Reduced port laparoscopic subtotal cholecystectomy for Mirizzi syndrome with a bilio-biliary fistula: A case report

A 65-year-old male diagnosed with Mirizzi syndrome with a bilio-biliary fistula was referred to our department and underwent single-incision laparoscopic surgery with an assistant trocar. As typical laparoscopic cholecystectomy could not be performed due to the coexistence of a bilio-biliary fistula, we performed laparoscopic subtotal cholecystectomy as a bail-out procedure according to the recommendation of the recent Tokyo Guidelines (TG18). The neck of the remnant gallbladder could be easily sutured with the effective use of an assistant trocar, and the surgery was completed without any complications. The patient was discharged 5 days after surgery without any complications. While little has been reported on the efficacy of reduced port surgery for Mirizzi syndrome, our surgical approach, i.e. reduced port surgery with an assistant trocar, enabled secure and easy suturing as a bail-out procedure and seemed to be an efficient method that is both less-invasive and safe.

[A Case of Surgical Resection for Ascending Colon Cancer with Protein-Losing Gastroenteropathy]

An 84-year-old man visited our department for further examination of anemia and elevation of tumor marker levels. Colonoscopy revealed a huge circumferential type 3 tumor in the ascending colon. Significant hypoalbuminemia was observed at 1.1 g/dL, and prolonged hypoalbuminemia was considered to be caused by protein-losing gastroenteropathy due to the large tumor. In this case, we performed right hemicolectomy, and performed single-stage anastomosis. The resected specimen showed a huge type 3 lesion with a diameter of 140×120 mm in the ascending colon, which directory invaded to the cecum and ileum. After the operation, there were no particular complications, and albumin levels gradually improved. Although hypoalbuminemia is one of the risks of anastomotic leakage, there are many reports with one-stage anastomosis and with a good course, including our case. Therefore, it was considered necessary to examine each case regarding the surgical procedure.

[A Case of Low-Grade Appendiceal Mucinous Neoplasm with Extra-Appendiceal Mucin Extrusion Successfully Treated with Laparoscopic Surgery]

A 49-year-old male patient, who presented with abdominal pain, was suspected of having acute appendicitis. Abdominal computed tomography revealed a swollen appendix, accompanied by a 40 mm low-density mass located behind the appendix. He was diagnosed with an appendiceal mucinous neoplasm, and laparoscopic ileocecal resection was performed. A soft tumor was found proximal to the swollen appendix and was adhered tightly to the iliopsoas muscle. The tumor cells were exfoliated carefully, and the tumor was excised en bloc without any injury. Histopathological examination revealed a low- grade appendiceal mucinous neoplasm(LAMN)accompanied by extra-appendiceal mucin extrusion due to the lack of epithelial lining. Because LAMN is potentially malignant, surgical excision was performed as first-line therapy. In the surgical management of LAMN, preventing intraoperative rupture is essential to avoid pseudomyxoma peritonei. To achieve this, a magnified laparoscopic surgery may be useful. Although no definitive guidelines describing the indications of lymph node dissection or the appropriate extent of resection exist, laparoscopic ileocecal resection may be used to manage cases of LAMN.

[Two Cases of Lower Rectal Cancer in Which Temporary Ileostomy Could Be Avoided by Using the Pull Through Procedure]

We report 2 cases of lower rectal cancer in which temporary ileostomy was avoided by using the Pull through procedure. Case 1 was a 59-year-old man with a BMI of 29.67 who was diagnosed as having lower rectal cancer after a positive stool occult blood test. He had a strong refusal to use a ileostomy and was obese, so he underwent laparoscopic intersphincteric resection using the Pull through procedure. Reconstruction was performed on the 7th postoperative day. He was discharged from the hospital on the 14th day after the initial surgery. Case 2 was a 65-year-old woman with a BMI of 27.65 who was referred to our department for additional resection after ESD for a lesion in the lower rectum. As in the previous case, she was obese and refused to use a ileostomy, so we chose to perform a laparoscopic intersphincteric resection using the Pull through procedure. Reconstruction was performed on the 7th postoperative day, and she was discharged on the 25th day after the initial surgery. Patient satisfaction was high, and the Pull through procedure may be an option for patients with lower rectal cancer who have difficulty in undergoing temporary ileostomy.

Foreign body granulomas mimic peritoneal dissemination caused by incarcerated femoral hernia perforation: A case report

BACKGROUND

Foreign body granuloma (FBG) is a well-known type of granulomatous formation, and intraabdominal FBG (IFBG) is primarily caused by surgical residues. Multifocal IFBGs caused by gastrointestinal perforation is an extremely rare and interesting clinicopathological condition that resembles peritoneal dissemination. Here, we present a case of IFBGs mimicking peritoneal dissemination caused by bowel perforation and describe the value of intraoperative pathological examinations for rapid IFBG diagnosis.

CASE SUMMARY

An 86-year-old woman with an incarcerated femoral hernia was admitted to the hospital and underwent operation. During the operation, the incarcerated ileum was perforated during repair due to hemorrhage necrosis, and a small volume of enteric fluid leaked from the perforation. The incarcerated ileum was resected, and the femoral hernia was repaired without mesh. Four months later, a second operation was performed for an umbilical incisional hernia. During the second operation, multiple small, white nodules were observed throughout the abdominal cavity, resembling peritoneal dissemination. The results of peritoneal washing cytology in Douglas’ pouch and the examination of frozen nodule sections were compatible with IFBG diagnosis, and incisional hernia repair was performed.

CONCLUSION

IFBGs can mimic malignancy. Intraoperative pathological examinations and operation history are valuable for the rapid diagnosis to avoid excessive treatments.

[A Case of Local Recurrence of Transverse Colon Cancer Radically Resected by Extended Surgery]

A 71-year-old male with a past history of Stage Ⅱb transverse colon cancer was pointed out a mass lesion penetrating into the stomach on abdominal computed tomography 1 year after surgery. The mass lesion was pathologically diagnosed as local recurrence of the previous colon cancer by upper gastrointestinal endoscopy. As he presented progressive anemia due to persistent tumor bleeding and no other recurrent lesion was recognized, surgical treatment was performed. Since intraoperative inspection suspected direct invasion to the pancreas, the patient underwent tumor resection in combination with distal pancreatectomy and partial resection of the stomach. Histopathological examination revealed negative surgical margins, resulting in R0 resection. Loco-regional therapies such as surgery and radiotherapy are considered appropriate for the treatment of local recurrence since pathogenesis of local recurrence is different from that of distant metastasis. As local recurrence may show various symptoms, we should aggressively consider surgical resection. Especially, complete resection of recurrent lesion is the only therapeutic strategy which can achieve radical cure. Although worsening of QOL might be a matter of concern depending on the site of recurrence, extended surgery with secure surgical margins is encouraged in cases of solitary recurrence.

[A Case of Primary Gastrointestinal Stromal Tumor with First Recurrence 13 Years after Surgery and Second Recurrence in the Omentum 6 Years Later]

A 63-year-old man underwent proximal gastrectomy for gastrointestinal stromal tumor(GIST)of the stomach 19 years ago. Local recurrence of GIST of the stomach occurred 13 years later, and the tumor was resected. Since then, he had adjuvant chemotherapy. Six years later, computed tomography revealed a soft-tissue shadow at the left lateral side of the stomach, and positron emission tomography also revealed fluorodeoxyglucose uptake at the same site. The recurrence of GIST was suspected, and therefore laparoscopic resection was performed. The operative time was 70 minutes. Blood loss was 10 g. Immunohistochemical examination showed positivity for c-kit and CD34, leading to a diagnosis of recurrence of GIST. The postoperative course was uneventful, and the patient was discharged on the fifth postoperative day. At present, the patient is alive without adjuvant chemotherapy 13 months since surgery. GIST may recur 10 years or more after surgery. Therefore, long-term surveillance seems to be mandatory.

[A Case of Initially Unresectable Advanced Gastric Cancer Radically Resected by Conversion Surgery after Nivolumab Immunotherapy]

A 77-year-old man was admitted to our hospital with symptoms of epigastralgia and vomiting. Detailed investigation revealed unresectable advanced gastric cancer accompanied by multiple lymph node metastases and invasion of the pancreas(UM, type 3, cT4b, N3, M0, Stage ⅢC). The patient received nivolumab immunotherapy after first-line S-1 plus oxaliplatin(SOX)chemotherapy and second-line nab-paclitaxel(PTX)plus ramucirumab(RAM)chemotherapy. Remarkable tumor reduction was observed after 3 courses of nivolumab immunotherapy, and the patient subsequently underwent radical total gastrectomy with splenectomy and D2 lymphadenectomy. Histopathological examination of the resected stomach showed a near complete response, and only small metastatic foci remained in No. 2 lymph nodes, resulting in R0 resection. The patient was followed up without adjuvant therapy, and he is alive 6 months after the treatment without any symptoms of recurrence. The mechanism of action of immune checkpoint inhibitors is fundamentally different from that of conventional cytotoxic chemotherapeutic agents. Recently, several reports have described good responses to immune checkpoint inhibitors in cases where conventional chemotherapy has been unsuccessful. When predictive biomarkers of response to immune checkpoint inhibitors are identified, a combination therapy of preceding immunotherapy and subsequent surgery might provide an efficient radical therapeutic effect even in cases of unresectable advanced gastric cancer.

Precise absolute Seebeck coefficient measurement and uncertainty analysis using high-Tc superconductors as a reference

The intrinsic properties of superconductors enable the direct determination of the absolute Seebeck coefficient at low temperature due to the disappearance of the Seebeck effect to obey the Meissner effect. We report a precision absolute Seebeck coefficient measurement for the fine Pt sample determined using the high-Tc YBa₂Cu₃O_7-x (YBCO) superconductor as a reference and an analysis of the measurement uncertainty. To make a precision measurement and aid in the verification of the uncertainty components, we developed a cryostat system that enables temperature control in a stable manner. The expected performance of the reference superconductor yielded a zero value well below Tc, which was validated by a superconductor-superconductor thermocouple experiment. Uncertainty analysis shows that the main limiting factor for this measurement is the accuracy of the temperature difference measurement using the resistance temperature sensors, along with its analog noise. We obtained values of S = 5.6 ± 0.2 µV/K with a relative expanded uncertainty of 3% at 80 K and precisely compared the Pt value with that determined by the high-Tc Bi₂Sr₂Ca₂Cu₃O_8+δ (Bi-2223) superconductor, which has a higher Tc. We found that there was no difference between the Seebeck coefficient values obtained from the YBCO and Bi-2223 references up to its Tc within the expanded measurement uncertainties of 0.3 µV/K (2σ). These results provide accurate validation that the high-Tc superconductor is a useful reference up to the liquid nitrogen temperature.

Needlescopic surgery for broad ligament hernia: A case report

Broad ligament hernia is a rare type of internal hernia. We herein report a case of broad ligament hernia successfully treated by needlescopic surgery. A 41-year-old woman was referred to our hospital with a complaint of nausea and vomiting. Abdominal contrast-enhanced computed tomography showed diffuse dilatation of the small bowel accompanied by a caliber change at the right side of the uterus. She was thus diagnosed with small bowel obstruction due to incarceration through right broad ligament hernia. After bowel decompression, she underwent elective needlescopic surgery using 2- and 3-mm instruments. The defect in the right broad ligament was closed with sutures, and she was discharged 2 days after surgery. In the treatment of broad ligament hernia without bowel ischemia, neither an abdominal incision nor any energy devices are required. In this respect, needlescopic surgery seems to be a promising approach among minimally invasive surgeries.

[A Case of Esophageal Gastrointestinal Stromal Tumor Resected by Mediastinoscope-Assisted Transhiatal Esophagectomy]

A 58-year-old man was followed up for esophageal submucosal tumor at our hospital. Esophagogastroduodenoscopy showed the tumor was located on the left side of the thoracic esophagus and had gradually increased in size. Endoscopic ultrasonography revealed an 18×11.5mm hypoechoic tumor connected to the fourth layer of the esophagus and fine needle biopsy revealed c-kit(+), desmin(-)and a-SMA(-). Double-contrast barium study detected a tumor of diameter 20 mm in the middle-lower thoracic esophagus. We diagnosed an esophageal gastrointestinal stromal tumor(GIST)and performed mediastinoscope-assisted transhiatal esophagectomy with gastric tube reconstruction. The maximum tumor diameter was 25mm and pathological evaluation showed c-kit(+), Ki-67 index of less than 5%, and low-risk GIST by the Fletcher classification. Mediastinoscope-assisted transhiatal esophagectomy might be a useful approach for esophageal GIST, because dissection along the esophagus can be performed without thoracotomy.

Impaired fracture healing in macrophage migration inhibitory factor-deficient mice

This study investigated the role of macrophage migration inhibitory factor (MIF) in fracture repair using MIF gene-deficient mice (MIF KO). Fracture healing was delayed in MIF KO, and this was mainly due to the delay in the mineralization of osteoid within the fracture callus.

INTRODUCTION

We previously reported that the expression of macrophage migration inhibitory factor (MIF) was up-regulated during the fracture healing process in rats. However, its role in the pathophysiology of this process remained unclear. The aim of the present study was to clarify the role of MIF in the fracture healing process using MIF gene-deficient mice (MIF KO).

METHODS

Bone repair in wild-type mice (WT) and MIF KO (n = 70, respectively) was investigated using a tibia fracture model. Radiographic, biomechanical, histological, bone histomorphometric, and molecular analyses were performed.

RESULTS

Post-fracture biomechanical testing showed that maximum load and stiffness were significantly lower in MIF KO than in WT on day 42. However, similar levels were observed between the two groups on day 84. Bone histomorphometric analysis revealed significantly higher osteoid volume, a lower mineral apposition rate, and smaller numbers of osteoclasts in the MIF KO callus compared to the WT callus. The messenger ribonucleic acid expressions of matrix metalloproteinase (MMP)-2, membranous type 1-MMP, cathepsin K, and tissue nonspecific alkaline phosphatase were found to be significantly suppressed in the MIF KO callus.

CONCLUSION

The results of the present study suggest that delayed fracture healing in MIF KO was mainly attributable to a delay in osteoid mineralization.

DNA-binding activity of TNF-alpha inducing protein from Helicobacter pylori

Tumor necrosis factor-alpha (TNF-alpha) inducing protein (Tipalpha) is a carcinogenic factor secreted from Helicobacter pylori (H. pylori), mediated through both enhanced expression of TNF-alpha and chemokine genes and activation of nuclear factor-kappaB. Since Tipalpha enters gastric cancer cells, the Tipalpha binding molecules in the cells should be investigated. The direct DNA-binding activity of Tipalpha was observed by pull down assay using single- and double-stranded genomic DNA cellulose. The surface plasmon resonance assay, indicating an association between Tipalpha and DNA, revealed that the affinity of Tipalpha for (dGdC)10 is 2400 times stronger than that of del-Tipalpha, an inactive Tipalpha. This suggests a strong correlation between DNA-binding activity and carcinogenic activity of Tipalpha. And the DNA-binding activity of Tipalpha was first demonstrated with a molecule secreted from H. pylori.

Flt3 ligand promotes myeloid dendritic cell differentiation of human hematopoietic progenitor cells: possible application for cancer immunotherapy

Current in vitro culture systems allow the generation of human dendritic progenitor cells (CFU-DCs). The aim of this study was to assess the effect of Flt3 ligand (FL) on the proliferation of human peripheral blood-derived myeloid CFU-DCs and their differentiation into more committed precursor cells (pDCs) using in vitro culture systems. Immunomagnetically separated CD34+ cells were cultured in serum-free, as well as in serum-containing, liquid suspension cultures to investigate the expansion and/or proliferation/differentiation of CFU-DCs, pDCs, and more mature dendritic cells (DCs). FACS-sorted CD34+Flt3+/- cells were cultured in methylcellulose to assay hematopoietic progenitors, including CFU-DCs. In the clonal cell culture supplemented with granulocyte/macrophage (GM) colony-stimulating factor (CSF), interleukin-4, and tumor necrosis factor alpha, the frequency of CFU-DCs was significantly higher in the CD34+Flt3+ fraction than in the CD34+Flt3- population, thus suggesting functional Flt3 expression on CFU-DCs. Serum-free suspension culture of CD34+ cells revealed the potent effect of FL on the expansion of CFU-DCs in synergy with GM-CSF and thrombopoietin (TPO). In addition, FL strongly induced the maturation of CFU-DCs into functional CD1a+ pDCs in serum-containing liquid suspension culture. Moreover, these FL-generated pDCs showed remarkable potential to differentiate into mature DCs with surface CD83/CD86 expression, which induced a distinct allogeneic T-cell response. These results clearly demonstrate that FL supports not only the proliferation of early hematopoietic progenitor cells, but also the maturation process of committed precursor cells along with the DC-lineage differentiation. Therefore, it is possible to develop a more efficient DC-based cancer immunotherapy using this specific cytokine combination, GM-CSF+TPO+FL in vitro in the near future.

Successful induction of clinically competent dendritic cells from granulocyte colony-stimulating factor-mobilized monocytes for cancer vaccine therapy

Recent studies have suggested that dendritic cell (DC)-based immunotherapy is one promising approach for the treatment of cancer. We previously studied the clinical toxicity, feasibility, and efficacy of cancer vaccine therapy with peptide-pulsed DCs. In that study, we used granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood monocytes as a cell source of DCs. However, previous investigations have suggested that G-CSF-mobilized peripheral blood monocytes produce reduced levels of proinflammatory cytokines such as interleukin (IL)-12 and tumor necrosis factor (TNF)-alpha. These T helper (Th)-1-type cytokines are thought to promote antitumor immune response. In this study, we assessed the functional abilities of DCs generated from G-CSF-mobilized monocytes obtained from 13 patients with CEA-positive advanced solid cancers. Peripheral blood mononuclear cells were obtained from leukapheresis products collected before and after systemic administration of G-CSF (subcutaneous administration of high-dose [5-10 microg/kg] human recombinant G-CSF for five consecutive days). In vitro cytokine production profiles after stimulation with lipopolysaccharide (LPS) were compared between monocytes with and without G-CSF mobilization. DCs generated from monocytes were also examined with respect to cytokine production and the capacity to induce peptide-specific T cell responses. Administration of G-CSF was found to efficiently mobilize peripheral blood monocytes. Although G-CSF-mobilized monocytes (G/Mo) less effectively produced Th-1-type cytokines than control monocytes (C/Mo), DCs generated from G/Mo restored the same level of IL-12 production as that seen in DCs generated from C/Mo. T cell induction assay using recall antigen peptide and phenotypic analyses also demonstrated that DCs generated from G/Mo retained characteristics identical to those generated from C/Mo. Our results suggest that G-CSF mobilization can be used to collect monocytes as a cell source for the generation of DCs for cancer immunotherapy. DCs generated in this fashion were pulsed with HLA-A24-restricted CEA epitope peptide and administered to patients safely; immunological responses were induced in some patients.

[A case of scirrhous carcinoma of the stomach with malignant pleural and peritoneal carcinomatosis responding to the local administration of docetaxel (TXT)]

We report the case of a 34-year-old woman who underwent total gastrectomy for scirrhous carcinoma in the stomach (T4, N0, H0, CY1, P1, Stage IV). Despite adjuvant chemotherapy with TS-1 and/or CDDP, ascites caused by peritoneal carcinomatosis increased four months after gastrectomy. Therefore, intraperitoneal administration of docetaxel (TXT) at a dosage of 45 mg/m2 was applied. This therapy successfully maintained her good quality of life by inhibiting the increase of ascites without any severe adverse side effects for more than six months. When the left effusion from pleural carcinomatosis appeared nine months after the surgery, the intrathoracic administration of TXT succeeded in inhibiting the increase of pleural effusion over five months or more. In this case, intraperitoneal and intrapleural administrations of TXT were effective and temporarily improved the patient's quality of life without any side effects. We thought that the local administration of TXT was a useful treatment without severe toxicities for malignant pleural effusion and ascites in scirrhous carcinoma of the stomach.

Mobilization of peripheral blood stem cells (PBSCs) after etoposide, adriamycin and cisplatin therapy, and a multimodal cell therapy approach with PBSCs in advanced gastric cancer

The EAP combination of etoposide (ETP), doxorubicin (ADM) and cisplatin (CDDP) has been reported to be highly active for advanced gastric cancer. However, it is associated with severe myelotoxicity, and its use has declined. We examined whether peripheral blood stem cells (PBSCs) could be mobilized during hematopoietic recovery after EAP, and assessed the possibility of using multimodal cell therapy with PBSCs for the treatment of advanced gastric cancer. Five men with advanced gastric adenocarcinoma were enrolled. All patients were chemotherapy-naïve. EAP (ETP, 360 mg/m2; ADM, 40 mg/m2; CDDP, 80 mg/m2) was given to each patient, and myelotoxicity was carefully monitored. Granulocyte colony-stimulating factor was administered after the neutrophil nadir, and PBSCs were collected by leukapheresis during hematopoietic recovery. The median nadir of the neutrophil count after EAP was 225/ml, occurring between day 17 and 20. Sufficient numbers of PBSCs [CD34(+) cells, CFU-GM] could be mobilized in 4/5 patients. A 45-year-old patient with extended lymph node metastasis received high-dose EAP with peripheral blood stem cell transplantation (PBSCT), followed by cancer vaccine therapy with dendritic cells (DCs), induced from cryopreserved PBSCs. Both high-dose EAP with PBSCT and DC-based immunotherapy was safely performed for the first time against gastric cancer. Although associated with severe myelotoxicity, EAP can mobilize sufficient numbers of PBSCs during hematopoietic recovery. Multimodal cell therapy combining high-dose chemotherapy with PBSCT and DC-based immunotherapy is feasible and can be a reasonable approach in advanced gastric cancer.

Carcinogenic potential of tobacco tar-resistant Staphylococcus aureus in buccal cavity

PURPOSE

The effects of cigarette smoking on the association between inflammation and cancer were studied, since some bacteria induce the production of tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine and endogenous tumor promoter, in cells.

METHODS

Bacteria from a gargled solution from the buccal cavity of 20 individuals were cultured in the presence of 4 mg/ml cigarette-smoke condensates. Although cigarette-smoke condensates inhibited growth of Staphylococcus aureus strongly and that of Staphylococcus warneri weakly, tobacco tar-resistant S. aureus and S. warneri were obtained.

RESULTS

One tobacco tar-resistant S. aureus strain (Sa-TA10) induced expression of the TNF-alpha gene in both Bhas 42 cells (v-Ha-ras transfected BALB/3T3 cells) and human lung cancer cell line H226B, while one tobacco tar-resistant S. warneri (Sw-TA75) did not induce it significantly. Moreover, Sa-TA10 induced formation of transformed foci and soft-agar colony in Bhas 42 cells in cooperation with the v-Ha-ras gene. The results suggested that Sa-TA10 has carcinogenic potential, whereas Sw-TA75 does not.

CONCLUSION

These data suggest that tobacco tar-resistant S. aureus, with carcinogenic potential, is present in the buccal cavity of some individuals, and that cigarette smoking simultaneously inhibits growth of most of the bacteria and selects carcinogenic bacteria.

Isolation and synthesis of TNF-alpha release inhibitors from Fijian kawa (Piper methysticum)

Two unique evidence that cancer incidence rates in Fiji were unusually low, compared with those of another Pacific islands and that green tea beverage is an acknowledged cancer preventive in Japan, allowed us to study a local beverage in Fiji, kawa (kava kava) or yangona (Piper methysticum) belonging to Piperaceae. We isolated five known kawapyrones (kavapyrones) (1-5) and a new additional kawapyrone, 7,8-epoxyyangonin (6), from kawa MeOH extract and subjected them to TNF-alpha (tumor necrosis factor-alpha) release assay from BALB/3T3 cells treated with okadaic acid, a tumor promoter. 5,6-Dehydrokawain (desmethoxyyangonin)(1) and yangonin (4) significantly inhibited TNF-alpha release with IC50 values of 17 microM and 40 microM; a potency as great as (-)-epigallocatechin gallate (EGCG) isolated from green tea extract. Among the experiments with 1-5, dihydrokawain (2) was unique in showing the strongest inhibitory activity against TNF-alpha release in mice, but the weakest activity in the cells. We synthesized 5,6-dehydrokawain (1) and yangonin (4) via three steps from the dianion of ethyl acetoacetate achieving a good yield and determined their conformations by high resolution NMR and x-ray crystallographic analysis.

Streptococcal preparation OK432 promotes functional maturation of human monocyte-derived dendritic cells

Streptococcal preparation OK432 is an immunomodulatory agent extensively used as adjuvant therapy for gastric cancer in Japan. OK432 augments the cytotoxic activity of various effector cells such as lymphocytes, macrophages and (natural killer) NK cells and induces the production of multiple cytokines. Dendritic cells (DC) are professional antigen-presenting cells (APC) that can be used for cancer vaccine therapy. In the present study, we investigated the effect of OK432 on the activation of DC. Here we report that OK432 induced phenotypic and functional maturation of human monocyte-derived DC. In vitro culture of immature DC generated from adherent peripheral blood mononuclear cells (PBMC) using granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) with OK432 at various doses (0.01 to 0.1 KE/ml) for 2 days resulted in increased cell surface expression of CD80, CD83, CD86 and ICAM-1 in a dose-dependent manner. The expression of CD83, a selective marker of mature DC, on DC activated by OK432 (OK-DC) was maximally enhanced after 3 days of incubation. Assay of cytokine production in OK-DC after 2 days in culture revealed that OK432 was a strong inducer of IL-12 and interferon-gamma (IFN-gamma). OK432 efficiently augmented the primary allogeneic T-cell responses by DC. This distinct phenotypic profile and allostimulatory capacity of OK-DC was stable for at least 48 h of additional culture in the absence of any cytokines. Moreover, the antiviral cytotoxic T lymphocytes (CTL) response in vitro was also enhanced by the addition of OK432 to the cultures. These findings suggest that OK432 is a potent stimulator of DC, and that stimulated DC are strong inducers of the T helper 1 (Th1)-type response. We conclude that OK-DC are likely candidates for use as an adjuvant for DC-based cancer immunotherapy.

Role of human interleukin-9 as a megakaryocyte potentiator in culture

OBJECTIVE

This study investigated the effect of interleukin-9 (IL-9) on the proliferation and differentiation of human colony-forming unit megakaryocytic progenitor cells (CFU-Meg).

MATERIALS AND METHODS

Peripheral blood-derived CD34(+)IL-6R(-) cells were sorted and cultured in the presence of IL-9, erythropoietin (Epo), stem cell factor (SCF), and thrombopoietin (TPO) alone or in combination. The number of pure and mixed megakaryocyte colonies, the size of pure megakaryocyte colonies, the ploidy distribution of megakaryocytes, and proplatelet formation were investigated.

RESULTS

Apart from TPO, no single factor could support CFU-Meg-derived colony formation, but each two-factor combination among IL-9, Epo, and SCF supported a few CFU-Meg colonies. Interestingly, the combination of Epo+SCF+IL-9 induced four to six times as many CFU-Meg colonies as any of the two-factor combinations. Neutralizing monoclonal antibodies (mAbs) for IL-9 receptor and c-kit completely abolished this synergistic effect. In contrast, addition of neutralizing anti-c-Mpl or anti-CXCR4 Abs did not influence colony formation, indicating that this synergistic effect was independent of TPO or SDF-1. Moreover, the endogenous production of TPO by cultured CD34(+)IL-6R(-) cells in the presence of Epo+SCF+IL-9 was ruled out by reverse transcriptase polymerase chain reaction for TPO mRNA. Interestingly, the combination of TPO, Epo, SCF, and IL-9 supported the largest number of pure and mixed megakaryocyte colonies, suggesting that this combination of cytokines might recruit primitive megakaryocytic as well as multipotential progenitors. This combination also potently enhanced proplatelet formation compared with TPO alone or a combination of Epo, SCF, and IL-9.

CONCLUSION

This study demonstrated for the first time that human IL-9 can potentiate human megakaryocytopoiesis in the presence of Epo and/or SCF.

Vascular relaxant effects of toborinone on the isolated canine internal mammary artery

This study was conducted to evaluate the vascular relaxant effects of toborinone on canine internal mammary ring preparations. We determined the concentration-contraction curves for various vasoconstrictors, namely norepinephrine, serotonin, U46619, endothelin-1, phenylephrine, and KCl in internal mammary artery (IMA) preparations, then assessed the vascular relaxant effects of the test drugs. As models, preparations with and without functional endothelium were used. As vasorelaxants, we used milrinone, papaverine, and nitroglycerin. Toborinone produced concentration-dependent relaxation in preparations precontracted with norepinephrine and serotonin. However, the vascular relaxant effect of toborinone on KCl-induced contraction was weaker than those on norepinephrine- and serotonin-induced contraction. Toborinone produced concentration-dependent relaxation in preparations with, and those without functional endothelium. There was no difference in the potency between the preparations with, and those without functional endothelium. The relaxing effect of toborinone on norepinephrine-induced contraction (EC50 = 1.3 x 10(-6) M) was significantly weaker than that of nitroglycerin (EC50 = 7.8 x 10(-8) M), equal to that of papaverine (EC50 = 2.2 x 10(-6) M), and significantly stronger than that of milrinone (EC50 = 3.3 x 10(-6) M). These results demonstrate that toborinone produces relaxant effects on canine IMA preparations, and that it may be effective in the treatment of IMA malperfusion syndrome.

Discrete roles of cytokines, TNF-alpha, IL-1, IL-6 in tumor promotion and cell transformation

Based on our previous results, which pointed to tumor necrosis factor-alpha (TNF-alpha) as the essential cytokine in tumor promotion in mouse skin, we present here three principal findings related to the specific roles of TNF-alpha, interleukin-1 (IL-1) and IL-6 in tumor promotion (using TNF-alpha- and IL-6-deficient mice) and in BALB/3T3 cell transformation: i) The previously reported residual tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) in TNF-/- mice was confirmed by experiments with TNF+/+ and TNF-/- 129/Svj mice of the same strain, using two-stage carcinogenesis experiments. TPA produced tumors in 100% of TNF+/+ and 78% of TNF-/- mice at 20 weeks, and the average number of tumors per mouse was 11.1 in the former group and 2.1 in the latter. Judging from the expression of various inflammatory cytokine genes in TNF+/+ and TNF-/- mice, the residual tumor promoting activity of TPA in TNF-/- mice may be dependent on expression of IL-1alpha and IL-1beta genes. ii) Tumor promotion by TPA and okadaic acid in IL-6+/+ and IL-6-/- C57/BL6 mice was studied, with TPA producing tumors in 57.1% of IL-6+/+ and 40.0% of IL-6-/- mice at 20 weeks, and okadaic acid in 40.0% of IL-6+/+ and 53.3% of IL-6-/- mice. Thus, there was no significant difference between TPA or okadaic acid tumor promotion in either group. In addition, expression of IL-6 gene in skin of both types of mice suggested that IL-6 is not the essential cytokine in tumor promotion, since it can be replaced by other cytokines. iii) In transformed clones of BALB/3T3 cells induced by TNF-alpha alone, IL-1alpha gene expression was induced after transformation by TNF-alpha had occurred, which did not occur in parental cells. Expression patterns of TNF-alpha, IL-1beta, IL-6 and IL-10, along with TGF-beta, were similar in both parental and transformed cells. Considering all these results, we conclude that various cytokines have discrete roles in tumor promotion and cell transformation.

Primary hepatic Burkitt's lymphoma with chronic hepatitis C

The liver is an uncommon primary site for malignant lymphoma, and primary hepatic lymphoma has been found to make up 0.4% of all extranodal lymphomas. We report a rare case of a 75-year-old Japanese male with primary hepatic Burkitt's lymphoma, according to both the revised European-American Lymphoma classification and the new World Health Organization classification. As not only histological findings but also immunological features are deemed essential in the diagnosis of Burkitt's lymphoma, the previous 7 cases of primary hepatic Burkitt's lymphoma were not fully evaluated, using these criteria. As far as we know, this is the first case of primary hepatic Burkitt's lymphoma with typical features on histological, immunological and cytogenetical analysis. He had a history of chronic hepatitis C over several decades with subsequent liver cirrhosis. From our review of the literature and our case, the relationship between hepatitis C virus infection and the development of primary hepatic Burkitt's lymphoma remains obscure.

New TNF-alpha releasing inhibitors, geraniin and corilagin, in leaves of Acer nikoense, Megusurino-ki

The success of green tea as a cancer preventive is based on evidence that green tea contains tannins and antioxidants, does not show toxicity in humans and has long traditional use in Asia. In the light of this, herbal medicines are now also attracting attention as potential sources of cancer preventive agents. Using the inhibition of TNF-alpha release assay, we studied Acer nikoense (Megusurino-ki in Japanese), one of the herbal medicines. The inhibitory activity of TNF-alpha release was found in the leaf extract rather than the bark extract, and the main active constituents were identified as geraniin and corilagin, which are present in another Japanese traditional herb, Geranium thunbergii (Genno-shoko). The IC50 values of TNF-alpha release inhibition were 43 microM for geraniin and 76 microM for corilagin, whereas that for (-)-epigallocatechin gallate (EGCG) was 26 microM. Treatment with geraniin prior to application of okadaic acid, a tumor promoter on mouse skin initiated with 7,12-dimethylbenz(a)anthracene, reduced the percentage of tumor-bearing mice from 80.0 to 40.0% and the average numbers of tumor per mouse from 3.8 to 1.1 in week 20. Thus, geraniin has slightly weaker inhibitory activity than EGCG. Since geraniin and corilagin have been well investigated as representative tannins, we discuss here the new possibility of classical herbal medicine in the development of preventive agents for cancer and other life-style related diseases.

Helicobacter pylori membrane protein 1: a new carcinogenic factor of Helicobacter pylori

Considering a suspected link between Helicobacter pylori infection and human stomach cancer, a new H. pylori gene for membrane protein 1 (HP-MP1) was recently cloned. Because HP-MP1 induces release of inflammatory cytokines and tumor necrosis factor-alpha acts as both initiator and tumor promoter, we studied the possible involvement of HP-MP1 in carcinogenesis of H. pylori. Two cell lines, BALB/3T3 cells as control and v-Ha-ras-transfected BALB/3T3 cells (Bhas 42 cells) as putative initiated cells, were each transfected with HP-MP1, urease B genes, or vector alone. All of the Bhas/mpl clones showed strong expression of tumor necrosis factor-alpha gene and produced tumors in 100% of nude mice. Two Bhas/ure clones showed weak tumorigenicity; the other Bhas and BALB clones showed none. Results indicate strong carcinogenic activity of HP-MP1 in cooperation with viral Ras protein and weak activity of urease B.

Cancer prevention with green tea and monitoring by a new biomarker, hnRNP B1

The study of green tea polyphenols as a cancer preventative is approaching a new era, with significant results accumulating rapidly. This paper briefly reviews four topics related to mechanisms of action of tea polyphenols: (I) identification of the genes commonly affected by EGCG, as demonstrated by Clontech's Atlas cDNA Expression Array; (II) the significance of heterogeneous nuclear ribonucleoprotein B1 (hnRNP B1) as a new biomarker for early detection of lung cancer, and inhibition of its expression by EGCG; (III) the synergistic or additive effects of EGCG with the cancer preventive agents, sulindac and tamoxifen, on induction of apoptosis in PC-9 cells and on inhibition of intestinal tumor development in multiple intestinal neoplasia (Min) mice; (IV) the results of a 10 year prospective cohort study demonstrating the effectiveness of daily consumption of green tea in preventing cancer, and a prototype study for developing green tea beverage as cancer preventive.

Thermodynamic stability of base pairs between 2-hydroxyadenine and incoming nucleotides as a determinant of nucleotide incorporation specificity during replication

We investigated the thermodynamic stability of double-stranded DNAs with an oxidative DNA lesion, 2-hydroxyadenine (2-OH-Ade), in two different sequence contexts (5'-GA*C-3' and 5'-TA*A-3', A* represents 2-OH-Ade). When an A*-N pair (N, any nucleotide base) was located in the center of a duplex, the thermodynamic stabilities of the duplexes were similar for all the natural bases except A (N = T, C and G). On the other hand, for the duplexes with the A*-N pair at the end, which mimic the nucleotide incorporation step, the stabilities of the duplexes were dependent on their sequence. The order of stability is T > G > C >> A in the 5'-GA*C-3' sequences and T > A > C > G in the 5'-TA*A-3' sequences. Because T/G/C and T/A are nucleotides incorporated opposite to 2-OH-Ade in the 5'-GA*C-3' and 5'-TA*A-3' sequences, respectively, these results agree with the tendency of mutagenic misincorporation of the nucleotides opposite to 2-OH-Ade in vitro. Thus, the thermodynamic stability of the A*-N base pair may be an important factor for the mutation spectra of 2-OH-Ade.

Modulation of gene expression by (-)-epigallocatechin gallate in PC-9 cells using a cDNA expression array

Green tea is the most effective cancer preventive beverage. In the light of this, the mechanisms of action of tea polyphenols were investigated on the molecular levels. We present here the effects of (-)-epigallocatechin gallate (EGCG) on expression of 588 genes in human lung cancer cell line PC-9 cells, using a human cancer cDNA expression array. The levels of gene expression in non-treated control cells, and cells treated with EGCG alone, with the tumor promoter okadaic acid alone, and with EGCG plus okadaic acid, were studied, and their expression levels were classified into down-regulation (under 0.5 fold) and up-regulation (over 2.0 fold) by comparing with the levels of control. Non-treated PC-9 cells expressed 163 genes out of 588, and EGCG-treated cells induced down-regulated expression of 12 genes and up-regulated expression of 4 other genes. From a comparison of gene expression in the cells treated with EGCG and in cells treated with EGCG plus okadaic acid, we found the following genes commonly affected by EGCG: down-regulation of four genes, NF-kappaB inducing kinase (NIK), death-associated protein kinase 1 (DAPK 1), rhoB and tyrosine-protein kinase (SKY); up-regulation of one gene, retinoic acid receptor alpha1. Among them, we think down-regulation of NIK gene expression is significant for cancer prevention, based on evidence that inhibition of NF-kappaB activation is a result of inhibition of NIK/IKK signalling complex.

A new function of green tea: prevention of lifestyle-related diseases

In the normal human life span, there occur lifestyle-related diseases that may be preventable with nontoxic agents. This paper deals with the preventive activity of green tea in some lifestyle-related diseases. Green tea is one of the most practical cancer preventives, as we have shown in various in vitro and in vivo experiments, along with epidemiological studies. Among various biological effects of green tea, we have focused on its inhibitory effect on TNF-alpha gene expression mediated through inhibition of NF-kappaB and AP-1 activation. Based on our recent results with TNF-alpha-deficient mice, TNF-alpha is an endogenous tumor promoter. TNF-alpha is also known to be a central mediator in chronic inflammatory diseases such as rheumatoid arthritis and multiple sclerosis. We therefore hypothesized that green tea might be a preventive agent for chronic inflammatory diseases. To test this hypothesis, TNF-alpha transgenic mice, which overexpress TNF-alpha only in the lungs, were examined. The TNF-alpha transgenic mouse is an animal model of human idiopathic pulmonary fibrosis which also frequently develops lung cancer. Expressions of TNF-alpha and IL-6 were inhibited in the lungs of these mice after treatment with green tea in drinking water for 4 months. In addition, judging from the results of a prospective cohort study in Saitama Prefecture, Japan, green tea helps to prevent cardiovascular disease. In this study, a decreased relative risk of death from cardiovascular disease was found for people consuming over 10 cups of green tea a day, and green tea also had life-prolonging effects on cumulative survival. These data suggest that green tea has preventive effects on both chronic inflammatory diseases and lifestyle-related diseases (including cardiovascular disease and cancer), resulting in prolongation of life span.

Heterogeneous nuclear ribonucleoprotein B1 as early cancer biomarker for occult cancer of human lungs and bronchial dysplasia

Heterogeneous nuclear ribonucleoprotein (hnRNP) B1 is a RNA-binding protein of Mr 37,000. We previously reported that hnRNP B1 was specifically overexpressed in the nuclei of human lung cancer cells, particularly in squamous cell carcinoma (E. Sueoka et al., Cancer Res., 59: 1404-1407, 1999). We extended this study to determine whether hnRNP BL was overexpressed in roentgenographically occult cancers of the lungs and premalignant lesions of squamous cell carcinomas, such as bronchial dysplasia. The additional object of our study was to examine the usefulness of hnRNP B1 as a potential diagnostic marker for squamous cell carcinoma of various organs, such as the oral cavity and esophagus in humans. Surgically resected specimens of bronchial dysplasia, lung cancers, and various human squamous cell carcinomas, collected at two hospitals in Japan, were subjected to immunohistochemical staining with anti-hnRNP B1 antibody. Overexpression of hnRNP B1 protein was observed in 100% of stage I lung cancer tissues, but it was not found in normal bronchial epithelium. Squamous cell carcinoma of the lungs showed stronger staining than other histological types, and elevation of hnRNP B1 was found in both roentgenographically occult lung cancers and bronchial dysplasia. Furthermore, cytological examination with anti-hnRNP B1 antibody detected cancer cells in sputum, suggesting the potential of hnRNP B1 protein as a new biomarker for the very early stage of lung cancer in humans. Because strong staining of hnRNP B1 was also observed in various squamous cell carcinomas of oral and esophageal tissues as shown in our recent reports, overexpression of hnRNP B1 seems to be a common event in the carcinogenic processes of squamous cell carcinoma. These results suggest that hnRNP B1 protein could be a useful diagnostic biomarker for both the very early stages of lung cancer and various squamous cell carcinomas in humans.

Signal through gp130 activated by soluble interleukin (IL)-6 receptor (R) and IL-6 or IL-6R/IL-6 fusion protein enhances ex vivo expansion of human peripheral blood-derived hematopoietic progenitors

This study was designed to investigate the effects of a combination of soluble interleukin (sIL)-6 receptor (R) and IL-6 on the ex vivo expansion of human peripheral blood (PB)-derived hematopoietic progenitor cells in a short-term serum-free liquid suspension culture system, using PB-derived CD34(+)IL-6R(+/-) cells as a target. In combination with stem cell factor (SCF), IL-3, and sIL-6R/IL-6, the expansion efficiency (EE) for granulocyte/macrophage colony-forming unit (CFU-GM) reached a peak level on day 10 of incubation. On the other hand, the EE for erythroid burst (BFU-E) and mixed colony-forming unit (CFU-Mix) reached a peak level on day 7 of incubation. Among the cytokine combinations tested, SCF + IL-3 + sIL-6R/IL-6 + flt3 ligand (FL) most effectively expanded CFU-GM and CFU-Mix. The maximum EEs for CFU-GM and CFU-Mix were 208-fold and 42-fold, respectively. While the EE for BFU-E was 70-90-fold in the presence of SCF + IL-3 + sIL-6R/IL-6, FL significantly augmented the EE for CFU-GM and CFU-Mix. In contrast, thrombopoietin (TPO) significantly augmented the EE for CFU-Mix. Interestingly, in combination with IL-3 and SCF, newly generated IL-6R/IL-6 fusion protein (FP) expanded PB-derived BFU-E and CFU-Mix twice more effectively than a combination of sIL-6R and IL-6. These results demonstrated that human PB-derived committed progenitors were effectively expanded in vitro using sIL-6R/IL-6 or FP, in combination with IL-3, SCF and/or FL or TPO, and that FP may transduce a stronger intracellular signal than a combination of sIL-6R and IL-6.

Combination cancer chemoprevention with green tea extract and sulindac shown in intestinal tumor formation in Min mice

Green tea is the most effective beverage for cancer prevention in humans. Looking at the concept of combination cancer chemoprevention, we previously reported the synergistic effects of (-)-epigallocatechin gallate (EGCG) with sulindac, and the additive effects of EGCG with tamoxifen, on cancer-preventive activity in human lung cancer cell line PC-9. This paper reports confirmation of the synergistic effects of EGCG with sulindac on the inhibition of intestinal tumors in multiple intestinal neoplasia (Min) mice. Treatment with both green tea extract and sulindac significantly reduced the number of tumors from 72.3 +/- 28.3 to 32.0 +/- 18.7 tumors per mouse, a decrease of 44.3%, whereas treatment with green tea extract alone or with sulindac alone reduced it to 56.7 +/- 3.5 and 49.0 +/- 12.7, respectively. The results also indicated that green tea extract inhibited tumor growth in Min mice almost as potently as sulindac itself did. The three treated groups did not show any adenocarcinomas, whereas 10.8% of the control group did. Since cancer-preventive agents like sulindac and tamoxifen are associated with adverse effects, we discuss the possibility of non-toxic, combination cancer chemoprevention with green tea, looking at the goal of truly effective cancer prevention.

[Locoregional adoptive immunotherapy using LAK cells and IL-2 against liver metastases from digestive tract cancer]

We investigated the clinical efficacy of locoregional and systemic adoptive immunotherapy (AIT) with or without interleukin-2 (IL-2) against solid metastatic lesions from digestive tract cancer. Eighteen patients, who were treated with more than 10(10) lymphokine-activated killer (LAK) cells, were enrolled in this study. Seven of the 18 patients received hepatic arterial infusion (HAI) of LAK cells with or without IL-2 against metastatic liver tumors (locoregional therapy group). The remaining 11 patients received systemic transfer of LAK cells with IL-2 against metastatic lesions located in organs other than the liver (systemic therapy group). Three of 7 locoregional therapy group patients showed clinically significant tumor regressions that were evaluated as being equivalent to partial response (PR). Two of the 11 systemic therapy group patients showed significant tumor regressions, but this response rate was much lower than that of the locoregional therapy group. The 2 effective cases in the systemic therapy group were esophageal cancer patients. Locoregional AIT with or without IL-2 against liver metastases from digestive tract cancer could be an effective therapeutic modality in some patients who are refractory to conventional therapies (e.g., chemotherapy and radiotherapy). It is necessary to find a new way to augment the anti-tumor effect of this therapy in combination with prior or concomitant chemotherapy.

Interleukin 6 receptor expression by human cord blood- or peripheral blood-derived primitive haematopoietic progenitors implies acquisition of different functional properties

The significance of interleukin 6 receptor (IL-6R) expression by cord blood (CB)- and peripheral blood (PB)-derived primitive haematopoietic progenitors was investigated. IL-6R was preferentially expressed by PB-derived myeloid progenitors. Most PB-derived erythroid bursts (BFU-E) and mixed colony-forming cells (CFU-Mix) did not express this receptor. However, CB-derived primitive progenitor cells possessed multipotentiality, irrespective of IL-6R expression. Interestingly, the long-term culture-initiating cell (LTC-IC) population was enriched in PB-derived CD34+ IL-6R+ cells, but the extended LTC-IC (ELTC-IC) population, which represents a less mature class of haematopoietic progenitors, seemed to be equally distributed in the IL-6R+ and IL-6R- cell populations. In contrast, the number of LTC-ICs and ELTC-ICs was similar in CB-derived CD34+ IL-6R+ or IL-6R- cells. It is noteworthy that the number of LTC-ICs and ELTC-ICs in CB-derived CD34+ cells was markedly higher than that in PB-derived CD34+ cells regardless of IL-6R expression. Telomerase activity was consistently lower in PB-derived CD34+ IL-6R- cells than in CD34+ IL-6R+ cells. In contrast, telomerase activity was similar in CB-derived CD34+ IL-6R+ or IL-6R- cells. The pattern of telomerase induction upon cytokine stimulation differed between CB- and PB-derived CD34+ IL-6R+ or IL-6R- cells. However, overall telomerase activity per dish was well correlated with the proliferative potential of both cell populations, suggesting that induction of telomerase plays an important role in the escape from replicative senescence of primitive haematopoietic progenitors. Collectively, these results suggest that CB-derived primitive progenitors are less mature than PB-derived progenitors and that the expression of IL-6R by primitive haematopoietic progenitors may have different implications for PB- and CB-derived CD34+ cells.

A new concept of tumor promotion by tumor necrosis factor-alpha, and cancer preventive agents (-)-epigallocatechin gallate and green tea--a review

The study of tumor promotion in rodent carcinogenesis using chemical tumor promoters has revealed various tumor promotion pathways, such as the 12-O-tetradecanoylphorbol-13-acetate (TPA) pathway mediated through activation of protein kinase C, and the okadaic acid pathway mediated through inhibition of protein phosphatases 1 and 2A (PP-1 and PP-2A). We previously demonstrated that application of TPA and okadaic acid induced tumor necrosis factor-alpha (TNF-alpha) gene expression in mouse skin, but that tautomycin, which is an inhibitor of PP-1 and PP-2A and not a tumor promoter on mouse skin, did not. Moreover, we found that TNF-alpha stimulated transformation of BALB/3T3 cells initiated with 3-methylcholanthrene 1,000 times stronger than did TPA (Cancer Res. 53, 1982-1985, 1993). This evidence demonstrates a link between the okadaic acid pathway and the endogenous tumor promotion pathway of TNF-alpha. Recently we presented the first evidence that tumor promotion in TNF-alpha(-/-) mice was significantly depressed compared with TNF-alpha(+/+) mice. Thus, in human carcinogenesis, we think that TNF-alpha and other inflammatory cytokines in preneoplastic lesion stimulate tumor promotion and progression of initiated cells as well as premalignant cells. The first part of this paper reports on this TNF-alpha tumor promotion pathway. In the second part, we report a promising screening method for cancer preventive agents, based on evidence that pretreatment with agents such as tamoxifen, sulindac, 1alpha, 25-(OH)2 vitamin D3, quercetin, caffeic acid phenethyl ester, and (-)-epigallocatechin gallate (EGCG) commonly inhibited TNF-alpha release from BALB/3T3 cells induced by okadaic acid. EGCG, the main constituent of Japanese green tea, and green tea itself are acknowledged cancer preventives in Japan, and this paper presents evidence of their effectiveness in both a high-risk group and the general population.

Differential properties of the optical-isomers of pranidipine, a 1,4-dihydropyridine calcium channel modulator

Pranidipine is an optically-active 1,4-dihydropyridine (DHP) voltage-dependent L-type calcium channel inhibitor. Certain enantiomeric pairs display opposite effects, i.e., inhibition and activation of the calcium channel while others exhibit the same qualitative actions. We investigated pranidipine, a new DHP, using a paradigm of vascular smooth muscle reactivity. In isolated rat aorta, depolarized with 80 mM KCl, both isomers of pranidipine caused a right-ward shift of the concentration-contraction curves for extracellular Ca2+. The apparent pA2, values of the S-isomer and R-isomer were 10.03 and 8.36, respectively, providing evidence that the calcium channel blocking action of the S-isomer was 50 times more potent than that of the R-isomer. Antihypertensive actions of these two isomers studied in pentobarbital-anaesthetized spontaneously hypertensive rats, revealed that the S-isomer, at doses of 3-30 microg/kg i.v. decreased blood pressure in a dose-dependent manner, while the R-isomer had no effect on blood pressure at those doses. We conclude that the pair of enantiomers of pranidipine qualitatively display the same Ca2+ channel blocking action and that neither isomer exhibits Bay K 8644-like activation. Pranidipine may be useful in studies on the architecture of the DHP receptor 'pocket'.

Mechanisms of cancer prevention by tea polyphenols based on inhibition of TNF-alpha expression

Among various biochemical and biological activities of tea polyphenols, we believe inhibition of the expression and release of tumor necrosis factor-alpha (TNF-alpha) is crucial, since our study with TNF-alpha-deficient mice has revealed that TNF-alpha is an essential factor in tumor promotion. We found that EGCG dose-dependently inhibited AP-1 and NF-kappaB activation in BALB/3T3 cells treated with okadaic acid, resulting in inhibition of TNF-alpha gene expression. Furthermore, treatment with 0.1% green tea extract in drinking water reduced TNF-alpha gene expression as well as TNF-alpha protein level in the lung of TNF-alpha transgenic mice; and IL-1beta and IL-10 gene expression in the lung was also inhibited by treatment with green tea extract, indicating that green tea inhibits both TNF-alpha and the cytokines induced by TNF-alpha in organs. We recently found synergistic effects of EGCG and cancer preventive agents such as tamoxifen and sulindac, on cancer preventive activity. Taken together, the results show that green tea is efficacious as a non-toxic cancer preventive for humans.