Modulation of drug resistance by artificial transcription factors

Abstract

The efficiency of chemotherapeutic treatments in cancer patients is often impaired by the acquisition of drug resistance. Cancer cells develop drug resistance through dysregulation of one or more genes or cellular pathways. To isolate efficient regulators of drug resistance in tumor cells, we have adopted a genome-wide scanning approach based on the screening of large libraries of artificial transcription factors (ATFs) made of three and six randomly assembled zinc finger domains. Zinc finger libraries were linked to a VP64 activation domain and delivered into a paclitaxelsensitive tumor cell line. Following drug treatment, several ATFs were isolated that promoted drug resistance. One of these ATFs, 3ZF-1-VP, promoted paclitaxel resistance in cell lines having mutated or inactivated p53, such as MDA-MB-435 and Kaposi's sarcoma cell lines. 3ZF-1-VP also induced strong resistance to etoposide, vincristine, and cisplatinum. Linkage of a repression domain to the selected ATF resulted in enhanced sensitivity to multiple drugs, particularly vincristine, cisplatinum, and 5-fluorouracil. Small interfering RNA -mediated inhibition of p53 revealed that 3ZF-1-VP activated both p53-dependent and p53-independent mechanisms to promote survival, whereas other ATF required intact p53. Real-time expression analysis and DNA microarrays showed that several ATFs up-regulated targets of p53, such as the cyclin-dependent kinase inhibitor p21 WAF1/CIP1 , and genes participating in the p14 ARF

ZNF139 promotes tumor metastasis by increasing migration and invasion in human gastric cancer cells

“…Study also confirmed ZNF217 could promote tumor progression by accelerating ovarian cancer cell proliferation and invasion [9]; ZBP-89, a member of the Krüppel family, was related to distant metastasis and prognosis of renal cell carcinoma [10]. There were other studies that confirmed that the artificial transcription factor could be used for the detection of resistance genes and pathways, which might reverse the drug tolerance of tumors [11]. But there had been no report on relationship between ZNF139 and metastasis of gastric cancer cell in migration and invasion ability.…”

Genome-Editing Technologies: Principles and Applications

“…Early work on the use of engineered zinc-finger transcription factors revealed that synthetic transcriptional modulators are effective tools for a broad range of applications, enabling such tasks as inhibiting viral replication (Papworth et al 2003;Reynolds et al 2003;Segal et al 2004;Eberhardy et al 2006), modulating the expression of disease-associated loci (Graslund et al 2005;Wilber et al 2010), inducing angiogenesis for accelerated wound healing (Rebar et al 2002), and genomic screening of cellular targets for cancer progression and drug resistance Blancafort et al 2005Blancafort et al , 2008. Facilitated by many of the insights gained from zinc-finger transcription factor technology, both TALEs and CRISPR-Cas9 have now further expanded the possibilities of engineered transcriptional activators and repressors.…”

Genome Editing: Innovation in Molecular Biology

“…Biomedicine: Nanoparticles mediated drug delivery systems, xenotransplantation, gene therapies, control and prevention of genetic diseases [25].…”