The Study Of Low-dose Lidamycin Induced Differentiation Of Mouse Embryonal Carcinoma Cells

The cancer stem cell hypothesis suggests that not all the cells in thetumour have the ability to proliferate and maintain growth of the tumour, butonly a small subpopulation of cells in the tumour with a self-renewal potentialand the capacity to form a tumour and maintain its growth, called cancer stemcells. Conventional chemotherapy and radiotherapy are effective against thebulk cancer cells, but the presence of rare resistant CSCs may lead to tumorrecurrence and poor survival outcomes. Therefore, CSCs are considered ascrucial targets for curing the cancer.Lidamycin (LDM, also known as C-1027) is an anticancer chromoproteinincluding an apoprotein and a chromophore. Its labile chromophore can directlybreak the DNA double-strand, and its noncovalently bound apoprotein acts as adelivery carrier targeting tumor tissue. LDM has been confirmed to inhibit thegrowth of most of cancers in vitro and in vivo by cell cycle arrest andapoptosis.P19embryonal carcinoma (EC) cells derived from an embryo-derivedteratocarcinoma in C3H/He mice are multipotent. High expression of markersof the inner cell mass of blastocysts, such as transcription factors Oct4, is theideal model in vitroto linkage between the tumors and cell differentiation. Oct4,a crucial transcriptional factor for maintaining self-renewal and pluripotency, ishigh expressed in the totipotent or multipotent stem cells and solid tumor cells,but not expressed in normal somatic tissues and normal differentiated daughtersof the adult stem cells. Therefore, some scholars have proposed that Oct4canact as one of cancer stem cell markers.Preliminary experimental results confirm that low dose of LDM induced G0/G1arrest of P19EC cells without apoptosis. Which relating todown-regulation of embryonic stem cell-like gene Oct4. This indicated thatLDM may be served as an inducer to study ES cell pluripotency anddifferentiation.In this study, we found the following results. Firstly, After low-doselidamycin induced differentiation of P19EC cells, the morphology of P19cells undergoing neural differentiation, on the level of mRNA and proteindetected the markers of neural cells; Secondly, Lidamycin suppressedexpression of transcriptional factor Oct4and activated p21gene in mouse P19EC cells；Thirdly, by chromatin immunoprecipitation analysis confirmed thatOct4binding to p21gene promoter was decreased. These results suggested thatsuppression of Oct4by lidamycin led to activation of the p21gene.We conclude that low-dose lidamycin induced neural differentiation inP19EC cell; low-dose lidamycin induced neuronal differentiation related todown regulation of Oct4;up regulation of p21played an important role incancer stem cell differentiation;low-dose lidamycin induced differentiation ofcells in chemotherapy,which provides a theoretical basis and experimentalevidence.