Smoothened (SMO) receptor mutations dictate resistance to\ua0vismodegib in basal cell carcinoma

Basal cell carcinomas (BCCs) and a subset of medulloblastomas are characterized by loss- of-function mutations in the tumor suppressor gene, PTCH1. PTCH1 normally functions by repressing the activity of the Smoothened (SMO) receptor. Inactivating PTCH1 mutations result in constitutive Hedgehog pathway activity through uncontrolled SMO signaling. Tar- geting this pathway with vismodegib, a novel SMO inhibitor, results in impressive tumor regression in patients harboring genetic defects in this pathway. However, a secondary mutation in SMO has been reported in medulloblastoma patients following relapse on vis- modegib to date. This mutation preserves pathway activity, but appears to confer resis- tance by interfering with drug binding. Here we report for the first time on the molecular mechanisms of resistance to vismodegib in two BCC cases. The first case, showing progression after 2 months of continuous vismo- degib (primary resistance), exhibited the new SMO G497W mutation. The second case, showing a complete clinical response after 5 months of treatment and a subsequent pro- gression after 11 months on vismodegib (secondary resistance), exhibited a PTCH1 nonsense mutation in both the pre- and the post-treatment specimens, and the SMO D473Y mutation in the post-treatment specimens only. In silico analysis demonstrated that SMOG497W undergoes a conformational rearrangement resulting in a partial obstruc- tion of the protein drug entry site, whereas the SMO D473Y mutation induces a direct effect on the binding site geometry leading to a total disruption of a stabilizing hydrogen bond network. Thus, the G497W and D473Y SMO mutations may represent two different mech- anisms leading to primary and secondary resistance to vismodegib, respectively

An Expanded Peripheral T Cell Population to a Cytotoxic T Lymphocyte (Ctl)-Defined, Melanocyte-Specific Antigen in Metastatic Melanoma Patients Impacts on Generation of Peptide-Specific Ctls but Does Not Overcome Tumor Escape from Immune Surveillance in Metastatic Lesions

It is not known if immune response to T cell–defined human histocompatibility leukocyte antigen (HLA) class I–restricted melanoma antigens leads to an expanded peripheral pool of T cells in all patients, affects cytotoxic T lymphocyte (CTL) generation, and correlates with anti-tumor response in metastatic lesions. To this end, a limiting dilution analysis technique was developed that allowed us to evaluate the same frequency of peptide-specific T cells as by staining T cells with HLA–peptide tetrameric complexes. In four out of nine patients, Melan-A/Mart-127–35–specific CTL precursors (CTLp) were ≥1/2,000 peripheral blood lymphocytes and found mostly or only in the CD45RO+ memory T cell subset. In the remaining five patients, a low (<1/40,000) peptide-specific CTLp frequency was measured, and the precursors were only in the CD45RA+ naive T cell subset. Evaluation of CTL effector frequency after bulk culture indicated that peptide-specific CTLs could be activated in all patients by using professional antigen-presenting cells as dendritic cells, but CTLp frequency determined the kinetics of generation of specificity and the final number of effectors as evaluated by both limiting dilution analysis and staining with HLA-A*0201–Melan-A/Mart-1 tetrameric complexes. Immunohistochemical analysis of 26 neoplastic lesions from the nine patients indicated absence of tumor regression in most instances, even in patients with an expanded peripheral T cell pool to Melan-A/Mart-1 and whose neoplastic lesions contained a high frequency of tetramer-positive Melan-A/Mart-1–specific T cells. Furthermore, frequent lack of a “brisk” or “nonbrisk” CD3+CD8+ T cell infiltrate or reduced/absent Melan-A/Mart-1 expression in several lesions and lack of HLA class I antigens were found in some instances. Thus, expansion of peripheral immune repertoire to Melan-A/Mart-1 takes place in some metastatic patients and leads to enhanced CTL induction after antigen-presenting cell–mediated selection, but, in most metastatic lesions, it does not overcome tumor escape from immune surveillance

A functional gene expression analysis in epithelial sinonasal cancer: Biology and clinical relevance behind three histological subtypes

Epithelial sinonasal cancers (SNCs) are rare diseases with overlapping morphological features and a dismal prognosis. We aimed to investigate the expression differences among the histological subtypes for discerning their molecular characteristics. We selected 47 SNCs: (i) 21 nonkeratinizing squamous cell carcinomas (NKSCCs), (ii) 13 sinonasal neuroendocrine cancers (SNECs), and (iii) 13 sinonasal undifferentiated cancers (SNUCs). Gene expression profiling was performed by DASL (cDNA-mediated annealing, selection, extension, and ligation) microarray analysis with internal validation by quantitative RT-PCR (RT-qPCR). Relevant molecular patterns were uncovered by sparse partial-least squares discriminant analysis (sPLS-DA), microenvironment cell type (xCell), CIBERSORT, and gene set enrichment (GSEA) analyses. The first two sPLS-DA components stratified samples by histological subtypes. xCell highlighted increased expression of immune components (CD8 + effector memory cells, in SNUC) and \u201cother cells\u201d: keratinocytes and neurons in NKSCC and SNEC, respectively. Pathway enrichment was observed in NKSCC (six gene sets, proliferation related), SNEC (one gene set, pancreatic \u3b2-cells), and SNUC (twenty gene sets, some of them immune-system related). Major neuroendocrine involvement was observed in all the SNEC samples. Our high-throughput analysis revealed a good diagnostic ability to differentiate NKSCC, SNEC, and SNUC, but indicated that the neuroendocrine pathway, typical and pathognomonic of SNEC is also present at lower expression levels in the other two histological subtypes. The different and specific profiles may be exploited for elucidating their biology and could help to identify prognostic and therapeutic opportunities

Gene expression profiling of advanced ovarian cancer: characterization of a molecular signature involving fibroblast growth factor 2

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Self-Assembled Nanomicelles as Curcumin Drug Delivery Vehicles: Impact on Solitary Fibrous Tumor Cell Protein Expression and Viability

Solitary fibrous tumors (SFTs) are rare soft tissue sarcomas that rely on several epithelial-mesenchymal transition (EMT) protein regulators for invasion/metastatic progression. Curcumin (CUR) has several pharmacological activities, including anticancer activity and the ability to suppress the EMT process. However, poor absorption, rapid metabolism, and side effects at high doses limit the clinical applications of CUR. Here we present the results obtained by treating SFT cells with free CUR and three different CUR-loaded nanomicelles (NMs), each of which has its surface decorated with different ligands. All CUR-loaded NMs were more efficient in suppressing SFT cell viability and expression of EMT markers than CUR alone. Combined treatments with the pan-histone deacetylase dual inhibitor SAHA revealed a differential ability in inhibiting EMT markers expression and SFT cell invasiveness, depending on the NM-ligand type. Finally, combinations of photodynamic therapy and CUR-loaded NM administrations resulted in almost complete SFT cell viability abrogation 24 h after laser irradiation

Activated Leukocyte Cell Adhesion Molecule Expression and Shedding in Thyroid Tumors

Activated leukocyte cell adhesion molecule (ALCAM, CD166) is expressed in various tissues, cancers, and cancer-initiating cells. Alterations in expression of ALCAM have been reported in several human tumors, and cell adhesion functions have been proposed to explain its association with cancer. Here we documented high levels of ALCAM expression in human thyroid tumors and cell lines. Through proteomic characterization of ALCAM expression in the human papillary thyroid carcinoma cell line TPC-1, we identified the presence of a full-length membrane-associated isoform in cell lysate and of soluble ALCAM isoforms in conditioned medium. This finding is consistent with proteolytically shed ALCAM ectodomains. Nonspecific agents, such as phorbol myristate acetate (PMA) or ionomycin, provoked increased ectodomain shedding. Epidermal growth factor receptor stimulation also enhanced ALCAM secretion through an ADAM17/TACE-dependent pathway. ADAM17/TACE was expressed in the TPC-1 cell line, and ADAM17/TACE silencing by specific small interfering RNAs reduced ALCAM shedding. In addition, the CGS27023A inhibitor of ADAM17/TACE function reduced ALCAM release in a dose-dependent manner and inhibited cell migration in a wound-healing assay. We also provide evidence for the existence of novel O-glycosylated forms and of a novel 60-kDa soluble form of ALCAM, which is particularly abundant following cell stimulation by PMA. ALCAM expression in papillary and medullary thyroid cancer specimens and in the surrounding non-tumoral component was studied by western blot and immunohistochemistry, with results demonstrating that tumor cells overexpress ALCAM. These findings strongly suggest the possibility that ALCAM may have an important role in thyroid tumor biology

O uso dos Objetos de Aprendizagem para integrar a diversidade existente na sala de aula de ensino regular do Ensino Fundamental

A pesquisa apresenta uma revisão bibliográfica em relação a importância do uso das tecnologias no âmbito educacional, destacando aqui, os objetos aprendizagem como recurso para mediar o conhecimento dentro da sala de aula, onde a diversidade humana encontra-se presente, buscando promover a interação dos sujeitos envolvidos frente às diferentes necessidades de aprendizagem. Sendo que, a pesquisa apresenta um estudo de caso realizado na Escola Estadual de Ensino Médio Ponche Verde, situada no município de Gravataí o qual pertence a região metropolitana de Porto Alegre, com uma turma de terceiro ano do ensino fundamental I, composta por vinte e oito alunos apresentando diferentes ritmos de aprendizagem, sendo que destes, sete são de inclusão. Os principais resultados obtidos nesta pesquisa referem-se à importância do uso adequado dos objetos de aprendizagem dentro da sala de aula, ressaltando os ganhos pedagógicos quando agregados aos conteúdos formais, de maneira adaptar suas atividades aos ritmos de aprendizagem da turma, favorecendo assim, a interação entre os sujeitos envolvidos