Abstract We have recently shown that polyploid giant cancer cells (PGCCs) are capable of tumor initiation and acquisition of embryonic-like stemness and thus represent a novel type of cancer stem cells. However, two important questions remain to be answered from this surprising finding: (1) how PGCCs acquire such stemness; (2) on which stage of normal development PGCCs correspond to. Here, we tracked the fate of single PGCCs induced via mitotic failure by paclitaxel. Morphologically, early spheroids derived from PGCCs were indistinguishable from human embryos at the polyploid blastomere, compaction, morula, and blastocyst-like stages by scanning electron microscopy. PGCCs showed time- and space-dependent activation of expression of the embryonic stem cell markers OCT4, NANOG, SOX2, and SSEA-1 and lacked expression of Xist. PGCCs also showed time-dependent activation of expression of the germ layer-specific markers alpha-fetoprotein, smooth muscle actin, and β3-tubulin and were capable of redifferentiation into three germ layers in vitro. PGCCs-derived daughter cells showed attenuated invasive ability and increased resistance to paclitaxel. PGCCs-derived spheroids grew into a wide spectrum of human neoplasms, including malignant dysgerminoma and embryonic carcinoma, poorly differentiated or well-differentiated carcinomas, and benign squamous tissue. We also observed PGCCs in ovarian cancer from patients treated with chemotherapy. Thus, our data demonstrated that PGCCs acquired novel cancer stem cell properties and capability to redifferentiate into different tumors including the germ cell tumors, which are at the topmost developmental hierarchy. Our studies, for the first time, link PGCCs to the polyploid blastomere-like cancer stem cells and thus offer a new paradigm for the origin of cancer. Citation Format: Na Niu, Jinsong Liu. Dedifferentiation into polyploid blastomere-like cancer stem cells via formation of polyploid giant cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 924. doi:10.1158/1538-7445.AM2017-924
Abstract Background Long noncoding RNAs (lncRNAs) OGFRP1 is up-regulated in endometrial cancer and cervical carcinoma, and OGFRP1 suppression inhibits the malignant behavior of cancer cells. Here, we evaluated the expression pattern, biological function and potential mechanism of OGFRP1 in non-small cell lung cancer (NSCLC). Methods The expression of target genes in 25 pairs of clinically collected NSCLC and normal lung tissue samples was detected by qRT-PCR or western blot. We screened the siRNA (siOGFRP1) to down-regulate the expression of OGFRP1 in A549 and H1299 cells. The biological function of A549 and H1299 cells were examined by CCK8, wound healing and transwell assays. The molecular mechanism of OGFRP1 was further explored. Results The expression of OGFRP1 in NSCLC tissues were higher than that in normal lung tissue. siOGFRP1 inhibited the proliferation, migration and invasion of A549 and H1299 cells. In addition, the expression of EMT-related and apoptosis-related proteins was changed by siOGFRP1 transfection. OGFRP1 can directly interact with miR-4640-5p, and siOGFRP1 increased the level of miR-4640-5p. Moreover, miR-4640-5p could directly bind to the 3’ UTR region of eIF5A mRNA. eIF5A was highly expressed in NSCLC tissues, and predicted a poor prognosis. In addition, the expression of miR-4640-5p and eIF5A in NSCLC tissues were negatively correlated, while the expression of OGFRP1 and eIF5A were positively correlated. Knockdown of OGFRP1 inhibited the expression of eIF5A, while transfection of miR-4640-5p inhibitor up-regulated the expression of eIF5A. Conclusions Taken together, we demonstrated that down-regulation of OGFRP1 inhibited the progression of NSCLC through miR-4640-5p/eIF5A axis.
Brown adipose tissue (BAT) is important in monitoring energy homeostasis and cancer cachexia. Different from white adipose tissue, BAT is characterized by the presence of a large number of mitochondria in adipocytes. Translocator protein 18 kDa (TSPO), a critical transporter, is expressed in the outer membrane of mitochondria. We speculated that [18F]DPA714, a specific TSPO tracer, may monitor BAT activity in tumor-bearing mice in vivo. We first analyzed the radioactive uptake of positron emission tomography (PET) tracers in BAT of CT26 xenograft mice with 18F-fluorodeoxyglucose ([18F]FDG) and [18F]DPA714. We also studied the BAT uptake of [18F]DPA714 in CT26, A549 and LLC tumor models. The dynamic distribution of [18F]FDG is quite variable among animals, even in mice of the same tumor model (%ID/g-mean: mean ± SDM, 8.61 ± 8.90, n = 16). Contrarily, [18F]DPA714 produced high-quality and stable BAT imaging in different tumor models and different animals of the same model. Interestingly, %ID/g-mean of [18F]DPA714 in BAT was significantly higher on day 26 than that on day 7 in CT26 xenograft model. Taken together, these results strongly indicate the potential feasibility of [18F]DPA714 PET imaging in investigating BAT and energy metabolism during tumor progression in preclinical and clinical study.
Alzheimer's disease is the most common cause of dementia in the current elderly population. PET can detect pathophysiological changes in Alzheimer's disease with different radiotracers. This paper will focus on evaluating the value of 18F-FDG, amyloid and tau protein PET imaging in Alzheimer's disease. PET has been demonstrated to play an important role in the research of etiology, early diagnosis, differential dignosis, prognosis and medical treatment of Alzheimer's disease. doi: 10.3969/j.issn.1672-6731.2014.03.007
Purpose.: RPE is a key component of the blood-ocular barrier (BOB) and is equipped with immunological molecules such as toll-like receptors (TLRs) and complement receptors, which together orchestrate the innate and adaptive immunity of the eye. Immunoglobulin G (IgG) in the aqueous humor and vitreous body has traditionally been thought to be derived from serum via transcytosis across the BOB. Our previous work validated production of endogenous IgG by RPE cells locally. However, the function and role of this IgG in the intraocular immunity is poorly understood. Methods.: After confirming IgG production in a human RPE cell line (ARPE-19) with immunofluorescence, in situ hybridization, and RT-PCR, we further investigated the function of endogenous IgG in RPE biology with MTS, flow cytometry, and cell invasion analysis after downregulation of IgG by siRNA. Involvement of the TLR4 pathway was also studied using Western blot, ELISA and confocal microscopy. Results.: Endogenous IgG is crucial for support of proliferation, mitosis, migration, and inhibition of apoptosis of RPE. Moreover, production of endogenous IgG by RPE is regulated by the TLR4 pathway in a concentration- and duration-dependent manner, and IgG affects the activation of the TLR4 pathway in a synergistic manner. Activation of the FcγR I pathway and production of IL-10 could be induced by IgG derived from RPE. Conclusions.: These data suggest that endogenous IgG may be a molecule that is essential for the physiological function of RPE, and suggest IgG is important for regulating intraocular immune responses under physiologic and pathologic conditions.
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