Inhibitor of apoptosis protein­like protein­2: A novel growth accelerator for breast cancer cells.

ABSTRACT

Although the inhibitor of apoptosis protein­like protein­2 (ILP­2) has been shown as a serological biomarker for breast cancer, its effect on breast cancer cell growth remains elusive. The present study aimed to determine the role of ILP­2 in breast cancer cell growth. We used immunohistochemistry to analyze ILP­2 expression in 59 tissue paraffin­embedded blocks, which included 35 breast cancer tissues and 24 galactophore hyperplasia tissues. Western blot analysis was used to detect protein expression levels of ILP­2 in breast cancer cell lines such as HCC­1937, MX­1 and MCF­7 as well as breast gland cell line MCF 10A. ILP­2 was silenced by siRNA in HCC­1937, MX­1 and MCF­7 cell lines. MTT assays, scratch assays and AO­EB double staining analysis were conducted to evidence the role of ILP­2 on breast cancer cell growth. Results from this study showed increased ILP­2 expression in breast cancer tissues and breast cancer cell lines such as HCC­1937, MX­1 and MCF­7. Cell viability or rate of cell migration of HCC­1937, MX­1 and MCF­7 cell lines was significantly inhibited when ILP­2 was knocked down by siRNA. The apoptosis rate of HCC­1937, MX­1 and MCF­7 cell lines was increased when compared with that of the control group. Thus, ILP­2 plays an active role in the growth of breast cancer cells.