Biology subjects

Hasan, T.

Publications and source records attributed to Hasan, T..

8 recordsLinked to original sources

bioRxiv2026

Photodynamic priming with Vitamin D and ALA-based PDT induces intratumoral immune cell recruitment and signaling pathway activation in murine cutaneous squamous cell carcinoma

Photodynamic therapy (PDT) is effective for early epithelial pre-cancers, yet its efficacy in fully-developed cutaneous squamous cell carcinoma (SCC) is limited by immunosuppression in the tumor microenvironment. Vitamin D (VitD) has emerged as a potential neoadjuvant to enhance photodynamic priming in several cancers. Here, we investigated how VitD pretreatment modulates local and systemic immune responses to aminolevulinic acid-based PDT in two immunocompetent murine SCC models (chronic UV-induced SCC, and subcutaneously implanted PDVC57B cells). VitD combined with PDT significantly amplified hallmarks of immunogenic cell death, including calreticulin and HMGB1 expression, and increased recruitment of neutrophils, macrophages, dendritic cells, and CD8 T cells into tumors. Importantly, VitD+PDT produced a higher M1/M2 macrophage ratio, and reduced the number of exhausted (PD-1 expressing) T cells compared to PDT alone. Immune profiling of blood demonstrated enhanced T-cell activation (CD69) and reduced TIM-3 expression on cytotoxic T cells. Transcriptomic analysis revealed pathway enrichment for interferon-/{gamma} signaling and suppression of pro-tumorigenic epithelial-mesenchymal transition and of angiogenesis after VitD+PDT. Collectively, these findings demonstrate that VitD reprograms the immune response to PDT by enhancing cytotoxic immunity while limiting immunosuppressive features. This suggests an immune-priming strategy to consider, possibly alongside immune checkpoint blockade, for treating cutaneous SCC.

cancer biology↗

bioRxiv2024

Efficacy of photodynamic therapy using 5-aminolevulinic acid-induced photosensitization is enhanced in pancreatic cancer cells with acquired drug resistance

The use of 5-aminolevulinic acid (ALA) as a precursor for protoporphyrin IX (PpIX) is an established photosensitization strategy for photodynamic therapy (PDT) and fluorescence guided surgery. Ongoing studies are focused on identifying approaches to enhance PpIX accumulation as well as to identify tumor sub-types associated with high PpIX accumulation. In this study, we investigated PpIX accumulation and PDT treatment response with respect to nodule size in 3D cultures of pancreatic cancer cells (Panc1) and a derivative subline (Panc1OR), which has acquired drug resistance and exhibits increased epithelial mesenchymal transition. In monolayer and 3D culture dose response studies the Panc1OR cells exhibit significantly higher cell killing at lower light doses than the drug naive cells. Panc1OR also exhibits increased PpIX accumulation. Further analysis of cell killing efficiency per molecule of intracellular PpIX indicates that the drug resistant cells are intrinsically more responsive to PDT. Additional investigation using exogenous delivery of PpIX also shows higher cell killing in drug resistant cells, under conditions which achieve approximately the same intracellular PpIX. Overall these results are significant as they demonstrate that this example of drug-resistant cells associated with aggressive disease progression and poor clinical outcomes, show increased sensitivity to ALA-PDT.

cancer biology↗

bioRxiv2024

Lymphatic dynamics visualized by native transient hypoxia imaging in areas of tissue damage, edema and in sentinel lymph nodes.

Imaging lymphatic compartments and their function has always been challenging, yet this capability is key to understanding the dynamics of immune response and lymph dysfunction in disease states. This study reports the first ever visualization of murine lymphatic pumping and function imaged from the inherent transient hypoxia that occurs within the lymph ducts and nodes. The lymphatic system appears as one of the few naturally hypoxic areas in vivo. Hypoxia in lymphatics is detected via delayed fluorescence (DF) of endogenous protoporphyrin IX (PpIX), enabling real-time imaging. Lymph nodes and their function were localized by hypoxia transcutaneous imaging and in surgically exposed nodes, followed by correlation of localization to indocyanine green (ICG) local injection. The lymphatic pumping frequency was altered through progressive damage from mild, moderate, and severe wound injuries, and hypoxia appeared readily in the sentinel lymph nodes near tumor regions. Cyclical pumping was observed at sites of edema and in nodes near tumors. Control data from uninjured anesthetized mice showed little lymphatic contrast, whereas awake mice exhibited hypoxia localized to lymph nodes. Unlike contrast injection-based regional lymph node imaging by ICG or MRI, DF hypoxia imaging appears to provide a natural whole-body contrast mechanism, highlighting its potential for visualizing lymphatic function and associated hypoxia dynamics. The value for localization of sentinel lymph nodes and for allowing for visualization of damaged lymph has very practical potential applications.

bioengineering↗

bioRxiv2023

A Dual Function Antibody Conjugate Enabled Photoimmunotherapy Complements Fluorescence and Photoacoustic Imaging of Head and Neck Cancer Spheroids

Several molecular-targeted imaging and therapeutic agents are in clinical trials for image-guided surgery and photoimmunotherapy (PIT) of head and neck cancers. In this context, we have previously reported the development, characterization, and specificity of a dual function antibody conjugate (DFAC) for multi-modal imaging and photoimmunotherapy (PIT) of EGFR over-expressing cancer cells. The DFAC reported previously and used in the present study, comprises of an EGFR targeted antibody - Cetuximab conjugated to Benzoporphyrin derivative (BPD) for fluorescence imaging and PIT, and a Si-centered naphthalocyanine dye for photoacoustic imaging. We report here the evaluation and performance of DFAC in detecting microscopic cancer spheroids by fluorescence and photoacoustic imaging along with their treatment by PIT. We demonstrate that while fluorescence imaging can detect spheroids with volumes greater than 0.049 mm3, photoacoustic imaging-based detection was possible even for the smallest spheroids (0.01 mm3), developed in the study. When subjected to PIT, the spheroids showed a dose-dependent response with smaller spheroids (0.01 and 0.018 mm3) showing a complete response with no recurrence when treated with 100 J/cm2. Together our results demonstrate the complementary imaging and treatment capacity of DFAC. This potentially enables fluorescence imaging to assess tumor presence on a macroscopic scale followed by photoacoustic imaging for delineating tumor margins guiding surgical resection and elimination of any residual microscopic disease by PIT, in a single intra-operative setting.

cancer biology↗

bioRxiv2022

Sparse-spectral microendoscopy for real-time visualization of tumor cell phenotype and microenvironment spatial heterogeneity in vivo

Cancer heterogeneity and its transformation with time propels treatment resistance and confounds patient outcomes. The inability to monitor in vivo the low abundance, heterocellular phenotypes that resist treatment and ultimately lead to patient death limits the ability to design precision therapies. Here we overcome limitations in multiplexed fluorescence phenotyping to introduce real-time, cellular resolution visualization of tumor heterogeneity in vivo. This method was performed to simultaneously map for the first time 5 individual biomarkers of stemness, proliferation, metabolism, leukocytes and angiogenesis deep within the peritoneal cavities of micrometastatic cancer mouse models at 17 frames per second (fps). The newly developed imaging system revealed distinct cancer cell phenotype-immune cell spatial correlations and clearly visualized the dynamic spatial response of resistant cancer cell niches following treatment. Furthermore, wide-field datasets were generated to facilitate derivation of a mathematical framework for quantifying biomarker spatial variation and thereby overcoming the area restrictions of conventional tumor biopsy. These results pave the way for real-time identification of cancer cell phenotypes in a clinical setting, on which optimized treatment regimens can be based for personalized treatment and precision therapy e.g., tumor margin determination during surgical resection. Additionally, this modality can be used to obtain more fundamental insights into tumor heterogeneity and how treatments affect the molecular and cellular responses of patient-specific disease.

bioengineering↗

bioRxiv2022

Pulsed transistor operation enables miniaturization of electrochemical aptamer based sensors

By simultaneously transducing and amplifying, transistors offer advantages over simpler, electrode-based transducers in electrochemical biosensors. However, transistor-based biosensors typically use static (i.e., DC) operation modes that are poorly suited for sensor architectures relying on the modulation of charge transfer kinetics to signal analyte binding. Thus motivated, here we translate the AC "pulsed potential" approach typically used with electrochemical aptamer-based sensor to an organic electrochemical transistor (OECT). Specifically, by applying a linearly sweeping square-wave potential to an aptamer-functionalized gate electrode, we produce current modulation across the transistor channel two orders of magnitude larger than seen for the equivalent, electrode-based biosensor. Critically, the resulting amplification is scalable, such that there is no signal loss with OECT miniaturization. The pulsed transistor operation demonstrated here could be applied generally to sensors relying on kinetics-based signaling, expanding opportunities for non-invasive and high spatial resolution biosensing.

bioengineering↗

bioRxiv2021

Photoimmunotherapy retains its anti-tumor efficacy with increasing stromal content in heterotypic pancreatic cancer spheroids

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease characterized by increased levels of desmoplasia that contributes to reduced drug delivery and poor treatment outcomes. In PDAC, the stromal content can account for up to 90% of the total tumor volume. The complex interplay between stromal components, including pancreatic cancer associated fibroblasts (PCAFs), and PDAC cells in the tumor microenvironment (TME) have a significant impact on prognoses and thus needs to be recapitulated in vitro when evaluating various treatment strategies. This study is a systematic evaluation of photodynamic therapy (PDT) in 3D heterotypic coculture models of PDAC with varying ratios of patient derived PCAFs that simulate heterogenous PDAC tumors with increasing stromal content. The efficacy of antibody-targeted PDT (photoimmunotherapy; PIT) using cetuximab photoimmunoconjugates (PICs) of benzoporphyrin derivative (BPD) is contrasted with that of liposomal BPD (Visudyne(R)), which is currently in PDT clinical trials for PDAC. We demonstrate that both Visudyne(R)-PDT and PIT were effective in heterotypic PDAC 3D spheroids with a low stromal content. However, as the stromal content increases above 50% in the 3D spheroids, the efficacy of Visudyne(R)-PDT is reduced by up to 10-fold, while PIT retains its efficacy. PIT was found to be 10-fold, 19-fold and 14-fold more phototoxic in spheroids with 50%, 75% and 90% PCAFs, respectively, as compared to Visudyne(R)-PDT. This marked difference in efficacy is attributed to the ability of PICs to penetrate and distribute within spheroids with a higher stromal content, whereas Visudyne(R) is restricted to the spheroid periphery. This study thus demonstrates how the stromal content in PDAC spheroids directly impacts their responsiveness to PDT and proposes PIT to be a highly suited treatment option for desmoplastic tumors with particularly high degrees of stromal content.

cancer biology↗

bioRxiv2018

Interleukin-8/CXCR2 signaling regulates therapy-induced plasticity and enhances tumorigenicity in glioblastoma

Glioblastoma (GBM) remains one of the least treatable types of cancer. Recent work highlights two key factors contributing to this resistant phenotype--cellular plasticity, the ability of GBM cells to adopt many phenotypes, and the microenvironment. Here, we provide evidence that Interleukin-8 (IL-8) plays a vital role in promoting cellular plasticity and cancer initiating cells (CICs) niche during anti-glioma chemotherapy. IL-8 expression is significantly elevated during chemotherapy, and immunohistochemical analysis of matched primary and recurrent patient GBM tissues revealed about 60% of recurrent tissues IL-8 expression is upregulated. In silico analysis of the TCGA data indicated that IL-8 signaling could promote epigenetic plasticity by altering the polycomb repressor complex activity. We are proposing that such regulation my promote epigenetic plasticity, which allows the GBM cells to adapt therapy and may promote therapeutic resistance. Our data show that IL-8 is a crucial microenvironmental factor involved in developing therapeutic adaptation and can be targeted in combination with conventional chemo-and radiotherapy to prevent disease recurrence.\n\nABSTRACTEmerging evidence reveals enrichment of glioma initiating cells (GICs) following therapeutic intervention. This enrichment occurs partly by dedifferentiation of non-GICs to GICs within the tumor, which may contribute to therapeutic resistance and the generation of lethal recurrent tumors. To elucidate the molecular mechanisms governing therapy-induced cellular plasticity, we performed genome-wide chromatin immunoprecipitation sequencing (ChIP-Seq) and gene expression analysis (gene microarray analysis) during treatment with standard of care temozolomide (TMZ) chemotherapy. Analysis revealed significant enhancement of open chromatin marks in known astrocytic enhancers for Interleukin-8 (IL-8) loci as well as elevated expression during anti-glioma chemotherapy. The Cancer Genome Atlas and Ivy Glioblastoma Atlas Project data demonstrated that IL-8 transcript expression is negatively correlated with GBM patient survival (p=0.001) and positively correlated with that of genes associated with the CIC phenotype such as KLF4, c-Myc and HIF2 (p<0.001). Immunohistochemical analysis of patient samples demonstrated elevated IL-8 expression in about 60% of recurrent GBM tumors relative to matched primary tumors and this expression also positively correlates with time to recurrence. Exposure to IL-8 significantly enhanced the self-renewing capacity of patient-derived xenograft (PDX) GBM (average 3-fold, p<0.0005). Furthermore, IL-8 knockdown significantly delayed PDX GBM tumor growth in vivo (p<0.0005). Finally, guided by in silico analysis of TCGA data, we examined the effect of therapy-induced IL-8 expression on the epigenomic landscape of GBM cells and observed increased trimethylation of H3K9 and H3K27. Our results show that IL-8 alters cellular plasticity and mediates alterations in histone status. These finding suggest that IL-8 signaling participates in regulating GBM adaptation to therapeutic stress and therefore represents a promising target for combination with conventional chemotherapy in order to limit GBM recurrence.

cancer biology↗