Neoadjuvant Imatinib in Gastrointestinal Stromal Tumors (GIST): The First Analysis of a Mexican Population.

Introduction Gastrointestinal stromal tumors (GISTs) are neoplasms originating from the interstitial cells of Cajal, pacemaker cells responsible for intestinal motility. Patients with locally advanced GISTs and those with borderline resections due to the proximity of vital anatomical structures, which could result in unacceptable post-surgical morbidity, require special therapeutic consideration. Imatinib, a tyrosine kinase inhibitor, has demonstrated significant success in the non-surgical management of metastatic GIST, and its favorable impact on overall survival in the adjuvant setting makes it logical to speculate on the benefit it could provide as a neoadjuvant medication in patients with locally advanced disease. Methods Patients aged 18-90 years with a diagnosis of GIST confirmed by immunohistochemistry (CD117 positivity) who were treated at the Oncology Hospital of Centro Médico Nacional Siglo XXI in Mexico City from January 2012 to December 2016 were included in the study. It is a retrospective study with a duration of four years. Clinical data were collected from the medical records, which included sex, age, tumor location, initial resectability, reason for unresectability, initial tumor size, and mitotic rate. In the case of unresectable disease, patients who were evaluated by medical oncology and who had received treatment with 400 mg of imatinib daily were evaluated. Results A total of 312 patients diagnosed with GIST were analyzed. One hundred thirty-one were men (42%) with a mean age of 57 years, and 181 were women (58%) with a mean age of 59 years. The most frequent anatomical location was the stomach (n=185, 59.2%). At the time of diagnosis, 210 patients (67.3%) presented with resectable disease, while n=102 patients (32.7%) had unresectable disease. A total of 102 patients with unresectable disease received therapy with 400 mg of imatinib per day. Sixteen patients (15.7%) presented a reduction in tumor dimensions and underwent surgery. Conclusion The study highlights the importance of complete surgical resection and the potential benefit of neoadjuvant imatinib therapy in converting unresectable to resectable disease. The results suggest that imatinib can be effective in converting unresectable GISTs to resectable ones, allowing for a complete resection to be performed and obtaining an R0 resection in 93.7% of these cases.

Clinicopathological Characteristics and the First Mutational Analysis of Gastrointestinal Stromal Tumors From Mexico: A Single Institution Experience.

Background Gastrointestinal stromal tumors (GISTs) arise from Cajal's interstitial cell precursors and display a variety of genetic mutations, primarily in the KIT and PDGFRA genes. These mutations are linked to tumor location, prognosis, and response to treatment. This study delves into the mutational patterns of GISTs in a Mexican population and their impact on overall survival (OS) and disease-free survival (DFS). Methodology This retrospective study examined 42 GIST cases diagnosed at the Oncology Hospital of the National Medical Center XXI Century between January 2018 and December 2020. Clinical, histological, and immunohistochemical data were gathered, and mutational analysis of KIT and PDGFRA genes was conducted using second-generation sequencing. Results The study group consisted of 52.4% females and 47.6% males, with an average age of 62.6 years. The most common tumor site was the stomach (59.5%), followed by the small intestine (26.2%). KIT mutations were detected in 71.4% of cases, predominantly involving exon 11. PDGFRA mutations were observed in 7.1% of cases. Recurrence was noted in 9.5% of patients, all with high-risk tumors. No significant link was identified between specific mutations and OS or DFS. Conclusions This investigation sheds light on the genetic landscape of GISTs in the Mexican population. While no significant association was established between particular mutations and survival outcomes, the study emphasizes the importance of molecular profiling in treatment decision-making. Further studies with larger sample sizes and longer follow-up periods are necessary to validate these results and explore their clinical relevance.

Mast cells in oral lichen planus and oral lichenoid lesions related to dental amalgam contact

Abstract The aim of this study was to analyze the expression of mast cell markers toluidine blue, c-kit, and tryptase and presence of mononuclear inflammatory cells in oral lichen planus (OLP) and oral lichenoid lesions related to dental amalgam. Nineteen specimens of OLP, OLLC, and healthy oral mucosa were selected. Mononuclear inflammatory cells were analyzed. Histochemical and immunohistochemical analyses were performed using toluidine blue, anti-c-kit and anti-tryptase reagents, and the results were quantified in areas A and B of connective tissue. Mast cells of all OLP and OLLC samples were positive for toluidine blue, c-kit, and tryptase. The density of toluidine blue+, c-kit+ and tryptase+ mast cells was higher in tissue with OLP and OLLC compared with healthy controls (p < 0.05). No difference was noted in mast cells density between OLP and OLLC (p > 0.05). The density of tryptase+ mast cells was higher in the subepithelial region (area A) than the region below it (Area B) in OLLC (p = 0.047). The mononuclear inflammatory cell density was higher in OLLC compared to OLP, but without statistical significance (p > 0.05). A positive statistical correlation was found between mononuclear immune cells and density of c-kit+ and tryptase+ mast cells in OLP (r = 0.943 and r = 0.886, respectively). Our data demonstrate that the etiopathogenesis process of OLP and OLLC modulates the expansion and degranulation of mast cells; mast cells density, however, was similar between OLP and OLLC. The distribution of mast cells appears to vary along the lamina propria.

Tumor-Infiltrating iNKT Cells Activated through c-Kit/Sca-1 Are Induced by Pentoxifylline, Norcantharidin, and Their Mixtures for Killing Murine Melanoma Cells.

The involvement of NK and other cytotoxic cells is considered the first defense line against cancer. However, a significant lack of information prevails on the possible roles played by factors considered characteristic of primitive cells, such as c-kit and Sca-1, in activating these cells, particularly in melanoma models subjected to treatments with substances under investigation, such as the case of norcantharidin. In this study, B16F1 murine melanoma cells were used to induce tumors in DBA/2 mice, estimating the proportions of NK and iNKT cells; the presence of activation (CD107a+) and primitive/activation (c-kit+/Lya6A+) markers and some tumor parameters, such as the presence of mitotic bodies, nuclear factor area, NK and iNKT cell infiltration in the tumor, infiltrated tumor area, and infiltrating lymphocyte count at 10x and 40x in specimens treated with pentoxifylline, norcantharidin, and the combination of both drugs. Possible correlations were estimated with Pearson's correlation analysis. It should be noted that, despite having demonstrated multiple correlations, immaturity/activation markers were related to these cells' activation. At the tumor site, iNKT cells are the ones that exert the cytotoxic potential on tumor cells, but they are confined to specific sites in the tumor. Due to the higher number of interactions of natural killer cells with tumor cells, it is concluded that the most effective treatment was PTX at 60 mg/kg + NCTD at 0.75 mg/kg.

Presença de mutações no gene BRAF e outros oncogenes e associação com características clínicas e epidemiológicas em pacientes com melanoma metastático / Presence of risk in the BRAF gene and other oncogenes and association with clinical and epidemiological characteristics in patients with metastatic melanoma

Embora o melanoma seja representado por apenas cerca de 5% dos casos de tumores malignos de pele, é responsável pela ampla maioria de óbitos relacionados a tumores cutâneos. Seu desenvolvimento está principalmente associado à presença de mutações em oncogenes específicos, como BRAF, c-KIT e PDGFRA, os quais estão relacionados ao metabolismo celular. OBJETIVOS: Avaliar retrospectivamente a presença de mutações nos genes BRAF (éxons 15), C-KIT (éxons 9,11,13 e 17) e PDGFRA (éxons 12 ,14 e 18) e correlacionar os resultados com as características clínicas e epidemiológicas e desfecho dos pacientes. METODOLOGIA: Foi realizado um estudo retrospectivo de 94 pacientes com melanoma metastático atendidos no Hospital Amaral Carvalho entre os anos de 2015 a 2022, de acordo com as seguintes variáveis: idade ao diagnóstico, gênero, cor, local do tumor primário, local de metástase, subtipo histológico de melanoma, dosagem de LDH, positividade para marcadores de imuno-histoquímica, espessura, presença de ulceração, metástase no linfonodo ao diagnóstico do tumor primário, espessura Breslow, classificação Clark, índice mitótico e desfecho (óbito, sobrevida). RESULTADOS: A maioria dos pacientes eram do sexo masculino (52,1%), de cor branca (97,9%) e com idade acima de 60 anos (42,5%). O subtipo histológico mais encontrado foi o extensivo superficial (42,5%), sendo os membros inferiores o local mais acometido (35,1%). O nível IV de Clark (39,4%) e índice de Breslow acima de 4mm (33,0%) foram os mais prevalentes. A maior parte dos tumores não apresentou ulceração (53,2%) e mais da metade dos pacientes apresentou mais de uma mitose por mm² (47,9%). A dosagem de desidrogenase láctica (LDH) se manteve dentro da normalidade na maioria dos pacientes no momento do diagnóstico (43,6%) e no surgimento de metástases (30,9%). Todos os pacientes apresentaram ao menos uma metástase, sendo os linfonodos regionais o local de maior incidência. A maioria dos pacientes faleceu em decorrência da doença (66,0%). A análise de BRAF apresentou significância estatística para as variáveis idade ao diagnóstico (p= 0,0085), tipo histológico (p= 0,048) e nível de Clark (p= 0,0290). A mediana de sobrevivência para pacientes com mutações em BRAF foi de 62 meses e 50 meses para aqueles que não apresentaram mutações. Não foram encontradas significâncias estatísticas entre c-KIT e as variáveis analisadas. A mediana de sobrevivência para pacientes com mutações em c-KIT foi de 38 meses e 70 meses para aqueles que não apresentaram mutações. CONCLUSÕES: A presença de mutação em BRAF esteve associada à menor idade e menores índices de Clark, e relacionada à ligeira maior sobrevida. O contrário foi observado para mutações em c-KIT, apesar da ausência de significância estatística: uma ligeira menor sobrevida foi observada em pacientes mutados. O LDH não esteve bem correlacionado à presença do melanoma metastático ao se apresentar normal na maioria dos casos. Grande parte dos pacientes tiveram o tumor primário localizado nos membros inferiores, diferentemente do relatado por outros estudos, e apesar de não significante, os tumores de tronco foram em sua maioria mutados para BRAF, e o oposto observado em membros inferiores e superiores. Assim, o papel prognóstico da mutação em BRAF na progressão da doença é ainda controverso. Tais dados podem fornecer mais informações para a adequação de protocolos de prevenção e tratamento de pacientes acometidos por melanoma.

INTRODUCTION: Although melanoma is represented by only about 5% of cases of malignant skin tumors, it is responsible for the vast majority of deaths related to skin tumors. Its development is mainly associated with the presence of mutations in specific oncogenes, such as BRAF, c-KIT and PDGFRA, which are related to cell metabolism. OBJECTIVES: Retrospectively evaluate the presence of mutations in BRAF (exons 15), C-KIT (exons 9,11,13 and 17) and PDGFRA (exons 12, 14 and 18) genes and correlate the results with the clinical and epidemiological characteristics and patient outcomes. METHODS: A retrospective study of 94 patients with metastatic melanoma treated at Hospital Amaral Carvalho between the years 2015 to 2022 was carried out, according to the following variables: age at diagnosis, gender, color, site of primary tumor, site of metastasis, histological subtype of melanoma, LDH dosage, positivity for immunohistochemical markers, thickness, presence of ulceration, lymph node metastasis at diagnosis of the primary tumor, Breslow thickness, Clark classification, mitotic index and outcome (death, survival). RESULTS: Most patients were male (52.1%), white (97.9%) and aged over 60 years (42.5%). The most common histological subtype was superficial extensive (42.5%), with the lower limbs being the most affected site (35.1%). Clark's level IV (39.4%) and Breslow thickness above 4mm (33.0%) were the most prevalent. Most tumors did not show ulceration (53.2%) and more than half of the patients had more than one mitosis per mm² (47.9%). The lactate dehydrogenase (LDH) dosage remained within the normal range in most patients at the time of diagnosis (43.6%) and at the onset of metastases (30.9%). All patients had at least one metastasis, with regional lymph nodes being the site with the highest incidence. Most patients died as a result of the disease (66.0%). BRAF analysis showed statistical significance for the variables age at diagnosis (p= 0.0085), histological type (p= 0.048) and Clark's level (p= 0.0290). Median survival for patients with BRAF mutations was 62 months and 50 months for those without mutations. No statistical significance was found between c-KIT and the analyzed variables. The median survival for patients with c-KIT mutations was 38 months and 70 months for those without mutations. CONCLUSIONS: The presence of a BRAF mutation was associated with younger age and lower Clark scores, and related to slightly longer survival. The opposite was observed for mutations in c-KIT, despite the absence of statistical significance: a slightly lower survival was observed in mutated patients. LDH was not well correlated with the presence of metastatic melanoma as it was normal in most cases. Most of the patients had the primary tumor located in the lower limbs, unlike what has been reported by other studies, and although not significant, the trunk tumors were mostly mutated to BRAF, and the opposite was observed in the lower and upper limbs. Thus, the prognostic role of the BRAF mutation in disease progression is still controversial. Such data may provide more information for the adequacy of prevention and treatment protocols for patients affected by melanoma.

c-Kit Induces Migration of Triple-Negative Breast Cancer Cells and Is a Promising Target for Tyrosine Kinase Inhibitor Treatment.

Triple-negative breast cancer (TNBC) is associated with a poor prognosis and the absence of targeted therapy. c-Kit, a receptor tyrosine kinase (RTK), is considered a molecular target for anticancer drugs. Tyrosine kinase inhibitors (TKIs) recognizing c-Kit are used for the treatment of c-Kit-expressing tumors. However, the expression, function, and therapeutic potential of c-Kit have been little explored in TNBC. Here, we studied the expression and effects of c-Kit in TNBC through in vitro and in silico analysis, and evaluated the response to TKIs targeting c-Kit. Analysis of TNBC cells showed the expression of functional c-Kit at the cell membrane. The stimulation of c-Kit with its ligand induced the activation of STAT3, Akt, and ERK1/2, increasing cell migration, but had no effect on cell proliferation or response to Doxorubicin. Analysis of public datasets showed that the expression of c-Kit in tumors was not associated with patient survival. Finally, TNBC cells were susceptible to TKIs, in particular the effect of Nilotinib was stronger than Doxorubicin in all cell lines. In conclusion, TNBC cells express functional c-Kit, which is a targetable molecule, and show a strong response to Nilotinib that may be considered a candidate drug for the treatment of TNBC.

Intranasal mast cell tumors: Clinical, immunohistochemical, and molecular features in 20 dogs.

Mast cell tumors (MCTs) are an uncommon primary neoplasm of the nasal cavity in dogs for which there is a paucity of existing literature regarding their clinical behavior and molecular features. The objectives of this retrospective study were to examine the clinical findings, histopathologic and immunohistochemical features, and c-KIT mutation status of primary intranasal MCTs in dogs and identify potential prognostic factors. Canine biopsies submitted to a diagnostic laboratory in Colorado between 2010 and 2019 with intranasal neoplasms diagnosed as MCTs and no history of cutaneous or oral MCT were considered. Immunohistochemistry for CD117 and Ki67 and polymerase chain reaction (PCR) for internal tandem duplications at exons 8 and 11 of the c-KIT gene were performed. Twenty out of 1849 (1%) primary intranasal neoplasms were MCTs. Metastases were reported in 11/20 cases (55%), with the mandibular lymph node representing the most common site. One case had distant metastases to abdominal viscera. Of the cases with available outcome data, 6/14 (43%) died or were euthanized from MCT-related disease within 1 year of the onset of clinical signs. Only one case had a c-KIT mutation at exon 11. In our study, intranasal MCTs were prone to metastasize and had a generally poor prognosis, resembling the behavior of MCTs arising in other mucosal locations. While dogs with metastatic disease and survival times of <1 year tended to have atypical KIT localization, moderate to high Ki67 indices, and mitotic counts ≥8, definitive prognosticators could not be identified due to the limited number of cases with favorable clinical outcomes.

Mast cell neoplasm: a challenging pathological diagnosis.

Systemic mastocytosis (SM) is a myeloid neoplasm characterized by abnormal growth and accumulation of neoplastic mast cells in at least one extracutaneous site. Clinical presentation and course are variable, most patients are developing an indolent disease and some, an aggressive/leukemic form. Because of its rarity, most physicians are unfamiliar with this disease and do not readily diagnose it. In the present retrospective study, the authors describe 12 patients diagnosed with mast cell neoplasm. Cases were selected from three institutions from Campinas and São Paulo City, Brazil. Morphological features and diagnostic pitfalls are emphasized. Patients' age ranged from 15 to 81 years (mean 51.6 years). Male and female were affected similarly (1:1). Ten patients were classified as aggressive SM, one patient as SM with an associated acute promyelocytic leukemia with t(15;17), and one patient with mast cell sarcoma. The most common clinical findings included anemia (9 patients), thrombocytopenia (3 patients), and skin lesions (3 patients). Bone marrow was involved in 11 patients at diagnosis, followed by skin (5 patients). Five morphological patterns were present: mast cell aggregates (5), plasmacytoid (4), monocytoid (2), spindle cell (2), and epithelioid/pleomorphic (1); two patients showed two histological patterns. In all cases, neoplastic cells were positive for CD117/C-KIT. C-KIT D816V mutation was present in four patients, C-KIT K509I in two, and del(7q22) in one; in five cases no mutational status was available. Despite limited resources, basically morphology and a restricted immunohistochemical panel, it is possible to diagnose mast cell neoplasm. Of note, the pathologist should recognize the different morphological variants of the disease and include adequate markers when requesting immunohistochemical studies.

Imatinib Mesylate for the Treatment of Canine Mast Cell Tumors: Assessment of the Response and Adverse Events in Comparison with the Conventional Therapy with Vinblastine and Prednisone.

Mast cell tumors (MCTs) are common neoplasms in dogs, and treatments for these diseases include surgery, polychemotherapy and targeted therapy with tyrosine kinase inhibitors. This study aimed to evaluate the response and the adverse events of treatment with imatinib mesylate (IM) compared to conventional therapy using vinblastine and prednisolone (VP) in canine cutaneous MCTs. Twenty-four dogs were included in the study; 13 animals were treated with IM and 11 with VP. Tumor tissue samples were submitted for histological diagnosis, grading and KIT immunostaining. The response to treatment was assessed by tomographic measurements according to VCOG criteria. Adverse events were classified according to VCOG-CTCAE criteria. The IM and VP groups had dogs with similar breeds, gender, ages, MCT localization, WHO stages and lymph node metastasis profiles. Most MCTs were grade 2/low and had KIT- patterns 2 and 3. The objective response rate (ORR) was significantly higher (30.79%) in the IM group then in VP group (9.09%). Adverse events (AE) in IM group were all grade 1, significantly different from VP. In conclusion, IM presented better ORR and less severe adverse events when compared to VP, representing a suitable option for the treatment of low-grade canine MCTs.

Ubiquitin-specific protease 1 acts as an oncogene and promotes lenvatinib efficacy in hepatocellular carcinoma by stabilizing c-kit.

INTRODUCTION AND OBJECTIVES: Ubiquitin-specific proteases (USPs) act as proto-oncogenes or tumor suppressors in a wide variety of cancers. In this study, we intended to explore the role of USP1 in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: The clinical significance of USP1 in HCC was analyzed based on The Cancer Genome Atlas (TCGA) data and immunohistochemical staining. siRNAs and lentivirus were used to knock down and overexpress indicated genes, respectively. qRT-PCR and immunoblotting were performed to examine mRNA and protein expression, respectively. CCK8, colony formation and PI/Annexin V-APC staining were performed to examine cellular function. Immunoprecipitation, coomassie blue staining, mass spectrum and immunoblotting were conducted to evaluate the interaction between USP1 and c-kit. RESULTS: USP1 was over-expressed in HCC patients. Patients with high expression of USP1 had shorter overall and disease free survival than those with low expression of USP1. Functional results showed that USP1 was critical for HCC cell growth and proliferation. Immunoprecipitation and immunoblotting results suggested that USP1 interacted with c-kit and promoted the stability of c-kit, which is an important target of lenvatinib in HCC. Knockdown of c-kit reversed the oncogenic function of USP1 on HCC cell growth. Lastly, USP1 upregulation conferred higher sensitivity of HCC cells to lenvatinib treatment. CONCLUSIONS: Our study demonstrated that USP1 acted as an oncogene in HCC. It also promoted lenvatinib efficacy by stabilizing c-kit.

Isolated cancer stem cells from human liver cancer: morphological and functional characteristics in primary culture.

BACKGROUND: Primary liver cancer cells (PLCs) could more directly simulate the human tumor microenvironment. Compared with liver cancer cell lines, PLCs could reflect the human situation. As in previous studies, tumor stem cells were a small number of cancer cells in the microenvironment and considered to be one of the origins of liver cancer. This study aimed to screen stem cells in PLCs, analyze their biological characteristics, propose the possibility that liver cancer originated from stem cells. METHODS: Liver cancer tissues of 17 patients were taken from the Affiliated Hospital of Guangdong Medical College, and PLCs were isolated by tissue slice method. The proliferation, tumor formation in nude mice, stem protein expression of PLCs were observed. C-kit+ liver cancer cells were screened and their biological characteristics were analyzed. RESULTS: PLCs could be stably passaged. Transmission electron microscopy indicated that the nucleus was irregular, there were many mitochondria, and the endoplasmic reticulum was irregularly distributed. PLCs could express E-Cadherin, Oct-4, ß-Catenin, Sox2, CD326, C-kit, GPC3, Nanog. The proliferation curve of PLCs and Hep3B cells were similar, and they all could form tumors in nude mice. Flow-sorted C-kit+ PLCs, as well as C-kit+ Hep3B cells could highly express Bmi1, Sox2, Oct4, Notch1, Nanog, C-kit, ß-Catenin, Smo, Nestin, ABCG2, ABCB1. And they also could clone and form tumors in vivo. But C-kit+ PLCs were more sensitive to chemotherapy drugs than C-kit+ liver cancer cell lines. CONCLUSION: C-kit+ PLCs had the characteristics of tumor stem cells and were more sensitive to chemotherapy drugs.

Virtual Screening and Molecular Docking: Discovering Novel c-KIT Inhibitors.

Gastrointestinal stromal tumors (GISTs) are unusual cancers, which are developed in specialized cells in the gastrointestinal tract wall. Various strategies involving single-agents, combinations, and rapid complementary inhibitor cycling are now being used to control such tumors. Based on promising early clinical trial experience, certain novel KIT and PDGFRA tyrosine kinase inhibitors have shown advanced clinical development. Resistance to tyrosine kinase inhibitors has brought immense difficulties, with patients now requiring additional therapeutic options. This review describes and discusses the last five years (2016-2020) in developing novel c-KIT kinase inhibitors using virtual screening and docking approaches. Computational techniques can be used to complement experimental studies to identify new candidate molecules for therapeutic use. Molecular modeling strategies allow the analysis of the required characteristics that compounds must have to effectively bind c-KIT. Through such analyses, it is possible to both discover and design novel inhibitors against cancer-related proteins that play a critical role in tumor development (including mutant strains). Docking showed potential in the detection of the key residues responsible for ligand recognition and is very helpful to understand the interactions in the active site that can be used to develop new compounds/classes of anticancer drugs and help millions of cancer patients.

Dietary biotin supplementation increases proliferation pathways in mice testes without affecting serum follicle-stimulating hormone levels and stem cell factor expression.

Supplements containing pharmacological concentrations of biotin are commercially available. The mechanisms by which biotin at pharmacological concentrations exerts its action have been the subject of multiple investigations, particularly for biotin's medicinal potential and wide use for cosmetic purposes. Several studies have reported that biotin supplementation increases cell proliferation; however, the mechanisms involved in this effect have not yet been characterized. In a previous study, we found that a biotin-supplemented diet increased spermatogonia proliferation. The present study was focused on investigating the molecular mechanisms involved in biotin-induced testis cell proliferation. Male BALB/cAnNHsd mice were fed a control or a biotin-supplemented diet (1.76 or 97.7 mg biotin/kg diet) for eight weeks. Compared with the control group, the biotin-supplemented mice presented augmented protein abundance of the c-kit-receptor and pERK1/2Tyr204 and pAKTSer473, the active forms of ERK/AKT proliferation signaling pathways. No changes were observed in the testis expression of the stem cell factor and in the serum levels of the follicle-stimulating hormone. Analysis of mRNA abundance found an increase in cyclins Ccnd3, Ccne1, Ccna2; Kinases Cdk4, Cdk2; and E2F; and Sp1 & Sp3 transcription factors. Decreased expression of cyclin-dependent kinase inhibitor 1a (p21) was observed but not of Cdkn2a inhibitor (p16). The results of the present study identifies, for the first time, the mechanisms associated with biotin supplementation-induced cell proliferation, which raises concerns about the effects of biotin on male reproductive health because of its capacity to cause hyperplasia, especially because this vitamin is available in large amounts without regulation.

Immunolocalization of stem/progenitor cell biomarkers Oct-4, C-kit and Musashi-1 in endometriotic lesions.

BACKGROUND: Human endometrium harbors stem/progenitor cells (SPCs) that may contribute to the establishment of endometriosis when seeded outside the uterus. Oct-4, C-kit and Musashi-1 are some of the many proteins used to characterize SPCs, but their association with endometriosis is uncertain. OBJECTIVE AND DESIGN: In this study, specimens of normal endometrium (n = 12), eutopic endometrium from women with endometriosis (n = 9), superficial peritoneal endometriosis (SUP, n = 12) and deep endometriosis (DE, n = 13) lesions were evaluated for localization and intensity of immunostaining for Oct-4, C-kit and Musashi-1. RESULTS: The three markers were abundantly expressed in normal endometrium, eutopic endometrium from endometriosis patients, SUP and DE specimens. Oct-4 and C-kit expression did not vary across groups as regards intensity or frequency. C-kit staining signal was seldom detected in vascular endothelium of normal or eutopic endometrium from endometriosis patients; however, it was positive in 67% of the SUP lesions and in 25% of the DE lesions (p = 0.042). Musashi-1 was expressed in some endometriotic glands as cell clusters, but its signal was similar between the four types of tissue (p = 0.971) CONCLUSION: The wide distribution of Oct-4, C-kit and Musashi-1 in endometria of patients with and without endometriosis and in SUP and DE endometriotic lesions suggests that these markers are not suitable for the in situ characterization of endometrial SPCs and should not be taken as surrogates for the study of SPCs in the pathogenesis of endometriosis.

Rare and unknown canine systemic mastocytosis: clinical and laboratory features of an aberrant c-Kit mutation neoplasia / A rara e desconhecida mastocitose sistêmica canina: características clínicas e laboratoriais de uma neoplasia aberrante na mutação c-Kit

Systemic mastocytosis (SM) pathology is extremely rare in canine practice, with insufficient reported data. The knowledge of the clinical behavior of this pathology is scarce. In human medicine, SM has been widely investigated, being defined as a rare hematopoietic disorder by the World Health Organization (2016), within the type of myeloproliferative neoplasms. Herein, we describe a systemic mastocytosis case in a Portuguese Serra-da-Estrela dog, where a cutaneous grade III/high-grade MCT was also diagnosed. The clinical decline of the animal and owner's insistence throughout anamnesis that the dog was markedly different after the cytologic exam performed in another clinic, along with both severe eosinophilia and hepatomegaly, led to the clinical suspicion of SM. The animal passed away 7 days later. Post-morteminvestigation confirmed SM pathology, and a deletion of 15 base pairs change on c-Kit gene exon 11 was identified. Contemplating the low number of cases described in the literature, this publication aims to disclose clinical and laboratory features of rare and poorly described canine SM, taking into consideration human outcomes described in the literature.(AU)

A patologia da mastocitose sistêmica (SM) é extremamente rara na prática clínica canina, com escassos casos descritos na literatura científica. O conhecimento do comportamento clínico desta patologia é mínimo. Na medicina humana, a SM tem sido amplamente investigada, sendo definida como uma doença hematopoiética rara pela Organização Mundial da Saúde (2016), dentro do tipo de neoplasias mieloproliferativas. Descrevemos aqui um caso de mastocitose sistêmica num cão Serra-da-Estrela português, diagnosticado também com um mastocitoma cutâneo grau III / alto grau. O declínio clínico do animal e a insistência do proprietário durante a anamnese de que o cão estava marcadamente diferente após o exame citológico realizado em outra clínica, juntamente com eosinofilia e hepatomegalia graves, levantaram a suspeita clínica de SM. O animal faleceu 7 dias depois. A investigação post-mortem confirmou a patologia SM, e o estudo molecular revelou uma deleção de 15 pares de bases no exon 11 do gene c-Kit. Contemplando o baixo número de casos descritos na literatura, o objetivo desta publicação é divulgar características clínicas e laboratoriais de SM canina, levando em consideração informações clínicas descritas em humanos.(AU)

Rare and unknown canine systemic mastocytosis: clinical and laboratory features of an aberrant c-Kit mutation neoplasia / A rara e desconhecida mastocitose sistêmica canina: características clínicas e laboratoriais de uma neoplasia aberrante na mutação c-Kit

Systemic mastocytosis (SM) pathology is extremely rare in canine practice, with insufficient reported data. The knowledge of the clinical behavior of this pathology is scarce. In human medicine, SM has been widely investigated, being defined as a rare hematopoietic disorder by the World Health Organization (2016), within the type of myeloproliferative neoplasms. Herein, we describe a systemic mastocytosis case in a Portuguese Serra-da-Estrela dog, where a cutaneous grade III/high-grade MCT was also diagnosed. The clinical decline of the animal and owner's insistence throughout anamnesis that the dog was markedly different after the cytologic exam performed in another clinic, along with both severe eosinophilia and hepatomegaly, led to the clinical suspicion of SM. The animal passed away 7 days later. Post-morteminvestigation confirmed SM pathology, and a deletion of 15 base pairs change on c-Kit gene exon 11 was identified. Contemplating the low number of cases described in the literature, this publication aims to disclose clinical and laboratory features of rare and poorly described canine SM, taking into consideration human outcomes described in the literature.(AU)

A patologia da mastocitose sistêmica (SM) é extremamente rara na prática clínica canina, com escassos casos descritos na literatura científica. O conhecimento do comportamento clínico desta patologia é mínimo. Na medicina humana, a SM tem sido amplamente investigada, sendo definida como uma doença hematopoiética rara pela Organização Mundial da Saúde (2016), dentro do tipo de neoplasias mieloproliferativas. Descrevemos aqui um caso de mastocitose sistêmica num cão Serra-da-Estrela português, diagnosticado também com um mastocitoma cutâneo grau III / alto grau. O declínio clínico do animal e a insistência do proprietário durante a anamnese de que o cão estava marcadamente diferente após o exame citológico realizado em outra clínica, juntamente com eosinofilia e hepatomegalia graves, levantaram a suspeita clínica de SM. O animal faleceu 7 dias depois. A investigação post-mortem confirmou a patologia SM, e o estudo molecular revelou uma deleção de 15 pares de bases no exon 11 do gene c-Kit. Contemplando o baixo número de casos descritos na literatura, o objetivo desta publicação é divulgar características clínicas e laboratoriais de SM canina, levando em consideração informações clínicas descritas em humanos.(AU)

Gastrointestinal stromal tumour of the rectum and intestinal obstruction: case report.

We report the case of a 75-year-old female patient with a big tumour in the lower rectum with intestinal obstruction and lower gastrointestinal bleeding history who underwent a tumour biopsy under laparotomy and end colostomy at another hospital in Peru. She came to our institution for clinical evaluation with a pathology result of a rectal gastrointestinal stromal tumour. An extra elevator abdominoperineal resection was performed with tumour-free margins. The histology confirmed a high-grade (G2) rectal gastrointestinal stromal tumour with a mitotic index of 27/50. DOC-1 (+) and CD117 (+) in immunohistochemistry. Genomic DNA was extracted from the paraffin-fixed tumour sample, and c.1504_1509dupGCCTAT (p.Ala502_Tyr503dup) mutation was detected in exon 9 of the KIT gene. Imatinib 400 mg per day for 3 years was indicated as adjuvant treatment. Currently, she has a disease-free survival of 12 months.

Explant culture: A relevant tool for the study of telocytes.

Telocytes are cells present in the stroma of various tissues including the prostate. The detection of telocytes is still very much dependent on obtaining ultrastructural data that show the presence of telopodes, which are cytoplasmic projections that alternate between dilated regions, the podoms, and thin segments, the podomers. These structures are the distinctive characteristics of the telocytes. Thus, in vitro assays are important for the study of telocytes, which are more easily identified in culture, which also enables the experimental manipulation of these cells. The isolation of telocytes per se does not allow the analysis of the behavior of these cells in relation to other cell types in a given organ. In this sense, in the prostate, explants could be a useful tool for the study of telocytes. The present study obtained prostatic explants and evaluated the influence of recombinant proteins, scattering factor (SCF) and stromal-derived factor 1 (SDF-1), which could impact on the migration of CD34-positive cells. Telocytes migrate out of explants and SDF-1 stimulates the proliferation and formation of telocyte networks in vitro. Telocytes are not smooth muscle cell progenitors in the prostate; on the contrary, they are CD90- and CD44-negative cells and, hence, have limited progenitor capacity. The present study demonstrated that explants are useful tools to elucidate the nature of telocytes and their functions.

[Jejunal gastrointestinal stromal tumor (GIST): clinical case]. / Tumor del estroma gastrointestinal (GIST) de yeyuno: caso clínico.

Background: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. It is exposed a clinical case of jejunal GIST from a second-level hospital in Mexico. Clinical case: Female patient of 76 years, with history of tobacco use (two cigarettes per day for 25 years), that is referred to General Surgery due to a four month evolution of symptoms, characterized by abdominal pain, hyporexia and urinary symptomatology. Physical examination revealed a non-pulsatile, solid, non-mobile, non-painful mass in the hypogastrium and right iliac fossa of approximately 15 cm in length. Ovarian tumor was ruled out, since CEA and CA-125 tumor markers were negative. Abdominopelvic ultrasound was performed and reported a solid tumor with cystic spaces inside. CT reported a solid tumor of 9.5 x 2.5 x 8.3 cm, with defined edges, multilobed, presence of some calcifications in its wall that did not show enhancement with the use of contrast media. Patient underwent exploratory laparotomy and it was found a jejunal tumor, 210 cm from the ligament of Treitz. Immunohistochemistry reported positivity to KIT and DOG1, confirming the diagnosis of GIST. Conclusion: GISTs are uncommon entities. Their clinical presentation is insidious and the preoperative diagnosis is complex due to the need for biopsy. The treatment is surgery, but tyrosine kinase inhibitors should be administered. Even in patients with response to treatment, follow-up is mandatory due to the risk of recurrence.

Introducción: los tumores del estroma gastrointestinal (GIST) son los tumores mesenquimatosos más comunes del tracto gastrointestinal. Se expone un caso clínico de GIST en yeyuno que se presentó en un hospital de segundo nivel en México. Caso clínico: femenino de 76 años, con antecedente de tabaquismo (dos cigarros diarios durante 25 años), referida a Cirugía General por cuadro de cuatro meses de evolución (dolor abdominal tipo cólico en hipogastrio, hiporexia y sintomatología urinaria). A la exploración física, se le detectó tumor no pulsátil, sólido, no móvil, no doloroso, adherido a planos profundos en hipogastrio y fosa ilíaca derecha de aprox. 15 cm de longitud. Se descartó tumor ovárico al resultar negativos los marcadores tumorales ACE y CA-125. Se realizó ultrasonido abdominopélvico que reportó imagen de tumoración sólida con zonas quísticas en su interior. La TC reportó tumoración sólida, de bordes definidos, multilobulada con algunas calcificaciones milimétricas en su pared de 9.5 x 2.5 x 8.3 cm y sin realce al administrar medio de contraste. La paciente se sometió a laparotomía exploradora y se encontró tumoración adherida a yeyuno a 210 cm del ligamento de Treitz. El tumor fue positivo a KIT y DOG1, lo que confirmó el diagnóstico de GIST de patrón fusiforme. Conclusión: los GIST son poco frecuentes. Su presentación clínica es insidiosa y el diagnóstico preoperatorio es complejo debido a la toma de biopsia. El tratamiento continúa siendo la cirugía, pero se deben administrar inhibidores de la tirosina cinasa. Incluso en pacientes con respuesta favorable al tratamiento, se recomienda seguimiento por riesgo de recidiva.

Bilateral canine seminoma with ocular metastasis: histochemical and immunohistochemical characterization

A 10-year old male dog was examined due to a buphthalmia in the left eye and a nodule in the two testicles. Due to the limited resources of the owner and loss of visual acuity of the patient, the enucleation and castration were chosen as treatment. Microscopic analysis of the testicular tissue revealed neoplastic germ cells. Morphologically, neoplastic cells were characterized by distinct cell borders, scarce and eosinophilic cytoplasm, large round nucleus, with thick chromatin and a prominent nucleolus. Binucleated and multinucleated neoplastic cells were also frequently observed. In 10 high powerfields (400x), 62 typical and atypical mitosis were counted. Similar neoplastic cells were identified within the vessels of theretina, sclera and in the sub-epithelial conjunctive tissue of the eyelid. The neoplastic cells observed in the testicle and in the eye were positive for PAS. By immunochemistry technique was identified an intense immunostaining of the neoplastic cells for Vimentin and Ki-67 in both testicular and ocular tissue. While, discrete immunoreactivity was identified to c-KIT from the neoplastic cells in both organs. Based on morphological, histochemical and immunohistochemical analysis, it was possible to characterize the ocular lesion as seminoma metastasis.