Outcomes of Robotic Versus Laparoscopic Pancreatoduodenectomy Following Learning Curves of Surgeons: A Multicenter Study on 2255 Patients.

OBJECTIVE: This study aimed to compare robotic pancreatoduodenectomy (RPD) with laparoscopic pancreatoduodenectomy (LPD) in operative and oncologic outcomes. BACKGROUND: Previous studies comparing RPD with LPD have only been carried out in small, single-center studies with variable quality. METHODS: Consecutive patients from nine centers in China who underwent RPD or LPD between 2015 and 2022 were included. A 1:1 propensity score matching (PSM) was used to minimize bias. RESULTS: Of the 2,255 patients, 1158 underwent RPD and 1097 underwent LPD. Following PSM, 1006 patients were enrolled in each group. The RPD group had significantly shorter operative time (270.0 vs. 305.0 minutes, P<0.001), lower intraoperative blood transfusion rate (5.9% vs. 12.0%, P<0.001), lower conversion rate (3.8% vs. 6.7%, P=0.004), and higher vascular reconstruction rate (7.9% vs. 5.6%, P=0.040) than the LPD group. There were no significant differences in estimated blood loss, postoperative length of stay, perioperative complications, and 90-day mortality. Patients who underwent vascular reconstruction had similar outcomes between the two groups, although they had significantly lower estimated blood loss (300.0 vs. 360.0 mL; P=0.021) in the RPD group. Subgroup analysis on pancreatic ductal adenocarcinoma (PDAC) found no significant differences between the two groups in median recurrence-free survival (14.3 vs. 15.3 mo, P=0.573) and overall survival (24.1 vs. 23.7 mo, P=0.710). CONCLUSIONS: In experienced hands, both RPD and LPD are safe and feasible procedures with similar surgical outcomes. RPD had the perioperative advantage over LPD especially in vascular reconstruction. For PDAC patients, RPD resulted in similar oncological and survival outcomes as LPD.

circFAM134B is a key factor regulating reticulophagy-mediated ferroptosis in hepatocellular carcinoma.

Ferroptosis is an important mode of regulated cell death (RCD). Its inhibition is closely related to therapeutic resistance and poor prognosis in hepatocellular carcinoma (HCC). Previous reports have demonstrated ferroptosis as a biological process highly dependent on selective autophagy, such as ferritinophagy, lipophagy, and clockophagy. Our study also revealed a role for ER-phagy-mediated ferroptosis in HCC cells treated with multi-targeted tyrosine kinase inhibitors (TKIs). In the current study, we found that the homologous circular RNA (circRNA) of the family with sequence similarity 134, member B (FAM134B), hsa_circ_0128505 (was abbreviated as circFAM134B in the present study), was identified to specifically target ER-phagy to promote lenvatinib (LV)-induced ferroptosis using reactive oxygen species (ROS), Fe2+, malondialdehyde (MDA), and western blot (WB) assays in HCC cells. RNA pull-down and mass spectrometry analyses suggested that circFAM134B and FAM134B mRNA were enriched with several common interacting proteins. Among them, poly (A) binding protein cytoplasmic 4 (PABPC4) was identified as the most enriched binding partner. It was proven to be a novel antagonist against the nonsense-mediated mRNA decay (NMD) mechanism. We then applied RNA immunoprecipitation (RIP), RNA pull-down, luciferase reporter, and NMD reporter gene assays to further explore the exact role and underlying mechanism of circFAM134B-PABPC4-FAM134B axis in HCC cells. circFAM134B was confirmed as a sponge that competitively interacted with PABPC4, thereby influencing FAM134B mRNA nonsense decay. Our results provide novel evidences and strategies for the comprehensive treatment of HCC.

Targeting FAM134B-mediated reticulophagy activates sorafenib-induced ferroptosis in hepatocellular carcinoma.

Ferroptosis is a kind of cell death closely related to selective autophagy, such as ferritinophagy, lipophagy, clockophagy and chaperone-mediated autophagy. However, the role of reticulophagy, which specifically degrades endoplasmic reticulum (ER) fragments (also known as ER-phagy), in ferroptosis regulation is still unclear. In this study, we found that sorafenib (ferroptosis inducer) can effectively activate the receptor protein FAM134B-mediated ER-phagy, and FAM134B knockdown not only blocked ER-phagy but also significantly strengthened cellular sensitivity to ferroptosis without affecting macroautophagy. In vivo experiments also yielded similar results. These evidences provided new clues for ferroptosis regulation. Subsequently, bioinformatic analysis combined with RNA binding protein immunoprecipitation and polyribosome fractionation preliminarily indicated that PABPC1 can interact with FAM134B mRNA and promote its translation. Taken together, this study revealed the role of the PABPC1-FAM134B-ER-phagy pathway on ferroptosis, providing important evidence for novel anti-cancer strategies.

RNA binding protein DAZAP1 promotes HCC progression and regulates ferroptosis by interacting with SLC7A11 mRNA.

RNA-binding proteins (RBPs) closely regulate the whole lifecycle of most RNA molecules, from the very early stage of transcription to RNA decay. Dysregulation of RBPs significantly affects the fate of cancer-related transcripts. Therefore, it is imperative to fully understand the complicated RBP-RNA regulatory networks in malignant diseases and to explore novel therapeutic targets. The RBP DAZAP1 (deleted in azoospermia-associated protein 1), originally identified as an important protein in spermatogenesis, had rarely been studied in the context of carcinogenesis. The role of DAZAP1 in hepatocellular carcinoma (HCC) was unveiled in this study. The relative expression of DAZAP1 was significantly upregulated in HCC and was positively associated with several key malignant characteristics and poor postoperative survival in patients. DAZAP1 knockdown by small interfering RNA markedly inhibited HCC cell proliferation, migration and invasion. Furthermore, DAZAP1 significantly reduced cellular sensitivity to sorafenib (SF), which had been proven to be an inducer of ferroptosis by targeting the system Xc- (composed of a light chain, xCT/SLC7A11, and a heavy chain, 4F2 heavy chain). At the mechanistic level, DAZAP1 was identified as a potent inhibitor of ferroptosis and an efficient binding partner of SLC7A11 mRNA. Further study revealed that DAZAP1 interacted with the 3'UTR (untranslated region) of SLC7A11 mRNA and positively regulated its stability. In our work, we clarified novel functions of DAZAP1 and preliminarily revealed its underlying mechanism in ferroptosis, which may be conducive to the exploration of biomarkers and therapeutic targets in HCC patients.

Circular RNA cIARS regulates ferroptosis in HCC cells through interacting with RNA binding protein ALKBH5.

Circular RNAs (circRNAs) are a novel and unique class of noncoding RNAs that are back-spliced from pre-mRNAs. It has been confirmed that circRNAs are involved in various malignant behaviors of hepatocellular carcinoma (HCC). However, the role of circRNA in the regulation of ferroptosis and the underlying mechanism remain unknown. Here, cIARS (hsa_circ_0008367) was found to be the most highly expressed circRNA after sorafenib (SF) treatment in HCC cells. Small interfering RNA against cIARS (si-cIARS) significantly suppressed the cellular sensitivity to SF or Erastin through inactivating ferroptosis, which may be partially attributed to the inhibition of autophagy and ferritinophagy. Prediction analysis and mechanistic identification revealed that cIARS physically interacted with RNA binding protein (RBP) ALKBH5, which was a negative regulator of autophagic flux in HCC. The dissociation of BCL-2/BECN1 complex, mediated by ALKBH5 silencing was effectively blocked by si-cIARS. Furthermore, the inhibition of ferroptotic events, autophagic flux and ferritinophagy resulted from si-cIARS, were significantly rescued by ALKBH5 downregulation. Overall, cIARS may be an important circRNA, positively regulating SF-induced ferroptosis through suppressing the ALKBH5-mediated autophagy inhibition.

Surgical method choice and coincidence rate of pathological diagnoses in transduodenal ampullectomy: A retrospective case series study and review of the literature.

BACKGROUND: Transduodenal ampullectomy (TDA) is not in wide clinical use due to its low radical effect and a high recurrence rate of tumors. However, TDA is still an effective treatment method; it has great clinical value in cases of duodenal benign tumors, precancerous lesions, and benign and malignant borderline tumors, and can avoid the risks associated with pancreaticoduodenectomy with larger resection range and greater thoroughness than endoscopic papillectomy. AIM: To investigate the surgical method choice and the coincidence rate of pathological diagnoses in TDA for ampullary neoplasms. METHODS: Ten patients with ampullary neoplasms underwent TDA based on the fact that their endoscopic biopsy results suggested benign lesions, and the endoscopic ultrasound (EUS)-assessed tumors were resectable. All cases underwent duodenal ampullary lesion endoscopic biopsy, intraoperative frozen-section pathological examination, and postoperative pathological examination. RESULTS: This study included seven patients with benign tumors and three with malignant tumors (1 pTis, 2 pT1), according to the postoperative pathology results. The coincidence rate of the postoperative pathology results with the intraoperative frozen-section biopsy results was 100% (10/10), and the coincidence rate with the endoscopic biopsy results was 70% (7/10) based on pathological characteristics. The endoscopic biopsy false-negative rate was 30% (3/10). All patients were followed for 6 to 70 mo without tumor recurrence or metastasis. CONCLUSION: The coincidence rate of postoperative pathology results, intraoperative frozen-section pathology results, and endoscopic biopsy results is the restraining factor of TDA clinical application. Endoscopic biopsy results and EUS have importance relevance to surgical planning. Intraoperative frozen-section pathology results have a significant influence on the choice of surgical procedure.

circ-BIRC6, a circular RNA, promotes hepatocellular carcinoma progression by targeting the miR-3918/Bcl2 axis.

Circular (circ)RNA is a special type of endogenous RNA consisting of a covalently closed loop structure without 5' to 3' polarity and a polyadenylated tail. Accumulating evidence suggests that circRNAs play important roles in the development and progression of human cancers. However, the role of circRNAs in the progression of hepatocellular carcinoma (HCC) is largely unknown. This was addressed in the present study using high-throughput sequencing to identify aberrantly expressed circRNAs in HCC patient tissue and cell lines. We found that circ-baculoviral IAP repeat-containing (BIRC)6 was upregulated in HCC tissue samples and cells; this was associated with the overall survival of HCC patients. circ-BIRC6 knockdown reduced HCC cell proliferation, migration, and invasion and enhanced their apoptosis. Additionally, circ-BIRC6 overexpression negatively regulated the expression of microRNA miR-3918, which was identified as an inhibitor of B cell lymphoma (Bcl)2. The tumor-suppressive effect of circ-BIRC6 deletion was abrogated by inhibiting miR-3918. These results indicate that circ-BIRC6 functions as a competing endogenous RNA that regulates Bcl2 expression by sponging miR-3918, and may serve as a prognostic biomarker and therapeutic target for the treatment of HCC.

Clinical applications of liquid biopsy as prognostic and predictive biomarkers in hepatocellular carcinoma: circulating tumor cells and circulating tumor DNA.

Hepatocellular carcinoma (HCC) is a highly malignant disease with a poor prognosis and high mortality due to a low early diagnosis rate, resistance to systemic treatments and progression to late-stage liver disease. Owing to limitations in the detection of HCC and the lack of awareness of healthcare systems, fewer than 40% of HCC patients are eligible for surgery due to advanced stages of the disease at the time of diagnosis and the occurrence of multiple lesions in the cirrhotic or fibrotic liver. At present, the updated American Association for the Study of Liver Disease (AASLD) guidelines no longer recommend alpha-fetoprotein (AFP) testing as a part of diagnostic evaluation. Thus, it is imperative to establish a novel diagnostic strategy with high sensitivity and reliability to monitor risk factors to detect HCC at an early stage. In recent years, "liquid biopsy," (including circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA)), has emerged as a technique for the characterization of circulating cells, providing a strong basis for the individualized treatment of patients. As a noninvasive detection method, liquid biopsy is expected to play an important role in the early diagnosis, dynamic monitoring of cancer patients and drug screening. In this review, we will focus on the clinical applications, recent studies and future prospects of liquid biopsy, particularly focusing on HCC.

Unicentric Castleman disease presenting as a retroperitoneal peripancreatic mass: A report of two cases and review of literature.

Castleman disease (CD) is a rare disorder of lymph nodes and related tissues. CD generally occurs in the mediastinum, as well as in cervical, retroperitoneal and axillary regions. The disease is classified into two major types: unicentric CD (UCD) and multicentric CD. The occurrence of UCD in the retroperitoneal peripancreatic region is quite rare. We encountered two cases of retroperitoneal peripancreatic UCD in our hospital during the past three years. Following a series of medical examinations, including magnetic resonance imaging, computed tomography, ultrasonography and postoperative histopathological examination, these two patients were diagnosed with UCD, which presented as a retroperitoneal peripancreatic mass. The mass in each patient was completely excised, and no postoperative radiochemotherapy was administered. Both patients recovered well without recurrence during a follow-up period of 30 mo and 8 mo.

P18 peptide, a functional fragment of pigment epithelial-derived factor, inhibits angiogenesis in hepatocellular carcinoma via modulating VEGF/VEGFR2 signalling pathway.

The P18 peptide is a functional fragment of pigment epithelial-derived factor (PEDF), which is an endogenic angiogenesis inhibitor. This study sought to determine the anti-angiogenic bioactivity of the P18 peptide in hepato-cellular carcinoma (HCC) and to elucidate the underlying mechanism. Xenograft tumour growth assays demonstrated the P18 peptide suppressed angiogenesis of HCC in vivo. Wound healing, Transwell and Matrigel-culture assays indicated that the P18 peptide inhibited the cell migration and tube formation of endothelial cells (ECs) in vitro. Cell viability and apoptosis assessed by Cell Counting Kit-8 (CCK-8) and flow cytometry assays suggested that the P18 peptide inhibited angiogenesis by inducing apoptosis of ECs. Angiogenesis- and signal transduction-associated molecules analysed by western blot demonstrated that the P18 peptide targets vascular endothelial cell growth factor receptor 2 (VEGFR2) on ECs. In conclusion, by inhibiting the phosphorylation of VEGFR2, the P18 peptide modulates signalling transduction between VEGF/VEGFR2 and suppresses activation of the PI3K/Akt cascades, leading to an increase in mitochondrial-mediated apoptosis and anti-angiogenic activity. This bioactivity of the P18 peptide may represent a novel therapeutic strategy for the treatment of HCC.

Hypoxia induces oncogene yes-associated protein 1 nuclear translocation to promote pancreatic ductal adenocarcinoma invasion via epithelial-mesenchymal transition.

Pancreatic ductal adenocarcinoma is one of the most lethal cancers. The Hippo pathway is involved in tumorigenesis and remodeling of tumor microenvironments. Hypoxia exists in the microenvironment of solid tumors, including pancreatic ductal adenocarcinoma and plays a vital role in tumor progression and metastasis. However, it remains unclear how hypoxia interacts with the Hippo pathway to regulate these events. In this study, expressions of yes-associated protein 1 and hypoxia-inducible factor-1α were found to be elevated in pancreatic ductal adenocarcinoma samples compared with those in matched adjacent non-tumor samples. Moreover, hypoxia-inducible factor-1α expression was positively correlated with yes-associated protein 1 level in pancreatic ductal adenocarcinoma tissues. The higher expression of nuclear yes-associated protein 1 was associated with poor histological grade and prognosis for pancreatic ductal adenocarcinoma patients. In vitro, yes-associated protein 1 was highly expressed in pancreatic ductal adenocarcinoma cells. Depletion of yes-associated protein 1 inhibited the invasion of pancreatic ductal adenocarcinoma cells via downregulation of Vimentin, matrix metalloproteinase-2, and matrix metalloproteinase-13, and upregulation of E-cadherin. In addition, hypoxia promoted the invasion of pancreatic ductal adenocarcinoma cells via regulating the targeted genes. Hypoxia also deactivated the Hippo pathway and induced yes-associated protein 1 nuclear translocation. Furthermore, depletion of yes-associated protein 1 or hypoxia-inducible factor-1α suppressed the invasion of pancreatic ductal adenocarcinoma cells under hypoxia. Mechanism studies showed that nuclear yes-associated protein 1 interacted with hypoxia-inducible factor-1α and activated Snail transcription to participate in epithelial-mesenchymal transition-mediated and matrix metalloproteinase-mediated remodeling of tumor microenvironments. Collectively, yes-associated protein 1 is an independent prognostic predictor that interacts with hypoxia-inducible factor-1α to enhance the invasion of pancreatic cancer cells and remodeling of tumor microenvironments. Therefore, yes-associated protein 1 may serve as a novel promising target to enhance therapeutic effects for treating pancreatic cancer.

Initial study of sediment antagonism and characteristics of silver nanoparticle-coated biliary stents in an experimental animal model.

OBJECTIVE: Plastic biliary stents used to relieve obstructive jaundice are frequently blocked by sediment, resulting in loss of drainage. We prepared stents coated with silver nanoparticles (AgNPs) and compared their ability to resist sedimentation with Teflon stents in a beagle model of obstructive jaundice. METHODS: AgNP-coated Teflon biliary stents were prepared by chemical oxidation-reduction and evaluated in an obstructive jaundice model that was produced by ligation of common bile duct (CBD); animals were randomized to two equal groups for placement of AgNP-coated or Teflon control stents. Liver function and inflammatory index were found to be similar in the two groups, and the obstruction was relieved. Stents were removed 21 days after insertion and observed by scanning and transmission electron microscopy. The AgNP coating was analyzed by energy dispersive X-ray analysis (EDXA), and the composition of sediment was assayed by Fourier-transform infrared (FTIR) spectroscopy. RESULTS: Electron microscopy revealed a black, closely adherent AgNP stent coating, with thicknesses of 1.5-6 µm. Sediment thickness and density were greater on Teflon than on AgNP-coated stents. EDXA confirmed the stability and integrity of the AgNP coating before and after in vivo animal experimentation. FTIR spectroscopy identified stent sediment components including bilirubin, cholesterol, bile acid, protein, calcium, and other substances. CONCLUSION: AgNP-coated biliary stents resisted sediment accumulation in this canine model of obstructive jaundice caused by ligation of the CBD.

Meloxicam suppresses hepatocellular carcinoma cell proliferation and migration by targeting COX-2/PGE2-regulated activation of the ß-catenin signaling pathway.

Recurrence and metastasis are the two leading causes of poor prognosis of hepatocellular carcinoma (HCC) patients. Cyclooxygenase (COX)-2 is overexpressed in many types of cancers including HCC and promotes its metastasis. Meloxicam is a selective COX-2 inhibitor that has been reported to exert an anti-proliferation and invasion/migration response in various tumors. In this study, we examined the role of meloxicam on HCC cell proliferation and migration and explored the molecular mechanisms underlying this effect. We found that meloxicam inhibited HCC cell proliferation and had a cell cycle arrest effect in human HCC cells. Furthermore, meloxicam suppressed the ability of HCC cells expressing higher levels of COX-2 and prostaglandin E2 (PGE2) to migration via potentiating expression of E-cadherin and alleviating expression of matrix metalloproteinase (MMP)-2 and -9. COX-2/PGE2 has been considered to activate the ß-catenin signaling pathway which promotes cancer cell migration. We found that treatment with PGE2 significantly enhanced nuclear accumulation of ß-catenin and the activation of GSK3ß which could be reversed by meloxicam in HCC cells. We also observed that HCC cell migration and upregulation of the level of MMP-2/9 and downregulation of E-cadherin induced by PGE2 were suppressed by FH535, an inhibitor of ß-catenin. Taken together, these findings provide a new treatment strategy against HCC proliferation and migration.

Targeting hypoxia-inducible factor-2α enhances sorafenib antitumor activity via ß-catenin/C-Myc-dependent pathways in hepatocellular carcinoma.

Sorafenib is a type of multikinase inhibitor that exhibits antiangiogenic and antiproliferative effects; in addition, sorafenib is a unique first-line drug recommended for the treatment of advanced hepatocellular carcinoma (HCC). However, the effectiveness of HCC treatment remains poor due to acquired drug resistance. It has been suggested that hypoxia, induced as a results of the antiangiogenic effects of sustained sorafenib treatment, may be an important factor in sorafenib resistance. The transcription factor hypoxia-inducible factor (HIF)-2α has been reported to be associated with cell proliferation under hypoxic conditions; therefore, it was hypothesized that hypoxia may enhance tumor cell proliferation via this mechanism. The present study aimed to evaluate whether the knock-down of HIF-2α was able to enhance the therapeutic efficacy of sorafenib in order to effectively treat HCC. The results demonstrated that hypoxia protected HCC cells against sorafenib; however, short hairpin RNA-HIF-2α transfection in combination with sorafenib treatment exhibited a significantly synergistic effect against HCC cell proliferation. In addition, HCC cells acquired increased ß-catenin/C-Myc expression, which enhanced proliferation under hypoxic conditions; however, targeted knock-down of HIF-2α or C-Myc markedly decreased cell proliferation in HCC cells. In conclusion, the results of the present study indicated that the targeted knock-down of HIF-2α in combination with sorafenib may be a promising strategy for the treatment of HCC.

Blocking autophagy enhances meloxicam lethality to hepatocellular carcinoma by promotion of endoplasmic reticulum stress.

OBJECTIVES: Meloxicam, a selective cyclooxygenase-2 (COX-2) inhibitor, has been demonstrated to exert anti-tumour effects against various malignancies. However, up to now, mechanisms involved in meloxicam anti-hepatocellular carcinoma effects have remained unclear. MATERIALS AND METHODS: Cell viability and apoptosis were assessed by CCK-8 and flow cytometry. Endoplasmic reticulum (ER) stress and autophagy-associated molecules were analysed by western blotting and immunofluorescence assay. GRP78 and Atg5 knock-down by siRNA or chemical inhibition was used to investigate cytotoxic effects of meloxicam treatment on HCC cells. RESULTS: We found that meloxicam led to apoptosis and autophagy in HepG2 and Bel-7402 cells via a mechanism that involved ER stress. Up-regulation of GRP78 signalling pathway from meloxicam-induced ER stress was critical for activation of autophagy. Furthermore, autophagy activation attenuated ER stress-related cell death. Blocking autophagy by 3-methyladenine (3-MA) or Atg5 siRNA knock-down enhanced meloxicam lethality for HCC by activation of ER stress-related apoptosis. In addition, GRP78 seemed to lead to autophagic activation via the AMPK-mTOR signalling pathway. Blocking AMPK with a chemical inhibitor inhibited autophagy suggesting that meloxicam-regulated autophagy requires activation of AMPK. CONCLUSIONS: Our results revealed that both ER stress and autophagy were involved in cell death evoked by meloxicam in HCC cells. This inhibition of autophagy to enhance meloxicam lethality, suggests a novel therapeutic strategy against HCC.

Meloxicam combined with sorafenib synergistically inhibits tumor growth of human hepatocellular carcinoma cells via ER stress-related apoptosis.

Sorafenib (SOR) is a promising treatment for advanced hepatocellular carcinoma (HCC). However, the precise mechanisms of toxicity and drug resistance have not been fully explored and new strategies are urgently needed for HCC therapy. Meloxicam (MEL) is a selective cyclooxygenase-2 (COX-2) inhibitor which elicits antitumor effects in human HCC cells. In the present study, we investigated the interaction between MEL and SOR in human SMMC­7721 cells and the role endoplasmic reticulum (ER) stress exerts in the combination of SOR with MEL treatment-induced cytotoxicity. Our results revealed that the combination treatment synergistically inhibited cell proliferation and enhanced apoptosis. Furthermore, the combination treatment enhanced ER stress-related molecules which involved in SMMC-7721 cell apoptosis. GRP78 knockdown by siRNA or co-treatment with MG132 significantly increased this combination treatment-induced apoptosis. In addition, we found that the combination treatment suppressed tumor growth by way of activation of ER stress in in vivo models. We concluded that the combination of SOR with MEL treatment-induced ER stress, and eventually apoptosis in human SMMC-7721 cells. Knockdown of GRP78 using siRNA or proteosome inhibitor enhanced the cytotoxicity of the combination of SOR with MEL-treatment in SMMC-7721 cells. These findings provided a new potential treatment strategy against HCC.

Integrin αvß3 is required for cathepsin B-induced hepatocellular carcinoma progression.

The cysteine protease cathepsin B (Cat B) is important in the progression of tumor cells, however, the function and molecular mechanisms of Cat B in hepatocellular carcinoma (HCC) remain to be elucidated. Our previous study demonstrated that integrin αvß3 regulated the biological behavior of HCC. The present study demonstrated that Cat B was also important in cell proliferation and apoptosis in HCC. Notably, Cat B was observed to activate the phosphoinositide 3­kinase (PI3K)/Akt signaling pathway to promote HCC proliferation. Furthermore, inhibition of integrin αvß3 significantly prevented Cat B­induced activation of PI3K/Akt and the progression of HCC. Thus, the results of the present study suggested the presence of a Cat B/integrin αvß3/PI3K/Akt axis in the regulation of the progression of HCC.

T7 peptide inhibits angiogenesis via downregulation of angiopoietin-2 and autophagy.

Angiogenesis is required for the invasion, metastasis and chemoresistance of tumor cells. In addition to vascular endothelial cell growth factor (VEGF), angiopoietin-2 (Ang2) is considered to be a promising target for anti-angiogenic therapy. The T7 peptide, an active fragment of full-length tumstatin [the noncollagenous 1 domain of the type IV collagen α3 chain, α3(IV)NC1], has equivalent anti-angiogenic activity to that of full-length tumstatin. This study aimed to explore the mechanisms of the T7 peptide in the regulation of Ang2 expression in endothelial cells (ECs) as well as inhibition of angiogenesis and invasion of hepatocellular carcinoma cells. We also examined the role of autophagy in angiogenesis. Human umbilical vein endothelial cells (HUVECs) were incubated with endothelial cell medium (ECM)-2 in a hypoxia chamber to mimic hypoxic conditions. The recombinant T7 peptide inhibited the cell viability, tube formation and induced apoptosis of the HUVECs. The T7 peptide downregulated the protein expression of Ang2 by inhibiting phosphorylation of AKT under hypoxic conditions. The migration of HUVECs and invasion of HepG2 cells were inhibited by the T7 peptide via inhibition of Ang2 expression. EC autophagy was induced by the T7 peptide. Inhibition of autophagy enhanced the anti­angiogenic activity of the T7 peptide by increasing EC apoptosis. In vivo, immunohistochemistry of VE-cadherin and CD31 showed that angiogenesis was decreased significantly by the T7 peptide in a nude mouse xenogeneic tumor model. In conclusion, the T7 peptide inhibited angiogenesis and exerted its antitumor effects by inhibition of Ang2, phosphorylation of AKT and matrix metalloproteinase-2 (MMP-2) regulated by Ang2. Furthermore, inhibition of autophagy may significantly enhance the anti-angiogenic activity of the T7 peptide.

Downregulating sCLU enhances the sensitivity of hepatocellular carcinoma cells to gemcitabine by activating the intrinsic apoptosis pathway.

PURPOSE: The purpose of this study was to investigate whether the therapeutic activity of gemcitabine (GCB) in hepatocellular carcinoma (HCC) could be increased by the down-regulation of secretory clusterin (sCLU), a glycoprotein that is considered to play a cytoprotective role in the resistance to chemotherapy. METHODS: The expression of sCLU was detected in HCC tumor tissues and cell lines. A cell viability and apoptosis assay were performed in parental HCC cells or the same cells transfected with sCLU shRNA and treated with or without GCB. The potential downstream pathways were investigated using the Human Apoptosis RT(2) Profiler™ PCR Array. RESULTS: The expression levels of sCLU in HCC tissues were significantly higher than in adjacent non-tumor liver tissues and were associated with the histological grade and transarterial chemoembolization. sCLU overexpression was also found in three HCC cell lines and hepatocytes. The depletion of sCLU synergistically increased GCB sensitivity in Bel7402 and SMMC7721 cells and induced cell apoptosis. Based on the PCR array analysis, sCLU depletion also resulted in the up-regulation of BNIP1, GADD45A, TNFRSF10A, and TRADD and down-regulation of AKT1 in Bel7402 and SMMC7721 cells compared with the parental controls. These results were further supported by a Western blot analysis, which showed increased GADD45a protein expression and the decreased expression of phosphorylated AKT. GADD45a overexpression also increased the sensitivity to GCB in the Bel7402 and SMMC7721 cells. CONCLUSION: Targeting sCLU may be a useful method to enhance the cytotoxic effect of GCB in hepatocellular carcinoma.