Molecular Pathological Analysis of Digestive Cancers around Semipalatinsk Nuclear Testing Site

自1949年以来，在前苏联时期，在哈萨克斯坦塞米巴拉金斯克核试验场进行了数百次核试验。由于前苏联的保密制度，澄清SNTS周围居民的健康影响是相当困难的。据估计，在核试验期间，SNTS周围的受照射人群有一定的辐射照射的远期效应，特别是恶性肿瘤的风险。然而，由于该地区的医疗和流行病学基础设施不足，很难弄清真实的情况。另一方面，为了弄清辐射对长崎和广岛原子弹幸存者的晚期影响，人们对辐射诱发癌症的分子机制进行了广泛的研究。据报道，原子弹爆炸30年后，胃癌的发病率增加了。然而，其机制尚未阐明。基于这些背景，我们与塞米巴拉金斯克医学院病理学系合作，推动了SNTS周围胃癌评估的分子病理学联合研究。此外，我们还通过原位杂交技术检测了EB病毒编码的小RNA-1（EBER-1）的表达，以评估该地区病毒诱导的胃癌的发病率，结果显示，EBER-1在俄罗斯人和亚洲人中的阳性率分别为10.8%和8.9%。这些结果表明，EBV感染引起的胃癌发病率不是评价辐射诱发癌症的重要混杂变量，因为该队列的EVB感染率在西方国家和日本之间没有显著差异。未来，我们计划发展针对p53和p21的分子病理学研究，以及引入新技术，如比较基因组杂交（CGH）。

Since 1949,hundreds of nuclear tests had been conducted at Semipalatinsk Nuclear Testing Site(SNTS) in Kazakhstan, during the period of former USSR. Due to the secret system of former USSR, clarification of health effect in the population residing around SNTS is quite difficult. It is estimated that irradiated population around SNTS during the periods of nuclear testing has a certain risk of late effects of radiation exposure, especially malignancy. However it is quite difficult to clarify the real situation, due to the insufficient medical and epidemiological infrastructure in this area.On the other hand, molecular mechanism of radiation induced cancer has been extensively investigated in order to clarify the late effect of radiation in A-bomb survivors in Nagasaki and Hiroshima. It was reported that the incidence of stomach cancer was increased after 30 years of A-bomb. However, its mechanism has not been clarified. Based on these backgrounds, we promoted the molecular pathological joint research on the evaluation of stomach cancer around SNTS, in cooperation with the Department of Pathology of Semipalatinsk Medical Academy. Furthermore, we screened the expression of EBV-encoded small RNA-1(EBER-1) by in situ hybridization, in order to evaluate the incidence of virus-induced stomach cancer in this area, and showed that the positive EBER-1 was observed in 10.8% of Russian and 8.9% of Asian population. These results suggest that the incidence of stomach cancer caused by EBV infection is not a significant confounding variable for the evaluation of radiation induced cancer, since the ratio of EVB infection of this cohort is not significantly different between Western countries and Japan. In future, we plan to develop the molecular pathological studies targeted p53 and p21, in addition to the introduction of new technologies, such as Comparative Genomic Hybridization(CGH).