TRPM2 regulates cell cycle through the Ca2+-CaM-CaMKII signaling pathway to promote HCC.

BACKGROUND: HCC is one of the most common causes of cancer-related deaths. Transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable cation channel, was reported to be involved in carcinogenesis and tumor growth recently. However, whether TRPM2 is involved in the pathogenesis and progression of HCC remains unclear. Herein, we systematically elucidated the functional role of TRPM2 in HCC cell cycle regulation and proliferation. APPROACH AND RESULTS: We determine TRPM2 expression to be strongly upregulated in the tumor tissues of HCC patients and associated with a negative prognosis. TRPM2 is highly expressed in HCC cell lines Huh-7 and HepG2 cells, rather than in normal hepatocytes. Inhibition or silencing of TRPM2, or inhibition of the downstream Ca2+-CaM-CaMKII signaling pathway, significantly suppressed the proliferation of Huh-7 and HepG2 cells by arresting the cell cycle at the G1/S phase, accompanied with reduced expression of G1/S checkpoint proteins. Importantly, inhibition or depletion of TRPM2 remarkably slowed down the growth of patient-derived xenografts and Huh-7 xenografts in mice. CONCLUSION: Our results indicate that TRPM2 promotes HCC cell proliferation via activating the Ca2+-CaM-CaMKII signaling pathway to induce the expression of the key G1/S regulatory proteins and accelerate the cell cycle. This study provides compelling evidence of TRPM2 involvement in a previously unrecognized mechanism that drives HCC progression and demonstrates that TRPM2 is a potential target for HCC treatment.

Fully end-to-end deep-learning-based diagnosis of pancreatic tumors.

Artificial intelligence can facilitate clinical decision making by considering massive amounts of medical imaging data. Various algorithms have been implemented for different clinical applications. Accurate diagnosis and treatment require reliable and interpretable data. For pancreatic tumor diagnosis, only 58.5% of images from the First Affiliated Hospital and the Second Affiliated Hospital, Zhejiang University School of Medicine are used, increasing labor and time costs to manually filter out images not directly used by the diagnostic model. Methods: This study used a training dataset of 143,945 dynamic contrast-enhanced CT images of the abdomen from 319 patients. The proposed model contained four stages: image screening, pancreas location, pancreas segmentation, and pancreatic tumor diagnosis. Results: We established a fully end-to-end deep-learning model for diagnosing pancreatic tumors and proposing treatment. The model considers original abdominal CT images without any manual preprocessing. Our artificial-intelligence-based system achieved an area under the curve of 0.871 and a F1 score of 88.5% using an independent testing dataset containing 107,036 clinical CT images from 347 patients. The average accuracy for all tumor types was 82.7%, and the independent accuracies of identifying intraductal papillary mucinous neoplasm and pancreatic ductal adenocarcinoma were 100% and 87.6%, respectively. The average test time per patient was 18.6 s, compared with at least 8 min for manual reviewing. Furthermore, the model provided a transparent and interpretable diagnosis by producing saliency maps highlighting the regions relevant to its decision. Conclusions: The proposed model can potentially deliver efficient and accurate preoperative diagnoses that could aid the surgical management of pancreatic tumor.

Overcoming Wnt-ß-catenin dependent anticancer therapy resistance in leukaemia stem cells.

Leukaemia stem cells (LSCs) underlie cancer therapy resistance but targeting these cells remains difficult. The Wnt-ß-catenin and PI3K-Akt pathways cooperate to promote tumorigenesis and resistance to therapy. In a mouse model in which both pathways are activated in stem and progenitor cells, LSCs expanded under chemotherapy-induced stress. Since Akt can activate ß-catenin, inhibiting this interaction might target therapy-resistant LSCs. High-throughput screening identified doxorubicin (DXR) as an inhibitor of the Akt-ß-catenin interaction at low doses. Here we repurposed DXR as a targeted inhibitor rather than a broadly cytotoxic chemotherapy. Targeted DXR reduced Akt-activated ß-catenin levels in chemoresistant LSCs and reduced LSC tumorigenic activity. Mechanistically, ß-catenin binds multiple immune-checkpoint gene loci, and targeted DXR treatment inhibited expression of multiple immune checkpoints specifically in LSCs, including PD-L1, TIM3 and CD24. Overall, LSCs exhibit distinct properties of immune resistance that are reduced by inhibiting Akt-activated ß-catenin. These findings suggest a strategy for overcoming cancer therapy resistance and immune escape.

Role of Collateral Venous Circulation in Prevention of Sinistral Portal Hypertension After Superior Mesenteric-Portal Vein Confluence Resection during Pancreaticoduodenectomy: a Single-Center Experience.

BACKGROUND: The ligation of the splenic vein (SV) during pancreaticoduodenectomy (PD) may result in sinistral portal hypertension (SPH). This study aimed to identify the collateral pathways that formed postoperatively and evaluate the impact of omentum and arc of Barkow preservation in PD. METHODS: Patients who underwent PD between January 2013 and May 2018 at the Second Affiliated Hospital of Zhejiang University were enrolled in this retrospective study. PD was performed with preservation of the greater omentum and arc of Barkow. Venous collaterals, spleen size, and platelet count were evaluated before and after surgery. RESULTS: In total, 330 patients underwent PD, of whom, 43 patients who underwent superior mesenteric vein (SMV)/portal vein (PV) reconstruction and splenic vein (SV) ligation were selected. No patient developed severe gastrointestinal bleeding. Three collateral routes were identified: the left gastric route, the colic marginal route, and the first jejunal route. Seventeen patients developed splenomegaly. Twenty-three patients developed thrombocytopenia. However, none of them developed gastrointestinal bleeding or other clinical complaints. CONCLUSION: Although subclinical SPH developed after SV ligation, postoperative gastrointestinal bleeding was uncommon.

Salvage Liver Transplant versus Primary Liver Transplant for Patients with Hepatocellular Carcinoma.

The strategy of salvage liver transplantation (SLT) originated for initially resectable and transplantable hepatocellular carcinoma (HCC) to preclude upfront transplantation, with SLT in the case of recurrence. However, SLT remains a controversial approach in comparison to primary liver transplant (PLT). The aim of our study was to conduct a systemic review and meta-analysis to assess the short-term outcomes, overall survival (OS), and disease-free survival (DFS) between SLT and PLT for patients with HCC, stratifying results according to the Milan criteria and donor types. A search of PubMed, EMBASE, and the Cochrane Library was conducted to identify studies comparing SLT and PLT. A fixed effects model and a random effects model meta-analysis were conducted to assess the short-term outcomes, OS, and DFS based on the evaluation of heterogeneity. SLT had superior 1-year, 3-year, and 5-year OS and DFS compared with that of PLT. After classifying data according to donor type and Milan criteria, our meta-analysis revealed: that for deceased-donor liver transplantation (DDLT) recipients, there were no significant differences in 1-year and 3-year OS rate between the SLT group and the PLT group. However, the 5-year OS rate was superior in the SLT group compared to the PLT group. Similarly, SLT had superior 1-year, 3-year, and 5-year OS rate compared to PLT in living-donor liver transplantation (LDLT) recipients. Moreover, 1-year, 3-year, and 5-year DFS were also superior in SLT compared to PLT in both the DDLT and LDLT recipients. In patients within Milan criteria there were no statistically significant differences in 1-year, 3-year, and 5-year OS and DFS between the SLT group and the PLT group. Similarly, in patients beyond Milan criteria, both SLT and PLT showed no significant difference for 1-year, 3-year, and 5-year OS rate. Our meta-analysis included the largest number of studies comparing SLT and PLT, and SLT was found to have significantly better OS and DFS. Moreover, this meta-analysis suggests that SLT has comparable postoperative complications to that of PLT, and thus, SLT may be a better treatment strategy for recurrent HCC patients and patients with compensated liver, whenever feasible, considering the severe organ limitation and the safety of SLT. However, PLT can be referred as a treatment strategy for HCC patients with cirrhotic and decompensated liver.

Plasma miRNA, an emerging biomarker for pancreatic cancer.

Pancreatic cancer (PC) is one of the most dangerous types of cancer, much due to the lack of clinical symptoms in early stages. Early, noninvasive methods of detecting PC remain a great challenge in clinical practices. MicroRNAs (miRNAs), small and non-coding single-strand RNAs, emerge as potential biomarkers for PC. MiRNAs are involved in PC progression and abnormal level of miRNAs in plasma has been observed in PC patients. A multi-center study recently conducted by Xu and colleagues demonstrated the potential value of using circulating miRNAs to distinguish PC from normal donors and other pancreas-related diseases.

Inhibition of mTORC2 Induces Cell-Cycle Arrest and Enhances the Cytotoxicity of Doxorubicin by Suppressing MDR1 Expression in HCC Cells.

mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0-G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027-induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. Mol Cancer Ther; 14(8); 1805-15. ©2015 AACR.

Expression of MMP-9 in hepatic sinusoidal obstruction syndrome induced by Gynura segetum.

BACKGROUND AND OBJECTIVE: Hepatic sinusoidal obstruction syndrome (HSOS) is characterized by painful hepatomegaly, ascites, increased body weight, and jaundice. Gynura segetum (Compositae), a plant widely used in Chinese traditional medicine, often leads to the development of HSOS. However, the mechanism is unclear. The aim was to study the role of matrix metalloproteinase-9 (MMP-9) in the onset of HSOS induced by Gynura segetum. METHODS: Twenty-five male Sprague-Dawley rats were randomly divided into two groups. Twenty were exposed to 600 mg/kg daily Gynura segetum extract solution for three weeks; five control rats were exposed to tap water alone. Liver sections were evaluated by light microscopy with a modified scoring system. Routine transmission electron microscopy (TEM) methods were used to evaluate the ultrastructual features of fixed liver tissue, and blood samples were collected to determine liver enzyme concentrations. MMP-9 expression was assessed by both immunohistochemical staining and enzyme-linked immunosorbent assay (ELISA) methods. RESULTS: A stable and reproducible rat model of HSOS was achieved by long-term exposure to Gynura segetum extract. The treated rats presented clinical symptoms and the histopathological manifestation of HSOS, including abnormal liver enzyme concentrations (alanine aminotransferase (ALT): (84.8±13.62) vs. (167.0±72.63) U/L, P<0.05; aspartate aminotransferase (AST): (27.6±6.31) vs. (232.8±108.58) U/L, P<0.05). Hematoxylin and eosin (H&E) staining and TEM together revealed deposition of red blood cells, the damage and destruction of hepatic sinusoidal endothelial cells, collapse of hepatic sinusoids, hemorrhage of subendothelial cells, atrophy and destruction of hepatocytes, etc. Compared with controls, the expression of MMP-9 in the blood sample, the lung and liver tissues of HSOS rats was increased. CONCLUSIONS: MMP-9 may have an important role in early pathological changes of HSOS, and thus the onset of the disease.

NSC 74859 enhances doxorubicin cytotoxicity via inhibition of epithelial-mesenchymal transition in hepatocellular carcinoma cells.

Doxorubicin-based therapy is not effective for the treatment of hepatocellular carcinomas (HCCs), which often undergo epithelial-mesenchymal transition (EMT) during tumor progression. Activation of signal transducer and activator of transcription 3 (STAT3) is associated with chemosensitivity and may contribute to EMT during HCC chemotherapy. Low doses of NSC 78459 (a novel STAT3 inhibitor) have little effect on HCC cell proliferation, but efficiently inhibit STAT3. HuH-7, Hep3B, and HepG2 cells, with epithelial phenotypes, show significantly enhanced doxorubicin cytotoxicity following co-treatment with NSC 74859, whereas mesenchymal SNU-449 cells show no such enhancement. NSC 74859 inhibits STAT3 activity and suppressed doxorubicin-induced EMT in epithelial HCC cells. siRNA-mediated STAT3 knockdown resulted in EMT inhibition, which led to attenuation of NSC 74859-mediated chemosensitivity. Our data indicate NSC 74859 co-administration enhances doxorubicin cytotoxicity by inhibiting STAT3 in epithelial HCC cells. STAT3 deactivation and associated EMT attenuation contribute to the synergistic anti-tumor effects of combined NSC 74859/doxorubicin therapy.

CD133, Stem Cells, and Cancer Stem Cells: Myth or Reality?

CD133, a member of the prominin family, is found in a variety of tissues with at least three variants. The function of CD133 is not well understood, but its expression is subject to changes in the microenvironment cues including bioenergetic stress. Knockout of CD133 does not affect renewal, but mammary gland branching. A point mutation of CD133 (R733C) leads to retinal disorder. CD133 is found in embryonic stem cells, normal tissue stem cells, stem cell niches, and circulating endothelial progenitors as well as cancer stem cells. Maintenance of stemness in cancer may be attributable to asymmetric cell division in association with a set of embryonic expression signatures in CD133+ tumor cells. CD133 could enrich cancer stem cells, which are associated with chemo- and radiation resistance phenotype. High CD133 is associated with poor survival in a variety of solid tumors, including lung, colon, prostate, etc. Monitoring CD133+ cells in peripheral blood, and targeting CD133 in cancer, may further predict and improve the clinical outcomes.

Sinusoidal microcirculatory changes after small-for-size liver transplantation in rats.

Small-for-size graft injury is characterized by portal venous hypertension and loss of intracellular homeostasis early after transplant. The long-term alteration of sinusoidal microcirculatory hemodynamic state remains unknown. A syngeneic rat orthotopic liver transplantation model was developed using small-for-size grafts (35% of recipient liver weight) or whole grafts (100% of recipient liver weight). Graft survival, portal pressure, liver function, hepatocellular apoptosis as well as morphological changes (by light microscopy and electron microscopy) were assessed. Sinusoidal microcirculatory hemodynamics was examined by intravital fluorescence microscopy. Although portal hypertension lasted only for 1 h after performance of small-for-size liver transplantation, a sustained microcirculatory disturbance was accompanied by dramatic reduction of sinusoidal perfusion rate, elevation of sinusoidal diameter as well as increase in the number of apoptotic hepatocytes during the first 7 days. These resulted in lower survival rate (50% vs. 100%, P = 0.012), higher level of liver function, and more severe morphological changes, which could induce small-for-size syndrome. In conclusion, persistent microcirculatory hemodynamic derangement during the first 7 days after reperfusion as well as transient portal hypertension is significant manifestation after small-for-size liver transplantation. Long-term microcirculation disturbance displayed as decrease of sinusoidal reperfusion area and increase of spread in functional liver mass seems to be the key factor for graft injuries.