YAP1 expression in colorectal cancer confers the aggressive phenotypes via its target genes

Handheld ISFET Lab-on-Chip detection of YAP1 nucleic acid and AR-FL and AR-V7 mRNA from liquid biopsies for prostate cancer prognosis

Prostate cancer (PCa) is a highly prevalent disease, causing the second largest amount of male cancer deaths worldwide. Currently, the prostate specific antigen (PSA) test remains the standard serum prognostic and diagnostic monitoring biomarker but it lacks specificity and sensitivity. PSA testing can lead to invasive biopsies which can result in under detection of clinically significant disease and potential overtreatment of indolent disease. Promising circulating biomarkers could facilitate less invasive and more accurate tests, but present challenges in robust quantitation and deployment in clinical settings. This work presents the detection of circulating YAP1 nucleic acid, androgen receptor (AR-FL) and AR-V7 mRNA for PCa prognostics in blood plasma from PCa patients. Sensitive detection of circulating YAP1 nucleic acid, AR-FL and AR-V7 mRNA extracted from PCa clinical samples was achieved with a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay. Optimisation of mRNA extraction methodologies for reliable detection of circulating mRNA for RT-LAMP and RT-qPCR detection took place. Multiplex testing of circulating AR-FL mRNA and YAP1 nucleic acid on an ISFET Lab-on-Chip platform was readily achieved with bio-electronic signal detection taking place within 15 min. Detection of AR-V7 and AR-FL mRNA could also be achieved simultaneously with the handheld device. Evaluation of clinical data indicated that circulating YAP1 nucleic acid presence in extracted RNA from the blood plasma of patients correlated with more advanced clinical cancer staging (p = 0.043) and PSA at diagnosis (p = 0.035). The work presents potential for Point-of-Care detection of circulating mRNA from clinical samples for PCa prognostics.

Inhibition of the AURKA/YAP1 axis is a promising therapeutic option for overcoming cetuximab resistance in colorectal cancer stem cells

BACKGROUND

Primary resistance to anti-EGFR therapies affects 40% of metastatic colorectal cancer patients harbouring wild-type RAS/RAF. YAP1 activation is associated with this resistance, prompting an investigation into AURKA's role in mediating YAP1 phosphorylation at Ser397, as observed in breast cancer.

METHODS

We used transcriptomic analysis along with in vitro and in vivo models of RAS/RAF wild-type CRC to study YAP1 Ser397 phosphorylation as a potential biomarker for cetuximab resistance. We assessed cetuximab efficacy using CCK8 proliferation assays and cell cycle analysis. Additionally, we examined the effects of AURKA inhibition with alisertib and created a dominant-negative YAP1 Ser397 mutant to assess its impact on cancer stem cell features.

RESULTS

The RAS/RAF wild-type CRC models exhibiting primary resistance to cetuximab prominently displayed elevated YAP1 phosphorylation at Ser397 primarily mediated by AURKA. AURKA-induced YAP1 phosphorylation was identified as a key trigger for cancer stem cell reprogramming. Consequently, we found that AURKA inhibition had the capacity to effectively restore cetuximab sensitivity and concurrently suppress the cancer stem cell phenotype.

CONCLUSIONS

AURKA inhibition holds promise as a therapeutic approach to overcome cetuximab resistance in RAS/RAF wild-type colorectal cancer, offering a potential means to counter the development of cancer stem cell phenotypes associated with cetuximab resistance.