Page 319 - 2014 Printable Abstract Book
P. 319
(PS5-55) Targeting radiation-inducible cell surface TIP-1 and GRP78 using monoclonal antibodies
and peptides as a novel imaging and therapeutic strategy for tumors. Vaishali Kapoor; Heping Yan; David
Dadey; Kim Nguyen; Hua Li; Buck Rogers; Dinesh Thotala; and Dennis Hallahan, Washington University
School of Medicine, St. Louis, MO
Ionizing radiation (IR) is commonly used to treat cancer. Radiation-inducible neo antigens are
proteins that are expressed on the cell surface after IR. Using this strategy, we can specifically target
tumors and spare normal tissues by radiation therapy. Tax interacting protein-1 (TIP-1) and Glucose-
regulated protein (GRP78) are two such proteins that are induced after irradiation of cancer cells. By
reverse biopanning we have identified two peptides HVGGSSV and GIRLRG that specifically bind TIP-1 and
GRP78 respectively. In this study, we evaluated their imaging potential using nano SPECT technology. For
longer circulation of these peptides we conjugated these peptides with a 40KDa PEG. These were
111
radiolabelled with Indium ( In) using diethylene triamine pentaacetic acid (DTPA) as the chelator. The
111
A549 tumor bearing nude mice that were irradiated (3Gy x 3 times) or sham irradiated were injected with
250µCi of 111 In labeled peptides via tail vein. The mice were imaged 48h and 96h post injection using
nanoCT-SPECT imager. The images revealed that the peptides specifically bound to the irradiated tumors
while little or no binding was seen in the sham irradiated tumors. The post-imaging bio-distrubution also
revealed a similar distribution. We earlier reported 2C6F3 monoclonal antibody against TIP-1, here we
developed and screened a panel of monoclonal antibodies against GRP78 using flow cytometry. These
were produced from hybridoma clones and 5 were prioritized using ELISA. The prioritized antibodies were
screened for surface binding on lung cancer, glioma and endothelial cell lines with and without IR. Of the
5 antibodies, 4A6O9 showed the greatest amount of surface binding. To further validate in vivo tumor
binding,we injected flourochrome conjugated 4A609 via tail vein in heterotopic D54 and A549 tumor
models. The near infrared images revealed specific binding of 4A609 to both D54 and A549 tumors that
were irradiated (3Gy x 3times). Little or no binding was observed in sham irradiated tumors. In conclusion
monoclonal antibodies 2C6F3 and 4A609 and peptides HVGGSSV and GIRLRG bind specifically to radiation
inducible neoantigens Tip-1 and GRP78 respectively. Presently we are testing these antibodies and
peptides conjugated with radio-nucleide in preclinical model for therapy for lung cancer.
(PS5-56) HPV16 variants and their relationship to treatment response in patients with invasive
squamous cell carcinoma of cervix undergoing radiotherapy. Pablo Moreno Acosta, PhD; Instituto
Nacional de Cancerologia, Bogota, Colombia
HPV infection has been established as an important initial event in the tumorigenesis of cervical
carcinoma. Sequence variations within the genome of human papillomavirus (HPV) type 16 have been
reported in different ethnic populations, with some evidence suggesting that non-European variants may
confer higher oncogenic potential. In a recent study, infection with multiple HPV types was also
considered an indicator of poor response to radiotherapy. However, reports on the presence of variants
of HPV 16 and its relationship with the response to treatment are unknown. Objective: To analyze the
presence of HPV16 variants and their relationship to treatment response in patients receiving
radiotherapy. From a group of 59 patients with invasive cervical cancer stage IIB to IVB, 34 (57.6%) were
HPV 16 (+). Study and detection of variants of HPV 16 by means of E6 and LCR analysis before treatment,
allowed to identify 2 groups: 1°, 30 (88.2%) patients had the European variant, 12 (35.2%) E-Class T350,
14 (41.1%) E-Class G350-included E-G131/G350 subclass (R10G), 4 (11.7%) Class E-not determined (Nd);
317 | P a g e
and peptides as a novel imaging and therapeutic strategy for tumors. Vaishali Kapoor; Heping Yan; David
Dadey; Kim Nguyen; Hua Li; Buck Rogers; Dinesh Thotala; and Dennis Hallahan, Washington University
School of Medicine, St. Louis, MO
Ionizing radiation (IR) is commonly used to treat cancer. Radiation-inducible neo antigens are
proteins that are expressed on the cell surface after IR. Using this strategy, we can specifically target
tumors and spare normal tissues by radiation therapy. Tax interacting protein-1 (TIP-1) and Glucose-
regulated protein (GRP78) are two such proteins that are induced after irradiation of cancer cells. By
reverse biopanning we have identified two peptides HVGGSSV and GIRLRG that specifically bind TIP-1 and
GRP78 respectively. In this study, we evaluated their imaging potential using nano SPECT technology. For
longer circulation of these peptides we conjugated these peptides with a 40KDa PEG. These were
111
radiolabelled with Indium ( In) using diethylene triamine pentaacetic acid (DTPA) as the chelator. The
111
A549 tumor bearing nude mice that were irradiated (3Gy x 3 times) or sham irradiated were injected with
250µCi of 111 In labeled peptides via tail vein. The mice were imaged 48h and 96h post injection using
nanoCT-SPECT imager. The images revealed that the peptides specifically bound to the irradiated tumors
while little or no binding was seen in the sham irradiated tumors. The post-imaging bio-distrubution also
revealed a similar distribution. We earlier reported 2C6F3 monoclonal antibody against TIP-1, here we
developed and screened a panel of monoclonal antibodies against GRP78 using flow cytometry. These
were produced from hybridoma clones and 5 were prioritized using ELISA. The prioritized antibodies were
screened for surface binding on lung cancer, glioma and endothelial cell lines with and without IR. Of the
5 antibodies, 4A6O9 showed the greatest amount of surface binding. To further validate in vivo tumor
binding,we injected flourochrome conjugated 4A609 via tail vein in heterotopic D54 and A549 tumor
models. The near infrared images revealed specific binding of 4A609 to both D54 and A549 tumors that
were irradiated (3Gy x 3times). Little or no binding was observed in sham irradiated tumors. In conclusion
monoclonal antibodies 2C6F3 and 4A609 and peptides HVGGSSV and GIRLRG bind specifically to radiation
inducible neoantigens Tip-1 and GRP78 respectively. Presently we are testing these antibodies and
peptides conjugated with radio-nucleide in preclinical model for therapy for lung cancer.
(PS5-56) HPV16 variants and their relationship to treatment response in patients with invasive
squamous cell carcinoma of cervix undergoing radiotherapy. Pablo Moreno Acosta, PhD; Instituto
Nacional de Cancerologia, Bogota, Colombia
HPV infection has been established as an important initial event in the tumorigenesis of cervical
carcinoma. Sequence variations within the genome of human papillomavirus (HPV) type 16 have been
reported in different ethnic populations, with some evidence suggesting that non-European variants may
confer higher oncogenic potential. In a recent study, infection with multiple HPV types was also
considered an indicator of poor response to radiotherapy. However, reports on the presence of variants
of HPV 16 and its relationship with the response to treatment are unknown. Objective: To analyze the
presence of HPV16 variants and their relationship to treatment response in patients receiving
radiotherapy. From a group of 59 patients with invasive cervical cancer stage IIB to IVB, 34 (57.6%) were
HPV 16 (+). Study and detection of variants of HPV 16 by means of E6 and LCR analysis before treatment,
allowed to identify 2 groups: 1°, 30 (88.2%) patients had the European variant, 12 (35.2%) E-Class T350,
14 (41.1%) E-Class G350-included E-G131/G350 subclass (R10G), 4 (11.7%) Class E-not determined (Nd);
317 | P a g e
