Research target: We conducted the research to determine the distribution of 131I-nimotuzumab through the indication of the radioactivity in tissues of nude mice bearing human head and neck cancer tumors.
JOURNAL OF MILITARY PHARMACO-MEDICINE No7-2015 BIODISTRIBUTION OF MONOCLONAL ANTIBODY NIMOTUZUMAB LABELED 131I ON NUDE MICE BEARING HUMAN HEAD AND NECK CANCER Nguyen Thi Kim Huong*; Ho Anh Son**; Nguyen Thi Thu*** Pham Huy Quyen*; Nguyen Linh Toan** SUMMARY 131 Research target: We conducted the research to determine the distribution of I-nimotuzumab through the indication of the radioactivity in tissues of nude mice bearing human head and neck 131 cancer tumors Subject and methods: The I-nimotuzumab was injected into the mice’s veins at the dose of 100 µCi per mouse, and radioactivity was counted at three time points: 24, 48, and 72 hours after the injection Results: The research results showed that all the tissues and organs manifested the radioactivity In tumor, the radioactivity count was higher than that of any other organs The highest indication was 48 hours after the injection, and then gradually declined Radioactivity of the tumor was 79,26% compared to blood count at 72 hours after the 131 injection Conclusion: With blood normalize, distribution of I-nimotuzumab in tumors is the highest compared with other tissues and organs of the nude mice * Key words: Head and neck cancer; Monoclonal antibody nimotuzumab labeled INTRODUCTION Head and neck cancer is a disease with high incidence in the world, as well as in Vietnam, about 10% of annual cancer patients diagnosed with head and neck cancer among total number of cancer patients [1] Head and neck cancer is varied and complex, expressed in multiple locations, offices, including throat cancer, mouth floor, lowering the larynx and throat, salivary glands, tongue, thyroid , causing the rear significant effects on health, the patient lives if not diagnosed early and treated promptly Head and neck cancer has higher expression amount of EGFR (EGFR: Epidermal Growth Factor Receptor) I; Nude mice in an unusual way, is one of the important pathogenetic factors of growth, invasion excessive encroachment cancer cells in multiple parts of the body [4] Previous studies have confirmed that blocking EGFR will inactivate or prevent the growth and metastasis of cancer cells, allowing the treatment to be effective One of the products targeted for treatment purposes is 131I-nimotuzumab To evaluation effect of 131I-nimotuzumab on head and neck cancer, in this study, we measured the distribution of 131I-nimotuzumab in the tissues of nude mice bearing human head and neck cancer * Institute of Nuclear Research ** Vietnam Military Medical University *** Haiphong Pharmaco-Medical University Corresponding author: Ho Anh Son (hoanhsonhp@gmail.com) 34 131 JOURNAL OF MILITARY PHARMACO-MEDICINE No7-2015 SUBJECTS AND METHODS Materials, chemicals - Nimotuzumab monoclonal antibodies labeled with 131I radioisotope, produced at the Institute of Nuclear Research, radioactive concentrations 100 mCi/mL - Gamma counting camera Research subjects BALB/c immune deficiency mice without T lymphocytes (nude mice, Foxn1nu) imported from Charlie - River Company (USA) They were kept in clean rooms, and filtered air with positive pressure Room temperature is maintained at 25 ± 20C and humidity of 55 ± 5%, the light is automatically switched control at 7h00, off at 19h00 Food (Zeigler, USA) and sterilized water were ad libitum Each mouse cage is put on a track system with independent ventilation and membrane filtration ensures the good isolation with pathogens to block the thyroid gland, and then, daily ingested water mix with lugol (1 drop of lugol/5 mL water) - 131I-nimotuzumab (100 Ci) was injected into mouse tail vein [2] Then, animals were deeply anesthetized and internal organs like liver, spleen, kidneys, heart, blood, muscle, intestine, lung, tumor and thyroid gland were removed to weigh and measure radiation in order to calculate the distribution for each tissue RESULTS Distribution of 131I-nimotuzumab in tissues of the mice Table 1: Distribution of 131I-nimotuzumab in tissues of mice after 24, 48 and 72 hours (counts/mg) n = 18 ORGANS AVERAGE RADIATION COUNTS (10s) 24 hours 48 hours 72 hours Blood 1114.42 832.16 320.01 Mice transplanted larynx cancer cells Hep (106 cells/mouse), after tumor reached diameter of about 10 mm, then each animal was injected 100 µL 131I-nimotuzumab (100 µCi each) and randomly divided into groups: Tumor 221.83 350.32 253.63 Muscle 95.94 61.24 32.95 Heart 204.65 164.19 75.84 Lung 351.78 301.84 128.67 Kidney 217.32 146.76 160.00 + Group (n = 6): Radiation measurements 24 hours after injection Liver 167.69 132.98 48.25 Bowel 163.99 71.06 34.87 + Group (n = 6): Radioactivity measured 48 hours after injection Thyroid 189.76 151.76 86.36 Spleen 189.12 127.00 44.04 + Group (n = 6): Radioactivity measured 72 hours after injection Research method - Mice took lugol 1%, drop/head, 24 hours before injecting 131I-nimotuzumab complex Results of biological distribution in mice showed that 131I-nimotuzumab radioactive compound distributed the highest in the blood at all the times and tend to decrease at the time 48 and 72 hours 35 JOURNAL OF MILITARY PHARMACO-MEDICINE No7-2015 1200.00 Activation of beta rays in tissues (count x 103/mg/10sec) 1000.00 800.00 ave24g Ave 24g 600.00 ave48g Ave 48g Ave 72g ave72g 400.00 200.00 0.00 Blood Tumor Muscle Heart Lung Kidney Liver Bowel Thyroid Spleen Figure 1: Kinetics of 131I-nimotuzumab distribution in mice tissues and organs The count in tumor tissue was the highest at 48 hours and equivalent compared with lung Other organ counts were lower than these two Radiation activity in other tissue was lower than those in tumor and lung Comparing 131I-nimotuzumab distribution in tissues compared to blood Table 2: Radiation counts of tissues compared with blood ORGANS 24 HOURS (n = 6) % 48 HOURS (n = 6) % 72 HOURS (n = 6) % Blood 100 100 100 Tumor 19.91 42.10 79.26 Muscle 8.61 7.36 10.30 Heart 18.36 19.73 23.70 Lung 31.57 36.27 40.21 Kidney 19.50 17.64 50.00 Liver 15.05 15.98 15.08 Bowel 14.72 8.54 10.90 Thyroid 17.03 18.24 26.99 Spleen 16.97 15.26 13.76 Biodistribution of 131I-nimotuzumab was the highest in blood at all time points and gradually reduced by the time 36 JOURNAL OF MILITARY PHARMACO-MEDICINE No7-2015 Counting ratios of tissues compared with the blood 100% 80% 72g 48g 24g 60% 40% 20% 0% Blood Tumor Muscle Heart Lung Kidney Liver Bowel Thyroid Spleen Figure 2: Percentage of organs compared with the blood of nude mice At the time 48 and 72 hours, normalize by blood counts, the radial activity of tumor was the highest compared to other tissues DISCUSSION The distribution of radioactivity on the tissues, including human head and neck cancer tumors in nude mice showed that it was expressed in all examined tissues, and the ratios were different among tissues, especially highest in the blood (1114.42 μCi/g) and lowest in muscle (95.94 μCi/g) at 24 hours after injection, and then the radioactivity tends to decrease at 48 hours and 72 hours after injection After injection of 131I-nimotuzumab, antibody molecules were concentrated in the blood and had the highest ratio, then they will move to the target tissue and attached to its EGFR, so radioactivity decreased due to degredation and elimination On the contrary, in tumor, radioactive count of 131I-nimotuzumab increased gradually in 48 hours and it was higher than other tissues which expressed high levels of EGFR in tumors, as other studies had demonstrated [4, 5], is the destination for the 131I-nimotuzumab attaches to and focus there, making the radiation increase in tumor High degree of EGFR expression in cancer cells is believed to be associated with increased levels of malignant progression as fast, easy-invasive and prone to relapse, but at the same time it is a favorable factor for therapy destination and treatment are much better prospects of therapeutic monoclonal antibodies used in combination with radiation and anti-cancer chemicals [3] CONCLUSION 131 I-nimotuzumab is showed in tissues after intravenous injection 24 hours and counting radioactive ratios in tissues were 37 JOURNAL OF MILITARY PHARMACO-MEDICINE No7-2015 not equal, the highest expression levels in time 48 hours after injection and then decreased gradually Distribution of 131 I-nimotuzumab in tumors compared with blood was the highest in compare to other tissues at 48 hours At 72 hours, it reached 79.26% against in blood Denis Rolando Beckford Vera, Sebastian Eigner, Milos Beran, Katherina Eigner Henke, Alice Laznickova, Milan Laznicez, Frantisek Melichar, and Marco Chinol Preclinical evaluation of 177Lu-nimotuzumab: a potential tool for radioimmunotherapy of epidermal growth factor receptor over expressing tumors cancer Biotherapy and Radiopharmaceuticals 2011, Vol 26, No REFERENCES Herbst RS Review of epidermal growth factor receptor biology Int J Radiat Oncol Biol Phys 2004, 59 University of Medicine and Pharmacy in Hochiminh City Thematic oncology, Cancer Prevention Workshop Hochiminh City 13th 2010, Appendix, Vol 14, No Gopal B Saha Fundamentals of Nuclear Pharmacy Sixth Edition Springer 2012 38 Ariel Talavera, Rosmarie Friemann, Silvia Gómez-Puerta et al Nimotuzumab, an antitumor antibody that targets the epidermal growth factor receptor, blocks ligand binding while permitting the active receptor conformation Cancer Res 2009 ... distribution of radioactivity on the tissues, including human head and neck cancer tumors in nude mice showed that it was expressed in all examined tissues, and the ratios were different among tissues,... therapeutic monoclonal antibodies used in combination with radiation and anti -cancer chemicals [3] CONCLUSION 131 I -nimotuzumab is showed in tissues after intravenous injection 24 hours and counting... lung, tumor and thyroid gland were removed to weigh and measure radiation in order to calculate the distribution for each tissue RESULTS Distribution of 131I -nimotuzumab in tissues of the mice Table