Beta 2-microglobulin and other proteins as parameter for tubular function

Urinary excretion of the low molecular weight protein beta 2-microglobulin and tubular enzymes--alanine aminopeptidase (AAP), gamma-glutamyl transpeptidase (gamma-GT) and alkaline phosphatase (AP)--are very sensitive parameters for proximal tubular lesions. In patients with preeclampsia the renal excretion of beta 2-microglobulin allows to differentiate between a primary preeclampsia and a preeclampsia superimposed upon chronic pyelonephritis. In the first group the increase is 3- to 4-fold and in the second group up to 300-fold. In patients with kidney transplantation the urinary excretion of beta 2-microglobulin, AAP, gamma-GT and AP are several times higher than in normals. In case of a rejection episode a further increase of these proteins occur in more than 80% several days before clinical symptoms are present. The application of analgetics (paracetamol, acetylsalicylic acid) in healthy individuals in therapeutical dosages on 3 consecutive days does not show any tubular alteration by the measurement of urinary beta 2-microglobulin. Aminoglycosides (tobramycin, UK 18,892) lead to a cumulative increase of the renal excretion of beta 2-microglobulin and AAP while cephalosporins induce an increase of total proteins in the final urine under the same conditions.

Local irradiation prior to stem cell harvest has no influence on CD34+ yield: a quantitative analysis

In patients with multiple myeloma, irradiation of bone marrow prior to mobilization of autologous peripheral blood progenitor cells (PBPCs) may lead to a reduced yield of CD34+ cells. Quantitative effects have not been sufficiently assessed. We retrospectively performed a multivariate analysis in 114 patients (67 men, 47 women) with multiple myeloma, of whom 53 (47%) patients had been irradiated prior to mobilization chemotherapy. High-dose cyclophosphamide followed by granulocyte colony-stimulating factor was used for mobilization in 84% of patients. In addition to previous chemotherapy, we quantitatively evaluated the dose and fractionation of prior irradiation, the volume of the irradiated bone marrow, and the time interval between radiation therapy and mobilization of PBPCs. The median volume of irradiated bone marrow was 9% (range 1-30%) of the estimated total hematopoietic bone marrow. The irradiated bone marrow volume and the number of CD34+ cells per kilogram of body weight in the first leukapheresis product showed no correlation. However, the time between irradiation and mobilization seemed to influence the yield of CD34+ cells. A comparison of irradiated patients with nonirradiated patients revealed no differences with respect to the CD34+ cell counts. We did not find a significant influence of the extent or the total dose of irradiation on the yield of CD34+ cells in the first leukapheresis product in patients with multiple myeloma. However, there may be an inverse correlation between the time elapsed since the last irradiation and the number of mobilized CD34+ cells.

Potent in vivo antineoplastic activity of MCR peptides MCR-4 and MCR-14 against chemotherapy-resistant human small cell lung cancer

Previous studies have shown that MCR peptides possessing the retinoblastoma protein (RB) fragment LFYKKV as the active site are able to inhibit the proliferation of human non-small cell lung cancer (NSCLC) cells in vitro and in vivo. The goal of the present study was to test these compounds against human small cell lung cancer (SCLC) in vivo since this tumor is notoriously resistant to conventional therapy or, respectively, is characterized by rapid relapse after initially successful treatment. We herein report that the MCR peptides MCR-4 and MCR-14 display potent antiproliferative activity against RB-negative H82 SCLC xenograft tumors in nude mice, whereas the chemotherapeutic agent VP-16 tested in parallel in a clinically relevant dose had no anti-tumor effect. These encouraging results warrant accelerating the introduction of MCR peptides into clinical trials in patients with RB-negative tumors such as SCLC in the near future.

Extracts of lung cancer cells reveal antitumour antibodies in sera of patients with lung cancer

The objective of the present study was to reveal antitumour antibodies in sera of patients with small cell lung cancer (SCLC). The antibodies in sera of patients with SCLC and other tumours were detected by immunoblotting with whole extracts of SCLC cells as the antigen source. Sera of patients with various pulmonological disorders, irradiated during the liquidation of consequences of the Chernobyl nuclear power plant incident (a high-risk group in lung cancer), were also analysed. The present authors' found that SCLC sera contain a set (pattern) of antitumour antibodies which are rarely detected in sera of patients with cancers different from SCLC and very rarely, if ever, present in sera of healthy individuals. The sensitivity and the specificity of the pattern are equal to 80% and 91%, correspondingly. In the high-risk group in lung cancer, the frequencies of the antibodies are somewhat lower than the corresponding values in SCLC sera, but significantly larger than those in healthy sera. The findings of the present study create a basis for clinical application of the antitumour antibodies described.

A PDZ domain protein interacts with the C-terminal tail of the insulin-like growth factor-1 receptor but not with the insulin receptor

In this study, we report on the isolation of a PDZ domain protein, here designated as IIP-1, insulin-like growth factor-1 (IGF-1) receptor-interacting protein-1, which binds to the IGF-1 receptor, but not to the related insulin receptor, and which is involved in the regulation of cell motility. The interaction between the IGF-1 receptor and IIP-1 as well as a splice variant IIP-1/p26 was demonstrated in the yeast two-hybrid system. Using co-precipitation experiments, we confirmed the interaction in transfected cells as well as in vitro. Analysis of deletion mutants indicates that the PDZ domain of IIP-1 mediates interaction with the C-terminal tail of the IGF-1 receptor (serine-threonine-cysteine). This finding demonstrates that the C terminus of the IGF-1 receptor acts as novel PDZ domain binding site. Immunofluorescence analysis revealed an overlapping localization of IIP-1 and the IGF-1 receptor in the breast cancer cell line MCF-7. A functional connection between IIP-1 and the IGF-1 receptor is further supported by the finding that the level of expression of IIP-1 and the IGF-1 receptor strongly correlates in different normal and cancer cells. Furthermore, overexpression of IIP-1 resulted in an attenuation of migration of MCF-7 cells, which is one of the biological activities mediated by the IGF-1 signaling system.

Transfection of human insulin-like growth factor-binding protein 3 gene inhibits cell growth and tumorigenicity: a cell culture model for lung cancer

IGF-I and IGF-II are potent mitogens, postulated to exert autocrine/paracrine effects on growth regulation in human lung cancer. Their proliferative effects are modulated by IGF-binding proteins (IGFBPs), which are found in conditioned medium (CM) of lung cancer cell lines. The biological role of the IGFBPs, which are ontogenetically and hormonally regulated, is not fully understood. Both inhibitory and stimulatory effects on cell growth have been demonstrated. Exogenous IGFBP-3 has been consistently shown to block IGF action, inhibiting cell growth in vitro. In order to evaluate the action of endogenously produced IGFBP-3 on cell growth in lung cancer, we stably transfected the non-small cell lung cancer cell line NCI-H23 with human IGFBP-3 cDNA (resulting in NCI-H23 pOPI3/BP-3) or with the vector pOPI3CAT as control (resulting in NCI-H23 pOPI3CAT). RT-PCR confirmed expression of IGFBP-3-specific mRNA in NCI-H23 pOPI3/BP-3, but not in N! CI-H23 or NCI-H23 pOPI3CAT. Western ligand blot and Western immunoblot analysis of CMs yielded strong signals of the characteristic 40-44 kDa human IGFBP-3 protein in NCI-H23 pOPI3/BP-3. An IGFBP-3 ELISA demonstrated a 20-fold increase in IGFBP-3 protein expression in NCI-H23 pOPI3/BP-3 as compared with NCI-H23. The growth of NCI-H23 pOPI3/BP-3 in serum-containing medium was significantly slower (1.7-fold) than that of NCI-H23 or the vector-transfected control NCI-H23 pOPI3CAT. While the proliferation rate of parental and vector-transfected cells could be stimulated by IGF-I, IGF-II, IGF-I analog Long R(3) IGF-I or insulin, that of NCI-H23 pOPI3/BP-3 could not. Xenotransplantation in nude mice resulted in marked tumor growth after the injection of NCI-H23 or NCI-H23 pOPI3CAT, but absent or minimal growth for the IGFBP-3-transfected cell line. These data suggest that IGFBP-3 is a potent inhibitor of cell growth in human lung cancer c! ell lines and may impair tumorigenicity in vivo.

Role of Bcl-2, Bax, and Bak in spontaneous apoptosis and proliferation in neuroendocrine lung tumors: immunohistochemical study

Fifty-six primary neuroendocrine lung tumors were examined morphologically and histologically and their apoptosis level was determined. Malignant carcinomas were characterized by increased apoptotic index and enhanced expression ofBcl-2, Bak, p53, and Ki-67 compared to typical carcinoid. However, apoptosis in these tumors was not completed. Proteins of the Bcl family play an important role in the regulation of spontaneous apoptosis in neuroendocrine lung tumors. Bcl-2 accumulating in the nucleus is a morphological analogue of phosphorylated inactive form of this protein, which does not inhibit apoptosis. Expression of Bcl-2 and Bax decreases in small-cell lung carcinoma (SCLC) with metastases indicating attenuation of apoptosis and development of metastatic clones resistant to apoptosis induces.

[Morphologic and molecular-genetic characteristics of keratinization and apoptosis in squamous cell lung carcinoma]

46 samples of squamous-cell lung carcinoma (SqCLC) from surgical patients were examined for biomolecular tumor markers (pancytokeratins, c-myc, p53, bcl-2, Bax, Ki-67, IGF-system) and apoptosis. Keratinization appeared an independent from apoptosis type of programmed cell death. It relates to cell death by differentiation, is followed by accumulation of c-fos, c-myc, Bax, IGF-II, IGFBP-2, IGFBP-5 this indicating their involvement in the regulation of this process. High level of apoptosis does not determine positive prognosis of the neoplastic process as it is not a single variant of programmed cell death in SqCLC. Malignant grade of SqCLC depends upon correlation between the proliferative processes and various types of cell death. Better prognosis of well and moderately differentiated SqCLC (as compared to poorly differentiated carcinomas) may be due to the fact that high proliferative activity of the tumor cells is balanced by their death by keratinization.

Selective inhibition of human lung cancer cell growth by peptides derived from retinoblastoma protein

Peptides containing retinoblastoma protein (RB) fragment 649-654 (LFYKKV) were tested for their ability to block the proliferation of RB-negative and RB-positive human non-small cell lung cancer (NSCLC) cells. These peptides potently restrained the growth of both types of tumor cells, as measured by metabolic (MTT) and cellular viability (trypan blue exclusion) assays. As such, and remarkably, the peptides were able to overcome the resistance of RB-positive cells usually observed with RB gene or protein replacement therapy. Compared to the overall performance of conventional chemotherapy tested in parallel, the peptides were more cytotoxic against RB-negative neoplastic cells and equipotent toward RB-positive tumor cells, yet less toxic toward normal human cells. Thus, these new molecules hold great promise to evolve into an efficient therapy for human lung cancer, a common malignancy still defying treatment and holding a poor prognosis, as well as for other human neoplasias.

[Molecular pathology of lung cancer and insulin-like growth factors]

Molecular pathology of lung cancer (LC) investigates molecular-genetic rearrangements initiating development and growth of the tumor. The system of insulin-like growth factors (IGF) and binding proteins (IGFBP) regulates cell proliferation in the majority of embryonal and tumor tissues of man and animals in the course of reparation processes and productive inflammatory reaction. A general property of all LC histological types is presence in their cells of various members of IGF-system. Content of IGFII in tumor cells correlated with IGFBP-1, IGFBP-2, IGFBP-5. Location of IGFII and IGFBP in LC was different. IGFBP-1, -2, and -5, blocking IGFII, are detected in large amounts in areas of cell death inducing apoptosis while IGFII accumulates in dividing cells and foci of keratinization. Nuclear deposits of IGFBP-3 in bronchioloalveolar LC create phenomenon of intranuclear inclusion of "owl's eye" type. Synthesis of the majority of IGF occurs in tumor cells. Stromal cells also produce and transport into the tumor some quantity of IGFII and IGFBP.

Nuclear localization of insulin-like growth factor binding protein 3 in a lung cancer cell line

Considerable evidence exists that lung cancer cell lines produce large amounts of insulin-like growth factor-binding proteins (IGFBPs). In addition, these cells are subject to an autocrine or paracrine growth control by insulin-like growth factors (IGFs). We now demonstrate by immunocytochemistry with IGFBP-3 antibodies that nuclei of a lung cancer cell line distinctly immunostain for IGFBP-3. This finding led us to investigate in more detail the localization of this protein that, to date, had only been known to occur extracellularly. Ligand blotting revealed that purified nuclear extracts contain a 43,000-Da IGFBP which can bind [I125]IGF-I. By Western blot this protein was identified as IGFBP-3. Thus, our data are consistent with the results of a previous structural study predicting a nuclear localization for IGFBP-3. Moreover, our findings raise the possibility that nuclear IGFBP-3 is functional and involved in the pathogenesis of lung cancer.

Soluble CD56 (NCAM): a new differential-diagnostic and prognostic marker in multiple myeloma

A retrospective study was carried out to determine the diagnostic and prognostic value of the soluble form of the embryonal neural cell adhesion molecule NCAM (CD56) in paraproteinemia. NCAM, beta 2-microglobulin, and interleukin-6 levels were measured in the sera of 170 patients with paraproteinemia. Of these, 125 had multiple myeloma, 20 Waldenström's disease, and 25 monoclonal gammopathy of unknown significance. Serum NCAM proved superior to beta 2-microglobulin and interleukin-6 in distinguishing multiple myeloma from paraproteinemias of various causes, with a high specificity of 95.5% in detecting multiple myeloma, although with a low sensitivity of 40%. In multiple myeloma NCAM is significantly correlated with beta 2-microglobulin, paraproteinemia, and low albumin levels. For the determination of tumor load beta 2-microglobulin levels accord best with the Salmon and Durie classification scheme. When patients are grouped according to their clinical course, the disease development is reflected better by NCAM than by beta 2-microglobulin or interleukin-6. Survival data indicate that all three markers have prognostic potential. Prognostic accuracy with respect to overall survival is best with beta 2-microglobulin.

Insulin-like growth factors stimulate the release of insulin-like growth factor-binding protein-3 (IGFBP-3) and degradation of IGFBP-4 in nonsmall cell lung cancer cell lines

Insulin-like growth factors (IGFs) are potent mitogens for lung cancer cells. Their proliferative activity is influenced by their binding proteins (IGFBPs). We report here on the regulatory effects of IGF-I and IGF-II on the production and release of IGFBPs by nonsmall cell lung cancer cell lines (NSCLC). The nine NSCLC cell lines used in this study showed messenger ribonucleic acid (mRNA) expression of all six IGFBPs known, as determined by PCR, and protein secretion of IGFBP-1, -2, -3, -4, and -5, as analyzed by Western immunoblots. The addition of IGFs to a serum-free medium showed divergent effects on IGFBP-3 and IGFBP-4 levels in a conditioned medium (CM). IGF-I and IGF-II, but not insulin, led to a much higher concentration of IGFBP-3 in the CM of all tested NSCLC cell lines, whereas the level of immunologically detected membrane-associated IGFBP-3 was decreased. Furthermore, Northern analysis of mRNA isolated from A549 revealed that IGFBP-3 specific mRNA was not changed by IGF-I or IGF-II, suggesting that the IGF-induced effects on IGFBP-3 depend on the release of cell-associated IGFBP-3. In contrast, IGFBP-4 levels were diminished by increasing concentrations of IGFs in the CM of the NSCLCs A549, NCI-H157, and U1752, with no response to insulin or the IGF-I analog, whereas IGFBP-4-specific mRNA was not changed by IGF-I or IGF-II, as determined by Northern analysis. The same effects were seen in a cell-free system after incubation of the CM with IGFs. The decrease in IGFBP-4 concentrations was prevented by coincubation of the CM with the IGFs and either ethylenediamine tetraacetate or 1,10-phenanthrolene, but not with other protease inhibitors. We suggest that IGFs may either activate an IGFBP-4-specific metalloprotease present in NSCLC CM or that the binding of IGFs to IGFBP-4 may enhance the susceptibility of IGFBP-4 to proteolytic degradation. Based on these data, we present evidence that IGFs may regulate their own availability both by releasing IGFBP-3 from cell membrances and through proteolytic degradation of IGFBP-4.

Serum neural cell adhesion molecule differentiates multiple myeloma from paraproteinemias due to other causes

Serum neural cell adhesion molecule (NCAM) has been described as a prognostic marker in multiple myeloma (MM). Both C-reactive protein (CRP) and beta 2-microglobulin (beta 2M) are established prognostic markers in MM. We tested the diagnostic value of these markers in 212 serum samples of patients with paraproteinemia registered prospectively in a population-based registry. Sixty patients had MM and 152 had other monoclonal gammopathies (hematologic diseases [48], paraneoplastic disease [35], autoimmune disease [15], and monoclonal gammopathy of undetermined significance [56]). CRP and beta 2M had wide and overlapping ranges in all diagnostic categories. However, serum neural cell adhesion molecule (NCAM) was low (< 20 U/mL) in all but 4 of 152 nonmyeloma cases and high (> or = 20 U/mL) in 31 (52%) of the 60 MM cases. Two patients with non-Hodgkin's lymphoma, 1 with chronic lymphatic leukemia, and 1 with autoimmune disease had serum NCAM values between 20 and 30 U/mL. In a discriminant analysis in which serum NCAM, CRP, beta 2M, paraprotein type and concentration, hemoglobin, leukocyte and thrombocyte counts, creatinine, corrected calcium, lactate dehydrogenase, and alkaline phosphatase were included, paraprotein type and concentration and serum NCAM turned out to be the best combination of parameters predicting whether a patient had MM, with 89% of cases being correctly classified. Even without bone marrow and x-ray examinations, serum NCAM, in combination with paraprotein type and concentration, can differentiate between MM and nonmyeloma patients.

Characterization of tumor-associated neural cell adhesion molecule in human serum

In human serum, at least two molecular species of the neural cell adhesion molecule (NCAM) with molecular weights of 110,000-130,000 and 150,000-180,000, respectively, can be identified by Western blotting. Both are characterized by the absence of epitopes for monoclonal antibodies KD11 and MG5, which specifically recognize intracellular domains of the human NCAM transmembrane isoforms, NCAM-140 and NCAM-180. In contrast to the M(r) 110,000-130,000 molecule also detectable in serum samples from healthy blood donors, the M(r) 150,000-180,000 molecule appears to be tumor associated. The only difference between these two species is shown to be the presence of long chains of alpha-(2,8)-linked N-acetylneuraminic acids, which are characteristic for the so-called embryonic NCAM form. After treatment with endoneuraminidase N, the M(r) 150,000-180,000 molecule can no longer be discriminated from the M(r) 110,000-130,000 molecule in Western blotting as well as gel and anion exchange chromatography experiments. The experimental data clearly show that only the embryonic NCAM molecule carrying the poly-alpha-(2,8)-linked N-acetylneuraminic acid moiety can be regarded as a specific serum marker for small cell lung cancer.

Re-assessment of acidic glycosphingolipids in small-cell-lung-cancer tissues and cell lines

The occurrence of tumor-associated glycosphingolipids (GSLs) has been documented in a variety of cancer tissues (Hakomori, 1984, 1985, 1989). In the case of small-cell lung cancer (SCLC), the monosialoganglioside IV2Fuc-II3NeuAc-Gg4Cer (Fuc-GM1; short notations of gangliosides are according to Svennerholm, 1963), first described from bovine liver (Wiegandt, 1973), was found to be a unique tumor-associated GSL (Nilsson et al., 1984). It is present in up to 90% of all SCLC cases as compared with 25% frequency in non-SCLC, and no occurrence in normal lung (Brezicka et al., 1989, 1992). Thus, Fuc-GM1 may represent a suitable target antigen for immunotherapy of SCLC, and successful experiments have been performed showing tumor-cell killing by monoclonal antibodies (MAbs) against Fuc-GM1, both in vitro and, in a mouse model, in vivo (Brezicka et al., 1991). However, an effective tumor vaccination in humans would require this antigen to be expressed by the primary tumor and also by all metastases. The co-expression of Fuc-GM1 has already been reported in primary tumors and in most but not all metastases of SCLC (Hanquing et al., 1986; Nilsson et al., 1986; Brezicka et al., 1989). In view of the significance this ganglioside may have for possible immunotherapeutical approaches to SCLC and of the difficulty in obtaining a sufficient number of samples for analysis, a re-assessment of Fuc-GM1 expression was made in SCLC primary tumors and their metastases, as well as in established SCLC cell lines. In addition, the possible presence of such gangliosides, that might help to explain the selective tetanus-toxin binding of SCLC cells (Critchley et al., 1986; Heymanns et al., 1989) was investigated. Finally, the typical occurrence of sulfatide in all SCLC tissues and cell lines could be established.

Evaluation of serum neural cell adhesion molecule as a new tumor marker in small cell lung cancer

BACKGROUND

Small cell lung cancer (SCLC) is distinguished from other histologic types of lung cancer by possessing a variety of neuroendocrine properties. Neuron-specific enolase (NSE) is the most frequently elevated tumor marker for patients with SCLC at diagnosis. To assess the value of neural cell adhesion molecules (NCAM), another possible tumor marker for small cell lung cancer, NCAM was evaluated in the sera of patients with histologically confirmed SCLC in two prospective multicenter trials.

METHODS

The study includes 221 patients with SCLC, normal human blood donors (n = 34), patients with benign lung disease (n = 53), and patients with non-small cell lung cancer (n = 28). NCAM was determined by means of an enzyme immunoassay, NSE by a radioimmunoassay.

RESULTS

The data show the following: (1) 51% (113 of 221) of all patients with SCLC had NCAM levels higher than 20 U/ml, 34% (75 of 221) had NSE levels higher than 25 ng/ml; (2) levels of both markers significantly differ between limited and extensive disease patients; (3) patients with pathologic NCAM and NSE levels have significantly shorter survival times; (4) a positive correlation between pretreatment NSE and NCAM levels was found (n = 221, r = 0.60); and (5) a correlation between serum marker levels and clinical status was found in follow-up studies of 19 patients.

CONCLUSIONS

From these data, it is concluded that NCAM is, along with NSE, a potential tumor marker for SCLC.

Molecular cloning of IGFBP-5 from SCLC cell lines and expression of IGFBP-4, IGFBP-5 and IGFBP-6 in lung cancer cell lines and primary tumours

We showed recently that insulin-like growth factor binding protein (IGFBP)-1, -2 and -3 are differentially expressed in lung cancer and permanent lung cancer cell lines. Elevated levels of IGF binding capacity in serum of lung cancer patients were also reported. The function and tissue specificity of IGFBP are still obscure but they are probably local regulators of IGF action. Here we show the expression of IGFBP-4 transcripts in 11/11 small cell lung cancer (SCLC) cell lines, in nine out of 11 non-small cell lung cancer (NSCLC) cell lines, in 11/11 lung tumour specimens (10 derived from patients with NSCLC and one from SCLC origin) and in normal lung. In addition we isolated IGFBP-5 cDNA from lambda gt10 libraries of SCLC cell lines. With this IGFBP-5 cDNA we detected transcripts of different lengths in seven out of 11 SCLC cell lines, in 11/11 lung cancer specimens but only in one out of 11 NSCLC cell lines and in normal lung. IGFBP-6 was not detected in northern analysis of any tested SCLC cell line but it was expressed in nine out of 11 NSCLC cell lines and in nine out of 11 human lung cancer specimens and in normal lung.

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.

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.

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.

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.

Growth regulation by insulin-like growth factors in lung cancer

Lung cancer is a major health problem, with over 38,000 new cases expected every year in West Germany. A more complete understanding of the biology of lung cancer will hopefully lead to therapeutic modalities. The possible autocrine growth regulation in small-cell lung cancer and non-small-cell lung cancer has been demonstrated for bombesin/GRP, vasopressin, neurotensin, EGF/TGF alpha, transferrin-related peptides and insulin-like growth factors. This contribution concentrates on recent data concerning binding sites, growth promoting effects and secretion of IGFs in lung cancer cell lines. The production of IGF-binding proteins which were also produced by lung cancer cell lines modifies the autocrine/paracrine model for IGFs since then proteins can either enhance or inhibit the effect of IGFs on tumor growth.

Carcinoembryonic antigen as differentiation marker for small cell lung cancer in vitro and its clinical relevance

Fifteen small cell lung cancer (SCLC) cell lines and 249 histopathological specimens from patients with SCLC were investigated for carcinoembryonic antigen (CEA) expression. Quantitative determinations of CEA in cell line homogenates correlated significantly (p less than 0.001) with L-DOPA decarboxylase (DDC) activities and population doubling times (PDT). Using monoclonal antibodies specific for CEA (BW 431/31) and crossreactive with non-specific crossreacting antigens (NCA) 55 and 95 (BW 250/183 and BW 374/14), the CEA-reactive moiety in SCLC was immunologically identified as CEA. In vivo studies demonstrated CEA by immunohistochemistry in 57% (141/249) of newly diagnosed SCLC. The presence of CEA and the degree of immunostaining did not correlate with clinical parameters.

Production of insulin-like growth factor binding proteins by small-cell lung cancer cell lines

Conditioned serum-free media (CM) from small-cell lung cancer (SCLC) cell lines were examined for the presence of insulin-like growth-factor-binding proteins (IGF-BP). 6/9 SCLC cell lines secreted binding proteins with high affinity for IGFs. When [125I]IGF-I or [125I]IGF-II was incubated with the CMs, complexes of tracer with proteins could be demonstrated by gel filtration, by precipitation with polyethylenglycol, and after adsorption of unbound tracer with activated charcoal. Analysis of binding data according to the method of Scatchard resulted in linear plots for IGF-I and IGF-II. The dissociation constants were determined to be 0.106 nM for IGF-I and 0.209 nM for IGF-II binding. Cross-linking of [125I]IGF-I or [125I]IGF-II to the CMs followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions revealed the presence of IGF-BPs with molecular masses in the range 24-32 kDa. The binding was competitively inhibited by addition of cold IGF-I and IGF-II but not by insulin. Northern blot hybridization with an IGF-BP cDNA probe encoding a low-molecular-weight IGF-BP from a human placenta cDNA library and Western blot analysis with a corresponding polyclonal antibody showed no expression of this gene. These data demonstrate that SCLC cell lines release IGF-BPs in culture supernatants, which differ from IGF-BPs detected in liver and placenta. These IGF-BPs might be important mediators in the autocrine/paracrine growth regulation of IGFs in SCLC.

Androgen receptors, androgen-dependent proliferation, and 5 alpha-reductase activity of small-cell lung cancer cell lines

We investigated the influence of testosterone on binding to established small-cell lung cancer (SCLC) cell lines and were able to show specific high-affinity and low-capacity binding sites in some cell lines with a typical receptor size, using sucrose density gradient centrifugation. In addition, we demonstrated marked growth stimulation with testosterone and dehydrotestosterone using different androgen-receptor-positive small-cell lung cancer cell lines. This growth stimulation could be counteracted by the addition of anti-androgens like cyproterone acetate or flutamide. The presence of 5 alpha-reductase activity, 17 beta-hydroxysteroid-dehydrogenase and 3 alpha-hydroxysteroid-dehydrogenase activities could be demonstrated, suggesting testosterone metabolism of small-cell lung cancer cell lines.

Prognostic value of pretreatment carcinoembryonic antigen, neuron-specific enolase, and creatine kinase-BB levels in sera of patients with small cell lung cancer

Carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and the BB isoenzyme of creatine kinase (CK-BB) were evaluated before therapy in the sera of 195 patients with histologically confirmed small cell lung cancer (SCLC) in a prospective multicenter trial. Forty-four percent (84 of 193) of all patients had CEA levels higher than 5 ng/ml, 66% (111 of 168) had NSE levels higher than 12.5 ng/ml, and 32% (40 of 123) had CK-BB levels higher than 10 ng/ml. Clear pathologic levels were less frequently observed. Significantly higher pretreatment titers for CEA, NSE, and CK-BB were found in patients with bone marrow and/or liver metastases. The most elevated marker levels were observed in the group of nonresponding patients with bone marrow and/or liver metastases. Only a slight correlation between the pretreatment CEA level and survival time could be observed. Patients with pathologic NSE (greater than or equal to 30 ng/ml) levels and, in particular, those with pathologic CK-BB (greater than or equal to 25 ng/ml) levels had a significantly shorter median survival than those with normal or elevated levels. In addition, a positive linear correlation between pretreatment NSE and CK-BB (n = 116, r = 0.54) levels was found, but CEA levels did not correlate with other marker levels. From these data it is concluded that pretreatment CEA, NSE, and CK-BB levels are helpful in the clinical management of a subset of patients with SCLC, i.e., those with bone marrow and/or liver metastases.

Peptides and growth factors in small cell lung cancer: production, binding sites, and growth effects

We investigated the production, binding to cell membranes, and influence on cell proliferation of peptides and growth factors in 4 classic, 5 transitional, and 5 variant SCLC cell lines. Glucagon, neurotensin, and TGF-alpha were present in all cell lines. Bombesin was predominantly found in classic cell lines and insulin in variant cell lines. Neurokinin A, calcitonin, CGRP, GHRF, somatostatin, and CNTF were detectable in some cell lines without prevalence for a particular cell type. We could not detect AVP, growth hormone, neuropeptide Y, substance P, VIP, and NGF. Insulin binding sites were present on 11/14 cell lines, and some cell lines specifically bound bombesin, calcitonin, and EGF. Growth effects were detectable for insulin, GRP-related peptides, tachykinins, and VIP. Using serum-free conditions, insulin and VIP had a growth stimulating effect in liquid culture at nanomolar concentrations. Bombesin and neuromedin B stimulated the clonal growth at a concentration of 3-30 nM. The tachykinins neurokinin A, neurokinin B, physalaemin, and eledoisin inhibited the clonal and mass culture growth with a peak effect in the range of 0.1 to 10 pM. Peptide-induced stimulating and inhibiting effects were within a magnitude of 2-fold. All other peptides and growth factors tested, including ACTH, AVP, calcitonin, glucagon, neurotensin, somatostatin, EGF, CNTF, and NGF did not affect the growth of SCLC. We conclude that the growth of SCLC is partly controlled by such peptides in an autocrine/paracrine fashion.

Production of immunoreactive insulin-like growth factor I and response to exogenous IGF-I in small cell lung cancer cell lines

Small cell lung cancer (SCLC) cell lines were examined for the presence of insulin-like growth factor I-related protein (IGF-I) in cell pellets and culture media. IGF-I immunoreactivity was detected in 11/14 pellets, ranging from 12 to 76 mIU/mg soluble protein. The IGF-I levels in the cell pellets showed a correlation to the corresponding culture media. IGF-I binding sites were found in all tested cell lines. The maximum binding (Bmax) ranged from 131 to 1230 fmol/mg protein and the dissociation constant (KD) from 0.89 to 5.21 nM. The incorporation of [3H]thymidine in the presence of recombinant human IGF-I resulted in a clearly increased DNA synthesis in two of seven cell lines. Thus, IGF-I may be an important growth factor in SCLC.

Characterization of the state of differentiation of six newly established human non-small-cell lung cancer cell lines

Six new non-small-cell lung cancer (NSCLC) cell lines were established directly from human tissue or indirectly via nude mouse xenografts in serum-supplemented media with success rates of 8% and 13%, respectively. They comprised one adenocarcinoma (ADLC-5M2), two squamous cell carcinomas (EPLC-32M1, EPLC-65H), two large cell carcinomas (LCLC-97TM1, LCLC-103H), and one malignant biphasic mesothelioma (MSTO-211H). All cell lines grew adherent to culture vessels with population doubling times (PDT) of 16-40 h, formed colonies in soft agarose with efficiencies of 0.1%-5.1%, and all grew in athymic nude mice. Xenograft histologies appeared as follows: (a) undifferentiated carcinomas with feeble resemblance to the original tumors in the case of adenocarcinomas and squamous cell carcinomas; (b) large cell carcinoma with high resemblance to the original tumor; (c) an undifferentiated tumor with predominance of large epithelial cells and few fibrous cells in the case of mesothelioma. Human chorionic gonadotropin (HCG) was found by radioimmunoassay and high-affinity binding sites for epidermal growth factor (EGF) by radio-receptor assay in 4/4 cell lines. A very low activity of L-DOPA decarboxylase (DDC) was detectable only in the adenocarcinoma cell line. All cell lines overexpressed the c-myc protooncogene, and no gene rearrangement or amplification was observed. Chromosome analysis revealed modal chromosome numbers of 70-73 in ADLC-5M2, EPLC-32M1, EPLC-65H, and MSTO-211H. Cell lines derived from large cell carcinoma had modal values of 65 and 170 and a wider chromosome distribution than all other cell lines. A NSCLC specific chromosomal aberration has been undetectable until now. These cell lines may aid in elucidating the biology of NSCLC and its interrelationship to other lung tumors.

Peptide hormones in patients with acute leukaemia

Paraneoplastic production and secretion of peptide hormones by numerous malignant tumours is a well-known phenomenon. The incidence of the production of six peptide hormones was evaluated in patients with acute leukaemia. Most often the calcitonin gene-related peptides were found to be elevated in sera at the time of diagnosis. The values evaluated for the hormones were: h-CT 46.7%, CGRP 51%, s-CT 20.7%, PTH 15.7%, beta-HCG 15%, and ACTH 11.6%. A significant coincidence of two or more hormones was not observed. In 83.4% of the patients increased concentrations of at least one of the six hormones were found. Clinical and biochemical parameters showed no influence on the serum levels of these peptides. Analysis of elevated hormone serum levels in subtypes of leukaemia revealed that the calcitonin-related hormones were significantly correlated to more immature forms of leukaemia such as AUL and M1. Synthesis of calcitonin gene-related peptides was also seen in established leukaemic cell lines and in buffy coat cells of untreated patients with acute leukaemia. This investigation provides further evidence that peptide hormone production in leukaemic blasts is a common finding. These results further suggest hormone production to be a universal concommitant of neoplasia. A possible influence of these peptide hormones on the biological behaviour of the malignant cells is discussed.

Markers and characteristics of human SCLC cell lines. Neuroendocrine markers, classical tumor markers, and chromosomal characteristics of permanent human small cell lung cancer cell lines

Permanent human small cell lung cancer (SCLC) cell lines established in our laboratory were investigated for their expression of the enzymatic neuroendocrine markers L-DOPA decarboxylase (DDC), neuron-specific enolase (NSE), and creatine kinase (CK), including its BB isoenzyme (CK-BB), the classical tumor markers carcinoembryonic antigen (CEA), the alpha and beta subunits of human chorionic gonadotropin (alpha-HCG, beta-HCG), and alpha-fetoprotein (alpha-FP), and their chromosomal characteristics. DDC activities were detectable in 5/6 SCLC cell lines and absent in non-SCLC. NSE levels ranged from 160 to 1422 ng/mg soluble protein and were less than 290 ng/mg soluble protein in non-SCLC. Activities of CK and levels of CK-BB clearly distinguished SCLC from non-SCLC with CK activities greater than 1000 munits/mg soluble protein and CK-BB levels greater than 3000 ng/mg soluble protein in SCLC and less than 300 munits/mg soluble protein and less than 2000 ng/mg soluble protein in non-SCLC. CEA was detectable in 5/6 SCLC cell lines but absent in non-SCLC, and its level seemed to correlate with those of DDC, NSE, and CK. One cell line, SCLC-16H, lost some of its neuroendocrine properties and CEA after 1 year of in vitro cultivation. Generally, marker levels were low in fast growing cell lines and high in slow growing cell lines. HCG alpha and beta subunit and alpha-FP were not detectable in SCLC cell lines. All SCLC cell lines examined had near diploid DNA indices and modal chromosome numbers. Double minute chromosomes and homogeneously staining regions were found in 2/5 and 4/5 SCLC cell lines respectively. With respect to chromosomal aberrations, we found a deletion of the short arm of at least one chromosome 3 in all SCLC cell lines (5/5). These data show that SCLC expresses neuroendocrine markers and CEA; CK is the most sensitive marker, and DDC and CEA are the most specific markers for SCLC in vitro; individual marker levels correlate with each other and the in vitro malignancy of SCLC; and SCLC cell lines have relatively uniform chromosomal characteristics. Our results suggest that patients whose tumors have high levels of DDC, NSE, CK-BB, and CEA have a better prognosis than those with low marker levels. This hypothesis could be proved by comparing pairs of patients that are matched for all known prognostic parameters, in particular tumor spread, for their serum and tumor marker levels with respect to the patients' outcome and prognosis.

Characterization of two cell lines with distinct phenotypes established from a patient with small cell lung cancer

Two small cell lung cancer (SCLC) cell lines were established from pericardial and pleural effusions of a patient with histopathologically proven SCLC of the oat cell type. Chemotherapy was administered without response during the 148-day period prior to the establishment of the first cell line, SCLC-22H, and some of the same drugs were administered in the 15 days prior to the establishment of the second cell line, SCLC-21H. Both cell lines differed markedly in their biochemical, kinetic, and morphological properties. Although the biomarkers L-Dopa decarboxylase, bombesin, carcinoembryonic antigen, and neurotensin were detectable in SCLC-22H, they were undetectable or low in SCLC-21H. The population doubling time was twice as fast and the colony forming efficiency higher in SCLC-21H than in SCLC-22H. They both expressed high concentrations of the SCLC marker enzymes neuron-specific enolase and the creatine kinase isoenzyme BB and showed no significant differences in their chromosomal characteristics. c-myc was amplified and expressed in both cell lines, and SCLC-21H had an additional rearranged and amplified EcoRI c-myc fragment. Morphological differences were apparent in liquid culture, cytology, and xenograft histology; SCLC-21H grew much more loosely than SCLC-22H, and had more prominent nucleoli and more abundant cytoplasm. Ultrastructurally dense core granules were present in both cell lines. SCLC-21H thus expressed properties of the variant cell type of SCLC, whereas SCLC-22H had mixed classic/variant features. An in vivo progression of the patient's tumor from a pure small cell to a mixed small cell/large cell morphology could be demonstrated, which suggests that cell line SCLC-22H represents a cell type characteristic for the transitional phase of the tumor. The features of this cell line therefore define a new subclass of SCLC called transitional cell type. SCLC-22H may be of use to study the mechanisms involved in the classic to variant transition, which probably has a considerable impact on the prognosis and response to therapy.

Establishment, growth properties, and morphological characteristics of permanent human small cell lung cancer cell lines

Cell lines from SCLC were established with a success rate of 43% from different metastatic sites of treated and untreated patients. All 6 SCLC cell lines grew as floating cell aggregates without substrate adherence. The degree of aggregation ranged from very tight spheroids to very loose sheets and chains. This gross morphological property showed a striking correlation to the PDT, with short PDTs in loose growing cell lines and long PDTs in tight growing cell lines. Cell size and nuclear features, i.e., chromatin pattern and nucleolar prominence, also seemed to correlate with the PDT and gross morphology. All SCLC cell lines had dense core granules by electron microscopical examination. Several different serum-free and serum-supplemented growth media were tested for their feasibility in establishing and permanently growing SCLC. Serum-free SIT medium and SIT2.5 medium provided the best results in liquid culture. For semisolid SCLC cultivation, R 10 medium was superior to all other media tested. These cell lines are currently under intensive biochemical, molecular biological, and cytogenetical investigation in different laboratories and thus provide a tool for studying the biology of lung cancer.