Publications by authors named "Sandra Sexton"

Photobac is a near infrared photosensitizer (PS) derived from naturally occurring bacteriochlorophyll- a, with a potential for treating a variety of cancer types (U87, F98 and C6 tumor cells in vitro). The main objective of the studies presented herein was to evaluate the efficacy, toxicity and pharmacokinetic profile of Photobac in animals (mice, rats and dogs) and submit these results to the United States Food and Drug Administration (US FDA) for its approval to initiate Phase I human clinical trials of glioblastoma, a deadly cancer disease with no long term cure. The photodynamic therapy (PDT) efficacy of Photobac was evaluated in mice subcutaneously implanted with U87 tumors, and in rats bearing C6 tumors implanted in brain.

View Article and Find Full Text PDF

Although melanoma accounts for only 5.3% of skin cancer, it results in >75% of skin-cancer-related deaths. To avoid disfiguring surgeries on the head and neck associated with surgical excision, there is a clear unmet need for other strategies to selectively remove cutaneous melanoma lesions.

View Article and Find Full Text PDF

Background: Cardioprotective effects of -acetyl-ser-asp-lys-pro (Ac-SDKP) have been reported in preclinical models of myocardial remodeling. However, the rapid degradation of this endogenous peptide in vivo limits its clinical use.

Method: To prolong its bioavailability, Ac-SDKP was encapsulated by phosphocholine lipid bilayers (liposomes) similar to mammalian cell membranes.

View Article and Find Full Text PDF

Purpose: We tested a recently developed short peptide radioligand for PET imaging of hepatocellular carcinoma (HCC) by targeting an oncoprotein, extra-domain B fibronectin (EDB-FN) in the tumor microenvironment.

Methods: The radioligand consists of a small linear peptide ZD2 with Ga-NOTA chelator, and specifically binds to EDB-FN. PET images were acquired dynamically for 1 hour after intravenously (i.

View Article and Find Full Text PDF

Increased red cell distribution width (RDW), which measures erythrocyte mean corpuscular volume (MCV) variability (anisocytosis), has been linked to early mortality in many diseases and in older adults through unknown mechanisms. Hypoxic stress has been proposed as a potential mechanism. However, experimental models to investigate the link between increased RDW and reduced survival are lacking.

View Article and Find Full Text PDF

Background And Aims: Radiolabeled short peptide ligands targeting prostate-specific membrane antigen (PSMA) were developed initially for imaging and treatment of prostate cancers. While many nonprostate solid tumors including hepatocellular carcinoma (HCC) express little PSMA, their neovasculature expresses a high level of PSMA, which is avid for Gallium-68-labeled PSMA-targeting radio-ligand (Ga-PSMA-11) for positron emission tomography (PET). However, the lack of a spontaneous animal model of tumor-associated vascular PSMA overexpression has hindered the development and assessment of PSMA-targeting radioligands for imaging and therapy of the nonprostatic cancers.

View Article and Find Full Text PDF

3-(1'-Hexyloxyethyl)-3-devinylpyropheophorbide-a (HPPH or Photochlor), a tumor-avid chlorophyll derivative currently undergoing human clinical trials, was conjugated with mono-, di-, and tri-Gd(III)tetraxetan (DOTA) moieties. The T/T relaxivity and PDT efficacy of these conjugates were determined. The tumor specificity of the most promising conjugate was also investigated at various time points in mice and rats bearing colon tumors, as well as rabbits bearing widespread metastases from VX2 systemic arterial disseminated metastases.

View Article and Find Full Text PDF

Background: Epidermal growth factor receptor (EGFR) inhibitors, including cetuximab and panitumumab, are valuable therapeutics for colorectal cancer (CRC), but resistance to these inhibitors is common. The reason for such resistance is not well understood, which hampers development of better therapeutic strategies. Although activating mutations in KRAS, BRAF and PIK3CA are considered major drivers of CRC resistance to EGFR inhibitors, therapeutic targeting of these drug resistance drivers has not produced substantial clinical benefit.

View Article and Find Full Text PDF

Interstitial photodynamic therapy (I-PDT) is a promising therapy considered for patients with locally advanced cancer. In I-PDT, laser fibers are inserted into the tumor for effective illumination and activation of the photosensitizer in a large tumor. The intratumoral light irradiance and fluence are critical parameters that affect the response to I-PDT.

View Article and Find Full Text PDF

Mice are the most common animal used to study disease, but there are real concerns about the reproducibility of many of these experiments. This review discusses how several different sources of chronic stress can directly impact experimental outcomes. Mandated housing conditions induce an underappreciated level of chronic stress but are not usually considered or reported as part of the experimental design.

View Article and Find Full Text PDF
Article Synopsis
  • T2 cells and innate lymphoid cells 2 (ILC2) can promote tumor growth by producing cytokines like IL-4, IL-5, and IL-13, but how these immune cells reach tumors is unclear.
  • This study reveals that oncogenic Kras enhances IL-33 levels in pancreatic ductal adenocarcinoma (PDAC) cells, which helps recruit and activate T2 and ILC2 cells, with deletion of IL-33 leading to reduced recruitment and tumor slowdown.
  • Interestingly, IL-33 secretion relies on the presence of intratumoral fungi, and blocking IL-33 or treating with anti-fungal methods can reduce T2 and ILC2 cell infiltration, potentially improving survival rates in
View Article and Find Full Text PDF

Background: Myocardial Gal3 (galectin-3) expression is associated with cardiac inflammation and fibrosis. Increased Gal3 portends susceptibility to heart failure and death. There are no data reporting the causative role of Gal3 to mediate cardiac fibro-inflammatory response and heart failure.

View Article and Find Full Text PDF

High liver uptake presents a problem for 3'-deoxy-3'-[F]fluorothymidine ([F]FLT) as a radiotracer for imaging cellular proliferation in the liver with positron emission tomography (PET). This investigation re-visited some issues related to the high liver background uptake of [F]FLT with an animal model of woodchucks. Several enzymes involved in the hepatic catabolism of FLT, thymidine phosphorylase (TP, TYMP), uridine 5'-diphospho-glucuronosyl-transferases (UDP-GTs, short for UGTs), and β-glucuronidase (GUSB), their homology as well as hepatic expression between the human and the woodchuck was examined.

View Article and Find Full Text PDF

Herein we report the positron emission tomography (PET) imaging potential of a I-labeled radiopharmaceutical (PET-ONCO). In tumored mice, it shows high uptake in a variety of tumors: brain (GL261, U87), Colon (Colon26), lung (Lewis lung), breast (4 T1), bladder (UMUC3), pancreas (PANC-1) implanted in mice. This agent also shows promise for imaging associated metastatic disease (breast to lung, to bone).

View Article and Find Full Text PDF

Hepatocellular carcinoma (HCC) has become one of the leading causes of cancer death worldwide. There has been anecdotal report regarding the effectiveness of proton beam treatment for HCC. In this pre-clinical investigation, the woodchuck model of viral hepatitis infection-induced HCC was used for proton beam treatment experiment.

View Article and Find Full Text PDF

Background: Woodchucks (Marmota monax) are a well-accepted animal model for the investigation of spontaneous hepatocellular carcinoma (HCC). As HCC tumors obtain nutrient blood supply exclusively from the hepatic artery, hepatic artery infusion (HAI) has been applied to HCC. However, there is a scarcity of experimental animal models to standardize drug regimens and examine novel agents.

View Article and Find Full Text PDF

There is increased interest in the use of magnetic resonance imaging (MRI) for guiding radiation therapy (RT) in the clinical setting. In this regard, preclinical studies can play an important role in understanding the added value of MRI in RT planning. In the present study, we developed and validated a clinically relevant integrated workflow for MRI-guided volumetric arc therapy (VMAT) in a VX2 rabbit neck tumor model of HNSCC.

View Article and Find Full Text PDF

The objective of the present study was to develop a predictive model for Photofrin -mediated interstitial photodynamic therapy (I-PDT) of locally advanced tumors. Our finite element method was used to simulate 630-nm intratumoral irradiance and fluence for C3H mice and New Zealand White rabbits bearing large squamous cell carcinomas. Animals were treated with light only or I-PDT using the same light settings.

View Article and Find Full Text PDF

Clinical diagnosis of hepatocellular carcinoma (HCC) relies heavily on radiological imaging. However, information pertaining to liver cancer treatment such as the proliferation status is lacking. Imaging tumor proliferation can be valuable in patient management.

View Article and Find Full Text PDF
Article Synopsis
  • - The study focused on developing a novel optical surface applicator (OSA) for intraoperative photodynamic therapy (IO-PDT) to improve control over light distribution, which is important for tissue and tumor treatment.
  • - The OSA was made from flexible silicone with diffusing optical fibers, and its light distribution was tested both directly on the applicator and through tissue-simulating phantoms using a dosimetry system.
  • - Results showed improved uniformity of light distribution in phantoms compared to the OSA surface, and the OSA successfully delivered the intended light dose in a pilot study with swine, indicating its potential for effective therapy in clinical settings.
View Article and Find Full Text PDF

Purpose: [C]methionine ([C]Met) was used for cancer imaging based on upregulated amino acid transport and protein synthesis in different tumor types. However, the short half-life of C decay limited further clinical development of [C]Met. Synthetic amino acid analog anti-1-amino-3-[F]fluoro-cyclobutyl-1-carboxylic acid ([F]FCABC) was developed and FDA-approved for PET imaging of recurrent prostate cancer.

View Article and Find Full Text PDF

The multikinase inhibitor sorafenib is the only standard first-line therapy for hepatocellular carcinoma (HCC). Here, we report the dose-dependent effects of sorafenib on the immune response, which is related to nuclear factor of activated T cells 1 (NFAT1) activity. In vitro and in vivo experiments were performed with low and high doses of sorafenib using human T cells and spontaneous developed woodchuck HCC models.

View Article and Find Full Text PDF