Deficiency in trefoil factor 1 (TFF1) increases tumorigenicity of human breast cancer cells and mammary tumor development in TFF1-knockout mice

Although trefoil factor 1 (TFF1; previously named pS2) is abnormally expressed in about 50% of human breast tumors, its physiopathological role in this disease has been poorly studied. Moreover, controversial data have been reported. TFF1 function in the mammary gland therefore needs to be clarified. In this study, using retroviral vectors, we performed TFF1 gain- or loss-of-function experiments in four human mammary epithelial cell lines: normal immortalized TFF1-negative MCF10A, malignant TFF1-negative MDA-MB-231 and malignant TFF1-positive MCF7 and ZR75.1. The expression of TFF1 stimulated the migration and invasion in the four cell lines. Forced TFF1 expression in MCF10A, MDA-MB-231 and MCF7 cells did not modify anchorage-dependent or -independent cell proliferation. By contrast, TFF1 knockdown in MCF7 enhanced soft-agar colony formation. This increased oncogenic potential of MCF7 cells in the absence of TFF1 was confirmed in vivo in nude mice. Moreover, chemically induced tumorigenesis in TFF1-deficient (TFF1-KO) mice led to higher tumor incidence in the mammary gland and larger tumor size compared with wild-type mice. Similarly, tumor development was increased in the TFF1-KO ovary and lung. Collectively, our results clearly show that TFF1 does not exhibit oncogenic properties, but rather reduces tumor development. This beneficial function of TFF1 is in agreement with many clinical studies reporting a better outcome for patients with TFF1-positive breast primary tumors

Lalande's geographical conception of Africa : European exploration and the scientific call of the Continent's 'Inner Regions' on the verge of the Revolutionary Era

This paper discusses the Mémoire sur l'intérieur de l'Afrique, written by the French scholar Joseph Jérôme Lefrançois de Lalande. It analyses Lalande's aims, arguments and claims regarding his subject of study - the "inner parts" of Africa - against the background of scientific, commercial, political and military tensions between France and Britain. It situates Lalande's discourse within the broader context of the competing "science policies" of both states in the second half of the eighteenth century. It is an investigation of the sudden re-emergence of Africa as an object of knowledge in the relationship between power and science. The paper focuses on the continuous interaction between France and Britain in African affairs, and highlights the shift from a mere "Enlightened" exploration from the 1720s to Lalande's revolutionary time, when Africa became the object of a "Banksian" takeover, enhancing British interest in the "unknown" interior of the African continent by setting up large-scale, interrelated research missions with practical goals. This provoked reactions from the French side, reflected in Lalande's dissertation