Project description:Retinoblastoma (RB) is an intraocular childhood tumor which, if left untreated, leads to blindness and mortality. Nucleolin (NCL) protein which is differentially expressed on the tumor cell surface, binds ligands and regulates carcinogenesis and angiogenesis. We found that NCL is over expressed in RB tumor tissues and cell lines compared to normal retina. We studied the effect of nucleolin-aptamer (NCL-APT) to reduce proliferation in RB tumor cells. Aptamer treatment on the RB cell lines (Y79 and WERI-Rb1) led to significant inhibition of cell proliferation. Locked nucleic acid (LNA) modified NCL-APT administered subcutaneously (s.c.) near tumor or intraperitoneally (i.p.) in Y79 xenografted nude mice resulted in 26 and 65% of tumor growth inhibition, respectively. Downregulation of inhibitor of apoptosis proteins, tumor miRNA-18a, altered serum cytokines, and serum miRNA-18a levels were observed upon NCL-APT treatment. Desorption electrospray ionization mass spectrometry (DESI MS)-based imaging of cell lines and tumor tissues revealed changes in phosphatidylcholines levels upon treatment. Thus, our study provides proof of concept illustrating NCL-APT-based targeted therapeutic strategy and use of DESI MS-based lipid imaging in monitoring therapeutic responses in RB. Overall design: Four Samples, two controls and two treated.
Project description:A novel one-dimensional on-line pH gradient-eluted strong cation exchange (SCX)-nano-ESI-MS/MS method was developed for protein identification and tested with mixture of six standard proteins, total lysate of HuH7 and N2a cells, as well as membrane fraction of N2a cells. This method utilized an on-line nano-flow SCX column in a nano-LC system coupled with a nano-electrospray high-resolution mass spectrometer. Protein digests were separated on a nano-flow SCX column with a pH gradient and directly introduced into a mass spectrometer through nano-electrospray ionization. SCXLC-MS/MS showed identification capability for higher proportion of basic peptides compared to RPLC-MS/MS method, especially for histidine-containing peptides. Our SCXLC-MS/MS method is an excellent alternative method to the RPLC-MS/MS method for analysis of standard proteins, total cell and membrane proteomes.
Project description:The 17.62 kDa vitellogenin B derived yolk protein was purified by a specific cation exchange chromatography, subjected to a liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) and finally identified using short MS/MS protein signatures similar to vitellogenin of a near species from the same family, red seabream, Pagrus major, (Temminck and Schlegel, 1843).
Project description:The clinical outcomes of M2 subtype Acute Myeloid Leukemia (AML-M2) with t(8;21) are poor. Here we report that FTY720 (Fingolimod), a sphingosine analogue and an FDA approved drug for treatment of multiple sclerosis, showed great antitumorigenic activity against Kasumi-1 cell line, xenograft mouse model and leukemic blasts isolated from AML-M2 with t(8;21) patients. Primary investigation indicated that FTY720 caused cell apoptosis through caspase and protein phosphatase 2A (PP2A) activation. Transcriptomic profiling further revealed that FTY720 treatment could upregulate AML1 target genes and interfere with genes involved in ceramide synthesis. FTY720 treatment led to the elimination of AML1-ETO oncoprotein and caused cell cycle arrest. More importantly, FTY720 treatment resulted in rapid and significant increment of pro-apoptotic ceramide levels, determined by HPLC-ESI-MS/MS (high-performance liquid chromatography-electrospray ionization tandem mass spectrometry) based lipidomic approaches. Additionally, structural simulation model indicated that the directly binding of ceramide to inhibitor 2 of PP2A (I2PP2A) could reactivate PP2A and cause cell death. This study demonstrates, for the first time, that accumulation of ceramide plays a central role in FTY720 induced cell death of AML-M2 with t(8;21). Targeting sphingolipid metabolism by using FTY720 may provide novel insight into drug development for AML-M2 treatment. A six chip study using total RNA recovered from three separate cultures of DMSO-treated Kasumi-1 cells and three separate cultures of FTY720-treated Kasumi-1 cells.Each chip measures the expression level of genes from DMSO-/FTY720-treated Kasumi-1 cells.
Project description:The objective of the present investigation was to consider the level of variation in the protein expression patterns of closely related Salmonella serovars, in order to search for protein factors with levels of expression or posttranslational modifications characteristic for each serovar. For the comparative expression analysis we have utilised classic 2D GE approach which revealed several proteins with serovar specific expression as well as proteins which do not alter their expression levels between serovars and strains. The proteins of interest were identified using LC/MS/MS. Keywords: 2D GE, MS/MS Overall design: Analysis of 12 strains of S. enterica representing five different serovars.
Project description:Here we examine the expression of genes in unstimulated or following intraperitoneal injection with MegaFasL in MSM/Ms and C57BL/6 mouse livers and thymi This dataset is from two groups of 2 mice (1 MSM/Ms [MSM] and 1 C57BL/6 [B6] mouse) - either untreated (#1-#4) or injected intraperitoneally with 1.5ug of MegaFasL (#5-#8). Each group has four (4) samples - one liver (L) and one thymus (T) sample from each mouse. The liver and thymi were harvested from the same mouse. Unstimulated samples: 1_S1 = B6 T, 2_S=MSM T, 3_S3=B6 L, 4_S4=MSM L; MegaFasL-injected samples: 5_S1=B6 T, 6_S2=MSM T, 7_S3=B6 L, 8_S4=MSM L.