Dataset Information

Beta emitters rhenium-188 and lutetium-177 are equally effective in radioimmunotherapy of HPV-positive experimental cervical cancer.

ABSTRACT: Cervical cancer caused by the infection with the human papillomavirus (HPV) remains the fourth leading killer of women worldwide. Therefore, more efficacious treatments are needed. We are developing radioimmunotherapy (RIT) of HPV-positive cervical cancers by targeting E6 and E7 viral oncoproteins expressed by the cancer cells with the radiolabeled monoclonal antibodies (mAbs). To investigate the influence of different radionuclides on the RIT efficacy-we performed RIT of experimental cervical cancer with Rhenium-188 ((188) Re) and Lutetium-177 ((177) Lu)-labeled mAb C1P5 to E6. The biodistribution of (188) Re- and (177) Lu-labeled C1P5 was performed in nude female mice bearing CasKi cervical cancer xenografts and the radiation dosimetry calculations for the tumors and organs were carried out. For RIT the mice were treated with 7.4 MBq of either (188) Re-C1P5 or (177) Lu-C1P5 or left untreated, and observed for their tumor size for 28 days. The levels of (188) Re- and (177) Lu-C1P5 mAbs-induced double-strand breaks in CasKi tumors were compared on days 5 and 10 post treatment by staining with anti-gamma H2AX antibody. The radiation doses to the heart and lungs were similar for both (177) Lu-C1P5 and (188) Re-C1P5. The dose to the liver was five times higher for (177) Lu-C1P5. The doses to the tumor were 259 and 181 cGy for (177) Lu-C1P5 and (188) Re-C1P5, respectively. RIT with either (177) Lu-C1P5 or (188) Re-C1P5 was equally effective in inhibiting tumor growth when each was compared to the untreated controls (P = 0.001). On day 5 there was a pronounced staining for gamma H2AX foci in (177) Lu-C1P5 group only and on day 10 it was observed in both (177) Lu-C1P5 and (188) Re-C1P5 groups. (188) Re- and (177) Lu-labeled mAbs were equally effective in arresting the growth of CasKi cervical tumors. Thus, both of these radionuclides are candidates for the clinical trials of this approach in patients with advanced, recurrent or metastatic cervical cancer.

SUBMITTER: Phaeton R

PROVIDER: S-EPMC4708900 | biostudies-other | 2016 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:A pentapeptide macrocyclic ligand, KYCAR (lysyl-tyrosyl-cystyl-alanyl-arginine), has been designed as a potential chelating ligand for SPECT imaging and therapeutic in vivo agents. This study shows the synthesis and characterization of KYCAR complexes containing nonradioactive rhenium, 99mTc, or 188Re. The metal complexes were also biologically evaluated to determine in vivo distribution in healthy mice. The overall goals of this project were (1) to synthesize the Tc/Re pentapeptide complexes, (2) to identify spectroscopic methods for characterization of syn versus anti rhenium peptide complexes, (3) to analyze the ex vivo stability, and (4) to assess the biological properties of the [99mTc]TcO-KYCAR and [188Re]ReO-KYCAR complexes in vivo. Details on these efforts are provided below.MethodsNatRe/99mTc/188ReO-KYCAR complexes were synthesized, and macroscopic species were characterized via HPLC, IR, NMR, and CD. These characterization data were compared to the crystallographic data of ReO-KYC to assist in the assignment of diastereomers and to aid in the determination of the structure of the complex.ResultsThe radiometal complexes were synthesized with high purity (>95%). HPLC, IR, NMR and CD data on the macroscopic natReO-KYCAR complexes confirm the successful complexation as well as the presence of two diastereomers in syn and anticonformations. Tracer level complexes show favorable stabilities ex vivo for 2+ h.ConclusionMacroscopic metal complexes form diastereomers with the KYCAR ligand; however, this phenomenon is not readily observed on the tracer level due to the rapid interconversion. It was determined through pKa measurements that the macroscopic natReO-KYCAR complex is 0 at physiological pH. The [99mTc]TcO-KYCAR is stable in vitro while the [188Re]ReO-KYCAR shows 50% decomposition in PBS and serum. Biologically, the tracer level complexes clear through the hepatobiliary pathway. Some decomposition of both tracers is evident by uptake in the thyroid and stomach.

Project description:PurposeIncreased angiogenesis is a marker of aggressiveness in many cancers. Targeted radionuclide therapy of these cancers with angiogenesis-targeting agents may curtail this increased blood vessel formation and slow the growth of tumors, both primary and metastatic. CD105, or endoglin, has a primary role in angiogenesis in a number of cancers, making this a widely applicable target for targeted radioimmunotherapy.MethodsThe anti-CD105 antibody, TRC105 (TRACON Pharmaceuticals), was conjugated with DTPA for radiolabeling with 177Lu (t 1/2 6.65 days). Balb/c mice were implanted with 4T1 mammary carcinoma cells, and five study groups were used: 177Lu only, TRC105 only, 177Lu-DTPA-IgG (a nonspecific antibody), 177Lu-DTPA-TRC105 low-dose, and 177Lu-DTPA-TRC105 high-dose. Toxicity of the agent was monitored by body weight measurements and analysis of blood markers. Biodistribution studies of 177Lu-DTPA-TRC105 were also performed at 1 and 7 days after injection. Ex vivo histology studies of various tissues were conducted at 1, 7, and 30 days after injection of high-dose 177Lu-DTPA-TRC105.ResultsBiodistribution studies indicated steady uptake of 177Lu-DTPA-TRC105 in 4T1 tumors between 1 and 7 days after injection (14.3 ± 2.3%ID/g and 11.6 ± 6.1%ID/g, respectively; n = 3) and gradual clearance from other organs. Significant inhibition of tumor growth was observed in the high-dose group, with a corresponding significant increase in survival (p < 0.001, all groups). In most study groups (all except the nonspecific IgG group), the body weights of the mice did not decrease by more than 10%, indicating the safety of the injected agents. Serum alanine transaminase levels remained nearly constant indicating no damage to the liver (a primary clearance organ of the agent), and this was confirmed by ex vivo histological analyses.Conclusion177Lu-DTPA-TRC105, when administered at a sufficient dose, is able to curtail tumor growth and provide a significant survival benefit without off-target toxicity. Thus, this targeted agent could be used in combination with other treatment options to slow tumor growth allowing the other agents to be more effective.

Project description:ObjectiveCharacterise the vaginal metabolome of cervical HPV-infected and uninfected women.DesignCross-sectional.SettingThe Center for Health Behavior Research at the University of Maryland School of Public Health.SampleThirty-nine participants, 13 categorised as HPV-negative and 26 as HPV-positive (any genotype; HPV+ ), 14 of whom were positive with at least one high-risk HPV strain (hrHPV).MethodSelf-collected mid-vaginal swabs were profiled for bacterial composition by 16S rRNA gene amplicon sequencing, metabolites by both gas and liquid chromatography mass spectrometry, and 37 types of HPV DNA.Main outcome measuresMetabolite abundances.ResultsVaginal microbiota clustered into Community State Type (CST) I (Lactobacillus crispatus-dominated), CST III (Lactobacillus iners-dominated), and CST IV (low-Lactobacillus, 'molecular-BV'). HPV+ women had higher biogenic amine and phospholipid concentrations compared with HPV- women after adjustment for CST and cigarette smoking. Metabolomic profiles of HPV+ and HPV- women differed in strata of CST. In CST III, there were higher concentrations of biogenic amines and glycogen-related metabolites in HPV+ women than in HPV- women. In CST IV, there were lower concentrations of glutathione, glycogen, and phospholipid-related metabolites in HPV+ participants than in HPV- participants. Across all CSTs, women with hrHPV strains had lower concentrations of amino acids, lipids, and peptides compared with women who had only low-risk HPV (lrHPV).ConclusionsThe vaginal metabolome of HPV+ women differed from HPV- women in terms of several metabolites, including biogenic amines, glutathione, and lipid-related metabolites. If the temporal relation between increased levels of reduced glutathione and oxidised glutathione and HPV incidence/persistence is confirmed in future studies, anti-oxidant therapies may be considered as a non-surgical HPV control intervention.Tweetable abstractMetabolomics study: Vaginal microenvironment of HPV+ women may be informative for non-surgical interventions.

Dataset Information

Beta emitters rhenium-188 and lutetium-177 are equally effective in radioimmunotherapy of HPV-positive experimental cervical cancer.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets