis was demonstrated by Hoechst staining, transmission electron microscopy (TEM) and ROS (reactive oxygen species) assay. Western Blotting was performed to validate the hub proteins, target functions and pathways. SRC, PIK3R1 and MAPK1 were identified as hub targets for HE in BLCA, involving the PI3k/AKT pathway. Furthermore, HE inhibited the proliferation and migration of BLCA cells. The MMP2/MMP9 proteins were significantly inhibited by HE. The increased expression of Bax and cleaved caspase-3 indicated that HE could promote BLCA cell apoptosis. In addition, Hoechst staining revealed concentrated and illuminated apoptotic nuclei. The activation of ROS and the decline of GPX4 expression suggested that HE might induce ferroptosis as an anti-BLCA process. Shrunk mitochondria and apoptotic bodies were observed in BLCA cells treated with HE, with reduced or absent mitochondrial cristae. We propose for the first time that HE could inhibit the proliferation and migration of BLCA cells and promote apoptosis and ferroptosis. HE may act by targeting proteins such as SRC, PIK3R1 and MAPK1 and the PI3K/AKT pathway.

Role of copper ionophore-induced death in immune microenvironment and clinical prognosis of ccRCC: An integrated analysis.

Background: Clear cell renal cell carcinoma (ccRCC) is a malignancy with a high incidence rate and poor prognosis worldwide. Copper ionophore-induced death (CID) plays an important role in cancer progression. Methods: One training and three validation datasets were acquired from TCGA, GEO and ArrayExpress. K-means clustering was conducted to identify the CID subtypes. The ESTIMATE and CIBERSORT algorithms were employed to illustrate the immune microenvironment of ccRCC. LASSO Cox regression was applied to construct the CID feature-based prognostic model. The immunotherapy cohort was acquired from the literature to explore the potential risk scores for predicting immunotherapy responsiveness. Results: Two CID-related cancer subtypes of ccRCC were identified that performed different immune microenvironment characteristics and prognosis. Based on the identified subtypes, we analyzed the biological heterogeneity and constructed a gene prognostic model. The prognostic model performed well in one training dataset, three validation datasets, and different clinical pathological groups. The prognostic model has a good potential for predicting cancer immune features and immunotherapy responsiveness. Conclusion: CID plays an important role in the tumor microenvironment progression of ccRCC. The robust gene prognostic model developed can help predict cancer prognosis, immune features, and immunotherapy responsiveness.

Properties of flavonoids in the treatment of bladder cancer (Review).

Given its high recurrence and rapid progress, bladder cancer (BLCA) treatment has become a major problem for clinicians. BLCA is difficult to control even with surgical resection and extensive use of chemotherapeutic drugs. The non-toxicity and ease of accessibility of natural compounds have attracted much attention in recent years. Flavonoids serve an essential role given their antioxidant, antibacterial, anticancer and cardiovascular properties. They are mainly divided into several subclasses; flavones, flavanones, flavonols, flavanols, anthocyanins isoflavones and chalcones. Over the years, the role of flavonoids in BLCA has been extensively studied. The present review provided a comprehensive overview of the classification of flavonoids and substantiate the role of epithelial-mesenchymal transition, cancer stem cells, angiogenesis, epigenetic regulation and programmed cell death in BLCA. The present review emphasized that flavonoids for BLCA treatment are worthy of further study and anti-BLCA drugs have huge prospects for clinical use.

LAMTOR3 is a prognostic biomarker in kidney renal clear cell carcinoma.

OBJECTIVE: The objective of the study was to investigate the expression of LAMTOR3 in kidney renal clear cell carcinoma (KIRC) and its clinical significance. METHODS: The expression of LAMTOR3 in KIRC and its relationship with clinical features were analyzed using the UALCAN online database. The results were verified using KIRC gene chip data and clinical specimens. The prognosis of KIRC patients was analyzed with the GEPIA2 database. GO, KEGG, and GSEA analyses were conducted to analyze the possible molecular mechanism of LAMTOR3 in KIRC. Immunohistochemical (IHC) and hematoxylin and eosin (H&E) staining were used for histopathological detection. RESULTS: UALCAN database analysis showed that LAMTOR3 expression in KIRC was significantly lower than in normal kidney tissues and correlated with the clinical stage, pathological grade, and tumor genotype (p < .05). GSE53757 dataset analysis consistently showed that the expression of LAMTOR3 in KIRC was significantly lower than in normal kidney tissues (p < .01). GEPIA2 database analysis indicated that patients with low LAMTOR3 expression had poor overall and disease-free survival rates. GSEA analysis suggested that LAMTOR3 positively regulated the citrate cycle and drug metabolism cytochrome P450 and negatively regulated folate biosynthesis and olfactory transduction. The expression of LAMTOR3 in KIRC was also significantly correlated with immune cell infiltration. Finally, IHC showed that LAMTOR3 expression in the KIRC tissues was lower than in the adjacent normal tissues. CONCLUSION: LAMTOR3 expression is significantly lower in KIRC. LAMTOR3 may be a potential marker for KIRC diagnosis and therapy.

Research Progress on the Functions and Mechanism of circRNA in Cisplatin Resistance in Tumors.

Cisplatin is a common chemotherapeutic drug that has been used to treat of numerous tumors, including testicular, lung, bladder, ovarian, liver and head and neck cancers. Although clinical chemotherapy based on cisplatin has shown a remarkable therapeutic effect, the resistance to cisplatin becomes increasingly obvious as a patient uses it for a prolonged period. It not only affects the prognosis of these tumors, but also causes the recurrence of cancer and decreases the overall survival rate. The development of cisplatin resistance involves several mechanisms, including DNA damage repair, ATP-binding cassette (ABC) transporter, autophagy, cancer stem cells (CSCs), epithelial-mesenchymal transition (EMT), and other related signaling pathways. Interestingly, these mechanisms have been found to be influenced by circular RNAs (circRNAs) to regulate tumor proliferation, invasion, chemosensitivity, and other biological behaviors in the tumor microenvironment (TME). In recent years, circRNAs in cisplatin resistance in tumors, especially lung cancer and gastric cancer, have gradually drawn peoples' attention. This review summarizes recent studies on the functions and mechanisms of circRNAs in cisplatin resistance. We emphasize that circRNA can be used as a promising target gene to improve drug resistance and therapeutic efficacy.

Feedback activation of GATA1/miR-885-5p/PLIN3 pathway decreases sunitinib sensitivity in clear cell renal cell carcinoma.

Sunitinib is the most commonly used first-line therapy for the treatment of advanced renal cell carcinoma (RCC), but intrinsic and extrinsic resistance to targeted therapies dramatically compromise the benefit of clinical outcome. Dissecting the underlying mechanisms and discovering reliable predictive biomarkers are urgently needed in clinic. Here, we discovered miR-885-5p was notably decreased after sunitinib treatment and associated with poor disease progression in clear cell renal cell carcinoma (ccRCC). In vitro and in vivo studies identified miR-885-5p inhibition contributed to sunitinib resistance. Mechanistically, sunitinib treatment reduced GATA1 expression, which in turn reduced its binding to MIR885 promoter and resulted in miR-885-5p downregulation in transcriptional level. In addition, PLIN3 was confirmed to be directly targeted by miR-885-5p and its upregulation significantly increased lipid droplets formation to decrease sunitinib sensitivity. Therefore, GATA1/miR-885-5p/ PLIN3 pathway may serve as a potential therapeutic strategy and a biomarker for sunitinib treatment in ccRCC.

Novel circRNA_0071196/miRNA­19b­3p/CIT axis is associated with proliferation and migration of bladder cancer.

Circular RNAs (circRNAs) are non­coding RNAs that are connected at the 3' and 5' ends by an exon or intron. Studies increasingly show that circRNAs play an important role in tumorigenesis by acting as a 'sponge' for microRNAs (miRNAs), which abrogates the latter's effect on their target mRNAs. To identify a possible circRNA/miRNA/mRNA network in bladder cancer (BCa), we analyzed the circRNA and mRNA expression profiles of BCa and adjacent normal bladder tissues. A total of 127 circRNAs and 1,612 mRNAs were differentially expressed in the tumor tissues, and were primarily associated with cancer­related pathways. A competing endogenous RNAs (ceRNA) network was then constructed which predicted a regulatory axis of circRNA_0071196, miRNA­19b­3p and its target gene citron Rho­interacting serine/threonine kinase (CIT). Luciferase reporter assay validated the relationship between circRNA_0071196 and miRNA­19b­3p and of the latter with CIT. Furthermore, CIT was overexpressed in the BCa tissues, and was found to be correlated with metastasis and tumor histological grade. Knockdown of CIT in the human bladder cancer cell line 5367 significantly inhibited the proliferation, migration and colony formation capacity of the cells, and also upregulated the mediators of the p53 and RhoA­ROCK signaling cascades that regulate cell cycle and migration. Taken together, our findings indicate that circRNA­0071196 upregulates CIT levels in BCa by sponging off miRNA­19b­3p, and the circRNA_0071196/miRNA­19b­3p/CIT axis is a potential therapeutic target in BCa.

Down-regulation of CIT can inhibit the growth of human bladder cancer cells.

OBJECTIVE: Our study is to examine the citron rho-interacting, serine/threonine kinase 21 (CIT) in bladder cancer. METHODS: We examined CIT level in human bladder cancer tissues by immunohistochemical staining. To explore the impact of CIT on cell proliferation and apoptosis, we down-regulated its expression in two human bladder cancer cell lines, 5367 and T24. We examined cell growth in 5367 and T24. We also performed in vivo analysis using T24 cells. We further used microarray expression profiling to investigate genes differentially expressed in T24 cells with CIT down-regulated. RESULTS: In 100 human samples, CIT was expressed by only 2 of 30 (6.7 %) controls in bladder tissues, whereas by 64 of 70 (91.4 %) cancer patients in tumor tissues (p < 0.001). in vitro analysis demonstrated that CIT knockdown represses cell proliferation by 50 % in both cells and colony formation (77 ± 5 vs. 13 ± 2, p = 0.001 for T24, 58 ± 3 vs. 1 ± 1, p < 0.001 for 5637). We also found CIT knockdown could induce cell cycle arrest, and promote apoptosis in both cells. Tumor-volume monitoring and live in vivo bladder cancer imaging in human xenograft model confirmed that CIT knockdown reduces tumor volume (668.4 ± 333.0 vs. 305.7 ± 170.4 mm3, p = 0.02) and weight (0.27 ± 0.15 vs. 0.57 ± 0.32 g, p = 0.02). Microarray analysis revealed that CIT may regulate cell cycle signalling pathway through various cell cycle regulators. CONCLUSIONS: In summary, we provided clinical and experimental evidence that CIT may promote bladder cancer through regulation of cell cycle pathway.

Downregulation of long non-coding RNA TRIM52-AS1 functions as a tumor suppressor in renal cell carcinoma.

Long non-coding RNAs (lncRNAs) are important regulators of gene expression, interacting with the major pathways of cell growth, proliferation, differentiation and survival. Alterations in the function of lncRNAs promote tumor formation, progression and metastasis. The purpose of the present study was to identify novel tumor suppressor lncRNAs, and elucidate their physiological function and mechanism in renal cell carcinoma (RCC). The results of the present study revealed that the expression of the lncRNA, TRIM52­AS1, was downregulated in RCC, which was demonstrated using reverse transcription­quantitative polymerase chain reaction analysis. Furthermore, the effects of TRIM52­AS1 on proliferation, cell migration and apoptosis were analyzed using a wound scratch assay, a 3­(4,5­dimethylthiazol­2yl)­2,5­diphenyl tetrazolium bromide assay and flow cytometric analysis, respectively. The overexpression of TRIM52­AS1 using a synthesized vector significantly suppressed cell migration and proliferation, and induced apoptosis of the RCC cells in vitro, and interference of its expression led to the opposite effects. The present study was the first, to the best of our knowledge, to demonstrate that TRIM52­AS1 functions as a tumor suppressor in RCC. Further investigation is required to elucidate the molecular mechanisms underlying the effects of TRIM52-AS1 in the development of RCC.

Evaluation of the improved tubeless cutaneous ureterostomy technique following radical cystectomy in cases of invasive bladder cancer complicated by peritoneal metastasis.

Radical cystectomy, as the most common surgical treatment for patients with invasive bladder cancer (IBC) complicated by peritoneal metastasis, is usually accompanied by a urinary diversion procedure. In this study, we evaluated the improved tubeless cutaneous ureterostomy technique by comparing the resulting clinical effects with either a traditional ureterostomy and an ileal conduit urinary diversion. Clinical data from 85 patients who underwent 1 of the 3 procedures between April 2012 and April 2015 were analyzed retrospectively. In total, 30 patients underwent improved tubeless cutaneous ureterostomy, 28 patients underwent a traditional cutaneous ureterostomy and 27 underwent an ileal conduit urinary diversion following radical cystectomy. The incidence of complications, including stoma infection, nipple atrophy, terminal necrosis, urine leakage, external orifice stenosis, uronephrosis and ureterectasia in the group of patients treated with the improved tubeless ureterostomy technique was significantly lower than that of the patients in the other 2 groups, and the difference was statistically significant (P<0.05). In addition, the duration of the surgery, intra-operative bleeding, the duration of the hospitalization period and the time to extubation in the patients treated with the improved tubeless ureterostomy technique were significantly decreased (P<0.05) compared with the patients in the other 2 groups. Finally, the health-related quality of life of the patients treated with the improved tubeless ureterostomy technique was significantly higher (P<0.05) than that of the patients in the other 2 groups. The findings of our study demonstrated that the use of the improved tubeless cutaneous ureterostomy technique following radical cystectomy in patients with IBC complicated by peritoneal metastasis resulted in improved clinical effects. Thus, improved tubeless cutaneous ureterostomy may be a promising alternative for enhancing the quality of life of patients with IBC.

MicroRNA-137 upregulation increases bladder cancer cell proliferation and invasion by targeting PAQR3.

There is increasing evidence suggesting that dysregulation of some microRNAs (miRNAs) may contribute to tumor progression and metastasis and have been proposed to be key regulators of diverse biological processes such as transcriptional regulation, cell growth and tumorigenesis. Previous studies have shown that miR-137 is dysregulated in some malignancies, but its role in bladder cancer is still unknown. In our study, we find that miR-137 is up-regulated in human bladder cancer tissues and cell lines. Moreover, the higher level of miR-137 was associated with pM or pTNM stage in clinical bladder cancer patients. Enforced expression of miR-137 in bladder cancer cells significantly enhanced their proliferation, migration and invasion. Bioinformatics analysis identified the tumor suppressor gene PAQR3 as a potential miR-137 target gene. Further studies indicated that miR-137 suppressed the expression of PAQR3 by binding to its 3'-untranslated region. Silencing of PAQR3 by small interfering RNAs phenocopied the effects of miR-137 overexpression, whereas restoration of PAQR3 in bladder cancer cells bladder cancer cells overexpressing miR-137, partially reversed the suppressive effects of miR-137. These findings indicate that miR-137 could be a potential oncogene in bladder cancer.

Long non-coding RNA identification over mouse brain development by integrative modeling of chromatin and genomic features.

In silico prediction of genomic long non-coding RNAs (lncRNAs) is prerequisite to the construction and elucidation of non-coding regulatory network. Chromatin modifications marked by chromatin regulators are important epigenetic features, which can be captured by prevailing high-throughput approaches such as ChIP sequencing. We demonstrate that the accuracy of lncRNA predictions can be greatly improved when incorporating high-throughput chromatin modifications over mouse embryonic stem differentiation toward adult Cerebellum by logistic regression with LASSO regularization. The discriminating features include H3K9me3, H3K27ac, H3K4me1, open reading frames and several repeat elements. Importantly, chromatin information is suggested to be complementary to genomic sequence information, highlighting the importance of an integrated model. Applying integrated model, we obtain a list of putative lncRNAs based on uncharacterized fragments from transcriptome assembly. We demonstrate that the putative lncRNAs have regulatory roles in vicinity of known gene loci by expression and Gene Ontology enrichment analysis. We also show that the lncRNA expression specificity can be efficiently modeled by the chromatin data with same developmental stage. The study not only supports the biological hypothesis that chromatin can regulate expression of tissue-specific or developmental stage-specific lncRNAs but also reveals the discriminating features between lncRNA and coding genes, which would guide further lncRNA identifications and characterizations.

Identification and characterization of long non-coding RNAs related to mouse embryonic brain development from available transcriptomic data.

Long non-coding RNAs (lncRNAs) as a key group of non-coding RNAs have gained widely attention. Though lncRNAs have been functionally annotated and systematic explored in higher mammals, few are under systematical identification and annotation. Owing to the expression specificity, known lncRNAs expressed in embryonic brain tissues remain still limited. Considering a large number of lncRNAs are only transcribed in brain tissues, studies of lncRNAs in developmental brain are therefore of special interest. Here, publicly available RNA-sequencing (RNA-seq) data in embryonic brain are integrated to identify thousands of embryonic brain lncRNAs by a customized pipeline. A significant proportion of novel transcripts have not been annotated by available genomic resources. The putative embryonic brain lncRNAs are shorter in length, less spliced and show less conservation than known genes. The expression of putative lncRNAs is in one tenth on average of known coding genes, while comparable with known lncRNAs. From chromatin data, putative embryonic brain lncRNAs are associated with active chromatin marks, comparable with known lncRNAs. Embryonic brain expressed lncRNAs are also indicated to have expression though not evident in adult brain. Gene Ontology analysis of putative embryonic brain lncRNAs suggests that they are associated with brain development. The putative lncRNAs are shown to be related to possible cis-regulatory roles in imprinting even themselves are deemed to be imprinted lncRNAs. Re-analysis of one knockdown data suggests that four regulators are associated with lncRNAs. Taken together, the identification and systematic analysis of putative lncRNAs would provide novel insights into uncharacterized mouse non-coding regions and the relationships with mammalian embryonic brain development.

Periurethral injection of autologous adipose-derived stem cells with controlled-release nerve growth factor for the treatment of stress urinary incontinence in a rat model.

BACKGROUND: Stem cell therapy is a promising therapeutic strategy for stress urinary incontinence (SUI). However, its current efficacy is insufficient. OBJECTIVE: We designed a stem cell transplantation system that contains autologous adipose-derived stem cells (ADSC) and controlled-release nerve growth factor (NGF). We evaluated whether this system could enhance the therapeutic efficacy of ADSCs by periurethral coinjection in SUI rats. DESIGN, SETTING, AND PARTICIPANTS: We first tested for the presence of NGF receptors in rat ADSCs and observed the effect of NGF on ADSCs in vitro and in vivo. NGF was encapsulated within poly(lactic-co-glycolic acid-PLGA) microspheres (PLGA/NGF) to control its release. SUI was created in rats, and ADSCs were harvested, cultured from fat tissue, and retained for later transplantation. SUI rats then received different forms of periurethral injection therapy. Their urodynamic index was monitored. Eight weeks after injection, the SUI rats were sacrificed and their urethra removed for histologic evaluation. INTERVENTION: Forty SUI rats were allocated to five groups for receiving periurethral injection with phosphate-buffered saline (PBS), ADSC, ADSC+PLGA, ADSC+NGF, or ADSC+PLGA/NGF. Bladder capacities, abdominal leak point pressure (ALPP), and retrograde urethral perfusion pressure (RUPP) were reassessed at 2, 6, and 8 wk after injection. MEASUREMENTS: The rat SUI model was generated by bilateral pudendal nerve transection (PNT). Real-time polymerase chain reaction (RT-PCR) and western blotting detected the NGF receptor Ark-A. The regeneration of muscles and peripheral nerves was evaluated by Masson's trichrome and immunohistochemical staining. RESULTS AND LIMITATIONS: Results revealed the presence of the NGF receptor Trk-A on rat ADSCs. Short-term observations showed that NGF could improve ADSCs' viability in vitro and in vivo. ADSCs delivered intramuscularly into the urethra in combination with PLGA/NGF resulted in significant improvements in ALPP and RUPP as well as the amount of muscle and ganglia. There was a significant difference between the ADSC+PLGA/NGF group and other groups. CONCLUSIONS: Periurethral coinjection of autologous ADSCs with controlled-release NGF may be a potential strategy for SUI treatment.

Additive antitumoral effect of interleukin-12 gene therapy and chemotherapy in the treatment of urothelial bladder cancer in vitro and in vivo.

BACKGROUND: We evaluated antitumoral effect of combined chemotherapy and interleukin-12 (IL-12) gene therapy in in vitro and in vivo experimental urothelial bladder cancer (UBC) model. MATERIALS AND METHODS: EJ UBC cells were transfected with recombinant IL-12 genes using a liposomal transfection agent. Pirarubicin (THP) was added to the experimental samples at a final concentration of 20 mg/l. Four groups were assigned in vitro: untreated cells, transfected cells, untransfected cells plus THP and transfected cells plus THP. Death rates (DR) and cellular micromorphologic changes were evaluated. Bladder tumor model was established by subcutaneous injection of EJ cells to the nude mice. Four groups were assigned in vivo: control group; THP group; IL-12 gene group and IL-12 gene plus THP group. After injection of combined THP and IL-12 gene therapy, tumor size and IL-12 levels were evaluated. RESULTS: In vitro study: DR in the THP + IL-12 gene therapy group (58.2 ± 15.8%) was significantly higher than transfected group (12.2 ± 5.6%; P = 0.01) and untransfected cells plus THP group (33.4 ± 7.8; P = 0.046). A higher amount of apoptotic changes and necrosis on transmission electron microscope analysis were observed in transfected cells plus THP group. In vivo study: A significant tumor attenuation was found in IL-12 gene in combination with THP group when compared with any other groups that were treated without Il-12 or THP (P < 0.05). IL-12 levels in serum were significant high in IL-12 gene groups (P < 0.01). CONCLUSION: The combination of THP chemotherapy and IL-12 gene therapy showed an additive antitumoral effect on bladder cancer cells in vitro and in vivo. Further investigation should be focused on high-level transgene protocols in vivo.

Mutational analysis of proto-oncogene Dbl on Xq27 in testicular germ cell tumors reveals a rare SNP in a patient with bilateral undescended testis.

OBJECTIVES: An abundance of X chromosomes in testicular germ cell tumors (TGCTs), and a candidate TGCTs susceptibility gene (TGCT1) on Xq27 highlight the potential involvement of X chromosomes in TGCT pathogenesis. However, the TGCT1 on Xq27 has so far not been identified. We hypothesized that a somatic mutation of dbl oncogene on Xq27 may play a role for the development of TGCTs. METHODS: We have screened 41 TGCT tissues for dbl mutations using single-strand conformation polymorphism (SSCP) analysis. These tissues are composed of 25 seminomatous TGCTs tissues and 16 non-seminomatous TGCTs tissues, including two cases with a rhabdomyosarcoma component. RESULTS: Somatic mutations were not detected in the 25 exons of dbl in these TGCTs. However, we found a rare single nucleotide polymorphism (SNP) (T to C nucleotide change) within intron 22 in one out of the 41 TGCTs cases (2%). Furthermore, the sample with the rare SNP was identified as the sole TGCTs case associated with bilateral undescended testis in our series. CONCLUSIONS: Our results indicate that proto-oncogene dbl is not a major target for sporadic TGCTs. However, the rare SNP in dbl may affect the susceptibility to undescended testis. Determining the frequency of this SNP in patients with various types of undescended testis in different ethnic groups is a warranted study.

Tissue-selective RNA interference in prostate cancer cell using prostate specific membrane antigen promoter/enhancer.

OBJECTIVES: RNA interference (RNAi) has the potential to be developed into therapeutics for prostate cancer, but the lack of cellular targets limits its application. In the present study we attempt to develop a prostate cancer-specific RNAi system using the human prostate specific membrane antigen (PSMA) promoter/enhancer; furthermore, we analyzed its inhibitive effect on STAT3 expression. METHODS: The adenoviral vectors containing a small hairpin RNA (shRNA) to target exogenous reporters enhance green fluorescent protein (EGFP) and endogenous gene signal transducers and activators of transcription 3 (STAT3) were constructed. After prostate cancer and other cells were transfected, reverse transcription-polymerase chain reaction (RT-PCR), fluorescence microscopy, and Western blotting were used to measure EGFP expression. Inhibition of STAT3 was evaluated by Western blotting. Cell proliferation and viability were measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Cell apoptosis was analyzed with double-staining of Annexin V and PI. RESULTS: Our study showed that with the PSMA promoter/enhancer directly driving shRNA transcription, expression of the exogenous reporters EGFP in prostate cancer cells, but not other cancer cells and normal cells, was specifically inhibited in vitro. The PSMA promoter/enhancer-driven shRNA also depressed the expression of STAT3 in only prostate cancer cells. Inhibition of STAT3 suppressed proliferation of PC-3 and LNCaP cells. CONCLUSIONS: The present study describes an efficient RNAi system for gene silencing that is specific to prostate cancer cells using the PSMA promoter/enhancer. Suppression of STAT3 by using this system decreased proliferation and induced apoptosis of PC-3 and LNCaP cells. This system may be useful for RNAi therapy for prostate cancer.

[Inhibitory effect of silencing STAT3 gene with short hairpin RNA mediated by polyamidoamine dendrimers on growth of prostate cancer].

OBJECTIVE: To investigate the possibility of using generation 5 polyamidoamine dendrimers (G5-PAMAM-D) as gene vector for eukaryotic expression plasmid of siRNA in prostate carcinoma in vitro and vivo. METHODS: Firstly, eukaryotic expression vector of siRNA pSilencing 4.1-EGFP-shRNA, specific for enhanced green fluorescent protein (EGFP), pSilencing 4.1-STAT3-shRNA for signal transducers and activators of transcription 3 (STAT3) was constructed. pEGFP-C1 and pSilencing 4.1-EGFP-shRNA were cotransfected into prostate cancer cells PC-3 and 22Rv1 with G5-PAPAM-D as vector, and to observe silencing of EGFP. Next, pSilencing 4.1-STAT3-shRNA was transfected into PC-3 and 22Rv1 cells by G5-PAPAM-D, Western blotting and apoptosis staining was used to detect silencing of STAT3 and growth inhibition. Thirdly, BALB/C mice subcutaneous tumor model was made with PC-3 cells. Polyplex of G5-PAMAM-D and pSilencing 4.1-STAT3-shRNA was injected intratumorally. The tumor volume was measured and recorded. RESULTS: Fluorescence detection and Western blotting analysis demonstrated that G5-PAMAM-D was able to deliver Silencing 4.1-EGFP-shRNA and pSilencing 4.1-STAT3-shRNA into the two prostate cancer cell lines, and shRNA was expressed to induce silence of EGFP and STAT3. MTT results showed that proliferation of prostate cancer cells was suppressed by G5-PAMAM-D/pSilencing 4.1-STAT3-shRNA and induced apoptosis of PC-3 cells in vitro. Human prostate cancer in mice was successfully formed by inoculation of PC-3 cells into male BABL/C mice. In G5-PAMAM-D/pSilencing 4.1-STAT3-shRNA treated group, the tumor volume was shrank remarkably at 9 days after treatment and tumor growth was retarded compared with control groups. CONCLUSION: GS-PAMAM-D nanoparticles can be used to deliver plasmid vector expressing shRNA into prostate cancer cells effectively in vitro and vivo. It appears to be a promising gene vector for RNA interference therapy in prostate cancer.