Bladder carcinoma cell line KU-19-19-derived cytokines support proliferation of growth factor-dependent hematopoietic cell lines: modulation by phorbol ester, interferon-gamma and interleukin-1 beta

Choosing the Right Cell Line for Acute Myeloid Leukemia (AML) Research

Immortalized cell lines are widely used in vitro tools in oncology and hematology research. While these cell lines represent artificial systems and may accumulate genetic aberrations with each passage, they are still considered valuable models for pilot, preliminary, and screening studies. Despite their limitations, cell lines are cost-effective and provide repeatable and comparable results. Choosing the appropriate cell line for acute myeloid leukemia (AML) research is crucial for obtaining reliable and relevant results. Several factors should be considered when selecting a cell line for AML research, such as specific markers and genetic abnormalities associated with different subtypes of AML. It is also essential to evaluate the karyotype and mutational profile of the cell line, as these can influence the behavior and response to the treatment of the cells. In this review, we evaluate immortalized AML cell lines and discuss the issues surrounding them concerning the revised World Health Organization and the French-American-British classifications.

The dark side of granulocyte-colony stimulating factor: a supportive therapy with potential to promote tumour progression

Granulocyte-colony stimulating factor (G-CSF) is one of several cytokines that can expand and mobilize haematopoietic precursor cells from bone marrow. In particular, G-CSF mobilizes neutrophils when the host is challenged by infection or tissue damage. Severe neutropenia, or febrile neutropenia is a life-threatening event that can be mitigated by administration of G-CSF. Consequently, G-CSF has been used to support patients undergoing chemotherapy who would otherwise require dose reduction due to neutropenia. Over the past 10-15 years it has become increasingly apparent, in preclinical tumour growth and metastasis models, that G-CSF can support tumour progression by mobilization of tumour-associated neutrophils which consequently promote tumour dissemination and metastasis. With the increasing use of G-CSF in the clinic, it is pertinent to ask if there is any evidence of a similar promotion of tumour progression in patients. Here, we have reviewed the preclinical and clinical data on the potential contribution of G-CSF to tumour progression. We conclude that, whilst the evidence for a promotion of metastasis is strong in preclinical models and that limited data indicate that high serum G-CSF levels in patients are associated with poorer prognosis, no studies published so far have revealed evidence of increased tumour progression associated with supportive G-CSF use during chemotherapy in patients. Analysis of G-CSF receptor positive cohorts within supportive trials, as well as studies of the role of G-CSF blockade in appropriate tumours in the absence of chemotherapy could yield clinically translatable findings.

Leukemoid reaction and autocrine growth of bladder cancer induced by paraneoplastic production of granulocyte colony-stimulating factor--a potential neoplastic marker: a case report and review of the literature

Introduction

Granulocyte colony-stimulating factor produced by nonhematopoietic malignant cells is able to induce a leukemoid reaction by excessive stimulation of leukocyte production. Expression of granulocyte colony-stimulating factor and its functional receptors have been confirmed in bladder cancer cells. In vitro studies have demonstrated that granulocyte colony-stimulating factor/receptor exhibits a high affinity binding and this biological axis increases proliferation of the carcinoma. Urothelial carcinoma of the bladder is rarely associated with a leukemoid reaction and autocrine growth induced by paraneoplastic production of granulocyte colony-stimulating factor. In the world literature, there have been less than 35 cases reported in the last 35 years. The clinicopathological aspects, biology, prognosis and management of granulocyte colony-stimulating factor-secreting bladder cancers are poorly understood.

Case presentation

A 39-year-old Caucasian woman with an invasive high-grade urothelial carcinoma presented with hematuria and low-grade fevers. Laboratory tests revealed an elevated white blood cell count and absolute neutrophil count and an elevated 24-hour urine protein. Upon further evaluation she was found to have locally advanced high-grade urothelial carcinoma without nodal or distant metastasis. Her serum granulocyte colony-stimulating factor level was 10 times the normal limit. This led to the diagnosis of a paraneoplastic leukemoid reaction. Her white blood cell count immediately normalized after cystectomy but increased in concordance with recurrence of her disease. Unfortunately, she rapidly progressed and expired within 10 months from the time of first diagnosis.

Conclusions

This is one of the few cases reported that illustrates the existence of a distinct and highly aggressive subtype of bladder cancer which secretes granulocyte colony-stimulating factor. Patients presenting with a leukemoid reaction should be tested for granulocyte colony-stimulating factor/receptor biological axis. Moreover, granulocyte colony-stimulating factor could be a potential neoplastic marker as it can follow the clinical course of the underlying tumor and thus be useful for monitoring its evolution. Neoadjuvant chemotherapy should be considered in these patients due to the aggressive nature of these tumors. With a better understanding of the biology, this autocrine growth signal could be a potential target for therapy in future.

Angiotensin II type 1 receptor antagonist candesartan as an angiogenic inhibitor in a xenograft model of bladder cancer

PURPOSE

There have been several studies on the antitumor activity of angiotensin II type 1 receptor (AT1R) antagonists. In this study, we evaluated the efficacy of the AT1R antagonist candesartan in bladder cancer.

EXPERIMENTAL DESIGN

For the study in vitro, human bladder cancer cells (KU-19-19) were cultured with or without angiotensin II and candesartan. Various cytokines and cell viability were analyzed. For the study in vivo, a tumor xenograft model was prepared in nude mice using KU-19-19 cells. Mice were given candesartan daily by oral gavage. Microvessel density, expression of vascular endothelial growth factor (VEGF), and apoptosis were assessed.

RESULTS

Candesartan did not induce direct toxicity in KU-19-19 cells, but VEGF and interleukin-8 were significantly lower in candesartan-treated cells (2.55 +/- 0.25 and 6.58 +/- 0.48 pg/10(3) cells) than in the angiotensin II-treated control cells (3.16 +/- 0.42 and 7.91 +/- 0.69 pg/10(3) cells). In mice, candesartan both at doses of 2 and 10 mg/kg/d significantly suppressed tumor growth in mice (35.4% and 33.5% reduction in tumor volume). Microvessel density was significantly decreased by candesartan (9.8 +/- 2.8 per field) compared with the control group (17.6 +/- 6.0 per field), and VEGF expression was significantly suppressed by this AT1R antagonist. However, candesartan did not induce apoptosis of cancer cells in the tumor.

CONCLUSIONS

Specific blockade of AT1R prevented bladder tumor growth by inhibiting angiogenesis. However, its antitumor effect was not due to direct toxicity. Because AT1R antagonists are widely used to treat hypertension, and a 2 mg/kg/d dose level of candesartan is clinically achievable, this AT1R antagonist could also be used to treat bladder cancer.

Herpes simplex virus based gene therapy enhances the efficacy of mitomycin C for the treatment of human bladder transitional cell carcinoma

PURPOSE

Oncolytic replication competent herpes simplex virus type-1 (HSV) mutants have the ability to replicate in and kill malignant cells. We have previously reported the ability of replication competent HSV to control bladder cancer growth in an orthotopic murine model. We hypothesized that the combination of a chemotherapeutic agent used for intravesical treatment, namely mitomycin C (MMC) (Bristol-Myers Squibb Oncology, Princeton, New Jersey), and oncolytic HSV would exert a synergistic effect for the treatment of human transitional cell carcinoma.

MATERIALS AND METHODS

We used mutant HSV NV1066 (Medigene, San Diego, California), which is deleted for viral genes ICP0 and ICP4, and selectively infects cancer cells, to treat the transitional cell carcinoma lines KU19-19 and SKUB. Cell survival was determined by lactate dehydrogenase assay for each agent as well as for drug-viral combinations from days 1 to 5. The isobologram method and the combination index method of Chou-Talalay were used to assess the synergistic effect.

RESULTS

NV1066 enhanced MMC mediated cytotoxicity at all combinations tested for KU19-19 and SKUB. The combination of the 2 agents demonstrated a synergistic effect and allowed dose reduction by 12 and 10.4 times (NV1066), and by 3 and 156 times (MMC) for the treatment of KU19-19 and SKUB, respectively, while achieving an estimated 90% cell kill.

CONCLUSIONS

These data provide the cellular basis for the clinical investigation of combined MMC and oncolytic HSV therapy for the treatment of bladder cancer.

Human monocytes differentiate into macrophages under the influence of human KPB-M15 conditioned medium

Culture medium conditioned by the L929 murine fibroblast cell line contains macrophage colony-stimulating factor (M-CSF), providing an alternative to recombinant M-CSF for in vitro generation of murine macrophages. No such alternative has been described for in vitro studies requiring human macrophages. We tested the differentiation of human blood monocytes into mature macrophages by culturing in media conditioned by the human KPB-M15 cell line, which produces M-CSF and interleukin 6 (IL-6). The phenotypes of macrophages cultured in KPB-M15 conditioned media and recombinant M-CSF were compared by examining viability, expression of cell surface markers, phagocytic/pinocytic activity, and cytokine/chemokine secretion in response to bacterial lipopolysaccharide (LPS). In conditioned medium, monocytes differentiated into a homogeneous population of large cells that exhibited higher expression of CD14 and the macrophage mannose receptor (CD206) than did M-CSF-cultured cells. Cells matured in KPB-M15 conditioned medium exhibited macrophage morphology, were phagocytic, and were activated in response to LPS. These data demonstrate that KPB-M15 conditioned medium can be used to differentiate human blood monocytes into macrophages in vitro.

Induction and regulation of endogenous granulocyte colony-stimulating factor formation

Granulocyte colony-stimulating factor (G-CSF) is one of the most prominent endogenous proteins in broad clinical use. While its biological and clinical effects are relatively well studied, little is known about its endogenous formation in health and disease. However, such knowledge is crucial to decide in which situations G-CSF should be applied efficiently in the clinic, ie. when endogenous production does not suffice. The dramatic changes induced by G-CSF in the differential blood cell count are directly immunomodulatory, strengthening the innate defence by multiplying neutrophilic granulocytes. A multitude of further immunomodulatory effects contribute to the regulation of the concerted host defence. In this review, following a short introduction into the biology of G-CSF, the available data on endogenous formation in a number of animal models and human diseases is compiled. The cellular sources and inducers of G-CSF formation are reviewed and the regulation of G-CSF expression on both the transcriptional and translational level are discussed. The emerging understanding of the role and regulation of endogenous G-CSF formation opens up possibilities to define therapeutic windows as well as targets for diagnostics or drug development. Lastly, the modulation of G-CSF formation by various pharmacological agents alerts to putative side effects of these drug treatments.

Secretion of functional hematopoietic growth factors by human carcinoma cell lines

We studied the constitutive production of hematopoietic cytokines in a large panel of human cell lines originating from a wide variety of solid tumors. Conditioned media (CM) from the carcinoma cell lines were collected and screened for proliferative activity using a bioassay with indicator cell lines. These indicator cell lines are dependent on hematopoietic growth factors and require the exogenous supply of at least one hematopoietic cytokine for proliferation. We found that CM of 27/70 cell lines were able to significantly and reproducibly stimulate [3H]-thymidine incorporation of the factor-dependent cell lines, indicating that the tumor cell lines secreted one or more functional cytokine(s). The CM-induced proliferation of the indicator cell lines was significantly inhibited by anti-serum against granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte-CSF (G-CSF). ELISA confirmed the presence of one or several of the following cytokines in the CM of carcinoma cell lines: GM-CSF, G-CSF, macrophage-CSF (M-CSF), stem cell factor (SCF) and IL-6. A strikingly high percentage of GM-, G- or M-CSF-secreting cell lines was found among those lines derived from carcinomas of the kidney (100%), urinary bladder (85%) and pancreas (100%). The large majority of tumor cell lines derived from breast, colon, esophagus, lung, nervous system and melanomas did not produce significant amounts of the cytokines we investigated here. The cytokines secreted have been proven to be functionally active and can support growth and viability of cytokine-dependent hematopoietic cell lines.