(1) Chromatographic separation revealed that the bulk (85%) of the mitogenic activity in SSV-transformed NRK cells was not due to p28v-sis but rather two distinct endothelial cell growth factors that eluted off heparin-Sepharose between 1 and 2 M NaCl.
(2) To get an insight into the nature of variant Ph translocations and the process of their formation, we examined the localization of the c-abl and c-sis oncogenes and the breakpoint cluster region (bcr) gene by chromosomal in situ hybridization in ten variant Ph translocations of CML including five simple and five complex ones as initially interpreted.
(3) Loss of a c-sis allele (allele I in all cases) was observed in 6 out of 10 tumors from heterozygous patients.
(4) Cells transformed by v-sis produce a platelet-derived growth factor-related molecule which is able to stimulate the platelet-derived growth factor receptor in an autocrine fashion.
(5) The v-sis oncogene of simian sarcoma virus (SSV) is a retroviral version of the PDGF B chain gene and SSV-transformation is mediated by an autocrine PDGF-like growth factor.
(6) Messenger RNA levels for v-sis were induced by tension in intact but not denuded vessels.
(7) In both loci, similar unique genetic sequences were found upstream of the v-sis homologous region and these hybridized to a 4.2 kbp c-sis transcript in human lung tumor cells.
(8) First, we investigated the expression of c-sis protooncogenes within cultured human glioma cell lines and also fresh glioma specimens by using polymerase chain reaction.
(9) The v-sis gene encodes chain B of platelet-derived growth factor.
(10) However, in tissue adjacent to 5 different tumors, approximately the same level of c-sis mRNA was seen.
(11) c-sis mRNA levels diminished with increased time of infection.
(12) For example, platelet-derived growth factor (PDGF) has been found in many normal tissues including the CNS, while minor changes in one of its forms (PDGF-B) converts it to the v-sis oncogene, capable of inducing sarcomas and astrocytomas in primates.
(13) SIS SVB was performed to a variety of vessel combinations using "Y" graft, continuous, or vein extension techniques achieving early patency in all limbs, despite pedal arch disease.
(14) Radiolabeled recombinant PDGF (c-sis) dissociated from Heparin-Sepharose within a concentration range of NaCl similar to that of RF I.
(15) increased cell size, reduced growth rate, megakaryocytic antigens, and expression of the sis proto-oncogene, the structural gene for the B-chain of platelet-derived growth factor.
(16) In human malignant mesothelioma cell lines elevated expression of the platelet-derived growth factor (PDGF) beta-chain (c-sis) gene was previously reported, while normal mesothelial cells barely express this gene.
(17) The same temporal dissociation was observed when a recombinant v-sis product was used instead of porcine PDGF.
(18) Reduced function of runt results in female-specific lethality and sexual transformation of XX animals that are heterozygous for Sxl or sis loss-of-function mutations.
(19) Several specific related questions are addressed in this discussion: Is the protein encoded by the v-sis gene functionally identical to PDGF?
(20) This suggests that H-ras is less efficient in relieving the insulin requirement than is sis.