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1
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Tyrosine phosphatases as a superfamily of tumor suppressors in colorectal cancer

100%
Laczmanska I., Sasiadek M. M.
Acta Biochimica Polonica
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2011
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vol. 58
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issue 4
467-470
EN
Phosphorylation and dephosphorylation processes catalyzed by numerous kinases and phosphorylases are essential for cell homeostasis and may lead to disturbances in a variety of vital cellular pathways, such as cell proliferation and differentiation, and thus to complex diseases including cancer. As over 80 % of all oncogenes encode protein tyrosine kinases (PTKs), protein tyrosine phosphatases (PTPs), which can reverse the effects of tyrosine kinases, are very important tumor suppressors. Alterations in tyrosine kinase and phosphatase genes including point mutations, changes in epigenetic regulation, as well as chromosomal aberrations involving regions critical to these genes, are frequently observed in a variety of cancers. Colorectal cancer (CRC) is one of the most common cancers in humans. CRCs occur in a familial (about 15 % of all cases), hereditary (about 5%) and sporadic (almost 75-80 %) form. As genetic-environmental interrelations play an important role in the susceptibility to sporadic forms of CRCs, many studies are focused on genetic alterations in such tumors. Mutational analysis of the tyrosine phosphatome in CRCs has identified somatic mutations in PTPRG, PTPRT, PTPN3, PTPN13 and PTPN14. The majority of these mutations result in a loss of protein function. Also, alterations in the expression of these genes, such as decreased expression of PTPRR, PTPRO, PTPRG and PTPRD, mediated by epigenetic mechanisms have been observed in a variety of tumors. Since cancer is a social and global problem, there will be a growing number of studies on alterations in the candidate cancer genes, including protein kinases and phosphatases, to determine the origin, biology and potential pathways for targeted anticancer therapy.
2
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Analysis of mutations in the p16/ CDKN2A gene in sporadic and familial melanoma in the Polish population.

100%
Lamperska K., Karczewska A., Kwiatkowska E., Mackiewicz A.
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vol. 49
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issue 2
369-376
EN
Mutations in CDKN2A have been found in sporadic cutaneous malignant (CMM), in familial CMM and in other syndromes associated with melanoma. In this study DNA was obtained from 207 individuals and five cell lines. There were 157 CMM patients and 50 healthy members of melanoma patients families. The CMM group included patients with one or two melanoma cases in the family, families with dysplastic nevus syndrom (DNS) and patients with a spectrum of other types of cancers in the family. PCR-SSCP analysis and sequencing identified: six substitutions in codon 58 CGA/TGA (Arg/Stop), 16 substitutions GAC/GAT in codon 84 (Asp/Asp), six substitutions CGA /TGA in codon 148 (Arg/Thr), 14 substitutions G/C in 3'UTR and 4 double changes (two in codon 84 and 3'UTR; two in codon 148 and 3'UTR). The mutation identified in codon 58 was found in tissue only. Other substitutions were polymorphisms found in DNA from tissue and blood samples. Most of them were identified in sporadic CMM (six in codon 148 Ala /Thr, 12 in codon 84 Asp/Asp and six in 3'UTR). The frequency of the polymorphisms was also high in DNS and CMM/DNS families (four in codon 84 Asp/Asp and six in 3'UTR). No mutations or polymorphisms were found in CMM patients with one or two melanoma cases and CMM patients, with other cancers in family history. The analysis of the CDKN2A gene mutations in the Polish population demonstrated: (i) no germline mutations; (ii) a relatively high number of genetic changes in sporadic melanoma; (iii) a high number of polymorphisms in DNS and CMM/DNS families.
3
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Expression of p16 in sporadic primary uveal melanoma.

100%
Lamperska K., Mackiewicz K., Kaczmarek A., Kwiatkowska E., Starzycka M., Romanowska B., Heizman J., Stachura J., Mackiewicz A.
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vol. 49
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issue 2
377-385
EN
Expression of p16 protein, intragenic mutations of CDKN2A and hypermethylation of CDKN2A promoter region in 41 sporadic primary uveal melanomas were studied. There were 2 cases of spindle cell B histological type, 11 of A + B and 28 of mixed type. All melanomas infiltrated sclera but in 28 cases infiltration was superficial while in 13 profound. In 7 cases the tumor infiltrated the optic nerve. Expression of p16 was studied by immunohistochemistry and recorded by assessment of the proportion of positive tumor cells and staining intensity. Results were expressed as staining index (IRS). Intragenic mutations were studied by PCR-SSCP followed by sequencing, while hypermethylation of the promoter region by CpG methylation assay. In 15% of cases less than 10% of melanoma cells were p16 positive, in 70% of cases less than 50% of cells, while in 7% more than 80% of cells stained for p16 (mean IRS for all cases was 4.87 ± 2.43). In B type the IRS was 8.5 ± 0.7, in A + B type 6.0 ± 2.1 and in the mixed type 4.17 ± 2.43 (differences statistically significant). In melanomas profoundly infiltrating sclera mean IRS was 4.16, while in those infiltrating optic nerve 3.71 (statistically not significant). Analysis of the intragenic mutations revealed in two patients a GAC/GAT substitution in codon 84 - a silent mutation. No hypermethylation of the CpG island of the p16 promoter region was found. In conclusion, we found that the degree of p16 expression is related to the histological type of tumor but not to the histological indicators of tumor invasiveness and that intragenic mutations and promoter hypermethylation are not major mechanisms of p16 inactivation in sporadic uveal melanoma.
4
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Altered oxidative stress levels in Indian Parkinson's disease patients with PARK2 mutations

100%
Vinish M., Anand A., Prabhakar S.
Acta Biochimica Polonica
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2011
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vol. 58
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issue 2
165-169
EN
The aim of this pilot study was to determine the baseline state of oxidative stress indices in patients with Parkinson's disease (PD). Peripheral blood samples of 15 PD subjects were analyzed and compared with ten age matched healthy controls. Patients with PARK2 mutations were also compared with PD patients without mutations. There was significant increase in malondialdehyde content and superoxide-dismutase (SOD) activity in peripheral blood parameters in PD patients (p < 0.05) in comparison to controls. These findings suggest an important role of oxidative stress in Parkinson's disease evolution and progress. No changes were observed in glutathione peroxidase and nitric oxide levels. We found significant correlation between SOD activity and lipid peroxidation when the biochemical data was further analyzed. In addition, significant increase in the levels of SOD among the PD patients with PARK2 mutations was observed, which can be ascribed to chronic oxidative stress induced by PARK2 mutations.
5
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An Outline of Cardiogenesis

88%
Piotrowski K., Mędrek K., Zajączek S.
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2014
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vol. 4
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issue 1
6-8
EN
The paper presents a description of the development of the human heart based on the present state of knowledge cytogenetics and molecular genetics. Despite the complexity of the genetic mechanisms described, the authors emphasize that it may be just a slice patterns in kardiogenezie. Aberrations and mutations lead to the formation of congenital heart defects in both isolated and components of genetic syndromes.
6
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Reversion of argE3 to Arg+ in Escherichia coli AB1157 -an informative bacterial system for mutation detection

75%
Sikora A., Grzesiuk E.
Acta Biochimica Polonica
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2010
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vol. 57
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issue 4
479-485
EN
This review concerns reversion of the argE3 (ochre) nonsense mutation to prototrophy in E. coli AB1157 strain as an informative system for mutation detection. Strain AB1157 bears the argE3 (ochre), hisG4 (ochre) and thr-1 (amber) mutations, and the supE44 amber suppressor on its chromosome. The Arg+ phenotype can be restored by (i) any base substitution at the argE3 site that changes the nonsense UAA codon to any sense nucleotide triplet or to UAG recognized by the supE44 amber suppressor, or (ii) suppressor mutations enabling the reading of the UAA nonsense codon. The argE3 → Arg+ reversion-based system enables (i) determination of the spontaneous or induced mutation level; (ii) determination of base substitutions (suppressor analysis); (iii) examination of transcription-coupled repair (TCR) since targets for DNA damage are situated on the transcribed or coding strand of DNA; (iv) detection of mutations resulting from single stranded DNA damage. This review focuses on studies carried out since the early 1990s till now with the application of the AB1157-based mutation detection system. Recently, the system has been used to obtain new data on the processes of methyl methanesulfonate-induced mutagenesis and DNA repair in E. coli alkB- mutants.
7
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Zaburzenia kaskady transformujących czynnikow wzrostu typu β w wybranych patologiach człowieka

63%
Zakrzewski P.
Folia Medica Lodziensia
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2012
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vol. 39
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issue 2
265-292
EN
A transforming growth factor β type (TGFβ) cascade is a multifactorial signalling pathway, which controls the plethora of cellular processes responsible for human organism homeostasis. The importance of alterations of TGFβ-induced signalling remains unknown. Up till now, impaired TGFβ signalling has been observed in pathologies of the musculoskeletal, cardiovascular and reproductive systems. Abnormalities in the TGFβ pathway can be either genetically determined or appear as spontaneous disorders which emerged during embryonic development. Understanding the role of the TGFβ pathway in the aetiology of various diseases appears to be necessary as it may serve in developing new strategies for therapeutic or diagnostic methods.
PL
Kaskada sygnalizacyjna transformujących czynników wzrostu typu β (TGFβ) stanowi indukowany przez wiele cytokin szlak przekazywania sygnału w komórce, pod kontrolą którego znajduje się szereg procesów komórkowych odpowiedzialnych za prawidłowe funkcjonowanie ludzkiego organizmu. Znaczenie zaburzeń sygnalizacji indukowanej czynnikami TGFβ pozostaje nadal nie do końca poznane. Niemniej jednak już na obecnym etapie badań stwierdzić można ich bezsprzeczny udział w patologiach układu kostno-mięśniowego, układu krwionośnego czy układu rozrodczego.
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