glycogen and Carcinoma--Non-Small-Cell-Lung

Glycogen-Interacting Protein 1 (GNIP1), an E3 ligase, is a member of the tripartite motif (TRIM) family proteins. Current studies on GNIP1 mainly focus on glycogen metabolism. However, the function and molecular mechanisms of GNIP1 in regulating autophagy still remains unclear. This study aimed to investigate the regulatory mechanism of GNIP1 in regulating autophagy in non-small cell lung cancer (NSCLC).. Crystal violet staining assays were used to evaluate the ability of cell growth and proliferation. Transwell and scratch wound healing assays were used to evaluate the cell migration ability. The protein expressions were measured by western blot and immunohistochemistry. Co-immunoprecipitation assays determined the protein-protein interactions. The in vivo effect of GNIP1 on tumor growth was determined by xenograft assay.. We found that GNIP1 was overexpressed in tumor tissues and the expression level of GNIP1 was related to the poor prognosis and the survival time of NSCLC patients. In non-small cell lung cancer (NSCLC), GNIP1 increased proliferation and migration of cancer cells by promoting autophagy. Mechanistic studies indicated that GNIP1, as a scaffold protein, recruited BECN1 and LC3B to promote the formation of autophagosomes. Besides, GNIP1 mediated the degradation of 14-3-3ζ, the negative regulator of VPS34 complex, thus promoting autophagy. Overexpressing GNIP1 promoted tumorigenesis and enhanced autophagy in xenograft models.. GNIP1 promotes proliferation and migration of NSCLC cells through mediating autophagy, which provides theoretical basis for targeting GNIP1 as anti-cancer drugs. Video Abstract.

Topics: 14-3-3 Proteins; Autophagy; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Glycogen; Humans; Lung Neoplasms; Tripartite Motif Proteins; Ubiquitin-Protein Ligases

Nuclear glycogen was first documented in the early 1940s, but its role in cellular physiology remained elusive. In this study, we utilized pure nuclei preparations and stable isotope tracers to define the origin and metabolic fate of nuclear glycogen. Herein, we describe a key function for nuclear glycogen in epigenetic regulation through compartmentalized pyruvate production and histone acetylation. This pathway is altered in human non-small cell lung cancers, as surgical specimens accumulate glycogen in the nucleus. We demonstrate that the decreased abundance of malin, an E3 ubiquitin ligase, impaired nuclear glycogenolysis by preventing the nuclear translocation of glycogen phosphorylase and causing nuclear glycogen accumulation. Re-introduction of malin in lung cancer cells restored nuclear glycogenolysis, increased histone acetylation, and decreased growth of cancer cells transplanted into mice. This study uncovers a previously unknown role for glycogen metabolism in the nucleus and elucidates another mechanism by which cellular metabolites control epigenetic regulation.

Topics: A549 Cells; Acetylation; Animals; Carbon; Carcinoma, Non-Small-Cell Lung; Cell Nucleus; Glycogen; Glycogen Phosphorylase; Glycogenolysis; HEK293 Cells; Histones; Humans; Lung Neoplasms; Mice; Mice, Knockout; Mice, Nude; Transfection; Ubiquitin-Protein Ligases

Radiation therapy is a standard form of treating non-small cell lung cancer, however, local recurrence is a major issue with this type of treatment. A better understanding of the metabolic response to radiation therapy may provide insight into improved approaches for local tumour control. Cyclic hypoxia is a well-established determinant that influences radiation response, though its impact on other metabolic pathways that control radiosensitivity remains unclear.. We report that xenografted NSCLC tumours demonstrate rapid and stable metabolic changes, following exposure to 15 Gy radiation doses, which can be measured by RS and are dictated by the extent of local tissue oxygenation. In particular, fluctuations in tissue glycogen content were observed as early as 2 h and as late as 10 days post irradiation. Metabolically, this signature was correlated to the extent of tumour regression. Immunofluorescence staining for γ-H2AX, pimonidazole and carbonic anhydrase IX (CAIX) correlated with RS-identified metabolic changes in hypoxia and reoxygenation following radiation exposure.. Our results indicate that RS can identify sequential changes in hypoxia and tumour reoxygenation in NSCLC, that play crucial roles in radiosensitivity.

Topics: Animals; Antigens, Neoplasm; Carbonic Anhydrase IX; Carcinoma, Non-Small-Cell Lung; Cell Hypoxia; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Glycogen; Histones; Humans; Lung Neoplasms; Mice; Mice, Inbred NOD; Neoplasm Transplantation; Nitroimidazoles; Radiation Dosage; Spectrum Analysis, Raman; Treatment Outcome

External beam radiation therapy is a standard form of treatment for numerous cancers. Despite this, there are no approved methods to account for patient specific radiation sensitivity. In this report, Raman spectroscopy (RS) was used to identify radiation-induced biochemical changes in human non-small cell lung cancer xenografts. Chemometric analysis revealed unique radiation-related Raman signatures that were specific to nucleic acid, lipid, protein and carbohydrate spectral features. Among these changes was a dramatic shift in the accumulation of glycogen spectral bands for doses of 5 or 15 Gy when compared to unirradiated tumours. When spatial mapping was applied in this analysis there was considerable variability as we found substantial intra- and inter-tumour heterogeneity in the distribution of glycogen and other RS spectral features. Collectively, these data provide unique insight into the biochemical response of tumours, irradiated in vivo, and demonstrate the utility of RS for detecting distinct radiobiological responses in human tumour xenografts.

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Disease Models, Animal; Energy Metabolism; Female; Glycogen; Humans; Lung Neoplasms; Metabolomics; Organ Specificity; Principal Component Analysis; Radiation Tolerance; Spectrum Analysis, Raman; Xenograft Model Antitumor Assays

The insulin-like growth factor type 1 receptor (IGF 1R) mediates the acute metabolic effects of IGF I as well as IGF I-stimulated cell proliferation and protection from apoptosis. IGF binding proteins (IGFBPs) can modulate these responses. We, therefore, investigated whether intrinsic IGFBPs interfere with IGF I-induced regulation of IGF 1R expression and with the biological response to IGF I in two human tumor cell lines, the non-small-cell lung cancer cell line A549 and the osteoblastic osteosarcoma cell line Saos-2/B-10. We compared the growth rates, IGFBP production, IGF I binding characteristics, IGF 1R protein and mRNA levels, and the acute IGF I response (stimulation of glycogen synthesis) after pretreatment of the cells in serum-free medium with or without added IGF I or medium supplemented with 5% fetal calf serum (FCS). In contrast to A549 cells, which produce IGF I and significant amounts of IGFBPs, survival and proliferation of Saos-2/B-10 cells, which do not produce IGF I or significant amounts of IGFBPs, depended on the addition of exogenous IGF I. IGF I increased the concentration of IGFBP-2 and -3 and decreased the concentration of IGFBP-4 in the medium of A549 cells. As compared to FCS, IGF I pretreatment in both cell lines decreased the number of specific IGF I binding sites, down-regulated total and membrane IGF 1R protein, and largely reduced or abolished the acute IGF I response without affecting IGF 1R mRNA levels. The data suggest that the IGF 1R protein of the two cell lines is translationally and/or posttranslationally down-regulated by its ligand in the presence and in the absence of locally produced IGFBPs and that the cell lines have retained this negative feedback to counteract IGF I stimulation.

Topics: Apoptosis; Binding Sites; Binding, Competitive; Blood Proteins; Bone Neoplasms; Carcinoma, Non-Small-Cell Lung; Cell Division; Culture Media, Conditioned; Down-Regulation; Feedback; Gene Expression Regulation, Neoplastic; Glucose; Glycogen; Humans; Insulin-Like Growth Factor Binding Proteins; Insulin-Like Growth Factor I; Iodine Radioisotopes; Lung Neoplasms; Osteosarcoma; Protein Biosynthesis; Radioligand Assay; Receptor, IGF Type 1; RNA, Messenger; Tumor Cells, Cultured