Hitoshi Fujiwara

HGF regulates VEGF expression via the c-Met receptor downstream pathways, PI3K/Akt, MAPK and STAT3, in CT26 murine cells

In the present study, we assessed the involvement of hepatocyte growth factor (HGF)/c-Met signalling with vascular endothelial cell growth factor (VEGF) and hypoxia inducible factor (HIF)-1α expression in the downstream pathways phosphatidylinositol 3-kinase (PI3K)/Akt, mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) in CT26 cells, to determine the mechanisms of the potent anti-angiogenic effect of NK4. We established genetically modified CT26 cells to produce NK4 (CT26-NK4). VEGF expression in subcutaneous CT26 tumours in vivo and in culture supernatants in vitro was determined by ELISA. HIF-1α expression in nuclear extracts was evaluated by western blot analysis. VEGF and HIF-1α mRNA levels were examined by real-time reverse transcription-polymerase chain reaction (RT-PCR). The DNA binding activity of HIF-1α was evaluated using an HIF-1α transcription factor assay kit. Our results demonstrated that VEGF expression was reduced in homografts of CT26-NK4 cells, compared to those of the control cells. In vitro, VEGF expression, which was induced by HGF, was inhibited by anti-HGF antibody, NK4 and by kinase inhibitors (PI3K, LY294002; MAPK, PD98059; and STAT3, Stattic). HGF‑induced HIF‑1α transcriptional activity was also inhibited by the kinase inhibitors. Real-time RT-PCR demonstrated that HGF‑induced HIF‑1α mRNA expression was not inhibited by LY294002 and PD98059, but was inhibited by Stattic. These data suggest that the PI3K/Akt, MAPK and STAT3 pathways, downstream of HGF/c‑Met signalling, are involved in the regulation of VEGF expression in CT26 cells. HGF/c‑Met signalling may be a promising target for anti-angiogenic strategies.

Perioperative outcomes of esophagectomy preceded by the laparoscopic transhiatal approach for esophageal cancer

This study was designed to determine the efficacy of esophagectomy preceded by the laparoscopic transhiatal approach (LTHA) with regard to the perioperative outcomes of esophageal cancer. The esophageal hiatus was opened by hand-assisted laparoscopic surgery, and carbon dioxide was introduced into the mediastinum. Dissection of the distal esophagus was performed up to the level of the tracheal bifurcation. En bloc dissection of the posterior mediastinal lymph nodes was performed using LTHA. Next, cervical lymphadenectomy, reconstruction via a retrosternal route with a gastric tube and anastomosis from a cervical approach were performed. Finally, a small thoracotomy (around 10u2009cm in size) was made to extract the thoracic esophagus and allow upper mediastinal lymphadenectomy to be performed. The treatment outcomes of 27 esophageal cancer patients who underwent LTHA-preceding esophagectomy were compared with those of 33 patients who underwent the transthoracic approach preceding esophagectomy without LTHA (thoracotomy; around 20u2009cm in size). The intrathoracic operative time and operative bleeding were significantly decreased by LTHA. The total operative time did not differ between the two groups, suggesting that the abdominal procedure was longer in the LTHA group. The number of resected lymph nodes did not differ between the two groups. Postoperative respiratory complications occurred in 18.5% of patients treated with LTHA and 30.3% of those treated without it. The increase in the number of peripheral white blood cells and the duration of thoracic drainage were significantly decreased by this method. Our surgical procedure provides a good surgical view of the posterior mediastinum, markedly shortens the intrathoracic operative time, and decreases the operative bleeding without increasing major postoperative complications.

A case involving long-term survival after esophageal cancer with liver and lung metastases treated by multidisciplinary therapy: report of a case

A 57-year-old male with lower esophageal cancer underwent subtotal esophagectomy with lymphadenectomy. The histopathological diagnosis was poorly differentiated squamous cell carcinoma, pT2N1M0 pStageIIB. After one course of postoperative adjuvant chemotherapy involving low-dose CDDP/5FU, a PET–CT scan obtained 12xa0months after surgery revealed a solitary liver metastasis in the S2 area. The patient then underwent five courses of docetaxel chemotherapy (80xa0mg/body, tri-weekly), and a partial response was observed. We also performed radiofrequency ablation (RFA), after which a complete response was observed. Twenty months after surgery, we detected local liver recurrence in the same position and performed additional RFA. Twenty-four months after surgery, a solitary lung metastasis was detected in the left S2 area and the patient was administered five additional courses of docetaxel therapy. Subsequently, PET–CT revealed growth of lung and liver tumors without recurrence in other areas. Twenty-nine months after surgery, we partially excised metastatic liver and lung tumors, and no subsequent recurrence has since been detected. The prognoses of patients who suffer from esophageal cancer organ recurrence are known to be extremely poor, and optimal therapeutic strategies for treating these patients have not been established. This long-term survival case suggests that multidisciplinary therapy for the treatment of liver and lung recurrence after esophagectomy is effective.

Ibuprofen enhances TRAIL-induced apoptosis through DR5 upregulation

Numerous human chemoprevention studies have demonstrated that non-steroidal anti-inflammatory drugs (NSAIDs) possess chemopreventive effects against a variety of malignant tumors. However, there have been many clinical studies on aspirin, but not ibuprofen, even though ibuprofen is one of the most clinically and safely used NSAIDs showing potent anti-inflammatory effects. Moreover, we reported that many chemopreventive agents enhance the apoptosis-inducing effects of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is known to be crucial for cancer prevention. We, therefore, investigated whether ibuprofen enhances the cytocidal effect of TRAIL and found that ibuprofen markedly stimulated the apoptosis-inducing efficacy of TRAIL against human colon cancer HCT116 cells. As detected by western blot analysis and real-time RT-PCR, ibuprofen upregulated the expression of death receptor 5 (DR5), a TRAIL receptor. TRAIL-induced apoptosis enhanced by ibuprofen was effectively decreased by a caspase inhibitor and dominant-negative DR5. Noteworthy, co-treatment of ibuprofen with TRAIL did not enhance apoptosis in normal peripheral blood mononuclear cells (PBMCs). These results demonstrated that ibuprofen and TRAIL synergistically induced apoptosis in human colon cancer HCT116 cells but not in normal PBMCs, raising the possibility that ibuprofen may be promising as a safe chemopreventive agent against colon cancer.

PSK induces apoptosis through the inhibition of activated STAT3 in human esophageal carcinoma cells.

PSK, a protein-bound polysaccharide, is widely used in Japan as an immunopotentiating biological response modifier for cancer patients. PSK exerts antitumor activities through stimulation of the hosts immune response; however, few studies have addressed the direct actions of PSK on tumor cells. Recently, it has been found that STAT3 is aberrantly activated in various types of malignancies, and plays a crucial role in tumor cell proliferation and survival. In the present study, STAT3 was constitutively activated in KYSE170 and TE13 esophageal carcinoma cells, and PSK inhibited proliferation and induced apoptosis in these cells in a dose-dependent manner. Based on these findings, the relationship between STAT3 and apoptosis in these cells was investigated. Results showed that PSK inhibited the expression of activated STAT3 and stimulated the expression of pro-apoptotic Bax in a dose-dependent manner, without affecting the expression of anti-apoptotic Bcl-xL and Mcl-1. These results indicate that PSK may induce apoptosis in esophageal carcinoma cells by inhibiting the expression of activated STAT3.

Ki-67 labeling index as an independent prognostic factor in human esophageal squamous cell carcinoma

BackgroundAlthough the Ki-67 labeling index (LI) is frequently used to determine the proliferative activity of malignant tumors, no consensus has been reached about its clinicopathological significance in esophageal squamous cell carcinoma (ESCC). In this study, we sought to determine an adequate Ki-67 LI cutoff value and investigated its prognostic significance in ESCC.MethodsThe Ki-67 LI was calculated by immunohistochemistry for 49 primary tumor samples obtained from ESCC patients who had undergone curative esophagectomy, and the correlations between the Ki-67 LI and various clinicopathological features or prognosis were analyzed.ResultsThe Ki-67 LI of the tumors ranged from 5.3 to 55.9xa0%. The mean Ki-67 LI increased from 27.4xa0% in pN0 tumors to 40.3xa0% in pN3 tumors. The 5-year survival rate decreased as the Ki-67 LI increased. When the patients were divided into two groups using an Ki-67 LI cutoff value of 35xa0%, the 5-year survival rate of the patients with Ki-67 LI of <35xa0% was 82.9xa0%, which was significantly higher than that of the patients with Ki-67 LI of ≥35xa0% (35.7xa0%). The percentage of pN-positive tumors was significantly higher among the patients with Ki-67 LI of ≥35xa0% (85.7xa0%) than in patients with Ki-67 LI of <35 (48.6xa0%). Multivariate analysis demonstrated that pT and pN categories and the Ki-67 LI were independent prognostic factors.ConclusionsThese observations indicate that the Ki-67 LI is correlated with lymph node metastasis and can be used as an independent prognostic factor for ESCC patients by selecting an adequate cutoff value.

The novel HDAC inhibitor OBP-801/YM753 enhances the effects of 5-fluorouracil with radiation on esophageal squamous carcinoma cells.

Histone deacetylase (HDAC) inhibitors have been shown to enhance the effects of 5-fluorouracil (5-FU) against various cancer cells; however, no report has shown that an HDAC inhibitor may enhance the effects of 5-FU with radiation. Therefore, we investigated whether the novel HDAC inhibitor OBP-801/YM753 could enhance the effects of 5-FU with radiation on esophageal squamous carcinoma KYSE170 cells. The inhibition of the cell growth was significantly stronger with the combination of OBP-801/YM753 with 5-FU than with the 5-FU treatment only. Furthermore, inhibition of the colony formation was the most effective with the combined treatment of OBP-801/YM753, 5-FU, and radiation. Western blot analysis showed that OBP-801/YM753 suppressed the expression of thymidylate synthase induced by 5-FU. Therefore, this three-combined therapy is promising for patients with esophageal squamous carcinoma.

A case of a superficial carcinoma of the esophagus with isolated lymph node metastasis around the abdominal aorta

Superficial carcinoma of the esophagus with isolated para-aortic lymph node metastasis is quite rare. A 56-year-old female demonstrated a type 0-IIa+IIb lesion in the middle thoracic esophagus on endoscopic examination. Enhanced computed tomography and positron emission tomography demonstrated two swollen lymph nodes on the right side of the inferior vena cava, but did not demonstrate either a primary lesion or regional lymph node metastasis. A retroperitoneal videoscopic lymph node biopsy was thus performed, and the histopathological diagnosis was metastasis of squamous cell carcinoma. Induction chemotherapy was administered with cisplatin/5-FU, and followed by definitive chemoradiotherapy with cisplatin/5-FU plus 60xa0Gy radiation. The patient showed satisfactory responses in both the primary and metastatic lesions. This is the first case report describing superficial carcinoma of the esophagus with isolated lymph node metastasis around the abdominal aorta. A precise histological diagnosis of the lymph node is quite important in such cases, and an adequate curative effect can be expected.

Spontaneous rupture of the esophagus with extensive bowel necrosis caused by nonocclusive mesenteric ischemia: report of a case

We report a case of spontaneous rupture of the esophagus accompanied by extensive bowel necrosis caused by nonocclusive mesenteric ischemia. The patient was treated successfully with prompt surgical intervention after an early diagnosis. A 61-year-old man was admitted to our hospital complaining of abdominal pain after drinking. On arrival, he was suffering shock. Thoracoabdominal computed tomography and esophagoscopy findings were highly suggestive of rupture of the esophagus above the esophagogastric junction and extensive bowel necrosis. Emergency laparotomy revealed extensive bowel necrosis from the jejunum to the transverse colon; thus, we resected the entire affected region and performed jejunostomy and transverse colostomy. After suturing the esophageal perforation directly, we performed intramediastinal packing of the omentum and inserted drains. The patient recovered well and was discharged from hospital on postoperative day 126. To the best of our knowledge, this is the first case report of spontaneous rupture of the esophagus with nonocclusive mesenteric ischemia.

Intrathoracic supercharge technique for esophageal reconstruction using colon interposition via a retrosternal route

Currently, when the colon is used for reconstruction after esophagectomy, the supercharge technique is occasionally employed. At our institution, we perform esophagectomy using a procedure in which the laparoscopic transhiatal approach and digestive reconstruction precede the specimen resection. In addition, a retrosternal route is selected for reconstruction. We have devised an intrathoracic supercharge technique for this type of esophagectomy. Two patients whose stomachs were not available for reconstruction underwent subtotal esophagectomy with this supercharge technique. In these cases, the right-side colon was pulled up via a retrosternal route for reconstruction, and anastomoses were performed between the ileocolic artery and right internal thoracic artery, and between the ileocolic vein and superior vena cava, without microsurgery in the pleural space after removing the esophagus. This supercharge technique has the advantage of being less cumbersome, and we consider it to be suitable for esophageal reconstruction.