الفهرس 
Breast CancerOnly 14 pages are availabe for public view
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Abstract
This study was done at Medical Biochemistry Department, Oncology Diagnostic Unit, Faculty of Medicine, Ain Sham University during the period from 2010 - 2012.
In the present study, we tried to validate the results obtained from the previous microarray data on breast cancer Hana et al. (2009). It showed that Grb7 overexpression has been of considerable interest in tumorigenesis. While, it also highlighted some genes to be related to breast cancer for the first time. Among these was the gene called TTYH1 which was found to be significantly underexpressed in Breast cancer. Also, we studied the relation between their abnormal protein expression and the initiation or development of breast cancer.
In the past several years, a new technology, called microarray, has attracted great interests among biologists. This is because traditional methods generally work on a gene in one experimental basis, which means that the throughput is very limited. This technology promises to monitor the whole genome on a single chip so that the researchers can have a better picture of the interactions among thousands of genes simultaneously. They are therefore useful when one wants to survey a large number of genes quickly or when the sample to be studied is small.
This study was conducted on 30 female patients with breast cancer. The studied individuals were classified into two main groups:
• Group A: malignant breast lesions mostly invasive ductal carcinomas of stages II and III.
• Group B: normal breast tissues (taken from the same breast away from the malignant mass by 5 cm) and served as a control group.
All patients were females. The age of patients in the malignant group ranged between 34 to 78 years old. In the malignant group, the postmenopausal patients (21) were more than the pre-menopausal patients (9).
All patients in our study were subjected to complete detailed history taking, general and local examination, routine laboratory investigations, radio diagnostic investigations as mammography, and all patients were subjected to surgery for excision of the tumor mass. Tumor samples were sent for pathological staging and grading according to (TNM) classification, and detection of estrogen, progesterone and HER-2/Neu receptors expression in the malignant samples.
RNA extraction of all samples was done for qualitative RT -PCR for Grb 7, TTYH1 genes and GAPDH to serve as a house keeping gene.
The obtained results revealed the following:
In group A: (malignant)
• Grb 7 was positive in 73% of malignant patients (22/30). This was validating the microarray study done by Hana et al. (2009). GAPDH was positive in all patients.
• Estrogen receptors were positive in 47% of patients (14/30), progesterone receptors were positive in 23% of patients (7/30) and HER-2/Neu were positive in 30% of patients (9/30).
• As regards the relation between Grb 7 expression and the different risk factors of breast cancer, there was no significant relation with menopausal status, breast feeding status , use of oral contraceptive pills and the presence of positive family history of first degree relatives (P>0.05).
• As regards the relation between Grb 7 expression and the different clinicopathological parameters of breast cancer, there was no significant difference between Grb7 expression and age of patients, size of the malignant tumor and its histological type in the breast cancer group (p>0.05).On the other hand, there was a high significant difference between Grb7 expression and the presence of lymph node metastasis, stage and histological grade of the malignant tumors (P= 0.009, 0.018 and 0.035 respectively).
• As regards the relation between Grb7 expression and the hormonal receptor state of breast cancer, a significant inverse relation was found between expression of Grb7 and both estrogen and progesterone receptors (P= 0.007and P= 0.034 respectively).
• As regards the relation between Grb7 expression and HER-2/Neu, no significant difference was found (P=0.207).
• As regards the relation between expression of Grb7 and the molecular subsets in breast cancer group, there was a significant relation (P= 0.029), especially with HER-2/Neu positive group.
• Qualitative RT-PCR for tissue Grb7 showed 73% sensitivity, 57% specificity, 63% PPV, 68% NPV and 65% accuracy.
In group B: (healthy tissues)
Grb7 was positive in 43% of patients (13/30) and GAPDH was positive in all patients.
In both groups (A& B):
• There was a highly significant difference between the studied groups as regards Grb7 expression (P= 0.018). This validates the study which reported overexpression of Grb7 gene in breast cancer (Hana et al., 2009).
• As regards the Tweety gene, it wasn’t expressed in either the malignant or the normal control samples. We used a liver tissue as a positive control for Tweety to ensure the accuracy of our work. This may point to the conclusion that the microarray analysis done by Hana et al.(2009) was not accurate for some genes e.g. Tweety.
• The current Tweety results failed to validate the results obtained by Hana et al. (2009) newly developed software.