Nonmonotone invasion landscape by noise-aware control of metastasis activator levels

Abstract

A major pharmacological assumption is that lowering disease-promoting protein levels is generally beneficial. For example, inhibiting metastasis activator BACH1 is proposed to decrease cancer metastases. Testing such assumptions requires approaches to measure disease phenotypes while precisely adjusting disease-promoting protein levels. Here we developed a two-step strategy to integrate protein-level tuning, noise-aware synthetic gene circuits into a well-defined human genomic safe harbor locus. Unexpectedly, engineered MDA-MB-231 metastatic human breast cancer cells become more, then less and then more invasive as we tune BACH1 levels up, irrespective of the native BACH1. BACH1 expression shifts in invading cells, and expression of BACH1ʼs transcriptional targets confirm BACH1ʼs nonmonotone phenotypic and regulatory effects. Thus, chemical inhibition of BACH1 could have unwanted effects on invasion. Additionally, BACH1ʼs expression variability aids invasion at high BACH1 expression. Overall, precisely engineered, noise-aware protein-level control is necessary and important to unravel disease effects of genes to improve clinical drug efficacy.

Design and Model-Driven Analysis of Synthetic Circuits with the Staphylococcus aureus Dead-Cas9 (sadCas9) as a Programmable Transcriptional Regulator in Bacteria

“…Together, these data demonstrate that the multiphasic output is reproducible, and its source was different from the previously analyzed NAND gate circuits. A multiphasic output was recently reported in more complex networks containing feedforward loops in mammalian cells . However, the generation of outputs with two rising phases in synthetic type-1 iFFLs in bacteria was still unreported.…”

Adaptive DNA amplification of synthetic gene circuit opens a way to overcome cancer chemoresistance

“…Customized qPCR primers for detecting hTetR, eGFP, PuroR, HygR, and internal reference Vinculin were designed using PrimerBlast (NCBI) and ordered from IDT and then verified for specificity and efficiency using serially diluted positive and negative CHO genomic DNA. qPCR and RT-qPCR were performed as previously described ( 48 ). Briefly, for circuit copy number detection in CHO cells, customized qPCR primers were used with PowerUp™ SYBR™ Green Master Mix (ThermoFisher Scientific, A25741).…”

Transcription factor BACH1 in cancer: roles, mechanisms, and prospects for targeted therapy

“…As mentioned above, BACH1 exerts a significant impact on carcinogenesis, making it possible that a single targeted agent may be effective. However, recent studies indicated that BACH1 nonmonotonically mediates the expression of multiple genes, including RKIP, CXCR4, MMP1 and BACH1 itself, serving alternatively as a transcriptional activator or a transcriptional repressor at different protein levels [ 164 ]. At the same time, some previous studies revealed its cancer-suppressing effect, and BACH1 may negatively affect cancer cell survival by mediating protein homeostasis [ 165 – 167 ].…”

“…The FBXO22-induced downregulation of BACH1 promotes AML progression, which means that BACH1 has a negative effect on tumor growth in this context [ 168 ]. Hence, a simple suppression for BACH1 may have negative effects on tumor metastasis in some cases [ 164 ]. The nonmonotone fitness landscape of BACH1 improves the accuracy and efficiency of targeted drug delivery, thereby increasing clinical benefits, which is an exciting direction worth pursuing in the future.…”