Tag Archives: Arun Dass

N-glycan MALDI mass spectrometry imaging analysis

Arun213 July 2016:

CNBP researchers have released a science paper investigating how N-glycan MALDI mass spectrometry imaging analysis is able to differentiate and delineate tissues as observed in a formalin-fixed ovarian cancer section.

Journal: Molecular and Cellular Proteomics.

Publication title: N-glycan MALDI Imaging Mass Spectrometry on Formalin-Fixed Paraffin-Embedded Tissue Enables the Delineation of Ovarian Cancer Tissues.

Authors: Arun V Everest-Dass (pictured top left), Matthew T Briggs, Gurjeet Kaur, Martin K Oehler, Peter Hoffmann, Nicolle H Packer.

Abstract:  Ovarian cancer is a fatal gynaecological malignancy in adult women with a five-year overall survival rate of only 30%. Glycomic and glycoproteomic profiling studies have reported extensive protein glycosylation pattern alterations in ovarian cancer. Therefore, spatio-temporal investigation of these glycosylation changes may unearth tissue-specific changes that occur in the development and progression of ovarian cancer. A novel method for investigating tissue-specific N-linked glycans is using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) on formalin-fixed paraffin-embedded (FFPE) tissue sections that can spatially profile N-glycan compositions released from proteins in tissue-specific regions. In this study, tissue regions of interest (e.g. tumor, stroma, adipose tissue and necrotic areas) were isolated from FFPE tissue sections of advanced serous ovarian cancers (n=3). PGC-LC-ESI-MS/MS and MALDI
-MSI were used as complementary techniques to firstly generate structural information on the tissue-specific glycans in order to then obtain high resolution images of the glycan structure distribution in ovarian cancer tissue. The N-linked glycan repertoires carried by the proteins in these tissue regions were structurally characterized for the first time in FFPE ovarian cancer tissue regions, using enzymatic peptide-N-glycosidase F (PNGase F) release of N-glycans. The released glycans were analyzed by porous graphitized carbon liquid chromatography (PGC-LC) and collision induced electrospray negative mode MS fragmentation analysis. The N-glycan profiles identified by this analysis were then used to determine the location and distribution of each N-glycan on FFPE ovarian cancer sections that were treated with PNGase F using high resolution MALDI-MSI. A tissue-specific distribution of N-glycan structures identified particular regions of the ovarian cancer sections. For example, high mannose glycans were predominantly expressed in the tumor tissue region whilst complex/hybrid N-glycans were significantly abundant in the intervening stroma. Therefore, tumor and non-tumor tissue regions were clearly demarcated solely on their N-glycan structure distributions.

The paper is available online.

 

Frontiers in Sialic Acid conference

Arun223 April 2016:

Arun Dass, CNBP researcher presented a poster at the ‘Frontiers in Sialic Acid Research Conference’ in Bad Lauterberg, Germany, 23-25 April 2016. The program of this meeting was dedicated to addressing and integrating all aspects of sialic acid related research. Internationally recognized experts met with junior scientists to establish a vivid and stimulating discussion platform.

Conference information is available online.

Proteomics paper examines knee osteoarthritis

Arun215 March 2016:

CNBP researcher Arun  Everest-Dass and CNBP Chief Investigator Prof Nicolle Packer have both co-authored a newly published paper that reports on a new approach, to better study and understand knee osteoarthritis. The paper was published in the journal ‘Proteomics’.

Title: MALDI mass spectrometry imaging of N-glycans on tibial cartilage and subchondral bone proteins in knee osteoarthritis.

Authors: Matthew T Briggs, Julia S Kuliwaba, Dzenita Muratovic, Arun V Everest-Dass, Nicolle H Packer, David M Findlay and Peter Hoffmann.

Abstract: Magnetic Resonance Imaging (MRI) is a non-invasive technique routinely used to investigate pathological changes in knee osteoarthritis (OA) patients. MRI uniquely reveals zones of the most severe change in the subchondral bone (SCB) in OA, called bone marrow lesions (BMLs). BMLs have diagnostic and prognostic significance in OA, but MRI does not provide a molecular understanding of BMLs. Multiple N-glycan structures have been observed to play a pivotal role in the OA disease process. We applied matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) of N-glycans to formalin-fixed paraffin-embedded (FFPE) SCB tissue sections from patients with knee OA, and liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was conducted on consecutive sections to structurally characterize and correlate with the N-glycans seen by MALDI-MSI. The application of this novel MALDI-MSI protocol has enabled the first steps to spatially investigate the N-glycome in the SCB of knee OA patients.

The paper can be accessed online.

 

Poster presented at ASMS

Arun24 June 2015:

CNBP researcher, Dr. Arun Dass presented a poster at the recent American Society for Mass Spectrometry (ASMS) 2015 conference titled: ‘A simple and sensitive method for the analysis of sphingolipid glycosylation enables the differentiation of ovarian cancer sub-types’.

The meeting took place  May 30-June 4th; St. Louis, USA.

The ASMS is a professional association based in the United States that supports the scientific field of mass spectrometry and publishes the Journal of the American Society for Mass Spectrometry. ASMS sponsors the Annual Conference on Mass Spectrometry and Allied Topics that is attended by more than 6,500 scientists from around the world. Approximately 3,000 papers are presented as posters and talks.

http://www.asms.org/

CNBP visits Port Lincoln High School

High Res Edit 027825 November 2014: Engaging with regional highs school students

A small team of CNBP researcher (A/Prof Andrew Greentree; Dr  Arun Dass, Ms Vicky Staikopoulos and Dr Kathy Nicholson met with over 100 Year 8 and 9 students at Port Lincoln High School to talk about Nanoscale BioPhotonics, Careers in science, and an exploration of physics, and the way that air can lead to surprising results.  In this image we see the use of pressure difference for levitation of a ball.

The Port Lincoln Times ran an article about this activity

Dr Mustafa visits key collaborators at Macquarie University

Sanam Mustafa High Res Edit 016620 October 2014: Dr Mustafa visit key collaborators at Macquarie University to discuss novel and interdisciplinary projects.

During her visit to Macquarie University, Dr Mustafa met with Prof Ewa Goldys and Dr Ayad Anwer to discuss the progress of a collaborative project. During her visit, Dr Mustafa shared her expertise in cell culture with Dr Anwer and discussed the progress of the project. Dr Anwer provided a tour of the facilities and explained the process behind image acquisition and data analysis for hyperspectral studies.

Dr Mustafa also discussed a new collaborative project with Prof Nicki Packer and Dr Arun Dass. This project is now in its initial planning stages and experimental work will start shortly.