细胞的增殖和分化受一系列调节因子的调控。许多事实表明,细胞增殖调控过程中任何一个环节的失调,都将引起细胞的增殖异常,甚至导致细胞的恶性转化。目前,除人们熟知的对细胞生长呈正调节作用的生长因子外,已从不同细胞或其条件培养液中陆续分离出一些对细胞生长呈负调节作用的生长抑制因子。我们近年来将多种肿瘤细胞与哺乳类网织红细胞杂交以分析其杂交子代细胞的恶性表型,所得到的结果一致表明,杂交细胞的恶性程度均明显降低。这些结果提示,在哺乳类网织红细胞中可能存在对细胞增殖呈负调节作用的 The proliferation and differentiation of cells are regulated by a series of regulatory factors. Many facts indicate that any disorder in the regulation of cell proliferation will cause abnormal cell proliferation and even lead to malignant transformation of cells. At present, in addition to well-known growth factors that positively regulate cell growth, growth inhibitory factors that negatively regulate cell growth have been successively isolated from different cells or their conditioned media. In recent years, we have hybridized a variety of tumor cells with mammalian reticulocytes to analyze the malignant phenotypes of hybrid progeny cells. The results obtained consistently show that the degree of malignancy of hybrid cells is significantly reduced. These results suggest that there may be negative regulation of cell proliferation in mammalian reticulocytes.