The placenta is a gatekeeper between the mother and fetus, adapting its structure and functions to support optimal fetal growth. Studies exploring adaptations of placentae that support the development of genetically small fetuses are lacking. Here, using a mouse model of impaired fetal growth, achieved by deleting insulin-like growth factor 2 (Igf2) in the epiblast, we assessed placental nutrient transfer and umbilical artery (UA) blood flow during late gestation. At embryonic day (E) 15.5, we observed a decline in the trans-placental flux of glucose and system A amino acids (by using 3H-MeG and 14C-MeAIB), proportionate to the diminished fetal size, whereas UA blood flow was normal. However, at E18.5, the trans-placental flux of both tracers was disproportionately decreased and accompanied by blunted UA blood flow. Feto-placental growth and nutrient transfer were more impaired in female conceptuses. Thus, reducing the fetal genetic demand for growth impairs the adaptations in placental blood flow and nutrient transport that normally support the fast fetal growth during late gestation. These findings have important implications for our understanding of the pathophysiology of pregnancies afflicted by fetal growth restriction.

Little is known about the influence of (impaired) neurodevelopment on cognitive aging. We here used a mouse model for tuberous sclerosis (TS) carrying a heterozygous deletion of the Tsc2 gene. Loss of Tsc2 function leads to mTOR hyperactivity in mice and patients. In a longitudinal behavioral analysis, we found premature decline of hippocampus-based cognitive functions together with a significant reduction of immediate early gene (IEG) expression. While we did not detect any morphological changes of hippocampal projections and synaptic contacts, molecular markers of neurodegeneration were increased and the mTOR signaling cascade was downregulated in hippocampal synaptosomes. Injection of IGF2, a molecule that induces mTOR signaling, could fully rescue cognitive impairment and IEG expression in aging Tsc2+/- animals. This data suggests that TS is an exhausting disease that causes erosion of the mTOR pathway over time and IGF2 is a promising avenue for treating age-related degeneration in mTORopathies.

BACKGROUND: Circular RNAs (circRNAs) are involved in the neuroblastoma (NB) development. Objectie: The study aimed to determine the biological behaviors of circ_0001361 and explore its underlying mechanism in NB.
METHODS: The circ_0001361, miR-490-5p, and IGF2 levels were measured using quantitative real-time polymerase chain reaction. Cellular processes were analyzed using MTT assay or fluorescence-activated cell sorting (FACS). Phosphorylated (p)-PI3K, p-AKT, Bax, and caspase-3 were tested by western blot. Dual-luciferase reporter analysis together with RNA pull-down analysis were utilized to evaluate the correlation of miR-490-5p and circ_0001361 or IGF2.
RESULTS: The results in this study illustrated that an elevation of circ_0001361 levels was observed in NB. Depletion of circ_0001361 suppressed the viability but facilitated apoptosis of NB cells. Circ_0001361 sponged miR-490-5p, which targeted to regulate IGF2. Inhibition of miR-490-5p rescued the effect induced by circ_0001361 knockdown, while deletion of IGF2 rescued the effect induced by the miR-490-5p inhibitor.
CONCLUSIONS: In summary, a loss of circ_0001361 inhibited NB progression via targeting the miR-490-5p/IGF2 axis, suggesting that circ_0001361 may be a novel therapeutical target of NB.

BACKGROUND: Solitary fibrous tumor (SFT) is a rare fibroblastic mesenchymal tumor that mostly involves the pleura and infrequently involves extra-pleural sites. De novo SFT of the kidney is uncommon, and malignant SFT is extremely rare.
METHODS: We report a case of a 51-year-old man with a large malignant SFT in the left kidney. Pathological examination confirmed the diagnosis of SFT based on typical morphology, nuclear STAT6 expression, and NAB2-STAT6 gene fusion. The malignant subtype was determined by a large tumor size (≥ 15 cm) and high mitotic counts (8/10 high-power fields). KRAS mutation was identified by DNA sequencing. Insulin-like growth factor 2 (IGF2) was diffusely and strongly expressed in tumor cells, however, hypoglycemia was not observed. Hyperglycemia and high adrenocorticotropic hormone (ACTH) concentration were observed one month after surgery. Hormone measurements revealed normal blood cortisol and aldosterone levels, and increased urinary free cortisol level. A pituitary microadenoma was identified using brain magnetic resonance imaging, which may be responsible for the promotion of hyperglycemia.
CONCLUSIONS: We report a case of renal malignant SFT with a KRAS mutation, which was previously unreported in SFT and may be associated with its malignant behavior. Additionally, we emphasize that malignant SFT commonly causes severe hypoglycemia due to the production of IGF2. However, this effect may be masked by the presence of other lesions that promote hyperglycemia. Therefore, when encountering a malignant SFT with diffuse and strong IGF2 expression and without hypoglycemia, other lesions promoting hyperglycemia need to be ruled out.

Skeletal muscle is crucial for animal movement and posture maintenance, and it serves as a significant source of meat in the livestock and poultry industry. The number of muscle fibers differentiated from myoblast in the embryonic stage is one of the factors determining the content of skeletal muscle. Insulin-like growth factor 2 (IGF2), a well-known growth-promoting hormone, is crucial for embryonic and skeletal muscle growth and development. However, the specific molecular mechanism underlying its impact on chicken embryonic myoblast differentiation remains unclear. To elucidate the molecular mechanism by which IGF2 regulates chicken myoblast differentiation, we manipulated IGF2 expression in chicken embryonic myoblast. The results demonstrated that IGF2 was upregulated during chicken skeletal muscle development and myoblast differentiation. On the one hand, we found that IGF2 promotes mitochondrial biogenesis through the PGC1/NRF1/TFAM pathway, thereby enhancing mitochondrial membrane potential, oxidative phosphorylation, and ATP synthesis during myoblast differentiation. This process is mediated by the PI3K/AKT pathway. On the other hand, IGF2 regulates BNIP3-mediated mitophagy, clearing dysfunctional mitochondria. Collectively, our findings confirmed that IGF2 cooperatively regulates mitochondrial biogenesis and mitophagy to remodel the mitochondrial network and enhance mitochondrial function, ultimately promoting myoblast differentiation.

Breast cancer recurrence is associated with the growth of disseminated cancer cells that separate from the primary tumor before surgical treatment and hormonal therapy and form a metastatic niche in distant organs. We previously demonstrated that IGFBP6 expression is associated with the risk of early relapse of luminal breast cancer. Knockdown of IGFBP6 in MDA-MB-231 breast cancer cells increased their invasiveness, proliferation, and metastatic potential. In addition, the knockdown of IGFBP6 leads to impaired lipid metabolism. In this study, we demonstrated that the knockdown of the IGFBP6 gene, a highly selective inhibitor of IGF-II, led to a significant decline in the number of secreted extracellular vesicles (EVs) and altered cholesterol metabolism in MDA-MB-231 cells. Knockdown of IGFBP6 led to a decrease in the essential proteins responsible for the biogenesis of cholesterol LDLR and LSS, which reduced the amount by more than 13 times. In addition, the knockdown of IGFBP6 led to a possible change in the profile of adhesion molecules on the surface of EVs. The expression of L1CAM, IGSF3, EpCAM, CD24, and CD44 decreased, and the expression of EGFR increased. We can conclude that the negative prognostic value of low expression of this gene could be associated with increased activity of IGF2 in tumor-associated fibroblasts due to low secretion of IGFBP6 by tumor cells. In addition, changing the profile of adhesion molecules on the surface of tumor EVs may contribute to the more efficient formation of metastatic niches.

PA28γ overexpression is aberrant and accompanied by poor patient prognosis in various cancers, the precise regulatory mechanism of this crucial gene in the tumor microenvironment remains incompletely understood. In this study, using oral squamous cell carcinoma as a model, we demonstrated that PA28γ exhibits high expression in cancer-associated fibroblasts (CAFs), and its expression significantly correlates with the severity of clinical indicators of malignancy. Remarkably, we found that elevated levels of secreted IGF2 from PA28γ+ CAFs can enhance stemness maintenance and promote tumor cell aggressiveness through the activation of the MAPK/AKT pathway in a paracrine manner. Mechanistically, PA28γ upregulates IGF2 expression by stabilizing the E2F3 protein, a transcription factor of IGF2. Further mechanistic insights reveal that HDAC1 predominantly mediates the deacetylation and subsequent ubiquitination and degradation of E2F3. Notably, PA28γ interacts with HDAC1 and accelerates its degradation via a 20S proteasome-dependent pathway. Additionally, PA28γ+ CAFs exert an impact on the tumor immune microenvironment by secreting IGF2. Excitingly, our study suggests that targeting PA28γ+ CAFs or secreted IGF2 could increase the efficacy of PD-L1 therapy. Thus, our findings reveal the pivotal role of PA28γ in cell interactions in the tumor microenvironment and propose novel strategies for augmenting the effectiveness of immune checkpoint blockade in oral squamous cell carcinoma.

UNASSIGNED: Esophageal squamous cell carcinoma (ESCC) is a disease with a high incidence rate and high mortality worldwide. The Never in Mitosis A (NIMA) family member NIMA-related kinase 2 (NEK2) plays an important role in mitosis. However, the role of NEK2 in the pathogenesis of ESCC remains unclear.
UNASSIGNED: The expression and function of NEK2 in TCGA and GEO data sets were analyzed by bioinformatics. We verified the expression of NEK2 in ESCC tissues and cell lines by Western blotting and immunohistochemical methods and further explored the relationship between tumor stage and NEK2 expression. The differences in NEK2 expression and survival in patients with EC were verified by bioinformatics analysis. ESCC cell lines with stable knockdown of NEK2 were established by lentivirus-mediated shRNA delivery. The effects of NEK2 on ESCC cells were analyzed on the cytological level with assays including CCK-8, EdU, cell scratch, Transwell migration and invasion, colony formation, flow cytometry and apoptosis assays. Tumor growth was measured in a mouse xenograft model.
UNASSIGNED: We found that NEK2 is highly expressed in ESCC tissues and ESCC cells and that the high expression of NEK2 is associated with poor tumor healing. Knockdown of the NEK2 gene inhibits the migration, proliferation, invasion and cell cycle of ESCC cells. Biologic analysis shows that NEK2 is involved in biological processes such as progression and apoptosis of esophageal cancer, and is related to E2F.Mechanistically, NEK2 knockdown decreases the expression levels of E2F1 and IGF2. NEK2 competes with the transcription factor E2F1 to bind CDC20, resulting in decreased degradation and increased expression of E2F1. IGF2 expression is also increased, which promotes the expression of thymidylate synthase, further promoting the drug resistance of ESCC cells. NEK2 is associated with immune infiltration in esophageal cancer.
UNASSIGNED: NEK2 is highly expressed in ESCC and can promote the migration, proliferation and invasion of ESCC cells. NEK2 mediates ESCC immunotherapy.

BACKGROUND: Ovarian cancer (OC) is a malignancy among female globally. Circular RNAs (circRNAs) are a family of circular endogenous RNAs generated from selective splicing, which take part in many traits. Former investigation suggested that circ-TFRC was abnormally expressed in breast cancer (BC). Further, the role of circ-TFRC to the progress of OC remains unclear. So, the aim of this study was to reveal the regulatory mechanism of circ-TFRC.
METHODS: Our team made the luciferase reporter assay to validate circ-TFRC downstream target. Transwell migration assay, 5-ethynyl-20-deoxyuridine, and cell counting kit-8 were applied to investigate both proliferation and migration. In vivo tumorigenesis and metastasis assays were performed to investigate the circ-TFRC role in OC.
RESULTS: The outputs elucidated that circ-TFRC expression incremented in OC cells and tissues. circ-TFRC downregulation inhibited OC cell proliferation as well as migration in in vivo and in vitro experiments. The luciferase results validated that miR-615-3p and IGF2 were circ-TFRC downstream targets. IGF2 overexpression or miR-615-3p inhibition reversed OC cell migration after circ-TFRC silencing. Also, IGF2 overexpression reversed OC cell migration and proliferation post miR-615-3p upregulation.
CONCLUSIONS: Results demonstrate that circ-TFRC downregulation inhibits OC progression and metastasis via IGF2 expression regulation and miR-615-3psponging.

Beckwith-Wiedemann Syndrome (BWS) is an imprinting disorder characterized by overgrowth, stemming from various genetic and epigenetic changes. This study delves into the role of IGF2 upregulation in BWS, focusing on insulin-like growth factor pathways, which are poorly known in this syndrome. We examined the IGF2R, the primary receptor of IGF2, WNT, and autophagy/lysosomal pathways in BWS patient-derived lymphoblastoid cell lines, showing different genetic and epigenetic defects. The findings reveal a decreased expression and mislocalization of IGF2R protein, suggesting receptor dysfunction. Additionally, our results point to a dysregulation in the AKT/GSK-3/mTOR pathway, along with imbalances in autophagy and the WNT pathway. In conclusion, BWS cells, regardless of the genetic/epigenetic profiles, are characterized by alteration of the IGF2R pathway that is associated with the perturbation of the autophagy and lysosome processes. These alterations seem to be a key point of the molecular pathogenesis of BWS and potentially contribute to BWS\'s characteristic overgrowth and cancer susceptibility. Our study also uncovers alterations in the WNT pathway across all BWS cell lines, consistent with its role in growth regulation and cancer development.