Natural history of inferior mesenteric arteriovenous malformation that led to ischemic colitis: A case report.

BACKGROUND: Ischemic colitis with inferior mesenteric arteriovenous malformation (AVM) is a rare disease. Although a few reports have been published, no report has described the natural history of idiopathic mesenteric AVM. CASE SUMMARY: A 50-year-old male was admitted to our hospital due to abdominal pain that had persisted for 3 mo and bloody diarrhea. He had no history of trauma or abdominal surgery. He had undergone two colonoscopies 6 mo and 2 years ago, and they showed only a polyp. He was diagnosed with ischemic colitis with inferior mesenteric AVM following contrast-enhanced abdominal computed tomography (CT) and underwent rectal low anterior resection. He has not had a recurrence of symptoms for 3 years. His history showed that he had undergone non-enhanced abdominal CT 2, 5, and 8 years ago when he had attacks of urinary stones. Retrospectively, dilation of blood vessels around the rectosigmoid colon could have been detected 5 years ago, and these findings gradually became more evident. CONCLUSION: This is the first report of the natural history of inferior mesenteric AVM.

A multicenter prospective phase II study of first-line modified FOLFIRINOX for unresectable advanced pancreatic cancer.

BACKGROUND: FOLFIRINOX (FX) has been reported as an effective treatment for unresectable advanced pancreatic cancer. However, FX is associated with a high incidence of adverse events (AEs). A previous phase II study in Japan showed high incidences of hematological AEs, including febrile neutropenia (22.2%). A modified FX regimen (mFX) may decrease the rates of AEs and be more effective than FX by improving the treatment compliance. AIMS: To assess the safety and efficacy of first-line mFX for unresectable advanced pancreatic cancer. PATIENTS AND METHODS: This was as a multicenter prospective phase II study in chemotherapy-naïve Japanese patients with pathologically confirmed unresectable advanced pancreatic adenocarcinoma or adenosquamous carcinoma. Treatment with mFX (85 mg/m2 oxaliplatin, 150 mg/m2 irinotecan, and 200 mg/m2 l-leucovorin, followed by 46-h continuous infusion of 2400 mg/m2 5-fluorouracil) was administered every 2 weeks. The primary endpoint was the response rate. The secondary endpoints were overall survival, progression-free survival, and safety. RESULTS: Thirty-one patients (18 men; median age, 64 years) were enrolled. A median of 13 treatment cycles were administered during a median follow-up period of 14.2 months. The response rate, median overall survival, and median progression-free survival were 38.7%, 14.9 months, and 7.0 months, respectively. Grade 3 or 4 AEs included neutropenia (83.9%), febrile neutropenia (16.1%), peripheral sensory neuropathy (9.7%), thrombocytopenia (6.5%), diarrhea (6.5%), anorexia (6.5%), and vomiting (3.2%). CONCLUSION: Compared to FX, mFX may result in fewer Grade 3 or 4 non-hematological AEs, with a comparable response rate. However, further efforts might be required to reduce hematological AEs.

Anticancer effect of arsenite on cell migration, cell cycle and apoptosis in human pancreatic cancer cells.

The standard treatment for advanced pancreatic cancer is chemotherapy, but its clinical outcome remains unsatisfactory. Therefore, the development of novel treatments for this malignancy is urgently required. In the present study, the anticancer effect of arsenite on platelet-derived growth factor (PDGF)-BB-induced migration, cell cycle and apoptosis was investigated in pancreatic cancer cells (AsPC-1 and BxPC-3), and compared with the effect on normal pancreatic epithelial (PE) cells. In the cell migration assay, arsenite clearly inhibited PDGF-BB-induced cell migration in AsPC-1 cells, but not in BxPC-3 or PE cells. Arsenite also caused cell apoptosis in AsPC-1 cells, but not in BxPC-3 or PE cells. In AsPC-1 cells, the levels of cyclin D1 and phosphorylated retinoblastoma protein decreased following treatment with arsenite, but this was not observed in BxPC-3 cells. To further examine the differences between these two cell lines, the effect of arsenite on upstream p44/p42 mitogen-activated protein kinase (MAPK) and Akt was investigated. PDGF-BB caused phosphorylation of p44/p42 MAPK and Akt in both cell lines. Pretreatment with arsenite significantly suppressed PDGF-BB-induced phosphorylation of Akt, but not of p44/p42 MAPK in AsPC-1 cells. By contrast, arsenite did not affect these molecules in BxPC-3 cells. Since the inhibition of the Akt signaling pathway markedly reduced PDGF-BB-induced migration in AsPC-1 cells, the present results strongly suggest that arsenite inhibits PDGF-BB-induced migration by suppressing the Akt signaling pathway in AsPC-1 cells. Therefore, arsenite may be a useful tool for the treatment of patients with certain types of pancreatic cancer, without causing adverse effects on normal pancreatic cells.

The significance of phosphorylated heat shock protein 27 on the prognosis of pancreatic cancer.

BACKGROUND AND AIM: The precise role of phosphorylated heat shock protein (HSP) 27 (p-HSP27) in pancreatic cancer remains to be elucidated. The aim of this study was to investigate whether the expression of p-HSP27 predicts the prognosis of patients with pancreatic cancer. METHODS: We retrospectively assessed 49 biopsied pancreatic cancer tissue samples that were obtained prior to the treatment with gemcitabine. The correlations between p-HSP27 and the clinicopathological characteristics were analyzed. RESULTS: p-HSP27 was not correlated with the response to chemotherapy or histological type. However, the median survival time was significantly longer in the patients with high p-HSP27 (275 days, n = 18) than those with low p-HSP27 (205 days, n = 31) (P = 0.0158). A multivariate Cox proportional hazards regression analysis revealed that low p-HSP27 predicted a worse prognosis. CONCLUSIONS: Higher p-HSP27 expression before chemotherapy was correlated with better survival, indicating that p-HSP27 expression could be used to predict the prognosis of pancreatic cancer.

Cisplatin and ultra-violet-C synergistically down-regulate receptor tyrosine kinases in human colorectal cancer cells.

BACKGROUND: Platinum-containing anti-cancer drugs such as cisplatin are widely used for patients with various types of cancers, however, resistance to cisplatin is observed in some cases. Whereas we have recently reported that high dose UV-C (200 J/m²) induces colorectal cancer cell proliferation by desensitization of EGFR, which leads oncogenic signaling in these cells, in this study we investigated the combination effect of low dose cisplatin (10 µM) and low dose UV-C (10 J/m²) on cell growth and apoptosis in several human colorectal cancer cells, SW480, DLD-1, HT29 and HCT116. RESULTS: The combination inhibited cell cycle and colony formation, while either cisplatin or UV-C alone had little effect. The combination also induced apoptosis in these cells. In addition, the combination caused the downregulation of EGFR and HER2. Moreover, UV-C alone caused the transient internalization of the EGFR, but with time EGFR recycled back to the cell surface, while cisplatin did not affect its localization. Surprisingly, the combination caused persistent internalization of the EGFR, which results in the lasting downregulation of the EGFR. CONCLUSIONS: The combination of low dose cisplatin and low dose UV-C synergistically exerted anti-cancer effect by down-regulating RTK, such as EGFR and HER2. These findings may provide a novel strategy for the treatment of patients with colorectal cancer.

UVC irradiation suppresses platelet-derived growth factor-BB-induced migration in human pancreatic cancer cells.

We have recently reported that short wavelength ultraviolet-C (UVC) irradiation inhibits cell growth and induces apoptosis in human pancreatic cancer cells. In this study, we investigated the effect of UVC on platelet-derived growth factor (PDGF)-BB-induced migration in pancreatic cancer cells, AsPC1 and BxPC3. In cell migration assays using a Boyden chamber Transwell, PDGF-BB exerted a maximum effect on migration of these cells at a dose of 70 ng/ml after 36 h of treatment. PDGF-BB also caused phosphorylation of p44/p42 mitogen-activated protein kinase (MAPK), stress-activated protein kinase/c-Jun-N-terminal kinase (SAPK/JNK) and Akt, but not of p38 MAPK in these cells. Pretreatment of these cells with UVC at a dose over 10 J markedly suppressed PDGF-BB-induced migration. Since UVC significantly inhibited PDGF-BB-induced phosphorylation of Akt, and subsequent glycogen synthase kinase (GSK) 3ß, but not p44/p42 MAPK and SAPK/JNK, it is likely that UVC inhibits PDGF-BB-induced migration by suppressing the Akt-GSK3ß pathway in pancreatic cancer cells. Taken together with our previous findings, UVC could be a useful tool for the treatment of patients with pancreatic cancer.

Phosphorylation status of heat shock protein 27 plays a key role in gemcitabine-induced apoptosis of pancreatic cancer cells.

Gemcitabine, an antitumor drug, is currently considered to be the standard of care for the treatment of advanced pancreatic cancer, but the clinical outcome is still not satisfactory. Although heat shock protein (HSP) 27 is implicated in the resistance to chemotherapy in several types of cancers, the precise role of phosphorylated HSP27 in cancer cells remains to be clarified. In this study, we investigated the relationship between the effect of gemcitabine and the phosphorylation status of HSP27 in pancreatic cancer cells, Panc1 and KP3. Gemcitabine suppressed pancreatic cancer cell growth and induced apoptosis. Gemcitabine caused activation of p38 mitogen-activated protein kinase (MAPK), MAPK-activated protein kinase 2 (MAPKAPK-2) and subsequently phosphorylation of HSP27 at Ser15, 78 and 82 without affecting total HSP27 levels. The inhibitions of p38 MAPK and MAPKAPK-2 reduced the phosphorylation of HSP27 and apoptosis in gemcitabine-treated cells. To further investigate the role of phosphorylated HSP27, we established Panc1 cell lines which were stably transfected with empty vector (empty cells), wild-type HSP27-encoding vector (WT cells) and 2 mutant HSP27-encoding vectors that mimic non-phosphorylated (3A), and phosphorylated (3D), respectively. In comparison of empty cells with WT cells, there was no difference in cell growth rate and the sensitivity to gemcitabine. Interestingly, cell growth of 3D cells was retarded as compared to that of 3A cells. Taken together, our results strongly suggest that phosphorylation status of HSP27 plays a key role in gemcitabine-induced growth suppression of pancreatic cancer.

Ultraviolet enhances the sensitivity of pancreatic cancer cells to gemcitabine by activation of 5' AMP-activated protein kinase.

Although gemcitabine is recognized as the standard drug for the treatment of advanced pancreatic cancer, the clinical outcome is not satisfactory. We recently reported that relatively high dose ultraviolet-C (UV-C; 200J) inhibits cell growth by desensitization of epidermal growth factor receptor (EGFR) in human pancreatic cancer cells. In the present study, we investigated the combination effects of low dose UV-C (10J) and gemcitabine on apoptosis and cell growth in these cells. UV-C enhanced gemcitabine-induced suppression of cell viability. In addition, the combination use clearly induced apoptosis, while neither UV-C nor gemcitabine alone did. Concurrently, combination use caused the decrease in the EGFR protein level and reduced EGF-induced activation of Akt pathway, subsequently resulting in accumulation of ß-catenin. The order of the treatment with UV-C and gemcitabine did not affect their synergistic effects on apoptosis and cell growth. Interestingly, combination use synergistically induced phosphorylation of 5' AMP-activated protein kinase (AMPK) alpha at Thr172 and acetyl-CoA carboxylase at Ser79 as a downstream molecular target of AMPK. AMPK activator, 5-aminoimidazole-4-carboxamide-1-ß-riboside, induced apoptosis and suppressed cell growth in these cells, thus suggesting that combination effects of UV-C and gemcitabine is due to the activation of AMPK. Together, our findings could provide a new aspect of pancreatic cancer therapy.

Ultra-violet irradiation induces apoptosis via mitochondrial pathway in pancreatic cancer cells.

Pancreatic cancer is a highly lethal disease and gemcitabine is considered to be the standard of care for the treatment of advanced pancreatic cancer. However, the outcome of the patients treated with gemcitabine is still unstatisfactory and further development of new treatments is required. We recently found that short wavelength ultra-violet (UV-C) suppresses cell proliferation with downregulation of epidermal growth factor receptor (EGFR) in human pancreatic cancer cells, but not in normal pancreatic epithelial (PE) cells. In this study, we investigated the effect of UV-C on apoptosis in several cell lines derived from the pancreas. UV-C induced poly(ADP-ribose) polymerase (PARP) cleavage, which is a marker of cells undergoing apoptosis, in Panc1, MiaPaca2, KP3 and BxPC3 pancreatic cancer cells, but not in PE cells. We also observed similar effects in Hoechst 33258 staining, which shows DNA fragmentation. While p53, a tumor suppressor protein, plays a critical role in UV-C-induced cell damage, we did not observe the correlation between the sensitivity to UV-C and p53 status. Thapsigargin, an agent that promotes endoplasmic reticulum (ER) stress by depletion of lumenal calcium stores, as well as cis-diamineplatinum (II) dichloride, a classical anti-cancer drug that causes DNA damage, induced PARP cleavage even in PE cells. Moreover, UV-C-induced apoptosis in Panc1 and KP3 cells was associated with the release of cytochrome c, indicating that it was mediated via mitochondrial pathway. Taken together, UV-C has a potent anti-cancer effect on pancreatic cancer cells without adverse effect on normal cells and it could be useful for the treatment of human pancreatic cancers.

Inhibition of Rho-associated coiled-coil containing protein kinase enhances the activation of epidermal growth factor receptor in pancreatic cancer cells.

BACKGROUND: Rho-associated coiled-coil containing protein kinase (Rho-kinase/ROCK) is involved in various cellular functions including cell proliferation, and is generally considered to be oncogenic, while some studies show that ROCK functions as a negative regulator of cancer progression. As a result, the precise role of ROCK remains controversial. We have previously reported that Rho-kinase/ROCK negatively regulates epidermal growth factor (EGF)-induced cell proliferation in SW480 colon cancer cells. In the present study, we investigated the role of ROCK in EGF receptor (EGFR) signaling in the pancreatic cancer cell lines, Panc1, KP3 and AsPc1. RESULTS: In these cells, Y27632, a specific ROCK inhibitor, enhanced EGF-induced BrdU incorporation. The blockade of EGF stimulation utilizing anti-EGFR-neutralizing antibodies suppressed Panc1 cell proliferation. EGF induced RhoA activity, as well as the phosphorylation of cofilin and myosin light chain (MLC), both targets of ROCK signaling, and Y27632 suppressed both of these processes, indicating that the phosphorylation of cofilin and MLC by EGF occurs through ROCK in Panc1 cells. EGF-induced phosphorylation of EGFR at tyrosine residues was augmented when the cells were pretreated with Y27632 or were subjected to gene silencing using ROCK-siRNA. We also obtained similar results using transforming growth factor-α. In addition, EGF-induced phosphorylation of p44/p42 mitogen-activated protein kinase and Akt were also enhanced by Y27632 or ROCK-siRNA. Moreover, an immunofluorescence microscope study revealed that pretreatment with Y27632 delayed EGF-induced internalization of EGFR. Taken together, these data indicate that ROCK functions to switch off EGFR signaling by promoting the internalization of the EGFR. CONCLUSIONS: While EGF first stimulates the activation of the EGFR and subsequently increases cancer cell proliferation, EGF concurrently induces the activation of ROCK, which then turns off the activated EGFR pathway via a negative feedback system.

Ultraviolet irradiation can induce evasion of colon cancer cells from stimulation of epidermal growth factor.

Receptor down-regulation is the most prominent regulatory system of EGF receptor (EGFR) signal attenuation and a critical target for therapy against colon cancer, which is highly dependent on the function of the EGFR. In this study, we investigated the effect of ultraviolet-C (UV-C) on down-regulation of EGFR in human colon cancer cells (SW480, HT29, and DLD-1). UV-C caused inhibition of cell survival and proliferation, concurrently inducing the decrease in cell surface EGFR and subsequently its degradation. UV-C, as well as EGFR kinase inhibitors, decreased the expression level of cyclin D1 and the phosphorylated level of retinoblastoma, indicating that EGFR down-regulation is correlated to cell cycle arrest. Although UV-C caused a marked phosphorylation of EGFR at Ser-1046/1047, UV-C also induced activation of p38 MAPK, a stress-inducible kinase believed to negatively regulate tumorigenesis, and the inhibition of p38 MAPK canceled EGFR phosphorylation at Ser-1046/1047, as well as subsequent internalization and degradation, suggesting that p38 MAPK mediates EGFR down-regulation by UV-C. In addition, phosphorylation of p38 MAPK induced by UV-C was mediated through transforming growth factor-ß-activated kinase-1. Moreover, pretreatment of the cells with UV-C suppressed EGF-induced phosphorylation of EGFR at tyrosine residues in addition to cell survival signal, Akt. Together, these results suggest that UV-C irradiation induces the removal of EGFRs from the cell surface that can protect colon cancer cells from oncogenic stimulation of EGF, resulting in cell cycle arrest. Hence, UV-C might be applied for clinical strategy against human colon cancers.

UVC radiation induces downregulation of EGF receptor via phosphorylation at serine 1046/1047 in human pancreatic cancer cells.

Epidermal growth factor receptor (EGFR) is overexpressed in human pancreatic cancer and is one of the clinical targets in its treatment. In the present study we investigated the mechanism underlying ultraviolet C (UVC)-radiation-induced cell growth inhibition and downregulation of EGFR in human pancreatic cancer cells (Panc1 and KP3). The cell proliferation assay indicated that Panc1 and KP3 cells were more sensitive to UVC radiation, and their growth was significantly inhibited compared to cells of the normal human pancreatic epithelial cell line, PE. Although EGFR levels was extremely low in PE cells, EGFR were highly overexpressed in Panc1 and KP3 cells, and UVC radiation downregulated the expression of EGFR in a time-dependent manner and induced phosphorylation of EGFR at Ser1046/1047 (S1046/7) in Panc1 and KP3 cells. UVC radiation induced activation of p38 mitogen-activated protein kinase (MAPK), and EGFR phosphorylation at S1046/7 induced by UVC radiation was markedly attenuated by the inhibition of p38 MAPK. Moreover, fluorescence microscopy revealed that p38 MAPK activated by UVC radiation triggered EGFR internalization and that this was not correlated with c-Cbl, an ubiquitin ligase, which plays an important role in EGF-induced EGFR downregulation. Taken together, our results suggest that in pancreatic cancer cells UVC radiation induced desensitization of the cells to EGFR stimuli via phosphorylation of EGFR at S1046/7 by activation of p38 MAPK, independent of c-Cbl.

Endoscopic ultrasound-guided fine-needle aspiration of lesions near the aortoiliac bifurcation via an upper gastrointestinal approach.

BACKGROUND AND AIMS: Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is widely used to investigate posterior mediastinal and upper abdominal lesions. Previously, we noticed that the aortoiliac bifurcation can be visualized by transduodenal EUS scanning, and the surrounding area might be a potential target for EUS-guided FNA. This study aimed to determine the feasibility of using EUS-guided FNA to study lesions near the aortoiliac bifurcation via the upper gastrointestinal approach. METHODS: This study was a prospective pilot study of consecutive patients with a lesion of unknown origin near the aortoiliac bifurcation. RESULTS: EUS-guided FNA was used in six patients. The aortoiliac bifurcation was visible from the inferior duodenal angle in all patients; however, the lesions could be visualized in only five patients (3 via the transduodenal approach, and 2 via the transgastric approach). In one patient with a lesion on the left side, the lesion could not be visualized by either the transgastric or transduodenal approach. In the other five patients, EUS-guided FNA was successful, and FNA specimens were adequate for histopathological assessment. The diagnoses were lymphoma (n = 3), plasmacytoma (n = 1), and neurinoma (n = 1). All lymphoma cases were subclassified as diffuse large B-cell lymphoma (n = 2) or grade 2 follicular lymphoma (n = 1). No complications were observed. CONCLUSIONS: The aortoiliac bifurcation was visible in all patients by transduodenal EUS scanning. FNA of the legions near the aortoiliac bifurcation was possible in five of six patients by using either the transgastric or transduodenal approach.

Inhibition of gastroesophageal reflux by semi-solid nutrients in patients with percutaneous endoscopic gastrostomy.

BACKGROUND: Aspiration is one of the major complications after percutaneous endoscopic gastrostomy (PEG). The administration of semi-solid nutrients by means of gastrostomy tube has recently been reported to be effective in preventing aspiration pneumonia. The effects of semi-solid nutrients on gastroesophageal reflux, intragastric distribution, and gastric emptying were evaluated. METHODS: Semi-solid nutrients were prepared by liquid nutrients mixed with agar at the concentration of 0.5%. The distribution of the administered radiolabeled liquid and semi-solid nutrients was monitored by a scintillation camera for 15 post-PEG patients. The percentage of esophageal reflux, the distribution of the proximal and distal stomach, and the gastric emptying time were evaluated. RESULTS: The percentage of gastroesophageal reflux was significantly decreased in semi-solid nutrients (0.82 +/- 1.27%) compared with liquid nutrients (3.75 +/- 4.25%), whereas the gastric emptying time was not different. The distribution of semi-solid nutrients was not different from liquid nutrients in the early phase, whereas higher retention of liquid nutrients in the proximal stomach was observed in the late phase. CONCLUSIONS: Gastroesophageal reflux was significantly inhibited by semi-solid nutrients. One of the mechanisms of the inhibition is considered to be an improvement in the transition from the proximal to distal stomach in semi-solid nutrients.