The Gary Kruh Cancer Research Virtual Poster competition is finished, but the work is far from over. The studies of six students was deemed best, and for their outstanding efforts each was awarded a $500 prize. The winners and their research are:
Assay Development for the Discovery of Early Autophagy Inhibitors to Serve as Potential Cancer Therapeutics
Presenter: Maryna Salkovski
College: Liberal Arts and Sciences
Mentor: Leslie Aldrich, PhD, Department of Chemistry
“The Dr. Gary Kruh Cancer Research Symposium and Virtual Poster Competition was inspiring, and I’m grateful to Dr. Kitajewski and everyone who organized and participated in the event. Kimberly Richardson, Dr. Califano, Dr. Gray and Dr. Paulovich were illuminating, and my peers’ posters thought-provoking. I feel privileged to have participated and honored to be one of the competition victors.“
Autophagy is a catabolic process that maintains cellular homeostasis by engulfing cytosolic waste into autophagosomes that fuse with lysosomes to degrade the cargo into other components the cell can use. Although basal levels of autophagy are necessary for a “housekeeping” role within the cell, autophagy’s role in tumorigenesis and metastasis is multifaceted and depends on the cell/tissue type, driving oncogene, and state of progression. Nevertheless, it is generally accepted that autophagy has a dichotomous role in cancer, as it suppresses benign tumor growth, but promotes advanced cancer growth. Therefore, autophagic inhibition may prevent cancer cells from fulfilling their metabolic needs and lead to their demise.
To identify specific inhibitors of early autophagy, a target-based, compound-multiplexed, fluorescence polarization, high-throughput screen that targets the ATG5-ATG16L1 protein-protein interaction (PPI) was developed. This interaction is critical for the formation of LC3-II, which is involved in phagophore maturation, and its disruption should inhibit autophagy. This assay is based on the polarization of light emitted by a fluorescent rhodamine tag conjugated to a peptide corresponding to the N-terminal region of ATG16L1 (ATG16L1-N). It was confirmed that this peptide binds specifically to ATG5, and the assay was validated by rapidly screening 4,800 molecules via compound-multiplexing. Through these initial screening efforts, a molecule was identified that disrupts the ATG5-ATG16L1 PPI with micromolar potency but was not efficacious in cell-based assays. Moving forward, analogs will be synthesized and re-screened for increased potency and activity in cells. We are confident a future analog screened through our FP assay will disrupt the ATG5-ATG16L1 PPI, resulting in inhibition of autophagy, and consequently, starve cancer cells to death.
Maintenance of Terminal Differentiation by Retinoblastoma and Hippo Tumor Suppressors
Presenter: Alexandra Rader
Mentor: Max Frolov, PhD, Department of Biochemistry and Molecular Genetics
“I am delighted to receive this award. It is wonderful to have others recognize merit and impact in my research.”
Both the Retinoblastoma (pRB) and Hippo tumor suppressor pathways have been implicated in regulation of differentiation and stemness. However, the role of pRB and Hippo pathways in maintaining terminal cell specification is currently unknown. Mature Drosophila melanogaster photoreceptor neurons with dual mutation in Rbf and wts abruptlylose neuronal specification and dedifferentiate into an uncommitted cell type. This does not occur in Rbf or wtssingle mutant photoreceptors. We employed single-cell RNA-sequencing on wildtype, Rbf[120a], wts[x1], and Rbf[120a] wts[x1] eye tissue to identify dedifferentiated photoreceptor neurons and understand the transcriptional changes accompanying loss of neuronal identity. We found three novel cell populations specific to the double mutant eye disc, including a cluster of proliferating early photoreceptors, a putative dedifferentiated photoreceptor cluster, and a population expressing both undifferentiated and differentiated cell markers.
We suggest that these populations reflect the process of dedifferentiation. We also identified that dedifferentiated photoreceptors aberrantly express genes specific to anterior, undifferentiated cells such as wingless, homothorax, and homothorax target genes. Additionally, we generated a new, robust model for studying photoreceptor dedifferentiation. Taken together, our work suggests that wts maintains terminal cell specification through cytosolic retention of yorkie transcription factor, while Rbf prevents expression of hth and its target genes.
Cancer Prevention and Control
Survivors Advising Scientists Educational Program: Collaborating to Create Educational Tools
Presenter: Tova Bergsten
College: Pharmacy, Medicine
Mentor: Joanna Burdette, PhD, Department of Pharmaceutical Sciences
Project Mentor: Kimberly Richardson
“Our team of advocates and scientists had a wonderful time collaborating together to submit our poster. It is an incredible feeling to have our advocacy work recognized by the UI Cancer Center, and we hope this helps spread the word about our bidirectional educational efforts.”
Survivors Advising Scientists Educational Program (SASEP) is a bidirectional educational platform that was developed to connect our scientific and advocacy communities. There is a noticeable lack of accessible educational materials to explain complex scientific and cancer health related topics to the people who need them, such as patients, survivors, and advocates. This platform was developed to help address this concern and ultimately increase scientific literacy and engagement.
A collaboration was formed to create educational narrated presentations to empower and educate all members of the community. First, UIC MD/PhD students drafted short 10-minute videos covering various basic scientific and experimental topics. These modules were reviewed by a group of cancer patients, survivors, and advocates to make them more understandable and accessible. Next, the students incorporated reviewer feedback before finalizing presentations and professionally recording them. Finally, the modules were disseminated to the cancer and scientific community with a certificate granted upon completion.
A survey was then distributed to participants in order to help both continue to provide feedback on the current modules and shape the direction of future working modules. The survey results included the respondents’ demographic information and their assessments on the modules. Both objective and subjective information was collected on their evaluation of the module content. They were asked multiple choice questions to gauge their level of agreement or disagreement with several statements and given open-ended questions to obtained diverse specific feedback.
Overwhelmingly the participants agreed that the modules were organized, helpful and a clear purpose. Interestingly, the module participants were not the only ones who were impacted by the work. The MD/PhD students stated that the collaboration with community members and patients was a priceless experience and will guide them in their journey to become better physician-scientists. In conclusion, we believe that this unique program has the potential to be the spark that lights the fire to inspire others within their research communities to develop their own bidirectional partnerships and take advocacy to a new level.
Guideline adherence for risk reducing salpingo-oophorectomy among diverse women with BRCA mutations at the University of Illinois Hospital
Presenter: Alexandra Lamacki
Mentor: Dr. Shannon MacLaughlan David, Department of Obstetrics and Gynecology
“My research aims to shed light on the BRCA carriers among our amazing patient population at UI Health, and I feel very honored to have the project recognized in this way.”
Rates of referral to genetic counseling are low for women of color and lower socioeconomic status, and these women are under-represented in studies examining decisional factors related to uptake of risk-reducing bilateral salpingo-oophorectomy (rrBSO) in patients with pathogenic BRCA1 or BRCA2 mutations. To address this gap in the literature, our objective is to report adherence to evidence-based guidelines for rrBSO recommendation and uptake among BRCA1 and BRCA2 mutation carriers at the University of Illinois Hospital – an urban, public academic center whose population is racially and socioeconomically diverse – and to identify any association of sociodemographic variables with rrBSO uptake.
The study population was made up of 167 eligible patients, 39% of whom were Black, 35% Caucasian, 19% Hispanic, and 7% self-identified as “other” race. Less than 5% of patients reported known Ashkenazi Jewish heritage. Approximately half carried either BRCA1 (51%) or BRCA2 (46%) mutations (unspecified BRCA mutation). Over 95% received the recommendation for age-appropriate rrBSO, and 52% underwent the surgery. Women who had rrBSO were older, with 56% being 50 years or older at the time of the study, compared to 35% in the group who had not undergone the surgery. There were no other differences between groups. Black race was associated with uptake of rrBSO, as were lower rates of unemployment, and documented recommendation for rrBSO. There was no significant association between rrBSO uptake and mutation type, age, parity, insurance type, level of education, neighborhood poverty, food security or violent crime, personal history of breast cancer, or family history of ovarian or other BRCA-related cancers.
This study demonstrates that the majority of BRCA1 and BRCA2 carriers at an urban, public hospital received the recommendation for age-appropriate rrBSO. Black race and lower unemployment were associated rrBSO uptake. Genetic counseling was associated with adherence to evidence-based guidelines for the recommendation, as well as patients’ odds of having the surgery. Future qualitative studies will report decisional factors in this diverse population. However, this current data shows us the importance of considering sociodemographics and representing the full diverse spectrum of women who carry these mutations in further research on the BRCA carrier population. It also demonstrates the need to improve rates of genetic counseling referrals as this is associated with increased BSO completion.
Garcinia mangostana xanthones degrade the androgen receptor in castration resistant prostate cancer cells
Presenter: Mirielle Nauman
Mentor: Jeremy Johnson, PhD, Department of Pharmacy Practice
“I always look forward to the Dr. Gary Kruh Cancer Research Symposium and am so honored to be recognized by the judges this year. I think this symposium provides a great space for students, researchers, survivors, advocates, and health care professionals to share their stories, which is not something we always get an opportunity to do. I am so encouraged by all the great work going on in the UI Cancer Center.
With five-year survival rates for prostate cancer approaching 100%, prostate cancer is seemingly a non-issue to many men. However, this statistic excludes the 5% of men that are identified to have distant (metastasized) prostate cancer, who have a five-year survival rate of about 30%. The striking contrast in these survival rates is due to the fact that currently, almost all prostate cancer drugs act on the androgen receptor. For prostate cancer treatments, the most popular approach is with anti-androgen drugs, which disrupt androgen receptor (AR) functionality and androgen signaling and can benefit up to 85% of prostate cancer patients. However, these benefits are short-lasting, with only about one year of efficacy. Undesirable side effects of anti-androgens including impotence, anemia, depression, osteoporosis, and hot flushes have been observed.
The Johnson lab has been studying xanthones, a class of compounds isolated from the Garcinia mangostana (purple mangosteen) fruit and plant, that have shown promise as anti-cancer agents. We are currently evaluating these xanthones for their in vitro mechanisms, pharmacokinetic profile, and in vivo efficacy in prostate cancer. My dissertation specifically focuses on how α-mangostin, one of the most abundant xanthones isolated from the purple mangosteen fruit, promotes the death of castration resistant prostate cancer (CRPC) cells. In many cases, CRPC is driven by mutant AR splice variants that develop as a response to androgen-deprivation therapy or surgery. It has recently been noted that almost all men who respond initially to abiraterone, a CRPC anti-androgen, will relapse within one to two years. Interestingly, my research has shown that α-mangostin can promote degradation of mutant AR, specifically of AR-V7, the most commonly expressed AR splice variant. AR-V7 lacks the ligand binding domain and is un-targetable by any drugs currently on the market. Xanthones, and α-mangostin specifically, exhibit promise for their ability to degrade full-length AR, AR with point mutations, and AR-V7.
Two different prostate cancer cell lines, 22Rν1 and LNCaP, are used throughout these experiments. Prostate cancer cells are treated with α-mangostin for 24 hours and are lysed, and then the total protein content is isolated. Total AR, phosphorylation of the AR at Serine 81, and BiP proteins are analyzed through immunoblotting. Immunoprecipitation was performed to analyze the ubiquitination of AR. Mutant AR plasmids containing single point mutations were transfected into prostate cancer cells and then cells were treated with α-mangostin for 24 hours, lysed, and analyzed for AR protein expression. In vivo studies were carried out in nude SCID mice that were given α-mangostin for 35 days through oral gavage.
Immunoblot data reveals a dose and time dependent decrease in AR, coupled with an increase in the chaperone protein BiP. Further analysis of post-translational modifications identified a reduction in phosphorylation of AR at S81. Along with the data showing that AR protein levels are decreased in the nucleus but not the cytoplasm, α-mangostin inhibits the nuclear translocation of AR. This inhibits the transcription of downstream genes that are necessary for cell growth and proliferation. Additionally, α-mangostin appears to decrease protein levels of AR with point mutations and of AR-V7, implicating that α-mangostin could be effective in castration resistant prostate cancer cases. Finally, α-mangostin is shown to have a good pharmacokinetic profile in vivo and to decrease prostate tumor size in mice, implicating that α-mangostin has anti-tumor properties. This data shows that α-mangostin may be helpful in developing new prostate cancer pharmacotherapies that act through a novel mechanism and that are effective in both primary and castration resistant prostate cancer cases.
Resolution of Tumor-related Lipid Exudation with Conservative Management
Presenter: Abid Haseeb
Mentor: Dr. William Mieler, Department of Ophthalmology
“I appreciate the UI Cancer Center conducting the Gary Kruh Symposium. It allowed me to present work that I worked hard on and care deeply about. To have that work recognized and appreciated is gratifying.”
Tumor-related lipid exudation (TRLE) is an infrequent but known complication after iodine-125 plaque brachytherapy treatment of uveal melanoma. To our knowledge, no studies or reports have been conducted on treatment strategies and clinical course in TRLE. Here, we report the successful anatomic resolution of a case of severe TRLE with conservative therapy.
Methods and Patient
We performed a detailed chart and imaging review for a single patient who developed tumor-related lipid exudation more than 1.5 years after receiving radiation brachytherapy for her posterior uveal melanoma. The initial presentation, diagnostic studies, management, and clinical course are discussed.
A 50-year-old Caucasian woman received iodine-125 plaque brachytherapy for a posterior uveal melanoma. She developed worsening peripheral vision and an exudative retinal detachment 19 months after radiotherapy and the diagnosis of TRLE was confirmed with optical coherence tomography and fundus examination. Treatment initially consisted of systemic corticosteroid therapy but was further supplemented with monthly injections of intravitreal anti-vascular endothelial growth factor, multiple sessions of focal laser photocoagulation, and intravitreal corticosteroid injection. By post-radiotherapy month 33, the patient achieved stabilization of her visual acuity and significant anatomic improvement as confirmed by imaging studies.
Given the poor visual prognosis in patients with TRLE, a conservative approach to treatment in these patients may be appropriate. Future prospective studies with a larger number of cases should be performed to investigate the efficacy of non-surgical intervention in these patients.
We report a case of TRLE following brachytherapy treatment of a uveal melanoma. The patient was successfully treated conservatively with corticosteroids, anti-VEGF injections, and photocoagulation. Treatment outcomes have yet to be reported in this patient population.