74 research outputs found

    Comparative lipidomics of 5-Fluorouracil-sensitive and -resistant colorectal cancer cells reveals altered sphingomyelin and ceramide controlled by acid sphingomyelinase (SMPD1).

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    5-Fluorouracil (5-FU) is a chemotherapeutic drug widely used to treat colorectal cancer. 5-FU is known to gradually lose its efficacy in treating colorectal cancer following the acquisition of resistance. We investigated the mechanism of 5-FU resistance using comprehensive lipidomic approaches. We performed lipidomic analysis on 5-FU-resistant (DLD-1/5-FU) and -sensitive (DLD-1) colorectal cancer cells using MALDI-MS and LC-MRM-MS. In particular, sphingomyelin (SM) species were significantly up-regulated in 5-FU-resistant cells in MALDI-TOF analysis. Further, we quantified sphingolipids including SM and Ceramide (Cer) using Multiple Reaction Monitoring (MRM), as they play a vital role in drug resistance. We found that 5-FU resistance in DLD-1/5-FU colorectal cancer cells was mainly associated with SM increase and Cer decrease, which are controlled by acid sphingomyelinase (SMPD1). In addition, reduction of SMPD1 expression was confirmed by LC-MRM-MS analysis and the effect of SMPD1 in drug resistance was assessed by treating DLD-1 cells with siRNA-SMPD1. Furthermore, clinical colorectal cancer data set analysis showed that down-regulation of SMPD1 was associated with resistance to chemotherapy regimens that include 5-FU. Thus, from our study, we propose that SM/Cer and SMPD1 are new potential target molecules for therapeutic strategies to overcome 5-FU resistance

    Helicobacter pylori infection combined with DENA revealed altered expression of p53 and 14-3-3 isoforms in Gulo−/− mice

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    AbstractUnlike most other mammals, human bodies do not have the ability to synthesize vitamin C inside of their own bodies. Therefore, humans must obtain vitamin C through daily diet. Gulo−/− mice strain is known with deficiency, in which vitamin C intake can be controlled by diet like human, and would be valuable for investigating the molecular mechanism of various diseases. In the present study, we established Gulo−/− mice model and investigated the differentially expressed proteins in stomach tissue of Gulo−/− mice after Helicobacter pylori-infected, and followed by DENA, using immunohistochemistry and proteomic approach. The results of immunohistochemistry analysis of stomach tissue showed that the tumor suppressor, p53 protein, expression was significantly decreased (p<0.05) but not messenger RNA (mRNA) transcriptional level, and 14-3-3ε, 14-3-3δ, Ki-67 and cleaved caspase 3 expressions were significantly increased (p<0.05) by H. Pylori infection, and followed by DENA treatment in Gulo−/− mice. Moreover, knockdown of 14-3-3 isoforms (14-3-3ε, 14-3-3σ, 14-3-3ζ and 14-3-3η) were significantly increased sub-G1 phase (characteristics of apoptosis) in AGS cells and, phenotypic changes like cell shrinkage, density and cleaved nuclei were also observed. Proteome analyses showed that 14-3-3σ, 14-3-3η, and tropomyosin alpha-1 chain were down-regulated, and Hspd1 protein and HSC70 were up-regulated after H. Pylori-infection, and followed by DENA. The combined results of immunohistochemistry and proteomic analysis suggest that H. pylori altered the p53 and 14-3-3 isoforms expression and DENA further enhanced the H. pylori effect, which might be involved in carcinogenesis and metastasis of gastric cancer on Gulo−/− mice

    Seborrheic Keratosis of the Conjunctiva: A Case Report

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    Seborrheic keratosis is a benign epithelial neoplasia that occurs mainly in the skin of the eyelids and face. We describe a case of seborrheic keratosis of the conjunctiva confirmed by histopathology. A 72-year-old man presented with a recurrent conjunctival mass involving the nasal side of his right eye. Clinically, a diagnosis of conjunctival papilloma was made, and a mass excision was performed. The histopathological analysis evidenced a conjunctival-covering epithelium with papillomatous changes and irregular acanthosis, at the expense of a proliferation of basaloid cells. In addition, the lesion exhibited multiple pseudohorn cysts containing keratin. With the above findings, a diagnosis of conjunctival seborrheic keratosis was established. The occurrence of seborrheic keratosis on the conjunctiva is rare. In this case, seborrheic keratosis was confirmed by pathologic report despite its similar appearance with papilloma. Seborrheic keratosis should be considered in the differential diagnosis of conjunctival lesions

    A Case of Santorinicele without Pancreas Divisum: Diagnosis with Multi-detector Row Computed Tomography

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    A santorinicele is defined as a focal cystic dilatation of the terminal portion of the dorsal pancreatic duct at the minor papilla. Most cases reported previously were associated with pancreas divisum and a santorinicele without pancreas divisum is known to be rare. We recently experienced a typical case of a santorinicele without pancreas divisum in a 67-yr-old woman with abdominal pain and hematochezia, subsequently proven to be the result of an ischemic colitis. The santorinicele was diagnosed incidentally with multi-detector row computed tomography using a minimum intensity projection technique, which clearly showed a cystic dilatation of the terminal portion of the dorsal pancreatic duct and a communication between the ventral and dorsal pancreatic ducts. This finding was also confirmed by a magnetic resonance cholangiopancreatography

    Long-term Treatment Outcomes for Autoimmune Hepatitis in Korea

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    Immunosuppressive therapy can improve clinical, biochemical and histological features and considerably prolong survival in patients with autoimmune hepatitis. Although ethnicity may affect disease severity and presentation, the long-term outcome of immunosuppression in Korean populations is unknown. This study was aimed to assess the efficacy of immunosuppressive therapy and determine the prognosis of autoimmune hepatitis in Korean populations. We reviewed the medical records of 86 patients diagnosed as having autoimmune hepatitis at the Samsung Medical Center between 1994 and 2008. Seventy-two (83.7%) patients reached remission after a median treatment duration of 3.5 months (range 1 to 44 months). Attempts to withdraw medications were made in 24 cases after the median treatment duration of 36 months (median 6 to 125 months). Thirteen of 24 (54.1%) patients relapsed after treatment withdrawal. Of the 86 patients, 6 (7.2%) experienced disease progression and the overall 5-and 10-yr progression-free survival rates were 91.2% and 85.5%, respectively. In conclusion, immunosuppressive therapy for autoimmune hepatitis results in a favorable rate of remission and excellent progression-free survival, but the relapse rate after treatment withdrawal is high. This suggests that long-term immunosuppressive therapy may be particularly important for treatment of Korean patients

    Extreme proximal migration of dislocated lunate over carpal ligament – A case report

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    Dislocation of the lunate and proximal pole of the scaphoid with displacement of the fragments proximal to the radiocarpal joint, characterized as a total dislocation, is very rare, with only six cases reported. Dislocated lunate are generally located around the radiocarpal joint or within carpal ligament. However, there have been no reports of dislocated lunate over the carpal ligament. We present a patient with volar dislocation of the lunate that featured extreme migration to approximately 6 cm proximal to flexor digitorum superficialis through the transcarpal ligament. Keywords: Lunate, Dislocation, Proximal migratio
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