Serum REIC/Dickkopf-3 Protein Level Predicts Disease-Free Survival in Patients with Hepatocellular Carcinoma.

The physiological role of the reduced expression of immortalized cells (REIC)/Dickkopf-3 (Dkk-3) protein in patients with hepatocellular carcinoma (HCC) remains unclear. In this study, we evaluated the effect of the REIC/Dkk-3 protein on HCC cell proliferation and assessed the relationship between the serum REIC/Dkk-3 protein level and the prognosis in patients with HCC. We evaluated the REIC/Dkk-3 protein-induced anticancer effects on Huh7 and Hep3B cells (HCC cell lines) in the presence of peripheral blood mononuclear cells (PBMCs), and found that combination treatment with REIC/Dkk-3 protein and PBMCs reduced the proliferation of HCC cells (Hep3B: 82.0%±16.3%; Huh7: 72.6%±9.1%). We also studied 194 HCC patients who underwent primary liver resection or primary radiofrequency ablation from 2008 to 2017. Serum REIC/Dkk-3 protein levels were measured by an enzyme-linked immunosorbent assay and compared to the prognostic data. The 3-year disease-free survival of the REIC/Dkk-3 high group was significantly higher than that in the REIC/Dkk-3 low group. In conclusion, this is the first study investigating the relationship between HCC patient survival and serum REIC/Dkk-3 protein levels in a large population. Based on the results, the serum REIC/Dkk-3 protein level should be considered a new prognostic marker for patients with HCC.

Promising therapeutic efficacy of a novel reduced expression in immortalized cells/dickkopf-3 expressing adenoviral vector for hepatocellular carcinoma.

BACKGROUND AND AIM: Reduced expression in immortalized cells (REIC)/dickkopf-3 (Dkk-3) is a tumor suppressor gene that is downregulated in various cancers. In our previous study of prostate cancer, the REIC/Dkk-3-expressing adenoviral vector (Ad-REIC) was found to induce cancer-selective apoptosis. This study recently developed a novel super gene expression (SGE) system and used this system to re-construct an Ad-REIC vector, termed the Ad-SGE-REIC, to achieve more effective therapeutic outcomes. In this study, the therapeutic effects of Ad-SGE-REIC on hepatocellular carcinoma (HCC) was assessed. METHODS: Human HCC cell lines (HLE, Huh7, HepG2, HLF, SK-Hep1, and PLC), human HCC tissues, and mouse HCC cell line (Hepa1-6) were used in this study. REIC/Dkk-3 expression was assessed by immunoblotting and immunohistochemistry. The relative cell viability and the apoptotic effect were examined in vitro, and the anti-tumor effects of Ad-SGE-REIC treatment were analyzed in the mouse xenograft model. This study additionally assessed anti-tumor immunological effects on the immunocompetent mice. RESULTS: REIC/Dkk-3 expression was decreased in HCC cell lines and HCC tissues. Ad-SGE-REIC reduced cell viability and induced apoptosis in HCC cell lines (HLE and Huh7), inhibited tumor growth in the mouse xenograft model, and demonstrated in vivo anti-cancer immunostimulatory effects on the HCC cell line (Hepa1-6). CONCLUSIONS: Ad-SGE-REIC treatment not only enhanced cell killing effects in vitro but also elicited significant therapeutic effects, with tumor growth suppression, in vivo. REIC/Dkk-3 gene therapy using Ad-SGE-REIC potentially represents an innovative new therapeutic tool for HCC.

Intravascular lymphoma with a gastric submucosal tumor.

A 75-year-old man was admitted to our hospital for further examination of swollen lymph nodes and a possible gastric submucosal tumor. He had persistent fever and anorexia. Blood examination showed anemia, thrombocytopenia, and elevated lactate dehydrogenase and soluble interleukin 2 receptor levels. Swollen lymph nodes and splenomegaly were evident on computed tomography, and the submucosal tumor was revealed by esophagogastric endoscopy. Cervical lymph node biopsy and endoscopic biopsy were performed, which revealed a diagnosis of intravascular lymphoma. In Asian countries, patients with intravascular lymphoma often have hemophagocytic syndrome without lesions of the central nervous system or skin, which is called the Asian variant of intravascular lymphoma. In this case, the patient had no indicative lesions and had no evidence of the hemophagocytic syndrome. He also had lymph node swelling and a gastric submucosal tumor, which are rare in intravascular lymphoma. The patient was treated with chemotherapy (R-CHOP;rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisolone), and complete response was demonstrated (based on the Response Evaluation Criteria for Solid Tumours [RECIST] guideline). In cases of possible intravascular lymphoma, gastrointestinal endoscopy and biopsy should be considered because they are a useful diagnostic strategy.

Synergistic anti-pancreatic cancer immunological effects by treatment with reduced expression in immortalized cells/dickkopf-3 protein and peripheral blood mononuclear cells.

BACKGROUND AND AIM: Reduced expression in immortalized cells/dickkopf-3 (REIC/DKK3) is a reported tumor suppressor gene and has potential to become an innovative therapy for various cancers. We examined the antitumor immunological effects of human REIC/DKK3 protein against pancreatic cancer. METHODS: Activation of extracellular signal-regulated kinases 1 and 2, mammalian target of rapamycin, and signal transducer and activator of transcription 3 by REIC/DKK3 protein was assessed in human peripheral blood mononuclear cells using immunoblotting. Pancreatic cancer cell lines (AsPC-1 and MIA Paca-2) were cocultured with peripheral blood mononuclear cells, and the anticancer effects of REIC/DKK3 protein were assessed using the methyl thiazole tetrazolium, cytotoxicity, and enzyme-linked immunospot assays. The antitumor immunological effects of the combined treatment with REIC/DKK3 protein and peripheral blood mononuclear cells were also assessed in a pancreatic cancer model using non-obese diabetic/severe combined immunodeficiency mice. RESULTS: The REIC/DKK3 protein activated extracellular signal-regulated kinases 1 and 2, mammalian target of rapamycin, and signal transducer and activator of transcription 3 in peripheral blood mononuclear cells. REIC/DKK3 protein inhibited in vitro cancer cell viability and enhanced cytotoxicity when incubated with peripheral blood mononuclear cells. REIC/DKK3 protein induced significant production of interferon gamma from lymphocytes incubated with pancreatic cancer cells, indicating that CD8+ T cells were activated in the peripheral blood mononuclear cells when cocultured with AsPC-1 and MIA Paca-2 in the presence of REIC/DKK3 protein. Combined treatment with REIC/DKK3 protein and peripheral blood mononuclear cells produced in vivo anticancer immunostimulatory effects on pancreatic cancer cells. CONCLUSIONS: The REIC/DKK3 protein and peripheral blood mononuclear cells synergistically enhanced anticancer immunological effects against pancreatic cancer cells. The observed immunomodulatory effect of combined treatment likely occurs in adenovirus-mediated REIC/DKK3 gene therapy and provides important clues to the therapeutic mechanisms involving immune cells.

Dipeptide γ-secretase inhibitor treatment enhances the anti-tumor effects of cisplatin against gastric cancer by suppressing cancer stem cell properties.

The γ-secretase inhibitor blocks Notch activity by preventing its cleavage at the cell surface. In the present study, the effect of the γ-secretase inhibitor on the viability of gastric cancer cells when administered in combination with cisplatin was investigated, with particular focus on CD44highLgr-5high cancer cells. The four gastric cancer cell lines, MKN45, MKN74, SC-6-JCK and SH-10-TC, were used for the experiments. In the MTT assay, treatment with 25 µM dipeptide γ-secretase inhibitor (DAPT) alone did not affect cell proliferation in any of the four cell lines. Gastric cancer cells subjected to combination treatment with DAPT and cisplatin exhibited decreased viability when compared with those treated with cisplatin alone. Flow cytometry was performed to evaluate the expression of cluster of differentiation (CD)-44 and leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr-5), two cancer stem cell markers in gastric cancers. Treatment with cisplatin alone significantly increased the proportion of CD44highLgr-5high cells. However, the addition of DAPT to cisplatin reduced the CD44highLgr-5high fraction, suggesting that DAPT reduced the number of gastric cancer cells. In conclusion, the present study demonstrated the synergistic effects of DAPT in combination with cisplatin by decreasing the survival of gastric cancer cells. In addition, combination treatment with DAPT reduced the number of CD44highLgr-5high cells, which are thought to exhibit cancer stem cell properties. These results highlight the therapeutic potential of DAPT in gastric cancer treatment.

[Corrigendum] Loss of Runt­related transcription factor 3 induces resistance to 5­fluorouracil and cisplatin in hepatocellular carcinoma.

Following the publication of this article, we realize that there were some errors in the manuscript. Details of the experiments describing the gene silencing of RUNX3 with small interfering RNA (siRNA) were erroneously included in this paper, and all references to siRNA should have been deleted from the manuscript prior to publication. In the subsection entitled 'Cell lines and cell culture' on page 2577, the left­hand column, the text should have indicated that the human HCC cell lines Hep3B and Huh7 were obtained from the American Type Culture Collection (ATCC; Manassas, VA, USA), whereas HLF cells were obtained from the Japanese Cancer Resources Bank (Tokyo, Japan). Lastly, an error was made in describing the calculation of the IC50 values, which did not correlate with the data shown in Fig. 2. Therefore, the subsection entitled 'Ectopic RUNX3 protein expression suppresses cell growth...' should have been entitled 'Ectopic RUNX3 protein expression increases 5­FU and CDDP sensitivity', and the text herein should have read as follows: We analyzed the effects of RUNX3 on chemosensitivity in the RUNX3­ or CAT (mock)­transfected Hep3B and Huh7 cells. RUNX3 expression enhanced 5­FU sensitivity in both cell lines; the cell viability with 5­FU (100 nM) decreased from 66.3±4.6 to 34.3±5.0%, and from 71.0±4.7% to 27.0±5.5% in the Hep3B and Huh7 cells, respectively (Fig. 2A). RUNX3 expression also enhanced CDDP sensitivity in both cell lines; the cell viability with CDDP (100 nM) decreased from 58.7±2.6% to 25.7±4.9%, and from 67.7±4.1% to 25.7±7.5% in the Hep3B and Huh7 cells, respectively (Fig. 2B). We sincerely apologize for these errors and oversights, which have not affected any of the overall conclusions reported in the study, and regret any inconvenience they may have caused. [the original article was published in the Oncology Reports 35: 2576-2582, 2016; DOI: 10.3892/or.2016.4681].

Loss of Runt-related transcription factor 3 induces resistance to 5-fluorouracil and cisplatin in hepatocellular carcinoma.

Runt-related transcription factor 3 (RUNX3) is known to function as a tumor suppressor in gastric cancer and other types of cancers, including hepatocellular carcinoma (HCC). However, its role has not been fully elucidated. In the present study, we aimed to evaluate the role of RUNX3 in HCC. We used the human HCC cell lines Hep3B, Huh7 and HLF; RUNX3 cDNA was introduced into Hep3B and Huh7 cells, which were negative for endogenous RUNX3 expression, and RUNX3 siRNA was transfected into HLF cells, which were positive for endogenous RUNX3. We analyzed the expression of RUNX3 and multidrug resistance-associated protein (MRP) by immunoblotting. MTT assays were used to determine the effects of RUNX3 expression on 5-fluorouracil (5-FU) and cisplatin (CDDP) sensitivity. Finally, 23 HCC specimens resected from patients with HCC at Okayama University Hospital were analyzed, and correlations among immunohistochemical expression of RUNX3 protein and MRP protein were evaluated in these specimens. Exogenous RUNX3 expression reduced the expression of MRP1, MRP2, MRP3 and MRP5 in the RUNX3-negative cells, whereas knockdown of RUNX3 in the HLF cells stimulated the expression of these MRPs. An inverse correlation between RUNX3 and MRP expression was observed in the HCC tissues. Importantly, loss of RUNX3 expression contributed to 5-FU and CDDP resistance by inducing MRP expression. These data have important implications in the study of chemotherapy resistance in HCC.

Hereditary Spherocytosis in a Middle-aged Man Complicated with Common Bile Duct Stones.

Hereditary spherocytosis is the most common form of hemolytic anemia and is characterized by spherical, osmotically fragile erythrocytes that are selectively trapped by the spleen. Hereditary spherocytosis is typically diagnosed in childhood. We herein experienced a rare case of hereditary spherocytosis diagnosed in middle age. The patient presented with cholelithiasis and hyperbilirubinemia. He had no anemia and was asymptomatic with mild splenomegaly. In the differential diagnosis of these symptoms, the possibility of hereditary spherocytosis should be considered, even in patients who are middle-aged and lack anemia.

Hepatic stellate cells promote upregulation of epithelial cell adhesion molecule and epithelial-mesenchymal transition in hepatic cancer cells.

Microenvironment plays an important role in epithelial-mesenchymal transition (EMT) and stemness of cells in hepatocellular carcinoma (HCC). Epithelial cell adhesion molecule (EpCAM) is known as a tumor stemness marker of HCC. To investigate the relationship between microenvironment and stemness, we performed an in vitro co-culture assay. Four HCC cell lines (HepG2, Hep3B, HuH-7 and PLC/PRF/5) were co-cultured with the TWNT-1 immortalized hepatic stellate cells (HSCs), which create a microenvironment with HCC. Cell proliferation ability was analyzed by flow cytometry (FCM) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while migration ability was assessed by a wound healing assay. Expression of EpCAM was analyzed by immunoblotting and FCM. HCC cell lines were co-cultured with TWNT-1 treated with small interfering RNA (siRNA) for TGF-ß and HB-EGF; we then analyzed proliferation, migration ability and protein expression using the methods described above. Proliferation ability was unchanged in HCC cell lines co-cultured with TWNT-1. Migration ability was increased in HCC cell lines (HepG2, Hep3B, HuH-7 and PLC/PRF/5) directly (216.2±67.0, 61.0±22.0, 124.0±66.2 and 51.5±40.3%) and indirectly (102.5±22.0, 84.6±30.9, 86.1±25.7 and 73.9±29.7%) co-cultured with TWNT-1 compared with the HCC uni-culture. Immunoblot analysis revealed increased EpCAM expression in the HCC cell lines co-cultured with TWNT-1. Flow cytometry revealed that the population of E-cadherin-/N-cadherin+ and EpCAM-positive cells increased and accordingly, EMT and stemness in the HCC cell line were activated. These results were similar in the directly and indirectly co-cultured samples, indicating that humoral factors were at play. Conversely, HCC cell lines co-cultured with siRNA­treated TWNT-1 showed decreased migration ability, a decreased population of EpCAM-positive and E-cadherin-/N-cadherin+ cells. Taken together, humoral factors secreted from TWNT-1 promote upregulation of EpCAM and EMT in hepatic cancer cells.