Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Parasitol Res. 2010 Mar;106(4):941-5. doi: 10.1007/s00436-010-1764-7. Epub 2010 Feb 18.
Blastocystis hominis is one of the most common intestinal protozoan parasites in humans, and reports have shown that blastocystosis is coupled with intestinal disorders. In the past, researchers have developed an in vitro model using B. hominis culture filtrates to investigate its ability in triggering inflammatory cytokine responses and transcription factors in human colonic epithelial cells. Studies have also correlated the inflammation by parasitic infection with cancer. The present study provides evidence of the parasite facilitating cancer cell growth through observing the cytopathic effect, cellular immunomodulation, and apoptotic responses of B. hominis, especially in malignancy. Here we investigated the effect of solubilized antigen from B. hominis on cell viability, using peripheral blood mononuclear cells (PBMCs) and human colorectal carcinoma cells (HCT116). The gene expressions of cytokines namely interleukin 6 (IL-6), IL-8, tumor necrosis factor alpha, interferon gamma, nuclear factor kappa light-chain enhancer of activated B cells (a gene transcription factor), and proapoptotic genes namely protein 53 and cathepsin B were also studied. Results exhibited favor the fact that antigen from B. hominis, at a certain concentration, could facilitate the growth of HCT116 while having the ability to downregulate immune cell responses (PBMCs). Therefore, there is a vital need to screen colorectal cancer patients for B. hominis infection as it possesses the ability to enhance the tumor growth.
人芽囊原虫是人体中最常见的肠道原生动物寄生虫之一，有报道称芽囊原虫病与肠道疾病有关。过去，研究人员已经开发了一种使用人芽囊原虫培养滤液的体外模型，以研究其在触发人类结肠上皮细胞炎症细胞因子反应和转录因子方面的能力。研究还将寄生虫感染引起的炎症与癌症相关联。本研究通过观察人芽囊原虫的细胞病变效应、细胞免疫调节和细胞凋亡反应，特别是在恶性肿瘤中，为寄生虫促进癌细胞生长提供了证据。在这里，我们研究了人芽囊原虫可溶性抗原对细胞活力的影响，使用外周血单核细胞（PBMC）和人结直肠癌细胞（HCT116）。还研究了细胞因子白细胞介素 6（IL-6）、IL-8、肿瘤坏死因子α、干扰素γ、核因子κB 轻链增强子的基因表达激活 B 细胞（一种基因转录因子）和促凋亡基因如蛋白 53 和组织蛋白酶 B。结果表明，在一定浓度下，人芽囊原虫的抗原能够促进 HCT116 的生长，同时具有下调免疫细胞反应（PBMC）的能力。因此，迫切需要筛查结直肠癌患者是否感染人芽囊原虫，因为它具有增强肿瘤生长的能力。
