Title page for etd-0705116-215810


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URN etd-0705116-215810
Author Shiou-Rong Wu
Author's Email Address No Public.
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Department Biological Sciences
Year 2015
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title The Role of NDC80 in Colon Cancer Progression, Altered Genomic Instability and Its Therapeutic Potential
Date of Defense 2016-07-14
Page Count 75
Keyword
  • Aneuploidy
  • chromosomal instability
  • RAPD-PCR
  • NDC80
  • colorectal cancer
  • Abstract Aneuploidy and chromosomal instability (CIN) are common abnormalities in human cancer. Alterations of the mitotic spindle checkpoint are likely to contribute to these phenotypes. To elucidate the correlation between chromosomal instability and colorectal cancer might serve as diagnostic or prognostic markers and form the basis for novel therapeutic strategies. In this study, we used aninfromatics-base analysis to figure out 58 chromosome segregation genes in CRC. Three of 58 chromosome segregation genes, NDC80, Nuf2 and SPC25 belong to the NDC80 complex, which complex play a critical role in chromosome segregation. In order to understand the NDC80 expression in colon cancer tissue, we performed the immunohistochemistry stain for NDC80 protein using the colorectal cancer tissue section. 90 out of 141 CRCs had high NDC80 expression, however NDC80 expression was not detectable in adjacent normal part. To elucidate the significance of NDC80 in the tumor progression of CRC, we correlated theNDC80 protein expression with the major clinicopathological features. Histopathologically, NDC80 high-expression closely correlated with high-pathological T-staging (T2~T3, p=0.002), and high-stage tumors (stages II, III, p<0.001). CRCs with NDC80 high-expression had lower 12-year survival than those without the high-expression in stage II and III CRC patients. To further elucidate the role of NDC80 and genomic instability in colon cancer cells, we used RAPD-PCR assay to investigate the correlation of NDC80 expression level and genomic instability in DLD-1 (diploidy/CIN -) and HT-29 (aneuploidy/ CIN+) colon cancer cells. Therewere higher genetic alterations inHT-29 cell by compared with the reference ARPE19 cell. Furthermore, usingthe DNA samples extracted from FFPE CRC tissue sections, there were differential genetic alterationpatern between the high-NDC80 expression and low-NDC80 expression.These results indicated the NDC80 expression level should be correlated to the genetic alteration. To investigate the role of NDC80 in colon cancer cell growth, NDC80 protein expression was knockdown in CRC cells. The cancer cell growth rates were decreased 50% in HT-29 cells but 70% in DLD-1 cells using the celltitler assay and clonogenic assay. Morphological examination in cell nucleus revealed that transfection with the NDC80 RNAi oligo lead to multi-nucleated cells, almost 5 folds rise in HT-29cell but 13 folds rise in DLD-1 cell. Using the Image flow-cytometry assay, Down-regulation of NDC80 increased the sub-G1 phase in both colon cancer cells and increased the G2/M phase in HT-29 cells. Moreover, we followed up some chromosome segregation related genes which also contributed to the chromo-somal instability (CIN), we could find the cyclin B1 protein was downregulation, sepa-rase and securin were up regulation in HT-29 cells but not in DLD-1 cell. These results indicate knockdown NDC80 gene expression in colon cancer cell may disrupt the ex-pression of chromosome segregation related genes and increase genomic instability than lead to cancer cell death.
    Advisory Committee
  • Chun-lin Chen - chair
  • Chung-Man Leung - co-chair
  • Ming-Hong Tai - advisor
  • Hung-Wei Pan - advisor
  • Files
  • etd-0705116-215810.pdf
  • Indicate in-campus at 5 year and off-campus access at 5 year.
    Date of Submission 2016-08-15

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