Spatiotemporal release of non-nucleotide STING agonist and AKT inhibitor from implantable 3D-printed scaffold for amplified cancer immunotherapy.

Immunotherapy through the activation of the stimulator of interferon genes (STING) signaling pathway is increasingly recognized for its robust anti-tumor efficacy. However, the effectiveness of STING activation is often compromised by inadequate anti-tumor immunity and a scarcity of primed immune cells in the tumor microenvironment. Herein, we design and fabricate a co-axial 3D-printed scaffold integrating a non-nucleotide STING agonist, SR-717, and an AKT inhibitor, MK-2206, in its respective shell and core layers, to synergistically enhance STING activation, thereby suppressing tumor recurrence and growth. SR-717 initiates the STING activation to enhance the phosphorylation of the factors along the STING pathway, while MK-2206 concurrently inhibits the AKT phosphorylation to facilitate the TBK1 phosphorylation of the STING pathway. The sequential and sustained release of SR-717 and MK-2206 from the scaffold results in a synergistic STING activation, demonstrating substantial anti-tumor efficacy across multiple tumor models. Furthermore, the scaffold promotes the recruitment and enrichment of activated dendritic cells and M1 macrophages, subsequently stimulating anti-tumor T cell activity, thereby amplifying the immunotherapeutic effect. This precise and synergistic activation of STING by the scaffold offers promising potential in tumor immunotherapy.

Sandwich-Structured Implants to Obstruct Multipath Energy Supply and Trigger Self-Enhanced Hypoxia-Initiated Chemotherapy Against Postsurgical Tumor Recurrence and Metastasis.

As a currently common strategy to treat cancer, surgical resection may cause tumor recurrence and metastasis due to residual postoperative tumors. Herein, an implantable sandwich-structured dual-drug depot is developed to trigger a self-intensified starvation therapy and hypoxia-induced chemotherapy sequentially. The two outer layers are 3D-printed using a calcium-crosslinked mixture ink containing soy protein isolate, polyvinyl alcohol, sodium alginate, and combretastatin A4 phosphate (CA4P). The inner layer is one patch of poly (lactic-co-glycolic acid)-based electrospun fibers loaded with tirapazamine (TPZ). The preferentially released CA4P destroys the preexisting blood vessels and prevents neovascularization, which obstructs the external energy supply to cancer cells but aggravates hypoxic condition. The subsequently released TPZ is bioreduced to cytotoxic benzotriazinyl under hypoxia, further damaging DNA, generating reactive oxygen species, disrupting mitochondria, and downregulating hypoxia-inducible factor 1α, vascular endothelial growth factor, and matrix metalloproteinase 9. Together these processes induce apoptosis, block the intracellular energy supply, counteract the disadvantage of CA4P in favoring intratumor angiogenesis, and suppress tumor metastasis. The in vivo and in vitro results and the transcriptome analysis demonstrate that the postsurgical adjuvant treatment with the dual-drug-loaded sandwich-like implants efficiently inhibits tumor recurrence and metastasis, showing great potential for clinical translation.

Self-intensified synergy of a versatile biomimetic nanozyme and doxorubicin on electrospun fibers to inhibit postsurgical tumor recurrence and metastasis.

Tumor-positive resection margins after surgery can result in tumor recurrence and metastasis. Although adjuvant postoperative radiotherapy and chemotherapy have been adopted in clinical practice, they lack efficacy and result in unavoidable side effects. Herein, a self-intensified in-situ therapy approach using electrospun fibers loaded with a biomimetic nanozyme and doxorubicin (DOX) is developed. The fabricated PEG-coated zeolite imidazole framework-67 (PZIF67) is demonstrated as a versatile nanozyme triggering reactions in cancer cells based on endogenous H2O2 and •O2-. The PZIF67-generated •OH induces reactive oxygen species (ROS) overload, implementing chemodynamic therapy (CDT). The O2 produced by PZIF67 inhibits the expression of hypoxia-up-regulated proteins, thereby suppressing tumor progression. PZIF67 also catalyzes the degradation of glutathione, further disturbing the intracellular redox homeostasis and enhancing CDT. Furthermore, the introduced DOX not only kills cancer cells individually, but also replenishes the continuously consumed substrates for PZIF67-catalyzed reactions. The PZIF67-weakened drug resistance strengthens the cytotoxicity of DOX. The combined application of PZIF67 and DOX also suppresses metastasis-associated genes. Both in vitro and in vivo results demonstrate that the self-intensified synergy of PZIF67 and DOX on electrospun fibers efficiently prevents postsurgical tumor recurrence and metastasis, offering a feasible therapeutic regimen for operable malignant tumors.

Enzyme-Enhanced Codelivery of Doxorubicin and Bcl-2 Inhibitor by Electrospun Nanofibers for Synergistic Inhibition of Prostate Cancer Recurrence.

One of the great challenges of postoperative prostate cancer management is tumor recurrence. Although postoperative chemotherapy presents benefits to inhibit unexpected recurrence, it is still limited due to the drug resistance or intolerable complications of some patients. Electrospun nanofiber, as a promising drug carrier, demonstrating sustained drug release behavior, can be implanted into the tumor resection site during surgery and is conductive to tumor inhibition. Herein, we fabricated electrospun nanofibers loaded with doxorubicin (DOX) and ABT199 to synergistically prevent postoperative tumor recurrence. Enzymatic degradation of the biodegradable electrospun nanofibers facilitated the release of the two drugs. The primarily released DOX from the electrospun nanofibers effectively inhibited tumor recurrence. However, the sustained release of DOX led to drug resistance of the tumor cells, yielding unsatisfactory eradication of the residual tumor. Remarkably, the combined administration of DOX and ABT199, simultaneously released from the nanofibers, not only prolonged the chemotherapy by DOX but also overcame the drug resistance via inhibiting the Bcl-2 activation and thereby enhancing the apoptosis of tumor cells by ABT199. This dual-drug-loaded implant system, combining efficient chemotherapy and anti-drug resistance, offers a prospective strategy for the potent inhibition of postoperative tumor recurrence.

Implantable Sandwich-like Scaffold/Fiber Composite Spatiotemporally Releasing Combretastatin A4 and Doxorubicin for Efficient Inhibition of Postoperative Tumor Recurrence.

Tumor recurrence is a critical conundrum in the postoperative therapy, on account of severe bleeding with disseminated tumor cells, residual tumor cells, and the rich nutrient and oxygen supply transported to tumors by the abundant blood vessels. Biodegradable drug-loaded implants, inserted in the resection cavity right away upon the surgery, possess bleeding prevention and efficient chemotherapeutic capabilities, considered to be a promising strategy to efficiently inhibit the recurrence of the solid tumor. Here, we developed a sandwich-like composite consisting of the combretastatin A4 (CA4)-loaded 3D-printed scaffold and doxorubicin (DOX)-loaded electrospun fiber (Scaffold-CA4@Fiber-DOX), presenting hemostatic, chemotherapeutic, and antibacterial potencies. The lyophilized 3D-printed scaffold with a porous structure rapidly absorbed and clotted the blood cells and disseminated tumor cells to prevent bleeding and tumor metastasis. Subsequently, the preferentially released CA4 from the scaffold disrupted the microtubules of the vascular endothelial cell, resulting in vascular deformation and consequent insufficient nutrient supply to the solid tumor. The sustained release of DOX from the sandwiched electrospun fiber dramatically inhibited the peripheral tumor cell proliferation. This all-in-one multifunctional implant system, combining efficient vascular disruption and chemotherapy, provides a promising strategy for postoperative tumor therapy.

Corrigendum: Blockade of IL-6/IL-6R Signaling Attenuates Acute Antibody-Mediated Rejection in a Mouse Cardiac Transplantation Model.

[This corrects the article DOI: 10.3389/fimmu.2021.778359.].

Blockade of IL-6/IL-6R Signaling Attenuates Acute Antibody-Mediated Rejection in a Mouse Cardiac Transplantation Model.

Acute antibody-mediated rejection (AAMR) is an important cause of cardiac allograft dysfunction, and more effective strategies need to be explored to improve allograft prognosis. Interleukin (IL)-6/IL-6R signaling plays a key role in the activation of immune cells including B cells, T cells and macrophages, which participate in the progression of AAMR. In this study, we investigated the effect of IL-6/IL-6R signaling blockade on the prevention of AAMR in a mouse model. We established a mouse model of AAMR for cardiac transplantation via presensitization of skin grafts and addition of cyclosporin A, and sequentially analyzed its features. Tocilizumab, anti-IL-6R antibody, and recipient IL-6 knockout were used to block IL-6/IL-6R signaling. We demonstrated that blockade of IL-6/IL-6R signaling significantly attenuated allograft injury and improved survival. Further mechanistic research revealed that signaling blockade decreased B cells in circulation, spleens, and allografts, thus inhibiting donor-specific antibody production and complement activation. Moreover, macrophage, T cell, and pro-inflammatory cytokine infiltration in allografts was also reduced. Collectively, we provided a highly practical mouse model of AAMR and demonstrated that blockade of IL-6/IL-6R signaling markedly alleviated AAMR, which is expected to provide a superior option for the treatment of AAMR in clinic.

Zinc Ion-Stabilized Aptamer-Targeted Black Phosphorus Nanosheets for Enhanced Photothermal/Chemotherapy Against Prostate Cancer.

Prostate cancer is the second most common malignancy among men worldwide. However, conventional chemotherapy, such as taxane therapy, fails to exhibit efficient treatment for almost half of the patients. In this study, a nano-drug delivery system based on black phosphorus nanosheets (BP NSs) was developed, which was then employed as a multifunctional nanoplatform for targeted combinational chemo-photothermal therapy against prostate cancer. Zinc ion (Zn2+), which has been proven to be able to inhibit prostate cancer cell proliferation, was also introduced into this system. Zn2+ coordination could not only enhance the therapeutic effect of combined chemo-photothermal therapy, but also improve the intrinsic instability of BP NSs through the stabilization of its lone pair electrons. The in vivo study showed the outstanding performance of this system in targeted photothermal/chemotherapy of prostate cancer without side effect to normal organs.

Aptamer-Conjugated Multifunctional Polymeric Nanoparticles as Cancer-Targeted, MRI-Ultrasensitive Drug Delivery Systems for Treatment of Castration-Resistant Prostate Cancer.

Nanoscopic therapeutic systems that incorporate therapeutic agents, molecular targeting, and imaging capabilities have gained momentum and exhibited significant therapeutic potential. In this study, multifunctional polymeric nanoparticles with controlled drug delivery, cancer-targeted capability, and efficient magnetic resonance imaging (MRI) contrast characteristics were formulated and applied in the treatment of castration-resistant prostate cancer (CRPC). The "core-shell" targeted nanoparticles (NPs) were synthesized by the self-assembly of a prefunctionalized amphiphilic triblock copolymer composed of poly(lactic-co-glycolic-acid) (PLGA), polyethylene glycol (PEG), and the Wy5a aptamer (Apt), which have been screened for targeting the CRPC cell line PC-3 by cell-SELEX technique as described in our previous study. Docetaxel (Dtxl) and a cluster of hydrophobic superparamagnetic iron oxide (SPIO) nanoparticles were simultaneously encapsulated into the targeted nanoparticles. The targeted NPs showed a controlled drug release and an increased contrast-enhanced MRI capability. The presence of Wy5a on the nanoparticle surface resulted in the cancer-targeted delivery to PC-3 cells in vitro and in vivo. In vitro MRI and cytotoxicity studies demonstrated the ultrasensitive MRI and increased cytotoxicity of these targeted NPs. In vivo studies revealed that the targeted NPs exhibited a more efficacious antitumor capability without significant systemic toxicity. Our data suggested that these targeted NPs may be a promising drug delivery system for the efficacious treatment of CRPC.

Real-Time Ultrasound-Guided Percutaneous Nephrolithotomy Using Newly Developed Wireless Portable Ultrasound: A Single-Center Experience.

OBJECTIVES: To assess the feasibility and utility of a newly developed wireless portable ultrasound "UProbe- 2" for puncture guidance in percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: The UProbe-2 consists of a probe with integrated ultrasound circuit boards inside, an intelligent terminal that installed specific ultrasound software, and a puncture trestle. The probe can connect to an intelligent terminal via WI-FI. It was used to guide puncture in PCNL in 31 patients who suffered kidney stones or large impacted proximal upper ureteral stones with hydronephrosis from June 2016 to July 2017. Patients' characteristics as well as parameters during operation were collected. RESULTS: PCNL was successfully performed in all patients with the guidance of the UProbe-2. The mean (standard deviation) puncture time was 3.6 (0.9) minutes, and the median operative duration was 50 (35-80) minutes. The primary stone clearance rate was 87% (27/31). No major intraoperative or postoperative complications occurred. CONCLUSION: The UProbe-2 ultrasound is safe and effective for puncture guidance during PCNL according to this initial study. It could provide a new and alternative choice for guidance of PCNL. However, more clinical trials especially randomized controlled trials should be performed.

Comparison of Transperitoneal and Retroperitoneal Laparoscopic Nephrectomy for Nonfunctional Tuberculous Kidneys: A Single-Center Experience.

OBJECTIVES: To compare the effectiveness and safety between retroperitoneal laparoscopic nephrectomy (RLN) and transperitoneal laparoscopic nephrectomy (TLN) for nonfunctional tuberculous kidneys (NTK). METHODS: From March 2013 to February 2016, 24 patients with NTK underwent laparoscopic nephrectomy in our department. Eleven patients underwent RLN, and 13 underwent TLN. The demographics and perioperative outcomes were compared retrospectively. RESULTS: Characteristics, including gender, age, body mass index, and location, were similar in these two groups. All operations were successfully completed in the RLN group, while 1 case in the TLN group was converted to open surgery due to severe adhesions and excessive bleeding (1 of 13 patients). Time to oral intake after surgery in the TLN and RLN group was 43.85 ± 6.01 hours and 27.45 ± 6.83 hours (P < .05). No notable differences were found between two groups in terms of estimated blood loss, operative time, days of drain removal, and postoperative hospital stay. No local or disseminated recurrence was identified during the follow-up period. CONCLUSION: Taking the same safety and effectiveness into consideration, TLN can be an alternative choice for experienced surgeons to deal with NTK. Also, further studies with a larger sample size should be performed to confirm this finding.

Potential Anticancer Mechanisms of a Novel EGFR/DNA-Targeting Combi-Molecule (JDF12) against DU145 Prostate Cancer Cells: An iTRAQ-Based Proteomic Analysis.

The development of multitargeting drugs is an emerging trend in cancer research. To promote further development and clinical application of multitargeting drugs, this research was performed. MTT assay and flow cytometry of Annexin V/propidium iodide staining were used to confirm the proapoptotic efficacy of a novel combi-targeting molecule, JDF12, against DU145 prostate cancer (PCa) cells. Differentially expressed proteins between control and JDF12-treated cultures were revealed by isobaric tags for relative and absolute quantitation (iTRAQ), and part of them was confirmed by quantitative PCR. Differentially expressed proteins were further analyzed for function, pathway association, and protein-protein interactions using GO, KEGG, and STRING databases. A total of 119 differentially expressed proteins, 70 upregulated and 49 downregulated, were implicated in the anticancer effects of JDF12. Many of these proteins are involved in biosynthesis, response to stress, energy metabolism, and signal transduction. This study provides important information for understanding the anti-PCa mechanisms of JDF12, and well-designed combi-targeting drugs may possess stronger anticancer efficacy than single-targeting drugs and are thus promising candidates for clinical application.

Formaldehyde Inhibits Sexual Behavior and Expression of Steroidogenic Enzymes in the Testes of Mice.

BACKGROUND: Formaldehyde, a ubiquitous environmental pollutant, is used extensively and has been proved to impair male reproduction in mammals. However, no trials have explored whether formaldehyde affects sexual function. AIM: To evaluate the effect of long-term formaldehyde exposure on sexual behavior and to investigate the potential mechanism. METHODS: Forty C57BL/6 male mice were randomly allocated to four equally sized groups. Mice were exposed to formaldehyde at a dose of 0 (control), 0.5, 5.0, or 10.0 mg/m3 by inhalation for 60 days. OUTCOMES: Sexual behavior, body and reproductive organ weights, testosterone concentration in serum and testicular tissue, expression of steroidogenic enzymes, quality of sperm, and testicular structure were measured. RESULTS: Formaldehyde inhibited sexual behavior and decreased reproductive organ weights in mice. Serum testosterone levels and intratesticular testosterone concentrations were decreased in the formaldehyde-treated groups. Expression levels of steroidogenic enzymes, including steroidogenic acute regulatory protein, cytochrome P450 cholesterol side-chain cleavage enzyme, and 3ß-hydroxysteroid dehydrogenase (3ß-HSD), also were decreased in the testes of mice exposed to formaldehyde. Moreover, the structure of seminiferous tubules was destroyed and sperm quality decreased after formaldehyde exposure. In addition, the results indicated that the effects of formaldehyde were dose dependent. CLINICAL IMPLICATIONS: Efforts should be undertaken to decrease impairment of sexual function caused by formaldehyde exposure. STRENGTHS AND LIMITATIONS: The relatively small sample might have affected the outcomes. Further experiments are needed to study the mechanism of action of formaldehyde. CONCLUSION: Exposure to formaldehyde gas inhibited sexual behavior, caused reproductive organ atrophy, and impaired spermatogenesis in male mice, which might have been induced by suppressed expression of steroidogenic enzymes in Leydig cells and decreased testosterone synthesis. Zang Z-J, Fang Y-Q, Ji S-Y, et al. Formaldehyde Inhibits Sexual Behavior and Expression of Steroidogenic Enzymes in the Testes of Mice. J Sex Med 2017;14:1297-1306.

Light of DNA-alkylating agents in castration-resistant prostate cancer cells: a novel mixed EGFR/DNA targeting combi-molecule.

OBJECTIVE: The mechanism underlying the therapeutic effects of combi-molecule JDF12 on prostate cancer (PCa) DU145 cells remains still unclear. This study aimed to investigate the proteomic profile after JDF12 treatment in DU145 cells by comparing with that in Iressa treated cells and untreated cells. METHODS: MTT was used to evaluate drug cytotoxicity, DAPI staining was done to assess apoptosis of cells, and flow cytometry was used to analyze cell cycle. iTRAQ and qPCR were employed to obtain the proteomic profiles of JDF12 treated, Iressa treated, and untreated DU145 cells, and validate the expression of selected differentially expressed proteins, respectively. RESULTS: JDF12 could significantly inhibit the proliferation and increase the apoptosis of DU145 cells when compared with Iressa or blank group. In total, 5071 proteins were obtained, out of which, 42, including 21 up-regulated and 21 down-regulated proteins, were differentially expressed in JDF12 group when compared with Iressa and blank groups. The up-regulated proteins were mainly involved in DNA damage/repair and energy metabolism; while the down-regulated proteins were mainly associated with cell apoptosis. qPCR confirmed the expression of several biologically important proteins in DU145 cells after JDF12 treatment. CONCLUSION: The molecular mechanisms of DNA alkylating agents on PCa therapy that with the assistant of EGFR-blocker were revealed on proteomic level, which may increase the possible applications of DNA alkylating agents and JDF12 on PCa therapy.

Computer tomography urography assisted real-time ultrasound-guided percutaneous nephrolithotomy on renal calculus.

This study aimed to assess the role of pre-designed route on computer tomography urography (CTU) in the ultrasound-guided percutaneous nephrolithotomy (PCNL) for renal calculus.From August 2013 to May 2016, a total of 100 patients diagnosed with complex renal calculus in our hospital were randomly divided into CTU group and control group (without CTU assistance). CTU was used to design a rational route for puncturing in CTU group. Ultrasound was used in both groups to establish a working trace in the operation areas. Patients' perioperative parameters and postoperative complications were recorded.All operations were successfully performed, without transferring to open surgery. Time of channel establishment in CTU group (6.5 ±â€Š4.3 minutes) was shorter than the control group (10.0 ±â€Š6.7 minutes) (P = .002). In addition, there was shorter operation time, lower rates of blood transfusion, secondary operation, and less establishing channels. The incidence of postoperative complications including residual stones, sepsis, severe hemorrhage, and perirenal hematoma was lower in CTU group than in control group.Pre-designing puncture route on CTU images would improve the puncturing accuracy, lessen establishing channels as well as improve the security in the ultrasound-guided PCNL for complex renal calculus, but at the cost of increased radiation exposure.

Safety and Efficacy of First-Line Treatments for Chemotherapy-Naive Metastatic Castration-Resistant Prostate Cancer: A Systematic Review and Indirect Comparison.

Recently, several drugs have been introduced for the first-line treatment of chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC), but few studies have compared treatment outcomes directly. This indirect comparison among 10 clinical trials (n = 4870 patients) retrieved from PubMed, Web of Science, Cochrane Collaboration, and ClinicalTrails.gov was performed to assess the safety and efficacy of docetaxel, cabazitaxel, abiraterone, enzalutamide, and sipuleucel-T for the initial treatment of mCRPC. No significant differences in primary outcome (overall survival) were found among initial treatments. However, docetaxel had the highest probability (37.53%) of being the most effective, but at the cost of more adverse events, while enzalutamide was associated with the best secondary outcomes (prostate-specific antigen response, progression-free survival, quality of life, and adverse event profile). Thus, docetaxel is recommended as the first agent used for the chemotherapy of mCRPC, while enzalutamide is recommended as the first nonchemotherapy treatment. Additional clinical trials are needed to confirm these findings and establish the optimal order for multidrug treatment of mCRPC.

Nanoparticle mediated chemotherapy of hormone refractory prostate cancer with a novel combi-molecule.

In previous study, we synthesized a novel combi-molecule, JDF-12, with superior cytotoxicity against prostate cancer cells, but it has a poor stability in liquid after preparation with traditional method and is susceptible to hydrolysis and binding to organs highly expressing epidermal growth factor receptor (EGFR), resulting in side effects. In this study, the nanotechnology was employed to prepare JDF-12 aiming to increase its anti-tumor effect and reduce its systemic side effects. The JDF-12 loaded nanoparticles were formulated with biocompatible and biodegradable poly (D,L-lactic-co-glycolic acid)-block-poly(ethyleneglycol) (PLGA-b-PEG) copolymer and surface functionalized with a single-chain antibody that recognizes the extracellular domain of prostate stem cell antigen (PSCA), enabling a controlled release, "stealth" property, and cell-specific targeting. The targeted nanoparticles exhibited a sustained drug release in vitro and were specifically endocytosed by prostate cancer cells though the receptor-mediated endocytosis resulting in enhanced cellular toxicity in vitro. Moreover, a better outcome with reduced drug toxicity was observed in a PC3M xenograft animal model after treatment with these nanoparticles. Our results demonstrate the feasibility of nanoparticle-based technology in the development of pharmaceutically suboptimal chemotherapeutics.

Biological effects of novel "combi-targeting" molecule and its effect on DNA repair pathway in hormone-refractory prostate cancer.

OBJECTIVE: This study aimed to investigate the biological effects of "combi-targeting" JDF12 and its effect on the DNA repair pathway in hormone-refractory prostate cancer (HRPC). METHODS: HRPC cell lines (PC3 cells and VCap cells) were treated with JDF12 at different concentrations, and SRB method was employed to detect the proliferation of HRPC cells; Annexin V-FITC kit was used to detect the apoptosis of PC3 cells; Alkaline comet assay was performed to detect DNA damage; Western blot assay was done to detect the expressions of autophosphorylated EGFR, XRCC1 and ERCC1 (later two are proteins in DNA repair pathway); the anti-tumor effect was evaluated in nude mice inoculated with PC3 cells. RESULTS: JDF12 could inhibit the proliferation of PC3 cells and VCap cells in a concentration dependent manner (IC50: 14.04 ± 1.22 for PC3 and 15.57 ± 1.13 for VCap) and significantly increase the apoptotic cells as compared to those treated with mitozolomide or iressa alone. In PC3 cells, JDF12 induced DNA damage and also inhibited the expressions of phosphorylated EGFR, XRCC1 and ERCC1 in a concentration dependent manner. Moreover, JDF12 markedly inhibited tumor growth in nude mice. CONCLUSION: The novel "combi-targeting" JDF12 may exert more potent anti-proliferative effect as compared to mitozolomide or iressa alone, and the inhibitory effect on the EGFR signaling pathway and down-regulated XRCC1 and ERCC1 expressions may be ascribed to the JDF12 induced DNA damage.

Acidic extracellular microenvironment promotes the invasion and cathepsin B secretion of PC-3 cells.

BACKGROUND: This study aimed to investigate the effect of acidic microenvironment on the invasion of prostatic carcinoma PC-3 cells and to explore the potential mechanism. MATERIAL AND METHODS: PC-3 cells were maintained in medium at different pHs (pH 7.4, pH 7.0 and pH 6.6). Invasion and metastasis of PC-3 cells were investigated in vitro. Acridine orange staining was performed, followed by laser confocal scanning microscopy for the localization of lysosomes. Western blot assay and ELISA were employed to evaluate the effect of acidic microenvironment on the cathepsin B secretion. RESULTS: Acidic microenvironment remarkably promote the invasion and migration of PC-3 cells (P<0.01). Moreover, at acidic extracellular pH (pHe), an obvious shift of lysosomes from the perinuclear region to the periphery was observed. Western blot assay and ELISA revealed that acidic microenvironment promoted the cathepsin B secretion in PC- cells. CONCLUSION: Acidic microenvironment may significantly promote the invasion of PC-3 cells and increase the secretion of cathepsin B. This suggests that the acidic microenvironment induced invasion of PC- cells is related to the elevated cathepsin B secretion.

Upregulation of CRMP4, a new prostate cancer metastasis suppressor gene, inhibits tumor growth in a nude mouse intratibial injection model.

Prostate cancer, the most commonly diagnosed male cancer in North America, has a high incidence of bone metastasis. Our previous study showed collapsin response mediator protein 4 (CRMP4) gene inhibited prostate cancer migration and invasion. In this study, we investigated whether overexpression of CRMP4 gene in prostate cancer cells inhibit tumor bone metastasis. The stable prostate cancer cells overexpressing the CRMP4 gene were constructed using lentivirus infection. Prostate cancer bone metastasis nude mouse model was built though orthotopic prostate implantation, intracardiac injection and intratibial injection with CRMP4 overexpress and control cancer cells. Small animal PET/CT scanning results showed no difference of bone metastatic capacity in orthotopic and intracardiac injection models between CRMP4 overexpression and control group, while CRMP4 overexpression inhibited tumor growth in the intratibial injection model. Moreover, our in vitro study showed CRMP4 overexpression downregulates the Neuropilin1 (NRP1) expression and upregulate the Noggin expression. Immunohistochemical staining of the hind limbs of intratibial injection model was confirmed with cytological experiments. Taken together, our research indicated CRMP4 inhibits prostate cancer cells growth in the nude mouse bone microenvironment and this effect may relate with regulation of NRP1 and Noggin expression.