Yifei Sanjie formula alleviates lung cancer progression via regulating PRMT6-YBX1-CDC25A axis.

Lung cancer (LC) is the most prevalent cancer type, with a high mortality rate worldwide. The current treatment options for LC have not been particularly successful in improving patient outcomes. Yifei Sanjie (YFSJ), a well-applicated traditional Chinese medicine formula, is widely used to treat pulmonary diseases, especially LC, yet little is known about its molecular mechanisms. This study was conducted to explore the molecular mechanism by which YFSJ ameliorated LC progression. The A549, NCI-H1975, and Calu-3 cells were treated with the YFSJ formula and observed for colony number, apoptosis, migration, and invasion properties recorded via corresponding assays. The PRMT6-YBX1-CDC25A axis was tested and verified through luciferase reporter, RNA immunoprecipitation, and chromatin immunoprecipitation assays and rescue experiments. Our results demonstrated that YFSJ ameliorated LC cell malignant behaviors by increasing apoptosis and suppressing proliferation, migration, and invasion processes. We also noticed that the xenograft mouse model treated with YFSJ significantly reduced tumor growth compared with the control untreated group in vivo. Mechanistically, it was found that YFSJ suppressed the expression of PRMT6, YBX1, and CDC25A, while the knockdown of these proteins significantly inhibited colony growth, migration, and invasion, and boosted apoptosis in LC cells. In summary, our results suggest that YFSJ alleviates LC progression via the PRMT6-YBX1-CDC25A axis, confirming its efficacy in clinical use. The findings of our study provide a new regulatory network for LC growth and metastasis, which could shed new insights into pulmonary medical research.

Specific knockdown of Y-box binding protein 1 in hepatic progenitor cells inhibits proliferation and alleviates liver fibrosis.

The proliferation of hepatic progenitor cells (HPCs) contributes to liver regeneration and fibrogenesis during chronic liver injury; however, the mechanism modulating HPC proliferation remains unknown. Y-box binding protein-1 (YB-1) is a transcription factor that regulates the transcription of several genes and is highly expressed in liver injury. We explored the role of YB-1 in HPC proliferation and liver fibrosis. We detected increased expansion of HPCs and elevated levels of YB-1 in HPCs from patients with hepatitis B virus-related fibrosis and choline-deficient ethionine-supplemented or 5-diethoxycarbonyl-1,4-dihydrocollidine diet-induced mice compared with those in control groups. HPC-specific deletion of YB-1 using YB-1flox/flox; Foxl1-Cre+/- mice led to reduced HPC expansion and less collagen deposition in the liver tissues compared with that in Cre-/- mice. In cultured primary HPCs, YB-1 knockdown inhibited HPC proliferation. Further experiments indicated YB-1 negatively regulated p53 expression, and silencing of p53 blocked YB-1 knockdown-mediated inhibition of HPC proliferation. Collectively, YB-1 negatively regulates HPC proliferation and alleviates liver fibrosis by p53.

Reducing Hypothalamic Stem Cell Senescence Protects against Aging-Associated Physiological Decline.

Age-dependent loss of hypothalamic neural stem cells (htNSCs) is important for the pathological consequences of aging; however, it is unclear what drives the senescence of htNSCs. Here, we report that a long non-coding RNA, Hnscr, is abundantly expressed in the htNSCs of young mice but decreases markedly in middle-aged mice. We show that depletion of Hnscr is sufficient to drive the senescence of htNSCs and aging-like phenotypes in mice. Mechanistically, Hnscr binds to Y-box protein 1 (YB-1) to prevent its degradation and thus the attenuation of transcription of the senescence marker gene p16INK4A. Through molecular docking, we discovered that a naturally occurring small compound, theaflavin 3-gallate, can mimic the activity of Hnscr. Treatment of middle-aged mice with theaflavin 3-gallate reduced the senescence of htNSCs while improving aging-associated pathology. These results point to a mediator of the aging process and one that can be pharmacologically targeted to improve aging-related outcomes.

Quercetin reversed MDR in breast cancer cells through down-regulating P-gp expression and eliminating cancer stem cells mediated by YB-1 nuclear translocation.

Overexpression of P-glycoprotein (P-gp) plays an important role in mediating multidrug resistance (MDR), resulting in chemotherapy failure of tumor patients and enhancement of cancer stem cell characteristics. By preparing doxorubicin (Dox) resistant human breast cancer MCF-7 cells, here, we wanted to evaluate the effects of quercetin (Que) on MDR reversal activity and investigate its possible mechanism. MCF-7 and MCF-7/dox cells were respectively treated by Dox, paclitaxel (Pac), or vincristine (Vcr) with or without Que intervention for 24 hr. Cell viability, cell apoptosis, cell cycle, intracellular drug accumulation, the expression of P-gp and Y-box binding protein 1 (YB-1), and breast cancer stem cells (BCSCs) were then assessed. The results showed that Que significantly enhanced the antitumor activities of Dox, Pac, and Vcr in breast cancer cells. In addition, combined treatment of Dox, Pac, or Vcr with Que significantly downregulated P-gp expression and eliminated BCSCs. Furthermore, combined treatment of Dox, Pac, or Vcr with Que significantly inhibited nuclear translocation of YB-1. Thus, we speculated that Que reversed MDR in breast cancer cells through downregulating P-gp expression and eliminating cancer stem cells mediated by YB-1 nuclear translocation.

Aloe-emodin inhibits HER-2 expression through the downregulation of Y-box binding protein-1 in HER-2-overexpressing human breast cancer cells.

Human epidermal growth factor receptor-2 (HER-2)-positive breast cancer tends to be aggressive, highly metastatic, and drug resistant and spreads rapidly. Studies have indicated that emodin inhibits HER-2 expression. This study compared the HER-2-inhibitory effects of two compounds extracted from rhubarb roots: aloe-emodin (AE) and rhein. Our results indicated that AE exerted the most potent inhibitory effect on HER-2 expression. Treatment of HER-2-overexpressing breast cancer cells with AE reduced tumor initiation, cell migration, and cell invasion. AE was able to suppress YB-1 expression, further suppressing downstream HER-2 expression. AE suppressed YB-1 expression through the inhibition of Twist in HER-2-overexpressing breast cancer cells. Our data also found that AE inhibited cancer metastasis and cancer stem cells through the inhibition of EMT. Interestingly, AE suppressed YB-1 expression through the downregulation of the intracellular integrin-linked kinase (ILK)/protein kinase B (Akt)/mTOR signaling pathway in HER-2-overexpressing breast cancer cells. In vivo study showed the positive result of antitumor activity of AE in nude mice injected with human HER-2-overexpressing breast cancer cells. These findings suggest the possible application of AE in the treatment of HER-2-positive breast cancer.

A novel EGR-1 dependent mechanism for YB-1 modulation of paclitaxel response in a triple negative breast cancer cell line.

Chemotherapy with taxanes such as paclitaxel (PTX) is a key component of triple negative breast cancer (TNBC) treatment. PTX is used in combination with other drugs in both the adjuvant setting and in advanced breast cancer. Because a proportion of patients respond poorly to PTX or relapse after its use, a greater understanding of the mechanisms conferring resistance to PTX is required. One protein shown to be involved in drug resistance is Y-box binding protein 1 (YB-1). High levels of YB-1 have previously been associated with resistance to PTX in TNBCs. In this study, we aimed to determine mechanisms by which YB-1 confers PTX resistance. We generated isogenic TNBC cell lines that differed by YB-1 levels and treated these with PTX. Using microarray analysis, we identified EGR1 as a potential target of YB-1. We found that low EGR1 mRNA levels are associated with poor breast cancer patient prognosis, and that EGR1 and YBX1 mRNA expression was inversely correlated in a TNBC line and in a proportion of TNBC tumours. Reducing the levels of EGR1 caused TNBC cells to become more resistant to PTX. Given that PTX targets cycling cells, we propose a model whereby high YB-1 levels in some TNBC cells can lead to reduced levels of EGR1, which in turn promotes slow cell cycling and resistance to PTX. Therefore YB-1 and EGR1 levels are biologically linked and may provide a biomarker for TNBC response to PTX.

Inhibition of pro­collagen I expression by oxymatrine in hepatic stellate cells is mediated via nuclear translocation of Y­box binding protein 1.

Accumulating evidence indicated that oxymatrine (OMT), an alkaloid compound from the Chinese medicinal herb Sophora flavescens, exhibits activity against hepatic fibrosis. The present study attempted to explore the underlying mechanisms of OMT­mediated inhibition of collagen production. For this, the LX­2 human hepatic stellate cell line was treated with OMT (240, 480 or 960 mg/l) for 3­5 days. The endogenic expression of pro­collagen I was decreased by OMT in a dose­ and time­dependent manner, accompanied with the downregulation of Y­box binding protein 1 (YB­1), a vital transcription factor, particularly on the fourth day of incubation with a high concentration of OMT. To further explore the intracellular changes in YB­1 levels, nuclear/cytoplasmic proteins were extracted separately, and subsequent western blot analysis revealed a significant upregulation of YB­1 in the nucleus in parallel with its downregulation in the cytoplasm, indicating the nuclear translocation of YB­1 induced by OMT treatment. In another experiment, knockdown of YB­1 using small interfering RNA led to elevated mRNA levels of collagen I, thereby reversing the effects of OMT treatment. In conclusion, these present study suggested that the attenuation of pro­collagen I expression caused by OMT was, to a certain extent, mediated via nuclear translocation of YB­1.

[Effects of changwelqing on nuclear translocation of Y-box binding protein-1 and expression of P-glycoprotein in human colon cancer cell line with drug-resistance induced by vincristine].

OBJECTIVE: To evaluate the effects and molecular mechanism of action of Changweiqing (CWQ) in reversing multidrug resistance by observing its impacts on nuclear translocation of Y-box binding protein-1 (YB-1), multi-drug resistance gene (MDR1) expression and P-glycoprotein (P-gp) expression in human colon cancer cell line HCT8/V with drug-resistance induced by vincristine. METHODS: Cultured HCT8/V cells were exposed to the CWQ-containing rat serum prepared by drug perfusion. YB-1 expressions in cell plasma and nuclei were examined by Western blot; the binding activity of YB-1 to MDR1 gene promoter sequences was detected by electrophoretic mobility shift assay (EMSA); the mRNA transcription levels of MDR1, YB-1 and multi-resistance related protein (MRP) were examined by RT-PCR; the expression of P-gp on cell membrane was determined by flow cytometry. Results Along with the increasing drug's concentration of CWQ-containing serum from 1.25% up to 2.5% and 5%, the expressions of YB-1 decreased in HCT8/V cell nuclear and increased in cytoplasm gradually; the binding activity of YB-1 to MDR1 gene promoter weakened (P < 0.01), MDR1 mRNA expression and fluorescence intensity of P-gp on cell membrane attenuated (P < 0.05 or P < 0.01), while YB-1 and MRP mRNA unchanged (P > 0.05). CONCLUSION: CWQ could reverse the drug-resistance of colon cancer cells by influencing nuclear translocation of YB-1 and reducing the expression of MDR1/P-gp.

Y-box binding protein 1 is up-regulated in proliferative breast cancer and its inhibition deregulates the cell cycle.

The Y-box-binding protein 1 (YB-1), a member of the cold-shock domain RNA-and DNA-binding protein family, has pleiotropic functions such as regulation of the cell cycle. The aim of this study was to evaluate if YB-1 is a proliferative marker in breast cancer and elucidate potential downstream targets involved in YB-1-mediated cell cycle regulation using RNA interference technology. YB-1 protein expression was evaluated in tissue microarrays of 131 breast invasive ductal carcinomas by immunohistochemistry, while the YB-1 gene expression profile was evaluated in the T-47D, MDA-MB-231, ZR-75-1 and MCF7 breast cancer cell lines. Silencing of the YB-1 gene in T-47D breast cancer cells was performed using siRNA and the effects of down-regulation of YB-1 on cell growth and regulation of the cell cycle were ascertained. A focused panel of 84 genes involved in cell cycle progression was also examined. In tissue microarrays, YB-1 expression was shown to be associated with proliferating cell nuclear antigen (PCNA) immunostaining. siRNA-mediated silencing of the YB-1 gene inhibited cell proliferation and induced G1 phase cell cycle arrest in T-47D breast cancer cells. Knockdown of the YB-1 gene induced up-regulation of two genes which contribute to G1-arrest (RAD9A and CDKN3 genes) and down-regulation of ten genes associated with positive regulation of the cell cycle (SKP2, SUMO1, ANAPC4, CCNB1, CKS2, MNAT1, CDC20, RBBP8, KPNA2 and CCNC genes). The data obtained from the tissue microarrays and cell lines provide evidence that YB-1 is a reliable marker of cell proliferation and possibly a potential molecular target in breast cancer therapy.