Ryan Fuller

Dr. Ryan Fuller

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 October 2023 in Cancers
Verified
Journal Article
Open access
PDF file
NWNathan Wall
Nathan Wall
RFRyan Fuller
Ryan Fuller
AMAnn Morcos
Ann Morcos
MLMarino De Leon
Marino De Leon
Pancreatic cancer (PCa) remains a formidable global health challenge, with high mortality rates and limited treatment options. While advancements in pharmacology have led to improved outcomes for various cancers, PCa continues to exhibit significant health disparities, disproportionately affecting certain populations. This paper explores the intersection of pharmacology and anthropology in understanding the health disparities associated with PCa. By considering the socio-cultural, economic, and behavioral factors that influence the development, diagnosis, treatment, and outcomes of PCa, pharmacologic anthropology provides a comprehensive framework to address these disparities and improve patient care.

27 September 2024 in Cancers
Verified
Journal Article
Open access
PDF file
AMAnn Morcos
Ann Morcos
YJYeonkyu Jung
Yeonkyu Jung
JBJoab Rafael Galvan Bustillos
Joab Rafael Galvan Bustillos
RFRyan Fuller
Ryan Fuller
DMDavid Caba Molina
David Caba Molina
NWNathan Wall
Nathan Wall
The duocarmycin family is a group of potent cytotoxic agents originally isolated from the bacterium Streptomyces. This discovery has spurred significant interest due to duocarmycins’ unique chemical structures and powerful mechanism of action. This review comprehensively details the history of the duocarmycin family, the current understanding of their therapeutic potential, and the major clinical trials that have been conducted. Chemically, the duocarmycin family is characterized by a DNA-binding unit that confers specificity, a subunit-linking amide that positions the molecule within the DNA helix, and an alkylating unit that interacts with the DNA. This configuration allows them to bind selectively to the minor groove of DNA and alkylate adenine bases, a notable deviation from the more common guanine targeting performed by other alkylating agents. Duocarmycin’s mechanism of action involves the formation of covalent adducts with DNA, leading to the disruption of the DNA architecture and subsequent inhibition of replication and transcription. Recent advancements in drug delivery systems, such as antibody–drug conjugates (ADCs), have further elevated the therapeutic prospects of duocarmycin analogs by providing a promising mechanism for enhancing intracellular concentrations and selective tumor delivery. Preclinical studies have highlighted the efficacy of duocarmycin derivatives in various in vitro models, providing a strong foundation for translational research. However, further biological research is required to fully understand the toxicology of duocarmycin family members before it can be clinically relevant. The major focus of this review is to cache the major biologically relevant findings of different duocarmycin analogs as well as their biological shortcomings to propose next steps in the field of cancer therapy with these potent therapeutics.

10 October 2022 in OncoTargets and Therapy
Verified
Journal Article
Open access
PDF file
RFRyan Fuller
Ryan Fuller
JKJanviere Kabagwira
Janviere Kabagwira
PVPaul A Vallejos
Paul A Vallejos
AFAndrew D Folkerts
Andrew D Folkerts
NWNathan Wall
Nathan Wall
Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with poor prognosis, as it is difficult to predict or circumvent, and it develops chemoresistance quickly. One cellular mechanism associated with chemoresistance is alternative splicing dysfunction, a process through which nascent mRNA is spliced into different isoforms. Survivin (Baculoviral IAP Repeat-Containing Protein 5 (BIRC5)), a member of the inhibitor of apoptosis (IAP) protein family and a cell cycle-associated oncoprotein, is overexpressed in most cancers and undergoes alternative splicing (AS) to generate six different splicing isoforms. Methods: To determine if survivin splice variants (SSV) could be involved in PDAC chemoresistance, a Gemcitabine (Gem) resistant (GR) cell line, MIA PaCa-2 GR, was created and assessed for its SSV levels and their potential association with GR. Cross-resistance was assessed in MIA-PaCa-2 GR cells to FIRINOX (5-fluorouracil (5-FU), irinotecan, and oxaliplatin). Once chemoresistance was confirmed, RT-qPCR was used to assess the expression of survivin splice variants (SSVs) in PDAC cell lines. To confirm the effect of SSVs on chemoresistance, we used siRNA to knockdown all SSVs or SSV 2β. Results: The MIA PaCa-2 GR cell line was 40 times more resistant to Gem and revealed increased resistance to FIRINOX (5-fluorouracil (5-FU), irinotecan, and oxaliplatin); when compared to the parental MIA-PaCa-2 cells. RT-qPCR studies revealed an 8-fold relative expression increase in SSV 2β and a 2- to 8-fold increase in the other five SSVs in the GR cells. Knockdown of all SSV or SSV 2β only, using small inhibitory RNA (siRNA), sensitized the GR cells to Gem, indicating that these SSVs play a role in PDAC chemoresistance. Conclusion: These findings provide evidence for the potential role of SSV 2β and other SSVs in innate and acquired PDAC chemoresistance. We also show that the expression of SSVs is not affected by the type of chemoresistance, therefore targeting survivin splice variants in combination with chemotherapy could benefit a wide range of patients.

1 January 2024 in OncoTargets and Therapy
Verified
Journal Article
Open access
PDF file
JKJanviere Kabagwira
Janviere Kabagwira
RFRyan Fuller
Ryan Fuller
PVPaul Vallejos
Paul Vallejos
CSChase S Sugiono
Chase S Sugiono
VAVola-Masoandro Andrianarijaona
Vola-Masoandro Andrianarijaona
NWNathan Wall
Nathan Wall
Introduction: Peritoneal metastases from colorectal cancer (CRC) present a significant clinical challenge with poor prognosis, often unresponsive to systemic chemotherapy. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment approach for select patients. The use of curcumin, a natural compound with antitumor properties, in HIPEC is of interest due to its lower side effects compared to conventional drugs and potential for increased efficacy through direct delivery to the peritoneal cavity. Methods: An in vitro hyperthermic model was developed to simulate clinical HIPEC conditions. Three colon cancer cell lines (SK-CO-1, COLO205, SNU-C1) representing different genetic mutations (p53, KRAS, BRAF) were treated with either curcumin (25 μM) or mitomycin-C (1 μM) for 1, 2, or 3 hours. Post-treatment, cells were incubated at 37°C (normothermia) or 42°C (hyperthermia). Cell viability and proliferation were assessed at 24, 48 and 72 hours post-treatment using Annexin V/PI, MTT assay, trypan blue exclusion, and Hoffman microscopy. Results: Hyperthermia significantly enhanced the antitumor efficacy of curcumin, evidenced by a two-fold reduction in cell viability compared to normothermia across all cell lines. In the SNU-C1 cell line, which harbors a p53 mutation, mitomycin-C failed to significantly impact cell viability, unlike curcumin, suggesting mutation-specific differences in treatment response. Discussion: The findings indicate that hyperthermia augments the antitumor effects of curcumin in vitro, supporting the hypothesis that curcumin could be a more effective HIPEC agent than traditional drugs like mitomycin-C. Mutation-associated differences in response to treatments were observed, particularly in p53 mutant cells. While further studies are needed, these preliminary results suggest that curcumin in HIPEC could represent a novel therapeutic strategy for CRC patients with peritoneal metastases. This approach may offer improved outcomes with fewer side effects, particularly in genetically distinct CRC subtypes. Plain Language Summary: In this study, we aimed to improve treatments for peritoneal carcinomatosis (PC), a challenging form of colorectal cancer (CRC) that does not respond well to regular chemotherapy. We explored an approach called hyperthermic intraperitoneal chemotherapy (HIPEC), which involves delivering potent chemotherapy directly to the abdominal area at an elevated temperature. Our innovative idea was to enhance HIPEC’s effectiveness by using curcumin, a natural compound with fewer side effects than conventional HIPEC drugs. To test our theory, we conducted experiments on colon cancer cells under high-temperature conditions, mimicking what occurs during HIPEC treatments. We also compared curcumin with the standard drug, mitomycin-C (MMC). We discovered that curcumin, when delivered under high temperatures, outperformed MMC in killing colorectal cancer cells. This is an exciting breakthrough because it suggests that curcumin in HIPEC could be a promising alternative for treating PC. While we are still working on more comparisons and further studies, this outcome represents a significant step towards better treatment options for patients with peritoneal carcinomatosis. In conclusion, our study was motivated by the need to find more effective ways to combat an aggressive form of colorectal cancer metastasis. By exploring the potential of curcumin in HIPEC, we hope to provide better treatment options for patients who face this challenging disease.

Verified
Journal Article
Open access
PDF file
AMAnn Morcos
Ann Morcos
YJYeonkyu Jung
Yeonkyu Jung
RFRyan Fuller
Ryan Fuller
ABAntonella Bertucci
Antonella Bertucci
ANAmy Nguyen
Amy Nguyen
MVMarcelo Vazquez
Marcelo Vazquez
Glioblastoma multiforme (GBM) is among the most lethal primary brain tumors and is characterized by significant cellular heterogeneity and resistance to conventional therapies. This study investigates the efficacy of seco-duocarmycin SA (seco-DSA), a novel DNA alkylating agent. Initial investigations using a colony formation assay revealed that seco-DSA exhibits remarkable potential with IC50 values lower than its natural DSA counterpart. Cell viability assay indicated that LN18 cells showed a markedly greater sensitivity to DSA than T98G cells. Furthermore, seco-DSA achieved its full cytotoxic effect within 8 h of drug incubation in GBM cell lines. Although seco-DSA induced a concentration-dependent increase in apoptotic cell death, the extent of apoptosis did not fully account for the observed decrease in cell viability. Instead, seco-DSA treatment resulted in significant cell cycle arrest in S and G2/M phases. These findings suggest that seco-DSA’s cytotoxicity in GBM cells is primarily due to its ability to disrupt cell cycle progression, though the precise mechanisms of action remain to be fully established, and further research is needed. Proteomic analysis of treated cells also indicates dysregulation of proteins involved in senescence, apoptosis, and DNA repair, alluding to seco-DSA-induced arrest as a major mechanism of GBM disruption. Data are available via ProteomeXchange with the dataset identifier “PXD061023”. Our reports promote the future exploration of seco-DSA’s therapeutic potential, representing a critical step toward developing a more targeted and effective treatment for GBM.

12 March 2025 in Biochimica et Biophysica Acta (BBA) - General Subjects
Verified
Journal Article
Closed access
CPChirstopher Perry
Chirstopher Perry
RSReinhard W Schulte
Reinhard W Schulte
RFRyan Fuller
Ryan Fuller
NWNathan Wall
Nathan Wall
KNKevin E. Nick
Kevin E. Nick
JMJamie R. Milligan
Jamie R. Milligan