Dissecting spatial heterogeneity and the immune-evasion mechanism of CTCs by single-cell RNA-seq in hepatocellular carcinoma.

Little is known about the transcriptomic plasticity and adaptive mechanisms of circulating tumor cells (CTCs) during hematogeneous dissemination. Here we interrogate the transcriptome of 113 single CTCs from 4 different vascular sites, including hepatic vein (HV), peripheral artery (PA), peripheral vein (PV) and portal vein (PoV) using single-cell full-length RNA sequencing in hepatocellular carcinoma (HCC) patients. We reveal that the transcriptional dynamics of CTCs were associated with stress response, cell cycle and immune-evasion signaling during hematogeneous transportation. Besides, we identify chemokine CCL5 as an important mediator for CTC immune evasion. Mechanistically, overexpression of CCL5 in CTCs is transcriptionally regulated by p38-MAX signaling, which recruites regulatory T cells (Tregs) to facilitate immune escape and metastatic seeding of CTCs. Collectively, our results reveal a previously unappreciated spatial heterogeneity and an immune-escape mechanism of CTC, which may aid in designing new anti-metastasis therapeutic strategies in HCC.

Circulating tumor cell detection and single-cell analysis using an integrated workflow based on ChimeraX® -i120 Platform: A prospective study.

Circulating tumor cell (CTC) analysis holds great potential to be a noninvasive solution for clinical cancer management. A complete workflow that combined CTC detection and single-cell molecular analysis is required. We developed the ChimeraX® -i120 platform to facilitate negative enrichment, immunofluorescent labeling, and machine learning-based identification of CTCs. Analytical performances were evaluated, and a total of 477 participants were enrolled to validate the clinical feasibility of ChimeraX® -i120 CTC detection. We analyzed copy number alteration profiles of isolated single cells. The ChimeraX® -i120 platform had high sensitivity, accuracy, and reproducibility for CTC detection. In clinical samples, an average value of > 60% CTC-positive rate was found for five cancer types (i.e., liver, biliary duct, breast, colorectal, and lung), while CTCs were rarely identified in blood from healthy donors. In hepatocellular carcinoma patients treated with curative resection, CTC status was significantly associated with tumor characteristics, prognosis, and treatment response (all P < 0.05). Single-cell sequencing analysis revealed that heterogeneous genomic alteration patterns resided in different cells, patients, and cancers. Our results suggest that the use of this ChimeraX® -i120 platform and the integrated workflow has validity as a tool for CTC detection and downstream genomic profiling in the clinical setting.

Detection of circulating tumour cells enables early recurrence prediction in hepatocellular carcinoma patients undergoing liver transplantation.

BACKGROUND & AIMS: Liver transplantation (LTx) is one of the most effective treatments for hepatocellular carcinoma (HCC); however, tumour recurrence after LTx often leads to poor outcomes. This study investigated the value of circulating tumour cells (CTCs) as a predictor of recurrence following LTx in patients with HCC. METHODS: This analysis included 193 patients with HCC who underwent LTx at our institute and accepted pre- and post-operative CTC detection; 38 were selected for serial CTC monitoring. The predictive value of CTCs for tumour recurrence in patients with HCC following LTx was evaluated. Single-cell whole genome sequencing was used to characterize CTCs. RESULTS: Overall, the CTC burden decreased after LTx (P < .05). Post-operative CTC count ≥ 1 per 5 mL peripheral blood was identified as a potential biomarker for predicting tumour recurrence after LTx, especially in patients with no detectable CTCs prior to LTx and negative tumour serological biomarkers. The predictive value of post-operative CTC count ≥ 1 per 5 mL blood was retained in patients who did not meet the Milan criteria, University of California San Francisco (UCSF) criteria, or Fudan criteria (all P < .05). Furthermore, post-operative serial CTC detection may be useful in post-surgical surveillance for HCC recurrence. CONCLUSIONS: CTCs may be a useful biomarker to evaluate recurrence risk following LTx in patients with HCC. Evaluation based on CTC detection may enhance the post-transplant management of HCC, and improve the therapeutic efficacy of LTx.