FAP-retargeted Ad5 enables in vivo gene delivery to stromal cells in the tumor microenvironment

Machine learning explores the prognostic and immuno-oncological impact of mitochondrial unfolded protein response in CESC

BACKGROUND

Cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) pose significant global health challenges. While the mitochondrial unfolded protein response (UPRmt) is known to influence cancer biology, its specific role in CESC remains unclear.

METHODS

We employed machine learning to analyze UPRmt genes in CESC using TCGA multi-omics data. Our comprehensive analysis included genetic alterations, prognostic significance, tumor-immune interactions, single-cell transcriptomics, pathway enrichment, and drug sensitivity assessments.

RESULTS

ATF5 emerged as the most significant prognostic factor among UPRmt genes, with high expression correlating with better overall survival. High ATF5 expression was associated with an immunologically active tumor microenvironment, characterized by enhanced immune cell infiltration, increased immune checkpoint expression, and higher tumor mutational burden. Single-cell RNA sequencing revealed ATF5's distinct expression patterns in stromal cells, particularly in endometrial stromal and smooth muscle cells. Gene set enrichment analysis provided mechanistic insight, revealing ATF5's connection to the immune response via the regulation of P-stalk ribosome functions, a finding that underscores a novel aspect of UPRmt's role in shaping the tumor immune landscape. Drug sensitivity analysis showed that low ATF5 expression correlated with resistance to conventional chemotherapeutics (cisplatin, paclitaxel, and etoposide) but increased sensitivity to imatinib, potentially through EP300-dependent mechanisms.

CONCLUSIONS

Our findings establish ATF5 as both a favorable prognostic marker and a key immune response regulator in CESC. Its influence on the tumor microenvironment and treatment response suggests potential therapeutic applications. These insights into UPRmt's role in CESC provide new directions for developing personalized treatment strategies.

αFAP-specific nanobodies mediate a highly precise retargeting of modified AAV2 capsids thereby enabling specific transduction of tumor tissues

Due to the refractiveness of tumor tissues to adeno-associated virus (AAV) transduction, AAV vectors are poorly explored for cancer therapy delivery. Here, we aimed to engineer AAVs to target tumors by enabling the specific engagement of fibroblast activation protein (FAP). FAP is a cell surface receptor distinctly upregulated in the reactive tumor stroma, but rarely expressed in healthy tissues. Thus, targeting FAP presents an opportunity to selectively transduce tumor tissues. To achieve this, we modified the capsid surface of AAV2 with an αFAP nanobody to retarget the capsid to engage FAP receptor. Following transduction, we observed a 23- to 80-fold increase in the selective transduction of FAP+ tumor cells in vitro, and greater than 5-fold transduction of FAP+ tumor tissues in vivo. Subsequent optimization of the VP1-nanobody expression cassette further enhanced the transduction efficiency of the modified capsids. Due to the limited αFAP nanobodies repertoires, we broadened the versatility of this high-fidelity platform by screening a naive VHH yeast display library, leading to the identification of several novel αFAP nanobody candidates (KD = 0.1 to >100 nM). Hence, our study offers new opportunity for the application of AAV vectors for highly selective delivery of therapeutics to the tumor stroma.

DARPin-fused T cell engager for adenovirus-mediated cancer therapy

Bispecific T cell engagers are a promising class of therapeutic proteins for cancer therapy. Their potency and small size often come with systemic toxicity and short half-life, making intravenous administration cumbersome. These limitations can be overcome by tumor-specific in situ expression, allowing high local accumulation while reducing systemic concentrations. However, encoding T cell engagers in viral or non-viral vectors and expressing them in situ ablates all forms of quality control performed during recombinant protein production. It is therefore vital to design constructs that feature minimal domain mispairing, and increased homogeneity of the therapeutic product. Here, we report a T cell engager architecture specifically designed for vector-mediated immunotherapy. It is based on a fusion of a designed ankyrin repeat protein (DARPin) to a CD3-targeting single-chain antibody fragment, termed DATE (DARPin-fused T cell Engager). The DATE induces potent T cell-mediated killing of HER2+ cancer cells, both as recombinantly produced therapeutic protein and as in situ expressed payload from a HER2+-retargeted high-capacity adenoviral vector (HC-AdV). We report remarkable tumor remission, DATE accumulation, and T cell infiltration through in situ expression mediated by a HER2+-retargeted HC-AdV in vivo. Our results support further investigations and developments of DATEs as payloads for vector-mediated immunotherapy.

Novel Drug Delivery Systems: An Important Direction for Drug Innovation Research and Development

The escalating demand for enhanced therapeutic efficacy and reduced adverse effects in the pharmaceutical domain has catalyzed a new frontier of innovation and research in the field of pharmacy: novel drug delivery systems. These systems are designed to address the limitations of conventional drug administration, such as abbreviated half-life, inadequate targeting, low solubility, and bioavailability. As the disciplines of pharmacy, materials science, and biomedicine continue to advance and converge, the development of efficient and safe drug delivery systems, including biopharmaceutical formulations, has garnered significant attention both domestically and internationally. This article presents an overview of the latest advancements in drug delivery systems, categorized into four primary areas: carrier-based and coupling-based targeted drug delivery systems, intelligent drug delivery systems, and drug delivery devices, based on their main objectives and methodologies. Additionally, it critically analyzes the technological bottlenecks, current research challenges, and future trends in the application of novel drug delivery systems.

Harnessing adenovirus in cancer immunotherapy: evoking cellular immunity and targeting delivery in cell-specific manner

Recombinant adenovirus (rAd) regimens, including replication-competent oncolytic adenovirus (OAV) and replication-deficient adenovirus, have been identified as potential cancer therapeutics. OAV presents advantages such as selective replication, oncolytic efficacy, and tumor microenvironment (TME) remodeling. In this perspective, the principles and advancements in developing OAV toolkits are reviewed. The burgeoning rAd may dictate efficacy of conventional cancer therapies as well as cancer immunotherapies, including cancer vaccines, synergy with adoptive cell therapy (ACT), and TME reshaping. Concurrently, we explored the potential of rAd hitchhiking to adoptive immune cells or stem cells, highlighting how this approach facilitates synergistic interactions between rAd and cellular therapeutics at tumor sites. Results from preclinical and clinical trials in which immune and stem cells were infected with rAd have been used to address significant oncological challenges, such as postsurgical residual tumor tissue and metastatic tissue. Briefly, rAd can eradicate tumors through various mechanisms, resulting from tumor immunogenicity, reprogramming of the TME, enhancement of cellular immunity, and effective tumor targeting. In this context, we argue that rAd holds immense potential for enhancing cellular immunity and synergistically improving antitumor effects in combination with novel cancer immunotherapies.