Department of Pediatric Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Surgery. 2011 Mar;149(3):425-32. doi: 10.1016/j.surg.2010.08.011. Epub 2010 Oct 29.
The overall survival for neuroblastoma remains dismal, in part due to the emergence of resistance to chemotherapeutic drugs. We have demonstrated that gastrin-releasing peptide (GRP), a gut peptide secreted by neuroblastoma, acts as an autocrine growth factor. We hypothesized that knockdown of GRP will induce apoptosis in neuroblastoma cells and potentiate the cytotoxic effects of chemotherapeutic agents.
The human neuroblastoma cell lines (JF, SK-N-SH) were transfected with small interfering (si) RNA targeted at GRP. Apoptosis was assessed by DNA fragmentation assay. Immunoblotting was used to confirm molecular markers of apoptosis, and flow cytometry was performed to determine cell cycle arrest after GRP knockdown.
siGRP resulted in an increase in apoptosis in the absence of chemotherapeutic interventions. A combination of GRP silencing and chemotherapeutic drugs resulted in enhanced apoptosis when compared to either of the treatments alone. GRP silencing led to increased expression of proapoptotic proteins, p53 and p21.
Silencing of GRP induces apoptosis in neuroblastoma cells; it acts synergistically with chemotherapeutic effects of etoposide and vincristine. GRP knockdown-mediated apoptosis appears to be associated with upregulation of p53 in neuroblastoma cells. Targeting GRP may be postulated as a potential novel agent for combinational treatment to treat aggressive neuroblastomas.
神经母细胞瘤的总体存活率仍然很差，部分原因是对化疗药物产生耐药性。我们已经证明，胃泌素释放肽（GRP）是一种由神经母细胞瘤分泌的肠道肽，作为一种自分泌生长因子。我们假设，下调 GRP 将诱导神经母细胞瘤细胞凋亡，并增强化疗药物的细胞毒性作用。
用人神经母细胞瘤细胞系（JF、SK-N-SH）转染靶向 GRP 的小干扰（si）RNA。通过 DNA 片段化测定评估细胞凋亡。免疫印迹用于确认细胞凋亡的分子标志物，流式细胞术用于确定 GRP 敲低后细胞周期停滞。
在没有化疗干预的情况下，siGRP 导致凋亡增加。与单独使用任何一种治疗方法相比，GRP 沉默和化疗药物的联合使用导致凋亡增强。GRP 沉默导致促凋亡蛋白 p53 和 p21 的表达增加。
沉默 GRP 可诱导神经母细胞瘤细胞凋亡；它与依托泊苷和长春新碱的化疗效果协同作用。GRP 敲低介导的凋亡似乎与神经母细胞瘤细胞中 p53 的上调有关。靶向 GRP 可能被推测为联合治疗治疗侵袭性神经母细胞瘤的一种新的潜在药物。
