1. Author: Cheng-Chi Wang, Chi-Huey Wong
Glycan microarray of Globo H and related structures for quantitative analysis of breast cancer
Author: Cheng-Chi Wang, Chi-Huey Wong
Presenter: Bernard Shen

2. Introduction
Breast cancer ranks as one of the leading cancer type in the world.
Development of a rapid and reliable method will help decrease the mortality rate in woman
Scientists seek molecular targets of cancer cells that are absent from normal cells

3. Globo H
A hexasaccharide and a member of cancer-associated carbohydrate antigens
Globo H expressed on the cancer cell surface, as a glycolipid and possibly as a glycoprotein.
Globo H is overexpressed on a variety of epithelial cell tumors such as lung and breast cancers, with the used of anti- Globo H monoclonal antibodies MBr1 or VK-9.

4. Question need to further investigate associated with Globo H?
(i) Are Globo H and Gb5 differentially expressed in disease stages?
(ii) Can the glycan array be used for the quantitative and high-sensitivity detection of anti-Globo H antibody present in the serum as an indication of cancer?
(iii) Can the array be used to measure the activity of fucosyltransferase in breast cancer cells at different stages, to screen inhibitors of the enzyme and to monitor the immune response to the Globo H-based vaccine?

5. Binding of monoclonal antibodies to Globo H and its analogues

6. Binding curves for Globo H printed at different concentrations

7. Glycan Microarray of Globo H
Good minic of cell surface expressing multiple glcans
very small amount of material is required
more appropriate and more sensitive system than the traditional solution- phase ELISA analysis

9. IgG ratios of Globo H analogs to Gb5 from breast cancer patients
GH/Gb5
Bb4/Gb5
Bb3/Gb5
Bb2/Gb5
Healthy
Cancer
Mean
26.92
58.31
11.91
17.84
15.22
22.54
78.02
120.8 SD
18.49
31.14
20.54
19.60
23.12
23.22
63.63
92.26 P
P < ***
(ns)
(ns)
0.0063**
IgM ratios of Globo H analogs to Gb5 from breast cancer patients
IgM ratio, %
GH/Gb5
Bb4/Gb5
Bb3/Gb5
Bb2/Gb5
Healthy
Cancer
Mean
27.82
53.98
15.73
22.74
15.36
40.51
16.19
30.36 SD
23.42
35.41
21.60
23.98
23.30
59.76
18.83
35.44 P
P < ***
0.1259*
0.0043**
0.0105*

10. ELISA (Enzyme-linked immunosorbent assay)
used mainly in immunology to detect the presence of an antibody in a sample
useful tool for determining serum antibody concentrations

11. The comparison of glycan micorarray and ELISA
The antibody levels were detectable up to 1:1,920 dilution method in Glycan microarray
1:240 dilution in ELISA
working concentration of Globo H in array is 4 orders of magnitude lower than ELISA

12. The comparison of sensitivity of glycan microarray and ELISA
Dilution
Increase fold of signal
Glycan microarray
ELISA 30
374.7 ± 87.83
4.01 ± 1.58
120
188.4 ± 78.93
1.92 ± 0.75
240
102.2 ± 44.21
1.08 ± 0.48
480
44.86 ± 17.05
0.20 ± 0.10
960
12.13 ± 4.08
0.30 ± 0.14
1,920
3.203 ± 1.048 ND

13. Conclusion
Quantitative analysis of the breast cancer- associated carbohydrate Globo H with minimizing the amount of serum and carbohydrate
Significant difference in anti-Globo H levels between normal and patient plasma
Demonstrate the superiority of our glycan microarray over conventional ELISA
Offer new way to analysis of fucosyltransferase activity

14. Improvement and further direction
The number of mice (4 in the experiment ) that use to gather data for the comparison of glycan microarray and ELISA should be larger