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1.
J Cutan Pathol ; 47(2): 139-145, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31677173

RESUMO

BACKGROUND: The spread and invasion of malignant melanoma cells involve degradation and reorganization of the extracellular matrix by the activation of several matrix metalloproteinases (MMPs). This study analyzed the expression of MMP-1, MMP-2, and MMP-13 proteins in primary nodular melanoma (NM) and dysplastic nevi (DN) as a significant risk factor for melanoma development. The secondary goal was to analyze the correlation of MMPs protein expression in NM with tumor invasion, BRAF V600 mutation status, and overall survival. METHODS: Immunohistochemistry for MMP-1, MMP-2, and MMP-13 was performed on nodular melanoma (n = 52) and dysplastic nevi (n = 28) on tissue microarray (TMA). BRAF V600 mutation analysis on NM samples was performed by the Sanger sequencing method. RESULTS: A high level of MMPs expression in NM samples (>30%) compared with DN (<8%) was statistically significant (P < 0.001). BRAF V600 mutations were detected in 15 of 39 (38.5%) NM samples. This study revealed an interesting finding that MMP-1 and MMP-13 protein expression in the BRAF V600 mutated melanomas were significantly lower than in the BRAF V600 wild type (P < 0.05). CONCLUSION: Cox analysis revealed that Clark categories, Breslow thickness, and MMP-1 high protein expression are predictive factors for shorter overall survival (P < 0.05).


Assuntos
Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Metaloproteinase 13 da Matriz/biossíntese , Metaloproteinase 1 da Matriz/biossíntese , Metaloproteinase 2 da Matriz/biossíntese , Melanoma , Proteínas de Neoplasias/biossíntese , Neoplasias Cutâneas , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Melanoma/enzimologia , Melanoma/patologia , Pessoa de Meia-Idade , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/patologia , Melanoma Maligno Cutâneo
2.
Coll Antropol ; 37(4): 1347-51, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24611355

RESUMO

Chronic recurrent multifocal osteomyelitis (CRMO) is an extremely rare and most severe form of chronic nonbacterial osteomyelitis of unknown etiology. Here we present the first case of a six-year-old girl in which was observed that the stress fracture mimic osteomyelitic foci in the course of CRMO.


Assuntos
Fraturas de Estresse/fisiopatologia , Osteomielite/fisiopatologia , Fraturas da Tíbia/fisiopatologia , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X
3.
Coll Antropol ; 37(1): 127-30, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23697261

RESUMO

Angiogenesis, the growth and proliferation of new blood vessels, is important in a variety of pathophysiological processes. However the role of angiogenesis in allergic rhinitis has not been well studied. Hence, the aim of this study was to compare the vascularisation of the nasal mucous membrane of non-allergic, non-treated allergic and allergic patients treated with mometasone furoate. A small piece of the nasal mucous membrane was taken from the frontal pole of the lower nasal shell from 90 patients. The patients were divided in three groups, each containing 30 patients. First group of patients (GP1) had a negative inhalatory allergen test, patients in second group (GP2) had positive test but were not under treatment and the third group of patients (GP3) had positive results with the same test and were treated with mometasone furoate for 15 days before analysis. Immunhistochemical staining with anti-CD31 and VEGF-C was performed. Vascular phase was determined by using length density. Differences in expression of CD31 and VEGF-C were compared using one-way ANOVA and Tukey HSD post-hoc tests. Significantly lower values of CD31 and VEGF-C expression were observed in GP1 in compare with GP2 and GP3 (p < 0.001, p = 0.013, resjpectively). In GP3 the microvessel density was significantly lower than in GP2 (p < 0.001), but higher than in GP1. Our results demonstrated that 15-day treatment with mometasone furoate results in a significant reduction of the density of vascular parameters in allergic patients.


Assuntos
Antialérgicos/farmacologia , Hipersensibilidade/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Nariz/irrigação sanguínea , Pregnadienodiois/farmacologia , Adolescente , Adulto , Idoso , Análise de Variância , Anti-Inflamatórios/uso terapêutico , Feminino , Humanos , Imuno-Histoquímica/métodos , Linfonodos/patologia , Masculino , Microcirculação , Pessoa de Meia-Idade , Modelos Estatísticos , Furoato de Mometasona , Mucosa/metabolismo , Projetos Piloto , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Fatores de Tempo , Fator C de Crescimento do Endotélio Vascular/metabolismo , Adulto Jovem
4.
Case Rep Endocrinol ; 2023: 5583344, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38023692

RESUMO

Acromegaly and gigantism are hormonal disorders which develop as a consequence of chronic growth hormone hypersecretion. The prefix pseudo- is used to describe a certain clinical condition without a clearly proven characteristic of pathophysiological mechanism and basic biochemical features; pseudoacromegaly or acromegaloidism match the definition from above. In this case reports, we will try to provide a concise overview of diagnostic evaluation of acromegaloid physical appearance, while discussing two cases of patients who have similar clinical acromegaloid features as the first sign of the disease but have completely different etiologic backgrounds of their acromegalic appearance. The first case is of a 57-year-old male who presented with a marked acral growth and coarse facial features, but the diagnosis of secondary amyloidosis caused by multiple myeloma was confirmed just after biopsy of tongue and buccal mucosa. The second case is that of a 63-year-old male with an acromegaloid appearance caused by ectopic secretion of GH secreting lung carcinoma. The early diagnosis of ectopic acromegaly and pseudoacromegaly is still a challenging process. The key task is to confirm the GH axis abnormalities and establish the underlying disease, as a crucial step for faster treatment and need to avoid unnecessary therapeutic procedures to decreased mortality and improved quality of life.

5.
Pathol Res Pract ; 229: 153725, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34942512

RESUMO

Malignant melanoma (MM) is known to avoid the host's immune response. Studies on in vitro melanoma cell lines link the microphthalmia-associated transcription factor (MITF) with the regulation of the PD-L1 expression. It seems that MITF affects the activation of the gene responsible for PD-L1 protein expression. Several proteins, including Bcl-2 and Cyclin D1, play major roles in malignant melanoma cell cycle regulation and survival. Our study aims to assess the relationship between MITF, Bcl-2, and cyclin D1 protein expression and the expression of the PD-L1 molecule. Additionally, we examined the association of BRAF mutation, MITF, and CCND1 gene amplification with PD-L1 protein expression. We performed immunohistochemical staining on fifty-two tumour samples from patients diagnosed with nodular melanoma (NM). BRAF V600 mutation, MITF, and CCND1 gene amplification analyses were analyzed by the Sanger sequencing and QRT-PCR methods, respectively. Statistical analyses confirmed the significant inverse correlation between cyclin D1 and PD-L1 expression (p = 0.001) and correlation between PD-L1 and MITF protein expression (p = 0.023). We found a statistically significant inverse correlation between the present MITF gene amplification and PD-L1 (p = 0.007) and MITF protein expression (p = 3.4 ×10-6), respectively. Our study, performed on clinical NM materials, supports the in vitro study findings providing a rationale for the potential MITF-dependent regulation of PD-L1 expression in malignant melanoma.


Assuntos
Antígeno B7-H1/genética , Ciclina D1/genética , Melanoma/genética , Fator de Transcrição Associado à Microftalmia/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Neoplasias Cutâneas/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Estudos Retrospectivos
6.
Coll Antropol ; 35(3): 933-5, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22053582

RESUMO

This report describes a case of a 29-year old patient with congenital pseudoarthrosis of the distal tibia previously treated unsuccessfully by a conventional surgical method. Tibial congenital pseudoarthrosis is a rare disease characterized by segmental osseous weakness resulting in deformation of the bone and spontaneous fractures which progresses to a tibial nonunion. In our case we used intramedullary stabilization with bone grafting and six month after operation congenital pseudarthrosis of the tibia healed.


Assuntos
Fixação Intramedular de Fraturas/métodos , Pseudoartrose/congênito , Tíbia/cirurgia , Fraturas da Tíbia/cirurgia , Adulto , Transplante Ósseo , Humanos , Masculino , Osteotomia , Pseudoartrose/cirurgia
7.
Clin Pract ; 11(1): 58-64, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33572607

RESUMO

Metastatic tumors to the oral cavity are uncommon, representing approximately 1% of all cases of oral malignant lesions even when a metastatic disease is present. The 53-year-old female is presented complaining of abdominal pain, weight loss, and a loose stool recurring not more than three times per day. A computed tomography (CT) scan of the abdomen showed a retroperitoneal mass expanding along the body of the pancreas. Colonoscopy and gastroscopy with a gastric mucosa biopsy showed a normal result. After laparoscopic surgery, the primary site of adenocarcinoma was not confirmed. The patient was referred to the Maxillofacial Surgery Clinic with pain, swelling, and occasional bleeding around the lower right second mollar. Immunohistochemicaly, the tumor cells were positive for Cytokeratin (CK) 19, Cytokeratin (CK) 7, and homebox protein (CDX-2), which are highly sensitive markers of pancreatobiliar cancer. Therefore, the patient was diagnosed with pancreatic carcinoma. This report describes a rare metastasis of malignant pancreatic tumor to the lower right gingiva and highlights the importance of immunohistochemical examination and how it helped identify both the origin and the nature of gingival neoplasm.

8.
Coll Antropol ; 34(4): 1401-4, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21874728

RESUMO

Skin melanoma is by far the most lethal skin cancer, it is unpredictable by nature and presents a severe diagnostic problem. One of the major issues in melanoma diagnostics is to differentiate it with confidence from a dysplastic nevus. Thus, the aim of this study was to evaluate hTERT expression on a spectrum of dermal lesions (from normal skin toprimary melanoma) in order to examine its possible role as a diagnostic marker in melanoma diagnostics. In this study we analyzed the expression of hTERT by real-time PCR on 58 freshly obtained biopsy samples (4 samples of normal skin, 12 dermal nevi, 23 dysplastic nevi, 19 primary melanomas). Our results showed slightly greater hTERT expression in dysplastic nevi than melanomas with major data overlap. Considering the given results, hTERT does not seem to be a reliable diagnostic marker for melanoma.


Assuntos
Melanoma/genética , Neoplasias Cutâneas/genética , Telomerase/genética , Biomarcadores Tumorais/genética , Biópsia , Humanos , Melanoma/patologia , Reação em Cadeia da Polimerase , Neoplasias Cutâneas/patologia
9.
Coll Antropol ; 33(4): 1363-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20102094

RESUMO

Global heating and increased solar ultraviolet irradiance have caused an increase in number of many diseases, particularly skin malignant diseases. Aim of this study was to investigate the influence of climate changes on the health of the population of the Primorsko-goranska and Istria Counties. We gathered and analyzed data about the frequency of skin malignant melanoma in the period of eight years (1998-2005). The data were collected from the Croatian cancer registry. The incidence of malignant skin cancer was estimated overall, by age group and gender. We found that the incidence of the skin melanoma was approximately the same in both counties during the period 1998-2005. However, significant increase has been noted when compared to the situation in the period 1977-1996 (p = 4.95 E-13) The incidence of malignant skin melanoma has risen during the last ten years. It is differently distributed between gender and age groups in Primorsko-goranska and Istria County. It can be related to climate changes, but also to different ways way of life between these two counties.


Assuntos
Melanoma/epidemiologia , Neoplasias Cutâneas/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Croácia/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Características de Residência , Distribuição por Sexo
10.
Clin Pract ; 9(2): 1157, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31285816

RESUMO

The aim of this report is to present a case of a patient with a recurrent nasal cavity amelanotic melanoma (AM), with emphasis on diagnosis and therapy options of this clinical entity. A 65-year-old female patient presented with pain in the right cheek region and nasal obstruction. In 2013, she was diagnosed with mucosal melanoma (MM) of the left nasal cavity. After endoscopic surgery and radiotherapy, the patient was followed by the oncology team. Five years after the initial diagnosis, rhinoscopy showed a tumorous formation in the right nasal cavity. The tumor mass was without black discoloration and was the same color as the surrounding nasal mucosa. Microscopic examination after biopsy of the tumor confirmed amelanotic MM. The patient underwent an additional endoscopic surgery. A complete standard diagnostic workup for MM found metastases in head and neck lymph nodes, on both sides. MMs of head and neck are uncommon malignancies. Unique biology of MM cells causes a high rate of recurrences. This report presents an example of recurrent AM of the nasal cavity, in treatment with checkpoint inhibitor (pembrolizumab), which could provide a good therapy option for patients with MM.

11.
Int J Surg Pathol ; 16(3): 337-40, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18387993

RESUMO

A case of rare tumor, Merkel cell carcinoma, located in the ear canal of a 25-year-old woman is presented. A polypoid tumor mass was extirpated, and tympanoplasty was done at the first operation, whereas at the second operation, all the bones of the ear canal were removed. Epitympanum and cavum were filled with tumor, and the tumor mass was removed in toto. The histopathology and immunohistochemical staining characteristics of tumor confirmed the presence of Merkel cell tumor. Postoperatively, radiation therapy to the tumor bed was completed. There was no clinical or radiographic evidence of recurrence or metastasis of Merkel cell tumor for 3 years.


Assuntos
Carcinoma de Célula de Merkel/patologia , Meato Acústico Externo/patologia , Neoplasias Cutâneas/patologia , Adulto , Carcinoma de Célula de Merkel/radioterapia , Carcinoma de Célula de Merkel/cirurgia , Intervalo Livre de Doença , Meato Acústico Externo/cirurgia , Feminino , Humanos , Recidiva Local de Neoplasia , Neoplasias Cutâneas/radioterapia , Neoplasias Cutâneas/cirurgia , Tomografia Computadorizada por Raios X
12.
Coll Antropol ; 32(2): 499-504, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18756900

RESUMO

Involution displayed by keratoacanthoma (KA) represents an important difference between KA and squamous cell carcinoma (SCC). It has been suggested that apoptosis plays a part in process of involution of KA. Altogether 150 specimens were included in this study, 30 cases of each; normal skin (NS), proliferative (pKA) and regressing keratoacanthoma (rKA), well differentiated (wdSCC) and poorly differentiated (pdSCC) squamous cell carcinoma. All samples were examined immunohistochemically for expression of M30 protein. A significantly lower number of M30 positive cells has been detected in NS as compared to skin tumors examined (p<0.001), except for rKA (p=0.057). The highest percentage of M30 positive cells was detected in pdSCC (p<0.001) as compared with all other examined groups. Keratinocytes of normal and changed epidermis expressing higher levels of M30 protein were predominately found in sun-exposed areas (chi2=14.93; p=0.060). There was an increasing trend of M30 protein expression with increasing age of the patient in NS and skin tumors examined. Majority of skin tumors with higher percentage of M30 positive cells tended to display higher Ki-67 expression. M30 expression was highly correlated with bak (r=0.811; p=0.048) and granzyme B expression in rKA (r=0.733; p=0.015). Cell apoptosis as assessed by M30 expression is, generally, increased in examined skin tumors and related to cell proliferation. Cell apoptosis mediated by bak and granzyme B expression could contribute to KA regression.


Assuntos
Apoptose , Carcinoma de Células Escamosas/metabolismo , Ceratoacantoma/metabolismo , Proteínas de Neoplasias/análise , Neoplasias Cutâneas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Imuno-Histoquímica , Ceratoacantoma/patologia , Antígeno Ki-67/análise , Masculino , Pessoa de Meia-Idade , Neoplasias Cutâneas/patologia
13.
Coll Antropol ; 32(2): 649-51, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18756926

RESUMO

Adverse cutaneous reactions to itraconazole are known to be quite rare. We report a case of maculopapular reaction caused by itraconazole. On the 7th day of itraconazole therapy for hand onychomycosis, in a 39-year-old woman pruritus occurred with a subsequent morbiliform, symmetric, maculopapular eruption on the upper torso, neck, trunk and pressure-bearing areas. Eruption progressed, becoming confluent and spreading to extremities. Due to increasing indications for the administration of itraconazole its increased usage as well as the possibility of allergic reactions should be expected even if these are a rare event.


Assuntos
Antifúngicos/efeitos adversos , Toxidermias/etiologia , Itraconazol/efeitos adversos , Adulto , Toxidermias/patologia , Exantema/induzido quimicamente , Feminino , Humanos , Onicomicose/etiologia
14.
Coll Antropol ; 32(3): 741-6, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18982746

RESUMO

The aim of this study was to analyse breast carcinomas with discordant receptor status, probably hormonal dependent (estrogen receptor (ER) positive, progesterone receptor (PR) negative or ER-PR + subgroup profile) infiltrating ductal breast carcinomas not otherwise specified (IDC NOS). Specimens from 90 IDC NOS were grouped into three categories according to hormonal status: dependent (D) (ER +PR +), probably dependent (PD) (ER +PR- or ER-PR +) and non-dependent (ND) (ER-PR-); they were evaluated considering some established prognostic parameters in breast carcinomas. Statistically significant difference was found between tumor receptor status distribution and menopausal status (p = 0.0235), age of the patients (p = 0.000467), histological grade (p = 0.000003), vascular invasion (p = 0.006), HER-2 status (p = 0.0039) and Ki-67 proliferation rate (p = 0.000311). D tumors were found exclusively in post-menopausal patients (average age 68.9 years), most of which had intermediate (II) grade, without vascular invasion, with HER-2 status score predominantly 0 or 1 + and lower Ki-67 proliferation rate. PD tumors were found predominantly in younger post-menopausal patients (average age 57.5 years), with vascular invasion found in 23% of the cases. ND tumors mostly had higher histological grade, showed the highest percentage of the Ki-67 positive tumor cells and vascular invasion in 30% of the cases. We conclude that the patients with PD breast carcinomas were younger post-menopausal women with the tumors moderately differentiated, HER-2 score 0 or 1+ and with lower Ki-67 proliferation rate.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/patologia , Antígeno Ki-67/análise , Receptor ErbB-2/análise , Adulto , Idoso , Neoplasias da Mama/diagnóstico , Carcinoma Ductal de Mama/diagnóstico , Feminino , Expressão Gênica , Humanos , Menopausa , Pessoa de Meia-Idade , Prognóstico
15.
J Craniomaxillofac Surg ; 46(1): 135-141, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29203089

RESUMO

PURPOSE: The goal of this study was to identify risk factors for wound infections in patients with oral cancer who underwent surgical procedures. MATERIALS AND METHODS: This study included 195 patients who underwent surgical treatment of oral and oropharyngeal cancer over a 7-year period. Wound infection was defined as the occurrence of purulent content from the wound or as an appearance of exudate with signs of local infection and positive cultures taken from the wound. For every patient who was suspected to have a wound infection, a swab from the wound was taken, and microbiological analysis was performed. The patients were divided into 2 groups: patients with postoperative wound infections, and patients with postoperative wound infection. RESULTS: Wound infection was present in 155 patients (59%). Univariate analysis indicated that the following factors were significantly related to the occurrence of wound infection: gender, smoking, tumor localization, size and stage of the tumor, type of surgery, neck dissection, type of reconstruction, nasogastric sonde, gastrostomy and tracheotomy. On multivariate analysis, statistically significant predictors of wound infection were gender, tumor localization and type of reconstruction. CONCLUSIONS: The occurrence of wound infection is high despite antibiotic prophylaxis. To minimize the risk of wound infection and for prompt recognition of risk factors, surgeons managing oral tumor patients should have a better understanding of the risk factors such as gender, tumor localization and type of reconstruction.


Assuntos
Neoplasias Bucais/cirurgia , Neoplasias Orofaríngeas/cirurgia , Infecção da Ferida Cirúrgica/epidemiologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores de Risco
16.
SAGE Open Med Case Rep ; 6: 2050313X18799239, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30210797

RESUMO

Kaposi's sarcoma is a neoplasm of endothelial cells. That vascular tumor is usually limited to the skin, but it may involve mucous membranes, visceral organs, and lymph nodes. Serological evidence has shown that human herpesvirus 8 infection is required for the development of Kaposi's sarcoma. Chronic lymphocytic leukemia is the most common leukemia all over the world. Increased skin cancer risk has been reported for patients with chronic lymphocytic leukemia. The relation between these two pathologies has not yet been clarified. We report a case of Kaposi's sarcoma along with chronic lymphocytic leukemia in a patient who did not receive therapy for chronic lymphocytic leukemia.

17.
J Dermatol Sci ; 47(1): 29-36, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17412565

RESUMO

BACKGROUND: Perforin is a membrane-disrupting protein that allows the entry of granzymes into a target cell inducing degradation of target substances in the cytoplasm and nucleus thus leading to programmed cell death or apoptosis. Recent work demonstrated a possible involvement of perforin mediated cytotoxicity in immunopathogenesis of psoriasis. OBJECTIVES: To investigate a difference in systemic (peripheral blood) and local (lesions) expression and distribution of perforin in psoriatic patients with severe and mild disease. METHODS: Flow cytometry was used for simultaneous detection of intracellular (perforin) and cell surface antigens in peripheral blood lymphocytes. The expression of perforin in skin lesions was evaluated by immunohistochemistry. RESULTS: Significant increase of perforin expression in T lymphocytes, especially cytotoxic CD8+ cells was found in severe psoriasis compared to mild disease (p<0.01 and p<0.05, respectively). There was also an increase of CD56+P+ NK cells (p<0.05) in severe compared to mild psoriasis. The psoriatic plaque of both, severe and mild disease were abundant with perforin showing no significant difference on local level. CONCLUSION: Based on our results we suggest the association between perforin expression and disease severity.


Assuntos
Células Matadoras Naturais/metabolismo , Glicoproteínas de Membrana/sangue , Proteínas Citotóxicas Formadoras de Poros/sangue , Psoríase/sangue , Linfócitos T Citotóxicos/metabolismo , Adulto , Estudos de Casos e Controles , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Masculino , Glicoproteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Perforina , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Psoríase/metabolismo
18.
Med Hypotheses ; 68(1): 128-30, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16935436

RESUMO

Telomerase is responsible for maintaining the length of telomeres at the end of chromosomes. It protects chromosomes from degradation and aberrant recombination during replication prolonging the life span of the cell. Human telomerase reverse transcriptase (hTERT) is highly expressed in >85% of cancer cells but its expression is repressed in most human somatic cells. It has been shown that expression of human telomerase reverse transcriptase greatly extends the life span of both human CD8+ and CD4+ T cells during activation and proliferation. hTERT-positive tumor cells can induce cytotoxic T lymphocyte response as well as T helper response. On the other hand, it is possible that cytotoxic immune response to hTERT-positive tumor cells can cause autoimmune reaction directed against T cells in a tumor bearing host. This could lead to apoptosis and decreased number of activated T cells and insufficient anti-tumor immunity resulting in tumor progression.


Assuntos
Autoanticorpos/imunologia , Imunidade Inata/imunologia , Neoplasias/enzimologia , Neoplasias/imunologia , Linfócitos T/imunologia , Telomerase/imunologia , Apoptose/imunologia , Proliferação de Células , Humanos , Modelos Imunológicos
19.
Med Hypotheses ; 68(1): 125-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16891062

RESUMO

Telomerase is a ribonucleoprotein reverse transcriptase which RNA component (TERC) and reverse transcriptase (TERT) function together to elongate telomeres. If cells are to survive and proliferate indefinitely, telomere preservation is essential for the immortalization process. Somatic cells rarely possess TA, but over 90% of tumor cells express active telomerase. Increased cell proliferation and deregulation of cell cycle occur in human cancers, including cutaneous melanoma. The exact nature of links between TA, cell proliferation and apoptosis has not been extensively elucidated in cutaneous melanoma. We hypothesize a relationship between TA and cutaneous melanoma cell proliferation in a way that TA in telomere elongation is only an early event in cell immortalization. The telomere elongation makes their proliferation possible and being, at the same time, one of its limiting factors. But the TA other than telomere elongation (TERC independent) is crucial to initiate or restore melanoma cell proliferation. On the other hand, TA in telomere elongation, together with other factors (for example TNF), has an active anti-apoptotic role. This way melanoma cells overwhelm the apoptotic defense mechanisms, finally resulting in their indefinite proliferation. In evaluation of our hypothesis, we suggest thorough studies of both telomerase activity and proliferation in cutaneous melanoma on multiple checkpoints and targets. We also suggest combined analyses of TA and telomere length. This approach seems inevitable since it is obvious that telomerase is no longer just for the elongation of telomeres and, to our knowledge, most of the studies conducted so far evaluated TA as an expression of a single subunit or associated molecule.


Assuntos
Melanoma/enzimologia , Melanoma/patologia , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/patologia , Telomerase/metabolismo , Animais , Proliferação de Células , Ativação Enzimática , Humanos , Melanoma/genética , Modelos Biológicos , Invasividade Neoplásica , Neoplasias Cutâneas/genética , Estatística como Assunto , Telomerase/genética
20.
Med Hypotheses ; 69(1): 117-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17197115

RESUMO

Multiple sclerosis (MS) is a chronic disease of the central nervous system characterized by chronic inflammation and demyelination. Studies suggested that the viral, especially Epstein-Barr virus infection, and bacterial infections, especially Borrelia burgdorferi infection, play a role in etiology of MS. MS prevalence parallels the distribution of the Lyme disease pathogen B. burgdorferi. Criteria used for diagnosis of MS can also be fulfilled in other conditions such as Lyme disease, a multisystem disorder resulting from infection by the tick-borne spirochete, B. burgdorferi. In the late period of Lyme disease demyelinating involvement of central nervous system can develop and MS can be erroneously diagnosed. A Lyme borreliosis can mimick central nervous system lymphoma. Also, B. burgdorferi has been implicated not only in etiology of MS, but also in etiology of lymphoma. Studies suggested that there is an increased risk of non-Hodgkin lymphoma in patients, who had a history of autoimmune diseases such as MS and that both non-Hodgkin's lymphomas and Hodgkin's disease were associated with Epstein-Barr virus infection. A small group of lymphomas called primary effusion lymphomas (PEL) is a recently individualized form of non-Hodgkin's lymphoma (WHO classification) that exhibit exclusive or dominant involvement of serous cavities, without a detectable solid tumor mass. These lymphomas have also been linked to Epstein-Barr virus and human herpes virus type 8 infections but virus negative cases have been described. Therefore, we propose that MS and neuroborreliosis are linked to central nervous system primary effusion lymphomas. As a first step in confirming or refuting our hypotheses, we suggest a thorough study of CSF in the patients suspected for the diagnosis of MS and Lyme borreliosis.


Assuntos
Neuroborreliose de Lyme/complicações , Neuroborreliose de Lyme/patologia , Linfoma/complicações , Linfoma/patologia , Modelos Biológicos , Esclerose Múltipla/complicações , Esclerose Múltipla/patologia , Derrame Pericárdico/complicações , Derrame Pericárdico/patologia , Humanos , Neuroborreliose de Lyme/líquido cefalorraquidiano , Linfoma/líquido cefalorraquidiano , Esclerose Múltipla/líquido cefalorraquidiano , Derrame Pericárdico/líquido cefalorraquidiano
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