PPDPF suppresses the development of hepatocellular carcinoma through TRIM21-mediated ubiquitination of RIPK1.

Pancreatic progenitor cell differentiation and proliferation factor (PPDPF) has been reported to play a role in tumorigenesis. However, its function in hepatocellular carcinoma (HCC) remains poorly understood. In this study, we report that PPDPF is significantly downregulated in HCC and the decreased PPDPF expression indicates poor prognosis. In the dimethylnitrosamine (DEN)-induced HCC mouse model, hepatocyte-specific depletion of Ppdpf promotes hepatocarcinogenesis, and reintroduction of PPDPF into liver-specific Ppdpf knockout (LKO) mice inhibits the accelerated HCC development. Mechanistic study shows that PPDPF regulates nuclear factor κB (NF-κB) signaling through modulation of RIPK1 ubiquitination. PPDPF interacts with RIPK1 and facilitates K63-linked ubiquitination of RIPK1 via recruiting the E3 ligase TRIM21, which catalyzes K63-linked ubiquitination of RIPK1 at K140. In addition, liver-specific overexpression of PPDPF activates NF-κB signaling and attenuates apoptosis and compensatory proliferation in mice, which significantly suppresses HCC development. This work identifies PPDPF as a regulator of NF-κB signaling and provides a potential therapeutic candidate for HCC.

Ryanodine receptor 2 promotes colorectal cancer metastasis by the ROS/BACH1 axis.

There is no targeted therapy for KRAS proto-oncogene, GTPase (KRAS)-mutant metastatic colorectal cancer (mCRC) because the underlying mechanism remains obscure. Based on bioinformatic analysis, this study aims to elucidate a potential gene target for which an approved drug is available, and to reveal the function as well as the underlying mechanism of the candidate gene. Here, we identified that ryanodine receptor 2 (RyR2) expression was upregulated in KRAS-mutant mCRC, and that this promoted cancer cell metastasis. S107, an approved drug to inhibit calcium release from RyR2 in the clinic, inhibited cancer cell metastasis both in vitro and in vivo. High expression of RyR2 predicts poor survival in our patient cohort. CRC patients with serosa invasion and vascular tumor thrombus are characterized by high RyR2 expression. Analysis of expression profiles upon RyR2 knockdown and inhibition, revealed a set of metastasis-related molecules, and identified BTB domain and CNC homolog 1 (BACH1) as the main transcription factor regulated by RyR2. RyR2 regulates cellular reactive oxygen species (ROS) levels, which activates nuclear factor erythroid 2-related factor 2 (Nrf2; also known as NFE2L2) and HMOX1 expression, and thus BACH1 accumulation. Collectively, this study provides evidence that the RyR2/ROS/BACH1 axis may be a potential intervention target for CRC metastasis.

PPDPF Promotes the Development of Mutant KRAS-Driven Pancreatic Ductal Adenocarcinoma by Regulating the GEF Activity of SOS1.

The guanine nucleotide exchange factor (GEF) SOS1 catalyzes the exchange of GDP for GTP on RAS. However, regulation of the GEF activity remains elusive. Here, the authors report that PPDPF functions as an important regulator of SOS1. The expression of PPDPF is significantly increased in pancreatic ductal adenocarcinoma (PDAC), associated with poor prognosis and recurrence of PDAC patients. Overexpression of PPDPF promotes PDAC cell growth in vitro and in vivo, while PPDPF knockout exerts opposite effects. Pancreatic-specific deletion of PPDPF profoundly inhibits tumor development in KRASG12D -driven genetic mouse models of PDAC. PPDPF can bind GTP and transfer GTP to SOS1. Mutations of the GTP-binding sites severely impair the tumor-promoting effect of PPDPF. Consistently, mutations of the critical amino acids mediating SOS1-PPDPF interaction significantly impair the GEF activity of SOS1. Therefore, this study demonstrates a novel model of KRAS activation via PPDPF-SOS1 axis, and provides a promising therapeutic target for PDAC.

ARID2 mitigates hepatic steatosis via promoting the ubiquitination of JAK2.

Non-alcoholic fatty liver disease (NAFLD) has become a growing public health problem. However, the complicated pathogenesis of NAFLD contributes to the deficiency of effective clinical treatment. Here, we demonstrated that liver-specific loss of Arid2 induced hepatic steatosis and this progression could be exacerbated by HFD. Mechanistic study revealed that ARID2 repressed JAK2-STAT5-PPARγ signaling pathway by promoting the ubiquitination of JAK2, which was mediated by NEDD4L, a novel E3 ligase for JAK2. ChIP assay revealed that ARID2 recruited CARM1 to increase H3R17me2a level at the NEDD4L promoter and activated the transcription of NEDD4L. Moreover, inhibition of Jak2 by Fedratinib in liver-specific Arid2 knockout mice alleviated HFD-induced hepatic steatosis. Downregulation of ARID2 and the reverse correlation between ARID2 and JAK2 were also observed in clinical samples. Therefore, our study has revealed an important role of ARID2 in the development of NAFLD and provided a potential therapeutic strategy for NAFLD.

PPDPF promotes lung adenocarcinoma progression via inhibiting apoptosis and NK cell-mediated cytotoxicity through STAT3.

Lung cancer is the most common malignancy and the leading cause of cancer death worldwide, and lung adenocarcinoma (LUAD) is the most prevalent subtype. Considering the emergence of resistance to therapies, it is urgent to develop more effective therapies to improve the prognosis. Here we reported that pancreatic progenitor cell differentiation and proliferation factor (PPDPF) deficiency inhibited LUAD development both in vitro and in vivo. Mechanistically, PPDPF induces hyperactive STAT3 by interfering STAT3-PTPN1 interaction. Activated STAT3 promoted BMPR2 transcription, which further inhibited apoptosis. Moreover, PPDPF reduced NK cell infiltration and activation to develop an immunosuppressive microenvironment, which was also mediated by STAT3. Furthermore, we identified that the expression of PPDPF was positively correlated with the malignant features of LUAD, as well as BMPR2 and p-STAT3 level in clinical samples. Therefore, our study suggests that PPDPF positively regulates BMPR2 expression and facilitates immune escape via regulating STAT3 activity, providing a potential therapy target for LUAD.

Targeting USP9X-AMPK Axis in ARID1A-Deficient Hepatocellular Carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is a highly heterogeneous solid tumor with high morbidity and mortality. AT-rich interaction domain 1A (ARID1A) accounts for up to 10% of mutations in liver cancer, however, its role in HCC remains controversial, and no targeted therapy has been established. METHODS: The expression of ARID1A in clinical samples was examined by Western blot and immunohistochemical staining. ARID1A was knocked out by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) in HCC cell lines, and the effects of glucose deprivation on cell viability, proliferation, and apoptosis were measured. Mass spectrometry analysis was used to find ARID1A-interacting proteins, and the result was verified by co-immunoprecipitation and Glutathione S Transferase (GST) pull-down. The regulation of ARID1A target gene USP9X was investigated by chromatin immunoprecipitation, Glutathione S Transferase (GST) pull-down, luciferase reporter assay, and so forth. Finally, drug treatments were performed to explore the therapeutic potential of the agents targeting ARID1A-deficient HCC in vitro and in vivo. RESULTS: Our study has shown that ARID1A loss protected cells from glucose deprivation-induced cell death. A mechanism study disclosed that AIRD1A recruited histone deacetylase 1 via its C-terminal region DUF3518 to the promoter of USP9X, resulting in down-regulation of USP9X and its target protein kinase AMP-activated catalytic subunit α2 (PRKAA2). ARID1A knockout and a 1989∗ truncation mutant in HCC abolished this effect, increased the levels of H3K9 and H3K27 acetylation at the USP9X promoter, and up-regulated the expression of USP9X and protein kinase AMP-activated catalytic subunit α2 (PRKAA2), which mediated the adaptation of tumor cells to glucose starvation. Compound C dramatically inhibited the growth of ARID1A-deficient tumors and prolongs the survival of tumor-bearing mice. CONCLUSIONS: HCC patients with ARID1A mutation may benefit from synthetic lethal therapy targeting the ubiquitin-specific peptidase 9 X-linked (USP9X)-adenosine 5'-monophosphate-activated protein kinase (AMPK) axis.

Ochratoxin A Induces Steatosis via PPARγ-CD36 Axis.

Ochratoxin A(OTA) is considered to be one of the most important contaminants of food and feed worldwide. The liver is one of key target organs for OTA to exert its toxic effects. Due to current lifestyle and diet, nonalcoholic fatty liver disease (NAFLD) has been the most common liver disease. To examine the potential effect of OTA on hepatic lipid metabolism and NAFLD, C57BL/6 male mice received 1 mg/kg OTA by gavage daily. Compared with controls, OTA increased lipid deposition and TG accumulation in mouse livers. In vitro OTA treatment also promoted lipid droplets accumulation in primary hepatocytes and HepG2 cells. Mechanistically, OTA prevented PPARγ degradation by reducing the interaction between PPARγ and its E3 ligase SIAH2, which led to activation of PPARγ signaling pathway. Furthermore, downregulation or inhibition of CD36, a known of PPARγ, alleviated OTA-induced lipid droplets deposition and TG accumulation. Therefore, OTA induces hepatic steatosis via PPARγ-CD36 axis, suggesting that OTA has an impact on liver lipid metabolism and may contribute to the development of metabolic diseases.

INTS6 promotes colorectal cancer progression by activating of AKT and ERK signaling.

INTS6 (integrator complex subunit 6) has been reported as a tumor suppressor in many cancers. However, the expression and biological function of INTS6 in colorectal cancer (CRC) has not been investigated yet. In this study, we found that INTS6 expression was significantly increased in CRC tissues when compared with normal tissues and was associated with poor prognosis. Downregulation of INTS6 induced G1/S-phase cell cycle arrest, and markedly suppressed the growth of CRC cells and the derived tumors, while overexpression of INTS6 showed opposite effect. Mechanism study revealed that INTS6 increased the levels of phosphorylated AKT (p-AKT) and ERK (p-ERK), and the growth-promoting effect of INTS6 was inhibited by AKT and ERK inhibitors. Besides, INTS6 also affected the expression of two targets of PI3K/AKT and MAPK signaling, c-Myc and CDK2, which contributed to cell cycle alteration. Altogether, the present study has revealed the oncogenic role of INTS6 in CRC, providing a novel therapeutic target for this malignant cancer.

Antifungal agent Terbinafine restrains tumor growth in preclinical models of hepatocellular carcinoma via AMPK-mTOR axis.

The prognosis of hepatocellular carcinoma (HCC) remains unsatisfactory due to limited effective treatment options. In this work, we investigated the therapeutic efficacy of Terbinafine for HCC and the underlying mechanism. The influence of Terbinafine on cell growth, 3D spheroid formation, clonogenic survival, and protein synthesis was investigated in human HCC cell lines. Co-immunoprecipitation, immunofluorescence, and other techniques were employed to explore how Terbinafine exerts its anticancer effect. Subcutaneous tumorigenicity assay, orthotopic and patient-derived xenograft (PDX) HCC models were used to evaluate the anticancer effect of Terbinafine monotherapy and the combinatorial treatment with Terbinafine and sorafenib against HCC. The anticancer activity of Terbinafine was Squalene epoxidase (SQLE)-independent. Instead, Terbinafine robustly suppressed the proliferation of HCC cells by inhibiting mTORC1 signaling via activation of AMPK. Terbinafine alone or in combination with sorafenib delayed tumor progression and markedly prolonged the survival of tumor-bearing mice. The synergy between Terbinafine and sorafenib was due to concomitant inhibition of mTORC1 and induction of severe persistent DNA double-strand breaks (DSBs), which led to the delayed proliferation and accelerated cell death. Terbinafine showed promising anticancer efficacy in preclinical models of HCC and may serve as a potential therapeutic strategy for HCC.

PPDPF alleviates hepatic steatosis through inhibition of mTOR signaling.

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease in the world, however, no drug treatment has been approved for this disease. Thus, it is urgent to find effective therapeutic targets for clinical intervention. In this study, we find that liver-specific knockout of PPDPF (PPDPF-LKO) leads to spontaneous fatty liver formation in a mouse model at 32 weeks of age on chow diets, which is enhanced by HFD. Mechanistic study reveals that PPDPF negatively regulates mTORC1-S6K-SREBP1 signaling. PPDPF interferes with the interaction between Raptor and CUL4B-DDB1, an E3 ligase complex, which prevents ubiquitination and activation of Raptor. Accordingly, liver-specific PPDPF overexpression effectively inhibits HFD-induced mTOR signaling activation and hepatic steatosis in mice. These results suggest that PPDPF is a regulator of mTORC1 signaling in lipid metabolism, and may be a potential therapeutic candidate for NAFLD.

A bibliometric analysis of income and cardiovascular disease: Status, Hotspots, Trends and Outlook.

BACKGROUND: Income is 1 of the socio-economic indicators and could directly influence the health outcomes of cardiovascular disease (CVD). The relationship between income and CVD has attracted more and more scholars' attention in the past 20 years. METHODS: To study the current research dynamics of this field, a bibliometric analysis was conducted to evaluate the publications from 1990 to 2018 based on the Science Citation Index Expanded database. By using the Derwent Date Analyzer software, the following aspects were explored: RESULTS:: The USA ranked first in this field, followed by UK and Canada in terms of number of publications. As for institutions, Harvard University took the leading place in the number of publications, as well as the h-index. Plos One had the most publications and "health" was the most frequent used keyword. The leading research area was "public environmental occupational health". CONCLUSIONS: In conclusion, the elderly, the children and the puerpera were the main study population in this field and "disease prevention" was the main study direction. The most concerned health issues in this field were "obesity" and "diet". There might be a lack of articles that explore the associations between income and CVD with a global perspective. Articles on this content are urgently warranted.

Chromatin remodeling factor ARID2 suppresses hepatocellular carcinoma metastasis via DNMT1-Snail axis.

Recurrence and metastasis remain the major obstacles to successful treatment of hepatocellular carcinoma (HCC). Chromatin remodeling factor ARID2 is commonly mutated in HCC, indicating its important role in cancer development. However, its role in HCC metastasis is largely elusive. In this study, we find that ARID2 expression is significantly decreased in metastatic HCC tissues, showing negative correlation with pathological grade, organ metastasis and positive association with survival of HCC patients. ARID2 inhibits migration and invasion of HCC cells in vitro and metastasis in vivo. Moreover, ARID2 knockout promotes pulmonary metastasis in different HCC mouse models. Mechanistic study reveals that ARID2 represses epithelial-mesenchymal transition (EMT) of HCC cells by recruiting DNMT1 to Snail promoter, which increases promoter methylation and inhibits Snail transcription. In addition, we discover that ARID2 mutants with disrupted C2H2 domain lose the metastasis suppressor function, exhibiting a positive association with HCC metastasis and poor prognosis. In conclusion, our study reveals the metastasis suppressor role as well as the underlying mechanism of ARID2 in HCC and provides a potential therapeutic target for ARID2-deficient HCC.