Weiland F, Weiland E, Mussgay M
Br J Cancer. 1979 Dec;40(6):932-42. doi: 10.1038/bjc.1979.288.
Transplantation of a Moloney sarcoma-virus (MSV-M)-transformed producer cell line (Sac(+)) induced progressively or regressively growing tumours in mice. Progressive growth always occurred after transplantation of an MSV-M non-producer transformant (Sac(-)), whereas the MSV-M released from the producer cells (Sac virus) always induced tumours which regressed. In contrast to the non-producer, the producer transformant Sac(+) as well as Sac virus induced a strong immune response, detected in vitro by cell- and antibody-mediated cytotoxicity assays, and in vivo by transplantation immunity. Implantation of Sac(-) cells led to solid, under-vascularized tumours, consisting histologically of uniform densely packed tumour cells. Sac-virus-induced tumours, however, were very well vascularized and arose by proliferation of different connective-tissue cells. After transplantation of Sac(+) cells, tumours were found to consist of typical tumour cells morphologically similar to Sac(-) cells intermingled with proliferated connective-tissue cells. Cultivation of tumour fragments from Sac(+) and Sac(-) tumours was followed by outgrowth of transformed tumour cells with the properties of the originally implanted cells. Tumour explant cultures from Sac-virus-induced tumours did not lead to growth of stably transformed cells. Co-culture of mouse embryo fibroblasts (MEF) with Sac(+) cells resulted in overgrowth of the transformed cells. Infection of MEF with Sac virus led to transiently transformed cells. It is concluded that Sac(+) cell tumours will resist the strong immune defence mechanisms they induce and grow progressively, if the inoculated cells are able to build up a solid, poorly vascularized nodule in the tissue. This always happens after implantation of 10(6) cells, but only occasionally when fewer cells are inoculated. Sac-virus-induced tumours will always regress owing to the strong immune response. The regression is furthered by the fact that MSV-M infection rarely if ever leads to a stable transformation.
移植莫洛尼肉瘤病毒（MSV-M）转化的产生细胞系（Sac(+)）可在小鼠体内诱导出渐进性生长或退行性生长的肿瘤。将MSV-M非产生转化体（Sac(-)）移植后总是出现渐进性生长，而从产生细胞释放的MSV-M（Sac病毒）总是诱导肿瘤发生退行。与非产生转化体不同，产生转化体Sac(+)以及Sac病毒均诱导了强烈的免疫反应，体外通过细胞介导和抗体介导的细胞毒性试验检测，体内通过移植免疫检测。植入Sac(-)细胞导致形成实体、血管化不良的肿瘤，组织学上由均匀密集排列的肿瘤细胞组成。然而，Sac病毒诱导的肿瘤血管化良好，由不同结缔组织细胞增殖形成。移植Sac(+)细胞后，发现肿瘤由形态上与Sac(-)细胞相似的典型肿瘤细胞与增殖的结缔组织细胞混合组成。培养来自Sac(+)和Sac(-)肿瘤的肿瘤片段后，具有原始植入细胞特性的转化肿瘤细胞生长。来自Sac病毒诱导肿瘤的肿瘤外植体培养未导致稳定转化细胞生长。将小鼠胚胎成纤维细胞（MEF）与Sac(+)细胞共培养导致转化细胞过度生长。用Sac病毒感染MEF导致瞬时转化细胞。得出的结论是，如果接种的细胞能够在组织中形成实体、血管化不良的结节，Sac(+)细胞肿瘤将抵抗它们诱导的强大免疫防御机制并渐进性生长。接种10(6)个细胞后总是会发生这种情况，但接种较少细胞时只是偶尔发生。Sac病毒诱导的肿瘤由于强烈的免疫反应总是会发生退行。MSV-M感染极少导致稳定转化这一事实进一步促进了退行。
