Daintain/AIF-1 accelerates the activation of insulin-like growth factor-1 receptor signaling pathway in HepG2 cells

AIF1: Function and Connection with Inflammatory Diseases

Macrophages are a type of immune cell distributed throughout all tissues of an organism. Allograft inflammatory factor 1 (AIF1) is a calcium-binding protein linked to the activation of macrophages. AIF1 is a key intracellular signaling molecule that participates in phagocytosis, membrane ruffling and F-actin polymerization. Moreover, it has several cell type-specific functions. AIF1 plays important roles in the development of several diseases: kidney disease, rheumatoid arthritis, cancer, cardiovascular diseases, metabolic diseases and neurological disorders, and in transplants. In this review, we present a comprehensive review of the known structure, functions and role of AIF1 in inflammatory diseases.

Allograft inflammatory factor 1 is a potential diagnostic, immunological, and prognostic biomarker in pan-cancer

BACKGROUND

Allograft Inflammatory Factor 1 (AIF-1) is a member of the allograft inflammatory factor gene family and plays an essential role in the occurrence and development of malignant tumors. However, little is known about the expression pattern, predictive value, and biological function of AIF-1 across cancers.

MATERIALS AND METHODS

We first analyzed AIF-1 expression across cancers based on data from public databases. Univariate Cox regression and Kaplan-Meier analyses were used to explore the predictive value of AIF-1 expression in various cancers. Moreover, gene set enrichment analysis (GSEA) was applied to determine the cancer hallmarks associated with AIF-1 expression. Spearman correlation analysis was performed to investigate the association between AIF-1 expression and tumor microenvironment scores, immune cell infiltration, immune-related genes, TMB, MSI, and DNA methyltransferases.

RESULTS

AIF-1 expression was upregulated in most cancer types and exhibited prognosis-predictive ability. AIF-1 expression was positively correlated with immune infiltrating cells and immune checkpoint-related genes in most cancers. Additionally, the promoter methylation level of AIF-1 was different in distinct tumors. High methylation levels of AIF-1 were associated with a worse prognosis in UCEC and melanoma, whereas they were associated with a better prognosis in GBM, KIRC, OV, and UVM. Finally, we found that AIF-1 was significantly highly expressed in KIRC tissues. Functionally, silencing AIF-1 dramatically decreased proliferation, migration, and invasion abilities.

CONCLUSION

Our results reveal that AIF-1 acts as a robust tumor biomarker and is closely correlated with tumor immune infiltration. Furthermore, AIF-1 may function as an oncogene and promote tumor progression in KIRC.

The Role of IGF/IGF-1R Signaling in Hepatocellular Carcinomas: Stemness-Related Properties and Drug Resistance

Insulin-like Growth Factor (IGF)/IGF-1 Receptor (IGF-1R) signaling is known to regulate stem cell pluripotency and differentiation to trigger cell proliferation, organ development, and tissue regeneration during embryonic development. Unbalanced IGF/IGF-1R signaling can promote cancer cell proliferation and activate cancer reprogramming in tumor tissues, especially in the liver. Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death, with a high incidence and mortality rate in Asia. Most patients with advanced HCC develop tyrosine kinase inhibitor (TKI)-refractoriness after receiving TKI treatment. Dysregulation of IGF/IGF-1R signaling in HCC may activate expression of cancer stemness that leads to TKI refractoriness and tumor recurrence. In this review, we summarize the evidence for dysregulated IGF/IGF-1R signaling especially in hepatitis B virus (HBV)-associated HCC. The regulation of cancer stemness expression and drug resistance will be highlighted. Current clinical treatments and potential therapies targeting IGF/IGF-1R signaling for the treatment of HCC will be discussed.

Knockdown of Orphan Transporter SLC22A18 Impairs Lipid Metabolism and Increases Invasiveness of HepG2 Cells

PURPOSE

The aim of this work is to investigate the roles of solute carrier family 22 member 18 (SLC22A18) in lipid metabolism and in establishing the tumor phenotype of HepG2 cells.

METHODS

SLC22A18-knockdown HepG2 cells were established by stable transfection with shRNA. Protein expression levels were measured by quantitative proteomics and Western blot analysis. Cell growth was examined by cell counting kit. Accumulation of triglyceride-rich lipid droplets was measured by Oil-Red O staining. Cell migration and invasion were examined by Transwell assays.

RESULTS

SLC22A18-knockdown HepG2 cells accumulated triglyceride-rich lipid droplets and showed decreased expression levels of lysosomal/autophagic proteins, suggesting that lipid degradation is suppressed. Growth of HepG2 cells was decreased by SLC22A18 knockdown, but was restored by free fatty acid supplementation. In addition, SLC22A18 knockdown decreased the expression of insulin-like growth factor-binding protein 1 (IGFBP-1) and increased the invasion ability of HepG2 cells. Exogenous IGFBP-1 blocked the increase of invasion activity induced by SLC22A18 knockdown.

CONCLUSION

Our results suggest that suppression of SLC22A18 decreased the supply of intracellular free fatty acids from triglyceride-rich lipid droplets by impairing the lysosomal/autophagy degradation pathway and reduced the invasive activity of HepG2 cells by decreasing IGFBP-1 expression.

Samsum Ant Venom Exerts Anticancer Activity Through Immunomodulation In Vitro and In Vivo

Samsum ant venom (SAV) is a rich repertoire of natural compounds with tremendous pharmacological properties. The present work explores its antineoplastic activity in different cell lines followed by its confirmation in vivo. The cell lines, HepG2, MCF-7, and LoVo showed the differential dose-dependent antineoplastic effect with an increased level of significant cytokines, including Interleukin (IL)-1β, IL-6, and IL-8 and transcription factor, Nuclear factor-kappa B (NF-κB). However, the venom was more effective on HepG2 and MCF-7 cells than LoVo cells. Furthermore, the extract was administered to four groups (n = 8) of rats. Group I was taken as a control without any treatment, whereas group II received CCl₄ (1 mL/kg) for induction of mild hepatoma. Group III was given 100 μg/kg of SAV twice a week for 1 month. Group IV was pretreated with the CCl₄ (like group II) followed by dosing with SAV (100 μg/kg) for 2 months as per the authors' prestandardized dosing schedule. Intriguingly, the rats of group IV demonstrated significant decrease in key cytokines, IL-1β and IL-6, as well as the transcription factors, including Tumor Necrosis Factor-alpha (TNF-α), NF-κB, and Inhibitor-kappa B (I-κB) as compared with group II. Furthermore, increase in IL-10 and First apoptosis signal (FAS) in the same group confirmed that SAV induces apoptosis at the given dose through immunomodulation leading to enhanced tumor killing in vivo. Hence, SAV has an excellent antineoplastic activity that can be directly used to treat certain types of cancer. Moreover, study of its ingredients can pave ways to design novel anticancer drugs. However, further in-depth investigation is required before its clinical trials.

Evolutionary conserved mechanisms pervade structure and transcriptional modulation of allograft inflammatory factor-1 from sea anemone Anemonia viridis

Gene family encoding allograft inflammatory factor-1 (AIF-1) is well conserved among organisms; however, there is limited knowledge in lower organisms. In this study, the first AIF-1 homologue from cnidarians was identified and characterised in the sea anemone Anemonia viridis. The full-length cDNA of AvAIF-1 was of 913 bp with a 5' -untranslated region (UTR) of 148 bp, a 3'-UTR of 315 and an open reading frame (ORF) of 450 bp encoding a polypeptide with149 amino acid residues and predicted molecular weight of about 17 kDa. The predicted protein possesses evolutionary conserved EF hand Ca²⁺ binding motifs, post-transcriptional modification sites and a 3D structure which can be superimposed with human members of AIF-1 family. The AvAIF-1 transcript was constitutively expressed in all tested tissues of unchallenged sea anemone, suggesting that AvAIF-1 could serve as a general protective factor under normal physiological conditions. Moreover, we profiled the transcriptional activation of AvAIF-1 after challenges with different abiotic/biotic stresses showing induction by warming conditions, heavy metals exposure and immune stimulation. Thus, mechanisms associated to inflammation and immune challenges up-regulated AvAIF-1 mRNA levels. Our results suggest its involvement in the inflammatory processes and immune response of A. viridis.

Lunasin: A promising polypeptide for the prevention and treatment of cancer

Strategies for the treatment of cancer remain unsatisfactory due to the poor understanding of the complicated underlying molecular mechanisms of carcinogenesis. A number of types of cancer exhibit a marked association with dietary habits and lifestyles. Therefore, the modulation of dietary habits or lifestyles may be an effective strategy for preventing the formation and progression of cancer. Proteins and polypeptides from soybean have been developed as healthcare products due to their marked activity in inhibiting the progression of cancer at various stages. Lunasin, containing 43 amino acid residues, is one such example of a soybean-derived polypeptide that has been demonstrated to exhibit marked anti-cancer activity. In the present review, studies of the underlying molecular mechanisms and potential advantages of lunasin in the prevention and treatment of cancer have been examined, to provide a theoretical reference for the development of natural product-based agents or healthcare products for the prevention and treatment of cancer.