Detection of ALDH1 activity in rabbit hepatic VX2 tumors and isolation of ALDH1 positive cancer stem cells

Integrating single-cell and bulk RNA sequencing reveals CK19 + cancer stem cells and their specific SPP1 + tumor-associated macrophage niche in HBV-related hepatocellular carcinoma

PURPOSE

Cytokeratin 19-positive cancer stem cells (CK19 + CSCs) and their tumor-associated macrophages (TAMs) have not been fully explored yet in the hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).

EXPERIMENTAL DESIGN

Single-cell RNA sequencing was performed on the viable cells obtained from 11 treatment-naïve HBV-associated HCC patients, including 8 CK19 + patients, to elucidate their transcriptomic landscape, CK19 + CSC heterogeneity, and immune microenvironment. Two in-house primary HCC cohorts (96 cases-related HBV and 89 cases with recurrence), TCGA external cohort, and in vitro and in vivo experiments were used to validate the results.

RESULTS

A total of 64,581 single cells derived from the human HCC and adjacent normal tissues were sequenced, and 11 cell types were identified. The result showed that CK19 + CSCs were phenotypically and transcriptionally heterogeneous, co-expressed multiple hepatics CSC markers, and were positively correlated with worse prognosis. Moreover, the SPP1 + TAMs (TAM_SPP1) with strong M2-like features and worse prognosis were specifically enriched in the CK19 + HCC and promoted tumor invasion and metastasis by activating angiogenesis. Importantly, matrix metalloproteinase 9 (MMP9) derived from TAM_SPP1, as the hub gene of CK19 + HCC, was activated by the VEGFA signal.

CONCLUSIONS

This study revealed the heterogeneity and stemness characteristics of CK19 + CSCs and specific immunosuppressive TAM_SPP1 in CK19 + HCC. The VEGFA signal can activate TAM_SPP1-derived MMP9 to promote the invasion and metastasis of CK19 + HCC tumors. This might provide novel insights into the clinical treatment of HCC patients.

Rabbit VX2 Liver Tumor Model: A Review of Clinical, Biology, Histology, and Tumor Microenvironment Characteristics

The rabbit VX2 is a large animal model of cancer used for decades by interventional radiologists to demonstrate the efficacy of various locoregional treatments against liver tumors. What do we know about this tumor in the new era of targeted therapy and immune-oncology? The present paper describes the current knowledge on the clinics, biology, histopathology, and tumor microenvironment of VX2 based on a literature review of 741 publications in the liver and in other organs. It reveals the resemblance with human cancer (anatomy, vascularity, angiogenic profile, drug sensitivity, immune microenvironment), the differences (etiology, growth rate, histology), and the questions still poorly explored (serum and tissue biomarkers, genomic alterations, immune checkpoint inhibitors efficacy).

In situ Thermal-Responsive Magnetic Hydrogel for Multidisciplinary Therapy of Hepatocellular Carcinoma

Current surgical single modality treatments for hepatocellular carcinoma (HCC) were restricted by recurrence, blood loss, significant trauma, and poor prognostic. Although multidisciplinary strategies for HCC treatment have been highly recommended by the clinical guidelines, there was limited choice of materials and treatments. Herein, we reported an in situ formed magnetic hydrogel with promising bioapplicable thermal-responsiveness, strong adhesion in wet conditions, high magnetic hyperthermia, and biocompatibility, leading to efficient HCC multidisciplinary treatment including postoperative treatment and transarterial embolization therapy. In vivo results indicated that this hydrogel could reduce the postoperative recurrence rate. The hemostatic ability of the thermal-responsive hydrogel was further demonstrated in both the liver scratch model and liver tumor resection. Computed tomography imaging suggested that the hydrogel could completely embolize the arterial vessels of rabbit liver tumor by vascular intervention operation, which could serve as multidisciplinary responsive materials to external magnetic field and body temperature for HCC treatment.

High-Performance Poly(lactic-co-glycolic acid)-Magnetic Microspheres Prepared by Rotating Membrane Emulsification for Transcatheter Arterial Embolization and Magnetic Ablation in VX2 Liver Tumors

Interventional embolization is a popular minimally invasive vascular therapeutic technique and has been widely applied for hepatocellular carcinoma (HCC) therapy. However, harmful effects caused by transcatheter arterial chemoembolization (TACE) and radioembolization, such as the toxicity of chemotherapy or excessive radiation damage, are serious disadvantages and significantly reduce the therapeutic efficacy. Here, a synergistic therapeutic strategy combined transcatheter arterial embolization and magnetic ablation (TAEMA) by using poly(lactic-co-glycolic acid) (PLGA)-magnetic microspheres (MMs) has been successfully applied to orthotopic VX₂ liver tumors of rabbits. These MMs fabricated by novel rotating membrane emulsification system with well-controlled sizes (100-1000 μm) exhibited extremely low hemolysis ratio and excellent biocompatibility with HepG2 cells and L02 cells. Moreover, experimental results demonstrated that, while exposed to alternating magnetic field (AMF) after TAE, the tumor edge could be heated up by more than 15 °C both in vivo and in vitro, whereas only a negligible increase of temperature was observed in the normal hepatic parenchyma (NHP) nearby. Sufficient temperature increase induces apoptosis of tumor cells. This can further inhibit the tumor angiogenesis and results in necrosis compared to the rabbits only treated with TAE. In stark contrast, tumors rapidly grow and subtotal metastasis occurs in the lungs or kidneys, causing severe complications for rabbits only irradiated under AMF. Importantly, the results from the biochemical examination and the gene expression of relative HCC markers further confirmed that the treatment protocol using PLGA-MMs could achieve good biosafety and excellent therapeutic efficacy, which are promising for liver cancer therapy.