In vivo tumor growth enhancement by granulocyte colony-stimulating factor

Paraneoplastic Leukocytosis: A Poor Prognostic Marker in Pancreatic Adenocarcinoma

Hyperleukocytosis is a rare form of paraneoplastic syndrome that has been reported in adenocarcinomas, particularly pancreatic cancer. We present an elderly man with chronic abdominal pain and weight loss for six months. On examination, he had diffuse tenderness and marked ascites. A workup with a CT scan revealed a pancreatic mass, which was confirmed to be pancreatic adenocarcinoma on biopsy. His lab work showed a significant leukocytosis. An extensive infectious workup was negative. He was not on any medications known to cause a leukocytosis; therefore, his leukocytosis was attributed to his cancer. Unfortunately, he died just a few days later. This case highlights hyperleukocytosis as a paraneoplastic syndrome that is a poor prognostic sign, and can be used as a marker for disease progression. 

Evaluation of pro‑ and anti‑tumor effects induced by three colony‑stimulating factors, G‑CSF, GM‑CSF and M‑CSF, in bladder cancer cells: Is G‑CSF a friend of bladder cancer cells?

Cytotoxic chemotherapy is the standard treatment for patients with advanced bladder cancer. However, this treatment can cause transient and prolonged neutropenia, which can result in fatal infection. Three recombinant human colony‑stimulating factors (CSFs), granulocyte CSF (G‑CSF), granulocyte‑macrophage CSF (GM‑CSF), and macrophage CSF (M‑CSF), are currently available to reduce the duration and degree of neutropenia. The present study investigated the pro‑ and anti‑tumor effects of these three CSFs and the changes in molecular profiles. Xenograft tumors in athymic mice were generated by subcutaneously inoculating the human bladder cancer cell lines MGH‑U3 and UM‑UC‑3. A total of 2 weeks after cell inoculation, mice were randomly divided into four groups (control, G‑CSF, GM‑CSF and M‑CSF) and treated thrice a week for 2 weeks. Tumor growth during monitoring and tumor weight at the time of euthanization were significantly higher in mice treated with G‑CSF and lower in mice treated with GM‑CSF compared with the control mice. Tumors were examined by immunostaining with antibodies against proteins associated tumor proliferation (Ki‑67), angiogenesis [CD31 and vascular endothelial growth factor (VEGF)], anti‑immunity (CD204) and epithelial‑mesenchymal transition (EMT; E‑cadherin). Immunohistochemical staining revealed that tumor proliferation, angiogenesis, recruitment of M2 macrophages and EMT were promoted by G‑CSF, whereas lymphangiogenesis and recruitment of M2 macrophages were inhibited by GM‑CSF. Treatment‑associated changes in serum pro‑ and anti‑tumoral cytokines and chemokines were evaluated by enzyme‑linked immunosorbent assay (ELISA)‑based arrays. In the ELISA for serum, the levels of cytokines associated with angiogenesis (interleukin‑6 and VEGF), and EMT (transforming growth factor‑β1 and ‑β2) were elevated in mice treated with G‑CSF. Treatment with GM‑CSF and M‑CSF also affected the level of these cytokines characteristically. The current results indicate that administration of exogenous G‑CSF to patients with bladder cancer promotes tumor growth through promotion of cell proliferation, angiogenesis, recruitment of M2 macrophages and enhancement of EMT through the modulation of the tumor microenvironment.

Paraneoplastic Hyperleukocytosis in Pancreatic Adenocarcinoma

Background: Paraneoplastic hyperleukocytosis is a rare phenomenon observed in patients with adenocarcinomas and other malignancies. In this study, we present a case of paraneoplastic hyperleukocytosis in pancreatic adenocarcinoma secondary to excessive secretion of serum granulocyte colony-stimulating factor (G-CSF).

Presentation: We report a 71-year-old Caucasian male who presented to our hospital with hyperleukocytosis in the setting of locally advanced pancreatic adenocarcinoma. The patient was recently diagnosed 4 months before presentation and received abraxane/gemcitabine in addition to palliative radiation therapy for continued gastrointestinal bleeding. During routine laboratory assessment, the patient was found to have a white blood cell (WBC) count of 153 K/UL (75% neutrophils and 14% bands). Bone marrow biopsy and cytology were negative for neoplastic features. Serum G-CSF levels returned markedly elevated, supporting the diagnosis of paraneoplastic hyperleukocytosis. Interestingly, the WBC count decreased significantly following each of two cycles of chemotherapy, further suggesting a paraneoplastic etiology of hyperleukocytosis. The patient did not receive any growth factor support at any point before or during treatment.

Conclusion: In conclusion, the presence of hyperleukocytosis in cancer should raise clinical suspicion of a paraneoplastic phenomenon when other possible causes have been excluded. Hyperleukocytosis in this setting may correlate with progression of disease and lessen with treatment.

Gastric adenosquamous carcinoma producing granulocyte-colony stimulating factor: a case of a rare malignancy

Background

A gastric adenosquamous carcinoma (ASC) that produces granulocyte-colony stimulating factor (G-CSF) is an uncommon malignancy with a poor prognosis. Due to the rarity of this lesion, a standard treatment for the disease has not been established.

Case presentation

We describe a case of a 66-year-old male with a G-CSF-producing gastric ASC who presented with severe anemia and leukocytosis. A radical resection was performed, followed by a course of adjuvant chemotherapy. Histopathologic examination revealed that the tumor consisted of areas of both squamous cell carcinoma and adenocarcinoma. Immunohistochemical staining with an anti-G-CSF antibody was also positive. He was started on adjuvant capecitabine and oxaliplatin (CapeOX) 6 weeks after surgery. The patient stopped treatment after 3 months due to his own preference. Eight months following surgery, the patient was found to have diffuse lymph node, liver, and peritoneal metastases.

Conclusions

G-CSF-producing gastric ASC is a rare and aggressive tumor. Because patients are usually diagnosed at an advanced stage, multidisciplinary evaluation and innovative treatments are needed. The rarity of this disease, with its aggressive features, poses a significant challenge in its treatment. In this brief case report, we summarize the management and outcomes of G-CSF-producing gastric ASC.

Granulocyte-macrophage colony-stimulating factor increases tumor growth and angiogenesis directly by promoting endothelial cell function and indirectly by enhancing the mobilization and recruitment of proangiogenic granulocytes

Granulocyte-macrophage colony-stimulating factor has been widely used as an adjuvant therapy for cancer patients exhibiting myelosuppression induced by chemotherapy or radiotherapy. However, the effects of granulocyte-macrophage colony-stimulating factor on tumor growth, as well as its precise mechanism, are still controversial due to inconsistent evidence. This study investigated the effect of exogenous granulocyte-macrophage colony-stimulating factor on the growth of B16 melanoma, S180 sarcoma, and U14 cervical carcinoma in mice. The angiogenesis and recruitment of bone-marrow-derived cells were analyzed in tumor tissues. Interactions among granulocyte-macrophage colony-stimulating factor, bone-marrow-derived cells, and B16 tumor cells were investigated in vitro. Proangiogenic types of bone-marrow-derived cells in blood were assessed both in vivo and in vitro. The results showed that granulocyte-macrophage colony-stimulating factor markedly facilitated the growth of B16 and S180 tumors, but not U14 tumors. Granulocyte-macrophage colony-stimulating factor increased the densities of blood vessels and the number of bone-marrow-derived cells in B16 tumor tissues. The granulocyte-macrophage colony-stimulating factor–induced enhancement of tumor cell proliferation was mediated by bone-marrow-derived cells in vitro. Meanwhile, a distinct synergistic effect on endothelial cell function between granulocyte-macrophage colony-stimulating factor and bone-marrow-derived cells was observed. After separating two types of bone-marrow-derived cells, granulocyte-macrophage colony-stimulating factor–induced enhancement of tumor growth and angiogenesis in vivo was mediated by proangiogenic cells in granulocytes, but not monocytes, with CD11b+, vascular endothelial growth factor receptor 2, and C-X-C chemokine receptor 4 granulocytes possibly involved. These data suggest that granulocyte-macrophage colony-stimulating factor contributes to the growth and angiogenesis of certain types of tumor, and these mechanisms are probably mediated by proangiogenic cells in granulocytes. Applying granulocyte-macrophage colony-stimulating factor may attenuate the antitumor effects of chemotherapy and radiotherapy in certain types of tumor.

A Case of G-CSF-Producing Histiocytic Sarcoma of the Stomach

No reports have been published to date regarding primary gastric granulocyte colony-stimulating factor (G-CSF)-producing histiocytic sarcoma. We encountered a case of primary gastric histiocytic sarcoma that also fulfilled the criteria for a G-CSF-producing tumor. A 75-year-old man was diagnosed with gastric cancer with poorly differentiated adenocarcinoma. The patient's white blood cell count was elevated to 20,700/μL, and the G-CSF level was elevated to 380 pg/mL. A computed tomography scan showed hepatic infiltration; therefore, a preoperative diagnosis of T4 (liver) N2H0M0 cStage IV gastric cancer was made, and surgery was performed. No. 11d lymphatic metastasis was noted, resulting in invasion of the pancreatic tail, and combined resection of the liver, pancreas, and spleen was conducted with complete gastrectomy. The results of hematoxylin-eosin and immunohistochemical staining were subsequently assessed. On discharge, the G-CSF level had fallen to 22.7 pg/mL. Currently, the patient is still alive and has experienced no recurrence approximately 4 years after the operation.

Polymorphonuclear neutrophils and cancer: intense and sustained neutrophilia as a treatment against solid tumors

Polymorphonuclear neutrophils (PMN) are the most abundant circulating immune cells and represent the first line of immune defense against infection. This review of the biomedical literature of the last 40 years shows that they also have a powerful antitumoral effect under certain circumstances. Typically, the microenvironment surrounding a solid tumor possesses many of the characteristics of chronic inflammation, a condition considered very favorable for tumor growth and spread. However, there are many circumstances that shift the chronic inflammatory state toward an acute inflammatory response around a tumor. This shift seems to convert PMN into very efficient anticancer effector cells. Clinical reports of unexpected antitumoral effects linked to the prolonged use of granulocyte colony-stimulating factor, which stimulates an intense and sustained neutrophilia, suggest that an easy way to fight solid tumors would be to encourage the development of intense peritumoral PMN infiltrates. Specifically designed clinical trials are urgently needed to evaluate the safety and efficacy of such drug-induced neutrophilia in patients with solid tumors. This antitumoral role of neutrophils may provide new avenues for the clinical treatment of cancer.

A Case of Ovarian Clear Cell Carcinoma Simultaneously Producing Parathyroid Hormone-related Protein and Granulocyte Colony-Stimulating Factor

We describe the first report of an ovarian clear cell carcinoma simultaneously producing parathyroid hormone-related protein (PTHrP) and granulocyte colony-stimulating factor (G-CSF). A 64-year-old woman complained of general fatigue, loss of appetite, nausea, vomiting and constipation. The results of blood and biochemistry tests were white blood cell count of 21,060 /ml and calcium of 18.0 mg/dl, indicating an increase in the number of leukocytes and hypercalcemia. A computerized tomography scan showed a tumor in the lower abdomen with a maximum diameter of 16 cm and containing both cystic and solid parts. There was a remarkable elevation of the tumor marker CA 19-9, to 1611 IU/ml, and serum level of PTHrP was elevated to 25.9 pmol/ml. The PTH-intact level was 14 pg/ml, which was at the lower limit of the normal range. In addition, the G-CSF level was also elevated to 73 pg/ml (normal range: <38 pg/ml). Since hypercalcemia caused by tumor PTHrP production was suspected, and as this required elimination of the primary disease, extirpation of the tumor was carried out. Serum calcium levels promptly returned to 11.1 mg/ml on the first day following surgery, and PTHrP also dropped to its normal level on the same day. Histological and immunohistochemical examinations revealed that the tumor was clear cell adenocarcinoma which was partially positive for PTHrP and positive for G-CSF, indicating the tumor simultaneously producing PTHrP and G-CSF.

A case of granulocyte-colony stimulating factor-producing hepatocellular carcinoma confirmed by immunohistochemistry

Granulocyte-colony stimulating factor (G-CSF) is a naturally occurring glycoprotein that stimulates the proliferation and maturation of precursor cells in the bone marrow into fully differentiated neutrophils. Several reports of G-CSF-producing malignant tumors have been published, but scarcely any in the hepatobiliary system, such as in hepatocellular carcinoma (HCC). Here, we encountered a 69-yr-old man with a hepatic tumor who had received right hepatic resection. He showed leukocytosis of 25,450/microL along with elevated serum G-CSF. Histological examination of surgical samples demonstrated immunohistochemical staining for G-CSF, but not for G-CSF receptor. The patient survived without recurrence for four years, but ultimately passed away with multiple bone metastases. In light of the above, clinicians may consider G-CSF-producing HCC when encountering patients with leukocytosis and a hepatic tumor. More cases are needed to clarify the clinical picture of G-CSF-producing HCC.

Granulocyte-colony stimulating factor-producing pancreatic adenosquamous carcinoma showing aggressive clinical course

Herein, we encountered an 89-year-old woman with pancreatic cancer who presented with fever without infective focus, leukocytosis of 45,860 /microL, and elevation of serum granulocyte-colony stimulating factor (G-CSF). The patient could not receive any curative therapy due to an extremely aggressive clinical course. Specimens taken at necropsy revealed an adenosquamous carcinoma positive for G-CSF by immunohistochemistry; it was only the second reported case to date. She was finally diagnosed with G-CSF-producing pancreatic cancer. In light of the above, clinicians should consider the presence of G-CSF-producing tumors, including pancreatic cancer, when presented with patients showing leukocytosis of unknown origin and fever without infective focus.

Granulocyte colony-stimulating factor promotes tumor angiogenesis via increasing circulating endothelial progenitor cells and Gr1+CD11b+ cells in cancer animal models

Recombinant granulocyte colony-stimulating factor (G-CSF) is used for cancer patients with myelosuppression induced by chemotherapy. G-CSF has been reported to progress tumor growth and angiogenesis, but the precise mechanism of tumor angiogenesis activated by G-CSF has not been fully clarified. N-terminal-mutated recombinant human G-CSF administration increased WBCs and neutrophils in peripheral blood and reduced bone marrow stromal cell-derived factor-1 in mice, indicating its biological relevance. Mice were inoculated with Lewis lung carcinoma cells (LLCs) or KLN205 cells and treated with G-CSF. G-CSF accelerated tumor growth and intratumoral vessel density, while it did not accelerate proliferation of LLCs, KLN205 cells or human umbilical vein endothelial cells in vitro. In the absence of tumors, G-CSF did not increase circulating cells that displayed phenotypic characteristics of endothelial progenitor cells (EPCs). In the presence of tumors, G-CSF increased circulating EPCs. In addition, G-CSF treatment increased immune suppressor and endothelial cell-differentiating Gr1+CD11b+ cells in tumor-bearing mice. We conclude that G-CSF promotes tumor growth by activating tumor angiogenesis via increasing circulating EPCs and Gr1+CD11b+ cells in cancer animal models.

Induction of multicellular 3-D spheroids of MCF-7 breast carcinoma cells by neutrophil-derived cathepsin G and elastase

In tumor metastasis, multicellular aggregates of tumor cells form and disseminate into the blood or lymph vessels from the tumor mass, following the formation of tumor cell emboli in distant vessels. However, the mechanism by which aggregates form in the tumor mass is unknown. Neutrophils often exist in tumors and are considered to affect tumor development. We observed that neutrophils had the capacity to induce the aggregation of MCF-7 human breast carcinoma cells adhering to culture substrates. When MCF-7 cells were cultured with rat inflammatory neutrophils, the soluble fraction of their lysate, and the conditioned medium of neutrophils stimulated with N-formyl-Met-Leu-Phe plus cytochalasin B, multicellular aggregates formed within 16 h, and tightly aggregated 3-D spheroids formed when the cultures were prolonged. The spheroid-inducing reaction was reversible and energy-dependent. The MCF-7 cells induced to aggregate by the neutrophil extract showed growth potential, although the growth rate of the cells was slightly reduced. The aggregation was dependent on E-cadherin, because the spheroids dispersed into isolated cells on incubation with EGTA or anti-E-cadherin antibody following pipetting. The aggregation-inducing activity in neutrophils was completely inhibited by soybean trypsin-chymotrypsin inhibitor. Moreover, the commercially available human neutrophil elastase and cathepsin G induced the aggregation of MCF-7 cells and formation of spheroids. The proteases secreted by infiltrated neutrophils in tumors are implicated in the dissemination of tumor aggregates from primary tumor sites.

Laryngeal squamous cell carcinoma with ectopic production of granulocyte colony-stimulating factor and parathyroid hormone-related protein

It is known that malignant tumors occasionally produce hormone-like substances. However, they rarely produce two or more kinds of hormonal factors simultaneously. We describe the clinical, biochemical, and immunohistochemical findings in a patient with squamous cell carcinoma of the larynx associated with leukocytosis and hypercalcemia, without bone metastasis. The serum granulocyte colony-stimulating factor (G-CSF) level was 222 pg/ml (normal, < 38 pg/ml), and decreased to 15 pg/ml after surgery. The serum parathyroid hormone-related protein (PTHrP) level was 5.6 pmol/l (normal, < 0.5 pmol/l), and this also decreased, to less than 0.5 pmol/l. G-CSF and PTHrP increased again with tumor recurrence. The production of G-CSF from the tumor was confirmed by immunohistochemical staining with monoclonal antibody against human recombinant G-CSF. The tumor was revealed to produce both G-CSF and PTHrP. In this article, we describe this very rare case of primary squamous cell carcinoma of the head and neck with the simultaneous ectopic production of more than one hormone-like substance.

Cooperative autocrine and paracrine functions of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor in the progression of skin carcinoma cells

Tumor growth and progression are critically controlled by alterations in the microenvironment often caused by an aberrant expression of growth factors and receptors. We demonstrated previously that tumor progression in patients and in the experimental HaCaT tumor model for skin squamous cell carcinomas is associated with a constitutive neoexpression of the hematopoietic growth factors granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF), causing an autocrine stimulation of tumor cell proliferation and migration in vitro. To analyze the critical contribution of both factors to tumor progression, G-CSF or GM-CSF was stably transfected in factor-negative benign tumor cells. Forced expression of GM-CSF resulted in invasive growth and enhanced tumor cell proliferation in a three-dimensional culture model in vitro, yet tumor growth in vivo remained only transient. Constitutive expression of G-CSF, however, caused a shift from benign to malignant and strongly angiogenic tumors. Moreover, cells recultured from G-CSF-transfected tumors exhibited enhanced tumor aggressiveness upon reinjection, i.e., earlier onset and faster tumor expansion. Remarkably, this further step in tumor progression was again associated with the constitutive expression of GM-CSF strongly indicating a synergistic action of both factors. Additionally, expression of GM-CSF in the transfected tumors mediated an earlier recruitment of granulocytes and macrophages to the tumor site, and expression of G-CSF induced an enhanced and persistent angiogenesis and increased the number of granulocytes and macrophages in the tumor vicinity. Thus both factors directly stimulate tumor cell growth and, by modulating the tumor stroma, induce a microenvironment that promotes tumor progression.

Expression profiles of angiogenic growth factors in squamous cell carcinomas of the head and neck

Inhibition of angiogenesis by blocking angiogenic cytokines or their pathways has become a major target in experimental cancer therapies. This therapeutical approach requires a profound knowledge of growth factor profiles that contribute to tumor growth and progression. The respective knowledge is presently rather incomplete for head and neck squamous cell carcinomas (HNSCC). Therefore we studied expression of several angiogenic cytokines including VEGF, bFGF, PDGF-AB, PDGF-BB, G-CSF and GM-CSF in HNSCC in vivo and in vitro. In tumor tissues expression of all cytokines was observed albeit with marked differences concerning intensity and distribution pattern. Quantification of the cytokines in the supernatant of 15 tissue-corresponding HNSCC cultures revealed that VEGF, PDGF-AB and less frequently GM-CSF were secreted in high amounts of up to 13 ng/ml/10(6) cells. Twenty percent of the HNSCC cultures expressed only 1 cytokine in biologically active amounts, 60% 2 or 3 and 20% expressed the maximum of 4 cytokines simultaneously. Interestingly, we observed a distinct cytokine pattern: HNSCC cells secreting only 1 or 2 cytokines presented always with either VEGF and/or PDGF-AB, while G-CSF and GM-CSF were secreted primarily together with VEGF and PDGF-AB. The number of cytokines expressed by HNSCC cells correlated with the microvessel density of the original tumor and with the clinical outcome: tumors producing at least 3 cytokines revealed a significantly poorer patient prognosis. Our data indicate a major role for VEGF and PDGF-AB in HNSCC and that the additional secretion of G-CSF or GM-CSF might contribute to a poorer prognosis in patients suffering from these tumors.

Apheresis of immune diseases and apheresis using immunological specificity

It has been clearly shown that autoimmune diseases can be treated by apheresis by eliminating immune complexes, however, the effects of therapeutic apheresis are not limited to immune disorders. Almost all diseases are associated with immune systems. Immune systems can be regulated by advanced techniques of apheresis, including immunoadsorption and immunocytapheresis, removing immune effector molecules and various immune-associated cells selectively. Therefore, apheresis can be used as a nondrug treatment for many diseases. In addition, disease-associated proteins that cause disease or are produced in the course of diseases and accumulate in the body could be eliminated selectively by apheresis using the extremely powerful ability of the immune system to recognize polypeptide structures specifically and distinguish miniscale differences among molecules. In this article, we discuss the current status of treatment of immune diseases by apheresis and possible treatment approach of a variety of diseases by apheresis based on immune reactions.

Does [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]- dichloro-platinum(II) act as an immune response modifier? Part III: Progressively growing MXT-M-3,2 breast cancer stimulates the proliferation of phagocytes in B6D2F1 mice

MXT-M-3,2 breast cancer implanted into female B6D2F1 mice accelerates the growth of an identical second tumor. This process is accompanied by a significant increase of the granulocyte and monocyte numbers in the blood and of the granulocyte and macrophage numbers in the spleen. A significant positive correlation of strong intensity was found between the tumor weight on the one hand and the number of the granulocytes and macrophages on the other hand. The tumor-dependent promotion of the myelopoiesis is explained with a secretion of hematopoietic growth factors, e.g. of the granulocyte-macrophage-stimulating growth factor (GM-CSF), by the breast cancer cells.

Granulocyte apheresis as a possible new approach in cancer therapy: A pilot study involving two cases

Patients with advanced cancer often develop immunodeficiency which may be associated with granulocytosis. The granulocytes have the potential to deplete cytotoxic T cells, resulting in accelerated tumor growth and metastasis. To study the elimination of excess granulocytes using granulocyte apheresis in patients with elevated granulocyte to lymphocyte ratios, 2 patients with recurrent metastatic tumors, were selected. Granulocyte apheresis was performed by extracorporeal vein-to-vein circulation with the G-1 granulocyte and monocyte/macrophage apheresis column filled with cellulose acetate beads, each 2 mm in diameter to adsorb granulocytes and monocytes/macrophages. The patients received 1 or 2 apheresis of 30 to 50 min duration per week, at a flow rate of 30-50 ml/min, with 15 sessions constituting one therapeutic course. Apheresis markedly reduced tumor size and prolonged patient survival time without causing any serious adverse events. The results of the present study suggest that granulocyte and monocyte/macrophage apheresis may be beneficial in patients with metastasizing tumors.

Morphological, biochemical and molecular biological characteristics of a granulocyte colony-stimulating factor-producing human eccrine carcinoma cell line

We describe here a newly established cell line from an eccrine carcinoma which produced an abundant amount of granulocyte colony-stimulating factor (G-CSF). An eccrine carcinoma of the scalp of a 69 year-old-Japanese female had metastasized to the pleura. Clinically, she had marked neutrophilia (up to 60,000/mm3), and a high level of G-CSF (38.7 x 10(3) pg/ml) was detected in the pleural effusion, as determined by enzyme-linked immunosorbent assay (ELISA). We established a cell line in vitro and maintained the cells in culture for 30 months in 90 subcultures. We investigated whether these tumor cells were able to produce G-CSF in culture and found that they were. We also found that the amount of G-CSF produced paralleled the rise in cell number (26.5 x 10(3) pg/ml at confluency). When culture media were administered to rabbits (25 ml/rabbit), the amount of circulating neutrophils increased until the number was equal to or greater than that resulting from injection of recombinant human G-CSF (rhG-CSF)(75 micrograms). This effect persisted for 7 days. When tumors were induced in SCID and nude mice by injecting cultured cells (1 x 10(7) cells/mouse), the number of circulating neutrophils also correlated well with tumor size in these mice (200,000/mm3, 3 cm tumor). After tumor removal, the neutrophil number returned to normal within 30 days. G-CSFmRNA in cultured, cells was detected by RT-PCR. Based on these results, it was confirmed that the marked neutrophilia observed in the patient was caused by the tumor-generated G-CSF. This is the first G-CSF-producing cell line developed from a cancer of the skin.

G-CSF prevents the suppression of bone marrow hematopoiesis induced by IL-12 and augments its antitumor activity in a melanoma model in mice

BACKGROUND

IL-12 has been successfully used in experimental tumor therapy. However, administration of this cytokine induces dose-dependent suppression of hematopoiesis that could potentially limit its use in clinical trials. We decided to examine whether the myelosuppressive activity of IL-12 could be corrected by the administration of G-CSF.

MATERIALS AND METHODS

In the initial experiments the influence of IL-12 and/or G-CSF on bone marrow and spleen GM-CFC was evaluated. To examine whether C-CSF could influence the antitumor activity of IL-12 the combination therapy with these agents was carried out starting on day seven following inoculation of melanoma MmB16 cells into the footpads of B6D2F1 mice. To obtain insight into the mechanism of the observed augmented antitumor activity of the combination therapy with IL-12 and G-CSF, the influence of these cytokines on macrophage activity (cytotoxicity and nitric oxide release) was analyzed.

RESULTS

In accord with our expectations, the application of G-CSF partially prevented the suppression of bone marrow myelopoiesis in IL-12 treated mice. Unexpectedly, G-CSF also showed potentiation of antitumor effects of IL-12 in this melanoma model. The augmented antitumor activity of combined IL-12/G-CSF immunotherapy could result from the enhanced stimulation of macrophage NO production and cytotoxicity.

CONCLUSION

The simultaneous administration of IL-12 and G-CSF partially prevented suppression of bone marrow myelopoiesis in IL-12-treated mice. Moreover, treatment with these cytokines also results in potentiated antitumor effects in a murine melanoma model.

Cytokine-mediated antitumor effect of OK-432 on urinary bladder tumor cells in vitro

Fatal complications from the intravesical instillation of bacillus Calmette-Guérin (BCG) for the treatment of superficial urinary bladder tumors have been reported. OK-432, an immunomodulating agent like BCG, may be an effective and safe agent for the treatment of urinary bladder tumors. We investigated the cytokine-mediated antitumor effect of OK-432 on established human bladder cancer cell lines (T24 and KK-47) in vitro. Peripheral blood mononuclear cells (PBMCs) from a healthy volunteer were cultured with OK-432 for various periods, and the culture supernatants were used as conditioned media. Cytokines in the culture supernatants were quantified. The antitumor effect of OK-432 was evaluated by colony-forming assays, using the conditioned media as the culture media. The colony survival of T24 and KK-47 cells was significantly inhibited by conditioned media from 24-h cultures of PBMCs incubated with OK-432 at concentrations of 0.05 and 0.1 Klinische Einheit (KE)/ml. Conditioned media from PBMCs cultivated with OK-432 for 7 days at 0.01 and 0.05 KE/ml also significantly inhibited the colony survival of both cell lines. Higher concentrations of interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF alpha) were detected in conditioned media cultivated with OK-432 for 24 h than in media from PBMCs alone. However, higher concentrations of interferon gamma (IFN gamma) were detected in conditioned media cultivated with OK-432 for 7 days. Approximately 90% of the inhibition of KK-47 cells by the 24-h conditioned media was neutralized by an anti-TNF monoclonal antibody. The inhibition of T24 cells was neutralized approximately 50% by the same antibody. The inhibition of T24 and KK-47 cells by 7-day conditioned media was completely neutralized by an anti-IFN gamma monoclonal antibody. The cultivation of PBMCs with OK-432 inhibited the production of granulocyte-colony-stimulating factor (G-CSF) by PBMCs. The inhibition may play a role in the mechanism of the antitumor effect of OK-432. Urinary bladder tumor cell lines have different sensitivities to cytokines. The cytokines induced by OK-432 vary with the concentration of OK-432 and the culture period. It is suggested that in intravesical instillation of OK-432 for treatment of urinary bladder tumor, the optimal dose and interval of instillation should be considered.

Granulocyte colony-stimulating factor (G-CSF) production by astrocytoma cells and its effect on tumor growth

We investigated the expression of granulocyte colony-stimulating factor (G-CSF), G-CSF mRNA, and G-CSF receptor mRNA in astrocytoma cell lines, G-CSF in astrocytoma cyst fluid, and the effect of recombinant G-CSF on the proliferation of astrocytoma cells in vitro and in vivo. We first examined supernatants from astrocytoma cell lines for the presence of G-CSF by ELISA. G-CSF was expressed by 6 of 14 astrocytoma cell lines constitutively, and, was detected after stimulation with tumor necrosis factor-alpha (TNF-alpha) in four of eight cell lines which did not produce G-CSF constitutively. G-CSF mRNA was detected by reverse-transcriptase polymerase chain reaction (RT-PCR) in all cell lines studied, suggesting that astrocytoma cells have the potential to produce G-CSF. We also analyzed the presence of G-CSF by ELISA in five astrocytoma cyst fluids. G-CSF was detected in one case. Although, in vitro study, the growth of glioma cells was not affected by rG-CSF, in a mouse model, the administration of G-CSF significantly shortened the time to tumor appearance and accelerated tumor growth. These data suggest that G-CSF has a stimulatory effect on the proliferation of astrocytoma cells in vivo through the mediation of host factors.

Growth modulatory effects of granulocyte-macrophage colony-stimulating factor on human cell lines derived from gynecologic malignancies

OBJECTIVE

In spite of increased expression of granulocyte-macrophage colony-stimulating factor surface receptors on solid tumors, the growth modulatory effects of granulocyte-macrophage colony-stimulating factor have not been well defined in gynecologic malignancies. We assessed the in vitro growth effects of granulocyte-macrophage colony-stimulating factor on such cell lines.

STUDY DESIGN

By use of a chromium 51 incorporation assay the in vitro growth effects of granulocyte-macrophage colony-stimulating factor on 12 cell lines derived from human malignancies were measured.

RESULTS

No growth stimulatory or inhibitory effect was mediated by granulocyte-macrophage colony-stimulating factor on six cell lines, whereas three lines showed consistent but not statistically significant dose-dependent growth stimulation. There was, however, a statistically significant increase in growth of short duration in three other cell lines at clinically relevant doses of granulocyte-macrophage colony-stimulating factor. Fluorometric cell cycle analysis demonstrated no change in cell-cycle distribution.

CONCLUSION

Within this in vitro system, stimulation of gynecologic malignancies in patients receiving granulocyte-macrophage colony-stimulating factor for mitigation of the myelosuppressive effects of cytotoxic chemotherapy does not appear to be widespread nor sustained beyond 48 hours.

New human oral squamous carcinoma cell line and its tumorigenic subline producing granulocyte colony-stimulating factor

A new human carcinoma cell line, MISK81-5, was established from a metastatic lymph node of oral squamous cell carcinoma. Immunocytochemical and ultrastructural observations revealed an obvious epithelial origin of the cell line. Chromosome analysis revealed a hypertriploid karyotype with numerical and structural anomalies. MISK81-5 cells could form a tumor mass in the subcutaneous tissue of recipient BALB/c athymic mice only when coinjected with Matrigel. A stem cell assay revealed that conditioned medium (CM) of MISK81-5 contained granulocyte colony-stimulating factor (G-CSF) or interleukin-6 activity. Quantitation by ELISA disclosed a higher concentration of G-CSF in the CM of MISK81-5 than in the CM of other squamous and gastric carcinoma cell lines. The sMISK, that was derived from MISK81-5 as a subpopulation of the cell line having higher tumorigenicity, also showed a similar hematopoietic stimulating activity to that of MISK81-5. These characteristics of the MISK81-5 cell line and its subpopulation, sMISK will be useful for studying the biological behavior of oral squamous cell carcinomas and its relation to hematopoietic stimulating factors.

Direct and indirect effects of recombinant human granulocyte-colony stimulating factor on in vitro colony formation of human bladder cancer cells

Although the present experimental use of recombinant human granulocyte-colony-stimulating factor (rG-CSF) has been proven to alleviate the myelosuppression induced by antitumor chemotherapy, it is also believed to stimulate growth of some nonhematopoietic tumor cells. We investigated both the direct and indirect effects of rG-CSF on in vitro colony formation of human bladder cancer cell lines using a modified human tumor clonogenic assay. Peripheral blood mononuclear cells (PBMC) were used as feeder cells (a mixture of 5 x 10(4) monocytes/dish and 5 x 10(5) lymphocytes/dish obtained from healthy donors). Human bladder cancer cell lines KK-47, TCCSUP and T24, all derived from human transitional-cell carcinomas, were incubated continuously with various concentrations of rG-CSF ranging from 0.01 ng/ml to 10 ng/ml both with and without PBMC for 7-21 days. The concentrations of rG-CSF used were chosen as being in the range of achievable serum concentrations in patients treated with rG-CSF. At the end of incubation, colonies were counted under an inverted phase-contrast microscope, and an increase in the number of colonies in comparison with the control was used to evaluate the effects of rG-CSF. Results were expressed as a percentage of controls. rG-CSF in the upper layer at concentrations ranging from 0.1 ng/ml to 10 ng/ml stimulated the colony formation of all the cancer cell lines tested in the absence of PBMC in the feeder layer, whereas cells with PBMC in the feeder layer were significantly stimulated more than those without PBMC in the feeder layer (P < 0.05) up to a certain concentration, which varied from cell line to cell line. At higher concentrations of rG-CSF, no further stimulation but, on the contrary, a decrease in colony formation was observed in cells with PBMC in the feeder layer in all the cell lines tested. Colony formation in KK-47 and T24 cell lines was significantly inhibited at 5 ng/ml and/or 10 ng/ml rG-CSF compared with cells without PBMC in the feeder layer. Our results suggest that rG-CSF may have both direct and indirect stimulatory effects on the growth of human bladder cancer cell lines in vitro. The results obtained also raise the possibility of adverse effects of rG-CSF in bladder cancer patients whose malignant cells may be directly and indirectly stimulated by this factor while it is being used clinically to alleviate the myelosuppression induced by antitumor chemotherapy.

A tumor cell line producing granulocyte colony-stimulating factor and an immune suppressive factor

From a patient, both a cell line incapable of secreting granulocyte colony-stimulating factor (G-CSF) (TC873) and a cell line capable of secreting G-CSF (TCM902) were established. The effector cells induced, with TC873 cells showed a high lytic capacity against two types of tumor cells. The effector cells induced by TCM902 cells did not show such capacity. Furthermore, the TCM902 cells excreted a factor suppressing the proliferation of lymphokine activated killer (LAK) cells and the autologous tumor cell lysis of tumor associated lymphocytes. This factor probably is TFG-beta 1.

Production of granulocyte colony-stimulating factor by head and neck carcinomas

Detectable levels of G-CSF by enzyme-linked immunosorbent assay (ELISA) were found in sera of 4 out of 15 patients with head and neck carcinomas. Also cells prepared from the tumors of these 4 patients secreted G-CSF. The supernatants of cells derived from all 15 patients did not contain granulocyte-monocyte CSF, monocyte CSF, tumor necrosis factor-alpha, transforming growth factor-beta 1, epidermal growth factor, interleukin (IL)-1 beta and IL-6. These findings suggest that leukocytosis in patients with carcinomas might be due to the production of G-CSF by tumor cells.