Insulin has been regarded as the central regulator of systemic glucose homeostasis through regulation of hepatic glucose metabolism. Loss of insulin leads to dysregulation of glucose homeostasis in diabetes. Physical activity improves glycemic control in insulin-resistant and insulin-deficient states. However, it remains unclear whether exercise regulates hepatic glucose metabolism independently of insulin signaling. Irisin, an exercise-induced myokine cleaved from fibronectin type III domain-containing 5 (FNDC5), has been implicated in systemic metabolic regulation; however, its role in hepatic glucose metabolism plasticity under insulin-deficient conditions remains unknown. To address this question, we employed persistent insulin-deficient Akita mice and found that circulating and hepatic Irisin levels were reduced in Akita mice, accompanied by impaired hepatic glucose metabolism. To restore Irisin level, adenoviral vectors encoding full-length FNDC5 and secreted-form Irisin were generated and administered. Notably, the secreted-form of Irisin was more effective in restoring circulating Irisin levels contributed to improving diabetic phenotypes. Dose- and time-dependent analyses further demonstrated that, upon reaching an effective dose, Irisin gene delivery improved diabetic phenotypes for up to 10-12 weeks. Mechanistically, Irisin was associated with coordinated changes in hepatic glucose metabolism, including increased expression of glucose uptake-related genes (PPAR-γ/GLUT2/GCK), enhanced glycogen synthesis-related signaling (GSK-dependent and -independent pathways), and reduced gluconeogenic activity, accompanied by reduced PEPCK expression and increased AMPK phosphorylation, despite no changes in circulating insulin or glucagon levels. In summary, our findings suggest that Irisin may contribute to the regulation of hepatic glucose metabolism under insulin-deficient conditions and represent a potential insulin-independent pathway for improving systemic glucose homeostasis.
Ovarian cancer is a heterogeneous gynecologic malignancy, with most cases diagnosed at an advanced stage. Despite the availability of effective treatments such as surgery and platinum/taxane-based chemotherapy, advanced ovarian cancer frequently recurs, highlighting the need to investigate mechanisms of chemotherapy resistance. Delta-like non-canonical Notch ligand 1 (DLK1), a transmembrane protein of the EGF-like family, is aberrantly expressed in several cancers. Our previous study demonstrated that DLK1 promotes oncogenic behaviors and epithelial-mesenchymal transition in ovarian high-grade serous carcinoma. In this study, we observed a positive correlation between DLK1 and stemness markers CD44 and CD133 in human epithelial ovarian cancer using tissue microarray analysis. Overexpression of DLK1 by an adenovirus vector accelerated sphere-forming capability and upregulated CD44, CD133, and ABCG2 expression in human ovarian cancer cell lines. Conversely, DLK1 silencing by siRNA abolished the stimulatory effects on the stem cell-like properties and reduced CD44 and CD133 expression in ovarian cancer cells. Furthermore, DLK overexpression by an adenovirus vector enhanced colony formation and suppressed the cisplatin- and taxol-induced death in human ovarian cancer cells. Conversely, DLK1 siRNA reversed cell death and colony formation induced by these chemotherapeutic agents. Finally, we demonstrated that DLK1 regulates CD44, CD133, and ABCG2 expression through the Notch1/AKT/STAT3 signaling pathway, involving the phosphorylation and translocation of STAT3. Collectively, these results suggest that targeting DLK1 may represent a potential therapeutic strategy to improve outcomes in recurrent ovarian cancer following chemotherapy. © 2026 The Pathological Society of Great Britain and Ireland.
Hepatoma-derived growth factor (HDGF) is located on chromosome 1q21-23, a locus frequently amplified in hepatocellular carcinoma (HCC), and has been proposed as an oncogenic factor by stimulating PI3K/Akt signaling. Phosphatase and tensin homolog (PTEN) acts as a tumor suppressor that antagonizes PI3K/Akt signaling, suggesting a possible regulatory effect of HDGF on PTEN. In this study, we aimed to investigate the regulatory role of HDGF on PTEN. The Cancer Genome Atlas cohort study was used to explore molecular significance and outcomes in liver cancer. Resected clinical specimens, consisting of paired tumor and adjacent nontumor tissue, were analyzed for expression of HDGF and PTEN in the liver cancer cohort. Liver tissue and primary hepatocytes derived from HDGF knockout mice were analyzed for PTEN status. The influence of HDGF on PTEN was investigated through in vitro and in vivo genetic manipulation studies. The Cancer Genome Atlas cohort study revealed an inverse correlation between HDGF and PTEN, with HDGF overexpression emerging as a dominant factor independent of PTEN levels and correlated with poor outcomes in patients with HCC. Paired clinical specimens revealed HDGF upregulation in tumor tissue is relevant to elevated alpha-fetoprotein, and poor survival and recurrent outcomes in the liver cancer cohort. HDGF knockout mice exhibited decreased liver C-tail--phosphorylated PTEN (p-PTEN) levels and increased PTEN expression. Furthermore, an in vitro study validated that overexpression of HDGF increased p-PTEN levels and tumor growth, whereas knockdown of HDGF yielded inverse results. Treatment with recombinant HDGF confirmed the stimulation of p-PTEN and accumulation of phosphatidylinositol 3,4,5-trisphosphate. Blockade of HDGF and casein kinase 2 signaling using anti-HDGF and a casein kinase 2 inhibitor validated the stimulation of p-PTEN. Our results reveal that HDGF is an oncogene frequently amplified and upregulated, leading to suppression of PTEN expression and activity, thereby contributing to malignant progression in liver cancer. HDGF upregulation in resected paired-HCC specimens may constitute a valuable prognostic biomarker for patients with HCC.
Hepatoma-derived growth factor (HDGF) overexpression and uncontrolled reactive oxygen species (ROS) accumulation are involved in malignant transformation and poor prognosis in various types of cancer. However, the interplay between HDGF and ROS generation has not been elucidated in hepatocellular carcinoma. Here, we first analyzed the profile of HDGF expression and ROS production in newly generated orthotopic hepatomas by ultrasound-guided implantation. In situ superoxide detection showed that HDGF-overexpressing hepatomas had significantly elevated ROS levels compared with adjacent nontumor tissues. Consistently, liver tissues from HDGF-deficient mice exhibited lower ROS fluorescence than those from age-and sex-matched WT mice. ROS-detecting fluorescent dyes and flow cytometry revealed that recombinant HDGF (rHDGF) stimulated the production of superoxide anion, hydrogen peroxide, and mitochondrial ROS generation in cultured hepatoma cells in a dose-dependent manner. In contrast, the inactive Ser103Ala rHDGF mutant failed to pro -mote ROS generation or oncogenic behaviors. Seahorse metabolic flux assays revealed that rHDGF dose dependently upregulated bioenergetics through enhanced basal and total oxygen consumption rate, extracellular acidification rate, and oxidative phosphorylation in hepatoma cells. Moreover, anti-oxidants of N-acetyl cysteine and MitoQ treatment significantly inhibited HDGF-mediated cell proliferation and invasive capacity. Genetic silencing of superoxide dismutase 2 augmented the HDGF-induced ROS generation and oncogenic behaviors of hepatoma cells. Finally, genetic knockdown nucleolin (NCL) and antibody neutralization of surface NCL, the HDGF receptor, abolished the HDGF-induced increase in ROS and mitochondrial energetics. In conclusion, this study has demonstrated for the first time that the HDGF/NCL signaling axis induces ROS generation by elevating ROS generation in mitochondria, thereby stimulating liver carcinogenesis.
PDF file - 1237K, Supplementary Figure 3. POMC gene transfer inhibited neovascularization of metastatic melanoma in vivo. (A) Growth of metastatic GFP-B16-F10 cells in lung was observed by merging the images of GFP (green) and rhodamine label-dextran (red). (B) Blood vessels were labeled by an antibody directed against CD31, a specific marker of endothelial cells. The number of blood vessels within the nodules was counted by image analysis. (Magnification, 4x and Bar, 1.0 mm; 20x and Bar, 200 μm) (n = 5; **: p < 0.01)
The mitochondrial chaperonin heat shock protein (HSP) 60 is indispensable in protein folding and the mitochondrial stress response; however, its role in nutrient metabolism remains uncertain. This study investigated the role of HSP60 in diet-induced non-alcoholic fatty liver disease (NAFLD). We studied human biopsies from individuals with NAFLD, murine high-fat-diet (HFD; a diet with 60
Microencapsulated epidermal growth factor (EGF) device has been applied topically for the management of several types of wounds to accelerate wound healing and prevent scar formation. However, it remains unclear whether such EGF device induced neoplastic transformation in the skin. In this study, we exploited a well-established murine B16-F10 melanoma model, coupled with MTT viability and colony formation assays, to investigate the influence of microencapsulated recombinant EGF (Me-EGF; brand name NewEpi®) and its ingredients on the tumorigenicity of skin cancer cells in vitro and in vivo. The results indicated that Me-EGF did not stimulate the viability nor the anchorage-dependent growth of B16-F10 melanoma cells. Western blot analysis showed that Me-EGF treatment increased the total and phosphorylated EGFR expression without affecting the HER2 expression in B16-F10 melanoma cells. In mice bearing established B16-F10 melanoma, continuous application of Me-EGF for 14 days did not enhance the melanoma tumor burden compared with control groups. Immunohistochemical analysis also revealed the similar expression of proliferative index Ki-67 between Me-EGF-treated melanoma and other groups. Altogether, these results suggest that the application of Me-EGF device did not promote the oncogenic potential of B16-F10 melanoma in vitro and in vivo.
PDF file - 1470K, Supplementary Figure 2. Evaluation of the Luc-B16-F10 cells delivery efficiency in vivo. Bioluminescence live images of day 0, day 7 and day 14 provided an estimation of the number of metastatic cells upon injection.
PDF file - 265K, Supplementary Figure 1. Experimental scheme of metastatic melanoma in C57BL/6 mice.
Neuroblastoma (NB) is characterized by several malignant phenotypes that are difficult to treat effectively without combination therapy. The therapeutic implication of mitochondrial ClpXP protease ClpP and ClpX has been verified in several malignancies, but is unknown in NB. Firstly, we observed a significant increase in ClpP and ClpX expression in immature and mature ganglion cells as compared to more malignant neuroblasts and less malignant Schwannian-stroma-dominant cell types in human neuroblastoma tissues. We used ONC201 targeting ClpXP to treat NB cells, and found a significant suppression of mitochondrial protease, i.e., ClpP and ClpX, expression and downregulation of mitochondrial respiratory chain subunits SDHB and NDUFS1. The latter was associated with a state of energy depletion, increased reactive oxygen species, and decreased mitochondrial membrane potential, consequently promoting apoptosis and suppressing cell growth of NB. Treatment of NB cells with ONC201 as well as the genetic attenuation of ClpP and ClpX through specific short interfering RNA (siRNA) resulted in the significant upregulation of the tumor suppressor alpha thalassemia/mental retardation X-linked (ATRX) and promotion of neurite outgrowth, implicating mitochondrial ClpXP proteases in MYCN-amplified NB cell differentiation. Furthermore, ONC201 treatment significantly decreased MYCN protein expression and suppressed tumor formation with the reactivation of ATRX expression in MYCN-amplified NB-cell-derived xenograft tumors. Taken together, ONC201 could be the potential agent to provide diversified therapeutic application in NB, particularly in NB with MYCN amplification.
Leukocyte cell-derived chemotaxin 2 (LECT2) acts as a tu-mor suppressor in hepatocellular carcinoma (HCC). However, the antineoplastic mechanism of LECT2, especially its influ-ence on hepatic cancer stem cells (CSCs), remains largely un-known. In The Cancer Genome Atlas cohort, LECT2 mRNA expression was shown to be associated with stage, grade, recurrence, and overall survival in human HCC patients, and LECT2 expression was downregulated in hepatoma tissues compared with the adjacent nontumoral liver. Here, we show by immunofluorescence and immunoblot analyses that LECT2 was expressed at lower levels in tumors and in poorly differ-entiated HCC cell lines. Using functional assays, we also found LECT2 was capable of suppressing oncogenic behaviors such as cell proliferation, anchorage-independent growth, migration, invasiveness, and epithelial-mesenchymal transition in hepa-toma cells. Moreover, we show exogenous LECT2 treatment inhibited CSC functions such as tumor sphere formation and drug efflux. Simultaneously, hepatic CSC marker expression was also downregulated, including expression of CD133 and CD44. This was supported by infection with adenovirus encoding LECT2 (Ad-LECT2) in HCC cells. Furthermore, in animal experiments, Ad-LECT2 gene therapy showed potent efficacy in treating HCC. We demonstrate LECT2 over -expression significantly promoted cell apoptosis and reduced neovascularization/CSC expansion in rat hepatoma tissues. Mechanistically, we showed using immunoblot and immuno-fluorescence analyses that LECT2 inhibited beta-catenin signaling via the suppression of the hepatocyte growth factor/c-MET axis to diminish CSC properties in HCC cells. In summary, we reveal novel functions of LECT2 in the suppression of he-patic CSCs, suggesting a potential alternative strategy for HCC therapy.
The authors regret the omission of one of the affiliations of Chieh-Shan Wu. Authors: Guei-Sheung Liu a,b,1, Jian-Ching Wu c,1, Han-En Tsai d, Gregory J. Dusting a,b, Elsa C. Chan a,b, Chieh-Shan Wu e,g,∗∗, Ming-Hong Tai c,d,f,∗ Affiliation: a. Center for Eye Research Australia, Melbourne, VIC3002, Australia b. Department of Ophthalmology, University of Melbourne, Melbourne, VIC3002, Australia. c. Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University and Academia Sinica, Kaohsiung 804, Taiwan d. Institute of Biomedical Science, and National Sun Yat-sen University, Kaohsiung 804, Taiwan e. Department of Dermatology, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan f. Center for Neuroscience, National Sun Yat-sen University, Kaohsiung 804, Taiwan. g. Department of Dermatology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 813, Taiwan. The authors would like to apologise for any inconvenience caused.
Hepatitis is an important health problem worldwide. Novel molecular targets are in demand for detection and management of hepatitis. Hepatoma-derived growth factor (HDGF) has been delineated to participate in hepatic fibrosis and liver carcinogenesis. However, the relationship between hepatitis and HDGF remains unclear. This study aimed to elucidate the role of HDGF during hepatitis using concanavalin A (ConA)-induced hepatitis model. In cultured hepatocytes, ConA treatment-elicited HDGF upregulation at transcriptional level and promoted HDGF secretion while reducing intracellular HDGF protein level and cellular viability. Similarly, mice receiving ConA administration exhibited reduced hepatic HDGF expression and elevated circulating HDGF level, which was positively correlated with serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. By using HDGF knockout (KO) mice, it was found the ConA-evoked cell death was prominently alleviated in KO compared with control. Besides, it was delineated HDGF ablation conferred protection by suppressing the ConA-induced neutrophils recruitment in livers. Above all, the ConA-mediated activation of tumor necrosis factor-α (TNF-α)/interleukin-1β (IL-1β)/interleukin-6 (IL-6)/cyclooxygenase-2 (COX-2) inflammatory signaling was significantly abrogated in KO mice. Treatment with recombinant HDGF (rHDGF) dose-dependently stimulated the expression of TNF-α/IL-1β/IL-6/COX-2 in hepatocytes, further supporting the pro-inflammatory function of HDGF. Finally, application of HDGF antibody not only attenuated the ConA-mediated inflammatory cascade in hepatocytes, but also ameliorated the ConA-induced hepatic necrosis and AST elevation in mice. In summary, HDGF participates in ConA-induced hepatitis via neutrophils recruitment and may constitute a therapeutic target for acute hepatitis.
Melanotan II (MTII), a synthetic analogue of the alpha-melanocyte stimulating hormone (α-MSH), has been applied for skin tanning in humans. However, the carcinogenic consequence of topical MTII has been equivocal. This study aims to delineate the anti-neoplastic efficacy and mechanism of MTII using the B16-F10 melanoma model in vitro and in vivo. It was found that, despite a lack of influence on proliferation, MTII potently inhibited the migration, invasion, and colony-forming capability of melanoma cells. Moreover, topical MTII application significantly attenuated the tumor progression in mice bearing established melanoma. Histological analysis revealed that MTII therapy induced apoptosis while inhibiting the proliferation and neovaluarization in melanoma tissues. By immunoblot and immunohistochemical analysis, it was found that MTII dose-dependently increased the phosphatase and tensin homolog (PTEN) protein level while reducing PTEN phosphorylation, which resulted in the inhibition of AKT/nuclear factor kappa B (NFκB) signaling. Consistently, MTII treatment inhibited cyclooxygenase II (COX-2) expression and prostaglandin E2 (PGE2) production in melanoma cells. Finally, studies of antibody neutralization suggest that the melanocortin 1 receptor (MC1R) plays a critical role in MTII-induced PTEN upregulation and melanoma suppression. Together, these results indicate that MTII elicits PTEN upregulation via MC1R, thereby suppressing melanoma progression through downregulating COX-2/PGE2 signaling. Hence, topical MTII therapy may facilitate a novel therapeutic strategy against melanoma.
Melanoma is notoriously resistant to current cancer therapy. However, the chemoresistance mechanism of melanoma remains unclear. The present study unveiled that chemotherapy drug cisplatin induced the formation of giant cells, which exhibited enlargement in cell diameter and nucleus in mice and human melanoma cells. Giant cells were positive with melanoma maker S100 and cancer stem cell markers including ABCB5 and CD133 in vitro and in vivo. Moreover, giant cells retained the mitotic ability with expression of proliferation marker Ki-67 and exhibited multiple drug resistance to doxorubicin and actinomycin D. The mitochondria genesis/activities and cellular ATP level were significantly elevated in giant cells, implicating the demand for energy supply. Application of metabolic blockers such as sodium azide or 2-deoxy glucose abolished the cisplatin-induced giant cells formation and expression of cancer stemness markers. The present study unveils a novel chemoresistance mechanism of melanoma cells via size alteration and the anti-neoplastic strategy by targeting giant cells.
Compromised autophagy and mitochondrial dysfunction downregulate chondrocytic activity, accelerating the development of osteoarthritis (OA). Irisin, a cleaved form of fibronectin type III domain containing 5 (FNDC5), regulates bone turnover and muscle homeostasis. Little is known about the effect of Irisin on chondrocytes and the development of osteoarthritis. This study revealed that human osteoarthritic articular chondrocytes express decreased level of FNDC5 and autophagosome marker LC3-II but upregulated levels of oxidative DNA damage marker 8-hydroxydeoxyguanosine (8-OHdG) and apoptosis. Intra-articular administration of Irisin further alleviated symptoms of medial meniscus destabilization, like cartilage erosion and synovitis, while improved the gait profiles of the injured legs. Irisin treatment upregulated autophagy, 8-OHdG and apoptosis in chondrocytes of the injured cartilage. In vitro, Irisin improved IL-1β-mediated growth inhibition, loss of specific cartilage markers and glycosaminoglycan production by chondrocytes. Irisin also reversed Sirt3 and UCP-1 pathways, thereby improving mitochondrial membrane potential, ATP production, and catalase to attenuated IL-1β-mediated reactive oxygen radical production, mitochondrial fusion, mitophagy, and autophagosome formation. Taken together, FNDC5 loss in chondrocytes is correlated with human knee OA. Irisin repressed inflammation-mediated oxidative stress and extracellular matrix underproduction through retaining mitochondrial biogenesis, dynamics and autophagic program. Our analyses shed new light on the chondroprotective actions of this myokine, and highlight the remedial effects of Irisin on OA development.
Helicobacter pylori (Hp) infection and overexpression of hepatoma-derived growth factor (HDGF) are involved in gastric carcinogenesis. However, the relationship between Hp-induced gastric diseases and HDGF upregulation is not yet completely clear. This study aimed to elucidate the role of HDGF in Hp-induced gastric inflammation and carcinogenesis. HDGF expression in gastric biopsy and serum from patients was analyzed by immunohistochemical and ELISA analysis, respectively. Hp and gastric cells coculture system was employed to delineate the mechanism underlying HDGF overexpression during Hp infection. The gastric pathologies of wild type and HDGF knockout mice after Hp infection were investigated by immunohistochemical, immunoblot, and immunofluorescence analyses. HDGF level was significantly elevated in patients with Hp infection or intestinal metaplasia (IM, a precancerous lesion), and HDGF overexpression was positively correlated with Hp load, IM, and neutrophil infiltration in gastric biopsy. Consistently, patients with Hp infection or IM had significantly higher serum HDGF level. By using coculture assay, Hp infection led to HDGF upregulation and secretion in gastric cells. In mice model, HDGF ablation significantly suppressed the Hp-induced neutrophil infiltration and inflammatory TNF-α/COX-2 signaling, thereby relieving the tissue damage in stomach. This was further supported by that recombinant HDGF (rHDGF) stimulated the differentiation/chemotaxis of cultured neutrophils and oncogenic behaviors of gastric cells. Time series studies showed that Hp infection elicited an inflammatory TNF-α/HDGF/COX-2 cascade in stomach. HDGF secretion by Hp infection promotes the neutrophils infiltration and relays Hp-induced inflammatory signaling. Thus, HDGF may constitute a novel diagnostic marker and therapeutic target for Hp-induced gastritis and carcinogenesis.
Hepatoma-derived growth factor (HDGF) participates in angiogenesis and represents a negative prognostic factor in oral cancer. The current study was designed to elucidate the regulatory mechanism between HDGF and vascular endothelial growth factor (VEGF) and the clinical impact of oral cancer. TCGA data and surgical samples from oral cancer patients were used for the clinicopathological parameter and survival analysis. Human oral cancer SCC4 and SAS cells were treated with recombinant HDGF protein. VEGF gene expression and protein level were analyzed by RT-PCR, Western blotting, and enzyme-linked immunosorbent assay. The signaling pathways for regulating VEGF expression were investigated. The nucleolin neutralizing antibody and HIF-1α inhibitor were applied to SCC4 cells to investigate their effects on the HDGF-stimulated VEGF pathways. TCGA and immunohistochemical analysis revealed a positive correlation between HDGF and VEGF expression in oral cancer tissues. Recombinant HDGF significantly increased VEGF gene and protein expression in oral cancer SCC4 cells in a dose-dependent manner. HDGF enhanced the phosphorylation levels of AKT and IkB and the protein level of HIF-1α and NF-κB. The nucleolin-neutralizing antibody abolished HDGF-stimulated HIF-1α, NF-κB and VEGF protein expression in SCC4 cells. The HIF-1α inhibitor antagonized the HDGF-induced VEGF gene expression. High VEGF expression was strongly correlated with HDGF expression, advanced disease, and poor survival. This study postulated a new pathway in which HDGF activated HIF-1α and then induced VEGF expression through binding to membrane nucleolin under normoxic conditions, leading to poor disease control. The HDGF/HIF-1α/VEGF axis is important for developing future therapeutic strategies.
Hypoxia in tumors is known to trigger the pro-survival pathways such as autophagy. Systemic proopiomelanocortin (POMC) gene therapy suppresses melanoma through apoptosis induction and neovascularization blockage. In this study, we investigated the crosstalk between autophagic and apoptotic signaling in POMC-mediated melanoma suppression. By histological and immunoblot analysis, it was shown that POMC-treated melanoma tissues exhibited the prominent LC3 immunostaining, which was correlated with reduced CD31-positive tumor vascularization. Such autophagy induction could be recapitulated in melanoma cells receiving POMC gene delivery and hypoxia-mimicking agent cobalt chloride (CoCl 2 ). We then utilized the POMC-derived peptide α-MSH with CoCl 2 to elicit the autophagy as well as apoptosis in cultured melanoma cells. To delineate the role of autophagy during cell death, application of autophagy-inducer rapamycin enhanced, whereas autophagy inhibitor 3-MA attenuated, the α-MSH-induced apoptosis in melanoma cells. Genetic silencing of ATG5, an autophagy regulator, by RNA interference perturbed the α-MSH-induced apoptosis in melanoma cells. Finally, it was delineated that α-MSH stimulated the HIF-1α signaling as well as the expression of BNIP3/BNIP3L, thereby promoting the autophagy and apoptosis in melanoma cells. Therefore, the present study unveiled a unique function of autophagy in promoting cell death during POMC-mediated melanoma suppression via α-MSH/HIF-1α/BNIP3/BNIP3L signaling pathway.