Small Activating RNA Restores the Activity of the Tumor Suppressor HIC-1 on Breast Cancer

Abstract

HIC-1 is a gene that is hypermethylated in cancer, and commonly downregulated in human breast cancer. However, the precise mechanisms and molecular pathways regulated by HIC-1 remain unclear. We assessed HIC-1 expression on a tissue microarray containing 80 cases of breast cancer. We also analyzed its biological function by restoring HIC-1 expression using 5-aza-2′ deoxycytidine (5-CdR) and small-activating RNAs for the reversal of HIC-1 tumor suppressive effects on MCF-7 and MDA-MB-231 cell lines. An Agilent Q44h global expressing microarray was probed after restoring the expression of HIC-1. Data demonstrated that HIC-1 expression was reduced significantly in breast cancer tissues. HIC-1 immunohistochemistry resulted in mean staining scores in cancer tissue and normal ductal epithelia of 3.54 and 8.2, respectively (p<0.01). 5-CdR partially reversed HIC-1 expression, and modulated cell growth and apoptosis. dsHIC1-2998, an saRNA, showed activating efficacy in breast cancer cells. A group of differentially expressed genes were characterized by cDNA microarray. Upon saRNA treatment, genes upregulated included those involved in immune activation, cell cycle interference, the induction of apoptosis, anti-metastasis, and cell differentiation. Downregulated genes included oncogenes and those that play roles in cell invasion, cell growth, and cell division. Our findings may provide valuable resources not only for gene functional studies, but also for potential clinical applications to develop novel drug targets.

Cross-Database Analysis Reveals Sensitive Biomarkers for Combined Therapy for ERBB2+ Gastric Cancer

“…ERBB2 is located in chromosome 17q21.2, where some common oncogenes or tumor suppressor genes, such as TOP2A, TAU, p53, and HIC-1 are located ( Zhang and Yu, 2011 ). Our previous studies confirmed that re-activation of tumor suppressor HIC-1 by small-activating RNAs inhibits cell division, growth and invasion ( Zhao et al, 2014 , 2015 ). Retinoic acid receptor alpha (RARA) is another gene located on chromosome 17q21.2.…”

Reactivation of HIC-1 gene by saRNA inhibits clonogenicity and invasiveness in breast cancer cells

“…dsHIC1-2998 was further confirmed as effective saRNA for gastric cancer and breast cancer cells. The saRNA-HIC-1 effectively activated the HIC-1 gene with evident suppression of cell growth and induction of apoptosis in breast cancer ( 14 ). In the current study, further evidence has been obtained, confirming that saRNA-HIC-1 effectively inhibits clonogenicity in both MCF-7 and MDA-MB-231 cells.…”

“…The dsRNA targeting the region (2998 bp) above from the transcription start site of human HIC-1 was designed based on the rational design rules described ( 9 , 15 ) and our previous reports ( 4 , 14 ). The sequences of saRNA-HIC-1 (dsHIC-1-2998) used in this experiment were as follows: Sense, 5′-CGGUUUCCMGGAGAAGUUATT-3′ and antisense, 5′-UAACUUCUCCAGGAAACCGTT-3′.…”

“…In addition, Ren et al ( 13 ) induced NKX3-1 in prostate tumor cells by saRNA. More recently, our research group successfully reactivated the HIC-1 tumor suppressor in gastric cancer and in breast cancer ( 4 , 14 ). Our previous studies disclosed that dsHIC1-2998, an saRNA, effectively activated HIC-1 with evident suppression of cell growth and induction of apoptosis in breast cancer.…”

miR‑28‑5p inhibits the migration of breast�cancer by regulating WSB2

“…The McF-7 cells were transfected as described above. At 24 h post-transfection, RNA was extracted using TRIzol (15596-018; Thermo Fisher Scientific, Inc.), purified using an RNeasy mini kit (74106; Qiagen GmbH), amplified and labeled using the low input quick amp labeling kit (5190-2305; Agilent Technologies, Inc.); each slide was then hybridized, scanned; and data were extracted, and normalized as previously described (12,17). Two samples were used for gene chip assay.…”