Characterization of two newly established human cell lines from patients with large-cell anaplastic lung carcinoma

Structural Analysis of the Colony-Stimulating Factor 3 Gene of Granulocyte Colony-Stimulating Factor-Producing Urothelial Cancer

Background Granulocyte colony-stimulating factor (G-CSF) is a member of the CSF family of glycoproteins that regulate the proliferation, differentiation, and mobilization of neutrophils. G-CSF-producing malignant cancers have been reported to occur in various organs and are mostly associated with poor clinical prognosis. Here, we analyzed the structure of the CSF3 gene encoding the G-CSF protein to delineate the mechanism of G-CSF production by the cancer cells. Methodology Two cases of G-CSF-producing urothelial cancers and three cases of G-CSF-nonproducing bladder cancers were enrolled for genetic analysis. Results In one case of G-CSF-producing bladder cancer, six somatic mutations were detected in the 5'- upstream region of the CSF3 gene. No somatic mutations in the CSF3 gene were detected in another case of G-CSF-producing renal pelvic cancer and G-CSF-nonproducing bladder cancers. Copy numbers of the CSF3 gene were not increased in G-CSF-producing urothelial cancers. Conclusions Somatic mutations in the 5'- upstream region of the CSF3 gene may cause G-CSF protein overproduction.

Stat3 is a positive regulator of gap junctional intercellular communication in cultured, human lung carcinoma cells

Background

Neoplastic transformation of cultured cells by a number of oncogenes such as src suppresses gap junctional, intercellular communication (GJIC); however, the role of Src and its effector Signal transducer and activator of transcription-3 (Stat3) upon GJIC in non small cell lung cancer (NSCLC) has not been defined. Immunohistochemical analysis revealed high Src activity in NSCLC biopsy samples compared to normal tissues. Here we explored the potential effect of Src and Stat3 upon GJIC, by assessing the levels of tyr418-phosphorylated Src and tyr705-phosphorylated Stat3, respectively, in a panel of NSCLC cell lines.

Methods

Gap junctional communication was examined by electroporating the fluorescent dye Lucifer yellow into cells grown on a transparent electrode, followed by observation of the migration of the dye to the adjacent, non-electroporated cells under fluorescence illumination.

Results

An inverse relationship between Src activity levels and GJIC was noted; in five lines with high Src activity GJIC was absent, while two lines with extensive GJIC (QU-DB and SK-LuCi6) had low Src levels, similar to a non-transformed, immortalised lung epithelial cell line. Interestingly, examination of the mechanism indicated that Stat3 inhibition in any of the NSCLC lines expressing high endogenous Src activity levels, or in cells where Src was exogenously transduced, did not restore GJIC. On the contrary, Stat3 downregulation in immortalised lung epithelial cells or in the NSCLC lines displaying extensive GJIC actually suppressed junctional permeability.

Conclusions

Our findings demonstrate that although Stat3 is generally growth promoting and in an activated form it can act as an oncogene, it is actually required for gap junctional communication both in nontransformed lung epithelial cells and in certain lung cancer lines that retain extensive GJIC.

Establishment and characterization of primary lung cancer cell lines from Chinese population

AIM

To establish and characterize primary lung cancer cell lines from Chinese population.

METHODS

Lung cancer specimens or pleural effusions were collected from Chinese lung cancer patients and cultured in vitro with ACL4 medium (for non-small cell lung carcinomas (NSCLC)) or HITES medium (for small cell lung carcinomas (SCLC)) supplemented with 5% FBS. All cell lines were maintained in culture for more than 25 passages. Most of these cell lines were further analyzed for oncogenic mutations, karyotype, cell growth kinetics, and tumorigenicity in nude mice.

RESULTS

Eight primary cell lines from Chinese lung cancer patients were established and characterized, including seven NSCLC cell lines and one SCLC cell line. Five NSCLC cell lines were found to harbor epidermal growth factor receptor (EGFR) kinase domain mutations.

CONCLUSION

These well-characterized primary lung cancer cell lines from Chinese population provide a unique platform for future studies of the ethnic differences in lung cancer biology and drug response.

Cancer-associated myeloproliferation: old association, new therapeutic target

The association between malignancy and development of a paraneoplastic leukocytosis, the so-called leukemoid reaction, has long been appreciated. Although a leukemoid reaction has conventionally been defined as a peripheral blood leukocytosis composed of both mature and immature granulocytes that exceeds 50,000/microL, a less profound leukocytosis may be appreciated in many patients harboring a malignant disease. More recent insights have shed new light on this long-recognized association, because research performed in both murine models and cancer patients has uncovered multiple mechanisms by which tumors both drive myelopoiesis, sometimes leading to a clinically apparent leukocytosis, and inhibit the differentiation of myeloid cells, resulting in a qualitative change in myelopoiesis. This qualitative change leads to the accumulation of immature myeloid cells, which due to their immune suppressive effects have been collectively called myeloid-derived suppressor cells. More recently, myeloid cells have been shown to promote tumor angiogenesis. Cancer-associated myeloproliferation is not merely a paraneoplastic phenomenon of questionable importance but leads to the suppression of host immunity and promotion of tumor angiogenesis, both of which play an integral part in tumorigenesis and metastasis. Therefore, cancer-associated myeloproliferation represents a novel therapeutic target in cancer that, decades after its recognition, is only now being translated into clinical practice.

Tumor-related leucocytosis and chemotherapy-induced neutropenia: linked or independent prognostic factors for advanced non-small cell lung cancer?

Tumor-related leucocytosis is a paraneoplastic syndrome that is encountered occasionally in the clinical course of patients with non-small cell lung cancer (NSCLC). Autonomous production of hematopoietic cytokines (granulocyte-colony stimulating factor, granulocyte-macrophage-colony stimulating factor) has been identified in some of the patients presenting with this syndrome. In addition to the widely accepted prognostic factors of performance status and disease stage, recently, leucocytosis has been found to be a significant negative prognostic factor for overall survival and time to progression in patients with advanced-stage NSCLC in a pooled analysis of North Central Cancer Treatment Group trials, with data from about 1000 patients. A pooled analysis of an Italian Group with data from about 1300 patients has recently shown that neutropenia during chemotherapy is associated with increased survival of patients with advanced NSCLC. Similar results on the independent prognostic value of chemotherapy-induced neutropenia, have been reported by the Hellenic Oncology Research Group in a retrospective analysis on 850 patients. The absence of chemotherapy-induced neutropenia can be interpreted as a result of chemotherapy-underdosing. However, considering the negative prognostic value of leucocytosis, another interpretation should be ruled out: a proportion of the patients who do not experience chemotherapy-induced neutropenia may be associated with a worst prognosis because they may be characterized by base-line tumor-related leucocytosis and autonomous production of hematopoietic cytokines protecting them from chemotherapy-induced neutropenia. Prospective trials are needed to assess if NSCLC-related leucocytosis and chemotherapy-induced neutropenia are two linked or independent prognostic factors for NSCLC. This paper is a review of the available retrospective evidence on the aetiology and prognostic value of tumor-related leucocytosis and on the prognostic value of chemotherapy-induced neutropenia in advanced NSCLC. Moreover we try to hypothesize a possible correlation between these two phenomena and to give suggestions on the prospective evaluation of this hypothetical correlation in the next future.

Constitutive activation of met kinase in non-small-cell lung carcinomas correlates with anchorage-independent cell survival

Lung cancer is currently the most frequent cause of cancer death in North America. Hepatocyte growth factor (HGF) and its receptor Met are frequently over-expressed in non-small-cell lung carcinomas (NSCLC), but their potential role in tumor progression is not clearly known. To assess the role of HGF/Met signaling in lung carcinomas, we have examined the expression, activation status, and function of Met in NSCLC cell lines (n = 7), established from primary tumors or pleural fluids of cancer patients. We observed Met expression in three NSCLC cell lines, two of which exhibited constitutive tyrosine-phosphorylation of Met, and Met kinase activity. In addition, the observed constitutive activation of Met was sustained under anchorage-independent conditions, and correlated with phosphatidyl inositol 3-kinase-dependent cell survival. Immunoreactive HGF-like protein was secreted by two Met-positive and two Met-negative NSCLC cell lines. However HGF activity, as determined by the ability to induce cell scattering and tyrosine-phosphorylation of Met in reporter cell lines, was detected in conditioned medium from only one Met-negative NSCLC cell line: none of the conditioned media from Met-expressing NSCLC cell lines showed detectable HGF activity. Thus, constitutive activation of Met in NSCLC cell lines may occur at least in part through intracrine, or HGF-independent mechanisms. Interestingly, additional paracrine stimulation with exogenous recombinant HGF was required for DNA synthesis and correlated with increased activation of ERK1/2 in all Met-positive NSCLC cell lines, regardless of the basal activation status of Met. These findings indicate that a medium level of constitutive activation of Met occurs in some NSCLC cell lines, and correlates with survival of detached carcinoma cells; whereas additional paracrine stimulation by recombinant HGF is required for DNA synthesis. Thus constitutive and paracrine activation of Met may provide complementary signals that promote survival and proliferation, respectively, during tumor progression of NSCLC.

Tumor-related leukocytosis is linked with poor prognosis in patients with lung carcinoma

BACKGROUND

Tumor-related leukocytosis is a paraneoplastic syndrome that is encountered occasionally in the clinical course of patients with lung carcinoma. Recently, autonomous production of hematopoietic cytokines (granulocyte-colony stimulating factor [G-CSF], granulocyte-macrophage-colony stimulating factor [GM-CSF], and interleukin-6 [IL-6]) were identified in some of these patients. However, the incidence and clinical characterization of this phenomenon have not been clarified.

METHODS

During a 7-year period, 227 patients with carcinoma of the lung were investigated, and 33 patients were diagnosed with tumor-related leukocytosis. Except for one patient with small cell lung carcinoma, the other 32 patients had nonsmall cell lung carcinoma, and the highest incidence is recognized in large cell carcinoma. These 33 patients were examined for serum G-CSF, GM-CSF, and IL-6 levels using enzyme immunoassays and enzyme-linked immunosorbent assays. Tumor specimens were stained for antihuman cytokine (G-CSF, GM-CSF, and IL-6) monoclonal antibodies.

RESULTS

Sixteen patients showed high serum G-CSF levels, 4 patients showed high serum GM-CSF levels, and 18 patients showed high serum IL-6 levels. Twelve specimens stained positively against anti-G-CSF antibody. Two specimens stained positively against anti-GM-CSF antibody, and three specimens were stained positively against anti-IL-6 antibody, including one double positive specimen for both G-CSF and IL-6. All specimens that were positive for monoclonal antibodies were from patients with nonsmall cell lung carcinoma. These patients had a poor outcome compared with the other patients.

CONCLUSIONS

Tumor-related leukocytosis and cytokine production frequently occur in the clinical course of lung carcinoma, and this phenomenon is related mainly to nonsmall cell lung carcinoma. Its occurrence appears to be an ominous prognostic sign in patients with lung carcinoma.

Establishment and characterization of 20 human non-small cell lung cancer cell lines in a serum-free defined medium (ACL-4)

To facilitate the studies in cell biology and drug sensitivity of non-small cell lung cancer, cell samples from 55 patients have been used to establish cell lines in culture using a chemically defined medium (ACL-4). A total of 20 cell lines (36 percent) were directly established and characterized: 14 (44 percent) from pleural effusions, five (29 percent) from resected primary tumors, and one (25 percent) from ascitic fluids. They comprised 16 adenocarcinoma, two large cell carcinoma, one squamous cell carcinoma, and one malignant mesothelioma. Each cell line had distinct gross morphologic features and population doubling times from 21 to 75 h. The plating efficiency was 0.01 to 9.51 percent. The modal chromosome number varied from 45 to 108. Secretion of tumor markers (carcinoembryonic antigen, sialyl Lewis Xi, CA 50, CA 125, and CA 19-9) into the medium was also different in each cell line. Most of the cell lines have been xenografted into nude mice and found to be tumorigenic. Survival of 20 patients whose tumor cell specimens continually grew in culture at any time during their clinical course was significantly shorter than that of 35 patients with no in vitro tumour growth (median survival time of 28 weeks vs 53 weeks, p = 0.0093). Our study indicates that in vitro tumor cell growth appears to be an adverse prognostic factor in patients with non-small cell lung cancer.

Nonrandom structural and numerical chromosome changes in non-small-cell lung cancer

Cytogenetic studies were performed on 27 tumor cell lines (most of which were derived from metastatic lesions) and four fresh malignant pleural and pericardial effusions from 30 patients with non-small-cell lung cancer (non-SCLC). Many clonal structural (deletions and nonreciprocal translocations) and numerical abnormalities were found in each specimen. Statistical analysis revealed these changes were nonrandomly distributed among the chromosomes. A statistically significant number of chromosomal breakpoints were seen in regions 1q1, 1q3, 3p1, 3p2, 3q1, 3q2, 7q1, 13p1, 14p1, 15p1, and 17q1 when the regions were compared to the total haploid complement. In addition, when a given region was compared to other regions within the same chromosome, statistically significant numbers of breakpoints were noted for regions 1q3, 5q1, 7q1, 13p1, 14p1, 15p1, 16q2, 17q1, and 21p1. Specific chromosome bands showing the most frequent involvement in structural abnormalities were (in descending order) 3p14.2, 3q21, 19q13, 11p15, 1q11, 7q11, 1q21, 3p23, and 3p21. The breakpoints indicate areas to look for new dominant oncogenes activated by translocations, while the areas of deletions and loss of material by nonreciprocal translocations highlight areas to search for recessive oncogenes. These cytogenetic studies represent strong evidence that multiple genetic lesions are associated with the development of metastatic lung cancer, and provide a roadmap to search for new genes involved in the pathogenesis of lung cancer.

Chromosome changes in a brain metastasis of a large cell lung cancer

Direct chromosome preparations were made on a brain metastasis of a large cell lung cancer from a 46-year-old female patient. In the 169 cells examined, the modal chromosomes number was 73, and the majority (53.2%) of mitoses were in the near-triploid region. The tumor cells showed considerable heterogeneity in chromosome number and content. Chromosomes 3, 4, and 5 were the most frequently involved in aberrations. The mean number of unidentified marker chromosomes was five per mitosis.

A23187 and protein kinase C activators stimulate phosphatidylinositol metabolism and prostaglandin synthesis in a human lung cancer cell line

Activation of cell phospholipase, release of arachidonic acid and stimulation of prostaglandin synthesis were studied in a newly described human tumor cell line (Lu-65). In the Lu-65 tumor cell line, the calcium ionophore A23187 (2 microM) caused a 100% increase in the release of 3H-arachidonic acid and a 7-fold increase in the synthesis of prostaglandin E2. 1-oleoyl, -2-acetyl-glycerol (100 microM) increased arachidonate release and prostaglandin E2 synthesis by 100%. A23187 and the protein kinase C activators, 1,2-dioctanoyl-glycerol and 1-oleoyl, -2-acetyl-glycerol, decreased the specific radioactivity of 3H-arachidonate in phosphatidylinositol by 37% and 57%, respectively. The effects of A23187 were blocked in Ca2+-free media or in the presence of the phospholipase A2 inhibitor, p-bromophenacyl bromide, while those of 1-oleoyl, -2-acetyl-glycerol were not. The data provide evidence in a human tumor cell line for calcium/phospholipase A2-dependent and independent pathways for arachidonic acid release, both of which preferentially hydrolyze phosphatidylinositol.

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.

Studying lung cancer in the laboratory: 1--Development of model systems

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Establishment of a human large cell lung tumor line (QU-DB) with metastatic properties in athymic mice

A continuous human cell line was established from a patient with large cell anaplastic lung carcinoma. This cell line, designated QU-DB, has been in culture for over 36 months and grows as an adherent monolayer with a doubling time of 10-12 hours. Its morphology, ultrastructure, karyotype, ability to grow in soft agar and heterotransplantability, indicate it is a large-cell lung tumor cell line of human origin. Three cell lines were established from metastatic tumors in nude mice receiving subcutaneous injections of QU-DB cells. The morphology and growth characteristics exhibited by these cell lines were similar to the primary cell line. Karyotypic analysis of cell lines derived from the primary tumor and a metastasis to the diaphragm were similar, but cells from a liver metastasis culture showed additional karyotypic changes. This large cell lung tumor cell line may prove useful as a model system for studies of human tumor progression and metastasis.

Characterization of prostaglandin endoperoxide synthase from a human cell line

Prostaglandin endoperoxide synthase has been purified from the recently established human lung tumor cell line, Lu-65. By gel filtration, the purified enzyme migrated with a relative molecular weight of 115,000, unlike the ovine enzyme, which migrated at 155,000. Two protein bands of 45,000 and 68,000 were seen when the purified Lu-65 enzyme was fractionated under reducing conditions by SDS-polyacrylamide gel electrophoresis; in contrast, purified ovine prostaglandin endoperoxide synthase showed the Mr 68,000 band under the same conditions. The purified Lu-65 enzyme showed both cyclooxygenase and hydroperoxidase activities, and metabolized [3H]arachidonic acid to 3H-labeled products that, when separated by reverse-phase HPLC, co-eluted with authentic prostaglandin D2 and prostaglandin E2. An apparent Km for arachidonic acid of 3 mM was measured for the purified enzyme, and the crude membrane-bound enzyme showed an apparent Km of 1.6 mM. Under the same conditions, an apparent Km of 17 microM was measured for the purified ovine enzyme.

Establishment and characterization of cell lines from human small cell and large cell carcinomas of the lung

Five new small cell carcinomas (SCC) cell lines and a large cell carcinoma (LCC) cell line were established from human lung cancers. The SCC cell lines had, as a group, common phenotypic properties which distinguished them from non-SCC cell lines. However, the studies also revealed a considerable biological heterogeneity among the individual SCC cell lines. Thus, the SCC cell lines had a typical growth pattern with cell clusters in suspension or partly adherent to the bottom. All the lines examined grew in agarose with variable cloning efficiencies, and all but one line formed tumors subcutaneously in nude mice. The ultrastructure of the SCC cell lines was characteristic with dense core granules at a variable frequency. Neuron-specific enolase was detectable in all SCC cell lines, usually in large amounts, and an inconstant production of a spectrum of polypeptide hormones was found, typical of SCC. The LCC cells proliferated in monolayers, formed colonies in agarose and grew in nude mice. Ultrastructurally, the LCC cell line differed from the SCC cell lines in having intra- and intercellular lumina and tonofilaments. The capacity of the LCC and a previously established squamous cell carcinoma cell line (U-1752) to produce neuron-specific enolase and polypeptide hormones was characteristically much lower than that of the SCC cell lines. We conclude from this study that SCC cell lines, although individually distinct from one another, are quite homogeneous as a group in expressing a set of basic common neuro-endocrine markers. However, these studies also suggest some biological relationship between SCC, LCC and SQC by virtue of their expression of some common neuro-endocrine markers, in support of the concept of a common histogenetic origin of human lung cancers.

Development of a new human breast cancer cell line Ia-270

A new human breast cancer cell line (Ia-270) has been isolated from a malignant pleural effusion from a woman with metastatic infiltrating ductal carcinoma of the breast. This cell line contains cytoplasmic estrogen (ER) and progesterone (PR) receptors. Following estradiol (E2) administration, PR synthesis is augmented and a higher level of saturation density is reached. In an athymic mouse, the cell line produced a tumor morphologically similar to the primary tumor. The results of isoenzyme and karyotype analyses demonstrate Ia-270 to be of human origin and free of HeLa cell contamination. The cell line has been maintained in continuous culture since April 1982 and may provide a useful in vitro system for studying the biology of human breast cancer.

Absence of parathyroid hormone messenger RNA in nonparathyroid tumors associated with hypercalcemia

We used a sensitive and specific hybridization assay that detects evidence of parathyroid hormone synthesis in tumors to investigate whether this hormone mediates the hypercalcemia of malignant disease. The assay uses radiolabeled, cloned parathyroid hormone DNA to hybridize selectively with parathyroid hormone messenger RNA. We assayed 13 human and 3 animal tumors of diverse cell origins that are frequently associated with the hypercalcemia of cancer. Five of the human tumors were obtained from patients known to be hypercalcemic at the time of tumor excision, two were from normocalcemic patients, and six were from patients with breast cancer whose serum calcium levels were unknown. Messenger RNA was prepared from cultured cell lines or tumors; active RNA fractions were hybridized with either human or bovine cloned parathyroid hormone DNA that had been labeled to a high specific activity with [32P]nucleotide. We were unable to detect parathyroid hormone RNA transcripts in any of the tumors. Our results indicate that parathyroid hormone rarely, if ever, causes hypercalcemia in malignant disease.