Aptamer-mediated doxorubicin delivery reduces HCC burden in 3D organoids model

A cutting-edge solution to a Gordian knot? Aptamers targeting cancer stem cell markers for strategic cancer therapy

Cancer stem cells (CSCs) are key drivers of tumor proliferation and serve as a basis for therapeutic resistance, metastasis, and recurrence. The erratic efficacy of conventional therapeutic approaches is limited because of their inability to exterminate CSCs. This has spurred the development of novel cancer treatment paradigms that target specifically these cells. Importantly, CSCs are identified and classified based on the differential expression of biomarkers, facilitating their precise isolation and tailored therapeutic interventions. Numerous promising approaches have been developed to target CSC markers, paving the way to precision medicine in cancer treatment. Aptamers are molecularly targeting agents comprising single-strand oligonucleotides arranged in a unique fashion that allows them to bind their targets, including cancer biomarkers, with high specificity and affinity. Given their programmable nature, they can be chemically modified and integrated with various diagnostic components, including nanoparticles (NPs), drugs, and therapeutic RNAs, thereby enhancing their applicability in disease treatment. In this review, we shed light on various aptamer designs that show potential to target putative CSC markers and to efficiently deliver therapeutic moieties.

Biological roles and clinical applications of EpCAM in HCC

Epithelial cell adhesion molecule (EpCAM) is an important biomarker in tumors. In hepatocellular carcinoma (HCC), EpCAM + cells exhibit high invasiveness, tumorigenic ability, therapeutic resistance, and self-renewal ability, often identified as liver cancer stem cells (CSCs). Detecting EpCAM + cells in tumor lesions and circulation is valuable for predicting patient prognosis and monitoring therapeutic outcomes, emphasizing its clinical significance. Given its broad expression in HCC, especially in CSCs and circulating tumor cells (CTCs), EpCAM-targeting agents have garnered substantial research interest. However, the role of EpCAM in HCC progression and its regulatory mechanisms remains poorly understood. Furthermore, clinical applications of EpCAM, such as liquid biopsy and targeted therapies, are still controversial. This review summarizes the biological properties of EpCAM + HCC cells, explores the regulatory mechanisms governing EpCAM expression, and discusses its clinical significance of using EpCAM as a prognostic marker and therapeutic target.

State-of-the-Art Liver Cancer Organoids: Modeling Cancer Stem Cell Heterogeneity for Personalized Treatment

Liver cancer poses a global health challenge with limited therapeutic options. Notably, the limited success of current therapies in patients with primary liver cancers (PLCs) may be attributed to the high heterogeneity of both hepatocellular carcinoma (HCCs) and intrahepatic cholangiocarcinoma (iCCAs). This heterogeneity evolves over time as tumor-initiating stem cells, or cancer stem cells (CSCs), undergo (epi)genetic alterations or encounter microenvironmental changes within the tumor microenvironment. These modifications enable CSCs to exhibit plasticity, differentiating into various resistant tumor cell types. Addressing this challenge requires urgent efforts to develop personalized treatments guided by biomarkers, with a specific focus on targeting CSCs. The lack of effective precision treatments for PLCs is partly due to the scarcity of ex vivo preclinical models that accurately capture the complexity of CSC-related tumors and can predict therapeutic responses. Fortunately, recent advancements in the establishment of patient-derived liver cancer cell lines and organoids have opened new avenues for precision medicine research. Notably, patient-derived organoid (PDO) cultures have demonstrated self-assembly and self-renewal capabilities, retaining essential characteristics of their respective in vivo tissues, including both inter- and intratumoral heterogeneities. The emergence of PDOs derived from PLCs serves as patient avatars, enabling preclinical investigations for patient stratification, screening of anticancer drugs, efficacy testing, and thereby advancing the field of precision medicine. This review offers a comprehensive summary of the advancements in constructing PLC-derived PDO models. Emphasis is placed on the role of CSCs, which not only contribute significantly to the establishment of PDO cultures but also faithfully capture tumor heterogeneity and the ensuing development of therapy resistance. The exploration of PDOs' benefits in personalized medicine research is undertaken, including a discussion of their limitations, particularly in terms of culture conditions, reproducibility, and scalability.

Current landscape of mRNA technologies and delivery systems for new modality therapeutics

Realizing the immense clinical potential of mRNA-based drugs will require continued development of methods to safely deliver the bioactive agents with high efficiency and without triggering side effects. In this regard, lipid nanoparticles have been successfully utilized to improve mRNA delivery and protect the cargo from extracellular degradation. Encapsulation in lipid nanoparticles was an essential factor in the successful clinical application of mRNA vaccines, which conclusively demonstrated the technology's potential to yield approved medicines. In this review, we begin by describing current advances in mRNA modifications, design of novel lipids and development of lipid nanoparticle components for mRNA-based drugs. Then, we summarize key points pertaining to preclinical and clinical development of mRNA therapeutics. Finally, we cover topics related to targeted delivery systems, including endosomal escape and targeting of immune cells, tumors and organs for use with mRNA vaccines and new treatment modalities for human diseases.

Organoid as a promising tool for primary liver cancer research: a comprehensive review

Primary liver cancer (PLC) is one of the most common malignant gastrointestinal tumors worldwide. Limited by the shortage of liver transplantation donors and the heterogeneity of tumors, patients with liver cancer lack effective treatment options, which leads to rapid progression and metastasis. Currently, preclinical models of PLC fall short of clinical reality and are limited in their response to disease progression and the effectiveness of drug therapy. Organoids are in vitro three-dimensional cultured preclinical models with a high degree of heterogeneity that preserve the histomorphological and genomic features of primary tumors. Liver cancer organoids have been widely used for drug screening, new target discovery, and precision medicine; thus representing a promising tool to study PLC. Here, we summarize the progress of research on liver cancer organoids and their potential application as disease models. This review provides a comprehensive introduction to this emerging technology and offers new ideas for researchers to explore in the field of precision medicine.

Cell-SELEX and application research of a DNA aptamer against esophageal squamous cell carcinoma (ESCC) cell line TE-1

Esophageal cancer is a common cancer with high morbidity and mortality that severely threatens the safety and quality of human life. The strong metastatic nature of esophageal cancer enables it to metastasize more quickly and covertly, making it difficult for current diagnostic and treatment methods to achieve efficient early screening, as well as timely and effective treatment. As a promising solution, nucleic acid aptamers, a kind of special single-stranded DNA or RNA oligonucleotide selected by the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technology, can specifically bind with different molecular targets. In this paper, random DNA single-stranded oligonucleotides were used as the initial library. Using TE-1 cells and HEEC cells as targets, specific binding sequences were selected by 15 rounds of the cell-SELEX method, and the aptamer sequence that binds to TE-1 cells with the most specificity was obtained and named Te4. The Te4 aptamer was further validated for binding specificity, binding affinity, type of target, in vitro cytotoxicity when conjugated with DOX(Te4-DOX), and in vivo distribution. Results of in vitro validation showed that Te4 has outstanding binding specificity with a Kd value of 51.16 ± 5.52 nM, and the target type of Te4 was preliminarily identified as a membrane protein. Furthermore, the cytotoxicity experiment showed that Te4-DOX has specific cytotoxicity towards cultured TE-1 cells. Finally, the results of the in vivo distribution experiment showed that the Te4 aptamer is able to specifically target tumor regions in nude mice, showing great potential to be applied in future diagnosis and targeted therapy of esophageal cancer.

Targeted silencing of SOCS1 by DNMT1 promotes stemness of human liver cancer stem-like cells

BACKGROUND

Human liver cancer stem-like cells (HLCSLCs) are widely acknowledged as significant factors in the recurrence and eradication of hepatocellular carcinoma (HCC). The sustenance of HLCSLCs' stemness is hypothesized to be intricately linked to the epigenetic process of DNA methylation modification of genes associated with anticancer properties. The present study aimed to elucidate the stemness-maintaining mechanism of HLCSLCs and provide a novel idea for the clearance of HLCSLCs.

METHODS

The clinical relevance of DNMT1 and SOCS1 in hepatocellular carcinoma (HCC) patients was evaluated through the GEO and TCGA databases. Cellular immunofluorescence assay, methylation-specific PCR, chromatin immunoprecipitation were conducted to explore the expression of DNMT1 and SOCS1 and the regulatory relationship between them in HLCSLCs. Spheroid formation, soft agar colony formation, expression of stemness-associated molecules, and tumorigenicity of xenograft in nude mice were used to evaluate the stemness of HLCSLCs.

RESULTS

The current analysis revealed a significant upregulation of DNMT1 and downregulation of SOCS1 in HCC tumor tissues compared to adjacent normal liver tissues. Furthermore, patients exhibiting an elevated DNMT1 expression or a reduced SOCS1 expression had low survival. This study illustrated the pronounced expression and activity of DNMT1 in HLCSLCs, which effectively targeted the promoter region of SOCS1 and induced hypermethylation, consequently suppressing the expression of SOCS1. Notably, the stemness of HLCSLCs was reduced upon treatment with DNMT1 inhibitors in a concentration-dependent manner. Additionally, the overexpression of SOCS1 in HLCSLCs significantly mitigated their stemness. The knockdown of SOCS1 expression reversed the effect of DNMT1 inhibitor on the stemness of HLCSLCs. DNMT1 directly binds to the SOCS1 promoter. In vivo, DNMT1 inhibitors suppressed SOCS1 expression and inhibited the growth of xenograft.

CONCLUSION

DNMT1 targets the promoter region of SOCS1, induces hypermethylation of its CpG islands, and silences its expression, thereby promoting the stemness of HLCSLCs.

Development of an efficient liposomal DOX delivery formulation for HCC therapy by targeting CK2α

Hepatocellular carcinoma (HCC) is a digestive tract cancer with high mortality and poor prognosis, especially in China. Current chemotherapeutic drugs lead to poor prognosis, low efficacy, and high side effects due to weak targeting specificity and rapidly formed multidrug resistance (MDR). Based on the previous studies on the doxorubicin (DOX) formulation for cancer targeting therapy, we developed a novel DOX delivery formulation for the targeting chemotherapy of HCC and DOX resistant HCC. HCSP4 was previously screened and casein kinase 2α (CK2α) was predicted as its specific target on HCC cells in our lab. In the study, miR125a-5p was firstly predicted as an MDR inhibiting miRNA, and then CK2α was validated as the target of HCSP4 and miR125a-5p using CK2α-/-HepG2 cells. Based on the above, an HCC targeting and MDR inhibiting DOX delivery liposomal formulation, HCSP4/Lipo-DOX/miR125a-5p was synthesized and tested for its HCC therapeutic efficacy in vitro. The results showed that the liposomal DOX delivery formulation targeted to HCC cells specifically and sensitively, and presented the satisfied therapeutic efficacy for HCC, particularly for DOX resistant HCC. The potential therapeutic mechanism of the DOX delivery formulation was explored, and the formulation inhibited the expression of MDR-relevant genes including ATP-binding cassette subfamily B member 1 (ABCB1, also known as P-glycoprotein), ATP-binding cassette subfamily C member 5 (ABCC5), enhancer of zeste homolog 2 (EZH2), and ATPase Na+/K+ transporting subunit beta 1 (ATP1B1). Our study presents a novel targeting chemotherapeutic drug formulation for the therapy of HCC, especially for drug resistant HCC, although it is primarily and needs further study in vivo, but provided a new strategy for the development of novel anticancer drugs.

Recent advances in aptamer-based therapeutic strategies for targeting cancer stem cells

Cancer stem cells (CSCs) are believed to be the main cause of chemotherapy resistance and tumor relapse. Various therapeutic strategies to eliminate CSCs have been developed recently. Aptamers, also called "chemical antibodies", can specifically bind with their molecular targets through special tertiary structures. The advantages of aptamers, such as lower immunogenicity and smaller size, make them superior to conventional antibodies. Therefore, aptamers have been used widely as targeting ligands for CSC-targeted therapeutic strategies in different tumor types. To date, various therapeutic cargoes have been conjugated to aptamers to kill CSCs, such as chemotherapy drugs, small interfering RNAs, and microRNAs. Aptamer-based targeted therapies for CSCs have made great progress in recent years, especially the development of multifunctional aptamer-based therapeutic strategies. Besides, cell-systematic evolution of ligands by exponential enrichment has been applied to screen new aptamers that might have a higher binding ability for CSCs. In this review, we focus on recent advances and introduce some new modalities of aptamer-drug conjugates against CSCs. Some considerations of the advantages and limitations of different aptamer-based targeted therapies for CSCs are also discussed.