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1.  Autophagy Activation Clears ELAVL1/HuR-Mediated Accumulation of SQSTM1/p62 during Proteasomal Inhibition in Human Retinal Pigment Epithelial Cells 
PLoS ONE  2013;8(7):e69563.
Age-related macular degeneration (AMD) is the most common reason of visual impairment in the elderly in the Western countries. The degeneration of retinal pigment epithelial cells (RPE) causes secondarily adverse effects on neural retina leading to visual loss. The aging characteristics of the RPE involve lysosomal accumulation of lipofuscin and extracellular protein aggregates called “drusen”. Molecular mechanisms behind protein aggregations are weakly understood. There is intriguing evidence suggesting that protein SQSTM1/p62, together with autophagy, has a role in the pathology of different degenerative diseases. It appears that SQSTM1/p62 is a connecting link between autophagy and proteasome mediated proteolysis, and expressed strongly under the exposure to various oxidative stimuli and proteasomal inhibition. ELAVL1/HuR protein is a post-transcriptional factor, which acts mainly as a positive regulator of gene expression by binding to specific mRNAs whose corresponding proteins are fundamental for key cellular functions. We here show that, under proteasomal inhibitor MG-132, ELAVL1/HuR is up-regulated at both mRNA and protein levels, and that this protein binds and post-transcriptionally regulates SQSTM1/p62 mRNA in ARPE-19 cell line. Furthermore, we observed that proteasomal inhibition caused accumulation of SQSTM1/p62 bound irreversibly to perinuclear protein aggregates. The addition of the AMPK activator AICAR was pro-survival and promoted cleansing by autophagy of the former complex, but not of the ELAVL1/HuR accumulation, indeed suggesting that SQSTM1/p62 is decreased through autophagy-mediated degradation, while ELAVL1/HuR through the proteasomal pathway. Interestingly, when compared to human controls, AMD donor samples show strong SQSTM1/p62 rather than ELAVL1/HuR accumulation in the drusen rich macular area suggesting impaired autophagy in the pathology of AMD.
PMCID: PMC3726683  PMID: 23922739
2.  Associations of Breast Cancer Risk Factors With Tumor Subtypes: A Pooled Analysis From the Breast Cancer Association Consortium Studies 
Yang, Xiaohong R. | Chang-Claude, Jenny | Goode, Ellen L. | Couch, Fergus J. | Nevanlinna, Heli | Milne, Roger L. | Gaudet, Mia | Schmidt, Marjanka K. | Broeks, Annegien | Cox, Angela | Fasching, Peter A. | Hein, Rebecca | Spurdle, Amanda B. | Blows, Fiona | Driver, Kristy | Flesch-Janys, Dieter | Heinz, Judith | Sinn, Peter | Vrieling, Alina | Heikkinen, Tuomas | Aittomäki, Kristiina | Heikkilä, Päivi | Blomqvist, Carl | Lissowska, Jolanta | Peplonska, Beata | Chanock, Stephen | Figueroa, Jonine | Brinton, Louise | Hall, Per | Czene, Kamila | Humphreys, Keith | Darabi, Hatef | Liu, Jianjun | Van ‘t Veer, Laura J. | van Leeuwen, Flora E. | Andrulis, Irene L. | Glendon, Gord | Knight, Julia A. | Mulligan, Anna Marie | O’Malley, Frances P. | Weerasooriya, Nayana | John, Esther M. | Beckmann, Matthias W. | Hartmann, Arndt | Weihbrecht, Sebastian B. | Wachter, David L. | Jud, Sebastian M. | Loehberg, Christian R. | Baglietto, Laura | English, Dallas R. | Giles, Graham G. | McLean, Catriona A. | Severi, Gianluca | Lambrechts, Diether | Vandorpe, Thijs | Weltens, Caroline | Paridaens, Robert | Smeets, Ann | Neven, Patrick | Wildiers, Hans | Wang, Xianshu | Olson, Janet E. | Cafourek, Victoria | Fredericksen, Zachary | Kosel, Matthew | Vachon, Celine | Cramp, Helen E. | Connley, Daniel | Cross, Simon S. | Balasubramanian, Sabapathy P. | Reed, Malcolm W. R. | Dörk, Thilo | Bremer, Michael | Meyer, Andreas | Karstens, Johann H. | Ay, Aysun | Park-Simon, Tjoung-Won | Hillemanns, Peter | Arias Pérez, Jose Ignacio | Rodríguez, Primitiva Menéndez | Zamora, Pilar | Benítez, Javier | Ko, Yon-Dschun | Fischer, Hans-Peter | Hamann, Ute | Pesch, Beate | Brüning, Thomas | Justenhoven, Christina | Brauch, Hiltrud | Eccles, Diana M. | Tapper, William J. | Gerty, Sue M. | Sawyer, Elinor J. | Tomlinson, Ian P. | Jones, Angela | Kerin, Michael | Miller, Nicola | McInerney, Niall | Anton-Culver, Hoda | Ziogas, Argyrios | Shen, Chen-Yang | Hsiung, Chia-Ni | Wu, Pei-Ei | Yang, Show-Lin | Yu, Jyh-Cherng | Chen, Shou-Tung | Hsu, Giu-Cheng | Haiman, Christopher A. | Henderson, Brian E. | Le Marchand, Loic | Kolonel, Laurence N. | Lindblom, Annika | Margolin, Sara | Jakubowska, Anna | Lubiński, Jan | Huzarski, Tomasz | Byrski, Tomasz | Górski, Bohdan | Gronwald, Jacek | Hooning, Maartje J. | Hollestelle, Antoinette | van den Ouweland, Ans M. W. | Jager, Agnes | Kriege, Mieke | Tilanus-Linthorst, Madeleine M. A. | Collée, Margriet | Wang-Gohrke, Shan | Pylkäs, Katri | Jukkola-Vuorinen, Arja | Mononen, Kari | Grip, Mervi | Hirvikoski, Pasi | Winqvist, Robert | Mannermaa, Arto | Kosma, Veli-Matti | Kauppinen, Jaana | Kataja, Vesa | Auvinen, Päivi | Soini, Ylermi | Sironen, Reijo | Bojesen, Stig E. | Dynnes Ørsted, David | Kaur-Knudsen, Diljit | Flyger, Henrik | Nordestgaard, Børge G. | Holland, Helene | Chenevix-Trench, Georgia | Manoukian, Siranoush | Barile, Monica | Radice, Paolo | Hankinson, Susan E. | Hunter, David J. | Tamimi, Rulla | Sangrajrang, Suleeporn | Brennan, Paul | McKay, James | Odefrey, Fabrice | Gaborieau, Valerie | Devilee, Peter | Huijts, P.E.A. | Tollenaar, RAEM. | Seynaeve, C. | Dite, Gillian S. | Apicella, Carmel | Hopper, John L. | Hammet, Fleur | Tsimiklis, Helen | Smith, Letitia D. | Southey, Melissa C. | Humphreys, Manjeet K. | Easton, Douglas | Pharoah, Paul | Sherman, Mark E. | Garcia-Closas, Montserrat
Previous studies have suggested that breast cancer risk factors are associated with estrogen receptor (ER) and progesterone receptor (PR) expression status of the tumors.
We pooled tumor marker and epidemiological risk factor data from 35 568 invasive breast cancer case patients from 34 studies participating in the Breast Cancer Association Consortium. Logistic regression models were used in case–case analyses to estimate associations between epidemiological risk factors and tumor subtypes, and case–control analyses to estimate associations between epidemiological risk factors and the risk of developing specific tumor subtypes in 12 population-based studies. All statistical tests were two-sided.
In case–case analyses, of the epidemiological risk factors examined, early age at menarche (≤12 years) was less frequent in case patients with PR− than PR+ tumors (P = .001). Nulliparity (P = 3 × 10−6) and increasing age at first birth (P = 2 × 10−9) were less frequent in ER− than in ER+ tumors. Obesity (body mass index [BMI] ≥ 30 kg/m2) in younger women (≤50 years) was more frequent in ER−/PR− than in ER+/PR+ tumors (P = 1 × 10−7), whereas obesity in older women (>50 years) was less frequent in PR− than in PR+ tumors (P = 6 × 10−4). The triple-negative (ER−/PR−/HER2−) or core basal phenotype (CBP; triple-negative and cytokeratins [CK]5/6+ and/or epidermal growth factor receptor [EGFR]+) accounted for much of the heterogeneity in parity-related variables and BMI in younger women. Case–control analyses showed that nulliparity, increasing age at first birth, and obesity in younger women showed the expected associations with the risk of ER+ or PR+ tumors but not triple-negative (nulliparity vs parity, odds ratio [OR] = 0.94, 95% confidence interval [CI] = 0.75 to 1.19, P = .61; 5-year increase in age at first full-term birth, OR = 0.95, 95% CI = 0.86 to 1.05, P = .34; obesity in younger women, OR = 1.36, 95% CI = 0.95 to 1.94, P = .09) or CBP tumors.
This study shows that reproductive factors and BMI are most clearly associated with hormone receptor–positive tumors and suggest that triple-negative or CBP tumors may have distinct etiology.
PMCID: PMC3107570  PMID: 21191117
3.  Twist and snai1 expression in pharyngeal squamous cell carcinoma stroma is related to cancer progression 
BMC Cancer  2011;11:350.
Epithelial-mesenchymal transition (EMT) is a crucial process in tumorigenesis since tumor cells attain fibroblast-like features enabling them to invade to surrounding tissue. Two transcription factors, TWIST and SNAI1, are fundamental in regulating EMT.
Immunohistochemistry was used to study the expression of TWIST and SNAI1 in 109 pharyngeal squamous cell carcinomas.
Tumors with intense stromal staining of TWIST relapsed more frequently (p = 0.04). Tumors with both positive TWIST and SNAI1 immunoreactivity in the stroma were at least Stage II (p = 0.05) and located more often in hypopharynx (p = 0.035). Tumors with negative immunostaining of TWIST and SNAI1 in the stromal compartment were smaller (T1-2) (p = 0.008), less advanced (SI-II) (p = 0.031) and located more often in the oropharynx (p = 0.007). Patients with negative SNAI1 and TWIST immunostaining in tumor stroma had a better 5-year disease-specific and overall survival (p = 0.037 and p = 0.014 respectively).
TWIST and SNAI1 expression in stromal cells is associated with clinical and histopathological characteristics that indicate progressive disease. Negative expression of these EMT-promoting transcription factors predicts a better outcome.
PMCID: PMC3173446  PMID: 21834956
Pharyngeal squamous cell carcinoma; Stromal cells; TWIST; SNAI1; Prognosis; Epithelial-mesenchymal transition
4.  Transcription factors zeb1, twist and snai1 in breast carcinoma 
BMC Cancer  2011;11:73.
Epitheliomesenchymal transition (EMT) is the process where cancer cells attain fibroblastic features and are thus able to invade neighboring tissues. Transcriptional factors zeb1, snai1 and twist regulate EMT.
We used immunohistochemistry to investigate the expression of zeb1, twist and snai1 in tumor and stromal compartments by in a large set of breast carcinomas. The results were compared with estrogen and progesterone receptor status, HER2 amplification, grade, histology, TNM status and survival of the patients.
Nuclear expression for twist was seen in the epithelial tumor cell compartment in 3.6% and for snai1 in 3.1% of the cases while zeb1 was not detected at all in these areas. In contrast, the tumor stromal compartment showed nuclear zeb1 and twist expression in 75% and 52.4% of the cases, respectively. Although rare, nuclear expression of twist in the epithelial tumor cell compartment was associated with a poor outcome of the patients (p = 0.054 log rank, p = 0.013, Breslow, p = 0.025 Tarone-Ware). Expression of snai1, or expression of zeb1 or twist in the stromal compartment did not have any prognostic significance. Furthermore, none of these factors associated with the size of the tumors, nor with the presence of axillary or distant metastases. Expression of zeb1 and twist in the stromal compartment was positively associated with a positive estrogen or progesterone receptor status of the tumors. Stromal zeb1 expression was significantly lower in ductal in situ carcinomas than in invasive carcinomas (p = 0.020). Medullary carcinomas (p = 0.017) and mucinous carcinomas (p = 0.009) had a lower stromal expression of zeb1 than ductal carcinomas. Stromal twist expression was also lower in mucinous (p = 0.017) than in ductal carcinomas.
Expression of transcriptional factors zeb1 and twist mainly occur in the stromal compartment of breast carcinomas, possibly representing two populations of cells; EMT transformed neoplastic cells and stromal fibroblastic cells undergoing activation of zeb1 and twist due to growth factors produced by the tumor. However, epithelial expression of twist was associated with a poor prognosis, hinting at its importance in the spread of breast carcinoma.
PMCID: PMC3055233  PMID: 21324165
5.  Hyaluronan synthases (HAS1-3) and hyaluronidases (HYAL1-2) in the accumulation of hyaluronan in endometrioid endometrial carcinoma 
BMC Cancer  2010;10:512.
Hyaluronan accumulation correlates with the degree of malignancy in many solid tumor types, including malignant endometrial carcinomas. To elucidate the mechanism of hyaluronan accumulation, we examined the expression levels of the hyaluronan synthases (HAS1, HAS2 and HAS3) and hyaluronidases (HYAL1 and HYAL2), and correlated them with hyaluronan content and HAS1-3 immunoreactivity.
A total of 35 endometrial tissue biopsies from 35 patients, including proliferative and secretory endometrium (n = 10), post-menopausal proliferative endometrium (n = 5), complex atypical hyperplasia (n = 4), grade 1 (n = 8) and grade 2 + 3 (n = 8) endometrioid adenocarcinomas were divided for gene expression by real-time RT-PCR, and paraffin embedded blocks for hyaluronan and HAS1-3 cytochemistry.
The mRNA levels of HAS1-3 were not consistently changed, while the immunoreactivity of all HAS proteins was increased in the cancer epithelium. Interestingly, HAS3 mRNA, but not HAS3 immunoreactivity, was increased in post-menopausal endometrium compared to normal endometrium (p = 0.003). The median of HYAL1 mRNA was 10-fold and 15-fold lower in both grade 1 and grade 2+3 endometrioid endometrial cancers, as compared to normal endometrium (p = 0.004-0.006), and post-menopausal endometrium (p = 0.002), respectively. HYAL2 mRNA was also reduced in cancer (p = 0.02) and correlated with HYAL1 (r = 0.8, p = 0.0001). There was an inverse correlation between HYAL1 mRNA and the epithelial hyaluronan staining intensity (r = -0.6; P = 0.001).
The results indicated that HYAL1 and HYAL2 were coexpressed and significantly downregulated in endometrioid endometrial cancer and correlated with the accumulation of hyaluronan. While immunoreactivity for HASs increased in the cancer cells, tumor mRNA levels for HASs were not changed, suggesting that reduced turnover of HAS protein may also have contributed to the accumulation of hyaluronan.
PMCID: PMC2956733  PMID: 20875124
6.  Nuclear expression of Snail1 in borderline and malignant epithelial ovarian tumours is associated with tumour progression 
BMC Cancer  2009;9:289.
Transcription factor Snail1 has a central role in induction of epithelial-mesenchymal transition (EMT). The aim of the present study was to elucidate the expression of Snail1 protein during epithelial ovarian tumourigenesis and to study the association of Snail1 expression with clinicopathological factors and prognosis.
Epithelial and stromal fibroblast-like fusiform cells of 14 normal ovarian samples, 21 benign, 24 borderline and 74 malignant epithelial ovarian tumours were studied for Snail1 protein using immunohistochemistry.
Nuclei of surface peritoneal cells of normal ovaries (n = 14) were regarded as negative for Snail1. Nuclear expression of Snail1 protein in epithelial ovarian tumours was increased during tumour progression from precursor lesions into carcinomas both in epithelial (p = 0.006) and stromal cells (p = 0.007). Nuclei of benign tumours (n = 21) were negative for Snail1. In borderline tumours (n = 24) occasional positive epithelial cells were found in 2 (8%) samples and in 3 (13%) samples stromal cells were focally positive for Snail1. In carcinomas (n = 74) focal Snail1 staining in epithelial cells was present in 17 (23%) tumours, and in stromal cells in 18 (24%) tumours. Nuclear expression of Snail1 in epithelial or stromal cells was not associated with clinicopathological factors or prognosis.
Nuclear Snail1 expression seems to be related to tumour progression, and expression in borderline tumours indicates a role for Snail1 in early epithelial ovarian tumour development. Snail1 also appears to function more generally in tissue remodelling as positive staining was demonstrated in stromal cells.
PMCID: PMC3087336  PMID: 19695091
7.  Expression of Hyaluronan Synthases (HAS1–3) and Hyaluronidases (HYAL1–2) in Serous Ovarian Carcinomas: Inverse Correlation between HYAL1 and Hyaluronan Content 
BMC Cancer  2009;9:143.
Hyaluronan, a tumor promoting extracellular matrix polysaccharide, is elevated in malignant epithelial ovarian tumors, and associates with an unfavorable prognosis. To explore possible contributors to the accumulation of hyaluronan, we examined the expression of hyaluronan synthases (HAS1, HAS2 and HAS3) and hyaluronidases (HYAL1 and HYAL2), correlated with hyaluronidase enzyme activity hyaluronan content and HAS1–3 immunoreactivity.
Normal ovaries (n = 5) and 34 serous epithelial ovarian tumors, divided into 4 groups: malignant grades 1+2 (n = 10); malignant grade 3 (n = 10); borderline (n = 4) and benign epithelial tumors (n = 10), were analyzed for mRNA by real-time RT-PCR and compared to hyaluronidase activity, hyaluronan staining, and HAS1–3 immunoreactivity in tissue sections of the same specimens.
The levels of HAS2 and HAS3 mRNA (HAS1 was low or absent), were not consistently increased in the carcinomas, and were not significantly correlated with HAS protein or hyaluronan accumulation in individual samples. Instead, the median of HYAL1 mRNA level was 69% lower in grade 3 serous ovarian cancers compared to normal ovaries (P = 0.01). The expression of HYAL1, but not HYAL2, significantly correlated with the enzymatic activity of tissue hyaluronidases (r = 0.5; P = 0.006). An inverse correlation was noted between HYAL1 mRNA and the intensity of hyaluronan staining of the corresponding tissue sections (r = -0.4; P = 0.025).
The results indicate that in serous epithelial ovarian malignancies HAS expression is not consistently elevated but HYAL1 expression is significantly reduced and correlates with the accumulation of hyaluronan. (233 words)
PMCID: PMC2689240  PMID: 19435493

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