Abstract A40: Pancreatic cancer patient-derived orthotopic xenograft (PDOX™) is effectively targeted by Salmonella typhimurium A1-R

The aim of this study is to determine the efficacy of tumor-targeting Salmonella typhimurium A1-R (A1-R) (Cancer Disc. 2, 588-590, 2012) on pancreatic cancer PDOX™ compared to standard chemotherapy. The PDOX™ was grown in transgenic nude red fluorescent protein (RFP) mice in order that the PDOX™ acquire RFP-expressing stroma in order to label the tumor. The RFP-PDOX™ were then orthotopically transplanted to non-transgenic nude mice in order to image tumor growth and drug efficacy. The RFP labeled stroma are stable upon passage. A1-R treatment significantly reduced tumor weight as well as tumor fluorescence area compared to untreated control (p = 0.011), with comparable efficacy of gemcitabine, cisplatin and 5-FU. A1-R had the highest efficacy compared to any of the chemotherapy drugs tested based on Evan's histological response criteria. The present report demonstrates Salmonella typhimurium A1-R was effective for human pancreatic PDOX™ and is a promising therapy for this highly treatment-resistant disease.

Citation Format: Yukihiko Hiroshima, Ming Zhao, Ali Maawy, Yong Zhang, Matthew H.G. Katz, Jason B. Fleming, Fuminari Uehara, Shinji Miwa, Shuya Yano, Masashi Momiyama, Atsushi Suetsugu, Takashi Chishima, Kuniya Tanaka, Michael Bouvet, Itaru Endo, Robert M. Hoffman. Pancreatic cancer patient-derived orthotopic xenograft (PDOX™) is effectively targeted by Salmonella typhimurium A1-R. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A40.

Fluorescence-guided surgery of prostate cancer bone metastasis

BACKGROUND

The aim of this study is to investigate the effectiveness of fluorescence-guided surgery (FGS) of prostate cancer experimental skeletal metastasis.

MATERIALS AND METHODS

Green fluorescent protein-expressing PC-3 human prostate cancer cells (PC-3-green fluorescent protein) were injected into the intramedullary cavity of the tibia in 32 nude mice. After 2 wk, 16 of the mice underwent FGS; the other 16 mice underwent bright-light surgery (BLS). Half of BLS and FGS mice (8 mice in each group) received zoledronic acid (ZOL). Weekly fluorescence imaging of the mice was performed. Six weeks after surgery, metastases to lung and inguinal lymph node were evaluated by fluorescence imaging.

RESULTS

The percentage of residual tumor after BLS and FGS was 9.9 ± 2.2% and 0.9 ± 0.3%, respectively (P < 0.001). FGS reduced recurrent cancer growth compared with BLS (P < 0.005). Although FGS alone had no significant effect on inguinal lymph node metastases, lung metastasis or disease-free survival (DFS), ZOL in combination with FGS significantly increased DFS (P = 0.01) in comparison with the combination of BLS and ZOL. ZOL reduced lymph node metastases (P = 0.033) but not lung metastasis.

CONCLUSIONS

FGS significantly reduced recurrence of experimental prostate cancer bone metastasis compared with BLS. The combination of FGS and ZOL increased DFS over BLS and ZOL. ZOL inhibited lymph node metastasis but not lung metastasis.

Abstract 2384: Time-lapse imaging of response to DNA damage occuring during mitosis

The DNA damage response protein 53BP1 forming foci when double-stranded breaks occur in DNA. In this study, the response to DNA damage during mitosis was visualized using fluorescent protein-based real-time imaging of 53BP1 linked to GFP (GFP-53BP1) focus formation by the fusion protein in the MiaPaCa2 Tet-On Advanced cell line. The MiaPaCa2Tet-On GFP-53BP1 cells were cultured in 35 mm dishes for 48 h. 53BP1 foci were observed every 30 minutes with the FluoView FV1000 confocal laser microscope (Olympus Corp., Tokyo, Japan). The increased expression of GFP-53BP1 was observed during mitosis in MiaPaCa2Tet-On GFP-53BP1 cells without any treatment Mitotic changes were observed 1.09 ± 0.10 times in each cell during over 24 h. Apoptotic changes were observed in 7.3 ± 3.3% of the cells during the 24 h. During the time-lapse imaging, focus formation of GFP-53BP1 was observed in 11.4 ± 2.1% of the mitotic cells during over 24 h. Non-mitotic cells did not have an increase in GFP-53BP1 focus formation. This study indicates that DNA strand breaks occur during mitosis and can be repaired, at least to some extent.

Citation Format: Shinji Miwa, Shuya Yano, Mako Yamamoto, Yukihiko Hiroshima, Fuminari Uehara, Yasunori Matsumoto, Hiroaki Kimura, Katsuhiro Hayashi, Elena V. Efimova, Hiroyuki Tsuchiya, Robert M. Hoffman. Time-lapse imaging of response to DNA damage occuring during mitosis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2384. doi:10.1158/1538-7445.AM2014-2384

Abstract 710: The efficacy of tumor-targeting Salmonella typhimurium A1-R on bone metastasis

We have previously developed a genetically-modified bacterial strain of Salmonella typhimurium (A1-R), which expresses GFP. In this study, we measured the efficacy of A1-R on breast cancer bone metastasis. We established an early-stage bone-metastasis model in nude mice by cardiac injection and a late-stage model by injection into the intramedullary cavity of the tibia using MDA-MB-435 human breast cancer cells (Human breast cancer cell lines co-express neuronal, epithelial, and melanocytic differentiation markers in vitro and in vivo. PLoS One 5, e9712, 2010). Both mouse models of bone metastasis were treated with A1-R. Fluorescence imaging of the mice was performed to visualize the metastatic bone lesions. In a first set of experiments, we showed that A1-R invaded and replicated intracellularly in MDA-MB-435-GFP cells in vitro. A1-R dose-dependently inhibited proliferation of MDA-MB-435-GFP cells. In the early-stage bone-metastasis model, A1-R significantly improved metastasis-free survival. In the advanced-stage bone-metastasis model, A1-R significantly inhibited the growth of the metastatic lesions. These data indicated that A1-R is useful to prevent and inhibit the growth of metastatic breast cancer bone tumors.

Citation Format: Shinji Miwa, Ming Zhao, Shuya Yano, Yong Zhang, Fuminari Uehara, Yasunori Matsumoto, Yukihiko Hiroshima, Mako Yamamoto, Hiroaki Kimura, Katsuhiro Hayashi, Hiroyuki Tsuchiya, Robert M. Hoffman. The efficacy of tumor-targeting Salmonella typhimurium A1-R on bone metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 710. doi:10.1158/1538-7445.AM2014-710

Abstract 711: Salmonella typhimurium A1-R induces quiescent FUCCI-expressing cancer cells to cycle and become chemosensitive

Quiescent cancer cells are resistant to cytotoxic agents which target only proliferating cancer cells. Time-lapse imaging showed that Salmonella typhimurium A1-R (A1-R) encircled and invaded quiescent cancer cells in monolayer culture, thereby eliminating them. Moreover A1-R infected and killed quiescent fluorescent ubiquitination-based cell cycle indicator (FUCCI)-expressing cancer cells in tumor spheres. In contrast, cytotoxic agents did not kill quiescent cancer cells in tumor spheres. A1-R infection of FUCCI-expressing subcutaneous tumors growing in nude mice resulted in killing quiescent cancer cells resistant to cytotoxic agents. Furthermore, the combination of A1-R and cisplatin reduced tumor size compared with A1-R monotherapy or cisplatin alone. This study demonstrates that A1-R can kill quiescent cancer cells and also sensitize them to conventional chemotherapy. These results suggest a new therapeutic paradigm potentially more effective than current therapeutics which are ineffective against quiescent cancer cells.

Citation Format: Shuya Yano, Yong Zhang, Ming Zhao, Yukihiko Hiroshima, Shinji Miwa, Fuminari Uehara, Hiroyuki Kishimoto, Hiroshi Tazawa, Toshiyoshi Fujiwara, Robert M. Hoffman. Salmonella typhimurium A1-R induces quiescent FUCCI-expressing cancer cells to cycle and become chemosensitive. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 711. doi:10.1158/1538-7445.AM2014-711

Abstract 3486: Efficacy of neoadjuvant chemotherapy in combination with fluorescence-guided surgery on a pancreatic cancer patient-derived orthotopic xenograft (PDOX)

The aim of this study is to determine the efficacy of neoadjuvant chemotherapy (NAC) in combination with fluorescence-guided surgery (FGS) on pancreatic cancer patient derived orthotopic xenograft (PDOX). We established the PDOX from the patient suffering from metastatic CA19-9-positive pancreatic cancer. Forty nude mice were implanted with tumor using surgical orthotopic implantation (SOI) on the nude mouse pancreas. Four weeks after implantation, the mice with tumor were randomized into 4 treatment groups: (1) bright-light surgery (BLS) only; (2) FGS; (3) NAC-BLS; (4) NAC-FGS. Gemcitabine (80 mg/kg, ip, weekly, 3 weeks) was used for NAC. Seven weeks after implantation, BLS was performed on all tumor-bearing mice. A monoclonal anti-human CA19-9 antibody conjugated with Dylight 650 was delivered to tumor-bearing mice in the FGS groups as a single intravenous dose 24 hours before BLS. Postoperatively, the surgical resection bed of FGS mice were imaged with the OV100 fluorescence imaging system to detect fluorescent residual tumors. The fluorescent residual tumors of FGS groups were then resected under fluorescence navigation. The average resected tumor weight of each group was as follows: (1) BLS, 188.5 ± 50.0 mg; (2) FGS, 278.0 ± 111.4 mg; (3) NAC-BLS, 84.5 ± 48.7 mg; (4) NAC-FGS, 141.8 ± 48.9 mg. The average resected tumor weight of NAC groups was significantly less than the non-NAC groups (113.1 ± 57.0 mg and 235.6 ± 94.3 mg, respectively; p&gt;0.001). The average resected tumor weight of the FGS groups was significantly larger than the BLS groups (213.4 ± 107.1 mg and 136.5 ± 73.8 mg, respectively; p=0.016). Eight weeks after resection, we performed laparotomy to examine recurrence. The recurrence rate of each group was as follows: (1) BLS, 9 / 9 (100%); (2) FGS, 4 / 8 (50%); (3) NAC-BLS, 6 / 9 (66.7%); (4) NAC-FGS, 2 / 8 (25%). The recurrence rate of FGS groups was significantly lower than BLS groups (6 /16; 37.5% and 15 / 18; 83.3%, respectively; p=0.012), whereas there was no significant difference between FGS and NAC-FGS groups (p=0.608). There was no significant difference in the total recurrence rate between NAC and non-NAC groups (p=0.157). However NAC significantly reduced peritoneal recurrence (29.4 % and 0%, respectively; p=0.044). The results indicate that NAC in combination with FGS might reduce or even eliminate the peritoneal recurrence of pancreatic cancer.

Citation Format: Yukihiko Hiroshima, Ali Maawy, Yong Zhang, Sho Sato, Takashi Murakami, Mako Yamamoto, Fuminari Uehara, Shinji Miwa, Shuya Yano, Masashi Momiyama, Takashi Chishima, Kuniya Tanaka, Michael Bouvet, Itaru Endo, Robert M. Hoffman. Efficacy of neoadjuvant chemotherapy in combination with fluorescence-guided surgery on a pancreatic cancer patient-derived orthotopic xenograft (PDOX). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3486. doi:10.1158/1538-7445.AM2014-3486

Abstract 5: Real-time in vivo imaging of osteosarcoma angiogenesis

We report here real-time color-coded imaging of osteosarcoma-induced angiogenesis in vivo. Gelfoam® (5×5 mm) treated with β fibroblast growth factor (bFGF) was initially transplanted subcutaneously in the flank of transgenic nestin-driven green fluorescent protein (ND-GFP) nude mice (n=12). In ND-GFP mice, nascent blood vessels are labeled with GFP, including those growing in Gelfoam®. Seven days after transplantation of Gelfoam®, skin flaps were made and human 143B osteosarcoma cells expressing GFP in the nucleus and red fluorescent protein (RFP) in the cytoplasm were injected into the transplanted Gelfoam®. The control group had only Gelfoam® transplanted without subsequent cancer-cell inoculation. Skin flaps were made at days 14, 21, 28 after transplantation of the Gelfoam® to allow observation of vascularization of the Gelfoam® using fluorescence imaging after both with and without cell inoculation. ND-GFP expressing nascent blood vessels penetrated and spread into the Gelfoam® in both the non-cellular control and after cancer-cell inoculation. The mean length of ND-GFP expressing blood vessels of mice with osteosarcoma cells seeded on the Gelfoam® increased compared to the Gelfoam®-only control at days 14, 21, 28 after transplantation of the Gelfoam® (at day 14, 21 ; p&lt;0.05, at day 28 ; p&lt;0.01). The results demonstrate that the osteosarcoma cells stimulated angiogenesis within the Gelfoam®. This model enables facile imaging of cancer-cell-induced angiogenesis and the study of its mechanism and inhibition.

Citation Format: Fuminari Uehara, Yasunori Tome, Hiroki Maehara, Fuminori Kanaya, Shinji Miwa, Yukihiko Hiroshima, Shuya Yano, Mako Yamamoto, Yasunori Matsumoto, Robert M. Hoffman. Real-time in vivo imaging of osteosarcoma angiogenesis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5. doi:10.1158/1538-7445.AM2014-5

Abstract 1982: Invading cancer cells are mostly in G0/G1 and resist chemotherapy demonstrated by real-time FUCCI imaging of cell-cycle kinetics in Gelfoam® histoculture

Invasive cancer cells are a critical target for chemotherapy in order to prevent metastasis. In the present report, we demonstrate real-time visualization of cell-cycle kinetics of invading cancer in three-dimensional (3D) Gelfoam® histoculture. A fluorescence ubiquitination cell cycle indicator (FUCCI) was used whereby G1/G0 cells express a red fluorescent protein and S/G2/M cells express a green fluorescent protein. With FUCCI imaging, we observed that cancer cells in G0/G1 phase in Gelfoam® histoculture migrated more rapidly and further than the cancer cells in S/G2/M phase. Cancer cells ceased migrating when they entered S/G2/M phases and restarted migrating after division and re-entry into G1/G0. Migrating cancer cells also were resistant to chemotherapy since they were preponderantly in G1/G2 and cytotoxic chemotherapy targets cells in S/G2/M phase. The results of the present report suggest that novel therapy targeting G1/G2 cancer cells is necessary to prevent metastasis.

Citation Format: Shuya Yano, Shinji Miwa, Sumiyuki Mii, Yukihiko Hiroshima, Fuminari Uehara, Hiroyuki Kishimoto, Hiroshi Tazawa, Ming Zhao, Michael Bouvet, Toshiyoshi Fujiwara, Robert M. Hoffman. Invading cancer cells are mostly in G0/G1 and resist chemotherapy demonstrated by real-time FUCCI imaging of cell-cycle kinetics in Gelfoam® histoculture. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1982. doi:10.1158/1538-7445.AM2014-1982

Abstract 4375: UVC irradiation in combination with fluorescence-guided surgery cures metastatic human pancreatic cancer in orthotopic mouse models

The aim of this study was to determine the efficacy of UVC irradiation in combination with fluorescence-guided surgery (FGS) in an orthotopic model of pancreatic cancer. Two weeks after orthotopic implantation of human MiaPaCa-2-GFP pancreatic cancer cells, bright-light surgery (BLS) was performed on all tumor-bearing mice (n=24). Postoperatively, the surgical resection bed was imaged with the OV100 variable magnification imaging system with a magnification of 0.56x to detect residual tumor. The mice which underwent BLS were randomized into 3 groups; BLS only (n=8) or FGS (n=8) or FGS-UVC (n=8). The residual tumors were resected with FGS using a portable, hand-held imaging system. After FGS, the surgical resection bed was imaged with the OV100 with a magnification of 0.89x, to detect minimal residual tumor and was irradiated with 2700 J/m2 UVC (emission peak 254 nm) from the bottom of a chamber using a Benchtop 3UV transilluminator (UVP, LLC, Upland, CA). The average residual tumor area after FGS was significantly smaller than BLS (0.135 ± 0.137 mm2 and 3.338 ± 2.929 mm2, respectively; p=0.007). Relapse-free survival (RFS) and overall survival (OS) were determined in 3 groups. Three-month RFS in the BLS, FGS and FGS-UVC were 0%, 50% and 100%, respectively. Five-month OS in BLS, FGS and FGS-UVC was 10%, 90% and 100%, respectively. FGS and FGS-UVC resulted in significantly increased survival compared to BLS for both RFS and OS. FGS-UVC showed significantly increased survival compared to the FGS for both RFS and OS (p=0.008 and p=0.025, respectively). These results suggests that UVC irradiation in combination with FGS could be a curative strategy for human pancreatic cancer.

Citation Format: Yukihiko Hiroshima, Ali Maawy, Sho Sato, Takashi Murakami, Mako Yamamoto, Fuminari Uehara, Shinji Miwa, Shuya Yano, Masashi Momiyama, Takashi Chishima, Kuniya Tanaka, Michael Bouvet, Itaru Endo, Robert M. Hoffman. UVC irradiation in combination with fluorescence-guided surgery cures metastatic human pancreatic cancer in orthotopic mouse models. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4375. doi:10.1158/1538-7445.AM2014-4375

Abstract 13: Color-coded imaging of vessel anastomosis in vivo using RFP and CFP transgenic mice

We previously report the development of a color-coded imaging model that can visualize the anastomosis between blood vessels of red fluorescent protein (RFP)-expressing vessels in Gelfoam® previously vascularized in RFP transgenic mice and blood vessels of nestin-driven green fluorescent protein (ND-GFP) mice that express GFP in nascent vessels (Anticancer Res. 33: 3041-3046, 2013). In the present study, fourteen days after transplantation into RFP transgenic nude mice, the Gelfoam® was removed and re-transplanted into the subcutis on the flank of cyan fluorescent protein (CFP) transgenic mice. Skin flaps were made and anastomosis between the CFP-expressing vessels and RFP blood vessels in the Gelfoam® was imaged 14 and 21 days after re-transplantation. The results presented in this and our previous report suggest a new paradigm of visualizing blood vessel anastomosis and its implications for tumor angiogenesis.

Citation Format: Fuminari Uehara, Yasunori Tome, Hiroki Maehara, Kazuhiro Tanaka, Fuminori Kanaya, Shinji Miwa, Yukihiko Hiroshima, Shuya Yano, Mako Yamamoto, Yasunori Matsumoto, Robert M. Hoffman. Color-coded imaging of vessel anastomosis in vivo using RFP and CFP transgenic mice. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 13. doi:10.1158/1538-7445.AM2014-13

Abstract 1230: Efficacy of Salmonella typhimurium A1-R and anti-VEGF therapy on a patient-derived orthotopic xenograft (PDOX) pancreatic cancer model

We have previously developed the genetically-modified Salmonella typhimurium A1-R (A1-R) strain that selectively targets tumors and demonstrated that A1-R was able to eradicate primary and metastatic tumors in monotherapy in nude mouse models of various cancers including pancreatic cancer. The aim of this study was to examine the efficacy of A1-R treatment on VEGF-positive human pancreatic cancer in a patient derived orthotopic xenograft (PDOX) model in combination with anti-VEGF therapy. A VEGF-positive human pancreatic cancer cell line (MiaPaCa-2-GFP) and VEGF-positive pancreatic cancer PDOX were orthotopically implanted in nude mice. The nude mice were treated in the following groups: (1) gemcitabine (GEM) (80 mg/kg, ip, weekly, 4 weeks); (2) GEM (80 mg/kg, ip, weekly, 4 weeks) + Bevacizumab (Bev) (5 mg/kg, ip, twice a week, 4 weeks); (3) GEM (80 mg/kg, ip, weekly, 2 weeks) + Bev (5 mg/kg, ip, twice a week, 2 weeks) → A1-R (1.5x108 CFU/body, ip, weekly, 2 weeks); and (4) saline (vehicle/control, ip, weekly, 4 weeks). The mean tumor weight of each group in the MiaPaCa-2-GFP model was as follows: (1) GEM; 775.9 ± 273.8 mg; (2) GEM/Bev; 413.5 ± 108.3 mg; (3) GEM/Bev→A1-R; 257.5 ± 57.1 mg; and (4) Control; 2655.4 ± 583.9 mg. GEM/Bev→A1-R significantly reduced tumor weight compared to GEM/Bev treatment in the MiaPaCa-2-GFP model (p=0.022). The tumor weight of each group in the PDOX model was as follows: (1) GEM; 263.1 ± 129.1 mg, (2) GEM/Bev; 65.9 ± 41.9 mg, (3) GEM/Bev→A1-R; 21.9 ± 6.2 mg and (4) Control; 998.8 ± 377.7 mg. GEM/Bev→A1-R significantly reduced tumor weight compared to GEM/Bev treatment in the PDOX model (p=0.029). These results demonstrate that A1-R is effective on pancreatic cancer in combination with anti-VEGF, including the PDOX model indicating the clinical potential of this combination.

Citation Format: Yukihiko Hiroshima, Ming Zhao, Matthew H.G. Katz, Jason B. Fleming, Sho Sato, Takashi Murakami, Mako Yamamoto, Fuminari Uehara, Shinji Miwa, Shuya Yano, Masashi Momiyama, Yong Zhang, Ali Maawy, Takashi Chishima, Kuniya Tanaka, Michael Bouvet, Itaru Endo, Robert M. Hoffman. Efficacy of Salmonella typhimurium A1-R and anti-VEGF therapy on a patient-derived orthotopic xenograft (PDOX) pancreatic cancer model. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1230. doi:10.1158/1538-7445.AM2014-1230

Abstract 3130: Zoledronic acid inhibits proliferation and metastasis of human pancreatic cancer in the patient-derived orthotopic xenograft (PDOX) model by targeting tumor-educated macrophages

Macrophages harvested from the peritoneal cavity of nude mice with subcutaneous human pancreatic tumors were defined as “tumor-educated macrophages” (EMϕ) and macrophages harvested from mice without tumors were defined as “naïve macrophages” (NMϕ). EMϕ promote tumor growth and metastasis. The aim of the present study was to determine the efficacy of Zoledronic acid (ZA) on EMϕ in a pancreatic cancer patient derived orthotopic xenograft (PDOX) nude mouse model. In this study, EMϕ and NMϕ were compared for their ability to enhance tumor progression. We initially demonstrated that the cancer cells exposed to the conditioned medium harvested from EMϕ culture significantly increased proliferation (p = 0.016) and had more migration stimulation capability (p &lt; 0.001) compared to cultured cancer cells treated with the conditioned medium from NMϕ. Next, we examined the efficacy of ZA on EMϕ, and NMϕ and found that ZA had the ability to kill both EMϕ and NMϕ in vitro. We then demonstrated that EMϕ promoted tumor growth and metastasis in an orthotopic mouse model of a human pancreatic cancer cell line, ZA reduced the tumor growth (p = 0.006) and metastasis (p = 0.025) promoted by EMϕ. Finally, we examined the efficacy of ZA for pancreatic cancer in the PDOX model, and found that the combination of gemcitabine (GEM) and ZA reduced tumor weight (p = 0.016) and tumor growth (p = 0.005) compared to GEM alone. ZA alone reduced metastasis (p = 0.009). These results suggest that ZA inhibits the proliferation and the metastasis of human pancreatic cancer by targeting EMϕ.

Citation Format: Yukihiko Hiroshima, Mohamed K. Hassenein, Rhiana Menen, Matthew H.g. Katz, Jason B. Fleming, Sho Sato, Takashi Murakami, Mako Yamamoto, Fuminari Uehara, Shinji Miwa, Shuya Yano, Masashi Momiyama, Ali Maawy, Takashi Chishima, Kuniya Tanaka, Michael Bouvet, Itaru Endo, Robert M. Hoffman. Zoledronic acid inhibits proliferation and metastasis of human pancreatic cancer in the patient-derived orthotopic xenograft (PDOX) model by targeting tumor-educated macrophages. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3130. doi:10.1158/1538-7445.AM2014-3130

Abstract 1983: Real-time imaging of exosomes dynamic of cross-talking and cell trafficking in 3D Gelfoam® histoculture

Exosomes are small membrane vesicles (30-100 nm) released by many types of cells during normal physiological processes and are thought to play an important role in cell-to-cell communication to promote tumor metastasis. Exosomes contain diffusible factors, such as cytokines, growth factors and extracellular matrix molecules and also mediate local and systemic cell communication through the horizontal transfer of information, such as mRNAs, microRNAs and proteins. However, the exosome dynamics and trafficking between cancer cells and tumor stromal cells in a metastatic niche are still unclear. In this study, in order to image the movement of cancer cell-derived exosomes, we developed a confocal time lapse imaging system to use green fluorescent protein (GFP)-tagged CD63, which is a general marker of exosomes, expressed in breast cancer cells cultured on 3-dimentional Gelfoam® histoculture. We demonstrated that 3D Gelfoam® culture enabled imaging of structural cell-to-cell contact between neighboring cells and exosome behavior in real-time. This system makes it possible to monitor real-time exosome dynamics and cross-talking between cancer cells and other cells and to identify the mechanism of exosome release and uptake such as in a metastatic niche.

Citation Format: Mako Yamamoto, Shinji Miwa, Yukihiko Hiroshima, Shuya Yano, Fuminari Uehara, Yasunori Matsumoto, Atsushi Suetsugu, Kimi Homma, Robert M. Hoffman. Real-time imaging of exosomes dynamic of cross-talking and cell trafficking in 3D Gelfoam® histoculture. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1983. doi:10.1158/1538-7445.AM2014-1983

Abstract 1979: Three-dimensional Gelfoam® histoculture enables cancer cells to mimic in vivo cancer cell cycling as visualized with FUCCI imaging

Collagen sponge-gel histoculture was developed by Leighton (In: Encyclopedia of Life Sciences. John Wiley and Sons, Ltd.: Chichester, 2010, Published Online. DOI: 10.1002/9780470015902.a0002573.pub2). In the 1950s, Leighton showed that placing cells in histoculture enables them to form 3-dimensional structures. Because of its architectural resemblance to native tissue, sponge gel histoculture represents a unique in vivo-like model to study cancer-cell behavior (Brenner's Encyclopedia of Genetics, 2nd Ed., Vol. 7, pp. 73-76. Elsevier, 2013). For example, Leighton observed that when C3HBA mouse mammary adenocarcinoma cells were grown on sponge-matrix histoculture, the cells aggregated similar to the original in vitro tumor. Distinct structures were formed within the tumors such as lumina and stromal elements, with some of the glandular structures similar to the original tumor (above-reference). We have further developed sponge gel histoculture using Gelfoam to grow tumors, nerves, hair follicles, skin with growing hair (above-reference). In the present report, we use fluorescence ubiquitination cell cycle indicator (FUCCI) imaging and Gelfoam® collagen sponge gel histoculture to demonstrate that the cell cycle phase distribution of cancer cells in Gelfoam® and in vivo tumors is similar whereby only the surface cells proliferate and interior cells are quiescent in G1/G0. This is markedly contrary to 2D culture where most cancer cells cycle. This observation explains, at least in part, the resistance of solid tumors to chemotherapy which targets only cycling cells.

Citation Format: Shuya Yano, Shinji Miwa, Sumiyuki Mii, Yukihiko Hiroshima, Fuminari Uehara, Hiroyuki Kishimoto, Hiroshi Tazawa, Ming Zhao, Toshiyoshi Fujiwara, Robert M. Hoffman. Three-dimensional Gelfoam® histoculture enables cancer cells to mimic in vivo cancer cell cycling as visualized with FUCCI imaging. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1979. doi:10.1158/1538-7445.AM2014-1979

Abstract 1204: Establishment of a patient-derived orthotopic xenograft (PDOX) model of patient cervical cancer

We implanted a tumor resected from a patient with metastatic HER-2-positive cervical cancer from 8 NOD/SCID mice (F1; NOD/SCID-sc) and 10 nude mice (F1; Nude-sc) subcutaneously, and 8 nude mice (F1; Nude-soi) orthotopically. Five out of 8 NOD/SCID mice died within 7 days after implantation. Infections around the surgical wound, loss of weight and of lethargy were observed in post-operatively in other mice. We examined the tumor-take rate of each model 8 weeks after implantation. Tumors grew in 3 out of 3 mice in F1; NOD/SCID-sc (100 %); 7 out of 10 mice in F1; nude-sc (70 %) and 6 out of 8 mice in F1; nude-soi group (75 %), respectively. The metastatic tumors (peritoneal dissemination, liver metastasis, lung metastasis or lymph node metastasis) were detected in 4 mice in F1; nude-soi mice (50 %). We found all xenografts including the metastatic tumors had histological structures similar to the original tumor and were stained by anti-human HER-2 antibody. Next, we implanted the small fragments of subcutaneous tumors from F1; Nude-sc mice (F2; sc-sc) or the primary tumors of F1; nude-soi mice (F2; soi-sc) to another set of nude mice (20 mice each) subcutaneously, and examined the tumor-take rate of each group 4 weeks and 8 weeks after implantation. Eight mice in the F2; sc-sc group (40 %) and 16 mice in the F2; soi-sc group (80 %) had tumors at week 4, and 15 mice in the F2; sc-sc group (75 %) and 19 mice in the F2; soi-sc group (95 %) had tumors at week 8. These results suggest that PDOX in nude mouse model recapitulates the biological behaviors of the original tumor and has the sufficient tumor-take rate.

Citation Format: Yukihiko Hiroshima, Yong Zhang, Ali Maawy, Sho Sato, Takashi Murakami, Mako Yamamoto, Fuminari Uehara, Shinji Miwa, Shuya Yano, Masashi Momiyama, Takashi Chishima, Kuniya Tanaka, Ali Maawy, Itaru Endo, Robert M. Hoffman. Establishment of a patient-derived orthotopic xenograft (PDOX) model of patient cervical cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1204. doi:10.1158/1538-7445.AM2014-1204

Abstract 2403: Imaging of UVB and UVC-induced DNA damage repair in cancer cells in Gelfoam histoculture and minimal cancer in mice

We compared the DNA damage repair response of cancer cells after UVB or UVC irradiation. The DNA-damage repair response to UV irradiation was imaged in tumors growing in 3D Gelfoam® histoculture and in superficial tumors grown in mice. UV-induced DNA damage repair was imaged with GFP fused to the DNA damage response (DDR)-related chromatin-binding protein 53BP1 in MiaPaCa-2 human pancreatic cancer cells. 53BP1 forms foci during DNA damage repair. A clonogenic assay initially showed that UVC and UVB inhibited MiaPaCa-2 cell proliferation in a dose-dependent manner, with UVC having more efficacy. Gelfoam® histocultures and confocal imaging enabled 53BP1-GFP nuclear foci to be observed within 1 h after UV irradiation, indicating the onset of DNA damage repair response. Induction of UVB-induced 53BP1-GFP focus formation was observed up to a depth of 120 µm in MiaPaCa-2 cells on Gelfoam®, while UVC induced foci only to a depth of 40 µm. The MiaPaCa-2 cells irradiated by both UVB and UVC light in a skin-flap mouse model had a significant decrease in tumor growth compared to untreated controls. Moreover, UVB-treatment had greater inhibition of tumor growth compared to UVC. Our results demonstrate that both UVB and UVC are useful tools for the treatment of residual cancer, and UVB was more effective than UVC in vivo, possibly due to greater tissue penetration of UVB because of its longer wavelength.

Citation Format: Fuminari Uehara, Shinji Miwa, Yasunori Tome, Hiroki Maehara, Fuminori Kanaya, Yukihiko Hiroshima, Shuya Yano, Mako Yamamoto, Yasunori Matsumoto, Elena V. Efimova, Robert M. Hoffman. Imaging of UVB and UVC-induced DNA damage repair in cancer cells in Gelfoam histoculture and minimal cancer in mice. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2403. doi:10.1158/1538-7445.AM2014-2403

Osteosarcoma cells enhance angiogenesis visualized by color-coded imaging in the in vivo Gelfoam® assay

We previously described a color-coded imaging model that can quantify the length of nascent blood vessels using Gelfoam® implanted in nestin-driven green fluorescent protein (ND-GFP) nude mice. In ND-GFP mice, nascent blood vessels are labeled with GFP. We report here that osteosarcoma cells promote angiogenesis in the Gelfoam® angiogenesis assay in ND-GFP mice. Gelfoam® was initially transplanted subcutaneously in the flank of transgenic ND-GFP nude mice. Seven days after transplantation of Gelfoam®, skin flaps were made and human 143B osteosarcoma cells expressing green fluorescent protein (GFP) in the nucleus and red fluorescent protein (RFP) in cytoplasm were injected into the transplanted Gelfoam®. The control-group mice had only implanted Gelfoam®. Skin flaps were made at days 14, 21, and 28 after transplantation of the Gelfoam® to allow imaging of vascularization in the Gelfoam® using a variable-magnification small animal imaging system and confocal fluorescence microscopy. ND-GFP expressing nascent blood vessels penetrated and spread into the Gelfoam® in a time-dependent manner in both control and osteosarcoma-implanted mice. ND-GFP expressing blood vessels in the Gelfoam® of the osteosarcoma-implanted mice were associated with the cancer cells and larger and longer than in the Gelfoam®-only implanted mice (P < 0.01). The results presented in this report demonstrate strong angiogenesis induction by osteosarcoma cells and suggest this process is a potential therapeutic target for this disease.

Efficacy of Salmonella typhimurium A1-R versus chemotherapy on a pancreatic cancer patient-derived orthotopic xenograft (PDOX)

The aim of this study is to determine the efficacy of tumor-targeting Salmonella typhimurium A1-R (A1-R) on pancreatic cancer patient-derived orthotopic xenografts (PDOX). The PDOX model was originally established from a pancreatic cancer patient in SCID-NOD mice. The pancreatic cancer PDOX was subsequently transplanted by surgical orthotopic implantation (SOI) in transgenic nude red fluorescent protein (RFP) mice in order that the PDOX stably acquired red fluorescent protein (RFP)-expressing stroma for the purpose of imaging the tumor after passage to non-transgenic nude mice in order to visualize tumor growth and drug efficacy. The nude mice with human pancreatic PDOX were treated with A1-R or standard chemotherapy, including gemcitabine (GEM), which is first-line therapy for pancreatic cancer, for comparison of efficacy. A1-R treatment significantly reduced tumor weight, as well as tumor fluorescence area, compared to untreated control (P = 0.011), with comparable efficacy of GEM, CDDP, and 5-FU. Histopathological response to treatment was defined according to Evans's criteria and A1-R had increased efficacy compared to standard chemotherapy. The present report is the first to show that A1-R is effective against a very low-passage patient tumor, in this case, pancreatic cancer. The data of the present report suggest A1-1 will have clinical activity in pancreatic cancer, a highly lethal and treatment-resistant disease and may be most effectively used in combination with other agents.

Fluorescence-guided surgery in combination with UVC irradiation cures metastatic human pancreatic cancer in orthotopic mouse models

The aim of this study is to determine if ultraviolet light (UVC) irradiation in combination with fluorescence-guided surgery (FGS) can eradicate metastatic human pancreatic cancer in orthotopic nude–mouse models. Two weeks after orthotopic implantation of human MiaPaCa-2 pancreatic cancer cells, expressing green fluorescent protein (GFP), in nude mice, bright-light surgery (BLS) was performed on all tumor-bearing mice (n = 24). After BLS, mice were randomized into 3 treatment groups; BLS-only (n = 8) or FGS (n = 8) or FGS-UVC (n = 8). The residual tumors were resected using a hand-held portable imaging system under fluorescence navigation in mice treated with FGS and FGS-UVC. The surgical resection bed was irradiated with 2700 J/m² UVC (254 nm) in the mice treated with FGS-UVC. The average residual tumor area after FGS (n = 16) was significantly smaller than after BLS only (n = 24) (0.135±0.137 mm² and 3.338±2.929 mm², respectively; p = 0.007). The BLS treated mice had significantly reduced survival compared to FGS- and FGS-UVC-treated mice for both relapse-free survival (RFS) (p<0.001 and p<0.001, respectively) and overall survival (OS) (p<0.001 and p<0.001, respectively). FGS-UVC-treated mice had increased RFS and OS compared to FGS-only treated mice (p = 0.008 and p = 0.025, respectively); with RFS lasting at least 150 days indicating the animals were cured. The results of the present study suggest that UVC irradiation in combination with FGS has clinical potential to increase survival.