Feline infectious peritonitis (FIP), a serious infectious disease in cats, has become a challenging problem for pet owners and the industry due to the lack of effective vaccinations and medications for prevention and treatment. Currently, most natural compounds have been proven to have good antiviral activity. Hence, it is essential to develop efficacious novel natural compounds that inhibit FIPV infection. Our study aimed to screen compounds with in vitro anti-FIPV effects from nine natural compounds that have been proven to have antiviral activity and preliminarily investigate their mechanisms of action. In this study, the CCK-8 method was used to determine the maximum noncytotoxic concentration (MNTC), 50% cytotoxic concentration (CC₅₀), and 50% effective concentration (EC₅₀) of natural compounds on CRFK cells and the maximum inhibition ratio (MIR) of the compounds inhibit FIPV. The effect of natural compounds on FIPV-induced apoptosis was detected via Annexin V-FITC/PI assay. Network pharmacology (NP), molecular docking (MD), and 4D label-free quantitative (4D-LFQ) proteomic techniques were used in the joint analysis the mechanism of action of the screened natural compounds against FIPV infection. Finally, Western blotting was used to validate the analysis results. Among the nine natural compounds, baicalin had good antiviral effects, with an MIR > 50% and an SI > 3. Baicalin inhibited FIPV-induced apoptosis. NP and MD analyses showed that AKT1 was the best target of baicalin for inhibiting FIPV infection. 4D-LFQ proteomics analysis showed that baicalin might inhibit FIPV infection by modulating the PI3K-AKT pathway and the apoptosis pathway. The WB results showed that baicalin promoted the expression of EGFR, PI3K, and Bcl-2 and inhibited the expression of cleaved caspase 9 and Bax. This study found that baicalin regulated the PI3K-AKT pathway and the apoptosis pathway in vitro and inhibited FIPV-induced apoptosis, thus exerting anti-FIPV effects.

Porcine recombinant NK-lysin (prNK-lysin) has been shown to inhibit the proliferation and metastasis of hepatocellular carcinoma (HCC) cells in vitro. However, its effects on the proliferation and metastasis of HCC cells in vivo remain unclear. In this study, an allograft murine model using the murine HCC cell line Hepa1-6 was employed to investigate the anticancer effects of prNK-lysin. Initially, the in vitro anticancer efficacy of prNK-lysin was evaluated in Hepa1-6 cells, demonstrating that prNK-lysin effectively inhibited both proliferation and metastasis. These effects were mediated through the induction of oncosis and suppression of Fascin-1, MMP-2, and MMP-9 protein expressions. Subsequently, the in vivo anticancer efficacy of prNK-lysin was assessed using a mouse liver orthotopic implantation model and a lung metastasis model of Hepa1-6 cells in BALB/cA-nu mice. The administration of 13 mg/kg of prNK-lysin could inhibit tumor growth in the liver and metastasis to the lungs. Our results demonstrate that prNK-lysin possesses strong anti-HCC effects both in vitro and in vivo, with the induction of oncosis and the inhibition of Fascin-1, MMP-2, and MMP-9 protein expressions as potential molecular mechanisms for its anticancer activity.

Canine mammary tumors (CMTs) are the most common type of tumor in female dogs. In this study, we obtained a metastatic key protein, Fascin-1, by comparing the proteomics data of in situ tumor and metastatic cell lines from the same individual. However, the role of Fascin-1 in the CMT cell line is still unclear. Firstly, proteomics was used to analyze the differential expression of Fascin-1 between the CMT cell lines CHMm and CHMp. Then, the overexpression (CHMm-OE and CHMp-OE) and knockdown (CHMm-KD and CHMp-KD) cell lines were established by lentivirus transduction. Finally, the differentially expressed proteins (DEPs) in CHMm and CHMm-OE cells were identified through proteomics. The results showed that the CHMm cells isolated from CMT abdominal metastases exhibited minimal expression of Fascin-1. The migration, adhesion, and invasion ability of CHMm-OE and CHMp-OE cells increased, while the migration, adhesion, and invasion ability of CHMm-KD and CHMp-KD cells decreased. The overexpression of Fascin-1 can upregulate the Tetraspanin 4 (TSPAN4) protein in CHMm cells and increase the number of migrations. In conclusion, re-expressed Fascin-1 could promote cell EMT and increase lamellipodia formation, resulting in the enhancement of CHMm cell migration, adhesion, and invasion in vitro. This may be beneficial to improve female dogs’ prognosis of CMT.

Porcine recombinant NK-lysin (prNK-lysin) has been shown to inhibit the proliferation and metastasis of hepatocellular carcinoma (HCC) cells in vitro. However, its effects on the proliferation and metastasis of HCC cells in vivo remain unclear. In this study, allograft murine model using the murine HCC cell line Hepa1-6 was employed to investigate the anticancer effects of prNK-lysin. Initially, the in vitro anticancer efficacy of prNK-lysin was evaluated on Hepa1-6 cells, demonstrating that prNK-lysin effectively inhibited both proliferation and metastasis through the induction of oncosis. Subsequently, the in vivo anticancer efficacy of prNK-lysin was assessed using a mouse liver orthotopic implantation model and a lung metastasis model of Hepa1-6 cells in BALB/cA-nu mice. Administration of 13 mg/kg prNK-lysin could inhibited tumor growth in the liver and metastasis to the lungs. Our results demonstrate that prNK-lysin possesses strong anti-HCC effects both in vitro and in vivo, with the induction of oncosis as potential molecular mechanisms for its anticancer activity.