TET2-STAT3-CXCL5 nexus promotes neutrophil lipid transfer to fuel lung adeno-to-squamous transition.

Phenotypic plasticity is a rising cancer hallmark, and lung adeno-to-squamous transition (AST) triggered by LKB1 inactivation is significantly associated with drug resistance. Mechanistic insights into AST are urgently needed to identify therapeutic vulnerability in LKB1-deficient lung cancer. Here, we find that ten-eleven translocation (TET)-mediated DNA demethylation is elevated during AST in KrasLSL-G12D/+; Lkb1L/L (KL) mice, and knockout of individual Tet genes reveals that Tet2 is required for squamous transition. TET2 promotes neutrophil infiltration through STAT3-mediated CXCL5 expression. Targeting the STAT3-CXCL5 nexus effectively inhibits squamous transition through reducing neutrophil infiltration. Interestingly, tumor-infiltrating neutrophils are laden with triglycerides and can transfer the lipid to tumor cells to promote cell proliferation and squamous transition. Pharmacological inhibition of macropinocytosis dramatically inhibits neutrophil-to-cancer cell lipid transfer and blocks squamous transition. These data uncover an epigenetic mechanism orchestrating phenotypic plasticity through regulating immune microenvironment and metabolic communication, and identify therapeutic strategies to inhibit AST.

Increased Factor VIII Activity Is Predictive of the Occurrence of Portal Vein Thrombosis in Cirrhosis.

BACKGROUND: The aim of this study was to identify the role of factor VIII (FVIII) in portal vein thrombosis (PVT) occurrence in cirrhotic patients with gastroesophageal variceal bleeding. METHODS: A total of 453 cirrhotic patients with gastroesophageal varices were enrolled. Computed tomography was performed at baseline and patients were divided into PVT and non-PVT groups (n = 131 vs. 322). Individuals without PVT at baseline were followed up for the development of PVT. Time-dependent receiver operating characteristic analysis of FVIII for PVT development was performed. The Kaplan-Meier methodology was used to analyze the predictive ability of FVIII for PVT incidence at 1 year. RESULTS: FVIII activity (177.00 vs. 153.70, p = 0.001) was significantly increased in the PVT group compared with the non-PVT group in cirrhotic patients with gastroesophageal varices. FVIII activity was positively correlated with the severity of PVT (161.50 vs. 171.07 vs. 187.05%, p = 0.001). Furthermore, FVIII activity (hazard ratio [HR]: 3.48, 95% confidence interval [CI]: 1.14-10.68, p = 0.029 in model 1; HR: 3.29, 95% CI: 1.03-10.51, p = 0.045 in model 2) was an independent risk factor of 1-year PVT development in patients without PVT at baseline, which was confirmed by two separate Cox regression analysis and competing risk models. Patients with elevated FVIII activity exhibit a higher incidence of PVT in the non-PVT group at 1 year (15.17 vs. 3.16%, p < 0.001). The predictive value of FVIII remains significant in individuals who have never received splenectomy (14.76 vs. 3.04%, p = 0.002). CONCLUSION: Elevated FVIII activity was potentially associated with the occurrence and the severity of PVT. It might be helpful to identify cirrhotic patients at risk of PVT.

TET2 deficiency sensitizes tumor cells to statins by reducing HMGCS1 expression.

TET2 (ten-eleven-translocation) protein is a Fe(II)- and α-ketoglutarate-dependent dioxygenase that catalyzes DNA demethylation to regulate gene expression. While TET2 gene is frequently mutated in hematological cancer, its enzymatic activity is also compromised in various solid tumors. Whether TET2 deficiency creates vulnerability for cancer cells has not been studied. Here we reported that TET2 deficiency is associated with the change of lipid metabolism processes in acute myeloid leukemia (AML) patient. We demonstrate that statins, the inhibitors of ß-Hydroxy ß-methylglutaryl-CoA (HMG-CoA) reductase and commonly used cholesterol-lowering medicines, significantly sensitize TET2 deficient tumor cells to apoptosis. TET2 directly regulates the expression of HMG-CoA synthase (HMGCS1) by catalyzing demethylation on its promoter region, and conversely TET2 deficiency leads to significant down-regulation of HMGCS1 expression and the mevalonate pathway. Consistently, overexpression of HMGCS1 in TET2-deficient cells rescues statin-induced apoptosis. We further reveal that decrease of geranylgeranyl diphosphate (GGPP), an intermediate metabolite in the mevalonate pathway, is responsible for statin-induced apoptosis. GGPP shortage abolishes normal membrane localization and function of multiple small GTPases, leading to cell dysfunction. Collectively, our study reveals a vulnerability in TET2 deficient tumor and a potential therapeutic strategy using an already approved safe medicine.

Platelet-derived TGF-ß1 is related to portal vein thrombosis in cirrhosis by promoting hypercoagulability and endothelial dysfunction.

Background: Portal vein thrombosis (PVT) is a serious complication of cirrhosis accompanied by unclear pathogenesis. Transforming growth factor-beta (TGF-ß) has been implicated in atherosclerosis and venous thrombosis whereas study regarding its part in PVT is lacking. The aim of this study was to explore the role of cytokine TGF-ß1 in PVT and the potential mechanism. Materials and methods: We included patients with cirrhotic gastroesophageal varices and divided them into two groups according to the presence of PVT. Serum levels of TGF-ß1 were detected using Cytometric Bead Array kit and compared between two groups. Coagulation status was assessed using thromboelastography (TEG). Primary liver sinusoidal endothelial cells were treated with TGF-ß1 and evaluated for endothelial dysfunction by RT-PCR. Results: Our results uncovered that TGF-ß1 (6,866.55 vs. 3,840.60 pg/ml, P = 0.015) significantly increased in the PVT group. Splenectomy might promote PVT by increasing platelet-derived TGF-ß1 levels. Other cytokines showed no difference between PVT and non-PVT groups. Besides, TGF-ß1 was correlated with platelet, fibrinogen, TEG-CI, TEG-MA, and TEG-α (coef = 0.733, 0.494, 0.604, 0.608, and 0.511; P < 0.001, 0.027, 0.004, 0.004, and 0.021, respectively), which indicated a hypercoagulable state in PVT patients. RT-PCR of liver sinusoidal endothelial cells showed a markable increment of von Willebrand Factor (vWF), thrombomodulin(TM), intercellular adhesion moleclar-1(ICAM-1), and vascular endothelial growth factor(VEGF) after TGF-ß1 treatment, suggesting the involvement of endothelial dysfunction. Conclusion: Elevated platelet-derived TGF-ß1 exhibited association with hypercoagulability and promoting effect on endothelial dysfunction, closely related with PVT in cirrhotic patients.

Characteristics of myeloproliferative neoplasm-associated portal hypertension and endoscopic management of variceal bleeding.

Background: Myeloproliferative neoplasms (MPNs) are a rare yet important clinical cause of portal hypertension, which may cause recurrent gastroesophageal variceal bleeding (GVB). MPN-associated variceal bleeding lacks specific guidelines and clinical consensus and desiderates cohort studies. We performed a multicenter retrospective study to investigate the efficacy of endoscopic management of bleeding in MPNs. Methods: We included consecutive MPN patients with gastroesophageal varices in eight tertiary university hospitals between January 2007 and March 2020. The clinical characteristics of participants were summarized. MPN patients with a history of GVB were followed up for the rebleeding and death, compared with controls suffering from schistosomiasis-associated portal hypertension who received endoscopic treatment for variceal bleeding at the same period. Results: A total of 62 MPN patients with gastroesophageal varices were identified, and 37 had a history of GVB. Of these, 24 patients received endoscopic variceal ligation and endoscopic injection of cyanoacrylate for the prophylaxis of variceal rebleeding. Endoscopic treatment significantly reduced the rebleeding rate in MPN patients with a history of GVB (28.2% versus 68.3%, p = 0.0269). Multivariable Cox regression indicated that endoscopic treatment (HR = 0.10, 95% CI: 0.02-0.54, p = 0.008) was the independent protective factor for decreasing the 3-year rebleeding rate, while the use of non-selective beta-blockers (NSBB) (HR = 13.41, 95% CI: 2.15-83.42, p = 0.005) was the risk factor for increasing the 3-year rebleeding rate. As for the efficacy of endoscopic management, 3-year rebleeding rate was significantly lower in MPN patients in contrast to 46 controls with schistosomiasis-associated variceal bleeding (32.9% versus 59.0%, p = 0.0346). Conclusion: Endoscopic treatment might be a feasible and potent approach in the management of gastroesophageal variceal rebleeding in MPNs, while NSBB might be ineffective.

ALK fusion promotes metabolic reprogramming of cancer cells by transcriptionally upregulating PFKFB3.

Anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase of the insulin receptor kinase subfamily, is activated in multiple cancer types through translocation or overexpression. Although several generations of ALK tyrosine kinase inhibitors (TKIs) have been developed for clinic use, drug resistance remains a major challenge. In this study, by quantitative proteomic approach, we identified the glycolytic regulatory enzyme, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), as a new target of ALK. Expression of PFKFB3 is highly dependent on ALK activity in ALK+ anaplastic large cell lymphoma and non-small-cell lung cancer (NSCLC) cells. Notably, ALK and PFKFB3 expressions exhibit significant correlation in clinic ALK+ NSCLC samples. We further demonstrated that ALK promotes PFKFB3 transcription through the downstream transcription factor STAT3. Upregulation of PFKFB3 by ALK is important for high glycolysis level as well as oncogenic activity of ALK+ lymphoma cells. Finally, targeting PFKFB3 by its inhibitor can overcome drug resistance in cells bearing TKI-resistant mutants of ALK. Collectively, our studies reveal a novel ALK-STAT3-PFKFB3 axis to promote cell proliferation and tumorigenesis, providing an alternative strategy for the treatment of ALK-positive tumors.

Elevated nuclear localization of glycolytic enzyme TPI1 promotes lung adenocarcinoma and enhances chemoresistance.

Increased glycolysis is a hallmark of tumor, which can provide tumor cells with energy and building blocks to promote cell proliferation. Recent studies have shown that not only the expression of glycolytic genes but also their subcellular localization undergoes a variety of changes to promote development of different types of tumors. In this study, we performed a comprehensive analysis of glycolysis and gluconeogenesis genes based on data from TCGA to identify those with significant tumor-promoting potential across 14 types of tumors. This analysis not only confirms genes that are known to be involved in tumorigenesis, but also reveals a significant correlation of triosephosphate isomerase 1 (TPI1) with poor prognosis, especially in lung adenocarcinoma (LUAD). TPI1 is a glycolytic enzyme that interconverts dihydroxyacetone phosphate (DHAP) to glyceraldehyde 3-phosphate (GAP). We confirm the upregulation of TPI1 expression in clinical LUAD samples and an inverse correlation with the overall patient survival. Knocking down of TPI1 in lung cancer cells significantly reduced cell migration, colony formation, and xenograft tumor growth. Surprisingly, we found that the oncogenic function of TPI1 depends on its translocation to cell nucleus rather than its catalytic activity. Significant accumulation of TPI1 in cell nucleus was observed in LUAD tumor tissues compared with the cytoplasm localization in adjacent normal tissues. Moreover, nuclear translocation of TPI1 is induced by extracellular stress (such as chemotherapy agents and peroxide), which facilitates the chemoresistance of cancer cells. Our study uncovers a novel function of the glycolytic enzyme TPI1 in the LUAD.

UPLC-MS/MS-Based Serum Metabolomics Signature as Biomarkers of Esophagogastric Variceal Bleeding in Patients With Cirrhosis.

Background: Esophagogastric variceal bleeding (EVB) is a common and ominous complication of cirrhosis and represents the degree of portal hypertension progression and cirrhosis decompensation, desiderating the investigation into sensitive and specific markers for early detection and prediction. The purpose of this study is to characterize unique metabolites in serum of cirrhotic EVB patients and identify potential noninvasive biomarkers for detecting and assessing risk of variceal bleeding and cirrhosis progression through metabolomics-based approaches and explore possible pathophysiological mechanisms. Methods: We used ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) to profile serum metabolomes. In one discovery cohort (n = 26, 13 cases of EVB), univariate and multivariate statistical analyses were performed to demonstrate separation between the two groups and identify differentially expressed metabolites. Potential biomarkers were screened by Boruta and logistic regression analyses, further evaluated by receiver operating characteristic analysis, and tested in two validation cohorts (n = 34, 17 cases and n = 10, 5 cases). Results: Bioinformatics analyses demonstrated that EVB patients possessed distinct metabolic phenotypes compared with nEVB controls, characterized by seven elevated and six downregulated metabolites, indicating that EVB-related metabolic disturbance might be associated with vitamin metabolism and fatty acid metabolism. Eight potential biomarkers were selected among which citrulline and alpha-aminobutyric acid with moderate AUC values, tested in the validation cohorts, were identified as specific biomarkers of EVB. Conclusion: Our metabolomic study provides an overview of serum metabolic profiles in EVB patients, highlighting the potential utility of UPLC-MS/MS-based serum fingerprint as a feasible avenue for early detection of EVB.

CBFB-MYH11 Fusion Sequesters RUNX1 in Cytoplasm to Prevent DNMT3A Recruitment to Target Genes in AML.

A growing number of human diseases have been found to be associated with aberrant DNA methylation, including cancer. Mutations targeting genes encoding DNA methyltransferase (DNMT), TET family of DNA demethylases, and isocitrate dehydrogenase (IDH1, IDH2) that produce TET inhibitory metabolite, 2-hyoxyglutarate (2-HG), are found in more than half of acute myeloid leukemia (AML). To gain new insights into the regulation of DNA de/methylation and consequence of its alteration in cancer development, we searched for genes which are mutated in a manner that is linked with gene mutations involved in DNA de/methylation in multiple cancer types. We found that recurrent CBFB-MYH11 fusions, which result in the expression of fusion protein comprising core-binding factor ß (CBFB) and myosin heavy chain 11 (MYH11) and are found in 6∼8% of AML patients, occur mutually exclusively with DNMT3A mutations. Tumors bearing CBFB-MYH11 fusion show DNA hypomethylation patterns similar to those with loss-of-function mutation of DNMT3A. Expression of CBFB-MYH11 fusion or inhibition of DNMT3A similarly impairs the methylation and expression of target genes of Runt related transcription factor 1 (RUNX1), a functional partner of CBFB. We demonstrate that RUNX1 directly interacts with DNMT3A and that CBFB-MYH11 fusion protein sequesters RUNX1 in the cytoplasm, thereby preventing RUNX1 from interacting with and recruiting DNMT3A to its target genes. Our results identify a novel regulation of DNA methylation and provide a molecular basis how CBFB-MYH11 fusion contributes to leukemogenesis.