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1.
Molecules ; 27(23)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36500205

RESUMO

Alchemilla vulgaris L. (lady's mantle) was used for centuries in Europe and Balkan countries for treatments of numerous conditions and diseases of the reproductive system, yet some of the biological activities of lady's mantle have been poorly studied and neglected. The present study aimed to estimate the potential of A. vulgaris ethanolic extract from Southeast Serbia to prevent and suppress tumor development in vitro, validated by antioxidant, genoprotective, and cytotoxic properties. A total of 45 compounds were detected by UHPLC-HRMS analysis in A. vulgaris ethanolic extract. Measurement of antioxidant activity revealed the significant potential of the tested extract to scavenge free radicals. In addition, the analysis of micronuclei showed an in vitro protective effect on chromosome aberrations in peripheral human lymphocytes. A. vulgaris extract strongly suppressed the growth of human cell lines derived from different types of tumors (MCF-7, A375, A549, and HCT116). The observed antitumor effect is realized through the blockade of cell division, caspase-dependent apoptosis, and autophagic cell death. Our study has shown that Alchemilla vulgaris L. is a valuable source of bioactive compounds able to protect the subcellular structure from damage, thus preventing tumorigenesis as well as suppressing tumor cell growth.


Assuntos
Alchemilla , Humanos , Alchemilla/química , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Etanol , Sérvia
2.
Pathol Res Pract ; 238: 154080, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35994808

RESUMO

BACKGROUND: Precise molecular characterization of breast cancer, especially triple negative (TNBC) as the most lethal subtype, is needed to stratify patients for the individual treatment approach. MicroRNA-205 (miR-205) has tumor-suppressive and oncogenic functions across different cancers. Therefore, miR-205 might have a different role in TNBC and estrogen receptor (ER) positive BC. Our aim was to investigate how miR-205 expression is associated with ER/progesteron receptor status, clinical parameters, pathohistological characteristics of BC, and survival of patients METHODS: We determined miR-205 relative expressions in 73 primary breast tumors (50 TNBC and 23 ER+) by quantitative Real-time polymerase chain reaction (qPCR) and compared it to clinicopathological characteristics and outcome. RESULTS: The highest levels of miR-205 were in the ER+ /PR+ group, and the lowest in the TNBC group (p = 0.009). Significantly higher levels of miR-205 were also observed in the ER+ compared with the ER-negative group, regardless of the PR status (p = 0.002). Low miR-205 expression level was associated with prognostic stage III in TNBC samples (p = 0.049). Patients who received adjuvant chemotherapy had significantly lower levels of miR-205 (p = 0.016). Patients who received hormone therapy had significantly higher levels of miR-205 (p = 0.007). The low-miR-205 patients had significantly higher 5-year survival rates (p = 0.041). CONCLUSION: The expression of miR-205 in BC is subtype-specific and high expression is associated with the ER+ tumors. The miR-205 expression might be a useful marker of TNBC progression. High miR-205 expression had a detrimental effect on BC patient outcome. Our results indicate that miR-205 might be utilized in clinical practice as a biomarker and an adjunct parameter for the selection of the most effective therapeutic modality.

3.
Biol Proced Online ; 24(1): 6, 2022 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-35658894

RESUMO

BACKGROUND: Metastatic Axillary Lymph Node (mALN) status is currently the most important prognostic factor in the management of primary breast cancer (BC). Thus, development of specimens which enable identification of new mALN markers, involved in the progression of the disease, are of considerable interest. The specific aim of this work was to describe the method of establishment of Metastatic Axillary Nodal Cell Suspension and its fractionation, termed Fractionated Nodal Cell Suspension (FNCS), into nuclear and cytosolic extracts to enable determination of protein expression levels of nuclear cFOS and cytosolic Transforming Growth Factor ß1 (TGFß1) in BC patients. RESULTS: To standardize the procedure, HeLa cells were successfully fractionated into nuclear/cytosolic extracts with confirmed presence of nuclear cFOS and cytosolic TGFß1 proteins. Subsequently, the ALN Cell Suspension specimens were obtained and further fractionated from a pilot sample of six ALN tissue pairs, mALN versus autologous normal ALN (nALN), dissected from invasive BC patients. The mALN/nALN results revealed overexpression of both nuclear cFOS and cytosolic TGFß1 protein levels. However, only the TGFß1 data exhibited statistically significant overexpression, which was proportional to the respective values of mALN diameter of tumor deposits. CONCLUSIONS: Detailed protocol for establishment and fractionation of mALN cell suspension specimens, termed FNCS, into nuclear and cytosolic extracts is here described for the first time. This approach might be a convenient ex vivo model for simultaneous analysis of protein, RNA and DNA biomarkers from nuclear/cytosolic extracts of the same mALN tissue sample. It might have potential to enable, in the age of genomics and personalized medicine, an identification of novel mALN biomarkers and thus improve the screening, diagnosis and prognosis of invasive BC.

4.
Life (Basel) ; 11(11)2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34833123

RESUMO

Breast cancer is the most commonly occurring malignancy and the leading cause of cancer-related death in women. Triple-negative breast cancer (TNBC) is the most aggressive subtype and is associated with high recurrence rates, high incidence of distant metastases, and poor overall survival. The aim of this study was to investigate the PI3K/PTEN/Akt/mTOR pathway as one of the most frequently deregulated pathways in cancer. We aimed to explore the impact of PI3K and mTOR oncogenes as well as the PTEN tumor suppressor on TNBC clinical behavior, prognosis, and multidrug resistance (MDR), using immunohistochemistry and copy number analysis by quantitative real-time PCR. Our results revealed that loss of PTEN and high expression of PI3K and mTOR proteins are associated with poor outcome of TNBC patients. PTEN deletions appeared as a major cause of reduced or absent PTEN expression in TNBC. Importantly, homozygous deletions of PTEN (and not hemizygous deletions) are a potential molecular marker of metastasis formation and good predictors of TNBC outcome. In conclusion, we believe that concurrent examination of PTEN/PI3K/mTOR protein expression may be more useful in predicting TNBC clinical course than the analysis of single protein expression. Specifically, our results showed that PTEN-reduced/PI3K-high/mTOR-high expression constitutes a 'high risk' profile of TNBC.

5.
Breast Cancer ; 28(3): 727-736, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33420675

RESUMO

BACKGROUND: ATP-binding cassette (ABC) transporters are responsible for the efflux of a wide variety of anti-cancer agents and have been implicated in the chemoresistance of various solid tumors. Chemoresistance is a major cause of therapeutic failure, especially in the highly aggressive triple-negative breast cancer (TNBC) in which, unlike estrogen receptor-expressing (ER+) BC, both endocrine and targeted treatments are ineffectual. We aimed to investigate the level and frequency of expression of the three most important ABC transporter, ABCG2, ABCC1, and ABCB1, according to breast cancer subtype. METHODS: We evaluated ABCG2, ABCC1, and ABCB1 protein expressions in 124 primary breast tumors (78 samples were classified as TNBC, while 46 were classified as ER+) by immunohistochemistry and correlated it to clinicopathological characteristics and outcome. RESULTS: All three transporters had significantly higher expression and were more frequently expressed in TNBC compared to ER+ tumors (p < 0.0001). ABCG2 and ABCC1 had a very high level of expression in TNBC that was significantly greater compared to ABCB1 (p < 0.0001). ABCB1 expression was associated with TNBC metastatic spread (p = 0.03). In contrast, TNBC patients with high ABCG2 expression level had significantly longer disease-free interval (p = 0.03) and overall survival (p = 0.007). CONCLUSION: ABCG2, ABCC1, and ABCB1 expression in breast cancer is subtype-specific and associated with triple-negative tumors. The expression of ABCB1 may be useful as a marker of metastatic spread. Moreover, unexpectedly, our results showed a beneficial effect of ABCG2 expression on TNBC clinical behavior. These findings could have implications for the implementation of future TNBC treatment strategies.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias de Mama Triplo Negativas/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Biomarcadores Tumorais/metabolismo , Resistencia a Medicamentos Antineoplásicos , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Estudos Retrospectivos , Neoplasias de Mama Triplo Negativas/patologia
6.
J Med Biochem ; 38(1): 63-70, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30820185

RESUMO

BACKGROUND: Triple negative breast cancer (TNBC) is characterized by aggressive clinical course and is unresponsive to anti-HER2 and endocrine therapy. TNBC is difficult to treat and is often lethal. Given the need to find new targets for therapy we explored clinicopathological significance of copy number gain of FGFR1 and c-MYC. Our aim was to determine the impact of FGFR1 and c-MYC copy number gain on clinical course and outcome of TNBC. METHODS: FGFR1 and c-MYC gene copy number alterations were evaluated in 78 archive TNBC samples using TaqMan based quantitative real time PCR assays. RESULTS: 50% of samples had increased c-MYC copy number. c-MYC copy number gain was associated with TNBC in contrast to ER positive cancers. Our results showed significant correlation between c-MYC copy number gain and high grade of TNBCs. This suggests that c-MYC copy number could be an useful prognostic marker for TNBC patients. c-MYC copy number gain was associated with high pTNM stage as well as lobular and medullary tumor subtypes. 43% of samples had increased FGFR1 copy number. No correlations between FGFR1 copy number gain and clinicopathological variables were observed. CONCLUSIONS: We identified c-MYC copy number gain as a prognostic marker for TNBC. Our results indicate that c- MYC may contribute to TNBC progression. We observed no significant association between c-MYC and/or FGFR1 copy number status and patient survival.

7.
Artigo em Inglês | MEDLINE | ID: mdl-29079368

RESUMO

OBJECTIVE: To investigate the prevalence of p16INK4 a, p14ARF, tumor protein p53 (TP53), and human telomerase reverse transcriptase (hTERT) promoter hypermethylation in mucoepidermoid carcinomas (MECs) and search for a possible association between methylation status and clinicopathological parameters. STUDY DESIGN: DNA extracted from 35 formalin-fixed and paraffin-embedded MEC samples and 10 normal salivary gland (NSG) tissue samples was analyzed for the presence of promoter hypermethylation using methylation-specific polymerase chain reaction testing. RESULTS: The percentages of gene hypermethylation in MECs versus NSGs were the following: p14: 100% versus 20% (P<.001); p16: 60% versus 20% (P = .035); hTERT: 54.3% versus 20% (P = .078); and TP53: 31.4% versus 30% (P = .981). Multiple sites were found to be methylated in 86% of MECs compared with 10% in NSGs (P< .001). TP53 and hTERT were more often methylated in lower clinical stages (P = .033 and P = .005, respectively). CONCLUSIONS: Hypermethylation of p14 appears to be an important event in the development of mucoepidermoid carcinoma. High frequency of gene hypermethylation and high incidence of methylation at multiple sites point to the importance of epigenetic phenomena in the pathogenesis of MECs, although with modest impact on clinical parameters.


Assuntos
Carcinoma Mucoepidermoide/genética , Metilação de DNA/genética , Neoplasias das Glândulas Salivares/genética , Proteína Supressora de Tumor p14ARF/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Epigenômica , Feminino , Genes p53/genética , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas/genética , Estudos Retrospectivos , Sérvia , Telomerase/genética
8.
Per Med ; 13(6): 523-530, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29754549

RESUMO

We present herein a case report style article on a rare advanced triple-negative breast cancer (TNBC) patient with 6-month disease-free interval, and 10-month overall survival. Our results demonstrate that the poor clinical outcome of this patient was associated with pronounced, more than fivefold higher, overexpression of both cFOS and TGF-ß1 proteins in its metastatic nodal tissue extracts, when compared with the values of the two non-TNBC controls (with 'zero' disease-free interval and overall survival). This original observation suggests, for the first time, that both the cFOS and TGF-ß1 may be considered as a pair of biomarkers for an early assessment of poor prognosis for TNBC patients. The possible clinical implication of this observation is discussed.

9.
Arch Oral Biol ; 60(11): 1662-6, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26351750

RESUMO

OBJECTIVES: to investigate p16(INK4a) and p14(ARF) tumor suppressor gene methylation status, determine telomere length and assess the importance of these epigenetic and genetic parameters in the development of pleomorphic adenoma and carcinoma ex pleomorphic adenoma of the parotid salivary glands. MATERIALS AND METHODS: Genomic DNA from paraffin-embedded samples of 50 pleomorphic adenomas and 10 carcinomas ex pleomorphic adenoma was subjected to methylation specific polymerase chain reaction for hypermethylation analyses and real time polymerase chain reaction for the relative telomere length calculations. RESULTS: Promoter hypermethylation of the two genes was a very frequent event in both neoplasms - between 60% and 90% of samples were hypermethylated - but without significant difference between the groups. The mean relative telomere length in the pleomorphic adenoma group was significantly increased in comparison to the control group (P=0.00), and significantly decreased in comparison to the carcinoma group (P=0.05). Telomeres were also longer in myxoid and cellular histological subtypes of adenomas than in the classic type (P=0.044 and P=0.018, respectively). Longer telomeres were more frequent in tumors with hypermethylated p14(ARF) alleles (P=0.013). CONCLUSION: Promoter hypermethylations seems to be an important mechanism of p16(INK4a) and p14(ARF) inactivation in parotid gland tumors. Telomeric lengthening appears to be involved in the pathogenesis of both benign and malignant tumors of the parotid glands.


Assuntos
Adenoma Pleomorfo/genética , Metilação de DNA , Genes p16 , Proteínas Oncogênicas/genética , Neoplasias Parotídeas/genética , Telômero/genética , Adenoma Pleomorfo/metabolismo , Adenoma Pleomorfo/patologia , Adulto , Idoso , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Feminino , Genes Supressores de Tumor , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Proteínas Oncogênicas/metabolismo , Neoplasias Parotídeas/metabolismo , Neoplasias Parotídeas/patologia , Regiões Promotoras Genéticas , Telômero/metabolismo , Homeostase do Telômero , Adulto Jovem
10.
Biomed Pharmacother ; 68(5): 521-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24767865

RESUMO

p53, p16 and PTEN are the most commonly altered tumor suppressor genes in human cancers. In the present study, we compared the presence of individual and multiple alterations of these tumor suppressors in non-small cell lung carcinoma (NSCLC), glioma and breast carcinoma, in order to evaluate specificity of each tumor type regarding the number of altered genes, as well as their combinations. We tested the mutational status, loss of heterozygosity and methylation status of these genes. Effects of gene alterations on patients' survival were also assessed. In NSCLC samples, single gene alterations occurred rarely, while there was considerable increase in incidence of double gene alterations. Furthermore, coexistence of aberrant p53, PTEN and p16 was the most frequent and had significant adverse effect on the survival of NSCLC patients. On the contrary, in glioma and breast cancer specimens, substantial number of cases had aberrant single gene only. Moreover, glioma and breast carcinoma also differ in genotypes that were predominant. Specifically, in glioma samples, prevalent were co-alterations of PTEN and p16, followed by aberrant only PTEN. In breast cancer samples, alterations in all three genes as well as in p53 and p16 were the most common. Moreover, PTEN was altered exclusively with aberrant p53, with statistically significant correlation among them. Overall, our results suggest that NSCLC, glioma and breast cancer need different approaches in molecular diagnosis and treatment with particular attention toward the number and combination of targeted genes.


Assuntos
Neoplasias da Mama/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Glioma/genética , Neoplasias Pulmonares/genética , Mutação/genética , PTEN Fosfo-Hidrolase/genética , Proteína Supressora de Tumor p53/genética , Neoplasias Encefálicas/genética , Feminino , Genes Supressores de Tumor , Instabilidade Genômica/genética , Humanos , Estimativa de Kaplan-Meier
11.
Cancer Biol Ther ; 13(12): 1165-74, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22892847

RESUMO

Tamoxifen is a standard therapeutical treatment in patients with estrogen receptor positive breast carcinoma. However, less than 50% of estrogen receptor positive breast cancers do not respond to tamoxifen treatment whereas 40% of tumors that initially respond to treatment develop resistance over time. The underlying mechanisms for tamoxifen resistance are probably multifactorial but remain largely unknown. The primary aim of this study was to investigate the impact of PTEN tumor suppressor gene on acquiring resistance to tamoxifen by analyzing loss of heterozygosity (LOH) and immunohystochemical expression of PTEN in 49 primary breast carcinomas of patients treated with tamoxifen as the only adjuvant therapy. The effect of PTEN inactivation on breast cancer progression and disease outcome was also analyzed. Reduced or completely lost PTEN expression was observed in 55.1% of samples, while 63.3% of samples displayed LOH of PTEN gene. Inactivation of PTEN immunoexpression significantly correlated with the PTEN loss of heterozygosity, suggesting LOH as the most important genetic mechanism for the reduction or complete loss of PTEN expression in primary breast carcinoma. Most importantly, LOH of PTEN and consequential reduction of its immunoexpression showed significant correlation with the recurrence of the disease. Besides, our study revealed that LOH of PTEN tumor suppressor was significantly associated with shorter disease free survival, breast cancer specific survival and overall survival. In summary, our results imply that LOH of PTEN could be used as a good prognostic characteristic for the outcome of breast cancer patients treated with tamoxifen.


Assuntos
Neoplasias da Mama , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Hormônio-Dependentes , PTEN Fosfo-Hidrolase , Tamoxifeno/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Estrogênios/metabolismo , Feminino , Genes Supressores de Tumor , Humanos , Perda de Heterozigosidade , Pessoa de Meia-Idade , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Neoplasias Hormônio-Dependentes/genética , Neoplasias Hormônio-Dependentes/metabolismo , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Prognóstico , Resultado do Tratamento , Proteínas Supressoras de Tumor/genética
12.
Eur J Oral Sci ; 117(3): 231-7, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19583749

RESUMO

Leukoplakias, clinically identifiable premalignant lesions, often precede oral squamous cell carcinoma (OSCC). Identification of leukoplakias that have the potential for transformation to malignancy is a key clinical problem. The aim of this study was to assess genomic instability, and to detect tumor-specific genomic alterations, in leukoplakias. Genomic instability was analyzed by comparing the DNA fingerprints of 32 leukoplakias with those of paired normal tissue. In addition, the mutational status of the p53 gene was analyzed using polymerase chain reaction-single-stranded conformational polymorphism (PCR-SSCP) and polymerase chain reaction-heteroduplex DNA (PCR-HET), and the mutations were subsequently confirmed by DNA sequencing. Moderate-to-significant genomic instability was detected in all leukoplakias analysed. Nine unique amplicons, present in leukoplakias but not in normal tissue, were retrieved and successfully characterized. The p53 gene was mutated in 40.6% of patients. Four patients with moderate instability and mutated p53 developed OSCC. The data obtained in this study support and concretize the thesis that premalignant lesions possess many of the alterations found in cancer before the development of a malignant phenotype. Inactivation or mutation of the p53 tumor-suppressor might be an early event contributing to genomic instability and increasing the risk of malignant transformation.


Assuntos
DNA de Neoplasias/genética , Instabilidade Genômica/genética , Leucoplasia Oral/genética , Carcinoma de Células Escamosas/genética , Transformação Celular Neoplásica/genética , Impressões Digitais de DNA , Éxons/genética , Seguimentos , Inativação Gênica/fisiologia , Genes p53/genética , Humanos , Leucoplasia Oral/sangue , Leucoplasia Oral/patologia , Mucosa Bucal/patologia , Neoplasias Bucais/genética , Mutação/genética , Ácidos Nucleicos Heteroduplexes/genética , Fenótipo , Polimorfismo Conformacional de Fita Simples/genética , Lesões Pré-Cancerosas/genética , Análise de Sequência de DNA
13.
Anal Quant Cytol Histol ; 31(5): 288-95, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20701096

RESUMO

OBJECTIVE: To use cytoplasmic tissue extract as a new specimen source to quantify transforming growth factor beta 1 (TGFbeta1) protein in metastatic axillary lymph node tissue (ALNT) of breast cancer (BC) patients and to confirm the feasibility of this approach in a prospective pilot study on a subgroup of patients with invasive BC. STUDY DESIGN: The 6 selected malignant and autologous nonmalignant pairs of ALNT were fractionated, under special preanalytical, nonaggressive/nondenaturing conditions, to obtain respective cytoplasmic extracts for TGFbeta1 detection by the Quantikine (R&D Systems Inc., Minneapolis, Minnesota, U.S.A.) enzyme-linked immunosorbent assay kit. RESULTS: The data indicated a highly significant (r = 0.973054) positive linear correlation between the TGFbeta1 concentration and total protein concentration in cytoplasmic extract of metastatic ALNT. The subsequent patients' pilot study, performed strictly before any clinicopathologic factors were accessible, revealed significantly (p < 0.01) elevated TGFbeta1 in malignant ALNT (median value: 1.05 ng/mg protein, range: 0.67-3.6 ng/mg protein, n = 6) vs. autologous nonmalignant ALNT controls (median value: 0.48 ng/mg protein, range: 0.29-0.90 ng/mg protein, n = 6). This elevation was correlated with the number of metastatic axillary lymph nodes with respect to the total and was consistent with an increase in size of tumor deposits in axillary lymph nodes. CONCLUSION: Our data provide for the first time suggestive evidence that the TGFbeta1 level in cytoplasmic extracts of metastatic ALNTs may be a promising biomarker of invasiveness for BC patients. Confirmatory, large-scale studies are needed to evaluate possible implications of this putative biomarker in BC diagnosis and treatment.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias da Mama/metabolismo , Linfonodos/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Adenocarcinoma/secundário , Adulto , Idoso , Axila , Neoplasias da Mama/patologia , Fracionamento Celular , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Invasividade Neoplásica
14.
Anticancer Res ; 26(3A): 2137-42, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16827156

RESUMO

BACKGROUND: Malignant melanoma resistance to chemotherapy remains a major limitation to treatment. Our aim was to identify genes associated with drug resistance, in order to better understand the molecular events underlying the drug-resistant phenotype. MATERIALS AND METHODS: A human melanoma cell line and its drug-resistant variants obtained by selection with MNNG or 6-thioguanine were used. Alterations in gene expression were characterized by differential display reverse transcription-polymerase chain reaction (DDRT-PCR). Prominent mRNA fragments present in selected variants and not in the parental cells were identified and characterized by cloning and sequencing. Differential expression was confirmed by real-time RT-PCR. RESULTS: Three functionally distinct transcriptional products were demonstrated: the chaperonin subunit TCP 1-zeta-6A (CCT6A), the hyaluronan receptor CD44 and LPPR-2, the lipid phosphate phosphatase-related protein type-2. CONCLUSION: Genes with altered expression were identified in drug-resistant variants. The identified molecules may provide new insights into the molecular basis for melanoma resistance to chemotherapy.


Assuntos
Melanoma/tratamento farmacológico , Melanoma/genética , RNA Mensageiro/biossíntese , Sequência de Bases , Linhagem Celular Tumoral , DNA Complementar/biossíntese , DNA Complementar/genética , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Resistencia a Medicamentos Antineoplásicos , Perfilação da Expressão Gênica/métodos , Humanos , Melanoma/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/genética , Reprodutibilidade dos Testes
15.
Chromosoma ; 113(8): 418-27, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15657744

RESUMO

Most B chromosomes are heavily heterochromatic, promoting the general idea that they are genetically inert. The B chromosomes of Apodemus flavicollis are euchromatic and show a high degree of homology with the A chromosomes. The euchromatic nature of B chromosomes in A. flavicollis suggests that they may carry active genes and have transcriptional activity. We applied the differential display reverse transcription-polymerase chain reaction (DD RT-PCR) in order to analyze and compare gene expression in animals possessing B chromosomes and animals without B chromosomes. After a second and third round of amplification, three cDNA fragments were differentially expressed in +B mice compared with 0B animals. These cDNAs were Chaperonin containing TCP-1, subunit 6b (zeta) (CCT6B), Fragile histidine triad gene (FHIT) and hypothetical gene XP transcript. The differential expression pattern was confirmed by Real Time RT-PCR. We suggest that altered expression of these important genes is due to the presence of B chromosomes. In elevating the expression of these genes, B chromosomes of A. flavicollis affect some of the crucial processes in the cell. The significance of these effects and the nature of B chromosomes of A. flavicollis are discussed in the context of the data presented.


Assuntos
Cromossomos de Mamíferos/fisiologia , Expressão Gênica , Muridae/genética , Hidrolases Anidrido Ácido/genética , Animais , Sequência de Bases , Feminino , Masculino , Dados de Sequência Molecular , Proteínas de Neoplasias/genética , Proteínas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
16.
Anticancer Res ; 23(3B): 2601-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12894547

RESUMO

Destabilization of the genome seems to be an important step in the generation of drug resistance. Since malignant melanoma is extremely resistant to chemotherapy, we used human melanoma cell lines as a model to investigate the putative role of genomic instability in the appearance of drug resistance. Drug-resistant variants were obtained with MNNG, BiCNU, doxorubicin and 6-thioguanine selection of melanoma cell lines. Genomic alterations in variant cells were detected by arbitrarily primed PCR of Alu-I digested DNA (Alu-I-AP-PCR). Two differential DNA bands from 6-TG-resistant cell variants were sequenced. One is homologous to intron 25 of the neural cell adhesion molecule L1 and the second to endogenous retroviral LTR sequences. We have shown that drug-resistant melanoma cell lines accumulate genomic alterations that are efficiently detected by Alu I-AP-PCR and that drug-resistant variants show genomic instability, including variations in LTR sequences, which may be associated with the appearance of the drug resistance phenotype.


Assuntos
Elementos Alu/genética , Melanoma/tratamento farmacológico , Melanoma/genética , Sequência de Bases , DNA de Neoplasias/química , DNA de Neoplasias/genética , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Metilnitronitrosoguanidina/farmacologia , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Tioguanina/farmacologia , Células Tumorais Cultivadas
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