Kimihiro Nishino

Establishment of a novel lectin–antibody ELISA system to determine core-fucosylated haptoglobin

BACKGROUND Fucosylated haptoglobin (Fuc-Hpt) is a novel cancer biomarker that increases in various pathological conditions. We previously established a Fuc-Hpt lectin-antibody assay using Aleuria aurantia lectin (AAL), and applied this to diagnose several diseases, including various cancers. AAL recognizes both α1-3/1-4 and α1-6 fucosylation on N/O-linked glycans. These fucosylation types differ in biological function, and in regulation by different fucosyltransferases. Recently, we identified a novel lectin, Pholiota squarrosa lectin (PhoSL), which specifically recognizes α1-6 fucosylation (core-fucosylation). METHODS We developed a lectin-antibody ELISA kit using PhoSL to determine core-Fuc-Hpt levels in sera from colorectal or pancreatic cancer patients. RESULTS Serum levels of AAL-reactive Hpt are higher in pancreatic cancer patients, whereas those of PhoSL-reactive Hpt are higher in colorectal cancer patients. Mass spectrometry analyses of Hpt fucosylation levels were consistent with lectin-antibody ELISA results. Hpt-transfected colorectal cancer cell lines produced significant amounts of core-Fuc-Hpt, suggesting that colorectal cancer tissues produce core-Fuc-Hpt. CONCLUSIONS These differences in Fuc-Hpt patterns might depend on cancer cells and the surrounding cells, which produce Hpt.

Serum Mac-2 binding protein is a novel biomarker for chronic pancreatitis

AIM To determine the efficacy of Mac-2 binding protein (Mac-2bp) for diagnosis of chronic pancreatitis. METHODS Fifty-nine healthy volunteers (HV), 162 patients with chronic pancreatitis (CP), and 94 patients with pancreatic ductal adenocarcinoma (PDAC) were enrolled in this study. We measured serum Mac-2bp using our developed enzyme-linked immunosorbent assay kit. Additional biochemical variables were measured using an automated analyzer (including aminotransferase, alanine aminotransferase, γ-glutamyltransferase, alkaline phosphatase, triglyceride, C-reactive protein, and amylase levels) or chemiluminescent enzyme immunoassay (carbohydrate antigen 19-9 and carcinoembryonic antigen). The ability of Mac-2bp to predict CP diagnosis accurately was assessed using receiver operating characteristic (ROC) analyses. RESULTS Serum Mac-2bp levels were significantly increased in CP patients compared to HV (P < 0.0001) and PDAC patients (P < 0.0001). Area under the ROC curve values of Mac-2bp for the discrimination of CP from HV and PDAC were 0.727 and 0.784, respectively. Multivariate analyses demonstrated that serum Mac-2bp levels were independent determinants for CP diagnosis from HV and PDAC patients. Immunohistological staining showed that Mac-2bp was expressed faintly in the pancreas tissues of both CP and PDAC patients. Serum aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, alkaline phosphatase, and triglyceride levels were significantly higher in patients with CP or PDAC. Serum Mac-2bp levels were highly correlated with protein levels of alanine aminotransferase, γ-glutamyltransferase, and C-reactive protein, but not amylase, suggesting that the damaged liver produces Mac-2bp. CONCLUSION Measurement of serum Mac-2bp may be a novel and useful biomarker for CP diagnosis as well as liver fibrosis in the general population.

Establishment of an antibody specific for cancer-associated haptoglobin: A possible implication of clinical investigation

We previously found that the serum level of fucosylated haptoglobin (Fuc-Hpt) was significantly increased in pancreatic cancer patients. To delineate the mechanism underlying this increase and develop a simple detection method, we set out to generate a monoclonal antibody (mAb) specific for Fuc-Hpt. After multiple screenings by enzyme-linked immunosorbent assay (ELISA), a 10-7G mAb was identified as being highly specific for Fuc-Hpt generated in a cell line as well as for Hpt derived from a pancreatic cancer patient. As a result from affinity chromatography with 10-7G mAb, followed by lectin blot and mass spectrometry analyses, it was found that 10-7G mAb predominantly recognized both Fuc-Hpt and prohaptoglobin (proHpt), which was also fucosylated. In immunohistochemical analyses, hepatocytes surrounding metastasized cancer cells were stained by the 10-7G mAb, but neither the original cancer cells themselves nor normal hepatocytes exhibited positive staining, suggesting that metastasized cancer cells promote Fuc-Hpt production in adjacent hepatocytes. Serum level of Fuc-Hpt determined with newly developed ELISA system using the 10-7G mAb, was increased in patients of pancreatic and colorectal cancer. Interestingly, dramatic increases in Fuc-Hpt levels were observed at the stage IV of colorectal cancer. These results indicate that the 10-7G mAb developed is a promising antibody which recognizes Fuc-Hpt and could be a useful diagnostic tool for detecting liver metastasis of cancer.

A novel mechanism of neovascularization in peritoneal dissemination via cancer-associated mesothelial cells affected by TGF-β derived from ovarian cancer

Epithelial ovarian cancer (EOC) is believed to cause peritoneum dissemination through microenvironmental cell‑to-cell communication between the tumor and mesothelium, leading to the further acquisition of progressive and metastatic potentials. In the present study, we aimed to determine the role of cancer-associated mesothelial cells (CAMCs) in the promotion of tumor neovascularization and vascular permeability via enhanced vascular endothelial growth factor (VEGF) production. We examined whether a characteristic morphological change in human peritoneal mesothelial cells (HPMCs) was observed in the presence of malignant ascites and tumor-derived TGF-β. We focused on the enhanced production of VEGF in CAMCs and its crucial role in endothelial migration and tube formation. Normal HPMCs showed an epithelial morphology with a cobblestone appearance. When HPMCs were co-cultured with malignant ascites from patients with advanced EOC, a dramatic morphologic change was noted from an epithelioid pattern to an α-SMA-positive fibroblastic, mesenchymal pattern. Additionally, we found that EOC-derived TGF-β induced typical EMT-like morphological alteration in HPMCs, which was associated with CAMCs. We further discovered that CAMCs play a crucial role in the enhanced migration and tube formation of endothelial cells by the promotion of VEGF production. In conclusion, our findings indicate the possible involvement of CAMCs in the neovascularization of EOC and enhancement of vascular permeability, resulting in the formation of malignant ascites. The novel mechanism of CAMCs as a facilitator of EOC progression is displayed by microenvironmental cell-to-cell communication between EOC and the mesothelium.

c-Rel Promotes Invasion of Choriocarcinoma Cells via PI3K/AKT Signaling

Objective: Choriocarcinoma is the most common epithelial cancer among gestational trophoblastic diseases (GTDs); the mechanism of trophoblastic carcinogenesis is unknown. This study aimed to examine the expression of NF-κB family proteins in GTDs and placental tissues as well as the roles of c-Rel in choriocarcinoma. Methods: We examined the expression of NF-κB family proteins in normal placenta and hydatidiform mole tissues as well as extravillous trophoblast (EVT) and choriocarcinoma cell lines by Western blot and immunohistochemistry. Immunoprecipitation was performed to determine which proteins can bind with c-Rel in choriocarcinoma cells. To investigate the roles of c-Rel in choriocarcinoma, we examined the effects of c-Rel knockdown and overexpression on cell proliferation, migration, and invasion using small interfering RNAs and gene activation plasmid. Results: The expression of c-Rel was strong in choriocarcinoma and EVTs, but very weak in villi of normal placenta and hydatidiform mole. Immunoprecipitation suggested that c-Rel heterodimerizes with p65 in choriocarcinoma. c-Rel knockdown reduced invasion, migration, and AKT phosphorylation in choriocarcinoma cells. c-Rel overexpression in choriocarcinoma increased migratory and invasive abilities, and the effect on invasion was inhibited by a PI3K inhibitor. Conclusion: These findings suggest that c-Rel might play a role in promoting the invasion of choriocarcinoma cells through PI3K/AKT signaling.

The possible existence of occult metastasis in patients with ovarian clear-cell carcinoma who underwent complete resection without any residual tumours

The objective of this study was to estimate the frequency of possible occult metastasis through long-term survival analyses in patients with clear cell carcinoma (CCC) who had undergone complete resection. During the period of 1990-2015, 799 patients with stage I-IV CCC were identified in the TOTSG database. Of these, a total of 528 patients without a residual tumor were enrolled in the study and classified into four groups: Group 1: FIGO stage IA-IB (N=104), Group 2: FIGO stage IC1 (N=170), Group 3: FIGO stage IC2/IC3 (N=98), and Group 4: FIGO stage II-III (no residual tumor: N=156). Cumulative incidences of recurrence (CIR) and death (CID) were examined. The median age was 54, ranging from 29-87. The 5-year CIR / CID of each group were as follows: Group 1 (7.3% / 3.8%), Group 2 (14.3% / 10.2%), Group 3 (37.7% / 18.4%), and Group 4 (46.5% / 33.8%), respectively {P<0.0001 (recurrence) / P<0.0001 (death)}. Furthermore, confining analysis to relapsed patients, 1-, 2-, and 3-year CID after recurrence were 41.5, 60.9, and 73.9, respectively. Confining analyses to patients with sufficient information about adjuvant chemotherapy, the 5-year CIR / CID of stage IA-IC1 patients with or without chemotherapy were as follows: recurrence {13.0% (yes) / 9.6% (no)}, death {9.3% (yes) / 4.2% (no)}, respectively {P=0.947 (CIR) / P=0.224 (CID)}. CCC patients staged greater than IC2/ IC3 show a marked risk of mortality, even after complete surgical resection.

Fertility-sparing surgery of malignant transformation arising from mature cystic teratoma of the ovary

Background The purpose of this study was to evaluate the long-term clinical outcome of young women with malignant transformation arising from mature cystic teratoma of the ovary (MT-MCT) by comparing radical surgery and fertility-sparing surgery (FSS). Patients and methods All patients treated with radical surgery or FSS for MT-MCT in multiple institutions were registered in this analysis. Univariate and multivariate analyses were performed to evaluate clinical outcome, including overall survival (OS) and disease-free survival (DFS). Results From 1986 to 2016, 62 patients with MT-MCT were treated in our group. The median follow-up period was 38.0 (2.0-227.9) months, and the median age was 54 (17-82) years old. Multivariate analysis revealed that only advanced stage was significantly correlated with poorer prognosis of patients [hazard ratio (HR) for death: 6.58, 95% confidence interval (CI): 1.82–24.78, P = 0.0048; HR for recurrence: 5.59, 95% CI: 1.52–21.83, P = 0.01]. Of a total of 13 women with stage I-II disease at less than 45 years old, 7 were treated with FSS, and there was no recurrence except for in one woman with stage II MT-MCT. There was no significant difference in long-term oncological outcome between radical surgery and FSS. Conclusion FSS may be indicated for patients with stage I MT-MCT, who hope to preserve fertility, as no relapse was found after FSS.

The upregulated expression of vascular endothelial growth factor in surgically treated patients with recurrent/radioresistant cervical cancer of the uterus

Vascular endothelial growth factor (VEGF) inhibitors have been utilized for the treatment against advanced or recurrent cervical carcinoma as a novel therapeutic modality. However, the expression level of VEGF in post-radiotherapy relapsed/persistent cervical cancer remains to be elucidated. The aim of the present study was to investigate the expression of VEGF and associated molecules using tumor samples from patients with post-radiotherapy relapsed/persistent cervical cancer. From a database of 826 patients who were treated at our institution between 2003 and 2015, eight patients with post-radiotherapy relapsed/persistent cervical cancer were identified, and 20 patients who underwent initial surgery alone were used as a control. Using samples from these patients, the expression levels of VEGF-A, VEGF receptor-1 (VEGFR-1) and hypoxia inducible factor-1α (HIF-1α) were immunohistochemically categorized as negative or weakly, moderately, or strongly positive according to the size of the staining area, and intensity. In carcinoma cells, the expression levels of VEGF-A, VEGFR-1 and HIF-1α were significantly higher in post-radiotherapy relapsed/persistent cervical cancer compared with control patients (P=0.0003, 0.0003, and 0.0001, respectively). In stroma cells, similar tendencies with statistical significance were observed (P=0.0014 and P<0.0001, respectively). In addition, the expression levels of VEGF-A and VEGFR-1 in carcinoma cells were significantly correlated with each other (P<0.0001). A significantly higher expression of VEGF was identified in post-radiotherapy relapsed/persistent cervical cancer compared with typical specimens from cervical cancer. The findings provide a novel insight into the clinical treatment for recurrent/persistent cervical cancer using a VEGF antagonist.

Reproductive outcomes of 105 malignant ovarian germ cell tumor survivors: a multicenter study

BACKGROUND: Malignant ovarian germ cell tumors usually occur in young women. Until the 1970s, before establishment of systemic chemotherapy, malignant ovarian germ cell tumors had a very poor prognosis. Recently, prognosis has improved, and fertility‐sparing treatment is being adopted in patients who desire to become pregnant. However, the number of malignant ovarian germ cell tumor survivors who actually became pregnant remains unknown. OBJECTIVE: The present study aimed to clarify the reproductive outcomes in malignant ovarian germ cell tumor survivors by using data from a multicenter database and an additional survey on reproductive outcomes. STUDY DESIGN: The study used the Tokai Ovarian Tumor Study Group database on ovarian cancer patients. We assessed the database from 1986 through 2016 and selected malignant ovarian germ cell tumor patients <40 years of age who received fertility‐sparing treatment. Questionnaires on reproductive outcomes were sent to the registered facilities. The following data were collected and used in this study: age, date of onset, surgical procedure, chemotherapy regimen, tumor type, International Federation of Gynecology and Obstetrics stage, survival outcome and period, number of pregnancies and childbirths, marital status, childbearing desire, method of pregnancy, gestational weeks at delivery, birthweight of the baby, obstetric complications, and menstrual status after fertility‐sparing treatment. RESULTS: A total of 110 malignant ovarian germ cell tumor patients who received fertility‐sparing treatment were identified. The median follow‐up period was 10.4 years. Five patients were excluded because of death or loss of fertility after treatment for recurrence. Thus, 105 patients were finally included. The additional survey revealed that 42 of 45 patients who desired childbirth became pregnant. The total number of pregnancies was 65, and 56 babies were born to 40 malignant ovarian germ cell tumor survivors. CONCLUSION: The reproductive outcomes of malignant ovarian germ cell tumor survivor are promising with fertility‐sparing treatment. Malignant ovarian germ cell tumor survivors can become pregnant and give birth if they desire.

Establishment and characterization of cell lines derived from complete hydatidiform mole

Gestational trophoblastic diseases (GTDs) are a group of diseases characterized by abnormal cellular proliferation of atypical trophoblasts. A hydatidiform mole is an abnormal pregnancy caused by genetic fertilization disorders, and it can be classified as a complete hydatidiform mole (CHM) or a partial hydatidiform mole. The aim of this study was to establish cell lines from CHMs and to characterize the cells for future studies concerning GTD. HMol1-2C, HMol1-3B, HMol1-8 and HMol3-1B were established from primary cultures of CHM explants following the introduction of different combinations of genes including human telomerase reverse transcriptase (hTERT), a mutant form of CDK (CDK4R24C), cyclin D1, p53C234, MYC and HRAS. HMol1-2C, HMol1-3B, and HMol3-1B were confirmed to originate from trophoblasts of androgenic, homozygous CHMs. These three cell lines exhibited low human chorionic gonadotropin secretion, low migration and invasion abilities, and the potential to differentiate into syncytiotrophoblastic cells via forskolin treatment. These results suggest that these cells exhibit characteristics of trophoblastic cells, especially cytotrophoblastic cells. HMol1-8 was found to consist of diploid cells and originated from maternal cells, suggesting that they were derived from decidual cells. In conclusion, we successfully established three cell lines from CHMs by introduction of hTERT and other genes. Analysis revealed that the genetic origin of each cell line was identical with that of the original molar tissue, and the cell lines exhibited characteristics of trophoblastic cells, which are similar to undifferentiated cytotrophoblasts.