Efficacy and safety of abiraterone acetate plus prednisolone in patients with early metastatic castration-resistant prostate cancer who failed first-line androgen-deprivation therapy: a single-arm, phase 4 study.

AIM: The aim was to evaluate the efficacy and safety of abiraterone acetate plus prednisolone in patients with chemotherapy-naïve early metastatic castration-resistant prostate cancer who failed first-line androgen deprivation therapy. METHODS: Patients with early metastatic castration-resistant prostate cancer with confirmed prostate-specific antigen progression within 1-year or prostate-specific antigen progression without having normal prostate-specific antigen level (<4.0 ng/mL) during first-line androgen deprivation therapy were enrolled and administered abiraterone acetate (1000 mg) plus prednisolone (10 mg). A minimum of 48 patients were required according to Simon's minimax design. The primary endpoint was prostate-specific antigen response rate (≥50% prostate-specific antigen decline by 12 weeks), secondary endpoints included prostate-specific antigen progression-free survival and overall survival. Safety parameters were also assessed. RESULTS: For efficacy, 49/50 patients were evaluable. Median age was 73 (range: 55-86) years. The median duration of initial androgen deprivation therapy was 32.4 (range: 13.4-84.1) weeks and 48 patients experienced prostate-specific antigen progression within 1-year after initiation of androgen deprivation therapy. prostate-specific antigen response rate was 55.1% (95% confidence interval: 40.2%-69.3%), median prostate-specific antigen-progression-free survival was 24.1 weeks, and median overall survival was 102.9 weeks (95% confidence interval: 64.86 not estimable [NE]). Most common adverse event was nasopharyngitis (15/50 patients, 30.0%). The most common ≥grade 3 adverse event was alanine aminotransferase increased (6/50 patients, 12.0%). CONCLUSIONS: Abiraterone acetate plus prednisolone demonstrated a high prostate-specific antigen response rate of 55.1%, suggesting tumor growth still depends on androgen synthesis in patients with early metastatic castration-resistant prostate cancer. However, prostate-specific antigen-progression-free survival was shorter than that reported in previous studies. Considering the benefit-risk profile, abiraterone acetate plus prednisolone would be a beneficial treatment option for patients with chemotherapy-naive metastatic prostate cancer who show early castration resistance.

Percutaneous thermal ablation for renal cell carcinoma in patients with Birt-Hogg-Dubé syndrome.

PURPOSE: The purpose of this study was to analyze the outcome of patients with Birt-Hogg-Dubé (BHD) syndrome who underwent percutaneous thermal ablation of renal cell carcinoma (RCC). MATERIALS AND METHODS: Six patients with genetically proven BHD syndrome who underwent one or more sessions of percutaneous thermal ablation for the treatment of RCC were included. There were 4 men and 2 women, with a mean age of 57.3±7.5 [SD] years (range: 44-67years). A total of 29 RCCs (1-16 tumors per patient) were treated during 20 thermal ablation sessions (7 with radiofrequency ablation and 13 with cryoablation). Outcomes of thermal ablation therapy were assessed, including technical success, adverse events, local tumor progression, development of metastases, survival after thermal ablation, and changes in renal function. RESULTS: Technical success was achieved in all ablation sessions (success rate, 100%). No grade 4 or 5 adverse events were observed. All patients were alive with no distant metastasis during a median follow-up period of 54months (range: 6-173months). No local tumor progression was found. The mean decrease in estimated glomerular filtration rate during follow-up was 10.7mL/min/1.73m2. No patients required dialysis or renal transplantation. CONCLUSION: Radiofrequency ablation and cryoablation show promising results for the treatment of RCCs associated with BHD syndrome. Percutaneous thermal ablation may be a useful treatment option for this rare hereditary condition.

Mid-term results of alumina ceramic unlinked total elbow arthroplasty with cement fixation for patients with rheumatoid arthritis.

Aims: The aim of this study was to report the mid-term clinical outcome of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties when used in patients with rheumatoid arthritis (RA). Patients and Methods: We retrospectively reviewed 87 elbows, in 75 patients with RA, which was replaced using a cemented JACE total elbow arthroplasty (TEA) between August 2003 and December 2012, with a follow-up of 96%. There were 72 women and three men, with a mean age of 62 years (35 to 79). The mean follow-up was nine years (2 to 14). The clinical condition of each elbow before and after surgery was assessed using the Mayo Elbow Performance Index (MEPI, 0 to 100 points). Radiographic loosening was defined as a progressive radiolucent line of >1 mm that was completely circumferential around the prosthesis. Results: The mean MEPI scores significantly improved from 40 (10 to 75) points preoperatively to 95 (30 to 100) points at final follow-up (p < 0.0001). Complications were noted in ten elbows (ten patients; 11%). Two had an intraoperative humeral fracture which was treated by fixation and united. One had a postoperative fracture of the olecranon which united with conservative treatment and one had a radial neuropathy which resolved. Further surgery was required for one with a dislocation, three with an ulnar neuropathy and one with a postoperative humeral fracture. Revision with removal of the components was performed in one elbow due to deep infection. There was no radiographic evidence of loosening around the components. With any revision surgery or revision with implant removal as the endpoint, the rates of survival up to 14 years were 93% (95% confidence interval (CI), 83.9 to 96.6) and 99% (95% CI 91.9 to 99.8), respectively, as determined by Kaplan-Meier analysis. Conclusion: With the appropriate indications, the mid-term clinical performance of the cemented JACE TEA is reliable and comparable to other established TEAs in the management of the elbow in patients with RA. Cite this article: Bone Joint J 2018;100-B:1066-73.

Adenovirus vector carrying REIC/DKK-3 gene: neoadjuvant intraprostatic injection for high-risk localized prostate cancer undergoing radical prostatectomy.

As the First-In-Human study of in situ gene therapy using an adenovirus vector carrying the human REIC (reduced expression in immortalized cell)/Dkk-3 gene (Ad-REIC), we conducted neoadjuvant intraprostatic injections in patients with high-risk localized prostate cancer undergoing radical prostatectomy (RP). Patients with recurrence probability of 35% or more within 5 years following RP, as calculated by Kattan's nomogram, were enrolled. Patients received two ultrasound-guided intratumoral injections at 2-week intervals, followed by RP 6 weeks after the second injection. After confirming the safety of the therapeutic interventions with initially planned three escalating doses of 1.0 × 1010, 1.0 × 1011 and 1.0 × 1012 viral particles (vp) in 1.0-1.2 ml (n=3, 3 and 6), an additional higher dose of 3.0 × 1012 vp in 3.6 ml (n=6) was further studied. All four DLs including the additional dose level-4 (DL-4) were feasible with no adverse events, except for grade 1 or 2 transient fever. Laboratory toxicities were grade 1 or 2 elevated aspartate transaminase/alanine transaminase (n=4). Regarding antitumor activities, cytopathic effects (tumor degeneration with cytolysis and pyknosis) and remarkable tumor-infiltrating lymphocytes in the targeted tumor areas were detected in a clear dose-dependent manner. Consequently, biochemical recurrence-free survival in DL-4 was significantly more favorable than in patient groups DL-1+2+3.

Novel REIC/Dkk-3-encoding adenoviral vector as a promising therapeutic agent for pancreatic cancer.

Reduced expression in immortalized cells (REIC)/dickkopf-3 (Dkk-3), a tumor suppressor gene, is downregulated in various cancers. We previously reported the tumor-inhibitory effects of the REIC/Dkk-3 gene, delivered by a conventional adenoviral vector (Ad-CAG-REIC) in pancreatic cancer. Here, we developed an Ad-REIC vector with a novel gene expression system, termed the super gene expression (SGE) system, and assessed its therapeutic effects relative to those of Ad-CAG-REIC in pancreatic cancer cells. Human pancreatic cancer cell lines ASPC1 and MIAPaCa2 were used. REIC/Dkk-3 expression was assessed by western blot analysis. Relative cell viability and apoptotic effects were examined in vitro. The anti-tumor effects of Ad-REIC treatment were assessed in the mouse xenograft model. Compared with Ad-CAG-REIC, Ad-SGE-REIC elicited a significant increase in REIC protein expression in the cells studied. Relative to Ad-CAG-REIC, Ad-SGE-REIC reduced cell viability and induced apoptosis in the ASPC1 and MIAPaCa2 cell lines in vitro, and achieved superior tumor growth inhibition in the mouse xenograft model. Compared with conventional Ad-REIC agents, Ad-SGE-REIC provided enhanced inhibitory effects against tumor growth. Our results indicate that Ad-SGE-REIC is an innovative therapeutic tool for pancreatic cancer.

The induction of antigen-specific CTL by in situ Ad-REIC gene therapy.

An adenovirus vector carrying the human Reduced Expression in Immortalized Cell (REIC)/Dkk-3 gene (Ad-REIC) mediates simultaneous induction of cancer-selective apoptosis and augmentation of anticancer immunity. In our preclinical and clinical studies, in situ Ad-REIC gene therapy showed remarkable direct and indirect antitumor effects to realize therapeutic cancer vaccines. We herein aimed to confirm the induction of tumor-associated antigen-specific cytotoxic T lymphocytes (CTLs) by Ad-REIC. Using an ovalbumin (OVA), a tumor-associated antigen, expressing E.G7 tumor-bearing mouse model, we investigated the induction and expansion of OVA-specific CTLs responsible for indirect, systemic effects of Ad-REIC. The intratumoral administration of Ad-REIC mediated clear antitumor effects with the accumulation of OVA-specific CTLs in the tumor tissues and spleen. The CD86-positive dendritic cells (DCs) were upregulated in the tumor draining lymph nodes of Ad-REIC-treated mice. In a dual tumor-bearing mouse model in the left and right back, Ad-REIC injection in one side significantly suppressed the tumor growth on both sides and significant infiltration of OVA-specific CTLs into non-injected tumor was also detected. Consequently, in situ Ad-REIC gene therapy is expected to realize a new-generation cancer vaccine via anticancer immune activation with DC and tumor antigen-specific CTL expansion.

Integrin antagonist augments the therapeutic effect of adenovirus-mediated REIC/Dkk-3 gene therapy for malignant glioma.

Reduced expression in immortalized cells/Dickkopf-3 (REIC/Dkk-3) was identified as a gene whose expression is reduced in many human cancers. REIC/Dkk-3 expression is also downregulated in malignant glioma and regulates cell growth through caspase-dependent apoptosis. cRGD (EMD121974), an antagonist of integrins, has demonstrated preclinical efficacy against malignant glioma. In this study, we investigated the antiglioma effect of combination therapy using an adenovirus vector carrying REIC/Dkk-3 (Ad-REIC) and cRGD. Quantitative real-time reverse-transcription PCR revealed the reduction of REIC/Dkk-3 mRNA levels in malignant glioma cell lines. The reduction of REIC/Dkk-3 protein expression in malignant glioma cell lines was also confirmed with western blot analysis. After treatment with Ad-REIC and cRGD, the proliferative rate of malignant glioma cells was significantly reduced in a time-dependent manner. In vivo, there was a statistically significant increase in the survival of mice treated with Ad-REIC and cRGD combination therapy compared with Ad-REIC monotherapy. We identified an apoptotic effect following monotherapy with Ad-REIC. Moreover, cRGD augmented the antiglioma efficacy of Ad-REIC. These results may lead to a promising new approach for the treatment of malignant glioma.

Potent antitumor effects of combined therapy with a telomerase-specific, replication-competent adenovirus (OBP-301) and IL-2 in a mouse model of renal cell carcinoma.

OBP-301 (a telomerase-specific, replication-competent adenovirus with hTERT promoter) was constructed in a previous study and it showed a strong anticancer effect by inducing cell lysis in human lung and prostate cancer cells. This study investigated the effectiveness of a combination therapy of OBP-301 and interleukin-2 (IL-2) in a mouse model of renal cell carcinoma (RCC). The cell-killing effect of OBP-301 was confirmed in vitro in the RENCA cancer cells. In in vivo experiment, luciferase-expressing RENCA cells were implanted in the left kidney and lung of BALB/c mice to prepare the RCC metastatic model. The animals were randomly divided into four treatment groups: PBS, IL-2 alone, OBP-301 alone and the combination. The analyses of orthotopic tumor weight, lung metastasis and luciferin-stained tumor images 14 days after each treatment showed significant tumor growth inhibition in the combination group in comparison with that in the OBP-301- or IL-2-treated groups. In addition, the percentage of regulatory T-cells (Tregs) in the combination group was significantly suppressed in comparison with that in the PBS and single-agent treatment groups. The outcomes of this study suggest that tumor-specific oncolytic immunovirotherapy may become an attractive strategy for the treatment of human RCC.

Overexpressing PKIB in prostate cancer promotes its aggressiveness by linking between PKA and Akt pathways.

Prostate cancer (PC) is the most common malignancy in males. Despite high response rates and clinical benefits, androgen-ablation therapy is ineffective for advanced or relapsed PC because of the emergence of aggressive castration-resistant prostate cancer (CRPC). Through our genome-wide gene expression analysis of PC cells purified from clinical CRPC tissues, we here identified a novel molecular target, PKIB (cAMP-dependent protein kinase inhibitor-beta), which was overexpressed specifically in CRPCs and aggressive PCs. Immunohistochemical analysis confirmed its overexpression in CRPCs and its strong correlation with high Gleason scores of PCs. Knockdown of PKIB by siRNA resulted in drastic growth suppression of PC cells, and, concordantly, exogenous introduction of PKIB into PC cells enhanced their growth and mobility. We found the direct interaction between PKIB and cAMP-dependent protein kinase A catalytic subunit (PKA-C), and showed that knockdown of PKIB in PC cells diminished the nuclear translocation of PKA-C. Knockdown of PKIB also decreased the phosphorylation level of Akt at Ser473 in PC cells, and exogenous PKIB introduction enhanced Akt phosphorylation in PC cells by incorporating with endogenous PKA-C kinase. In vitro kinase assay validated the recombinant PKIB enhanced phosphorylation of Akt at Ser473 by PKA-C kinase. These findings show that PKIB and PKA-C kinase can have critical functions of aggressive phenotype of PCs through Akt phosphorylation and that they should be a promising molecular target for PC treatment.

REIC/Dkk-3 overexpression downregulates P-glycoprotein in multidrug-resistant MCF7/ADR cells and induces apoptosis in breast cancer.

The overexpression of reduced expression in immortalized cells (REIC)/Dickkopf-3 (Dkk-3), a tumor suppressor gene, induced apoptosis in human prostatic and testicular cancer cells. The aim of this study is to examine the potential of REIC/Dkk-3 as a therapeutic target against breast cancer. First, the in vitro apoptotic effect of Ad-REIC treatment was investigated in breast cancer cell lines and the adenovirus-mediated overexpression of REIC/Dkk-3 was thus found to lead to apoptotic cell death in a c-Jun-NH(2)-kinase (JNK) phosphorylaion-dependent manner. Moreover, an in vivo apoptotic effect and MCF/Wt tumor growth inhibition were observed in the mouse model after intratumoral Ad-REIC injection. As multidrug resistance (MDR) is a major problem in the chemotherapy of progressive breast cancer, the in vitro effects of Ad-REIC treatment were investigated in terms of the sensitivity of multidrug-resistant MCF7/ADR cells to doxorubicin and of the P-glycoprotein expression. Ad-REIC treatment in MCF7/ADR cells also downregulated P-glycoprotein expresssion through JNK activation, and sensitized its drug resistance against doxorubicin. Therefore, not only apoptosis induction but also the reversal of anticancer drug resistance was achieved using Ad-REIC. We suggest that REIC/Dkk-3 is a novel target for breast cancer treatment and that Ad-REIC might be an attractive agent against drug-resistant cancer in combination with conventional antineoplastic agents.

Hepatocyte growth factor activator inhibitor-2 (HAI-2) is a favorable prognosis marker and inhibits cell growth through the apoptotic pathway in cervical cancer.

BACKGROUND: In light of the poor prognosis for cervical cancer, research continues into the development of innovative and efficacious treatment modalities for this disease. We investigated the role of hepatocyte growth factor activator inhibitor-2 (HAI-2) and evaluated its clinical importance in cervical cancer. PATIENTS AND METHODS: HAI-2 expression was examined in cervical cancer specimens (n=52) by immunohistochemistry. We further attempted to investigate the biological functions and inhibitory effects of HAI-2 using human papillomavirus (HPV) 16 type SiHa and HPV 18 type HeLa cervical cancer cell lines. RESULTS: There were significant correlations between HAI-2 expression and stage (P=0.017), lymph node metastasis (P=0.005) and ovarian metastasis (P=0.038). Low HAI-2 expression was a significant predictor for a poor prognosis compared with high HAI-2 expression (disease-free survival rate, P=0.016; overall survival rate, P=0.021). After transient transfection into the SiHa and HeLa cell lines, HAI-2 showed potential inhibitory effects mediated by reductions in hepsin and matriptase expression, which led to apoptosis by increasing the level of Bak and reducing the level of Bcl-2. CONCLUSIONS: The present findings indicate that low HAI-2 expression in cervical cancer may be associated with a poor prognosis. We propose that HAI-2 may represent a therapeutic target for the treatment of cervical cancer.

Direct and distant antitumor effects of a telomerase-selective oncolytic adenoviral agent, OBP-301, in a mouse prostate cancer model.

We previously constructed OBP-301 (Telomelysin, a telomerase-specific replication-competent adenovirus with human telomerase reverse transcriptase (hTERT) promoter), which showed a strong anticancer effect by inducing cell lysis of human non-small cell lung cancer and colorectal cancer cells. To investigate the utility of OBP-301 for prostate cancer treatment, we herein evaluate the cell killing and antitumor effects. First, in vitro hTERT-specific adenovirus transduction in human prostate cancer cells (LNCaP, PC3, DU145) was confirmed using OBP-401 (Telomelysin-green fluorescent protein (GFP)). There was no detectable GFP transduction in the human prostate normal cells (PrEC, PrSC). Consistently, the cell-killing effect of OBP-301 was observed only in the cancer cells. Second, using an in vivo subcutaneous LNCaP tumor model in nude mice, we demonstrated that three intratumoral OBP-301 injections (10(7) PFU per tumor x 3 days) were sufficient to eradicate the detectable LNCaP prostate tumor. We also demonstrated that the ispilateral treatment with OBP-301 significantly suppressed contralateral LNCaP tumor growth in both sides of the tumor model. Histological and immunohistochemical analyses revealed diffuse oncolytic degeneration and adenoviral E1A protein expression in both sides of the tumors. Therefore, in situ OBP-301 administration could be a promising therapeutic strategy against prostate cancer and its metastatic lesions.

Inhibition of histone deacetylase down-regulates the expression of hypoxia-induced vascular endothelial growth factor by rheumatoid synovial fibroblasts.

OBJECTIVE: To investigate the effect of FK228 on the in vitro expression of hypoxia-inducible factor-1 alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) by rheumatoid arthritis synovial fibroblasts (RASFs), and on the in vivo expression of VEGF and angiogenesis in the synovial tissue of mice with collagen-antibody-induced arthritis (CAIA). METHODS: RASFs were stimulated with IL-1beta and TNFalpha and then incubated under hypoxia (1 % O(2)) with various concentrations of FK228. The effects of FK228 on the expression of HIF-1alpha and VEGF mRNA were examined by quantitative real-time PCR. Changes in HIF-1alpha protein expression and the secretion of VEGF protein into the culture medium were examined by Western blot analysis and ELISA, respectively. Immunohistochemical analysis was carried out to investigate the expression and distribution of VEGF in synovial tissues of CAIA mice. RESULTS: The cytokine-stimulated expression of HIF-1alpha and VEGF mRNA was inhibited by FK228 in a dose-dependent manner. FK228 also reduced the expression of HIF-1alpha and VEGF protein. Intravenous administration of FK228 (2.5 mg/kg) suppressed VEGF expression, and also blocked angiogenesis in the synovial tissue of CAIA. CONCLUSION: FK228 may exhibit a therapeutic effect on RA by inhibition of angiogenesis through down-regulation of angiogenesis related factors, HIF-1alpha and VEGF.

Intra-articular injection of interleukin-4 decreases nitric oxide production by chondrocytes and ameliorates subsequent destruction of cartilage in instability-induced osteoarthritis in rat knee joints.

OBJECTIVE: To investigate the in vitro and in vivo effects of interleukin (IL)-4 on mechanical stress-induced nitric oxide (NO) expression by chondrocytes, and destruction of cartilage and NO production in an instability-induced osteoarthritis (OA) model in rat knee joints, respectively. MATERIALS AND METHODS: Cyclic tensile stress (CTS; 0.5Hz and 7% elongation) was applied to cultured normal rat chondrocytes with or without pre-incubation with recombinant rat IL-4 (rrIL-4). Inducible NO synthase (iNOS) mRNA expression and NO production were examined with real-time polymerase chain reaction and the Griess reaction, respectively. OA was induced in rat knee joints by transection of the anterior cruciate and medial collateral ligaments and resection of the medial meniscus. rrIL-4 (10, 50, and 100 ng/joint/day) was injected intra-articularly, and knee joint samples were collected 2, 4, and 6 weeks after surgery. Cartilage destruction was evaluated by the modified Mankin score and Osteoarthritis Research Society International scoring system on paraffin-embedded sections stained with safranin O. Cleavage of aggrecan and NO production were examined by immunohistochemistry for aggrecan neoepitope (NITEGE) and of nitrotyrosine (NT), respectively. RESULTS: rrIL-4 down-regulated CTS-induced iNOS mRNA expression and NO production by chondrocytes. The intra-articular injection of rrIL-4 gave rise to a limited, but significant amelioration of cartilage destruction, prevention of loss of aggrecan, and decrease in the number of NT-positive chondrocytes, an effect that was not dose-dependent. CONCLUSION: The present study suggests that IL-4 may exert chondroprotective properties against mechanical stress-induced cartilage destruction, at least in part, by inhibiting NO production by chondrocytes.

Trichostatin A, a histone deacetylase inhibitor, suppresses synovial inflammation and subsequent cartilage destruction in a collagen antibody-induced arthritis mouse model.

OBJECTIVE: To investigate the effect of the histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), on joint inflammation and cartilage degeneration in a collagen antibody-induced arthritis (CAIA) mouse model. METHODS: CAIA mice were given daily subcutaneous injections of various concentrations of TSA (0, 0.5, 1.0, and 2.0 mg/kg) and various parameters were monitored for 14 days. On Day 15, the hind paws were examined histologically. To investigate the effects of TSA on the expressions of matrix metalloproteinase (MMP)-3, MMP-13, tissue inhibitor of MMP-1 (TIMP-1), and acetyl-H4 by chondrocytes, another group of mice was sacrificed on Day 6. In vitro direct effect of TSA was examined by real-time PCR for mRNA of type II collagen, aggrecan, MMP-3, and MMP-13 in murine chondrogenic ATDC5 cells after pro-inflammatory cytokine stimulation. RESULTS: In the TSA-treated group, clinical arthritis was significantly ameliorated in a dose-dependent manner. The severity of synovial inflammation and the cartilage destruction score were significantly lower in the TSA 2.0 mg/kg group compared to the other TSA-treated groups. On immunohistochemistry, the number of MMP-3 and MMP-13-positive chondrocytes was significantly lower in the TSA 2.0 mg/kg group than in the control group. In contrast, the number of TIMP-1-positive cells and acetyl-histone H4-positive cells was significantly higher in the TSA 2.0mg/kg group than in the control group. TSA suppressed interleukin 1-beta and tumor necrosis factor-alpha-stimulated up-regulation of MMP-3, but not MMP-13 mRNA expression by ATDC5. CONCLUSION: The systemic administration of TSA ameliorated synovial inflammation in CAIA mice. Subsequently cartilage destruction was also suppressed by TSA, at least in part, by modulating chondrocyte gene expression.

New highly potent and specific E6 and E7 siRNAs for treatment of HPV16 positive cervical cancer.

Persistent infection by high-risk types of human papillomaviruses (HPV) is a necessary cause of cervical cancer, with HPV16 the most prevalent, accounting for more than 50% of reported cases. The virus encodes the E6 and E7 oncoproteins, whose expression is essential for maintenance of the malignant phenotype. To select efficacious siRNAs applicable to RNAi therapy for patients with HPV16+ cervical cancer, E6 and E7 siRNAs were designed using siDirect computer software, after which 10 compatible with all HPV16 variants were selected, and then extensively examined for RNAi activity and specificity using HPV16+ and HPV16-cells. Three siRNAs with the highest RNAi activities toward E6 and E7 expression, as well as specific and potent growth suppression of HPV16+ cancer cells as low as 1 nM were chosen. Growth suppression was accompanied by accumulation of p53 and p21(WAF1/CIP1), as well as morphological and cytochemical changes characteristic of cellular senescence. Antitumor activity of one of the selected siRNAs was confirmed by retarded tumor growth of HPV16+ cells in NOD/SCID mice when locally injected in a complex with atelocollagen. Our results demonstrate that these E6 and E7 siRNAs are promising therapeutic agents for treatment of virus-related cancer.

Adenovirus-mediated REIC/Dkk-3 gene transfer inhibits tumor growth and metastasis in an orthotopic prostate cancer model.

We had previously reported that REIC/Dkk-3, a member of the Dickkopf (Dkk) gene family, works as a tumor suppressor. In this study, we evaluated the therapeutic effects of an intratumoral injection with adenoviral vector encoding REIC/Dkk-3 gene (Ad-REIC) using an orthotopic mouse prostate cancer model of RM-9 cells. We also investigated the in vivo anti-metastatic effect and in vitro anti-invasion effect of Ad-REIC gene delivery. We demonstrated that the Ad-REIC treatment inhibited prostate cancer growth and lymph node metastasis, and prolonged mice survival in the model. These therapeutic responses were consistent with the intratumoral apoptosis induction and in vitro suppression of cell invasion/migration with reduced matrix metalloprotease-2 activity. We thus concluded that in situ Ad-REIC/Dkk-3 gene transfer may be a promising therapeutic intervention modality for the treatment of prostate cancer.

Induction of cell death in human papillomavirus 18-positive cervical cancer cells by E6 siRNA.

Human cervical cancer is caused by high-risk types of human papillomavirus (HPV) such as HPV16 and HPV18, which possess the E6 and E7 oncogenes, whose concurrent expression is a prerequisite for cancer development and maintaining malignant phenotypes. Silencing these oncogenes is considered to be applicable in molecular therapies of human cervical cancer. However, it remains to be determined whether E6, E7, or both should be silenced to obtain most efficient antitumor activity by an HPV small-interfering RNA (siRNA). Herein, we report two types of siRNAs targeting HPV18 E6, that exerted a negative growth effect on HPV18-positive cervical cancer cells (HeLa and SW756), in part, inducing cell death. One siRNA (Ex-18E6), designed to target both E6-E7 mRNA and its splicing variant, E6*I-E7 mRNA, efficiently knocked down both E6 and E7 expression. The other (Sp-18E6), designed to specifically target E6-E7 mRNA but not E6*I-E7 mRNA, suppressed E6 to a similar level as Ex-18E6; however, it less efficiently inhibited E7 as compared to Ex-18E6. Although both siRNAs induced cell death, Sp-18E6 siRNA induced more prominent cell death than Ex-18E6. Our results suggest that E6-specific suppression may induce more potent anticancer activity than simultaneous E6 and E7 suppression, and that E6-specific targeting is a promising strategy for siRNA-based therapy for HPV-positive cervical cancer.

Adeno-associated virus-mediated human IL-10 gene transfer suppresses the development of experimental autoimmune orchitis.

Testicular germ cell-induced autoimmune orchitis is characterized by inflammatory cell infiltration followed by disturbance of spermatogenesis. Experimental autoimmune orchitis (EAO) is an animal model for human immunological male infertility; delayed-type hypersensitivity (DTH) response plays a key role in its induction. Interleukin-10 (IL-10) is a regulatory cytokine that is critical in preventing organ-specific autoimmune inflammation. To determine the effects on EAO of human IL-10 (hIL-10) gene transfer, C3H/He mice immunized by unilateral testicular injury were administered intramuscular (i.m.) injections of adeno-associated viral (AAV) vector-encoding hIL-10 on the day of immunization. Serum hIL-10 was detected beginning at 1 week postinjection, and peaked at 3 weeks. Histological examinations showed a significantly low incidence of orchitis and disturbance of spermatogenesis in AAV hIL-10-treated mice, and the DTH response to autologous testicular cells was significantly suppressed. Immunohistochemical analysis of IFN- and IL-2, T-cell-associated cytokines, in the spleen and testes revealed significantly fewer cytokine-expressing cells after treatment. We conclude that a single i.m. administration of AAV hIL-10 significantly suppresses EAO and hypospermatogenesis by regulating cell-mediated immunity in the testes.

Validation of transrectal ultrasonographic volumetry for orthotopic prostate tumours in mice.

Orthotopic human prostate tumour models in athymic nude mice are regarded as being most suitable for fundamental and pre-clinical research on prostate cancer. The anatomic localization of the tumour in the pelvis, however, provides little possibility for monitoring tumour growth or regression. To assess time-related changes in orthotopic tumour volume, we applied transrectal ultrasonography (TRUS) to the murine prostate. This technique has the advantages of allowing accurate monitoring of tumours during therapeutic manipulations and a reduction of animal use due to a reduction of sacrificing endpoints. To validate the TRUS method, the mouse prostate reconstitution model, RM-9, and the prostate-specific antigen (PSA) producing human prostate cancer xenograft PC-346 were used. Volumetric calliper measurements were performed with a 30 MHz ultrasound probe designed for intra-arterial use in humans. Tumour weight, determined at various time-points, was found to be closely related to actual tumour weight (R = 0.99) and, in the PC-346 model, to the level of PSA in the plasma. Furthermore, the interobserver variation for TRUS was low for tumours above 50 mg. Thus, TRUS for murine prostate tumours proves to be an accurate, reproducible and sensitive method.