József Tímár

Semmelweis University, Budapeŝto, Budapest, Hungary

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Publications (277)834.59 Total impact

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    ABSTRACT: Beside smoking and alcohol consumption, human papillomavirus (HPV) infection is the most common risk factor of squamous cell carcinoma in the head and neck region (HNSCC). The latter group of patients associates with better prognosis. During HPV infection, the level of p16 tumor suppressor elevates, which could give an additional opportunity for diagnosis: instead of molecular diagnostic tools, the application of immunohistochemistry is acceptable. However, the majority of the published studies focused on the whole head and neck region and did not separately handled cancers of the oral cavity. Our recent work analyzed the expression of p16 in 67 oral squamous cancers, and compared to routine clinicopathologic parameters. From surgical samples tissue microarray blocks were prepared and expression of p16 as well as other molecular markers (p53, Ki67, EGFR) were studied. In contrast to previous studies on HNSCC, with the exception of recurrence, the expression of p16 was not found associated to clinicopathologic parameters. Nuclear stabilization of p53 appeared mainly in younger patients. The expression of p53 and EGFR significantly correlated to each other. We concluded that traditional molecular categorization of HNSCC could not be completely adaptable to Hungarian samples. Potential coexposition of common etiological factors (e.g. HPV, smoking, alcohol) could blur borders between distinct categories.
    No preview · Article · Dec 2015 · Magyar Onkológia
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    ABSTRACT: Melanoma research has a two decade history in Hungary and is based on three groups located at the National Institute of Oncology (NIO), the University of Debrecen (DU) and Semmelweis University (SU). Previously we have summarized the achievements of the NIO group in this Journal, now this paper summarizes the recent results of their collaborations. The research group of DU revealed several novel genetic alterations in the melanoma genome which might have clinical relevance as prognosticators or predictors in light of the novel target therapies. Data indicating unique, perhaps melanoma-specific epigenetic changes during progression might be even more important, identifying novel genes otherwise not detected as genetically altered ones. The research group in Budapest extensively used experimental human melanoma models and demonstrated the host sex as a key factor in progression due to the specific function of NK cells. Identification of functional glucocorticoid receptor in human melanoma might lead to therapeutic exploitation similar to certain leukemias. Studies on extracellular matrix revealed collagen XVII and CD44 splice variants as progression associated factors of melanoma. Since the double wild type genotype of melanoma is lacking effective therapy, data on the use of FGFR2, c-met or cannabinoid receptor as target can be important. On the other hand, experimental data on the antitumoral effects of heparin derivatives or bisphosphonate in melanoma models can also be encouraging.
    Full-text · Article · Dec 2015 · Magyar Onkológia
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    ABSTRACT: Lung cancer places a significant socio-economic burden on the Hungarian population. This overview summarizes the findings of collaborative translational lung cancer research efforts of three Hungarian flagship academic institutions, the Semmelweis University, the National Institute of Oncology and the National Koranyi Institute of TB and Pulmonology. With regards to the molecular factors regulating tumor angiogenesis, we identified the prognostic significance of apelin and erythropoietin receptor (EPOR) expression in non-small cell lung cancer (NSCLC). Furthermore, the impact of KRAS mutation subtypes and ERCC1 (excision repair cross-complementation group 1) expression on the response to platinum-based chemotherapy have been studied. We also described the epidemiology and predictive power of rare EGFR (epidermal growth factor receptor) mutations in a large Hungarian patient cohort. Lastly, the expression of molecular factors associated with NSCLC progression was studied specifically in brain metastatic matched cases series. These preclinical and clinical studies provide clinically relevant information that hopefully will contribute to the improvement of lung cancer patient care.
    No preview · Article · Dec 2015 · Magyar Onkológia
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    ABSTRACT: Background: The local immune responses to chronic echinococcal infections in various organs are largely unknown. Since the liver is the most frequently involved organ in such infections in human we aimed to characterize the inflammatory as well as immune cell infiltrate around hydatid cysts in the liver and compared to common inflammatory processes of the liver. Method: Surgical samples from the liver of 21 cystic echinococcosis (CE) patients were studied and the distribution of different types of inflammatory and immune cells were determined by immunohistochemistry. Furthermore, expression levels of costimulatory CTLA4, CD28, CD80 and CD86 molecules were measured at RNA level by PCR. Liver biopsy samples from patients with steatohepatitis (SH, n = 11) and chronic hepatitis (CH, n = 11) were used as non-inflammatory and chronic inflammatory controls, respectively. The composition and density of the inflammatory and immune cell infiltrates have been compared by using morphometry. Results: CD3+ T cells predominated the inflammatory infiltrate in all pathological processes, while in CE samples CD20+ B cells, in CH samples CD68+ macrophages were also frequent. Both myeloperoxidase (MPO) + leukocytes and CD68+ macrophages were found to be significantly decreased in CE as compared to either SH or CH samples. Concerning T cell subtypes, only CD8+ T cells were found to be significantly decreased in SH samples. CD1a + dendritic cells were almost completely missing from CE biopsies unlike in any other sample types. There were no differences detected in the mRNA expression of costimulatory molecules except decreased expression of CD28 in CE samples. Conclusion: In the hydatid lesions of the liver of chronic echinococcal infections T cell-mediated immunity seems to be impaired as compared to other types of chronic inflammatory processes, suggesting an immunosuppressive role for Echinococcus granulosus, which deserve further attentions.
    Full-text · Article · Dec 2015 · BMC Infectious Diseases
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    ABSTRACT: Background: BRCA mutation-associated (BRCAmut) breast cancer represents a heterogeneous group displaying certain molecular features. Claudin-low breast cancers (CLBC) overlap with characteristics of BRCAmut tumors; therefore, we have investigated whether these are identical subtypes. Methods: Using public gene expression data, CLDN, CDH1, 9-cell line claudin-low predictor (9CLCLP) and PAM50 expression was evaluated in BRCAmut and BRCA wild-type (BRCAwt) breast cancer cases focusing on their possible overlap with the CLBC subtype. A separate formalin-fixed, paraffin-embedded (FFPE) cohort of 22 BRCAmut and 19 BRCAwt tumor tissues was used for immunohistochemical examination of AR, CD24, CD44, CK5/6, claudin-1, -3, -4 and -7, E-cadherin, EGFR, estrogen receptor (ER), EZH2, HER2, Ki67, p53, progesterone receptor (PgR) and vimentin expression. Results: In the data sets, CLDN1 (ROC = 0.785, p low/CD44high phenotype was found in BRCAmut tumors upon comparison with BRCAwt cases (p Conclusions: There is a prominent correlation between the genes under focus herein and BRCA mutation status. BRCAmut tumors bear stem cell characteristics displaying a distinct cell adhesion molecule profile characterized by high expression of CDH1 and CLDN4 according to public gene expression data set analysis, and higher claudin-3 expression as detected by IHC; thus, BRCAmut breast carcinomas are not identical with the previously identified claudin-low subtype of breast cancer.
    Full-text · Article · Nov 2015 · Pathobiology

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  • No preview · Article · Aug 2015 · Cancer Research
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    ABSTRACT: We have attempted to characterize the changes occurring on the host side during the progression of human melanoma. To investigate the role of tumor microenvironment, we set up such an animal model, which was able to isolate the host related factors playing central role in metastasis formation. One of these 'factors', CCL12, was consequently selected and its behavior was examined alongside its human homologue (CCL8). In our animal model, metastasis forming primary melanoma in the host exhibited increased level of CCL12 mRNA expression. In clinical samples, when examining the tumor and the host together, the cumulative (tumor and host) CCL8 expression was lower in the group in which human primary melanoma formed lung metastasis compared to non-metastatic primary tumors. We could not detect significant difference in CCL8 receptor (CCR1) expression between the two groups. Increased migration of the examined tumor cell lines was observed when CCL8 was applied as a chemoattractant. The tumor cells and their interactions can be influenced the expression of CCL8 by dermal fibroblasts, as a significant change in the metastatic microenvironment. Furthermore, we examined changes in miRNA profile resulted by CCL8 and miR146a appears to be a promising prognostic marker for following this process.
    Preview · Article · Jul 2015 · Oncotarget

  • No preview · Article · Jun 2015 · Pancreatology
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    ABSTRACT: BRAF and NRAS are the two most frequent oncogenic driver mutations in melanoma and are pivotal components of both the EGF and FGF signaling network. Accordingly, we investigated the effect of BRAF and NRAS oncogenic mutation on the response to the stimulation and inhibition of epidermal and fibroblast growth factor receptors in melanoma cells. In the three BRAF mutant, two NRAS mutant and two double wild-type cell lines growth factor receptor expression had been verified by qRT-PCR. Cell proliferation and migration were determined by the analysis of 3-days-long time-lapse videomicroscopic recordings. Of note, a more profound response was found in motility as compared to proliferation and double wild-type cells displayed a higher sensitivity to EGF and FGF2 treatment when compared to mutant cells. Both baseline and induced activation of the growth factor signaling was assessed by immunoblot analysis of the phosphorylation of the downstream effectors Erk1/2. Low baseline and higher inducibility of the signaling pathway was characteristic in double wild-type cells. In contrast, oncogenic BRAF or NRAS mutation did not influence the response to EGF or FGF receptor inhibitors in vitro. Our findings demonstrate that the oncogenic mutations in melanoma have a profound impact on the motogenic effect of the activation of growth factor receptor signaling. Since emerging molecularly targeted therapies aim at the growth factor receptor signaling, the appropriate mutational analysis of individual melanoma cases is essential in both preclinical studies and in the clinical trials and practice.
    No preview · Article · Mar 2015 · Pathology & Oncology Research
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    ABSTRACT: While targeted therapy brought a new era in the treatment of BRAF mutant melanoma, therapeutic options for non-BRAF mutant cases are still limited. In order to explore the antitumor activity of prenylation inhibition we investigated the response to zoledronic acid treatment in thirteen human melanoma cell lines with known BRAF, NRAS and PTEN mutational status. Effect of zoledronic acid on proliferation, clonogenic potential, apoptosis and migration of melanoma cells as well as the activation of downstream elements of the RAS/RAF pathway were investigated in vitro with SRB, TUNEL and PARP cleavage assays and videomicroscopy and immunoblot measurements, respectively. Subcutaneous and spleen-to-liver colonization xenograft mouse models were used to evaluate the influence of zoledronic acid treatment on primary and disseminated tumor growth of melanoma cells in vivo. Zoledronic acid more efficiently decreased short-term in vitro viability in NRAS mutant cells when compared to BRAF mutant and BRAF/NRAS wild-type cells. In line with this finding, following treatment decreased activation of ribosomal protein S6 was found in NRAS mutant cells. Zoledronic acid demonstrated no significant synergism in cell viability inhibition or apoptosis induction with cisplatin or DTIC treatment in vitro. Importantly, zoledronic acid could inhibit clonogenic growth in the majority of melanoma cell lines except in the three BRAF mutant but PTEN wild-type melanoma lines. A similar pattern was observed in apoptosis induction experiments. In vivo zoledronic acid did not inhibit the subcutaneous growth or spleen-to-liver colonization of melanoma cells. Altogether our data demonstrates that prenylation inhibition may be a novel therapeutic approach in NRAS mutant melanoma. Nevertheless, we also demonstrated that therapeutic sensitivity might be influenced by the PTEN status of BRAF mutant melanoma cells. However, further investigations are needed to identify drugs that have appropriate pharmacological properties to efficiently target prenylation in melanoma cells.
    Full-text · Article · Feb 2015 · PLoS ONE
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    ABSTRACT: The appearance of lung metastases is associated with poor outcome and the management of patients with secondary pulmonary tumours remains a clinical challenge. We examined the vascularisation process of lung metastasis in six different preclinical models and found that the tumours incorporated the pre-existing alveolar capillaries (i.e. vessel co-option). During the initial phase of vessel co-option, the incorporated capillaries were still sheathed by pneumocytes, but these incorporated vessels subsequently underwent different fates dependent on the model. In five of the models examined (B16, HT1080, HT25, C26 and MAT B-III), the tumour cells gradually stripped the pneumocytes from the vessels. These dissected pneumocytes underwent fragmentation, but the incorporated microvessels survived. In the sixth model (C38), the tumour cells failed to invade the alveolar walls. Instead, they induced the development of vascularised desmoplastic tissue columns. Finally, we examined the process of arterialisation in lung metastases and found that they became arterialized when their diameter grew to exceed 5 mm. In conclusion, our data show that lung metastases can vascularise by co-opting the pulmonary microvasculature. This is likely to have important clinical implications, especially with respect to anti-angiogenic therapies.
    No preview · Article · Feb 2015 · The Journal of Pathology
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    ABSTRACT: While classic sensitizing mutations of epidermal growth factor receptor (EGFR) are positive predictive markers for EGFR tyrosine kinase inhibitors (TKIs) in lung adenocarcinoma, there are rare EGFR mutations with unknown epidemiology and influence on prognosis and TKI response. 814 lung adenocarcinoma patients with KRAS and/or EGFR mutation analyses for TKI therapy indication were identified. 645 patients were included in the epidemiological analysis. The clinical outcome was analyzed in 419 advanced stage patients with follow-up data. 480 (59%) KRAS/EGFR double wild-type, 216 (27%) KRAS mutant, 42 (5%) classic, 49 (6%) rare and 27 (3%) synonymous EGFR mutant cases were identified. 20 previously unpublished non-synonymous mutations were found. Rare EGFR mutations were significantly associated with smoking (vs classic EGFR mutations; P=.0062). Classic EGFR mutations but not rare ones were independent predictors of increased overall survival (HR, 0.45; 95% CI, 0.25-0.82; P=.009). TKI therapy response rate (RR) of patients harboring classic EGFR mutations was significantly higher (vs rare EGFR mutations; 71% vs 37%; P=.039). Patients with classic or sensitizing rare (G719x and L861Q) EGFR mutations had significantly longer progression-free survival when compared to the remaining rare mutation cases (12 vs 6.2 months; P=.048). The majority of rare EGFR mutations was associated with smoking, shorter overall survival and decreased TKI response when compared to classic EGFR mutations. However, studies characterizing the TKI sensitizing effect of individual rare mutations are indispensable to prevent the exclusion of patients with sensitizing rare EGFR mutations who may benefit from anti-EGFR therapy.
    Full-text · Article · Jan 2015 · Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer

  • No preview · Article · Dec 2014 · Molecular Cancer Research
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    ABSTRACT: We report a case of basaloid pancreatic carcinoma with clinical, pathological, and genomic data. The 73-year-old male patient had jaundice, acholic stool, diarrhea, weight loss, and a large, painless gall bladder. His GGTwas highly elevated. The pancreatic head contained a tumor, which was resected by partial pancreatoduodenectomy with pancreatogastric anastomosis, cholecystectomy, and lymphadenectomy. On gross examination, a 3.8-cm white firm nodule was found, which microscopically was composed of basaloid cell nests with a less than usual desmoplastic stromal background and focally PANIN. Immunohistochemical profile displayed strong CK5/6, CK19, p63, EGFR, vimentin, and evident CK14 expression and absence of expression of CK7, chromogranin, synaptophysin, and BRCA1. A high Ki-67 index and p53 expression were noted. Sequencing of the most frequent 46 oncogenes with ionTorrent (AmpliSeq PCR) method identified PIK3CA, KRAS, and TP53 genes as drivers and variants of the FGFR3, PDGFRA, KIT, KDR, EGFR, RET, and ATM genes. The tumor we report displays histopathological appearances similar to the previously described case and a genomic landscape fitting to the general population of pancreatic carcinomas.We hypothesize that this tumor may belong to the group of DNA damage repair-deficient pancreatic carcinoma subgroup.
    Full-text · Article · Nov 2014 · Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin
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    ABSTRACT: From the aspect of the contemporary pathologic diagnostics of lung cancer, it is a key issue of the tissue obtained since small biopsies and cytology still play a major role. In the non-small cell lung cancer era, cytology considered equal to biopsy. However, in recent years it is unable to provide quality diagnosis and must be replaced by biopsy. Various molecular techniques can handle various different tissue samples which must be considered during molecular pathology diagnosis. Besides, tumor cell-normal cell ratio in the obtained tissue as well as the absolute tumor cell number have great significance whose information must be provided in the primary lung cancer diagnosis. Last but not least, for continuous sustainable molecular diagnostics of lung cancer rational algorythms, affordable technology and appropriate reimbursement are equally necessary.
    No preview · Article · Oct 2014
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    ABSTRACT: Aim: We investigated tissue biomarkers in non-small cell lung cancer (NSCLC) to find indicators of brain metastasis and peritumoral brain edema. Patients and methods: Fifty-two cases were studied out of which 26 had corresponding brain metastatic tissue. Clinicopathological characteristics of tumors were correlated with biomarkers of cell adhesion, cell growth, cell cycle and apoptosis regulation that were previously immunohistochemically studied but never analyzed separately according to histological subgroups, gender and smoking history. Results: Increased collagen XVII in adenocarcinoma (ADC) and increased caspase-9, CD44v6, and decreased cellular apoptosis susceptibility protein (CAS) and Ki-67 in squamous cell carcinoma (SCC) correlated significantly with brain metastasis. Increased β-catenin, E-cadherin and decreased caspase-9 expression in primary SCC, and decreased CD44v6 expression in brain metastatic SCC tissues showed a significant correlation with the extent of peritumoral brain edema. Positive correlation between smoking and biomarker expression could be observed in metastatic ADCs with p16 and caspase-8, while-negative correlation was found in SCC without brain metastasis with caspase-3, and in SCC with brain metastasis with p27. Conclusion: Our results highlight the importance of separate analysis of biomarker expression in histological subtypes of NSCLC.
    No preview · Article · Oct 2014 · Anticancer research
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    ABSTRACT: The clinical expectations how pathologists should submit lung cancer diagnosis have changed dramatically. Until mid 90-ties a clear separation between small cell lung carcinoma (SCLC) and nonsmall cell lung carcinoma (NSCLC) was mostly sufficient. With the invention of antiangiogenic treatment a differentiation between squamous and non-squamous NSCLC was requested. When epidermal growth factor receptor (EGFR) mutation was detected in patients with pulmonary adenocarcinomas and subsequent specific treatment with tyrosine kinase inhibitors (TKIs) was invented, sub-classification of NSCLC and molecular analysis of the tumor tissue for mutations was asked for. Pathologists no longer submit just a diagnosis, but instead are involved in a multidisciplinary team for lung cancer patient management. After EGFR several other driver genes such as echinoderm microtubule associated protein like 4-AL-Kinase 1 (EML4-ALK1), c-ros oncogene 1 , receptor tyrosine kinase (ROS1), discoidin domain receptor tyrosine kinase 2 (DDR2), fibroblast growth factor receptor 1 (FGFR1) were discovered, and more to come. Due to new developments in bronchology (EUS, EBUS) the amount of tissue submitted for diagnosis and molecular analysis is decreasing, however, the genes to be analyzed are increasing. Many of these driver gene aberrations are inversions or translocations and thus require FISH analysis. Each of these analyses requires a certain amount of tumor cells or one to two tissue sections from an already limited amount of tissues or cells. In this respect new genetic test systems have been introduced such as next generation sequencing, which enables not only to detect multiple mutations in different genes, but also amplifications and fusion genes. As soon as these methods have been validated for routine molecular analysis this will enable the analysis of multiple genetic changes simultaneously. In this review we will focus on genetic aberrations in NSCLC, resistance to new target therapies, and also to methodological requirements for a meaningful evaluation of lung cancer tissue and cells.
    No preview · Article · Oct 2014 · Lung Cancer: Targets and Therapy
  • József Tímár
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    ABSTRACT: The molecular genetic dogma is valid that the histological variants of a given cancer represent genetic variants. Basis of this subclassification is known in clear cell renal cancer but still a mistery in prostate or bladder cancers. Meanwhile another genetic dogma developed recently that a given histological variant of a cancer can further be subdivided based on molecular characteristics. Best examples are clear cell renal cancer, adenocarcinoma of the prostate or transitional cell carcinoma of the bladder. This new knowledge helps in the differential diagnostics of cancer, and in determining prognosis, but also provides an opportunity to better tailor existing therapies even to consider novel target agents. Discovery of the molecular subtypes of cancers (such as leukemia or lung adenocarcinoma) contributed significantly to the extension of the progression-free or overall survival of cancer patients, and it is expected that it could lead to similar effects in case of urogenital cancers.
    No preview · Article · Sep 2014 · Magyar Onkológia
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    ABSTRACT: Prostate cancer is one of the leading cancer types in males in the developed world. Radiotherapy is a major method in the curative treatment of prostate cancer however, up to 30% of the patients experience local relapse. Arachidonic acid metabolites have been shown to have important role in cancer. 12-lipoxygenase (12-LOX) has been proven to significantly influence prostate cancer progression, by apoptosis regulation and by promoting cancer cell survival. In this study we examined whether 12-LOX inhibition may increase radiation sensitivity of prostate cancer cells in vitro and in vivo. Prostate cancer cell lines were treated with 12-LOX inhibitors, different doses of radiation and the combination of 12-LOX inhibitors and radiation. We measured the effect of these treatments through clonogenic survival and apoptosis in vitro and tumor growth in vivo in a tumor xenograft model. 12-LOX inhibition and radiation both increased apoptosis and decreased clonogenic survival of prostate cancer cell lines in vitro. Combined treatment resulted in a supra-additive effect in vitro. In vivo both 12-LOX inhibition and radiotherapy caused delay in growth of the xenograft tumors but the combined treatment resulted in the strongest growth inhibition. The presented data prove that 12-LOX and its metabolite 12(S)-HETE have a major role in prostate cancer cell progression and radiosensitivity. We have shown by different methods in vitro and in vivo that inhibition of 12-LOX activity significantly sensitizes prostate cancer cells to radiation. Therefore we can state that 12-LOX inhibitors are promising compounds to be developed to become a new class of clinical radiation sensitizers in prostate cancer.
    No preview · Article · Sep 2014 · Magyar Onkológia

Publication Stats

5k Citations
834.59 Total Impact Points

Institutions

  • 1990-2015
    • Semmelweis University
      • • First Department of Pathology and Experimental Cancer Research
      • • Faculty of Medicine
      Budapeŝto, Budapest, Hungary
  • 2000-2011
    • National Institute of Oncology
      • Department of Molecular Immunology and Toxicology (MITO)
      Budapeŝto, Budapest, Hungary
    • University of Debrecen
      • School of Public Health
      Debreczyn, Hajdú-Bihar, Hungary
  • 2010
    • National Koranyi Institute of TB and Pulmoology
      Budapeŝto, Budapest, Hungary
  • 2005-2008
    • Gottsegen György Országos Kardiológiai Intézet
      Budapeŝto, Budapest, Hungary
  • 1991-1998
    • Semmelweis University
      Budapeŝto, Budapest, Hungary
    • Wayne State University
      • • Department of Radiation Oncology
      • • Department of Pathology
      Detroit, MI, United States