Jia Xiaoyuan, Zhao Yujia, Li Qiang, Lu Xiaming, Wang Xiaoyan, Wang Hui, Shi Ziyi, Xu Yipeng, Huang Biao, Huang Fang, Wang Yigang
College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China.
Cancer Center, Department of Pathology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital), Hangzhou Medical College, Hangzhou, China.
J Breast Cancer. 2024 Oct;27(5):293-304. doi: 10.4048/jbc.2024.0063. Epub 2024 Sep 2.
Vaccinia virus is widely used as an oncolytic agent for human cancer therapy, and several versions of vaccinia virus have demonstrated robust antitumor effects in breast cancer. Most vaccinia viruses are modified by thymidine kinase (TK) deletion. The function of the cyclin-dependent kinase inhibitor p21 in breast cancer remains controversial. We explored the impact of p21 gene knockdown (KD) on breast cancer cells and whether p21 KD interferes with the antitumor effect of TK-negative vaccinia virus.
p21 KD MDA-MB-231 and p21 KD MCF-7 cells were prepared, and cell proliferation and migration rates were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and scratch healing assays. The tumor growth of xenografts originating from p21KD MDA-MB-231 cells and control cells was compared in a mouse model. The colony formation and sphere-forming abilities of p21 KD breast cancer cells were also determined using low-melting agarose and serum-free culture. The tumor-killing effect of the vaccinia virus was determined in breast cancer cells and mouse models using an MTT assay and tumor cell xenografts.
p21 KD increased the growth and migration of MDA-MB-231 and MCF-7 cells and promoted the cell growth of MDA-MB-231 cells in mice, while decreasing the colony formation and sphere formation abilities. Expression of TK was reduced in p21 KD MDA-MB-231 cells. Oncolytic effects of both wild-type and TK-deleted vaccinia viruses were attenuated in p21KD MDA-MB-231 cells. The tumor-killing effect of TK-deleted vaccinia virus was also weakened in xenografted mice bearing p21 KD MDA-MB-231 cells.
Targeted inhibition of p21 accelerates the proliferation and migration of breast cancer cells and impairs the tumor-killing effect of vaccinia virus, suggesting that p21 levels in cancer cells interfere with vaccinia virus oncolytic therapy.
痘苗病毒被广泛用作人类癌症治疗的溶瘤剂，几种痘苗病毒版本已在乳腺癌中显示出强大的抗肿瘤作用。大多数痘苗病毒通过缺失胸苷激酶（TK）进行改造。细胞周期蛋白依赖性激酶抑制剂p21在乳腺癌中的功能仍存在争议。我们探讨了p21基因敲低（KD）对乳腺癌细胞的影响，以及p21 KD是否会干扰TK阴性痘苗病毒的抗肿瘤作用。
制备p21 KD MDA-MB-231和p21 KD MCF-7细胞，使用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）和划痕愈合试验评估细胞增殖和迁移率。在小鼠模型中比较源自p21KD MDA-MB-231细胞和对照细胞的异种移植瘤的肿瘤生长情况。还使用低熔点琼脂糖和无血清培养来确定p21 KD乳腺癌细胞的集落形成和球形成能力。使用MTT试验和肿瘤细胞异种移植在乳腺癌细胞和小鼠模型中确定痘苗病毒的杀肿瘤效果。
p21 KD增加了MDA-MB-231和MCF-7细胞的生长和迁移，并促进了MDA-MB-231细胞在小鼠体内的生长，同时降低了集落形成和球形成能力。p21 KD MDA-MB-231细胞中TK的表达降低。野生型和TK缺失的痘苗病毒在p21KD MDA-MB-231细胞中的溶瘤作用均减弱。在携带p21 KD MDA-MB-231细胞的异种移植小鼠中，TK缺失的痘苗病毒的杀肿瘤作用也减弱了。
靶向抑制p21可加速乳腺癌细胞的增殖和迁移，并损害痘苗病毒的杀肿瘤作用，表明癌细胞中的p21水平会干扰痘苗病毒溶瘤治疗。
