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Biomedical subjects

G Jaques

Publications and source records attributed to G Jaques.

5 recordsLinked to original sources
PubMed1992

Characterization of insulin-like growth factor I receptors and growth effects in human lung cancer cell lines.

Small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) cell lines were studied for insulin-like growth factor I (IGF-I) receptor expression and with regard to the influence of IGF-I on cell proliferation. IGF-I receptors on the cells were characterized by competitive binding assays, chemical crosslinking and northern blot hybridization of IGF-I receptor mRNA. All SCLC and NSCLC cell lines showed specific IGF-I binding sites with an affinity (KD) of 0.69-5.21 nM. The amount of binding sites ranged from 59 fmol/mg to 1230 fmol/mg protein. The IGF-I binding was inhibited by the IGF-I receptor antibody (alpha-IR-3). Northern blot hybridization indicated that IGF-I receptor mRNA was being produced by all SCLC and NSCLC cell lines. We used the soft-agarose clonogenic assay to evaluate the influence of IGF-I on the in vitro proliferation of the cells. Our results have shown that IGF-I stimulates the growth of all tested cell lines ranging from a factor of 1.6 to 4.2 in SCLC and from 1.1 to 2.7 in NSCLC. The data indicate that the IGF-I receptor thus appears to be the common pathway for the mitogenic activity of IGF-I and IGF-II with regard to human lung cancer cells.

Binding, Competitive↗
PubMed1992

Differential expression of insulin-like growth factor binding proteins in human non-small cell lung cancer cell lines.

The possible expression and secretion of insulin-like growth factor binding proteins (IGFBPs) by non-small cell lung cancer (NSCLC) cell lines was investigated and compared with possible IGFBP expression by primary NSCLC tumours. Cells growing under serum-free conditions released binding proteins with apparent molecular masses of 26-43 kD when analysed by a ligand blotting method under non-reducing conditions. Additionally, northern blot analysis of total RNA from NSCLC cell lines and tumours was performed using cDNAs coding for each of IGFBP-1, IGFBP-2, and IGFBP-3. This analysis revealed expression of all three mRNAs to varying degrees by all cell lines. In contrast all primary tumours analysed expressed predominantly IGFBP-2 and IGFBP-3 and none showed any evident expression of IGFBP-1. Both NSCLC cell lines and tumours synthesise IGFBPs but the pattern of expression differs significantly between cell lines and primary tumours.

Blotting, Northern↗
PubMed1991

Human chorionic gonadotropin and related glycoprotein hormones in lung cancer cell lines.

Twenty-five non-small cell lung cancer (NSCLC), 42 small cell lung carcinoma (SCLC), one extrapulmonary small cell carcinoma, 4 carcinoid, and 13 non-lung cancer cell lines were analyzed for human chorionic gonadotropin (HCG) and related glycoprotein hormones. HCG or its subunits were present in 72% of NSCLC, 10% of SCLC, one extrapulmonary small cell carcinoma, 3/4 carcinoids and 2/13 non-lung cancer cell lines. Related glycoprotein hormones were undetectable. These data indicate a frequent production of HCG or its subunits by NSCLC cell lines and cell lines from tumors with carcinoid features. They confirm the clinical inclusion of carcinoids under the broad category of NSCLC rather than SCLC despite their neuroendocrine features. Clinicians should not assume that undifferentiated NSCLC with HCG production represent germ cell tumors.

Biomarkers, Tumor↗
PubMed1991

Insulin-like growth factor binding protein expression in human small cell lung cancer cell lines.

Insulin-like growth factor binding proteins (IGF-BP) are secreted by several human small cell lung cancer cell lines (SCLC). In order to identify the IGF-BPs from SCLC cell lines the RNA from 10 different SCLC cell lines was analyzed by Northern blot analysis with the probes for three different IGF-BPs, IGFBP-1, IGFBP-2, and IGFBP-3. No hybridization signal could be detected with the probes encoding for IGFBP-1 and IGFBP-3. The hybridization with different IGFBP-2-specific oligodeoxynucleotide probes and with the corresponding full-length cDNA showed that all SCLC cell lines which secreted IGF-BPs express IGFBP-2.

Base Sequence↗