Cell division cyclin 25C knockdown inhibits hepatocellular carcinoma development by inducing endoplasmic reticulum stress.

BACKGROUND: Cell division cyclin 25C (CDC25C) is a protein that plays a critical role in the cell cycle, specifically in the transition from the G2 phase to the M phase. Recent research has shown that CDC25C could be a potential therapeutic target for cancers, particularly for hepatocellular carcinoma (HCC). However, the specific regulatory mechanisms underlying the role of CDC25C in HCC tumorigenesis and development remain incompletely understood. AIM: To explore the impact of CDC25C on cell proliferation and apoptosis, as well as its regulatory mechanisms in HCC development. METHODS: Hepa1-6 and B16 cells were transduced with a lentiviral vector containing shRNA interference sequences (LV-CDC25C shRNA) to knock down CDC25C. Subsequently, a xenograft mouse model was established by subcutaneously injecting transduced Hepa1-6 cells into C57BL/6 mice to assess the effects of CDC25C knockdown on HCC development in vivo. Cell proliferation and migration were evaluated using a Cell Counting Kit-8 cell proliferation assays and wound healing assays, respectively. The expression of endoplasmic reticulum (ER) stress-related molecules (glucose-regulated protein 78, X-box binding protein-1, and C/EBP homologous protein) was measured in both cells and subcutaneous xenografts using quantitative real-time PCR (qRT-PCR) and western blotting. Additionally, apoptosis was investigated using flow cytometry, qRT-PCR, and western blotting. RESULTS: CDC25C was stably suppressed in Hepa1-6 and B16 cells through LV-CDC25C shRNA transduction. A xenograft model with CDC25C knockdown was successfully established and that downregulation of CDC25C expression significantly inhibited HCC growth in mice. CDC25C knockdown not only inhibited cell proliferation and migration but also significantly increased the ER stress response, ultimately promoting ER stress-induced apoptosis in HCC cells. CONCLUSION: The regulatory mechanism of CDC25C in HCC development may involve the activation of ER stress and the ER stress-induced apoptosis signaling pathway.

Anti-hepatoma Effect of DC2.4 Cells Transfected with Tumor-Associated Antigen Cdc25C In Vitro.

OBJECTIVE: Cell division cyclin 25 homolog C (Cdc25C) is a tumor-associated antigen candidate gene, and this may be used as an effective target in cancer treatment. The present study aims to evaluate the lysis effect of cytotoxic T lymphocytes (CTLs) induced by dendritic cell line DC2.4 overexpressing Cdc25C, and the feasibility of Cdc25C as a component in hepatoma immunotherapy. METHODS: The mouse Cdc25C gene was ligated into a lentiviral vector, and transfected into DC2.4 cells. The DC2.4 cell phenotype and cytokine secretion were determined by flow cytometry and ELISA, respectively. CD8+ T cells were sorted from the spleens of C57BL/6 mice using a magnetic bead sorting kit obtained from Miltenyi Biotech, Germany, and co-cultured with DC2.4 cells for one week as effector cells. Then, IL-2, granzyme B and perforin were detected in the CTL culture medium by ELISA. Next, time-resolved fluorescence immunoassay was used to detect the immune killing effect of Cdc25C-specific CTLs on target cells. Meanwhile, the effect of blocking MHC-I sites on target cells with a monoclonal anti-MHC-I antibody was evaluated. RESULTS: The results revealed that Cdc25C could be stably overexpressed in DC2.4 cells by LV-Cdc25C infection. DC2.4 cells transfected with LV-Cdc25C secreted more IL-6, IL-12, TNF-α and IFN-γ, and had higher expression levels of CD40, CD86, CCR7 and MHC-II than unaltered DC2.4 cells. The elevated Cdc25C in dendritic cells also further increased the secretion of IL-2, granzyme B and perforin to elicit Cdc25C-specific CTLs, and induced the higher cytotoxicity in Hepa1-6 cell lines (P<0.05), but this had no effect on the target cells when MHC-I monoclonal antibodies were blocked. CONCLUSION: DC2.4 cells transfected with LV-Cdc25C can induce specific CTLs, and result in a strong cellular immune response. The dendritic cells that overexpress Cdc25C may be useful for hepatoma immunotherapy.

Laminarin from Seaweed (Laminaria japonica) Inhibits Hepatocellular Carcinoma Through Upregulating Senescence Marker Protein-30.

Objective: This study aimed at investigating the specific roles of laminarin from seaweed (Laminaria japonica) in hepatocellular carcinoma (HCC) and its potential mechanisms related to senescence marker protein-30 (SMP-30). Materials and Methods: Human HCC cell lines, including Bel-7404 and HepG2, were incubated with different concentrations of laminarin (0, 5, 15, 25, 35, and 45 mg/mL). The cell viability and apoptosis rates were detected by WST-8 cell proliferation assay and flow cytometry, respectively. Hepa 1-6 tumor-bearing mice were injected with different concentrations of laminarin (400, 800, and 1200 mg/kg·d), and tumor volume and weight were measured. The expression of SMP-30 was detected in laminarin-treated Bel-7404 and HepG2 HCC cells and LO2 normal liver cells by quantitative real-time PCR and Western blotting. Results: The treatment with laminarin (48 h) significantly decreased the viability and increased the apoptosis rates of Bel-7404 and HepG2 cells in a dose-dependent manner. The injection of laminarin also significantly decreased the tumor volumes (beginning on the 10th day) and tumor weights (30 d post-injection) of mice in a dose-dependent manner. In addition, the treatment with laminarin (35 mg/mL for 48 h) significantly upregulated SMP-30 in Bel-7404 and HepG2 cells but not in LO2 cells. Conclusion: Laminarin inhibited the proliferation of Bel-7404 and HepG2 cells and inhibited the growth of tumors in Hepa 1-6 tumor-bearing mice by upregulating SMP-30.

Hsp72 protects against liver injury via attenuation of hepatocellular death, oxidative stress, and JNK signaling.

BACKGROUND & AIMS: Heat shock protein (Hsp) 72 is a molecular chaperone that has broad cytoprotective functions and is upregulated in response to stress. To determine its hepatic functions, we studied its expression in human liver disorders and its biological significance in newly generated transgenic animals. METHODS: Double transgenic mice overexpressing Hsp72 (gene Hspa1a) under the control of a tissue-specific tetracycline-inducible system (Hsp72-LAP mice) were produced. Acute liver injury was induced by a single injection of acetaminophen (APAP). Feeding with either a methionine choline-deficient (MCD; 8 weeks) or a 3,5-diethoxycarbonyl-1,4-dihydrocollidine-supplemented diet (DDC; 12 weeks) was used to induce lipotoxic injury and Mallory-Denk body (MDB) formation, respectively. Primary hepatocytes were treated with palmitic acid. RESULTS: Patients with non-alcoholic steatohepatitis and chronic hepatitis C infection displayed elevated HSP72 levels. These levels increased with the extent of hepatic inflammation and HSP72 expression was induced after treatment with either interleukin (IL)-1ß or IL-6. Hsp72-LAP mice exhibited robust, hepatocyte-specific Hsp72 overexpression. Primary hepatocytes from these animals were more resistant to isolation-induced stress and Hsp72-LAP mice displayed lower levels of hepatic injury in vivo. Mice overexpressing Hsp72 had fewer APAP protein adducts and were protected from oxidative stress and APAP-/MCD-induced cell death. Hsp72-LAP mice and/or hepatocytes displayed significantly attenuated Jnk activation. Overexpression of Hsp72 did not affect steatosis or the extent of MDB formation. CONCLUSIONS: Our results demonstrate that HSP72 induction occurs in human liver disease, thus, HSP72 represents an attractive therapeutic target owing to its broad hepatoprotective functions. LAY SUMMARY: HSP72 constitutes a stress-inducible, protective protein. Our data demonstrate that it is upregulated in patients with chronic hepatitis C and non-alcoholic steatohepatitis. Moreover, Hsp72-overexpressing mice are protected from various forms of liver stress.

Cancer testis antigen OY-TES-1 expression and serum immunogenicity in colorectal cancer: its relationship to clinicopathological parameters.

Cancer testis (CT) antigens are attractive targets for cancer immunotherapy because their expression is restricted in normal germ line tissues but frequently detected in variety of tumors. OY-TES-1 is identified as a member of CT antigens. Current knowledge about OY-TES-1 expression in colorectal cancer (CRC) is solely based on mRNA analysis. None of previous researches has studied OY-TES-1 at protein level. In this study, OY-TES-1 polyclonal antibody was generated. The expression of OY-TES-1 mRNA and protein was detected by RT-PCR and immunohistochemistry in 60 CRC and paired adjacent non-tumor tissues, 24 colorectal adenoma and 3 normal colon tissues, respectively. Sera from 73 CRC patients were also tested for OY-TES-1 antibody by ELISA. Our results showed that the frequency of OY-TES-1 mRNA expression was statistically higher in CRC (73.3%, 44/60) than that in adjacent non-tumor tissue (55.0%, 33/60) and colorectal adenoma (45.8%, 11/24). For the first time, OY-TES-1 protein expression was found in (43.3%, 26/60) of CRC tissues, but absent in any of adjacent non-tumor and colorectal adenoma tissues. No OY-TES-1 expression was found in normal colon by either RT-PCR or immunohistochemistry. Furthermore, OY-TES-1 protein expression was correlated with tumor invasion stage (P=0.004) and histological grade (P=0.040). Anti-OY-TES-1 antibody was detected in (9.6%, 7/73) of CRC patients' sera but not in 76 healthy donors. This finding demonstrates that OY-TES-1 is frequently expressed in CRC and is able to induce humoral immune response spontaneously in CRC patients, suggesting that it might be a promising immunotherapy target for CRC.

Serum immunoreactivity of SMP30 and its tissues expression in hepatocellular carcinoma.

OBJECTIVES: To detect serum antibody against SMP30 in HCC patients and to evaluate its potential associations with HCC patient's clinical parameter and expression levels in HCC tissues. DESIGN AND METHODS: Serum antibody to SMP30 was tested by ELISA method; SMP30 mRNA and protein expression in HCC patients were analyzed using the methods of in situ nucleic acid hybridization and immunohistochemistry, respectively. RESULTS: The highest relevance of SMP30 antibody was associated with HCC (32.4%). The positive rate of SMP30 antibody was not related to the age of patients, tumor size, metastasis and infections of HBV, but the positive rate for SMP30 antibody in the HCC sera with alpha-fetoprotein (AFP) negative was higher (43.6%) compared with that AFP positive (26.2%). Both SMP30 mRNA and protein expression levels were downregulated in HCC and upregulated in adjacent tissues. CONCLUSIONS: SMP30 may be useful for HCC serologic screening, especially for the patients with AFP negative.