Abstract

Breast cancer is one of the most common cancers in women, and rated the second most common cancer and a significant cause of death in females in the Sudan. This study aims to identify tumor protein that elicits humoral immune responses in breast cancer patient in comparison to tissues from healthy individuals as well as from normal tissues of the cancer patient. Serum samples and breast cancer tissue specimens were collected from breast cancer patients (n = 9) and from healthy individuals (n = 5) at Khartoum Teaching Hospital. Breast cancer tissues were homogenized in PBS, centrifuged and the supernatants were lysed in 2X SDS-PAGE sample buffer. The preparation then boiled and the resulting supernatants were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. Total proteins were separated on SDS-PAGE and transferred to the nitrocellulose paper, then analyzed by immunoblotting for total proteins and serum antibodies using serum from patients with breast cancer and from healthy individuals to enhance humoral immune responses. The SDS-PAGE analysis showed an increase in size of protein bands in the normal control tissues than from breast cancer patients. The Western blot analysis of breast cancer tissues with the serum from breast cancer patients specifically detected major bands than in the normal tissues from the healthy tissues of cancer patients or from healthy individuals. Beside the major bands, additional bands have been detected in breast cancer tissues with the serum from breast cancer patients. The reactive auto-antibodies in patient’s tissues bound to the circulating tumor antigen in patient’s serum and immune complexes would result by Western blotting indication of strong immune response to these proteins. The present study demonstrated that there was a clear decline in the expression of some proteins among breast cancer patients which has been confirmed by strong immune reactions in the Western blotting analysis.

Key words: breast cancer , protein expression, SDS-PAGE, Commasie brilliant blue, Western blot.