Genomes contain various types of repetitive sequences. They may be used as probes for seeking genome rearrangements because they are rather free from the natural selection if they are located in the intergenic regions. In this study, we searched for tandem repeats (TRs) in 44 prokaryotic genomes by the color-coding method and sought the signs of genome rearrangements by detailed analysis of the detected TRs. We found 13,542 tandem repeats from 44 prokaryotic genomes in total ranging from several tens to one thousand per genome. The results of statistical analysis show that TRs tend to exist on high base composition bias regions in some genomes. Moreover, we recognized the characteristic distribution patterns of equivalent TR-pairs in 12 genomes, which are expected to indicate the occurrence of whole-genome duplication (WGD) on the genomes. It is demonstrated that TRs could indeed be used for seeking genome rearrangements. Although it has not been made clear at this time whether or not WGD had occurred in prokaryotic genomes, the results of the analyses of equivalent TR-pairs in this study are thought to be evidences of WGD in these genomes. 相似文献
There may exist a connection between Echinococcus granulosus infection and cancer development. Here, it is aimed to investigate specific effects of E. granulosus protoscoleces (PSCs) on the proliferation and invasion capacities of hepatocellular carcinoma (HCC) cells in vitro and ex vitro. HepG2 cells were cultured with different quantities of E. granulosus PSCs in vitro. MTT analysis was used to evaluate effects of E. granulosus PSCs on the proliferation of HepG2 cells. Besides, scratch and transwell assays were respectively used for the detection of HepG2 cells migration and invasion capacities after co-culture with E. granulosus PSCs. Then, HepG2 cells were subcutaneously transplanted into nude mice with or without E. granulosus PSCs. From the 25th day of transplantation, the volume of subcutaneous lesions was measured every four days. At the 37th day, subcutaneous lesions were removed and their weight was evaluated. H&E staining was used for detecting basic pathological changes. HepG2 cells grew well without obvious morphological changes. Proliferation rate and migration capacity of HepG2 cells were higher in the co-culture group than the control group, which was closely associated with quantities of E. granulosus PSCs and co-culture time length. Moreover, HepG2 cells co-cultured with E. granulosus PSCs had stronger invasion ability than the control HepG2 cells. Importantly, there existed significant differences in the volume and weight of subcutaneous lesions after transplanting HepG2 cells with E. granulosus PSCs than the control group. HepG2 cells were also more pathologically heterogeneous in morphology after transplantation with E. granulosus PSCs. Thus, E. granulosus PSCs may promote proliferation and invasion of HCC cells. 相似文献
The tumor suppressor protein p53 is a most promising target for the development of anticancer drugs. Allicin (diallylthiosulfinate) is one of the most active components of garlic (Alliium sativum L.) and possesses a variety of health-promoting properties with pharmacological applications. However, whether allicin plays an anti-cancer role against breast cancer cells through the induction of p53-mediated apoptosis remains unknown.
Methods and results
In this study, we investigate the anti-breast cancer effect of allicin in vitro by using MCF-7 and MD-MBA-231 cells. We found that allicin reduces cell viability, induces apoptosis and cell cycle arrest in both cells. Allicin activated p53 and caspase 3 expressions in both cells but produced different effects on the expression of p53-related biomarkers. In MDA-MB-231 cells, allicin up-regulated the mRNA and protein expression of A1BG and THBS1 while down-regulated the expression of TPM4. Conversely, the mRNA and protein expression of A1BG, THBS1 and TPM4 were all reduced in MCF-7 cells. Hence, allicin induces cell cycle arrest and apoptosis in breast cancer cells through p53 activation but it effects on the expression of p53-related biomarkers were dependent upon the specific type of breast cancer involved.
Conclusions
These findings suggest that allicin induces apoptosis and regulates biomarker expression in breast cancer cell lines through modulating the p53 signaling pathway. Furthermore, our results promote the utility of allicin as compound for further studies as an anticancer drug targeting p53.