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1.
Genes (Basel) ; 14(6)2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37372454

RESUMO

Tremendous amount of financial resources and manpower have been invested to understand the function of numerous genes that are deregulated during the carcinogenesis process, which can be targeted for anticancer therapeutic interventions. Death-associated protein kinase 1 (DAPK-1) is one of the genes that have shown potential as biomarkers for cancer treatment. It is a member of the kinase family, which also includes Death-associated protein kinase 2 (DAPK-2), Death-associated protein kinase 3 (DAPK-3), Death-associated protein kinase-related apoptosis-inducing kinase 1 (DRAK-1) and Death-associated protein kinase-related apoptosis-inducing kinase 2 (DRAK-2). DAPK-1 is a tumour-suppressor gene that is hypermethylated in most human cancers. Additionally, DAPK-1 regulates a number of cellular processes, including apoptosis, autophagy and the cell cycle. The molecular basis by which DAPK-1 induces these cell homeostasis-related processes for cancer prevention is less understood; hence, they need to be investigated. The purpose of this review is to discuss the current understanding of the mechanisms of DAPK-1 in cell homeostasis-related processes, especially apoptosis, autophagy and the cell cycle. It also explores how the expression of DAPK-1 affects carcinogenesis. Since deregulation of DAPK-1 is implicated in the pathogenesis of cancer, altering DAPK-1 expression or activity may be a promising therapeutic strategy against cancer.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina , Neoplasias , Humanos , Proteínas Quinases Associadas com Morte Celular/genética , Proteínas Quinases Associadas com Morte Celular/metabolismo , Proteínas Quinases Associadas com Morte Celular/uso terapêutico , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas Reguladoras de Apoptose/genética , Apoptose/genética , Neoplasias/patologia , Carcinogênese/genética
2.
Noncoding RNA Res ; 7(3): 184-196, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35991514

RESUMO

There is accruing data implicating long non-coding RNAs (lncRNAs) in the development and progression of non-communicable diseases such as cancer. These lncRNAs have been implicated in many diverse HIV-host interactions, some of which are beneficial to HIV propagation. The virus-host interactions induce the expression of HIV-regulated long non-coding RNAs, which are implicated in the carcinogenesis process, therefore, it is critical to understand the molecular mechanisms that underpin these HIV-regulated lncRNAs, especially in cancer formation. Herein, we summarize the role of HIV-regulated lncRNAs targeting cancer development-related processes including apoptosis, cell cycle, cell survival signalling, angiogenesis and drug resistance. It is unclear how lncRNAs regulate cancer development, this review also discuss recent discoveries regarding the functions of lncRNAs in cancer biology. Innovative research in this field will be beneficial for the future development of therapeutic strategies targeting long non-coding RNAs that are regulated by HIV, especially in HIV associated cancers.

3.
Front Mol Biosci ; 9: 875208, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35620479

RESUMO

Cervical cancer is a Human Papilloma virus-related disease, which is on the rise in a number of countries, globally. Two essential oncogenes, E6 and E7, drive cell transformation and cancer development. These two oncoproteins target two of the most important tumour suppressors, p53 and pRB, for degradation through the ubiquitin ligase pathway, thus, blocking apoptosis activation and deregulation of cell cycle. This pathway can be exploited for anticancer therapeutic interventions, and Human Immunodeficiency Virus Protease Inhibitors (HIV-PIs) have attracted a lot of attention for this anticancer drug development. HIV-PIs have proven effective in treating HPV-positive cervical cancers and shown to restore impaired or deregulated p53 in HPV-associated cervical cancers by inhibiting the 26S proteasome. This review will evaluate the role players, such as HPV oncoproteins involved cervical cancer development and how they are targeted in HIV protease inhibitors-induced p53 restoration in cervical cancer. This review also covers the therapeutic potential of HIV protease inhibitors and molecular mechanisms behind the HIV protease inhibitors-induced p53-dependent anticancer activities against cervical cancer.

4.
Front Genet ; 13: 841639, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35391801

RESUMO

There are a plethora of cancer causes and the road to fully understanding the carcinogenesis process remains a dream that keeps changing. However, a list of role players that are implicated in the carcinogens process is getting lengthier. Cholesterol is known as bad sterol that is heavily linked with cardiovascular diseases; however, it is also comprehensively associated with carcinogenesis. There is an extensive list of strategies that have been used to lower cholesterol; nevertheless, the need to find better and effective strategies remains vastly important. The role played by cholesterol in the induction of the carcinogenesis process has attracted huge interest in recent years. Phytochemicals can be dubbed as magic tramp cards that humans could exploit for lowering cancer-causing cholesterol. Additionally, the mechanisms that are regulated by phytochemicals can be targeted for anticancer drug development. One of the key role players in cancer development and suppression, Tumour Protein 53 (TP53), is crucial in regulating the biogenesis of cholesterol and is targeted by several phytochemicals. This minireview covers the role of p53 in the mevalonate pathway and how bioactive phytochemicals target the mevalonate pathway and promote p53-dependent anticancer activities.

5.
Am J Cancer Res ; 11(3): 866-883, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33791160

RESUMO

It has been estimated that worldwide up to 10% of all human cancers are the result of viral infection, with 7.2% of all cancers in the developed world have a viral aetiology. In contrast, 22.9% of infections in the developing world are the result of viral infections. This number increases to 30% in Sub-Saharan Africa. The ability of viral infections to induce the transformation of normal cells into cancerous cells is well documented. These viruses are mainly Hepatitis B and C viruses, Epstein Barr virus, Human papillomavirus and Human Cytomegalovirus. They can induce the transformation of normal cells into cancer cells and this may be the underlying cause of carcinogenesis in many different types of cancer. These include liver cancer, lymphoma, nasopharyngeal cancer, cervical cancer, gastric cancer and even glioblastoma. Long non-coding RNAs (LncRNAs) can function by regulating the expression of their target genes by controlling the stability of the target mRNAs or by blocking translation of the target mRNA. They can control transcription by regulating the recruitment of transcription factors or chromatin modification complexes. Finally, lncRNAs can control the phosphorylation, acetylation, and ubiquitination of proteins at the post-translation level. Thus, altering protein localisation, function, folding, stability and ultimately expression. In addition to these functions, lncRNA also regulate alternate pre-mRNA splicing in ways that contribute to the formation of tumours. This mainly involves the interaction of lncRNAs with splicing factors, which alters their activity and function. The ability of lncRNAs to regulate the stability, expression and function of tumour suppressor proteins is important in the development and progression of cancers. LncRNAs also regulate viral replication and latency, leading to carcinogenesis. These factors all make lncRNAs ideal targets for the development of biomarker arrays that can be based on secreted lncRNAs leading to the development of affordable non-invasive biomarker tests for the stage specific diagnosis of tumours. These lncRNAs can also serve as targets for the development of new anticancer drug treatments.

6.
Future Sci OA ; 5(8): FSO409, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31534777

RESUMO

AIM: To determine the expression patterns of the RBBP6 spliced variants during arsenic trioxide-mediated cell cycle arrest and curcumin-induced apoptosis in MCF-7 cells. MATERIALS & METHODS: As2O3 and curcumin were used to study cytotoxicity, cell cycle arrest, apoptosis and the expression of RBBP6 variants. The MUSE Cell Analyser was used to analyze cell cycle arrest, apoptosis and multicaspase activity while apoptosis was further confirmed using microscopy. Semi-quantitative RT-PCR was employed to quantitate the expression of the RBBP6 variants. RESULTS: This study showed that the MCF-7 cells expressed RBBP6 variant 1 but lacked both variant 2 and variant 3. Both As2O3 and curcumin significantly downregulated RBBP6 variant 1 (p < 0.001). CONCLUSION: RBBP6 variants are promising therapeutic targets.

7.
Anticancer Drugs ; 30(8): 767-773, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31274515

RESUMO

Retinoblastoma binding protein 6 (RBBP6) is a cancer-related protein that has been implicated in the regulation of cell cycle and apoptosis. RBBP6 isoform 1 has been demonstrated to interact with two tumour suppressors, p53 and pRB. Isoform 1 been shown to regulate p53 through its ubiquitin ligase activity, thus implicating in cell cycle regulation and apoptosis. Isoforms 1 and 2 are multidomain proteins containing a domain with no name (DWNN) domain, a Zinc Finger, a RING Finger, an Rb-binding domain and a p53-binding domain. The RBBP6 isoform 3 comprises the DWNN domain only. Isoform 4 lacks the Rb-binding domain but its role is less understood. RBBP6 isoform 3 has been reported as a cell cycle regulator with anticancer potential. There have been several studies that have clearly demonstrated that RBBP6 may be an important biomarker for cancer diagnosis and a potential drug target for cancer treatment. This work focused on differential expression of RBBP6 transcripts in different cancers, providing detailed analysis of their potential as diagnostic biomarkers for different cancers. These cancers include breast, liver, cervical and colon carcinomas. The expression of RBBP6 transcripts may further provide better understanding of the role of the RBBP6 in carcinogenesis and cell homeostasis.


Assuntos
Biomarcadores Tumorais/metabolismo , Proteínas de Ligação a DNA/metabolismo , Terapia de Alvo Molecular , Neoplasias/diagnóstico , Neoplasias/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Humanos , Neoplasias/terapia , Prognóstico
8.
Biomark Cancer ; 11: 1179299X19829149, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30886526

RESUMO

RBBP6 is a novel gene encoding splicing-associated proteins. There are 3 protein isoforms (isoforms 1-3). RBBP6 isoforms 1 has been shown to interact with both p53 and Rb. It also plays a role in the induction of apoptosis and the regulation of the cell cycle. The expression of RBBP6 has been documented in several cancers but RBBP6 expression in cervical cancer has not been well studied. The aim of this study was to establish expression levels and tissue distribution of the RBBP6 gene products at both protein and messenger RNA (mRNA) levels in cervical cancer by immunocytochemistry and in situ hybridization (ISH). A link between RBBP6 expression, apoptosis, and cervical cancer progression was also investigated. RBBP6 mRNA was expressed in the nuclei and cytoplasm of normal and tumour cervical epithelium. In general, expression was high in the cytoplasm and nuclei of moderately differentiated and invasive carcinoma. Immunolabelling results were confirmed by image analysis and ISH experiments. Apoptosis assays using TUNEL correlated with the expression of the RBBP6 gene in all examined cases. This is the first report on the abundant expression of RBBP6 in cervical cancer and its involvement in the malignant progression of cervical cancer. Because of the high expression and corresponding pro-apoptotic activity observed in cervical cancer cells in this study, we suggest that RBBP6 is involved in the malignant progression of cervical cancer. RBBP6 proteins can therefore be targeted for therapeutic interventions against cervical cancer.

9.
Genes (Basel) ; 10(1)2019 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-30646589

RESUMO

Several pathways are deregulated during carcinogenesis but most notably, tumour cells can lose cell cycle control and acquire resistance to apoptosis by expressing a number of anti-apoptotic proteins such as the Inhibitors of Apoptosis Protein (IAP) family of proteins that include survivin, which is implicated in cancer development. There is no study which had proven that arsenic trioxide (As2O3) has any effect on the splicing machinery of survivin and its splice variants, hence this study was aimed at determining the cytotoxic effect of As2O3 and its effect on the expression pattern of survivin splice variants in MCF-7 cells. As2O3 inhibited the growth of the MCF-7 cells in a concentration-dependent manner. The Muse® Cell Analyser showed that As2O3-induced G2/M cell cycle arrest, promoted caspase-dependent apoptosis without causing any damage to the mitochondrial membrane of MCF-7 cells. As2O3 also deactivated two survival pathways, Mitogen-Activated Protein Kinase (MAPK) and Phosphoinositide 3-Kinase (PI3K) signalling pathways in MCF-7 cells. Deactivation of the two pathways was accompanied by the upregulation of survivin 3α during As2O3-induced G2/M cell cycle arrest and apoptosis. Survivin 2B was found to be upregulated only during As2O3-induced G2/M cell cycle arrest but downregulated during As2O3-induced apoptosis. Survivin wild-type was highly expressed in the untreated MCF-7 cells, the expression was upregulated during As2O3-induced G2/M cell cycle arrest and it was downregulated during As2O3-induced apoptosis. Survivin variant ΔEx3 was undetected in both untreated and treated MCF-7 cells. Survivin proteins were localised in both the nucleus and cytoplasm in MCF-7 cells and highly upregulated during the As2O3-induced G2/M cell cycle arrest, which can be attributed to the upregulation of survivin-2B. This study has provided the first evidence showing that the novel survivin 2B splice variant may be involved in the regulation of As2O3-induced G2/M cell cycle arrest only. This splice variant can therefore, be targeted for therapeutic purposes against Luminal A breast cancer cells.


Assuntos
Antineoplásicos/farmacologia , Trióxido de Arsênio/farmacologia , Sistema de Sinalização das MAP Quinases , Splicing de RNA , Survivina/genética , Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Trióxido de Arsênio/toxicidade , Ciclo Celular/efeitos dos fármacos , Humanos , Células MCF-7 , Fosfatidilinositol 3-Quinases/metabolismo , Survivina/metabolismo
10.
Int J Mol Sci ; 19(8)2018 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-30044440

RESUMO

TSPO is a receptor involved in the regulation of cellular proliferation, apoptosis and mitochondrial functions. Previous studies showed that the expression of TSPO protein correlated positively with tumour malignancy and negatively with patient survival. The aim of this study was to determine the transcription of Tspo mRNA in various types of normal and cancer tissues. In situ hybridization was performed to localise the Tspo mRNA in various human normal and cancer tissues. The relative level of Tspo mRNA was quantified using fluorescent intensity and visual estimation of colorimetric staining. RT-PCR was used to confirm these mRNA levels in normal lung, lung cancer, liver cancer, and cervical cancer cell lines. There was a significant increase in the level of transcription in liver, prostate, kidney, and brain cancers while a significant decrease was observed in cancers of the colon and lung. Quantitative RT-PCR confirmed that the mRNA levels of Tspo are higher in a normal lung cell line than in a lung cancer cell line. An increase in the expression levels of Tspo mRNA is not necessarily a good diagnostic biomarker in most cancers with changes not being large enough to be significantly different when detected by in situ hybridisation.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias/diagnóstico , Neoplasias/metabolismo , Receptores de GABA/metabolismo , Células A549 , Análise de Variância , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Feminino , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Ligantes , Masculino , Neoplasias/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de GABA/genética
11.
HIV AIDS (Auckl) ; 9: 77-93, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28694706

RESUMO

Alternative splicing of mRNA leads to an increase in proteome biodiversity by allowing the generation of multiple mRNAs, coding for multiple protein isoforms of various structural and functional properties from a single primary pre-mRNA transcript. The protein isoforms produced are tightly regulated in normal development but are mostly deregulated in various cancers. In HIV-infected individuals with AIDS, there is an increase in aberrant alternative splicing, resulting in an increase in HIV/AIDS-related cancers, such as Kaposi's sarcoma, non-Hodgkin's lymphoma, and cervical cancer. This aberrant splicing leads to abnormal production of protein and is caused by mutations in cis-acting elements or trans-acting factors in angiogenesis-related genes. Restoring the normal regulation of alternative splicing of angiogenic genes would alter the expression of protein isoforms and may confer normal cell physiology in patients with these cancers. This review highlights the abnormalities in alternative splicing of angiogenesis-related genes and their implication in HIV/AIDS-related cancers. This allows us to gain an insight into the pathogenesis of HIV/AIDS-related cancer and in turn elucidate the therapeutic potential of alternatively spliced genes in HIV/AIDS-related malignancies.

12.
Histol Histopathol ; 32(6): 561-570, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27452861

RESUMO

Oesophageal cancer ranks as the sixth most common malignancy in the world, and recent evidence has shown that its incidence is increasing. ACBPs (Acyl-coA binding proteins) act as intracellular carrier-proteins for medium to long chain acyl-coA, mediating fatty acid transport to the mitochondrion for ß-oxidation. ACBPs are also believed to be putative ligands of PBR (peripheral benzodiazepine receptor), and once they bind to this receptor they facilitate mitochondrial membrane permeabilization, presumably favouring apoptosis. The main aim of the study was to establish the expression patterns of 1- Acyl-coA binding proteins (1-ACBP), B- Acyl-coA binding proteins (B-ACBP), and peripheral bezodiazepine receptor (PBR) in oesophageal cancer, and to link their roles with the disease. In situ hybridization and quantitative real-time PCR methods were performed to determine localization and the expression levels of the three genes in oesophageal cancer. All three genes illustrated substantial up-regulation within the malignant tissue sections as compared to normal oesophageal sections, all three transcripts localized specifically to mast cells, plasma cells and lymphocytes in diseased and normal tissue section. In the diseased tissue B-ACBP and 1-ACBP mRNA localized to endothelial cells of blood vessels in the submucosa. B-ACBP also localized to the nucleus of squamous epithelial cells. PBR localization was indicated in tumour islands of invasive tissue sections. Quantitative RT-PCR also indicated that the expression levels of PBR were higher as compared to the ACBP genes expression in tumours. These results show that 1-ACBP, B-ACBP and PBR play a role in the pathogenesis of oesophageal tumours and possibly in carcinogenic angiogenesis.


Assuntos
Carcinoma de Células Escamosas/patologia , Inibidor da Ligação a Diazepam/biossíntese , Neoplasias Esofágicas/patologia , Neovascularização Patológica/patologia , Receptores de GABA-A/biossíntese , Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/imunologia , Inibidor da Ligação a Diazepam/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/imunologia , Carcinoma de Células Escamosas do Esôfago , Humanos , Hibridização In Situ , Linfócitos/metabolismo , Mastócitos/metabolismo , Plasmócitos/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de GABA-A/genética , Regulação para Cima
14.
J Mol Histol ; 47(2): 169-82, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26905308

RESUMO

Apoptosis is normally kept under strict control by a range of regulators and inhibitors, and loss of this regulation strongly directs tumour progression. The novel RBBP6 gene has been implicated in apoptosis due to its ability to bind both p53 and Rb, as well as its structural and functional affiliation to ubiquitin and E3 ligases. RBBP6 has already been implicated as an important marker for cancer diagnosis and many studies have investigated its suitability as a potential genetic target for cancer treatment. This study endeavoured to assess the transcription and expression patterns and levels of the three isoforms of RBBP6 in colon cancer and to evaluate its potential role in apoptosis. Colorimetric and fluorescent in situ hybridisation was used to localise the mRNA and the different RBBP6 mRNA transcripts in normal and cancerous colon tissue. Immunohistochemistry was used to localise different RBBP6 isoforms in normal and cancerous tissues. All the RBBP6 transcripts were found to be up-regulated in cancerous tissues, and the expression levels of the RBBP6-1 and RBBP6-3 (DWNN) proteins were also found to be increased in cancerous structures. Higher levels of apoptosis were detected in the same regions as those that showed increased expression of RBBP6-3 transcript and protein, whereas Bcl-2 was down-regulated in these areas. In contrast we observed an increase in Bcl-2 levels in areas where RBBP6-3 was down-regulated. These results suggest that the RBBP6-3 isoform may be involved in promoting apoptosis in cancerous cells.


Assuntos
Apoptose/genética , Proteínas de Transporte/genética , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Proteínas de Ligação a DNA/genética , Proteínas de Transporte/metabolismo , Proliferação de Células , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Marcação In Situ das Extremidades Cortadas , Antígeno Ki-67/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Gênica , Ubiquitina-Proteína Ligases
15.
Methods Mol Biol ; 1379: 201-11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26608302

RESUMO

RT-PCR is an invaluable tool for the detection and characterization of mRNA. Cancer cell lines are treated with crude plant extracts and RNA is extracted and purified with DNase prior to RT-PCR. RT-PCR first-strand cDNA synthesis is done using random primers and can be refrigerated at 4 °C. PCR from the stored cDNA is performed using transcript-specific primers and electrophoresed on a molecular grade agarose gel to separate the splice variants.


Assuntos
Antineoplásicos/farmacologia , Extratos Vegetais/farmacologia , Splicing de RNA/efeitos dos fármacos , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Quimioprevenção , Eletroforese em Gel de Ágar , Humanos , Extratos Vegetais/uso terapêutico , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação
16.
Exp Mol Pathol ; 99(1): 74-80, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25910411

RESUMO

South Africa has one of the highest HIV infection rates in the world. One of the complications of HIV infection is the development of HIV-associated nephropathy (HIVAN), which is characterized by deregulation in tubular epithelial apoptosis. The pathways that HIV-1 promotes in the pathogenesis of HIVAN remain less understood. There are many genes that have not been characterized in the pathogenesis of HIVAN. On the other hand, RBBP6 has been shown to play a role in both promoting and inhibiting apoptosis in human cancers. This study was aimed at determining an association between RBBP6 isoform 3 expression and the levels of apoptosis in HIVAN cases. HIVAN biopsy tissues from Johannesburg patients in South Africa were used in this study. These tissues were stained for RBBP6 expression and apoptosis levels using immunohistochemistry staining and TUNEL method respectively. Image analysis was used for quantitative analysis and GraphPad Version 4 was used for statistical analysis. High expression levels of RBBP6 were found in HIVAN cases (n=30) relative to the normal tissues (n=10). High apoptosis levels were also obtained in the HIVAN tissues. This direct association between RBBP6 expression and apoptosis levels suggests that RBBP6 may play a role in HIVAN pathogenesis. RBBP6 may then be targeted for both diagnostic and therapeutic strategies in HIVAN.


Assuntos
Nefropatia Associada a AIDS/genética , Apoptose , Proteínas de Transporte/genética , Proteínas de Ligação a DNA/genética , Variação Genética , Proteínas de Transporte/metabolismo , Fragmentação do DNA , Proteínas de Ligação a DNA/metabolismo , Células HEK293 , Humanos , Processamento de Imagem Assistida por Computador , Hibridização In Situ , Marcação In Situ das Extremidades Cortadas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , África do Sul , Técnicas de Cultura de Tecidos , Ubiquitina-Proteína Ligases
17.
Exp Mol Pathol ; 2015 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-25794975

RESUMO

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.yexmp.2015.03.023. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

18.
Exp Mol Pathol ; 98(3): 574-84, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25794976

RESUMO

Pyruvate dehydrogenase kinase 4 (PDK4), a mammalian mitochondrial serine kinase has emerged as an interesting candidate for diabetes therapy. Due to the high prevalence of this disease especially type 2 diabetes (T2D) and the health complications associated with it, there is extensive effort to find the appropriate treatment. Understanding the regulation of PDK4 activity would therefore contribute significantly to the development of therapeutic agents. This research outlines the utilization of bioinformatics tools such as Interweaver, ClustalW and Protein Structure Visualizer, in order to predict proteins that potentially interact with PDK4 and possibly regulate its activity. Interweaver database identified 96 proteins that have possible interaction sites for PDK4. Protein p100/p49, containing a death domain that is known to have a role in suppressing apoptosis, was identified as a potential partner for PDK4. The alignment between p100/p49 primary sequence and that of PDK4 using ClustalW demonstrated sequence similarity between the two proteins. Swiss PDB Viewer then located the positions of the amino acids that are in the hypothetical protein binding motif of p100/p49 within the 3D structure of hPDK4. These amino acids were found to be located in the region of PDK4 which is known to bind protein substrates of PDK4 and may be accessible to other proteins as well. These findings were very interesting as PDK4 has not previously been associated with apoptosis and this could be the link between apoptosis and insulin resistance. Cell biology studies were then performed to verify the relationship between PDK4 and apoptosis. In this regard, HeLa and HepG2 cells were treated with apoptosis-inducing agents such as TNFα, C2-ceramide, and linoleic acid. These cells were then monitored for apoptosis and PDK4 mRNA expression using a DNA laddering assay as well as Real Time PCR. The results showed that these factors induced apoptosis in a concentration dependent manner and suppressed PDK4 mRNA levels. These findings suggested a relationship between PDK4 and apoptosis.


Assuntos
Apoptose , Proteínas Serina-Treonina Quinases/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Sítios de Ligação , Células HeLa , Células Hep G2 , Humanos , Resistência à Insulina , Dados de Sequência Molecular , Subunidade p52 de NF-kappa B/química , Subunidade p52 de NF-kappa B/metabolismo , Ligação Proteica , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
19.
Exp Mol Pathol ; 98(3): 585-92, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25779024

RESUMO

Ceramide synthases (CerSs) also known as Longevity Assurance (LASS) genes belong to a family of six related genes. CerS gene products have been shown to produce ceramide, hence their name CerSs. Ceramide is a bio-effector molecule, belonging to the family of sphingolipids (SLs), which are important components of cell membranes, and has been implicated in cancer and apoptosis. Cancer still remains the second leading cause of death, both globally and in South Africa. The proper regulation of the balance between cell growth and cell death is essential for cellular homeostasis. Failure to properly regulate this balance may lead to pathologic conditions such as cancer development. CerSs have been implicated in cancer biology, especially in apoptosis, through the action of ceramide. Although knowledge of the role that CerSs play in cancer biology is advancing, the precise roles of distinct CerSs in different cancers are not yet fully understood, especially the roles of CerS4 and CerS5 in endometrial and colon cancers. The aim of this study was to investigate the link of CerS4 and CerS5 in apoptosis and, thus in cancers of the endometrium and colon, which are amongst the most prevalent cancers globally. Apoptosis was induced using anastrozole in endometrial cells and 5-FU in colon cells. Fluorescence activated cell sorting was used to analyse and quantify apoptosis and total RNA was extracted from both treated and untreated cells. Quantitative relative expression of CerS4 and CerS5 mRNA was then determined in all cells (treated and untreated), normalised to ß-actin. Bio-informatics was used to compare CerS4 and CerS5 sequences. The endometrial cancer cells were more prone to apoptosis compared to their non-cancerous counterparts, while the colon cancer cells were more responsive to apoptosis induction after 48h, especially the HT-29 cells. Using quantitative real-time PCR, both CerS4 and CerS5 were shown to be up-regulated in endometrial and colon cancer cells. Apoptosis induction resulted in down-regulation of CerS4 and CerS5 in endometrial and colon cancers. These findings implicate these genes in cancer and apoptosis. Whether these genes play pro- or anti-apoptotic roles in cancers of the endometrium and colon is not conclusive at this stage. It may also be possible that these genes could exert opposing roles in the same or different tissues. Targeting this family of genes and understanding their precise individual roles in different types of cancer, are a promising therapeutic tool to new anti-cancer drug discovery or improving existing treatments.


Assuntos
Apoptose , Neoplasias do Colo/metabolismo , Neoplasias do Endométrio/metabolismo , Esfingosina N-Aciltransferase/metabolismo , Sequência de Aminoácidos , Células CACO-2 , Regulação para Baixo , Feminino , Células HT29 , Humanos , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Esfingosina N-Aciltransferase/genética
20.
Noncoding RNA ; 1(3): 192-221, 2015 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-29861424

RESUMO

MicroRNAs (miRNAs) are short noncoding RNAs that regulate pathophysiological processes that suppress gene expression by binding to messenger RNAs. These biomolecules can be used to study gene regulation and protein expression, which will allow better understanding of many biological processes such as cell cycle progression and apoptosis that control the fate of cells. Several pathways have also been implicated to be involved in kidney diseases such as Transforming Growth Factor-ß, Mitogen-Activated Protein Kinase signaling, and Wnt signaling pathways. The discovery of miRNAs has provided new insights into kidney pathologies and may provide new innovative and effective therapeutic strategies. Research has demonstrated the role of miRNAs in a variety of kidney diseases including renal cell carcinoma, diabetic nephropathy, nephritic syndrome, renal fibrosis, lupus nephritis and acute pyelonephritis. MiRNAs are implicated as playing a role in these diseases due to their role in apoptosis, cell proliferation, differentiation and development. As miRNAs have been detected in a stable condition in different biological fluids, they have the potential to be tools to study the pathogenesis of human diseases with a great potential to be used in disease prognosis and diagnosis. The purpose of this review is to examine the role of miRNA in kidney disease.

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