Fine Robert L, Mao Yuehua, Garcia-Carracedo Dario, Su Gloria H, Qiu Wanglong, Hochfeld Uri, Nichols Gwen, Li Yong-Liang, Dinnen Richard D, Raffo Anthony, Brandt-Rauf Paul W
Experimental Therapeutics Program, Division of Medical Oncology, The Pancreas Center at Columbia, Herbert Irving Comprehensive Cancer Center, NYPH-Columbia University Medical Center, New York, NY 10032, USA.
Department Pathology and Otolaryngology, Herbert Irving Comprehensive Cancer Center, NYPH-Columbia University Medical Center, New York, NY 10032, USA.
Biomedicines. 2023 Jan 18;11(2):258. doi: 10.3390/biomedicines11020258.
Any gene therapy for cancer will be predicated upon its selectivity against cancer cells and non-toxicity to normal cells. Therefore, safeguards are needed to prevent its activation in normal cells. We designed a minimal p14 promoter with upstream Ap1 and E2F enhancer elements and a downstream MDR1 inhibitory element, TATA box, and a transcription initiation site (hereafter p14min). The modified p14min promoter was linked to bicistronic and truncated () genes, which led to synergistic apoptosis via the intrinsic and extrinsic pathways of apoptosis when expressed. The promoter was designed to be preferentially activated by mutant Ras and completely inhibited by wild-type p53 so that only cells with both mutant Ras and mutant p53 would activate the construct. In comparison to most p53 gene therapies, this construct has selective advantages: (1) p53-based gene therapies with a constitutive CMV promoter cannot differentiate between normal cells and cancer cells, and can be toxic to normal cells; (2) our construct does not induce p21 in contrast to other p53-based gene therapies, which can induce cell cycle arrest leading to increased chemotherapy resistance; (3) the modified construct (p14min-p14-tBID) demonstrates bidirectional control of its promoter, which is completely repressed by wild-type p53 and activated only in cells with both and mutations; and (4) a novel combination of genes (p14 and tBID) can synergistically induce potent intrinsic and extrinsic apoptosis in cancer cells.
任何癌症基因治疗都将基于其对癌细胞的选择性和对正常细胞的无毒性。因此，需要采取措施防止其在正常细胞中被激活。我们设计了一个最小化的p14启动子，其上游带有Ap1和E2F增强子元件，下游带有MDR1抑制元件、TATA盒和转录起始位点（以下简称p14min）。修饰后的p14min启动子与双顺反子和截短的（）基因相连，当表达时，通过凋亡的内在和外在途径导致协同凋亡。该启动子被设计为优先被突变型Ras激活，并被野生型p53完全抑制，因此只有同时具有突变型Ras和突变型p53的细胞才能激活该构建体。与大多数p53基因治疗相比，该构建体具有选择性优势：（1）具有组成型CMV启动子的基于p53的基因治疗无法区分正常细胞和癌细胞，可能对正常细胞有毒性；（2）与其他基于p53的基因治疗不同，我们的构建体不会诱导p21，其他基于p53的基因治疗可诱导细胞周期停滞，导致化疗耐药性增加；（3）修饰后的构建体（p14min-p14-tBID）显示其启动子具有双向控制，被野生型p53完全抑制，仅在同时具有和突变的细胞中被激活；（4）一种新的基因组合（p14和tBID）可协同诱导癌细胞中强大的内在和外在凋亡。
