CircHAS2 activates CCNE2 to promote cell proliferation and sensitizes the response of colorectal cancer to anlotinib.

BACKGROUND: Tyrosine kinase inhibitors (TKIs) are crucial in the targeted treatment of advanced colorectal cancer (CRC). Anlotinib, a multi-target TKI, has previously been demonstrated to offer therapeutic benefits in previous studies. Circular RNAs (circRNAs) have been implicated in CRC progression and their unique structural stability serves as promising biomarkers. The detailed molecular mechanisms and specific biomarkers related to circRNAs in the era of targeted therapies, however, remain obscure. METHODS: The whole transcriptome RNA sequencing and function experiments were conducted to identify candidate anlotinib-regulated circRNAs, whose mechanism was confirmed by molecular biology experiments. CircHAS2 was profiled in a library of patient-derived CRC organoids (n = 22) and patient-derived CRC tumors in mice. Furthermore, a prospective phase II clinical study of 14 advanced CRC patients with anlotinib-based therapy was commenced to verify drug sensitivity (ClinicalTrials.gov identifier: NCT05262335). RESULTS: Anlotinib inhibits tumor growth in vitro and in vivo by downregulating circHAS2. CircHAS2 modulates CCNE2 activation by acting as a sponge for miR-1244, and binding to USP10 to facilitate p53 nuclear export as well as degradation. In parallel, circHAS2 serves as a potent biomarker predictive of anlotinib sensitivity, both in patient-derived organoids and xenograft models. Moreover, the efficacy of anlotinib inclusion into the treatment regimen yields meaningful clinical responses in patients with high levels of circHAS2. Our findings offer a promising targeted strategy for approximately 52.9% of advanced CRC patients who have high circHAS2 levels. CONCLUSIONS: CircHAS2 promotes cell proliferation via the miR-1244/CCNE2 and USP10/p53/CCNE2 bidirectional axes. Patient-derived organoids and xenograft models are employed to validate the sensitivity to anlotinib. Furthermore, our preliminary Phase II clinical study, involving advanced CRC patients treated with anlotinib, confirmed circHAS2 as a potential sensitivity marker.

A pH-responsive cetuximab-conjugated DMAKO-20 nano-delivery system for overcoming K-ras mutations and drug resistance in colorectal carcinoma.

Cetuximab (Cet) and oxaliplatin (OXA) are used as first-line drugs for patients with colorectal carcinoma (CRC). In fact, the heterogeneity of CRC, mainly caused by K-ras mutations and drug resistance, undermines the effectiveness of drugs. Recently, a hydrophobic prodrug, (1E,4E)-6-((S)-1-(isopentyloxy)-4-methylpent-3-en-1-yl)-5,8-dimethoxynaphthalene-1,4­dione dioxime (DMAKO-20), has been shown to undergo tumor-specific CYP1B1-catalyzed bioactivation. This process results in the production of nitric oxide and active naphthoquinone mono-oximes, which exhibit specific antitumor activity against drug-resistant CRC. In this study, a Cet-conjugated bioresponsive DMAKO-20/PCL-PEOz-targeted nanocodelivery system (DMAKO@PCL-PEOz-Cet) was constructed to address the issue of DMAKO-20 dissolution and achieve multitargeted delivery of the cargoes to different subtypes of CRC cells to overcome K-ras mutations and drug resistance in CRC. The experimental results demonstrated that DMAKO@PCL-PEOz-Cet efficiently delivered DMAKO-20 to both K-ras mutant and wild-type CRC cells by targeting the epidermal growth factor receptor (EGFR). It exhibited a higher anticancer effect than OXA in K-ras mutant cells and drug-resistant cells. Additionally, it was observed that DMAKO@PCL-PEOz-Cet reduced the expression of glutathione peroxidase 4 (GPX4) in CRC cells and significantly inhibited the growth of heterogeneous HCT-116 subcutaneous tumors and patient-derived tumor xenografts (PDX) model tumors. This work provides a new strategy for the development of safe and effective approaches for treating CRC. STATEMENT OF SIGNIFICANCE: (1) Significance: This work reports a new approach for the treatment of colorectal carcinoma (CRC) using the bioresponsible Cet-conjugated PCL-PEOz/DMAKO-20 nanodelivery system (DMAKO@PCL-PEOz-Cet) prepared with Cet and PCL-PEOz for the targeted transfer of DMAKO-20, which is an anticancer multitarget drug that can even prevent drug resistance, to wild-type and K-ras mutant CRC cells. DMAKO@PCL-PEOz-Cet, in the form of nanocrystal micelles, maintained stability in peripheral blood and efficiently transported DMAKO-20 to various subtypes of colorectal carcinoma cells, overcoming the challenges posed by K-ras mutations and drug resistance. The system's secure and effective delivery capabilities have also been confirmed in organoid and PDX models. (2) This is the first report demonstrating that this approach simultaneously overcomes the K-ras mutation and drug resistance of CRC.