Shuya Yano1, Kiyoto Takehara1, Shinji Miwa2, Hiroyuki Kishimoto3, Hiroshi Tazawa4, Yasuo Urata5, Shunsuke Kagawa3, Michael Bouvet6, Toshiyoshi Fujiwara3, Robert M Hoffman7. 1. AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A. Department of Gastroenterological Surgery, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. 2. AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A. 3. Department of Gastroenterological Surgery, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan. 4. Center for Innovative Clinical Medicine, Okayama University Hospital, Okayama, Japan. 5. Oncolys BioPharm Inc., Tokyo, Japan. 6. Department of Surgery, University of California, San Diego, CA, U.S.A. 7. AntiCancer, Inc., San Diego, CA, U.S.A. Department of Surgery, University of California, San Diego, CA, U.S.A. all@anticancer.com.
Abstract
AIM: We describe 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. MATERIALS AND METHODS: MDA-MB-231 cells expressing red fluorescent protein (RFP) (1×10(7) cells/site) were initially injected subcutaneously in the flank of nude mice. After the subcutaneous tumors grew, they were harvested and cut into small pieces for orthotopic implantation in the right lower mammary gland. After the orthotopic tumors grew, they were resected and cut into small pieces and orthotopically re-implanted into the mammary gland of nude mice. The tumors grew and metastasized to lymph nodes. The lymph node metastases were harvested and cut into small pieces and orthotopically re-implanted into the mammary gland of nude mice. After the orthotopic tumors grew, the tumor was removed leaving residual cancer cells, which grew and metastasized to lymph nodes. The lymph node metastases were harvested, cut into pieces and orthotopically re-implanted into the mammary gland of nude mice for two cycles and then isolated. RESULTS: The isolated variant is highly invasive in the mammary gland and metastasized to lymph nodes in 10 of 12 mice compared to 2 of 12 of the parental cell line. CONCLUSION: The availability of a highly invasive variant of TNBC targeting lymph nodes will be very useful for drug discovery of TNBC, a recalcitrant cancer and for mechanistic studies of its aggressiveness. Copyright
AIM: We describe the development of a highly-invasive, triple-negative breast cancer (TNBC) variant using serial orthotopic implantation of MDA-MB-231 humanbreast cancer in nude mice. MATERIALS AND METHODS: MDA-MB-231 cells expressing red fluorescent protein (RFP) (1×10(7) cells/site) were initially injected subcutaneously in the flank of nude mice. After the subcutaneous tumors grew, they were harvested and cut into small pieces for orthotopic implantation in the right lower mammary gland. After the orthotopic tumors grew, they were resected and cut into small pieces and orthotopically re-implanted into the mammary gland of nude mice. The tumors grew and metastasized to lymph nodes. The lymph node metastases were harvested and cut into small pieces and orthotopically re-implanted into the mammary gland of nude mice. After the orthotopic tumors grew, the tumor was removed leaving residual cancer cells, which grew and metastasized to lymph nodes. The lymph node metastases were harvested, cut into pieces and orthotopically re-implanted into the mammary gland of nude mice for two cycles and then isolated. RESULTS: The isolated variant is highly invasive in the mammary gland and metastasized to lymph nodes in 10 of 12 mice compared to 2 of 12 of the parental cell line. CONCLUSION: The availability of a highly invasive variant of TNBC targeting lymph nodes will be very useful for drug discovery of TNBC, a recalcitrant cancer and for mechanistic studies of its aggressiveness. Copyright
Keywords:
Breast cancer; MDA-MB-231; high metastasis variant; in vivo selection; lymph node; metastasis; nude mice; orthothopic transplantation; red fluorescent protein (RFP); triple negative