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Biology subjects

Suk, J. S.

Publications and source records attributed to Suk, J. S..

5 recordsLinked to original sources

Blood-brain barrier-traversing multivalent TGFβ trap for anti-cancer immunomodulation of gliomas

Clinical studies have revealed that glioblastoma (GBM) is refractory to immunotherapy, such as immune checkpoint inhibitors (ICIs), due to the immunosuppressive tumor microenvironment (TME) primarily intensified by intratumoral upregulation of transforming growth factor-{beta} (TGF{beta}). Primary GBM tumor bulks are surgically removed in clinic, but invasive tumor cells infiltrated into surrounding normal brain tissue cannot be eradicated by systemic therapy due to the integral blood-brain barrier (BBB), leading to near-inevitable tumor recurrence. To address these translational challenges, we have engineered a TGF{beta}-inhibiting protein nanocage comprising human heavy-chain ferritin protein and TGF{beta} receptor II ectodomain that enables BBB penetration and multivalent TGF{beta} entrapment, respectively. We demonstrate that the nanocage platform, denoted T{beta}R2-HFt, following systemic administration, traverses the BBB, and extensively modulates immunosuppressive TME, both stromal and immune components, thereby potentiating the therapeutic efficacy of a clinically used ICI in multiple mouse glioma models. Notably, a majority of the glioma-bearing animals that received surgical tumor resection, followed by treatment with T{beta}R2-HFt and the ICI, survived the tumor and resisted tumor rechallenge, providing a potential means to control GBM in a durable manner.

bioengineering↗

An immune-stimulating antibody conjugate spatiotemporally targeting CD47 and TLR9 elicits macrophage-dependent tumor clearance and durable anti-cancer adaptive immunity

Cluster of differentiation 47 (CD47) blockade promotes tumor cell phagocytosis; however, transitioning this initial innate immune event into durable anti-cancer adaptive immunity and tumor control remains a critical challenge. To address this translational gap, we have engineered aCD47 - CpG, a novel immune-stimulating antibody conjugate (ISAC) coupling a CD47-blocking antibody (aCD47) to a Toll-like receptor 9 agonist, unmethylated CpG, to enable synchronized deployment of co-stimulatory signals during tumor engulfment. This ISAC, aCD47-CpG, but not the parent aCD47, reprograms macrophages toward an anti-tumor M1-like phenotype, enhances antigen cross-presentation, and promotes robust CD8+ T cell priming. We found that systemically administered aCD47-CpG drove macrophage-dependent tumor suppression in a human lymphoma xenograft model. In parallel, the treatment in immunocompetent syngeneic models of lymphoma and highly immunosuppressive triple-negative breast cancer resulted in profound tumor regression, metastasis inhibition, and durable anti-cancer immune memory. These effects were accompanied by remodeling of the immunosuppressive tumor microenvironment toward an immune-permissive state, characterized by M2-to-M1 macrophage repolarization, intratumoral infiltration of cytotoxic and memory T cells, and depletion of regulatory T cells. This spatiotemporally coordinated immunotherapy platform offers a promising strategy to bridge innate and adaptive immunity, thereby advancing the translational potential of CD47-targeted cancer therapies.

cancer biology↗

Discovery and therapeutic exploitation of Master Regulatory miRNAs in Glioblastoma

Glioblastoma is a fatal primary malignant brain tumor, with an average survival of only 15 months despite surgical resection, chemotherapy, and radiation therapy. Due to the concurrent deregulation of numerous genes in glioblastoma, molecular monotherapies have not improved clinical outcomes. Evidence suggests that effectively targeting multiple deregulated molecules is essential for better therapies; however, this is limited by the lack of suitable drugs and the increased toxicity of combination therapies. To address this, we hypothesized that miRNAs, small gene-regulatory RNAs that suppress multiple target genes via sequence complementarity, could be developed to inhibit multiple deregulated genes simultaneously, leading to more effective treatments. We identified master regulatory miRNAs--those that target several deregulated genes in glioblastoma--using PAR-CLIP screenings in glioblastoma cells and analyzed TCGA tumor data to find which targets were deregulated. An algorithm ranked these targets based on their significance in glioblastoma malignancy. We selected two tumor suppressor master regulatory miRNAs, miR-340 and miR-382, and one oncogenic miRNA, miR-17. Validation showed that these miRNAs target critical glioblastoma pathways and significantly inhibit cell growth, survival, invasion, and tumor growth in vivo. We developed an innovative therapeutic delivery approach using Brain Penetrating Nanoparticles in combination with MRI-guided focused ultrasound and microbubbles, resulting in reduced tumor volume and extended survival in glioblastoma-bearing mice. This strategy offers a promising pathway for translating miRNA-based therapies into clinical trials for glioblastoma and other cancers. One Sentence SummaryWe developed and used new computational, experimental, and therapeutic approaches to identify and therapeutically deliver master regulatory miRNAs to inhibit the growth of glioblastoma, the most common and deadly primary brain tumor.

cancer biology↗

Keratin 19 interacts with GSK3β to regulate its nuclear accumulation and degradation of cyclin D3

Cyclin D3 regulates the G1/S transition and is frequently overexpressed in several cancer types including breast cancer, where it promotes tumor progression. Here, we show that a cytoskeletal protein keratin 19 (K19) physically interacts with a serine/threonine kinase GSK3{beta} and prevents GSK3{beta}-dependent degradation of cyclin D3. The absence of K19 allowed active GSK3{beta} to accumulate in the nucleus and degrade cyclin D3. Specifically, the head domain of K19 was required to sustain inhibitory phosphorylation of GSK3{beta} Ser9, prevent nuclear accumulation of GSK3{beta}, and maintain cyclin D3 levels and cell proliferation. K19 was found to interact with GSK3{beta} and K19-GSK3{beta} interaction was mapped out to require Ser10 and Ser35 residues on the head domain of K19. Unlike wildtype K19, S10A and S35A mutants failed to maintain total and nuclear cyclin D3 levels and induce cell proliferation. Finally, we show that the K19-GSK3{beta}-cyclin D3 pathway affected sensitivity of cells towards inhibitors to cyclin dependent kinase 4 and 6 (CDK4/6). Overall, these findings establish a role for K19 in the regulation of GSK3{beta}-cyclin D3 pathway and demonstrate a potential strategy for overcoming resistance to CDK4/6 inhibitors.

cancer biology↗

Disulfide disruption reverses mucus dysfunction in allergic airway disease

Airway mucus is essential for healthy lung defense1, but excessive mucus in asthma obstructs airflow, leading to severe and potentially fatal outcomes2-5. Current asthma therapies reduce allergic inflammation and relax airway smooth muscle, but treatments are often inadequate due to their minimal effects on mucus obstruction6,7. The lack of efficacious mucus-targeted treatments stems from a poor understanding of healthy mucus function and pathological mucus dysfunction at a molecular level. The chief macromolecules in mucus, polymeric mucins, are massive glycoproteins whose sizes and biophysical properties are dictated in part by covalent disulfide bonds that link mucin molecules into assemblies of 10 or more subunits8. Once secreted, mucin glycopolymers can aggregate to form plugs that block airflow. Here we show that reducing mucin disulfide bonds depolymerizes mucus in human asthma and reverses pathological effects of mucus hypersecretion in a mouse allergic asthma model. In mice challenged with a fungal allergen, inhaled mucolytic treatment acutely loosened mucus mesh, enhanced mucociliary clearance (MCC), and abolished airway hyperreactivity (AHR) to the bronchoprovocative agent methacholine. AHR reversal was directly related to reduced mucus plugging. Furthermore, protection in mucolytic treated mice was identical to prevention observed in mice lacking Muc5ac, the polymeric mucin required for allergic AHR in murine models9. These findings establish grounds for developing novel fast-acting agents to treat mucus hypersecretion in asthma10,11. Efficacious mucolytic therapies could be used to directly improve airflow, help resolve inflammation, and enhance the effects of inhaled treatments for asthma and other respiratory conditions11,12.

physiology↗