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Lactococcus petauri CF11 was originally isolated from the gut of healthy humans. To determine the underlying molecular and genetic mechanisms of the probiotic potential of CF11, we performed complete genome sequencing, annotation, and comparative genome analysis. The complete genome of L. petauri CF11 comprised of 1,997,720 bp, with a DNA G+C content of 38.21 mol% containing 1982 protein coding genes and 16 rRNA operons. We found that 1206 genes (56.05%) were assigned a putative function using the gene ontology (GO) resource. The gene products of CF11 were primarily concentrated in molecular function and biological processes, such as catalysis, binding, metabolism, and cellular processes. Furthermore, 1,365 (68.87%) genes were assigned an illative function using COGs. CF11 proteins were associated with carbohydrate transport and metabolism, and amino acid transport and metabolism. This indicates that CF11 bacteria can perform active energy exchange. We classified 1,111 (56.05%) genes into six KEGG functional categories; fructose-bisphosphate aldolase and the phosphoenol pyruvate:phosphotransferase system (PTS), which are necessary in producing short-chain fatty acids (SCFAs), were excited in the carbohydrate metabolic pathway. This suggests that L. petauri CF11 produces SCFAs via glycolysis. The genomic island revealed that some regions contain fragments of antibiotic resistance and bacteriostatic genes. In addition, ANI analysis showed that L. petauri CF11 had the closest relationship with L. petauri 159469 T , with an average nucleotide consistency of 98.03%. Taken together, the present study offers further insights into the functional and potential role of L. petauri CF11 in health care.

It appears to be more practical and effective to prevent carcinogenesis by targeting the tumor promotion stage. Gap junctional intercellular communication (GJIC) is strongly involved in carcinogenesis, especially the tumor promotion stage. Considerable interest has been focused on the chemoprevention activities of soyasaponin (SS), which are major phytochemicals found in soybeans and soy products. However, less is known about the preventive effects of SS (especially SS with different chemical structures) against tumor promoter-induced inhibition of GJIC. We investigated the protective effects of SS-A1, SS-A2, and SS-I against hydrogen peroxide (H2O2)-induced GJIC inhibition and reactive oxygen species (ROS) production in Buffalo rat liver (BRL) cells. The present results clearly show for the first time that SS-A1, SS-A2, and SS-I prevent the H2O2-induced GJIC inhibition by scavenging ROS in BRL cells in a dose-dependent manner at the concentration range of from 25 to 100 μg/mL. Soyasaponins attenuated the H2O2-induced ROS through potentiating the activities of superoxide dismutase and glutathione peroxidase. This may be an important mechanism by which SS protects against tumor promotion. In addition, various chemical structures of SS appear to exhibit different protective abilities against GJIC inhibition. This may partly attribute to their differences in ROS-scavenging activities.

Voltage-gated sodium channel activity enhances the motility and oncogene expression of metastasic cancer cells that express a neonatal alternatively spliced form of the NaV1.5 isoform. We reported previously that FS50, a salivary protein from Xenopsylla cheopis, showed inhibitory activity against the NaV1.5 channel when assayed in HEK 293T cells and antiarrhythmia effects on rats and monkeys after induction of arrhythmia by BaCl2. This study aims to identify the effect of FS50 on voltage-gated sodium channel activity and the motility of MDA-MB-231 human breast cancer cells in vitro. NaV1.5 was abnormally expressed in the highly metastatic breast cancer cell line MDA-MB-231, but not in the MCF-7 cell line. FS50 significantly inhibited sodium current, migration, and invasion in a dose-dependent manner, but had no effect on the proliferation of MDA-MB-231 cells at the working concentrations (1.5-12 μmol/l) after a long-term treatment for 48 h. Meanwhile, FS50 decreased NaV1.5 mRNA expression without altering the total protein level in MDA-MB-231 cells. Correspondingly, the results also showed that MMP-9 activity and the ratio of MMP-9 mRNA to TIMP-1 mRNA were markedly decreased by FS50. Taken together, our findings highlighted for the first time an inhibitory effect of a salivary protein from a blood-feeding arthropod on breast cancer cells through the NaV1.5 channel. Furthermore, this study provided a new candidate leading molecule against antitumor cells expressing NaV1.5.