Adult T-Cell Leukemia/Lymphoma in a Caucasian Patient After Sexual Transmission of Human T-Cell Lymphotropic Virus Type 1.

Adult T-cell leukemia/lymphoma (ATLL), a T-cell neoplasm caused by human T-cell lymphotropic virus type 1 (HTLV-1), develops in the majority of cases in individuals who were infected with HTLV-1 as young children, by their mother during prolonged breastfeeding. We report the case of a Caucasian French man, whose parents were HTLV-1-seronegative and who developed ATLL after HTLV-1 sexual transmission by a Cameroonian woman. This hypothesis was corroborated by genotyping of the patient's virus, which revealed an HTLV-1B strain, found only in Central Africa, especially in Cameroon. Thus, ATLL may develop after HTLV-1 infection during adulthood, outside breastfeeding.

GLI2-mediated melanoma invasion and metastasis.

BACKGROUND: The transforming growth factor-beta (TGF-beta) pathway, which has both tumor suppressor and pro-oncogenic activities, is often constitutively active in melanoma and is a marker of poor prognosis. Recently, we identified GLI2, a mediator of the hedgehog pathway, as a transcriptional target of TGF-beta signaling. METHODS: We used real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blotting to determine GLI2 expression in human melanoma cell lines and subsequently classified them as GLI2high or as GLI2low according to their relative GLI2 mRNA and protein expression levels. GLI2 expression was reduced in a GLI2high cell line with lentiviral expression of short hairpin RNA targeting GLI2. We assessed the role of GLI2 in melanoma cell invasiveness in Matrigel assays. We measured secretion of matrix metalloproteinase (MMP)-2 and MMP-9 by gelatin zymography and expression of E-cadherin by western blotting and RT-PCR. The role of GLI2 in development of bone metastases was determined following intracardiac injection of melanoma cells in immunocompromised mice (n = 5-13). Human melanoma samples (n = 79) at various stages of disease progression were analyzed for GLI2 and E-cadherin expression by immunohistochemistry, in situ hybridization, or RT-PCR. All statistical tests were two-sided. RESULTS: Among melanoma cell lines, increased GLI2 expression was associated with loss of E-cadherin expression and with increased capacity to invade Matrigel and to form bone metastases in mice (mean osteolytic tumor area: GLI2high vs GLI2low, 2.81 vs 0.93 mm(2), difference = 1.88 mm(2), 95% confidence interval [CI] = 1.16 to 2.60, P < .001). Reduction of GLI2 expression in melanoma cells that had expressed high levels of GLI2 substantially inhibited both basal and TGF-beta-induced cell migration, invasion (mean number of Matrigel invading cells: shGLI2 vs shCtrl (control), 52.6 vs 100, difference = 47.4, 95% CI = 37.0 to 57.8, P = .024; for shGLI2 + TGF-beta vs shCtrl + TGF-beta, 31.0 vs 161.9, difference = -130.9, 95% CI = -96.2 to -165.5, P = .002), and MMP secretion in vitro and the development of experimental bone metastases in mice. Within human melanoma lesions, GLI2 expression was heterogeneous, associated with tumor regions in which E-cadherin was lost and increased in the most aggressive tumors. CONCLUSION: GLI2 was directly involved in driving melanoma invasion and metastasis in this preclinical study.

The contribution of high-resolution ultrasonography in preoperatively detecting sentinel-node metastases in melanoma patients.

To evaluate the ability of high-resolution ultrasonography (hrUS) to detect sentinel-node (SN) melanoma metastases preoperatively before sentinel-node biopsy (SNB), to define hrUS resolution, and to evaluate which US criteria should be used. During a 6.5-year period, 131 consecutive patients with 132 >or=1-mm thick or ulcerated cutaneous melanomas, who were followed up at a single center, were enrolled. All patients underwent preoperative regional lymph-node hrUS and SNB. We used the recently evaluated ultrasonographic stringent and nonstringent hrUS criteria to detect SN metastases. Sizes of the SN metastatic deposits were measured under light microscopy. Thirty-five (27%) patients had a positive SNB. HrUS identified only three positive SNs as being metastatic. Sensitivity and specificity using stringent criteria were 8.8% [95% confidence interval (CI, 2.3-24.8%) and 95.9% (95% CI, 89.3-98.7%)], respectively. Positive-predictive value was 42.9% (95% CI, 11.9-79.9%). The nonstringent criteria provided four additional true-positive results, but lowered specificity (89.8%; 95% CI, 81.6-94.7%) with no significant improvement in sensitivity (20.6%; 95% CI, 9.3-38.4%). Positive-predictive value using nonstringent criteria was 41.2% (95% CI, 19.3-66.4%). HrUS failed to detect all metastatic deposits <5 mm in diameter. HrUS assessment of early-stage melanomas cannot replace surgical SNB. Owing to its low positive-predictive value, hrUS was unable to identify patients who would have to proceed directly to completion lymphadenectomy.

A clonogenic bone marrow progenitor specific for macrophages and dendritic cells.

Macrophages and dendritic cells (DCs) are crucial for immune and inflammatory responses and belong to a network of cells that has been termed the mononuclear phagocyte system (MPS). However, the origin and lineage of these cells remain poorly understood. Here, we describe the isolation and clonal analysis of a mouse bone marrow progenitor that is specific for monocytes, several macrophage subsets, and resident spleen DCs in vivo. It was also possible to recapitulate this differentiation in vitro by using treatment with the cytokines macrophage colony-stimulating factor and granulocyte-macrophage colony-stimulating factor. Thus, macrophages and DCs appear to renew from a common progenitor, providing a cellular and molecular basis for the concept of the MPS.