Expression levels of autophagy related proteins and their prognostic significance in retinocytoma and retinoblastoma

·AIM: To discuss the prognostic significant of autophagy related proteins(ARPs) in retinoblastoma(RB)and to find the molecular marker to distinguish retinocytoma(RC) and RB by investigating the different expression profiling of microtubule-associated protein light chain 3(LC3B) and other ARPs in RC and RB.·METHODS: Specimens with retinocytoma region(RCR)or mainly composed with Flexner-Winterstein rosettes(FWR) were screen out from 219 paraffin-embedded RB samples and respectively taken as RCR group and FWR group. Others were taken as undifferentiated(UD) group.Immunochemistry(IHC) of LC3 B and electronic microscopy was used to identify autophagy. The IHC scores of LC3 B and other ARPs, such as Beclin, PTEN,p27, p16INK4 a, mTOR and BCL-2 were compared and correlation analysis was applied to find potential proteins which may involve in autophagy regulation. The prognostics significance of LC3 B was evaluated by comparing the high risk features(HRFs) in 3 groups of total 219 samples.·RESULTS: Twenty-one specimens with RCR and 36 specimens mainly composed with FWR were screen out.RCR cell had a high level of LC3 B and lots of autophagic vacuoles. Beclin, PTEN, p27 had positive correlation with LC3, and p16INK4 ahad negative correlation, while the expression of mTOR and BCL-2 in RCR and RB region did not show any difference. Cases with RCR had lower rate of HRFs than undifferentiated cases.·CONCLUSION: ARPs had different expression pattern between RCR and other pathological types of RB, and could be ideal markers to distinguish RC from RB. Our finding indicated cases with RCR had favorable prognosis just like those with FWR.

Autophagy related protein 9A increase in hepatitis B virusassociated hepatocellular carcinoma and the role in apoptosis

The majority of hepatocellular carcinoma(HCC)cases are associated with the hepatitis B virus(HBV)infection.Autophagy related protein 9A(ATG9A)is a transmembrane protein required for autophagosome formation.In order to investigate the role of ATG9A in HBV-associated HCC,ATG9A protein expression was determined in tumor liver tissues and compared with adjacent nontumor tissues from HCC patients with or without HBV infection.In HBVassociated HCC tissues,ATG9A protein level was increased in tumor liver tissues,but not in cases of non-HBV HCC.Our findings suggested that ATG9A might be involved in HBV and cancer cell survival.Therefore,we aimed to analyze the function of ATG9A in HBV replication using RNA interference to evaluate the HBV DNA level using real-time PCR.In the present study,there were no significant differences between shATG9A-transfected HepG2.2.15 cells and the mock control.However,we found that silencing ATG9A affected apoptosis in HepG2.2.15 and HepG2 cell lines.Our results indicated that ATG9A might be partly involved in the survival of HCC.Thus,the inhibition of ATG9A together with other targets might be a potential drug target for HCC treatment.

Autophagy activator promotes neuronal differentiation of adult adipose-derived stromal cells

Preliminary research from our group found altered autophagy intensity during adipose-derived stromal cell differentiation into neuronal-like cells, and that this change was associated with morphological changes in differentiated cells. This study aimed to verify the role of rapamycin, an autophagy activator, in the process of adipose-derived stromal cell differentiation into neuronal-like cells. Immunohistochemical staining showed that expression of neuron-specific enolase and neurofilament-200 were gradually upregulated in adipose-derived stromal cells after 5 mM 13-mercaptoethanol induction, and the differentiation rate gradually increased with induction time. Using transmission electron microscopy, induced cells were shown to exhibit cytoplasmic autophagosomes, with bilayer membranes, and autolysosomes. After rapamycin （200 IJg/L） induction for 1 hour, adipose-derived stromal cells began to extend long processes, similar to the morphology of neuronal-like cells, while untreated cells did not exhibit similar morphologies until 3 hours after induction. Moreover, the differentiation rate was significantly increased after rapamycin treatment. Compared with untreated cells, expression of LC3, an autophagy protein, was also significantly upregulated. Positive LC3 expression tended to concentrate at cell nuclei with increasing induction times. Our experimental findings indicate that autophagy can significantly increase the speed of adipose-derived stromal cell differentiation into neuronal-like cells.

MiR-3653 blocks autophagy to inhibit epithelial-mesenchymal transition in breast cancer cells by targeting the autophagy-regulatory genes ATG12 and AMBRA1

Background:Metastasis is the main cause of tumor-associated death and mainly responsible for treatment failure of breast cancer.Autophagy accelerates tumor metastasis.In our work,we aimed to investigate the possibility of microRNAs(miRNAs)which participate in the regulation of autophagy to inhibit tumor metastasis.Methods:MiRNA array and comprehensive analysis were performed to identify miRNAs which participated in the regulation of autophagy to inhibit tumor metastasis.The expression levels of miR-3653 in breast cancer tissues and cells were detected by quantitative real-time polymerase chain reaction.In vivo and in vitro assays were conducted to determine the function of miR-3653.The target genes of miR-3653 were detected by a dual luciferase reporter activity assay and Western blot.The relationship between miR-3653 and epithelial-mesenchymal transition(EMT)was assessed by Western blot.Student’s t-test was used to analyze the difference between any two groups,and the difference among multiple groups was analyzed with one-way analysis of variance and a Bonferroni post hoc test.Results:miR-3653 was downregulated in breast cancer cells with high metastatic ability,and high expression of miR-3653 blocked autophagic flux in breast cancer cells.Clinically,low expression of miR-3653 in breast cancer tissues(0.054±0.013 vs.0.131±0.028,t=2.475,P=0.014)was positively correlated with lymph node metastasis(0.015±0.004 vs.0.078±0.020,t=2.319,P=0.023)and poor prognosis(P<0.001).miR-3653 ameliorated the malignant phenotypes of breast cancer cells,including proliferation,migration(MDA-MB-231:0.353±0.013 vs.1.000±0.038,t=16.290,P<0.001;MDA-MB-468:0.200±0.014 vs.1.000±0.043,t=17.530,P<0.001),invasion(MDA-MB-231:0.723±0.056 vs.1.000±0.035,t=4.223,P=0.013;MDA-MB-468:0.222±0.016 vs.1.000±0.019,t=31.050,P<0.001),and colony formation(MDA-MB-231:0.472±0.022 vs.1.000±0.022,t=16.620,P<0.001;MDA-MB-468:0.650±0.040 vs.1.000±0.098,t=3.297,P=0.030).The autophagy-associated genes autophagy-related gene 12(ATG12)and activating molecule in beclin 1-regulated autophagy protein 1(AMBRA1)are target genes of miR-3653.Further studies showed that miR-3653 inhibited EMT by targeting ATG12 and AMBRA1.Conclusions:Our findings suggested that miR-3653 inhibits the autophagy process by targeting ATG12 and AMBRA1,thereby inhibiting EMT,and provided a new idea and target for the metastasis of breast cancer.

Conformation-dependent recognition of mutant HTT proteins by selective autophagy

With the support by the National Natural Science Foundation of China,a study led by Prof.Lu Boxun(鲁伯埙)from Fudan University demonstrates that a toxic mutant HTT species is resistant to selective autophagy,revealing the fundamental mechanism of Huntington’s Disease.The study was published