Mifepristone Derivative FZU-00,003 Suppresses Triple-negative Breast Cancer Cell Growth partially via miR-153-KLF5 axis

DANCR Induces Cisplatin Resistance of Triple-Negative Breast Cancer by KLF5/p27 Signaling

An increasing body of evidence suggests that long noncoding RNAs play critical roles in human cancer. Breast cancer is a heterogeneous disease and the potential involvement of long noncoding RNAs in breast cancer remains poorly understood. Herein, the study identified a long noncoding RNA, DANCR, which promotes cisplatin chemoresistance in triple-negative breast cancer (TNBC) cells. Mechanistically, binding of DANCR to Krüppel-like factor 5 (KLF5) induced acetylation of KLF5 at lysine 369 (K369), and DANCR knockdown resulted in down-regulation of KLF5 protein levels. Furthermore, DANCR/KLF5 signaling pathway induced hypersensitivity to cisplatin in chemoresistant patients by inhibiting p27 transcription. In summary, this study reinforced the potential presence of a growth regulatory network in TNBC cells, and documented a DANCR/KLF5/p27 signaling pathway mediating cisplatin chemoresistance in TNBC.

Targeting Breast Cancer Stem Cells

The potential roles of breast cancer stem cells (BCSCs) in tumor initiation and recurrence have been recognized for many decades. Due to their strong capacity for self-renewal and differentiation, BCSCs are the major reasons for poor clinical outcomes and low therapeutic response. Several hypotheses on the origin of cancer stem cells have been proposed, including critical gene mutations in stem cells, dedifferentiation of somatic cells, and cell plasticity remodeling by epithelial-mesenchymal transition (EMT) and the tumor microenvironment. Moreover, the tumor microenvironment, including cellular components and cytokines, modulates the self-renewal and therapeutic resistance of BCSCs. Small molecules, antibodies, and chimeric antigen receptor (CAR)-T cells targeting BCSCs have been developed, and their applications in combination with conventional therapies are undergoing clinical trials. In this review, we focus on the features of BCSCs, emphasize the major factors and tumor environment that regulate the stemness of BCSCs, and discuss potential BCSC-targeting therapies.

A comprehensive review on miR-153: Mechanistic and controversial roles of miR-153 in tumorigenicity of cancer cells

miRNAs play a crucial role in regulating genes involved in cancer progression. Recently, miR-153 has been mainly well-known as a tumor suppressive miRNA modulating genes in proliferation, metastasis, EMT, angiogenesis and drug resistance ability of a variety types of cancer. Mechanistic activity of miR-153 in tumorigenicity has not been fully reviewed. This manuscript presents a comprehensive review on the tumor suppressive activity of miR-153 as well as introducing the controversial role of miR-153 as an oncogenic miRNA in cancer. Furthermore, it summarizes all potential non-coding RNAs such as long non-coding RNAs (LncRNAs), transcribed ultra-conserved regions (T-UCRs) and circular RNAs (CircRNAs) targeting and sponging miR-153. Understanding the critical role of miR-153 in cell growth, metastasis, angiogenesis and drug resistance ability of cancer cells, suggests miR-153 as a potential prognostic biomarker for detecting cancer as well as providing a novel treatment strategy to combat with several types of cancer.

Clinical Utility of Mifepristone: Apprising the Expanding Horizons

Mifepristone is a progesterone and glucocorticoid receptor antagonist. Medical abortion with mifepristone and prostaglandin has revolutionized the abortion process extending abortion care to the doors of females. From as low as 2 mg/day to doses extending to 600 mg, from daily dosing to single dosage treatment, mifepristone has a wide perspective in the treatment of various pathologies. Cervical dilatation and myometrial contractility have made the utility of mifepristone feasible for second-trimester termination of pregnancy and induction of labor awaiting Food and Drug Administration approvals. Its anti-progesterone action on the menstrual cycle has a new dimension of use as a contraceptive, as well as use as a menstruation inductive agent. Its role in endometriosis, ectopic pregnancy, and adenomyosis requires more intensive research. Apoptotic action of mifepristone, interference of heterotypic cell adhesion to the basement membrane, cell migration, growth inhibition of various cancer cell lines, decreased epidermal growth factor expression, suppression of invasive and metastatic cancer potential, increase in tumor necrosis factor, downregulation of cyclin-dependent kinase 2, B-cell lymphoma 2, and Nuclear factor kappa B have opened its potential to be explored as anti-cancer treatment and its effects on leiomyoma. The drug needs to be studied more for the prospectus of its anti-glucocorticoid actions in a wider dimension beyond its acquiescence for the treatment of Cushing syndrome.

STAMBPL1 promotes breast cancer cell resistance to cisplatin partially by stabilizing MKP-1 expression

Dual-specificity mitogen-activated protein kinase phosphatase-1 (MKP-1/DUSP1/CL-100) has been documented to promote breast cancer cell survival and chemoresistance. MKP-1 is an unstable protein that is ubiquitinated and degraded via the ubiquitin-proteasome system. However, it is not clear how MKP-1 protein stability is regulated in breast cancer. In this study, we performed a genome-wide siRNA library screen of deubiquitinases (DUBs) and identified STAMBPL1 as an MKP-1 DUB in breast cancer cells. STAMBPL1 interacts with MKP-1 and stabilizes MKP-1 via deubiquitination. Both STAMBPL1 and MKP-1 depletion sensitize breast cancer cells to cisplatin in vitro and in vivo, and ectopic overexpression of MKP-1 partially rescues STAMBPL1 depletion-induced cisplatin sensitivity. Furthermore, STAMBPL1 and MKP-1 depletion increased breast cancer sensitivity to cisplatin by increasing the phosphorylation and activation of c-Jun N-terminal protein kinase (JNK). Collectively, our findings not only identify STAMBPL1 as an MKP-1 DUB but also reveal a critical mechanism that regulates MKP-1 expression in breast cancer. Our findings indicate that the STAMBPL1/MKP-1 axis represents a potential therapeutic target in breast cancer.

Fasting-mimicking diet blocks triple-negative breast cancer and cancer stem cell escape

Metastatic tumors remain lethal due to primary/acquired resistance to therapy or cancer stem cell (CSC)-mediated repopulation. We show that a fasting-mimicking diet (FMD) activates starvation escape pathways in triple-negative breast cancer (TNBC) cells, which can be identified and targeted by drugs. In CSCs, FMD lowers glucose-dependent protein kinase A signaling and stemness markers to reduce cell number and increase mouse survival. Accordingly, metastatic TNBC patients with lower glycemia survive longer than those with higher baseline glycemia. By contrast, in differentiated cancer cells, FMD activates PI3K-AKT, mTOR, and CDK4/6 as survival/growth pathways, which can be targeted by drugs to promote tumor regression. FMD cycles also prevent hyperglycemia and other toxicities caused by these drugs. These data indicate that FMD has wide and differential effects on normal, cancer, and CSCs, allowing the rapid identification and targeting of starvation escape pathways and providing a method potentially applicable to many malignancies.

In vivo and in vitro impact of miRNA-153 on the suppression of cell growth apoptosis through mTORC2 signaling pathway in breast cancer

PURPOSE

To investigate the effects and mechanism of miRNA-153 on breast cancer cells in vitro and in vivo.

MATERIAL AND METHODS

The cells and mice were divided into five groups: miRNA-153 mimic, miRNA-153 NC, miRNA-153 inhibitor, miRNA-153 inhibitor-NC, and blank control groups. The real-time PCR and western blot were used to detect the rictor expression regulated by miRNA-153. The western blot was used to explore the expression levels of p-Akt Ser473, p-SGK1 Ser422, and p-FOXO1 Thr24 regulated by miRNA-153. The H&E stain was used to detect the morphology and vitality of tumor cells. Flow cytometry analysis or TUNEL detection was used to evaluate the apoptosis of tumor cells.

RESULTS

MiRNA-153 was significantly reduced in breast cancer cell lines. The real-time PCR and western blot assay suggested that the miRNA-153 downregulation of rictor expression, which was correlated with the antitumor effects both in vitro and in vivo. The western blot assay also showed that the expression levels of p-Akt Ser473, p-SGK1 Ser422, and p-FOXO1 Thr24 were largely reduced in miRNA-153 treated group, which indicated that miRNA-153 inhibited breast cancer growth by regulation of mTORC2 signaling pathway. The H&E stain demonstrated that the morphology and vitality of tumor cells in tumor tissues were influenced in miRNA-153 mimic treated group. The TUNEL detection also showed a great quantity of apoptotic cells in the miRNA-153 mimic group.

CONCLUSIONS

All these results uncovering that the miRNA-153 inhibited breast cancer growth via regulation of mTORC2 signaling pathway, which provided breast cancer treatment a novel direction.

The roles and regulation of the KLF5 transcription factor in cancers

Krüppel‐like factor 5 (KLF5) is a member of the KLF family. Recent studies have suggested that KLF5 regulates the expression of a large number of new target genes and participates in diverse cellular functions, such as stemness, proliferation, apoptosis, autophagy, and migration. In response to multiple signaling pathways, various transcriptional modulation and posttranslational modifications affect the expression level and activity of KLF5. Several transgenic mouse models have revealed the physiological and pathological functions of KLF5 in different cancers. Studies of KLF5 will provide prognostic biomarkers, therapeutic targets, and potential drugs for cancers.

Research on the effect of interfering with miRNA-155 on triple-negative breast cancer cells

BACKGROUND

Triple negative breast cancer (TNBC) is a poor prognosis breast cancer with the highest mutation rate and limited treatment options. MiR-155 is highly expressed in TNBC, but its role and potential mechanism in TNBC remain to be elucidated.

OBJECTIVE

The aim of this study is to examine the effect of interfering with miRNA-155 on the inflammatory pathway of NLRP 3 in TNBC (MDA-MB-231).

METHODS

MiRNA-155-specific interference (Si-miR-155) on MDA-MB-231 cell was manifested by transfection of miRNA-155 inhibitor. Meanwhile, blank control (Blank) and negative control (NC) were set. Cell growth and proliferation rate were detected by MTT; apoptosis rate were detected by flow cytometry; colony forming test was used to detected cell viability; cell migration ability was detected by Wound healing assay; TNF-α, IL-18, IL-6 and IL-1β levels were detected by ELISA. The mRNA of miRNA-155, NLRP3, ASC, caspase-1 and Ki67 were detected by qRT-PCR. The expression levels of NLRP3, caspase-1, ASC and Ki67 were detected by Western blotting.

RESULTS

The proliferation rate of Si-miRNA-155 group decreased, while the apoptosis rate increased significantly. After interfering with miRNA-155, the number of cancer cell colonies and the migration ability was decreased, and the secretion levels of IL-18, TNF-α, IL-6 and IL-1β were also inhibited. Moreover the mRNA and protein expression of NLRP3, caspase-1, ASC and Ki67 were significantly suppressed.

CONCLUSIONS

Interference with miRNA-155 can inhibit the NLRP3 pathway of MDA-MB-231 cells, as well as the proliferation, migration and inflammatory factor secretion of MDA-MB-231 cell, and can accelerate its apoptosis.

KLF5 promotes HpSlyD induced gastric intestinal metaplasia by activating Wnt/β-catenin pathway

BACKGROUND

Krüppel like factor 5 (KLF5) and the Wnt/β-catenin pathway are hot topics in the research of tumorigenesis. Some studies have found that KLF5 is related to the differentiation and proliferation of intestinal epithelial cells, suggesting that KLF5 may be involved in the occurrence of intestinal metaplasia. However, there are few reports on the effect of KLF5 on intestinal metaplasia and the underlying molecular mechanism.

AIM

To explore the effect of KLF5 on gastric intestinal metaplasia (GIM) induced by Helicobacter pylori (H. pylori) and the underlying mechanism.

METHODS

The mRNA and protein expression of KLF5 and Wnt3a was detected by RT-PCR and Western blot, respectively. Gastric epithelial cell line GES1 was cultured in vitro and divided into a blank control group, HpSlyD group (200 ng/mL HpSlyD + negative sequence), KLF5 interference group (200 ng/mL HpSlyD + KLF5 siRNA), Wnt agonist group (200 ng/mL HpSlyD + KLF5 siRNA + lithium chloride), and Wnt agonist + KLF5 interference group. GES1 cell proliferation and apoptosis were determined by MTT assay and flow cytometry, respectively. RT-PCR was used to detect KLF5, Wnt3a, beta-catenin, wool protein 1 (VIL1), trefoil factor 2 (TFF2), and caudal homeobox factor 2 (CDX2) mRNA expression. The expression of VIL1, TFF2, and CDX2 proteins was detected by Western blot.

RESULTS

The expression of KLF5 and Wnt3a mRNA and protein in intestinal metaplasia was significantly higher than that in the normal gastric mucosa (P < 0.01). The cell proliferation rates in the HpSlyD group and interference control group were significantly higher than that of the blank control group, and the apoptosis rates were significantly lower than that of the blank control group (P < 0.05). The cell proliferation rate of the KLF5 interference group was significantly lower than that of the HpSlyD group, and the apoptosis rate was significantly higher than that of the HpSlyD group (P < 0.05). The mRNA and protein expression of VIL1, TFF2, and CDX2 in the HpSlyD group and interference control group was significantly higher than that of the blank control group (P < 0.05), while the mRNA and protein expression of VIL1, TFF2, and CDX2 in the KLF5 interference group were significantly lower than those of the HpSlyD group (P < 0.05). The expression of Wnt3a, β-catenin, and CDX2 mRNA in the KLF5 interference group was significantly lower than that of the HpSlyD group (P < 0.05). The expression of Wnt3a, β-catenin, and CDX2 mRNA in the Wnt agonist + KLF5 interference group was significantly higher than that of the KLF5 interference group (P < 0.05).

CONCLUSION

Interference of KLF5 expression can significantly inhibit HpSlyD induced gastric metaplasia. KLF5 may promote HpSlyD induced gastric metaplasia by activating the Wnt/β-catenin pathway, which provides a new target for clinical prevention of gastric cancer.