Henkens Rachel, Delvenne Philippe, Arafa Mohammad, Moutschen Michel, Zeddou Mustapha, Tautz Lutz, Boniver Jacques, Mustelin Tomas, Rahmouni Souad
Immunology and Infectious Diseases Unit, GIGA-R, Liège University, Liège, Belgium.
BMC Cancer. 2008 May 27;8:147. doi: 10.1186/1471-2407-8-147.
The 21-kDa Vaccinia virus VH1-related (VHR) dual-specific protein phosphatase (encoded by the DUSP3 gene) plays a critical role in cell cycle progression and is itself regulated during the cell cycle. We have previously demonstrated using RNA interference that cells lacking VHR arrest in the G1 and G2 phases of the cell cycle and show signs of beginning of cell senescence.
In this report, we evaluated successfully the expression levels of VHR protein in 62 hysterectomy or conization specimens showing the various (pre) neoplastic cervical epithelial lesions and 35 additional cases of hysterectomy performed for non-cervical pathologies, from patients under 50 years of age. We used a tissue microarray and IHC technique to evaluate the expression of the VHR phosphatase. Immunofluorescence staining under confocal microscopy, Western blotting and RT-PCR methods were used to investigate the localization and expression levels of VHR.
We report that VHR is upregulated in (pre) neoplastic lesions (squamous intraepithelial lesions; SILs) of the uterine cervix mainly in high grade SIL (H-SIL) compared to normal exocervix. In the invasive cancer, VHR is also highly expressed with nuclear localization in the majority of cells compared to normal tissue where VHR is always in the cytoplasm. We also report that this phosphatase is highly expressed in several cervix cancer cell lines such as HeLa, SiHa, CaSki, C33 and HT3 compared to primary keratinocytes. The immunofluorescence technique under confocal microscopy shows that VHR has a cytoplasmic localization in primary keratinocytes, while it localizes in both cytoplasm and nucleus of the cancer cell lines investigated. We report that the up-regulation of this phosphatase is mainly due to its post-translational stabilization in the cancer cell lines compared to primary keratinocytes rather than increases in the transcription of DUSP3 locus.
These results together suggest that VHR can be considered as a new marker for cancer progression in cervix carcinoma and potential new target for anticancer therapy.
21 kDa痘苗病毒VH1相关（VHR）双特异性蛋白磷酸酶（由DUSP3基因编码）在细胞周期进程中起关键作用，其本身在细胞周期中也受到调控。我们之前利用RNA干扰证明，缺乏VHR的细胞在细胞周期的G1期和G2期停滞，并显示出细胞衰老开始的迹象。
在本报告中，我们成功评估了62例子宫切除或锥切标本中VHR蛋白的表达水平，这些标本显示了各种（癌前）宫颈上皮病变，另外还评估了35例因非宫颈病变而进行子宫切除的病例，患者年龄均在50岁以下。我们使用组织微阵列和免疫组化技术评估VHR磷酸酶的表达。采用共聚焦显微镜下的免疫荧光染色、蛋白质印迹法和逆转录-聚合酶链反应方法研究VHR的定位和表达水平。
我们报告，与正常宫颈外口相比，VHR在子宫颈（癌前）病变（鳞状上皮内病变；SILs）中上调，主要在高级别SIL（H-SIL）中。在浸润性癌中，与VHR始终位于细胞质的正常组织相比，VHR在大多数细胞中也高度表达且定位于细胞核。我们还报告，与原代角质形成细胞相比，这种磷酸酶在几种宫颈癌细胞系如HeLa、SiHa、CaSki、C33和HT3中高度表达。共聚焦显微镜下的免疫荧光技术显示，VHR在原代角质形成细胞中定位于细胞质，而在所研究的癌细胞系中它定位于细胞质和细胞核。我们报告，与原代角质形成细胞相比，这种磷酸酶的上调主要是由于其在癌细胞系中的翻译后稳定，而非DUSP3基因座转录增加。
这些结果共同表明，VHR可被视为宫颈癌进展中的一个新标志物和抗癌治疗的潜在新靶点。
