Pongpudpunth Marinya, Bhawan Jag, Al-Natour Sahar H, Mahalingam Meera
Dermatopathology Section, Department of Dermatology, Boston University School of Medicine, MA 02118, USA.
Am J Dermatopathol. 2010 Aug;32(6):574-7. doi: 10.1097/DAD.0b013e3181cc8c7c.
Recently, we found discrete foci of melanin deposits but diffuse positivity with MART-1/MelanA in a neurofibroma from a patient with neurofibromatosis type 1 (NF1).
To ascertain the frequency of cells that had the capacity for melanogenesis in neurofibromas from patients with NF1. Given that nestin-positive mammalian neural crest cells are potentially capable of forming neurons and Schwann cells, an additional aim was to assess the proportion of nestin-positive cells to test our hypothesis that the frequency of melanogenic cells is a direct function of the stem cell population harbored.
Antibodies used included MART-1/MelanA, a transmembrane protein that is present in normal melanocytes and nestin, a type VI intermediate filament protein present in neuronal precursor cells. Seventy-two neurofibromas from 18 patients (10 with multiple and 8 with single) with NF1 were studied. The control group included solitary sporadic neurofibromas from 24 patients.
Expression of markers was as follows: MART-1/MelanA staining in 5/72 cases (7%) from neurofibromas from 2/18 patients with NF1 versus 0/24 (0%) in the sporadic neurofibroma group (P = 0.33) and nestin in 33/72 cases (49%) from neurofibromas from 9/18 patients with NF1 versus 3/24 (12.5%) in the sporadic neurofibroma group (P = 0.003). All 5 cases of neurofibroma that were MART-1/MelanA positive also demonstrated positive staining with nestin.
Although we found no difference in melanogenic cells in neurofibromas from patients with NF1 relative to the sporadic group, we did find a significant population of nestin-positive progenitor cells in neurofibromas from patients with NF1. In light of recent evidence linking formation of neural neoplasms such as neurofibroma to alterations in the self-renewal program of stem/progenitor cells, our findings reinforce the potentially tumorigenic role of nestin-positive progenitor cells in neurofibromas from patients with NF1.
最近，我们在一名1型神经纤维瘤病（NF1）患者的神经纤维瘤中发现了离散的黑色素沉积灶，但MART-1/MelanA呈弥漫性阳性。
确定NF1患者神经纤维瘤中具有黑色素生成能力的细胞频率。鉴于巢蛋白阳性的哺乳动物神经嵴细胞可能能够形成神经元和施万细胞，另一个目的是评估巢蛋白阳性细胞的比例，以检验我们的假设，即黑色素生成细胞的频率是所包含干细胞群体的直接函数。
使用的抗体包括MART-1/MelanA，一种存在于正常黑素细胞中的跨膜蛋白，以及巢蛋白，一种存在于神经元前体细胞中的VI型中间丝蛋白。研究了18例NF1患者（10例多发，8例单发）的72个神经纤维瘤。对照组包括24例患者的孤立性散发性神经纤维瘤。
标志物表达情况如下：NF1患者的2/18例神经纤维瘤中有5/72例（7%）MART-1/MelanA染色阳性，而散发性神经纤维瘤组为0/24例（0%）（P = 0.33）；NF1患者的9/18例神经纤维瘤中有33/72例（49%）巢蛋白染色阳性，而散发性神经纤维瘤组为3/24例（12.5%）（P = 0.003）。所有5例MART-1/MelanA阳性的神经纤维瘤也显示巢蛋白染色阳性。
虽然我们发现NF1患者的神经纤维瘤中黑色素生成细胞与散发性组相比没有差异，但我们确实在NF1患者的神经纤维瘤中发现了大量巢蛋白阳性的祖细胞。鉴于最近有证据表明神经纤维瘤等神经肿瘤的形成与干细胞/祖细胞自我更新程序的改变有关，我们的发现强化了巢蛋白阳性祖细胞在NF1患者神经纤维瘤中潜在的致瘤作用。
