United States

Introduction
By 2045 the number of adults living with type I diabetes is projected to increase to 783 million. Current guidelines recommend exogenous insulin replacement therapy, which entails significant adverse effects and inhibiting cost. Surgical transplantation of insulin-producing pancreatic cells has been proposed as a potential lasting curative treatment for diabetes. Current techniques are fraught with post operative complications and life-long immunosuppression. There is a persistent need for a reliable platform that can facilitate pancreatic tissue transplantation without these limitations. Here, we present our novel Arterio-Venous Graft Rx (AVGRx) which sustains both stem-cell derived beta cells (SCDßCs)and human pancreatic tissue viability and function in vivo in a large animal porcine host without immune suppression. 

Methods
The AVGRx contains a treatment zone that is shielded from the host immune cells while facilitating contact with the host arterial blood stream for nutrient and hormone exchange. Adult male Yorkshire pigs were obtained for graft implantation. The common carotid artery and distal external jugular vein were surgically exposed, and an end-to-side anastomosis with both graft ends was performed. The AVGRx treatment zone was then injected with either SCDßCs or human pancreatic islets. No immunosuppression was administered. 1-, 2- and 3-weeks post implantation, the porcine host was injected with a 500mg/kg dextrose injection, and blood was collected to measure human insulin using ELISA. To evaluate cell morphology post-explantation, SCDßCs were evaluated using Nkx (beta cell marker), C-peptide (terminal insulin sequence) immunofluorescence. Following explantation, purified human islets were exposed to 2mM and then 20mM glucose solutions. Their supernatant was collected, and human insulin concentrations were measured. 

Results
Quantification of cellular markers demonstrated unchanged cell count of Nkx (p=0.12) or C-peptide (p=0.13) positive cells between weeks 0, 1 and 2. Compared to baseline insulin secretion, post-explanted human islets demonstrated similar insulin secretion in both low (p=0.68) and high (p=0.31) glucose concentration solutions. Following dextrose bolus, human insulin was detected in vivo each week for three weeks during graft implantation. 
Conclusion

Conclusion
The AVGRx is a novel means to reliably sustain implanted xenograft cells without the need for immunosuppression. SCDßCs and human pancreatic islets were observed to have maintained viability within porcine models for up to 21 days. These findings demonstrate the ability of the AVGRx to interface its payload with a host’s arterial blood supply while also protecting it from a immune response. The AVGRx platform may have a major impact on the future of islet transplant therapy.


AMA Research Challenge 2024 

Human Pancreatic Cells Survive Porcine Implantation Without Immune Suppression Using Novel Arteriovenous Graft

Welcome to the **largest national, multi-specialty research** event featuring research from nearly 700 medical students, residents, fellows, and international medical graduates.

Use the buttons below or navigation menu to access the event.
 


[![](https://assets.underline.io/uploads/markdown_image/1/image/3e33a8c754cc49610b30950617d813e7.png)](https://underline.io/events/434/sessions?searchGroup=all)
 
[![](https://assets.underline.io/uploads/markdown_image/1/image/551404d429c4e274f9a54cbdd7081918.png)](https://underline.io/events/434/posters?searchGroup=all)
 
[![](https://assets.underline.io/uploads/markdown_image/1/image/677d92f566b880cebd36905fc738fc10.png)](https://underline.io/events/434/lounge)
 
[![](https://assets.underline.io/uploads/markdown_image/1/image/c7392833c7261c3874c5b43fa2f4df19.png)](https://underline.io/events/434/help-desk)
 

#### Event Details

The 2023 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
* **Attend education sessions** with physician experts on key research topics

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 sponsored by Laurel Road. 

### 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 the judging or scoring process to select the winner. The winner will be announced on February 4, 2024 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)

**There is no registration fee for this event! **

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/about/events/ama-research-challenge) to register for free.**

Registration Is Required

AMA Research Challenge 2023

Join the AMA Research Challenge poster symposium and semifinals to explore top research posters, score posters in the semifinals (an AMA member exclusive opportunity) and attend education sessions with experienced physicians to learn tips to advance your research and career. 

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.
 

[![](https://assets.underline.io/markdown_image/1/image/20e1e77aa954efeac7a15d84c85eb383.jpg)](https://underline.io/events/468/sessions?searchGroup=all)
 
[![](https://assets.underline.io/markdown_image/1/image/068522d81aca0b68a369787c7dfccd1b.jpg)](https://underline.io/events/468/posters?searchGroup=all)
 
[![](https://assets.underline.io/markdown_image/1/image/d3971ece79d5e5575b178bdc2c8bbfae.jpg)](https://underline.io/events/468/help-desk)
 

#### 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. 

### 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/)

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.

Please log in to explore this event.

**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.**

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).

Kevin Lopez B.S.1, Nizam Karim B.S.1
1The University of Texas Medical Branch (UTMB) John Sealy School of Medicine, Galveston, TX

Background
• Post-operative cognitive dysfunction (POCD) is a detrimental neurocognitive disorder that occurs after surgery with anesthesia where a substantial change in a patient’s baseline cognitive ability leads to difficulty completing activities of daily living, socializing, maintaining a job, and is associated with an increased risk of death.1
• POCD can affect anyone, but patients over 60 years old are at increased risk, lasting from weeks to over a year in some cases.1
• Currently, no treatment exists, and research is very limited. Recently, the Gut-Brain-Axis has been implicated in the pathogenesis of POCD.
• This systematic review aims to summarize recent animal studies and controlled human trials focusing on mechanisms of pathogenesis and/or therapeutic targets for POCD relating to gut microbiome dysbiosis and its role in cognition and neuroinflammation.

Methods
• Systematic review conducted in PubMed database over 5-year period, 2019-2024, using relevant search/MeSH terms.
• Review designed according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. SYRCLE's risk of bias tool and revised Cochrane risk of bias tool (Rob 2) were used. 

Results
• 2 articles demonstrate healthy donor fecal matter transplantation (FMT) to POCD-animals ameliorates POCD-like symptoms. 
• 3 articles demonstrate that POCD-donor FMT to healthy germ-free animals induces dysbiosis and POCD-like symptoms.
• 1 article demonstrated perioperative probiotic administration in humans as effective to reduce incidence of POCD in elderly patients undergoing non-cardiac surgery.

Potential Mechanisms of POCD
Dysregulated Signaling pathways inducing POCD Symptoms:
ERK/Nrf2, ACCS2/HDAC, BTG2/Bax, TLR4/NF-kB, Keap1/Nrf2
“Toxicity”: Increased molecule/compound inducing POCD Symptoms:
Trimethylamine N-oxide (TMAO), NLRP3 inflammasome, Palmitic acid, Valeric acid, IL17A/IL17RA, intestinal exosomes
“Deficiency”: Decreased molecule/compound inducing POCD Symptoms:
C1BR, SIRT1, tight junction protein, methionine sulfoxide reductase (MsrA)
“Protective”: Increased molecule/compound ameliorating POCD Symptoms:
CB1R, SIRT1, and miR-146a (via BTG2/Bax axis)

Novel Therapeutics Ameliorating POCD Symptoms
Short chain fatty acid (SCFA) (via ACCS2/HDAC2 axis), Sodium butyrate (NaB), indole propionic acid, propionic acid, 4 octyl itaconate (via ERK/Nrf2 axis), exogenous dietary restriction (via TLR4/MyD88/NF-kB axis), Sulforaphane (via Keap/Nrf2 axis), and exosome inhibitor GW4869, PLX5622, probiotics, exercise, Cefazolin, Ibuprofen, prebiotic xylooligosaccharides (XOS)

Discussion
Interestingly, it was determined that anesthesia may induce microbiome dysbiosis independently from surgery. This suggests that anesthesia plus surgery may induce dysbiosis in an additive manner in addition to other predisposing factors such as age and anesthesia dose, type, route of administration, and duration of use, comorbidities, pre-existing cognitive dysfunction or other psychiatric conditions.

Future Directions
Further translational research evaluating perioperative administration of novel therapeutic agents, such as those in this search, could provide promising results. Further evaluation of changes in the Gut-Brain-Axis could uncover a deeper understanding of the pathogenesis of POCD.

References
1. Brodier, E., & Cibelli, M. (2020). Postoperative cognitive dysfunction in clinical practice. BJA Education, 21(2), 75–82. https://doi.org/10.1016/j.bjae.2020.10.004


Exploring Mechanisms in the Gut-Brain-Axis for Anesthesia-induced POCD: A Systematic Review

Background
The serotonin transporter (SERT, encoded by SLC6A4) is downregulated in patients with inflammatory bowel disease (IBD) and in pre-clinical IBD models. While serotonin (5-HT) and SERT are known to play crucial roles in gut health and the microbiome, the therapeutic potential of targeting SERT in intestinal inflammation remains unexplored.
Methods
SERT knockout (KO) and wild-type (WT) mice were treated with dextran sulfate sodium (DSS) to induce chronic colitis. Fecal and serum samples were subjected to metabolomic analysis. Bioinformatic tools identified enriched metabolic pathways and microbial-related metabolites. Disease severity was assessed via myeloperoxidase (MPO) activity, RT-PCR, immunoblotting, and immunohistochemistry. Tight junction integrity was evaluated using immunofluorescence, Western blotting, RT-PCR, and serum endotoxin levels. Spearman correlation coefficients were calculated to determine the relationship between metabolite abundance and disease activity.
Results
SERT KO mice with chronic colitis exhibited increased disease severity. Baseline metabolomic profiles of SERT KO mice resembled those of WT mice with chronic colitis, indicating a predisposition to metabolic dysregulation. Metabolomic analysis revealed distinct fecal and serum profiles associated with chronic colitis, mirroring human IBD, including variations in purine and plasmalogen metabolites. SERT deficiency alone led to altered tryptophan metabolism, oxidative metabolism changes, and dysregulation of phosphatidylcholines and plasmalogens. Mechanistically, SERT deficiency in an inflammatory context resulted in reduced ileal tight junction expression and increased serum endotoxin levels, exacerbating disease. Additionally, several microbial metabolites in feces and serum correlated with disease activity. Specifically, indolepropionate levels were reduced in the serum of both chronic colitis and SERT KO mice, with significant negative correlations with histology scores and MPO activity. Conversely, tyrosol excretion was increased in feces of both chronic colitis and SERT KO mice, showing significant positive correlations with histology scores and MPO.
Conclusion
SERT deficiency exacerbates DSS-induced chronic inflammation, disrupts intestinal barrier function, and causes microbially influenced metabolic changes corresponding to disease activity. This study highlights novel changes in host-derived and bacteria-derived metabolites in serum and feces due to SERT loss. Our findings suggest that SERT deficiency leads to a loss of beneficial anti-inflammatory and antioxidant compounds. Future research will explore the therapeutic potential of fecal supernatants containing these beneficial compounds for treating intestinal inflammation. These findings underscore the disruptive role of SERT in metabolic pathways associated with IBD and suggest potential therapeutic targets for intestinal inflammation.

Global serotonin transporter deficiency induces a metabolomic signature resembling chronic intestinal inflammation

Gastrointestinal microbes modulate peristalsis and stimulate the enteric nervous system (ENS), whose development, as in the central nervous system (CNS), continues into the murine postweaning period. Given that adult CNS function depends on stimuli received during critical periods of postnatal development, we hypothesized that adult ENS function, namely motility, depends on microbial stimuli during similar critical periods. We gave fecal microbiota transplantation (FMT) to germ-free mice at weaning or as adults, then measured gastrointestinal transit time either 4 weeks post-FMT or age-matched at 16 weeks. We performed RNAseq of colonic muscularis propria to compare gene expression patterns between mice with or without early life microbiota exposure. We found that only the mice given FMT at weaning recovered normal transit, while those given FMT as adults showed limited improvements. RNAseq of colonic muscularis propria revealed enrichments in neuron developmental pathways in mice exposed to gut microbes earlier in life, while mice exposed later – or not at all – showed exaggerated expression of inflammatory pathways. These findings highlight a microbiota-dependent sensitive period in ENS development, pointing to potential roles of the early life microbiome in later life dysmotility.

Microbiota-dependent early life programming of gastrointestinal motility

Background
Trauma patients with hemorrhagic shock (HS) accounts for 40% of preventable death. Shock-induced endotheliopathy has garnered interest recently and one aspect of this, endothelial glycocalyx shedding (EGX), has shown to promote coagulopathy following hemorrhage. Ferroptosis is an iron dependent, non-apoptotic form of controlled cell death triggered by the oxidation of membrane phospholipids. Liproxstatin-1 is an inhibitor of this process and can protect against oxidative damage to the endothelial cell membrane and subsequent shedding of glycocalyx. Our goal is to determine if administration of Liproxstatin-1, a ferroptosis inhibitor can reduce glycocalyx shedding in hemorrhaged rats providing evidence of its therapeutic value in the setting of hemorrhagic shock. 

Methods
A rat model of hemorrhagic shock and resuscitation was used to assess glycocalyx disruption in the lungs via fluorescent-labeled wheat germ agglutinin staining in frozen tissue and by syndecan-1 ELISA on plasma samples. A control group (n=5) resuscitated only with Lactated Ringer’s solution, following hemorrhage and resuscitation (H/R) was compared against an experimental group (n=1) that received Liproxstatin-1 following hemorrhage and before resuscitation.

Results
Glycocalyx shedding (assessed by an increase in plasma syndecan-1 levels) was significantly lower in the Liproxstatin-1 treated group compared to control group. Additionally, Liproxstatin-1 treated animals were able to sustain a higher mean arterial pressure (MAP), and oxygen saturation throughout the resuscitation period measured at 15- and 30-minutes following Liproxstatin-1 infusion. 

Conclusion
Ferroptosis inhibitor Liproxstatin-1 can reduce morbidity acutely during hemorrhagic shock and protect endothelial cell membrane from oxidative damage due to its ability to slow the generation of reactive oxygen species (ROS) and lipid hydroperoxides. 

Further experiments will be performed to complete the Liproxstatin-1 experimental group (n=5) as well as a control group using Cyrene (n=5), a DMSO-like solvent used to dissolve Liproxstatin-1 for intravenous administration. Additionally, tissue staining of lung vasculature will be performed to evaluate the glycocalyx disruption in the vascular beds of the lungs in the Cyrene, and Liproxstatin-1 groups as well as a group resuscitated with Lactated Ringers solution (H/R) alone. 


Can Inhibiting Ferroptosis Mitigate Vascular Injury and Subsequent Glycocalyx Shedding in the Setting of Hemorrhagic Shock?

Background 

Known to be one of the four major anastomoses between the median (MN) and ulnar (UN) nerves, the Martin-Gruber Anastomosis (MGA) has drawn much attention. Although previous studies have reported data regarding its prevalence, pattern and associated function, there is much variation within the given data. This present study’s aim is to dive further via dissections to further enhance our understanding of both the prevalence and patterns of the MGA. 

Methods 

Human cadaveric forearms (n = 66) were carefully dissected in the anatomy labs of Tilman J. Fertitta Family College of Medicine (TJFFCOM) and Baylor College of Medicine (BCM) for identification of various MGA nerve pathways. MGA patterns (Type I, Type II Type III) were photographed, documented, and stored. They were then compared to previous literature and studies for assessment of prevalence and pattern types. 

Results 

The MGA prevalence found within this study was 42%. Type I pattern anastomosis was measured to have approximately 54% prevalence. Type II showed the lowest prevalence in pattern type at 14% prevalence. Type III was found to be at 32% prevalence. It was also noted that unilateral MGA distribution was at 60% (n = 12) compared to bilateral at 40% (n = 8). Furthermore, bilateral distribution often showed congruence within pattern type. 

Conclusion 

It was noted that the prevalence found within this study seemed significantly higher compared to the reported median within previous literature (42% vs 20%). A notable highlight that resembled previous literature was the high occurrence of MGA buried within the flexor digitorum profundus (FDP) muscle. 

The MGA has significant clinical implications for iatrogenic injuries. Exploring the connectional relationship between MGA and associated structures may provide further insights in both prevention and treatment of related injuries including Carpal Tunnel Syndrome, peripheral neuropathies, and nerve transplant. 

However, it is noted that Type I pattern is often fibrous due to its embedding nature within the muscle. Often, there were findings that seemed to resemble Type I or II pattern types but could not adequately be confirmed as true MGA incidence. Due to this interesting finding, underlying nerve connections and structures can be further researched to provide additional explanation.

Delving Deeper into the Martin-Gruber Anastomosis – A Pilot Cadaveric Study

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. 


Preliminary results of Polyvinyl Alcohol Coated Medical Device Therapeutic Conjugation

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. 


Premium content

Downloads

Next from AMA Research Challenge 2024

Exploring Mechanisms in the Gut-Brain-Axis for Anesthesia-induced POCD: A Systematic Review

Similar lecture

Generation of stem-cell derived, vascularized islets for transplantation in Type 1 Diabetes Mellitus therapy.