The Zygomatic Anatomy-Guided Approach, Zygomatic Orbital Floor Classification, and ORIS Criteria-A 10-Year Follow-Up

BACKGROUND

Presently, the management of patients with maxilla bone defects of the Cawood V or VI class is achieved using zygomatic or individual implants or through augmentation of the bone. For zygomatic implants, the ORIS criteria represent the most common factor in helping practitioners register success rates. The zygomatic anatomy-guided approach (ZAGA)and zygomatic orbital floor (ZOF) are factors that are crucial to examining the anatomy of a particular patient before the procedure. The aim of thisarticle is to find the statistical relationship between the abovementioned terms and other factors.

METHODS

A total of 81 patients underwent zygomatic implant procedures in different configurations. The ORIS, ZAGA, and ZOF parameters were compared with other factors such as type of surgery, sex, age, and the anatomy of the zygomatic bone.

RESULTS

Most patients in this article were classified as ZAGA Class 2. The relationships between type of surgery and ZAGA classification, and ZAGA and sinus/maxilla zygomatic implant localization were statistically significant.

CONCLUSIONS

The ZAGA and ZOF scales are practical and valuable factors that should be taken into account before surgery, whereas to date, criteria better than the ORIS scale have not been described in terms of the success of zygomatic implants. The ZOF scale might omit perforation of the orbit because this parameter warns a practitioner to be aware of the anatomy of the orbit.

d-Glucose- and d-mannose-based antimetabolites. Part 4: Facile synthesis of mono- and di-acetates of 2-deoxy-d-glucose prodrugs as potentially useful antimetabolites

2-Deoxy-d-glucose (2-DG), a compound known to interfere with d-glucose and d-mannose metabolism, has been tested as a potential anticancer and antiviral agent. Preclinical and clinical studies focused on 2-DG have highlighted several limitations related to 2-DG drug-like properties, such as poor pharmacokinetic properties. To overcome this problem, we proposed design and synthesis of novel 2-DG prodrugs that subsequently could be tested using a variety of biochemical and molecular methods. We narrowed here our focus to esters of 2-DG as potential prodrugs based on the hypothesis that ubiquitous esterases will regenerate 2-DG, leading to increased circulation time of drug and adequate organ and tumor penetration. Testing this hypothesis in vitro and, especially, in vivo requires significant amounts of respective pure mono- and previously unknown di-acetylated water-soluble derivatives of 2-DG. Development of their efficient and practical method of synthesis was imperative. We describe novel facile and scalable syntheses of seven selectively acetylated water-soluble derivatives of 2-DG and present a detailed ¹H and ¹³C NMR analysis of all final products. X-ray diffraction analysis has been performed for compound WP1122 that was selected for detailed preclinical and subsequent clinical evaluation as potential anticancer or antiviral agent.

Collagen matrix scaffolds: Future perspectives for the management of chronic liver diseases

Approximately 1.5 billion chronic liver disease (CLD) cases have been estimated worldwide, encompassing a wide range of liver damage severities. Moreover, liver disease causes approximately 1.75 million deaths per year. CLD is typically characterized by the silent and progressive deterioration of liver parenchyma due to an incessant inflammatory process, cell death, over deposition of extracellular matrix proteins, and dysregulated regeneration. Overall, these processes impair the correct function of this vital organ. Cirrhosis and liver cancer are the main complications of CLD, which accounts for 3.5% of all deaths worldwide. Liver transplantation is the optimal therapeutic option for advanced liver damage. The liver is one of the most common organs transplanted; however, only 10% of liver transplants are successful. In this context, regenerative medicine has made significant progress in the design of biomaterials, such as collagen matrix scaffolds, to address the limitations of organ transplantation (e.g., low donation rates and biocompatibility). Thus, it remains crucial to continue with experimental and clinical studies to validate the use of collagen matrix scaffolds in liver disease.

Anthracycline-induced cardiotoxicity – are we about to clear this hurdle?

Anthracyclines have contributed significantly to remarkable improvements in overall survival and are regarded as the most effective cytostatic drug for cancer treatment in various malignancies. However, anthracyclines are a significant cause of acute and chronic cardiotoxicity in cancer patients, and long-term cardiotoxicity can lead to death in about one-third of patients. Several molecular pathways have been implicated in the development of anthracycline-induced cardiotoxicity, although the underlying mechanisms of some molecular pathways are not fully elucidated. It is now generally believed that anthracycline-induced reactive oxygen species (resulting from intracellular metabolism of anthracyclines) and drug-induced inhibition of topoisomerase II beta are the key mechanisms responsible for the cardiotoxicity. To prevent cardiotoxicity, several strategies are being followed: (i) angiotensin-converting enzyme inhibitors, sartans, beta-blockers, aldosterone antagonists, and statins; (ii) iron chelators; and (iii) by development of new anthracycline derivatives with little or no cardiotoxicity. This review will discuss clinically evaluated doxorubicin analogues that were developed as potentially non-cardiotoxic anticancer agents and include recent development of a novel liposomal anthracycline (L-Annamycin) for the treatment of soft-tissue sarcoma metastatic to the lung and acute myelogenous leukaemia.

Abstract P218: Annamycin, a novel non-cardiotoxic anthracycline with high activity against sarcomas metastatic to lungs

Introduction. Annamycin (ANN) is a non-cardiotoxic potent topoisomerase II poison structurally resembling doxorubicin (Dox). Specific structural modification altered ANN properties dramatically when compared with Dox. This novel drug also includes high activity against multidrug-resistant (MDR) tumors, unique subcellular distribution, and different tissue-organ distribution. Especially high differences have been noted in the lung uptake when compared with DOX. ANN is formulated in multilamellar liposomes (L-Annamycin, L-ANN), and such formulation additionally contributes to the high ANN lung uptake. Objective. The objective of this study was to reconfirm the unique tissue-organ distribution pattern in rats and explore ANN high lung uptake to target pulmonary sarcoma metastases by assessing the efficacy of L-ANN in the experimental models of lung metastases. Methods. Pharmacokinetics and biodistribution studies of ANN were performed in rats after bolus injection of L-ANN, free ANN, and Dox. Detection of Dox and ANN in plasma and different organs was accomplished using LC/MS/MS. In vivo efficacy was tested in two experimental lung metastatic models. The tumors were established by intravenous injection of MCA205 or K7M3 cells. The treatment consisted of weekly intravenous injections of 4 mg/kg of L-ANN or Dox. Metastatic nodules were visualized by computer tomography or bioluminescent imaging (BLI). Results. Pharmacokinetic and tissue-organ distribution of L-ANN in rats confirmed unusually high uptake of ANN in lungs: the Cmax of ANN was 30-fold higher than Dox after bolus administration of L-ANN or Dox. A remarkable extension of the survival was observed in two syngeneic sarcoma lung metastasis models. In the MCA205 fibrosarcoma model, the median survival of L-ANN treated mice was 87.5 days vs. 21 days for the vehicle-treated mice (p<0.0001), and 40% of animals were still alive when the experiment has been terminated on day 140. L-ANN also appeared highly efficacious in the osteosarcoma K7M3 model. Median survival has not been reached due to the high efficacy of L-ANN treatment. The experiment has been terminated on day 220 (the median survival for the vehicle-treated was 58 days, p=0.0002). Additionally, L-ANN and Dox were compared in the K7M3-Luc model. The BLI revealed a potent inhibition of the tumor growth by L-ANN-, but not in Dox-treated animals. Consequently, there was no extension of the survival in DOX-treated animals, while no deaths were recorded in L-ANN treated group as of day 90 (MS for Dox-treated mice was 59 days, ongoing study). Conclusion. Annamycin (ANN) is a novel non-cardiotoxic anthracycline that exhibits very high uptake in the lungs compared to Dox. Furthermore, ANN’s rapid cellular uptake and preferential nanomolar cytotoxicity against cancer led to major efficacy in sarcoma lung metastasis models. These promising preclinical results led to the initiation of a multicenter sarcoma-specific clinical study (NCT04887298).

Citation Format: Rafal Zielinski, Krzysztof Grela, Roberto Cardenas-Zuniga, Stanislaw Skora, Izabela Fokt, Maria Poimenidou, Salah-Eddine Lamhamedi-Cherradi, Joseph Ludwig, Waldemar Priebe. Annamycin, a novel non-cardiotoxic anthracycline with high activity against sarcomas metastatic to lungs [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P218.

Abstract P129: Ketogenic diet (KD) and targeting Warburg effect: Apparent toxicity of KD combination with 2-deoxy-D-glucose

Introduction: Cancer dependence on glucose metabolism has been recognized as a potential target for the development of new anticancer therapies. Ketogenic low-carbohydrate diet (KD) and aerobic glycolysis is known as a Wartburg effect are two approaches linked by a common aim to reduce cancer glucose metabolism. 2-Deoxy-D-glucose (2-DG) has been shown to inhibit glycolysis and in effect to inhibit glucose metabolism and tumor growth in vitro and in vivo in a wide range of cancer models. Anticancer effects of 2-DG can be impacted by several factors including competition of glucose from the food intake. Ketogenic diet has been proposed as a strategy to inhibit proliferation of cancer cells that are highly dependent on glucose for growth and survival by reducing glucose access from food intake and switch to lipid metabolism. Combination of both approaches seemed to be a logical step to increase overall antitumor effects. Objective: The objective of the study was to determine safe doses of 2-DG in mice fed with KD and determine potential toxic side effects of 2-DG in mice maintained on carbohydrate-reduced vs. regular diet. Methods: Female CD-1 mice were maintained on a regular grain-based or carbohydrates-reduced diet (Research Diets (20 % Kcal Protein, 60 % Kcal Fat, 20 % Kcal carbohydrate). Animals were dosed with 2-DG once a day five times a week by oral gavage (PO) or intraperitoneal (IP) injections. Animals were watched daily for the development of toxicity symptoms. Results: No toxic side effects in mice fed with a regular, chow-base diet and treated orally with 2-DG were noted during the six-week treatment (doses ranged from 0.25 to 2.0 g/kg, five times/week). In the contrary, 2-DG-treaded animals maintained on KD showed dose-dependent toxicity with median survival (MS) 10 and 11 days for 1.0 and 2.0 g/kg respectively. For mice receiving 2-DG at 0.5 g/kg MS was 28 days and only 20% mice died in the group receiving 0.25 g/kg. In separate experiments mice treated with 2-DG orally or by intraperitoneal injections IP (1.5 g/kg) showed similar MS of 11 days. Complete blood count analysis of 2-DG treated animals fed with KD revealed acute thrombocytopenia. Post-mortem analysis of dissected organs indicated the development of acute interstitial pneumonia in treated mice. Conclusion: A highly reproducible toxicity leading to a rapid death of all treated animals maintained on a ketogenic diet was observed for 2-DG at doses 1.0 and 2.0 g/kg administered PO or IP. The same doses appeared to be safe in mice fed with a regular diet. The combination treatment toxic effects include acute thrombocytopenia and acute interstitial pneumonia. Delineation of the exact mechanism of toxicity requires additional studies. This study provides an important insight on the apparent toxicity of 2-DG when combined with the ketogenic diet and should serve as a reference for any future studies aimed to combine the ketogenic diet with inhibitors of glycolysis or other metabolic inhibitors.

Citation Format: Rafal Zielinski, Maria Poimenidou, Matthew Khuong, Krzysztof Grela, Roberto Cardenas-Zuniga, Stanislaw Skora, Izabela Fokt, Michael Gagea, Jody Swain, Sigmund Zhou, Waldemar Priebe. Ketogenic diet (KD) and targeting Warburg effect: Apparent toxicity of KD combination with 2-deoxy-D-glucose [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P129.

Abstract PO-066: High uptake, retention, and in vivo activity of L-Annamycin in pancreatic cancer models

Introduction: Annamycin (ANN) is a non-cardiotoxic potent topoisomerase II poison that is structurally related to doxorubicin (Dox) but it displays significantly different biological properties. ANN is formulated in multilamellar liposomes to enable effective in vivo administration as L-ANN. Pancreatic ductal adenocarcinoma (PDAC) represents a major challenge and is the deadliest cancer in decades. Pancreas drug uptake and retention remains a significant factor contributing to the chemoresistance of PDAC. Additionally, drug resistance on a cellular level further limits the therapeutic options for pancreatic cancer patients. Based on unique biological properties, we select L-ANN for detailed characterization of anti-tumor potency in preclinical PDAC models. Objective: The objective of this study was to validate the L-ANN exceptional uptake in pancreatic cancer cells and tumors and explore its high pancreas uptake to target PDACs by assessing the efficacy of L-ANN in the preclinical mouse models. Methods: The uptake, cytotoxicity, and L-ANN-induced apoptosis were studied in human MDA-PATC50 and MDA-PATC53 cell lines. L-ANN pharmacokinetics and tissue-organ distribution were analyzed in CD-1 mice after bolus administration of L-ANN, ANN or DOX. Subcutaneous and orthotopic MDA-PATC50 and MDA-PATC53 mouse models were used to assess activity of L-ANN in vivo. Results: Fluorescent microscopy and FACS analysis showed significantly higher uptake of ANN in MDA-PATC50 and MDA-PATC53 when compared to DOX-treated cells. Interestingly, ANN displayed distinct subcellular distribution with predominantly cytosolic localization. Average IC50 of ANN or DOX treated MDA-PATC50 and MDA-PATC53 cells were 25.1 nM and 41.9 nM for ANN and 32.8 nM and 130.4 nM for DOX respectively (72h exposure). Biodistribution study showed rapid L-Ann absorption in the pancreas. The Cmax of L-Ann was 15-fold higher than Dox after administration of L-ANN or Dox (both at 4 mg/kg) in pancreatic tissue. The subcutaneous models demonstrated dose-dependent reduction in tumor volumes after 3 doses of L-Ann in both PDAC models. Additionally, efficacy of L-ANN was assessed in two orthotopic PDAC models. MRI confirmed tumor volume reduction in L-Ann 3 mg/kg and 4 mg/kg doses in MDA-PATC50 model (p<0.05 for both 3 and 4 mg), and in MDA-PATC53 model (p<0.001 and p<0.0001, respectively). The median survivals (MS) were 135 and 103 days for L-Ann at 3 mg/kg and 4 mg/kg respectively (MS for vehicle was 49 days, p<0.0001). MDA-PATC50 orthotopic model demonstrated the similar results (ongoing study). Conclusion: Annamycin exhibits high and rapid uptake in the pancreatic cancer cells and in pancreas itself when compared to Dox. Subsequently, ANN appeared to be highly cytotoxic against tested pancreatic cancer cell lines and as L-ANN potently inhibits tumor growth and increase survival in experimental models of pancreatic cancer. These experiments demonstrate remarkable activity of L-ANN in PDAC models and support future clinical studies.

Citation Format: Ya'an Kang, Rafal Zielinski, Roberto Cardenas Zuniga, Radjendirane Venugopal, Maria Poimenidou, Magdalena Remiszewski, Shaohua Peng, Edd Felix, Krzysztof Grela, Stanislaw Skora, Van N. Nguyen, Izabela Fokt, Waldemar Priebe. High uptake, retention, and in vivo activity of L-Annamycin in pancreatic cancer models [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-066.

EXTH-78. WP1874, A HIGHLY POTENT UNIQUE DNA BINDING AGENT WITH ENHANCED CNS UPTAKE

As part of our drug discovery program, we have developed structure-based modular designs of unique DNA-binding agents. The approach combines DNA intercalating and DNA “minor-groove-binding” modules. We have discovered compound WP1244 that potentially binds up to 10 bp long sequences of DNA. The unique and intriguing feature of WP1244 is its high CNS uptake combined with the picomolar to low nanomolar cytotoxicity against ependymoma and glioblastoma multiforme (GBM) cell lines and demonstrated in vivo activity in the orthotopic model of GBM. To improve water solubility and develop an IV formulation, we have synthesized WP1874, a mesylate salt of WP1244, and initiated its preclinical characterization. WP1874, similarly to its parental compound, shows high cytotoxicity in ependymoma, GBM, and medulloblastoma cell lines with IC50 in low nanomolar range and it was up to 100 to 200 times more potent than doxorubicin. Interestingly, WP1874 does not appear to be cytotoxic against normal kidney cells (VeroC1008) with IC50 > 10 μM. Preliminary pharmacokinetic and biodistribution studies performed in CD-1 mice with intact brains revealed enhanced penetration of WP1874 to the brain with Cmax 1.5-fold greater than in plasma. Respectively, WP1874 Cmax in the brain was 2.3 ug/g (~2.0 μM) vs. 1.5 μg/ml (1.3 μM) in plasma. Acute toxicity in intravenously administered WP1874 was LD50 >15mg/kg. No mortalities or any apparent toxicity symptoms were recorded for six intravenous weekly doses of WP1874 at 2.5 or 5 mg/kg in CD-1, Balb/c, or nude athymic mice. Intraperitoneal administration was well-tolerated up to 5 mg/kg given three times a week for four cycles. High CNS uptake, excellent cytotoxicity against different brain cancer cell lines, and low toxicity in vivo and in vitro against normal cells warrant further investigation of WP1874 as a mechanically unique potential anticancer agent against CNS malignancies.

Impaired anaplerosis is a major contributor to glycolysis inhibitor toxicity in glioma

BACKGROUND

Reprogramming of metabolic pathways is crucial to satisfy the bioenergetic and biosynthetic demands and maintain the redox status of rapidly proliferating cancer cells. In tumors, the tricarboxylic acid (TCA) cycle generates biosynthetic intermediates and must be replenished (anaplerosis), mainly from pyruvate and glutamine. We recently described a novel enolase inhibitor, HEX, and its pro-drug POMHEX. Since glycolysis inhibition would deprive the cell of a key source of pyruvate, we hypothesized that enolase inhibitors might inhibit anaplerosis and synergize with other inhibitors of anaplerosis, such as the glutaminase inhibitor, CB-839.

METHODS

We analyzed polar metabolites in sensitive (ENO1-deleted) and resistant (ENO1-WT) glioma cells treated with enolase and glutaminase inhibitors. We investigated whether sensitivity to enolase inhibitors could be attenuated by exogenous anaplerotic metabolites. We also determined the synergy between enolase inhibitors and the glutaminase inhibitor CB-839 in glioma cells in vitro and in vivo in both intracranial and subcutaneous tumor models.

RESULTS

Metabolomic profiling of ENO1-deleted glioma cells treated with the enolase inhibitor revealed a profound decrease in the TCA cycle metabolites with the toxicity reversible upon exogenous supplementation of supraphysiological levels of anaplerotic substrates, including pyruvate. ENO1-deleted cells also exhibited selective sensitivity to the glutaminase inhibitor CB-839, in a manner rescuable by supplementation of anaplerotic substrates or plasma-like media Plasmax^TM. In vitro, the interaction of these two drugs yielded a strong synergistic interaction but the antineoplastic effects of CB-839 as a single agent in ENO1-deleted xenograft tumors in vivo were modest in both intracranial orthotopic tumors, where the limited efficacy could be attributed to the blood-brain barrier (BBB), and subcutaneous xenografts, where BBB penetration is not an issue. This contrasts with the enolase inhibitor HEX, which, despite its negative charge, achieved antineoplastic effects in both intracranial and subcutaneous tumors.

CONCLUSION

Together, these data suggest that at least for ENO1-deleted gliomas, tumors in vivo-unlike cells in culture-show limited dependence on glutaminolysis and instead primarily depend on glycolysis for anaplerosis. Our findings reinforce the previously reported metabolic idiosyncrasies of in vitro culture and suggest that cell culture media nutrient composition more faithful to the in vivo environment will more accurately predict in vivo efficacy of metabolism targeting drugs.

An enolase inhibitor for the targeted treatment of ENO1-deleted cancers

Inhibiting glycolysis remains an aspirational approach for the treatment of cancer. We have previously identified a subset of cancers harbouring homozygous deletion of the glycolytic enzyme enolase (ENO1) that have exceptional sensitivity to inhibition of its redundant paralogue, ENO2, through a therapeutic strategy known as collateral lethality. Here, we show that a small-molecule enolase inhibitor, POMHEX, can selectively kill ENO1-deleted glioma cells at low-nanomolar concentrations and eradicate intracranial orthotopic ENO1-deleted tumours in mice at doses well-tolerated in non-human primates. Our data provide an in vivo proof of principle of the power of collateral lethality in precision oncology and demonstrate the utility of POMHEX for glycolysis inhibition with potential use across a range of therapeutic settings.

Abstract 3074: Targeting sanctuary sites of cancer: Novel approaches to treatment of lung localized tumors

The lung is one of the most common sites of cancer metastasis. We hypothesize that the lack of effective chemotherapeutics for lung localized tumors might in part be due to the lungs acting as a sanctuary site for cancer cells. To identify more effective anticancer therapies, we focused on the discovery and development of drugs reaching tumor sanctuaries either by design and synthesis of novel drugs, use of a compatible delivery system or a combination of both. To test our hypothesis and develop a novel approach to eliminate cancer sanctuary sites we focused on anthracycline antibiotics, specifically on the therapeutic limitations of doxorubicin (DOX). We have developed Annamycin (ANN), a novel, non-cardiotoxic DOX analog formulated in multilamellar liposomes (L-ANN) with high activity against multidrug resistant (MDR) cancer cells and an organ distribution dramatically different from that of DOX. L-ANN is currently in multicenter Phase I clinicals studies.

Objective: The objective of our study was to confirm high uptake and retention of free ANN in lungs, demonstrate the same for L-ANN, and to assess the efficacy of L-ANN in lung metastatic cancer models.

Methods: Pharmacokinetics and biodistribution of ANN were tested using LC/MS/MS in naïve CD-1 mice after intravenous administration of the drug. In vitro activity of ANN was analyzed in different human and murine cancer cells. Cellular uptake and subcellular distribution of ANN was assessed using fluorescent microscopy and FACS. Efficacy of L-ANN was tested in CT26 colon and 4T1 triple negative breast cancer lung metastatic mouse models.

Results: Biodistribution experiments showed high levels of ANN in lung tissue either for free or L-ANN that exceeded that in plasma by 7 to 10 fold. ANN levels in lungs were also more than 6-fold greater than that of DOX. In addition, on a cellular level, immunofluorescence and FACS analysis demonstrated significantly higher uptake of ANN than that of DOX, as well as potent induction of double-strand DNA breaks. ANN showed consistently high cytotoxicity across all tested cell lines including MDR cells with IC50s in the low nanomolar range. Based on bioluminescent imaging in models of lung localized cancers, L-ANN displayed high antitumor activity ranging from inhibition of tumor progression to complete tumor eradication. Importantly, the delay in tumor growth and, in some cases, tumor regression led to significant improvement of survival in all tested models.

Conclusion: The high cytotoxic potency of ANN against MDR cancer cells is related, in part, to its ability to overcome ABC transporter-mediated efflux and, in contrast to DOX, achieve high intracellular uptake. A greatly increased concentration of ANN in the lung, as compared to DOX, leads to high drug efficacy in vivo in lung-localized tumor models. In summary, our studies (1) support the hypothesis of lungs being a sanctuary site for cancer cells and (2) demonstrate that effective targeting of cancers metastatic to the lung is possible by chemical modification of clinically used but currently ineffective drugs, especially in combination with appropriate drug delivery. In more general terms, these studies indicate that the proposed approach can also lead to the identification and elimination of cancer sanctuary sites other than the lungs and creation of more effective anticancer therapies.

Citation Format: Rafal Zielinski, Krzysztol Grela, Roberto Cardena Zuniga, Yaan Kang, Stanislaw Skora, Edward Felix, Julia Tuchalska-Czuron, Izabela Fokt, Waldemar Priebe. Targeting sanctuary sites of cancer: Novel approaches to treatment of lung localized tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3074.

Epigenetic Reprogramming of Cancer-Associated Fibroblasts Deregulates Glucose Metabolism and Facilitates Progression of Breast Cancer

The mechanistic contributions of cancer-associated fibroblasts (CAFs) in breast cancer progression remain to be fully understood. While altered glucose metabolism in CAFs could fuel cancer cells, how such metabolic reprogramming emerges and is sustained needs further investigation. Studying fibroblasts isolated from patients with benign breast tissues and breast cancer, in conjunction with multiple animal models, we demonstrate that CAFs exhibit a metabolic shift toward lactate and pyruvate production and fuel biosynthetic pathways of cancer cells. The depletion or suppression of the lactate production of CAFs alter the tumor metabolic profile and impede tumor growth. The glycolytic phenotype of the CAFs is in part sustained through epigenetic reprogramming of HIF-1α and glycolytic enzymes. Hypoxia induces epigenetic reprogramming of normal fibroblasts, resulting in a pro-glycolytic, CAF-like transcriptome. Our findings suggest that the glucose metabolism of CAFs evolves during tumor progression, and their breast cancer-promoting phenotype is partly mediated by oxygen-dependent epigenetic modifications.

Abstract P2-15-03: Liposomal annamycin inhibition of lung localized breast cancer

Background and Rationale: Annamycin is an anthracycline antibiotic currently in clinical studies in AML patients. Our earlier studies showed that Annamycin is not cross-resistant with doxorubicin (DOX) and is a poor substrate for P-glycoprotein 1 (P-gp) [aka ATP-binding cassette sub-family B member 1 (ABCB1) or multidrug resistance protein 1 (MDR1)], a major mechanism of doxorubicin resistance in different types of cancer. Annamycin, in contrast to DOX, achieves relatively high levels of cellular accumulation, especially in multidrug resistant (MDR) cell lines, and induces significant DNA damage in MDR cancer cells. Clinically, Annamycin is administered in a liposomal formulation (L-Annamycin) the in vivo activity of which has been demonstrated in different tumor models. IND aimed preclinical studies revealed that in sharp contrast to DOX, Annamycin displays dramatically reduced to no cardiotoxicity. Subsequent pharmacokinetic and organ distribution studies revealed surprisingly high levels of Annamycin in lung tissue. Annamycin levels (AUC, 24 h) in lungs were over 10-fold greater than in plasma. In addition, when compared with DOX, lung levels of Annamycin were 6-fold higher than those achievable with DOX. Thus, studies aimed to assess efficacy of L-Annamycin in lung localized tumor models were initiated.

Objective: The objective of this study was to assess the in vitro and in vivo activity of L-Annamycin in 4T1, a highly aggressive triple negative breast cancer (TNBC) lung colonization model.

Methods: In vitro efficacy of Annamycin was investigated in a panel of TNBC cell lines including murine 4T1 and human MDA-MB 231, MDA-MB-468, BT20, and SUM149 cell lines. Uptake and subcellular distribution of Annamycin was assessed using fluorescent microscopy and FACS. Biodistribution of Annamycin was tested in naïve CD-1 mice after intravenous administration of the drug. Efficacy of L-Annamycin was tested in a syngeneic TNBC lung model, specifically, in immune-competent Balb/c mice injected intravenously with 4T1 cells expressing firefly luciferase.

Results: Annamycin shows consistently high cytotoxicity across all tested cell lines with IC50s in the low nanomolar range. Uptake analysis performed on 4T1 cells indicated significantly higher uptake of the drug as compared to DOX. Annamycin shows distinct subcellular distribution with high cytosolic deposition, while DOX was mostly confined to the nucleus. In vivo efficacy studies in mice treated with L-Annamycin showed significantly increased survival when compared to vehicle treated animals. Delayed tumor progression was assessed by bioluminescent imaging and correlated with increased survival.

Conclusion: Our in vitro studies demonstrate the high potency of L-Annamycin in vitro and in vivo. Its unique intracellular uptake and distribution might in part be responsible for L-Annamycin’s activity profile and lack of cardiotoxicity. The observed high in vivo efficacy of L-Annamycin in an aggressive TNBC lung metastasis model coupled with consistently high accumulation of L-Annamycin in lung parenchyma, may prove to open new therapeutic options for patients with tumors metastatic to the lung.

Citation Format: Rafal Zielinski, Krzysztol Grela, Stanislaw Skora, Izabela Fokt, Matthew Sander, Adam Didluch, Waldemar Priebe. Liposomal annamycin inhibition of lung localized breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-15-03.

Abstract C094: Dose and schedule-dependent efficacy of liposomal Annamycin in pre-clinical models of acute myeloid leukemia

Annamycin (Ann) is a clinically evaluated anthracycline whose antitumor activity is not cross-resistant with that of doxorubicin (DOX). Formulated in liposomes, L-Annamycin (L-Ann) is currently in clinical studies in acute myeloid leukemia (AML) patients. In contrast to DOX, high levels of cellular accumulation of Ann were observed in multidrug resistant (MDR) cell lines, and consequently there was a significant degree of DNA damage and apoptosis. In vivo activity of L-Ann and free Ann was confirmed in different tumor models. In addition, preclinical toxicology studies revealed that both L-Ann as well as free Ann displayed dramatically reduced or no cardiotoxicity, in sharp contrast to DOX. In the current study, we assessed the anti-AML efficacy of Ann using multiple in vitro and in vivo models. In vitro efficacy was assessed in a panel of human AML cell lines including THP-1, OCI-AML3 and MV4;11. The uptake and subcellular distribution of Ann was evaluated using flow cytometry and fluorescence microscopy. In vivo biodistribution of Ann was tested in naïve B6 mice after intravenous administration of the drug followed by fluorescence microscopy. Anti-tumor efficacy was extensively tested in syngeneic AML-Turq 2 model in immunocompetent B6 mice, and subsequently in human OCI-AML3 model in immunosuppressed NSG mice. In the murine syngeneic AML-Turq 2 model, AML cells were visualized based on the mTurquoise fluorescence. AML disease progression was monitored using whole body bioluminescence imaging or flow cytometry, respectively. We observed a high potency of Ann against established human AML cell lines, with the IC50 in low nanomolar range. Saturation experiments indicated high uptake of Ann by the cancer cells. Interestingly, in addition to the expected uptake of Ann in the nucleus, Ann was also localized in the cytosol of the cells. This bi-compartmental intracellular distribution pattern contrasted with the nuclear-only localization of DOX. In vivo studies confirmed anti-tumor efficacy of the Annamycin in both human and murine AML models. Based on bioluminescence imaging, the liposomal formulation of the drug significantly delayed AML progression in the human OCL-AML3/NSG model at 4 mg/kg with once weekly dosing. Similarly, significant dose-dependent reduction of peripheral blood AML blasts was observed in the murine AML-Turq2 model, and this reduction was strongly correlated with prolongation of animals survival. The median survival of mice receiving four doses of L-Ann once a week at 4 mg/ml was 37 days while mice receiving vehicle lived only 14 days (p=0.0002). Different doses and administration schedules of L-Ann were tested in effort to maximize survival benefits. In summary L-Ann is effective in AML, demonstrating significant activity in both in vitro and in vivo mouse models with a distinct pattern of intracellular uptake and organ distribution using a once a week schedule. This suggests that L-Ann with this profile, including a lack of cardiotoxicity and activity against DOX resistant tumors, may be an advantageous approach in the treatment of AML.

Citation Format: Rafal Zielinski, Tomasz Zal, Krzysztof Grela, Stanislaw Skora, Izabela Fokt, Matthew Sander, Magdalena Remiszewski, Edward Felix, Meenakshi Shanmugasundaram, Waldemar Priebe. Dose and schedule-dependent efficacy of liposomal Annamycin in pre-clinical models of acute myeloid leukemia [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C094. doi:10.1158/1535-7163.TARG-19-C094

Abstract LB-A16: Imaging of glioblastoma using LDLR-based targeted delivery system

Introduction: Glioblastoma is the most agressive brain tumor with average life expectancy of 12-15 months from diagnosis. One of the factors that limit efficacy of drug, especially in primary brain tumor is permeability of the blood brain barrier (BBB). The low-density lipoprotein receptor (LDLR) expressed at the BBB mediates the transport of endogenous ligands through the BBB, a process referred to as receptor-mediated transcytosis. VECT-HORUS (VH) has identified and chemically optimized a family of peptide-vectors targeting both the human and murine LDLR and able i) to cross the BBB and ii) to target tumors such as glioblastoma that express high levels of the LDLR. The objective of this study was to determine the LDLR targeting properties of 68Ga/177Lu- radiolabeled peptide vectors developed by the VH proprietary platform using a glioblastoma model that expresses the human LDLR (hLDLR) at high levels. Methods: The LDLR targeted DOTA-conjugates (VH-DO31, VH-DO33) and NODAGA conjugate (VH-NO31), (10-30ug, VECT-HORUS SAS, France) were labeled with 68Ga (1.5mCi) eluted from 68Ge/68Ga generator (100mCi, ITG GmBH, Germany) or with 177Lu n.c.a (1mCi, ITG GmBH, Germany). The U87MG cell line has been shown to express high levels of the hLDLR. The LDLR targeting properties of these conjugates were thus determined in vitro in U87MG cellular uptake studies, as well as in vivo in U87MG xenografted mice. The PET/CT images of U87MG xenograft generated in athymic nude mice (10 weeks, n=3) were acquired using G4 PET/Xray camera (Sofie Biosciences; 10min/scan) at 1h, 2h, 3h and 4h post-injection. Results: All 68Ga/177Lu-labeled conjugates were synthesized with radiochemical purity higher than 91 % as determined by radio-HPLC. Radiolytic stability of agents was increased using C18 ethanol purification of the final products. 177Lu-VH-DO33 showed the highest retention of the agent in U87MG cell line at 1h (13.88± 1.6 %ID/mg) and 21h incubation time (8.7± 4 %ID/mg) compared to 177Lu-VH-DO31 (8.28 ±6.2 %ID/mg) The microPET imaging studies showed rapid accumulation and retention of all VH derivatives in tumor as monitored up to 4h post injection. All agents were eliminated through bladder and kidneys. There was no accumulation of agents in the bone marrow. The image based biodistribution studies of 68Ga-VH-DO31, 68Ga-VH-DO33 and 68Ga-VH-NO31 showed that the tumor to muscle ratios (SUV ratio) after 30 min post-injection were 4.12, 5.07 and 3.88, respectively and remained at the same levels up to 3h post-injection. The SUV ratios of tumor to kidneys were as follows: 68Ga-VH-DO31 (0.46), 68Ga-VH-DO33 (0.84) and 68Ga-VH-NO31 (0.46) confirming renal elimination of the agents. Conclusions: VH derivatives showed favorable hLDLR and tumor-targeting properties both in in vitro as well as in vivo in U87MG xenografts. These results can postulate that hLDLR may serve as a target for the development of theranostic probes for the diagnosis and radiotherapy of glioblastoma.

Citation Format: Izabela Tworowska, Leo G Flores II, Rafal Zielinski, Jonathan Nowak, Pascaline Lecorche, Cedric Malicet, Michel Khrestchatisky, Jamal Temsamani, Ebrahim Delpassand. Imaging of glioblastoma using LDLR-based targeted delivery system [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr LB-A16. doi:10.1158/1535-7163.TARG-19-LB-A16

Abstract 4799: Inhibition of STAT3 in pancreatic ductal adenocarcinoma and immunotherapeutic implications

Introduction: Signal Transducer and Activators of Transcription 3 (STAT3) plays a pivotal role in carcinogenesis, chemo- and radio-sensitivity, metastasis and immune evasion in multiple malignances including Pancreatic Ductal Adenocarcinoma (PDAC). Our drug discovery program focused on modulators of transcriptional activity led us to identify small molecules that potently inhibits tyrosine 705 phosphorylated STAT3 (p-STAT3). Compound WP1066, currently being evaluated in a Phase I clinical trial (NCT01904123) as orally administered agent and its novel, analog WP1732 suitable for IV administration, were selected as promising, potent p-STAT3 inhibitors with drug-like properties for further development as lead compounds. The purpose of these study is to perform a preclinical evaluation of WP1066 and WP1732 aiming at their future application for treatment of PDAC.

Materials and Methods: The chemical synthesis of WP1066 and WP1732 and their characterization was performed at UT MD Anderson Cancer Center. In vitro efficacy of both inhibitors was assessed using proliferation and apoptosis induction assays in a panel of patient-derived and commercially-available PDAC cell lines. Inhibition of p-STAT3 was investigated using western blot (WB) and immunofluorescence. Acute and multiple dose toxicity of WP1732 was tested in CD-1 mice. Pharmacokinetic parameters of WP1732 after intravenous administration was evaluated in naïve CD-1 mice using Mass Spectrometry LC/MS/MS or rats by liquid scintillation counting (LSC) using radio-labeled agent. Efficacy of both agents alone or in combination with immune checkpoints inhibitors was tested in PDAC tumor models.

Results: Both WP1066 and WP1732 were shown to induce apoptosis and inhibit p-STAT3 and its nuclear localization in all tested PDAC cell lines. Observed IC50 values ranged from 0.5 to 2 µM. WP1732 was well tolerated by mice (LD50 85 mg/kg given IV). Pharmacokinetic and biodistribution studies indicate high plasma levels of the drug and significant accumulation of WP1732 in the pancreas of mice and rats after a single bolus injection of the drug. Importantly, both agents show in vivo efficacy in preliminary experiments when tested alone or in combination with T cell immune checkpoint inhibitors.

Conclusion: WP1066 and WP1732 are inhibitors of p-STAT3 with demonstrated in vitro and in vivo activity against PDAC tumor models. Our preliminary data warrant the further pre-clinical and clinical evaluation of these oncology agents alone and in combination with immunotherapy as a promising new therapeutics for pancreatic cancer.

Citation Format: Rafal Zielinski, Izabela Fokt, Stanislaw Skora, Edward Felix, Krzysztof Grela, Jayakumar Arumugam, Radj Venugopal, Midan Ai, Genevieve Hartley, Michael Curran, Waldemar Priebe. Inhibition of STAT3 in pancreatic ductal adenocarcinoma and immunotherapeutic implications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4799.

Abstract 1927: Targeting IL-13RA2 in melanoma and pancreatic cancer

Background. Interleukin receptor alpha 1 (IL-13RA1) is a component of a heterodimeric IL-13 receptor that is shared with IL-4 and it is ubiquitously expressed in normal tissues and also tumors. In contrast, IL-13RA2 is a monomeric receptor which is overexpressed in various solid tumors, but is virtually absent in normal tissues. Ligands specifically targeting IL-13RA2 but not IL-13RA1, such as Pep-1L and IL-13.E13K.D2.Cys, have been developed and validated [1,2].

Objective. To assess the expression of IL-13RA2 in pancreatic ductal adenocarcinoma and metastatic melanoma specimens and to develop tracers for selective recognition of the tumors.

Methods. The expression of IL-13RA2in patient specimens, patient-derived xenografts (PDX) and established cell lines was assessed using Western blot, immunochemistry or immunofluorescence. The ligands were conjugated to a chelator and labeled with Yttrium 86. Ligand specificity was confirmed using IL-13RA2 positive and negative cells and blocking with a “cold” ligand. Biodistribution studies and PET/CT imaging were conducted to assess distribution of the tracer in IL-13RA2 positive tumors models.

Results. IL-13RA2 receptor is overexpressed in melanoma and pancreatic cell lines and tumor tissues. Western blot analysis of 56 patients tumor tissue lysates obtained from pancreatic cancer PDX models showed the presence of IL-13RA2 in over 60% of patients. Similarly, tissue microarray analysis of metastatic melanoma samples identified IL-13RA2 receptor expression in 40% of tumor specimens. Uptake study performed in receptor positive and negative cells confirmed the specificity of radiotracer binding. In vivo experiments indicated fast clearance of 86Y- Pep1L ligand with glomerular filtration as a primary mechanism of the tracer removal. Mice bearing IL-13RA2 positive tumors had up taken the tracer with “tumor to muscle” ratio of 5.6 1 h after probe administration. Yttrium 86-labelled IL-13-E13K.D2.Cys was also taken up by IL-13 RA2 positive tumors.

Conclusion. IL-13RA2 is an attractive target for the development of comprehensive theranostic strategies for melanoma and pancreatic cancer.

References

1. Pandya, H., et al., An interleukin 13 receptor alpha 2-specific peptide homes to human Glioblastoma multiforme xenografts. Neuro Oncol, 2012. 14(1): p. 6-18.

2. Nguyen, V., et al., A novel ligand delivery system to non-invasively visualize and therapeutically exploit the IL13Ralpha2 tumor-restricted biomarker. Neuro Oncol, 2012. 14(10): p. 1239-53.

Citation Format: Rafal Zielinski, Izabela Tworowska, Stanislaw Skora, Aleksandra Rusin, Radjendirane Venugopal, Arumugam Jayakumar, Izabela Fokt, Yaan Kang, Jason Fleming, Yue Huang, Denise Herpai, Waldemar Debinski, Waldemar Priebe. Targeting IL-13RA2 in melanoma and pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1927.

Evaluation of nasal fluid flow in fetuses by Doppler ultrasound

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Abstract 50: 2-Deoxy-2-halo-D-glucose derivatives inhibition of glycolysis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most hypoxic and subsequently glycolytic tumors. Thus the inhibition of glycolysis appears to be an attractive therapeutic approach that should be explored.

Methods: A series of 2-deoxy analogs of D-glucose, namely, 2-deoxy-D-glucose (2-DG), 2-fluoro-D-glucose (2-FG), 2-chloro-D-glucose (2-CG), 2-bromo-D-glucose (2-BG), and 2,2-difluoro-D-glucose (2,2-diFG) were synthesized in our laboratory. The ability of 2-deoxy-2-halo-D-glucose derivatives to inhibit glycolysis in pancreatic cancer cell lines was tested using Seahorse 96 analyzer and XF Glycolysis Stress Test kit. The cellular ATP level was measured using CellTiter-Glo assay. Viability of cells cultured in normoxic and hypoxic conditions were assessed using MTS assay.

Results: 2,2-diFG and 2-FG were significantly more potent inhibitors than 2-DG of the Extracellular Acidification Rate (ECAR) of medium in oligomycin-stimulated PDAC cells (complete inhibition at <12.5 mM, whereas, the 100 mM is a commonly used concentration for 2-DG in Seahorse 96 experiments). Interestingly, 2-bromo (2-BG) and 2-chloro (2-CG) analogs have a limited or no effect on glycolysis at tested concentration. Consistently, both, 2,2-diFG and 2-FG, inhibited proliferation of pancreatic cancer cell lines more potently than 2-DG in either normoxic and hypoxic conditions, with the differential effects being significantly more pronounced under hypoxia.

Conclusion: Both, 2,2-diFG and 2-FG have a superior to 2-DG ability to inhibit glycolysis in vitro and should be further evaluated in vivo in the PDAC models as a potential anticancer agents.

Citation Format: Rafal Zielinski, Izabela Fokt, Aleksandra Rusin, Stanislaw Skora, Waldemar Priebe. 2-Deoxy-2-halo-D-glucose derivatives inhibition of glycolysis in pancreatic cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 50.

A case of intraparotid schwannoma in a juvenile: Clinical, pathological, ultrastructural, and immunohistopathological study, including an examination of Ki-67 and MCM-3 expressions

Pleomorphic adenoma, the most common benign nonvascular tumor of the parotid gland in juveniles, should be differentiated from other extremely rare tumors, including schwannoma. In this article, we present a rare case of an intraparotid schwannoma in a juvenile, along with the patient history, a description of pathological features, and the results of ultrastructural and immunohistochemical examination. The respective labeling indexes of Ki-67 and MCM-3, i.e., the mean proportions of positive tumor cells out of 1000 tumoral cells counted in 10 microscopic fields at ×400 magnification, given as a percentage, were found to be 0.82% and 0.4%, respectively.

Cardiovascular profile score in 44 fetuses with cervicofacial tumors

BACKGROUND

Cervicofacial tumors are rarely detected by prenatal ultrasound, and prenatal counseling is very difficult as not much information is available about this problem in the literature, other than cases reports.

OBJECTIVES

The aim of this study was to know if fetal echocardiography examination is helpful in those cases.

MATERIAL AND METHODS

Forty-four fetuses with cervicofacial tumors detected in utero by ultrasonography and referred to our unit were assessed and the cardiovascular profile score (CVPS) based on echocardiography examinations was calculated. The data were analyzed by the standard statistical tests and Pearson's χ2-test (significance level P=0.05).

RESULTS

CVPS<8 was diagnosed in 10 fetuses (23%). Structural or functional cardiovascular anomalies were present in 17 fetuses (39%). The statistically significant correlation between the CVPS<8 and the poor outcome was confirmed (P<0.05).

CONCLUSION

We recommend fetal echocardiography and CVPS evaluation before counseling in fetuses with cervicofacial tumors as cardiovascular dysfunction diagnosed prenatally may seriously affect survival of the fetus as well as prenatal counseling and need for cardiac treatment.

Abstract POSTER-THER-1436: Image-guided and targeted therapy of advanced ovarian cancer using theranostic nanoparticles

About 80% of ovarian cancer patients are diagnosed at the advanced stage due to lack of a specific symptom for early detection. The major clinical challenges in the treatment of advanced ovarian cancer are inability of complete removal of peritoneal tumor metastases by debulking surgery, and drug resistant recurrent tumors developed in the majority of the patients. To address those clinical challenges, we have developed HER2/neu targeted magnetic iron oxide nanoparticles (IONPs) that efficiently deliver therapeutic and imaging agents into HER2 expressing ovarian cancer cells. Amphiphilic polymer coated 10 nm core size IONPs, without or with PEG modification, were conjugated with near infrared dye (NIR-830) labeled HER2 affibody or HER2 affitoxin, which is a fusing protein containing a HER2 affibody for targeting and a modified PE38 toxin as a therapeutic agent. A chemotherapy drug cisplatin, commonly used for ovarian cancer therapy, was further conjugated to carboxyl groups on the polymer coating of IONP via a coordinate bond. First, we demonstrated targeted drug delivery, and specificity and sensitivity of non-invasive tumor imaging by optical and MR imaging following intravenous (i.v.) or intraperitoneal (i.p.) delivery of the targeted theranostic IONPs in an orthotopic SKOV3 human ovarian cancer xenograft model with a high level of HER2/neu expression. Significant inhibition of the growth of primary ovarian tumor, and peritoneal and lung metastases was found after i.v. or i.p. delivery of cisplatin using 0.5 to 5 mg/Kg of cisplatin equivalent doses of HER2 affibody- or HER2 affitoxin-IONP in the tumor bearing mice once every 5 days for five injections. Furthermore, i.p. delivery of HER2 targeted theranostic IONP-cisplatin showed significantly better responses compared with i.v. delivery of the same nanoparticles. HER2 affitoxin-IONP-cisplatin treated mouse group showed enhanced anti-tumor effect compared to HER affibody-IONP-cisplatin treated mouse group. For both delivery approaches, we detected stronger tumor growth inhibitory effect on peritoneal metastatic tumors compared to the response in the primary ovarian tumors. Interestingly, we observed marked differences in the response to HER2 targeted therapy in different tumor bearing mice in the same group, and in different tumors in the same mouse. We also found that non-invasive optical imaging and MRI can be used to monitor IONP-drug delivery into tumors and to detect good responder or poor responder tumors during the treatment. Therefore, the HER2 targeted and image-guided treatment approach using theranostic IONPs has the potential for further development of a new biomarker targeted therapy for significantly improving survival of the ovarian cancer patients

Citation Format: Lily Yang, Minati Satpathy, Liya Wang, Rafal Zielinski, Weiping Qian, Malgorzata Lipowska, Jacek Capala, Andrew Wang, Hui Mao. Image-guided and targeted therapy of advanced ovarian cancer using theranostic nanoparticles [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-THER-1436.

Abstract 2096: High sensitivity of cutaneous T-cell lymphoma (CTCL) to CABE, a component of propolis

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of diseases characterized by clonal expansion of malignant T-cells in the skin. In the course of our quest to screen and identify a potent, selective anti-proliferative drug for CTCL, we discovered that caffeic acid benzyl ester (CABE), a natural component of edible plant species found in high concentrations in propolis, showed increased potency for CTCL (IC50 4 μM) in vitro compared to other tumor types such as melanoma (IC50 25 μM), glioma (IC50 25 μM), multiple myeloma (MM) (IC50 70 μM), head and neck squamous cell carcinoma (HNSCC) (IC50 25 μM), ovarian cancer (OC) (IC50 17 μM), breast carcinoma (IC50 43 μM), and Hodgkin's B-cell lymphoma (IC50 33 μM). Cell death in CTCL MJ and HH cell lines was accompanied by increased caspase-3 and poly (ADP-ribose) (PARP) cleavage and annexin V staining. There is growing evidence that CABE and its analogs exert their anticancer activity by modulating expression level of key transcription factors. Here, we evaluated the effects of CABE on the activity of different transcription factors and the expression of total and phosphorylated proteins in MJ cells by use of the transcription factor activation profiling array (TFAPA) and the reverese-phase protein array profiling (RPPA) assays. The activity of 48 transcription factors (TFs) and expression of 225 unique total and phosphorylated proteins could be monitored simultaneously by using a collection of biotin-labeled DNA probes and 225 unique antibodies. TFAPA analysis revealed that 18 TFs (including STAT1, STAT4, and RXR) were up-regulated and 3 TFs (STAT3, STAT5, and SATB1) were down-regulated to a variable extent in cells treated with 10 μM CABE for 5 h as compared to vehicle-treated control. RPPA analysis revealed 41 differentially expressed proteins between vehicle control and cells treated with 10 μM CABE. These can be functionally categorized into functional groups: DNA repair, cell cycle, apoptosis, phosphoinositide 3-kinase (PI3K)/AKT/mTOR, and receptor kinase pathways. Our results suggest that CABE targets multiple signaling pathways in CTCL in vitro, warranting the development of a pre-clinical animal model for the testing of CABE efficacy in vivo.

Acknowledgement: These studies were supported in part by the grant from Moleculin, LLC

Citation Format: Arumugam Jayakumar, Radjendirane Venugopal, Rafal Zielinski, Aleksandra Rusin, Izabela Fokt, Stanislaw Skora, Xiao Ni, Madeleine Duvic, Waldemar Priebe. High sensitivity of cutaneous T-cell lymphoma (CTCL) to CABE, a component of propolis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2096. doi:10.1158/1538-7445.AM2015-2096

Retrospective chart review of 44 fetuses with cervicofacial tumors in the sonographic assessment

OBJECTIVES

The aim of this retrospective study was to review and analyze ultrasonography examinations and follow-up of fetuses with cervicofacial tumors to develop bases for counseling specialist involved in perinatal treatment.

METHODS

The study consisted of case series with chart review of 44 fetuses with cervicofacial tumors diagnosed in utero by ultrasonography. The study was carried in Department of Diagnosis and Prevention of Congenital Malformations, Medical University of Lodz in years 1998-2013. The analysis of the fetuses with cervicofacial tumors included assessment of fetal sonographic features, neonatal survival and in utero as well as perinatal treatments. The obtained data were analyzed by the standard statistical tests and the Pearson's Chi square test, statistical significance at p=0.05.

RESULTS

Cervicofacial tumors were detected at mean 19±7 weeks of gestation. Eighty-two percent of the fetuses were males. Lymphatic malformations followed by teratomas were the most common fetal tumors in the cervicofacial region. In most cases, fetuses with cervicofacial tumors had other abnormalities. Mortality rate in our case series was 43%. In utero treatment was introduced in 6 fetuses. In 4 neonates prenatal sonographic assessment revealed upper airway patency and EXIT procedure (ex-utero intrapartum treatment) was introduced.

CONCLUSION

Prenatal sonographic detection of cervicofacial tumor, in case of lymphatic malformations possibly as early as in the first trimester, in case of craniofacial teratomas, cervical teratomas, hemangiomas and thyroid tumors possibly as early as in the second trimester, and in case of epignathi possibly in the third trimester, permits planning further course of pregnancy as well as EXIT procedure before delivery.

Optical imaging of ovarian cancer using HER-2 affibody conjugated nanoparticles

Computed Tomography (CT), Ultrasound (US), and Magnetic Resonance Imaging (MRI) have been the mainstay of clinical imaging regimens for the detection of ovarian cancer. However, without tumor specific contrast enhancement, these imaging modalities lack specificity and sensitivity in the detection of small primary and disseminated tumors in the peritoneal cavity. Herein, we illustrate a fairly new near infrared (NIR) optical imaging approach developed in our laboratory for the noninvasive detection of ovarian tumors using a HER-2 targeted nanoparticle-based imaging agent in an orthotopic mouse model of ovarian cancer. We used multimodal imaging approaches to detect the disease accurately and rapidly by utilizing a single imaging agent, NIR dye-labeled HER-2 affibody conjugated iron oxide nanoparticles. This agent targets HER-2 receptors, which are overexpressed in ovarian tumors. This chapter outlines materials and methods for the: (1) production of HER-2 targeted nanoparticles; (2) establishment of an orthotopic human ovarian cancer xenograft model; (3) monitoring of tumor growth by bioluminescence imaging; (4) administration of targeted nanoparticles followed by NIR optical imaging for the detection of orthotopic ovarian cancers with targeted accumulation of the nanoparticle imaging probes.

Submental epidermoid cysts in children

Epidermoid cysts are lesions, which form as a result of implantation of the epidermis in the layers of the dermis or the mucous membrane. The lesions are rare in adults with 7% occurring in the head and neck area and most often located in the submental region. In children population submental epidermoid cysts are extremely rare. The differential diagnosis of the lesions is necessary as it affects the choice of treatment methods. Among the pathological conditions occurring in that region, salivary retention cyst (ranula), thyroglossal duct cyst, vascular lymphatic malformation (cystic hygroma), median neck cyst, lymphadenopathy, thyroid gland tumor, laryngeal cyst, epidermoid and dermoid cysts, submental abscess, sialolithiasis and salivary gland inflammation should be considered. The authors of the present report demonstrate two cases of submental epidermoid cysts in children. Differential diagnosis in case of suspected submental epidermoid cyst in a child with proposed clinical practice and literature review is provided.

Abstract 2946: Status of STAT3, STAT5, and NF-κB in pancreatic cancer cell lines, small molecule inhibitors, and potential clinical implications

BACKGROUND: Pancreatic cancer (PC) is one of the most deadly forms of human cancer with 5-year survival less than 5%. Presently the nucleoside analog gemcitabine is used for front line disease management but its low response rate and the frequent development of drug resistance, which is poorly understood, limits its effectiveness. A large body of literature indicates that the STAT3, STAT5, and NF-κB pathways are active drivers of pancreatic cancer development and progression. Agents targeting STAT3 and NF-κB pathways are being actively being considered as potentially effective drugs and have been tested in in vitro and in vivo pancreatic tumor models with limited success.

EXPERIMENTAL DESIGN: We aimed to reassess the role and function of these three transcription factors in a panel of PC cell lines and assess the activity of WP1066, our lead STAT3/STAT5 inhibitor, and its close congeners in the same lines. Our reevaluation studies of the oncogenic function of STAT3, STAT5 and NF-κB were carried out in 3 established pancreatic cancer cell lines (PANC-1, Colo357, and MIAPaCa2) and 2 primary tumor cell lines (MDAPATC53 and MDAPATC50) isolated from patient tumor specimens with known clinical features and available relevant in vivo models. PC cells were separately treated with cytokines (IL-6 and IFN-α), gemcitabine and TNF-α and fractionated into cytoplasmic and nuclear portions. Levels of p-STAT3, p-STAT5, and NF-κB were assessed using Western blot, MesoScaleDiscovery, DNA binding activity, and confocal methods.

RESULTS: Collectively, our data showed that STAT3 was constitutively activated and that tyrosine-phosphorylated STAT3 (p-STAT3Y705) is exclusively located in the nucleus of the ColoFG357 and MiaPaCa2 cell lines. IL-6 and IFN-α treatment induced p-STAT3Y705, and their combined use resulted in synergistically higher levels of p-STAT3Y705 and in nuclear localization in all five PC cell lines. In contrast, and rather surprisingly, the tyrosine-phosphorylated STAT5Y694 and NF-κB were mostly localized in the cytoplasm in all five cell lines. Consistent with these results, the DNA binding activity of p-STAT5 and NF-κB is very low compared to p-STAT3. Interestingly, our studies revealed that gemcitabine treatment triggers the nuclear accumulation of NF-κB in a time-dependent manner suggesting that a combination of gemcitabine with NF-κB inhibitors can have synergistic activity in PDAC.

CONCLUSION: Our findings contribute to unraveling the functional significance of p-STAT3 and NF-κB as oncogenic transcription factors during pre- and post- gemcitabine treatment and the critical need to concurrently inhibit several targets and develop drug combinations or multitargeted drugs that block these pathways. Acknowledgement: This research was supported by the grant from Viragh's Foundation.

Citation Format: Arumugam Jayakumar, Venugopal Radjendirane, Jason Fleming, Yaan Kang, Aleksandra Rusin, Rafal Zielinski, Stanislaw Skora, Izabela Fokt, Waldemar Priebe. Status of STAT3, STAT5, and NF-κB in pancreatic cancer cell lines, small molecule inhibitors, and potential clinical implications. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2946. doi:10.1158/1538-7445.AM2014-2946

Abstract 3806: STAT3/STAT5 blockade by WP1066 inhibits ovarian cancer cell proliferation and induces cell death

BACKGROUND: Ovarian cancer is the most deadly gynecologic malignancy with 22,240 new cases and 14,030 deaths estimated in 2013. In order to improve the clinical management of women with ovarian cancer, it is critical to dissect the molecular drivers of ovarian neoplastic transformation and find efficient means of pharmacologic control.

Constitutive activation of the signal transducer and activator of transcription 3 and 5 (STAT3 and STAT5) pathways is found in 70% of ovarian cancer patients. Overexpression of STATs is associated with a malignant phenotype and confers resistance to chemotherapy.

Our drug discovery and development program has led to the development of a series of unique, small molecule inhibitors of STATs including a promising lead compound WP1066. The aim of this work was to investigate the antiproliferative and proapoptotic effects of WP1066 in selected ovarian cancer cells with constitutively activated or inducible STAT3 and STAT5.

EXPERIMENTAL DESIGN: The effects of WP1066 on the levels of p-STAT3 and p-STAT5 were assessed with Western blotting and the MSD assay. Nuclear translocation of p-STAT3 and p-STAT5 was confirmed with confocal microscopy.

Cell viability was determined with the MTS assay and dye exclusion test. Apoptosis induction was assessed on the basis of morphological markers using live-cell imaging (cell rounding, membrane blebbing and chromatin condensation) and biochemical markers using the MSD assay and confocal microscopy (cleaved PARP, cleaved caspase 3). SK-OV-3, SK-OV-3 CR (carboplatin resistant) and OVCAR-5 cells were used for in vitro studies.

RESULTS: SK-OV-3 and OVCAR-5 cells grown in vitro show constitutive activation of STAT3, but not STAT5. Treatment of ovarian cancer cells with IL-6 or IFN-α and -β results in high levels of p-STAT3 with subsequent p-STAT3 translocation to the nucleus. Treatment with EGF results in low level STAT3 activation. Cells treated with IFN-α and β or EGF exhibit activation of STAT5, while IL-6 treatment does not affect p-STAT5 level. Importantly, cells extracted from disseminated intraperitoneal ovarian tumors express high levels of phosphorylated STAT3 and clearly show nuclear p-STAT3 localization. WP1066 inhibits both p-STAT3 and p-STAT5 but not STAT3 and STAT5 in the panel of tested ovarian cancer cells. Treatment with WP1066 inhibits cell growth, is cytotoxic to SK-OV-3 and OVCAR-5 cells as well as the carboplatin resistant subline, SK-OV-3 CR, all at low micromolar concentrations. We found that WP1066 induces robust apoptosis, starting 4h after its addition to the culture medium.

CONCLUSION: Coordinated inhibition of p-STAT3/p-STAT5 by WP1066 results in profound apoptosis in ovarian cancer cells. Inhibition of STATs in ovarian cancer should be further explored as a potential therapeutic strategy for women with ovarian cancer.

Citation Format: Rafal Zielinski, Aleksandra Rusin, Anna Priebe, Jayakumar Arumugam, Radjendirane Venugopal, Stanislaw Skora, Izabela Fokt, Waldemar A. Priebe. STAT3/STAT5 blockade by WP1066 inhibits ovarian cancer cell proliferation and induces cell death. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3806. doi:10.1158/1538-7445.AM2014-3806

Probing the repulsive core of the nucleon-nucleon interaction via the (4)He(e,e'pN) triple-coincidence reaction

We studied simultaneously the (4)He(e,e'p), (4)He(e,e'pp), and (4)He(e,e'pn) reactions at Q(2)=2(GeV/c)(2) and x(B)>1, for an (e,e'p) missing-momentum range of 400 to 830  MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum, in a region where the nucleon-nucleon (NN) force is expected to change from predominantly tensor to repulsive. The abundance of neutron-proton pairs is reduced as the nucleon momentum increases beyond ∼500  MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum. Our data are compared with calculations of two-nucleon momentum distributions in (4)He and discussed in the context of probing the elusive repulsive component of the NN force.

In vivo fluorescence lifetime imaging for monitoring the efficacy of the cancer treatment

PURPOSE

Advances in tumor biology created a foundation for targeted therapy aimed at inactivation of specific molecular mechanisms responsible for cell malignancy. In this paper, we used in vivo fluorescence lifetime imaging with HER2-targeted fluorescent probes as an alternative imaging method to investigate the efficacy of targeted therapy with 17-DMAG (an HSP90 inhibitor) on tumors with high expression of HER2 receptors.

EXPERIMENTAL DESIGN

HER2-specific Affibody, conjugated to Alexafluor 750, was injected into nude mice bearing HER2-positive tumor xenograft. The fluorescence lifetime was measured before treatment and monitored after the probe injections at 12 hours after the last treatment dose, when the response to the 17-DMAG therapy was the most pronounced as well as a week after the last treatment when the tumors grew back almost to their pretreatment size.

RESULTS

Imaging results showed significant difference between the fluorescence lifetimes at the tumor and the contralateral site (∼0.13 ns) in the control group (before treatment) and 7 days after the last treatment when the tumors grew back to their pretreatment dimensions. However, at the time frame that the treatment had its maximum effect (12 hours after the last treatment), the difference between the fluorescence lifetime at the tumor and contralateral site decreased to 0.03 ns.

CONCLUSIONS

The results showed a good correlation between fluorescence lifetime and the efficacy of the treatment. These findings show that in vivo fluorescence lifetime imaging can be used as a promising molecular imaging tool for monitoring the treatment outcome in preclinical models and potentially in patients.

Active targeting using HER-2-affibody-conjugated nanoparticles enabled sensitive and specific imaging of orthotopic HER-2 positive ovarian tumors

Despite advances in cancer diagnosis and treatment, ovarian cancer remains one of the most fatal cancer types. The development of targeted nanoparticle imaging probes and therapeutics offers promising approaches for early detection and effective treatment of ovarian cancer. In this study, HER-2 targeted magnetic iron oxide nanoparticles (IONPs) are developed by conjugating a high affinity and small size HER-2 affibody that is labeled with a unique near infrared dye (NIR-830) to the nanoparticles. Using a clinically relevant orthotopic human ovarian tumor xenograft model, it is shown that HER-2 targeted IONPs are selectively delivered into both primary and disseminated ovarian tumors, enabling non-invasive optical and MR imaging of the tumors as small as 1 mm in the peritoneal cavity. It is determined that HER-2 targeted delivery of the IONPs is essential for specific and sensitive imaging of the HER-2 positive tumor since we are unable to detect the imaging signal in the tumors following systemic delivery of non-targeted IONPs into the mice bearing HER-2 positive SKOV3 tumors. Furthermore, imaging signals and the IONPs are not detected in HER-2 low expressing OVCAR3 tumors after systemic delivery of HER-2 targeted-IONPs. Since HER-2 is expressed in a high percentage of ovarian cancers, the HER-2 targeted dual imaging modality IONPs have potential for the development of novel targeted imaging and therapeutic nanoparticles for ovarian cancer detection, targeted drug delivery, and image-guided therapy and surgery.

In vivo assessment of HER2 receptor density in HER2-positive tumors by near-infrared imaging, using repeated injections of the fluorescent probe

HER2 overexpression and amplification of the HER2/neu gene have been found in approximately 25% of invasive breast carcinomas. They are associated with a poor prognosis and resistance to therapy in breast cancer patients. Up to now, clinical evaluation of human epidermal growth factor receptor 2 (HER2) expression is based on ex vivo methods (immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH) staining of biopsied tissue). Our goal is to realize “image and treat” paradigm using targeted fluorescent probes to evaluate expression levels of cell biomarkers responsible for cancer progression and to monitor the efficacy of corresponding monoclonal antibody treatments. We used fluorescent Affibody-based probes for in vivo analysis of HER2 receptors using near-infrared optical imaging that do not interfere with binding of the therapeutic agents to these receptors. We have analyzed two types of breast carcinoma xenografts with significant differences in HER2 expression (3+ and 2+ according to classification) in the mouse model. Using our kinetic model to analyze the temporal variations of the fluorescence intensity in the tumor area after two subsequent injections allowed us to assess quantitatively the difference in HER2 expression levels for two tumor types (BT-474 and MD-MBA-361). This result was substantiated by ELISA ex vivo assays of HER2 expression in the same tumors.

Abstract 2671: Multimodality imaging of ovarian cancer using HER2 affibody conjugated nanoparticles

Objectives: Specific and sensitive detection of ovarian cancer using non-invasive or intraoperative imaging approaches holds great promise for improving survival of the cancer patients through early diagnosis of ovarian cancer and image-guided surgery. In this study, we have developed Near infrared (NIR) dye labeled HER2 targeted magnetic iron oxide nanoparticles (IONPs) that enable detecting orthotopic ovarian cancers in nude mice using five imaging approaches, including 2D optical imaging, 3D-fluorescence tomography, MRI, spectroscopic imaging, and photoacoustic imaging.Methods: HER2 affibodies (ZHER2:342) were labeled with a NIR-dye 830 and then conjugated to a 10 nm core size IONP coated with amphiphilic polymer. Sensitivity of different imaging approaches in cancer detection was determined by direct injection of 5 x 103 to 3 x 106 of the nanoparticle probe-labeled tumor cells into the ovary of the mice and then imaged using 2D Kodak in vivo optical imaging system, MRI, and three new intraoperative hand-held imaging devices, including Spectroscopic, 3D-fluorescent tomography and photoacoustic imaging. Specificity of targeted tumor imaging was demonstrated by system delivery of the NIR830-ZHER2:342-IONP imaging probes in orthotopic human ovarian cancer xenograft models in nude mice. Histological examination of tumor and normal tissues further confirmed tumor targeting specificity.Results: HER2 affibody conjugated IONPs are excellent imaging probes for 2D-NIR optical, 3D-fluorescence tomography, spectroscopic device, photoacoustic and MR imaging of HER2 positive ovarian cancer lesions. Both 2D-optical imaging and MRI were able to detect ovarian tumors as small as 2 mm in size non-invasively. Photoacoustic imaging showed 5-times higher NIR signal in the tumor bearing mice injected with HER2 targeted IONPs than that of non-targeted IONP injected mice. However our handheld spectroscopic device result illustrated a high sensitivity in detection of small metastatic tumor lesions in the peritoneal cavity intra-operatively . Prussian blue staining revealed the presence of HER2 targeted IONPs in the tumor lesion as well as distant metastases lesions. Similarly all the above imaging systems were sensitive to detect at least 104 tumor cells labeled with HER2 affibody conjugated IONPs and implanted into the ovary for 24h. The ability of multi-modality tumor imaging following systemic delivery of single targeted nanoparticle platform make it possible for taking advantages of different imaging methods to increase sensitivity and specificity of tumor targeting and imaging. Conclusion: Based on the above results, the NIR dye-labeled and HER2 targeted IONPs developed by our group have great potential for development of multimodality imaging approaches that can be applied to ovarian cancer detection, image-guided and targeted therapy, and image-guided surgery.

Citation Format: Minati Satpathy, Weiping Qian, Rafal Zielinski, Liya Wang, Lei Xi, Jacek Capala, Andrew Wang, Malgorzata Lipowska, Brad A. Kairdolf, Huabei Jiang, Shuming Nie, Hui Mao, Lily Yang. Multimodality imaging of ovarian cancer using HER2 affibody conjugated nanoparticles. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2671. doi:10.1158/1538-7445.AM2013-2671

Affibody-DyLight conjugates for in vivo assessment of HER2 expression by near-infrared optical imaging

Purpose

Amplification of the HER2/neu gene and/or overexpression of the corresponding protein have been identified in approximately 20% of invasive breast carcinomas. Assessment of HER2 expression in vivo would advance development of new HER2-targeted therapeutic agents and, potentially, facilitate choice of the proper treatment strategy offered to the individual patient. We present novel HER2-specific probes for in vivo evaluation of the receptor status by near-infrared (NIR) optical imaging.

Experimental Design

Affibody molecules were expressed, purified, and labeled with NIR-fluorescent dyes. The binding affinity and specificity of the obtained probe were tested in vitro. For in vivo validation, the relationship of the measured NIR signal and HER2 expression was characterized in four breast cancer xenograft models, expressing different levels of HER2. Accumulation of Affibody molecules in tumor tissue was further confirmed by ex vivo analysis.

Results

Affibody-DyLight conjugates showed high affinity to HER2 (K_D = 3.66±0.26). No acute toxicity resulted from injection of the probes (up to 0.5 mg/kg) into mice. Pharmacokinetic studies revealed a relatively short (37.53±2.8 min) half-life of the tracer in blood. Fluorescence accumulation in HER2-positive BT-474 xenografts was evident as soon as a few minutes post injection and reached its maximum at 90 minutes. On the other hand, no signal retention was observed in HER2-negative MDA-MB-468 xenografts. Immunostaining of extracted tumor tissue confirmed penetration of the tracer into tumor tissue.

Conclusions

The results of our studies suggest that Affibody-DyLight-750 conjugate is a powerful tool to monitor HER2 status in a preclinical setting. Following clinical validation, it might provide complementary means for assessment of HER2 expression in breast cancer patients (assuming availability of proper NIR scanners) and/or be used to facilitate detection of HER2-positive metastatic lesions during NIR-assisted surgery.

In vivo method to monitor changes in HER2 expression using near-infrared fluorescence imaging

Human epidermal growth factor receptor type 2 (HER2) is a well-known biomarker that is overexpressed in many breast carcinomas. HER2 expression level is an important factor to optimize the therapeutic strategy and monitor the treatment. We used albumin binding domain-fused HER2-specific Affibody molecules, labeled with Alexa Fluor750 dye, to characterize HER2 expression in vivo. Near-infrared optical imaging studies were carried out using mice with subcutaneous HER2-positive tumors. Animals were divided into groups of five: no treatment and 12 hours and 1 week after treatment of the tumors with the Hsp90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG). The compartmental ligands-receptor model, describing binding kinetics, was used to evaluate HER2 expression from the time sequence of the fluorescence images after the intravenous probe injection. The normalized rate of accumulation of the specific fluorescent biomarkers, estimated from this time sequence, linearly correlates with the conventional ex vivo enzyme-linked immunosorbent assay (ELISA) readings for the same tumor. Such correspondence makes properly arranged fluorescence imaging an excellent candidate for estimating HER2 overexpression in tumors, complementing ELISA and other ex vivo assays. Application of this method to the fluorescence data from HER2-positive xenografts reveals that the 17-DMAG treatment results in downregulation of HER2. Application of the AngioSense 750 probe confirmed the antiangiogenic effect of 17-DMAG found with Affibody-Alexa Fluor 750 conjugate.

PET of HER2-positive pulmonary metastases with 18F-ZHER2:342 affibody in a murine model of breast cancer: comparison with 18F-FDG

Targeted therapies often depend on the expression of the target present in the tumor. This expression can be difficult to ascertain in widespread metastases. (18)F-FDG PET/CT, although sensitive, is nonspecific for particular tumor markers. Here, we compare the use of a human epidermal growth factor receptor 2 (HER2)-specific (18)F-Z(HER2)(:342)-Affibody and (18)F-FDG in HER2-expressing pulmonary metastases in a murine model of breast cancer.

METHODS

The lung metastasis model was established by intravenous injection of MDA-MB-231(HER2)-Luc human breast cancer cells into the tail vein. Bioluminescence imaging was used to evaluate metastasis progression. Uptake of (18)F-Z(HER2)(:342)-Affibody and (18)F-FDG was confirmed by coregistration of the PET images with MR and CT images. At the end of the study, the presence of neoplastic cells and HER2 expression in lung tissues, and distribution of the tracer, were assessed ex vivo by immunohistochemistry and autoradiography.

RESULTS

(18)F-Z(HER2)(:342)-Affibody successfully targeted HER2-positive lesions in the lung and allowed detection of metastases as early as 9 wk after injection of cells. In contrast, (18)F-FDG uptake was often masked by surrounding inflammatory changes and was nonspecific for HER2 expression. HER2 expression at a cellular level correlated well with tracer uptake on autoradiography.

CONCLUSION

(18)F-Z(HER2)(:342)-Affibody is a promising tracer for evaluation of HER2 status of breast cancer metastases and is more specific for detecting HER2-positive lesions than (18)F-FDG.

HER2-affitoxin: a potent therapeutic agent for the treatment of HER2-overexpressing tumors

PURPOSE

Cancers overexpressing the HER2/neu gene are usually more aggressive and are associated with poor prognosis. Although trastuzumab has significantly improved the outcome, many tumors do not respond or acquire resistance to current therapies. To provide an alternative HER2-targeted therapy, we have developed and characterized a novel recombinant protein combining an HER2-specific Affibody and modified Pseudomonas aeruginosa exotoxin A (PE 38), which, after binding to HER2, is internalized and delivered to the cytosol of the tumor cell, where it blocks protein synthesis by ADP ribosylation of eEF-2.

EXPERIMENTAL DESIGN

The effect of the Affitoxin on cell viability was assessed using CellTiter-Glo (Promega). To assess HER2-specific efficacy, athymic nude mice bearing BT-474 breast cancer, SK-OV-3 ovarian cancer, and NCI-N87 gastric carcinoma xenografts were treated with the Affitoxin (HER2- or Tag-specific), which was injected every third day. Affitoxin immunogenicity in female BALB/c mice was investigated using standard antibody production and splenocyte proliferation assays.

RESULTS

In vitro experiments proved that HER2-Affitoxin is a potent agent that eliminates HER2-overexpressing cells at low picomolar concentrations. Therapeutic efficacy studies showed complete eradication of relatively large BT-474 tumors and significant effects on SK-OV-3 and NCI-N87 tumors. HER2-Affitoxin cleared quickly from circulation (T(1/2) < 10 minutes) and was well tolerated by mice at doses of 0.5 mg/kg and below. Immunogenicity studies indicated that HER2-Affitoxin induced antibody development after the third injected dose.

CONCLUSIONS

Our findings showed that HER2-Affitoxin is an effective anticancer agent and a potential candidate for clinical studies.

Quantitative analysis of Her2 receptor expression in vivo by near-infrared optical imaging

Human epidermal growth factor receptor 2 (HER2) overexpression in breast cancers is associated with poor prognosis and resistance to therapy. Current techniques for estimating this important characteristic use ex vivo assays that require tissue biopsies. We suggest a novel noninvasive method to characterize HER2 expression in vivo, using optical imaging, based on HER2-specific probes (albumin-binding domain-fused-(ZHER2:342)2-Cys Affibody molecules [Affibody AB, Solna, Sweden], labeled with Alexa Fluor 750 [Molecular Probes, Invitrogen, Carlsbad, CA]) that could be used concomitantly with HER2-targeted therapy. Subcutaneous tumor xenografts, expressing different levels of HER2, were imaged with a near-infrared fluorescence small-animal imaging system at several times postinjection of the probe. The compartmental ligand-receptor model was used to calculate HER2 expression from imaging data. Correlation between HER2 amplification/overexpression in tumor cells and parameters, directly estimated from the sequence of optical images, was observed (eg, experimental data for BT474 xenografts indicate that initial slope, characterizing the temporal dependence of the fluorescence intensity detected in the tumor, linearly depends on the HER2 expression, as measured ex vivo by an enzyme-linked immunosorbent assay for the same tumor). The results obtained from tumors expressing different levels of HER2 substantiate a similar relationship between the initial slope and HER2 amplification/overexpression. This work shows that optical imaging, combined with mathematical modeling, allows noninvasive monitoring of HER2 expression in vivo.