Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Non-histone chromatin proteins of myeloma cells RPC 5, synthesizing gamma 2A and ABPC 22 synthesizing IgM as well as non-histone chromatin proteins of spleen cells from mice bearing these tumours and from control mice were labelled during culture in vitro with 3H-tryptophan, 3H-leucine or 3H-methionine. Electrophoretic patterns of labelled chromatin proteins indicated, that in myeloma cells, producing spontaneously immunoglobulins, any characteristic fraction of non-histone chromatin proteins, described previously in immunoglobulin producing spleen cells, could not be detected, although the profiles of these proteins in myeloma cells, spleen cells from mice bearing these tumours and control spleen cells varied.
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PMID:Synthesis of non-histone chromatin proteins of mice in spleen cells and myeloma cells RPC 5 and ABPC 22. 746 26

The development of an increasing number of tumors has been shown to involve the deregulation of not only cell proliferation but also normal cell death by apoptosis. Expression of the bcl-2 proto-oncogene has been shown to inhibit the apoptotic cell death of many types of cells. Recent work also has revealed the existence of several bcl-2-related genes that also can inhibit (e.g., bcl-X(L) and Mcl-1) or activate (e.g., bax, bcl-X(s), bag, and bad) apoptosis in several systems. Myelomas are antibody-secreting tumor cells derived from terminally differentiated B lymphocytes, and previous work from our laboratory showed that murine SP2/0 myeloma cells and derived B-cell hybridomas were highly sensitive to apoptosis induction by a block of gene expression (cycloheximide). Additional work revealed that a related murine myeloma cell line, P3X63Ag8.653, was resistant to apoptosis induction in similar conditions. To understand the genetic basis of this differential susceptibility, we examined the expression of apoptosis-related genes in these cell lines. Northern blot experiments showed no significant difference in the expression of myc and bax apoptosis-promoting genes in susceptible (SP2/0 and D5) and resistant (P3X63) cell lines. Also, no significant expression of the bcl-2 gene could be detected in these cell lines. However, a much higher expression level of bcl-X(L) mRNA was observed in apoptosis-resistant P3X63Ag8.653 cells. The role of bcl-X(L) was supported by the finding that expression of bcl-X(L) cDNA in transfected, apoptosis-sensitive D5 cells increased the viability of these cells greatly and reduced DNA fragmentation following apoptosis induction. Significant bcl-X(L) but not bcl-2 expression was also detected in three other murine myeloma cell lines (MOPC 315, RPC 5.4, and J558) derived from different plasmacytoma tumors. These results indicate a predominant role of bcl-X(L) in preventing apoptosis in myeloma cells and suggest that the expression of bcl-2 or bcl-X(L) genes in B-cell tumors depends on the differentiation stage of the precursor normal cell.
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PMID:Role of bcl-X(L) in the control of apoptosis in murine myeloma cells. 864 Aug 39

This paper describes an attempt to find a difference between the patterns of methylation of E. coli tRNA by extracts of two mouse tissues. Two samples of tRNAs, methylated in two separate experiments with extracts of myeloma and of liver in presence of either 14C or 3H S-Adenosyl-L-Methionine, were pooled and fractionated together on a RPC column. The results show a difference in the specificities of the two extracts. Chromatography on DEAE Sephadex suggests that the tRNA Met is methylated by the enzymes on the myeloma, while enzymes from liver react very little, if at all, with that particular tRNA species. Studies have been undertaken in order to find out whether similar differences can also be demonstrated in homologous systems.
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PMID:??? 1194 21


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