Sphingosine-1-phosphate-evoked invasion of follicular thyroid cancer cells : evidence for the involvement of HIF-Iα, MMP2 and MMP9

Sphingolipids are widely expressed molecules, which traditionally were considered to have majorly structural properties. Nowadays, however, they are implicated in a wide range of different biological processes. The bioactive lipid sphingosine 1-phosphate (S1P) has emerged during the past decade as one of the most studied molecules due to its proliferative and pro-migratory abilities both during normal physiology and in the pathology of a subset of different diseases. Migration and invasion of cancer cells require changes in cell behavior and modulation of the tissue microenvironment. Tumor aggressiveness is markedly enhanced by hypoxia, in which hypoxia inducible transcription factors 1-2α (HIF-1-2α) are activated to promote metabolism, proliferation and migration. Invasion requires degradation of the extracellular matrix (ECM) achieved by several degrading and remodeling enzymes. Matrix metalloproteinases (MMPs) are broadly expressed and well accepted as proteolytic enzymes with essential roles both in normal physiology and in pathology. Previously, S1P was shown to strongly evoke migration of follicular ML-1 thyroid cancer cells. The objective of this study was to further investigate and understand the mechanisms behind this regulation. In the first project it was demonstrated that S1P enhances the expression and activity of HIF-1α. S1P enhanced the expression of HIF-1α by increasing its synthesis and stability. The S1P-increased HIF-1α was mediated via S1P3, Gi/0, PI3K, PKCβI, ERK1/2, mTOR and translation factors p70S6K and eIF4E. Finally, it was shown that HIF-1α mediated S1P-induced migration. The ECM is constituted of a complex and coordinated assembly of many types of proteins. In order to be able to invade, cells need to break down the ECM, therefore several key players in this event were investigated in the second project. S1P increased the secretion and activity of MMP2 and MMP9 via S1P-receptor 1 and 3 and that these MMPs participated in the S1P-facilitated invasion of ML-1 cells. In this interplay, calpains and Rac1 were involved, both of which are crucial players in migration and invasion. The prognosis for some types of thyroid cancer is relatively good. However, there are forms of thyroid cancers, for which there are no treatments or the current available treatments are inefficient. Thus, new medical interventions are urgently needed. In the third project the significance of the S1P-receptor modulating drug FTY720, which is currently used for the treatment of multiple sclerosis (MS), was studied. The effect of FTY720 was tested on several thyroid cancer cell lines, and it inhibited the proliferation and invasion of all cancer cell lines tested. In ML-1 cells, FTY720 attenuated invasion by blocking signaling intermediates important for migration and invasion of the cells. Moreover, FTY720 inhibited the proliferation of ML-1 cells by increasing the expression of p21 and p27, hence, inducing cell arrest in G1 phase of the cell cycle. Thus, it can be suggested that FTY720 could be used in the treatment of thyroid cancer.

Myyjien tietämyksen jakaminen organisaatiolle osana myyntiprosessia

Diplomityön tavoitteena on tutkia myyjien tietämyksen jakamista ja sen yhteyttä myyntiprosessiin. Tutkimus on toteutettu systemaattisena kirjallisuuskatsauksena. Työssä pyritään löytämään kirjallisuuden pohjalta yhteydet myyntiprosessin vaiheiden ja vaatimusten sekä myyjien tietämyksen jakamisen väliltä. Teoreettisena taustana esitellään myyntiprosessin kuvauksia, vaiheita ja haasteita yleisellä tasolla, jotta löydetään tehokkaan prosessin edellyttämät tekijät. Lisäksi tutkitaan tietämyksen vaikutusta myyntitehokkuuteen ja etsitään tietämyksen jakamiseen ja hyödyntämiseen vaikuttavia tekijöitä yleisesti ja myyntityöhön liittyen. Työn soveltavassa osuudessa tarkasteltiin tietämyksen kannalta tärkeitä myyntiprosessin vaiheita: asiakasvalinta, esivalmistelu, presentaatio ja neuvottelu sekä kaupan päättäminen. Jokaisessa vaiheessa todettiin olevan hyötyä myyjien tietämyksen jakamisesta. Läpikäydyn aineiston pohjalta tehtiin kaksi keskeistä huomiota. Ensinnäkin myyjien tietämyksen jakaminen on johdettavissa suoraan osaksi myyntiprosessia ja tietämyksellä on merkittävä rooli myyntityössä. Toiseksi myyntiprosessi ja myyjien tietämyksen jakaminen edellyttävät monia samoja asioita. Asiakas ja asiakkaan tarpeet ovat molemmissa keskiössä ja molempiin linkittyy henkilökuntaa yli osastorajojen. Tietoa on olemassa paljon joten on tärkeää suunnata resurssit oleelliseen. Tietotekniikan kehitys auttaa myyntitoiminnan jäsentämisessä ja tietämyksen jakamisessa, mutta on syytä pitää mielessä, että tietotekniikan rooli on tukitoiminto. Molemmat ovat turhia jos sovittuja pelisääntöjä ei noudateta. Lisäksi onnistunut implementointi edellyttää johdon sitoutumista ja riittävän laajaa henkilökunnan osallistamista.

On the effect of molecular structure and composition on the photofragmentation of biomolecules

The research on the interaction between radiation and biomolecules pro-vides valuable information for both radiobiology and molecular physics. While radiobiology is interested in the damage inflicted on the molecule upon irradiation, molecular physics exploits these studies to obtain infor-mation about the physical properties of the molecule and the quantum me-chanical processes involved in the interaction. This thesis work investigated how a small change in the structure or composition of a biomolecule changes the response of the molecule to ioniz-ing radiation. Altogether eight different biomolecules were studied: nucleo-sides uridine, 5-methyluridine and thymidine; amino acids alanine, cysteine and serine; and halogenated acetic acids chloro- and bromoacetic acids. The effect of ionizing radiation on these molecules was studied on molecular level, investigating the samples in gas phase. Synchrotron radiation of VUV or soft x-ray range was used to ionize sample molecules, and the subsequent fragmentation processes were investigated with ion mass spectroscopy and ion-ion-electron coincidence spectroscopy. The comparison between the three nucleosides revealed that adding or removing a single functional group can affect not only the bonds from which the molecule ruptures upon ionization but also the charge localiza-tion in the formed fragments. Studies on amino acids and halogenated acetic acids indicated that one simple substitution in the molecule can dramatical-ly change the extent of fragmentation. This thesis work also demonstrates that in order to steer the radiation-induced fragmentation of the molecules, it is not always necessary to alter the amount of energy deposited on the molecules but selecting a suitable substitution may suffice.