Autonomous expressions of cytokine genes by human lung cancer cells and their paracrine regulation

Collapse of Intra-Tumor Cooperation Induced by Engineered Defector Cells

Anti-cancer therapies promote clonal selection of resistant cells that evade treatment. Effective therapy must be stable against the evolution of resistance. A potential strategy based on concepts from evolutionary game theory is to impair intra-tumor cooperation using genetically modified cells in which genes coding for essential growth factors have been knocked out. Such engineered cells would spread by clonal selection, driving the collapse of intra-tumor cooperation and a consequent reduction in tumor growth. Here, I test this idea in vitro in four cancer types (neuroendocrine pancreatic cancer, mesothelioma, lung adenocarcinoma and multiple myeloma). A reduction, or even complete eradication, of the producer clone and the consequent reduction in cell proliferation, is achieved in some but not all cases by introducing a small fraction of non-producer cells in the population. I show that the collapse of intra-tumor cooperation depends on the cost/benefit ratio of growth factor production. When stable cooperation among producer and non-producer cells occurs, its collapse can be induced by increasing the number of growth factors available to the cells. Considerations on nonlinear dynamics in the framework of evolutionary game theory explain this as the result of perturbation of the equilibrium of a system that resembles a public goods game, in which the production of growth factors is a cooperative phenotype. Inducing collapse of intra-tumor cooperation by engineering cancer cells will require the identification of growth factors that are essential for the tumor and that have a high cost of production for the cell.

Serum Interleukin-6 Levels Correlate with Malnutrition and Survival in Patients with Advanced Non-Small Cell Lung Cancer

Aim

To investigate the level of interleukin-6 in advanced non-small cell lung cancer and to analyze the relationship with malnutrition and survival.

Methods and study design

Seventy-one newly diagnosed advanced non-small cell lung cancer patients were enrolled in this prospective study. Malnutrition was defined by using subjective global assessment. Performance status was assessed by the Karnofsky scale. Serum levels of albumin, transferrin, C-reactive protein, lymphocytes/mm3, lactate dehydrogenase and growth hormone were determined before treatment. The patients were followed, and the factors affecting survival were analyzed.

Results

The mean follow-up after diagnosis was 180 days. IL-6 levels increased in 48 (68%) of 71 patients. According to the subjective global assessment, 28 (39%) patients were well nourished and 43 (61%) were malnourished. Of the 43 malnourished patients, 29 (41%) were moderately malnourished or suspected of being malnourished and 14 (20%) were severely malnourished. The IL-6 level was related to impaired performance status (P = 0.0001), severe malnutrition (P = 0.004), increased C-reactive protein (P = 0.013), higher growth hormone (P = 0.025) and transferrin (P = 0.03) levels. On univariate analysis, impaired performance status, moderate and severe malnutrition, decreased serum albumin and transferrin, a raised IL-6 and lactate dehydrogenase levels were the significant prognostic factors for survival. Multivariate analysis indicated that a raised IL-6, severe malnutrition and a low serum level of albumin were independent prognostic factors for survival in patients with advanced non-small cell lung cancer.

Conclusions

IL-6 secretion may play a role in the pathophysiology of malnutrition in advanced lung cancer. Results show a relation between elevated IL-6 serum levels and malnutrition, poor performance status, acute phase response and shorter survival in patients affected by advanced non-small cell lung cancer.

Expression of human granulocyte colony stimulating factor (hG-CSF) in colon adenocarcinoma cell line (Caco-2)

Growth and progression of many cancer cells are mediated by alterations in the microenvironment often caused by an aberrant expression of growth factors and receptors. There is no report on expression of growth factor granulocyte colony-stimulating factor (G-CSF) in the experimental model, colon adenocarcinoma cell line (Caco2), that is commonly used in drug permeability assays. We hypothesize that in vitro, the Caco2 model is associated with a constitutive neo-expression of the hematopoietic G-CSF thereby causing an autocrine stimulation of Caco2 growth and proliferation in vitro. To test our hypothesis, we analyzed mRNA and protein expression of G-CSF in Caco2 cells using reverse transcriptase-PCR and SDS-PAGE. G-CSF mRNA and protein were detected in Caco2 cells. Expression of G-CSF protein was similar at different passages of this cell line. The expression of G-CSF has a significant role in the autocrine regulation of Caco2 cell growth and proliferation.

Cancer is a functional repair tissue

When a wound occurs, growth and repair genes (GR genes, such as oncogenes, proto-oncogenes, etc.) in surrounding cells are activated and secretion of growth and repair factors (GR factors, such as growth, stem cell, and stimulating factors, etc.) is induced to heal the wound. However, if the wound is persistent due to chronic physical (radiation, electromagnetic field, trauma, particles, etc.), chemical (carcinogens, toxic chemicals, heavy metals etc.) or biological (aging, free radicals, inflammation, nutrient deficiency, bacteria and virus infections, stress, etc.) damage, amplification of GR gene activation in surrounding cells may lead to a clinical cancer. Based on the commonalities between cancer and wound healing, a new hypothesis of cancer is presented: malignancies are not passive mutated useless masses; rather, they are functional tissues produced by GR gene activation to secrete GR factors in an effort to heal persistent wounds in the body. Based on the hypothesis, current cancer treatments aimed at killing cancer cells only may be misguided. The logical extension of the hypothesis is that cancer treatment focused on wound healing by limiting causes of persistent wounds, providing repair cells, GR factors, and substrates required by repair cells may yield more fruitful results than treatments focused on killing cancer cells alone. Spontaneous regressions of cancer, although rare, may be successful examples of serendipitous spontaneous wound healing. Standard therapies aimed at killing cancer cells, should be limited to adjuvant status for limiting symptoms or buying time for completion of the wound healing process. Attempts to destroy cancer cells without healing underlying persistent wounds will allow for eventual recurrence.

Expression of granulocyte colony stimulating factor receptor in human colorectal cancer

AIMS

To discover if human colorectal cancer expresses granulocyte colony stimulating factor receptor (G-CSFR) and if granulocyte colony stimulating factor (G-CSF) plays an important part in the development and progression of human colorectal cancer.

METHODS

Forty two specimens of colorectal cancer and normal colorectal mucosa were investigated, taken from the colon or rectum in group of colorectal cancer patients. Immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) technique were used to show G-CSFR expression. The relation between expression of G-CSFR and clinical or pathological factors was analysed.

RESULTS

Immucohistochemical analyses showed that G-CSFR was expressed in the human colorectal cancer (25 of 42, 59.52%) and seemed to be up-regulated compared with the normal mucosa (14 of 42, 33.33%, p<0.001). In pronounced contrast with mostly strongly positive tumours, corresponding normal colorectal mucosa was negative or weakly positive. A significant correlation was found between G-CSFR expression and tumour stage (p = 0.001), tumour differentiation (p<0.001), but there was no significant relation between the expression of G-CSFR and the age, sex, and tumour size (p = 0.346, p = 0.686, p = 0.459). In RT-PCR, 21 of all 42 tumours had G-CSFR mRNA expression, while only 11 of 42 normal colorectal mucosa had such expression.

CONCLUSIONS

These data show that G-CSFR is commonly expressed in human colorectal cancers, thus supporting a possible role for G-CSF in colorectal cancer physiology.

Hematopoietic cytokines as tumor markers

Stem cell factor (SCF), interleukin 3 (IL-3), granulocyte-macrophage-colony stimulating factor (GM-CSF), granulocyte-colony stimulating factor (G-CSF) and macrophage-colony stimulating factor (M-CSF) are members of a group of glycoproteins called hematopoietic cytokines (HCs). These cytokines regulate the growth and differentiation of hematopoietic progenitor cells and functionally activate mature neutrophils or macrophages. The effect of HCs is not limited to bone marrow cells. Some studies have shown that HCs can also stimulate the proliferation of non-hematopoietic cells. The receptors for HCs have been detected in cancer cell lines, and stimulation of HCs receptors induced proliferation of tumor cells. Moreover, some investigations have shown HC mRNA expression in these cell lines and recent studies have demonstrated that HCs can stimulate tumor progression. Several cells of malignant tumors have been observed to secrete large amounts of HCs and increased concentrations of HCs have been found in the sera of cancer patients. There are a number of situations in which the measurement of HCs may provide clinically useful information, particularly regarding prognosis and response to treatment. In this paper we discuss the results of studies that have examined the potential use of HCs as tumor markers.

Multifunctional interleukin-1beta promotes metastasis of human lung cancer cells in SCID mice via enhanced expression of adhesion-, invasion- and angiogenesis-related molecules

We examined whether interleukin-1 (IL-1), a multifunctional proinflammatory cytokine, progresses or regresses metastasis of lung cancer. Exogenous IL-1beta enhanced expression of various cytokines (IL-6, IL-8, and vascular endothelial growth factor (VEGF)) and intracellular adhesion molecule-1 (ICAM-1) by A549, PC14, RERF-LC-AI, and SBC-3 cells expressing IL-1 receptors. A549 cells transduced with human IL-1beta-gene with the growth-hormone signaling-peptide sequence (A549/IL-1beta) secreted a large amount of IL-1beta protein. Overexpression of IL-1beta resulted in augmentation of expression of the cytokines, ICAM-1, and matrix metalloproteinase-2 (MMP-2). A549/IL-1beta cells intravenously inoculated into severe combined immunodeficiency (SCID) mice distributed to the lung more efficiently and developed lung metastasis much more rapidly than did control A549 cells. Treatment of SCID mice with anti-IL-1beta antibody inhibited formation of lung metastasis by A549/IL-1beta cells. Moreover, A549/IL-1beta cells inoculated in the subcutis grew more rapidly, without necrosis, than did control A549 cells, which produced smaller tumors with central necrosis, suggesting involvement of angiogenesis in addition to enhanced binding in the high metastatic potential of A549/IL-1beta cells. Histological analyses showed that more host-cell infiltration, fewer apoptotic cells, more vascularization, and higher MMP activity were observed in tumors derived from A549/IL-1beta cells, compared with tumors derived from control A549 cells. These findings suggest that IL-1beta facilitates metastasis of lung cancer via promoting multiple events, including adhesion, invasion and angiogenesis.

Increased interleukin-6 in aqueous humor of a patient with lung-metastatic intraocular adenocarcinoma

PURPOSE

We report increased interleukin (IL)-6 level in aqueous humor of a case of lung adenocarcinoma with metastasis to iris and anterior chamber.

DESIGN

Interventional case report.

METHODS

In one case and 11 healthy cataract patients as controls, we checked the levels of IL-6, IL-2, and tumor necrosis factor (TNF)-alpha in aqueous humor and serum by enzyme-linked immunosorbent assay.

RESULTS

Levels of these three cytokines in serum were almost the same as with the levels in aqueous humor in the control group. The IL-6 concentrations ranged from 12.6 to 27.0 pg/ml (mean, 23.5 pg/ml) in serum and 15.0 to 43.1 pg/ml (mean, 22.4 pg/ml) in aqueous humor. There was no statistically significant difference between them. Compared with the control, the IL-6 concentration in aqueous humor of this patient, 282.0 pg/ml, increased more than 10-fold.

CONCLUSION

This is a report describing elevated IL-6 level in the aqueous humor of a patient with intraocular metastasis from lung adenocarcinoma.

Cytokine serum levels in soft tissue sarcoma patients: correlations with clinico-pathological features and prognosis

We investigated the correlations between serum levels of selected proinflammatory, hematopoietic and angiogenic cytokines and soluble cytokine receptors with the clinico-pathological features and prognosis in soft tissue sarcoma patients. Serum levels of 9 cytokines (TNFalpha, IL-1ra, IL-6, IL-8, IL-10, M-CSF, G-CSF, VEGF, bFGF) and 4 free cytokine receptors (sIL-2R alpha, sIL-6R, TNFRI, TNFRII) were measured by means of an enzyme-linked immunoadsorbent assay kit in 156 soft tissue sarcoma patients before the treatment and in 50 healthy controls. Serum levels of 10 cytokines and cytokine receptors were also assayed during patients' follow-up after the treatment. Significantly elevated pretreatment serum levels of 11/13 cytokines and cytokine receptors were found in sarcoma patients, as compared to healthy controls. In 40.4% of patients 6 or more cytokines and cytokine receptors (most frequently: TNF RI, IL-6, IL-8) were elevated in parallel. Serum levels of IL-6, sIL-2R, VEGF, M-CSF and TNF RI correlated significantly with tumor size and serum levels of IL-8 and IL-6 were significantly higher in patients with Grade 2/3 vs. Grade 1 tumors. We did not observe any significant differences in cytokine serum levels between patients with primary and recurrent tumors and patients with and without distant metastases. Using univariate analysis, overall survival (OS) in all patients was affected by tumor size (<5 cm vs. 5-10 cm vs. >10 cm), tumor grade (G1 vs. G2/3), presence of metastases, pretreatment serum levels of 8 cytokines (IL-6, IL-8, IL-10, sIL-2R, TNF RI, TNF RII, M-CSF, VEGF) and the number of cytokines increased (0-1 vs. 2-5 vs. < or = 6). Elevated serum levels of IL-6, IL-8, IL-10 and sIL-2R alpha, high tumor grade and larger tumor size strongly correlated with shorter disease-free survival (DFS). Multivariate analysis identified G2/3 tumor grade (p = 0.001), the presence of metastases (p = 0.004), elevated IL-6 serum level (p = 0.02), elevated IL-8 serum level (p = 0.048) and the number of cytokine serum levels above upper cut-off values (p = 0.01) as the independent prognostic factors related to OS, and G2/3 tumor grade (p = 0.005) and increased IL-6 serum level (p = 0.035) as independent prognostic factors related to DFS. In a group of patients without metastases (M0) higher tumor grade, elevated serum level of IL-6 and TNF RII, and the number of elevated cytokine serum levels correlated independently with poor survival. We found a significant decrease of several cytokine serum levels in patients after treatment (IL-1ra, IL-6, IL-8, IL-10, TNF RII, M-CSF) [p < 0.05]. Persistently elevated serum level of IL-6 after the treatment has also shown negative prognostic significance for OS (univariate analysis). Serum levels of some proinflammatory, hematopoietic and angiogenic cytokines and cytokine receptors are elevated, frequently in parallel, in a large percentage of soft tissue sarcoma patients. Significant correlations of serum cytokine levels with tumor size and grade suggest that some of these cytokines may be directly or indirectly involved in the progression of soft tissue sarcomas. Serum assays of IL-6, IL-8 and TNF RII before or after the treatment may be useful in establishing soft tissue sarcoma patients prognosis.

Lung macrophages and dendritic cells express HLA-G molecules in pulmonary diseases

HLA-G is selectively expressed in extravillous trophoblast of human placenta, which does not express classical HLA-A and -B molecules. Several studies report the role of HLA-G as a molecule involved in immune tolerance. By interacting with NK and T cells inhibitory receptors, HLA-G may downregulate their cytotoxicity functions. To appreciate the biologic and clinical relevance of HLA-G expression in lung diseases, HLA class I and HLA-G expression were analyzed in a panel of 36 ex vivo neoplastic tissues and 8 non-neoplastic lung tissues. Immunohistochemical analysis was performed using a pan-HLA class I antibody (W6/32) and three different specific anti-HLA-G antibodies (87G, MEMG/9 and 4H84). These findings demonstrated that HLA-G products were not expressed in pulmonary structural cells. However, HLA-G molecules were detected in activated macrophages and dendritic cells infiltrating lung carcinomas (33%) and nontumoral pulmonary diseases (25%). HLA-G expression was not correlated with classical HLA alterations. No statistical correlation was found between HLA-G expression and clinical or biologic parameters except high tumor size. The expression of HLA-G in myelo-monocytic cells infiltrating lung pathologic tissues could alter antigenic presentation and contribute to decrease immune response efficiency, subsequently favoring the progression of tumoral or inflammatory processes.

Granulocyte-Colony stimulating factor and macrophage-colony stimulating factor in patients with non-small-cell lung cancer

We have investigated the serum level of granulocyte-colony stimulating factor (G-CSF) and macrophagecolony stimulating factor (M-CSF) in non-small-cell lung cancer (NSCLC), in relation to the control group and commonly accepted tumor markers, such as carcinoembryonic antigen (CEA) and cytokeratin fragment 19 (CYFRA 21-1). Additionally, we have defined the diagnostic sensitivity, specificity, positive predictive value, negative predictive value and receiver-operating characteristics (ROC) curve of G-CSF and M-CSF. Serum levels of cytokines were measured in 61 patients with NSCLC and in 20 healthy subjects. G-CSF and M-CSF were determined using ELISA. CYFRA 21-1 was measured by radioimmunoassay and CEA by microparticle enzyme immunoassay. There were significant increases in the level of circulating G-CSF in the lung cancer patients compared to the control group. Moreover, the diagnostic sensitivity of G-CSF was higher (56%) than the sensitivity of CYFRA 21-1 (51%), but lower than the CEA sensitivity (62%). The diagnostic specificity of G-CSF was higher (70%) than the M-CSF specificity (40%) and the G-CSF predictive values were higher in relation to the predictive values of M-CSF. These results suggest a potential role of G-CSF as a tumor marker for NSCLC.

Induction of cytosolic phospholipase A2 by oncogenic Ras is mediated through the JNK and ERK pathways in rat epithelial cells

Mutations in ras genes have been detected with high frequency in nonsmall cell lung cancer cells (NSCLC) and contribute to transformed growth of these cells. It has previously been shown that expression of oncogenic forms of Ras in these cells is associated with elevated expression of cytosolic phospholipase A(2) (cPLA(2)) and cyclooxygenase-2 (COX-2), resulting in high constitutive levels of prostaglandin production. To determine whether expression of constitutively active Ras is sufficient to induce expression of these enzymes in nontransformed cells, normal lung epithelial cells were transfected with H-Ras. Stable expression of H-Ras increased expression of cPLA(2) and COX-2 protein. Transient transfection with H-Ras increased promoter activity for both enzymes. H-Ras expression also activated all three families of MAP kinase: ERKs, JNKs, and p38 MAP kinase. Expression of constitutively active Raf did not increase either cPLA(2) or COX-2 promoter activity, but inhibition of the ERK pathway with pharmacological agents or expression of dominant negative ERK partially blocked the H-Ras-mediated induction of cPLA(2) promoter activity. Expression of dominant negative JNK kinases decreased cPLA(2) promoter activity in NSCLC cell lines and inhibited H-Ras-mediated induction in normal epithelial cells, whereas expression of constructs encoding constitutively active JNKs increased promoter activity. Inhibition of p38 MAP kinase or NF-kappaB had no effect on cPLA(2) expression. Truncational analysis revealed that the region of the cPLA(2) promoter from -58 to +12 contained sufficient elements to mediate H-Ras induction. We conclude that expression of oncogenic forms of Ras directly increases cPLA(2) expression in normal epithelial cells through activation of the JNK and ERK pathways.

Elevated expression of interleukins in lung adenocarcinomas induced by N-Nitrosobis(2-hydroxypropyl)amine in rats

The expression of interleukins (ILs) in lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats was investigated using a multiprobe RNase protection assay (RPA) followed by densitometric quantification. Male Wistar rats, 6 weeks old, were given 2000 ppm BHP in their drinking water for 12 weeks and maintained without further treatment until they were killed at week 25. Total RNAs were extracted from 14 individual adenocarcinomas and 2 specimens of normal lung tissue of untreated rats. In adenocarcinomas, elevated expression of IL-1alpha (6 / 14), IL-1beta (14 / 14), IL-3 (7 / 14), IL-4 (11 / 14), IL-5 (9 / 14), IL-6 (11 / 14) and IL-10 (8 / 14) was observed, compared with normal lung tissues. In contrast, no expression of IL-2 was detected in any case. The results suggest that preferential expression of these ILs and their complex networks may contribute to the development and progression of lung adenocarcinomas induced by BHP in rats.

Stem cell factor and granulocyte-macrophage-colony stimulating factor as candidates for tumour markers for non-small-cell lung cancer

We have investigated the serum level of stem cell factor (SCF) and granulocyte-macrophage-colony stimulating factor (GM-CSF) in relation to a control group and commonly accepted tumour markers, such as carcinoembryonic antigen (CEA) and cytokeratin fragment 19 (CYFRA 21-1). Additionally, we have defined the diagnostic sensitivity, specificity, positive predictive value, negative predictive value and receiver-operating characteristics (ROC) curve of SCF and GM-CSF in non-small-cell lung cancer (NSCLC). The serum levels of cytokines were measured in 50 patients with NSCLC and in 20 healthy subjects. SCF and GM-CSF were determined using enzyme-linked immunosorbent assay (ELISA), CYFRA 21-1 was measured by radioimmunoassay and CEA by microparticle enzyme immunoassay. There were significant increases in circulating SCF and GM-CSF in the lung cancer patients compared to the control group. The diagnostic sensitivity of GM-CSF was higher (70%) than the sensitivity of CEA (62%) and CYFRA 21-1 (51%). The diagnostic specificity of GM-CSF was lower (65%) than SCF specificity (70%), but the GM-CSF predictive values were higher in relation to the predictive values of SCF. These results suggest a potential role of SCF and GM-CSF as tumour markers for NSCLC.

Evaluation of interleukin-6 in bronchoalveolar lavage fluid and serum of patients with lung cancer

Increased levels of serum interleukin 6 (IL-6) are found in patients with lung cancer, and it has been shown that this is part of a systemic inflammatory response syndrome. This study was designed to measure IL-6 levels in bronchoalveolar lavage (BAL) fluid of patients with lung cancer and to describe the relationship of BAL fluid IL-6 to the known systemic increase in IL-6. Increased levels of BAL fluid IL-6 can be found in patients with lung cancer as compared with patients with chronic obstructive pulmonary disease who have acute infection (P = .007). In patients with cancer, no correlation between BAL fluid IL-6 and serum IL-6 was found (P = .8). BAL fluid IL-6 did not correlate with the number of lymphocytes or macrophages found in this fluid. BAL fluid IL-6 does not correlate with tumor size. Although serum IL-6 was higher in patients with extensive stage small cell lung cancer as compared with levels in patients with limited stage disease (P = .06), their corresponding BAL fluid levels were not different (P = .9). Serum IL-6 correlated with other acute phase reactants. This study thus demonstrates the feasibility of utilizing BAL fluid analysis for local cytokine/tumor marker production in lung carcinoma. It also shows that a local increase in IL-6 in the BAL fluid is independent of the systemic inflammatory response syndrome, whereas the serum increase in IL-6 is part of this syndrome.

Monocyte chemoattractant protein-1 gene modification of multidrug-resistant human lung cancer enhances antimetastatic effect of therapy with anti-P-glycoprotein antibody in SCID mice

Distant metastases and multidrug resistance are critical problems in the therapy of human small cell lung cancer (SCLC). In this study, we investigated whether transduction of the monocyte chemoattractant protein-1 (MCP-1) gene into multidrug-resistant (MDR) human lung cancer cells affected the formation of metastases or their inhibition by the anti-P-glycoprotein (P-gp) monoclonal antibody (MAb) MRK16. MDR human SCLC (H69/VP) cells were transduced with the human MCP-1 gene inserted into the expression vector BCMGSNeo. MCP-1 gene transduction had no effect on drug sensitivity, the expression of surface antigens or the in vitro proliferation of H69/VP cells. Using the metastatic model of NK cell-depleted SCID mice, H69/VP cells transduced with the MCP-1 gene were inoculated intravenously (i.v.) and formed metastatic colonies in the liver, kidneys and lymph nodes, similar to those formed by parent or mock-transduced cells. However, systemic treatment of the mice with MRK16 reduced the metastases of H69/VP cells in the liver, kidneys and lymph nodes, and was significantly more effective in inhibiting the metastases of MCP-1 producing H69/VP than those of mock-transduced cells. MCP-1 gene transduction significantly prolonged the survival of tumor-bearing mice treated with MRK16. Our findings suggest that local production of MCP-1 in the tumor site increases the anti-P-gp antibody-dependent cell-mediated cytotoxicity, and the MCP-1 gene-induced modification of MDR human SCLC cells thereby enhances the antimetastatic effect of therapy with anti-P-gp antibody. Thus, the accumulation of effector cells in the tumor site is a very important factor in the therapy using the anti-P-gp antibody.

Involvement of interleukin-6 in the elevation of plasma fibrinogen levels in lung cancer patients

BACKGROUND

Involvements of interleukin-6 (IL-6) and fibrinogen in cancer development have been independently studied. However, the association of these molecules in cancer patients remains uncertain. This study was conducted to clarify the association according to the clinicopathological characteristics of lung cancer patients.

METHODS

Serum IL-6 levels assayed in 339 patients without pleural effusion were assessed according to clinical stage, histological type of the cancer and levels of fibrin (ogen) degradation products (FDP), and C-reactive protein (CRP).

RESULTS

Elevations of serum IL-6 levels more than 4 pg/ml were found in 37.8% of all patients. According to the clinical stage and histological type, the elevations were significantly more frequent in the advanced stage (44.7%), in squamous cell (49.1%) and large cell carcinomas (63.6%). Similarly, the frequency of the elevated cases (> 400 mg/dl) and the mean value of the fibrinogen level were also higher in the advanced stage (54.2%, 455.0 mg/dl) and large cell carcinoma (54.6%, 459.3 mg/dl), respectively. The elevations of fibrinogen, FDP and CRP levels were found to be related to those of the IL-6 level.

CONCLUSION

In lung cancer, serum IL-6 elevations are particularly frequent in the advanced stages of patients with squamous cell and large cell carcinoma, which are associated with the elevated levels of fibrinogen, suggesting a possibility that IL-6 was involved not only directly, but also indirectly, through regulating plasma fibrinogen with promotion of cancer development in vivo.

Granulocyte colony-stimulating factor and interleukin-6-producing lung cancer cell line, LCAM

BACKGROUND AND OBJECTIVES

We describe a case of granulocyte colony-stimulating factor (GCSF) and interleukin-6 (IL-6)-producing lung cancer.

METHODS

A 53-year-old man underwent left upper lobectomy under diagnosis of lung cancer. The tumor obtained by a preoperative biopsy was analyzed.

RESULTS

Preoperative data showed leukocytosis with left-shift of leukocytic morphology and thrombocytosis and an elevated serum GCSF level. Histological examination revealed poorly differentiated adenocarcinoma. A cell line, named LCAM, was established from the tumor and the cytokines in the culture medium were measured by enzyme immunoassay. GCSF and IL-6 were produced in large amounts by LCAM, but granulocyte-macrophage colony-stimulating factor (GMCSF) and interleukin-3 (IL-3) were not. A proportion of LCAM expressed GCSF receptor on the cell surface, but IL-6 receptor could not be detected. LCAM proliferation was inhibited in the culture with antihuman GCSF antibody in a dose-dependent manner.

CONCLUSIONS

We suggest that LCAM proliferation is positively regulated by GCSF.

Palliative steroid therapy and serum interleukin-6 levels in a patient with lung cancer

We report a patient with metastatic adenocarcinoma of the lung who had a detectable serum interleukin-6 (IL-6) level. Despite systemic chemotherapy, the tumor progressed, with elevation of serum IL-6 level. Palliative steroid therapy with 20 mg/day of prednisolone resulted in the decline of serum IL-6 level and, simultaneously, improved anorexia and oral intake. Although there was no weight gain or improvement in hypoalbuminemia, these results suggest that steroids may suppress the abnormal production of IL-6 in cancer patients and that this action affects symptoms. Further study is warranted to clarify the role of IL-6 in tumor-related symptoms and the effect of steroid therapy in relation to IL-6 production in cancer patients.

Serum levels of interleukin 6 in patients with lung cancer

Serum interleukin 6 (IL-6) levels were measured in 75 patients with lung cancer and in 20 patients with benign lung diseases. IL-6 was detectable in 29 patients with lung cancer (39%), but was not detectable in any of the patients with benign lung diseases. Serum C-reactive protein levels and plasma fibrinogen levels were significantly higher and serum albumin concentration was significantly lower in lung cancer patients with detectable serum IL-6 levels than in those without detectable serum IL-6 levels and in patients with benign lung diseases. On the other hand, no significant difference was observed in blood platelet counts in these three groups. Moreover, serum IL-6 levels were not significantly different in lung cancer patients with or without clinically demonstrated distant metastasis. These results suggest that IL-6 may be a mediator of various reactions including an inflammatory response in lung cancer patients.