Pharmacy Doctoral Work

Permanent URI for this collectionhdl:10365/32397

Browse

Browsing Pharmacy Doctoral Work by Subject "breast cancer"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Determination of Growth Inhibitory Effect of Iminodibenzyl Against Breast Cancer
    (North Dakota State University, 2021) Shah, Harshit Pareshbhai
    Breast cancer arises from the culmination of complex process enclosing multiple gene modifications such as cyclooxygenase-2 (COX-2). It catalyzes arachidonic acid (AA, downstream ω-6 polyunsaturated fatty acid (ω-6 PUFA)) metabolism to cancer-promoting prostaglandin E2 (PGE2). Hence, COX-2 inhibition was considered an ideal strategy to inhibit the cancer progression. However, COX-2 inhibitors are no longer advised for cancer management due to life threatening cardiovascular adverse events. Recently, we found that inhibition of delta-5-desaturase (D5D, enzyme catalyzing di homo-gamma-linolenic acid (DGLA) metabolism to AA) in breast cancer cells by siRNA/shRNA caused the diversion of DGLA metabolism from PGE2 to anticancer metabolite 8-hydroxyoctanoic acid (8-HOA). But, the approach of using siRNA/shRNA was limited by endonucleases mediated physiological degradation and inability to cross the cell membrane. Therefore, to overcome the limitation and to stimulate DGLA metabolism towards anti-cancer activity, small molecule D5D activity inhibitor Iminodibenzyl was identified. Here, we have hypothesized that Iminodibenzyl could inhibit the DGLA metabolism by inhibiting the D5D activity, and simultaneously overexpressed COX-2 in breast cancer cells would peroxidize the accumulated DGLA to an anti-cancer metabolite 8-HOA. To achieve the research goal, we have performed various in vitro and in vivo studies (orthotopic breast cancer model). From these studies, we noted that Iminodibenzyl could alter DGLA metabolism to anti-cancer metabolite 8-HOA in 4T1 and MDA-MB-231 breast cancer cells. After treating cancer cells with the combination of Iminodibenzyl and DGLA, a significant increase in apoptosis was observed through the caspasedependent mechanism, which was validated by pretreating cells with nonspecific caspase inhibitor Z-VAD-FMK. Additionally, a significant reduction in HDAC activity and β-Catenin was observed, which might have reduced cancer cell survival fraction and proliferation. We believe that all the above mechanisms affected by the combination might have reduced the cancer growth resulting in significant reduction in tumor size. Additionally, combination treatment also reduced lamellipodia and filopodia, and EMT markers resulting in reduction in cancer cell migration as visible from larger wound size and less number of metastatic nodules. Hence, all the above findings provide evidence about the efficacy of Iminodibenzyl to shift the DGLA metabolism producing anti-cancer activity in breast cancer cells.
  • No Thumbnail Available
    Item
    Development of Nano-Architecture Systems for High-Efficiency Tumor-Targeted Drug Delivery
    (North Dakota State University, 2021) Mamnoon, Babak
    Breast cancer is the most common malignancy and the second leading cause of death among women in the United States. The commonly used breast cancer treatment strategies include surgery, chemotherapy, radiation, and hormonal therapy. Since chemotherapeutic agents do not adequately differentiate between normal and cancerous cells, systemic toxicity and adverse effects associated with these anticancer drugs limit their therapeutic efficacy. In addition, uncontrolled cell proliferation and insufficient blood supply produce low oxygen partial pressure or hypoxia in almost all solid tumors. Hypoxia increases cancer cell survival through aggressiveness, metastasis, and resistance to chemotherapy, leading to poor clinical outcomes. Targeted drug delivery nanoparticles can significantly reduce off-target toxicity of chemotherapy by selectively targeting tumor tissues. Polymersomes are self-assembled drug-encapsulated polymeric nanoparticles in which an aqueous core is enclosed by a bilayer membrane. To attain the appropriate therapeutic efficacy, polymersomes need to rapidly release their anticancer drug at the tumor sites. To fulfill this requirement, stimuli-responsive polymersomes have been developed. Since most of the tumors have hypoxic areas inside, hypoxia-responsive polymersomes are one of the most effective drug delivery vehicles for cancer treatment. To prepare targeted drug delivery systems, functionalizing polymersomes with specific ligands intended to be recognized by the receptors of the cancer cells, is the most common strategy. Herein, we designed three distinct hypoxia-responsive polymersomes for targeting breast cancer tissues. More than 80% of breast cancers express estrogen receptor (ER-positive), and about 15-25% of them do not express any receptors (triple-negative). Hence, we decorated our polymersomes with three different ligands including estradiol and endoxifen for targeting ER-positive breast microtumors, and iRGD peptide for targeting triple-negative breast tumors.