Ways to Enhance Lymphocyte Trafficking into Tumors and Fitness of Tumor Infiltrating Lymphocytes

The tumor is a hostile microenvironment for T lymphocytes. Indeed, irregular blood flow, and endothelial cell (EC) anergy that characterize most solid tumors hamper leukocyte adhesion, extravasation, and infiltration. In addition, hypoxia and reprograming of energy metabolism within cancer cells transform the tumor mass in a harsh environment that limits survival and effector functions of T cells, regardless of being induced in vivo by vaccination or adoptively transferred. In this review, we will summarize on recent advances in our understanding of the characteristics of tumor-associated neo-angiogenic vessels as well as of the tumor metabolism that may impact on T cell trafficking and fitness of tumor infiltrating lymphocytes. In particular, we will focus on how advances in knowledge of the characteristics of tumor ECs have enabled identifying strategies to normalize the tumor-vasculature and/or overcome EC anergy, thus increasing leukocyte-vessel wall interactions and lymphocyte infiltration in tumors. We will also focus on drugs acting on cells and their released molecules to transiently render the tumor microenvironment more suitable for tumor infiltrating T lymphocytes, thus increasing the therapeutic effectiveness of both active and adoptive immunotherapies

Nanomedicine-driven molecular targeting, drug delivery, and therapeutic approaches to cancer chemoresistance

Cancer cell resistance to chemotherapeutics (chemoresistance) poses a significant clinical challenge that oncology research seeks to understand and overcome. Multiple anticancer drugs and targeting agents can be incorporated in nanomedicines, in addition to different treatment modalities, forming a single nanoplatform that can be used to address tumor chemoresistance. Nanomedicine-driven molecular assemblies using nucleic acids, small interfering (si)RNAs, miRNAs, and aptamers in combination with stimuli-responsive therapy improve the pharmacokinetic (PK) profile of the drugs and enhance their accumulation in tumors and, thus, therapeutic outcomes. In this review, we highlight nanomedicine-driven molecular targeting and therapy combination used to improve the 3Rs (right place, right time, and right dose) for chemoresistant tumor therapies

Enhancing the efficacy of near-infrared photoimmunotherapy through intratumoural delivery of CD44–targeting antibody–photoabsorber conjugates

Adachi Y., Miyake K., Ohira K., et al. Enhancing the efficacy of near-infrared photoimmunotherapy through intratumoural delivery of CD44–targeting antibody–photoabsorber conjugates. eBioMedicine 112, 105566 (2025); https://doi.org/10.1016/j.ebiom.2025.105566.Background: Photoimmunotherapy (PIT) is a potent modality for cancer treatment. The conventional PIT regimen involves the systemic delivery of an antibody–photoabsorber conjugate, followed by a 24-h waiting period to ensure adequate localisation on the target cells. Subsequent exposure to near-infrared (NIR) light selectively damages the target cells. We aimed to improve the efficacy of PIT in vivo by evaluating the effects of the different routes of conjugate administration on treatment outcomes. Methods: Subcutaneous Lewis lung carcinoma tumours were established in mice, targeting cluster of differentiation (CD)44 with an anti-CD44 antibody conjugated to IRDye700DX (IR700). The conjugate was administered via the intravenous or intratumoural route followed by the assessment of antibody binding and therapeutic effects of PIT. Findings: Compared to intravenous administration, intratumoural delivery of the CD44-IR700 conjugate significantly increased the number of cells binding to the conjugate by >five-fold. This method, combined with NIR light irradiation, halved tumour growth when compared to intravenous delivery. Reducing the interval between intratumoural injection and NIR light exposure to 30 min did not diminish efficacy, thereby demonstrating the feasibility of a 1-h procedure. Interpretation: Intratumoural administration of the antibody–photoabsorber conjugate enhanced the efficacy of PIT in vivo. A simplified, 1-h procedure involving conjugate tumour injection followed by irradiation emerged as a potent cancer treatment strategy. Funding: This study was supported by theJapan Society for the Promotion of Science, theJapan Agency for Medical Research and Development,Japan Science and Technology Agency, and theOsaka Medical Research Foundation for Intractable Diseases

Development of Targeted Alpha Particle Therapy for Solid Tumors

Abstract: Targeted alpha-particle therapy (TAT) aims to selectively deliver radionuclides emitting α-particles (cytotoxic payload) to tumors by chelation to monoclonal antibodies, peptides or small molecules that recognize tumor-associated antigens or cell-surface receptors. Because of the high linear energy transfer (LET) and short range of alpha (α) particles in tissue, cancer cells can be significantly damaged while causing minimal toxicity to surrounding healthy cells. Recent clinical studies have demonstrated the remarkable efficacy of TAT in the treatment of metastatic, castration-resistant prostate cancer. In this comprehensive review, we discuss the current consensus regarding the properties of the α-particle-emitting radionuclides that are potentially relevant for use in the clinic; the TAT-mediated mechanisms responsible for cell death; the different classes of targeting moieties and radiometal chelators available for TAT development; current approaches to calculating radiation dosimetry for TATs; and lead optimization via medicinal chemistry to improve the TAT radiopharmaceutical properties. We have also summarized the use of TATs in pre-clinical and clinical studies to dat

THE ROLE OF TUMOR DESMOPLASIA IN NANOPARTICLE DELIVERY OF DRUGS AND GENES

In desmoplastic tumors, stroma cells capture nanoparticles (NPs), preventing them from reaching tumor cells, resulting in compromised anti-tumor efficacy. This dissertation focuses on understanding the basis role of tumor associated fibroblasts (TAFs), one of the major stroma cells constituting desmoplasia, in NP delivery and tumor resistance, as well as proposing strategies to overcome the TAF-elicited barriers and improve efficacy. While the capture of therapeutic NPs in TAFs interferes tumor-stroma crosstalk and inhibits tumor progression, we found that the chronic exposure of NPs paradoxically induced the secretion of survival factors (e.g., Wnt16) from the damaged TAFs, facilitating tumor proliferation and metastasis. Therefore, we proposed the delivery of siRNA against Wnt16 to TAFs via the off-target capture, to downregulate this survival factor. The priming of damaged fibroblasts could synergize with a nanoformulation of cisplatin, and benefit the treatment of a desmoplastic bladder cancer xenograft (UMUC3/3T3). Since the off-target delivery of NPs have been verified, we further utilized the same rationale to generate a group of tumor-suppressive TAFs through transfecting TAFs with a plasmid encoding highly secretable TNF-related apoptosis-inducing ligand (sTRAIL). The production of sTRAIL from TAFs bypassed the stroma barrier and resulted in efficient killing of tumor cells. Furthermore, we also proposed a stroma depletion method via combination therapy of cisplatin NPs and gemcitabine NPs. This combination was not only detrimental to tumor cells, but induced superior apoptosis in TAFs of the UMUC3/3T3 model. To ensure the sufficient synergy, we further designed a nano-formulation with ratiometric co-loading and co-delivery of these two regimens. The design of converting these two drugs with totally different physicochemical properties into nano-cores with similar hydrophobic surface and particle size, allows for their simultaneously and ratiometric loading in a single PLGA NPs. This combinatory NPs showed potent anti-cancer efficacy compared to each regimens in separate NPs. In summary, the stroma modulating strategies proposed in the current dissertation provide new paradigms for the treatment of desmoplastic tumors. Combined with cancer immunology, a more prolonged and efficient outcome can be anticipated. The ratiometric combination nano-platform also provides a promising approach for encapsulating agents with different physicochemical properties.Doctor of Philosoph

CAR T Cell Therapy of Non-hematopoietic Malignancies: Detours on the Road to Clinical Success

Chimeric antigen receptor (CAR)-engineered T cells represent a breakthrough in personalized medicine. In this strategy, a patient's own T lymphocytes are genetically reprogrammed to encode a synthetic receptor that binds a tumor antigen, allowing T cells to recognize and kill antigen-expressing cancer cells. As a result of complete and durable responses in individuals who are refractory to standard of care therapy, CAR T cells directed against the CD19 protein have been granted United States Food and Drug Administration (FDA) approval as a therapy for treatment of pediatric and young adult acute lymphoblastic leukemia and diffuse large B cell lymphoma. Human trials of CAR T cells targeting CD19 or B cell maturation antigen in multiple myeloma have also reported early successes. However, a clear and consistently reproducible demonstration of the clinical efficacy of CAR T cells in the setting of solid tumors has not been reported to date. Here, we review the history and status of CAR T cell therapy for solid tumors, potential T cell-intrinsic determinants of response and resistance as well as extrinsic obstacles to the success of this approach for much more prevalent non-hematopoietic malignancies. In addition, we summarize recent strategies and innovations that aim to augment the potency of CAR T cells in the face of multiple immunosuppressive barriers operative within the solid tumor microenvironment. Advances in the field of CAR T cell biology over the coming years in the areas of safety, reliability and efficacy against non-hematopoietic cancers will ultimately determine how transformative adoptive T cell therapy will be in the broader battle against cancer

Synthesis and functionalization of protease-activated nanoparticles with tissue plasminogen activator peptides as targeting moiety and diagnostic tool for pancreatic cancer

Background: Functionalized nanoparticles (NPs) are one promising tool for detecting specific molecular targets and combine molecular biology and nanotechnology aiming at modern imaging. We aimed at ligand-directed delivery with a suitable target-biomarker to detect early pancreatic ductal adenocarcinoma (PDAC). Promising targets are galectins (Gal), due to their strong expression in and on PDAC-cells and occurrence at early stages in cancer precursor lesions, but not in adjacent normal tissues. Results: Molecular probes (10-29 AA long peptides) derived from human tissue plasminogen activator (t-PA) were selected as binding partners to galectins. Affinity constants between the synthesized t-PA peptides and Gal were determined by microscale thermophoresis. The 29 AA-long t-PA-peptide-1 with a lactose-functionalized serine revealed the strongest binding properties to Gal-1 which was 25-fold higher in comparison with the native t-PA protein and showed additional strong binding to Gal-3 and Gal-4, both also over-expressed in PDAC. t-PA-peptide-1 was selected as vector moiety and linked covalently onto the surface of biodegradable iron oxide nanoparticles (NPs). In particular, CAN-doped maghemite NPs (CAN-Mag), promising as contrast agent for magnetic resonance imaging (MRI), were selected as magnetic core and coated with different biocompatible polymers, such as chitosan (CAN-Mag-Chitosan NPs) or polylactic co glycolic acid (PLGA) obtaining polymeric nanoparticles (CAN-Mag@PNPs), already approved for drug delivery applications. The binding efficacy of t-PA-vectorized NPs determined by exposure to different pancreatic cell lines was up to 90%, as assessed by flow cytometry. The in vivo targeting and imaging efficacy of the vectorized NPs were evaluated by applying murine pancreatic tumor models and assessed by 1.5 T magnetic resonance imaging (MRI). The t-PA-vectorized NPs as well as the protease-activated NPs with outer shell decoration (CAN-Mag@PNPs-PEG-REGAcp-PEG/tPA-pep1Lac) showed clearly detectable drop of subcutaneous and orthotopic tumor staining-intensity indicating a considerable uptake of the injected NPs. Post mortem NP deposition in tumors and organs was confirmed by Fe staining of histopathology tissue sections. Conclusions: The targeted NPs indicate a fast and enhanced deposition of NPs in the murine tumor models. The CAN-Mag@PNPs-PEG-REGAcp-PEG/tPA-pep1Lac interlocking steps strategy of NPs delivery and deposition in pancreatic tumor is promising