United States

Background
Protein-based therapeutics are limited by their route of administration and inability to confine them to their site of action. One innovative approach would be to chemically bind therapeutics to medical devices, allowing localized and concentrated delivery to the site of action. This study aims to evaluate if GLP-2 can be covalently bound to our Vaginal Expansion Sleeve (VES) and Intestinal Expansion Sleeve (IES) in measurable quantities.

Methods
Expansion sleeves were coated and crosslinked with polyvinyl alcohol (PVA) making a chemically reactive surface capable of binding amine-containing therapeutics such as GLP-2. A standard curve was created by adding 250ug, 100ug, 50ug, 25ug, and 0ug of GLP-2 into respective wells with PVA of a 24-well plate. A rabbit anti-GLP-2 antibody followed by a goat anti-rabbit IgG alkaline phosphatase secondary antibody was added to the wells to allow the addition of SeraCare KPL BluePhos Microwell Phosphate Substrate System. Once added, the color changes from yellow to blue depending on the concentration of GLP-2 bound antibodies, allowing the absorbance to be read at 620nm to generate the standard curve and calculate the concentration of GLP-2 on the PVA-coated sleeves. 


Results
Addition of 50ug of GLP-2, each IES and VES device bound an average 22.69 ± 9.32 ug/cm2 of GLP-2 after adjustment for an external surface area of 9.425 cm2, allowing for 44% of added GLP-2 to remain fixated to the PVA coated sleeves. 



Conclusion
Current GLP-2 dosing in humans in 0.6mg/70Kg. With an external surface area of 9.425 cm2, each sleeve is capable of giving a localized delivery of 213.85ug of GLP-2, which is 25.2x greater dose than systemic dosing. This methodology makes it possible to add dramatically lower doses of therapeutic agents to get the same effect as systemic administration of the GLP-2 drug while also avoiding systemic effects. 


AMA Research Challenge 2024 

Preliminary results of Polyvinyl Alcohol Coated Medical Device Therapeutic Conjugation

Congratulations to all the researchers who have qualified for the AMA Research Challenge virtual poster symposium and semifinals!

Welcome to the **largest national, multi-specialty research event** featuring research from nearly 1,000 medical students, residents, fellows, and international medical graduates across six topic areas - basic science, clinical and translational research, clinical vignettes, health systems science, medical education, and public health and health policy.

#### Access the Event
Use the buttons below or navigation menu to access the event. 

[![](https://assets.underline.io/markdown_image/1/image/d4076f2146939317a29eb9f69c53ad41.png)](https://underline.io/events/506/sessions?searchGroup=all)
[![](https://assets.underline.io/markdown_image/1/image/6bcee0b523a4874c4292ca0415d88dde.png)](https://underline.io/events/506/posters?searchGroup=all)

#### Event Details
The 2025 AMA Research Challenge includes the following symposium halls:
* **Semifinals hall:** Features research from 54 medical students, residents and international medical graduates that received top scores during first round scoring. 
* **Poster symposium hall:** Features research from nearly 1,000 medical students, residents and international medical graduates categorized by topics and subtopics.

**Here’s how to participate:**
* **View posters and presentations** on a variety of topics and specialties
* **Score posters in the semifinals** to help decide the top five finalists (AMA member exclusive opportunity)
* **Connect with presenters** and provide feedback to help advance their research
* **New this year: Watch live poster presentations** by topic area and engage directly with researchers

At the conclusion of this event, the AMA announced the top five finalists who advanced to the AMA Research Challenge final round, presented their research to an elite panel of judges, and competed to win a $10,000 grand prize presented by Laurel Road.

**Addison Shenk, a fourth-year medical student from Edward Via Virginia College of Osteopathic Medicine, was the winner of the 2025 AMA Research Challenge and was awarded the grand prize of $10,000, presented by Laurel Road.**

#### A message from Dr. Bobby Mukkamala, AMA President
<div style="position: relative; width: 100%; padding-bottom: 56.25%; height: 0; overflow: hidden;">
  <iframe 
    src="https://underline.io/embed/136894-ama-video?t=0"
    title="AMA Welcome Video"
    allowfullscreen
    style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: 0;">
  </iframe>
</div>


#### Recognized Institutions
In 2025, 1,400 abstracts were submitted across six topic areas representing 174 medical schools and more than 150 residency and health care institutions. [See if your institution is represented this year!](https://drive.google.com/file/d/1eFrTqCmCeobx9pr5drJK2hllvsIpFNOY/view?usp=drive_link)

#### Grand Prize Sponsor
AMA would like to thank Laurel Road, a brand of KeyBank, for sponsoring a $10,000 grand prize for the winner of the AMA Research Challenge. Laurel Road and KeyBank are not involved in winner selection process. The winner will be announced during the AMA Research Challenge final round. Payment of the grand prize will be directly from Laurel Road/KeyBank. See the [AMA Research Challenge Official Rules for terms and conditions](https://www.ama-assn.org/system/files/research-challenge-official-rules.pdf).

[![](https://assets.underline.io/uploads/markdown_image/1/image/611e331d4a0eba0920f240cfc04b4d77.png)](https://www.laurelroad.com/)

#### Code of Conduct
<html>
AMA has a code of conduct for its meetings – we ask all attendees to adhere to this code to participate in this year’s meeting. Please read and <a href="https://www.ama-assn.org/about/code-conduct" target="_blank">learn more here</a> about your conduct requirements.
<br><br>
	</html>
	

#### Semifinals Judges

You need to log in with the email address you registered with. Access credentials have been sent to your email. 

Please be sure to check your spam and other email folders if you do not see an email confirmation right away.

Need help? Contact us at <support@underline.io>.

Please log in to explore this event.

If you have used the AMA Research Challenge platform previously, please click the ‘Log-in’ button below. If you do not remember your password, please click “forgot password” and follow prompts to reset your password. After resetting your password, please refresh your webpage to access the platform. 

Register to explore research in a variety of topics. AMA members get exclusive access to score posters in the semifinals. 

**Please use [this link here](https://www.ama-assn.org/member-benefits/events/ama-research-challenge) to register for free. **

Registration Is Required

AMA Research Challenge 2025 

Join the AMA Research Challenge poster symposium and semifinals to explore top research posters and score posters in the semifinals (an AMA member exclusive opportunity).

poster

Welcome to the **largest national, multi-specialty research** event featuring research from more than 750 medical students, residents, fellows, and international medical graduates.

Use the buttons below or navigation menu to access the event.
<br><br><br>

[![](https://assets.underline.io/markdown_image/1/image/20e1e77aa954efeac7a15d84c85eb383.jpg)](https://underline.io/events/468/sessions?searchGroup=all)
<br>
[![](https://assets.underline.io/markdown_image/1/image/068522d81aca0b68a369787c7dfccd1b.jpg)](https://underline.io/events/468/posters?searchGroup=all)
<br>
[![](https://assets.underline.io/markdown_image/1/image/d3971ece79d5e5575b178bdc2c8bbfae.jpg)](https://underline.io/events/468/help-desk)
<br><br>

#### Event Details

The 2024 American Medical Association Research Challenge includes a poster symposium hall and a semifinals hall with the top scored research. **Log in at any time throughout the event to:**

* **View posters and presentations** on a variety of topics and specialties
* **Score posters in the semifinals** to help decide the top five finalists (AMA member exclusive opportunity)
* **Connect with participants** and provide feedback to help advance their research

At the conclusion of this event, the AMA will announce the top five finalists who will advance to the AMA Research Challenge finals, present their research to an elite panel of judges, and compete to win a $10,000 grand prize presented by Laurel Road.<br><br>

### Grand Prize Sponsor

AMA would like to thank Laurel Road for sponsoring a $10,000 grand prize for the winner of the AMA Research Challenge. Laurel Road is not involved in winner selection process. The winner will be announced on February 20, 2025 during the AMA Research Challenge finals. Payment of the grand prize will be directly from Laurel Road. See the AMA Research Challenge Official Rules for terms and conditions.

[![](https://assets.underline.io/uploads/markdown_image/1/image/611e331d4a0eba0920f240cfc04b4d77.png)](https://www.laurelroad.com/)

<br><br>

You need to log in with the email address you registered with. Access credentials have been sent to your email. 

Please be sure to check your spam and other email folders if you do not see an email confirmation right away.

**There is no registration fee for this event! **

If you have used the AMA Research Challenge platform previously, please click the ‘Log-in’ button below. If you do not remember your password, please click “forgot password” and follow prompts to reset your password. After resetting your password, please refresh your webpage to access the platform.

Register to explore research in a variety of topics. AMA members get exclusive access to score posters in the semifinals. 

**Please use this link [here](https://www.ama-assn.org/member-benefits/events/ama-research-challenge) to register for free.**

Background: Liver transplantation (LTx) is the only curative treatment for end-stage liver disease. However, due to the shortage of high-quality deceased donor (DD) organs, 2,000 patients die annually while waiting for suitable livers. DD marginal livers (i.e. prolonged ischemic damage or fatty livers) could address this disparity, though it is associated with primary graft non-function and decreased recipient survival post-LTx. Advances in Normothermic Machine Perfusion (NMP) technology allow for extended preservation and ex-situ assessment of DD livers before transplant to guide decisions on liver quality and transplantability. Understanding the molecular mechanisms of injury, repair, and recovery during NMP is crucial for identifying safe transplant organs and potential pharmaceutical intervention targets to optimize marginal organ quality before transplant. This study aims to evaluate these mechanisms by analyzing temporal gene expression signatures using whole genome RNA sequencing in transplantable and non-transplantable livers during NMP.

Methods: Human donor livers without significant steatosis (n=6) and fatty donor livers (n=5) were subjected to 12 hours of NMP. Livers were categorized based on predefined criteria for demonstrating adequate hepatocellular function (transplantable vs. non-transplantable). Core needle biopsies were taken immediately before NMP and after 3 and 6 hours of NMP for bulk RNA sequencing. Bioinformatic analysis evaluated temporal changes in gene expression between functional and nonfunctional lean and fatty livers during NMP.

Results: Principal component analysis (PCA) revealed that gene expression changed for both fatty and lean livers during NMP. PCA effectively differentiated functional lean and fatty livers from non-functional fatty livers when all four categories were examined together. However, PCA was less sensitive in distinguishing functional lean and fatty livers from non-functional lean livers. The transcriptomic profile of biopsies from functional lean and fatty livers showed strong activation of mTORC1 signaling (growth/regeneration pathway) and protein secretion throughout NMP, correlating with improved hepatocellular function. Conversely, nonfunctional fatty livers exhibited a gradual decrease in the expression of both pathways during NMP.

Conclusion: We demonstrated that temporal overexpression of genes associated with liver regeneration and normal synthetic function during NMP can differentiate between transplantable and non-transplantable lean and fatty livers. Targeting the mTORC1 and protein secretion pathways may represent viable therapeutic interventions for rehabilitating the function of marginal livers, thus improving their quality and making them safe for transplantation. This can potentially reduce organ shortages. Our findings provide a foundation for future research aimed at predicting the recovery of marginal livers and enhancing liver transplantation outcomes through targeted therapies.


Studying the Molecular Pathways Involved in Hepatocellular Recovery During Normothermic Machine Perfusion to Identify Livers Safe for Transplantation

Background: Colorectal Cancer (CRC) ranks as the third leading cause of cancer-related deaths in the United States. Current guidelines recommend initiating CRC screening at age 50; however, there has been a concerning rise in CRC incidence among younger populations. Genetic predisposition, oxidative stress, and inflammation are believed to contribute to CRC pathogenesis. However, when treated via conventional methods like chemotherapy and bowel resection, some patients are met with undesirable side effects, such as cardiotoxicity associated with agents like anthracyclines. Vialinin A, an extract from the Chinese mushroom Thelephora Vialis, demonstrates both antioxidant and anti-inflammatory properties.

Moreover, we propose that Vialinin A has potential anticarcinogenic mechanisms that may be utilized in the treatment of CRC cell proliferation and metastasis.
Methods: To assess the impact of Vialinin A on both SW480 and CaCO-2 CRC cell lines, we exposed them to increasing concentrations of Vialinin A. Viability of these cells after 24 and 48 hours was evaluated using an MTT assay. Subsequently, specific assay kits were employed to measure caspase-3 activity and apoptosis induction. Additionally, an RD Systems Antibody Multiplex Array was utilized to ascertain the expression levels of diverse apoptosis markers in Vialinin A-treated CRC cell lysates. Moreover, a mitochondrial reactive oxygen species (MT-ROS) assay was performed to measure the ROS production of CaCO-2 cells pre and post-treatment with Vialinin A. Furthermore, a trans-well migration, scratch assay, and multiplex array are slated for use to identify the antimetastatic potentials of Vialinin A, as well as the oncogenic, inflammatory markers expressed in its presence. Ultimately, in vivo experiments using nude mice xenografts will further allow us to examine the potential chemopreventive role of Vialinin A.

Results: Our findings indicate that Vialinin A inhibits CRC cell growth in a concentration-dependent manner. Additionally, Vialinin A suppresses reactive oxygen species production, activates caspase-3, and triggers apoptosis in growth factor-stimulated cancer cells. Moreover, Vialinin A modulates the expression of various apoptotic markers in CRC cells. Ongoing investigations aim to elucidate the underlying mechanisms by which Vialinin A hinders CRC growth.



An Antioxidant, Vialinin A, Extracted from An Edible Chinese Mushroom Prevents Colon Cancer Cell Proliferation.

Abstract Title
BRCA1 Is Required for DNA2 Deficiency-Induced Replication Stress Response at the ALT Telomeres

Background
Cancer cells bypass senescence and achieve replicative immortality by elongating their telomeres. They accomplish this through two primary mechanisms: telomerase activation and the Alternative Lengthening of Telomere (ALT) pathway. Approximately 85-90% of cancers utilize telomerase (TEL+), while 10-15% of cancers employ ALT (ALT+). Notably, about 60% of osteosarcomas rely on ALT for telomere maintenance. There are currently no targeted therapies for ALT+ cancers, highlighting the need for research into specific molecular targets for the ALT pathway. FDA-approved PARP inhibitors are effective for treating the BRCA1/2 mutated cancers, highlighting the importance of understanding BRCA1-deficient cells in ALT contexts. Previously, the Zhang lab showed that depletion of FANCM induces a robust replication stress response at the ALT telomeres, which requires a functional BRCA1, emphasizing BRCA1's critical function in this pathway. Most recently, the Zhang lab found that depletion of DNA2 also induces a robust replication stress response at the ALT telomeres. This study aims to elucidate the functional interplay between BRCA1 and DNA2 at the ALT telomeres.

Methods
U2OS cancer cells underwent two rounds of siRNA transfection. The transfection was followed by immunofluorescent staining where the cells were seeded onto coverslips. The cells were then fixed with 3% paraformaldehyde containing 2% sucrose for 10 minutes, followed by treatment with Triton X-100 solution on ice for 5 minutes. Subsequently, the cells were stained with primary antibodies and the respective Alexa-488 and Alexa-546 conjugated secondary antibodies. Colocalization of DNA damage markers and TRF2 was quantified to determine telomere DNA damage in BRCA1 and DNA2 depleted U2OS cell lines.

Results
Our study utilized siRNA transfection to investigate the roles of BRCA1 and DNA2 in ALT+ cancer cells. Depletion of BRCA1 and DNA2 followed by immunofluorescence staining revealed the recruitment of critical cell cycle regulator proteins - pChK1, pRPA, BLM, and yH2AX - to telomeres. Our results demonstrate an increase of pChK1, pRPA, BLM and yH2AX to the telomere in DNA2-depleted cells, however the recruitment does not occur in BRCA1-DNA2 co-depleted cells. 

Conclusion
These findings highlight BRCA1 and DNA2 as crucial regulators of telomeric replication stress in ALT+ cancers. BRCA1 is necessary for the DNA damage response in DNA2-depleted ALT+ cells. Understanding BRCA1 and DNA2-mediated pathways may provide a promising approach to disrupt ALT-specific telomere maintenance, potentially advancing therapeutic strategies tailored to ALT+ cancers and improving treatment outcomes in these malignancies.

BRCA1 Is Required for DNA2 Deficiency-Induced Replication Stress Response at the ALT Telomeres

Melanoma is the second leading invasive cancer with a greater capacity to invade and metastasize. Increased oxidative stress has been shown to be involved in melanoma growth and spread. Several antioxidants, vitamins, and other phytochemicals have been shown to prevent melanoma cancer growth. However, the chemopreventive efficacy of vialinin-A, an edible mushroom-derived p-terphenyl antioxidant, on cancer growth and invasion is unknown. We, therefore, hypothesized that with its potent anti-oxidative and anti-inflammatory actions, vialinin-A could prevent melanoma cell growth and invasion. B16-F10 melanoma cells were treated without or with various concentrations of vialinin-A. The cell viability was determined by MTT assay and apoptosis by annexin-V staining. Our results suggest that vialinin-A prevents melanoma cell growth in a dose-dependent manner. Vialinin-A also prevents the invasion and migration of melanoma cells. Further, vialinin-A prevents the generation of reactive oxygen species and promotes apoptosis of B16-F10 cells. In addition, vialinin-A increases the activation of caspase-3 and cleavage of PARP protein. Vialinin-A also regulated the expression of various anti-apoptotic, pro-apoptotic, and inflammatory markers in melanoma cells. In conclusion, our results suggest that vialinin-A, through regulating oxidative stress-modulated apoptotic pathways, could prevent melanoma cell growth and invasion and has potential chemopreventive properties. 


Edible mushroom-derived antioxidant, vialinin-A, prevents melanoma growth and invasion


Abstract Title
Harnessing the anti-neoplastic potential of novel mannose-binding lectins on human urothelial and breast cell carcinomas.
Authors and Affiliation: 
Julie Marchioni, BS; Alec Skomo, BS; and Prerna Sharma, PhD*
Geisinger Commonwealth School of Medicine, Scranton PA 18509

Background
Mannose-binding lectins (MBLs) are a class of carbohydrate-binding proteins that are important in modulation of viral infections, inflammation, and cancer progression through interactions with glycosylated regions. High grade cancer cell lines have their membranes decorated with oligomannosidic sugars that can be harnessed to develop anticancer drugs. The model MBL, cyanovirin-N (CVN-N) has shown promise as an antiviral. However, its widespread use is limited due to difficult isolations, poor stability, and limited applicability to cancer targets. This led us to identify novel MBLs and test their anti-neoplastic effects on human cancer cell lines.
Methods
The novel proteins were expressed with the pET23a/BL21(DE3) Escherichia coli expression system and purified using Nickel-NTA chromatography. The purified proteins were assessed for their structure, folding, thermal, and chemical stability using circular dichroism (CD) spectroscopy. Mannose-binding studies using model glycoproteins were performed with electrophoretic mobility shift assay, EMSA. Functional studies to assess the antineoplastic effects were performed on human urinary bladder carcinoma, T24, and breast cell adenocarcinoma, MDA-MB-231, using MTS and WST-1-based assays.
Results
We identified two novel fungal lectins, LC-3 (17 kDa) and LC-4 (13 kDa) with proposed mannose binding ability by data mining using BLAST search. Their predicted secondary structure aligned well with the model structure of CVN-N. The far UV-CD spectra of LC-3 and LC-4 proteins displayed a well folded structure with single negative peaks at 215 and 219 nm respectively. Both the proteins were found to be thermostable up to 90°C. Chemical denaturation studies of LC-3 with guanidinium hydrochloride reveal a Cm of 2.75 M and a ΔG of unfolding to be 7241.7 J/mol. Chemical denaturation studies for LC-4 were significant for a ΔG of unfolding of 1458.4 J/mol and for cooperativity of unfolding of two sub-domains. Positive shifts with Fetuin A, a sialylated ligand, and RNase B, a mannosylated ligand were observed for both proteins in EMSA. Significant inhibition of cell proliferation by both the proteins were observed in low micromolar concentrations (1-5 µM) for the mannose expressing cell lines, T24 and MDA-MB-231, when compared to control groups.

Conclusion
The identified fungal lectins, LC-3 and LC-4 are thermochemically stable and have high specificity for mannosylated ligands. The high yield, thermochemical stability, and significant anti-proliferative effects of LC-3 and LC-4 against urinary bladder and breast cell carcinomas make them a potential candidate for clinical applications.

Harnessing the Anti-Neoplastic Potential of Novel Mannose-Binding Lectins on Human Urothelial and Breast Cell Carcinomas.

Immunosuppressive effects of Transforming Growth Factor Beta (TGFβ) on cytotoxic function of human natural killer cells are reversible

Anjali Patel 1, Giuseppe Maiocco 1, Catherine Mirto 1, Donald S. Torry 1,2,3, and Andrew Wilber 1,3

1 Medical Microbiology, Immunology and Cell Biology, 2 Obstetrics and Gynecology, and 3 Simmons Cancer Institute, SIU School of Medicine, Springfield, IL 62702

Background: Natural killer (NK) cells are innate immune cells that are CD56pos/CD16pos and have anti-tumor function. We have shown that NK cells recovered from human kidney tumors are CD56pos/CD16dim/neg and poorly cytotoxic. These features are analogous to human decidual NK (dNK) cells, which are found at the maternal-fetal interface and support development of the placenta development during embryo implantation. The decidua and kidney tumor environment have high levels of transforming growth factor beta (TGFβ), which is known to convert peripheral blood NK (pNK) cells to dNK-like cells in vitro. We hypothesized that TGFβ-mediated inhibition of NK cell cytotoxic function is transient and therefore reversible.

Methods: pNK cells were isolated negative selection from blood of healthy donors (HD) or purchased from ATCC (NK-92; CRL-2407). RT-qPCR and flow cytometry were used to assess levels of TGFβ receptors (R1, R2, and R3) mRNA and protein, respectively. NK cells were cultured for 4-5 days with the proliferative cytokine IL2 without or with TGFβ (2-5 ng/mL). Cytotoxic function of NK cells (effectors) was quantified by lysis of human K562 cells engineered to express firefly luciferase (targets). For this, cells were mixed at 1:1, 1:2, and 1:5 target to effector ratio and cultured overnight. Statistics (ANOVA/t-test) were performed using GraphPad Prism with p≤0.05 considered significant.

Results: pNK cells from HD were CD56pos/CD16pos and NK-92 cells were CD56pos/CD16neg as reported. Both expressed equivalent levels of all three TGFβ receptors and were potently cytotoxic against K562 target cells. NK cells treated with TGFβ retained only 15% cytotoxic function compared with untreated cells (p≤0.05). Cytotoxic function was completely restored when TGFβ treatment was discontinued and NK cells cultured in standard conditions for 4-5 days.

Conclusions: Despite differences in CD16 expression, pNK cells and NK-92 cells are potently cytotoxic and represent an effective cancer therapy. TGFβ limits this potential in the tumor environment by converting pNK cells to non-cytotoxic dNK-like cells. Importantly, NK regained complete cytotoxic function when they were no longer exposed to TGFβ. Thus, inhibition of TGFβ signaling could preserve NK function in the tumor environment and have implications for anti-cancer therapies. Efforts to explore this possibility using selective inhibitors or genome editing technology are underway. 



Immunosuppressive effects of Transforming Growth Factor Beta (TGFβ) on cytotoxic
function of human natural killer cells are reversible

Abstract Title
Loss of BCLAF1 impairs AML pathogenesis
Background
Acute myelogenous leukemia (AML) pathologically activates self-renewal programs of normal hematopoietic stem cells (HSCs) to promote proliferation and prevent differentiation. We identified that BCLAF1, a transcriptional repressor, has critical roles regulating HSC self-renewal. Both fetal and adult Bclaf1-deficient HSCs have impaired repopulation activity in competitive transplantation experiments. BCLAF1 is upregulated in pediatric and adult AML, and previous literature demonstrated that BCLAF1 suppression is detrimental to AML. We aim to define the function of BCLAF1 in AML transformation and progression, and we hypothesized that BCLAF1 is essential for AML pathogenesis.
Methods
Wild-type and Bclaf1-deficient hematopoietic progenitors were transduced with a retrovirus expressing MLL-AF9 to generate AML, then transferred into recipients. Hematopoietic progenitor cells from Mx-Cre:Bclaf1fl/fl mice, which inducibly delete Bclaf1 after pIpC treatment, were transduced with the MLL-AF9 construct and transplanted. Additionally, primary haploinsufficient Mx-Cre:Bclaf1fl/- and wild-type Bclaf1fl/fl AMLs were transferred into new recipients and treated with pIpC two weeks later. Haploinsufficient Mx-Cre:Bclaf1fl/- cells were also treated with Tat-Cre
recombinase to delete the remaining floxed allele. Lastly, Bclaf1-depletion was performed in human K562 AML cells.
Results
All mice receiving transduced wild-type cells developed AML, while only 50% of mice that received Bclaf1-deficient cells developed AML. Interestingly, mice that received Bclaf1fl/fl or Mx-Cre:Bclaf1fl/fl transduced cells developed AML at similar incidences; genotyping demonstrated all Mx-Cre:Bclaf1fl/fl AMLs were haploinsufficient for Bclaf1. No Bclaf1-deficient AMLs propagated from Mx-Cre:Bclaf1fl/fl, despite 85% of hematopoietic progenitors losing both floxed alleles after pIpC treatment. AML progressed equivalently in recipients of Bclaf1fl/fl or Mx-Cre:Bclaf1fl/- AML cells, and genotyping showed all Mx-Cre:Bclaf1fl/- AMLs remained haploinsufficient. Tat-Cre treatment of Mx-Cre:Bclaf1fl/- cells generated Bclaf1-/- cells (confirmed via genotyping). These Bclaf1-deficient AML cells had reduced colony formation in semisolid culture compared to haploinsufficient (Mx-Cre:Bclaf1fl/-) AML cells. K562 cells expressing shBclaf1 were selectively depleted in culture compared to cells expressing a non-targeting shRNA. Additionally, using an
inducible CRISPR-Cas9 system, K562 cells expressing a guide RNA against Bclaf1 formed fewer colonies after single-cell subcloning than cells expressing a non-targeting guide RNA. Recovered colonies predominantly expressed BCLAF1 despite loss of BCLAF1 in the bulk CRISPR-generated BCLAF1-depleted K562 cells prior to subcloning.
Conclusion
Collectively, these studies demonstrate that BCLAF1 has critical functions in AML and will define its functions in AML transformation and maintenance. Ongoing studies will define chromatin binding patterns of BCLAF1 and BCLAF1-mediated transcriptional programs in AML.

Loss of BCLAF1 impairs AML pathogenesis

Sickle cell disease (SCD) is a genetic blood disorder affecting approximately 100,000 people in the United States, 90% of whom are African American. This disorder causes abnormal hemoglobin production due to defects in the beta-globin protein. As a result, oxygen transport by erythrocytes (a type of erythroid cell) is hindered, leading to severe symptoms and complications. 

Current treatments for this disorder have limited effectiveness and/or accessibility and often have side effects. Recent studies, however, suggest that fetal hemoglobin (HbF) can compensate for the defective adult hemoglobin in SCD patients. HbF is naturally inhibited throughout adulthood by several transcription factors, including ZBTB7A. While transcription factors have historically been deemed “undruggable,” new advancements in therapeutic modalities, like molecular glue degraders, have spurred interest in targeting them. 

We previously identified and characterized SH6, a novel small molecule degrader, to induce gamma-globin (a component of HbF) through ZBTB7A degradation. It is still unclear, though, if SH6 is as effective as other gamma-globin inducers (e.g., thalidomide, decitabine, and hydroxyurea) or if SH6’s action can be amplified with them.

HUDEP-2 cells were treated with 0.05%-0.2% DMSO, pomalidomide (an analog of thalidomide), decitabine, hydroxyurea, SH6, or SH6 with decitabine or pomalidomide during their 5-day long differentiation phase. qPCR was then conducted to measure gamma-globin mRNA expression. HUDEP-2 cells without a combination treatment were also accessed via flow cytometry for gamma-globin protein production. Singlet cells were selected based on FSC/SSC, while CD235+ bright differentiated erythroid cells were gated.

SH6 had a stronger gamma globin induction effect on both mRNA and protein levels than other non-combination treatments. Synergistic effects were also seen between SH6 and decitabine, with mRNA gamma-globin expression increasing 4-fold compared to SH6 alone and 9-fold compared to decitabine alone.

So, although some gamma-globin inducers are available in the market or are in clinical trials, they are less effective than SH6 in HUDEP-2 cells. However, HUDEP-2 cells differentiate into normal erythrocytes and thus are not representative of erythrocytes found in SCD patients. SH6-mediated gamma-globin induction would need further investigation using SCD patient-derived iPSCs or CD34+ cells to ensure SH6’s efficacy in SCD physiological conditions. Despite the limited realm within which it has been studied, SH6 shows promising pre-clinical results as a potential therapy for sickle cell disease.

SH6 Outperforms Known Gamma-Globin Inducers for Treatment of Sickle Cell Disease in Vitro

Background
Hydrocephalus (HC) is a common pediatric neurosurgical condition characterized by the accumulation of cerebrospinal fluid (CSF) and elevated intracranial pressure. Without treatment, HC causes substantial neurological morbidity and mortality. The gold-standard treatment for HC, CSF shunting, is associated with high rates of shunt infection, obstruction, and malfunction and requires lifelong access to prompt neurosurgical care. Endoscopic third ventriculostomy with choroid plexus cauterization (ETV-CPC) was thus developed as an alternative to CSF shunting in low and middle-income countries (LMICs); however, the impact of this treatment on neurological function or brain development remains unclear.

Methods
The current study details the technical development of an experimental, large animal model of ETV-CPC to examine the neurobiological and neurobehavioral effects of ETV-CPC versus CSF shunting.

Results
Hydrocephalus was induced in juvenile pigs by cisternal injection of 25% kaolin and confirmed with high-resolution MRI after 10-14 days post-induction. For surgical treatment of HC, frameless stereotactic Stealth neuronavigation was registered to the animal's head and an orthogonal trajectory to the foramen of Monro was planned with entry 1 cm lateral to midline. After incision, a burr hole was fashioned, the dura cauterized, and a ventricular catheter was passed into the right lateral ventricle. After the collection of ~1 ml of CSF for later analyses, the catheter was removed and a flexible ventriculoscope was inserted along the track. The endoscope was navigated through the foramen of Monro and into the 3rd ventricle, where a flexible Bugbee wire was used to make an ETV in the lamina terminalis. After completion of the ETV, the endoscope was withdrawn into the right lateral ventricule, and the choroid plexus was cauterized, beginning at the foramen of Monro and moving toward the atrium/glomus, and then into the temporal horn to the temporal tip. In most cases, the septum pellucidum was incompetent, and the same procedure was used to cauterize the entirety of the choroid plexus in the left lateral ventricle. After the ETV-CPC, the endoscope was removed and a ventricular catheter was affixed to a ventricular reservoir, inserted into the right lateral ventricle, and secured in place with pericranial sutures. The wound was irrigated and closed.

Conclusion
This experimental juvenile porcine model of ETV-CPC offers the opportunity to study the neurobiological and neurobehavioral effects of ETV-CPC and CSF shunting in a novel way. Understanding the long-term effects of these treatments is paramount in identifying the optimal treatment for children with HC.

Experimental  Endoscopic Third Ventriculostomy With Choroid Plexus Cauterization: A Novel Model For Physiological Investigation

Background: 
The unfolded protein response (UPR) is activated by stresses in tumor cells, including hypoxia, acidosis, reactive oxygen species, radiation, and chemotherapy. It responds to unfolded/misfolded proteins in the endoplasmic reticulum (ER) by initiating pathways to enhance chaperone expression, boost protein degradation, and reduce protein synthesis, thereby regulating ER stress. If ER homeostasis cannot be restored, the UPR can shift from promoting cell survival to cell death. Targeting the UPR is a novel therapeutic approach for glioblastoma (GBM), especially against GBM stem-like cells (GSCs) that drive tumor regrowth, heterogeneity, and resistance. This strategy also shows potential for use before surgical resection of this aggressive brain tumor.

Methods
We evaluated a series of curcumin derivatives against three GSC lines. MTS assay was used to determine the IC50 of the compounds. Western blot analysis determined protein expression of targets and downstream effectors, including C/EBP Homologous Protein (CHOP), GRP78/Bip, caspase 7, and PARP.

Results
A trimethoxy bis-chalcone compound was identified that induces robust cell death in GSCs, with an average IC50 of just below 300 nM — 100-fold increase in potency compared to curcumin. This bis-chalcone showed minimal toxicity towards normal human mesenchymal stem cells. Western blot revealed that this compound effectively activated the pro-death UPR protein CHOP while reducing the expression of the pro-survival chaperone GRP78/Bip. It also induced caspase 7 expression and PARP cleavage, indicating apoptosis.

Conclusion
Most ER stress-inducing agents activate both survival pathways and cell death pathways of UPR. In contrast, our identified compound selectively promotes UPR cell death signaling and is highly toxic against radiation and temozolomide-resistant GSCs, while showing no toxicity to non-tumor cells. This bis-chalcone compound is a promising lead for developing UPR-targeted therapies, particularly for GBM. Its potential application in pre-surgical resection of GBM is noteworthy due to its ability to reduce cell migration and tumor size.

Premium content

Next from AMA Research Challenge 2024

Studying the Molecular Pathways Involved in Hepatocellular Recovery During Normothermic Machine Perfusion to Identify Livers Safe for Transplantation

Similar lecture

Multimodal Assessment of Bone Health in GLP-1 Agonist Users