The role of PI3K/AKT/TSC/p70S6K1 pathway in tumor growth and angiogenesis

PI3K/AKT pathway plays an important role in tumor progression and angiogenesis. To determine the specific role of PI3K isoform p110alpha in ovarian cancer, we designed small interfering RNA (siRNA) against p110alpha. The expression of p110alpha siRNA significantly decreased cell migration, invasion, and proliferation. AKT has three different isoforms: AKT1, AKT2 and AKT3. We found that downregulation of AKT1 is sufficient to inhibit cell migration, invasion, and proliferation in ovarian cancer cells. The activation of p70S6K1 was decreased in both p110alpha and AKT1 siRNA-expressing cells. Inhibition of p70S6K1 activity also decreased cell migration, invasion, and proliferation.;The tuberous sclerosis complex-2 (TSC2) lies upstream of mTOR/p70S61 and downstream of AKT. Loss of TSC2 expression is observed in human cancer. To study the function of TSC2 in ovarian tumor angiogenesis, we established stable cell lines that express siRNA specific to TSC1 and TSC2. In this study, we show that inhibition of TSC1 and TSC2 increased the expression of HIF-1alpha in ovarian cancer cells. Inhibition of TSC1 and TSC2 upregulated VEGF expression at both mRNA and protein levels. Downregulation of TSC2 induced ovarian tumor angiogenesis and tumor growth through mTOR/p70S6K1. The expression of p70S6K1 siRNA decreased VEGF protein expression and VEGF transcriptional activation through the HIF-1alpha binding site. The expression of p70S6K1 siRNA specifically inhibited HIF-1alpha expression in ovarian cancer cells. We also found that p70S6K1 down-regulation decreased ovarian tumor growth and tumor angiogenesis. This study provides a novel molecular mechanism of human ovarian cancer induced by the activation of p70S6K1.;Survivin gene is highly expressed in ovarian cancer cell lines and is a potential target of gene therapy for ovarian cancer. Our study showed that expression of survivin siRNA induced cell apoptosis when combined with LY294002 or taxol treatment. We determined that suvivin mRNA is regulated by PI3K/AKT/p70S6K1 pathway. Survivin is an important downstream molecule of PI3K/AKT/p70S6K1 pathway that plays a role in antiapoptosis in ovarian cancer cells

Resistance against and collusion with colonialism: Eileen Chang’s writing and translation of “Steamed Osmanthus Flower Ah Xiao’s Unhappy Autumn”

Despite rising to stardom with her brilliant writings in Shanghai in the 1940s, Eileen Chang was criticised by the Leftist writers of her time and other later critics for failing to represent the general political panorama in China. In fact, they studied her works only with regard to the relations between her and China, but ignored the relationship between her, a writer of a semi-colonised nation, and the colonisers. However, through the analysis of her Chinese short story “Steamed Osmanthus Flower Ah Xiao’s Unhappy Autumn” (1944) and her own translation of it into English nentitled “Shame, Amah!” (1962) after her migration to the United States, this study explores how Chang resists colonialism through various means in the original text, and how such resistance is largely changed to collusion in the translation. The comparison between the source text and the translation reveals the dilemma of the diasporic writer - under the powerful domination of the host society, assimilation is inevitable; but at the same time, the writer is also trying hard to hold on to his or her own cultural traces

Grassland ecology : an analysis of Wolf Totem from an ecological perspective.

Much discussion has been done on Jiang Rong’s presentation of the national character of the Chinese in Wolf Totem, so that it overshadows an equally important aspect of the novel: the grassland ecology. Thus, we aim to contrast the different attitudes towards nature of the nomadic Mongols on the one pole, and the Han Chinese, the migrant and young Mongols on the other. Besides, we try to summarize the nomads’s ecosophy as reflected in the novel. Ecotheory, especially Arne Naess’ ecosophy T offers a very efficient tool for our exploration. One problem yet to be solved, however, is the regression of the traditional ecosophy engendered by the challenges from different social forces such as politics and economy. Thus, how to preserve the traditional positive ecosophy needs efforts from all parties apart from the ecologists

The Imperial Discourse and Roger’s Tragic Death in “Aloewood Incense: Second Burning”

Some scholars hold that Roger’s death in “Aloewood Incense: Second Burning” (1943) was caused by the repulsion from his colleagues and students, this paper, however, maintains that the imperial discourse regarding sexuality and the grand design of colonialism deprived Roger of a sense of belonging in Hong Kong and marginalised him, leaving him with nothing but alienation within the diasporic community and no choice but death. Chang’s exposure of the devastating effect of imperial discourse on its expatriates denounced the superiority of the western culture, indicating her sharp vision as an intellectual

Ethnicity and the Subjectivity of Malaysian-Chinese Diasporic Writers

Diasporic writers are blessed with two cultures. Their choice of which culture to identify with may be promoted by social circumstances. During the 1970s and the 1980s when Malaysia prioritized the Malays and the Chinese were marginalized and reduced to an inferior position in the country, Malaysian-Chinese writers turned traditional Chinese culture into cultural capital to bring comfort and consolation for their community. Besides, they wrote to protest the country’s unfair treatment of the Chinese, lamented the aphasiac state of their fellowmen and defied the nation’s actualizing attempts to stifle the ethnicity of the Chinese. The Malaysian-Chinese writers’ choice of ethnic identity indicated that they were not passive targets to consent the power of the dominant discourse; and it highlighted their subjectivity as diasporic writers

Pure Ethnicity in Hybridisation: A Returnee’s Quest for Chineseness in Love in a Fallen City.

Some critics find Fan Liuyuan, the male protagonist in Eileen Chang’s novella Love in a Fallen City (1943), to be a rake; what they fail to take into account, however, is the complexity of Fan Liuyuan’s identity as well as his predicaments, both before and after his return to China. By adopting the concept of diaspora, the present study explores how his desire for the absent authentic Chinese culture is developed, and how his failure to come to terms with the paradox of hybridization and pure ethnicity results in a process of fruitless attempts to construct his cultural identity in his homeland. Eileen Chang’s depiction of this futile pursuit indicates that pure “Chineseness” exists only in the diasporic imagination, rather than in any tangible object or place, not even in the Chinese homeland. Such a revelation negates the essentialization of pure Chineseness, and allows for more diverse articulations of diasporic ethnicity

Radio-to-TeV Phase-resolved Emission from the Crab Pulsar: The Annular Gap Model

In the framework of the three-dimensional (3D) annular gap model with reasonable parameters (the magnetic inclination angle \alpha = 45 deg and the view angle \zeta = 63 deg), we first use the latest hight energy data to self-consistently calculate radio, X-ray, gamma-ray and TeV (MAGIC and VERITAS) light curves, phase-averaged spectrum and phase-resolved spectra for the Crab pulsar. It is found that the acceleration electric field and potential in the annular gap and core gap are huge enough in the several tens of neutron star radii. The pulsed emission of radio, X-ray, gamma-ray and TeV are mainly generated from the emission of primary particles or secondary particles with different emission mechanisms in the nearly similar region of the annular gap located in the only one magnetic pole, which leads to the nearly "phase-aligned" multi-wavelength light curves. The emission of peak 1 (P1) and peak 2 (P2) is originated from the annular gap region near the null charge surface, while the emission of bridge is mainly originated from the core gap region. The phase-averaged spectrum and phase-resolved spectra of the Crab pulsar from soft X-ray to TeV band are produced by four components: synchrotron radiation from CR-induced and ICS-induced pairs dominates the X-ray band to soft gamma-ray band (100 eV to 10 MeV); curvature radiation and synchrotron radiation from the primary particles mainly contribute to gamma-ray band (10 MeV to \sim 20 GeV); ICS from the pairs significantly contributes to the TeV gamma-ray band (\sim 20 GeV to 400 GeV). The multi-wavelength pulsed emission from the Crab pulsar has been well modeled with the annular gap and core gap model. To distinguish our single magnetic pole model from two-pole models, the convincing values of the magnetic inclination angle and the viewing angle will play a key role.Comment: 12 pages, 7 figures, 3 tables; published in ApJ on March 12. Due to the character limitation, the abstract here has been adopted a shortened versio