Biomedical subjects

Jesse Li-Ling

Publications and source records attributed to Jesse Li-Ling.

6 recordsLinked to original sources

PubMed2005

STK15 gene overexpression, centrosomal amplification, and chromosomal instability in the absence of STK15 mutations in laryngeal carcinoma.

Centrosomes regulate cell division by forming bipolar mitotic spindles and, thus, play an essential role in the maintenance of chromosomal stability. Centrosomal amplification has been found commonly among tumor cells. Previous studies have suggested that a STK15 (serine/threonine kinase 15) gene can induce centrosomal amplification, chromosomal instability, and cell transformation. To investigate the role of STK15 gene abnormalities in the occurrence of centrosomal amplification and chromosomal instability, a combinatory approach has been taken to investigate the expression level and point mutations of the STK15 and centrosomal/chromosomal aberrations among 72 cases of laryngeal squamous cell carcinoma and a representative Hep-2 cell line. Although no mutation was detected within its exons 6 or 7, overexpression of STK15 has been found in 47 cases (65 percent) as well as in the Hep-2 cell line; for the latter apparent centrosomal amplification also has been noted, with the number of centrosomes within a single cell varying between 1 and 7 and the proportion of cells with amplified centrosomes reaching 11 approximately 23 percent. Karyotype analysis of Hep-2 cell line has suggested common occurrence of chromosomal aberrations, with the number of chromosomes ranging between 43 and 84, modal number between 69 and 74, and structural aberrations, represented by 13 marker chromosomes, including translocations, deletions, and isochromosomes found in various subclones. Our results suggest that in Hep-2 cell line overexpression of STK15 gene may cause centrosomal amplification thereby result in chromosomal instability through abnormal mitosis. Detection of STK15 overexpression in laryngeal carcinoma has led us to propose that the above may be one of the mechanisms underlying laryngeal carcinogenesis.

Aurora Kinase A↗

PubMed2004

HMMGEP: clustering gene expression data using hidden Markov models.

SUMMARY: The package HMMGEP performs cluster analysis on gene expression data using hidden Markov models. AVAILABILITY: HMMGEP, including the source code, documentation and sample data files, is available at http://www.bioinfo.tsinghua.edu.cn:8080/~rich/hmmgep_download/index.html.

Algorithms↗

PubMed2003

Comparative analysis of amino acid usage and protein length distribution between alternatively and non-alternatively spliced genes across six eukaryotic genomes.

Alternative splicing has been discovered in nearly all metazoan organisms as a mechanism to increase the diversity of gene products. However, the origin and evolution of alternatively spliced genes are still poorly understood. To understand the mechanisms for the evolution of alternatively spliced genes, it may be important to study the differences between alternatively and non-alternatively spliced genes. The aim of this research was to compare amino acid usage and protein length distribution between alternatively and non-alternatively spliced genes across six nearly complete eukaryotic genomes, including those of human (Homo sapiens), mouse (Mus musculus), rat (Rattus norvegicus), fruit fly (Drosophila melanogaster), Caenorhabditis elegans, and bovine (Bos taurus). Our results have suggested the following: (1) across the six species, alternatively and non-alternatively spliced genes have very similar tendency for amino acids usage for not only the overall scale but also those highly expressed genes, with all of the highly expressed genes having preferred amino acids including A, E, G, K, L, P, S, V, R, T, and D. (2) For not only the overall genes but also those highly expressed ones, the average length of the protein products of alternatively spliced genes is significantly greater than that of non-alternatively spliced ones. In contrast, distributions of protein lengths for the two groups of genes are very similar among all six species. Based on these results, we propose that alternatively spliced genes may have originated from non-alternatively spliced ones through events such as DNA mutations or gene fusion.

Alternative Splicing↗

PubMed2003

Mining gene expression data using a novel approach based on hidden Markov models.

In this work we have developed a new framework for microarray gene expression data analysis. This framework is based on hidden Markov models. We have benchmarked the performance of this probability model-based clustering algorithm on several gene expression datasets for which external evaluation criteria were available. The results showed that this approach could produce clusters of quality comparable to two prevalent clustering algorithms, but with the major advantage of determining the number of clusters. We have also applied this algorithm to analyze published data of yeast cell cycle gene expression and found it able to successfully dig out biologically meaningful gene groups. In addition, this algorithm can also find correlation between different functional groups and distinguish between function genes and regulation genes, which is helpful to construct a network describing particular biological associations. Currently, this method is limited to time series data. Supplementary materials are available at http://www.bioinfo.tsinghua.edu.cn/~rich/hmmgep_supp/.

Algorithms↗

PubMed2003

The Jing-Mai connections of the heart.

BACKGROUND: The Jing-Mai (variously translated as the Channel, Vessel or Meridians), as described by traditional Chinese medicine, probably exists and has represented the connections between various parts of human body during embryonic development. According to the Chinese theories, there are 14 major Jing-Mai within the human body, of which four are directly connected with the Heart. METHODS: The described paths of the four Jing-Mai were compared with features of congenital syndromes involving particular types of congenital heart defects. RESULTS: Specific correlation seem to exist between such four Jing-Mai and known developmental mechanisms underlying various congenital heart defects: the Kidney Jing-Mai-ectomesenchymal tissue migration abnormalities; the Spleen Jing-Mai-situs and looping defects; the Heart Jing-Mai-abnormal cell death; the Small Intestine Jing-Mai (and the Heart Jing-Mai)-extracellular matrix anomalies. CONCLUSIONS: The Chinese theories seem to provide some intriguing insights into the pathogeneses of congenital heart defects. The Jing-Mai seems to distinguish from, but nevertheless have a close relationship with the blood vessels. Utilization of the Jing-Mai will probably enable a better understanding and development of new treatments for cardiovascular diseases.

Heart Defects, Congenital↗

PubMed2003

Human Phenome based on traditional Chinese medicine--a solution to congenital syndromology.

The occurrence of many congenital syndromes has long been an enigma. Clinically, the phenotype of any given genetic defect usually varies to some extent, whilst, pathogenetically, features within each syndrome are probably interconnected, albeit by largely unknown mechanisms. Through its unique theories such as the Jing-Mai (variously translated as the Channels, Vessels or Meridians), Zang-Fu (the Yin and Yang internal organs) and Wu-Xing (translated as the Five-Phase Correspondence or Five-Element theory), traditional Chinese medicine (TCM) seems to have comprehensively summarized the makeup of the human phenotypes. By combining the above TCM theories with modem medical knowledge, the intrinsic mechanisms between various aspects of the phenotypic makeup of the human individual, i.e. the Human Phenome, may be deduced. Analysis of congenital syndromes in light of the Human Phenome seems to suggest that various genetic defects may cause diseases in a similar fashion; i.e. primarily with structural abnormalities distributed along the four Jing-Mai connected with the Kidneys (midline defects) as well as "Marrow" aberrations (anomalies of hematology/immunology, endocrine, central nervous system and the bones). The derived Human Phenome may thereby enable a better understanding of such conditions and provide a model for the study of multigenic traits. On the other hand, blind spots of clinical observation and unknown aspects of human nature, e.g. circuits formed by the JingMai, symmetries of the Jing-Mai and Zang-Fu, and correspondences between body physiques, spiritual factors and the external world may also be deduced. The TCM-based Human Phenome may thereby offer a fresh view for genotype-phenotype correlations, insights into genedevelopment mechanisms, as well as potential directions for the development of new treatments.

Congenital Abnormalities↗