methylcellulose and Bone-Neoplasms

The human osteosarcoma cell line, MG63, responds both to GM-CSF and to G-CSF in vitro. To assess the significance of these observations to tumor growth in vivo, MG63 cells were engineered by retroviral infection to produce human GM-CSF or G-CSF. These retrovirally infected cells become autostimulatory as measured by increased [3H]-thymidine incorporation (3- to 7-fold) and anchorage-independent colony formation (7- to 10-fold) as compared with uninfected MG63 cells or cells infected with control (neor) retrovirus. The increased proliferation induced by exogenous GM-CSF or G-CSF on uninfected MG63 cells in both assays could be completely inhibited by anti-GM-CSF or anti-G-CSF antibodies, while the same antibodies only partially abrogated proliferation by the growth-factor-producing cells. None of 34 nude or SCID mice developed tumors when injected s.c. with uninfected or neor-virus-infected cells. In contrast, all 30 mice injected with GM-CSF- or G-CSF-producing MG63 cells developed tumors which were G418-resistant and factor-producing. Tumor cell DNA showed a polyclonal retroviral integration pattern indistinguishable from that in the DNA of cells injected into mice. Tumors that formed following injection of a mixture of G418-resistant, GM-CSF-producing cells and cells infected with virus containing only the hygror gene contained hygromycin-resistant cells in the same proportion as was present in the original cell mixture. These data indicate that GM-CSF and G-CSF can support the growth of an osteosarcoma cell line both in vitro and in vivo whether the factor is supplied by autocrine production or from exogenous sources.

Topics: 3T3 Cells; Animals; Blotting, Southern; Bone Neoplasms; Carcinogenicity Tests; Cell Division; Disease Models, Animal; Female; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Male; Methylcellulose; Mice; Mice, Inbred BALB C; Mice, Nude; Mice, SCID; Osteosarcoma; Retroviridae; Stimulation, Chemical; Tumor Cells, Cultured

Polyinosinic-polycytidylic acid, a double-stranded ribonucleic acid that is a potent inducer of interferon production, was used in a stabilized form to treat 11 patients with metastatic renal cell carcinoma. Seven patients completed a full course of 8 infusions at maximum tolerated dosage. All patients experienced transient fever and marked fatigue. Anorexia was mild. Transient leukopenia occurred in 3 patients and reversible elevation in creatinine was observed in 1. All 4 patients with brain metastases became lethargic, and 3 died during or shortly after therapy. Only 2 patients demonstrated measurable total regression of isolated metastases (pleural/pulmonary in 1 and bone in 1) but in both metastases at other sites progressed. No partial regressions were seen. Metastases at all other sites (liver, brain and renal fossa) progressed during therapy. Patients who appeared to respond and who performed best during therapy generally demonstrated a higher performance status initially. Expression of natural cytotoxicity in in vitro testing did not correlate with a demonstrated response to treatment.

Topics: Bone Neoplasms; Brain Neoplasms; Carboxymethylcellulose Sodium; Carcinoma, Renal Cell; Humans; Interferon Inducers; Kidney Neoplasms; Lung Neoplasms; Methylcellulose; Poly I-C; Polylysine