title: Labeling and Biological Evaluation of (99m)Tc-HYNIC-Trastuzumab as a Potential Radiopharmaceutical for In Vivo Evaluation of HER2 Expression in Breast Cancer.
abstract: The amplification of HER2 gene has been described in several tumor types, mainly breast cancer with a subsequent increase in HER2 protein expression. Trastuzumab is a humanized monoclonal antibody that recognizes selectively the HER2 extracellular domain. The objective of the present work was to standardize the conjugation of Trastuzumab with Succinimidyl-hydrazinonicotinamide (HYNIC) and labeling with (99m)Tc to obtain (99m)Tc-HYNIC-Trastuzumab for use as in vivo tracer of the HER2 expression in breast cancer. The labeling procedure involved derivatization of 0.067 μmol of Trastuzumab with 0.33 μmols of HYNIC in dimethyl sulfoxide (DMSO). The mixture was incubated for 30 min. A mixture of Tricine and SnCl2.2H2O was prepared by add a solution of 44.6 μmols Tricine in 0.05 mL HCl 2.0 M and a similar volume of another solution containing 44.3 μmols SnCl2.2H2O in 0.5 mL HCl 2.0 M. Then, 0.05 mL of this mixed was added to the conjugated with 296 MBq of 99mTcO-4. The final mixture was incubated at room temperature (18-25°C) for 30 min. Radiochemical purity of the labeled solution was studied by chromatography, to evaluate (99m)Tc-Tricine, (99m)TcO2.H2O, and free (99m)TcO4 (-). Radiochemical purity was also evaluated by HPLC. Stability studies were tested in solution at 4°C and lyophilized at 4°C. Biodistribution studies were performed in healthy CD-1 female mice at 2, 5, and 24 h (n = 3) and CD-1 female mice spontaneous breast adenocarcinoma (n = 3). Scintigraphic images of spontaneous breast adenocarcinoma in female CD-1 mice were acquired in a gamma camera at 2, 5, and 24 h post-injection. Labeling was easily performed with high yields (>90%) and radiopharmaceutical stability for 24 h post-labeling. Stability studies revealed that antibody derivative must be lyophilized for undamaged storage. Biodistribution studies and imaging revealed excellent uptake in the tumor. Based on the results it was concluded that (99m)Tc-HYNIC-Trastuzumab could be a promising radiopharmaceutical for in vivo diagnosis of the HER2 status in breast with impact on treatment planning.
authors: Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la Republica, Montevideo, Uruguay.
authors: Victoria
authors: V
authors: Calzada
authors: Fernanda
authors: F
authors: Garcia
authors: Marcelo
authors: M
authors: Fernández
authors: Williams
authors: W
authors: Porcal
authors: Thomas
authors: T
authors: Quinn
authors: Omar
authors: O
authors: Alonso
authors: Juan Pablo
authors: JP
authors: Gambini
authors: Pablo
authors: P
authors: Cabral
keywords: 99mTc-labeling; Breast cancer; hydrazinonicotinamide; scintigraphy; trastuzumab
references: Genes Dev. 2003 Mar 1;17(5):545-80
references: 12629038
references: J Cell Sci. 2008 Oct 1;121(Pt 19):3207-17
references: 18782861
references: Bioconjug Chem. 1996 Jan-Feb;7(1):63-71
references: 8741992
references: Ann Oncol. 2007 Sep;18 Suppl 8:viii3-7
references: 17890212
references: Int J Clin Oncol. 2006 Jun;11(3):199-208
references: 16850126
references: J Clin Oncol. 2001 Jan 15;19(2):354-63
references: 11208826
references: Nucl Med Commun. 2005 May;26(5):427-32
references: 15838425
references: J Nucl Med. 2003 Jun;44(6):947-52
references: 12791824
references: Radiology. 2001 May;219(2):316-33
references: 11323453
references: Growth Factors. 2008 Oct;26(5):263-74
references: 18800267
references: J Clin Oncol. 1999 Sep;17(9):2639-48
references: 10561337
references: Science. 1987 Jan 9;235(4785):177-82
references: 3798106
references: Cancer Res. 1990 Mar 1;50(5):1550-8
references: 1689212
references: Eur J Nucl Med Mol Imaging. 2008 Jan;35(1):186-208
references: 17846765
references: Biochim Biophys Acta. 1994 Dec 30;1198(2-3):165-84
references: 7819273
references: Int J Rad Appl Instrum B. 1989;16(2):171-6
references: 2654090
references: J Clin Oncol. 2007 Aug 10;25(23):3525-33
references: 17687157
references: J Cell Physiol. 2004 Sep;200(3):343-50
references: 15254961
references: Oncology. 2001;61 Suppl 2:1-13
references: 11694782
references: Nature. 2000 Aug 17;406(6797):747-52
references: 10963602
references: Br J Cancer. 1993 Dec;68(6):1140-5
references: 7903153
references: Ann Oncol. 2001;12 Suppl 1:S3-8
references: 11521719
references: Nucl Med Biol. 2000 Aug;27(6):599-604
references: 11056376
references: Stem Cells. 1998;16(6):413-28
references: 9831867
references: J Clin Oncol. 2002 Feb 1;20(3):719-26
references: 11821453
references: Growth Factors. 2008 Dec;26(6):316-24
references: 18937111
references: Cancer Treat Res. 2000;103:57-75
references: 10948442
references: J Nucl Med. 2006 Dec;47(12):1968-76
references: 17138739
references: Clin Cancer Res. 2006 Jan 15;12(2):424-31
references: 16428482
references: Int J Radiat Oncol Biol Phys. 2004 Mar 1;58(3):932-40
references: 14967453
references: Chem Soc Rev. 2004 Sep 10;33(7):445-61
references: 15354226
references: J Nucl Med. 2003 Sep;44(9):1413-20
references: 12960185
references: J Nucl Med. 1990 Dec;31(12):2022-8
references: 2266401