Gene and protein expression of mTOR and LC3 in hepatocellular carcinoma, colorectal liver metastasis and "normal" liver tissues.
ABSTRACT: The physiological role of autophagy in the progression of liver diseases is still debated. To understand the clinical relevance of autophagy in primary e secondary hepatic tumors, we analyzed the expression of mTOR (mammalian target of rapamycin), a key regulator of autophagy; Raptor (regulatory-associated protein of mTOR); ULK1 (Unc-51 like kinase 1) determinant in the autophagy initiation; LC3 (microtubule-associated protein 1A/1B-light chain 3), a specific marker of autophagosomes; and p62, a selective autophagy receptor. Samples from subjects with chronic hepatitis (n.58), cirrhosis (n.12), hepatocellular carcinoma (HCC, n.56), metastases (n.48) from colorectal cancer and hyperplasia or gallbladder stones (n.7), the latter considered as controls, were examined. Gene expression analysis was carried out in n.213 tissues by absolute q-PCR, while protein expression by Western Blot in n.191 lysates, including tumoral, surrounding tumoral and normal tissues. Nonparametric statistical tests were used for comparing expression levels in the above-mentioned groups. Subgroup analysis was performed considering viral infection and chemotherapy treatment. The mTOR transcriptional level was significantly lower in metastases compared to HCC (P = 0.0001). p-mTOR(Ser2448) and LC3II/LC3I protein levels were significantly higher in metastases compared to HCC (P = 0.008 and P<0.0001, respectively). ULK(Ser757) levels were significantly higher in HCC compared to metastases (P = 0.0002) while the HCV- and HBV- related HCC showed the highest p62 levels. Chemotherapy induced a down-regulation of the p-mTOR(Ser2448) in metastases and in non-tumor surrounding tissues in treated patients compared to untreated (P = 0.001 and P = 0.005, respectively). Conclusions: the different expression of proteins considered, owning their interaction and diverse tissue microenvironment, indicate an impairment of the autophagy flux in primary liver tumors that is critical for the promotion of tumorigenesis process and a coexistence of autophagy inhibition and activation mechanisms in secondary liver tumors. Differences in mTOR and LC3 transcripts emerged in tumor-free tissues, therefore particular attention should be considered in selecting the control group.
Project description:BACKGROUND:The role of autophagy-related markers as the prognostic factor of post-operative hepatocellular carcinoma (HCC) recurrence remained controversial. METHODS:Overall, 535 consecutive HCC patients undergoing curative resection from 2010 to 2014 were followed and classified with early (ER, <2 years) or late recurrence (LR). Autophagy-related markers, LC3, Beclin-1, and p62 expression was immunohistochemically assessed in HCC and adjacent non-tumor (ANT) tissues. RESULTS:HCC recurred in 245 patients: 116 with ER and 129 with LR. The cumulative incidence of recurrence at 1, 3, 5, and 7 years was 9.7%, 33.9%, 53.3%, and 66.3%, respectively. In multivariate analysis, HCC recurrence was significantly associated with low LC3 expression in tumor and ANT tissues, HCC tissues only and ANT tissues only (hazard ratio/95% confidence interval: 6.12/2.473-17.53, 4.18/1.285-13.61, and 1.89/1.299-2.757) and macrovascular invasion (1.63/1.043-2.492) and cirrhosis (1.59/1.088-2.326). ER was significantly associated with low LC3 expression in tumor and ANT tissues, HCC tissues only and ANT tissues only (6.54/2.934-15.81, 3.26/1.034-10.27, and 2.09/1.313-3.321) and macrovascular and microvascular invasion (2.65/1.306-5.343 and 2.55/1.177-5.504). LR was significantly associated with low LC3 expression in tumor and ANT tissues, HCC tissues only and ANT tissues only (5.02/1.372-18.83, 3.19/1.13-12.09, and 1.66/1.051-2.620) and cirrhosis (1.66/1.049-2.631). Patients with low and high LC3 expression in tumor and ANT tissues showed a 5-year cumulative recurrence of 94.3% and 41.7%, respectively (p?<?0.001). CONCLUSIONS:The high LC3 expression in the tumor and liver microenvironments is significantly associated with lower HCC recurrence. Furthermore, tumor characteristics and liver microenvironment were also significantly associated with ER and LR, respectively. TRANSLATIONAL IMPACT:The analysis for LC3 expression in both the HCC and ANT tissues could identify patients at risk of HCC recurrence.
Project description:BACKGROUND:Long noncoding RNA HULC is highly up-regulation in human hepatocellular carcinoma (HCC). However, the functions of HULC in hepatocarcinogenesis remains unclear. METHODS:RT-PCR, Western blotting, Chromatin immunoprecipitation (CHIP) assay, RNA Immunoprecipitation (RIP) and tumorignesis test in vitro and in vivo were performed. RESULTS:HULC is negatively associated with expression of PTEN or miR15a in patients of human liver cancer. Moreover, HULC accelerates malignant progression of liver cancer cells in vitro and in vivo. Mechanistically, HULC increasesthe expression of P62 via decreasing mature miR15a. On the other hand, excessive HULC increases the expression of LC3 on the level of transcription and then activates LC3 through Sirt1 (a deacetylase). Notably, HULC enhanced the interplay between LC3 and ATG3. Furthermore, HULC also increases the expression of becline-1(autophagy related gene). Therefore, HULC increases the cellular autophagy by increasing LC3II dependent on Sirt1.Noteworthy, excessive HULC reduces the expression of PTEN, ?-catenin and enhances the expression of SAPK/JUNK, PKM2, CDK2, NOTCH1, C-Jun in liver cancer cells. Of significance, our observations also revealed that HULC inhibited PTEN through ubiquitin-proteasome system mediated by autophagy-P62.Ultimately,HULC activates AKT-PI3K-mTOR pathway through inhibiting PTEN in human liver cancer cells. CONCLUSIONS:This study elucidates a novel mechanism that lncRNA HULC produces a vital function during hepatocarcinogenesis.
Project description:<h4>Background</h4>Autophagy is an important adaptive survival mechanism, which has been postulated to be involved in cancer metastasis. The purpose of this study was to investigate autophagy in metastasis of hepatocellular carcinoma (HCC).<h4>Methods</h4>Immunohistochemical analysis of autophagic activity in metastatic and paired primary HCC tissues using LC3 as autophagosome marker was performed in samples from 216 HCC patients diagnosed with metastasis (including 158 intravascular, 42 intrabiliary, 8 lymph node, 4 bone and 4 lung metastases). Then a mouse model of pulmonary metastasis was established using a highly metastatic HCC cell line (HCCLM3). Autophagy in pulmonary metastases and paired primary tumors were analyzed by LC3 immunohistochemistry, transmission electron microscopy (TEM) and western blot analysis. Further, mouse model of pulmonary metastasis and in vitro cell migration, invasion and detachment models were established using a stable GFP-LC3-expressing HCCLM3 cell line (HCCLM3-GFP-LC3). Autophagic alterations during metastatic colonization, migration, invasion and detachment were determined by GFP-LC3 analysis and western blot analysis.<h4>Results</h4>LC3 immunohistochemistry of metastases and primary tumors from HCC patients revealed significantly higher LC3 expression in metastases than primary HCC, which suggested a higher level of autophagy in HCC metastases. Further immunohistochemical, TEM, western blot and in vivo GFP-LC3 analyses of lung metastases and primary tumors in mouse model of pulmonary metastasis confirmed that metastatic colonies displayed higher level of autophagy than primary tumors and the early metastatic colonies displayed highest level. The dynamic monitoring of autophagy in cell migration, invasion and detachment showed that autophagy did not significantly alter in those processes.<h4>Conclusions</h4>Autophagy is activated in metastatic colonization but not in invasion, migration and detachment of HCC cells. Autophagy may play a role in HCC metastasis via promoting metastatic colonization of HCC cells.
Project description:The remnant liver's ability to regenerate may affect post-hepatectomy immediate mortality. The promotion of autophagy post-hepatectomy could enhance liver regeneration and reduce mortality. This study aimed to identify predictive factors of immediate mortality after surgical resection for hepatocellular carcinoma (HCC). A total of 535 consecutive HCC patients who had undergone their first surgical resection in Taiwan were enrolled between 2010 and 2014. Clinicopathological data and immediate mortality, defined as all cause-mortality within three months after surgery, were analyzed. The expression of autophagy proteins (LC3, Beclin-1, and p62) in adjacent non-tumor tissues was scored by immunohistochemical staining. Approximately 5% of patients had immediate mortality after surgery. The absence of LC3, hypoalbuminemia (<3.5 g/dl), high alanine aminotransferase, and major liver surgery were significantly associated with immediate mortality in univariate analyses. Multivariate logistic regression demonstrated that absence of LC3 (hazard ratio/95% confidence interval: 40.8/5.14-325) and hypoalbuminemia (2.88/1.11-7.52) were significantly associated with immediate mortality. The 3-month cumulative incidence of mortality was 12.1%, 13.0%, 21.4% and 0.4%, respectively, among patients with absence of LC3 expression, hypoalbuminemia, both, or neither of the two. In conclusion, the absence of LC3 expression in adjacent non-tumor tissues and hypoalbuminemia were strongly predictive of immediate mortality after resection for HCC.
Project description:Deficiency in autophagy, a lysosome-dependent cell degradation pathway, has been associated with a variety of diseases especially cancer. Recently, the activation of autophagy by hepatitis B virus X (HBx) protein, which is implicated in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC), has been identified in hepatic cells. However, the underlying mechanism and the relevance of HBx-activated autophagy to the carcinogenesis caused by HBV remain elusive. Here, by transfection of HBV genomic DNA and HBx in hepatic and hepatoma cells, we showed that HBV- or HBx-induced autophagosome formation was accompanied by unchanged MTOR (mechanistic target of rapamycin) activity and decreased degradation of LC3 and SQSTM1/p62, the typical autophagic cargo proteins. Further functional and morphological analysis indicated that HBx dramatically impaired lysosomal acidification leading to a drop in lysosomal degradative capacity and the accumulation of immature lysosomes possibly through interaction with V-ATPase affecting its lysosome targeting. Moreover, clinical specimen test showed increased SQSTM1 and immature lysosomal hydrolase CTSD (cathepsin D) in human liver tissues with chronic HBV infection and HBV-associated liver cancer. These data suggest that a repressive effect of HBx on lysosomal function is responsible for the inhibition of autophagic degradation, and this may be critical to the development of HBV-associated HCC.
Project description:Prostate cancer (PC) is one of the leading causes of death in males. Available treatments often lead to the appearance of chemoresistant foci and metastases, with mechanisms still partially unknown. Within tumour mass, autophagy may promote cell survival by enhancing cancer cells tolerability to different cell stresses, like hypoxia, starvation or those triggered by chemotherapic agents. Because of its connection with the apoptotic pathways, autophagy has been differentially implicated, either as prodeath or prosurvival factor, in the appearance of more aggressive tumours. Here, in three PC cells (LNCaP, PC3, and DU145), we tested how different autophagy inducers modulate docetaxel-induced apoptosis. We selected the mTOR-independent disaccharide trehalose and the mTOR-dependent macrolide lactone rapamycin autophagy inducers. In castration-resistant PC (CRPC) PC3 cells, trehalose specifically prevented intrinsic apoptosis in docetaxel-treated cells. Trehalose reduced the release of cytochrome c triggered by docetaxel and the formation of aberrant mitochondria, possibly by enhancing the turnover of damaged mitochondria via autophagy (mitophagy). In fact, trehalose increased LC3 and p62 expression, LC3-II and p62 (p62 bodies) accumulation and the induction of LC3 puncta. In docetaxel-treated cells, trehalose, but not rapamycin, determined a perinuclear mitochondrial aggregation (mito-aggresomes), and mitochondria specifically colocalized with LC3 and p62-positive autophagosomes. In PC3 cells, rapamycin retained its ability to activate autophagy without evidences of mitophagy even in presence of docetaxel. Interestingly, these results were replicated in LNCaP cells, whereas trehalose and rapamycin did not modify the response to docetaxel in the ATG5-deficient (autophagy resistant) DU145 cells. Therefore, autophagy is involved to alter the response to chemotherapy in combination therapies and the response may be influenced by the different autophagic pathways utilized and by the type of cancer cells.
Project description:Autoimmune hepatitis (AIH) is characterized by massive immune cell-mediated hepatocyte destruction. Glucocorticoids, particularly methylprednisolone (MP), are the most effective treatment for AIH; however, the mechanism underlying the effects of glucocorticoid treatment has not been fully elucidated. The present study explored the effects of MP on damaged hepatocytes in mice with concanavalin A (ConA)-induced experimental autoimmune hepatitis (EAH). C57BL/6 mice were divided into three groups: a normal control group (injected with normal saline), a ConA (20 mg/kg) group, and a ConA + MP (3.12 mg/kg) group. The serum levels of liver enzymes, cytokines, activated T cells, and apoptosis- and autophagy-associated marker proteins were determined 12 h after ConA injection. Human hepatocyte cell line LO2 was used to verify the effects of ConA and MP in vitro. MP treatment significantly decreased inflammatory reactions in the serum and liver tissues and activated the Akt/mTOR signaling pathway to inhibit apoptosis and autophagy in hepatocytes in vivo. Transmission electron microscopy (TEM) revealed fewer autophagosomes in the MP-treated group than in the ConA-treated group. MP treatment obviously suppressed apoptosis and mitochondrial membrane potential (??m) loss in hepatocytes in vitro. Furthermore, ConA treatment increased the levels of LC3-II, p62/SQSTM1, and Beclin-1, while bafilomycin A1 did not augment the levels of LC3-II. MP treatment decreased the levels of LC3-II, p62/SQSTM1, and Beclin-1 and upregulated the levels of phosphorylated (p)-Akt and p-mTOR. In conclusion, MP ameliorated mitochondria-mediated apoptosis and autophagy dysfunction in ConA-induced hepatocyte injury in vivo and in vitro via the Akt/mTOR signaling pathway.
Project description:Hepatocellular carcinoma (HCC) is a fatal and dominant form of liver cancer that currently has no effective treatment or positive prognosis. In this study, we explored the antitumor effects of cryptotanshinone (CPT) against HCC and the molecular mechanisms underlying these effects using a systems pharmacology and experimental validation approach. First, we identified a total of 296 CPT targets, 239 of which were also HCC-related targets. We elucidated the mechanisms by which CPT affects HCC through multiple network analysis, including CPT-target network analysis, protein-protein interaction network analysis, target-function network analysis, and pathway enrichment analysis. In addition, we found that CPT induced apoptosis in Huh7 and MHCC97-H ells due to increased levels of cleaved PARP, Bax, and cleaved caspase-3 and decreased Bcl-2 expression. CPT also induced autophagy in HCC cells by increasing LC3-II conversion and the expression of Beclin1 and ATG5, while decreasing the expression of p62/SQSTM1. Autophagy inhibitors (3-methyladenine and chloroquine) enhanced CPT-induced proliferation and apoptosis, suggesting that CPT-induced autophagy may protect HCC cells against cell death. Furthermore, CPT was found to inhibit the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. Interestingly, activation of PI3K by insulin-like growth factor-I inhibited CPT-induced apoptosis and autophagy, suggesting that the PI3K/AKT/mTOR signaling pathway is involved in both CPT-induced apoptosis and autophagy. Finally, CPT was found to inhibit the growth of Huh7 xenograft tumors. In conclusion, we first demonstrated the antitumor effects of CPT in Huh7 and MHCC97-H cells, both in vitro and in vivo. We elucidated the potential antitumor mechanism of CPT, which involved inducing apoptosis and autophagy by inhibiting the PI3K/Akt/mTOR signaling pathway. Our findings may provide valuable insights into the clinical application of CPT, serving as a potential candidate therapeutic agent for HCC treatment.
Project description:p62/SQSTM1 is a multifunctional signaling hub and autophagy adaptor with many binding partners, which allow it to activate mTORC1-dependent nutrient sensing, NF-κB-mediated inflammatory responses, and the NRF2-activated antioxidant defense. p62 recognizes polyubiquitin chains via its C-terminal domain and binds to LC3 via its LIR motif, thereby promoting the autophagic degradation of ubiquitinated cargos. p62 accumulates in many human liver diseases, including nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC), where it is a component of Mallory-Denk bodies and intracellular hyaline bodies. Chronic p62 elevation contributes to HCC development by preventing oncogene-induced senescence and death of cancer-initiating cells and enhancing their proliferation. In this review, we discuss p62-mediated signaling pathways and their roles in liver pathophysiology, especially NASH and HCC.
Project description:Introduction:Aerobic training has a beneficial effect on enhancing liver functions. Autophagy might potentially play a role in preventing excessive lipid accumulation, regulating oxidative stress, and inflammation in the liver. Objective:To investigate the potential linking role of autophagy-related gene expressions and protein levels with histopathology changes in Wistar rat livers after treadmill training under different intensities. Methods:20 rats were divided into 4 groups (control, low intensity, moderate intensity, and high intensity). 8 weeks of treadmill training was conducted with a frequency of 5 days per week, for a duration of 30 min per day. Liver histopathology was studied using hematoxylin-eosin, and oil red O staining. RNA and protein from the liver tissues were extracted to examine the autophagy-related gene (LC3, p62) and protein levels (Beclin, ATG5, LC3, p62). The gene expressions of CPT1a, CD36, FATP 2,3,5, GLUT2, and FGF21 were also studied. Results:Different intensities of training might potentially modulate autophagy-related gene expressions in rat livers. LC3 and p62 mRNA expressions in moderate and high intensities decreased compared to control. Beclin, ATG5, and LC3 protein level increased compared to control, while p62 protein level decreased compared to control. Whereas for the other genes, we found an increase in CPT1a, but we did not observed any changes in the expression of the other genes. Interestingly, autophagy-related gene expressions might be correlated with the changes of sinusoidal dilatation, cloudy swelling, inflammation, and lipid droplets of the liver tissues. Conclusion:Moderate and high intensities of training induce autophagy activity, combined with a shift in metabolic zonation in liver that might be potentially correlated with lipophagy. Our results showed the potential interplay role between autophagy and liver histopathology appearances as a part of the adaptation process to training.