细胞生长因子是指通过与细胞膜表面受体特异性结合来刺激细胞增殖,影响细胞分化的一类多肽物质。严格说来,细胞生长因子不属于内分泌激素,它们只能对邻近的或自身细胞发生作用。例如,血浆中存在的细胞生长因子主要与损伤的生理性愈合有关。我们知道,正常二倍体细胞的体外培养需要培液中血清成分的存在,而肿瘤细胞的培养对培液中血清成分的需要明显减少,或不需要血清成分。这是因为 Cell growth factor refers to a class of polypeptide substances that stimulate cell proliferation through specific binding to receptors on the surface of cell membranes and affect cell differentiation. Strictly speaking, cell growth factors are not endocrine hormones; they can only act on adjacent or own cells. For example, the presence of cell growth factors in plasma is mainly related to the physiological healing of damage. We know that in vitro culture of normal diploid cells requires the presence of serum components in the culture fluid, whereas the culture of tumor cells requires significantly less serum components in the culture fluid, or does not require serum components. This is because