Acyclic retinoid synergises with valproic acid to inhibit growth in human hepatocellular carcinoma cells.

A malfunction of retinoid X receptor-alpha (RXRalpha) due to phosphorylation is associated with the development of hepatocellular carcinoma (HCC) and acyclic retinoid (ACR), which targets RXRalpha, can prevent the development of second primary HCC. Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, induces apoptosis and cell cycle arrest in cancer cells. VPA can also enhance the sensitivity of cancer cells to retinoids. The present study examined the possible combined effects of ACR plus VPA in HepG2 human HCC cell line. The combination of 5muM ACR and 1mM VPA, about the IC(25) value for both compounds, synergistically inhibited the growth of HepG2 cells without affecting the growth of Hc normal human hepatocytes. The combined treatment with ACR plus VPA also acted synergistically to induce apoptosis and G(0)-G(1) cell cycle arrest in HepG2 cells. This combination further exerted a synergistic inhibition of the phosphorylation of RXRalpha, ERK, Akt and GSK-3beta proteins and caused an accumulation of acetylated histones H3 and H4 proteins. VPA enhanced the ability of ACR to raise the cellular levels of RARbeta and p21(CIP1). The combination of these agents markedly increased both the RARE and RXRE promoter activities in HepG2 cells. These results suggest that ACR and VPA cooperatively increase the expression of RARbeta and p21(CIP1), while inhibiting the phosphorylation of RXRalpha, and these effects were associated with induction of apoptosis and the inhibition of cell growth in HepG2 cells. This combination might therefore be an effective regimen for the chemoprevention and chemotherapy of HCC.

Synergistic effects of acyclic retinoid and gemcitabine on growth inhibition in pancreatic cancer cells.

Pancreatic cancer is a serious healthcare problem worldwide because of its high mortality. Gemcitabine, a DNA synthesis inhibitor, is the standard first-line treatment for advanced pancreatic cancer and is also expected as a key drug for the combination therapy of this malignancy. Retinoids, which are derivatives of vitamin A, exert anti-tumor effects in various types of human malignancies, including pancreatic cancer. This study examined whether combination therapy with gemcitabine and acyclic retinoid (ACR), a new synthetic retinoid, had enhanced anti-tumor efficacy in pancreatic cancer. ACR, 9-cis-retinoic acid and gemcitabine preferentially inhibited the growth of human pancreatic cancer cells (Panc-1 and KP-2) in comparison to PE normal human pancreatic epithelial cells. The combination of ACR plus gemcitabine synergistically inhibited the growth of Panc-1 cells. The combined treatment with these two agents also acted synergistically to induce apoptosis and to inhibit Ras activation in these cancer cells. In vivo, the combination therapy augmented tumor growth inhibition through the induction of apoptosis and inhibition of cell proliferation in tumor tissue. These results suggest that the combination of ACR plus gemcitabine may therefore be an effective regimen for the chemotherapy of pancreatic cancer.

Impaired autonomic function in type 2 diabetic patients during upper gastrointestinal endoscopy.

BACKGROUND: Cardiac autonomic neuropathy, representing decreased parasympathetic nerve activity and predominance of sympathetic tone, is often encountered in diabetic patients, and leads to an increased risk of cardiovascular events including arrhythmia. To evaluate the potential cardiovascular risk of diabetics in performing esophagogastroduodenoscopy (EGD), we compared the autonomic function and cardiovascular parameters during EGD between diabetic and nondiabetic patients. METHODS: The autonomic nervous responses in 86 consecutive outpatients (42 type 2 diabetics and 44 nondiabetics) were determined by power spectral analysis (PSA) of heart-rate variations on an electrocardiogram. PSA data were based on two peaks in the low-frequency (LF) and high-frequency (HF) ranges. HF power and the ratio of LF power/HF power represented parasympathetic and sympathetic nerve activities, respectively. RESULTS: Diabetic patients showed significantly lower DeltaHF power and significantly higher DeltaLF power/HF power than nondiabetics, suggesting enhanced predominance of sympathetic activity and marked suppression of parasympathetic function. Significant correlations were found between these autonomic parameters and the diabetic duration. A slightly higher incidence of ventricular premature contractures was observed in diabetics during EGD. However, no significant difference was found in pulse or blood pressure increments during EGD between the two groups. CONCLUSIONS: This is the first study demonstrating an imbalance of autonomic function in diabetics during EGD, which may be linked to a slightly higher risk of arrhythmia.

Synergistic growth inhibition by 9-cis-retinoic acid plus trastuzumab in human hepatocellular carcinoma cells.

PURPOSE: A malfunction of retinoid X receptor-alpha (RXRalpha) due to phosphorylation by the Ras/mitogen-activated protein kinase signaling pathway is associated with the development of hepatocellular carcinoma (HCC). The humanized anti-HER2 monoclonal antibody trastuzumab inhibits the activation of HER2 and its multiple downstream signaling pathways, including the Ras/mitogen-activated protein kinase pathway. In this study, the effects of phosphorylation of RXRalpha on the ability of RXRalpha ligand 9-cis-retinoic acid (9cRA) and trastuzumab to inhibit growth of HCC cells was examined. EXPERIMENTAL DESIGN: The effects of a combination of 9cRA plus trastuzumab on the inhibition of cell growth in HLF human HCC cells which express constitutive activation of HER2 protein were examined. RESULTS: The combination of 9cRA plus trastuzumab synergistically inhibited the growth of HLF cells without affecting the growth of Hc normal human hepatocytes. Combined treatment with these agents acted synergistically to induce apoptosis in HLF cells. The treatment of HLF cells with trastuzumab alone inhibited the phosphorylation of HER2, RXRalpha, ERK, Akt, and Stat3 proteins and these effects were enhanced when the cells were cotreated with 9cRA. Reporter assays indicated that the combination of 9cRA plus trastuzumab markedly increased both the retinoic acid responsive element and retinoid X responsive element promoter activities in HLF cells. CONCLUSION: 9cRA and trastuzumab cooperatively inhibit the activation of HER2 and its downstream signaling pathways, subsequently inhibiting the phosphorylation of RXRalpha and the growth of HCC cells. This combination might therefore be effective for the chemoprevention and chemotherapy of HCC.

Transnasal endoscopic retrograde chalangiopancreatography using an ultrathin endoscope: a prospective comparison with a routine oral procedure.

AIM: To investigate if transnasal endoscopic retrograde cholangiopancreatography (n-ERCP) using an ultrathin forward-viewing scope may overcome the disadvantages of conventional oral ERCP (o-ERCP) related to the large-caliber side-viewing duodenoscope. METHODS: The study involved 50 patients in whom 25 cases each were assigned to the o-ERCP and n-ERCP groups. We compared the requirements of esophagogastroduodenoscopy (EGD) prior to ERCP, rates and times required for successful cannulation into the pancreatobiliary ducts, incidence of post-procedure hyperamylasemia, cardiovascular parameters during the procedure, the dose of a sedative drug, and successful rates of endoscopic naso-biliary drainage (ENBD). RESULTS: Screening gastrointestinal observations were easily performed by the forward-viewing scope and thus no prior EGD was required in the n-ERCP group. There was no significant difference in the rates or times for cannulation, or incidence of hyperamylasemia between the groups. However, the cannulation was relatively difficult in n-ERCP when the scope appeared U-shape under fluoroscopy. Increments of blood pressure and the amount of a sedative drug were significantly lower in the n-ERCP group. ENBD was successfully performed succeeding to the n-ERCP in which mouth-to-nose transfer of the drainage tube was not required. CONCLUSION: n-ERCP is likely a well-tolerable method with less cardiovascular stress and no need of prior EGD or mouth-to-nose transfer of the ENBD tube. However, a deliberate application is needed since its performance is difficult in some cases and is not feasible for some endoscopic treatments such as stenting.

Autonomic nervous function in upper gastrointestinal endoscopy: a prospective randomized comparison between transnasal and oral procedures.

BACKGROUND: Transnasal esophagogastroduodenoscopy (EGD) using an ultrathin endoscope is less stressful to the cardiovascular system with less elevation of systolic blood pressure (BP) than oral procedures. To elucidate the mechanism of such beneficial cardiovascular responses, we performed a prospective patient-centered randomized study in which BP and pulse rate (P), as well as autonomic nervous functions, were estimated during transnasal EGD compared with those in oral procedures using the same ultrathin endoscope. METHODS: The study involved 781 patients, among whom 55 and 56 cases were assigned to transnasal and oral EGD groups, respectively. The autonomic nervous responses were determined employing power spectral analysis (PSA) of heart-rate variations on electrocardiogram. PSA data were based on two peaks in low frequency (LF) and high-frequency (HF) ranges. HF power and the ratio of LF power/HF power represented parasympathetic and sympathetic nervous activities, respectively. RESULTS: Our study confirmed the lesser elevation of BP and P in patients undergoing transnasal EGD than in those undergoing oral procedures. PSA revealed a lower increase in LH power/HF power in transnasal EGD than in oral EGD. However, both endoscopic procedures equally suppressed HF power. Significant correlations were found between the parameters of cardiovascular response (P and BP) and autonomic functions (LF power/HF power ratio and HF power). CONCLUSIONS: This is the first study demonstrating less sympathetic stimulation in patients undergoing transnasal EGD, leading to lesser elevation of BP and P.

EGCG inhibits activation of the insulin-like growth factor (IGF)/IGF-1 receptor axis in human hepatocellular carcinoma cells.

The receptor tyrosine kinase (RTK) insulin like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) axis plays an important role in the development of hepatocellular carcinoma (HCC). EGCG inhibits activation of the various types of RTKs and that this is associated with inhibition of multiple downstream signaling pathways. In this study we examined the effects of EGCG on activity of the IGF/IGF-1R axis in HepG2 human HCC cells which express constitutive activation of this axis. The level of phosphorylated (i.e. activated) form of the IGF-1R protein (p-IGF-1R) was increased in a series of human HCC cell lines when compared with the Hc normal human hepatocytes. EGCG preferentially inhibited growth of HepG2 cells when compared with Hc cells. Treatment of HepG2 cells with EGCG induced apoptosis and caused a decrease in the p-IGF-1R protein and its downstream signaling molecules including the p-ERK, p-Akt, p-Stat-3, and p-GSK-3ß proteins, both in the absence or presence of ligand stimulation. EGCG also decreased the levels of both IGF-1 and IGF-2 proteins and mRNAs, but increased the levels of the IGFBP-3 protein. These findings suggest that EGCG can overcome the stimulatory effects of IGFs on the IGF-1R dependent signaling pathway, thus expanding the roles of EGCG as an inhibitor of critical RTKs involved in HCC cell proliferation. These results provide further evidence that EGCG may be useful in the chemoprevention or treatment of liver cancer.

[Clinical applications of imaging reconstruction by virtual sonography].

AIM: One of the pitfalls in managing multiple liver tumors is the difficulty in identifying individual tumors on ultrasonography. Computed tomography (CT)-assisted virtual sonography has been shown to improve sonographic diagnosis, however it requires additional equipment and software. We have developed a simple reconstruction method of virtual sonography (SRVS). METHODS: We reconstructed SRVS mimicking ultrasonographic images, utilizing a workstation software attached to a multi-detector row CT system without any additional program. RESULTS: We have performed SRVS in 32 patients with 41 liver tumors that could hardly be identify on ultrasonography. SRVS assisted the identification of malignant form non-pathologic ones and thereby contributed to the appropriate clinical strategy including RFA (18 tumors), liver biopsy (2 tumors), other therapies (4 tumors) and follow-up (17 tumors). CONCLUSION: We have developed virtual sonography using conventional CT software. SRVS seems useful in the clinical practice in managing liver tumors.

A novel technique for the internal drainage of extrahepatic biloma complicating transarterial embolization of hepatocellular carcinoma.

Biloma is an infrequent complication of nonsurgical treatments of hepatocellular carcinoma (HCC), including transarterial embolization (TAE), and it is often associated with ischemic injuries of the biliary tract after therapy. We here report on a case featuring successful internal drainage of an extrahepatic biloma into the duodenum by a route via the cholecyst, cholecystic duct, and common bile duct under fluoroscopic control. An extrahepatic biloma developed after urgent TAE for ruptured HCC and became contaminated. Radiography with contrast medium through the percutaneous drainage tube revealed a fistula between the biloma and gallbladder. The drainage catheter was introduced into the gallbladder through the fistula, from where it subsequently reached the duodenum via the cholecystic and common bile ducts. The internal drainage route played a major role in the rapid elimination of the biloma, which did not recur after the tube was withdrawn. To our knowledge, this is the first report of internal drainage of a biloma through the cholecystic and common bile ducts.