Tregs are associated with HCC invasiveness, and intratumoral balance of regulatory and cytotoxic T cells is a promising independent predictor for recurrence and survival in HCC. A combination of depletion of Tregs and concomitant stimulation of effector T cells may be an effective immunotherapy to reduce recurrence and prolong survival after surgery.

Purpose: The aberrant expression of programmed cell death 1ligands 1and 2 (PD-Ls) on tumor cells dampens antitumor immunity, resulting in tumor immune evasion. In this study, we investigated the expression of PD-Ls in human hepatocellular carcinoma (HCC) to define their prognostic significance after curative surgery. Experimental Design: Immunohistochemistry was used to investigate PD-Ls expression as well as granzyme B + cytotoxic and FoxP3 + regulatory T cell infiltration on tissue microarrays containing 240 randomly selected HCC patients who underwent surgery. The results were further verified in an independent cohort of 125 HCC patients. PD-Ls expression on HCC cell lines was detected by Western blot assay. Results: Patients with higher expression of PD-L1 had a significantly poorer prognosis than patients with lower expression. Although patients with higher expression of PD-L2 also had a poorer survival, the difference in recurrence was not statistically significant. Multivariate analysis identified tumor expression of PD-L1 as an independent predictor for postoperative recurrence. No correlation was found between PD-Ls expression and granzyme B + lymphocyte infiltration, whereas a significant positive correlation was detected between PD-Ls expression and FoxP3 + lymphocyte infiltration. In addition, tumor-infiltrating cytotoxic and regulatory T cells were also independent prognosticators for both survival and recurrence. The prognostic value of PD-L1 expression was validated in the independent data set. Conclusion: Our data suggest for the first time that PD-L1 status may be a new predictor of recurrence for HCC patients and provide the rationale for developing a novel therapy of targeting the PD-L1/PD-1pathway against this fatal malignancy.

Highlights d Proteomic subgroups stratify patient survival and allocate specific treatments d Alterations of the liver-specific proteome and metabolism in HCC are identified d Multi-omics profile of key signaling and metabolic pathways in HCC is depicted d CTNNB1 mutation-associated ALDOA phosphorylation promotes HCC cell proliferation

Liver metastasis, the leading cause of colorectal cancer mortality, exhibits a highly heterogeneous and suppressive immune microenvironment. Here, we sequenced 97 matched samples by using single-cell RNA sequencing and spatial transcriptomics. Strikingly, the metastatic microenvironment underwent remarkable spatial reprogramming of immunosuppressive cells such as MRC1+ CCL18+ M2-like macrophages. We further developed scMetabolism, a computational pipeline for quantifying single-cell metabolism, and observed that those macrophages harbored enhanced metabolic activity. Interestingly, neoadjuvant chemotherapy could block this status and restore the antitumor immune balance in responsive patients, whereas the nonresponsive patients deteriorated into a more suppressive one. Our work described the immune evolution of metastasis and uncovered the black box of how tumors respond to neoadjuvant chemotherapy. Significance: We present a single-cell and spatial atlas of colorectal liver metastasis and found the highly metabolically activated MRC1+ CCL18+ M2-like macrophages in metastatic sites. Efficient neoadjuvant chemotherapy can slow down such metabolic activation, raising the possibility to target metabolism pathways in metastasis. This article is highlighted in the In This Issue feature, p. 1