Ornitiinidekarboksylaasin toiminta ja säätely

Ornithine decarboxylase (ODC) regulates the synthesis of polyamines which are involved in many cellular functions e.g. proliferation and differentiation. Due to its critical role, ODC is a tightly regulated enzyme by antizymes and antizyme inhibitors. If the regulation fails, the activity of ODC increases and may lead to malignant transformation of a cell. Increased ODC activity is found in many common cancers, including colon, prostate, and breast cancer. In a transformed cell, dynamics of the actin cytoskeleton is disturbed. A small G-protein, RhoA regulates organization of the cytoskeleton, and its overactivity increases malignant potential of the cell. The present results indicate that covalent attachment of polyamines by transglutaminase is a physiological means of regulating the activity of RhoA. The translocation of RhoA to the plasma membrane, where it exerts its activity is dependent on the presence of catalytically active ODC. As the overactivity of ODC and RhoA are implicated in cell transformation, the results provide a mechanistic explanation of the interrelationship between the polyamine metabolism and the reorganization of the actin cytoskeleton occurring in cancer cells. ODC and polyamines have also an important role in the function of central nervous system. They participate in the regulation of brain morphogenesis in embryos. In adult nervous tissue, polyamines regulate K+ and glutamate channels. K+ inward rectifying channels control membrane potentials and NMDA-type glutamate receptors (NMDAR) regulate synaptic plasticity. High ODC activity and polyamine levels are considered important in the development of ischemic brain damage and they are implicated in the pathogenesis of Alzheimer s disease (AD). A homolog of ODC was cloned from a human brain cDNA library, and several alternatively spliced variants were detected in human brain and testis. The novel protein was nevertheless devoid of ODC catalytic activity. It was subsequently found to be a novel inductor of ODC activity and polyamine synthesis, called antizyme inhibitor 2 (AZIN2). The accumulation of AZIN2 in vesicle-like formations along the axons and beneath the plasma membrane of neurons as well as in steroid hormone producing Leydig cells and luteal cells of the gonads implies that AZIN2 plays a role in secretion and vesicle trafficking. An accumulation of AZIN2 was detected also in specimens of AD brains. This increased expression of AZIN2 was specific for AD and was not found in brains with other neurodegenerative diseases including CADASIL or dementia with Lewy bodies.Polyamiinit ovat pieniä, sähköisesti varautuneita molekyylejä, joita on runsaasti soluissa, pääosin sitoutuneena perintöainekseen. Polyamiineja saadaan ruuasta, mutta pääosan solu valmistaa itse. Ne ovat välttämättömiä monen solun keskeisen toiminnan, kuten jakautumisen ja erilaistumisen kannalta. Ornitiinidekarboksylaasi (ODC) säätelee polyamiinien tuotantoa solussa. Keskeisen roolinsa vuoksi ODC on erittäin tarkasti säädelty entsyymi, ja säätelyn pettäessä ja ODC:n aktiivisuuden noustessa solu saattaa transformoitua eli muuttua pahanlaatuiseksi. ODC-aktiivisuuden kasvu on nähtävissä monissa syövissä, kuten rinta- eturauhas- ja paksusuolen syövissä. Syöpähoitoja, joissa säädellään ODC:n aktiivisuutta ja polyamiinien pitoisuutta on pyritty kehittämään, mutta tulokset ovat olleet heikkoja johtuen ODC:n monimutkaisesta ja osittain vielä tuntemattomasta säätelystä. Väitöskirjatutkimuksissani olen osoittanut molekulaarisen mekanismin, jolla ODC ja polyamiinit säätelevät solun aktiinitukirangan muovautumista ja vaikuttavat solun transformaatioon. Tutkimustuloksemme viittaavat siihen, että ODC säätelee pientä G-proteiinia, RhoA:ta, joka on aktiinitukirangan säätelijä, vaikuttamalla sen solunsisäiseen sijoittumiseen ja polyaminaatioon. Nämä interaktiot vaikuttavat solun jakautumissyklin etenemiseen ja solun transformaatioon. ODC:lla ja polyamiineilla on tärkeä rooli myös keskushermoston toiminnassa. Ne osallistuvat aivojen morfogeneesin säätelyyn ja toisaalta aikuisen aivoissa säätelevät eksitatorista glutamaattireseptoria, NMDAR:ia. NMDAR on keskeinen oppimisen ja muistin toiminnan kannalta, ja sillä epäillään olevan osallisuutta myös Alzheimerin taudin patogeneesissä. Myös ODC:n aktiivisuuden ja polyamiinien pitoisuuden tiedetään olevan koholla monissa keskushermoston patologisissa tiloissa, kuten aivoverenkiertohäiriöissä ja Alzheimerin taudissa. Olemme kuvanneet aivoista aiemmin tuntemattoman ODC:n säätelijän, antitsyymi-inhibiittori 2:n (AZIN2). Tulostemme mukaan AZIN2 sijoittuu samoihin soluihin NMDAR:n kanssa, ja sen määrä on ODC:n tavoin lisääntynyt Alzheimerin taudissa. AZIN2 ilmentyy myös kivesten ja munasarjojen sukupuolihormoneja tuottavissa soluissa viitaten toiminnalliseen rooliin solun hormonituotannossa tai erityksessä

Kielisyöpä - varhainen toteaminen parantaa ennustetta

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Päänsärky kallonsisäisen verenvuodon oireena

English summaryPeer reviewe

MMP-7 expression may influence the rate of distant recurrences and disease-specific survival in HPV-positive oropharyngeal squamous cell carcinoma

The objective of this study was to determine if matrix metalloproteinase-7 (MMP-7) expression is related to human papilloma virus (HPV) status, clinical parameters, and outcome in oropharyngeal squamous cell carcinoma (OPSCC). Tumor tissue specimens from 201 OPSCC patients treated with curative intent were available for immunohistochemistry, and the samples were stained with monoclonal MMP-7 antibody. All the patients were followed up at least 3 years or until death. MMP-7 expression did not differ between HPV-positive and HPV-negative patients. MMP-7 was not prognostic among patients with HPV-negative OPSCC. In the HPV-positive subgroup, patients with moderate, high, or very high MMP-7 expression had significantly worse 5-year disease-specific survival (DSS) (56.6%) than patients with absent, or low MMP-7 expression (77.2%), and MMP-7 expression appeared as a prognostic factor in the multivariate analysis. In addition, among HPV-positive OPSCC with moderate, high, or very high MMP-7 expression, the 5-year distant recurrence-free survival was significantly lower (69.6%) than in those who had low or absent MMP-7 expression (97.5%). Our results suggest that among HPV-positive OPSCC patients, high MMP-7 expression is related to worse 5-year DSS and increased rate of distant recurrences.Peer reviewe

The expression and prognostic relevance of CDH3 in tongue squamous cell carcinoma

Publisher Copyright: © 2021 Scandinavian Societies for Medical Microbiology and Pathology.P-cadherin (CDH3) is a cell-to-cell adhesion molecule that regulates several cellular homeostatic processes in normal tissues. Lack of CDH3 expression is associated with aggressive behavior in oral squamous cell carcinoma (OSCC). Previous studies have shown that CDH3 is downregulated in high-grade OSCC and its reduced expression is predictive for poorer survival. The aim of this study was to evaluate the expression and prognostic relevance of CDH3 in tongue squamous cell carcinoma (TSCC). A retrospective series of 211 TSCC and 50 lymph node samples were stained immunohistochemically with polyclonal antibody (anti-CDH3). CDH3 expression was assessed semi-quantitatively with light microscopy. Fisher’s exact test was used to compare patient and tumor characteristics, and the correlations were tested by Spearman correlation. Survival curves were drawn by the Kaplan–Meier method and analyzed by the log-rank test. Univariate and multivariate Cox regression was used to estimate the association between CDH3 expression and survival. CDH3 expression did not affect TSCC patient’s disease-specific survival or overall survival. Strong CDH3 expression in the primary tumor predicted poor disease-specific and overall survival in patients with recurrent disease. CDH3 expression in lymph nodes without metastasis was negative in all cases. CDH3 expression was positive in all lymph node metastases with extranodal extension. In contrast to previous report about the prognostic value of CDH3 in OSCC, we were not able to validate the result in TSCC.Peer reviewe

The expression and prognostic relevance of CDH3 in tongue squamous cell carcinoma

Publisher Copyright: © 2021 Scandinavian Societies for Medical Microbiology and Pathology.P-cadherin (CDH3) is a cell-to-cell adhesion molecule that regulates several cellular homeostatic processes in normal tissues. Lack of CDH3 expression is associated with aggressive behavior in oral squamous cell carcinoma (OSCC). Previous studies have shown that CDH3 is downregulated in high-grade OSCC and its reduced expression is predictive for poorer survival. The aim of this study was to evaluate the expression and prognostic relevance of CDH3 in tongue squamous cell carcinoma (TSCC). A retrospective series of 211 TSCC and 50 lymph node samples were stained immunohistochemically with polyclonal antibody (anti-CDH3). CDH3 expression was assessed semi-quantitatively with light microscopy. Fisher’s exact test was used to compare patient and tumor characteristics, and the correlations were tested by Spearman correlation. Survival curves were drawn by the Kaplan–Meier method and analyzed by the log-rank test. Univariate and multivariate Cox regression was used to estimate the association between CDH3 expression and survival. CDH3 expression did not affect TSCC patient’s disease-specific survival or overall survival. Strong CDH3 expression in the primary tumor predicted poor disease-specific and overall survival in patients with recurrent disease. CDH3 expression in lymph nodes without metastasis was negative in all cases. CDH3 expression was positive in all lymph node metastases with extranodal extension. In contrast to previous report about the prognostic value of CDH3 in OSCC, we were not able to validate the result in TSCC.Peer reviewe

Expression of ODC Antizyme Inhibitor 2 (AZIN2) in Human Secretory Cells and Tissues

Ornithine decarboxylase (ODC) antizyme inhibitor 2 (AZIN2), originally called ODCp, is a regulator of polyamine synthesis that we originally identified and cloned. High expression of ODCp mRNA was found in brain and testis. We reported that AZIN2 is involved in regulation of cellular vesicle transport and/or secretion, but the ultimate physiological role(s) of AZIN2 is still poorly understood. In this study we used a peptide antibody (K3) to human AZIN2 and by immunohistochemistry mapped its expression in various normal tissues. We found high expression in the nervous system, in type 2 pneumocytes in the lung, in megakaryocytes, in gastric parietal cells co-localized with H, K-ATPase beta subunit, in selected enteroendocrine cells, in acinar cells of sweat glands, in podocytes, in macula densa cells and epithelium of collecting ducts in the kidney. The high expression of AZIN2 in various cells with secretory or vesicle transport activity indicates that the polyamine metabolism regulated by AZIN2 is more significantly involved in these events than previously appreciated.Peer reviewe

High-throughput compound screening identifies navitoclax combined with irradiation as a candidate therapy for HPV-negative head and neck squamous cell carcinoma

Conventional chemotherapeutic agents are nonselective, often resulting in severe side effects and the development of resistance. Therefore, new molecular-targeted therapies are urgently needed to be integrated into existing treatment regimens. Here, we performed a high-throughput compound screen to identify a synergistic interaction between ionizing radiation and 396 anticancer compounds. The assay was run using five human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC) cell lines cultured on the human tumor-derived matrix Myogel. Our screen identified several compounds with strong synergistic and antagonistic effects, which we further investigated using multiple irradiation doses. Navitoclax, which emerged as the most promising radiosensitizer, exhibited synergy with irradiation regardless of the p53 mutation status in all 13 HNSCC cell lines. We performed a live cell apoptosis assay for two representative HNSCC cell lines to examine the effects of navitoclax and irradiation. As a single agent, navitoclax reduced proliferation and induced apoptosis in a dose-dependent manner, whereas the navitoclax-irradiation combination arrested cell cycle progression and resulted in substantially elevated apoptosis. Overall, we demonstrated that combining navitoclax with irradiation resulted in synergistic in vitro antitumor effects in HNSCC cell lines, possibly indicating the therapeutic potential for HNSCC patients.Peer reviewe

Small oral tongue cancers (ae 4 cm in diameter) with clinically negative neck : from the 7th to the 8th edition of the American Joint Committee on Cancer

One of the main changes in the 8th edition of the American Joint Committee on Cancer (AJCC) for staging of oral cancer is the inclusion of depth of invasion (DOI) in the T category. However, cancers in different oral subsites have variable behavior, with oral tongue squamous cell carcinoma (OTSCC) being the most aggressive one even at early stage. Thus, it is necessary to evaluate the performance of this new T category in homogenous cohort of early OTSCC. Therefore, we analyzed a large cohort of patients with a small (ae4 cm) OTSCC to demonstrate the differences in T stage between the AJCC 7th and 8th editions. A total of 311 early-stage cases (AJCC 7th) of OTSCC were analyzed. We used 5 mm and 10 mm DOI for upstaging from T1 to T2 and from T2 to T3 respectively, as in the AJCC 8th. We further reclassified the cases according to our own proposal suggesting 2 mm to upstage to T2 and 4 mm to upstage to T3. According to AJCC 7th, there were no significant differences in the survival analysis. When we applied the 8th edition, many cases were upstaged to T3 and thus associated with worse disease-specific survival (HR 2.37, 95% CI 1.12-4.99) and disease-free survival (HR 2.12, 95% CI 1.09-4.08). Based on our proposal, T3 cases were associated with even worse disease-specific survival (HR 4.19, 95% CI 2.27-7.74). The 8th edition provides better survival prediction for OTSCC than the 7th and can be further optimized by lowering the DOI cutoffs.Peer reviewe

Morphology and histology of silent and symptom-causing atherosclerotic carotid plaques - Rationale and design of the Helsinki Carotid Endarterectomy Study 2 (the HeCES2)

Introduction: Every fifth ischemic stroke is caused by thromboembolism originating from an atherosclerotic carotid artery plaque. While prevention is the most cost-effective stroke therapy, antiplatelet and cholesterol-lowering drugs have a ceiling effect in their efficacy. Therefore, discovery of novel pathophysiologic targets are needed to improve the primary and secondary prevention of stroke. This article provides a detailed study design and protocol of HeCES2, an observational prospective cohort study with the objective to investigate the pathophysiology of carotid atherosclerosis.Materials and Methods: Recruitment and carotid endarterectomies of the study patients with carotid atherosclerosis were performed from October 2012 to September 2015. After brain and carotid artery imaging, endarterectomised carotid plaques (CPs) and blood samples were collected from 500 patients for detailed biochemical and molecular analyses.Findings to date: We developed a morphological grading for macroscopic characteristics within CPs. The dominant macroscopic CP characteristics were: smoothness 62%, ulceration 61%, intraplaque hemorrhage 60%, atheromatous gruel 59%, luminal coral-type calcification 34%, abundant (44%) and moderate (39%) intramural calcification, and symptom-causing hot spot area 53%.Future plans: By combining clinically oriented and basic biomedical research, this large-scale study attempts to untangle the pathophysiological perplexities of human carotid atherosclerosis.Key MessagesThis article is a rationale and design of the HeCES2 study that is an observational prospective cohort study with the objective to investigate the pathophysiology of carotid atherosclerosis.The HeCES2 study strives to develop diagnostic algorithms including radiologic imaging to identify carotid atherosclerosis patients who warrant surgical treatment.In addition, the study aims at finding out new tools for clinical risk stratification as well as novel molecular targets for drug development.Peer reviewe