Alternative Methods for the Treatment of Chemo-Resistant Cancers

Great strides have been made in cancer therapy in the past century, yet it remains one of the leading causes of death in the United States today. This work aimed to shed light on novel methods to treat a variety of aggressive and often chemo-resistant cancers both in vitro and in vivo. The first aim of this work was to evaluate the therapeutic efficacy of poly(methacryloyloxyethyl phosphorylcholine) (polyMPC) prodrugs compared to standard chemotherapeutic agents. Conjugation of polyMPC to drugs such as doxorubicin (Dox) can result in its improved solubility, prolonged half-life and therapeutic efficacy. PolyMPC and polyMPC-Dox (at a dose less than 10mg/kg) was observed to be safe for systemic administration in a murine model. Additionally, treatment with polyMPC-Dox resulted in improved survival and reduced off target toxicities in mice with orthotopic human ovarian xenografts. Further, mesenchymal stem cells (MSCs) were observed to successfully uptake polyMPC and home to breast cancer xenografts in vivo and thus can potential serve as a vehicle to improve drug delivery. Additional aims of this work focused on evaluating the root extract of Rhodiola crenulata (RC) plants for the treatment of aggressive cancers derived from the neural crest, including neuroblastoma and melanoma. RC was observed to reduce growth and migration of melanoma in vitro. Further, RC resulted in reduction of aggressive tumor characteristics upon topical therapy as well as the reduced establishment of metastatic foci upon enteral administration in mice with melanoma. While no difference in outcomes was observed upon RC treatment in a disseminated neuroblastoma model in vivo, RC did result in striking cytotoxic effects upon treatment of neuroblastoma cells in vitro. These cytotoxic effects of RC likely resulted from derangements altering the cell’s ability to undergo optimal cellular metabolism

The Effects of Rhodiola Crenulata Extract on Proliferation and Differentiation in Glioblastoma Multiforme

Purpose: Purpose of the study was to evaluate the effects of rhodiola crenulata plant extract on glioblastoma in vitro. Methods: U-87MG glioblastoma multiforme cell line was utilized for evaluation in this study. Cells were treated with 100ug/ml or 200ug/ml of rhodiola crenulata and compared to ethanol vehicle control. Proliferation was measured at 24, 48, 72, and 96 hours after treatment utilizing an MTS proliferation assay. To further assess proliferation a clonogenicity assay was conducted. These cells were treated with ethanol vehicle control, 100ug/ml of rhodiola, radiation, or combined rhodiola/radiation treatment. To evaluate differentiation the expression of glial fibrillary acidic protein (GFAP), a protein marker of differentiation, was assessed with immunocytochemistry. Results: Effects on proliferation were initially noted at 48hours after treatment and observed through the 96-hour period. The effects on proliferation were noted in both treatment groups. At 96-hours after treatment significant difference was noted between the 100ug/ml of rhodiola and control group (p=0.0065) and significant difference noted between the 200ug/ml of rhodiola and control group (p=0.0006). Cell clonogenicity was reduced in the cells treated with 100ug/ml of rhodiola. The decreased number of colonies was significant when comparing the radiation treated cells with 100ug/ml rhodiola treated cells (p=0.0030). GFAP was overexpressed in the rhodiola treatment group when compared to expression in the control group (Figure 1). Conclusion: Rhodiola crenulata extract effectively decreases proliferation and increases differentiation of glioblastoma cells in vitro. Further work is required to fully understand the extent and full effects rhodiola crenulata has glioblastoma cells

A Novel Approach to Targeted Oncologic Therapy - Co-culture Viability of Polymer Prodrug Conjugation to Mesenchymal Stem Cells

Background/Purpose: Conjugation of polymer prodrugs to tumor homing cells, such as Mesenchymal Stem Cells (MSCs), could provide a vehicle for actively targeted delivery of polymer prodrugs. Methods: Human Bone Marrow MSCs were conjugated to either a doxorubicin polymer prodrug or free doxorubicin and were co-cultured with T-cells. Viability was assessed through the use of a Vi-cell counter. In Vivo Migration Analysis was performed NOD SCID mice implanted with subcutaneous MDA MB-231 breast cancer xenografts. Following tumor establishment, mice were injected via lateral tail vein injection with either saline or polymer loaded MSCs. Five days following stem cell injection, mice were euthanized, tumors were harvested and sections were analyzed using fluorescent microscopy and immuno-histochemical staining for cd105. Results: T-cell viability was reduced when co-cultured with MSCs conjugated to free doxorubicin although cells co-cultured with MSCs conjugated to doxorubicin polymer did not exhibit reduced viability. Polymer loaded MSCs displayed intact tumor homing migratory ability in vivo (Figure 1). Conclusion: MSCs conjugated to doxorubicin released the drug, resulting in reduced neighboring T-cells viability. MSCs loaded with polymer maintained their migratory capacity were able to migrate to tumors in vivo. MSCs therefore represent a potential vehicle for targeted drug delivery. Future work will focus on developing methods for releasing the drug upon successful delivery to the target in vivo

Human Trial of a Genetically Modified Herpes Simplex Virus for Rapid Detection of Positive Peritoneal Cytology in the Staging of Pancreatic Cancer

AbstractIntroductionPatients with peritoneal dissemination of pancreatic adenocarcinoma do not benefit from surgical resection, but radiologic and cytologic detection of peritoneal cancer lack sensitivity. This trial sought to determine if an oncolytic virus may be used as a diagnostic agent to detect peritoneal cancer.MethodsPeritoneal washings from patients with pancreatic adenocarcinoma were incubated with the enhanced green fluorescent protein (eGFP)-expressing oncolytic herpes simplex virus (HSV) NV1066. eGFP-positive or negative status was recorded for each specimen and compared to results obtained by conventional cytologic evaluation. These results were correlated with recurrence and survival for patients who underwent R0 resection.ResultsOf 82 patients entered in this trial, 12 (15%) had positive cytology and 50 (61%) had virally-mediated eGFP positive cells in peritoneal washings. All cytology-positive patients were also eGFP positive. HSV-mediated fluorescence detection had sensitivities of 94% and 100% for detection of any and peritoneal metastatic disease; respectively. Median recurrence free and disease specific survival were 6.5 and 18.3months for eGFP positive patients, versus 12.2 and 36.2months for eGFP negative patients (P=0.01 and 0.19); respectively.ConclusionsA genetically modified HSV can be used as a highly sensitive diagnostic agent for detection of micro-metastatic disease in patients with pancreatic adenocarcinoma and may improve patient selection for surgery

In Vivo Evaluation of a Biomimetic Polymer-Doxorubicin Conjugate for Cancer Therapy

This poster will describe a novel polymer pro-drug platform designed for conjugation and delivery of chemotherapeutics. Specifically, polymer pro-drugs were prepared from functional polymer zwitterions and doxorubicin (DOX), and evaluated in vivo to assess toxicological, pharmacokinetic and therapeutic properties. The biocompatible polymer scaffold (PolyMPC) consists of zwitterionic phosphorylcholine pendent groups, which mimic the natural hydrophilic moieties of phospholipids in cell membranes, and hydrazone linkages that allow for pH-triggered release of DOX. PolyMPC-DOX pro-drugs were isolated as dry solids using a facile strategy that allows for precise control of molecular weight and DOX incorporation. In vivo toxicity of PolyMPC and PolyMPC-DOX was assessed in a murine model. The maximum tolerated dose of the pro-drug was five times greater than that of free DOX, while PolyMPC alone exhibited no toxicity even at a dose of 800 mg/kg. A pharmacokinetic study in tumor-bearing mice demonstrated a significant increase in circulation half-life of conjugated DOX (t1/2=2 hours) compared to free DOX (t1/2=15 minutes), with conjugated DOX detectable in blood serum for longer than 24 hours. This pronounced enhancement in circulation time was attributed to the macromolecular scaffold, which precludes rapid renal clearance compared to native DOX. Examination of mice given PolyMPC-DOX five days after injection in the PK study showed a three-fold increase of drug accumulated in tumor tissue compared to that of mice treated with free DOX and drug accumulation in off-target organs was reduced for mice given DOX conjugate. The therapeutic efficacy of the PolyMPC-DOX conjugates was then assessed in an orthotopic murine breast cancer model. The treatment group given PolyMPC-DOX exhibited a two-fold increase in overall survival and a significant reduction in average tumor volume compared to the free DOX and saline control groups. A study evaluating the therapeutic efficacy of PolyMPC-DOX in a human ovarian xenograft tumor model is ongoing

Direct Measurement of the Visible to UV Photodissociation Processes for the PhotoCORM TryptoCORM

PhotoCORMs are light‐triggered compounds that release CO for medical applications. Here, we apply laser spectroscopy in the gas phase to TryptoCORM, a known photoCORM that has been shown to destroy Escherichia coli upon visible‐light activation. Our experiments allow us to map TryptoCORM’s photochemistry across a wide wavelength range by using novel laser‐interfaced mass spectrometry (LIMS). LIMS provides the intrinsic absorption spectrum of the photoCORM along with the production spectra of all of its ionic photoproducts for the first time. Importantly, the photoproduct spectra directly reveal the optimum wavelengths for maximizing CO ejection, and the extent to which CO ejection is compromised at redder wavelengths. A series of comparative studies were performed on TryptoCORM‐CH3CN which exists in dynamic equilibrium with TryptoCORM in solution. Our measurements allow us to conclude that the presence of the labile CH3CN facilitates CO release over a wider wavelength range. This work demonstrates the potential of LIMS as a new methodology for assessing active agent release ( e.g. CO, NO, H2S) from light‐activated prodrugs

Proceedings of the 2023 Hawk Talks

This volume contains the proceedings of the 2023 Hawk Talk Conference held on April 28th at the University of Kansas Edwards Campus in Overland Park, Kansas.The 2023 Hawk Talks Conference features work from students representing a diverse range of programs, including Applied Biological Sciences, American Sign Language and Deaf Studies, Psychology, and Biotechnology. Hawk Talks Conference are opportunities for students to present year-end capstone, honors, and independent research projects. The agenda of talks and poster presentations, abstracts, and short biographies appear for all presenters. Hawk Talks provides a platform for student researchers to come together and share their latest findings and discoveries. This convention serves as a means to stay up-to-date with the latest research taking place on the University of Kansas’ Edwards Campus

A Maternal High-Fat, High-Sucrose Diet Has Sex-Specific Effects on Fetal Glucocorticoids with Little Consequence for Offspring Metabolism and Voluntary Locomotor Activity in Mice

Maternal overnutrition and obesity during pregnancy can have long-term effects on offspring physiology and behaviour. These developmental programming effects may be mediated by fetal exposure to glucocorticoids, which is regulated in part by placental 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 and 2. We tested whether a maternal high-fat, high-sucrose diet would alter expression of placental 11β-HSD1 and 2, thereby increasing fetal exposure to maternal glucocorticoids, with downstream effects on offspring physiology and behaviour. C57BL/6J mice were fed a high-fat, high-sucrose (HFHS) diet or a nutrient-matched low-fat, no-sucrose control diet prior to and during pregnancy and lactation. At day 17 of gestation, HFHS dams had ~20% lower circulating corticosterone levels than controls. Furthermore, there was a significant interaction between maternal diet and fetal sex for circulating corticosterone levels in the fetuses, whereby HFHS males tended to have higher corticosterone than control males, with no effect in female fetuses. However, placental 11β-HSD1 or 11β-HSD2 expression did not differ between diets or show an interaction between diet and sex. To assess potential long-term consequences of this sex-specific effect on fetal corticosterone, we studied locomotor activity and metabolic traits in adult offspring. Despite a sex-specific effect of maternal diet on fetal glucocorticoids, there was little evidence of sex-specific effects on offspring physiology or behaviour, although HFHS offspring of both sexes had higher circulating corticosterone at 9 weeks of age. Our results suggest the existence of as yet unknown mechanisms that mitigate the effects of altered glucocorticoid exposure early in development, making offspring resilient to the potentially negative effects of a HFHS maternal diet