Radinsky R, Flickinger K S, Kosir M A, Zardi L, Culp L A
Department of Molecular Biology and Microbiology, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106.
Cancer Res. 1990 Jul 15;50(14):4388-400.
Adhesion has been evaluated for tumor cell populations derived from Kirsten murine sarcoma virus (KiMSV)-transformed BALB/c 3T3 cells responding to substrata coated with intact plasma fibronectin (pFN), a family of related proteolytic fragments from pFN or cellular fibronectins (FNs), and the heparan sulfate-binding platelet factor-4 (PF4). Both early-passage KiMSV cells, harboring the viral Kirsten ras oncogene (v-Ki-ras+), and late-passage KiMSV cells, in which most cells have lost the oncogene (v-Ki-ras-), are compared with primary tumor and lung metastatic tumor cells after three routes of injection into nude mice; nontumorigenic v-Ki-ras- revertant cells have been cloned from the late-passage KiMSV population. Attachment of early-passage KiMSV, primary tumor, and lung metastatic tumor cells was optimal and resistant to soluble RGDS peptide in the medium on intact pFN, on fragment F-155 from pFN containing the RGDS cell-binding domain and the heparinII domain, and on PF4 but decreased for metastatic cells on F110 containing only the RGDS domain (and sensitive to RGDS peptide). Cytoplasmic spreading of early-passage KiMSV and all tumor cells was good to excellent in polygonal patterns on pFN and on F155, while most cells remained round on F110. Responses for KiMSV and tumor cells varied on different heparin-binding proteins; cells remained rounded or detached on F38 derived from pFN or on PF4 but spread effectively with long linear process extension on cellular FN-derived fragments F44 + 47 harboring the extra domaina sequence. That F44 + 47 may contain a new cell-binding site for v-Ki-ras+ cells was also indicated by resistance to bacterial heparitanase in cell responses on F44 + 47 but not on PF4 and extensive catabolism of proteoglycans in the substratum-attached material of these cells. v-Ki-ras- revertant cells, nontumorigenic in nude mice, have reacquired 3T3-like responses to proteolytic fragments, including much more effective spreading on PF4 or on F38 substrata, and have reverted in generating microfilament stress fibers on pFN, a competence lacking in all v-Ki-ras+ cells. These results indicate that (a) v-Ki-ras+ primary and metastatic tumor cells respond similarly to most proteolytic fragments of FNs harboring known binding domains, with a few exceptions; (b) v-Ki-ras gene expression correlates with a new cell surface receptor activity recognized by extra domaina-containing fragments from cellular FNs; and (c) loss of the viral oncogene to generate v-Ki-ras- revertant cells reverts their FN-mediated adhesion responses.
对源自 Kirsten 小鼠肉瘤病毒（KiMSV）转化的 BALB/c 3T3 细胞的肿瘤细胞群体进行了黏附评估，这些细胞对包被有完整血浆纤连蛋白（pFN）、pFN 或细胞纤连蛋白（FN）的一系列相关蛋白水解片段以及硫酸乙酰肝素结合血小板因子 4（PF4）的基质产生反应。将携带病毒 Kirsten ras 癌基因（v-Ki-ras+）的早期传代 KiMSV 细胞和大多数细胞已失去该癌基因（v-Ki-ras-）的晚期传代 KiMSV 细胞，与经三种途径注射到裸鼠体内后的原发性肿瘤细胞和肺转移肿瘤细胞进行比较；已从晚期传代 KiMSV 群体中克隆出无致瘤性的 v-Ki-ras- 回复细胞。早期传代 KiMSV 细胞、原发性肿瘤细胞和肺转移肿瘤细胞在完整 pFN、含有 RGDS 细胞结合结构域和肝素 II 结构域的 pFN 片段 F-155 以及 PF4 上的黏附最佳，且对培养基中的可溶性 RGDS 肽具有抗性，但在仅含有 RGDS 结构域的 F110 上，转移细胞的黏附减少（且对 RGDS 肽敏感）。早期传代 KiMSV 细胞和所有肿瘤细胞在 pFN 和 F155 上以多边形模式进行的细胞质铺展良好至极佳，而大多数细胞在 F110 上仍保持圆形。KiMSV 细胞和肿瘤细胞对不同肝素结合蛋白的反应各不相同；细胞在源自 pFN 的 F38 或 PF4 上保持圆形或 detached，但在含有额外结构域 a 序列的细胞 FN 衍生片段 F44 + 47 上以长线性突起延伸的方式有效铺展。F44 + 47 可能含有一个针对 v-Ki-ras+ 细胞的新细胞结合位点，这也通过 F44 + 47 上细胞反应对细菌肝素酶的抗性（而不是在 PF4 上）以及这些细胞附着于基质的材料中蛋白聚糖的广泛分解代谢得以表明。v-Ki-ras- 回复细胞在裸鼠中无致瘤性，已重新获得对蛋白水解片段的 3T3 样反应，包括在 PF4 或 F38 基质上更有效的铺展，并且在 pFN 上重新产生微丝应力纤维，这是所有 v-Ki-ras+ 细胞所缺乏的能力。这些结果表明：（a）v-Ki-ras+ 原发性和转移性肿瘤细胞对大多数含有已知结合结构域的 FN 蛋白水解片段的反应相似，但有一些例外；（b）v-Ki-ras 基因表达与细胞 FN 中含额外结构域 a 的片段所识别的新细胞表面受体活性相关；（c）病毒癌基因的缺失产生 v-Ki-ras- 回复细胞，使其 FN 介导的黏附反应得以恢复。
