Establishment of a three-dimensional human prostate organoid coculture under microgravity-simulated conditions: Evaluation of androgen-induced growth and psa expression

Summary A novel in vitro human prostate cancer model was established by using a coculture technique in which isolated human prostate fibroblasts were observed to grow as a mixed culture with isolated human prostate cancer cells (LNCaP) on microcarrier beads under microgravity-simulated conditions. This model appears to be promising and deserves further exploration because: (a) cocultured human prostate fibroblasts and cancer epithelial cells appear to undergo patterns of histogenesis similar to those observed in human prostate tumors and (b) unlike the conventional cell culture on plastic dishes, cocultured human prostate fibroblasts and LNCaP cells in microgravity-simulated conditions responded to the inductive signals of growth and differentiation from dihydrotestosterone in a manner similar to that observed in the in vivo condition. These results offer an opportunity to examine molecular mechanisms of cellular signaling in response to androgen stimulation during normal and aberrant human prostate development. The microgravity-simulated three-dimensional prostate epithelial cell culture with prostate fibroblasts can be further explored as an ideal in vitro model for the study of normal and neoplastic prostate development. This model could also be adopted as a drug screening program for the discovery of novel therapeutic agents in the treatment of human prostate cancer and benign hyperplastic growth.     

Development of near-infrared imaging agents for detection of junction adhesion molecule-A protein

IntroductionProstate and breast cancer are the most prevalent primary malignant human tumors globally. Prostatectomy and breast conservative surgery remain the most common definitive treatment option for the >500,000 men and women newly diagnosed with localized prostate and breast cancer each year only in the US. Morphological examination is the mainstay of diagnosis but margin under-sampling of the excised cancer tissue may lead to local recurrence. In despite of the progress of non-invasive optical imaging, there is still a clinical need for targeted optical imaging probes that could rapidly and globally visualize cancerous tissues.MethodsElevated expression of junctional adhesion molecule-A (JAM-A) on tumor cells and its multiple pro-tumorigenic activity make the JAM-A a candidate for molecular imaging. Near-infrared imaging probe, which employed anti-JAM-A monoclonal antibody (mAb) phthalocyanine dye IR700 conjugates (JAM-A mAb/IR700), was synthesized and used to identify and visualize heterotopic human prostate and breast tumor mouse xenografts in vivo.ResultsThe intravenously injected JAM-A mAb/IR700 conjugates enabled the non-invasive detection of prostate and breast cancerous tissue by fluorescence imaging. A single dose of JAM-A mAb/IR700 reduced number of mitotic cancer cells in vivo, indicating theranostic ability of this imaging agent. The JAM-A mAb/IR700 conjugates allowed us to image a specific receptor expression in prostate and breast tumors without post-image processing.ConclusionThis agent demonstrates promise as a method to image the extent of prostate and breast cancer in vivo and could assist with real-time visualization of extracapsular extension of cancerous tissue.     

长链非编码RNA LINC01006对前列腺癌细胞增殖和侵袭的影响

摘要 目的：探究长链非编码RNA LINC01006对前列腺癌（prostate cancer, PCa）细胞增殖和侵袭能力的影响。方法：体外培养人前列腺正常上皮细胞系RWPE-1,人PCa细胞系LNCaP、22Rv1、PC3、C4-2b,应用实时定量PCR（qRT-PCR）技术检测上述细胞LINC01006的表达;分别通过转染小干扰RNA（siRNA）或过表达LINC01006的慢病毒载体,在LNCaP和PC3细胞中敲减LINC01006或稳定过表达LINC01006;应用CCK8、克隆形成实验检测LINC01006对PCa细胞增殖能力的影响;应用Transwell侵袭实验检测LINC01006对PCa细胞侵袭能力的影响;通过网站预测LINC01006的转录调控因子及其结合位点。结果：相较于正常前列腺上皮细胞系RWPE-1,PCa细胞系LNCaP、22Rv1、C4-2b和PC3中LINC01006表达明显升高（P<0.05）。敲减LINC01006后的PCa细胞系LNCaP和PC3的增殖和侵袭能力被显著抑制（P<0.05）,过表达LINC1006则明显促进PCa细胞系LNCaP和PC3的增殖、侵袭能力（P<0.05）。通过PROMO网站预测可见AR是LINC01006的潜在转录调控因子,通过Cistrome DB数据库发现LINC01006上游启动子区域存在AR富集;敲减、抑制AR后LNCaP细胞中LINC01006表达明显升高（P<0.05）。结论：LINC01006在PCa细胞系中呈高表达,促进PCa细胞的增殖和侵袭,其受到AR负向调控,可能在PCa发生发展和去势抵抗形成过程中发挥作用。     

Anti-tumor effect against human cancer xenografts by a fully human monoclonal antibody to a variant 8-epitope of CD44R1 expressed on cancer stem cells

Background

CD44 is a major cellular receptor for hyaluronic acids. The stem structure of CD44 encoded by ten normal exons can be enlarged by ten variant exons (v1-v10) by alternative splicing. We have succeeded in preparing MV5 fully human IgM and its class-switched GV5 IgG monoclonal antibody (mAb) recognizing the extracellular domain of a CD44R1 isoform that contains the inserted region coded by variant (v8, v9 and v10) exons and is expressed on the surface of various human epithelial cancer cells.

Methods and Principal Findings

We demonstrated the growth inhibition of human cancer xenografts by a GV5 IgG mAb reshaped from an MV5 IgM. The epitope recognized by MV5 and GV5 was identified to a v8-coding region by the analysis of mAb binding to various recombinant CD44 proteins by enzyme-linked immunosorbent assay. GV5 showed preferential reactivity against various malignant human cells versus normal human cells assessed by flow cytometry and immunohistological analysis. When ME180 human uterine cervix carcinoma cells were subcutaneously inoculated to athymic mice with GV5, significant inhibition of tumor formation was observed. Furthermore, intraperitoneal injections of GV5markedly inhibited the growth of visible established tumors from HSC-3 human larynx carcinoma cells that had been subcutaneously transplanted one week before the first treatment with GV5. From in vitro experiments, antibody-dependent cellular cytotoxicity and internalization of CD44R1 seemed to be possible mechanisms for in vivo anti-tumor activity by GV5.

Conclusions

CD44R1 is an excellent molecular target for mAb therapy of cancer, possibly superior to molecules targeted by existing therapeutic mAb, such as Trastuzumab and Cetuximab recognizing human epidermal growth factor receptor family.     

shRNA抑制活化诱导的胞苷脱氨酶（AID）对前列腺癌细胞C4-2表型的影响

目的:探讨AID在前列腺癌中的表达情况,AID对前列腺癌细胞C4-2的侵袭、迁移、增殖以及凋亡方面的影响。方法:应用靶向敲减AID的慢病毒对前列腺癌细胞C4-2进行干扰,运用Western-blot、免疫组化、平板克隆形成、流式、Transwell实验对前列腺癌组织和前列腺癌细胞C4-2表型的变化情况进行研究。结果:临床前列腺癌样本中AID高表达,良性前列腺增生组织中AID低表达,正常前列腺组织不表达(*P0.05);shRNA干扰以后的shAICDA-C4-2单克隆细胞株中AID的表达量显著降低,其增殖、迁移和侵袭能力阳性对照组(Monoclonal6)与阴性对照组(NC)相比分别降低49%、80%、63%,凋亡率阳性对照组(Monoclonal6)为阴性对照组(NC)的3.2倍。结论:前列腺癌组织中AID高表达,AID在促进前列腺癌细胞的增殖、迁移、侵袭,抑制前列腺自细胞的凋亡中具有极其重要的作用。AID表达极可能与前列腺癌的进展、预后明显相关。     

miR-182在前列腺癌组织中的表达及其对前列腺癌细胞增殖和凋亡的影响

目的:观察前列腺癌组织及不同前列腺癌细胞系中miR-182的表达,并探讨下调其表达对前列腺癌细胞增殖和凋亡的影响及机制。方法:采用实时荧光定量PCR(q RT-PCR)检测30例前列腺癌组织和30例相应的癌旁组织以及前列腺正常上皮RWPE-1细胞、前列腺癌PC-3、LNCa P和DU145细胞中miR-182的表达,进一步采用Lipfectamine 2000脂质体转染miRNA-182 inhibitor和阴性对照miRNA于PC-3细胞后,通过噻唑蓝(MTT)比色法检测细胞增殖情况,流式细胞术检测细胞凋亡率,免疫印迹(Western blot)法检测转录因子FOXO1、血管内皮生长因子(VEGF)和抑癌基因p53蛋白的表达。结果:miR-182在前列腺癌组织中的表达明显高于癌旁组织(P0.05);miR-182在前列腺癌细胞系PC-3、LNCa P和DU145中的表达均高于前列腺正常上皮细胞RWPE-1(P0.05),其中PC-3细胞中miR-182表达水平最高。转染miRNA-182 inhibitor至PC-3细胞成功下调miR-182表达后,细胞的增殖能力明显受到抑制,细胞凋亡能力明显增强,FOXO1表达水平显著升高,VEGF和p53的表达明显降低,差异均具有统计学意义(P0.05)。结论:miR-182在前列腺癌组织及细胞中呈高表达,下调miR-182的表达可能通过增加FOXO1的表达并减少VEGF和p53的表达,抑制前列腺癌细胞增殖并诱导细胞凋亡。     

前列腺癌细胞系中环状RNA circRNA-1565的表达及鉴定

目的:探讨前列腺癌细胞系中的环状RNA circRNA-1565的表达及鉴定。方法:培养前列腺正常上皮细胞(RWPE-1)、4种前列腺癌细胞(22RV1、LNCap、PC-3、DU145),提取总RNA,采用RT-PCR检测不同细胞系中circRNA-1565的表达,并对其进行成环性验证及细胞内亚定位实验,进行差异比较。结果:circRNA-1565在正常前列腺细胞系(RWPE-1)中表达量极低,在转移性前列腺癌细胞系中高表达,在非转移性前列腺癌细胞系中低表达。且circRNA-1565是一条主要定位于细胞质内的具有有效环状结构的RNA分子。结论:circRNA-1565在不同前列腺癌细胞系中存在差异表达,可能会通过mi RNA sponge途径发挥生物学作用。     

IgM monoclonal antibody JD118 recognizes an inducible antigen target for human-complement-mediated cytotoxicity against neoplastic B cells

Cancer therapy using unconjugated monoclonal antibodies (mAb) has been limited by the lack of immune effector function of the mAb and antigenic modulation. JD118 is a cytotoxic murine IgM mAb with reactivity restricted to a subset of normal B cells, some monocytic series cells, and a large percentage of B cell hematopoietic neoplasms including acute and chronic leukemias and lymphomas. Specificity was determined on several hundred normal and neoplastic, hematopoietic and non-hematopoietic cells and tissues, as well as progenitor cells. JD118 was able to kill fresh human leukemias and lymphomas in the presence of human serum as a complement source with an LD₅₀ of 100 ng/ml. At this mAb concentration, fewer than 4% of more than 10⁵ available target sites were bound. Killing was not affected by changes in antigen expression observed during the cell cycle nor by loss of cell-surface targets via antigenic modulation. Cytotoxicity could be achieved with human serum diluted as low as 5%, suggesting that complement depletion in vivo should not limit activity. Autologous human serum could be used effectively as a complement source. The JD118 antigen target has not been identified, but it appears to be a glycoprotein. Up-regulation of antigen expression on normal B cells and chronic lymphocytic leukemia cells in vitro resulted in antigen-negative neoplasms becoming positive and thus targets for JD118 killing. The restricted expression, potent cytotoxic characteristics, and potential for up-regulation of its antigen make JD118 a possible candidate for ex vivo autologous bone marrow purging and in vivo therapeutic trials in patients with B cell neoplasms.This work was supported by ACS grants PRTF-135 and IM-551, the Michael and Ethel Cohen Fellowship Fund, and the Lucille P. Markey Trust. D. A. Scheinberg is a Lucille P. Markey Scholar Correspondence to: Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10021, USA     

Alpha-tomatine induces apoptosis and inhibits nuclear factor-kappa B activation on human prostatic adenocarcinoma PC-3 cells

Background

Alpha-tomatine (α-tomatine) is the major saponin in tomato (Lycopersicon esculentum). This study investigates the chemopreventive potential of α-tomatine on androgen-independent human prostatic adenocarcinoma PC-3 cells.

Methodology/Principal Findings

Treatment of highly aggressive human prostate cancer PC-3 cells with α-tomatine resulted in a concentration-dependent inhibition of cell growth with a half-maximal efficient concentration (EC₅₀) value of 1.67±0.3 µM. It is also less cytotoxic to normal human liver WRL-68 cells and normal human prostate RWPE-1 cells. Assessment of real-time growth kinetics by cell impedance-based Real-Time Cell Analyzer (RTCA) showed that α-tomatine exhibited its cytotoxic effects against PC-3 cells as early as an hour after treatment. The inhibitory effect of α-tomatine on PC-3 cancer cell growth was mainly due to induction of apoptosis as evidenced by positive Annexin V staining and decreased in mitochondrial membrane potential but increased in nuclear condensation, polarization of F-actin, cell membrane permeability and cytochrome c expressions. Results also showed that α-tomatine induced activation of caspase-3, -8 and -9, suggesting that both intrinsic and extrinsic apoptosis pathways are involved. Furthermore, nuclear factor-kappa B (NF-κB) nuclear translocation was inhibited, which in turn resulted in significant decreased in NF-κB/p50 and NF-κB/p65 in the nuclear fraction of the treated cells compared to the control untreated cells. These results provide further insights into the molecular mechanism of the anti-proliferative actions of α-tomatine.

Conclusion/Significance

α-tomatine induces apoptosis and inhibits NF-κB activation on prostate cancer cells. These results suggest that α-tomatine may be beneficial for protection against prostate cancer development and progression.     

Extracellular stimulation of VSIG4/complement receptor Ig suppresses intracellular bacterial infection by inducing autophagy

VSIG4/CRIg (V-set and immunoglobulin domain containing 4) is a transmembrane receptor of the immunoglobulin superfamily that is expressed specifically on macrophages and mature dendritic cells. VSIG4 signaling accelerates phagocytosis of C3-opsonized bacteria, thereby efficiently clearing pathogens within macrophages. We found that VSIG4 signaling triggered by C3-opsonized Listeria (opLM) or by agonistic anti-VSIG4 monoclonal antibody (mAb) induced macrophages to form autophagosomes. VSIG4-induced autophagosomes were selectively colocalized with the intracellular LM while starvation-induced autophagosomes were not. Consistent with these results, the frequency of autophagosomes induced by infection with opLM was lower in VSIG4-deficient bone marrow-derived macrophages (BMDMs) than in WT BMDMs. Furthermore, when VSIG4 molecules were overexpressed in HeLa cells, which are non-macrophage cells, VSIG4 triggering led to efficient uptake of LM, autophagosome formation, and killing of the infected LM. These findings suggest that VSIG4 signaling not only promotes rapid phagocytosis and killing of C3-opsonized intracellular bacteria, as previously reported, but also induces autophagosome formation, eliminating the LM that have escaped from phagosomes. We conclude that VSIG4 signaling provides an anti-immune evasion mechanism that prevents the outgrowth of intracellular bacteria in macrophages.     

Arg-Gly-Asp (RGD)-Modified E1A/E1B Double Mutant Adenovirus Enhances Antitumor Activity in Prostate Cancer Cells In Vitro and in Mice

CAR is a transmembrane protein that is expressed in various epithelial and endothelial cells. CAR mediates adenoviral infection, as well as adenovirus-mediated oncolysis of AxdAdB-3, an E1A/E1B double-restricted oncolytic adenovirus, in prostate cancer cells. This study further assessed the therapeutic efficacy of AxdAdB-3 with Arg-Gly-Asp (RGD)-fiber modification (AxdAdB3-F/RGD), which enables integrin-dependent infection, in prostate cancer. Susceptibility of prostate cancer cells LNCaP, PC3, and DU145 to adenovirus infection was associated with CAR expression. All of the prostate cancer cell lines expressed integrin α_vβ₃ and α_vβ₅. AxdAdB-3 was more cytopathic in CAR-positive prostate cancer cells than in CAR-negative cells, whereas AxdAdB3-F/RGD caused potent oncolysis in both CAR-positive and CAR-negative prostate cancer cells. In contrast, AxdAdB3-F/RGD was not cytopathic against normal prostate epithelial cells, RWPE-1. Intratumoral injection of AxdAdB3-F/RGD into CAR-negative prostate cancer cell xenografts in nude mice inhibited tumor growth. The current study demonstrates that E1A/E1B double-restricted oncolytic adenovirus with an RGD-fiber modification enhances infection efficiency and anti-tumor activity in CAR-deficient prostate cancer cells, while sparing normal cells. Future studies will evaluate the therapeutic potential of AxdAdB3-F/RGD in prostate cancer.     

前列腺癌患者组织中RPL6的表达及临床意义

目的:探讨前列腺癌患者组织中核糖体蛋白L6(RPL6)表达,分析其对肿瘤恶性程度的评估作用。方法:收集2013年12月-2015年12月在本院接受治疗的前列腺疾病患者117例,根据病理结果分为前列腺炎组63例、前列腺癌组54例;另取同期进行健康体检的健康者80例作为正常对照组。采用Western-blot法检测三组研究对象的前列腺组织RPL6表达,采用酶联免疫吸附法(ELISA)测定血清肿瘤标志物含量,采用RT-PCR法检测前列腺组织增殖基因、侵袭基因mRNA表达,采用Pearson检验分析RPL6表达量与肿瘤恶性程度的相关关系。结果:前列腺癌组患者的前列腺组织RPL6表达量高于前列腺炎组及正常对照组(P0.05);前列腺癌组患者的血清前列腺特异性抗原(PSA)、前列腺特异性酸性磷酶(PSAP)、尿激酶型纤溶酶原激活剂(u PA)、硫氧还蛋白(TRX)含量高于前列腺炎组及正常对照组(P0.05);前列腺癌组患者的前列腺组织增殖基因URG11、PTEN mRNA表达量高于前列腺炎组及正常对照组,PRDM5 mRNA表达量低于前列腺炎组及正常对照组,侵袭基因IgGHG1、TMPRSS2-ER、PIK3C2B mRNA表达量高于前列腺炎组及正常对照组(P0.05)。前列腺癌患者的组织RPL6表达量与肿瘤标志物含量、增殖及侵袭基因活性均呈直接相关关系(P0.05)。结论:高表达的RPL6是前列腺癌早期诊断的可靠指标,且与肿瘤恶性程度直接相关,有望成为前列腺癌辅助诊断及预后评估的重要手段。     

Radiopotentiation of enzalutamide over human prostate cancer cells as assessed by real-time cell monitoring

AimTo evaluate the radiopotentiation of enzalutamide in human prostate cancer cells.BackgroundWhile radiotherapy is the first line of treatment for prostate cancer, androgen blockade therapies are demonstrating significant survival benefit as monotherapies. As androgen blockade can cause cell death by apoptosis, it is likely that androgen blockade will potentiate the cytotoxic activities of radiotherapy.Materials and methodsHere, we tested the potential synergistic effects of these two treatments over two human metastatic prostate cancer cells by real-time cell analysis (RTCA), androgen-sensitive LNCaP cells (Lymph Node Carcinoma of the Prostate) and androgen-independent PC-3. Both cell lines were highly resistant to high doses of radiotherapy.ResultsA pre-treatment of LNCaP cells with IC50 concentrations of enzalutamide significantly sensitized them to radiotherapy through enhanced apoptosis. In contrast, enzalutamide resistant PC-3 cells were not sensitized to radiotherapy by androgen blockade.ConclusionsThese results provide evidence that the enzalutamide/radiotherapy combination could maximize therapeutic responses in patients with enzalutamide-sensitive prostate cancer.     

Galiellalactone inhibits stem cell-like ALDH-positive prostate cancer cells

Galiellalactone is a potent and specific inhibitor of STAT3 signaling which has been shown to possess growth inhibitory effects on prostate cancer cells expressing active STAT3. In this study we aimed to investigate the effect of galiellalactone on prostate cancer stem cell-like cells. We explored the expression of aldehyde dehydrogenase (ALDH) as a marker for cancer stem cell-like cells in different human prostate cancer cell lines and the effects of galiellalactone on ALDH expressing (ALDH+) prostate cancer cells. ALDH+ subpopulations were detected and isolated from the human prostate cancer cell lines DU145 and long-term IL-6 stimulated LNCaP cells using ALDEFLUOR® assay and flow cytometry. In contrast to ALDH− cells, ALDH+ prostate cancer cells showed cancer stem cell-like characteristics such as increased self-renewing and colony forming capacity and tumorigenicity. In addition, ALDH+ cells showed an increased expression of putative prostate cancer stem cell markers (CD44 and integrin α2β1). Furthermore, ALDH+ cells expressed phosphorylated STAT3. Galiellalactone treatment decreased the proportion of ALDH+ prostate cancer cells and induced apoptosis of ALDH+ cells. The gene expression of ALDH1A1 was downregulated in vivo in galiellalactone treated DU145 xenografts. These findings emphasize that targeting the STAT3 pathway in prostate cancer cells, including prostate cancer stem cell-like cells, is a promising therapeutic approach and that galiellalactone is an interesting compound for the development of future prostate cancer drugs.     

Inflammatory Cytokines and Survival Factors from Serum Modulate Tweak-Induced Apoptosis in PC-3 Prostate Cancer Cells

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK, TNFSF12) is a member of the tumor necrosis factor superfamily. TWEAK activates the Fn14 receptor, and may regulate cell death, survival and proliferation in tumor cells. However, there is little information on the function and regulation of this system in prostate cancer. Fn14 expression and TWEAK actions were studied in two human prostate cancer cell lines, the androgen-independent PC-3 cell line and androgen-sensitive LNCaP cells. Additionally, the expression of Fn14 was analyzed in human biopsies of prostate cancer. Fn14 expression is increased in histological sections of human prostate adenocarcinoma. Both prostate cancer cell lines express constitutively Fn14, but, the androgen-independent cell line PC-3 showed higher levels of Fn14 that the LNCaP cells. Fn14 expression was up-regulated in PC-3 human prostate cancer cells in presence of inflammatory cytokines (TNFα/IFNγ) as well as in presence of bovine fetal serum. TWEAK induced apoptotic cell death in PC-3 cells, but not in LNCaP cells. Moreover, in PC-3 cells, co-stimulation with TNFα/IFNγ/TWEAK induced a higher rate of apoptosis. However, TWEAK or TWEAK/TNFα/IFNγ did not induce apoptosis in presence of bovine fetal serum. TWEAK induced cell death through activation of the Fn14 receptor. Apoptosis was associated with activation of caspase-3, release of mitochondrial cytochrome C and an increased Bax/BclxL ratio. TWEAK/Fn14 pathway activation promotes apoptosis in androgen-independent PC-3 cells under certain culture conditions. Further characterization of the therapeutic target potential of TWEAK/Fn14 for human prostate cancer is warranted.     

Modulation of CD4 cell cytokine production by colon cancer-associated mucin

Mucins have been implicated in tumor-associated immunosuppression. The possibility that colon cancer mucin (CCM) may modulate T-helper 1 (TH1) activity was evaluated by investigating its effect on the production of interleukin-2 (IL-2) by CD4⁺ cells, a process that requires antigen-specific and costimulatory signals. Methods: CCM was purified from human colorectal cancer cells by gel-exclusion fast-pressure liquid chromatography. Cytokine production of purified CD4⁺ cells was evaluated at the protein and gene level in the presence of a phorbol ester or an anti-CD3 monoclonal antibody (mAb) plus mAb against the CD28 costimulatory receptor to mimic two-signal activation. Results: Soluble CCM, which contains mucins MUC2 as well as MUC1, inhibited IL-2 mRNA expression and secretion of CD4⁺ stimulated with a phorbol ester or an anti-CD3 mAb plus anti-CD28 mAb. Pretreatment of CD4⁺ cells with anti-CD28 mAb abrogated the suppressive effects of CCM on IL-2 production, and flow cytometry showed decreased binding of anti-CD28 mAb to its receptor in the presence of mucin. In addition, Ca²⁺ mobilization after T cell receptor cross-linking with anti-CD3 mAb was maintained in the presence of CCM. Although interferon γ production was also diminished, CCM did not induce a general inhibition of cytokine production, nor did it decrease cell viability. Macrophage inflammatory protein 1α production was up-regulated; the production of IL-10 and transforming growth factor β was unchanged. Conclusions: The results indicate that CCM can alter TH1 activity and suggest that the modulation of costimulatory interactions is involved. They provide another mechanism of immunosuppression mediated by these highly expressed tumor products. Received: 23 March 1999 / Accepted: 3 August 1999     

Migration of iron-labeled KHYG-1 natural killer cells to subcutaneous tumors in nude mice, as detected by magnetic resonance imaging

Background aimsA novel cell line of cytotoxic natural killer (NK) cells, KHYG-1, was examined in vivo for immunotherapy against prostate cancer. The feasibility of using magnetic resonance imaging (MRI) tracking to monitor the fate of injected NK cells following intravenous (i.v.), intraperitoneal (i.p.) and subcutaneous (s.c.) administration was assessed.MethodsPC-3M human prostate cancer cells were injected s.c. into the flank of nude mice (day 0). KHYG-1 NK cells were labeled with an iron oxide contrast agent and injected s.c., i.v. or i.p. on day 8. Mice were imaged by MRI on days 7, 9 and 12. Tumor sections were examined with fluorescence microscopy and immunohistologic staining for NK cells.ResultsNK cells were detected in the tumors by histology after all three administration routes. NK cells and fluorescence from the iron label were co-localized. Signal loss was seen in the areas around the tumors and between the tumor lobes in the s.c. group.ConclusionsWe are the first to label this cell line of NK cells with an iron oxide contrast agent. Accumulation of NK cells was visualized by MRI after s.c. injection but not after i.v. and i.p. injection.     

TLR3 engagement induces IRF‐3‐dependent apoptosis in androgen‐sensitive prostate cancer cells and inhibits tumour growth in vivo

Toll‐like receptors (TLRs) are a family of highly conserved transmembrane proteins expressed in epithelial and immune cells that recognize pathogen associated molecular patterns. Besides their role in immune response against infections, numerous studies have shown an important role of different TLRs in cancer, indicating these receptors as potential targets for cancer therapy. We previously demonstrated that the activation of TLR3 by the synthetic double‐stranded RNA analogue poly I:C induces apoptosis of androgen‐sensitive prostate cancer (PCa) LNCaP cells and, much less efficiently, of the more aggressive PC3 cell line. Therefore, in this study we selected LNCaP cells to investigate the mechanism of TLR3‐mediated apoptosis and the in vivo efficacy of poly I:C‐based therapy. We show that interferon regulatory factor‐3 (IRF‐3) signalling plays an essential role in TLR3‐mediated apoptosis in LNCaP cells through the activation of the intrinsic and extrinsic apoptotic pathways. Interestingly, hardly any apoptosis was induced by poly I:C in normal prostate epithelial cells RWPE‐1. We also demonstrate for the first time the direct anticancer effect of poly I:C as a single therapeutic agent in a well‐established human androgen‐sensitive PCa xenograft model, by showing that tumour growth is highly impaired in poly I:C‐treated immunodeficient mice. Immunohistochemical analysis of PCa xenografts highlights the antitumour role of poly I:C in vivo both on cancer cells and, indirectly, on endothelial cells. Notably, we show the presence of TLR3 and IRF‐3 in both human normal and PCa clinical samples, potentially envisaging poly I:C‐based therapy for PCa.     

血管内皮细胞通过诱导ERG表达促进前列腺癌耐药

目的:探讨血管内皮细胞对前列腺癌细胞耐药能力的影响,并进一步研究血管内皮细胞作用于前列腺癌细胞的可能的分子机制。方法:1.利用Transwell小室构建共培养体系,通过CCK-8和Annexin V-FITC/PI检测细胞耐药的能力并通过蛋白印迹法(WB)检测凋亡相关分子的表达;2.利用聚合酶链式反应(PCR)及WB检测共培养后前列腺癌细胞中成红细胞病毒E26致癌物(ERG)的表达情况;利用酶联免疫吸附实验(ELISA)筛选出共培养组与非共培养组细胞上清之间有差异的细胞因子,并通过WB检测各个细胞因子与ERG的关系,确定影响ERG表达最明显的细胞因子。结果:1.前列腺癌细胞与血管内皮细胞共培养后,前列腺癌细胞对多西他赛的耐药性增加,细胞凋亡减少;2.共培养后前列腺癌细胞ERG的表达增高;血管内皮细胞分泌的成纤维细胞生长因子2(FGF2)在共培养后有明显增加,FGF2可以促进前列腺癌ERG的表达,并且这种病效应会被FGF2的抑制剂所逆转。结论:血管内皮细胞分泌的FGF2可促进前列腺癌细胞ERG的表达,促进前列腺癌细胞对多西他赛的耐药性。     

Analysis of the in vitro and in vivo effects of photodynamic therapy on prostate cancer by using new photosensitizers,protoporphyrin IX-polyamine derivatives

BackgroundPhotodynamic therapy, using porphyrins as photosensitizers (PS), has been approved in treatment of several solid tumors. However, commonly used PS induce death but also resistance pathways in cancer cells and an alteration of surrounding normal tissues. Because polyamines (PA) are actively accumulated in cancer cells by the Polyamine Transport System (PTS), they may enable PS to specifically target cancer cells. Here, we investigated whether new protoporphyrin IX-polyamine derivatives were effective PS against prostate cancer and whether PA increased PDT specificity after 630 nm irradiation.MethodsCHO and CHO-MG cells (differing in their PTS activity) were used to assess efficacy of polyamine vectorization. MTT assays were performed on human prostate non-malignant (RWPE-1) and malignant (PC-3, DU 145 and LNCaP) cell lines to test PS phototoxicity. ROS generation, DNA fragmentation and cell signalling were assessed by ELISA/EIA, western-blots and gel shift assays. Finally, PS effects were studied on tumor growth in nude mice.ResultsOur PS were more effective on cancer cells compared to non-malignant cells and more effective than PpIX alone. PpIX-PA generated ROS production involved in induction of apoptotic intrinsic pathways. Different pathways involved in apoptosis resistance were studied: PS inhibited Bcl-2, Akt, and NF-κB but activated p38/COX-2/PGE₂ pathways which were not implicated in apoptosis resistance in our model. In vivo experiments showed PpIX-PA efficacy was greater than results obtained with PpIX.ConclusionsAll together, our results showed that PpIX-PA exerted its maximum effects without activating resistance pathways and appears to be a good candidate for prostate cancer PDT treatment.