Displaying publications 41 - 60 of 89 in total

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  1. Othman EQ, Kaur G, Mutee AF, Muhammad TS, Tan ML
    J Clin Lab Anal, 2009;23(4):249-58.
    PMID: 19623642 DOI: 10.1002/jcla.20309
    Autophagy is a protein degradation process within the cell and its deregulation has been linked to various diseases and the formation of cancer. One of the important proteins involved in the autophagy process is microtubule-associated protein 1 light chain 3 (MAP1LC3). The aims of this study were to determine the MAP1LC3A and MAP1LC3B protein expression in both normal and cancer breast tissues and to determine the relationship between the expression of these proteins and type of tissues. Immunohistochemistry assessments were carried out on tissue microarrays consisting of breast tissues. MAP1LC3A expression was detected in 52/56 of normal breast tissue cores and 65/67 of breast cancer tissue cores. MAP1LC3B expression was detected in 55/56 of normal breast tissue cores and 67/67 of breast cancer tissue cores. MAP1LC3A and MAP1LC3B protein are expressed in the majority of normal and cancer breast tissues. A large number of MAP1LC3A and MAP1LC3B positive breast cancer tissues cores have high proportion of stained cells (81-100%) as compared with normal breast tissues. However, a significantly higher number of breast cancer tissues were found to express the MAP1LC3A protein with strong immunoreactivity as compared with the normal tissues, suggesting that MAP1LC3A may play a role in breast cancer development.
  2. Boyle ST, Mittal P, Kaur G, Hoffmann P, Samuel MS, Klingler-Hoffmann M
    J Proteome Res, 2020 10 02;19(10):4093-4103.
    PMID: 32870688 DOI: 10.1021/acs.jproteome.0c00511
    Tumorigenesis involves a complex interplay between genetically modified cancer cells and their adjacent normal tissue, the stroma. We used an established breast cancer mouse model to investigate this inter-relationship. Conditional activation of Rho-associated protein kinase (ROCK) in a model of mammary tumorigenesis enhances tumor growth and progression by educating the stroma and enhancing the production and remodeling of the extracellular matrix. We used peptide matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to quantify the proteomic changes occurring within tumors and their stroma in their regular spatial context. Peptides were ranked according to their ability to discriminate between the two groups, using a receiver operating characteristic tool. Peptides were identified by liquid chromatography tandem mass spectrometry, and protein expression was validated by quantitative immunofluorescence using an independent set of tumor samples. We have identified and validated four key proteins upregulated in ROCK-activated mammary tumors relative to those expressing kinase-dead ROCK, namely, collagen I, α-SMA, Rab14, and tubulin-β4. Rab14 and tubulin-β4 are expressed within tumor cells, whereas collagen I is localized within the stroma. α-SMA is predominantly localized within the stroma but is also expressed at higher levels in the epithelia of ROCK-activated tumors. High expression of COL1A, the gene encoding the pro-α 1 chain of collagen, correlates with cancer progression in two human breast cancer genomic data sets, and high expression of COL1A and ACTA2 (the gene encoding α-SMA) are associated with a low survival probability (COLIA, p = 0.00013; ACTA2, p = 0.0076) in estrogen receptor-negative breast cancer patients. To investigate whether ROCK-activated tumor cells cause stromal cancer-associated fibroblasts (CAFs) to upregulate expression of collagen I and α-SMA, we treated CAFs with medium conditioned by primary mammary tumor cells in which ROCK had been activated. This led to abundant production of both proteins in CAFs, clearly highlighting the inter-relationship between tumor cells and CAFs and identifying CAFs as the potential source of high levels of collagen 1 and α-SMA and associated enhancement of tissue stiffness. Our research emphasizes the capacity of MALDI-MSI to quantitatively assess tumor-stroma inter-relationships and to identify potential prognostic factors for cancer progression in human patients, using sophisticated mouse cancer models.
  3. Rusli N, Amanah A, Kaur G, Adenan MI, Sulaiman SF, Wahab HA, et al.
    Naunyn Schmiedebergs Arch Pharmacol, 2019 04;392(4):481-496.
    PMID: 30604191 DOI: 10.1007/s00210-018-01605-y
    Mitragynine is a major component isolated from Mitragyna speciosa Korth or kratom, a medicinal plant known for its opiate-like and euphoric properties. Multiple toxicity and fatal cases involving mitragynine or kratom have been reported but the underlying causes remain unclear. P-glycoprotein (P-gp) is a multidrug transporter which modulates the pharmacokinetics of xenobiotics and plays a key role in mediating drug-drug interactions. This study investigated the effects of mitragynine on P-gp transport activity, mRNA, and protein expression in Caco-2 cells using molecular docking, bidirectional assay, RT-qPCR, Western blot analysis, and immunocytochemistry techniques, respectively. Molecular docking simulation revealed that mitragynine interacts with important residues at the nucleotide binding domain (NBD) site of the P-gp structure but not with the residues from the substrate binding site. This was consistent with subsequent experimental work as mitragynine exhibited low permeability across the cell monolayer but inhibited digoxin transport at 10 μM, similar to quinidine. The reduction of P-gp activity in vitro was further contributed by the downregulation of mRNA and protein expression of P-gp. In summary, mitragynine is likely a P-gp inhibitor in vitro but not a substrate. Hence, concurrent administration of mitragynine-containing kratom products with psychoactive drugs which are P-gp substrates may lead to clinically significant toxicity. Further clinical study to prove this point is needed.
  4. Balasubramaniam SD, Wong KK, Oon CE, Balakrishnan V, Kaur G
    Life Sci, 2020 Sep 01;256:118026.
    PMID: 32615187 DOI: 10.1016/j.lfs.2020.118026
    AIM: We aimed to determine the biological processes and pathways involved in cervical carcinogenesis associated with high-risk human papillomavirus (HPV) infection.

    MATERIALS AND METHODS: Total RNA was extracted from three formalin-fixed paraffin-embedded (FFPE) samples each of normal cervix, HPV-infected low-grade squamous intraepithelial lesion (LSIL), high-grade SIL (HSIL) and squamous cell carcinoma (SCC). Transcriptomic profiling by microarrays was conducted followed by downstream Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses.

    RESULTS: We examined the difference in GOs enriched for each transition stage from normal cervix to LSIL, HSIL, and SCC, and found 307 genes to be differentially expressed. In the transition from normal cervix to LSIL, the extracellular matrix (ECM) genes were significantly downregulated. The MHC class II genes were significantly upregulated in the LSIL to HSIL transition. In the final transition from HSIL to SCC, the immunoglobulin heavy locus genes were significantly upregulated and the ECM pathway was implicated.

    CONCLUSION: Deregulation of the immune-related genes including MHC II and immunoglobulin heavy chain genes were involved in the transitions from LSIL to HSIL and SCC, suggesting immune escape from host anti-tumour response. The extracellular matrix plays an important role during the early and late stages of cervical carcinogenesis.

  5. Everest-Dass AV, Briggs MT, Kaur G, Oehler MK, Hoffmann P, Packer NH
    Mol Cell Proteomics, 2016 09;15(9):3003-16.
    PMID: 27412689 DOI: 10.1074/mcp.M116.059816
    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 whereas 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.
  6. Zahary MN, Kaur G, Abu Hassan MR, Singh H, Naik VR, Ankathil R
    World J Gastroenterol, 2012 Feb 28;18(8):814-20.
    PMID: 22371642 DOI: 10.3748/wjg.v18.i8.814
    To investigate the protein expression profile of mismatch repair (MMR) genes in suspected cases of Lynch syndrome and to characterize the associated germline mutations.
  7. Moad AI, Lan TM, Kaur G, Hashim H, Mabruk MJ
    J Cutan Pathol, 2009 Feb;36(2):183-9.
    PMID: 18564286 DOI: 10.1111/j.1600-0560.2008.00989.x
    The tumor suppressor gene p15(INK4b) is a cyclin-dependent kinase inhibitor, in which its inactivation has been determined in primary tumors and in several tumor-derived cell lines. The precise role of p15(INK4b) protein expression in cutaneous squamous cell carcinoma (SCC) is currently not known. In a previous study, we have shown the frequent occurrence of allelic imbalance/loss of heterozygosity in cutaneous SCC using two microsatellite markers flanking the p15(INK4b) gene. This study is a continuation of our previous study and aims to determine the possible role of p15(INK4b) protein expression in the genesis of cutaneous SCC. P15(INK4b) protein expression was determined using immunohistochemical approach in 107 cases of cutaneous SCC tissue arrays and 19 cases of normal human skin tissues. The expression of p15(INK4b) was significantly reduced in the cutaneous SCC cases as compared with normal human skin (p = 0.017 and p < 0.05). However, there were no significant relationship between clinicopathologic variables of the patients (age, sex and tumor grade) and p15(INK4b) protein expression. The absence of p15(INK4b) expression in the majority of tissue microarray cores of cutaneous SCC indicated that p15(INK4b) could possibly be involved in the pathogenesis of cutaneous SCC.
  8. Young C, Condina MR, Briggs MT, Moh ESX, Kaur G, Oehler MK, et al.
    Front Chem, 2021;9:653959.
    PMID: 34178940 DOI: 10.3389/fchem.2021.653959
    Protein glycosylation is a common post-translational modification that modulates biological processes such as the immune response and protein trafficking. Altered glycosylation profiles are associated with cancer and inflammatory diseases, as well as impacting the efficacy of therapeutic monoclonal antibodies. Consisting of oligosaccharides attached to asparagine residues, enzymatically released N-linked glycans are analytically challenging due to the diversity of isomeric structures that exist. A commonly used technique for quantitative N-glycan analysis is liquid chromatography-mass spectrometry (LC-MS), which performs glycan separation and characterization. Although many reversed and normal stationary phases have been utilized for the separation of N-glycans, porous graphitic carbon (PGC) chromatography has become desirable because of its higher resolving capability, but is difficult to implement in a robust and reproducible manner. Herein, we demonstrate the analytical properties of a 15 cm fused silica capillary (75 µm i.d., 360 µm o.d.) packed in-house with Hypercarb PGC (3 µm) coupled to an Agilent 6550 Q-TOF mass spectrometer for N-glycan analysis in positive ion mode. In repeatability and intermediate precision measurements conducted on released N-glycans from a glycoprotein standard mixture, the majority of N-glycans reported low coefficients of variation with respect to retention times (≤4.2%) and peak areas (≤14.4%). N-glycans released from complex samples were also examined by PGC LC-MS. A total of 120 N-glycan structural and compositional isomers were obtained from formalin-fixed paraffin-embedded ovarian cancer tissue sections. Finally, a comparison between early- and late-stage formalin-fixed paraffin-embedded ovarian cancer tissues revealed qualitative changes in the α2,3- and α2,6-sialic acid linkage of a fucosylated bi-antennary complex N-glycan. Although the α2,3-linkage was predominant in late-stage ovarian cancer, the alternate α2,6-linkage was more prevalent in early-stage ovarian cancer. This study establishes the utility of in-house packed PGC columns for the robust and reproducible LC-MS analysis of N-glycans.
  9. Mittal P, Briggs M, Klingler-Hoffmann M, Kaur G, Packer NH, Oehler MK, et al.
    Anal Bioanal Chem, 2021 Apr;413(10):2721-2733.
    PMID: 33222001 DOI: 10.1007/s00216-020-03039-z
    It is well established that cell surface glycans play a vital role in biological processes and their altered form can lead to carcinogenesis. Mass spectrometry-based techniques have become prominent for analysing N-linked glycans, for example using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Additionally, MALDI MS can be used to spatially map N-linked glycans directly from cancer tissue using a technique termed MALDI MS imaging (MALDI MSI). This powerful technique combines mass spectrometry and histology to visualise the spatial distribution of N-linked glycans on a single tissue section. Here, we performed N-glycan MALDI MSI on six endometrial cancer (EC) formalin-fixed paraffin-embedded (FFPE) tissue sections and tissue microarrays (TMA) consisting of eight EC patients with lymph node metastasis (LNM) and twenty without LNM. By doing so, several putative N-linked glycan compositions were detected that could significantly distinguish normal from cancerous endometrium. Furthermore, a complex core-fucosylated N-linked glycan was detected that could discriminate a primary tumour with and without LNM. Structural identification of these putative N-linked glycans was performed using porous graphitized carbon liquid chromatography tandem mass spectrometry (PGC-LC-MS/MS). Overall, we observed higher abundance of oligomannose glycans in tumour compared to normal regions with AUC ranging from 0.85-0.99, and lower abundance of complex N-linked glycans with AUC ranges from 0.03-0.28. A comparison of N-linked glycans between primary tumours with and without LNM indicated a reduced abundance of a complex core-fucosylated N-glycan (Hex)2(HexNAc)2(Deoxyhexose)1+(Man)3(GlcNAc)2, in primary tumour with associated lymph node metastasis. In summary, N-linked glycan MALDI MSI can be used to differentiate cancerous endometrium from normal, and endometrial cancer with LNM from endometrial cancer without.
  10. Cheng WK, Kaur G, Sjöberg E, Frödin M, Egevad L, Harmenberg U, et al.
    Exp Mol Pathol, 2021 Aug 08;122:104667.
    PMID: 34371013 DOI: 10.1016/j.yexmp.2021.104667
    Renal cell carcinoma (RCC) is the most common type of kidney cancer and has the highest mortality rate among genitourinary cancers. Despite the advances in molecular targeted therapies to treat RCC, the inevitable emergence of resistance has delineated the need to uncover biomarkers to prospectively identify patient response to treatment and more accurately predict patient prognosis. Fringe is a fucose specific β1, 3N-acetylglucosaminyltransferase that modifies the Notch receptors. Given the link between its function and aberrant Notch activation in RCC, Fringe may be implicated in this disease. The Fringe homologs comprise of Lunatic fringe (LFng), Manic fringe (MFng) and Radical fringe (RFng). MFng has been reported to play a role in cancer. MFng is also essential in the development of B cells. However, the expression profile and clinical significance of MFng, and its association with B cells in RCC are unknown. CD20 is a clinically employed biomarker for B cells. This pilot study aimed to determine if MFng protein expression can be utilized as a prospective biomarker for therapeutics and prognosis in RCC, as well as to determine its association with CD20+ B cells. Analysis of publicly available MFng gene expression datasets on The Cancer Genome Atlas Netlwork (TCGA) identified MFng gene expression to be up-regulated in Kidney Clear Cell Renal Carcinoma (KIRC) patients. However there was no significant association between the patient survival probability and the level of MFng expression in this cohort. Immunohistochemistry performed on a tissue microarray containing cores from 64 patients revealed an elevated MFng protein expression in the epithelial and stromal tissues of RCC compared to the normal kidney, suggesting a possible role in tumorigenesis. Our study describes for the first time to our knowledge, the protein expression of MFng in the nuclear compartment of normal kidney and RCC, implicating a prospective involvement in gene transcription. At the cellular level, cytoplasmic MFng was also abundant in the normal kidney and RCC. However, MFng protein expression in the malignant epithelial and stromal tissue of RCC had no positive correlation with the patients' overall survival, progression-free survival and time to metastasis, as well as the gender, age, tumor stage and RCC subtype, indicating that MFng may not be an appropriate prognostic marker. The association between CD20+ B cells and epithelial MFng was found to approach borderline insignificance. Nonetheless, these preliminary findings may provide valuable information on the suitability of MFng as a potential therapeutic molecular marker for RCC, thus warrants further investigation using a larger cohort.
  11. Ong KL, Kaur G, Pensupa N, Uisan K, Lin CSK
    Bioresour Technol, 2018 Jan;248(Pt A):100-112.
    PMID: 28662903 DOI: 10.1016/j.biortech.2017.06.076
    Staggering amounts of food waste are being generated in Asia by means of agricultural processing, food transportation and storage, and human food consumption activities. This along with the recent sustainable development goals of food security, environmental protection, and energy efficiency are the key drivers for food waste valorization. The aim of this review is to provide an insight on the latest trends in food waste valorization in Asian countries such as India, Thailand, Singapore, Malaysia and Indonesia. Landfilling, incineration, and composting are the first-generation food waste processing technologies. The advancement of valorisation alternatives to tackle the food waste issue is the focus of this review. Furthermore, a series of examples of key food waste valorization schemes in this Asian region as case studies to demonstrate the advancement in bioconversions in these countries are described. Finally, important legislation aspects for food waste disposal in these Asian countries are also reported.
  12. Saini S, Thakur CJ, Kumar V, Tandon S, Bhardwaj V, Maggar S, et al.
    Mol Biol Res Commun, 2018 Sep;7(3):107-118.
    PMID: 30426028 DOI: 10.22099/mbrc.2018.29577.1322
    Current re-emergence of Nipah virus (NiV) in India caused 11 deaths so far and many patients were kept in quarantine. A thorough study of previous outbreaks occurred in Malaysia, Bangladesh and India represents cases with high rate of fatality due to acute encephalitis. Our work involves genome analysis of NiV for prediction of miRNAs and their targeted genes in human in order to understand encephalitis origin. Ab-intio program-VMir was used for initial screening of genome, obtained nine pre-miRNAs was analyzed by ViralMir to check for any pseudo pre-miRNAs. Eighteen functional mature miRNAs were extracted from pre-miRNAs by using Mature-Bayes tool, which targets 669 genes in human genome as retrieved by miRDB. Gene ontology terms by PANTHER provide important pathways in which target genes were involved like Axon guidance, T cell activation, and nicotinic acetylcholine receptor signaling. Significant outcome was obtained after NCBI Gene and OMIM database mining and literature search for predicted target genes. TLR3, TJP1, NOTCH2, FHL1, and GRIA3 target genes obtained showed their involvement in host defense, blood brain barrier, neurogenesis, mental retardation and encephalitis. To conclude, we predicted significant genes in human that can be inhibited by miRNAs of NiV and results in etiology of encephalitis.
  13. Kaur G, Balasubramaniam SD, Lee YJ, Balakrishnan V, Oon CE
    Asian Pac J Cancer Prev, 2019 Oct 01;20(10):3043-3049.
    PMID: 31653153 DOI: 10.31557/APJCP.2019.20.10.3043
    OBJECTIVE: Minichromosome maintenance complex (MCM) proteins are essential for the process of DNA replication and cell division. This study aimed to evaluate MCM genes expression profiles and MCM2 protein in HPV-associated cervical carcinogenesis.

    METHODOLOGY: MCM2, 4, 5 and 7 genes expression profiles were evaluated in three cervical tissue samples each of normal cervix, human papillomavirus (HPV)-infected low grade squamous intraepithelial lesion (LSIL), high grade squamous intraepithelial lesion (HSIL) and squamous cell carcinoma (SCC), using Human Transcriptome Array 2.0 and validated by nCounter® PanCancer Pathway NanoString Array. Immunohistochemical expression of MCM2 protein was semi-quantitatively assessed by histoscore in tissue microarrays containing 9 cases of normal cervix, 10 LSIL, 10 HSIL and 42 cases of SCC.

    RESULTS: MCM2, 4, 5 and 7 genes expressions were upregulated with increasing fold change during the progression from LSIL to HSIL and the highest in SCC. MCM2 gene had the highest fold change in SCC compared to normal cervix. Immunohistochemically, MCM2 protein was localised in the nuclei of basal cells of normal cervical epithelium and dysplastic-neoplastic cells of CIN and SCC. There was a significant difference in MCM2 protein expression between the histological groups (P = 0.039), and histoscore was the highest in HSIL compared to normal cervix (P = 0.010).

    CONCLUSION: The upregulation of MCM genes expressions in cervical carcinogenesis reaffirms MCM as a proliferative marker in DNA replication pathway, whereby proliferation of dysplastic and cancer cells become increasingly dysregulated and uncontrolled. A strong expression of MCM2 protein in HSIL may aid as a concatenated screening tool in detecting pre-cancerous cervical lesions.

  14. Chen WK, Oon CE, Kaur G, Sainson RCA, Li JL
    Microvasc Res, 2022 Feb 11.
    PMID: 35157839 DOI: 10.1016/j.mvr.2022.104341
    Clear cell renal cell carcinoma (ccRCC) is a highly angiogenic cancer. Manic fringe (MFng) is elevated in ccRCC compared to the normal kidney. However, its role in ccRCC tumour angiogenesis remains elusive. This study seeks to determine the expression pattern of MFng in ccRCC blood vessels and its role in angiogenesis. The association between MFng and the blood vessels was established through online compendia, immunohistochemistry and qPCR analyses. The anti-angiogenic potential of lentiviral-mediated MFng knockdown in endothelial cells (EC shMFng) was assessed for viability, proliferation, apoptosis, migration, adhesion, cell cycle, vessel sprouting, and molecular expression of adhesion and apoptosis markers. Finally, EC shMFng were co-cultured with 786-0 renal cancer cells to determine their impact on cancer cell migration. The online dataset analyses and immunostaining on ccRCC tissues revealed high expression of MFng in ECs. MFng and CD31/PECAM-1 genes were up-regulated in ccRCC tissue samples compared to normal kidney tissues. EC shMFng demonstrated decreased cell viability due to G1 cell cycle arrest and reduced Ki-67 protein expression. In addition, shMFng down-regulated endothelial adhesion molecules and hindered EC migration, network formation and sprouting, compared to their respective empty vector (EV) controls. Co-culture assay of EC shMFng with 786-0 renal cancer cells inhibited cancer cell migration. These findings underscore the potential role of MFng in ECs in influencing renal cancer cell migration, thus opening an avenue for anti-angiogenic strategy targeting MFng to treat ccRCC.
  15. Earnest BS, Men LC, Sukvinder Kaur G, Alias RB, Sunita Devi H
    J Assoc Physicians India, 2010 Feb;58(2):118-20.
    PMID: 20653157
    The neurological manifestations of chronic hepatitis C is most often a peripheral sensory neuropathy characterised by numbness, burning and sensation of "pins and needles". Peripheral motor neuropathy, mononeuropathy, mononeuropathy multiplex and transverse myelitis also occur. Ischemic stroke and transient cerebral ischemia have also been reported. Anterior ischemic optic neuropathy is seen, often following interferon therapy. We report an exceptional case of neuromyelitis optica in chronic hepatitis C infection in the absence of interferon therapy.
  16. Weiland F, Arentz G, Klingler-Hoffmann M, McCarthy P, Lokman NA, Kaur G, et al.
    J Proteome Res, 2016 11 04;15(11):4073-4081.
    PMID: 27569743
    Although acetylation is regarded as a common protein modification, a detailed proteome-wide profile of this post-translational modification may reveal important biological insight regarding differential acetylation of individual proteins. Here we optimized a novel peptide IEF fractionation method for use prior to LC-MS/MS analysis to obtain a more in depth coverage of N-terminally acetylated proteins from complex samples. Application of the method to the analysis of the serous ovarian cancer cell line OVCAR-5 identified 344 N-terminally acetylated proteins, 12 of which are previously unreported. The protein peptidyl-prolyl cis-trans isomerase A (PPIA) was detected in both the N-terminally acetylated and unmodified forms and was further analyzed by data-independent acquisition in carboplatin-responsive parental OVCAR-5 cells and carboplatin-resistant OVCAR-5 cells. This revealed a higher ratio of unacetylated to acetylated N-terminal PPIA in the parental compared with the carboplatin-resistant OVCAR-5 cells and a 4.1-fold increase in PPIA abundance overall in the parental cells relative to carboplatin-resistant OVCAR-5 cells (P = 0.015). In summary, the novel IEF peptide fractionation method presented here is robust, reproducible, and can be applied to the profiling of N-terminally acetylated proteins. All mass spectrometry data is available as a ProteomeXchange repository (PXD003547).
  17. Briggs MT, Ho YY, Kaur G, Oehler MK, Everest-Dass AV, Packer NH, et al.
    Rapid Commun Mass Spectrom, 2017 May 30;31(10):825-841.
    PMID: 28271569 DOI: 10.1002/rcm.7845
    RATIONALE: Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) of the proteome of a tissue has been an established technique for the past decade. In the last few years, MALDI-MSI of the N-glycome has emerged as a novel MALDI-MSI technique. To assess the accuracy and clinical significance of the N-linked glycan spatial distribution, we have developed a method that utilises MALDI-MSI followed by liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) in order to assign glycan structures to the differentiating MALDI-MSI glycan masses released from the tissue glycoproteins.

    METHODS AND RESULTS: Our workflow presents a comprehensive list of instructions on how to (i) apply MALDI-MSI to spatially map the N-glycome across formalin-fixed paraffin-embedded (FFPE) clinical samples, (ii) structurally characterise N-glycans extracted from consecutive FFPE tissue sections by LC/MS/MS, and (iii) match relevant N-glycan masses from MALDI-MSI with confirmed N-glycan structures determined by LC/MS/MS.

    CONCLUSIONS: Our protocol provides groups that are new to this technique with instructions how to establish N-glycan MALDI-MSI in their laboratory. Furthermore, the method assigns N-glycan structural detail to the masses obtained in the MALDI-MS image. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Kumarasamy G, Ismail MN, Tuan Sharif SE, Desire C, Mittal P, Hoffmann P, et al.
    Curr Issues Mol Biol, 2023 Apr 20;45(4):3603-3627.
    PMID: 37185759 DOI: 10.3390/cimb45040235
    Nearly 90% of cervical cancers are linked to human papillomavirus (HPV). Uncovering the protein signatures in each histological phase of cervical oncogenesis provides a path to biomarker discovery. The proteomes extracted from formalin-fixed paraffin-embedded tissues of the normal cervix, HPV16/18-associated squamous intraepithelial lesion (SIL), and squamous cell carcinoma (SCC) were compared using liquid chromatography-mass spectrometry (LC-MS). A total of 3597 proteins were identified, with 589, 550, and 1570 proteins unique to the normal cervix, SIL, and SCC groups, respectively, while 332 proteins overlapped between the three groups. In the transition from normal cervix to SIL, all 39 differentially expressed proteins were downregulated, while all 51 proteins discovered were upregulated in SIL to SCC. The binding process was the top molecular function, while chromatin silencing in the SIL vs. normal group, and nucleosome assembly in SCC vs. SIL groups was the top biological process. The PI3 kinase pathway appears crucial in initiating neoplastic transformation, while viral carcinogenesis and necroptosis are important for cell proliferation, migration, and metastasis in cervical cancer development. Annexin A2 and cornulin were selected for validation based on LC-MS results. The former was downregulated in the SIL vs. normal cervix and upregulated in the progression from SIL to SCC. In contrast, cornulin exhibited the highest expression in the normal cervix and lowest in SCC. Although other proteins, such as histones, collagen, and vimentin, were differentially expressed, their ubiquitous expression in most cells precluded further analysis. Immunohistochemical analysis of tissue microarrays found no significant difference in Annexin A2 expression between the groups. Conversely, cornulin exhibited the strongest expression in the normal cervix and lowest in SCC, supporting its role as a tumor suppressor and potential biomarker for disease progression.
  19. Yehya AHS, Subramaniam AV, Asif M, Kaur G, Abdul Majid AMS, Oon CE
    World J Gastroenterol, 2022 Aug 28;28(32):4620-4634.
    PMID: 36157930 DOI: 10.3748/wjg.v28.i32.4620
    BACKGROUND: Pancreatic cancer is the most aggressive cancer type. Gemcitabine is the first line chemo-drug used for pancreatic cancer but exerts a broad spectrum of organ toxicities and adverse effects in patients.

    AIM: To evaluate the anti-tumour activity and toxicological effects of Orthosiphon stamineus extract formulation (ID: C5EOSEW5050ESA trademarked as Nuva-staticTM), and gemcitabine combination on pancreatic xenograft model.

    METHODS: Mice were randomly divided into six groups of 6 mice each (n = 6) and given different treatments for 28 d. The study design consisted of a 2 x 3 factorial treatment structure, with gemcitabine (yes/no) by oral (at 1200 and 400 mg/kg per day). Human pancreatic cancer cells were injected subcutaneously into the flanks of athymic nude mice. C5EOSEW5050ESA (200 or 400 mg/kg per day) was administered orally, while gemcitabine (10 mg/kg per 3 d) was given intraperitoneally either alone or in combination treatment. Histopathological analyses of vital organs, tumour tissues, and incidence of lethality were analysed. Analyses of tumour necrosis and proliferation were determined by haematoxylin-eosin staining and immunohistochemistry for Ki-67, respectively.

    RESULTS: No signs of toxicity or damage to vital organs were observed in all treatment groups compared to the untreated group. C5EOSEW5050ESA at 200 mg/kg and gemcitabine combination had no additive antitumor effects compared to a single treatment. Remarkably, a comparably greater response in a reduction in tumour growth, Ki-67 protein expression, and necrosis was demonstrated by 400 mg/kg of C5EOSEW5050ESA and gemcitabine combination than that of the individual agents.

    CONCLUSION: These results highlighted the synergistic activity of C5EOSEW5050ESA with gemcitabine to reduce pancreatic tumour growth in mice compared to a single treatment. Thus, this study provides valuable insights into using C5EOSEW5050ESA as a complementary treatment with gemcitabine for pancreatic cancer.

  20. Contractor AA, Almeida IM, Fentem A, Griffith EL, Kaur G, Slavish DC
    Trauma Violence Abuse, 2024 Apr;25(2):1468-1483.
    PMID: 37427484 DOI: 10.1177/15248380231184207
    Substantial comorbidity exists between posttraumatic stress disorder and sleep disturbances/disorders. Such comorbidities are understudied in minority groups, including Asian Indians residing in countries outside India. Thus, we synthesized the existing literature specific to this group of Asian Indians to determine (a) prevalence estimates of posttraumatic stress disorder (PTSD) and sleep disturbances/disorders; and (b) PTSD-sleep comorbidity estimates. For this systematic review, we searched four databases (PubMed, PsycInfo, PTSDpubs, Web of Science) using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 3,796 screened articles, 9 articles (10 studies) met inclusion criteria. Study sample sizes ranged from 11 to 2,112 Asian Indians; studies were conducted in Singapore or Malaysia. No reviewed study examined PTSD. All studies examined sleep disturbances/disorders among Asian Indians; prevalence estimates were: 8.3% to 70.4% for short sleep duration, 2.0% to 22.9% for long sleep duration, 25.9% to 56.3% for poor sleep quality, 3.4% to 67.5% for insomnia diagnosis or probable insomnia, 7.7% for excessive daytime sleepiness, 3.8% to 54.6% for obstructive sleep apnea (OSA) diagnosis or high OSA risk, and 5.1% to 11.1% for sleep-disordered breathing. Specific to Asian Indians residing in countries outside India, this review advances PTSD-sleep literature by (a) suggesting substantial prevalence of sleep disturbances/disorders; (b) highlighting the need for culturally relevant sleep interventions; and (c) highlighting research gaps (e.g., no PTSD-focused research).
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