Haiyu Wang

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, leading to a large global cancer burden. Hepatocyte growth factor (HGF) and its high-affinity receptor, mesenchymal epithelial transition factor (c-Met), are closely related to the onset, progression, and metastasis of multiple tumors. The HGF/c-Met axis is involved in cell proliferation, movement, differentiation, invasion, angiogenesis, and apoptosis by activating multiple downstream signaling pathways. In this review, we focus on the function of the HGF/c-Met axis in HCC. The HGF/c-Met axis promotes the onset, proliferation, invasion, and metastasis of HCC. Moreover, it can serve as a biomarker for diagnosis and prognosis, as well as a therapeutic target for HCC. In addition, it is closely related to drug resistance during HCC treatment.

Semiconducting polymer dots (Pdots) represent a new class of fluorescent nanoparticles for biological applications. In this study, we investigated their size-dependent fluorescence and cellular labeling properties. We demonstrate that the polymer conformation in solution phase largely affects the polymer folding and packing during the nanoparticle preparation process, resulting in solution-phase control over the fluorescence properties of semiconducting polymer nanoparticles. The resulting Pdots exhibit apparent size dependent absorption and emission, a characteristic feature of different chain packing behaviors due to the preparation conditions. Single-particle fluorescence imaging was employed to perform a side-by-side comparison on the Pdot brightness, indicating a quadratic dependence of single-particle brightness on particle size. Upon introducing a positively charged dye Nile blue, all the three type of Pdots were quenched very efficiently (Ksv > 1 × 10(7) M(-1)) in an applied quenching process at low dye concentrations, but exhibit apparent difference in quenching efficiency with increasing dye concentration. Furthermore, Pdots of different sizes were used for cell uptake and cellular labeling involving biotin-streptavidin interactions. Fluorescence imaging together with flow cytometry studies clearly showed size dependent labeling brightness. Small-sized Pdots appear to be more effective for immunolabeling of cell surface, whereas medium-sized Pdots exhibit the highest uptake efficiency. This study provides a concrete guidance for selecting appropriate particle size for biological imaging and sensing applications.

As a tumor-targeting and ‑penetrating peptide, iRGD binds to αv integrins and neuropilin‑1 receptors, which are expressed at high levels on tumor cells and the surfaces of vasculature. Subsequently, iRGD penetrates deep into the tumor parenchyma with antitumor drugs, imaging agents, immune modulators and biological products. These substances are either chemically linked to the peptide or co‑injected with the peptide. The iRGD peptide can be readily synthesized, exhibits significantly improved penetration, compared with traditional peptides, and can effectively inhibit tumor metastasis. Therefore, the peptide is now used widely for the diagnosis and treatment of cancer. However, whether the peptide is able to promote the entry of drugs into non‑targeted cells remains to be fully elucidated. In this review, an overview of iRGD is presented, focusing on its identification, mechanism of action and previous studies on its roles in various types of cancer. Studies in previous years have demonstrated the potential of the iRGD protein for tumors diagnosis and targeted treatment, which warrants further investigation.