Mechanism of the reversal effect of mifepristone on drug resistance of the human cervical cancer cell line HeLa/MMC

Metapristone (RU486-derivative) inhibits endometrial cancer cell progress through regulating miR-492/Klf5/Nrf1 axis

Background

Endometrial cancer is an invasive gynecological cancer prevalent in the world. The pathogenesis of endometrial cancer is related to multiple levels of regulation, referring to oestrogen, tumor-suppressor gene (e.g. PTEN) or microRNAs (e.g. miR-23a and miR-29b). Metapristone is a hormone-related drug, which is widely used in clinical treatment of endometrial cancer. However, the underlying regulatory mechanism of metapristone on endometrial cancer is still unclear, especially the regulatory effect on microRNAs. The aim of this study is to investigate the specific molecular mechanism of metapristone regulating microRNAs in the treatment of endometrial cancer.

Methods

RL95-2 cells and Ishikawa cells were used as the endometrial cancer models. MiR-492 or si-miR-492 was transfected into RL95-2 cells and Ishikawa cells to explore the role of miR-492 in endometrial cancer. The cell cancer model and mice cancer model were used to confirm the function and mechanism of metapristone affected on endometrial cancer in vitro and in vivo. Mechanically, cell proliferation was monitored using MTT assay, cell colony formation assay and EdU assay. Luciferase reporter assay was used to identify the downstream target gene of miR-492. The protein expression and RNA expression were respectively measured by western blot and qRT-PCR for cell signaling pathway research, subsequently, were verified in the mice tumor model via immunohistochemistry.

Results

Metapristone as a kind of hormone-related drug significantly inhibited the endometrial cancer cell growth through regulating cell apoptosis-related gene expression. Mechanically, miR-492 and its target genes Klf5 and Nrf1 were highly expressed in the endometrial cancer cell lines, which promoted cell proliferation and inhibited cell apoptosis. Metapristone decreased the expression of miR-492 and its target genes Klf5 and Nrf1, leading to endometrial cancer cell growth inhibition in vitro and in vivo.

Conclusion

Metapristone inhibited the endometrial cancer cell growth through regulating the cell apoptosis-related signaling pathway and decreasing the expression of miR-492 and its downstream target genes (Klf5 and Nrf1), which provided the theoretical basis in clinical treatment of endometrial cancer.

Rapid detection of low-level HeLa cell contamination in cell culture using nested PCR

HeLa cells are a commonly used cell line in many biological research areas. They are not picky for culture medium and proliferate rapidly. HeLa cells are a notorious source of cell cross‐contamination and have been found to be able to contaminate a wide range of cell lines in cell culture. In this study, we reported a simple and efficient method for detecting the presence of HeLa cell contamination in cell culture. HPV‐18 was used as a biomarker. The cell culture supernatant was used directly as the template for nested PCR without extracting nucleic acid. By PCR amplification of the cell culture supernatant with the designed primers, we were able to detect the presence of HeLa cells in the culture. The sensitivity of this method can reach 1%, which is 10‐fold higher than Short tandem repeat sequence (STR) profiling. This simple, rapid, and “noninvasive” quality checking method should find applications in routine cell culture practice.

Mifepristone inhibits proliferation, migration and invasion of HUUA cells and promotes its apoptosis by regulation of FAK and PI3K/AKT signaling pathway

Purpose

The aim was to investigate mifepristone effects on endometrial carcinoma and the related mechanism.

Methods

HHUA cells were treated with DMEM containing different concentrations of mifepristone. HHUA cells treated with 100 μmol/L mifepristone were named the Mifepristone group. HHUA cells co-transfected with pcDNA3.1-PI3K and pcDNA3.1-AKT overexpression vectors were treated with 100 μmol/L mifepristone and named the Mifepristone + PI3K/AKT group. mRNA expression was detected by quantitative reverse transcription PCR. Protein expression was performed by Western blot. Cell proliferation was conducted by MTT assay. Wound-healing assay was conducted. Transwell was used to detect cells migration and invasion. Apoptosis detection was performed by flow cytometry.

Results

Mifepristone inhibited HHUA cells proliferation in a dose-dependent manner. Compared with HHUA cells treated with 0 μmol/L mifepristone, HHUA cells treated by 50–100 μmol/L mifepristone had a lower wound-healing rate, a greater number of migrating and invasive cells (P<0.01), as well as a higher percentage of apoptotic cells and Caspase-3 expression (P<0.01). When HHUA cells were treated with 50–100 μmol/L of mifepristone, FAK, p-FAK, p-PI3K and p-AKT relative expression was all significantly lower than HHUA cells treated with 0 μmol/L of mifepristone (P<0.01). Compared with the Mifepristone group, HHUA cells of the Mifepristone + PI3K/AKT group had a lower cell growth inhibition rate and percentage of apoptotic cells (P<0.01).

Conclusion

Mifepristone inhibited HUUA cells proliferation, migration and invasion and promoted its apoptosis by regulation of FAK and PI3K/AKT signaling pathway.

The UDP-glucose ceramide glycosyltransferase (UGCG) and the link to multidrug resistance protein 1 (MDR1)

The UDP-glucose ceramide glycosyltransferase (UGCG) is a key enzyme in the sphingolipid metabolism by generating glucosylceramide (GlcCer), the precursor for all glycosphingolipids (GSL), which are essential for proper cell function. Interestingly, the UGCG is also overexpressed in several cancer types and correlates with multidrug resistance protein 1 (MDR1) gene expression. This membrane protein is responsible for efflux of toxic substances and protects cancer cells from cell damage through chemotherapeutic agents. Studies showed a connection between UGCG and MDR1 overexpression and multidrug resistance development, but the precise underlying mechanisms are unknown. Here, we give an overview about the UGCG and its connection to MDR1 in multidrug resistant cells. Furthermore, we focus on UGCG transcriptional regulation, the impact of UGCG on cellular signaling pathways and the effect of UGCG and MDR1 on the lipid composition of membranes and how this could influence multidrug resistance development. To our knowledge, this is the first review presenting an overview about UGCG with focus on the relationship to MDR1 in the process of multidrug resistance development.

Metapristone (RU486 derivative) inhibits cell proliferation and migration as melanoma metastatic chemopreventive agent

Uncontrolled cell proliferation and metastasis are the two well-known manifestations of melanoma. We hypothesized that metapristone, a potential cancer metastatic chemopreventive agent derived from mifepristone (RU486), had a dual function to fight cancer. In the present study, our findings clearly demonstrated that metapristone had modest cytostatic effect in melanoma cells. Metapristone inhibited cell viability and induced both early and late apoptosis in B16F10 and A375 cells in a time- and concentrate-dependent manner. Metapristone-treatment caused the cell arrest at the G0/G1 stage, and the inhibition of colony formation in B16F10 cells. Western blot analysis further revealed that metapristone treatment elicited a decline of Akt and ERK phosphorylation and Bcl-2, and facilitated expression of total P53 and Bax in A375 cells. In addition, cell migration and invasion were significantly suppressed by metapristone through down-regulating the expression of MMP-2, MMP-9, N-cadherin and vimentin, whereas up-regulating E-cadherin expression. Notably, metapristone exhibited anti-metastatic activity in melanoma B16F10 cells in vivo. Our results reveal metapristone, having the dual function of anti-proliferation and anti-migration for melanoma cell lines, may be a useful chemopreventive agent to reduce the risk of melanoma cancer metastasis.

Antiprogestins in gynecological diseases

Antiprogestins constitute a group of compounds, developed since the early 1980s, that bind progesterone receptors with different affinities. The first clinical uses for antiprogestins were in reproductive medicine, e.g., menstrual regulation, emergency contraception, and termination of early pregnancies. These initial applications, however, belied the capacity for these compounds to interfere with cell growth. Within the context of gynecological diseases, antiprogestins can block the growth of and kill gynecological-related cancer cells, such as those originating in the breast, ovary, endometrium, and cervix. They can also interrupt the excessive growth of cells giving rise to benign gynecological diseases such as endometriosis and leiomyomata (uterine fibroids). In this article, we present a review of the literature providing support for the antigrowth activity that antiprogestins impose on cells in various gynecological diseases. We also provide a summary of the cellular and molecular mechanisms reported for these compounds that lead to cell growth inhibition and death. The preclinical knowledge gained during the past few years provides robust evidence to encourage the use of antiprogestins in order to alleviate the burden of gynecological diseases, either as monotherapies or as adjuvants of other therapies with the perspective of allowing for long-term treatments with tolerable side effects. The key to the clinical success of antiprogestins in this field probably lies in selecting those patients who will benefit from this therapy. This can be achieved by defining the genetic makeup required - within each particular gynecological disease - for attaining an objective response to antiprogestin-driven growth inhibition therapy.Free Spanish abstractA Spanish translation of this abstract is freely available at http://www.reproduction-online.org/content/149/1/15/suppl/DC1.