Yu Lou

Characteristics of Tumor Infiltrating Lymphocyte and Circulating Lymphocyte Repertoires in Pancreatic Cancer by the Sequencing of T Cell Receptors

Pancreatic cancer has a poor prognosis and few effective treatments. The failure of treatment is partially due to the high heterogeneity of cancer cells within the tumor. T cells target and kill cancer cells by the specific recognition of cancer-associated antigens. In this study, T cells from primary tumor and blood of sixteen patients with pancreatic cancer were characterized by deep sequencing. T cells from blood of another eight healthy volunteers were also studied as controls. By analyzing the complementary determining region 3 (CDR3) gene sequence, we found no significant differences in the T cell receptor (TCR) repertoires between patients and healthy controls. Types and length of CDR3 were similar among groups. However, two clusters of patients were identified according to the degree of CDR3 overlap within tumor sample group. In addition, clonotypes with low frequencies were found in significantly higher numbers in primary pancreatic tumors compared to blood samples from patients and healthy controls. This study is the first to characterize the TCR repertoires of pancreatic cancers in both primary tumors and matched blood samples. The results imply that specific types of pancreatic cancer share potentially important immunological characteristics.

Hypoxia-inducible factor-2α promotes tumor progression and has crosstalk with Wnt/β-catenin signaling in pancreatic cancer

BackgroundPancreatic cancer is a devastating disease that is characterized by persistent hypoxia. The roles of hypoxia-inducible factor-2α (hif-2α) are different to those of hif-1α, although both are critical for tumor cells to adapt to the hypoxic microenvironment. However, unlike the well-studied hif-1α, the role of hif-2α in tumors, including pancreatic cancer, is poorly understood.MethodsHerein, we used a mutated hif-2α (A530T) to figure out the problem that wild-type hif-2α is quickly degraded which limits the study of its function. Using several cell lines, mouse models, and human tissues, we obtained a general picture of hif-2α in pancreatic cancer progression.ResultsFunctional assays revealed that hif-2α promotes epithelial-to-mesenchymal transition, enhances tumor proliferation and invasion, increases stemness, facilitates angiogenesis, and up-regulates aerobic glycolysis. We identified an interaction between hif-2α and β-catenin, and found that hif-2α/β-catenin complex formation increased the activity of β-catenin and the protein stability of hif-2α. In vivo study confirmed the pro-oncogenic role of hif-2α, whose expression correlated with those of E-cadherin, vimentin, Ki-67, and CD31, but not hif-1α. A human tissue study showed that hif-2α was associated with lymph node metastasis, pathological grade, stroma abundance, vascularization and patient survival. High expression of hif-2α was also identified as an independent indicator of poor prognosis in patients with pancreatic cancer.ConclusionsOur systematic study revealed the roles of hif-2α in pancreatic cancer, and may provide a novel target for this highly malignant disease.

Prognostic value of the neutrophil‐to‐lymphocyte ratio in patients with acute‐on‐chronic liver failure

The neutrophil‐to‐lymphocyte ratio (NLR) is a novel inflammation index that has been shown to independently predict poor clinical outcomes. We aimed to evaluate the role of NLR in the prediction of 3‐month mortality in patients with acute‐on‐chronic liver failure (AoCLF).

Hypoxia‐inducible factor‐1α/interleukin‐1β signaling enhances hepatoma epithelial–mesenchymal transition through macrophages in a hypoxic‐inflammatory microenvironment

The development and progression of hepatocellular carcinoma (HCC) are dependent on its local microenvironment. Hypoxia and inflammation are two critical factors that shape the HCC microenvironment; however, the interplay between the two factors and the involvement of cancer cells under such conditions remain poorly understood. We found that tumor‐associated macrophages, the primary proinflammatory cells within tumors, secreted more interleukin 1β (IL‐1β) under moderate hypoxic conditions due to increased stability of hypoxia inducible factor 1α (HIF‐1α). Under persistent and severe hypoxia, we found that the necrotic debris of HCC cells induced potent IL‐1β release by tumor‐associated macrophages with an M2 phenotype. We further confirmed that the necrotic debris–induced IL‐1β secretion was mediated through Toll‐like receptor 4/TIR domain–containing adapter‐inducing interferon‐β/nuclear factor kappa‐light‐chain‐enhancer of activated B cells signaling in a similar, but not identical, fashion to lipopolysaccharide‐induced inflammation. Using mass spectrometry, we identified a group of proteins with O‐linked glycosylation to be responsible for the necrotic debris–induced IL‐1β secretion. Following the increase of IL‐1β in the local microenvironment, the synthesis of HIF‐1α was up‐regulated by IL‐1β in HCC cells through cyclooxygenase‐2. The epithelial–mesenchymal transition of HCC cells was enhanced by overexpression of HIF‐1α. We further showed that IL‐1β promoted HCC metastasis in mouse models and was predictive of poor prognosis in HCC patients. Conclusion: Our findings revealed an HIF‐1α/IL‐1β signaling loop between cancer cells and tumor‐associated macrophages in a hypoxic microenvironment, resulting in cancer cell epithelial–mesenchymal transition and metastasis; more importantly, our results suggest a potential role of an anti‐inflammatory strategy in HCC treatment. (Hepatology 2018;67:1872‐1889)

LB-100 sensitizes hepatocellular carcinoma cells to the effects of sorafenib during hypoxia by activation of Smad3 phosphorylation

Hepatocellular carcinoma (HCC) is a common cancer with poor prognosis. The multikinase inhibitor sorafenib is the only clinically proved systematic treatment for HCC. However, few patients respond to sorafenib. Hypoxic microenvironments contribute to sorafenib resistance. LB-100, a serine/threonine protein phosphatase 2A (PP2A) inhibitor was previously found to be a chemosensitizer in HCC. Here, we tested whether LB-100 could sensitize HCC to the effects of sorafenib. Intriguingly, LB-100 enhanced the effects of sorafenib in HCC cells only during hypoxic environments. LB-100 dramatically increased intracellular p-Smad3 level, which was responsible for the effect of LB-100 as a sensitizer. LB-100 downregulated Bcl-2 expression and enhanced sorafenib-induced apoptosis in HCC cells. We further proved that PP2A mediated LB-100-induced p-Smad3 overexpression. In addition, p38 mitogen-activated protein kinase pathway was activated in hypoxic conditions, and enhanced p-Smad3-dependent Bcl-2 inhibition and consequent apoptosis. In conclusion, LB-100 sensitized HCC cells to sorafenib in hypoxic environments. This effect was mediated by inactivation of PP2A, resulting in enhanced level of p-Smad3. Increased p-Smad3 downregulated Bcl-2, causing increased apoptosis of HCC cells.

Hook1 inhibits malignancy and epithelial-mesenchymal transition in hepatocellular carcinoma.

Hook1 is a member of the hook family of coiled-coil proteins, which is recently found to be associated with malignant tumors. However, its biological function in hepatocellular carcinoma is yet unknown. Here, we evaluated the Hook1 levels in human hepatocellular carcinoma samples and matched peritumoral tissues by real-time polymerase chain reaction. Small interfering RNA knockdown and a transforming growth factor-β-induced epithelial–mesenchymal transition model were employed to investigate the biological effects of Hook1 in hepatocellular carcinoma. Our results indicated that Hook1 levels were significantly lower in hepatocellular carcinoma tissues than in the peritumoral tissues. In addition, Hook1 expression was significantly associated with hepatocellular carcinoma malignancy. Hook1 was downregulated after transforming growth factor-β-induced epithelial–mesenchymal transition. Moreover, Hook1 knockdown promoted epithelial–mesenchymal transition and attenuated the sensitivity of hepatocellular carcinoma cells to doxorubicin. In summary, our results indicate that downregulation of Hook1 plays a pivotal role in hepatocellular carcinoma progression via epithelial–mesenchymal transition. Hook1 may be used as a novel marker and therapeutic molecular target in hepatocellular carcinoma.

Immunometabolism: A novel perspective of liver cancer microenvironment and its influence on tumor progression

The initiation and progression of liver cancer, including hepatocellular carcinoma and intrahepatic cholangiocarcinoma, are dependent on its tumor microenvironment. Immune cells are key players in the liver cancer microenvironment and show complicated crosstalk with cancer cells. Emerging evidence has shown that the functions of immune cells are closely related to cell metabolism. However, the effects of metabolic changes of immune cells on liver cancer progression are largely undefined. In this review, we summarize the recent findings of immunometabolism and relate these findings to liver cancer progression. We also explore the translation of the understanding of immunometabolism for clinical use.

Primary tumor-derived exosomes facilitate metastasis by regulating adhesion of circulating tumor cells via SMAD3 in liver cancer

Hepatocellular carcinoma (HCC) is a fatal disease and patients with HCC frequently die from metastasis. The mechanisms of HCC metastasis are not completely understood. In the present study, in vitro and in vivo data showed that HCC cells promoted cancer cell proliferation and lung metastases formation in a paracrinal/endocrinal way. We found that HCC-derived exosomes mediated this phenomenon and observed enhanced cell adhesion in the presence of these malignant exosomes. We further identified that reactive oxygen species (ROS) regulated the adhesive molecules. Intriguingly, attached HCC cells released exosomes containing both SMAD Family Member 3 (SMAD3) protein and mRNA, which were delivered to detached HCC cells and facilitated their adhesion. These exosomes induced enhanced SMAD3 signaling in the recipient HCC cells and increased their adhesive ability. In addition, we showed that SMAD3-abundant exosomes existed in the peripheral blood of patients with HCC, and their levels correlated with disease stage and the SMAD3 expression of primary tumors. Our study suggested a possible mechanism by which primary HCC supported metastases formation and revealed the role of SMAD3 in the exosomes-mediated crosstalk between primary and circulating HCC cells.