Co-silencing of Birc5 (survivin) and Hspa5 (Grp78) induces apoptosis in hepatoma cells more efficiently than single gene interference

Abstract

Birc5 (previously known as survivin) is a cancer-specific protein. Due to the upregulation of its expression in various human malignancies and its key role in apoptosis, proliferation and angiogenesis, Birc5 has attracted attention as a target for anticancer therapies. In this study, when Birc5 was silenced in HepG2 cells, 29.7±3.3% cells underwent apoptosis as expected. It was found that the expression levels of glucose-regulated protein 78 (Hspa5, previously known as Grp78) was increased by almost 3-fold in Birc5-silenced HepG2 cells. Hspa5, a master regulator of the anti-apoptotic unfolded protein response signalling network, can also promote tumor proliferation, survival and metastasis. Hence, we hypothesized that the co-silencing of Birc5 and Hspa5 may exert a stronger apoptosis-inducing effect than single gene interference. To verify this, the expression levels of Birc5 and Hspa5 in human hepatocellular carcinoma tissues were determined. Immunohistochemical staining showed that the expression of Birc5 and Hspa5 was elevated in 28 out of 31 samples. Additionally, plasmid-based siRNA against Birc5 and/or Hspa5 were constructed and transfected into the human hepatocellular liver carcinoma cell line, HepG2. Compared with the HepG2 cells, in which Birc5 or Hspa5 were silenced alone, only 44.2±3.4% of the co-silenced cells proliferated, and 40.3±3.7% co-silenced cells underwent apoptosis (p<0.05). Furthermore, tumor formation from inoculated subcutaneous co-silenced cells in nude mice was inhibited significantly. The current study suggests that Birc5 and Hspa5 could be important survival factors for hepatoma carcinoma cells and that the simultaneous knockdown of Birc5 and Hspa5 is more effective in inducing apoptosis in HepG2 cells than the knockdown of Birc5 or Hspa5 alone. The co-silencing of Birc5 and Hspa5 could be warranted for cancer therapy.

Multistep Model of Cervical Cancer: Participation of miRNAs and Coding Genes

“…The mRNAs modulated by miR-218 are baculoviral inhibitor of apoptosis repeat containing 5 (BIRC5), roundabout (ROBO1), connexin 43 (GJA1) and laminin 5 β3 (LAMB3) [ 26 , 61 , 102 ]. BIRC5 is a cancer-specific protein that has been shown to be up-regulated in cervical cancer and participates in apoptosis, proliferation, and angiogenesis [ 118 , 119 ]. ROBO 1 is repressed by epigenetic changes [ 120 ], however, the mRNA has been detected in SiHa cells [ 102 ].…”

Enhanced Inhibition of Bladder Cancer Cell Growth by Simultaneous Knockdown of Antiapoptotic Bcl-xL and Survivin in Combination with Chemotherapy

“…Since the inhibition of a single target might be easily bypassed by cancer cells, e.g., by upregulation of other tumor growth-promoting genes [27,28], a multitarget approach seems to be more promising. As well, in the combination therapy settings where target-specific inhibitors and conventional treatments such as chemotherapy and radiotherapy were applied together, the simultaneous knockdown of carefully selected genes can be superior to single target inhibition.…”

Establishment of a hTfR mAb-functionalized HPPS theranostic nanoplatform

“…HepG2 cells were treated with HPPS-isotype/ siRNA and HPPS-mAb/siRNA for 48 h. Then cells were lyzed using Trizol (Thermo Fisher Scientific, USA) according to manufacturer's recommendation. The achieved mRNA was reverse transcribed to cDNA and amplified as previously reported [25]. Agarose gel electrophoresis was used to detect the PCR reaction product and results were quantified by Image J software.…”