Protein antigen-i parasit ikan C. irritans berpotensi tinggi digunakan sebagai calon dalam pembangunan vaksin komersial terhadap C. irritans. Walau bagaimanapun, kewujudan variasi pada antigen-i serotip C. irritans yang berbeza mempengaruhi tahap perlindungan yang bakal diberikan terhadap varians C. irritans yang berbeza apabila antigen-i digunakan sebagai vaksin. Kajian ini dijalankan untuk membandingkan jujukan pelbagai antigen-i pencilan C. irritans di Malaysia berbanding antigen-i pencilan C. irritans yang pernah dilaporkan. Perbandingan filogenetik dijalankan untuk meramalkan potensi protein tersebut dalam usaha membangunkan calon serodiagnostik dan pemvaksinan terhadap pencilan C. irritans yang berlainan. Penjajaran jujukan berbilang bagi jujukan asid amino antigen-i dilakukan dengan perisian CLUSTALX dan analisis filogenetik antigen-i dilakukan menggunakan kaedah parsimoni maksimum (MP) dan kaedah Bayes. Sembilan transkrip unik (TU) C. irritans yang mempunyai padanan signifikan dengan antigen-i di pangkalan data protein NCBI didapati mempunyai peratus kesamaan antara 41% hingga 71%. Kedua-dua pohon MP dan Bayesian yang dijana menunjukkan varians antigen-i cn56 and cn57 terkelompok bersama dalam satu kumpulan manakala varians antigen-i yang lain terbahagi kepada dua kumpulan berasingan dan pengkelompokan ini disokong oleh kehadiran asid amino yang terpulihara dalam kumpulan masing-masing. Kajian lanjutan boleh dilakukan untuk mengenal pasti varians antigen-i yang sesuai sebagai calon serodiagnosis dan juga dapat memberi perlindungan silang terhadap pelbagai pencilan C. irritans di serata dunia.
ABSTRACT
Metabolic footprinting involves the determination of metabolites excreted or secreted by the cells.
This study aimed to identify the differential extracellular metabolites in colorectal cancer (CRC)
cells for the determination of molecular changes that occur as CRC progresses. CRC cells at
different stages ie; SW 1116 (stage A), HT 29 and SW 480 (stage B), HCT 15 and DLD-1 (stage
C), and HCT 116 (stage D) were grown in culture. The media in which the cells were grown are
subjected to metabolomics profiling using Liquid Chromatography Mass SpectrometryQuadrupole Time of Flight (LC/MS Q-TOF). Statistical and metabolic pathway analysis was
performed using Metaboanalyst software and identification of metabolites was determined by the
METLIN database. A total of 27 differential extracellular metabolites were identified in CRC cells
of different stages compared to stage A cells. Data from the Partial least squares-discriminant
analysis (PLS-DA) score plot shows a clear separation between CRC cells of different stages with
a few overlaps between stage B and C. Further analysis using variable importance in projection
(VIP) revealed 14 differential extracellular metabolites that were most significant in differentiating
CRC cells of the advanced stages from stage A which are 5-hydroxy-L-tryptophan,
indoleacetaldehyde, 4,5-dimethylthiazole, 8-oxodiacetoxyscirpenol, bisnorbiotin, 5-amino-6-
(5'phosphoribosylamino) uracil, glyceryl 5-hydroxydecanoate, sphinganine, 8,8-diethoxy-2,6-
dimethyl-2-octanol, l-cystine, thiamine acetic acid, phytosphingosine, PE
(20:4(5Z,8Z,11Z,14Z)/22:6(4Z,7Z,10Z,13Z,16Z,19Z)), N-(2R-hydroxypentacosano-yl)-2Samino-1,3S,4R-octadecanetriol. The different expressions of metabolites may indicate altered
metabolic pathways in the more advanced CRC cells compared to stage A. This study highlights
the importance of conducting both metabolomics profiling of extracellular and intracellular to
generate a more complete understanding on the molecular changes that occur as CRC progresses