Wolowiec D, Ciszak L, Kosmaczewska A, Bocko D, Teodorowska R, Frydecka I, Kuliczkowski K
Department of Hematology, Medical University, ul. Pasteura 4, PL-50.367 Wroclaw, Poland.
Haematologica. 2001 Dec;86(12):1296-304.
The pathogeny of B-cell chronic lymphocytic leukemia (B-CLL) involves both deregulated proliferation and inhibition of cell death. A particular role in the regulation of these phenomena is played by proteins involved in early G1 phase regulation: pRb kinases: cyclin-dependent kinases (cdk): cdk4 and cdk6 activated by cyclins D, and universal cdk inhibitor p27(Kip1).
We determined by flow cytometry the expression of p27(Kip1) and cyclins D (D2 and D3) in populations of peripheral blood lymphocytes obtained from 59 (for p27(Kip1)) and 31 (for cyclins D) previously untreated patients with B-CLL, and compared them with cell cycle parameters, cell viability and apoptosis in 72-hour cultures in medium only. As a control we determined the expression of p27(Kip1), cyclin D2 and D3 in peripheral blood CD5+/CD19+ lymphocytes from 15 healthy donors.
p27(Kip1) was present in nearly 100% of lymphocytes in all B-CLL populations tested. Its cellular content estimated semiquantitatively by specific mean fluorescence intensity was higher than in normal CD5+/CD19+ lymphocytes, p27(Kip1) was inversely correlated with patients' age and not correlated with other clinical variables, cell cycle or apoptosis rate. Cyclin D2 was detectable in 25 out of 31, and cyclin D3 in all B-CLL lymphocytes populations studied. In contrast to p27Kip1 present in all CD5+/CD19+ lymphocytes, both cyclins were detected only in a subset of neoplastic cells: 27.5 to 87% (mean 51.2) for cyclin D2 and 20.3 to 98% (mean 76.5) for cyclin D3. In cyclin D2- and D3-positive normal CD5+/CD19+ lymphocytes and B-CLL cell populations, cyclin D3 was expressed in a higher percentage of cells than cyclin D2. Both cyclin D2-and cyclin D3-positive fractions of B-CLL cells were, on average, larger than corresponding fractions of normal CD5+/CD19+ peripheral blood lymphocytes.
Our results indicate that cyclin D3 plays an important role in the regulation of normal and neoplastic CD5+/CD19+ cells, and point to the possibility of the exit of a number of CLL lymphocytes from quiescence.
B 细胞慢性淋巴细胞白血病（B-CLL）的发病机制涉及增殖失调和细胞死亡抑制。参与早期 G1 期调控的蛋白质在这些现象的调节中起特殊作用：pRb 激酶、细胞周期蛋白依赖性激酶（cdk）、由细胞周期蛋白 D 激活的 cdk4 和 cdk6，以及通用的 cdk 抑制剂 p27（Kip1）。
我们通过流式细胞术测定了 59 例（针对 p27（Kip1））和 31 例（针对细胞周期蛋白 D）未经治疗的 B-CLL 患者外周血淋巴细胞群体中 p27（Kip1）和细胞周期蛋白 D（D2 和 D3）的表达，并将其与仅在培养基中培养 72 小时后的细胞周期参数、细胞活力和凋亡情况进行比较。作为对照，我们测定了 15 名健康供者外周血 CD5⁺/CD19⁺淋巴细胞中 p27（Kip）、细胞周期蛋白 D2 和 D3 的表达。
在所检测的所有 B-CLL 群体中，近 100%的淋巴细胞中存在 p27（Kip1）。通过特异性平均荧光强度半定量估计的其细胞含量高于正常 CD5⁺/CD19⁺淋巴细胞，p27（Kip1）与患者年龄呈负相关，与其他临床变量、细胞周期或凋亡率无关。在所研究的 31 个 B-CLL 淋巴细胞群体中，25 个可检测到细胞周期蛋白 D2，所有群体均可检测到细胞周期蛋白 D3。与所有 CD5⁺/CD19⁺淋巴细胞中存在的 p27Kip1 不同，这两种细胞周期蛋白仅在一部分肿瘤细胞中检测到：细胞周期蛋白 D2 为 27.5%至 87%（平均 51.2%），细胞周期蛋白 D3 为 20.3%至 98%（平均 76.5%）。在细胞周期蛋白 D2 和 D3 阳性的正常 CD5⁺/CD19⁺淋巴细胞和 B-CLL 细胞群体中，细胞周期蛋白 D3 在细胞中的表达百分比高于细胞周期蛋白 D2。B-CLL 细胞中细胞周期蛋白 D2 和 D3 阳性部分的平均比例均大于正常 CD5⁺/CD19⁺外周血淋巴细胞的相应部分。
我们的结果表明，细胞周期蛋白 D3 在正常和肿瘤性 CD5⁺/CD19⁺细胞的调节中起重要作用，并指出许多 CLL 淋巴细胞可能从静止状态中脱离。
