Winners of the Outstanding Dissertation and DNP Project Awards
Jennifer Dine, PhD
University of Missouri
Characterization of a Novel Regulator and Predictors of Sensitivity to
TRAIL-induced Apoptosis in Breast Cancer Cells
Chair - Dr. Jane M. Armer
DESCRIPTION OF DISSERTATION
Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) is a protein that selectively induces apoptotic cell death via TRAIL receptor (TRAIL-R) activation in cancer cells. TRAIL-R agonists have been well-tolerated but demonstrated very little activity in patients. Interestingly, triple negative breast cancer (TNBC) cells were found to be sensitive to TRAIL-induced apoptosis while breast cancer cells representative of the other subtypes (estrogen/progesterone receptor positive or HER2 amplified) were comparatively resistant in vitro. Characterizing regulators and predictive biomarkers of TRAIL-R agonist sensitivity may help identify TRAIL-R sensitizing combinatorial therapies and TNBC-affected patients who might benefit the most from a TRAIL-R agonist therapy.
The first objective was to characterize the protein, gp78, as a negative regulator of TRAIL-induced apoptosis in breast cancer cells. The second objective was to evaluate the sensitivity of different subtypes of breast cancer cells in vitro to drozitumab, a TRAIL-R agonist that was well-tolerated in patients. The third objective was to identify potentially predictive biomarkers of TRAIL-R agonist sensitivity. The fourth objective was to evaluate expression of the potentially predictive biomarkers in patient samples. To address the first objective in evaluating the negative regulatory effects of gp78 on TRAIL pathway sensitivity, gp78 function was transiently inhibited using 10 gp78-targeting siRNAs in the TNBC cell lines MB231. gp78 function was also chronically inhibited by generating MB231 cells with stable gp78 knockdown. Cells with and without gp78 knockdown were then treated with and without TRAIL, and loss in cell viability and caspases-3/7 activity, which is a direct measure of TRAIL pathway activation, were assessed. To address the second objective, a panel of breast cancer cell lines representative of the different subtypes of disease (estrogen/progesterone receptor positive, HER2 amplified, and TNBC) were treated with and without drozitumab and evaluated for loss in viability. To address the third objective, immunoblot analyses were used to assess for potentially predictive protein markers of drozitumab sensitivity in the cell lines used in the second objective. Finally, to address the fourth objective, 177 TNBC tumor samples from a publically available cDNA microarray dataset were evaluated for the differential transcriptional regulation of genes whose protein products were identified as potentially predictive biomarkers of drozitumab sensitivity in the third objective. Additionally, 53 TNBC tumor samples were evaluated using immunohistochemistry to assess the protein expression of the identified potentially predictive biomarkers using a clinically relevant assay system.
The results from the first objective indicated that gp78 inhibited TRAIL-induced apoptosis in breast cancer cells in a mechanism that was dependent on the cell death-mediating proteins, caspases. The findings from the second objective demonstrated that TNBC cells, but not breast cancer cells representative of the other subtypes of breast cancer, were sensitive to drozitumab-induced cell death. In the third objective, the proteins Axl and vimentin were expressed only in the breast cancer cells that were sensitive to drozitumab-induced cell death. Axl and vimentin were thus selected as candidate predictive biomarkers of TRAIL-R sensitivity. Finally, in the fourth objective, Axl and imentin were found to be highly transcriptionally co-expressed (p<0.0001) in the cDNA microarray datasets of 177 TNBC tumors and were also highly co-expressed in the top quartile of Axl and vimentin-expressing tumor samples in the 53 TNBC tumor samples characterized by immunohistochemistry.
The findings from this study demonstrate that gp78 negatively regulates TRAIL-induced apoptosis in a caspase-dependent manner. TNBC cells were also determined to be sensitive to drozitumab, a TRAIL-R agonist, and those cells also expressed the proteins Axl and vimentin. Axl and vimentin were identified as candidate predictive biomarkers of drozitumab sensitivity and were determined to be expressed in human TNBC tumors at the transcriptional and protein levels. Therefore, Axl and vimentin expression in tumors may be utilized to aid in the selection of TNBC-affected patients who might benefit from a TRAIL-R agonist therapy.
The findings from this study characterize the protein gp78 as a novel negative regulator of TRAIL-induced apoptosis. Little is known about the regulatory mechanisms that govern TRAIL sensitivity in cancer cells. Therefore, these findings contribute significantly to an area of TRAIL-related research that has been poorly described. The gp78 protein may also provide information about targetable pathways in cancer cells that could be inhibited or enhanced pharmacologically to promote TRAIL-R agonist activity in patients. The identification of the potentially predictive biomarkers of TRAIL-R agonist sensitivity, Axl and vimentin, may also aid in promoting TRAIL-R agonist activity in patients by helping identify those individuals whose TNBC tumors would most likely respond to a TRAIL-R agonist. In light of the limited success of TRAIL-R agonist strategies tested in clinical trials to date, using predictive biomarkers is a novel but potentially highly useful system for selecting patients for TRAIL-R agonist treatment. Collectively, these findings reflect elements from across the translational spectrum with respect to describing the fundamental regulatory processes of a biological system to the application of clinically relevant strategies for improving therapeutic effectiveness in patients.
Honorable Mention went to:
Veronica Brady, PhD, RN, FNP-BC, BC-ADM, CDE; University of Texas Health Science Center at Houston
Prevalence of Steroid Induced Hyperglycemia in Patients with Mantle Cell Carcinoma Receiving High Dose Steroid
Ariana Chao, PhD, FNP; Yale University
Obesity-Related Eating Phenotypes and the Relationships with Food Cravings, Stress, and Metabolic Abnormalities
Michelle Davis, DNP, NNP, RNC-OB
Arizona State University
Implementing Skin-to-Skin Contact in the Operating Room Following a Cesarean Delivery.
DNP Program Advisor- Dr. Heather Ross
DESCRIPTION OF DNP PROJECT
Cesarean delivery is the most common major surgical procedure in the United States, representing 38.2% of live births in 2012 (Boyle et al., 2013). Infants delivered by cesarean section may face a more difficult transition to extrauterine life due to retained fluid within the alveoli (Blake & Murray, 2006). Skin-to-skin contact (SSC) and breastfeeding have been shown to help these newborns. However, one large urban medical center in the Southwest US did not have a policy to support immediate SSC and breastfeeding after cesarean delivery. This was a barrier to obtaining “Baby-Friendly Hospital” status (Baby-Friendly USA, Inc., 2012), despite being a Magnet hospital credited by the American Nurses Credentialing Center for excellence in patient care – with a level III perinatal and neonatal unit. The medical center is a busy urban academic hospital with 5,847 infant deliveries in 2013.
An evidence-based pilot protocol for SSC in the operating room (OR) immediately following a cesarean delivery was implemented in order to provide clinical impact data. Immediate SSC in the OR helps newborns adapt to extrauterine life and assists with infant-parent bonding and breastfeeding success. SSC can decrease the amount of time the infant spends in the Neonatal Intensive Care Unit (NICU), resulting in fewer nursing hours and overall cost savings for both hospital and patients.
The EBP project was conducted with approval from the Institutional Review Board at Arizona State University with reciprocal hospital agreement. The 7-step Iowa Model of Evidence-Based Practice (EBP) guided the EBP project. Step 1: topic selection (discussed above). Step 2: EBP team was formed and met biweekly, with members including project lead (L&D nurse and DNP student), L&D nurse manager, surgical scrub technician, obstetrician, nursing representative from the nursery team, and anesthesiologist. Step 3: systematic evidence retrieval to support the “triggering" question. Step 4: EBP team critically appraised the evidence to build obstetric section stakeholder buy-in. Step 5: development of standards for the pilot SSC protocol. Step 6: 3-month implementation of the pilot SSC protocol for all mother-infant dyads admitted for scheduled or repeat cesarean delivery with a live, singleton fetus greater than 37 weeks gestation, with no pre-existing medical complications or fetal anomaly (n=193). Nursery staff tracked neonatal outcomes including temperature, respirations, glucose, and disposition during the two-hour transition after birth. These data were compared to historical data for mother-infant dyads meeting protocol inclusion criteria in the 3 months prior to protocol implementation (n=302). A double-entry process was used to verify the data. Data were analyzed using chi-square test to compare rates of SSC application and infant disposition, and paired t-test to compare pre- and post-protocol neonatal outcomes including temperature, heart rate, respiratory rate, and blood glucose. Step 7: evaluation of the overall SSC procedure, including process review, outcomes data, and staff feedback for protocol evaluation and modification.
There were no baseline demographic differences between pre- and post-intervention groups. Neonatal outcomes were significantly different for infant temperature (SSC = lower), heart rate (SSC = lower), respiratory rate (SSC = lower), and blood glucose (SSC = higher) between pre- and post-intervention groups. Notably, SSC resulted in statistically and clinically significant reduction in hypoglycemia (p = .002). Additional outcomes included an increase in exclusive breastfeeding by 38.3% (p=0.000) in the intervention group, and an 84% decrease in NICU admissions (p=0.000) in the intervention group. SSC in the OR is a valuable and feasible intervention following a cesarean delivery, with no additional expense to the facility, and potential for significant cost savings due to deceased NICU admissions. This EBP outcome supports the American Academy of Pediatrics’ (AAP) recommendation for SSC in the first hour after birth (AAP, 2005) and promotes exclusive breastfeeding, one of the Joint Commission’s mandated initiatives (United States Breastfeeding Committee [USBC], 2010) and Healthy People 2020 goal ((Office of Disease Prevention and Health Promotion, 2015). The average cost of NICU admission for a normal term infant for hypoglycemia and hypothermia is $76,164 (March of Dimes Perinatal Data Center, 2011). This EBP SSC intervention reduced NICU admissions by 84% for normal term cesarean section births, representing $2 million cost savings to the hospital over 3 months.
The results of this EBP study led to the medical center including the SSC intervention in all new hire training and required annual skills competency training for seasoned employees. This training addition required minimal resources and additional costs or staffing.
The SSC intervention is included in the existing charting system. This EBP project has been disseminated at the following events:
- Arizona Nurses Association Conference, October 2014 – poster
- Highlighted in the Chief Nursing Officer’s Weekly Journal - October 2014
- Medical Center’s Poster Walk Showcase, November 2014
- Voted as the “Best Practice” Innovation for the medical center
- Systemwide Shared Governance Conference April 2015 - podium
- Advance Practice Neonatal Forum in Washington, D.C., May 2015 – podium and poster
- Highlighted as part of the medical center’s Magnet Documentation and presented to Magnet recertification evaluators, July 2015
- Invited podium presentation at the National Phoenix Perinatal Associate Challenges in Obstetric Care Conference, April 2016
Honorable mention went to:
Susan Klein, DNP, FNP-C, OCN; University of San Diego
Transition After Breast Cancer Treatment: Implementing Survivorship Care Plans