The metastasis-promoting protein S100A4 regulates mammary branching morphogenesis

AbstractHigh levels of the S100 calcium binding protein S100A4 also called fibroblast specific protein 1 (FSP1) have been established as an inducer of metastasis and indicator of poor prognosis in breast cancer. The mechanism by which S100A4 leads to increased cancer aggressiveness has yet to be established; moreover, the function of this protein in normal mammary gland biology has not been investigated. To address the role of S100A4 in normal mammary gland, its spatial and temporal expression patterns and possible function in branching morphogenesis were investigated. We show that the protein is expressed mainly in cells of the stromal compartment of adult humans, and during active ductal development, in pregnancy and in involution of mouse mammary gland. In 3D culture models, topical addition of S100A4 induced a significant increase in the TGFα mediated branching phenotype and a concomitant increase in expression of a previously identified branching morphogen, metalloproteinase-3 (MMP-3). These events were found to be dependent on MEK activation. Downregulation of S100A4 using shRNA significantly reduced TGFα induced branching and altered E-cadherin localization. These findings provide evidence that S100A4 is developmentally regulated and that it plays a functional role in mammary gland development, in concert with TGFα by activating MMP-3, and increasing invasion into the fat pad during branching. We suggest that S100A4-mediated effects during branching morphogenesis provide a plausible mechanism for how it may function in breast cancer progression

Hvordan leser Amir og Amrit? : en studie med vekt på sammenhengen mellom ordforråd og leseforståelse på norsk hos minoritetstospråklige elever i 5. klasse

SAMMENDRAG Tittel Hvordan leser Amir og Amrit? En studie med vekt på sammenhengen mellom ordforråd og leseforståelse på norsk hos minoritetstospråklige elever i 5. klasse Bakgrunn og formål Bakgrunnen for denne undersøkelsen er de minoritetstospråklige elevenes dårlige resultater på nasjonale og internasjonale leseprøver, og myndighetenes satsning på å bedre opplæringssituasjonen for elever fra språklige minoriteter. Formålet med å kartlegge de minoritetstospråklige elevenes ordforråd og leseforståelse på norsk i 5. klasse, er blant annet å belyse elevenes behov for en undervisningen tilpasset deres språklige situasjon. Sammenhengen mellom elevenes akademiske ordforråd og deres mulighet for å forstå faglitterære tekster, er viet spesiell oppmerksomhet både teoretisk og empirisk. Problemstilling og forskningsspørsmål Oppgavens overordnede problemstilling er: Hvordan er ordforråd og leseferdighet på norsk hos minoritetstospråklige elever i 5. klasse, og hvordan er sammenhengen mellom elevenes ordforråd og leseferdighet? Med utgangspunkt i oppgavens problemstilling og teori om minoritetstospråklige elevers ordforråd og leseferdighet på et andrespråk, er det utledet 9 forskningsspørsmål. Metode Oppgavens problemstilling og forskningsspørsmål er søkt besvart gjennom en kvantitativ, ikke-eksperimentell tilnærming. Det er brukt standardiserte kartleggingsverktøy for å operasjonalisere hovedbegrepene i problemstillingen. For ordforråd er dette BPVS (British Picture Vocabulary Scale), og for leseferdighet er det Kartlegging av leseferdighet for 5. klasse (Nasjonalt Læremiddelsenter 1997). Undersøkelsen er gjennomført på 37 minoritetstospråklige elever og 14 norskspråklige elever i 5. klasse ved to Osloskoler. Dataanalyse Statistikkprogrammet SPSS 11.0 er benyttet til behandling og analyse av datamaterialet. I hovedsak er det foretatt deskriptive analyser, sammenligningsanalyser korrelasjonsanalyser og regresjonsanalyser. Resultater Denne undersøkelsen viser at de minoritetstospråklige elevene i 5. klasse har signifikant dårligere gjennomsnittlig ordforråd (målt med BPVS) og leseforståelse på norsk, enn de norskspråklige elevene i samme gruppe. Mye tyder på at den gjennomsnittlige utviklingen av deres akademiske ordforråd er forsinket i forhold til aldersnormen. 35 av 37 minoritets-tospråklige elever skårer under 100 ord, mens bare 2 av de norskspråklige elevene skårer under 100 ord på BPVS. Ingen elever med skåre lavere enn 83 ord, klarer å lese en aldersadekvat tekst med god forståelse. De minoritetstospråklige elevenes ordforråd, slik det måles med BPVS, forklarer 30-40% av variasjonen i deres leseforståelse. Regresjonsanalyse viser at en økning i skåre med 10 ord på BPVS, i gjennomsnitt vil føre til en bedring av leseforståelsen med ca 10%. Data og teori i denne undersøkelsen må samlet sett kunne sies å gi indikasjoner på at det er nødvendig å tilpasse språk- og leseopplæring for mange av de minoritetstospråklige elevene, også etter at de er kommet opp på mellomtrinnet i skolen. Da vil de få en sjanse til å tette gapet mellom seg og de norskspråklige elevene, og en likeverdig mulighet til å lykkes i utdanning og arbeidsliv

p38 MAPK activation through B7-H3-mediated DUSP10 repression promotes chemoresistance

Immunoregulatory protein B7-H3 is involved in the oncogenic and metastatic potential of cancer cells, as well as in drug resistance. Resistance to conventional chemotherapy is an important aspect of melanoma treatment, and a better understanding of how B7-H3 enhances drug resistance may lead to the development of more effective therapies. We investigated the in vitro and in vivo sensitivity of chemotherapeutic agents dacarbazine (DTIC) and cisplatin in sensitive and drug resistant melanoma cells with knockdown expression of B7-H3. We found that knockdown of B7-H3 increased in vitro and in vivo sensitivity of melanoma cells to the chemotherapeutic agents dacarbazine (DTIC) and cisplatin, in parallel with a decrease in p38 MAPK phosphorylation. Importantly, in B7-H3 knockdown cells we observed an increase in the expression of dual-specific MAP kinase phosphatase (MKP) DUSP10, a MKP known to dephosphorylate and inactivate p38 MAPK. DUSP10 knockdown by siRNA resulted in a reversion of the increased DTIC-sensitivity seen in B7-H3 knockdown cells. Our findings highlight the potential therapeutic benefit of combining chemotherapy with B7-H3 inhibition, and indicate that B7-H3 mediated chemoresistance in melanoma cells is driven through a mechanism involving DUSP10-mediated inactivation of p38 MAPK

Decreased expression of B7-H3 reduces the glycolytic capacity and sensitizes breast cancer cells to AKT/mTOR inhibitors

B7 family proteins are important immune response regulators, and can mediate oncogenic signaling and cancer development. We have used human triple-negative breast cancer cell lines with different expression levels of B7-H3 to evaluate its effects on the sensitivity to 22 different anticancer compounds in a drug screen. API-2 (triciribidine) and everolimus (RAD-001), two inhibitors that target the PI3K/AKT/mTOR pathway, showed enhanced inhibition of cell viability and proliferation in B7-H3 knockdown tumor cells compared to their B7-H3 expressing counterparts. Similar inhibition was seen in control cells treated with an anti-B7-H3 monoclonal antibody. In B7-H3 overexpressing cells, the effects of the two drugs were reduced, supported also by in vivo experiments in which B7-H3 overexpressing xenografts were less sensitive to everolimus than control tumors. In API-2 and everolimus-treated B7-H3 overexpressing cells, phospho-mTOR levels were decreased. However, phosphorylation of p70S6K was differentially regulated in B7-H3 cells treated with API-2 or everolimus, suggesting a different B7-H3-mediated mechanism downstream of mTOR. Both API-2 and everolimus decreased the glycolysis of the cells, whereas knockdown of B7-H3 decreased and B7-H3 overexpression increased the glycolytic capacity. In conclusion, we have unveiled a previously unknown relationship between B7-H3 expression and glycolytic capacity in tumor cells, and found that B7-H3 confers resistance to API-2 and everolimus. The results provide novel insights into the function of B7-H3 in cancer, and suggest that targeting of B7-H3 may be a novel alternative to improve current anticancer therapies

The expression pattern of pyruvate dehydrogenase kinases predicts prognosis and correlates with immune exhaustion in clear cell renal cell carcinoma

Abstract Renal cancer cells constitute a paradigm of tumor cells with a glycolytic reprogramming which drives metabolic alterations favouring cell survival and transformation. We studied the expression and activity of pyruvate dehydrogenase kinases (PDK1-4), key enzymes of the energy metabolism, in renal cancer cells. We analysed the expression, subcellular distribution and clinicopathological correlations of PDK1-4 by immunohistochemistry of tumor tissue microarray samples from a cohort of 96 clear cell renal cell carcinoma (ccRCC) patients. Gene expression analysis was performed on whole tumor tissue sections of a subset of ccRCC samples. PDK2 and PDK3 protein expression in tumor cells correlated with lower patient overall survival, whereas PDK1 protein expression correlated with higher patient survival. Gene expression analysis revealed molecular association of PDK2 and PDK3 expression with PI3K signalling pathway, as well as with T cell infiltration and exhausted CD8 T cells. Inhibition of PDK by dichloroacetate in human renal cancer cell lines resulted in lower cell viability, which was accompanied by an increase in pAKT. Together, our findings suggest a differential role for PDK enzymes in ccRCC progression, and highlight PDK as actionable metabolic proteins in relation with PI3K signalling and exhausted CD8 T cells in ccRCC