140 results on '"Ouhtit, Allal"'
Search Results
102. Histopathological effects of cisplatin, doxorubicin and 5-flurouracil (5-FU) on the liver of male albino rats
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El-Sayyad, Hassan I, primary, Ismail, Mohamed F, additional, Shalaby, F M, additional, Abou-El-Magd, RF, additional, Gaur, Rajiv L, additional, Fernando, Augusta, additional, Raj, Madhwa HG, additional, and Ouhtit, Allal, additional
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- 2009
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103. Chemoprevention of rat liver toxicity and carcinogenesis by Spirulina
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Ismail, Mohamed F, primary, Ali, Doaa A, additional, Fernando, Augusta, additional, Abdraboh, Mohamed E, additional, Gaur, Rajiv L, additional, Ibrahim, Wael M, additional, Raj, Madhwa HG, additional, and Ouhtit, Allal, additional
- Published
- 2009
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104. Synergistic action of dietary phyto-antioxidants on survival and proliferation of ovarian cancer cells
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Raj, Madhwa H.G., primary, Abd Elmageed, Zakaria Y., additional, Zhou, Jing, additional, Gaur, RL, additional, Nguyen, Lan, additional, Azam, Ghazala A, additional, Braley, Patricia, additional, Rao, Prakash N., additional, Fathi, Ismail M., additional, and Ouhtit, Allal, additional
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- 2008
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105. In Vivo Evidence for the Role of CD44s in Promoting Breast Cancer Metastasis to the Liver
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Ouhtit, Allal, primary, Abd Elmageed, Zakaria Y., additional, Abdraboh, Mohamed E., additional, Lioe, Tong F., additional, and Raj, Madhwa H.G., additional
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- 2007
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106. Survivin is not only a death encounter but also a survival protein for invading tumor cells
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Ouhtit, Allal, primary
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- 2007
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107. Dysfunction of p53 in photocarcinogenesis
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Ouhtit, Allal, primary
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- 2003
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108. A Model for UV-Induction of Skin Cancer
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Ouhtit, Allal, primary and Ananthaswamy, Honnavara N., additional
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- 2001
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109. Loss of Fas-Ligand Expression in Mouse Keratinocytes during UV Carcinogenesis
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Ouhtit, Allal, primary, Gorny, Alexander, additional, Muller, H. Konrad, additional, Hill, Laurie L., additional, Owen-Schaub, Laurie, additional, and Ananthaswamy, Honnavara N., additional
- Published
- 2000
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110. Temporal Events in Skin Injury and the Early Adaptive Responses in Ultraviolet-Irradiated Mouse Skin
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Ouhtit, Allal, primary, Muller, H. Konrad, additional, Davis, Darren W., additional, Ullrich, Stephen E., additional, McConkey, David, additional, and Ananthaswamy, Honnavara N., additional
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- 2000
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111. Visualization of gene expression of prolactin receptors (PRL-R) by in situ hybridization, in Typhlonectes compressicaudus, a gymnophionan amphibian
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Exbrayat, Jean-Marie, primary, Ouhtit, Allal, additional, and Morel, Gérard, additional
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- 1997
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112. Prolactin Receptor Immunoreactivity in Rat Anterior Pituitary
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Morel, Gérard, primary, Ouhtit, Allal, additional, and Kelly, Paul A., additional
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- 1994
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113. Ultrastructural expression of prolactin receptor in rat liver
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Ouhtit, Allal, primary, Ronsin, Brice, additional, Kelly, Paul A., additional, and Morel, Gérard, additional
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- 1994
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114. Visualization of Gene Expression of Short and Long Forms of Prolactin Receptor in Rat Reproductive Tissues
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Ouhtit, Allal, primary, Morel, Gérard, additional, and Kelly, Paul A., additional
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- 1993
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115. ULTRASTRUCTURAL EVIDENCE FOR PROLACTING RECEPTOR PRESENCE IN RAT PITUITARY
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Morel Gérard, Ouhtit Allal, and Paul A. Kelly
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Rat Pituitary ,medicine.medical_specialty ,Endocrinology ,Internal medicine ,medicine ,Ultrastructure ,Cell Biology ,General Medicine ,Biology ,Receptor - Published
- 1993
116. UV-radiation-specific p53 mutation frequency in normal skin as a predictor of...
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Tan, Ernest, English, Dallas R., Ouhtit, Allal, Nakazawa, Hisayoshi, Armstrong, Bruce K., Kricker, Anne, and Yamasaki, Hiroshi
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P53 antioncogene ,SKIN cancer ,ULTRAVIOLET radiation ,HEALTH - Abstract
States that a strong association has been found between skin cancer and exposure to ultra-violet (UV) radiation. What role the p53 tumor suppressor gene plays in UV radiation-associated skin carcinogenesis; Development of a sensitive, polymerase chain reaction-based method capable of detecting and quantifying a UV radiation-specific mutation in the p53 gene.
- Published
- 1998
117. In VivoEvidence for the Role of CD44s in Promoting Breast Cancer Metastasis to the Liver
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Ouhtit, Allal, Abd Elmageed, Zakaria Y., Abdraboh, Mohamed E., Lioe, Tong F., and Raj, Madhwa H.G.
- Abstract
The hyaluronan receptor CD44 plays an important role in facilitating invasion and metastasis of a variety of tumors, including breast carcinomas. CD44 functions as a bioactive signaling transmitter. Although a number of studies have implicated CD44 in breast tumor invasion, the evidence is still circumstantial. We have developed a tetracycline-regulated CD44s (standard form) system in the weakly metastatic breast cancer cell MCF7, which exhibits low endogenous expression of CD44 and generated a new cell line, MCF7F-B5. Induction of CD44s alone affected the growth characteristics of MCF7F-B5 cells by increasing their abilities to proliferate, migrate, and invade in vitro. In addition, we have identified and validated cortactin as a novel transcriptional target of hyaluronan/CD44s signaling in underpinning breast tumor invasion. To test these observations in vivo, we developed a doxycycline (DOX)-regulated CD44s breast cancer xenograft model. Induction of CD44s did not affect the growth rate or local invasion of the primary tumor. However, although no mice from the +DOX group developed metastasis, 8 of 11 mice from the −DOX group developed secondary tumors to the liver only. Interestingly, metastatic breast tumors expressed high levels of CD44. This study provides in vivoevidence for the role of the standard form of CD44 in promoting breast tumor invasion and metastasis to the liver.
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- 2007
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118. Differential Effects of Leptin on the Invasive Potential of Androgen-Dependent and -Independent Prostate Carcinoma Cells
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D. Deo, Dayanand, P. Rao, Ashwin, S. Bose, Saideep, Ouhtit, Allal, B. Baliga, Surendra, A. Rao, Shilpa, J. Trock, Bruce, Thouta, Rajesh, HG Raj, Madhwa, and N. Rao, Prakash
- Abstract
Obesity has been linked with an increased risk of prostate cancer. The formation of toxic free oxygen radicals has been implicated in obesity mediated disease processes. Leptin is one of the major cytokines produced by adipocytes and controls body weight homeostasis through food intake and energy expenditure. The rationale of the study was to determine the impact of leptin on the metastatic potential of androgen-sensitive (LNCaP) cells as well as androgen-insensitive (PC-3 and DU-145) cells. At a concentration of 200_nm, LNCaP cells showed a significant increase (20% above control; P<.0001) in cellular proliferation without any effect on androgen-insensitive cells. Furthermore, exposure to leptin caused a significant (P<.01 to P<.0001) dose-dependent decrease in migration and invasion of PC3 and Du-145 prostate carcinoma cell lines. At the molecular level, exposure of androgen-independent prostate cancer cells to leptin stimulates the phosphorylation of MAPK at early time point as well as the transcription factor STAT3, suggesting the activation of the intracellular signaling cascade upon leptin binding to its cognate receptor. Taken together, these results suggest that leptin mediates the invasive potential of prostate carcinoma cells, and that this effect is dependent on their androgen sensitivity.
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- 2008
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119. Profile of Mental and Behavioral Disorders Among Preschoolers in a Tertiary Care Hospital in Oman: A Retrospective Study.
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Al-Sharbati, Marwan M., Al-Farsi, Yahya M., Al-Sharbati, Zena M., Al-Sulaimani, Fatima, Ouhtit, Allal, and Al-Adawi, Samir
- Subjects
- *
ATTENTION-deficit hyperactivity disorder , *AUTISM , *DEVELOPMENTAL disabilities , *LANGUAGE disorders , *RESEARCH methodology , *CLASSIFICATION of mental disorders , *METHYLPHENIDATE , *OMEGA-3 fatty acids , *RISPERIDONE , *SYMPTOMS , *BEHAVIOR disorders , *MEDICAL records , *RETROSPECTIVE studies , *ATOMOXETINE - Abstract
Objectives: Early diagnosis and prompt treatment of mental and behavioral disorders in preschoolers is critical for a better prognosis, ultimately leading to improved quality of life for both the child and the family. Our study investigated the clinical profile of mental and behavioral disorders in children < 7 years of age, seeking consultation at Sultan Qaboos University Hospital, Muscat, Oman, between 1 June 2006 and 31 December 2010. The objective was to explore demographic variables, intervention types, and annual trends. Methods: This retrospective, descriptive study was conducted by reviewing the electronic records of preschoolers seeking consultation on mental and behavioral disorders at the Department of Behavioral Medicine. The diagnosis was based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. Results: The total number of cases was 466, the majority (77.9%) being boys. The cumulative frequencies and annual hospital-based prevalence rates were estimated for each category of mental and behavioral disorders. Our findings showed increased service utilization among preschoolers, as reflected in the annual trend and case-specific prevalence rates. While comorbidity was common, the most frequent disorders encountered were attention deficit hyperactivity disorder (70.8%), developmental language disorder (23.6%), autism spectrum disorders (20.2%), and disruptive behavior disorders (11.6%). The most commonly prescribed drugs/supplementation were risperidone (18.7%), atomoxetine (9.7%), omega-3 (8.8%), and methylphenidate (6.2%). Conclusions: Consultations for mental and behavioral disorders are being sought for Omani preschoolers. Beside pharmacotherapy, other interventions, which are an integral part of a much desired multidisciplinary approach should be introduced. Readdressing the missing needs is essential for a comprehensive approach to managing mental and behavioral disorders. [ABSTRACT FROM AUTHOR]
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- 2016
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120. The Novel Role of BRIP1 in Breast Tumor Development and Progression
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RIZEQ, BALSAM RIAD, Ouhtit, Allal, and Sif, Saïd
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Breast cancer (BC) ,NOVEL ROLE ,BRCA - Abstract
Breast cancer (BC) is the most common malignancy and the leading cause of death in women worldwide. Only 5-10% of mutations in the BRCA genes are attributed to familial breast tumors in Eastern countries, suggesting the contribution of other genes to be identified. Pursuant to this goal, our literature search led to the following observations: 1) in a recent study of my supervisor’s team using microarray gene expression profiling of BC in Omani population identified BRIP1 (5 fold upregulation) as a potential gene associated with BC progression; 2) BRIP1 is a tumor suppressor that inhibits cell growth and controls DNA repair mechanisms. Despite its role as a tumor suppressor, the precise role of BRIP1 in breast tumor cell progression has not been explored yet; this prompted us to hypothesize that BRIP1 is upregulated during breast tumorigenesis to promote breast tumor cell proliferation and invasion. Using a combination of cellular and molecular approaches, our results of structural validation experiments showed differential over-expression of BRIP1 in different BC cell lines. Functional assays confirmed the novel role of BRIP1 in malignant phenotype. siRNA Down-regulation of BRIP1 attenuated cell proliferation significantly and induced cell cycle arrest in G1/S phase. Furthermore, siRNA-mediated BRIP1 knockdown significantly reduced both cell migration and invasion by targeting a number of potential cell motility-associated genes. Altogether, our investigation is the first to validate the novel function of BRIP1 in promoting breast tumor cell invasion, and identifying a unique set of pro-invasive genes to predict the mechanisms that underpin BRIP1-promoting BC progression. Ongoing/future experiments combining bioinformatics analysis and functional cell approaches aim to validate the relevance of these genes in BC progression. This is in order to better understand the exact molecular mechanisms that underpin BRIP1-promoting cell invasion, and validate the genes mediating BRIP1 function in cell proliferation and invasion as biomarkers and/or targets to guide the design of appropriate BC targeted therapies.
- Published
- 2020
121. Characterization of Coordinated Immediate Responses by p16INK4A and p53 Pathways in UVB-Irradiated Human Skin Cells.
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Abd Elmageed, Zakaria Y., Gaur, Rajiv L., Williams, Mandy, Abdraboh, Mohamed E., Rao, Prakash N., Raj, Madhwa H. G., Ismail, Fathi M., and Ouhtit, Allal
- Subjects
- *
MELANOMA , *HUMAN cell culture , *APOPTOSIS , *ORGAN culture , *IRRADIATION , *ULTRAVIOLET radiation , *GENETICS - Abstract
While the precise mechanisms of melanoma development are unknown, recent in vivo studies have revealed that the p16Ink4a/Rb pathway is disrupted in melanomagenesis. Here, we characterize the role of p16/Rb in coordinating the early events in UVB-irradiated skin. Foreskins and melanoma cell cultures were irradiated with low and high acute UVB doses and examined for cell-cycle- and apoptosis-associated genes. In melanoma cells, low UVB dose upregulated p16, p53, and p21 expression levels in Malme-3M, and high UVB dose accentuated the expression of p53 and p21Cip1/Waf1, in particular; however, in SkMel-28 cells only p16 expression was upregulated in response to UV irradiation. In HaCaT cells, high UVB dose caused dramatic increase in p53 expression followed by upregulation of p21Cip1/Waf1 and Bax, and downregulation of Bcl-2 leading to apoptosis. In HaCaT cells, reinstatement of p16 pathway restored cell-cycle arrest in response to low dose. Foreskin organ culture experiments confirmed our in vitro cell results. These data indicate that the p53 and p16 pathways respond independently to UVB insult. The p16 pathway is favored at low doses and results in cell-cycle arrest; the p53 pathway is more responsive to higher doses and induces apoptosis depending on p53 mutation status.Journal of Investigative Dermatology (2009) 129, 175–183; doi:10.1038/jid.2008.208; published online 21 August 2008 [ABSTRACT FROM AUTHOR]
- Published
- 2009
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122. ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF SELECTED QATARI FLORA
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AL-ABBASI, WA'ED AHMAD MOSTAFA, Ouhtit, Allal, and Abu-Dieyeh, Mohammed
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Alternative medicine ,Medicinal Plant ,Qatari Flora ,food and beverages - Abstract
Conventional medicine has been challenged by various issues, including drug resistance and safety. On the other hand, Complementary Alternative Medicine has been increasingly gaining the interest of the scientific community and the public for its efficacy and safety. Therefore, the search for cytotoxic and antimicrobial agents from plants has been booming in the last few decades. This study was designed to investigate the anticancer and antifungal activities of the crude extracts (aqueous and organic) from four native Qatari plant species; Aerva javanica, Limonium axillare, Salsola soda and Suaeda vermiculata. The antifungal activity of their crude extracts on the species; Alternaria alternata, Cladosporium sphaerospermum, Fusarium oxysporum, and Botrytis cinerea, was assessed in vitro by two methods; poisoned food and agar diffusion method. While aqueous extracts were not effective, the ethanolic extracts of all plant (aerial parts) were active against all of the tested fungi, and the concentration of 10 mg/ml was enough to inhibit fungal growth. Extracts of L. axillare had the highest activity, with minimal concentration values between 5 and 2.5 mg/ml. The anti-cancer activity of the crude extracts was also assessed on the MCF-7 breast cancer cell line, indicating that with water crude extracts of S. vermiculata at concentrations of 400 and 300 μg/μl were the only effective doses worked against MCF-7 cell proliferation. A comprehensive study is needed to assess the anticancer activity of the S. vermiculata crude extract, using normal human epithelial breast cells and various additional breast cancer cell lines. Last but not least, fractionation will be carried out to identify the bioactive ingredients that are responsible for both anti-cancer and anti-fungal activities.
- Published
- 2018
123. Antibody-dependent enhancement (ADE) of SARS-CoV-2 in patients exposed to MERS-CoV and SARS-CoV-2 antigens.
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Thomas S, Smatti MK, Alsulaiti H, Zedan HT, Eid AH, Hssain AA, Abu Raddad LJ, Gentilcore G, Ouhtit A, Althani AA, Nasrallah GK, Grivel JC, and Yassine HM
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- Humans, Coronavirus Infections immunology, Coronavirus Infections virology, Middle Aged, Male, Female, Neutralization Tests, Adult, COVID-19 Vaccines immunology, Antigens, Viral immunology, Animals, Aged, Spike Glycoprotein, Coronavirus immunology, Vaccination, Middle East Respiratory Syndrome Coronavirus immunology, Antibodies, Viral blood, SARS-CoV-2 immunology, Immunoglobulin G blood, Antibodies, Neutralizing blood, Antibodies, Neutralizing immunology, COVID-19 immunology, Antibody-Dependent Enhancement
- Abstract
This study evaluated the potential for antibody-dependent enhancement (ADE) in serum samples from patients exposed to Middle East respiratory syndrome coronavirus (MERS-CoV). Furthermore, we evaluated the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination on ADE in individuals with a MERS infection history. We performed ADE assay in sera from MERS recovered and SARS-CoV-2-vaccinated individuals using BHK cells expressing FcgRIIa, SARS-CoV-2, and MERS-CoV pseudoviruses (PVs). Further, we analyzed the association of ADE to serum IgG levels and neutralization. Out of 16 MERS patients, nine demonstrated ADE against SARS-CoV-2 PV, however, none of the samples demonstrated ADE against MERS-CoV PV. Furthermore, out of the seven patients exposed to SARS-CoV-2 vaccination after MERS-CoV infection, only one patient (acutely infected with MERS-CoV) showed ADE for SARS-CoV-2 PV. Further analysis indicated that IgG1, IgG2, and IgG3 against SARS-CoV-2 S1 and RBD subunits, IgG1 and IgG2 against the MERS-CoV S1 subunit, and serum neutralizing activity were low in ADE-positive samples. In summary, samples from MERS-CoV-infected patients exhibited ADE against SARS-CoV-2 and was significantly associated with low levels of neutralizing antibodies. Subsequent exposure to SARS-CoV-2 vaccination resulted in diminished ADE activity while the PV neutralization assay demonstrated a broadly reactive antibody response in some patient samples., (© 2024 The Authors. Journal of Medical Virology published by Wiley Periodicals LLC.)
- Published
- 2024
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124. Molecular Evidence of Breast Cancer Cell Proliferation Inhibition by a Combination of Selected Qatari Medicinal Plants Crude Extracts.
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Alateyah N, Alsafran M, Usman K, and Ouhtit A
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- Infant, Newborn, Humans, Animals, Mice, Female, Tumor Suppressor Protein p53, Cell Line, Tumor, Apoptosis, Cell Proliferation, Cell Movement, Breast Neoplasms metabolism, Plants, Medicinal
- Abstract
Breast cancer (BC) is the most common malignancy, and conventional medicine has failed to establish efficient treatment modalities. Conventional medicine failed due to lack of knowledge of the mechanisms that underpin the onset and metastasis of tumors, as well as resistance to treatment regimen. However, Complementary and Alternative medicine (CAM) modalities are currently drawing the attention of both the public and health professionals. Our study examined the effect of a super-combination (SC) of crude extracts, which were isolated from three selected Qatari medicinal plants, on the proliferation, motility and death of BC cells. Our results revealed that SC attenuated cell growth and caused the cell death of MDA-MB-231 cancer cells when compared to human normal neonatal fibroblast cells. On the other hand, functional assays showed that SC reduced BC cell migration and invasion, respectively. SC-inhibited cell cycle and SC-regulated apoptosis was most likely mediated by p53/p21 pathway and p53-regulated Bax/BCL-2/Caspace-3 pathway. Our ongoing experiments aim to validate these in vitro findings in vivo using a BC-Xenograft mouse model. These findings support our hypothesis that SC inhibited BC cell proliferation and induced apoptosis. These findings lay the foundation for further experiments, aiming to validate SC as an effective chemoprevention and/or chemotherapeutic strategy that can ultimately pave the way towards translational research/clinical trials for the eradication of BC.
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- 2023
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125. ITGB1BP1 , a Novel Transcriptional Target of CD44-Downstream Signaling Promoting Cancer Cell Invasion.
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Ahmad SMS, Nazar H, Rahman MM, Rusyniak RS, and Ouhtit A
- Abstract
Breast cancer (BC) is the most common malignancy worldwide and has a poor prognosis, because it begins in the breast and disseminates to lymph nodes and distant organs. While invading, BC cells acquire aggressive characteristics from the tumor microenvironment through several mechanisms. Thus, understanding the mechanisms underlying the process of BC cell invasion can pave the way towards the development of targeted therapeutics focused on metastasis. We have previously reported that the activation of CD44 receptor with its major ligand hyaluronan (HA) promotes BC metastasis to the liver in vivo. Next, a gene expression profiling microarray analysis was conducted to identify and validate CD44-downstream transcriptional targets mediating its pro-metastatic function from RNA samples collected from Tet CD44-induced versus control MCF7-B5 cells. We have already validated a number of novel CD44-target genes and published their underlying signaling pathways in promoting BC cell invasion. From the same microarray analysis, Integrin subunit beta 1 binding protein 1 ( ITGB1BP1 ) was also identified as a potential CD44-target gene that was upregulated (2-fold) upon HA activation of CD44. This report will review the lines of evidence collected from the literature to support our hypothesis, and further discuss the possible mechanisms linking HA activation of CD44 to its novel potential transcriptional target ITGB1BP1 ., Competing Interests: The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of the data; in the writing of the manuscript, or in the decision to publish the results., (© 2023 Ahmad et al.)
- Published
- 2023
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126. Influenza prevalence and vaccine efficacy among diabetic patients in Qatar.
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Thomas S, Emara MM, Ouhtit A, Nader JD, Nasrallah GK, Coyle PV, Althani AA, Al Maslamani MA, and Yassine HM
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- Humans, Influenza A Virus, H3N2 Subtype, Prevalence, Qatar epidemiology, Pandemics, Vaccine Efficacy, Seasons, Influenza, Human epidemiology, Influenza, Human prevention & control, Influenza Vaccines, Influenza A Virus, H1N1 Subtype, COVID-19 epidemiology, Respiratory Tract Infections epidemiology, Diabetes Mellitus epidemiology
- Abstract
Seasonal influenza viruses may lead to severe illness and mortality in patients with comorbidities, including Diabetes Mellitus (DM). Vaccination against influenza in DM patients may reduce influenza incidence and severity. Before the emergence of the COVID-19 pandemic, influenza infections were the most prevalent respiratory infections in Qatar. Still, reports about influenza prevalence and vaccine efficacy in DM patients have not been reported. This study aimed to analyze influenza prevalence among other respiratory infections and assess influenza vaccine efficacy in DM patients in Qatar. Statistical analysis was performed on data obtained from Hamad Medical Corporation (HMC) database for patients that visited the emergency department (ED) with respiratory-like illnesses. The analysis was done for the period between January 2016 to December 2018. Among 17,525 patients who visited HMC-ED with clinical symptoms of respiratory infections, 2611(14.9%) were reported to have DM. Among DM patients, influenza was the most prevalent respiratory pathogen at 48.9%. Influenza virus A (IVA) was the most circulating type, contributing to 38.4%, followed by IVB contributing to 10.4% of total respiratory infections. Among the typed IVA-positive cases, 33.4% were H1N1, and 7.7% were H3N2. A significant decrease in influenza infections was reported in vaccinated DM patients (14.5%) when compared to non-vaccinated patients (18.9%) (p-value = 0.006). However, there was no significant relaxation in the clinical symptoms among vaccinated DM patients compared to their non-vaccinated counterparts. In conclusion, influenza was the most common etiology for respiratory viral infection among diabetic patients at the leading healthcare provider in Qatar. Although vaccination reduced the incidence rate among DM patients, it was less effective in preventing symptoms. Further studies on a larger cohort and for a more extended period are required to investigate influenza prevalence and vaccine efficacy among DM patients., Competing Interests: Conflict of interest There is no conflicts of interest declared by any author., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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127. Docosahexaenoic Acid, a Key Compound for Enhancing Sensitization to Drug in Doxorubicin-Resistant MCF-7 Cell Line.
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Crovella S, Ouhtit A, Rahman SM, and Rahman MM
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- Humans, Animals, Female, MCF-7 Cells, Docosahexaenoic Acids pharmacology, Docosahexaenoic Acids therapeutic use, Drug Resistance, Neoplasm, Doxorubicin therapeutic use, Apoptosis, Cell Line, Tumor, Antineoplastic Agents pharmacology, Antineoplastic Agents therapeutic use, Breast Neoplasms metabolism
- Abstract
Drug resistance is a well-known and significant obstacle in the battle against cancer, rendering chemotherapy treatments often ineffective. To improve the effectiveness of chemotherapy, researchers are exploring the use of natural molecules that can enhance its ability to kill cancer cells and limit their spread. Docosahexaenoic acid (DHA), a lipid found in marine fish, has been shown to enhance the cytotoxicity of various anti-cancer drugs in vitro and in vivo. While the combined use of chemotherapeutic drugs with DHA demonstrated promising preliminary results in clinical trials, there is still a significant amount of information to be discovered regarding the precise mechanism of action of DHA. As the biological pathways involved in the chemosensitization of already chemoresistant MCF-7 cells are still not entirely unraveled, in this study, we aimed to investigate whether DHA co-treatment could enhance the ability of the chemotherapy drug doxorubicin to inhibit the growth and invasion of MCF-7 breast cancer cells (MCF-7/Dox) that had become resistant to the drug. Upon treating MCF-7/Dox cells with DHA or DHA-doxorubicin, it was observed that the DHA-doxorubicin combination effectively enhanced cancer cell death by impeding in vitro propagation and invasive ability. In addition, it led to an increase in doxorubicin accumulation and triggered apoptosis by arresting the cell cycle at the G2/M phase. Other observed effects included a decrease in the multi-drug resistance (MDR) carrier P-glycoprotein (P-gp) and TG2, a tumor survival factor. Augmented quantities of molecules promoting apoptosis such as Bak1 and caspase-3 and enhanced lipid peroxidation were also detected. Our findings in the cell model suggest that DHA can be further investigated as a natural compound to be used alongside doxorubicin in the treatment of breast cancer that is unresponsive to chemotherapy.
- Published
- 2023
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128. Bacteriocin-Nanoconjugates (Bac10307-AgNPs) Biosynthesized from Lactobacillus acidophilus -Derived Bacteriocins Exhibit Enhanced and Promising Biological Activities.
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Siddiqui AJ, Patel M, Adnan M, Jahan S, Saxena J, Alshahrani MM, Abdelgadir A, Bardakci F, Sachidanandan M, Badraoui R, Snoussi M, and Ouhtit A
- Abstract
The proteinaceous compounds produced by lactic acid bacteria are called bacteriocins and have a wide variety of bioactive properties. However, bacteriocin's commercial availability is limited due to short stability periods and low yields. Therefore, the objective of this study was to synthesize bacteriocin-derived silver nanoparticles (Bac10307-AgNPs) extracted from Lactobacillus acidophilus ( L. acidophilus ), which may have the potential to increase the bioactivity of bacteriocins and overcome the hurdles. It was found that extracted and purified Bac10307 had a broad range of stability for both temperature (20-100 °C) and pH (3-12). Further, based on Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis, its molecular weight was estimated to be 4.2 kDa. The synthesized Bac10307-AgNPs showed a peak of surface plasmon resonance at 430 nm λmax. Fourier transform infrared (FTIR) confirmed the presence of biological moieties, and transmission electron microscopy (TEM) coupled with Energy dispersive X-Ray (EDX) confirmed that AgNPs were spherical and irregularly shaped, with a size range of 9-20 nm. As a result, the Bac10307-AgNPs displayed very strong antibacterial activity with MIC values as low as 8 μg/mL for Staphylococcus aureus ( S. aureus ) and Pseudomonas aeruginosa ( P. aeruginosa ), when compared to Bac10307 alone. In addition, Bac10307-AgNPs demonstrated promising in vitro antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC
50 = 116.04 μg/mL) and in vitro cytotoxicity against human liver cancer cells (HepG2) (IC50 = 135.63 μg/mL), more than Bac10307 alone (IC50 = 139.82 μg/mL against DPPH and 158.20 μg/mL against HepG2). Furthermore, a protein-protein molecular docking simulation study of bacteriocins with target proteins of different biological functions was also carried out in order to ascertain the interactions between bacteriocins and target proteins.- Published
- 2023
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129. Antibody-Dependent Enhancement (ADE) and the role of complement system in disease pathogenesis.
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Thomas S, Smatti MK, Ouhtit A, Cyprian FS, Almaslamani MA, Thani AA, and Yassine HM
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- Humans, Antibody-Dependent Enhancement, Complement C1q, Antigen-Antibody Complex, Antibodies, Viral, Severe Acute Respiratory Syndrome, COVID-19
- Abstract
Antibody-dependent enhancement (ADE) has been associated with severe disease outcomes in several viral infections, including respiratory infections. In vitro and in vivo studies showed that antibody-response to SARS-CoV and MERS-CoV could exacerbate infection via ADE. Recently in SARS CoV-2, the in vitro studies and structural analysis shows a risk of disease severity via ADE. This phenomenon is partially attributed to non-neutralizing antibodies or antibodies at sub-neutralizing levels. These antibodies result in antigen-antibody complexes' deposition and propagation of a chronic inflammatory process that destroys affected tissues. Further, antigen-antibody complexes may enhance the internalization of the virus into cells through the Fc gamma receptor (FcγR) and lead to further virus replication. Thus, ADE occur via two mechanisms; 1. Antibody mediated replication and 2. Enhanced immune activation. Antibody-mediated effector functions are mainly driven by complement activation, and the first complement in the cascade is complement 1q (C1q) which binds to the virus-antibody complex. Reports say that deficiency in circulating plasma levels of C1q, an independent predictor of mortality in high-risk patients, including diabetes, is associated with severe viral infections. Complement mediated ADE is reported in several viral infections such as dengue, West Nile virus, measles, RSV, Human immunodeficiency virus (HIV), and Ebola virus. This review discusses ADE in viral infections and the in vitro evidence of ADE in coronaviruses. We outline the mechanisms of ADE, emphasizing the role of complements, especially C1q in the outcome of the enhanced disease., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2022
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130. Burden and disease pathogenesis of influenza and other respiratory viruses in diabetic patients.
- Author
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Thomas S, Ouhtit A, Al Khatib HA, Eid AH, Mathew S, Nasrallah GK, Emara MM, Al Maslamani MA, and Yassine HM
- Subjects
- Hospitalization, Humans, Diabetes Mellitus, Type 2, Influenza Vaccines, Influenza, Human complications, Influenza, Human epidemiology, Influenza, Human prevention & control, Respiratory Tract Infections complications, Respiratory Tract Infections epidemiology, Respiratory Tract Infections prevention & control, Viruses
- Abstract
Over the past two decades, diabetes mellitus (DM) has been receiving increasing attention among autoimmune diseases. The prevalence of type 1 and type 2 diabetes has increased rapidly and has become one of the leading causes of death worldwide. Therefore, a better understanding of the genetic and environmental risk factors that trigger the onset of DM would help develop more efficient therapeutics and preventive measures. The role and mechanism of respiratory viruses in inducing autoimmunity have been frequently reported. On the other hand, the association of DM with respiratory infections might result in severe complications or even death. Since influenza is the most common respiratory infection, DM patients experience disease severity and increased hospitalization during influenza season. Vaccinating diabetic patients against influenza would significantly reduce hospitalization due to disease severity. However, recent studies also report the role of viral vaccines in inducing autoimmunity, specifically diabetes. This review reports causes of diabetes, including genetic and viral factors, with a special focus on respiratory viruses. We further brief the burden of influenza-associated complications and the effectiveness of the influenza vaccine in DM patients., Competing Interests: Competing interests All authors declare no conflict of interest., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2022
- Full Text
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131. Recent Advances on Utilization of Bioprinting for Tumor Modeling.
- Author
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Oztan YC, Nawafleh N, Zhou Y, Liyanage PY, Hettiarachchi SD, Seven ES, Leblanc RM, Ouhtit A, and Celik E
- Abstract
Despite the recent rigorous studies towards a possible cure, cancer still remains as one of the most daunting problems faced by the humanity. Currently utilized two-dimensional cancer models are known to have various insuperable limitations such as insufficient biomimicry of the heterogeneous conditions of tumors and their three-dimensional structures. Discrepancies between the laboratory models and the actual tumor environment significantly impair a thorough comprehension of the carcinogenesis process and development of successful remedies against cancer. Modeling tumor microenvironments through bioprinting poses strong potential to minimize the effects of the aforementioned issues thanks to its freeform nature, adaptability, customizability, scalability and diversity. Numerous research studies involving three-dimensional modeling of various cancer types using bioprinting technologies have been reported, recently. In this review, we provide a broad summary of these studies to help better represent their potential and analyze their contribution to cancer research., Competing Interests: 5.Conflict of Interest The authors declare no conflict of interest. Declaration of interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Published
- 2020
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- View/download PDF
132. Nanoparticle-mediated targeted drug delivery for breast cancer treatment.
- Author
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Liyanage PY, Hettiarachchi SD, Zhou Y, Ouhtit A, Seven ES, Oztan CY, Celik E, and Leblanc RM
- Subjects
- Animals, Female, Humans, Antineoplastic Agents administration & dosage, Breast Neoplasms drug therapy, Drug Delivery Systems methods, Molecular Targeted Therapy methods, Nanoparticles
- Abstract
Breast cancer (BC) is the most common malignancy in women worldwide, and one of the deadliest after lung cancer. Currently, standard methods for cancer therapy including BC are surgery followed by chemotherapy or radiotherapy. However, both chemotherapy and radiotherapy often fail to treat BC due to the side effects that these therapies incur in normal tissues and organs. In recent years, various nanoparticles (NPs) have been discovered and synthesized to be able to selectively target tumor cells without causing any harm to the healthy cells or organs. Therefore, NPs-mediated targeted drug delivery systems (DDS) have become a promising technique to treat BC. In addition to their selectivity to target tumor cells and reduce side effects, NPs have other unique properties which make them desirable for cancer treatment such as low toxicity, good compatibility, ease of preparation, high photoluminescence (PL) for bioimaging in vivo, and high loadability of drugs due to their tunable surface functionalities. In this study, we summarize with a critical analysis of the most recent therapeutic studies involving various NPs-mediated DDS as alternatives for the traditional treatment approaches for BC. It will shed light on the significance of NPs-mediated DDS and serve as a guide to seeking for the ideal methodology for future targeted drug delivery for an efficient BC treatment., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
133. Towards understanding the genetics of Autism.
- Author
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Shailesh H, Gupta I, Sif S, and Ouhtit A
- Subjects
- Autism Spectrum Disorder therapy, DNA Copy Number Variations, Epigenesis, Genetic, Genetic Association Studies, Humans, Autism Spectrum Disorder genetics
- Abstract
Autism spectrum disorder (ASD) includes a group of neurodevelopmental disorders that affect communication skills, social interaction and intellectual ability. Despite evidence suggesting a strong genetic link with ASD, the genetic determinant remains unclear. Early studies focusing on candidate genes have shown that several genes associated with neuronal synaptic function are involved in development of ASD. Linkage studies have identified several single nucleotide polymorphisms (SNPs) associated with ASD, and genome-wide association studies have implicated several loci, but failed to recognize a single specific locus with strong significance, indicating heterogeneity in ASD genetic determinants. Detection of de novo copy number variations and single nucleotide variants in several ASD probands has confirmed the genetic heterogeneity of the disease. More interestingly, next generation sequencing approaches have recently identified novel candidate genes and several point mutations in sporadic ASDs, thus increasing our knowledge of ASD etiology. The current review summarizes the findings of recent studies using genetic and genomic approaches to understand the underlying molecular mechanisms of ASD.
- Published
- 2016
- Full Text
- View/download PDF
134. BRIP1, a potential candidate gene in development of non-BRCA1/2 breast cancer.
- Author
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Ouhtit A, Gupta I, and Shaikh Z
- Subjects
- Fanconi Anemia Complementation Group Proteins, Female, Genes, BRCA1, Genes, BRCA2, Humans, Breast Neoplasms genetics, DNA-Binding Proteins genetics, RNA Helicases genetics
- Abstract
BRIP1 encodes a protein belonging to the RecQ DEAH helicase family. It interacts with BRCA1, and is involved in the repair of DNA damage and tumor suppression. Aberrations in BRIP1 have been mainly associated with the development of breast cancer (BC), ovarian cancer, and type J Fanconi anemia. Based on recent work, we hypothesize that BRIP1 might be the gene involved in the onset of BC in families that do not show BRACA1/2 mutations. This review will focus on the findings supporting this hypothesis, the mechanisms linking BRIP1 to the onset of BC, and the potential clinical relevance of its various inhibitors.
- Published
- 2016
- Full Text
- View/download PDF
135. Underlying Factors Behind the Low Prevalence of Autism Spectrum Disorders in Oman: Sociocultural perspective.
- Author
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Ouhtit A, Al-Farsi Y, Al-Sharbati M, Waly M, Gupta I, Al-Farsi O, Al-Khaduri M, Al-Shafaee M, and Al-Adawi S
- Abstract
Epidemiological surveys from various countries indicate an increased prevalence of autism spectrum disorders (ASD), leading researchers to debate whether there are now 'more affected' or 'more detected'. The epidemiology of ASD in developing countries, such as Oman, has generally indicated a lower prevalence compared to developed countries in the West. In Oman, the prevalence is low; however, this article highlights some of the factors that could contribute to the appearance of a low ASD rate: cross-cultural variations in the presentation of distress; a lack of reliable biological markers for diagnosing ASD, and a lack of health services for children with ASD, thus limiting the number of participants in epidemiological surveys. While the defining features of ASD have yet to be established, pilot studies in Oman indicate a substantial number of children with these disorders. Therefore, it is important that these discrepancies be addressed and the need for appropriate services for this patient population in Oman be highlighted.
- Published
- 2015
136. Awareness about autism among school teachers in Oman: a cross-sectional study.
- Author
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Al-Sharbati MM, Al-Farsi YM, Ouhtit A, Waly MI, Al-Shafaee M, Al-Farsi O, Al-Khaduri M, Al-Said MF, and Al-Adawi S
- Subjects
- Adult, Child Development Disorders, Pervasive, Cross-Sectional Studies, Female, Humans, Mainstreaming, Education, Male, Middle Aged, Oman, Social Stigma, Surveys and Questionnaires, Young Adult, Autistic Disorder, Faculty, Health Knowledge, Attitudes, Practice
- Abstract
Children with special needs such as those with autism spectrum disorder have been recorded as ostracized and stigmatized in many parts of the world. Little is known about whether such negative views are present among mainstream teachers in Oman. A cross-sectional study was conducted to evaluate school teachers' awareness about autism spectrum disorder in an urban region in Oman. A total of 164 teachers were randomly enrolled from five schools. Misconceptions about autism spectrum disorder were found to be common among mainstream teachers in the country. We posit that such lack of awareness was likely to be rooted with sociocultural patterning as well as conflicting views often "spun" by the scientific community and mass media. Enlightened views toward children with autism spectrum disorder should be presented to Omani teachers to overcome misconceptions and negative attitudes toward children with autism spectrum disorder., (© The Author(s) 2013.)
- Published
- 2015
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137. The shady side of sunlight: current understanding of the mechanisms underlying UV-induction of skin cancers.
- Author
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Trappey A, Fernando A, Gaur R, Raj M, and Ouhtit A
- Subjects
- Cyclin-Dependent Kinase Inhibitor p16, Humans, Neoplasm Proteins metabolism, Tumor Suppressor Protein p53 metabolism, Apoptosis drug effects, DNA Damage radiation effects, Melanoma etiology, Neoplasms, Radiation-Induced etiology, Skin Neoplasms etiology, Sunlight adverse effects, Ultraviolet Rays adverse effects
- Abstract
The incidence of skin cancer has been rising at an astonishing rate, particularly that of the deadliest skin cancer, melanoma. While the molecular mechanisms of sunlight ultraviolet radiation (UV)-induced non-melanoma skin cancer (NMSC) have been well documented, there is a major gap in our current knowledge of how UV initiates melanoma. However, the components of the retinoblastoma (Rb) pathway, the p53 and the p16 pathways are considered the major targets of UV-induced NMSC and melanoma, respectively. Our recent study has revealed that these two pathways coordinate the early responses to UV radiation in the skin. Here, we review the value of studies targeting these early events of skin carcinogenesis, with specific focus on the critical role of the components of the Rb pathway.
- Published
- 2010
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138. Biochemical characterization of riboflavin carrier protein (RCP) in prostate cancer.
- Author
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Johnson T, Ouhtit A, Gaur R, Fernando A, Schwarzenberger P, Su J, Ismail MF, El-Sayyad HI, Karande A, Elmageed ZA, Rao P, and Raj M
- Subjects
- Amino Acid Sequence, Blotting, Western, Cell Line, Tumor, Humans, Immunohistochemistry, Immunoprecipitation, Male, Molecular Sequence Data, Prostatic Neoplasms pathology, RNA, Small Interfering, Riboflavin metabolism, Thymidine metabolism, Membrane Transport Proteins metabolism, Prostatic Neoplasms metabolism
- Abstract
Riboflavin carrier protein (RCP) is a growth- and development-specific protein. Here, we characterized the expression of this protein in prostate cancer by polyclonal and monoclonal antibodies against chicken RCP. RCP was localized to both androgen-dependent and independent prostate cancer cell lines. Compared to controls, RCP was over-expressed in all 45 prostate adenocarcinomas, irrespective of the Gleason's score or the stage of the disease. The identified RCP had a molecular weight of 38 kDa, similar to RCP purified from chicken. Presence of this protein was also confirmed by siRNA inhibition analysis. Antibodies to chicken RCP inhibited incorporation of tritiated thymidine into DNA and prevented riboflavin uptake in PC3 prostate cancer cells, suggesting a critical function of this protein in prostate cancer cell growth. These data suggest that RCP can be used as a tumor biomarker in prostate cancer.
- Published
- 2009
- Full Text
- View/download PDF
139. Hydrogen peroxide acts as relaxing factor in human vascular smooth muscle cells independent of map-kinase and nitric oxide.
- Author
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Palen DI, Ouhtit A, Belmadani S, Lucchesi PA, and Matrougui K
- Subjects
- Angiotensin II physiology, Arteries drug effects, Arteries physiology, Cell Culture Techniques, Charybdotoxin pharmacology, Humans, Neurotoxins pharmacology, Nitric Oxide physiology, Nitric Oxide Synthase metabolism, Peptides pharmacology, Potassium Channels physiology, Extracellular Signal-Regulated MAP Kinases metabolism, Hydrogen Peroxide pharmacology, Muscle, Smooth, Vascular cytology, Muscle, Smooth, Vascular drug effects, Oxidants pharmacology, Vascular Resistance drug effects
- Abstract
We previously showed that hydrogen peroxide (H2O2) induced resistance artery relaxation independent of endothelium. Thus, in this study we investigated the mechanism of relaxation induced by H2O2 on human renal vascular smooth muscle cell (HVSMC). HVSMC were stimulated with H2O2 and/or angiotensin II (Ang II), proline-rich-tyrosine-kinase-2 (PYK2), ERK1/2 MAP-Kinase, and myosin light chain 20 phosphorylation (Lc20) were assessed using Western blot analysis in the presence of potassium channel blockers, MAP-Kinase, and nitric oxide synthesis (NOS) inhibitors. H2O2 increased PYK2 and ERK1/2 phosphorylation, and at the same time decreased Lc20 phosphorylation. AngII increased phosphorylation of PYK2, ERK1/2 and Lc20, whereas, the pretreatment of HVSMC with H2O2 decreased Lc20 phosphorylation induced by AngII. MEK inhibition, decreased ERK1/2 phosphorylation, but had no effect on the inhibition of phosphorylation of Lc20 induced by H2O2. The inhibition of Ca2(+)-dependent K+ channels (BKCa) and NOS did not block the decrease of Lc20 phosphorylation in response to H2O2. On the other hand, pretreatment of HVSMC with 60 mM of KCl, increased rather than decreased Lc20 phosphorylation in response to H2O2. This study shows the evidence that H2O2 acts as a relaxing factor and as an activator of PYK2 and ERK1/2 in Human renal VSMC. The relaxation induced by H2O2 is independent of BKCa, ERK1/2 MAP-Kinase and NOS pathways. The relaxing effect to H2O2 changes to contracting effect when the potassium channels are compromised.
- Published
- 2006
- Full Text
- View/download PDF
140. Dysfunction of p53 in photocarcinogenesis.
- Author
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Gervin CM, McCulla A, Williams M, and Ouhtit A
- Subjects
- Genes, p53, Humans, Melanoma physiopathology, Neoplasms, Radiation-Induced physiopathology, Skin Neoplasms physiopathology, Tumor Suppressor Protein p53 physiology, Ultraviolet Rays
- Abstract
The tumor suppressor protein p53 plays a critical role in the orchestration of the cellular responses to a variety of genotoxic and cytotoxic stresses. Mutations or functional inactivation of p53 seriously compromise these cellular processes and foster tumor development. p53 is the most frequently mutated gene in human cancers and over 90% of human non-melanoma skin cancers (NMSC) harbour p53 mutation. It plays a vital role in the control of the immediate and adaptive responses to ultraviolet radiation (UV) and the onset of NMSC. During the process of photocarcinogenesis, UV-specific p53 mutations occur early in the keratinocytes resulting in the loss of the wild type p53 function and continued UV exposure leads to clonal expansion of p53-mutated keratinocytes and promotion of skin tumors. Precisely how clones of keratinocytes containing such mutations, in an apparently normal epidermis, progress to a malignant carcinoma is unknown. Further examination of the functional significance of these UV-p53 mutations in affecting the immediate and adaptive responses of the skin to UV is critical to the development of effective prevention and therapeutic strategies for human skin cancer. The purpose of this article is to provide an overview of accumulating evidence pointing towards a critical role for p53 mutation in photocarcinogenesis.
- Published
- 2003
- Full Text
- View/download PDF
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