Construction of lncRNA/Pseudogene-miRNA Network Based on In Silico Approaches for Glycolysis Pathway to Identify Prostate Adenocarcinoma-Related Potential Biomarkers

LncRNAs, pseudogenes, and miRNAs participate a fundamental function in tumorigenesis, metabolism, and invasion of cancer cells, although their regulation of tumor glycolysis in prostate adenocarcinoma (PRAD) is thoroughly not well studied. In this study, we applied transcriptomic, proteomic, and medical information to identify glycolysis-related key genes and modules associated with PRAD. Then, the glycolysis-related lncRNA/lncRNAs/pseudogenes-miRNA-mRNA network was constructed. Analysis of DNA methylation status and expression data determined a DNA methylation-dysregulated three-DE-mRNAs signature for predicting diagnosis, ANGPTL4, GNE, and HSPA in PRAD patients and healthy control. Several lncRNAs/pseudogenes, significantly correlated with the overall survival PVT1, CA5BP1, MIRLET7BHG, SNHG12, and ZNF37BP and disease-free survival status, MALAT1, GUSBP11, MIRLET7BHG, and SNHG1, of patients with PRAD were determined. The methylation profile of DE-lncRNA/pseudogenes was significantly proper for predicting PRAD prognostic model. The transcription level of 6 DE-mRNA ANGPTL4, QSOX1, BIK, CLDN3, DDIT4, and TFF3 was correlated with cancer-related fibroblast infiltration in PRAD. The mutated form of 7 mRNAs, COL5A1, IDH1, HK2, DDIT4, GNE, and QSOX1, was associated with PRAD. In addition to the glycolysis pathway, DE-RNAs play regulatory roles on several pathways, including DNA damage, RTK, cell cycle, RAS/MAPK, TSC/mTOR and PI3K/AKT, AR hormone, and EMT. Overall, our study improves our knowledge of the relation between lncRNAs/pseudogenes and miRNA related to glycolysis and PRAD pathogenesis.

Exosomes: Promising Delivery Tools for Overcoming Blood-Brain Barrier and Glioblastoma Therapy

Gliomas make up virtually 80% of all lethal primary brain tumors and are categorized based on their cell of origin. Glioblastoma is an astrocytic tumor that has an inferior prognosis despite the ongoing advances in treatment modalities. One of the main reasons for this shortcoming is the presence of the blood-brain barrier and blood-brain tumor barrier. Novel invasive and non-invasive drug delivery strategies for glioblastoma have been developed to overcome both the intact blood-brain barrier and leverage the disrupted nature of the blood-brain tumor barrier to target cancer cells after resection-the first treatment stage of glioblastoma. Exosomes are among non-invasive drug delivery methods and have emerged as a natural drug delivery vehicle with high biological barrier penetrability. There are various exosome isolation methods from different origins, and the intended use of the exosomes and starting materials defines the choice of isolation technique. In the present review, we have given an overview of the structure of the blood-brain barrier and its disruption in glioblastoma. This review provided a comprehensive insight into novel passive and active drug delivery techniques to overcome the blood-brain barrier, emphasizing exosomes as an excellent emerging drug, gene, and effective molecule delivery vehicle used in glioblastoma therapy.

Long non-coding RNAs (lncRNAs); roles in tumorigenesis and potentials as biomarkers in cancer diagnosis

New research has indicated that long non-coding RNAs (lncRNAs) play critical roles in a broad range of biological processes, including the pathogenesis of many complex human diseases, including cancer. The detailed regulation mechanisms of many lncRNAs in cancer initiation and progression have yet to be discovered, even though a few of lncRNAs' functions in cancer have been characterized. In the present study, we summarize recent advances in the mechanisms and functions of lncRNAs in cancer. We focused on the roles of newly-identified lncRNAs as oncogenes and tumor suppressors, as well as the potential pathways these molecules could play. The paper also discusses their potential uses as biomarkers for the diagnosis and prognosis of cancer.

Combinatorial effects of telmisartan and docetaxel on cell viability and metastatic gene expression in human prostate and breast cancer cells

The epithelial-to-mesenchymal transition (EMT) is a unique process resulting in enhanced cell motility, invasiveness, and metastasis in cancer. The EMT is regulated by several transcription factors, including Snail and Slug, which exert crucial roles during cancer progression. We have studied the effects of Docetaxel as the first-line chemotherapy agent for prostate cancer, and Telmisartan as an anti-hypertensive drug on the expression level of Snail and Slug. In addition, the effects of Docetaxel, Telmisartan and their combination on cancer cell proliferation were investigated. The PC3, DU145, MDA-MB468, and HEK cell lines were used for this study. Quantitative RT-PCR analysis and MTT assay were used to study the expression of Snail and Slug level and cell proliferative assay, respectively. We found that a combination of Docetaxel + Telmisartan effectively inhibits the cell proliferation in cancerous cells in comparison with each drug alone (P<0.05). Furthermore, in these cell lines, Docetaxel, Telmisartan and their combination significantly diminished the expression level of Snail and Slug genes compared to control cells (P<0.001), however, in the HEK cell line, this effect was seen only in the combination group. Our data imply that Telmisartan and its combination with Docetaxel exert strong inhibitory effects on the expression level of Snail and Slug genes. Also, these drugs and their combination could inhibit cancer cell proliferation. In conclusion, the combination of Telmisartan and Docetaxel has the potential to suppress the metastasis of prostate and breast cancer cells.

Telmisartan anti‐cancer activities mechanism through targeting N‐cadherin by mimicking ADH‐1 function

This study aimed to investigate if Telmisartan as a novel N‐cadherin antagonist, can overcome cell migration of cancer cells. We investigated the mechanism and influence of Docetaxel and Telmisartan (as an analogous to ADH‐1, which is a well‐known N‐cadherin antagonist) on cancer cells. The effect of ADH‐1 and Telmisartan on cell attachment in PC3, DU145, MDA‐MB‐468 cell lines using recombinant human N‐cadherin was studied. Cell viability assay was performed to examine the anti‐proliferative effects of Telmisartan, ADH‐1 and Docetaxel. Migration was examined via wound healing assay, and apoptosis was determined by flow cytometry. The expression of AKT‐1 as a downstream gene of N‐cadherin signalling pathway was assayed by real‐time PCR. Treatment of PC3, MDA‐MB‐468 and DU145 cells with Telmisartan (0.1 µM) and ADH‐1 (40 µM) resulted in 50%, 58% and approximately 20% reduction in cell attachment to N‐cadherin coated plate respectively. It shows reduction of cell attachment in PC3 and MDA‐MB‐468 cell lines appeared to be more sensitive than that of DU145 cells to the Telmisartan and ADH‐1 treatments. Telmisartan (0.1 µM) and Docetaxel (0.01 nM) significantly reduced cell migration in PC3 and MDA‐MB‐468 cell lines compared with the control group. Using Real‐time PCR, we found that Telmisartan, Docetaxel and ADH‐1 had significant influence on the AKT‐1 mRNA level. The results of the current study for the first time suggest that, Telmisartan, exerts anti‐proliferation and anti‐migration effects by targeting antagonistically N‐cadherin. Also, these data suggest that Telmisartan as a less expensive alternative to ADH‐1 could potentiate Docetaxel anticancer effects.

Erythrocyte glucose-6-phosphate dehydrogenase activity and risk of gestational diabetes

Purpose

Glucose-6-phosphate dehydrogenase (G6PD) is the regulating enzyme in the pentose phosphate pathway. A link between the activity of G6PD and diabetes mellitus has previously been reported. The association of G6PD activity with the pathogenesis of gestational diabetes mellitus (GDM) has not yet been investigated. The aim of the present study was to investigate the association of erythrocyte G6PD activity with major characteristics of GDM.

Methods

This case-control study was conducted at Hafez Hospital, Shiraz University of Medical Sciences, Shiraz, Iran from March to November 2017. Eighty-four age-matched pregnant women including GDM (n = 33), impaired glucose tolerance (IGT; n = 7), and normal glucose tolerance (NGT; n = 44) subjects were enrolled in this study. The levels of erythrocyte G6PD activity, fasting plasma glucose (FPG), insulin, malondialdehyde (MDA), and ferric reducing power (FRAP) of serum were measured. The level of homeostasis model for the assessment of insulin resistance (HOMA-IR) was calculated. The data were analyzed using SPSS software. P < 0.05 was considered statistically significant.

Results

The values of FPG, insulin, HOMA-IR, G6PD activity, and FRAP were significantly higher in GDM patients compared to NGT subjects. G6PD activity was correlated with FPG ((r = 0.224; P = 0.041). Binary logistic regression analysis revealed independent association of body mass index >25.88 [OR = 3.23, 95% CI 1.071-9.75, P = 0.037], HOMA- IR >2.33 [OR = 7.15, 95% CI 2.26-22.56, P < 0.001], and G6PD activity>21.17 U/g Hb [OR = 4.63, 95% CI 1.49-14.38, P = 0.008] with an increased risk of GDM. No significant change was observed among serum MDA levels in the three groups.

Conclusion

The findings demonstrate that increased G6PD activity is positively associated with the risk of GDM.

Efficacy of melatonin in restoring the antioxidant status in the lens of diabetic rats induced by streptozotocin

Background

Melatonin is a well-known free radical scavenger. The present study aimed to investigate the effects of melatonin treatment on the antioxidant status in the lenticular tissue of streptozotocin (STZ)-induced diabetic rats.

Methods

Thirty-four male rats were randomly divided into four groups as follows: healthy control rats (group 1, n = 10); diabetic control rats (group 2, n = 10); melatonin-treated (5 mg/kg·day) diabetic rats (group 3, n = 10) and melatonin-treated (5 mg/kg·day) healthy rats (group 4, n = 4). Diabetes was induced by injection of streptozotocin (50 mg/kg, ip). Following 8-weeks of melatonin treatment, all rats were killed and the blood plasma and their lenses were stored at -70 °C for antioxidant enzyme activities assay and biochemical determination.

Results

The plasma glucose and lens malondialdehyde (MDA) increased significantly in the rats of group 2 as compared to the group 1. Also, a significant decrease in the levels of catalase (CAT) and glutathione reductase (GR) activities in the lenses and plasma reduced glutathione (GSH) was found. However, the levels of lenticular MDA (not significant) and the plasma glucose significantly decreased in the rats of group 3 compared to the group 2. Besides, the levels of CAT, GR in the rats lens and plasma GSH increased significantly.

Conclusion

Diabetes mellitus induced hyperglycemia and oxidative stress, whereas melatonin decreased the blood glucose levels and lipid peroxidation and increased the activities of antioxidant enzymes in diabetic rat lenses.

Effects of Two-by-Two Combination Therapy with Valproic Acid, Lithium Chloride, and Celecoxib on the Angiogenesis of the Chicken Chorioallantoic Membrane

BACKGROUND

The synergistic effects of valproic acid (VPA), lithium (Li), and celecoxib (CX) have been shown in combination therapy against the proliferation and metastasis of numerous cancers. Angiogenesis plays a critical role in the pathogenesis of tumor growth and metastasis. The aim of the present study was to evaluate the antiangiogenic effects of VPA, lithium chloride (LiCl), and CX, alone or in 2-by-2 combinations, using the chicken chorioallantoic membrane (CAM) assay.

METHODS

Fertilized chicken eggs were randomly divided into 10 groups: control, VPA (1.8 and 3.6 µmol/CAM), Li (0.15 and 0.60 µmol/CAM), CX (0.02 and 0.08 µmol/CAM), VPA+Li, VPA+CX, and CX+Li (n=10 per group). A window was made on the eggshells and the CAMs were exposed to a filter disk containing VPA, LiCl, and CX, alone or in 2-by-2 combinations. The control CAMs were treated with distilled water (vehicle). Three days after the treatment, the number of vessel branch points was counted in each CAM. The data were analyzed using SPSS, version 15.One-way ANOVA, followed by the Tukey tests, was used to compare the groups. A P<0.05 was considered a statistically significant difference between the groups.

RESULTS

According to the results, all the tested drugs decreased the number of the vessel branch points in a dose-dependent manner compared to the control group (P<0.001). In addition, combinations of the drugs were more effective in decreasing angiogenesis than the use of each drug alone.

CONCLUSION

These findings suggest that 2-by-2 combinations of VPA, CX, and LiCl can be considered an effective antiangiogenesis therapeutic modality.

Serum ischemia modified albumin is a possible new marker of oxidative stress in phenylketonuria

The role of oxidative stress in the pathogenesis of phenylketonuria (PKU)-associated disorders has been implicated. Ischemia modified albumin (IMA) is a modified form of serum albumin, which is produced under the conditions of oxidative stress. The aim of this study was to measure the serum level of IMA in the PKU patients and to investigate its ability in predicting the status of oxidative stress in these patients. Fifty treated-PKU patients and fifty age- and sex-matched healthy subjects were included in the study. The blood samples were obtained and the serum level of phenylalanine (Phe) was measured using reverse phase HPLC method. The levels of IMA, malondialdehyde (MDA), gamma-glutamyl transferase (GGT) activity, and uric acid (UA) were determined using colorimetric methods. The levels of serum Phe, IMA, and MDA were significantly higher (p < 0.001) and the level of UA (p < 0.05) was lower in the PKU patients compared to control group. Serum IMA level was positively correlated with MDA (r = 0.585, p < 0.001) and UA (r = 0.6, p < 0.001). An inverse relationship was observed between the serum level of IMA and Phe (r = - 0.410, p < 0. 01). Results of the present study suggest that serum IMA level could be used as a novel marker for the evaluation of oxidative stress in the PKU patients.

The protective effect of sodium benzoate on aluminum toxicity in PC12 cell line

Sodium benzoate (SB) is one of the food additives and preservatives that prevent the growth of fungi and bacteria. SB has been shown to improve the symptoms of neurodegenerative disease such as Alzheimer's disease. The aim of this study was to evaluate the effect of SB on the cell survival and cellular antioxidant indices after exposure to aluminum maltolate (Almal) in PC12 cell line as a model of neurotoxicity. The cells exposed to different concentrations of SB (0.125 to 3 mg/mL) in the presence of Almal (500 µM) and cell viability, the level of reactive oxygen species (ROS), glutathione content and catalase activity were measured. The results showed that low concentrations of SB caused an increase in the cell survival, but cell viability was reduced in high concentrations. SB could neither prevent the level of ROS production nor change glutathione content. SB (0.5 mg/mL) significantly increased the catalase enzyme activity as compared to the Almal. This study suggested that SB did not completely protect the cell to aluminum-induced free radicals toxicity. Possibly SB improves the symptoms of neurodegenerative disease by other mechanisms.

Central venous device-related infection and thrombosis in patients treated with moderate dose continuous-infusion interleukin-2

BACKGROUND

This study was performed to determine the incidence of central venous device-related blood stream infection and thrombosis in patients treated with moderate dose continuous-infusion interleukin-2 (IL-2).

METHODS

The records of 160 consecutive patients treated at the University of Wisconsin Hospital and Clinics, between June 1990 and June 1997, with moderate dose continuous-infusion IL-2 (IL-2 [1.5-3.0 x 10(6) U/m(2)/day] Hoffman-LaRoche, Nutley, NJ or IL-2 [4.5 x 10(6) U/m(2)/day] Chiron Corporation, Berkley, CA) were reviewed retrospectively. The majority of patients had metastatic melanoma (78 patients) or renal cell carcinoma (70 patients). All of the patients had a surgically implanted central venous device placed before starting IL-2 therapy; 89% of these were cuffed Hickman catheters. Eighty-four patients received 1 mg of warfarin per day as prophylaxis against device-related thrombosis; none received periinsertion prophylactic antibiotics.

RESULTS

Twenty-one patients (13%) developed central venous device-related bloodstream infection (DRBSI) during the study period, a rate of 2 DRBSI per 1000 device-days. DRBSIs were associated with the type of immunotherapy given with IL-2 (P = 0.01) and with thrombosis (odds ratio, 4.1; 95% confidence interval, 1.5-11.4; P = 0.008) but not with patient gender, type of cancer, duration of the central device, or site of device placement. Twenty-six patients (16%) developed central venous device-related thrombosis (DRT) during immunotherapy. Low dose warfarin did not appear to prevent thrombosis. Device-related thrombosis was associated with DRBSI but not with patient gender, type of cancer, type of device, duration or location of device, or concomitant immunotherapy.

CONCLUSIONS

Central venous DRBSI and DRT are significant complications that can occur during moderate dose continuous-infusion IL-2 therapy. The risk of DRBSI appears lower than the risk reported with high dose IL-2 therapy by previous investigators. The risk of DRT appears to be higher than the risk reported for patients with similar devices but not given IL-2. Low dose warfarin did not prevent DRT when started after device placement.

A phase Ib/II trial of granulocyte-macrophage-colony stimulating factor and interleukin-2 for renal cell carcinoma patients with pulmonary metastases: a case of fatal central nervous system thrombosis

BACKGROUND

Interleukin-2 (IL-2) and granulocyte-macrophage-colony stimulating factor (GM-CSF) are cytokines with nonoverlapping pleiotropic effects. In a prior Phase Ib study, this combination of agents exhibited antitumor effects in the lungs of four of eight patients with renal cell carcinoma and pulmonary metastases. We conducted this Phase Ib/II trial to determine the response rate of renal cell carcinoma patients with pulmonary metastases treated with continuous infusion IL-2 plus GM-CSF.

METHODS

Patients with renal cell carcinoma and pulmonary metastases were treated with 1.5, 2.25, or 4.5 x 10(6) IU/m(2)/day 96-hour continuous infusion IL-2 on Days 1-4, 8-11, and 15-18, and 1.25, 2.25, or 2.5 microg/kg/day GM-CSF on Days 8-19.

RESULTS

Sixteen patients were treated per protocol, 14 of whom could be evaluated for disease progression. None of these 14 patients had >50% shrinkage of either total tumor burden or pulmonary metastasis. One patient developed Grade 5 neurotoxicity. Autopsy revealed acute multifocal cerebral venous thrombosis as well as acute subdural and subarachnoid hemorrhage.

CONCLUSIONS

The combination of IL-2 and GM-CSF may be associated with marked morbidity and, as in one case in this study, mortality. No significant antitumor activity was appreciated. Thus, the combination of IL-2 and GM-CSF, when administered at this dose and according to this schedule, does not appear to be active in renal cell carcinoma and is associated with significant toxicities. Further studies using this combination of agents should only be undertaken with extreme caution and particular attention to neurotoxicity.

Distinct clinical and laboratory activity of two recombinant interleukin-2 preparations

Interleukin-2 (IL-2) is a potent lymphokine that activates natural killer cells, T cells, and other cells of the immune system. Several distinct recombinant human IL-2 preparations have shown antitumor activity, particularly for renal cell cancer and melanoma. Somewhat distinct immune and clinical effects have been noted when different IL-2 preparations have been tested clinically; however, the regimens and doses used were not identical. To compare these more directly, we have evaluated two clinical recombinant IL-2 preparations in vitro and in vivo using similar regimens and similar IUs of IL-2. We used the Food and Drug Administration-approved, commercially available Chiron IL-2 and the Hoffmann LaRoche (HLR) IL-2 supplied by the National Cancer Institute. Using equivalent IUs of IL-2, we noted quantitative differences in vitro and in vivo in the IL-2 activity of these two preparations. In patients receiving comparable IUs of the two preparations, HLR IL-2 induced the release of more soluble IL-2 receptor alpha into the serum than Chiron IL-2. In addition, more toxicities were noted in patients receiving 1.5 x 10(6) IU of HLR IL-2 than were seen in patients treated with 1.5 x 10(6) or even 4.5 x 10(6) IU of Chiron IL-2. These toxicities included fever, nausea and vomiting, and hepatic toxicity. In vitro proliferative assays using IL-2-dependent human and murine cell lines indicated that the IU of HLR IL-2 was more effective than Chiron IL-2 at inducing tritiated thymidine incorporation. Using flow cytometry, we also found quantitative differences in the ability of these two preparations to bind to IL-2 receptors. These findings indicate that approximately 3-6 IU of Chiron IL-2 are required to induce the same biological effect as 1 IU of HLR IL-2.

Phase IB trial of chimeric antidisialoganglioside antibody plus interleukin 2 for melanoma patients

We conducted a Phase IB trial of antidisialoganglioside chimeric 14. 18 (ch14.18) antibody and interleukin 2 (IL-2) to determine the maximal tolerated dose (MTD), immunological effects, antitumor effects, and toxicity of this treatment combination. Twenty-four melanoma patients received immunotherapy with ch14.18 antibody and a continuous infusion of Roche IL-2 (1.5 x 10(6) units/m2/day) given 4 days/week for 3 weeks. The ch14.18 antibody (dose level, 2-10 mg/m2/day) was scheduled to be given for 5 days, before, during, or following initial systemic IL-2 treatment. The ch14.18 MTD was 7.5 mg/m2/day, and 15 patients were treated with the ch14.18 MTD. Immunological effects included the induction of lymphokine-activated killer activity and antibody-dependent cellular cytotoxicity by peripheral blood mononuclear cells. In addition, serum samples obtained following ch14.18 infusions were able to facilitate in vitro antibody-dependent cellular cytotoxicity. Antitumor activity included one complete response, one partial response, eight patients with stable disease, and one patient with >50% decrease of hepatic metastases in the face of recurrence of a s.c. lesion. Dose-limiting toxicities were a severe allergic reaction and weakness, pericardial effusion, and decreased performance status. Most patients treated at the MTD had abdominal, chest, or extremity pain requiring i.v. morphine. One patient had an objective peripheral neuropathy. This IL-2 and ch14.18 treatment combination induces immune activation in all patients and antitumor activity in some melanoma patients. We are attempting to enhance this treatment approach by addition of the anti-GD3 R24 antibody to this IL-2 and ch14.18 regimen.

Phase II trial of oral piritrexim in advanced, previously treated transitional cell cancer of bladder

Oral piritrexim (PTX), a second generation antimetabolite, has been shown to be an active agent against methotrexate refractory transitional cell cancer (TCC) of the bladder in phase I trials. We conducted a phase II trial of this drug in patients with TCC of the bladder who failed a first line chemotherapy regimen.

METHODS

Oral PTX was started at the dose of 25 mg three times per day for 5 days weekly for 3 weeks followed by one week of rest. If this was tolerated the dose was increased to 50 mg three times a day. Patients were monitored for response rate and toxicity.

RESULTS

Seventeen patients were entered into the trial. Two patients did not complete the required 2 courses of treatment to be evaluable. There were 13 evaluable patients. Among the 13 no one achieved a complete response (CR), however, there were 3 partial responses (PRs = RR: 23%) and 5 stable diseases (SDs). The responses lasted 2, 8 and 14 months. The major dose-limiting toxicity was myelosuppression. Two patients died on treatment. One death was due to neutropenic fever and the cause of death in the second patient is thought to be a cerebral vascular accident (CVA).

CONCLUSION

PTX is an active drug in the treatment of TCC of the bladder. Bone marrow suppression is the most common dose-limiting toxicity. In view of the observed responses and toxicities in this study and other studies, we suggest that the role of PTX be further investigated in the following clinical settings: 1. Palliative initial treatment in patients with TCC of the bladder who are not candidates for more aggressive chemotherapy. 2. As first line chemotherapy in combination with other active drugs.

Multiple cerebral lesions complicating therapy with interleukin-2

We reviewed the records and radiologic studies of eight patients who developed new focal neurologic abnormalities while receiving interleukin-2 (IL2)-based immunotherapy for malignancy or HIV infection. Initial confusion and delirium in the patients evolved into coma, ataxia, hemiparesis, seizures, and cortical syndromes including aphasia, apraxia, and cortical blindness. Imaging studies showed multiple white and gray matter lesions with a predilection for the occipital poles, centrum semiovale, and cerebellum. After cessation of IL2 treatment, seven patients improved to normal or near-normal neurologic function paralleled by resolution of the lesions on scans. One patient improved only minimally. Possible etiologies for the lesions include an IL2-induced cerebral vasculopathy, a direct toxic effect of IL2, or immunologically mediated damage.

Clinical and immunological effects of granulocyte-macrophage colony-stimulating factor coadministered with interleukin 2: a phase IB study

Interleukin 2 (IL-2) and granulocytes-macrophage colony-stimulating factor (GM-CSF) are activators of the lymphocyte and granulocyte/macrophage series, respectively. We conducted a phase IB trial to identify the maximally tolerated dose and to assess immunological effects of the combination. Thirty-four patients with incurable cancers received 2.5, 5, or 10 microgram/kg GM-CSF s.c. either before or concurrently with 1.5 or 3.0 million units/m2/day IL-2. The most common laboratory and clinical side effects included an elevation of the total WBC or eosinophil count due to GM-CSF, and constitutional symptoms due to IL-2. Grade 3 or 4 toxicities included hypotension, thrombocytopenia, elevations in aspartate aminotransferase or bilirubin, renal toxicity, gastrointestinal hemorrhage, arrhythmia, and constitutional symptoms. Two patients receiving 5.0 microgram/kg GM-CSF plus concurrent 3.0 million units IL-2 experienced dose-limiting grade 3 or 4 neurological toxicity, which reversed almost completely. An increase in the serum-soluble IL-2 alpha chain receptor was observed with administration of GM-CSF, IL-2, or the combination. IL-2 therapy enhanced lymphokine-activated killer activity, antibody-dependent cellular cytotoxicity, and lymphocyte activation, with increased CD16 and CD56 expression. GM-CSF increased expression of human leukocyte antigen DR on peripheral blood monocytes and decreased surface expression of CD16 on circulating monocytes and polymorphonuclear cells. Lymphokine-activated killer activity and CD16 expression on monocytes and lymphocytes and CD56 expression on lymphocytes were significantly lower in patients receiving GM-CSF simultaneously with IL-2 than in patients receiving the sequential treatment. Antitumor activity was observed in the lungs of four of eight renal cell carcinoma patients with pulmonary metastases treated with concurrent GM-CSF and IL-2. Although no or minimal shrinkage was observed in the patients' large primary tumors, these results warrant further study. The recommended initial Phase II dose and schedule is 1.25 microgram/kg/day GM-CSF, given concurrently with 1.5 million Roche units/m2/day (4.5 x 10(6) international units/m2/day) IL-2, with subsequent escalation of GM-CSF to 2.5 microgram/kg/day after careful observation for toxicities.