Detachable MOF-Based Core/Shell Nanoreactor for Cancer Dual-Starvation Therapy With Reversing Glucose and Glutamine Metabolisms.

Tumor-dependent glucose and glutamine metabolisms are essential for maintaining survival, while the accordingly metabolic suppressive therapy is limited by the compensatory metabolism and inefficient delivery efficiency. Herein, a functional metal-organic framework (MOF)-based nanosystem composed of the weakly acidic tumor microenvironment-activated detachable shell and reactive oxygen species (ROS)-responsive disassembled MOF nanoreactor core is designed to co-load glycolysis and glutamine metabolism inhibitors glucose oxidase (GOD) and bis-2-(5-phenylacetmido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES) for tumor dual-starvation therapy. The nanosystem excitingly improves tumor penetration and cellular uptake efficiency via integrating the pH-responsive size reduction and charge reversal and ROS-sensitive MOF disintegration and drug release strategy. Furthermore, the degradation of MOF and cargoes release can be self-amplified via additional self-generation H2 O2 mediated by GOD. Last, the released GOD and BPTES collaboratively cut off the energy supply of tumors and induce significant mitochondrial damage and cell cycle arrest via simultaneous restriction of glycolysis and compensatory glutamine metabolism pathways, consequently realizing the remarkable triple negative breast cancer killing effect in vivo with good biosafety via the dual starvation therapy.

Cascade amplification of tumor chemodynamic therapy and starvation with re-educated TAMs via Fe-MOF based functional nanosystem.

Tumor microenvironment is characterized by the high concentration of reactive oxygen species (ROS), which is an effective key used to open the Pandora's Box against cancer. Herein, a tumor-targeted nanosystem HFNP@GOX@PFC composed of ROS-cleaved Fe-based metal-organic framework, hyaluronic acid (HA), glucose oxidase (GOX) and perfluorohexane (PFC) has been developed for tumor cascade amplified starvation and chemodynamic therapy (CDT). In response to the high concentration of hydrogen peroxide (H2O2) intratumorally, HFNP@GOX@PFC endocytosed by tumor cells can specially be disassembled and release GOX, PFC and Fe2+, which can collectively starve tumor and self-produce additional H2O2 via competitively glucose catalyzing, supply oxygen to continuous support GOX-mediated starvation therapy, initiate CDT and cascade amplify oxidative stress via Fe2+-mediated Fenton reaction, leading to the serious tumor damage with activated p53 signal pathway. Moreover, HFNP@GOX@PFC also significantly initiates antitumor immune response via re-educating tumor-associated macrophages (TAMs) by activating NF-κB and MAPK signal pathways. In vitro and in vivo results collectively demonstrate that nanosystem not only continuously initiates starvation therapy, but also pronouncedly cascade-amplify CDT and polarize TAMs, consequently efficiently inhibiting tumor growth with good biosafety. The functional nanosystem combined the cascade amplification of starvation and CDT provides a new nanoplatform for tumor therapy.

MiR-33b inhibits osteosarcoma cell proliferation through suppression of glycolysis by targeting Lactate Dehydrogenase A (LDHA).

Osteosarcoma (OS) is one of the most common types of malignant bone tumor in adolescent. MicroRNAs (miRNAs) are widely studied regulatory molecules which play important roles in tumor development, differentiation, growth, invasion, chemosensitivity and cellular metabolism. Recently, miR-33b has been reported to act as a tumor suppressor in osteosarcoma. However, the detailed mechanism of miR-33b in regulating osteosarcoma cell proliferation remains unclear. In this study, we detected miR-33b was significantly downregulated in osteosarcoma tissues compared to their matched adjacent nontumor tissues. The decreased expressions of miR-33b were also found in multiple osteosarcoma cell lines, including MG63, Saos-2, U2OS and SOSP-9607 when compared to normal osteoblast cell line hFOB. Overexpression of miR-33b suppressed U2OS cell proliferation and anaerobic glycolysis. We identified Lactate dehydrogenase-A (LDHA) as a direct target of miR-33b in osteosarcoma tumors and cells by Western blot and luciferase assay. Moreover, inhibition of LDHA significantly suppressed glycolysis and cell proliferation of osteosarcoma cells. Restoration of LDHA in miR-33b-overexpressing osteosarcoma cells reversed the suppressive effect of miR-33b on cell proliferation. In addition, we report a significantly negative correlation between LDHA mRNA and miR-33b expression in osteosarcoma tumors: miR-33b is downregulated in OS tumors with high levels of LDHA (92.9%). Meanwhile, high miR-33b expressions were found majorly in OS tumors with low LDHA mRNA levels (82.4%). This study reveals that miR-33b plays a suppressive role in the regulation of osteosarcoma cell proliferation through direct targeting LDHA. The miR-33b/glycolysis/LDHA axis may contribute to development of therapeutic anti-tumor agents for osteosarcoma.

ФC31 Integrase-Mediated Isolation and Characterization of Novel Safe Harbors for Transgene Expression in the Pig Genome.

Programmable nucleases have allowed the rapid development of gene editing and transgenics, but the technology still suffers from the lack of predefined genetic loci for reliable transgene expression and maintenance. To address this issue, we used ФC31 integrase to navigate the porcine genome and identify the pseudo attP sites suitable as safe harbors for sustained transgene expression. The combined ФC31 integrase mRNA and an enhanced green fluorescence protein (EGFP) reporter donor were microinjected into one-cell zygotes for transgene integration. Among the resulting seven EGFP-positive piglets, two had transgene integrations at pseudo attP sites, located in an intergenic region of chromosome 1 (chr1-attP) and the 6th intron of the TRABD2A gene on chromosome 3 (chr3-attP), respectively. The integration structure was determined by TAIL-PCR and Southern blotting. Primary fibroblast cells were isolated from the two piglets and examined using fluorescence-activated cell sorting (FACS) and enzyme-linked immunosorbent assay (ELISA), which demonstrated that the chr1-attP site was more potent than chr3-attP site in supporting the EGFP expression. Both piglets had green feet under the emission of UV light, and pelleted primary fibroblast cells were green-colored under natural light, corroborating that the two pseudo attP sites are beneficial to transgene expression. The discovery of these two novel safe harbors for robust and durable transgene expression will greatly facilitate the use of transgenic pigs for basic, biomedical and agricultural studies and applications.

Comparison of perioperative, functional, and oncologic outcomes between standard laparoscopic and robotic-assisted radical prostatectomy: a systemic review and meta-analysis.

BACKGROUND: Robotic surgery has been developed with an attempt to reduce the difficulty of complex laparoscopic procedures. The goal of this study was to perform a systemic review and meta-analysis to evaluate the perioperative, functional, and oncologic outcomes between laparoscopic radical prostatectomy (LRP) and robotic-assisted radical prostatectomy (RARP) through all relevant comparative studies. METHODS: A literature search of EMBASE, MEDLINE, PubMed, and Cochrane Library databases was conducted. We selected randomized controlled trials (RCTs) and non-randomized comparative studies (including prospective and retrospective studies) comparing perioperative, functional, or oncologic outcomes of both LRP and RARP, and meta-analysis was applied using the Review Manager V5.3 software. RESULTS: Twenty-four studies were identified in the literature search, including 2 RCTs, 7 prospective studies, and 15 retrospective studies. LRP and RARP showed similarity in the operative time, catheterization duration, in-hospital stay, and overall complication rate. However, blood loss [mean difference (MD) 75.94; p = 0.03] and transfusion rate [odds ratio (OR) 2.08; p = 0.001] were lower in RARP. Moreover, RARP was associated with significantly improved outcomes for continence and potency rates to those of LRP at 3, 6, and 12 months postoperatively. Overall positive surgical margin (PSM) rate (OR 0.88; p = 0.03) was lower in LRP. However, there was no significant differences in ≤pT2 (OR 0.94; p = 0.69) and ≥pT3 (OR 0.94; p = 0.73) PSM rates between LRP and RARP. Additionally, LRP and RARP owned similar biochemical recurrence (BCR) rate (OR 1.15; p = 0.90). CONCLUSIONS: RARP was associated with lower blood loss and transfusion rate and much greater functional outcomes in contrast to LRP. However, there was no conclusive evidence that RARP was advantaged in terms of perioperative (except for blood loss and transfusion rate) and oncologic outcomes.

Poor Prognosis Associated with High Levels of Thymidine Phosphorylase and Thrombocytosis in Patients with Renal Cell Carcinoma.

PURPOSE: The study aimed to investigate the expression of thymidine phosphorylase (TP) in renal cell carcinoma (RCC) and its correlation with clinicopathological features and thrombocytosis, and also to determine their prognostic significance. PATIENTS AND METHODS: TP expression in 127 RCC specimens was evaluated with immunohistochemistry assays. Platelet (PLT) counts of patients before surgery were recorded. Correlations among TP expression, PLT and the clinicopathological features of the patients and their prognostic values were studied statistically. RESULTS: Sixty-eight patients of high TP expression (54%) and 59 of low TP expression (46%) were detected. There were 25 patients with thrombocytosis (20%). High TP expression was significantly associated with tumor stage (p = 0.004), histological grade (p = 0.001) and thrombocytosis (p = 0.012). The 5-year overall survival rate was 88.1% in patients with low TP expression, whereas it was 61.8% in patients with high TP expression (p < 0.001). The 5-year survival rates for patients with and without thrombocytosis were 16.0% and 88.2%, respectively (p < 0.001). The multivariate analysis showed that high TP expression and thrombocytosis would play a role as independent prognostic factors in RCC patients. CONCLUSION: High TP expression and thrombocytosis can be regarded as independent prognostic factors of poor survival in patients with RCC.

Activation of Src and transformation by an RPTPα splice mutant found in human tumours.

Receptor protein tyrosine phosphatase α (RPTPα)-mediated Src activation is required for survival of tested human colon and oestrogen receptor-negative breast cancer cell lines. To explore whether mutated RPTPα participates in human carcinogenesis, we sequenced RPTPα cDNAs from five types of human tumours and found splice mutants in ∼30% of colon, breast, and liver tumours. RPTPα245, a mutant expressed in all three tumour types, was studied further. Although it lacks any catalytic domain, RPTPα245 expression in the tumours correlated with Src tyrosine dephosphorylation, and its expression in rodent fibroblasts activated Src by a novel mechanism. This involved RPTPα245 binding to endogenous RPTPα (eRPTPα), which decreased eRPTPα-Grb2 binding and increased eRPTPα dephosphorylation of Src without increasing non-specific eRPTPα activity. RPTPα245-eRPTPα binding was blocked by Pro210 → Leu/Pro211 → Leu mutation, consistent with the involvement of the structural 'wedge' that contributes to eRPTPα homodimerization. RPTPα245-induced fibroblast transformation was blocked by either Src or eRPTPα RNAi, indicating that this required the dephosphorylation of Src by eRPTPα. The transformed cells were tumourigenic in nude mice, suggesting that RPTPα245-induced activation of Src in the human tumours may have contributed to carcinogenesis.

Doxorubicin-loaded magnetic nanoparticle clusters for chemo-photothermal treatment of the prostate cancer cell line PC3.

In addition to the conventional cancer treatment such as radiotherapy, chemotherapy and surgical management, nanomedicine-based approaches have attracted widespread attention in recent years. In this paper, a promising nanocarrier, magnetic nanoparticle clusters (MNCs) as porous materials which provided enough room on the surface, was developed for loading chemotherapeutic agent of doxorubicin (DOX). Moreover, MNCs are a good near-infrared (NIR) photothermal mediator. Thus, MNCs have great potential both in photothermal therapy (PTT) and drug delivery for chemo-photothermal therapy of cancer. We firstly explored the destruction of prostate cancer in vitro by the combination of PTT and chemotherapy using DOX@MNCs. Upon NIR irradiation at 808 nm, more cancer cells were killed when PC3 cells incubated with DOX@MNCs, owing to both MNCs-mediated photothermal ablation and cytotoxicity of light-triggered DOX release. Compared with PTT or chemotherapy alone, the chemo-photothermal therapy by DOX@MNCs showed a synergistically higher therapeutic efficacy.

Role of oxidative stress in surgical cavernous nerve injury in a rat model.

This study investigates the role of oxidative stress in surgical cavernous nerve (CN) injury in a rat model. Eighty-four male Sprague-Dawley rats were randomly divided into three groups: group 1, sham-operated rats; group 2, bilateral CN-crushed rats; and group 3, bilateral CN-transection-and-sutured-immediately rats. Oxidative stress was evaluated by malondialdehyde levels, super oxide dismutase (SOD) activities, and glutathione peroxidase (GPX) activities in serum. Erectile function was assessed by CN electrostimulation at 3 months with mean maximal intracavernous pressure (ICP) and maximal ICP per mean arterial pressure. Nerve injury was assessed by toluidine blue staining of CNs and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining of penile tissue. GPX protein expression and nitrotyrosine-3 (NT-3) levels in penile tissue were measured. Erectile function and the number of myelinated axons of CNs and NADPH-diaphorase-positive nerve fibers were statistically decreased between groups, from sham to crush to transection. For markers, both nerve-injury groups showed increased oxidative stress markers at early time points, with the transection group showing greater oxidative stress than the crushed group and values normalizing to sham levels by week 12. GPX expression and NT-3 levels in penile tissue were in concordance with the results of SOD and GPX. These results show that oxidative stress plays an important role in injured CNs, and different methods of CN injury can lead to different degrees of oxidative stress in a rat model.

Somatic mutational analysis of FAK in breast cancer: a novel gain-of-function mutation due to deletion of exon 33.

Focal adhesion kinase (FAK) regulates cell adhesion, migration, proliferation, and survival. We identified a novel splicing mutant, FAK-Del33 (exon 33 deletion, KF437463), in both breast and thyroid cancers through colony sequencing. Considering the low proportion of mutant transcripts in samples, this mutation was detected by TaqMan-MGB probes based qPCR. In total, three in 21 paired breast tissues were identified with the FAK-Del33 mutation, and no mutations were found in the corresponding normal tissues. When introduced into a breast cell line through lentivirus infection, FAK-Del33 regulated cell motility and migration based on a wound healing assay. We demonstrated that the expression of Tyr397 (main auto-phosphorylation of FAK) was strongly increased in FAK-Del33 overexpressed breast tumor cells compared to wild-type following FAK/Src RTK signaling activation. These results suggest a novel and unique role of the FAK-Del33 mutation in FAK/Src signaling in breast cancer with significant implications for metastatic potential.

An aberrant spliced transcript of focal adhesion kinase is exclusively expressed in human breast cancer.

PURPOSE: To clarify the roles of a new aberrantly spliced transcript of FAK that lacks exon 26 (denoted -26-exon FAK) in human breast cancers. METHODS: Transcripts of FAK expressed in 102 human breast tumor tissues and 52 corresponding normal tissues were analyzed by RT-PCR and DNA sequencing, as well as agarose gel electrophoresis. The cDNA of -26-exon FAK was cloned and expressed in MCF-10A cells, and then the kinase activity, cellular localization and migration capability of FAK were examined by western blotting, immunofluorescent staining and migration assays, respectively. The expression levels of FAK were analyzed by western blotting in MCF-7 cells treated with TNF-α or in MCF-10A cells upon serum deprivation. The MCF-10A cells transfected with a plasmid expressing -26-exon FAK were cultured in serum-free medium and cell apoptosis was analyzed by flow cytometry. RESULTS: The -26-exon FAK transcript was exclusively present in human breast tumor tissues and the encoded protein possessed the same kinase activity, cellular localization and cell migration-promoting ability as wild-type FAK. In MCF-7 cells treated with TNF-α, and in MCF-10A cells upon serum deprivation, the -26-exon FAK was resistant to proteolysis while wild-type FAK was largely cleaved. In addition, the -26-exon FAK, but not wild-type FAK, inhibited cell apoptosis. CONCLUSIONS: The -26-exon FAK transcript, which is exclusively expressed in human breast tumor tissues, encodes a protein that possesses the same kinase activity and biological function as the wild-type FAK, but because it is resistant to the caspase-mediated cleavage that induces the proteolysis of the wild-type form, it ultimately prevents apoptosis.

Erectile function restoration after repair of resected cavernous nerves by adipose-derived stem cells combined with autologous vein graft in rats.

Cavernous nerve (CN) injury is the main cause of erectile dysfunction (ED) following radical prostatectomy. The recovery of erectile function following this procedure remains challenging. Here, we investigated the ability of adipose-derived stem cells (ADSCs) combined with autologous vein graft to improve erectile function in a rat model of bilateral long CN resection. Sprague-Dawley rats (n = 36) were randomized into four groups. Group A underwent sham operation. In Groups B, C, and D, an 8-mm segment of CN was excised bilaterally. In Group B and C, a 10-mm segment of autologous saphenous vein was interposed bilaterally at the site of injury, and the two nerve stumps were inserted into the vein lumen. 50 µL ADSCs were injected into each vein in Group B, and 50 µL of phosphate-buffered saline was injected in Group C. Group D underwent no repair. Erectile function assessed after 3 months by measuring intracavernosal pressure demonstrated significant recovery in erectile function in Group B with minimal recovery in Group C or D. Immunohistochemical staining showed that the nNOS-positive area was significantly larger in Group B than in Group D. ADSCs combined with autologous vein graft treatment had beneficial effects on the smooth muscle/collagen ratio in the corpus cavernosum. This procedure, therefore, provided a means of regenerating CN tissue and restoring autonomic erectile function after long bilateral CN resection (0.8 cm) in rats.

MiR-506 inhibits PRRSV replication in MARC-145 cells via CD151.

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important diseases of swine, which is caused by PRRS virus (PRRSV). CD151, one of PRRSV entry mediators, determines the cell susceptibility for PRRSV. Emerging evidence indicates that the host microRNAs (miRNAs) play key roles in modulating virus infection and viral pathogenesis. In the present study, targeting porcine CD151 miRNAs were identified, and their function during PRRSV infection in MARC-145 cells was further verified. We found that miR-506 could directly target porcine CD151 3'-UTR mRNA by luciferase reporter assay. Overexpression of miR-506 significantly decreased CD151 expression at both mRNA and protein levels. Furthermore, overexpression of miR-506 reduced cellular PRRSV replication and virus release in MARC-145 cells. Our results suggested that miR-506 could inhibit PRRSV replication by directly targeting PRRSV receptor of CD151 in MARC-145 cells. However, the molecular mechanisms of miR-506 and its function in vivo need further investigation.

The impact of gut microbial signals on hematopoietic stem cells and the bone marrow microenvironment.

Hematopoietic stem cells (HSCs) undergo self-renewal and differentiation in the bone marrow, which is tightly regulated by cues from the microenvironment. The gut microbiota, a dynamic community residing on the mucosal surface of vertebrates, plays a crucial role in maintaining host health. Recent evidence suggests that the gut microbiota influences HSCs differentiation by modulating the bone marrow microenvironment through microbial products. This paper comprehensively analyzes the impact of the gut microbiota on hematopoiesis and its effect on HSCs fate and differentiation by modifying the bone marrow microenvironment, including mechanical properties, inflammatory signals, bone marrow stromal cells, and metabolites. Furthermore, we discuss the involvement of the gut microbiota in the development of hematologic malignancies, such as leukemia, multiple myeloma, and lymphoma.

[Retracted] MicroRNA­30e inhibits adhesion, migration, invasion and cell cycle progression of prostate cancer cells via inhibition of the activation of the MAPK signaling pathway by downregulating CHRM3.

Following the publication of the above article, a concerned reader drew to the Editor's attention that certain of the Transwell invasion assay data shown in Fig. 7B on p. 451 were strikingly similar to data that had appeared in Fig. 3D in a previously published paper written by different authors at a different research institute, which had been received at the journal Cancer Letters at around the same time, and which has subsequently been retracted [Gu J, Wang Y, Wang X, Zhou D, Shao C, Zhou M and He Z: Downregulation of lncRNA GAS5 confers tamoxifen resistance by activating miR­222 in breast cancer. Cancer Lett 434: 1­10, 2018]. In addition, there were potentially anomalous features associated with the western blot and cell cycle data in this paper.  In view of the fact that certain of the data in the above article were also submitted to a different journal within the space of a few days, the Editor of International Journal of Oncology has decided that this paper should be retracted from the publication. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Oncology 54: 443­454, 2019; DOI: 10.3892/ijo.2018.4647].

An Adjuvant Micelle-Based Multifunctional Nanosystem for Tumor Immunotherapy by Remodeling Three Types of Immunosuppressive Cells.

Immunotherapy is restricted by a complex tumor immunosuppressive microenvironment (TIM) and low drug delivery efficiency. Herein, a multifunctional adjuvant micelle nanosystem (PPD/MPC) integrated with broken barriers and re-education of three classes of immune-tolerant cells is constructed for cancer immunotherapy. The nanosystem significantly conquers the penetration barrier via the weakly acidic tumor microenvironment-responsive size reduction and charge reversal strategy. The detached core micelle MPC could effectively be internalized by tumor-associated macrophages (TAMs), tumor-infiltrating dendritic cells (TIDCs), and myeloid-derived suppressor cells (MDSCs) via mannose-mediated targeting endocytosis and electrostatic adsorption pathways, promoting the re-education of immunosuppressive cells for allowing them to reverse from pro-tumor to antitumor phenotypes by activating TLR4/9 pathways. This process in turn leads to the remodeling of TIM. In vitro and in vivo studies collectively indicate that the adjuvant micelle-based nanosystem not only relieves the intricate immune tolerance and remodels TIM via reprogramming the three types of immunosuppressive cells and regulating the secretion of relevant cytokines/immunity factors but also strengthens immune response and evokes immune memory, consequently suppressing the tumor growth and metastasis.

Heterogeneous stiffness of the bone marrow microenvironment regulates the fate decision of haematopoietic stem and progenitor cells.

The bone marrow (BM) niches are the complex microenvironments that surround cells, providing various external stimuli to regulate a range of haematopoietic stem cell (HSC) behaviours. Recently, it has been proposed that the fate decision of HSCs is often correlated with significantly altered biophysical signals of BM niches. To thoroughly elucidate the effect of mechanical microenvironments on cell fates, we constructed 2D and 3D cell culture hydrogels using polyacrylamide to replicate the mechanical properties of heterogeneous sub-niches, including the inherent rigidity of marrow adipose tissue (2 kPa), perivascular tissue (8 kPa) and endosteum region (35 kPa) in BM. Our observations suggest that HSCs can respond to the mechanical heterogeneity of the BM microenvironment, exhibiting diversity in cell mechanics, haematopoietic pool maintenance and differentiated lineages. Hydrogels with higher stiffness promote the preservation of long-term repopulating HSCs (LT-HSCs), while those with lower stiffness support multi-potent progenitors (MPPs) viability in vitro. Furthermore, we established a comprehensive transcriptional profile of haematopoietic subpopulations to reflect the multipotency of haematopoietic stem and progenitor cells (HSPCs) that are modulated by niche-like stiffness. Our findings demonstrate that HSPCs exhibit completely distinct downstream differentiated preferences within hydrogel systems of varying stiffness. This highlights the crucial role of tissue-specific mechanical properties in HSC lineage decisions, which may provide innovative solutions to clinical challenges.

Pseudo attP sites in favor of transgene integration and expression in cultured porcine cells identified by Streptomyces phage phiC31 integrase.

Phage PhiC31 integrase integrates attB-containing plasmid into pseudo attP site in eukaryotic genomes in a unidirectional site-specific manner and maintains robust transgene expression. Few studies, however, explore its potential in livestock. This study aims to discover the molecular basis of PhiC31 integrase-mediated site-specific recombination in pig cells. We show that PhiC31 integrase can mediate site-specific transgene integration into the genome of pig kidney PK15 cells. Intramolecular recombination in pig PK15 cell line occurred at maximum frequency of 82% with transiently transfected attB- and attP-containing plasmids. An optimal molar ratio of pCMV-Int to pEGFP-N1-attB at 5:1 was observed for maximum number of cell clones under drug selection. Four candidate pseudo attP sites were identified by TAIL-PCR from those cell clones with single-copy transgene integration. Two of them gave rise to higher integration frequency occurred at 33%. 5' and 3' junction PCR showed that transgene integration mediated by PhiC31 integrase was mono-allelic. Micro- deletion and insertion were observed by sequencing the integration border, indicating that double strand break was induced by the recombination. We then constructed rescue reporter plasmids by ABI-REC cloning of the four pseudo attP sites into pBCPB + plasmid. Transfection of these rescue plasmids and pCMV-Int resulted in expected intramolecular recombination between attB and pseudo attP sites. This proved that the endogenous pseudo attP sites were functional substrates for PhiC31 integrase-mediated site-specific recombination. Two pseudo attP sites maintained robust extracellular and intracellular EGFP expression. Alamar blue assay showed that transgene integration into these specific sites had little effect on cell proliferation. This is the first report to document the potential use of PhiC31 integrase to mediate site-specific recombination in pig cells. Our work established an ideal model to study the position effect of identical transgene located in diverse chromosomal contexts. These findings also form the basis for targeted pig genome engineering and may be used to produce genetically modified pigs for agricultural and biomedical uses.

Effects of intracavernous injection of adipose-derived stem cells on cavernous nerve regeneration in a rat model.

The aim of this study was to investigate effects of intracavernous injection of adipose-derived stem cells (ADSCs) on cavernous nerve (CN) regeneration and functional status in a nerve-crush rat model. Thirty Sprague-Dawley male rats were randomly divided into three equal groups: one group underwent sham operation, while two groups underwent bilateral CN crush. Crush-injury group was treated at the time of injury with intracavernous injection of ADSCs, or injured control group with no further intervention. Erectile function was assessed by CN electrostimulation after 3 months. Penile tissue and crushed nerves were collected for histology. Three months after surgery, in the group that underwent bilateral nerve crushing with no further intervention, the functional evaluation showed a lower mean maximal intracavernous pressure (ICP) and maximal ICP per mean arterial pressure (MAP) with CN stimulation than those in the sham group. In the group with an immediate intracavernous injection of ADSCs, the mean maximal ICP and maximal ICP/MAP were significantly higher than those in the injured control group. Histologically, the group with the intracavernous injection of ADSCs had more myelinated axons of CNs and more NADPH-diaphorase-positive nerve fibers than the injured control group but fewer than the sham group. Intracavernous injection of ADSCs treatment had beneficial effects on the smooth muscle/collagen ratio in the corpus cavernosum. These results show that the intracavernous injection of ADSCs to the site of CN-crush injury facilitates nerve regeneration and recovery of erectile function. Our research indicates that penile injection of ADSCs can improve recovery of erectile function in a rat model of neurogenic ED.

PTPα-mediated Src activation by EGF in human breast cancer cells.

Protein tyrosine phosphatase alpha (PTPα) functions as an activator of Src by dephosphorylating Tyr527/530, a critical negative regulatory site. The increase of PTPα catalytic activity requires its phosphorylation at Ser180 and/or Ser204 and its dissociation from PTPα/Grb2 complex. Here, we show that epidermal growth factor (EGF) stimulation increases the ability of PTPα to activate Src by dephosphorylating Tyr530 in BT-20 and SKBR3 breast cancer cell lines. Treatment of these cells with EGF transiently decreased the association of PTPα with Grb2 and enhanced PTPα catalytic activity via Ser180 and Ser204 phosphorylation that was blocked by the protein kinase C delta (PKCδ) inhibitor rottlerin or knockdown of PKCδ by siRNA or by the overexpression of PTPαS180A/S204A mutant. PTPα siRNA blocked EGF-mediated Src activation in cancer cells and inhibited on colony formation, whereas control siRNA did not. These results suggested that PTPα links activation of epidermal growth factor receptor (EGFR) signaling with Src activation and may provide a novel therapeutic target for treatment of breast cancer.