Acute myeloid leukemia is an aggressive disease characterized by clonal proliferation and differentiation into immature hematopoietic cells of dysfunctional myeloid precursors. Accumulating evidence shows that CD34+CD38- leukemia stem cells (LSCs) are responsible for drug resistance, metastasis, and relapse of leukemia. In this study, we found that Nanog, a transcription factor in stem cells, is significantly overexpressed in CD34+ populations from patients with acute myeloid leukemia and in LSCs from leukemia cell lines. Our data demonstrate that the knockdown of Nanog inhibited proliferation and induced cell cycle arrest and cell apoptosis. Moreover, Nanog silencing suppressed the leukemogenesis of LSCs in mice. In addition, we found that these functions of Nanog were regulated by the insulin-like growth factor receptor (IGF1R) signaling pathway. Nanog overexpression rescued the colony formation ability of LSCs treated with picropodophyllin (PPP), an IGF1R inhibitor. By contrast, knockdown of Nanog abolished the effects of IGF2 on the colony formation ability of these LSCs. These findings suggest that the IGF2/IGF1R/Nanog signaling pathway plays a critical role in LSC proliferation.
Pogostemon cablin (Blanco) Benth. (Patchouli) is not only an important essential oil plant, but also a valuable medicinal plant in China. P . cablin in China can be divided into three cultivars (Shipai, Gaoyao, and Hainan) and two chemotypes (pogostone-type and patchoulol-type). The pogostone-type and patchoulol-type are, respectively, used for medicinals and perfumes. In this study, we sequenced and characterized the plastid genomes for all three Chinese cultivars and aimed to develop a chemotype-specific barcode for future quality control. The plastid genomes of P . cablin cultivars ranged from 152,461 to 152,462 bp in length and comprise 114 genes including 80 protein coding genes, 30 tRNA genes, and four rRNA genes. Phylogenetic analyses suggested that P . cablin cultivars clustered with the other two Pogostemon species with strong support. Although extremely conserved in P . cablin plastid genomes, 58 cpSSRs were filtered out among the three cultivars. One single variable locus, cpSSR, was discovered. The cpSSR genotypes successfully matched the chemotypes of Chinese patchouli, which was further supported by PCR-based Sanger sequences in more Chinese patchouli samples. The barcode developed in this study is thought to be a simple and reliable quality control method for Chinese P . cablin on the market.
Polycystic ovary syndrome (PCOS) is an endocrinopathy with complex pathophysiology that is a common cause of anovulatory infertility in women. Although the disruption of circadian rhythms is indicated in PCOS, the role of the clock in the etiology of these pathologies has yet to be appreciated. The nuclear receptors REV-ERBα and REV-ERBβ are core modulators of the circadian clock and participate in the regulation of a diverse set of biological functions. However, in PCOS, the expression of REV-ERBs and their effects remain unclear. Here, we demonstrate that the levels of REV-ERBα and REV-ERBβ expression were lower in the granulosa cells of PCOS patients than in control subjects. In vitro, we found that the overexpression of REV-ERBα and REV-ERBβ, and their agonist SR9009, promoted the expression of mitochondrial biosynthesis genes PGC-1α, NRF1, and TFAM and inhibited autophagy in KGN cells. Our results also indicate that REV-ERBα and REV-ERBβ can inhibit apoptosis in granulosa cells and promote proliferation. Importantly, the REV-ERB agonist SR9009 ameliorates abnormal follicular development by promoting mitochondrial biosynthesis and inhibiting autophagy in a mouse PCOS model. This allows us to speculate that SR9009 has potential as a therapeutic agent for the treatment of PCOS.
Background Endometriosis, the presence of active endometrial tissue outside the lining membrane of the uterine cavity, is a common disease in women of childbearing age. The ectopic endometrium has some characteristics of tumor tissue, including invasive and migratory abilities. In addition, endometriosis is associated with inflammation and reduced cellular apoptosis. Methods Western blot analysis, qPCR, immunohistochemistry, immunofluorescence microscopy, Transwell assay, wound healing assay, and TUNEL staining. Results Interleukin-1β (IL-1β) induced WEE1 expression in endometrial stromal cells (ESCs), suggesting that WEE1 may be upregulated during the endometriosis-induced inflammatory response. Overexpression of WEE1 in cultured ESCs promoted ESC migration while inhibiting apoptosis, whereas WEE1 knockdown reduced ESC migration while promoting apoptosis. Inhibition of WEE1 attenuates fibrosis in ESCs and female C57BL/6 J mice. This pro-fibrotic effect of WEE1 was significantly decreased by treatment with the Wnt/β-catenin inhibitor XAV939, suggesting that WEE1 acts via the Wnt/β-catenin signaling pathway. Conclusion Our study demonstrates that WEE1 promotes ESC migration and fibrosis via the Wnt/β-catenin signaling pathway. Thus, WEE1 may serve as a potential therapeutic target for the treatment of endometriosis.
Many studies have demonstrated that cancer stem cells (CSCs) or tumor-initiating cells (TICs) are responsible for tumor cell proliferation, chemotherapy resistance, metastasis, and relapse in various cancers. We, and others, have previously shown that the signal transducer and activator of transcription 3 (STAT3) signaling pathway is responsible for CSCs and TICs growth. Recent reports have indicated that the heat shock protein 90 (Hsp90) is also essential for the survival of CSCs and TICs. SNX-2112 is an Hsp90 inhibitor. However, it remains unclear whether proliferation of esophageal cancer stem-like cells (ECSLCs) is suppressed by SNX-2112 with knockdown of STAT3 (shSTAT3). Here, we explored the association between SNX-2112 with shSTAT3 and the suppression of ECSLCs growth. We found that the expression level of both STAT3 and p-STAT3 was higher in clinical esophageal cancer tissue than in the adjacent normal tissue, using western blot and qPCR analysis. Furthermore, differential expression analysis demonstrated that STAT3 was overexpressed in clinical specimens. We demonstrated that SNX-2112 inhibited cancer cell proliferation, decreased ABCB1 and ABCG2 gene expression levels and reduced the colony formation capacity of ECSLCs, which was enhanced by STAT3 silencing. Flow cytometry analysis revealed that the combination of SNX-2112 and shSTAT3 significantly induced apoptosis and cell cycle arrest at G2/M phase in ECSLCs. Levels of proliferation pathway proteins, including p38, c-Jun N-terminal kinase (JNK), and extracellular signal–regulated kinase (ERK) which were also client proteins of Hsp90, were also reduced. In addition, SNX-2112 with shSTAT3 inhibited the proliferation of ECSLCs in vivo. Finally, STAT3 overexpression eliminated the apoptotic and antiproliferative effects of SNX-2112 on ECSLCs. Hence, these results provide a rationale for the therapeutic potential of the combination of SNX-2112 with shSTAT3 in esophageal cancer, and may indicate new targets for clinical intervention in human cancer.
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