Timea Varjas

Dr. Timea Varjas

orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2016 in Imaging
Verified
Journal Article
Closed access
Bence RaposaBence Raposa
Bence Raposa
RPR Pónusz
R Pónusz
GGG Gerencsér
G Gerencsér
FBF Budán
F Budán
ZGZoltán Gyöngyi
Zoltán Gyöngyi
TVTimea Varjas
Timea Varjas
It has been reported that some of the food additives may cause sensitization, inflammation of tissues, and potentially risk factors in the development of several chronic diseases. Thus, we hypothesized that expressions of common inflammatory molecules – known to be involved in the development of various inflammatory conditions and cancers – are affected by these food additives. We investigated the effects of commonly used food preservatives and artificial food colorants based on the expressions of NFκB, GADD45α, and MAPK8 (JNK1) from the tissues of liver. RNA was isolated based on Trizol protocol and the activation levels were compared between the treated and the control groups. Tartrazine alone could elicit effects on the expressions of NFκB (p = 0.013) and MAPK8 (p = 0.022). Azorubine also resulted in apoptosis according to MAPK8 expression (p = 0.009). Preservatives were anti-apoptotic in high dose. Sodium benzoate (from low to high doses) dose-dependently silenced MAPK8 expression (p = 0.004 to p = 0....

22 October 2018 in In Vivo
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Journal Article
Open access
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EOEnikő Orosz
Enikő Orosz
IKIstván Kiss
István Kiss
ZGZoltán Gyöngyi
Zoltán Gyöngyi
TVTimea Varjas
Timea Varjas
Background: Colorectal cancer is an increasing cause of death. Circulating microRNAs (miRs) could be great diagnostic and prognostic biomarkers of colorectal cancer, but further continuation of their utility is needed for their comprehensive application. Materials and Methods: Twenty-seven patients with colonic cancer, 16 with rectal cancer and 12 healthy volunteers as controls, were involved in this study. Expression of miR-155, miR-21, miR-221, miR-30a, miR-34a and miR-29a were determined by reverse transcription polymerase chain reaction (RT-PCR) from sera of patients. Results: Expression of miR-155, miR-21 and miR-221 was significantly higher in rectal cancer than in colonic cancer. There was no difference found between those with TNM1 cancer and controls for both cancer types. miR-155, miR-34a and miR-29a were down-regulated in all patients with cancer compared to controls. We did not find any statistically significant up-regulation of miR-221 in patients with colonic cancer compared to controls. In contrast, in patients with rectal cancer, miR-221 expression was higher than in controls. Advanced stage was also linked to higher miR-221 expression compared to early stage. Slight, but statistically significant increase was observed in miR-30a expression in patients with colon cancer compared to control individuals. Conclusion: Our results partly support previous findings. Here we report on differences in the expression of circulating microRNA between colonic and rectal tumours for the first time.

13 April 2023 in Nutrients
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Journal Article
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GNGhodratollah Nowrasteh
Ghodratollah Nowrasteh
Afshin ZandAfshin Zand
Afshin Zand
Bence RaposaBence Raposa
Bence Raposa
LSLászló Szabó
László Szabó
ATAndrás Tomesz
András Tomesz
TVTimea Varjas
Timea Varjas
Recently, the field of epigenetics has been intensively studied in relation to nutrition. In our study, the gene expression patterns of histone deacetylases (HDACs), which regulate the stability of histone proteins, and DNA methyltransferases (DNMTs), which regulate DNA methylation, were determined in mice. The animals were fed a human-equivalent dose of the aqueous extract of fruit seeds and peels, which is rich in flavonoids and polyphenols, for 28 days and then exposed to the carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). The concentrations of trans-resveratrol and trans-piceid were determined in the consumed extract by HPLC and were 1.74 mg/L (SD 0.13 mg/L) and 2.37 mg/L (SD 0.32 mg/L), respectively, which corresponds to the consumption of 0.2–1 L of red wine, the main dietary source of resveratrol, in humans daily. Subsequently, 24 h after DMBA exposure, the expression patterns of the HDAC and DNMT genes in the liver and kidneys were determined by qRT-PCR. The DMBA-induced expression of the tested genes HDAC1, HDAC2, DNMT1, DNMT3A and DNMT3B was reduced in most cases by the extract. It has already been shown that inhibition of the DNMT and HDAC genes may delay cancer development and tumour progression. We hypothesise that the extract studied may exert chemopreventive effects.

1 December 2022 in Cancer Cell International
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Journal Article
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John Macharia MachariaJohn Macharia Macharia
John Macharia Macharia
LZLu Zhang
Lu Zhang
RMRuth W. Mwangi
Ruth W. Mwangi
NRNora Rozmann
Nora Rozmann
ZKZsolt Kaposztas
Zsolt Kaposztas
Bence RaposaBence Raposa
Bence Raposa
After cardiovascular diseases, cancer is the second main cause of death globally. Mushrooms have been demonstrated to contain amalgamation with properties capable of inhibiting carcinogenesis and microbial growth, principally secondary metabolites such as quinolones, steroids, terpenes, anthraquinones, and benzoic acid derivatives among others. This study aimed to substantiate their potency concerning colon cancer carcinogenesis and antimicrobial growth. A systematic search of important literature was performed considering all the articles published until April 2022. Screening was performed by searching the BMC Springer, Elsevier, Embase, Web of Science, Ovid, and MEDLINE databases. In addition, Google Scholar was used to supplement information. Titles and abstracts that matched the established criteria were selected for full-text article scrutiny and subsequently used in the updated present review. Bioactive compounds present in medicinal mushrooms such as ascorbic acid, organic acids, flavonoids, polysaccharides, glycosides, phenols, linoleic acid, grifolin, and tocopherols among other compounds play a key role in suppressing the proliferation of cancerous cells and selectively act as antibacterial and antifungal agents. These metabolites actively scavenge oxygen free radicals, hydroxyl radicals, and nitrite radicals that would otherwise increase the risks of the growth and development of cancerous cells. Mushrooms' bioactive compounds and metabolites actively inhibit nuclear factor-kappa activation, protein kinase B processes, and ultimately the expression of Cyclooxygenases 2 in cancerous cells. Medicinal mushrooms should be considered as alternative natural chemo-preventive agents in the global fight against colon cancer and the evolution of drug-resistant pathogenic microorganisms, as they exhibit robust potency. They have not been reported to exhibit adverse harmful effects compared to synthetic chemotherapies, yet they have been reported to demonstrate significant beneficial effects.

20 April 2021 in PLOS ONE
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Journal Article
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LSLaszlo Szabo
Laszlo Szabo
RMRichard Molnar
Richard Molnar
ATAndras Tomesz
Andras Tomesz
ADArpad Deutsch
Arpad Deutsch
RDRichard Darago
Richard Darago
IKIstvan Kiss
Istvan Kiss
The intake of carcinogenic and chemopreventive compounds are important nutritional factors related to the development of malignant tumorous diseases. Repetitive long interspersed element-1 (LINE-1) DNA methylation pattern plays a key role in both carcinogenesis and chemoprevention. In our present in vivo animal model, we examined LINE-1 DNA methylation pattern as potential biomarker in the liver, spleen and kidney of mice consuming green tea (Camellia sinensis) extract (catechins 80%), a chinese bayberry (Morella rubra) extract (myricetin 80%), a flavonoid extract (with added resveratrol) and coffee (Coffee arabica) extract. In the organs examined, carcinogen 7,12-dimethylbenz(a)anthracene (DMBA)-induced hypomethylation was prevented by all test materials except chinese bayberry extract in the kidneys. Moreover, the flavonoid extract caused significant hypermethylation in the liver compared to untreated controls and to other test materials. The tested chemopreventive substances have antioxidant, anti-inflammatory properties and regulate molecular biological signaling pathways. They increase glutathione levels, induce antioxidant enzymes, which decrease free radical damage caused by DMBA, and ultimately, they are able to increase the activity of DNA methyltransferase enzymes. Furthermore, flavonoids in the liver may inhibit the procarcinogen to carcinogen activation of DMBA through the inhibition of CYP1A1 enzyme. At the same time, paradoxically, myricetin can act as a prooxidant as a result of free radical damage, which can explain that it did not prevent hypomethylation in the kidneys. Our results demonstrated that LINE-1 DNA methylation pattern is a useful potential biomarker for detecting and monitoring carcinogenic and chemopreventive effects of dietary compounds.

16 March 2024 in Nutrients
Verified
Journal Article
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Afshin ZandAfshin Zand
Afshin Zand
ESEnkhbilguun Sodbuyan
Enkhbilguun Sodbuyan
John Macharia MachariaJohn Macharia Macharia
John Macharia Macharia
KVKrisztina Varajti
Krisztina Varajti
ISIstvan Szabo
Istvan Szabo
TVTimea Varjas
Timea Varjas
Dermal photoaging refers to the skin’s response to prolonged and excessive ultraviolet (UV) exposure, resulting in inflammation, changes to the tissue, redness, swelling, and discomfort. Betanin is the primary betacyanin in red beetroot (Beta vulgaris) and has excellent antioxidant properties. Yet, the specific molecular mechanisms of betanin in HaCaT cells have not been fully clarified. The objective of this study was to investigate the activity of betanin and the underlying mechanisms in HaCaT cells; furthermore, in this study, we explored the protective effect of various concentrations of betanin against UVB irradiation on HaCaT cells. Additionally, we assessed its influence on the transcription of various epigenetic effectors, including members of the DNA methyltransferase (DNMT) and histone deacetylase (HDAC) families. Our findings demonstrate a notable downregulation of genes in HaCaT cells, exhibiting diverse patterns upon betanin intake. We considered the involvement of DNMT and HDAC genes in distinct stages of carcinogenesis and the limited exploration of the effects of daily exposure dosages. Our results indicate that betanin may protect the skin from damage caused by UV exposure. Further investigation is essential to explore these potential associations.