Abstract

Objective: The aim of the present study was to build protein profiles of untreated breast cancer patients of invasive ductal carcinoma grade II at tissue level in Pakistani population and to compare 2-D profiles of breast tumor tissues with matched normal tissues in order to evaluate for variations of proteins among them.

Materials & Methods: Breast tissue profiles were made after polytron tissue lysis and rehydrated proteins were further characterized by using two-dimensional gel electrophoresis. On the basis of isoelectric point (pI) and molecular weight, proteins were identified by online tool named Siena 2-D database and their identification was further confirmed by using MALDI-TOF.

Results: Among identified spots, 10 proteins were found to be differentially expressed i.e.; COX5A, THIO, TCTP, HPT, SODC, PPIA, calreticulin (CRT), HBB, albumin and serotransferrin. For further investigation, CRT was selected. The level of CRT in tumors was found to be significantly higher than in normal group (p < 0.05). The increased expression of CRT level in tumor was statistically significant (p = 0.010) at a 95% confidence level (p <0.05) as analyzed by Mann-Whitney. CRT was found distinctly expressed in high amount in tumor tissue as compared to their matched normal tissues.

Conclusion: It has been concluded that CRT expression could discriminate between normal tissue and tumor tissue so it might serve as a possible candidate for future studies in cancer diagnostic markers.

Keywords: Breast cancer, two-dimensional gel electrophoresis, MALDI, serum albumin, tumor, biomarkers.

Graphical Abstract