Tumor-targeting Salmonella typhimurium A1-R combined with temozolomide regresses malignant melanoma with a BRAF-V600E mutation in a patient-derived orthotopic xenograft (PDOX) model
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Kei Kawaguchi1,2,3, Kentaro Igarashi1,2, Takashi Murakami1,2, Bartosz Chmielowski4, Tasuku Kiyuna1,2, Ming Zhao1, Yong Zhang1, Arun Singh4, Michiaki Unno3, Scott D. Nelson5, Tara A. Russell6, Sarah M. Dry5, Yunfeng Li5, Fritz C. Eilber6, Robert M. Hoffman1,2
1AntiCancer, Inc., San Diego, CA, USA
2Department of Surgery, University of California, San Diego, CA, USA
3Department of Surgery, Graduate School of Medicine, Tohoku University, Sendai, Japan
4Division of Hematology-Oncology, University of California, Los Angeles, CA, USA
5Department of Pathology, University of California, Los Angeles, CA, USA
6Division of Surgical Oncology, University of California, Los Angeles, CA, USA
Robert M. Hoffman, email: [email protected]
Fritz C. Eilber, email: [email protected]
Keywords: melanoma, PDOX, nude mice, orthotopic, drug-response
Received: September 14, 2016 Accepted: October 27, 2016 Published: November 09, 2016
Melanoma is a recalcitrant disease in need of transformative therapuetics. The present study used a patient-derived orthotopic xenograft (PDOX) nude-mouse model of melanoma with a BRAF-V600E mutation to determine the efficacy of temozolomide (TEM) combined with tumor-targeting Salmonella typhimurium A1-R. A melanoma obtained from the right chest wall of a patient was grown orthotopically in the right chest wall of nude mice to establish a PDOX model. Two weeks after implantation, 40 PDOX nude mice were divided into 4 groups: G1, control without treatment (n = 10); G2, TEM (25 mg/kg, administrated orally daily for 14 consecutive days, n = 10); G3, S. typhimurium A1-R (5 × 107 CFU/100 μl, i.v., once a week for 2 weeks, n = 10); G4, TEM combined with S. typhimurium A1-R (25 mg/kg, administrated orally daily for 14 consecutive days and 5 × 107 CFU/100 μl, i.v., once a week for 2 weeks, respectively, n = 10). Tumor sizes were measured with calipers twice a week. On day 14 from initiation of treatment, all treatments significantly inhibited tumor growth compared to untreated control (TEM: p < 0.0001; S. typhimurium A1-R: p < 0.0001; TEM combined with S. typhimurium A1-R: p < 0.0001). TEM combined with S. typhimurium A1-R was significantly more effective than either S. typhimurium A1-R (p = 0.0004) alone or TEM alone (p = 0.0017). TEM combined with S. typhimurium A1-R could regress the melanoma in the PDOX model and has important future clinical potential for melanoma patients.
Melanoma becomes a recalcitrant cancer when it metastasizes to regional lymph nodes, with a 5-year survival rate of 29% and 7% when it metastasizes to organs . Dacarbazine and cisplatinum have been used to treat melanoma with limited efficacy [1–5]. Temozolomide (TEM) is an alkylating agent, had been widely used as a first-line chemotherapy for melanoma but with limited efficacy [1–5]. Although recently-developed immuno-therapy has extended survival to some extent, the 5-year survival rate has not significantly increased [1–5]. There is still no cure for stage III and IV melanoma due to drug resistance, tumor heterogeneity and an immune-suppressed tumor microenvironment . Therefore, more effective approaches to melanoma treatment are needed.
Clinically-relevant mouse models of melanoma could permit evaluation of tailor-made therapy based on the patient-derived tumor. Our laboratory pioneered the patient-derived orthotopic xenograft (PDOX) nude mouse model with the technique of surgical orthotopic implantation (SOI), including pancreatic [6–9], breast , ovarian , lung , cervical , colon [14–16], stomach , sarcoma [18–22], and melanoma .
The tumor-targeting Salmonella typhimurium A1-R (S. typhimurium A1-R), developed by our laboratory , is auxotrophic for Leu-Arg, which prevents it from mounting a continuous infection in normal tissues. S. typhimurium A1-R was effective against primary and metastatic tumors as monotherapy in nude mouse models of major cancers including prostate [25, 26], breast [27–29], lung [30, 31], pancreatic [8, 32–35], ovarian [36, 37] stomach , and cervical cancer , as well as sarcoma cell lines [40–42] and glioma [43, 44], all of which are highly aggressive tumor models. In addition, S. typhimurium A1-R was effective against patient-derived orthotopic models of pancreatic cancer [8, 35], sarcoma [20–22] and melanoma .
In a previous study, we used the PDOX model of melanoma to test sensitivity to three molecularly-targeted drugs and one standard chemotherapeutic. A melanoma with a BRAF-V600E mutation was resected from the right chest wall of a patient. The melanoma was grown orthotopically in the right chest wall of nude mice to establish a PDOX model. Trametinib (TRA), a MEK inhibitor caused tumor regression. In contrast, another MEK inhibitor, cobimetinib (COB), slowed but did not arrest growth or cause regression of the melanoma. TEM could slow but not arrest tumor growth or cause regression. Vemrafenib (VEM), which targets the BRAF-V600E mutation would be considered to be a strong candidate for VEM as first-line therapy, was not effective. These results demonstrated the powerful precision of the PDOX model for cancer therapy, not achievable by genomic analysis alone .
The combination of S. typhimurium A1-R and cisplatinum (CDDP), both at low-dose, also significantly suppressed the growth of another melanoma PDOX with less side effects than high-dose CDDP monotherapy .
In the present study, we evaluated the efficacy of S. typhimurium A1-R alone and in combination with TEM on a PDOX model for melanoma with the BRAF-V600E mutation.
RESULTS AND DISCUSSION
All treatments significantly inhibited tumor growth compared to untreated control (TEM: p < 0.0001; S. typhimurium A1-R: p < 0.0001; TEM combined with S. typhimurium A1-R: p < 0.0001) on day 14 after initiation. TEM combined with S. typhimurium A1-R was significantly more effective than both S. typhimurium A1-R (p = 0.0004) and TEM alone (p = 0.0017) and regressed the tumor. There was no significant difference between the efficacy of S. typhimurium A1-R and TEM on the melanoma PDOX (p = 0.5205) (Figures 1, 2). The relative body weight on day 14 compared with day 0 did not significantly differ between each treatment group (Figure 3).
Figure 1: Macroscopic demonstration of therapeutic efficacy of TEM and S. typhimurium A1-R on a melanoma PDOX. (A) Tumor size of the untreated control mice increased over time. (B, C) Tumors treated with TEM or S. typhimurium A1-R were inhibited. (D) Tumors treated with TEM combined with S. typhimurium A1-R regressed. Yellow arrows show PDOX tumors on right chest wall. Scale bar: 20 mm.
Figure 2: TEM combined with S. typhimurium A1-R regressed a melanoma PDOX model. Line graph shows relative tumor volume at each point relative to the initial tumor volume. TEM combined with S. typhimurium A1-R significantly regressed tumor growth compared to both untreated control and monotherapy of either agent. **p < 0.01. Error bars: ± SD.
Figure 3: Effect of TEM combined with S. typhimurium A1-R on mouse body weight. Bar graph shows relative body weight in each treatment group at pre- and post-treatment relative to initial body weight. There were no significant differences between any of the treatment groups and control.
Figure 4: Fluorescence imaging of S. typhimurium A1-R-GFP targeting the melanoma PDOX. Confocal imaging with the FV1000 demonstrated S. typhimurium A1-R-GFP targeting the melanoma PDOX. Bars: left panel: 5 mm, right panel: 12.5 μm.
Figure 5: Tumor histology. (A) Untreated control was comprised of viable cells without obvious necrosis. (B) Tumor treated with S. typhimurium A1-R had significant necrosis. (C) Tumor treated with the combination of TEM and S. typhimurium A1-R showed more necrosis. White allows: necrotic areas. Scale bars: 100 μm.
The histology of the original patient tumor and the untreated PDOX tumor were similar, containing the same types of cells. However, nests of cancer cells were seen in the original, but not in the PDOX. Also, the original tumor was slightly melanotic, but the PDOX tumor did not appear to contain melanin .
TEM, an alkylating agent, had been widely used as a standard chemotherapy for melanoma. Currently, several molecular targeting agents or immunotherapy are often the first line for melanoma treatment. However, not all melanomas have mutations that are targeted by these new agents and not all patients with these mutations are responsive to these drugs .
We previously showed with the present melanoma PDOX that TRA, a MEK inhibitor, was very active and could arrest this tumor, but that COB, another MEK inhibitor, could not arrest the melanoma PDOX. In addition, we showed the VEM was inactive against this melanoma PDOX , even though it targets the BRAF-V600E mutation in this melanoma .
Despite progress in melanoma therapy, there is still no cure for stage III and IV disease due to drug resistance, tumor heterogeneity and an immunosuppressive tumor microenvironment [1–5]. In addition, the presence of melanin appears to interfere with chemotherapy and radiotherapy of this recalcitrant disease . The present results demonstrate the potential of S. typhimurium A1-R to significantly increase the efficacy of first-line melanoma therapy, TEM.
MATERIALS AND METHODS
Athymic nu/nu nude mice (AntiCancer Inc., San Diego, CA), 4–6 weeks old, were used in this study. All mouse surgical procedures and imaging were performed with the animals anesthetized by subcutaneous injection of a ketamine mixture (0.02 ml solution of 20 mg/kg ketamine, 15.2 mg/kg xylazine, and 0.48 mg/kg acepromazine maleate). The response of animals during surgery was monitored to ensure adequate depth of anesthesia. The animals were observed on a daily basis and humanely sacrificed by CO2 inhalation if they met the following humane endpoint criteria: severe tumor burden (more than 20 mm in diameter), prostration, significant body weight loss, difficulty breathing, rotational motion and body temperature drop. Animals were housed in a barrier facility on a high efficacy particulate arrestance (HEPA)-filtered rack under standard conditions of 12-hour light/dark cycles. The animals were fed an autoclaved laboratory rodent diet. All animal studies were conducted in accordance with the principles and procedures outlined in the National Institutes of Health Guide for the Care and Use of Animals under Assurance Number A3873-1.
A 75-year-old female patient diagnosed with a melanoma of the right chest wall. The tumor was resected in the Department of Surgery, University of California, Los Angeles (UCLA). Written informed consent was provided by the patient, and the Institutional Review Board (IRB) of UCLA approved this experiment .
Establishment of PDOX models of melanoma by surgical orthotopic implantation (SOI)
A fresh sample of the melanoma of the patient was obtained and transported immediately to the laboratory at AntiCancer, Inc., on wet ice. The sample was cut into 5-mm fragments and implanted subcutaneously in nude mice. After three weeks, the subcutaneously-implanted tumors grew to more than 10 mm in diameter. The subcutaneously-grown tumors were then harvested and cut into small fragments (3 mm3). After nude mice were anesthetized with the ketamine solution described above, a 5-mm skin incision was made on the right chest into the chest wall, which was split to make space for the melanoma tissue fragment. A single tumor fragment was implanted orthotopically into the space to establish the PDOX model. The wound was closed with a 6–0 nylon suture (Ethilon, Ethicon, Inc., NJ, USA) .
Preparation and administration of S. typhimurium A1-R
GFP-expressing S. typhimurium A1-R bacteria (AntiCancer Inc.,) were grown overnight on LB medium (Fisher Sci., Hanover Park, IL, USA) and then diluted 1:10 in LB medium. Bacteria were harvested at late-log phase, washed with PBS, and then diluted in PBS. S. typhimurium A1-R was injected intravenously. A total of 5 × 107 CFU S. typhimurium A1-R in 100 μl PBS was administered to each mouse [25–27].
Treatment study design in the PDOX model of melanoma
PDOX mouse models were randomized into four groups of 10 mice each: untreated control (n = 10); treated with TEM (25 mg/kg, administrated orally daily for 14 consecutive days, n = 10) ; treated with S. typhimurium A1-R (5 × 107 CFU/100 μl, i.v., once a week for 2 weeks, n = 10); treated with TEM (25 mg/kg, administrated orally daily for 14 consecutive days) combined with S. typhimurium A1-R (5 × 107 CFU/100 μl, i.v., once a week for 2 weeks, n = 10). Tumor length and width were measured twice a week. Tumor volume was calculated with the following formula: Tumor volume (mm3) = length (mm) × width (mm) × width (mm) × 1/2. Data are presented as mean ± SD. The tumor volume ratio is defined at the tumor volume at any given time point relative to the initial tumor volume.
The FV1000 confocal microscope (Olympus, Tokyo, Japan) was used for high-resolution imaging. Fluorescence images were obtained using the 20×/0.50 UPlan FLN and 40×/1.3 oil Olympus UPLAN FLN objectives .
Fresh tumor samples were fixed in 10% formalin and embedded in paraffin before sectioning and staining. Tissue sections (5 μm) were deparaffinized in xylene and rehydrated in an ethanol series. Hematoxylin and eosin (H&E) staining was performed according to standard protocols. Histological examination was performed with a BHS System Microscope (Olympus Corporation, Tokyo, Japan). Images were acquired with INFINITY ANALYZE software (Lumenera Corporation, Ottawa, Canada) .
JMP version 11.0 was used for all statistical analyses. Significant differences for continuous variables were determined using the Mann-Whitney U test. Line graphs expressed average values and error bar showed SD. A probability value of P ≤ 0.05 was considered statistically significant.
The combination of TEM and S. typhimurium A1-R was more effective than each mono-therapy for melanoma in a PDOX mouse model and could regress the tumor. This treatment strategy has important future clinical application, which possibly can be realized in the near future.
Previously-developed concepts and strategies of highly-selective tumor targeting can take advantage of molecular targeting of tumors, including tissue-selective therapy which focuses on unique differences between normal and tumor tissues [48–53].
ACKNOWLEDGMENTS AND FUNDING
This paper is dedicated to the memory of A.R. Moossa, MD, and Sun Lee, MD.
CONFLICTS OF INTEREST
There are no competing interests.
1. Chapman PB, Hauschild A, Robert C, Haanen JB, Ascierto P, Larkin J, Dummer R, Garbe C, Testori A, Maio M, Hogg D, Lorigan P, Lebbe C, et al. Improved survival with vemurafenib in melanoma with BRAF V600E mutation. N Engl J Med. 2011; 364:2507–2516.
2. Tang H, Wang Y, Chlewicki LK, Zhang Y, Guo J, Liang W, Wang J, Wang X, Fu YX. Facilitating T Cell infiltration in tumor microenvironment overcomes resistance to PD-L1 blockade. Cancer Cell. 2016; 29:285–296.
3. Brożyna AA, Jóźwicki W, Roszkowski K, Filipiak J, Slominski AT. Melanin content in melanoma metastases affects the outcome of radiotherapy. Oncotarget. 2016; 7:17844–17853. doi: 10.18632/oncotarget.7528.
4. Slominski AT, Carlson JA. Melanoma resistance: a bright future for academicians and a challenge for patient advocates. Mayo Clin Proc. 2014; 89:429–433.
5. Flaherty LE, Othus M, Atkins MB, Tuthill RJ, Thompson JA, Vetto JT, Haluska FG, Pappo AS, SosmanJA, Redman BG, Moon J, Ribas A, Kirkwood JM, et al. Southwest Oncology Group S0008: a phase III trial of high-dose interferon Alfa-2b versus cisplatin, vinblastine, and dacarbazine, plus interleukin-2 and interferon in patients with high-riskmelanoma--an intergroup study of cancer and leukemia Group B, Children’s Oncology Group, Eastern Cooperative Oncology Group, and Southwest Oncology Group. J Clin Oncol. 2014; 32:3771–3778.
6. Fu X, Guadagni F, Hoffman RM. A metastatic nude-mouse model of human pancreatic cancer constructed orthotopically with histologically intact patient specimens. Proc Natl Acad Sci USA. 1992; 89:5645–5649.
7. Hiroshima Y, Maawy A, Zhang Y, Murakami T, Momiyama M, Mori R, Matsuyama R, Katz MH, Fleming JB, Chishima T, Tanaka K, Ichikawa Y, Endo I, et al. Metastatic recurrence in a pancreatic cancer patient derived orthotopic xenograft (PDOX) nude mouse model is inhibited by neoadjuvant chemotherapy in combination with fluorescence-guided surgery with an anti-CA 19–9-conjugated fluorophore. PLOS ONE. 2014; 9:e114310.
8. Hiroshima Y, Zhang Y, Murakami T, Maawy AA, Miwa S, Yamamoto M, Yano S, Sato S, Momiyama M, Mori R, Matsuyama R, Chishima T, Tanaka K, et al. Efficacy of tumor-targeting Salmonella typhimurium A1-R in combination with anti-angiogenesis therapy on a pancreatic cancer patient-derived orthotopic xenograph (PDOX) and cell line mouse models. Oncotarget. 2014; 5:12346–12357. doi: 10.18632/oncotarget.2641.
9. Hiroshima Y, Maawy AA, Katz MH, Fleming JB, Bouvet M, Endo I, Hoffman RM. Selective efficacy of zoledronic acid on metastasis in a patient-derived orthotopic xenograph (PDOX) nude-mouse model of human pancreatic cancer. J Surg Oncol. 2015; 111:311–315.
10. Fu X, Le P, Hoffman RM. A metastatic-orthotopic transplant nude-mouse model of human patient breast cancer. Anticancer Res. 1993; 13:901–904.
11. Fu X, Hoffman RM. Human ovarian carcinoma metastatic models constructed in nude mice by orthotopic transplantation of histologically-intact patient specimens. Anticancer Res. 1993; 13:283–286.
12. Wang X, Fu X, Hoffman RM. A new patient-like metastatic model of human lung cancer constructed orthotopically with intact tissue via thoracotomy in immunodeficient mice. Int J Cancer. 1992; 51:992–995.
13. Hiroshima Y, Zhang Y, Zhang M, Maawy A, Mii S, Yamamoto M, Uehara F, Miwa S, Yano S, Murakami T, Momiyama M, Chishima T, Tanaka K, et al. Establishment of a patient-derived orthotopic xenograph (PDOX) model of HER-2-positive cervical cancer expressing the clinical metastatic pattern. PLOS ONE. 2015; 10:e0117417.
14. Fu X, Besterman JM, Monosov A, Hoffman RM. Models of human metastatic colon cancer in nude mice orthotopically constructed by using histologically intact patient specimens. Proc Natl Acad Sci USA. 1991; 88:9345–9349.
15. Metildi CA, Kaushal S, Luiken GA, Talamini MA, Hoffman RM, Bouvet M. Fluorescently-labeled chimeric anti-CEA antibody improves detection and resection of human colon cancer in a patient-derived orthotopic xenograft (PDOX) nude mouse model. J Surg Oncol. 2014; 109:451–458.
16. Hiroshima Y, Maawy A, Metildi CA, Zhang Y, Uehara F, Miwa S, Yano S, Sato S, Murakami T, Momiyama M, Chishima T, Tanaka K, Bouvet M, et al. Successful fluorescence-guided surgery on human colon cancer patient-derived orthotopic xenograft mouse models using a fluorophore-conjugated anti-CEA antibody and a portable imaging system. J Laparoendosc Adv Surg Tech A. 2014; 24:241–247.
17. Furukawa T, Kubota T, Watanabe M, Kitajima M, Fu X, Hoffman RM. Orthotopic transplantation of histologically intact clinical specimens of stomach cancer to nude mice: correlation of metastatic sites in mouse and individual patient donors. Int J Cancer. 1993; 53:608–612.
18. Hiroshima Y, Zhang Y, Zhang N, Uehara F, Maawy A, Murakami T, Mii S, Yamamoto M, Miwa S, Yano S, Momiyama M, Mori R, Matsuyama R, et al. Patient-derived orthotopic xenograft (PDOX) nude mouse model of soft-tissue sarcoma more closely mimics the patient behavior in contrast to the subcutaneous ectopic model. Anticancer Res. 2015; 35:697–701.
19. Hiroshima Y, Zhao M, Zhang Y, Zhang N, Maawy A, Murakami T, Mii S, Uehara F, Yamamoto M, Miwa S, Yano S, Momiyama M, Mori R, et al. Tumor-targeting Salmonella typhimurium A1-R arrests a chemo-resistant patient soft-tissue sarcoma in nude mice. PLOS ONE. 2015; 10:e0134324.
20. Murakami T, DeLong J, Eilber FC, Zhao M, Zhang Y, Zhang N, Singh A, Russell T, Deng S, Reynoso J, Quan C, Hiroshima Y, Matsuyama R, et al. Tumor-targeting Salmonella typhimurium A1-R in combination with doxorubicin eradicate soft tissue sarcoma in a patient-derived orthotopic xenograft PDOX model. Oncotarget. 2016; 7:12783–12790. doi: 10.18632/oncotarget.7226.
21. Kiyuna T, Murakami T, Tome Y, Kawaguchi K, Igarashi K, Zhang Y Zhao M, Li Y, Bouvet M, Kanaya F, Singh A, Dry S, Eilber FC, et al. High efficacy of tumor-targeting Salmonella typhimurium A1-R on a doxorubicin- and dactolisib-resistant follicular dendritic-cell sarcoma in a patient-derived orthotopic xenograft nude mouse model. Oncotarget. 2016; 7:33046–33054. doi: 10.18632/oncotarget.8848.
22. Murakami T, Singh AS, Kiyuna T, Dry SM, Li Y, James AW, Igarashi K, Kawaguchi K, DeLong JC, Zhang Y, Hiroshima Y, Russell T, Eckardt MA, et al. Effective molecular targeting of CDK4/6 and IGF-1R in a rare FUS-ERG fusion CDKN2A-deletion doxorubicin-resistant Ewing’s sarcoma patient-derived orthotopic xenograft (PDOX) nude-mouse model. Oncotarget. 2016; 7:47556–47564. doi: 10.18632/oncotarget.9879.
23. Yamamoto M, Zhao M, Hiroshima Y, Zhang Y, Shurell E, Eilber F,C, Bouvet M, Noda M, Hoffman RM. Efficacy of tumor-targeting Salmonella typhimurium A1-R on a melanoma patient-derived orthotopic xenograft (PDOX) nude-mouse model. PLoS One 2016; 11:e0160882.
24. Hoffman RM, Zhao M. Methods for the development of tumor-targeting bacteria. Expert Opin Drug Discov. 2014; 9:741–750.
25. Zhao M, Yang M, Li XM, Jiang P, Baranov E, Li S, Xu M, Penman S, Hoffman RM. Tumor-targeting bacterial therapy with amino acid auxotrophs of GFP-expressing Salmonella typhimurium. Proc Natl Acad Sci USA. 2005; 102:755–760.
26. Zhao M, Geller J, Ma H, Yang M, Penman S, Hoffman RM. Monotherapy with a tumor-targeting mutant of Salmonella typhimurium cures orthotopic metastatic mouse models of human prostate cancer. Proc Natl Acad Sci USA. 2007; 104:10170–10174.
27. Zhao M, Yang M, Ma H, Li X, Tan X, Li S, Yang Z, Hoffman RM. Targeted therapy with a Salmonella typhimurium leucine-arginine auxotroph cures orthotopic human breast tumors in nude mice. Cancer Res. 2006; 66:7647–7652.
28. Zhang Y, Tome Y, Suetsugu A, Zhang L, Zhang N, Hoffman RM, Zhao M. Determination of the optimal route of administration of Salmonella typhimurium A1-R to target breast cancer in nude mice. Anticancer Res. 2012; 32:2501–2508.
29. Zhang Y, Miwa S, Zhang N, Hoffman RM, Zhao M. Tumor-targeting Salmonella typhimurium A1-R arrests growth of breast-cancer brain metastasis. Oncotarget. 2015; 6:2615–2622. doi: 10.18632/oncotarget.2811.
30. Uchugonova A, Zhao M, Zhang Y, Weinigel M, König K, Hoffman RM. Cancer-cell killing by engineered Salmonella imaged by multiphoton tomography in live mice. Anticancer Res. 2012; 32:4331–4339.
31. Liu F, Zhang L, Hoffman RM, Zhao M. Vessel destruction by tumor-targeting Salmonella typhimurium A1-R is enhanced by high tumor vascularity. Cell Cycle. 2010; 9:4518–4524.
32. Nagakura C, Hayashi K, Zhao M, Yamauchi K, Yamamoto N, Tsuchiya H, Tomita K , Bouvet M, Hoffman RM. Efficacy of a genetically-modified Salmonella typhimurium in an orthotopic human pancreatic cancer in nude mice. Anticancer Res. 2009; 29:1873–1878.
33. Yam C, Zhao M, Hayashi K, Ma H, Kishimoto H, McElroy M, Bouvet M, Hoffman RM. Monotherapy with a tumor-targeting mutant of S. typhimurium inhibits liver metastasis in a mouse model of pancreatic cancer. J Surg Res. 2010; 164:248–255.
34. Hiroshima Y, Zhao M, Zhang Y, Maawy A, Hassanein MK, Uehara F, Miwa S, Yano S, Momiyama M, Suetsugu A, Chishima T, Tanaka K, Bouvet M, et al. Comparison of efficacy of Salmonella typhimurium A1-R and chemotherapy on stem-like and non-stem human pancreatic cancer cells. Cell Cycle. 2013; 12:2774–2780.
35. Hiroshima Y, Zhao M, Maawy A, Zhang Y, Katz MH, Fleming JB, Uehara F, Miwa S, Yano S, Momiyama M, Suetsugu A, Chishima T, Tanaka K, et al. Efficacy of Salmonella typhimurium A1-R versus chemotherapy on a pancreatic cancer patient-derived orthotopic xenograft (PDOX). J Cell Biochem. 2014; 115:1254–1261.
36. Matsumoto Y, Miwa S, Zhang Y, Hiroshima Y, Yano S, Uehara F, Yamamoto M, Toneri M, Bouvet M, Matsubara H, Hoffman RM, Zhao M. Efficacy of tumor-targeting Salmonella typhimurium A1-R on nude mouse models of metastatic and disseminated human ovarian cancer. J Cell Biochem. 2014; 115:1996–2003.
37. Matsumoto Y, Miwa S, Zhang Y, Zhao M, Yano S, Uehara F, Yamamoto M, Hiroshima Y, Toneri M, Bouvet M, Matsubara H, Tsuchiya H, Hoffman RM. Intraperitoneal administration of tumor-targeting Salmonella typhimurium A1-R inhibits disseminated human ovarian cancer and extends survival in nude mice. Oncotarget 2015; 6:11369–11377. doi: 10.18632/oncotarget.3607.
38. Yano S, Zhang Y, Zhao M, Hiroshima Y, Miwa S, Uehara F, Kishimoto H, Tazawa H, Bouvet M, Fujiwara T, and Hoffman RM. Tumor-targeting Salmonella typhimurium A1-R decoys quiescent cancer cells to cycle as visualized by FUCCI imaging and become sensitive to chemotherapy. Cell Cycle. 2014; 13:3958–3963.
39. Hiroshima Y, Zhang Y, Zhao M, Zhang N, Murakami T, Maawy A, Mii S, Uehara F, Yamamoto M, Miwa S, Yano S, Momiyama M, Mori R, et al. Tumor-targeting Salmonella typhimurium A1-R in combination with Trastuzumab eradicates HER-2-positive cervical cancer cells in patient-derived mouse models. PLoS One. 2015; 10:e0120358.
40. Hayashi K, Zhao M, Yamauchi K, Yamamoto N, Tsuchiya H, Tomita K, Hoffman RM. Cancer metastasis directly eradicated by targeted therapy with a modified Salmonella typhimurium. J Cell Biochem. 2009; 106:992–998.
41. Hayashi K, Zhao M, Yamauchi K, Yamamoto N, Tsuchiya H, Tomita K, Kishimoto H, Bouvet M, Hoffman RM. Systemic targeting of primary bone tumor and lung metastasis of high-grade osteosarcoma in nude mice with a tumor-selective strain of Salmonella typhimurium. Cell Cycle. 2009; 8:870–875.
42. Miwa S, Zhang Y, Baek K-E, Uehara F, Yano S, Yamamoto M, Hiroshima Y, Matsumoto Y, Kimura H, Hayashi K, Yamamoto N, Bouvet M, Tsuchiya H, et al. Inhibition of spontaneous and experimental lung metastasis of soft-tissue sarcoma by tumor-targeting Salmonella typhimurium A1-R. Oncotarget. 2014; 5:12849–12861. doi: 10.18632/oncotarget.2561.
43. Kimura H, Zhang L, Zhao M, Hayashi K, Tsuchiya H, Tomita K, Bouvet M, Wessels J, Hoffman RM. Targeted therapy of spinal cord glioma with a genetically-modified Salmonella typhimurium. Cell Proliferation. 2010; 43:41–48.
44. Momiyama M, Zhao M, Kimura H, Tran B, Chishima T, Bouvet M, Endo I, Hoffman RM. Inhibition and eradication of human glioma with tumor-targeting Salmonella typhimurium in an orthotopic nude-mouse model. Cell Cycle. 2012; 11:628–632.
45. Kawaguchi K, Murakami T, Chmielowski B, Igarashi K, Kiyuna T, Unno M, Nelson SD, Russell T, Dry SM, Li Y, Eilber FC, Hoffman RM. Vemurafenib-resistant BRAF-V600E mutated melanoma is regressed by MEK targeting drug trametinib, but not cobimetinib in a patient-derived orthotopic xenograft (PDOX) mouse model. Oncotarget. 2016; 7:71737–71743. doi: 10.18632/Oncotarget.12328.
46. Larkin J, Ascierto PA, Dréno B, Atkinson V, Liszkay G, Maio M, Mandalà M, Demidov L, Stroyakovskiy D, Thomas L, de la Cruz-Merino L, Dutriaux C, Garbe C, Sovak MA, Chang I, Choong N, Hack SP, McArthur GA, Ribas A. Combined vemurafenib and cobimetinib in BRAF-mutated melanoma. N Engl J Med. 2014; 371:1867–1876.
47. Uchugonova A, Duong J, Zhang N, König K, Hoffman RM. The bulge area is the origin of nestin-expressing pluripotent stem cells of the hair follicle. J Cell Biochem. 2011; 112:2046–2050.
48. Blagosklonny MV. Matching targets for selective cancer therapy. Drug Discov Today. 2003; 8:1104–1107.
49. Blagosklonny MV. Teratogens as anti-cancer drugs. Cell Cycle. 2005; 4:1518–1521.
50. Blagosklonny MV. Treatment with inhibitors of caspases, that are substrates of drug ransporters, selectively permits chemotherapy-induced apoptosis in multidrug-resistant cells but protects normal cells. Leukemia. 2001; 15:936–941.
51. Blagosklonny MV. Target for cancer therapy: proliferating cells or stem cells. Leukemia. 2006; 20:385–391.
52. Apontes P, Leontieva OV, Demidenko ZN, Li F, Blagosklonny MV. Exploring long-term protection of normal human fibroblasts and epithelial cells from chemotherapy in cell culture. Oncotarget. 2011; 2:222–233. doi: 10.18632/oncotarget.248.
53. Blagosklonny MV. Tissue-selective therapy of cancer. Br J Cancer. 2003; 89:1147–1151.
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