ABSTRACT
Parenchyma-sparing pancreatic resections have been reported increasingly in recent years; however, for multifocal diseases involving the head and the tail of the pancreas, total pancreatectomy is still the preferred procedure. The possible consequence of this procedure is loss of normal pancreatic parenchyma, resulting in insufficiency of pancreatic exocrine and endocrine functions. Various types of limited resection have been introduced for isolated or multiple pancreatic lesions, depending on the location of the tumor. Even for multifocal diseases, if the pancreatic body is spared, a middle-preserving pancreatectomy (MPP) can be performed to assure maximal pancreatic function and uncompromised quality of life. Yet, few papers have introduced the feasibility of MPP for a better outcome. This report describes a new surgical technique for MPP using an alternative approach for the remnant pancreas anastomosis. We used this technique successfully to remove a bifocal neoplasm: adenocarcinoma of the distal bile duct and mucinous cyst adenoma in the tail of the pancreas.
Subject(s)
Adenocarcinoma/surgery , Anastomosis, Surgical/methods , Bile Duct Neoplasms/surgery , Cystadenoma, Mucinous/surgery , Gastrostomy/methods , Neoplasms, Multiple Primary , Organ Sparing Treatments/methods , Pancreas/surgery , Pancreatectomy/methods , Pancreatic Neoplasms/surgery , Aged, 80 and over , Humans , Treatment OutcomeABSTRACT
The major vault protein (MVP) is the major constituent of the vault particle, the largest ribonuclear protein complex described to date and is identical to lung resistance-related protein (LRP). Although MVP is also expressed in several normal tissues, little is known about its physiological role. MVP played a protective role against some xenobiotics and other stresses. We thus investigated the effect of osmotic stress on MVP expression by treating human colon cancer SW620 cells with sucrose or NaCl. The expression level of both MVP protein and MVP mRNA was increased by the osmostress. Sucrose or sodium chloride could also enhance MVP promoter activity. Inhibition of p38 MAPK in SW620 cells by SB203580 inhibited the expression of MVP under hyperosmotic stress. These findings suggested that osmotic stress up-regulated the MVP expression through p38 MAPK pathway. Down-regulation of MVP expression by MVP interfering RNA (RNAi) in SW620 cells increased the sensitivity of the cells to hyperosmotic stress and enhanced apoptosis. Furthermore, MVP RNAi prevented the osmotic stress-induced, time-dependent increase in phosphorylated Akt. These findings suggest that the PI3K/Akt pathway might be implicated in the cytoprotective effect of MVP. Our data demonstrate that exposure of cells to hyperosmotic stress induces MVP that might play an important role in the protection of the cells from the adverse effects of osmotic stress.
Subject(s)
Cell Line, Tumor , Colonic Neoplasms/metabolism , Gene Expression Regulation , Vault Ribonucleoprotein Particles/metabolism , Animals , Cell Survival , Chromones/metabolism , Enzyme Inhibitors/metabolism , Genes, Reporter , Humans , Morpholines/metabolism , Osmotic Pressure , Promoter Regions, Genetic , RNA Interference , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Sodium Chloride/metabolism , Sucrose/metabolism , Vault Ribonucleoprotein Particles/genetics , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
Vaults are barrel-shaped cytoplasmic ribonucleoprotein particles composed of three proteins. One of the components, the major vault protein (MVP) initially named the lung resistance-related protein (LRP), was found to be overexpressed in various multidrug resistant cancer cell lines and clinical samples. In this study, we investigated whether anticancer drugs could directly induce MVP protein or gene expression in the SW-620 human colorectal cancer cell line, in which MVP has been shown to be induced by the differentiation-inducing agent, sodium butyrate (NaB). MVP protein levels were enhanced in SW-620 cells after a 72 h treatment with doxorubicin (Adr), etoposide (VP-16), cis-platinum (II) diammine dichloride (CDDP) or SN-38, but not vincristine (VCR) or paclitaxel (Taxol) at their IC50 concentration. Treatment for 48 h with Adr, VP-16 and SN-38 at their IC50 concentration also enhanced the expression of MVP mRNA. Moreover, Adr could directly enhance the transcriptional activity of MVP promoter regions. On the other hand, the Adr treatment did not affect the stability of MVP mRNA. Furthermore, MVP levels were also elevated after treatment with the DNA-damaging agents, ethidium bromide (EtBr) and ultraviolet light (UV) irradiation. Our findings therefore suggest that DNA damage enhances MVP promoter activity. Since the MVP protein and mRNA have low turnover rates, a slight enhancement of MVP promoter activity could lead to a considerable increase in the level of MVP.
