UBE2C promotes leptomeningeal dissemination and is a therapeutic target in brain metastatic disease.

Background: Despite current improvements in systemic cancer treatment, brain metastases (BM) remain incurable, and there is an unmet clinical need for effective targeted therapies. Methods: Here, we sought common molecular events in brain metastatic disease. RNA sequencing of thirty human BM identified the upregulation of UBE2C, a gene that ensures the correct transition from metaphase to anaphase, across different primary tumor origins. Results: Tissue microarray analysis of an independent BM patient cohort revealed that high expression of UBE2C was associated with decreased survival. UBE2C-driven orthotopic mouse models developed extensive leptomeningeal dissemination, likely due to increased migration and invasion. Early cancer treatment with dactolisib (dual PI3K/mTOR inhibitor) prevented the development of UBE2C-induced leptomeningeal metastases. Conclusions: Our findings reveal UBE2C as a key player in the development of metastatic brain disease and highlight PI3K/mTOR inhibition as a promising anticancer therapy to prevent late-stage metastatic brain cancer.

Development of Dl1.72, a Novel Anti-DLL1 Antibody with Anti-Tumor Efficacy against Estrogen Receptor-Positive Breast Cancer.

The Notch-signaling ligand DLL1 has emerged as an important player and promising therapeutic target in breast cancer (BC). DLL1-induced Notch activation promotes tumor cell proliferation, survival, migration, angiogenesis and BC stem cell maintenance. In BC, DLL1 overexpression is associated with poor prognosis, particularly in estrogen receptor-positive (ER+) subtypes. Directed therapy in early and advanced BC has dramatically changed the natural course of ER+ BC; however, relapse is a major clinical issue, and new therapeutic strategies are needed. Here, we report the development and characterization of a novel monoclonal antibody specific to DLL1. Using phage display technology, we selected an anti-DLL1 antibody fragment, which was converted into a full human IgG1 (Dl1.72). The Dl1.72 antibody exhibited DLL1 specificity and affinity in the low nanomolar range and significantly impaired DLL1-Notch signaling and expression of Notch target genes in ER+ BC cells. Functionally, in vitro treatment with Dl1.72 reduced MCF-7 cell proliferation, migration, mammosphere formation and endothelial tube formation. In vivo, Dl1.72 significantly inhibited tumor growth, reducing both tumor cell proliferation and liver metastases in a xenograft mouse model, without apparent toxicity. These findings suggest that anti-DLL1 Dl1.72 could be an attractive agent against ER+ BC, warranting further preclinical investigation.

Actin stress fiber organization promotes cell stiffening and proliferation of pre-invasive breast cancer cells.

Studies of the role of actin in tumour progression have highlighted its key contribution in cell softening associated with cell invasion. Here, using a human breast cell line with conditional Src induction, we demonstrate that cells undergo a stiffening state prior to acquiring malignant features. This state is characterized by the transient accumulation of stress fibres and upregulation of Ena/VASP-like (EVL). EVL, in turn, organizes stress fibres leading to transient cell stiffening, ERK-dependent cell proliferation, as well as enhancement of Src activation and progression towards a fully transformed state. Accordingly, EVL accumulates predominantly in premalignant breast lesions and is required for Src-induced epithelial overgrowth in Drosophila. While cell softening allows for cancer cell invasion, our work reveals that stress fibre-mediated cell stiffening could drive tumour growth during premalignant stages. A careful consideration of the mechanical properties of tumour cells could therefore offer new avenues of exploration when designing cancer-targeting therapies.

Fatores de risco associados à tuberculose pulmonar paucibacilar em pacientes atendidos em centros de saúde da cidade do Rio de Janeiro, Brasil / Risk factors for pulmonary tubercolosis among negative sputum smear patientes attended in community health centers in Rio de Janeiro, Brasil

Objetivo: identificar fatores de risco associados à ocorrência de tuberculose pulmonar (TBP) paubacilar. Métodos: estudo transversal avaliando o resultado dos exames bacteriológicos de pacientes suspeitos de TBP atendidos em onze Centros Municipais de Saúde (CMS) na cidade do Rio de Janeiro, Brasil. Resultados: entre 1°. de Julho e 31 de Dezembro de 1996 foram entrecistados 423 pacientes com diagnóstico clínico-radiológico de TBP ativa. Noventa e quatro por cento (397/423) forneceram pelo menos duas amostras de escarro espontâneo para análise. A cultura foi positiva para Mycobacterium tuberculosis em 84% (333/397), com baciloscopia positiva em 64% (213/333) e baciloscopia negativa em 36% (121/333). Não se observou associação entre lesão pulmonar paucibacilar e gênero, vacinação com BCG, tempo de sintomas respiratórios, admissão prévia em prisão ou em asilos nos últimos 24 meses, comportamento sexual, uso de droga injetável, tratamento anti-TB no passado, contado com paciente tuberculoso pulmonar bacilífero nos últimos 12 meses, condições de moradia e residir em determinada área pragmática. Entretanto, a lesão pulmonar paucibacilar esteve associada significamente a escolaridade superior de 4 anos (1,87; 0,98-3,55; p=0,05), admissão prévia em hospital nos últimos 24 meses (2,53; 1,39-4,60; p=0,001) e sorologia positiva para infecção pelo vírus da imunodeficiência humana (HIV) (4,48;1,74-11,81; p=0,006). Conclusão: tuberculose pulmonar paubacilar deve ser considerada um problema em centros urbanos com elevada co-infecção /TB e HIV, onde a cultura para micobactéria e a testagem anti-HIV dvem ser disponibilizados para os pacientes com tais características.

Objective: to identify risk factors for negative sputum acid -fast bacilli smear among pulmonary tuberculosis (PTB) patients in CHC. Methods: cross sectional study, performed through bacteriological evaluation of mear negative/culture positive PTB cases attended in eleven Community Health Centers (CHC) in Rio de Janeiro City, Brazil. Results: from July 1st to December 31th, 1996, 423 patients with active PTB were interviewed and 397 had their spontaneous sputum evaluated. Afterwards 333 patients presented positive culture results for mycobacterium tuberculosis and among them 121 (36.2%) were smear negative. The agreement results (kappa value) between the first and the second sputa for smear acid-fast bacilli was moderate (0.49) but for culture was fair (0.31). No statistically significant association were identified among smear negative/culture positive results and be following variables: gender, BCG vaccionation, length of respiratory symptoms, previous admission at jails or at shelters in the previous 24 months, sexual behavior, intravenous drug use, anti-TB treatment in the past, contact with infectious PTB patients in the previous 12 months, living conditions and planning City Areas residence. Nevertheless, smear negative/culture positive PTB were observed as associated to 4.60; p=0.001) and, seropositivity for human immunodeficiency virus (HIV) (4.48; 1.74-11.81; p=0.006). Conclusion: Smear negative PTB should be considered a significant clinical problem, particularly in settings affected by dual HIV/TB epidemic. A wider availability of TB culture facilities should be pursued as well HIV testing for PTB suspect smear negative. So, to improve TB control in developing countries is urgently needed to update guidelines by both TB Control Program and AIDS Control Program.

Sensitivity of amplicor mtb on direct detection of Mycobacterium tuberculosis in smear-negative specimens from outpatients in Rio de Janeiro

We evaluated the performance of the AMPLICOR MTB assay for detection of M. tuberculosis in clinical specimens obtained from 98 smear-negative tuberculous patients (43 with positive and 55 with negative culture results). The sensitivity of the AMPLICOR MTB was 44.9(per cent) (44/98) and that of culture was 43.8(per cent) (43/98). No significant difference was observed between the results obtained by AMPLICOR MTB and by culture. We conclude that amplification assays could be used for testing smear-negative specimens because a rapid diagnosis will benefit those patients.