UP-3.003: Antitumor Activity of Conditionally Replicating Adenoviruses Expressing KI67-Specific Short Hairpin RNAs for Bladder Cancer

A method for high-throughput cloning and analysis of short hairpin RNAs (shRNAs) is described. Using this approach, 464 shRNAs against 116 different genes were screened for knockdown efficacy, enabling rapid identification of effective shRNAs against 74 genes. Statistical analysis of the effects of various criteria on the activity of the shRNAs confirmed that some of the rules thought to govern small interfering RNA (siRNA) activity also apply to shRNAs. These include moderate GC content, absence of internal hairpins, and asymmetric thermal stability. However, the authors did not find strong support for positionspecific rules. In addition, analysis of the data suggests that not all genes are equally susceptible to RNAinterference (RNAi).

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Optimized RNA-targeting CRISPR/Cas13d technology outperforms shRNA in identifying functional circRNAs

Genome Biology ◽

10.1186/s13059-021-02263-9 ◽

2021 ◽

Vol 22 (1) ◽

Cited By ~ 1

Author(s):

Yang Zhang ◽

Tuan M. Nguyen ◽

Xiao-Ou Zhang ◽

Limei Wang ◽

Tin Phan ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

High Throughput ◽

Biological Effect ◽

Human Hepatocellular Carcinoma ◽

Guide Rnas ◽

Rna Targeting ◽

Short Hairpin ◽

Short Hairpin Rnas ◽

Screening Library ◽

High Throughput Study

AbstractShort hairpin RNAs (shRNAs) are used to deplete circRNAs by targeting back-splicing junction (BSJ) sites. However, frequent discrepancies exist between shRNA-mediated circRNA knockdown and the corresponding biological effect, querying their robustness. By leveraging CRISPR/Cas13d tool and optimizing the strategy for designing single-guide RNAs against circRNA BSJ sites, we markedly enhance specificity of circRNA silencing. This specificity is validated in parallel screenings by shRNA and CRISPR/Cas13d libraries. Using a CRISPR/Cas13d screening library targeting > 2500 human hepatocellular carcinoma-related circRNAs, we subsequently identify a subset of sorafenib-resistant circRNAs. Thus, CRISPR/Cas13d represents an effective approach for high-throughput study of functional circRNAs.

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Surface Labeling with Adhesion Protein FimH Improves Binding of Immunotherapeutic Agent Salmonella Ty21a to the Bladder Epithelium

Bladder Cancer ◽

10.3233/blc-200382 ◽

2020 ◽

pp. 1-12

Author(s):

Maroeska J. Burggraaf ◽

Lisette Waanders ◽

Mariska Verlaan ◽

Janneke Maaskant ◽

Diane Houben ◽

...

Keyword(s):

Bladder Cancer ◽

Antitumor Activity ◽

Bladder Wall ◽

Bladder Epithelium ◽

Modest Improvement ◽

Adhesion Protein ◽

Survival Experiment ◽

Muscle Invasive

BACKGROUND: Bladder cancer is the ninth most common cancer in men. 70% of these tumors are classified as non-muscle invasive bladder cancer and those patients receive 6 intravesical instillations with Mycobacterium bovis BCG after transurethral resection. However, 30% of patients show recurrences after treatment and experience severe side effects that often lead to therapy discontinuation. Recently, another vaccine strain, Salmonella enterica typhi Ty21a, demonstrated promising antitumor activity in vivo. Here we focus on increasing bacterial retention in the bladder in order to reduce the number of instillations required and improve antitumor activity. OBJECTIVE: To increase the binding of Ty21a to the bladder wall by surface labeling of the bacteria with adhesion protein FimH and to study its effect in a bladder cancer mouse model. METHODS: Binding of Ty21a with surface-labeled FimH to the bladder wall was analyzed in vitro and in vivo. The antitumor effect of a single instillation of Ty21a+FimH in treatment was determined in a survival experiment. RESULTS: FimH-labeled Ty21a showed significant (p < 0.0001) improved binding to mouse and human cell lines in vitro. Furthermore, FimH labeled bacteria showed ∼5x more binding to the bladder than controls in vivo. Enhanced binding to the bladder via FimH labeling induced a modest improvement in median but not in overall mice survival. CONCLUSIONS: FimH labeling of Ty21a significantly improved binding to bladder tumor cells in vitro and the bladder wall in vivo. The improved binding leads to a modest increase in median survival in a single bladder cancer mouse study.

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