Characterization of tumorigenic features of uterine leiomyoma

用该子宫肌瘤体外实验系统研究了促性腺激素释放激素类似物(GnRH)治疗子宫肌瘤过程中子宫肌瘤缩小的机制。在此之前，我们证明了来自肌瘤的细胞形成球状聚集体，我们称之为球状聚集体(BLAS)。由于子宫肌瘤细胞的球状聚集似乎与子宫肌瘤的体内特征相似，这使得我们能够评估目前用于子宫肌瘤化疗的GnRH类似物的有效性。结果表明，GnRH类似物的加入使肌瘤细胞球状聚集的形态消失。GnRH与培养的子宫肌瘤细胞直接结合，GnRH受体的存在以及GnRH在子宫肌瘤细胞的表达。此外，加入小剂量和短剂量的促性腺激素释放激素类似物可刺激…细胞的增殖大剂量GnRH类似物长期治疗可抑制子宫肌瘤细胞周期相关基因的表达，但对晚期细胞周期相关基因的表达无明显影响。这些结果提示，GnRH类似物可能直接调节子宫肌瘤的生长，子宫肌瘤的体内系统有助于评价目前用于子宫肌瘤化疗的药物的有效性。肥大细胞广泛分布于大多数人类组织和肿瘤中，包括子宫肌瘤。GnRHa最近被应用于治疗子宫肌瘤。为阐明MC在子宫肌瘤中的作用，我们分析了肌瘤中MC的数量与组织学特征的关系，并比较了未治疗的肌瘤和GnRHa治疗的肌瘤中MC的数量。结果显示，未经治疗的子宫肌瘤中MC数量广泛分布，但肌瘤中MC较多，胶原基质较少，细胞密度较高，T2加权像高信号。此外，GnRHa高度缩小的肌瘤含有大量的MC，GnRHa不增加这些MC，但在治疗前这些MC在肌瘤中已经存在。结果提示，MC可能与肌瘤的增殖活性有关，并在GnRHa治疗中起到作用。PR在UL中的表达与月经周期的各个阶段无关。PR在CL、UMP和BL3种肿瘤中也有表达，但在BL3种肿瘤中ER和PR的表达变化不同。与这些肿瘤相比，LMS中ER和PR的表达均明显降低。RT-PCR扩增ER和PR转录本的结果与免疫组织化学结果一致。LMS中Ki-67阳性细胞数显著高于UMP、BL、CL和UL，P53免疫反应较弱

The mechanisms regarding to the shrinkage of leiomyoma during the treatment with GnRH analogue (GnRH) analogue have been investigated using this in vitro system of uterine leiomyoma. Previously, we demonstrated that the cells from leiomyoma formed ball-like aggregations which we named "ball-like aggregations (BLAs)". Since the ball-like aggregations of cells from leiomyoma seem to be close to the features of uterine leiomyoma in vivo, this allows us to evaluate the efficiency of GnRH analogue currently used for chemotherapy of uterine leiomyomas. The results showed that the addition of GnRH analogue caused disappearance of the figure of the ball-like aggregations of cells from leiomyoma. The results also showed that GnRH directly binds to the cultured cells from leiomyoma and that the existence of GnRH receptor as well as GnRH expression in the cells from leiomyomas. Furthermore, the addition of small and short doses of GnRH analogue stimulates the proliferation of smooth muscle cells … More of leiomyoma, but the late G1 phase cell cycle related genes' expression were suppressed by the addition of high doses GnRH analogue for long treatment. These results suggested that GnRH analogue may directly regulate the growth of uterine leiomyomas, and that the in vivo system of uterine leiomyoma is useful to evaluate the efficiency of drugs currently used for chemotherapy of uterine leiomyomas. Mast cells (MCs) are widely distributed in most human tissues and neoplasms, including a leiomyoma. GnRHa has been recently applied for the treatment of a leiomyoma. To elucidate the role of MCs in a leiomyoma, the relationship between the number of MCs in leiomyomas and the histological features was analyzed, furthermore, the number of MCs in untreated leiomyomas was compared with that of MCs in the leiomyomas treated with GnRHa. The results showed that the number of MCs in untreated leiomyomas was widely distributed, but there were more Mcs in leiomyomas with fewer collagen matrix, with higher cellularity, and with high intensity of T2 weighted MR image. In addition, the leiomyomas which had highly shrinked with GnRHa contained a larger number of MCs, and these MCs were not increased by GnRHa, but before therapy they had existed in the leiomyomas The findings suggest that MCs may associated with prolierative activity of leiomyoma and play a role in shirnkage of the size in GnRHa therapy.Both ER and PR are immunohistochemically expressed in all ULs. PR was definitely experssed in UL irrespective of the phase of the menstrual cycle. This staining pattern of PR was also observed in CL,UMP and BL,although BL showed variable staining for ER.Compared to these tumors, the expression of both ER and PR was markedly reduced in LMS.The results of ER and PR transcripts by RT-PCR amplification were compatible with those of immunohistochemistry. The number of Ki-67 positive cells in LMS was extraordinary and significantly higher than in UMP,BL,CL and UL.P53 immunoreactivity was seen Less