HIF-1α@Fe3O4 labeled pancreatic cancer PANC1 cells under hypoxia and its MRI detection / 中华胰腺病杂志

Objective To explore the feasibility of novel nano-particle HIF-1 α@Fe3 O4 labeled pancreatic cancer PANC1 cells as well as the changes of signal intensity in 3.0T MRI scan.Methods Pancreatic cancer PANC1 cells were cultured in hypoxia condition,and hypoxia-inducible-factor-1 α(HIF-1 α) and stem cell markers CD133,Oct-4,Sox-2 were detected by Western blot assay.Cells cultured under hypoxia for 24 h were collected and then co-incubated with 5,15 and 45 μg/ml HIF-1α@Fe3O4 for 24 h.The number of HIF-1 α@Fe3O4 labeled PANC1 cells and cell survival rate were detected,and the signal intensity of T2 WI image for PANC1 cells was measured by a 3.0T MRI system.Results In hypoxia condition,HIF-1 α level was obviously increased compared with that of normoxic culture,which was further increased with the increase of hypoxia time(all P ＜ 0.05).Stem-cell markers CD133,Oct-4 and Sox-2 was positively correlated with HIF-1α level.Co-cultured with different concentrations of HIF-1α@Fe3O4 for 24 h,blue-stained iron particles in cytoplasm of PANC1 cells was dosage-dependently increased,and the peak was at the concentration of 45 μg/ml,which could reach 100％.The survival rate of the PANC1 cells cultured in normoxic condition,the unlabeled and labeled in hypoxic condition group were(87.0 ± 2.1) ％,(84.7 ± 2.7) ％ and (85 ± 3.8) ％,respectively,and the difference was not statistically significant (P ＞ 0.05).In 3.0T MRI scan,T2 WI signal intensity in unlabeled group and 5,15 and 45 μg/ml labeled group was 1.017 ± 0.046,0.793 ± 0.041,0.447 ± 0.032 and 0.240 ± 0.031,and the difference was not statistically significant (F =80.0,P ＞ 0.05).Conclusions Hypoxia condition could promote and maintain the stemness in PANC1 cells.HIF-1α@Fe3O4 probe could successfully label HIF-1α highly expressed PANC1 cells during hypoxia condition,and a significant decrease in T2WI signal intensity can be detected by a 3.0T MRI system.

Biological characteristics of drug induced tumor cells and its medicine prevention and treatment / 药学学报

Recently, the incidence and mortality of cancer has raised. More and more cytotoxic drugs and molecular targeted medicines have been used in clinic. However, most drugs just display a short-term anti-tumor effect. If patients received treatment for a long time, it would arise resistance to chemotherapy frequently. One of its important reasons is the accumulation of drug induced cancer cells. Thus, this paper emphasizes on biological character of drug induced cells, including cell biological phenotype, the change of gene and protein, variation of metabolism, dynamic change of signal transduction pathway and so on. Meanwhile, according to the characteristics of drug induced cells, we propose some strategies to inhibit drug induced cells, which would provide the foundation of clinical therapy and novel anti-tumor drug research and development.

Characterization of sphere-forming HCT116 clones by whole RNA sequencing

PURPOSE: To determine CD133+ cells defined as cancer stem cells (CSCs) in colon cancer, we examined whether CD133+ clones in HCT116 demonstrate known features of CSCs like sphere-forming ability, chemodrug-resistance, and metastatic potential. METHODS: Magnetic cell isolation and cell separation demonstrated that <1% of HCT116 cells expressed CD133, with the remaining cells being CD133- clones. In colon cancer cells, radioresistance is also considered a CSC characteristic. We performed clonogenic assay using 0.4 Gy γ-irradiation. RESULTS: Interestingly, there were no differences between HCT116 parental and HCT116 CD133+ clones when the cells comprised 0.5% of the total cells, and CD133- clone demonstrated radiosensitive changes compared with parental and CD133+ clones. Comparing gene expression profiles between sphere-forming and nonforming culture conditions of HCT116 subclones by whole RNA sequencing failed to obtain specific genes expressed in CD133+ clones. CONCLUSION: Despite no differences of gene expression profiles in monolayer attached culture conditions of each clone, sphere-forming conditions of whole HCT116 subclones, parental, CD133+, and CD133- increased 1,761 coding genes and downregulated 1,384 genes related to CSCs self-renewal and survival. Thus, spheroid cultures of HCT116 cells could be useful to expand colorectal CSCs rather than clonal expansion depending on CD133 expressions.

Study on the biological characteristics of human breast cancer cell mammospheres / 重庆医学

Objective To study the biological characteristics of the human breast cancer cell mammospheres (MSs) ,and con‐struct breast cancer stem cell experiment model .Methods MCF‐7 cells were cultured in the serum‐free media supplemented with growth factors (the MCF‐7 group) ,and the MSs was collected (the MSs group) .The migration ,invasive and animal tumor forma‐tion abilities of MSs were detected by wound healing ,transwell invasive assay and animal tumor formation test .Results The wound line of MSs healed after 48 hours ,but the line of MCF‐7cells could not heal after 48 h .The number of the cells going through the membrane in MSs group was (76 .24 ± 0 .35) ,and the number in MCF‐7cells was (17 .38 ± 0 .18)(P<0 .05) .MSs had stronger ani‐mal tumor formation ability than MCF‐7 cells .Conclusion MSs have stronger abilities in migration ,invasive and animal tumor for‐mation ,and could be used in the studies of breast cancer stem cell as experimental model .

The Role of ATF3 Expression and Calcineurin Inhibition in the Putative Cancer Stem Cell Fraction of Human Cutaneous Squamous Cell Carcinoma / 대한피부과학회지

BACKGROUND: A previous study reported that calcineurin inhibition by cyclosporin A (CsA) showed tumor-enhancing effects through the induction of the ATF3 transcription factor and the associated suppression of p53. The development and aggressiveness of cutaneous squamous cell carcinoma (SCC) may be determined by cancer stem cell populations, which have self-renewing potential. OBJECTIVE: To determine the role of ATF3 and calcineurin inhibition in the proliferation of SCC and evaluate the existence of putative SCC stem cells. METHODS: We performed real-time PCR, fluorescence activated cell sorting, and clonogenicity assays in SCC13 cells under conditions of calcineurin inhibition by CsA or ATF3 and p53 overexpression. The relationships amongst calcineurin inhibition, p53, and ATF3 were demonstrated by western blot analysis and transient transfection assays in SCC13 cells. RESULTS: In putative stem cell populations of SCC13 cells enriched in self-renewal potential, p53 expression was lower than that in differentiated SCC13 cells. CsA treatment or ATF3 overexpression caused an expansion of stem cell populations. Additionally, p53 overexpression inhibited cellular proliferation and reduced clonogenicity in SCC13 cells. CsA treatment led to a decrease in p53 expression and an increase in ATF3 in SCC13 cells on western blots. SCC13 cells with CsA and small interfering RNA against ATF3 demonstrated lower cell viability than SCC13 cells with CsA only and SCC13 cells with CsA and small interfering control RNA after 14 days. CONCLUSION: Putative cancer stem cell populations and differentiated cell populations in SCCs are positively regulated by ATF3 and p53, respectively.

The application and limitation of suspension culture in the study of neoplastic stem cells / 肿瘤

Neoplastic stem cells are generally recognized as a key factor in carcinogenesis and progression and metastasis of cancer. Recently, many studies have been focused on neoplastic stem cells. However, in consideration of lack of specific biological marker and unclear information about the allocation and morphology of neoplastic stem cells, it is difficult to separate them from tumor cells directly. The difference in function between neoplastic stem cells and the tumor cells was commonly used to distinguish them. Suspension culture is one of the most widely used methods to identify, enrich and purify neoplastic stem cells. It can conveniently demonstrate the capabilities of self-renewal and proliferation at the single-cell level. However, the neoplastic stem cells harvested from suspension culture are different from the original neoplastic stem cells, and not all of the cells sharing the features of neoplastic stem cells can survive in the suspension culture. Thus, the limitation of application of suspension culture in the study of neoplastic stem cells should be emphasized, and which is reviewed in this paper. Copyright © 2012 by TUMOR.