The http://www.selleckchem.com/products/PF-2341066.html question whether taxol is more active than baccatin III in the induction of apoptosis because the ester is readily transported in the cell remains to be answered. As fungal baccatin III was found to be less active than fungal taxol in the in vitro studies, it is possible that fungal taxol, apart from its microtubule binding kinetics and interactions with other proteins may have advantage over baccatin III particularly in the cellular uptake process. Background Cervical cancer is a common gynecological malignancy. Persistent human papilloma virus infection has been rec ognized as the primary pathogenic factor for the devel opment of cervical cancer, however its mechanism remains unclear. Recent studies have shown that tumor tissues contain a very small number of stem like cells that are responsible for self renewal, differentiation, tumor growth, metastasis and recurrence.

Hence, an increasing number of studies have been conducted on cancer stem cells in an attempt to identify the mechanisms of the genesis, development and drug re sistance of tumors. The principal problem of the relevant research is the isolation and identification of CSCs. Be cause of lack of markers, CSCs have been mainly isolated by approach of isolating adult stem cells. These methods include cell sorting based on the expression of surface biomarkers, suspension sphere culture, and functional cell sorting based on the biological characteristics of the cells cell sorting. In 1996, Goodell et al. discovered SP cells when examining mouse bone marrow hematopoietic stem cells using the fluorescent dye Hoechst 33342.

After more than a decade of research, SP cells are considered to be a com mon phenotype of stem cells. To date, SP cells have been isolated from many tumor tissues and cell lines such as blood, breast, glioma, cervix, liver, ovar ian, lung, and pancreas. Further experiments have confirmed that SP cells possess CSC like features in cluding self renewal, asymmetric division into SP and non SP cells, and apparent drug resistance. Many reports indicate that SP cells are an ideal model for stem cell research. The characteristic of SP cells to rapidly extrude Hoechst 33342 is based on the expression of ABCG2/BCRP1, a breast cancer resistance protein of the ATP binding cassette transporter family. ABCG2/BCRP1 is a transmembrane protein that plays an important role in the multidrug resistance of tumor cells.

The expression of ABCG2/BCRP1 shows a strong positive correlation with the phenotype AV-951 of SP cells in a series of studies, which is the molecular basis of the phenotypic characteristics of SP cells. High ex pression of ABCG2/BCRP1 in SP cells is contributed to drug resistance and tumor recurrence. In 2004, Kondo et al. reported that the SP cells iso lated from the cervical cancer cell line HeLa account for approximately 1. 2% of the total number of HeLa cells.