published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

published_or_final_version / Pathology / Master / Master of Medical Sciences

No description available.

No description available.

No description available.

No description available.

No description available.

Acute lymphoblastic leukaemia is the most common childhood cancer with cure rates of approximately 80%. This success can be attributed to the introduction of risk stratification for patients and employment of intensified treatment regimes for patients with high risk disease. However, the identification of prognostically important leukaemia subtypes, unfortunately, is an labour-intensive process. In addition, despite the success in treating childhood ALL, specific subgroups of patients nevertheless still have poor survival rates. This is particularly true for leukaemias characterised by chromosomal translocations involving the MLL oncogene on chromosome 11q23. By using a novel bioinformatics approach, GeneRave, a set of 12 classifier genes (PTPRK, FOS, ENG, Lgal-S1, TCFL5, LRMP, CTGF, IGJ, MX1, PENK, CD3D and HBG1) was selected from a publicly available U95 Affymetrix microarray dataset. Real time PCR carried out on a blinded cohort of 58 primary ALL samples yielded an accuracy of 86%. The absence of PENK gene expression in the majority of ALL samples tested appears to have decreased the overall accuracy. Nevertheless, the results indicate that this method of classification can be easily and quickly performed and therefore may be useful as an adjunct to routinely used methodology in the diagnostic classification of childhood ALL. Parellal screening of a 34,000 chemical small molecules library identified 30 ???hits??? that exhibited specificity toward leukaemia, and many of which shared structural similarity. The cytotoxic effect of these compounds was further investigated in a panel of 19 cell lines that included 3 MLL-translocated (MV411, THP-1 and PER-485), 7 non-MLL-translocated leukaemias (REH, Jurkat, K562, HL60, Hal-01, UOB-B, NB4), 2 immortalized normal blood cell lines, 4 non-leukaemic tumour cell lines (Calu6, MCF7, BE(2)-C, and HeLa) and 3 normal cell lines (HSF, MCF10a and MRC5). In particular, two compounds were identified, SM6 and SM7, that were highly effective at killing MLL-translocated cell lines in the low micromolar range while having little or no effect on the other cell lines. Treatment of PER-485 cells with SM6 and SM7 showed mark down-regulation of the MLL chimaeric fusion protein together with its down-stream targets. One other more broadly acting anti-leukaemia compounds were also identified.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Also available online.