Hisatoshi Nakagawara

The nature of neural invasion by pancreatic cancer.

Objectives: Neural invasion is one of the most important modes of tumor extension in pancreatobiliary tract cancer. However, the precise pattern of neural invasion and the relationship between neural invasion and nodal involvement are unknown. Methods: Using 8 surgical specimens from patients with pancreatic cancer, 4973 sections were created and examined histopathologically. A total of 961 sections of VX2 tumor grown in the retroperitoneum of rabbits also were examined histologically. The precise mechanism by which neural invasion occurs and the relationship between nerve fascicle and lymph node involvement were determined by histological examination of serial sections. Results: Histological evaluation of the surgical specimens revealed continuity between the cancer cells between the inside and the outside of the perineurium. Tumor cells grew mainly in a continuous fashion along the branches of nerves. An advancing tip of the tumor cells was identified. The pattern of tumor spread in the experimental study was similar to that in the clinical study. Continuity was found between the cancer cells inside some lymph nodes and the cancer cells within the perineural space. This finding suggests that neural invasion might be a pathway to lymphatic involvement. Conclusions: Neural invasion is a common, but not a specific, feature of pancreatic cancer. Tumor cells in the perineural space grow in a continuous fashion and may be responsible for some cases of lymphatic spread.

Prognostic factors for gallbladder cancer in Japan.

Objective:The objective of this study was to evaluate prognostic predictors for patients with gallbladder cancer (GBC) in a Japanese nationwide data base. Summary Background Data:GBC is the most common cancer of the biliary tract in Japan. Differences in the survival rates between Japan and other countries have been noted. Methods:The authors analyzed 4424 patients with GBC in Japan between 1988 and 1997. Staging was determined in accordance with American Joint Committee on Cancer stage. Results:Survival is related closely to the surgical stage. Five-year survival rates for stage I, II, III, IVA, and IVB (5th edition) were 83%, 70%, 45%, 23%, and 9%, respectively. These differences were significant (P < 0.0001). The survival rate for patients aged <60 years was significantly better (P < 0.05). The survival rate for patients aged >69 years was significantly worse (P < 0.01). The cholecystectomy plus combined resection of bile duct and/or liver bed resection had an effect on prolonging the survival in stage II or III disease, but extended resection did not. The patients with anomalous pancreaticobiliary ductal junction had a survival advantage over those with cholelithiasis by univariate analysis. However, multivariate analyses indicated that only age, sex, stage, operative procedures were independent prognostic factors. Stage was the strongest covariate; patients diagnosed with stage II, III, IVA, or IVB disease were 2.2, 4.2, 8.1, and 13.6 times, respectively, were more likely to die. Conclusions:Staging is the strongest prognostic factor for GBC, but patient outcomes were also affected by age, sex, and operative procedures. The data do not support any advantage for extended resection. Neither gallstones nor anomalous pancreaticobiliary ductal junction influenced the GBC patient outcome.

Angiotensin II enhances epithelial-to-mesenchymal transition through the interaction between activated hepatic stellate cells and the stromal cell-derived factor-1/CXCR4 axis in intrahepatic cholangiocarcinoma

We previously reported that hepatic stellate cells (HSCs) activated by angiotensin II (AngII) facilitate stromal fibrosis and tumor progression in intrahepatic cholangiocarcinoma (ICC). AngII has been known as a growth factor which can promote epithelial-to-mesenchymal transition (EMT) in renal epithelial cells, alveolar epithelial cells and peritoneal mesothelial cells. However, in the past, the relationship between AngII and stromal cell-derived factor-1 (SDF-1) in the microenvironment around cancer and the role of AngII on EMT of cancer cells has not been reported in detail. SDF-1 and its specific receptor, CXCR4, are now receiving attention as a mechanism of cell progression and metastasis. In this study, we examined whether activated HSCs promote tumor fibrogenesis, tumor progression and distant metastasis by mediating EMT via the AngII/AngII type 1 receptor (AT-1) and the SDF-1/CXCR4 axis. Two human ICC cell lines and a human HSC line, LI-90, express CXCR4. Significantly higher concentration of SDF-1α was released into the supernatant of LI-90 cells to which AngII had been added. SDF-1α increased the proliferative activity of HSCs and enhanced the activation of HSCs as a growth factor. Furthermore, addition of SDF-1α and AngII enhanced the increase of the migratory capability and vimentin expression, reduced E-cadherin expression, and translocated the expression of β-catenin into the nucleus and cytoplasm in ICC cells. Co-culture with HSCs also enhanced the migratory capability of ICC cells. These findings suggest that SDF-1α, released from activated HSCs and AngII, play important roles in cancer progression, tumor fibrogenesis, and migration in autocrine and paracrine fashion by mediating EMT. Our mechanistic findings may provide pivotal insights into the molecular mechanism of the AngII and SDF-1α-initiated signaling pathway that regulates fibrogenesis in cancerous stroma, tumor progression and meta-stasis of tumor cells expressing AT-1 and CXCR4.

Valproic acid, a histone deacetylase inhibitor, enhances radiosensitivity in esophageal squamous cell carcinoma

Histone deacetylase (HDAC) inhibitors have been shown to enhance radiation response in various cancer cell lines. Valproic acid (VPA) has been used in clinical practice for the treatment of epilepsy and other seizure disorders and is also one of the most represented HDAC inhibitors. The aim of this study was to evaluate the radiosensitizing ability of VPA and its mechanisms in four esophageal squamous cell carcinoma (ESCC) cell lines (TE9, TE10, TE11 and TE14). VPA inhibited the viability of all ESCC cells in a dose-dependent manner. The 50% inhibitory concentration (IC50) value of VPA in each cell line was between 1.02-2.15 mM, which is higher than clinically used safe concentrations. VPA induced the hyperacetylation of histones H3 and H4, as well as apoptosis and had a radiosensitizing effect on all four ESCC cell lines at a concentration of 0.5 mM which is equivalent to the therapeutic plasma concentration of anti-epilepsy therapy in humans. The radiosensitization was accompanied by an increase in γH2AX levels, indicating the presence of double-strand breaks (DSBs), and decrease in Rad51 expression, a DSB repair protein. These results suggest that a clinically safe dose of VPA can enhance radiation-induced cytotoxicity in human ESCC cells by chromatin decondensation with histone hyperacetylation and downregulation of Rad51. In conclusion, VPA appears to be a safe and promising radiosensitizer for esophageal cancer radiotherapy.

Prospective randomized controlled study on the effects of perioperative administration of a neutrophil elastase inhibitor to patients undergoing video-assisted thoracoscopic surgery for thoracic esophageal cancer.

Sivelestat sodium hydrate (Ono Pharmaceutical Co., Osaka, Japan) is a selective inhibitor of neutrophil elastase (NE) and is effective in reducing acute lung injury associated with systemic inflammatory response syndrome (SIRS). We conducted a prospective randomized controlled study to investigate the efficacy of perioperative administration of sivelestat sodium hydrate to prevent postoperative acute lung injury in patients undergoing thoracoscopic esophagectomy and radical lymphadenectomy. Twenty-two patients with thoracic esophageal cancer underwent video-assisted thoracoscopic esophagectomy with extended lymph node dissection in our institution between April 2007 and November 2008. Using a double-blinded method, these patients were randomly assigned to one of two groups preoperatively. The active treatment group received sivelestat sodium hydrate intravenously for 72 hours starting at the beginning of surgery (sivelestat-treated group; n= 11), while the other group received saline (control group; n= 11). All patients were given methylprednisolone immediately before surgery. Postoperative clinical course was compared between the two groups. Two patients (one in each group) were discontinued from the study during the postoperative period because of surgery-related complications. Of the remaining 20 patients, 2 patients who developed pneumonia within a week after surgery were excluded from some laboratory analyses, so data from 18 patients (9 patients in each group) were analyzed based on the arterial oxygen pressure/fraction of inspired oxygen ratio, white blood cell count, serum C-reactive protein level, plasma cytokine levels, plasma NE level, and markers of alveolar type II epithelial cells. In the current study, the incidence of postoperative morbidity did not differ between the two groups. The median duration of SIRS in the sivelestat-treated group was significantly shorter than that in the control group: 17 (range 9-36) hours versus 49 (15-60) hours, respectively (P= 0.009). Concerning the parameters used for the diagnosis of SIRS, the median heart rates on postoperative day (POD) 2 were significantly lower in the sivelestat-treated group than in the control group (P= 0.007). The median arterial oxygen pressure/fraction of inspired oxygen ratio of the sivelestat-treated group were significantly higher than those of the control group on POD 1 and POD 7 (POD 1: 372.0 [range 284.0-475.0] vs 322.5 [243.5-380.0], respectively, P= 0.040; POD 7: 377.2 [339.5-430.0] vs 357.6 [240.0-392.8], P= 0.031). Postoperative white blood cell counts, serum C-reactive protein levels, plasma interleukin-1beta, tumor necrosis factor-alpha levels, and plasma NE levels did not differ significantly between the two groups at any point during the postoperative course, nor did serum Krebs von den Lungen 6, surfactant protein-A, or surfactant protein-D levels, which were used as markers of alveolar type II epithelial cells to evaluate the severity of lung injury. Plasma interleukin-8 levels were significantly lower in the sivelestat-treated group than in the control group on POD 3 (P= 0.040). In conclusion, perioperative administration of sivelestat sodium hydrate (starting at the beginning of surgery) mitigated postoperative hypoxia, partially suppressed postoperative hypercytokinemia, shortened the duration of SIRS, and stabilized postoperative circulatory status after thoracoscopic esophagectomy.

Efficacy of pre-operative chemotherapy with docetaxel, cisplatin, and S-1 (DCS therapy) and curative resection for gastric cancer with pathologically positive para-aortic lymph nodes

The prognosis of gastric cancer with para‐aortic lymph node (PAN) metastasis is poor. We applied triple combination chemotherapy with docetaxel, cisplatin, and S‐1 (DCS therapy) as pre‐operative chemotherapy and investigated the outcome of the combination of this therapy and gastrectomy with para‐aortic lymph node dissection (PAND).

Carcinomas of the ventral and dorsal pancreas exhibit different patterns of lymphatic spread

In patients with carcinoma of the head of the pancreas with positive lymph nodes, the extent of an adequate lymph node dissection beyond peripancreatic area has remained controversial. Based on the two anlagens, the ventral or dorsal pancreas, we assessed the lymphatic spread pattern in 58 primary adenocarcinoma of head of the pancreas. Detection of lymph node metastasis was based on microscopic detection of carcinoma in consecutive serial sections of resected specimens including lymph nodes. When the tumor was confined to the ventral pancreas domain (n=20), the lymph node metastases were limited to areas along the superior mesenteric artery (SMA) besides peripancreatic lymph nodes. When the tumor was in the dorsal pancreas domain (n=6), the lymph node metastases were limited to areas along the common hepatic artery (CHA) and the hepatoduodenal ligament besides peripancreatic lymph nodes. When the tumor was extended into both domains (n=32), the lymph node metastases were distributed widely in areas along the SMA, CHA and the hepatoduodenal ligament besides peripancreatic lymph nodes. Based on these findings, the lymphatic spread of carcinomas of the head of the pancreas can be divided into two patterns by tumor location based on the two anlagens of the pancreas.

Duodenogastric Reflux Sustains Helicobacter pylori Infection in the Gastric Stump

BACKGROUND Duodenogastric reflux (DGR) and Helicobacter pylori infection have been suspected of being contributing agents to the genesis of gastritis and subsequent cancer, but compelling, conclusive data about the exact relationship have been lacking. METHODS We investigated the effect of DGR on H. pylori infection in 95 gastrectomized subjects divided into four groups according to type of reconstruction: the jejunal pouch interposition group (JPI, n = 36); the Roux-en-Y group (RY, n = 17); the Billroth I group (B-I, n = 20); and the Billroth II group (B-II, n = 22). The following items were examined for each group: the duration of DGR; the prevalence of H. pylori infection; other bacterial identification and quantity; and the severity of gastritis. RESULTS The percent of total time of DGR was lower in the JPI (7%) and RY groups (28%) than in the B-I (59%) and B-II groups (88%) (P < 0.02). The prevalence of H. pylori infection was lower in the JPI (28%) and RY groups (29%) than in the B-I (60%) and B-II groups (73%) (P < 0.02). Inversely, the JPI and the RY groups had a higher quantity of other bacteria than the B-I group (P = 0.02). For all four groups, the stomachs infected with H. pylori were fewer than those tested negative for the organism (P < 0.0001). Inflammation scores were lower in both the JPI and RY groups than in the B-I and B-II groups (P < 0.05, respectively). CONCLUSIONS Duodenogastric reflux facilitates the survival of H. pylori in the gastric stump after a distal gastrectomy.Background: Duodenogastric reflux (DGR) and Helicobacter pylori infection have been suspected of being contributing agents to the genesis of gastritis and subsequent cancer, but compelling, conclusive data about the exact relationship have been lacking. Methods: We investigated the effect of DGR on H. pylori infection in 95 gastrectomized subjects divided into four groups according to type of reconstruction: the jejunal pouch interposition group (JPI, n r = r 36); the Roux-en-Y group (RY, n r = r 17); the Billroth I group (B-I, n r = r 20); and the Billroth II group (B-II, n r = r 22). The following items were examined for each group: the duration of DGR; the prevalence of H. pylori infection; other bacterial identification and quantity; and the severity of gastritis. Results: The percent of total time of DGR was lower in the JPI (7%) and RY groups (28%) than in the B-I (59%) and B-II groups (88%) ( P r < r 0.02). The prevalence of H. pylori infection was lower in the JPI (28%) and RY groups (29%) than in the B-I (60%) and B-II groups (73%) ( P r < r 0.02). Inversely, the JPI and the RY groups had a higher quantity of other bacteria than the B-I group ( P r = r 0.02). For all four groups, the stomachs infected with H. pylori were fewer than those tested negative for the organism ( P r < r 0.0001). Inflammation scores were lower in both the JPI and RY groups than in the B-I and B-II groups ( P r < r 0.05, respectively). Conclusions: Duodenogastric reflux facilitates the survival of H. pylori in the gastric stump after a distal gastrectomy.

Nonclosure technique with saline‐coupled bipolar electrocautery in management of the cut surface after distal pancreatectomy

BACKGROUND/PURPOSE Management of the pancreatic remnant after distal pancreatectomy is still debated, the most serious complication is development of a pancreatic fistula. We developed a nonclosure technique with saline-coupled bipolar electrocautery for preventing fistula formation after distal pancreatectomy as an alternative to traditional stump closure methods. METHODS The distinguishing feature of this technique is nonclosure of the stump, relying instead upon dependable ligation of the main pancreatic duct and sealing of the cut surface by shrinkage accomplished by low-temperature coagulation using saline-coupled bipolar electrocautery. A recent addition has been intraoperative stenting of the remnant pancreatic duct. RESULTS To date we have used the nonclosure technique in 40 cases, among which 5 (12.5%) developed fistulas: 4 in the nonstenting subgroup (14.8%) and 1 in the stenting subgroup (7.7%). According to a recent classification, 4 fistulas were considered grade A; 1, grade B; and 0, grade C. The grade B patient did not undergo stenting. CONCLUSION Our preliminary experience should prompt more widespread evaluation of the nonclosure technique.

Valproic acid inhibits proliferation of HER2-expressing breast cancer cells by inducing cell cycle arrest and apoptosis through Hsp70 acetylation

Breast cancer encompasses a heterogeneous group of diseases at the molecular level. It is known that chemo-sensitivity of breast cancer depends on its molecular subtype. We investigated the growth inhibitory effect of valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, and the mechanism of this inhibition on four breast cancer cell lines with different molecular subtypes. The growth inhibitory effect of VPA in the four different breast cancer cell lines was investigated. The alteration of levels of p21 WAF1, cleaved caspase-3, acetylated Heat shock protein (Hsp) 90, acetylated Hsp70, and acetylated α-tubulin by VPA was examined in VPA-sensitive, human epidermal receptor 2 (HER2)-overexpressing SKBR3 cells. The cell growth inhibition of breast cancer cell lines was dependent on the dose and exposure time of VPA. The cell growth of HER2-overexpressing SKBR3 cell line was inhibited by VPA to a much greater degree than other cell lines studied. In SKBR3 cell line, VPA upregulated expression of p21 WAF1 and cleaved caspase-3 in the early phase. VPA markedly increased Hsp70 acetylation in a time-dependent manner but did not increase Hsp90 acetylation. Our data demonstrated that VPA inhibited cell proliferation and induced cell cycle arrest and apoptosis of HER2-overexpressing breast cancer cells. This anti-proliferation effect might be the direct function of VPA as an HDAC inhibitor. We propose an alternative mechanism whereby acetylation of Hsp70 disrupts the function of Hsp90 and leads to downregulation of its client proteins, including HER2 that might be the indirect function of VPA, in the sense that non-histone proteins are acetylated.