Skripsi

Investigating Levels of KLF4 Expression in Normoxic and Hypoxic CD24 - /CD44 + Breast Cancer Stem Cells

Background: Cancer has become one major health problem worldwide and cause so many death. Cancer can be found in many organ with breast cancer as one of the most commonly found form of cancer. Cancer stem cell is one breakthrough founding that thought to be the cause of cancer progression and invasion. Cancer stem cells suggested to have same pluripotency property as in Embryonic Stem cells. As in Embryonic Stem cells, the maintenance of it’s pluripotency and expression of their pluripotent gene are found in hypoxic condition which is favourable for them. Breast cancer stem cells CD24-/CD44+ are studied to observe their expression of pluripotency gene under hypoxia condition. Such one of the pluripotency gene to be observed is KLF4, which role is as the master regulator of other pluripotent gene in core pluripotency network (NANOG, SOX2, OCT4) Method: Breast cancer stem cells CD44 + /CD24 - exposed to hypoxic condition (1% O 2 , 5% CO ) and then the RNA isolated to be used for KLF4 gene detection using one-step qRT-PCR. Gene expression analysis obtained from Ct calculation from qRT-PCR using Livak Method as attached in appendix 1. Confirmation of product using electrophoresis with Gel dox imaging. Results: KLF4 expression is downregulated in all sample undergo hypoxia condition. Conclusions: In all of the hypoxic breast cancer stem cells samples, the expression is downregulated, while KLF4 supposed to be upregulated. Downergulation of the KLF4 expression indicating the lost of pluripotency property such in differentiated cells.
Keywords: Cancer, Breast cancer stem cell, CD24-/CD44+, hypoxia, pluripotency, KLF4