肿瘤干细胞与胃癌

最近的一项研究报导,采用流式细胞仪分选技术从人胃癌细胞株中分离出CD44^＋胃癌干细胞. 20～30×10³个CD44＋细胞入NOD/SCID 鼠腹部皮下和胃浆膜下能形成胃癌移植瘤, 100×10³个CD44^－的细胞入NOD/SCID 鼠体内不形成肿瘤.采用无血清、无粘附间质的干细胞体外培养方法,发现CD44^＋的细胞能形成肿瘤微球体,具有自我更新能力,而CD44^－的细胞则不形成球形克隆.上述的实验结果说明,在人胃癌细胞株中存在胃癌肿瘤干细胞.据此可以相信,胃癌干细胞是胃癌细胞中具有自我更新及分化潜能的一小群细胞,不能被目前的化疗、放疗等抗癌治疗措施所杀灭,是胃癌术后复发、肿瘤进展扩散转移的根源.胃癌干细胞可能来源于骨髓干细胞.随着对胃癌肿瘤干细胞生物学研究的深入,必将为胃癌的临床诊断和治疗提供新的策略.     

Bladder Cancer After Radiotherapy for Prostate Cancer

External beam radiotherapy (EBRT) is frequently used in the management of prostate cancer (PCa) as definitive, postoperative, or salvage local treatment. Although EBRT plays a central role in the management of PCa, complications remain a troubling by-product. Several studies have demonstrated an association between radiotherapy and elevated risk of acute and late toxicities. A secondary malignancy induced by initial therapy represents one of the most serious complications related to definitive cancer treatment. The radiation-related secondary primary malignancy risk increases with increasing survival time. Transitional cell carcinoma of the bladder is the most frequent secondary primary malignancy occurring after radiotherapy and is described as more aggressive; it may be diagnosed later because some radiation oncologists believe that the hematuria that occurs after prostate EBRT is normal. Some patients treated for localized PCa will subsequently develop invasive bladder cancer requiring surgical intervention. Patients with PCa treated with EBRT should be monitored closely for the presence of bladder cancer.Key words: Bladder cancer, Prostate cancer, Radiotherapy, External beam radiotherapyThe phenomenon of radiation-inducing the carcinogenesis has been well described in literature for decades. The correlation between ionizing radiation and DNA damage has been discussed in several studies.^1–4 Most of these studies evaluated the growth of solid tumors in a large population exposed to moderate to heavy doses of radiation, such as factory workers, patients exposed to a large number of diagnostic radiographic studies, and survivors of atomic and nuclear explosions. ¹ The casual effects of radiation exposure with subsequent mutagenesis are quite clear, shown both in vivo and in vitro.² Previous radiotherapy (RT) for prostate cancer (PCa) may play an important role in the development of secondary primary bladder cancer. This is a fairly uncommon event but a very real entity, of which both urologists and radiation oncologists need to be aware.     

乳腺癌干细胞和乳腺癌

肿瘤干细胞既包含干细胞的特性也包含肿瘤细胞的特性。乳腺癌起源于乳腺癌干细胞的说法能够合理地解释乳腺癌的不均一性及其治疗后的复发,这些变异的干细胞可能作为肿瘤预防策略的靶标。而且,由于乳腺癌干细胞能够抵抗辐射治疗和化学治疗,所以要想更好地治疗乳腺癌就需要寻找针对这些干细胞的靶标。我们综述了乳腺癌干细胞的发现、富集和分离、相关的信号途径,以及在乳腺癌治疗中的应用。     

肿瘤干细胞与卵巢癌研究进展

近年来,肿瘤干细胞学说作为肿瘤发生发展的重要原因获得越来越多的认可。肿瘤干细胞是指肿瘤中存在的含量极少、具有无限增殖潜能的干细胞样肿瘤细胞,它们能自我更新、分化、迁徙,是导致肿瘤发生、发展、转移和耐药的重要原因。卵巢癌也可能是卵巢癌干细胞所致的疾病。卵巢癌干细胞的分离鉴定正处于起始阶段,针对卵巢癌干细胞的靶向治疗可能在卵巢癌治疗中具有重要作用,为临床彻底治愈卵巢癌带来希望。