P-610 Endoplasmic reticulum stress-induced Notch signaling stimulates cumulus-oocyte complex expansion in PCOS

Study question

Does endoplasmic reticulum (ER) stress and Notch signaling affect cumulus-oocyte complex (COC) expansion in pathophysiology of polycystic ovary syndrome (PCOS)?

Summary answer

Notch signaling is induced via activation of ER stress in granulosa cells (GCs) of PCOS and stimulates COC expansion that is abrogated by Notch inhibition.

What is known already

PCOS presents a variety of symptoms including ovarian dysfunction which is caused by various local factors in follicular microenvironment; among them, ER stress and following activation of unfolded protein response are critical, causing ovarian fibrosis, growth arrest of antral follicles and other ovarian dysfunctions. While Notch signaling pathway plays an important role of various ovarian functions such as ovarian development, follicle growth, luteinization and steroid hormone synthesis, the potential interaction between Notch signaling and ER stress in ovarian function is not determined.

Study design, size, duration

To examine expression levels of Notch signaling, ovaries and granulosa-lutein cells (GLCs) were collected from PCOS patients undergoing surgery or IVF. Human GLCs were collected from follicular fluid of IVF patients and cultured under ER-stressed condition. COCs obtained from PMSG-primed mice were subjected to examine the in vitro effects of ER stress activation and Notch inhibition on COC expansion. To examine the in vivo effects of Notch inhibition, dehydroepiandrosterone-induced PCOS mouse model was used.

Participants/materials, setting, methods

The expression levels of Notch signaling in ovaries and GLCs were investigated by immunohistochemistry and real time qPCR. To examine whether Notch signaling is activated by ER stress, human GLCs were incubated with ER stress inducer or inhibitor and ATF4 was knocked down by RNA interference. To investigate COC expansion level, murine COCs were cultured under ER stress condition with/without Notch signaling inhibitor. The COCs were collected from PCOS mice treated with/without Notch inhibitor.

Main results and the role of chance

We found that the expression levels of Notch2 and Hey2, a transcription factor activated by Notch signaling, were upregulated in GCs of antral follicles from PCOS patients and PCOS mice by using immunohistochemical analysis. Similarly, mRNA levels of these genes were higher in GLCs from PCOS patients than those from control patients. Notch signaling was induced in cultured human GLCs incubated with an ER stress inducer, tunicamycin; the effect was abrogated by incubation with an ER stress inhibitor, tauroursodeoxycholic acid (TUDCA), or knockdown of activating transcription factor 4 (ATF4, a transcription factor induced by ER stress). These findings suggest that Notch signaling is induced by ER stress via ATF4 pathway in human GCs. Measuring under a microscope, the area of expanded COCs was increased in cultured murine COCs incubated with tunicamycin, while this stimulatory effect of tunicamycin was abrogated by adding a Notch signaling inhibitor, DAPT. The area of expanded COCs obtained from PCOS model mice was increased compared to control mice, while administration of DAPT to these mice reduced the area. These results suggest that ER stress-induced Notch signaling stimulate COC expansion contributing PCOS pathophysiology.

Limitations, reasons for caution

COC expansion area was measured only in PCOS model mouse; it is unknown whether COC expansion is induced in PCOS patients. This point requires further investigation in PCOS patients.

Wider implications of the findings

Our findings suggest that ER stress-induced Notch signaling affects COC expansion, associated with ovulatory dysfunction in PCOS. The detailed understandings of PCOS pathophysiology may be beneficial for substantial clinical implications and inhibition of ER stress or Notch signaling may serve as a novel therapeutic approach for PCOS.

Trial registration number

This study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) (19k09749, 19k24045, 19k24021, 21k16808, 21j12871,), a grant from the Takeda Science Foundation, a grant from The Tokyo Society of Medical Science, a grant from The Japan Society of Fertility Preservation, and a grant from The Japan Society for Menopause and Women’s Health (JMWH) (a JMWH Bayer Grant).

P–632 Examination of temporal changes in phenotype and gut microbiome during the process of growth in polycystic ovary syndrome (PCOS) model induced by prenatal androgen exposure

Study question

From when do abnormality in gut microbiome and phenotypes of PCOS appear during the process of growth?

Summary answer

Reproductive phenotypes of PCOS appear from 6 weeks and metabolic phenotypes from 12 weeks onward. Alteration in gut microbiome appears as early as 4 weeks.

What is known already

The etiology of PCOS remains largely unknown, however PCOS is considered as a complex multigenic disorder with strong epigenetic and environmental influence. Previous studies have suggested that fetal over-exposure to androgens could be the main factor of the development of PCOS after birth. On the other hands, recent studies on both human and PCOS rodent models have demonstrated the association between PCOS and alteration of gut microbiome in adulthood. Furthermore, it was recently reported that gut microbiome in obese adolescent with PCOS is different from obese adolescent without PCOS.

Study design, size, duration

A rodent PCOS model induced by prenatal dehydroepiandrosterone (DHT) exposure was applied to this study. Phenotypes and gut microbiome were compared between PCOS model mice (n = 12/group) and control mice (n = 10/group) at each stage of growth; 4 weeks (prepuberty), 6 weeks (puberty), 8 weeks (adolescent), 12 weeks (young adult), and 16 weeks (adult). The determinants for PCOS phenotypes are onset of puberty, estrous cycle, morphology of ovaries, serum testosterone level, body weight, and insulin resistance.

Participants/materials, setting, methods

Pregnant dams were subcutaneously injected on days of 16, 17, and 18 of gestation with either sesame oil for control groups or sesame oil containing 250µg of DHT for prenatal DHT groups. The evaluation of PCOS phenotypes and gut microbiome in female offspring were performed at each stage of growth. For examination of gut microbiota, next generation sequencing and bioinformatics analysis of 16S rRNA genes were performed on DNA extracted from mouse fecal samples.

Main results and the role of chance

Prenatal DHT mice exhibited delayed puberty onset, disrupted estrous cycle, and significantly increased testosterone levels from 6 weeks onward. Significantly increased atretic antral follicles were observed in prenatal DHT mice at 6, 12, and 16 weeks. Prenatal DHT mice showed significantly decreased body weight at 4, 6, 8 weeks and increased body weight from 12 weeks onward. As for gut microbiome, alpha-diversity was significantly different between control and prenatal DHT mice from 8 weeks onward and beta-diversity was significantly different at 6 and 8 weeks. Altered composition of gut microbiota was observed as early as 4 weeks. At phylum level, Firmicutes are significantly increased in prenatal DHT mice at 4 and 8 weeks and decreased at 16 weeks. Actinobacteria phylum showed significant decrease at 6 and 8 weeks in prenatal DHT mice. At genus level, relative abundance of several bacterial taxa significantly differed between control and prenatal DHT mice; some taxa, such as Allobaculum, Adlercreutzia, Bilophila, Clostridium, Gemella, Gemmiger, Roseburia, Ruminococcus, Staphylococcus, and Sutterella, exhibited constant increase or decrease in prenatal DHT mice during the process of growth. Interestingly, Roseburia was never detected in prenatal DHT mice, while approximately half of control mice harbored Roseburia at 12 and 16 weeks.

Limitations, reasons for caution

It is not clearly determined whether alteration in gut microbiome is cause or result of PCOS development, although the changes in gut microbiome seemed to precede the appearance of typical PCOS phenotypes in the present study. Mouse model does not completely recapitulate human PCOS.

Wider implications of the findings: Our findings suggest that prenatal androgen exposure causes alteration of gut microbiome from pre-puberty onward, even before PCOS phenotypes become apparent. Intervention for girls at risk of PCOS with pre/pro-biotics may prevent them from developing PCOS in future.

Trial registration number

Not applicable

POS0286 INCIDENCE OF MALIGNANCIES IN JAPANESE PATIENTS WITH RHEUMATOID ARTHRITIS: DATA FROM A LARGE JAPANESE NATIONAL REGISTRY

Background:

Patients (pts) with rheumatoid arthritis (RA) have an increased risk of some malignancies vs the general population, and this can vary by region/race.1,2 Data on the epidemiology and impact of biological (b)DMARDs and targeted synthetic (ts)DMARDs, such as Janus kinase (JAK) inhibitors, on the incidence of malignancies in Japanese pts with RA are limited. The National Database of Rheumatic Diseases in Japan (NinJa) is one of the largest RA registries in Japan.

Objectives:

To evaluate the incidence of malignancies in Japanese pts with RA using NinJa registry data.

Methods:

This retrospective observational study analysed NinJa registry data for Japanese pts with RA aged ≥18 years with ≥1 data entry between 2013 (first JAK inhibitor approval for RA in Japan) and 2018. The overall cohort included all pts with RA, and two sub-cohorts were analysed: pts exposed and unexposed to bDMARDs (exposure defined as ≥1 bDMARD reported in database). Crude incidence rates (IRs) for malignancies (including non-melanoma skin cancer) were calculated as the number of events per 100 pt-years of follow-up (time between start of follow-up or the date of first bDMARD exposure [for bDMARD-exposed pts] and end of observation period, or withdrawal from database). The most recent data for incidence of malignancy in the Japanese general population (2013–2017 data from the National Cancer Center, Japan) were used to calculate standardised incidence ratios (SIRs) and age- and sex-adjusted standardised rates (ASRs) for malignancies. Cross-sectional (per calendar year) and cumulative analyses were performed for the overall cohort. Cumulative rates were calculated for sub-cohorts, and all cumulative analyses were repeated excluding pts exposed to JAK inhibitors (ie ≥1 JAK inhibitor reported in database).

Results:

Data were collected for 26 607 Japanese pts with RA from 2013–2018. In the cross-sectional analysis (Table 1), the SIR and ASR for malignancies in all pts with RA were generally consistent from 2013–2018. In the cumulative analysis, the SIR (95% CI) for malignancies from 2013–2018 was 0.97 (0.91, 1.03) in all pts with RA, and 0.93 (0.82, 1.04) and 0.99 (0.92, 1.07) in pts exposed and unexposed to bDMARDs, respectively (Figure 1). Adjusting for age/sex, the cumulative ASR (95% CI) for malignancies from 2013–2018 was 0.83 (0.76, 0.90) in all pts with RA, and 0.82 (0.69, 0.95) and 0.86 (0.77, 0.96) in pts exposed and unexposed to bDMARDs, respectively (Figure 1). In all cohorts, the cumulative SIR and ASR were similar when pts exposed to JAK inhibitors were excluded (Figure 1).

Table 1.

Cross-sectional analysis of the incidence of malignancies in Japanese pts with RA from 2013–2018

All RA2013 (N=13 423)2014 (N=15 584)2015 (N=15 751)2016 (N=16 107)2017 (N=15 994)2018(N=15 003)Total follow-up, PY13 35314 86614 82914 97014 74814 898Pts with events, n140164174168161211Crude IRa(95% CI)1.05(0.89, 1.24)1.10(0.95, 1.29)1.17(1.01, 1.36)1.12(0.97, 1.31)1.09(0.94, 1.27)1.42(1.24, 1.62)ASRa,b(95% CI)0.76(0.60, 0.93)0.76(0.62, 0.90)0.90(0.68, 1.11)0.88(0.68, 1.07)0.80(0.62, 0.98)0.88(0.74, 1.01)SIRb(95% CI)0.97(0.82, 1.14)1.01(0.86, 1.17)1.02(0.87, 1.18)0.88(0.75, 1.02)0.86(0.73, 1.00)1.10(0.95, 1.25)

aIR/ASR were calculated as number of events per 100 PY of follow-up

bData from a Japanese general population database of malignancy incidence from 2013–2017, provided by the Center for Cancer Control and Information Services, National Cancer Center, Japan

PY, pt-years

Conclusion:

The incidence of malignancies in Japanese pts with RA, registered in the NinJa database from 2013–2018, was similar to that in the Japanese general population. The SIR and ASR for malignancies were comparable in pts exposed and unexposed to bDMARDs. In all cohorts, rates did not increase when pts exposed to JAK inhibitors were included.

References:

[1] Dougados et al. Ann Rheum Dis 2014; 73: 62-68.

[2] Parikh-Patel et al. Cancer Causes Control 2009; 20: 1001-1010.

Acknowledgements:

Study sponsored by Pfizer Inc. Medical writing support was provided by Christina Viegelmann, CMC Connect, and funded by Pfizer Inc.

Disclosure of Interests:

Toshihiro Matsui Speakers bureau: Astellas, Ayumi, Chugai, Daiichi-Sankyo, Eli Lilly, Ono, Pfizer Inc, Takeda, Tanabe-Mitsubishi, Consultant of: Pfizer Inc, Grant/research support from: Chugai, Naonobu Sugiyama Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Shigeyuki Toyoizumi Employee of: Pfizer R&D Japan, Fujio Matsuyama Consultant of: Pfizer Inc, Employee of: CRECON Medical Assessment Inc, Tatsunori Murata Consultant of: Pfizer Inc, Employee of: CRECON Medical Assessment Inc, Yukitomo Urata Speakers bureau: Asahi Kasei, Chugai, Eli Lilly, Pfizer Inc, Consultant of: AbbVie, Asahi Kasei, Chugai, Pfizer Inc, Kimito Kawahata Speakers bureau: Pfizer Inc, Consultant of: Pfizer Inc, Grant/research support from: Pfizer Inc, Shigeto Tohma Speakers bureau: Astellas, Ayumi, Chugai, Ono, Pfizer Inc, Takeda, Consultant of: Pfizer Inc

Extracellular Vesicles of Stem Cells to Prevent BRONJ

Extracellular vesicles (EVs), several tens to hundreds of nanometers in size, are vesicles secreted by cells for intercellular communication. EVs released from mesenchymal stem cells (MSC-EVs) have the potential to treat multiple diseases. This study aimed to determine the effects of MSC-EVs on bisphosphonate-related osteonecrosis of the jaw (BRONJ), whose pathogenesis and treatment are not yet established. To this end, zoledronic acid (ZOL) was administered to bone marrow cells and fibroblasts in vitro. In vivo, a BRONJ model was produced by administering ZOL to rats and extracting teeth. Each MSC-EV-treated and nontreated group was compared histologically and molecularly. In vitro, the nontreated group showed an increased number of β-galactosidase-positive cells and expression of senescence-associated genes p21, pRB and senescence-related inflammatory cytokines. Conversely, MSC-EV administration decreased the number of senescent cells and expression levels of p21, pRB and inflammatory cytokines. In vivo, in the nontreated group, the socket was partially uncovered by the oral epithelium, leaving an exposed bone. Conversely, in the MSC-EV-treated group, the socket was healed. Besides, in the nontreated group, β-galactosidase-positive cells existed in the socket and colocalized with the CD90 and periostin-positive cells. However, there were few β-galactosidase-positive cells in the MSC-EV-treated group. Furthermore, gene expression of stem cell markers Bmi1 and Hmga2 and the vascular endothelial marker VEGF was significantly increased in the MSC-EV-treated group, compared with that in the nontreated group. These results indicate that MSC-EVs prevent ZOL-induced senescence in stem cells, osteoblasts, and fibroblasts and reduce inflammatory cytokines. Furthermore, administration of MSC-EVs prevented senescence of cells involved in wound healing and the spread of chronic inflammation around senescent cells, thereby promoting angiogenesis and bone regeneration and preventing BRONJ.

OBP-401-GFP telomerase-dependent adenovirus illuminates and kills high-metastatic more effectively than low-metastatic triple-negative breast cancer in vitro

We previously described the development of a highly-invasive, triple-negative breast cancer (TNBC) variant using serial orthotopic implantation of MDA-MB-231 human breast cancer in nude mice. The isolated variant is highly invasive in the mammary gland and metastasized to lymph nodes in 10 of 12 mice compared with 2 of 12 of the parental cell line. OBP-401 is a telomerase-dependent cancer-specific, green fluorescent protein (GFP)-expressing adenovirus. OBP-401 was used to infect parental MDA-MB-231P cells and high-metastatic MDA-MB-231H and MDA-MB-231HLN isolated from a lymph node metastasis and MDA-MB-231HLM isolated from a lung metastasis. Time-course imaging showed that OBP-401 labeled MDA-MB-231HP, MDA-MB-231HLN, and MDA-MB-231HLM cells more brightly than MDA-MB-231 parental cells. OBP-401 killed MDA-MB-231H, MDA-MB-231HLN, and MDA-MB-231HLM cells more efficiently than MDA-MB-231P parental cells. These results indicate that OBP-401 could infect, label and then kill high-metastatic MDA-MB-231 more efficiently than low-metastatic MDA-MB-231.

Randomized, placebo-controlled single-ascending-dose study to evaluate the safety, tolerability and pharmacokinetics of the HIV nucleoside reverse transcriptase inhibitor, BMS-986001, in healthy subjects

The objectives of this study were to evaluate the safety, tolerability and pharmacokinetics (PK) of BMS-986001 as a single oral dose in healthy male subjects. Sixty-four healthy male subjects were randomized to receive a single dose of BMS-986001 or placebo in this single-blind, placebo-controlled, sequential ascending-dose study. There were eight treatment groups (10, 30, 100, 300, 600, and 900 mg fed; and 100 and 300 mg fasted) of eight subjects each (BMS-986001 n = 6/placebo n = 2). BMS-986001 was well tolerated, with no serious adverse events (AEs), deaths, or discontinuations due to AEs reported. AEs were experienced by 14.6% of subjects receiving BMS-986001; however, these did not appear to be dose related and were not considered to be related to study drug. BMS-986001 was rapidly absorbed and exhibited a linear dose-exposure relationship across the dose range studied. PK appeared similar whether administered with or without food. Administration of BMS-986001 as a single dose was generally safe and well tolerated. A linear dose-exposure relationship was seen across all doses studied, with no apparent food effect. Further clinical development is warranted.

Detection of viable human circulating tumor cells using telomerase-specific GFP-expressing bioengineered adenovirus in patients with gastric cancer: A feasibility study

18

Background: The presence of circulating tumor cells (CTC) in the peripheral blood is associated with short survival and, therefore, the detection of CTC is clinically useful as prognostic factors of disease outcome and/or surrogate markers of treatment response. Recent technical advances in immunocytometric analysis and quantitative real-time PCR have made possible to detect a few CTC in the blood; however, there is no sensitive assay for detecting viable CTC. We developed a new approach to visually detect live CTC among millions of peripheral blood leukocytes using telomerase-specific replication-selective adenovirus expressing green fluorescent protein (GFP).

Methods: We constructed a GFP-expressing attenuated adenovirus, in which the telomerase promoter regulates viral replication (OBP-401, TelomeScan). The detection method for viable human CTC in the peripheral blood involves a three-step procedure including the lysis of red blood cells, the subsequent addition of OBP-401 to the cell pellets, and the automated scan under the fluorescent microscope. We analyzed fresh blood samples collected from 37 patients with histologically confirmed gastric cancer. We further assessed the CTC dynamics in patients who were undergoing chemotherapy or surgery to demonstrate the clinical potential of our approach for monitoring treatment responses.

Results: OBP-401 increased the signal-to-background ratio as a tumor-specific probe, because the fluorescent signal can be amplified only in viable human tumor cells by viral replication. Although the CTC level varied widely, ranging from 0 to 47 in 5-ml samples, 26 gastric cancer patients (70.3%) had more than one CTC; there was, however, no apparent relationship between CTC counts and TNM stages. Patients who had a recurrence of gastric cancer had decreased CTC counts after systemic chemotherapy. In the patients who underwent surgery, the CTC level dropped after complete resection.

Conclusions: This GFP-expressing virus-based method is simple and allows precise enumeration of CTC, which might be useful for monitoring the efficacy of local and systemic treatments.

[Table: see text]

Intraperitoneal administration of telomerase-specific oncolytic adenovirus sensitizes ovarian cancer cells to cisplatin and affects survival in a xenograft model with peritoneal dissemination

Despite tremendous development in chemotherapy for ovarian cancer over the past few decades, the prognosis of advanced cases with massive peritoneal dissemination is still unsatisfactory, and novel treatment modalities that can combine with chemotherapy are urgently needed. We recently developed virotherapy for solid tumors using telomerase-specific replication-selective adenoviruses (Telomelysin: OBP-301), in which the human telomerase reverse transcriptase (hTERT) gene promoter has been inserted to direct tumor-specific E1 gene expression. In this study, we investigated the anti-tumor effects of OBP-301, combined with cisplatin (CDDP), on ovarian cancer cells. In vitro treatment of SKOV3 cells with OBP-301 at a multiplicity of infection (MOI) of 0.01–100 induced significant cell death in a dose-dependent manner, with moderate cytotoxicity at an MOI of 1–10 and maximal cytotoxicity at an MOI of 100. In contrast, OBP-301 treatment of normal human cells showed no significant cell death at an MOI of 1–10 and exhibited modest cytotoxicity at an MOI of 100. The effects of low-dose CDDP at 0.5–1 μM, which induced only 20% cell death, were significantly augmented by combination with OBP-301 at an MOI of 1–10, finally achieving 40% cell death. Such enhancement of CDDP sensitivity was also observed in CDDP-resistant ovarian cancer cells. The combinatorial effects were further tested using a xenograft mouse model of SKOV3 with peritoneal dissemination. After intraperitoneal administration of OBP-301, we confirmed that injected OBP-301 fused with the green fluorescent protein (GFP) gene (OBP-401) was preferentially localized to peritoneal disseminations, as determined by fluorescence imaging. Treatment of mice with CDDP at low dose (0.5 mg kg^–1) had modest effects, showing a 10% decrease in disseminations, whereas combination with intraperitoneal administration of OBP-301 at an MOI of 10 led to enhanced effects, achieving an approximately 80% decrease in disseminations. Kaplan–Meier analysis showed improved overall survival of mice treated with CDDP plus OBP-301 compared with CDDP alone. These findings support the therapeutic potential of intraperitoneal administration of OBP-301 to sensitize ovarian cancer cells to CDDP.

Breast Cancer Gene Expression Profile in Post-Menopausal Patients Supplemented with Vitamin D

Vitamin D supplementation is indicated for post-menopausal women to prevent osteoporosis and lower 25(OH)2D3 or 1,25(OH)2D3 serum levels have been associated with breast cancer incidence or prognosis (metastasis). The antiproliferative effects of vitamin D are observed in breast cancer cell lines exposed to phamacological doses of calcitriol (1,25(OH)2D3, 100nM) but whether physiological doses are sufficient to produce growth inhibition in vivo is not known. The aim of our study was to investigate gene expression profile changes of breast cancer samples from patients supplemented with calcitriol, presenting an anti-proliferative effect on the tumor. Post-menopausal women diagnosed with breast cancer were instructed to take one (0.25ug/day, n=8) or two (0.50ug/day, n=8) tablets of calcitriol after tumor biopsy. Median time of supplementation was 30 days. Sixteen tumor samples were collected during biopsy (before supplementation) and breast surgery (after supplementation). Proliferation index was evaluated by tumor Ki-67 immunohistochemistry (IHC) expression in breast cancer samples before and after calcitirol supplementation and 1000 cells were counted by three observers (p < 0,001, Pearson's correlation). After establishing a counting error between observers, the cut-off value was fixed in 26.53% (percentile 60%) to define response. Patients were then categorized as responsive (a reduction of more than 26.53% on positive Ki-67 positive cells) and non-responsive (difference between samples before and after supplementation not exceeding 26.53%). Among our sixteen patients, all were categorized as responsive to calcitriol supplementation except for two. So far, gene expression profile of two patients (both categorized as responsive) has been analyzed using the U133 Plus 2.0 Affymetrix Gene Chips from 100ng of total RNA. To verify signalling pathways possibly involved in response to vitamin D exposure, additional five samples from a parallel study, in which breast cancer samples from post menopausal patients were collected at surgery and treated in vitro with a low concentration of calcitriol, 0.5nM (that can be attained with subcutaneous administration of doses of 8ug calcitriol, without hypercalcemia) for 24h, were included in the analysis. All samples had RNA hybridized to the same gene chips. Results were normalized and analyzed using RMA and Mev.TM4 softwares. CYP24A1, a target gene of vitamin D, presented a positive regulation after calcitriol supplementation in all samples analyzed. Differentially expressed genes were involved in the regulation of cell cycle [SMAD2, cyclin E, YWHAQ (14-3-3 family] and calcium signalling (HTR7, PTGER1 and PTGER2). Our results indicate that the tumor proliferation index is reduced upon calcitriol supplementation. Moreover, potentially regulated pathways in breast cancer specimens after administration of low doses of calcitriol are regulation of cell cycle and calcium signaling.Supported by FAPESP 2007/01111-0 – 2007/04799-2

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6128.

Detection of Circulation Tumor Cells Using Telomerase-Selective Adenoviral Marker (OBP-401®) in Breast Cancer Patients

Background: The detection of circulating tumor cells (CTCs) is a potential method to predict survival of metastatic breast cancer patients as well as outcomes of early breast cancer patients. However, no method for CTCs has yet proven to be the golden standard. We developed a new approach for detecting CTCs using telomerase-specific replication-competent adenovirus expressing green fluorescent protein (GFP) (OBP-401®, Oncolys Biopharma™).Methods: OBP-401® contains the replication cassette, in which the human telomerase reverse transcriptase promoter drives expression of E1 genes, and the GFP gene for monitoring viral replication. This system is consisted of the following steps; (1) virus-infection for 7.5 ml whole blood (incubated with 4 X 108 Plaque Forming Unit OBP-401 virus for 24 hours at 37 Celsius), (2) dead cell staining using L23102 (invitrogen™), (3) virus-inactivation and RBC elimination, and (4) detection of GFP expressing cells using fluorescence microscopy. In a preclinical study, the sensitivity of this system was assessed using cell lines. Next, we conducted feasibility studies for CTCs detection in 80 healthy individuals, 50 metastatic, and 27 early breast cancer patients. In metastatic and early breast cancer patients, we compared the sensitivity of this system with that of CellSearch® (Veridex™) and tumor makers (CEA and CA15-3). GFP-positive cells (viable CTCs) and L23102 expressing cells measuring ≥ 20µm in diameter (dead CTCs) were considered as CTCs in this system.Results: The sensitivity of this system, which was determined by a serial dilution of MDA-MB-468 cells against healthy volunteer's blood, was 1 cell per 7.5 ml. No CTCs were detected in any of healthy controls. Of 50 metastatic patients, 12% were primary breast cancers with stage IV disease, 24% were in the 1st line chemotherapy setting, and 42% were heavily pretreated with chemotherapy. The sensitivities of tumor markers, CellSearch®, and OBP-401® were 78%, 54%, and 66%, respectively. Neither CTCs detected with CellSearch® nor OBP-401® were significantly associated with clinicopathologic parameters. However, CTCs-positivity detected with CellSearch® were strongly associated with CA15-3 positivity (p = 0.003). Of 14 patients with normal CA15-3 levels, CellSearch® detected CTCs in three patients (21%) but OBP-401® in nine patients (64%). The sensitivity of the combination of tumor markers and OBP-401® was 92%. In 27 early breast cancers (Stage1 7, StageII 17, StageIII 3), three patients were treated with neoadjuvant chemotherapy (NAC). All blood samples were drawn before surgery or NAC. The sensitivities of tumor markers, CellSearch®, and OBP-401® were 7%, 0%, 67%, respectively. There were no significant correlations between CTCs detected with OBP-401® and clinicopathologic features.Conclusion: OBP-401® showed no false positive in healthy controls, and a high sensitivity for CTCs detection, particular in metastatic breast cancer patients with normal 15-3 levels and early breast cancer patients, compared with CellSearch®.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3012.

Autophagy-inducing agents augment the antitumor effect of telerase-selve oncolytic adenovirus OBP-405 on glioblastoma cells

Oncolytic adenoviruses are a promising tool in cancer therapy. In this study, we characterized the role of autophagy in oncolytic adenovirus-induced therapeutic effects. OBP-405, an oncolytic adenovirus regulated by the human telomerase reverse transcriptase promoter (hTERT-Ad, OBP-301) with a tropism modification (RGD) exhibited a strong antitumor effect on glioblastoma cells. When autophagy was inhibited pharmacologically, the cytotoxicity of OBP-405 was attenuated. In addition, autophagy-deficient Atg5(-/-) mouse embryonic fibroblasts (MEFs) were less sensitive than wild-type MEFs to OBP-405. These findings indicate that OBP-405-induced autophagy is a cell killing effect. Moreover, autophagy-inducing therapies (temozolomide and rapamycin) synergistically sensitized tumor cells to OBP-405 by stimulating the autophagic pathway without altering OBP-405 replication. Mice harboring intracranial tumors treated with OBP-405 and temozolomide survived significantly longer than those treated with temozolomide alone, and mice treated with OBP-405 and the rapamycin analog RAD001 survived significantly longer than those treated with RAD001 alone. The observation that autophagy inducers increase OBP-405 antitumor activity suggests a novel strategy for treating patients with glioblastoma.

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.

[Mediastinal abdominal wall fistula due to ePTFE membrane]

A 78-year-old woman who had undergone double valve replacement 13 years before was referred to our department because of postoperative wound dehiscence and exudate. Although the result of exudate culture was negative, the wound was disinfected continuously for 4 weeks and showed a transient remission. However, the exudate was observed again 3 weeks later. By chest computed tomography (CT), a highly bright shadow was revealed in the mediastinum, which was suspected to be a foreign body and, therefore, the cause of the exudate. Considering the possibility of infection, the patient underwent an operation. Following incision of the epigastric region and the resection of the xiphoid process, ePTFE membrane with poor granulation tissue was found. The membrane was removed, the lesion was washed with warm saline, and then the wound was closed. The postoperative course was uneventful without recurrence. This complication was considered to be caused by biological reaction to a foreign body.

Virus-mediated oncolysis induces danger signal and stimulates cytotoxic T-lymphocyte activity via proteasome activator upregulation

Dendritic cells (DCs) are the most potent antigen-presenting cells and acquire cellular antigens and danger signals from dying cells to initiate antitumor immune responses via direct cell-to-cell interaction and cytokine production. The optimal forms of tumor cell death for priming DCs for the release of danger signals are not fully understood. OBP-301 (Telomelysin) is a telomerase-specific replication-competent adenovirus that induces selective E1 expression and exclusively kills human cancer cells. Here, we show that OBP-301 replication produced the endogenous danger signaling molecule, uric acid, in infected human tumor cells, which in turn stimulated DCs to produce interferon-gamma (IFN-gamma) and interleukin 12 (IL-12). Subsequently, IFN-gamma release upregulated the endogenous expression of the proteasome activator PA28 in tumor cells and resulted in the induction of cytotoxic T-lymphocytes. Our data suggest that virus-mediated oncolysis might be the effective stimulus for immature DCs to induce specific activity against human cancer cells.

Solitary myofibroma of the lumbar vertebra: adult case

We present the first known adult case of solitary myofibroma of bone, which affected a lumbar vertebra in a 33-year-old male. Radiography identified a purely lytic lesion with a sclerotic rim in the right pedicle of L1. CT showed an expansile lytic lesion with a sclerotic rim. MRI of the lesion revealed an isointense signal on T1-weighted images, an inhomogeneously hyperintense signal on T2-weighted images, and marked enhancement with gadolinium. Pathological study showed a mixed picture of nodular proliferation of spindle-shaped myoid cells and hemangiopericytomatous proliferation of short spindle/small round cells. The tumor cells were immunoreactive for smooth muscle actin and immunonegative for desmin. This case of solitary myofibroma of bone is exceptionally rare because of its occurrence in an adult older than 20 years of age and its location at an extra-craniofacial site.

Predictive factors associated with prolonged survival in patients with advanced non-small-cell lung cancer (NSCLC) treated with gefitinib

This study aimed to identify predictive factors associated with prognostic benefits of gefitinib. A total of 221 Japanese patients who received gefitinib (250 mg day(-1)) were examined retrospectively and potential predictive factors analysed. Overall response rate (ORR) was 24.4% and median survival time (MST) was 8.0 months. In a log-rank test, survival was significantly better in females, patients with adenocarcinoma, never-smokers, favourable performance status (PS) and patients with epidermal growth factor receptor (EGFR) mutation. The lower the smoking exposure (Brinkman Index (BI)=cigarettes per day x years smoked), the better the MST (BI 0: 14.5 months, BI <500: 9.5 months, BI 500 to <1000: 6.9 months, BI > or =1000: 4.0 months). Positive-EGFR mutation status and PS 0-1 were independent predictors of favourable prognosis by multivariate analysis. Prognosis was significantly different according to EGFR mutation status (with the same smoking status), but not according to smoking status (with the same EGFR mutation status). EGFR mutation status is the most important independent predictor of survival benefit with gefitinib treatment. Although differences in prognosis were observed according to relative smoking status and smoking exposure, the results suggested that smoking is not a direct predictor of prognosis, yet is a surrogate marker of EGFR mutation status.

A novel telomerase-specific oncolytic virotherapy for human cancer: preclinical evaluation of safety, biodistribution, and efficacy

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Background: Replication-selective tumor-specific viruses present a novel approach for treating neoplastic disease. These vectors are designed to induce virus-mediated lysis of tumor cells after selective viral propagation within the tumor. Telomerase activation is considered to be a critical step in carcinogenesis and its activity is closely correlated with human telomerase reverse transcriptase (hTERT) expression. We constructed an adenovirus 5 vector (Telomelysin [OBP-301]), in which the hTERT promoter element drives expression of E1A and E1B genes linked with an IRES. Methods: We examined the antitumor effect of Telomelysin as a single agent or in combination with systemic administration of chemotherapeutic drugs such as docetaxel in tumor xenograft models. IND-supporting preclinical toxicology and pharmacodynamic studies were also performed to characterize the safety, pharmacokinetics and biological activity of Telomelysin. Results: Telomelysin replicated efficiently and induced marked cell killing in a panel of human cancer cell lines derived from various organs, whereas replication as well as cytotoxicity was highly attenuated in normal human cells lacking telomerase activity. In nu/nu mice carrying subcutaneous human tumor xenografts, intratumoral injection of Telomelysin resulted in a significant inhibition of tumor growth, which was significantly enhanced in combination with systemic administration of docetaxel. Moreover, Telomelysin replication in the distant, un-injected tumors was demonstrated. Viral DNA was identified in tissues outside of the injection site; however, toxicology studies including pathological examinations in mice and cotton rats demonstrated that local injection of Telomelysin could be well-tolerated with an acceptable safety profile. Conclusions: The hTERT promoter confers competence for selective replication of Telomelysin in human cancer cells, an outcome that has important implications for the treatment of human cancers. Telomelysin has been already manufactured under GMP conditions for initial clinical trials. Upon FDA approval, a phase I dose-escalation study of intratumoral injection of Telomelysin for various solid tumors will be started.

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The predictive factors and patient-selection associated with the survival benefits of gefitinib in patients with advanced non-small cell lung cancer (NSCLC)

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Background: Gefitinib, an inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, has shown meaningful antitumor activity for advanced NSCLC. Survival benefit of treatment with gefitinib has not been shown in unselected patients, however heterogeneity in survival outcomes between sub-group (histological types, gender, smoking status and ethnicity) of patients has been observed. The aim of this study was to identify the potential predictive features associated with the survival benefit of treatment with gefitinib. Methods: All NSCLC patients who began taking gefitinib during the period from July 2002 until July 2005 in our institute were retrospectively reviewed. Potential factors analyzed included age, gender, smoking history, performance status (PS), histology, stage, and prior chemotherapy. Results: Overall 221 patients were analyzed. The overall response rate of gefitinib was 26.7%. Median survival time (MST) was 8.0 months. MST of patients whose tumor response was partial response (PR) was 34.5 months. Univariate analysis revealed that the predictive factors of favorable survival were female (p = 0.001), never-smoker (p < 0.0001), good PS (p < 0.0001) and adenocarcinoma (p < 0.0001). Multivariate analysis showed that never-smoking history (p = 0.005), adenocarcinoma (p = 0.004), and better PS (P < 0.001) were significant independent predictors of long survival. The Brinkman index (BI), number of cigarettes per day multiplied by number of years smoked, was associated with survival benefit. MST was 17.6 months in the BI = 0 group (never-smokers), 9.7 months in 1 ≤BI <500, 6.9 months in 500 ≤BI <1000, 4.4 months in 1000 ≤BI <1500, and 4.0 months in BI ≥1500. Conclusion: Never-smokers and adenocarcinoma are predictive factors for prolonged survival. As for smoking status, lower BI is associated with better prognosis after treatment with gefitinib. Therefore, histological factors and smoking status must be considered when treating with gefitinib.

No significant financial relationships to disclose.

EGFR mutation-based phase II multicenter trial of gefitinib in advanced non-small cell lung cancer (NSCLC) patients (pts): Results of West Japan Thoracic Oncology Group trial (WJTOG0403)

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Background: Recently several retrospective analyses have reported that somatic activating mutations in the EGFR tyrosine kinase domain underlie responsiveness to gefitinib. In the present study, we have prospectively assessed whether these specific mutations in EGFR gene affect the clinical outcomes of NSCLC pts treated with gefitinib. Method: Pts with a histologically confirmed, recurrent or metastatic NSCLC that harbored EGFR mutations were eligible for the study. Direct sequencing using DNA extracted from paraffin-embedded tumor specimens to detect mutations in EGFR (exons 18, 19 and 21) was performed in a central laboratory. Eligible pts with measurable lesions, ECOG PS of 0–2, adequate organ functions and less than 2 prior chemotherapy regimens were treated with gefitinib 250 mg orally once daily. The primary objective of this study was to determine the objective response rate of single-agent gefitinib in NSCLC pts with EGFR mutations. With the target activity level of 50% and the lowest response rate of interest set at 25%, 23 eligible patients were required with an 80% power to accept the hypothesis and a 5% significance level to reject the hypothesis. Allowing for a 10% loss to follow-up rate, a total of 25 patients with EGFR mutations were planned to enroll. Results: Between March 2005 and December 2005, 104 patients were recruited from fifteen study centers in Japan and screened for the presence of EGFR mutations. EGFR mutations were detected in 28 pts (27%). Twenty-five of the 28 pts have been enrolled onto this study; 12 pts had deletional mutations in exon 19 and 13 pts had missense mutations (L858R) in exon 21. Of the 25 pts with EGFR mutations: adenocarcinoma (24), female (17), never smoker (18), and PS 0–1 (22). Median age was 69 years (range, 54 to 89 years). Previous therapy included surgery in 9 pts (36%), chemotherapy in 7 pts (28%), and radiotherapy in 1 pts (4%). Conclusions: Efficacy and safety data will be mature in March 2006 and will be presented at the ASCO meeting. These are the first prospective studies targeted at NSCLC pts harboring EGFR mutations.

No significant financial relationships to disclose.