Tumor-Targeted Gene Silencing IDO Synergizes PTT-Induced Apoptosis and Enhances Anti-tumor Immunity.

Background: Photothermal therapy (PTT) has been demonstrated to be a promising cancer treatment approach because it can be modulated to induce apoptosis instead of necrosis via adjusting irradiation conditions. Recently, an abscopal anti-tumor immunity has been highlighted, in which PTT on the primary tumor also induced repression of distant tumors. In PTT cancer treatments, the mechanism and the role of immune checkpoints to enhance anti-tumor immunity needs to be investigated. Methods: We prepared a multi-functional gold nanorod reagent, GMPF-siIDO, that is composed of gold nanorods (GNRs) that act as the nano-platform and photothermal sensitizer; folic acid (FA) as the tumor-targeting moiety; and IDO-specific RNA (siIDO) as an immune-stimulator functionality for inducing anti-tumor immunity. For this study, we adjusted the irradiation condition of PTT to induce apoptosis and to silence the immune checkpoint indoleamine 2,3 dioxygeonase (IDO), simultaneously. Results: Our studies provide evidence that photothermal effects kill tumor cells mainly via inducing apoptosis, which can significantly improve antitumor immunity when IDO was down-regulated in TME through significant increases of localized CD8+ and CD4+ lymphocytes in tumor tissue, the downregulation of CD8+ and CD4+ lymphocyte apoptosis, and the upregulation of antitumor cytokines, TNF-α and IFN-γ. Conclusion: In this study, we, for the first time, validated the role of IDO as a negative regulator for both PTT-induced tumor cell apoptosis and anti-tumor immunity; IDO is a critical immune checkpoint that impedes PTT while combination of gene knockdown of IDO in TME enhances anti-tumor efficacy of PTT.

Targeted Gene Silencing BRAF Synergized Photothermal Effect Inhibits Hepatoma Cell Growth Using New GAL-GNR-siBRAF Nanosystem.

Liver cancer is one of the most common malignancies worldwide. The RAF kinase inhibitors are effective in the treatment of hepatocellular carcinoma (HCC); therefore, inhibition of the BRAF/MEK/ERK pathway has become a new therapeutic strategy for novel HCC therapy. However, targeted specific delivery systems for tumors are still significant obstacle to clinical applications. Galactose (GAL) can target the asialoglycoprotein receptor (ASGPR) that is highly expressed on liver cancer cells. In this study, we designed a novel multifunctional nanomaterial GAL-GNR-siBRAF which consists of three parts, GAL as the liver cancer-targeting moiety, golden nanorods (GNR) offering photothermal capability under near infrared light, and siRNA specifically silencing BRAF (siBRAF). The nanocarrier GAL-GNR-siBRAF showed high siRNA loading capacity and inhibited the degradation of siRNA in serum. Compared with naked gold nanorods, GAL-GNR-siBRAF possessed lower biotoxicity and higher efficacy of gene silencing. Treatment with GAL-GNR-siBRAF significantly downregulated the expression of BRAF and impaired proliferation, migration, and invasion of liver cancer cells. Moreover, combinatorial photothermal effects and BRAF knockdown by GAL-GNR-siBRAF effectively given rise to tumor cell death. Therefore, our study developed a new type of targeted multi-functional nanomaterial GAL-GNR-siBRAF for the treatment of liver cancer, which provides ideas for the development of new clinical treatment methods.

Gene silencing of indoleamine 2,3-dioxygenase 1 inhibits lung cancer growth by suppressing T-cell exhaustion.

Indoleamine 2,3-dioxygenase 1 (IDO1), which degrades the essential amino acid tryptophan, exerts immunosuppressive functions and serves a crucial role in multiple types tumor progression, including non-small-cell lung cancer (NSCLC) and melanoma. Recent studies have reported that T-cell exhaustion is increased during tumor progression, which impairs the antitumor immune response. However, the association between IDO1 and T-cell exhaustion during tumor progression remains unknown. The present study evaluated the effect of IDO1 on T-cell exhaustion in lung cancer mice. The present study demonstrated that IDO1 knockdown by small interfering RNA in the LLC cell line inhibited T-cell exhaustion. Furthermore, the role of IDO1 in T-cell exhaustion during lung cancer progression was determined in an in vivo mouse model using IDO1 short hairpin RNA (shRNA). The results demonstrated that inhibition of IDO1 activity by shRNA administration in vivo significantly delayed the onset and growth of tumors. In addition, the expression levels of the inhibitory receptors programmed death-1 (PD-1) and B and T lymphocyte attenuator (BTLA) were increased in T-cells from the lung tumor-bearing mice, whereas interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-α) levels in serum were decreased compared with the control mice. However, no difference in the absolute number of T cells was observed, including CD4+ and CD8+ T cells. In addition, IDO1 knockdown by shRNA inhibited T-cell exhaustion in lung tumor-bearing mice, which was characterized by decreased expression of PD-1 and BTLA on T cells. By contrast, IL-2 and TNF-α levels in serum were increased in IDO1-shRNA-treated mice. By using a shRNA approach, the present study demonstrated that IDO1 activity may be involved in tumor growth, and that IDO1 silencing may inhibit tumor progression by impeding the process of T-cell exhaustion.

miRNA-5119 regulates immune checkpoints in dendritic cells to enhance breast cancer immunotherapy.

Dendritic cell (DC) based immunotherapy is a promising approach to clinical cancer treatment. miRNAs are a class of small non-coding RNA molecules that bind to RNAs to mediate multiple events which are important in diverse biological processes. miRNA mimics and antagomirs may be potent agents to enhance DC-based immunotherapy against cancers. miRNA array analysis was used to identify a representative miR-5119 potentially regulating PD-L1 in DCs. We evaluated levels of ligands of immune cell inhibitory receptors (IRs) and miR-5119 in DCs from immunocompetent mouse breast tumor-bearing mice, and examined the molecular targets of miR-5119. We report that miRNA-5119 was downregulated in spleen DCs from mouse breast cancer-bearing mice. In silico analysis and qPCR data showed that miRNA-5119 targeted mRNAs encoding multiple negative immune regulatory molecules, including ligands of IRs such as PD-L1 and IDO2. DCs engineered to express a miR-5119 mimic downregulated PD-L1 and prevented T cell exhaustion in mice with breast cancer homografts. Moreover, miR-5119 mimic-engineered DCs effectively restored function to exhausted CD8+ T cells in vitro and in vivo, resulting in robust anti-tumor cell immune response, upregulated cytokine production, reduced T cell apoptosis, and exhaustion. Treatment of 4T1 breast tumor-bearing mice with miR-5119 mimic-engineered DC vaccine reduced T cell exhaustion and suppressed mouse breast tumor homograft growth. This study provides evidence supporting a novel therapeutic approach using miRNA-5119 mimic-engineered DC vaccines to regulate inhibitory receptors and enhance anti-tumor immune response in a mouse model of breast cancer. miRNA/DC-based immunotherapy has potential for advancement to the clinic as a new strategy for DC-based anti-breast cancer immunotherapy.

TLR2 agonist Pam3CSK4 enhances the antibacterial functions of GM-CSF induced neutrophils to methicillin-resistant Staphylococcus aureus.

A proliferation of studies have demonstrated that the toll-like receptor 2 (TLR2) pathway affects the chemotaxis, phagocytosis, and cytokine release of neutrophils when pathogens invade. Our previous studies have demonstrated that pretreatment with high doses of Pam3CSK4 (>25 µg/ml) improves the antimicrobial activity of neutrophils, however, short-lived neutrophils limit their therapeutic functions. Here, we used granulocyte macrophage-colony stimulating factor (GM-CSF) to generate neutrophils from murine bone marrow, and assessed their effect on the immune response against methicillin-resistant Staphylococcus aureus. As comparing with classical method of generating neutrophils directly from murine bone marrow, our findings show that pretreatment with Pam3CSK4 enhanced the phagocytic and killing activities against MRSA by the GM-CSF induced neutrophils (GM-CSF neutrophils). Chemotaxis of GM-CSF induced neutrophils was significantly increased after the pretreatment with Pam3CSK4. Furthermore, Pam3CSK4 pretreatment enhanced iNOS, CRAMP, TNF-α, IL-1ß, IL-10, and IL-6 expression. Finally, we observed that p38MAPK and Akt phosphorylation kinases were increased significantly in GM-CSF neutrophils pretreatment with Pam3CSK4 in a dose- and time-dependent manner, whereas p38MAPK inhibitor (SB2021190) and PI3K inhibitor (LY294002) attenuated the antimicrobial activities including phagocytosis, killing activity, respiratory burst, and the release of lactoferrin(LTF) by the GM-CSF induced neutrophils. Together, these findings suggest that pretreatment with Pam3CSK4 enhances the antibacterial function of GM-CSF neutrophils against MRSA, and this could be related to the p38MAPK and PI3K signaling pathways.

TdIF1: a putative oncogene in NSCLC tumor progression.

TdT-interacting factor 1 (TdIF1) is a ubiquitously expressed DNA- and protein-binding protein that directly binds to terminal deoxynucleotidyl transferase (TdT) polymerase. Little is known about the functional role of TdIF1 in cancer cellular signaling, nor has it previously been identified as aberrant in any type of cancer. We report here for the first time that TdIF1 is abundantly expressed in clinical lung cancer patients and that high expression of TdIF1 is associated with poor patient prognosis. We further established that TdIF1 is highly expressed in human non-small cell lung cancer (NSCLC) cell lines compared to a normal lung cell line. shRNA-mediated gene silencing of TdIF1 resulted in the suppression of proliferation and anchorage-independent colony formation of the A549 adenocarcinoma cell line. Moreover, when these TdIF1-silenced cells were used to establish a mouse xenograft model of human NSCLC, tumor size was greatly reduced. These data suggest that TdIF1 is a potent regulator of lung tumor development. Several cell cycle-related and tumor growth signaling pathways, including the p53 and HDAC1/2 pathways, were identified as participating in the TdIF1 signaling network by in silico analysis. Microarray, transcriptome and protein-level analyses validated p53 and HDAC1/2 modulation upon TdIF1 downregulation in an NSCLC cellular model. Moreover, several other cell cycle regulators were affected at the transcript level by TdIF1 silencing, including an increase in CDKN1A/p21 transcripts. Taken together, these results indicate that TdIF1 is a bona fide tumor-promoting factor in NSCLC and a potential target for therapy.

Temperature-dependent cell death patterns induced by functionalized gold nanoparticle photothermal therapy in melanoma cells.

Photothermal therapy (PTT) is a promising approach for cancer targeting therapy. However, the temperature-dependent killing of tumor cells in PTT remains unclear. In this study, we report necroptosis plays a role in the anti-tumor effects observed in gold nanorod (GNR)-mediated PTT in melanoma. We first synthesized gold nanorods with a targeting adaptor FA (GNRs-FA), which achieved high efficacy of targeted delivery to melanoma cells. We further demonstrated PTT, precipitated by GNRs-FA under the induction of near-infrared laser, was temperature-dependent. Furthermore, the photothermal killing of melanoma cells showed different patterns of cell death depending on varying temperature in PTT. In a lower temperature at 43 °C, the percentages of apoptosis, necroptosis and necrosis of tumor cells were 10.2%, 18.3%, and 17.6%, respectively, suggesting the cell killing is ineffective at lower temperatures. When the temperature increased to 49 °C, the cell death pattern switched to necrosis dominant (52.8%). Interestingly, when the PTT achieved a moderate temperature of 46 °C, necroptosis was significantly increased (35.1%). Additionally, GNRs-FA/PPT-mediated necroptosis was regulated by RIPK1 pathway. Taken together, this study is the first to demonstrate that temperature-dependent necroptosis is an important mechanism of inducing melanoma cell death in GNR-mediated PTT in addition to apoptosis and necrosis.

A new cancer immunotherapy via simultaneous DC-mobilization and DC-targeted IDO gene silencing using an immune-stimulatory nanosystem.

The activity of negative immune regulatory molecules, such as indoleamine 2,3-oxygenase (IDO), significantly attenuates DC (Dendritic cells)-mediated immunotherapy. We have previously reported that knockdown of IDO using siRNA can reinstall anti-tumor immunity. However, a DC-targeted siRNA delivery system for in vivo mobilized DCs remains to be developed, while gene silencing in mobilized DCs for cancer immunotherapy has never been explored. In our study, we developed a novel DC-targeted siRNA delivery system, man-GNR-siIDO, using as a nanocarrier of siRNA specific for IDO (siIDO) and mannose (man) as a guide molecule for targeting DCs. We explored the immunostimulatory man-GNR-siIDO nano-construct in DCs mobilized by Flt3-L, a receptor-type tyrosine kinase ligand, for lung cancer immunotherapy. In vivo DC-targeted gene silencing of IDO resulted in robust anti-tumor immunity as evidenced by promoting DC maturation, up-regulating tumor antigen-specific T-cell proliferation and enhancing tumor-specific cytotoxicity. A combinatorial treatment for Lewis Lung Carcinoma (LLC)-bearing mice, with man-GNR-siIDO and Flt3-L, significantly attenuated tumor growth and delayed tumor formation, suggesting the treatment feasibility of the man-GNR-siIDO system in Flt3-L mobilized DCs in the immunotherapy of lung cancer. Therefore, our study highlights a clinical potential for a first-in-class anti-cancer immunotherapy through simultaneous DC-mobilization and DC-targeted gene silencing of IDO with man-GNR-siIDO and Flt3-L treatments.

Targeted-gene silencing of BRAF to interrupt BRAF/MEK/ERK pathway synergized photothermal therapeutics for melanoma using a novel FA-GNR-siBRAF nanosystem.

Melanoma is significantly associated with mutant BRAF gene, a suitable target for siRNA-based anti-melanoma therapy. However, a tumor-specific delivery system is a major hurdle for clinical applications. Here, we developed a novel nano-carrier, FA-GNR-siBRAF for safe topical application, which consists of folic acid (FA) as the tumor-targeting moiety, golden nanorods (GNR) providing photothermal capability to kill tumor cells under laser irradiation, and siRNA specifically silencing BRAF (siBRAF). The in vitro and in vivo results revealed that FA-GNR-siBRAF displayed high transfection rates, and subsequently induced remarkable gene knockdown of BRAF, resulting in suppression of melanoma growth due to the interruption of the MEK/ERK pathway. Combinatorial photothermal effects and BRAF knockdown by FA-GNR-siBRAF effectively killed tumor cells through apoptosis, with enhanced efficiency than individual treatments. Therefore, the FA-GNR-siBRAF simultaneously induced BRAF gene silencing and photothermal effects which achieved synergistic efficacy in the treatment of melanoma, paving a new path for developing clinical treatment methods for melanoma.

Gene silencing of indoleamine 2,3-dioxygenase hinders tumor growth through angiogenesis inhibition.

The significance of indoleamine 2,3-dioxygenase-1 (IDO1) has been studied in various types of tumors, but the relationship between IDO1 and tumor angiogenesis needs further delineation. We aimed to clarify the relationship between tumor angiogenesis and IDO1 expression, and to explore the possibility of IDO1-targeting molecular therapy for lung cancer. For the first time, we found that silencing the IDO1 gene using small interfering RNA (siRNA) inhibits in vitro cancer cell invasion and migration. We further demonstrated that knockdown of IDO1 decreased the formation of vasculogenic mimicry. In addition to these in vitro findings, we also demonstrated that in vivo IDO1 gene silencing using short hairpin RNA (shRNA) delayed tumor onset and inhibited tumor growth in the mouse model. Immunostaining showed that IDO1 gene silencing inhibited tumor angiogenesis. Moreover, the expression of IDO1 was associated with microvessel density (MVD) labeled by CD34 and CD146. These findings indicate that IDO1 has the potential to participate in or contribute to the formation of new capillaries, supporting the applicability of IDO1-targeting molecular therapy in lung cancer.

Synergistic suppression of autoimmune arthritis through concurrent treatment with tolerogenic DC and MSC.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by progressive immune-mediated joint deterioration. Current treatments are not antigen specific and are associated with various adverse. We have previously demonstrated that tolerogenic dendritic cells (Tol-DC) are potent antigen-specific immune regulators, which hold great promise in immunotherapy of autoimmune diseases. In this study, we aimed to develop new immunotherapy by combining Tol-DC and mesenchymal stem cells (MSC). We demonstrated that RelB gene silencing resulted in generation of Tol-DC that suppressed T cell responses and selectively promoted Treg generation. The combination of MSC synergized the tolerogenic capacity of Tol-DC in inhibition of T cell responses. In murine collagen-induced arthritis (CIA) model, we demonstrated that progression of arthritis was inhibited with administration of RelB gene-silenced Tol-DC or MSC. This therapeutic effect was remarkably enhanced with concurrent treatment of combination Tol-DC and MSC as demonstrated by improved clinical symptoms, decreased clinical scores and attenuated joint damage. These therapeutic effects were associated with suppression of CII-specific T cell responses, polarization of Th and inhibition of proinflammatory cytokines, and reduced cartilage degeneration. This study for the first time demonstrates a new approach to treat autoimmune inflammatory joint disease with concurrent treatment of RelB gene-silenced Tol-DC and MSC.

[Effects of IFN-γ treatment on biological characteristics and functions of dendritic cells].

Objective To investigate the effect of IFN-γ treatment on the biological characteristics and functions of C57BL/6 murine dendritic cells (DCs). Methods In the process of DC culture, 20 ng/mL IFN-γ was added in the DCs at the early (day 2) or late (day 5) stage, and on day 7, LPS was added to stimulate DC maturation. The expressions of DC surface molecules CD11c, CD80 and CD86 were determined by flow cytometry. To analyze cell functions, DCs were co-cultured with BALB/c mouse-derived lymphocyte cells. The 5, 6-carboxyfluorescein diacetate N-succinimidyl ester (CFSE) labelling was used to detect their ability to stimulate allogeneic lymphocyte proliferation and flow cytometry was used to measure their ability to induce the production of regulatory T cells (Tregs). Results Compared with the control group, the early IFN-γ treatment group had decreased DC number and inhibited cell differentiation; though there was no difference in the expression of co-stimulatory molecules, early IFN-γ treatment resisted the stimulatory effect of LPS on DC maturation, weakened the ability to stimulate allogeneic lymphocyte proliferation and enhanced the ability to induce more Tregs. Compared with the control group, the late IFN-γ treatment group showed no change in DC number and differentiation; the expressions of co-stimulatory molecules CD86 and CD80 were upregulated; the results of DC maturation and mixed allogeneic lymphocyte reaction stimulated by LPS were similar to those in the control group, but its ability to induce Tregs was stronger. Conclusion DCs treated with IFN-γ at early stage and those at late stage showed obvious difference in biological characteristics and functions.

miRNA let-7b modulates macrophage polarization and enhances tumor-associated macrophages to promote angiogenesis and mobility in prostate cancer.

Macrophage polarization is a highly plastic physiological process that responds to a variety of environmental factors by changing macrophage phenotype and function. Tumor-associated macrophages (TAMs) are generally recognized as promoting tumor progression. As universal regulators, microRNAs (miRNAs) are functionally involved in numerous critical cellular processes including macrophage polarization. Let-7b, a miRNA, has differential expression patterns in inflamed tissues compared with healthy controls. However, whether and how miRNA let-7b regulates macrophage phenotype and function is unclear. In this report, we find that up-regulation of let-7b is characteristic of prostatic TAMs, and down-regulation of let-7b in TAMs leads to changes in expression profiles of inflammatory cytokines, such as IL-12, IL-23, IL-10 and TNF-α. As a result, TAMs treated with let-7b inhibitors reduce angiogenesis and prostate carcinoma (PCa) cell mobility. Let-7b may play a vital role in regulating macrophage polarization, thus modulating the prognosis of prostate cancer.

Gene silencing of indoleamine 2,3-dioxygenase 2 in melanoma cells induces apoptosis through the suppression of NAD+ and inhibits in vivo tumor growth.

Indoleamine 2,3-dioxygenase 2 (IDO2) is a newly discovered enzyme that catalyzes the initial and rate-limiting step in the degradation of tryptophan. As a homologous protein of IDO1, IDO2 plays an inhibitory role in T cell proliferation, and it is essential for regulatory T cell (Treg) generation in healthy conditions. Little is known about the immune-independent functions of IDO2 relevant to its specific contributions to physiology and pathophysiology in cancer cells. The purpose of this study was to assess the impact of IDO2 gene silencing as a way to inhibit B16-BL6 cancer cells in a murine model. Here, for the first time, we show that knockdown of IDO2 using small interfering RNA (siRNA) inhibits cancer cell proliferation, arrests cell cycle in G1, induces greater cell apoptosis, and reduces cell migration in vitro. Knockdown of IDO2 decreased the generation of nicotinamide adenine dinucleotide (NAD+) while increasing the generation of reactive oxygen species (ROS). We further demonstrate that cell apoptosis, induced by IDO2 downregulation, can be weakened by addition of exogenous NAD+, suggesting a novel mechanism by which IDO2 promotes tumor growth through its metabolite product NAD+. In addition to in vitro findings, we also demonstrate that IDO2 silencing in tumor cells using short hairpin RNA (shRNA) delayed tumor formation and arrested tumor growth in vivo. In conclusion, this study demonstrates a new non-immune-associated mechanism of IDO2 in vitro and IDO2 expression in B16-BL6 cells contributes to cancer development and progression. Our research provides evidence of a novel target for gene silencing that has the potential to enhance cancer therapy.

Control of Methicillin-Resistant Staphylococcus aureus Pneumonia Utilizing TLR2 Agonist Pam3CSK4.

The spread of methicillin-resistant Staphylococcus aureus (MRSA) is a critical health issue that has drawn greater attention to the potential use of immunotherapy. Toll-like receptor 2 (TLR2), a pattern recognition receptor, is an essential component in host innate defense system against S. aureus infection. However, little is known about the innate immune response, specifically TLR2 activation, against MRSA infection. Here, we evaluate the protective effect and the mechanism of MRSA murine pneumonia after pretreatment with Pam3CSK4, a TLR2 agonist. We found that the MRSA-pneumonia mouse model, pretreated with Pam3CSK4, had reduced bacteria and mortality in comparison to control mice. As well, lower protein and mRNA levels of TNF-α, IL-1ß and IL-6 were observed in lungs and bronchus of the Pam3CSK4 pretreatment group. Conversely, expression of anti-inflammatory cytokine IL-10, but not TGF-ß, increased in Pam3CSK4-pretreated mice. Our additional studies showed that CXCL-2 and CXCL1, which are necessary for neutrophil recruitment, were less evident in the Pam3CSK4-pretreated group compared to control group, whereas the expression of Fcγ receptors (FcγⅠ/Ⅲ) and complement receptors (CR1/3) increased in murine lungs. Furthermore, we found that increased survival and improved bacterial clearance were not a result of higher levels of neutrophil infiltration, but rather a result of enhanced phagocytosis and bactericidal activity of neutrophils in vitro and in vivo as well as increased robust oxidative activity and release of lactoferrin. Our cumulative findings suggest that Pam3CSK4 could be a novel immunotherapeutic candidate against MRSA pneumonia.

[Effect of Crude Antigens from Ascaris lumbricoides on the Apoptosis and Secretion of IL-6 and TGF-ß of Human Lung Adenocarcinoma Cells].

OBJECTIVE: To investigate the effect of crude antigens of Ascaris lumbricoides on the secretion of IL-6 and TGF-ß of human lung adenocarcinoma cells (A549 cells), and the apoptosis of A549 cells. METHODS: Crude antigens of A. lumbricoides were prepared. A549 cells were co-cultured with 25, 125, and 500 µg/ml crude antigens of A. lumbricoides for 1, 18, and 24 h, named as low concentration group, medium concentration group, and high concentration group, respectively. Meanwhile, A549 cells were co-cultured with culture medium (negative control) and 12.5 µg/ml adriamycin (positive control). The apoptosis rate was detected by using Annexin V-FITC apoptosis detection kit. The cell changes were determined by flow cytometry. The levels of mRNA expression of IL-6 and TGF-ß were detected by ELISA and real time PCR, respectively. RESULTS: The apoptosis rate of A549 cells induced by crude antigens for 1, 18, and 24 h was significantly higher than that of negative control (P < 0.01). The apoptosis rate in medium concentration group (treated for 18 h) was highest [(47.10 ± 3.68)%]. After co-culture with 125 µg/ml crude antigens for 18 h, the proportion of G0/G1 phase cells increased and that of S phase cells decreased, and there was a significant difference between medium concentration group and negative control group. At the same time, the level of IL-6 increased with the increasing concentration of crude antigens. However, no significant difference was found in the level of TGF-ß among the groups. In the medium concentration group, mRNA expression levels of IL-6 (5.95 ± 0.31) and TGF-ß (3.43 ± 0.35) of A549 cells reached peak on the 18th hour, and were significantly higher than that of the control (P < 0.01). CONCLUSION: The cell cycle of A549 cells is blocked in G0/G1 phase induced by crude antigens of A. lumbricoides. And the apoptosis may be related to the changes in the level of TGF-ß and IL-6.

A novel GNRs-PEI/GNRs-PEI-folate for efficiently delivering siRNA.

RNA interference (RNAi) employs double-stranded RNA or siRNA (small interfering RNA) to silence gene expression in cells. The widespread use of RNAi therapeutics requires the development of clinically suitable, safe and effective delivery vehicles. PEI (Poly(ethylene imine)) carrying the positive charges has attracted considerable attention for siRNA delivery. Gold nanorods (GNRs) exhibit specially localized surface plasmon resonance when excited by the visible and near-infrared laser, which is useful for photothermal therapy. However, the toxicity derived from a large amount of the surfactant cetyltrimethylammonium bromide (CTAB) during GNR synthesis severely limits their medical applications. Here, we report the synthesis of GNRs-PEI/GNRs-PEI-folate to improve biocompatibility, siRNA delivery and photothermal therapy of GNRs. Firstly, GNRs were synthesized according to the seed-mediated template-assisted protocol. The characterization results of GNRs showed: the size was length about 218 nm and width about 26.8 nm; the Zeta potential was +38.1 mV derived from CTAB on their surface; the dipole resonance extinction spectrum peak was 752 nm which is effective for photothermal therapy in vivo. Secondly, we synthesized PEI-MUA (Mercaptoundecanoic acid) and PEI-MUA-folate based on the chemical reaction between amino group of PEI and carboxyl group of MUA or Folate. PEI-MUA or PEI-MUA-folate to replace CTAB on GNRs obtained the GNRs-MUA-PEI system or the GNRs-MUA-PEI-folate system due to the solid conjugation between the thiol group of MUA and GNRs. The products were measured using the FTIR Spectrometer, and the spectra suggest MUA-PEI or PEI-MUA-folate has successfully replaced CTAB on the surface of GNRs. Finally, GNRs-MUA-PEI was incubated with siRNA-Cy3. The unbound siRNA-Cy3 was measured the intensity of fluorescence for calculating the uploaded amount of siRNA by GNRs-MUA-PEI, and the results indicate that the uploaded percentage of siRNA is about 70%. We conclude that the GNRs-MUA-PEI system is an effective siRNA loading vehicle.

Microencapsulation improves inhibitory effects of transplanted olfactory ensheathing cells on pain after sciatic nerve injury.

Olfactory bulb tissue transplantation inhibits P2X2/3 receptor-mediated neuropathic pain. However, the olfactory bulb has a complex cellular composition, and the mechanism underlying the action of purified transplanted olfactory ensheathing cells (OECs) remains unclear. In the present study, we microencapsulated OECs in alginic acid, and transplanted free and microencapsulated OECs into the region surrounding the injured sciatic nerve in rat models of chronic constriction injury. We assessed mechanical nociception in the rat models 7 and 14 days after surgery by measuring paw withdrawal threshold, and examined P2X2/3 receptor expression in L4-5 dorsal root ganglia using immunohistochemistry. Rats that received free and microencapsulated OEC transplants showed greater withdrawal thresholds than untreated model rats, and weaker P2X2/3 receptor immunoreactivity in dorsal root ganglia. At 14 days, paw withdrawal threshold was much higher in the microencapsulated OEC-treated animals. Our results confirm that microencapsulated OEC transplantation suppresses P2X2/3 receptor expression in L4-5 dorsal root ganglia in rat models of neuropathic pain and reduces allodynia, and also suggest that transplantation of microencapsulated OECs is more effective than transplantation of free OECs for the treatment of neuropathic pain.

Five COX-2 gene polymorphisms and risk of breast cancer: an updated meta-analysis based on 19 case-control studies.

The correlationship between COX-2 gene polymorphisms and breast cancer has been wildly studied, but the results remain controversial. Hence, the present meta-analysis aimed to investigate the association between COX-2 SNPs (rs5275, rs20417, rs689466, rs5277, rs2206593) and risk of breast cancer. Data were collected from PubMed, Embase and China National Knowledge Infrastructure. Summary odds ratio (OR) with 95 % confidence interval (CI) was applied to assess the relationship. Heterogeneity test, sensitivity analysis and publication bias test were also performed. There were 17 articles that contained 19 studies in this research. Fourteen case-control studies with 15,007 breast cancer cases and 20,005 controls were concerning rs5275 polymorphism, and 8 case-control studies with 10,216 cases and 12,839 controls were about rs20417 polymorphism. Other three polymorphisms (rs689466, rs2206593, rs5277) were studied in 5, 3 and 3 studies, respectively. COX-2-rs20417 CC genotype was significantly associated with increased risk of breast cancer when comparing to G allele [ORs were 1.231 (1.050-1.444) for CC vs. GG, P = 0.01, 1.223 (1.045-1.432) for CC vs. G carrier, P = 0.01]. Furthermore, the results of the subgroup analysis by ethnicity suggested that C allele significantly contributed to the risk of breast cancer for Asians [1.459 (1.182-1.802) for GC vs. GG, 1.472 (1.201-1.805) for C carrier vs. GG]. However, no association was found for rs5275, rs689466, rs5277 and rs2206593 in all comparison modes. This meta-analysis indicated that the COX-2 rs20417 polymorphism contributed to genetic susceptibility of breast cancer. In contrast, COX-2 rs5275, rs689466, rs2206593 and rs5277 polymorphisms might be not associated with the risk of breast cancer.

Targeted siRNA silencing of indoleamine 2, 3-dioxygenase in antigen-presenting cells using mannose-conjugated liposomes: a novel strategy for treatment of melanoma.

Indoleamine 2, 3-dioxygenase (IDO) expression in dendritic cells (DCs) leads to the inhibition of T-cell activation, induction of T-cell apoptosis, and promotion of T-cell differentiation into regulatory T cells. All of these could promote tumor escapement of the host's immune surveillance system. We hypothesized that DC-targeted gene silencing of IDO would enhance antitumor immunity and thus restrain tumor growth. Mannose receptors are highly expressed in antigen-presenting cells (APCs) including DCs. In this study, we developed a novel APC-targeted small interfering RNA delivery system using mannosed liposomes (Man-lipo) with encapsulated IDO small interfering RNA (Man-lipo-siIDO), which preferentially knocked down IDO expression in draining lymph node and spleen of melanoma-bearing mice. Mice treated with Man-lipo-siIDO displayed a delayed time of onset of implanted murine melanomas, increased survival time, reduced tumor size, and increased reactivity of T cells from spleen and lymph nodes against melanoma antigens. The enhanced antitumor immunity may be linked to inhibition of apoptosis in CD8 and CD4 T cells as well as Treg cells in spleen and lymph nodes. This study is the first to demonstrate that Man-lipo-siIDO can preferentially targets APCs and efficiently silence IDO expression in vitro and in vivo; events expected to enhance antitumor immune reactions against melanoma xenografts. This study supports the hypothesis that Man-lipo-siIDO may possess the potential for development as an immune-targeting therapeutic anticancer agent.