Autocrine laminin-5 ligates α6β4 integrin and activates RAC and NFκB to mediate anchorage-independent survival of mammary tumors

Invasive carcinomas survive and evade apoptosis despite the absence of an exogenous basement membrane. How epithelial tumors acquire anchorage independence for survival remains poorly defined. Epithelial tumors often secrete abundant amounts of the extracellular matrix protein laminin 5 (LM-5) and frequently express α6β4 integrin. Here, we show that autocrine LM-5 mediates anchorage-independent survival in breast tumors through ligation of a wild-type, but not a cytoplasmic tail–truncated α6β4 integrin. α6β4 integrin does not mediate tumor survival through activation of ERK or AKT. Instead, the cytoplasmic tail of β4 integrin is necessary for basal and epidermal growth factor–induced RAC activity, and RAC mediates tumor survival. Indeed, a constitutively active RAC sustains the viability of mammary tumors lacking functional β1 and β4 integrin through activation of NFκB, and overexpression of NFκB p65 mediates anchorage-independent survival of nonmalignant mammary epithelial cells. Therefore, epithelial tumors could survive in the absence of exogenous basement membrane through autocrine LM-5–α6β4 integrin–RAC–NFκB signaling

Autocrine laminin-5 ligates {alpha}6{beta}4 integrin and activates RAC and NF{kappa}B to mediate anchorange-independent survival of mammary tumors

Invasive carcinomas survive and evade apoptosis despite the absence of an exogenous basement membrane. How epithelial tumors acquire anchorage independence for survival remains poorly defined. Epithelial tumors often secrete abundant amounts of the extracellular matrix protein laminin 5 (LM-5) and frequently express α6β4 integrin. Here, we show that autocrine LM-5 mediates anchorage independent survival in breast tumors through ligation of a wild-type, but not a cytoplasmic tail–truncated α6β4 integrin. α6β4 integrin does not mediate tumor survival through activation of ERK or AKT. Instead, the cytoplasmic tail of β4 integrin is necessary for basal and epidermal growth factor–induced RAC activity, and RAC mediates tumor survival. Indeed, a constitutively active RAC sustains the viability of mammary tumors lacking functional β1 and β4 integrin through activation of NFκB, and overexpression of NFκB p65 mediates anchorage-independent survival of nonmalignant mammary epithelial cells. Therefore, epithelial tumors could survive in the absence of exogenous basement membrane through autocrine LM-5–α6β4 integrin–RAC–NFκB signaling

Mechanisms Suppressing Superheavy Element Yields in Cold Fusion Reactions

Superheavy elements are formed in fusion reactions which are hindered by fast nonequilibrium processes. To quantify these, mass-angle distributions and cross sections have been measured, at beam energies from below-barrier to 25% above, for the reactions of 48Ca,50Ti, and 54Cr with 208 Pb. Moving from 48Ca to 54Cr leads to a drastic fall in the symmetric fission yield, which is reflected in the measured mass-angle distribution by the presence of competing fast nonequilibrium deep inelastic and quasifission processes. These are responsible for reduction of the compound nucleus formation probablity PCN (as measured by the symmetric-peaked fission cross section), by a factor of 2.5 for 50Ti and 15 for 54Cr in comparison to 48 Ca. The energy dependence of PCN indicates that cold fusion reactions (involving 208Pb) are not driven by a diffusion process.The authors acknowledge the Australian Research Council for support through Discovery Grants No. DP140101337, No. DP160101254, No. DP170102318, No. FL110100098, and No. DE140100784. Financial support from the NCRIS HIA capability for operation of the Heavy Ion Accelerator Facility is acknowledged. The authors acknowledge the support of the German Academic Exchange Service (DAAD) via funds of the German Federal Ministry of Education and Research (BMBF)

Strongly Coupled Magnetic and Electronic Transitions in Multivalent Strontium Cobaltites

The topotactic phase transition in SrCoOx (x = 2.5-3.0) makes it possible to reversibly transit between the two distinct phases, i.e. the brownmillerite SrCoO2.5 that is a room-temperature antiferromagnetic insulator (AFM-I) and the perovskite SrCoO3 that is a ferromagnetic metal (FM-M), owing to their multiple valence states. For the intermediate x values, the two distinct phases are expected to strongly compete with each other. With oxidation of SrCoO2.5, however, it has been conjectured that the magnetic transition is decoupled to the electronic phase transition, i.e., the AFM-to-FM transition occurs before the insulator-to-metal transition (IMT), which is still controversial. Here, we bridge the gap between the two-phase transitions by density-functional theory calculations combined with optical spectroscopy. We confirm that the IMT actually occurs concomitantly with the FM transition near the oxygen content x = 2.75. Strong charge-spin coupling drives the concurrent IMT and AFM-to-FM transition, which fosters the near room-T magnetic transition characteristic. Ultimately, our study demonstrates that SrCoOx is an intriguingly rare candidate for inducing coupled magnetic and electronic transition via fast and reversible redox reactions

Repeat Placental Growth Factor-Based Testing in Women With Suspected Preterm Preeclampsia: A Stratified Analysis of the PARROT-2 Trial

BACKGROUND: PlGF (placental growth factor)-based testing reduces severe maternal adverse outcomes. Repeat PlGF-based testing is not associated with improved perinatal or maternal outcomes. This planned secondary analysis aimed to determine whether there is a subgroup of women who benefit from repeat testing. METHODS: Pregnant individuals with suspected preterm preeclampsia were randomized to repeat revealed PlGF-based testing, compared with usual care where testing was concealed. Perinatal and maternal outcomes were stratified by trial group, by initial PlGF-based test result, and by PlGF-based test type (PlGF or sFlt-1 [soluble fms-like tyrosine kinase-1]/PlGF ratio). RESULTS: A total of 1252 pregnant individuals were included. Abnormal initial PlGF-based test identified a more severe phenotype of preeclampsia, at increased risk of adverse maternal and perinatal outcomes. Repeat testing was not significantly associated with clinical benefit in women with abnormal initial results. Of women with a normal initial result, 20% developed preeclampsia, with the majority at least 3 to 4 weeks after initial presentation. Repeat test results were more likely to change from normal to abnormal in symptomatic women (112/415; 27%) compared with asymptomatic women (163/890; 18%). A higher proportion of symptomatic women who changed from normal to abnormal were diagnosed with preeclampsia, compared with asymptomatic women. CONCLUSIONS: Our results do not demonstrate evidence of the clinical benefit of repeating PlGF-based testing if the initial result is abnormal. Judicious use of repeat PlGF-based testing to stratify risk may be considered at least 2 weeks after a normal initial test result, particularly in women who have symptoms or signs of preeclampsia. REGISTRATION: URL: XXX; Unique identifier: ISRCTN85912420

Monoclonal antibody against a human sperm protein recognizes multiple epitopes on rabbit and human sperm and blocks sperm function

A monoclonal antibody was raised against a human sperm protein of apparent molecular size of 40 kDa. Of the 6 hybridoma clones selected for study, one clone (B - 12) was chosen for further investigations. The antibody secreted by the clone agglutinated human and rabbit spermatozoa in vitro. The antibody belonged to IgM class. In indirect immunofluorescence studies this antibody reacted to acrosome of living human and rabbit spermatozoa. On fixed sperm of the same species it recognized midpiece and parts of tail along with the acrosome. Mouse, hamster, guineapig, monkey and rat sperm showed similar localization. Interaction between rabbit sperm and oocyte was inhibited in vitro by this antibody. On western blots of human and rabbit sperm extracts the antibody recognized more than one epitope