Matching Items (3)
Description
The anthracycline drug Doxorubicin (DOX) is a highly effective treatment for breast cancer, but its clinical utility is limited by dose-dependent cardiovascular toxicity. The toxic effects are partly attributed to DOX-induced generation of reactive oxygen species, which may impair nitric oxide-mediated vasodilation. Exercise training activates antioxidant defense mechanisms and is thus hypothesized to counteract oxidative stress when initiated prior to DOX administration. Adult 8-week old, ovariectomized female Sprague-Dawley rats were divided into 4 groups: sedentary + vehicle (Sed+Veh); Sed+DOX; exercise + veh (Ex+Veh); and Ex+DOX. Rats in the exercise groups were preconditioned with high intensity interval training consisting of 4x4 minute bouts of exercise at 85-95% of VO2peak separated by 2 minutes of active recovery performed 5 days per week. Exercise was implemented one week prior to the first injection and continued throughout the study. Animals received either DOX (4mg/kg) or veh (saline) intraperitoneal injections bi-weekly for a cumulative dose of 12 mg/kg per animal. Five days following the final injection, animals were anesthetized with isoflurane, decapitated and aortas and perivascular adipose tissue (PVAT) were removed for western blot analyses. No significant differences in aortic protein expression were detected for inducible nitric oxide synthase (iNOS) or the upstream activator of endothelial nitric oxide synthase (eNOS), Akt, across groups (p>0.05), whereas eNOS protein expression was significantly downregulated in Sed+DOX (p=0.003). In contrast, eNOS expression was not altered in Ex+DOX treated animals. Protein expression of iNOS in PVAT was upregulated with exercise in the DOX-treated groups (p=0.039). These findings suggest that exercise preconditioning may help mitigate vascular effects of DOX by preventing downregulation of eNOS in the aorta.
ContributorsO'Neill, Liam Martin (Author) / Sweazea, Karen (Thesis director) / Angadi, Siddhartha (Committee member) / Dickinson, Jared (Committee member) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Triple-negative breast cancer (TNBC) is defined by the lack of three receptors (estrogen, progesterone, and HER2 receptors) and accounts for 12-17% of breast cancers. TNBC is an aggressive form of the disease associated with high rates of recurrence and mortality within five years. Inhibitor of Growth 4 (ING4) is a gene deleted in 16.5% and downregulated in 34% of breast tumors. The correlation between ING4 deficiencies and advanced tumors and poor patient survival implicates its tumor suppressive function in breast cancer. Low ING4 expression has been correlated with NFκB activation in metastatic breast tumors. Moreover, ING4 has been shown to inhibit NFkB-mediated gene transcription in various cancers, suggesting that ING4 may suppress cancer by inhibiting NFkB activation. However, the contribution of ING4 deficiencies and NFkB activation to aggressive TNBC progression is currently not well understood. We investigated the role of ING4 in the MDAmb231 TNBC cell line by genetically engineering the cells to overexpress or delete ING4. Cell growth and sensitivity to the chemotherapeutic agent doxorubicin were evaluated between the ING4-modified cell lines with or without TNFα to activate NFκB. The results showed that cell growths were comparable between the vector controls and ING4 overexpressing or deleted cell lines. In addition, TNFα treatment did not alter the growths of all cell lines, indicating that ING4 with or without NFkB activation did not play a role in determining the growth rates of TNBC. However, ING4 overexpressing cells were 20-30% more sensitive to 10 μM doxorubicin treatment, whereas ING4-deleted cells were 20-50% more resistant, suggesting that ING4 may determine chemotherapy response in TNBC. These findings suggest that tumors with low levels of ING4 may be more resistant to chemotherapy, thus requiring higher dosage and/or additional chemotherapy in patient treatment. Unexpectedly, TNFα sensitized all cell lines to doxorubicin regardless of ING4 expression levels, suggesting a TNFα function outside of NFκB activation in increasing doxorubicin sensitivity. It implicates that TNFα treatment may increase chemotherapy response in TNBC patients.
ContributorsUngor, Ashley Jordyn (Author) / Capco, David (Thesis director) / Kim, Suwon (Committee member) / Compton, Carolyn (Committee member) / Sanford School of Social and Family Dynamics (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Plasmid DNA (pDNA) purification has been extensively investigated for various biological and biochemical applications such as transfection, polymerase chain reaction and DNA therapeutics. In the previous paper, we have described the synthesis, characterization and evaluation of microbeads (“Amikabeads”) derived from aminoglycoside amikacin for pDNA binding via anion-exchange chromatography. Here, we investigated the pDNA binding performance of conjugating Amikabeads with two highly specific DNA binding ligands via minor groove hydrophobic interaction. The pDNA maximum binding capacity of doxorubicin drug-conjugated Amikabeads (“doxo-beads”) was found out to be 429 μg pDNA/ mg of doxo-beads with a Langmuir constant of 8.21*10-4 L/mg, whereas the binding performance of berenil drug-conjugated "mikabeads (“berenil-beads”) was 142 μg pDNA/mg of berenil-beads with a adsorption constant of 4.71*10-5 L/mg. In addition, the desorption percentage of doxo-beads and berenil-beads was obtained as 52% and 41%, respectively. Our results indicate that by conjugating with highly specific DNA binding ligands, Amikabeads-drug complex enhances the pDNA binding performance and contains a promising potential for future applications in biotechnology field.
ContributorsLin, Nan (Author) / Rege, Kaushal (Thesis director) / Grandhi, Taraka Sai Pavan (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05