Tumor-associated antigen-specific cell imaging based on upconversion luminescence and nucleic acid rolling circle amplification.

Tumor-associated antigen (TAA)-based diagnosis has gained prominence for early tumor screening, treatment monitoring, prognostic assessment, and minimal residual disease detection. However, limitations such as low sensitivity and difficulty in extracting non-specific binding membrane proteins still exist in traditional detection methods. Upconversion luminescence (UCL) exhibits unique physical and chemical properties under wavelength near-infrared light excitation. Rolling circle amplification (RCA) is an efficient DNA amplification technique with amplification factors as high as 105. Therefore, the above two excellent techniques can be employed for highly accurate imaging analysis of tumor cells. Herein, we developed a novel nanoplatform for TAA-specific cell imaging based on UCL and RCA technology. An aptamer-primer complex selectively binds to Mucin 1 (MUC1), one of TAA on cell surface, to trigger RCA reaction, generating a large number of repetitive sequences. These sequences provide lots of binding sites for complementary signal probes, producing UCL from lanthanide-doped upconversion nanoparticles (UCNPs) after releasing quencher group. The experimental results demonstrate the specific attachment of upconversion nanomaterials to cancer cells which express a high level of MUC1, indicating the potential of UCNPs and RCA in tumor imaging.

RAB3D, upregulated by aryl hydrocarbon receptor (AhR), promotes the progression of prostate cancer by activating the PI3K/AKT signaling pathway.

Many patients with prostate cancer (PCa) cannot be diagnosed until an advanced stage, which make PCa become a large threat to human health. It is an urgent need to explore novel biomarkers for accurate diagnosis and targets for the effective treatment of PCa. This study aimed to investigate the effects of RAB3D (which belongs to the secretory Rab GTPases) on the progression of PCa. The results showed that RAB3D was highly expressed in PCa tissues compared to normal tissues according to the gene expression omnibus dataset. Consistent with the bioinformatics results, RAB3D exhibited a higher expression in PCa cells. Overexpression of RAB3D promoted the proliferation, migration, and invasion of PCa cells, whereas the knockdown of RAB3D led to the opposite results. The procancer effects of RAB3D were further confirmed by the in vivo growth of xenograft model. Subsequently, RAB3D upregulated the PI3K/AKT signaling pathway both in vivo and in vitro. LY294002 (a PI3K inhibitor) rescued the RAB3D upregulation-induced promotion of malignant phenotypes of PCa cells. Furthermore, the transcription activity of RAB3D was found to be enhanced by aryl hydrocarbon receptor (AhR; a transcription factor). The AhR silencing-induced inhibition of the proliferation and migration of PCa cells was reversed by the overexpression of RAB3D. Taken together, RAB3D, upregulated by AhR, promotes the PCa progression by activating the PI3K/AKT signaling pathway.