Single-cell analysis defines LGALS1 + fibroblasts that promote proliferation and migration of intrahepatic cholangiocarcinoma.

The incidence rate of intrahepatic cholangiocarcinoma (ICC), which has a poor prognosis, is rapidly increasing. To investigate the intratumor heterogeneity of ICC, we analyzed single-cell RNA sequencing data from the primary tumor and adjacent normal tissues of 14 treatment-naïve patients. We identified ten major cell types, along with 45 subclusters of cells. Notably, we identified a fibroblast cluster, Fibroblast_LUM+, which was preferably enriched in tumor tissues and actively interacted with cholangiocytes. LGALS1 was verified as a marker gene of Fibroblast_LUM+, contributing to the malignant phenotype of ICC. The higher amount of LGALS1 + fibroblasts were associated with poorer overall survival in ICC patients. LGALS1 + fibroblasts activated the proliferation and migration of tumor cells by upregulating the expression levels of CCR2, ADAM15, and ß-integrin. Silencing LGALS1 in cancer-associated fibroblasts (CAFs) suppressed CAF-augmented tumor cell migration and invasion in vitro as well as tumor formation in vivo, suggesting that blockade of LGALS1 serves as a potential therapeutic approach for ICC. Taken together, our single-cell analysis provides insight into the interaction between malignant cells and specific subtypes of fibroblasts. Our work will further the understanding of the intratumor heterogeneity of ICC and provide novel strategies for the treatment of ICC by targeting fibroblasts in the tumor microenvironment.

Skullcapflavone II, a novel NQO1 inhibitor, alleviates aristolochic acid I-induced liver and kidney injury in mice.

Aristolochic acid I (AAI) is a well established nephrotoxin and human carcinogen. Cytosolic NAD(P)H quinone oxidoreductase 1 (NQO1) plays an important role in the nitro reduction of aristolochic acids, leading to production of aristoloactam and AA-DNA adduct. Application of a potent NQO1 inhibitor dicoumarol is limited by its life-threatening side effect as an anticoagulant and the subsequent hemorrhagic complications. As traditional medicines containing AAI remain available in the market, novel NQO1 inhibitors are urgently needed to attenuate the toxicity of AAI exposure. In this study, we employed comprehensive 2D NQO1 biochromatography to screen candidate compounds that could bind with NQO1 protein. Four compounds, i.e., skullcapflavone II (SFII), oroxylin A, wogonin and tectochrysin were screened out from Scutellaria baicalensis. Among them, SFII was the most promising NQO1 inhibitor with a binding affinity (KD = 4.198 µmol/L) and inhibitory activity (IC50 = 2.87 µmol/L). In human normal liver cell line (L02) and human renal proximal tubular epithelial cell line (HK-2), SFII significantly alleviated AAI-induced DNA damage and apoptosis. In adult mice, oral administration of SFII dose-dependently ameliorated AAI-induced renal fibrosis and dysfunction. In infant mice, oral administration of SFII suppressed AAI-induced hepatocellular carcinoma initiation. Moreover, administration of SFII did not affect the coagulation function in short term in adult mice. In conclusion, SFII has been identified as a novel NQO1 inhibitor that might impede the risk of AAI to kidney and liver without obvious side effect.