CRISPR-Cas13a Targeting the Enhancer RNA-SMAD7e Inhibits Bladder Cancer Development Both in vitro and in vivo

Abstract

Enhancers are cis-acting elements that can promote the expression of target genes and respond to estrogen to induce the transcription of eRNAs, which are closely associated with cancer development. Further study on eRNAs may lead to a better understanding of the significance of transcriptional regulation and the progression of malignant tumors. SMAD7 enhancer RNA (SMAD7e) is an estrogen-responsive eRNA. However, the relationship between SMAD7e and bladder cancer remains unclear. SMAD7e was significantly upregulated in bladder cancer tissues and estrogen-stimulated cells. Knockdown of SMAD7e by CRISPR-Cas13a suppressed cell proliferation and migration, and induced cell apoptosis and inhibited cell invasion. Estrogen caused overexpression of SMAD7e and played a facilitating role in bladder cancer cells. Furthermore, knockdown of SMAD7e by CRISPR-Cas13a prevented the cancer-promoting effects of estrogen on bladder cancer both in vitro and in vivo . The present study suggested the crucial role of SMAD7e in bladder cancer. Estrogen might promote the development of bladder cancer by inducing SMAD7e production. These findings may provide a potential target for CRISPR-mediated gene therapy for bladder cancer in the future.

SPRY4-AS1, A Novel Enhancer RNA, Is a Potential Novel Prognostic Biomarker and Therapeutic Target for Hepatocellular Carcinoma

“…For instance, FOXP4-AS1, a prognosis-related eRNA, was reported to be lowly expressed in ovarian cancer specimens and predicted a shorter 5-year overall survival of ovarian cancer patients ( 29 ). The eRNA SMAD7e was found to promote the proliferation and metastasis of bladder cancer ( 30 ). Located in the tissue-specific enhancer of a tumor suppressor gene EMX2, eRNA EMX2OS was lowly expressed in kidney renal clear cell carcinoma specimens and associated with poor prognosis of tumor patients ( 31 ).…”

Current Advances on the Important Roles of Enhancer RNAs in Molecular Pathways of Cancer

“…CRISPR-Cas13a is also an appropriate method for the targeted knockdown of eRNAs. Che et al used CRISPR-Cas13a targeting SMAD7e to measure the effect of SMAD7e knockdown on biological behaviors of bladder cancer cells [ 51 ]. Ding et al cultured and transfected bladder cells with specific CRISPR-Cas13a vectors and siRNA to investigate the influence of P2RY2e down-regulation on bladder cancer cells.…”

“…SMAD7e production is induced by estrogen, and its over-expression appears to promote the development of bladder cancer. SMAD7e knockdown led to cell apoptosis, and the suppression of cell proliferation, migration, and invasion, as well as an attenuation of the carcinogenic effect of estrogen in bladder cancer cells [ 51 ].…”

RNA-based gene targeting therapies for human papillomavirus driven cancers

“…Although initially approved to treat HNCs, Gendicine has been used to treat various other cancer types, including CC patients in combination with radiotherapy Though idea of knocking down mRNAs via siRNA was discussed earlier, the CRISPR-Cas13a system posseses a similar ability. This system has been tested in various cancers models, including pancreatic cancer to inhibit mutant KRAS mRNA expression, as well as inhibiting SMAD7 eRNA (mRNA enhanced by oestrogen) [48,49]. In both cases cellular apoptosis occurred and significant tumour shrinkage was observed.…”