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Background: To clarify the injury mechanism of the avulsion fracture of the fifth metatarsal combining 3-dimensional (3D) fracture mapping with anatomical measurements. Materials and Methods: 222 patients with the fifth metatarsal base avulsion fractures, who were admitted to our hospital from August 2015 to August 2020. The 3D images of all mapped fracture lines for the fifth metatarsal base avulsion fractures were compiled in an overall 3D image. The fifth metatarsal base of 8 unpaired lower limbs of adult Asian frozen cadaveric specimens were also dissected to observe and measure the specific locations of the attachment points of the peroneus brevis, lateral band of the plantar fascia, and peroneus tertius to the fifth metatarsal base. Results: Based on the type of fracture line produced and the specific locations of the attachment points of the tendons, the fifth metatarsal base avulsion fractures can be classified into three types: type I predominantly involves the action of the lateral band of the plantar fascia; type II predominantly involves the action of the peroneus brevis; type IIIA involves the joint action of the peroneus brevis and lateral band of the plantar fascia with one fracture line; type IIIB involves the joint action of the peroneus brevis and lateral band of the plantar fascia with two fracture lines. Conclusion: The lateral band of the plantar fascia and peroneus brevis play a major role in the fifth metatarsal base avulsion fracture together or separately and proposed a novel classification based on the injury mechanism, which can serve as a reference for clinical treatment and diagnosis.Level of Evidence: Level Ⅲ, retrospective case series.

RAS protein activator like 2 (Rasal2) exerts pro-proliferative effect in several types of cells. However, whether Rasal2 is involved in the regulation of pulmonary artery smooth muscle cell (PASMC) remains unclear. In the current study, we explored the role of Rasal2 in proliferation and migration of PASMC during the development of pulmonary arterial hypertension (PAH). We found that the protein level of Rasal2 was increased in both pulmonary arteries of chronic hypoxia-induced pulmonary hypertension (CH-PH) mice and hypoxia-challenged PASMC. Overexpression of Rasal2 caused enhanced proliferation and migration of PASMC after hypoxia exposure. Mechanistically, we found elevated phosphorylation of AKT and two downstream effectors of mammalian target of Rapamycin complex 1 (mTORC1), S6 and 4E-Binding Protein 1 (4EBP1) after Rasal2 overexpression in hypoxia-challenged PASMC. Inactivation of mTORC1 abolished Rasal2-mediated enhancement of proliferation and migration of PASMC. Furthermore, we also demonstrated that AKT might act downstream of Rasal2 to enhance the activity of mTORC1. Once AKT was inactivated by MK-2206 application, overexpression of Rasal2 failed to further increase the phosphorylation level of S6 and 4EBP1. Finally, inhibition of AKT also blocked Rasal2-induced proliferation and migration in hypoxia-challenged PASMC. In conclusion, Rasal2 promotes the proliferation and migration of PASMC during the development of PAH via AKT/mTORC1 pathway.

Osteoporosis is a metabolic disease affecting 40% of postmenopausal women. It is characterized by decreased bone mass per unit volume and increased risk of fracture. We investigated the molecular mechanism underlying osteoporosis by identifying the genes involved in its development. Osteoporosis-related genes were identified by analyzing RNA microarray data in the GEO database to detect genes differentially expressed in osteoporotic and healthy individuals. Enrichment and protein interaction analyses carried out to identify the hub genes among the deferentially expressed genes revealed TP53, MAPK1, CASP3, CTNNB1, CCND1, NOTCH1, CDK1, IGF1, ERBB2, CYCS to be the top 10 hub genes. In addition, p53 had the highest degree score in the protein-protein interaction network. In vivo and in vitro experiments showed that TP53 gene expression and serum p53 levels were upregulated in osteoporotic patients and a mouse osteoporosis model. The elevated p53 levels were associated with decreases in bone mass, which could be partially reversed by knocking down p53. These findings suggest p53 may play a central role in the development of osteoporosis.

In this study, we used bioinformatics tools, and experiments with patient tissues and human mesenchymal stem cells (hMSCs) to identify differentially regulated genes (DEGs) and microRNAs (miRNAs) that promote postmenopausal osteoporosis. By analyzing the GSE56815 dataset from the NCBI GEO database, we identified 638 DEGs, including 371 upregulated and 267 downregulated genes, in postmenopausal women with low bone density. Enrichment and protein-protein interaction network analyses showed that TP53, RPS27A, and VEGFA were the top three hub genes with the highest degree of betweenness and closeness centrality. TargetScanHuman and DIANA software analyses and dual luciferase reporter assays confirmed that miR-16a-5p directly targets the 3’UTR of VEGFA. Postmenopausal patients with osteoporosis showed higher miR-16-5p and lower VEGFA levels than those without osteoporosis (n=10 each). VEGFA levels were higher in miR-16-5p knockdown hMSCs and were reduced in miR-16-5p-overexpressing hMSCs. mRNA expression of osteogenic markers, ALP, OCN, and RUNX2, as well as calcium deposition based on Alizarin red staining, correlated inversely with miR-16-5p levels and correlated positively with VEGFA levels. These findings suggest that miR-16-5p suppresses osteogenesis by inhibiting VEGFA expression and is a promising target for postmenopausal osteoporosis therapy.

Osteoporosis is a common metabolic bone disease that affects about 40% of postmenopausal women. Treatment options for osteoporosis are limited, however. Icariin is an herbal substance that has been shown to improve bone mass, but the mechanisms are largely unknown. Using bioinformatics analysis, we have identified the hub genes and KEGG pathways shared between icariin-targeted genes and osteoporosis. The top five shared KEGG pathways were the Toll-like receptor signaling pathway, adipocytokine pathway, neurotrophin signaling pathway, NOD-like receptor signaling, and B cell receptor signaling pathway; the hub genes were RELA, NFKBIA, and IKBKB, belonging to the NF-κB family. The identified icariin-targeted genes are involved in inflammation, insulin resistance, apoptosis, and immune responses, and regulate the PI3K-Akt, NF-κB, MAPK, and JNK signaling pathways. Our in vitro data show that icariin inhibits apoptosis in human mesenchymal stem cells by suppressing JNK/c-Jun signaling pathway. Together, these findings indicate that icariin exerts its anti-osteoporotic function by inhibiting JNK/c-Jun signaling pathway, and suggest that icariin may be a promising treatment option for osteoporosis.

Background: Children with flexible flatfoot is common in clinics and there is no unified conclusion on surgical treatment. And for some patients with severe deformities, the correction of the subtalar joint arthroereisis combine the release of the Achilles tendon or gastrocnemius muscle release is still not satisfactory. The main aim of the present study was to investigate the therapeutic outcomes of subtalar arthroereisis combined with Achilles tendon or gastrocnemius recession and medial soft tissue (spring ligament, talonavicular joint capsule, tibionavicular ligaments and tibiospring ligaments) tightening for treating flexible flatfoot with severe deformities.Methods: Thirty patients (32 feet) with pediatric flexible flatfoot who underwent subtalar arthroereisis and soft tissue procedures during January 2016 to January 2018. There were 18 males (20 feet) and 12 females (12 feet) with an average age of 9.5 years (range, 8–12 years). We used the AOFAS scores and VAS scores combined with angles measure to evaluate the pre-operative and post-operative status.Results: Thirty patients (32 feet) were followed up for 25.3 months on average (range, 18–36 months). There was no infection. Post-operative foot pain, arch collapse, and other symptoms improved. At last follow-up, the Meary angle was decreased from 17.5° ± 4.4° to 4.1° ± 1.2° (P < 0.05), the talar-first metatarsal (AP) was decreased from 15.3° ± 3.1° to 4.8° ± 1.3°(P < 0.05), The mean AOFAS score was rose from 66.6 ± 5.8 to 88.6 ± 7.9 (P < 0.05), the mean VAS score was decreased from 6.6 ± 0.6 to 1.7 ± 0.3 (P < 0.05).Conclusion: The subtalar arthroereisis combined with soft tissue procedures can effectively correct flexible flatfoot in children and it is a significant method for severe forefoot abduction reconstruction.Level of Evidence: IV

Hyperbranched polyglycerol (HPG) is a biocompatible polyether polymer that is a potential colloid component in a preservation solution for suppressing interstitial edema during cold storage of a donor organ. This study evaluated the outcomes of kidney transplants after cold perfusion and storage with a HPG‐based preservation solution (HPGS) in a pig model of kidney autotransplantation. The left kidneys of farm pigs (weighing 35–45 kg) were perfused with and stored in either cold HPGS or standard UW solution (UWS), followed by transplantation to the right side after right nephrectomy. The survival and function of transplants were determined by the urine output, and serum creatinine (SCr) and blood urea nitrogen (BUN) of recipients. Transplant injury was examined by histological analysis. Here, we showed that there was no significant difference between HPGS and UWS in the prevention of tissue edema, but HPGS was more effective than UWS for initial blood washout of kidney perfusion and for the prevention of cold ischemia injury during cold storage. After autotransplantation, the kidneys preserved with HPGS (HPG group) had better functional recovery than those with UWS (UW group), indicated by significantly more urine output and lower levels of SCr and BUN. The survived grafts in HPG group had less tissue damage than those in UW group. In conclusion, as compared to the UWS the HPGS has less negative impact on kidney cold ischemia during cold storage, resulting in improving immediate functional recovery after transplantation, suggesting that HPG is a promising colloid for donor kidney preservation.

BACKGROUND As a common metabolic disorder, osteoporosis is characterized by decreasing bone mass density and increased possibility of fragility fracture. The incidence of senile osteoporosis increases year by year. There is no gold standard of treatment for osteoporosis. Tomatidine is the aglycone derivative of tomatine, having the ability to treat various diseases, including osteoporosis. However, the mechanism by which tomatidine improves osteoporosis has not been fully elucidated. Tomatidine is a potential and promising drug for osteoporosis. MATERIAL AND METHODS In this study, the KEGG pathways that tomatidine-targeted genes enriched in were obtained using bioinformatics methods. The KEGG pathways involved in osteoporosis that were also associated with tomatidine-targeted genes were selected. After analysis of these pathways, essential genes that may be involved in this biological process were identified and validated experimentally. RESULTS We found 110 osteoporosis related KEGG pathways and 76 tomatidine-targeted genes-related KEGG pathways were obtained. 39 shared KEGG pathways were identified. The top 5 pathways were: pathway of chronic myeloid leukemia, pathway of B cell receptor signaling, pathway in cancer, bladder cancer pathway, and progesterone-mediated oocyte maturation pathway. MAPK1, MAP2K1, MAPK3, RAF1 were involved in all the 5 pathways. The p53 signaling pathway and the MAPK signaling pathway were involved in the 5 KEGG pathways. In vitro experiments showed that downregulating p53 expression could be potentially protective for osteoporosis. CONCLUSIONS Tomatidine can improve osteoporosis, and one of the mechanisms of its action is achieved by modulating p53. Tomatidine may be a promising drug for osteoporosis.

Although osteoporosis is one of the most common chronic age-related diseases, there is currently no gold standard for treatment. Evidence suggests resveratrol, a natural polyphenolic compound, may be helpful in the treatment of osteoporosis and other diseases. However, the molecular mechanisms underlying the anti-osteoporotic effects of resveratrol remain largely unknown. In the present study, KEGG pathway enrichment analysis of resveratrol-targeted genes identified 33 associated pathways, 12 of which were also involved in osteoporosis. In particular, the MDM2/p53 signaling pathway was identified as a potential key pathway among the shared pathways. In vitro experiments indicated that MDM2-mediated p53 degradation induced osteoblast differentiation, and resveratrol could partially reverse p53-dependent inhibition of osteogenic differentiation. These findings suggest resveratrol may alleviate osteoporosis at least in part by modulating the MDM2/p53 signaling pathway.

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is a negative regulator of T cell activation, which competes with CD28 for B7.1/B7.2 binding with a greater affinity. Co-expression specific antigens and extracellular domain of CTLA4 represents a promising approach to increase the immunogenicity of DNA vaccines. In this study, we evaluated this interesting approach for its enhancement on G250/MN/CA IX (G250)-specific immune responses and its anti-tumor effects in renal carcinoma mice model. Consequently, we constructed a DNA vaccine containing the G250 and the CTLA-4 gene. Vaccination with the co-expression DNA not only induced much higher level of anti-CTLA4 and anti-G250 antibody, but also increased G250-specific T cell response in mice. To evaluate the anti-tumor efficacy of the plasmids, murine models with G250-expressing tumors were generated. After injection into the tumor-bearing mouse model, the plasmid carrying the co-expression gene of CTLA4 and G250 showed stronger inhibition of tumor growth than the plasmid expressing CTLA4 or G250 alone. These observations emphasize the potential of the CTLA4 and G250 co-expression DNA vaccine, which could represent a promising approach for tumor immunotherapy.

Uncovering new therapeutic targets for renal fibrosis holds promise for the treatment of chronic kidney diseases. Bromodomain and extra-terminal (BET) protein inhibitors have been shown to effectively ameliorate pathological fibrotic responses. However, the pharmacological effects and underlying mechanisms of these inhibitors in renal fibrosis remain elusive. In this study, we determined that the inhibition of Brd4, a BET family member, with a selective potent chemical inhibitor, JQ1, could prevent the development of renal fibrosis and block the progression of fibrosis in rats that have undergone unilateral ureteral obstruction (UUO). Inhibiting Brd4 with either JQ1 or genetic knockdown resulted in decreased expression of fibrotic genes such as α-smooth muscle actin, collagen IV and fibronectin both in UUO-induced fibrosis and upon TGF-β1 stimulation in HK-2 cells. Brd4 inhibition also suppressed the oxidative stress induced by UUO in vivo or by TGF-β1 in HK-2 cells. Moreover, Nox4, which is constitutively active in renal cells and is involved in the generation of hydrogen peroxide, was up-regulated during UUO-mediated fibrosis and induced by TGF-β1 in HK-2 cells, and this up-regulation could be blunted by Brd4 inhibition. Consistently, Nox4-mediated ROS generation and fibrotic gene expression were attenuated upon Brd4 inhibition. Further, the transcriptional activity of Nox4 was suppressed by JQ1 or siRNA against Brd4. Additionally, Smad3 and ERK1/2 phosphorylation, which are upstream signals of Nox4 expression, were inhibited both in JQ1-administered UUO rats and Brd4-inhibited HK-2 cells. In conclusion, these results indicated that the inhibition of Brd4 might protect against renal fibrosis by blocking the TGF-β-Nox4-ROS-fibrosis axis, suggesting that Brd4 could be a promising therapeutic target., Graphical abstract fx1, Highlights • Brd4 was up-regulated in the progression of renal fibrosis. • Brd4 inhibitor JQ1 prevented renal fibrosis and delayed the fibrotic progression. • Brd4 inhibition blocked TGF-β1-induced oxidative stress and fibrosis through Nox4. • Brd4 regulated Nox4 expression via Smad and ERK pathways.

Objective To study and compare the clinical outcomes of open reduction and internal fixation via extensile L-shape incision and limited open reduction via the sinus tarsi approach using the medial distraction technique for intra-articular calcaneal fractures. Methods We performed a retrospective review of 65 intra-articular calcaneal fractures treated operatively between March 2012 and February 2015. Patients were divided into two groups: 28 were in the sinus tarsi approach group and 37 were in the extensile lateral approach group. All patients were asked to return for a research visit that included radiography and clinical evaluation. The postoperative function was evaluated using the ankle and hindfoot score of the American Orthopaedic Foot and Ankle Society (AOFAS) and the visual analogue scale (VAS). Results No significant difference was found in demographics between the two groups. The corrected value of the calcaneal varus angle between the two groups is statistically significant (P < 0.05). The overall wound complication rate was 3.6% in the minimally invasive group versus 13.5% in the extensile group. Four patients in the extensile lateral approach group had developed hindfoot varus deformity at last follow-up. At the last follow-up, the average AOFAS ankle and the hindfoot score of the minimal group was 88.4 ± 6.6, and the VAS score was 1.9 ± 0.7, while that of the extensile lateral approach group was 83.2 ± 5.6 and 2.3 ± 1.0, respectively. Conclusion Limited open reduction via the sinus tarsi approach for intra-articular calcaneal fractures could reduce the incidence of wound complications effectively, and the medial distraction technique is helpful for correcting the calcaneus varus deformity.

The prognosis of patients with malignant glioma is always quite poor, and this poor prognosis is probably due to our incomplete understanding of the molecular mechanisms underlying malignant glioma. It is known that myocyte enhancer factor-2D (MEF2D) plays an oncogenic role in hepatocellular carcinoma and promotes the survival of various types of cells. However, little is known about the expression profile and function of MEF2D in malignant glioma. In this study, we investigated the function and expression of MEF2D in malignant glioma. We found that in malignant glioma, there is an aberrantly high expression of MEF2D, which leads to poor prognosis of malignant glioma. The downregulation of MEF2D suppresses the proliferation of malignant glioma cell lines by inducing delay of S and G2/M phases of cell cycle and promoting apoptosis. Furthermore, the overexpression of MEF2D in astrocytes accelerates cell proliferation by regulating cell cycle progression. Furthermore, a mouse malignant glioma model demonstrated that MEF2D deficiency blocks malignant glioma formation in vivo. We conclude that MEF2D may act as a potential oncogene in malignant glioma and thus serve as a candidate target for malignant glioma therapy.

To investigate whether ESM-1 expression change reflects the impairment of endothelial cells and rejection after kidney transplantation, ESM-1 expression was detected under various immune states in this study.Kidney transplantations were performed from BN to LEW rats. Syngenic LEW-LEW grafts were used as controls. The LEW recipient rats were divided into acute rejection (AR) group, ciclosporin A (CsA) group and control group. In each group, 10 rats were sacrificed at 1, 5, and 7d after operation, respectively, and blood and kidney samples were collected. In the rat model of kidney transplantation, ESM-1 mRNA and ESM-1 protein expression were detected in various immune states to verify if ESM-1 can reflect endothelial cell impairment sensitively.ESM-1 mRNA (1d vs. 3d, P0.01;3d vs. 7d, P=0.018) and ESM-1 protein expression was upregulated significantly in the AR group (P0.01, 5 and 7d), when compared to CsA group and control group. In CsA group, the cell apoptosis rate decreased when compared to AR group (P0.01). Pathological impairment was more serious in AR group than in CsA group (P0.01).Peripheral blood ESM-1 mRNA and ESM-1 protein expression in kidney grafts can reflect the severity of endothelial cell impairment. Thus, ESM-1 may be used as a new indicator for AR prediction and diagnosis. Nevertheless, further investigation is required to test if it meets the criteria for clinical utility.

Müller-Weiss disease is a rare spontaneous osteonecrosis of the tarsal and navicular bones in adults. From April 2008 to April 2011, we treated 7 patients with Müller-Weiss disease by surgical fusion of the talonavicular and naviculocuneiform joints with tricortical autologous iliac crest block fixated by screws and plate. Preoperative and postoperative clinical outcomes were evaluated with the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale. The median follow-up time was 22 (range 3 to 38) months. All of the operated feet fused solidly. The median time for solid fusion was 13 (range 12 to 16) weeks. The median American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved from 49 (range 15 to 66) points preoperatively to 82 (range 68 to 87) points at last follow-up. The results suggest that this type of fusion is an effective surgical treatment for Müller-Weiss disease.

Visfatin, a recently discovered adipocytokine, has been shown to have an important role in the pathogenesis of diabetic nephropathy (DN). The farnesoid X receptor (FXR), a ligand-activated nuclear receptor, plays a protective role in DN. The regulation between FXR and visfatin and their interaction in DN has not been well established. In this study, we reported that FXR agonist GW4064 reduced high glucose induced human mesangial cells (HMCs) inflammation, fibrosis and proliferation by downregulating visfatin expression, which can be blunted by exogenous visfatin treatment. Moreover, luciferase reporter assay showed FXR regulated visfatin transcription activity probably by binding to the -1607 bp and -1192 bp region of the visfatin promoter. In vivo study also showed that GW4064 ameliorated the progression of DN in db/db mice with a decreased visfatin expression. These findings suggest that FXR activation delayed the progression of diabetic nephropathy and this effect is through downregulating visfatin.

To investigate the effectiveness of double arthrodesis to correct flatfoot deformity with pes valgus.Between May 2009 and May 2012, 12 patients with flatfoot deformity and pes valgus were treated using subtalar and talonavicular joints arthrodesis through a single medial incision approach. There were 5 males and 7 females with an average age of 53.3 years (range, 21-78 years), including 5 left feet and 7 right feet. Of them, 11 cases had posterior tibial tendon dysfunctions; 6 cases were at Johnson-Strom stage III, 5 cases at stage II(c); and 1 case had tarsal coalition. Preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score and visual analogue scale (VAS) score were 48.75 ± 3.46 and 6.08 ± 1.14, respectively.The mean operation time was 85.6 minutes (range, 65-125 minutes). Eleven patients were followed up for 19.4 months on average (range, 13-30 months). All of the cases obtained primary healing of incision, with no complication of infection and nerve or blood vessel injury. X-ray film showed that the mean time of bone union was 9.8 weeks (range, 7-18 weeks): no bone nonunion occurred. No loosening or breakage of internal fixation was observed. Pain occurred at the calcaneal-cuboid joint (1 case) and at fixation site (1 case), and was relieved after symptomatic treatment. The mean AOFAS score and VAS score were significantly increased to 81.36 ± 2.98 and 0.72 ± 0.11 respectively, showing significant differences when compared with preoperative scores (t = 19.946, P = 0.000; t = 16.288, P = 0.000).Subtalar and talonavicular joints arthrodesis by a single medial incision approach is a useful alternative to triple arthrodesis for the correction of flatfoot deformity with pes valgus.

Controversy exists concerning the need for operative repair of the deltoid ligament during management of acute ankle fractures. The purpose of our report was to identify the indications for surgical intervention for deltoid ligament injury in the setting of ankle fractures. Furthermore, we aimed to elucidate the clinical outcomes after deltoid ligament repair in this setting. This was a multicenter study, involving 4 clinical institutions. From January 2006 to December 2011, 1533 ankle fractures underwent surgical intervention. Of this group, 131 deltoid ligament ruptures (8.55%) were identified and repaired operatively. Of the 131 patients, 74 were male (56.5%) and 57 were female (43.5%), with a mean age of 33.2 (range 16 to 63) years. The outcome measures included the clinical examination findings, radiographic findings, American Orthopaedic Foot and Ankle Society ankle-hindfoot scores, visual analog scale (VAS) scores, and Medical Outcomes Study Short Form 36-item questionnaire scores. All incisions healed primarily. A total of 106 patients were followed up for a minimum of 12 (range 12 to 72) months, with an average follow-up period of 27 months. The mean interval to fracture union was 14.5 (range 9 to 16) weeks. The mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score at the latest follow-up visit was 91.4 (range 83 to 100) points. The mean visual analog scale score was 1.2 (range 0 to 6) points. The mean Short Form-36 score was 91.2 (range 80 to 96) points. Compared with the preoperative scores, all the 3 outcome measures had improved significantly postoperatively (p < .05). The postoperative stress radiographs did not reveal any ankle instability. None had evidence of post-traumatic arthritis of the ankle from the clinical examination and radiographs. A reasonable clinical evaluation and surgical repair was executed, with an appropriate repair technique chosen according to the site of deltoid ligament rupture. The results of the present multicenter study have shown that deltoid ligament rupture can be repaired in patients with an unstable medial ankle after fracture fixation and prevent ankle stabilization-related complications.

Oleanolic acid (OA) has been widely studied because of its pleiotropic therapeutic and preventive effect on various diseases. However, the mechanisms of OA's action are still not clear yet, especially its suppressing effect on transformed cells. In this work, we found that OA induced autophagy in normal tissue-derived cells without cytotoxicity. OA-induced autophagy was shown to decrease the proliferation of KRAS-transformed normal cells and to impair their invasion and anchorage-independent growth. Interrupting autophagy rescued OA's effect on the transformed cells. Mouse model experiments also demonstrated that OA suppressed the growth of KRAS-transformed breast epithelial cell MCF10A-derived tumor xenograft by inducing autophagy. Finally, we identified that OA induced autophagy in normal cells by inhibiting the activation of Akt/mTOR/S6K signaling. In conclusions, we found that OA treatment permitted normal cells to undergo autophagy. The induced autophagy was required for OA to prevent or delay the growth of transformed normal cells. (C) 2014 Published by Elsevier Inc.

Background Bladder transitional cell carcinoma greatly threatens human health all over the world. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) shows a strong apoptosis-inducing effect on a variety of cancer cells including bladder cancer. However, adenovirus-mediated TRAIL expression still showed cytotoxicity to normal cells mainly due to lack of tumor specificity. Methods To solve the problem, we applied miRNA response elements (MREs) of miR-1, miR-133 and miR-218 to confer TRAIL expression with specificity to bladder cancer cells. Results Expression of miR-1, miR-133 and miR-218 was greatly decreased in bladder cancer than normal bladder tissue. Luciferase assay showed that application of the 3 MREs was able to restrain exogenous gene expression to within bladder cancer cells. Subsequently, we constructed a recombinant adenovirus with TRAIL expression regulated by MREs of miR-1, miR-133 and miR-218, namely Ad-TRAIL-MRE-1-133-218. qPCR, immunoblotting and ELISA assays demonstrated that Ad-TRAIL-MRE-1-133-218 expressed in bladder cancer cells, rather than normal bladder cells. The differential TRAIL expression also led to selective apoptosis-inducing and growth-inhibiting effect of Ad-TRAIL-MRE-1-133-218 on bladder cancers. Finally, bladder cancer xenograft in mouse models further confirmed that Ad-TRAIL-MRE-1-133-218 effectively suppressed the growth of bladder cancers. Conclusions Collectively, we demonstrated that MREs-based TRAIL delivery into bladder cancer cells was feasible and efficient for cancer gene therapy.

Adenoviral vectors are widely used for cancer therapy and show a tumor-suppressing effect. However, bladder cancers are found to be resistant against infection of Ad5-derived adenoviral vector, limiting the application of the existing strategy of gene therapy. Therefore, efforts to develop novel types of adenoviral vector aimed for improving the viral infection and enhancing expression level of tumor-inhibiting transgene is urgently required. We constructed a 5/35 fiber-modified E1A-deleted adenoviral vector armed with TRAIL gene. Its ability to express this gene for inhibition of bladder cancer cell growth was investigated in our work. The results showed that this modification in fiber region facilitates adenoviral infection to bladder cancer, perhaps due to high expression of CD46 on target cell surface. Subsequently, we found an enhanced expression level of TRAIL mediated by 5/35 fiber-modified adenoviral vectors in bladder cancer cells, leading to an increased tumor-inhibiting capability of 5/35 adenoviral vector against bladder cancer cells. Consistently, growth of xenograft tumors in mice was also effectively inhibited by 5/35 fiber-modified vector-mediated gene therapy strategy. The 5/35 fiber-modified adenoviral vector-based gene transfer shows an improved efficacy against bladder cancers. The application of this novel gene therapy vector may benefit the patients in clinical bladder cancer treatment.