Structure and function analyses of the SRC gene in Pacific white shrimp Litopenaeus vannamei.

SRC gene encodes scavenger receptor class C, a member of the scavenger receptor family, and has only been identified and investigated in invertebrates. Our previous studies have revealed that SRC is a novel candidate gene associated with body weight in Pacific white shrimp (Litopenaeus vannamei). In order to comprehend the underlying mechanism by which LvSRC affects shrimp growth, we analyzed the structure, phylogeny, expression profiles and RNA interference (RNAi) of this gene in L. vannamei. We found that LvSRC contains two CCP domains and one MAM domain, with the highest expression level in the heart and relatively low expression level in other tissues. Notably, LvSRC exhibited significantly higher expression levels in the fast-growing group among groups with different growth rates, suggesting its potential involvement as a gene contributing to the growth of L. vannamei. RNAi of LvSRC inhibited body length and body weight gain compared to the control groups. Moreover, through RNA-seq analysis, we identified 598 differentially expressed genes (DEGs), including genes associated with growth, immunity, protein processing and modification, signal transduction, lipid synthesis and metabolism. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed significant changes in the signaling pathways related to growth, lipid metabolism and immune response, suggesting that LvSRC exhibits the potential to participate in diverse physiological processes and immune regulation. These findings deepen our understanding of the structure and function of the SRC in shrimp and lay the foundation for further research into the regulatory mechanism of LvSRC. Additionally, they provide potential applications in shrimp genetics and breeding.

c-SRC knockdown decreases phosphorylated STAT3 expression and viability of HeLa cells / 生理学报

The present study was to determine the effect of c-SRC on the viability of human cervical cancer HeLa cells and the expression of phosphorylated signal transducer and activator of transcription-3 (p-STAT3) of the cell. Post-transfection of c-SRC RNA interference vector, RT-PCR and Western blot were utilized to observe the contents of c-SRC mRNA and protein, respectively, in HeLa cells. The MTT was used to observe the viability of the cells. Cell cycle was observed by flow cytometry. The content of p-STAT3 in the cells was also investigated after knockdown of c-SRC. Knockdown of c-SRC significantly decreased the contents of c-SRC mRNA and protein in the cells. The viability of the cells decreased by 23.1%, 29.3%, 38.6% and 45.0% (all P < 0.05), respectively, after the cells were transfected with c-SRC RNA interference vector for 24, 48, 72, and 96 h. The number of S-phase cells decreased by 5.6%, 10.0%, 15.2% and 19.9% (all P < 0.05), respectively, after transfection of c-SRC RNA interference vector for 24, 48, 72, and 96 h. The content of p-STAT3 also decreased when c-SRC was knockdowned. Compared with the control group, after treatment of HeLa cells with STAT3 inhibitor Piceatannol for 24, 48, 72, and 96 h, the cell viability decreased by 23.8%, 29.7%, 37.3% and 45.4% (all P < 0.05), respectively, while increase of c-SRC content could not reverse the inhibitory effect. These results suggest that the inhibited viability of HeLa cells caused by knockdown of c-SRC is associated with the decreased content of p-STAT3 protein.

Proto-oncogene c-src regulates the viability of rat spermatogonial stem cells in vitro through phosphorylated signal transducer and activator of transcription-3 / 生理学报

The present study aimed to investigate the effect of proto-oncogene c-src on the viability of rat spermatogonial stem cells from 9 day-old rat in vitro. MTT method was used to observe the viability of the spermatogonial stem cells treated with antisense c-src oligodeoxynucleotides (ODNs) in vitro; RT-PCR was utilized to observe the expression of c-src mRNA and Western blot was used to observe the protein expressions of pp60c-src and phosphorylated signal transducer and activator of transcription-3 (p-STAT3). Compared with that in control group, the viability of spermatogonial stem cells decreased by 8.1% (P<0.05) and the expression of c-src mRNA decreased significantly after treatment with 10 μmol/L antisense c-src ODNs for 12 h. Compared with that in the control group, the protein expressions of pp60c-src and p-STAT3 decreased by 33.8% and 45.3% (both P<0.01), respectively, in the spermatogonial stem cells after being transfected with antisense c-src ODNs. The results suggest that proto-oncogene c-src regulates the viability of rat spermatogonial stem cells through p-STAT3.

Metastasis-suppressor KAI1/CD82 induces homotypic aggregation of human prostate cancer cells through Src-dependent pathway

To investigate the functional role of KAI1/CD82, a metastasis suppressor for human prostate cancer, in the regulation of homotypic cell adhesion, we transfected KAI1 cDNA into DU 145 human prostate cancer cells and established stable transfectant clones with high KAI1/CD82 expression. The KAI1 transfectant cells exhibited significantly increased homotypic cell aggregation in comparison with the control transfectant cells. This aggregation of the KAI1 transfectants was further enhanced upon exposure to anti-CD82 antibody, suggesting that KAI1/CD82 may be involved in the intracellular signaling for the cell adhesion. Among several signal pathway inhibitors tested, PP1, an inhibitor of Src family kinases, significantly suppressed homotypic aggregation of the KAI1 transfectant cells. Ligation of KAI1/CD82 with anti-CD82 antibody increased endogenous Src kinase activity of the KAI1 transfectant cells. When different types of src expression constructs were retransfected into the KAI1-transfected DU 145 cells, kinase-negative mutant src transfectant cells exhibited much lower homotypic aggregation than the mock cells transfected with an empty vector. Moreover, homotypic aggregation of the mutant src transfectant cells was not enhanced by KAI1/CD82 ligation with anti- CD82 antibody. These results suggest that Src mediates the intracellular signaling pathway of KAI1/CD82 for the induction of homotypic adhesion of human prostate cancer cells.