Circular RNA circ_0096041 promotes osteosarcoma cell proliferation and migration via sponging miR-556-5p and regulating LIN28A expression.

Strategies targeting lin-28 homolog A (LIN28A) for the treatment of osteosarcoma are limited, even though salient findings have illustrated the crucial role of LIN28A in bone deformities and cancer. In the present study, we proved circ_0096041, one of the circular RNAs (circRNAs) with significant upregulated expression in osteosarcoma, to be notably engaged in the progression of osteosarcoma. We elucidated that osteosarcoma patients with highly expressed circ_0096041 had relatively worse prognoses. We determined that circ_0096041 potentially sponge miR-556-5p using the Circular RNA Interactome database. Meanwhile, we proved circ_0096041 was associated with miR-556-5p. Furthermore, we determined that miR-556-5p was targeted by LIN28A directly, evidenced by in silico analysis using the miRWALK tool and in vitro analysis. Functionally, our experimental setting aimed to explore the function of circ_0096041/miR-556-5p/LIN28A axis in vitro and in vivo. Our findings demonstrated that circ_0096041 boosted the proliferation and migration of osteosarcoma via LIN28A/miR-556-5p axis. In vivo models were further established to estimate the metastasis promoted by circ_0096041. This research elucidated the enhanced osteosarcoma progression by circ_0096041 and its potential mechanism, which provided innovative targets for osteosarcoma treatment.

Development of public sports and optimization of sports mode under the influence of covid-19 epidemic / Desenvolvimento de esportes públicos e otimização do modo esportivo sob influência da epidemia de covid-19 / El desarrollo del deporte público y la optimización del modelo deportivo bajo la influencia de la epidemia de covid - 19

ABSTRACT Introduction: The sports psychology of athletes and public service policies in various places have been adjusted under the influence of the epidemic of COVID-19. However, team sports also need adjustments, and the paucity of evidence prevents safe decision-making. Objective: Research the current model to outline optimizations to team sports public service during the epidemic of COVID-19. Methods: The mechanism of athletes' satisfaction was investigated, mainly involving organizing activities in sports venues, including geographical distribution, technical guidance, health services, etc. Results: According to the survey, the first concern was "organization of activities," with a score of 3.783; followed by "number of places," with a score of 3.252; and "health service," with a score of 3.142. In the athletes' satisfaction score relative to supply and demand, the first concern highlighted was "distribution of seats", with a score of 3.682; followed by "number of seats", with a score of 3.484; and "organization of activities", with a score of 3.112. Conclusion: In optimizing the public team sports service model, the actual needs of the facilities should be fully considered to achieve scientific optimization of supply and demand. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Tanto a psicologia esportiva dos atletas quanto as políticas de serviço público em vários lugares foram ajustadas sob a influência da epidemia da COVID-19. Os esportes em equipe também necessitam de adaptações e a escassez de evidências impede tomadas de decisões seguras neste aspecto. Objetivo: Pesquisar o modelo atual para traçar otimizações ao serviço público esportivo de equipe durante a epidemia da COVID-19. Métodos: O mecanismo de satisfação dos atletas foi investigado, envolvendo principalmente a organização de atividades em locais esportivos, incluindo distribuição geográfica, orientação técnica, serviços de saúde, etc. Resultados: De acordo com a pesquisa levantada, a primeira preocupação foi "organização de atividades", com pontuação de 3.783; seguido de "número de vagas", com pontuação de 3.252; e "serviço de saúde", com pontuação de 3.142. Na pontuação de satisfação das atletas relativa à oferta e demanda, a primeira preocupação destacada foi "distribuição de lugares", com pontuação de 3,682; seguida de "número de lugares", com pontuação de 3,484; e "organização de atividades", com pontuação de 3,112. Conclusão: No processo de otimização do modelo de serviço público esportivo de equipes, as necessidades reais das instalações devem ser plenamente consideradas, a fim de alcançar a otimização científica da oferta e da demanda. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: Tanto la psicología deportiva de los atletas como las políticas de servicios públicos en diversos lugares se han ajustado bajo la influencia de la epidemia de COVID-19. Los deportes de equipo también necesitan ajustes y la escasez de pruebas impide tomar decisiones seguras al respecto. Objetivo: Investigar el modelo actual para delinear optimizaciones al servicio público de los deportes de equipo durante la epidemia de COVID-19. Métodos: Se investigó el mecanismo de satisfacción de los atletas, que involucra principalmente la organización de actividades en las instalaciones deportivas, incluyendo la distribución geográfica, la orientación técnica, los servicios de salud, etc. Resultados: Según la encuesta realizada, la primera preocupación era la "organización de las actividades", con una puntuación de 3,783; seguida del "número de plazas", con una puntuación de 3,252; y del "servicio sanitario", con una puntuación de 3,142. En la puntuación de satisfacción de los atletas en relación con la oferta y la demanda, la primera preocupación destacada fue la "distribución de los lugares", con una puntuación de 3,682; seguida del "número de lugares", con una puntuación de 3,484; y de la "organización de las actividades", con una puntuación de 3,112. Conclusión: En el proceso de optimización del modelo de servicio público de deportes de equipo, deben tenerse plenamente en cuenta las necesidades reales de las instalaciones para lograr una optimización científica de la oferta y la demanda. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Exosome-mediated circ_0001846 participates in IL-1ß-induced chondrocyte cell damage by miR-149-5p-dependent regulation of WNT5B.

AIMS: Osteoarthritis (OA) is the leading cause of physical disability in middle-aged and elderly people globally. Previous studies have revealed that circular RNA (circRNA) is involved in the pathogenesis of OA. In this study, we studied the role of circ_0001846 in interleukin-1ß (IL-1ß)-induced OA progression. METHODS: Twenty-one patients with OA and 17 volunteers were recruited for the collection of articular cartilage tissues. The expression of circ_0001846, microRNA-149-5p (miR-149-5p) and Wingless-type MMTV integration site family, member 5B (WNT5B) was detected by quantitative real-time polymerase chain reaction. The protein expression was determined by western blot analysis. Cell viability, apoptosis, invasion and migration were demonstrated by cell counting kit-8, flow cytometry analysis, transwell invasion and wound-healing assays, respectively. The levels of IL-6 and tumor necrosis factor-α were detected by Enzyme-linked immunosorbent assay. The interaction between miR-149-5p and circ_0001846 or WNT5B was predicted by starbase online database, and proved by dual-luciferase reporter and RIP assays. RESULTS: Circ_0001846 and WNT5B expression were upregulated, while miR-149-5p expression was downregulated in articular cartilage tissues from patients with OA and IL-1ß-treated CHON-001 cells compared with normal articular cartilage tissues or untreated CHON-001 cells. Circ_0001846 expression was increased in IL-1ß-treated CHON-001 cell exosomes. Circ_0001846 knockdown reversed IL-1ß-mediated cell proliferation, apoptosis, migration, invasion, inflammation and extracellular matrix (ECM) degradation in CHON-001 cells. Additionally, circ_0001846 participated in IL-1ß-induced chondrocyte cell damage by sponging miR-149-5p. MiR-149-5p mediated IL-1ß-induced chondrocyte cell dysfunction by targeting WNT5B. Furthermore, circ_0001846 secretion was mediated by exosomes in IL-1ß-treated CHON-001 cells. CONCLUSION: Exosome-mediated transfer of circ_0001846 modulated IL-1ß-induced chondrocyte cell damage by miR-149-5p/WNT5B axis, providing a novel avenue for the therapy of OA.

Fatty acid synthase inhibition activates AMP-activated protein kinase in SKOV3 human ovarian cancer cells.

Fatty acid synthase (FAS), the enzyme responsible for the de novo synthesis of fatty acids, is highly expressed in ovarian cancers and most common human carcinomas. Inhibition of FAS and activation of AMP-activated protein kinase (AMPK) have been shown to be cytotoxic to human cancer cells in vitro and in vivo. In this report, we explore the cytotoxic mechanism of action of FAS inhibition and show that C93, a synthetic FAS inhibitor, increases the AMP/ATP ratio, activating AMPK in SKOV3 human ovarian cancer cells, which leads to cytotoxicity. As a physiologic consequence of AMPK activation, acetyl-CoA carboxylase (ACC), the rate-limiting enzyme of fatty acid synthesis, was phosphorylated and inhibited whereas glucose oxidation was increased. Despite these attempts to conserve energy, the AMP/ATP ratio increased with worsening cellular redox status. Pretreatment of SKOV3 cells with compound C, an AMPK inhibitor, substantially rescued the cells from C93 cytotoxicity, indicating its dependence on AMPK activation. 5-(Tetradecyloxy)-2-furoic acid, an ACC inhibitor, did not activate AMPK despite inhibiting fatty acid synthesis pathway activity and was not significantly cytotoxic to SKOV3 cells. This indicates that substrate accumulation from FAS inhibition triggering AMPK activation, not end-product depletion of fatty acids, is likely responsible for AMPK activation. C93 also exhibited significant antitumor activity and apoptosis against SKOV3 xenografts in athymic mice without significant weight loss or cytotoxicity to proliferating cellular compartments such as bone marrow, gastrointestinal tract, or skin. Thus, pharmacologic FAS inhibition selectively activates AMPK in ovarian cancer cells, inducing cytotoxicity while sparing most normal human tissues from the pleiotropic effects of AMPK activation.

Fatty acid synthase inhibition triggers apoptosis during S phase in human cancer cells.

C75, an inhibitor of fatty acid synthase (FAS), induces apoptosis in cultured human cancer cells. Its proposed mechanism of action linked high levels of malonyl-CoA after FAS inhibition to potential downstream effects including inhibition of carnitine palmitoyltransferase-1 (CPT-1) with resultant inhibition of fatty acid oxidation. Recent data has shown that C75 directly stimulates CPT-1 increasing fatty acid oxidation in MCF-7 human breast cancer cells despite inhibitory concentrations of malonyl-CoA. In light of these findings, we have studied fatty acid metabolism in MCF7 human breast cancer cells to elucidate the mechanism of action of C75. We now report that: (a) in the setting of increased fatty acid oxidation, C75 inhibits fatty acid synthesis; (b) C273, a reduced form of C75, is unable to inhibit fatty acid synthesis and is nontoxic to MCF7 cells; (c) C75 and 5-(tetradecyloxy)-2-furoic acid (TOFA), an inhibitor of acetyl-CoA carboxylase, both cause a significant reduction of fatty acid incorporation into phosphatidylcholine, the major membrane phospholipid, within 2 h; (d) pulse chase studies with [(14)C]acetate labeling of membrane lipids show that both C75 and TOFA accelerate the decay of (14)C-labeled lipid from membranes within 2 h; (e) C75 also promotes a 2-3-fold increase in oxidation of membrane lipids within 2 h; and (f) because interference with phospholipid synthesis during S phase is known to trigger apoptosis in cycling cells, we performed double-labeled terminal deoxynucleotidyltransferase-mediated nick end labeling and BrdUrd analysis with both TOFA and C75. C75 triggered apoptosis during S phase, whereas TOFA did not. Moreover, application of TOFA 2 h before C75 blocked the C75 induced apoptosis, whereas etomoxir did not. Taken together these data indicate that FAS inhibition and its downstream inhibition of phospholipid production is a necessary part of the mechanism of action of C75. CPT-1 stimulation does not likely play a role in the cytotoxic response. The continued ability of TOFA to rescue cancer cells from C75 cytotoxicity implies a proapoptotic role for malonyl-CoA independent of CPT-1 that selectively targets cancer cells as they progress into S phase.

Variable levels of chromosomal instability and mitotic spindle checkpoint defects in breast cancer.

Cytogenetic analyses have revealed that many aneuploid breast cancers have cell-to-cell variations of chromosome copy numbers, suggesting that these neoplasms have instability of chromosome numbers. To directly test for possible chromosomal instability in this disease, we used fluorescent in situ hybridization to monitor copy numbers of multiple chromosomes in cultures of replicating breast cancer-derived cell lines and nonmalignant breast epithelial cells. While most (7 of 9) breast cancer cell lines tested are highly unstable with regard to chromosome copy numbers, others (2 of 9 cell lines) have a moderate level of instability that is higher than the "background" level of normal mammary epithelial cells and MCF-10A cells, but significantly less than that seen in the highly unstable breast cancer cell lines. To evaluate the potential role of a defective mitotic spindle checkpoint as a cause of this chromosomal instability, we used flow cytometry to monitor the response of cells to nocodazole-induced mitotic spindle damage. All cell lines with high levels of chromosomal instability have defective mitotic spindle checkpoints, whereas the cell lines with moderate levels of chromosomal instability (and the stable normal mammary cells and MCF10A cells) arrest in G(2) when challenged with nocodazole. Notably, the extent of mitotic spindle checkpoint deficiency and chromosome numerical instability in these cells is unrelated to the presence or absence of p53 mutations. Our results provide direct evidence for chromosomal instability in breast cancer and show that this instability occurs at variable levels among cells from different cancers, perhaps reflecting different functional classes of chromosomal instability. High levels of chromosomal instability are likely related to defective mitotic checkpoints but not to p53 mutations.

Staurosporine-induced G(1) arrest in cancer cells depends on an intact pRB but is independent of p16 status.

Staurosporine and its derivative 7-hydroxystaurosporine are protein kinase inhibitors that are being considered for treatments of cancers. Several recent studies have shown that cells with defective pRB protein are resistant to the G(1) cell cycle-inhibiting effects of staurosporine compounds. In this study, we examined the effect of staurosporine on two breast cancer-derived and three lung cancer-derived cell lines characterized by deficiencies in the p16 tumor suppressor. All of these p16-deficient cell lines are highly sensitive to staurosporine-induced inhibition of pRB phosphorylation and induction of arrest in G(1). This response is similar to that seen in cultured normal human bronchial epithelial cells and normal mammary epithelial cells, but strikingly different than the staurosporine resistance seen in cancer cells with defective pRB. Interestingly, inhibition of pRB phosphorylation could be seen within 4 h of treatment, suggesting that this inhibition is a consequence of direct effects of staurosporine on protein kinase(s) rather than a result of induction of other cyclin-dependent kinase inhibitors. Our findings suggest that different types of cancer cells have vastly different responses to the staurosporine class of agents, and that evaluation of pRB and p16 will help predict the response of the cancer cells to these agents.