EMX2 is epigenetically silenced and suppresses growth in human lung cancer

Lung cancer is a common cancer and the leading cause of cancer-related death worldwide. Aberrant activation of WNT signaling is implicated in lung carcinogenesis. EMX2, a human homologue of the Drosophila empty spiracles gene is a homeodomain-containing transcription factor. The function of EMX2 has been linked to the WNT signaling pathway during embryonic patterning in mice. However, little is known about the role of EMX2 in human tumorigenesis. In this study, we found that EMX2 was dramatically downregulated in lung cancer tissue samples and this downregulation was associated with methylation of the EMX2 promoter. Restoration of EMX2 expression in lung cancer cells lacking endogenous EMX2 expression suppressed cell proliferation and invasive phenotypes, inhibited canonical WNT signaling, and sensitized lung cancer cells to the treatment of the chemo cytotoxic drug cisplatin. On the other hand, knockdown of EMX2 expression in lung cancer cells expressing endogenous EMX2 promoted cell proliferation, invasive phenotypes and canonical WNT signaling. Taken together, our study suggests that EMX2 may have important roles as a novel suppressor in human lung cancer.

Phase 1/2 trial of autologous tumor mixed with an allogeneic GVAX vaccine in advanced-stage non-small-cell lung cancer

Tumor vaccines composed of autologous tumor cells genetically modified to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) (GVAX) have demonstrated clinical activity in advanced-stage non-small-cell lung cancer (NSCLC). In an effort to remove the requirement for genetic transduction of individual tumors, we developed a 'bystander' GVAX platform composed of autologous tumor cells mixed with an allogeneic GM-CSF-secreting cell line. We conducted a phase I/II trial of this vaccine (3-12 biweekly vaccinations) in advanced-stage NSCLC. Tumors were harvested from 86 patients, tumor cell processing was successful in 76, and 49 proceeded to vaccination. The most common toxicity was local vaccine injection site reactions. Serum GM-CSF pharmacokinetics were consistent with secretion of GM-CSF from vaccine cells for up to 4 days with associated transient leukocytosis confirming the bioactivity of vaccine-secreted GM-CSF. Evidence of vaccine-induced immune activation was demonstrated; however, objective tumor responses were not seen. Compared with autologous GVAX vaccines prepared by transduction of individual tumors with an adenoviral GM-CSF vector, vaccine GM-CSF secretion was approximately 25-fold higher with the bystander GVAX vaccine used in this trial. However, the frequency of vaccine site reactions, tumor response, time to disease progression, and survival were all less favorable in the current study.

Stage II (N1) lung cancer

As therapies evolve and mature, the authors predict that the next 20 years will see significant advances in the understanding of non-small-cell lung cancer (NSCLC), in molecular stratification of NSCLC, and significant improvement in survival and cure rates. This survival will be achieved through early detection and combined treatments using effective surgical interventions, improved radiotherapeutics, and especially significantly enhanced, rationally designed systemic therapies.

Giant tumors of the chest: preoperative embolization and resection

Giant tumors of the chest are rare. These tumors comprise a spectrum of disease from benign lesions to highly aggressive malignant tumors with cells of origin in the pleura, pulmonary parenchyma, blood vessels, thymus, and connective tissues. We report four cases of giant tumors of the thorax treated with preoperative arterial embolization followed by complete surgical resection. Their diagnostic and treatment courses, imaging, and pathology are described.

Positron emission tomography with f18-fluorodeoxyglucose in the staging and preoperative evaluation of malignant pleural mesothelioma

OBJECTIVES

The purpose of this study was to evaluate the utility of positron emission tomography with F18-fluorodeoxyglucose in the preoperative evaluation and staging of malignant mesothelioma in patients who were candidates for aggressive combined modality therapy.

METHODS

Eighteen consecutive patients with biopsy-proven malignant mesothelioma underwent positron emission tomographic scanning. The results of positron emission tomographic imaging were compared with results obtained by computed tomography, mediastinoscopy, thoracoscopy, and pathologic examination of surgical specimens. All patients fasted and received an average of 14.5 +/- 2.7 mCi of F18-fluorodeoxyglucose for positron emission tomographic scanning. Attenuation-corrected whole-body and regional emission images of the chest and upper abdomen were acquired and formatted into transaxial, coronal, and sagittal images.

RESULTS

All primary malignant mesotheliomas accumulated F18-fluorodeoxyglucose, and the mean standardized uptake value was 7. 6 (range, 3.33-14.85; n = 9). There were no false-negative results of positron emission tomography. Identification of occult extrathoracic metastases by positron emission tomography was the basis for excluding two patients from surgical therapy. There were two false-positive results of positron emission tomography: increased F18-fluorodeoxyglucose uptake in the contralateral chest that was negative by thoracoscopic biopsy (n = 1) and increased abdominal F18-fluorodeoxyglucose uptake after partial colectomy for diverticular disease (n = 1).

CONCLUSIONS

Positron emission tomography can identify malignant pleural mesothelioma and appears to be a useful noninvasive staging modality for patients being considered for aggressive combined modality therapy.

Tumor-derived EMMPRIN (extracellular matrix metalloproteinase inducer) stimulates collagenase transcription through MAPK p38

EMMPRIN (extracellular matrix metalloproteinase inducer) stimulates fibroblast metalloproteinases (MMP) 1, 2 and 3 (Kataoka et al. (1993) Cancer Res. 53, 3154-3158). Here we focus on MMP-1, showing that in lung tumors, MMP-1's cognate mRNA is strongly expressed in stromal fibroblasts adjacent to EMMPRIN-expressing tumor cells. In vitro, EMMPRIN upregulates MMP-1 mRNA expression in a concentration-dependent manner, with a peak accumulation at 24 h. The response is genistein-sensitive, suggesting it is dependent on tyrosine kinase activity. Analysis of tyrosine phosphorylation-dependent MAP kinases ERK 1/2, SAPK/JNK, and p38 showed that the activity of p38 but not that of the other 2 kinases was elevated in response to EMMPRIN. That p38 activity was required for EMMPRIN stimulation of MMP-1 was evident from results showing that the p38 inhibitor SB203580 blocked this response. This is the first available information regarding the mechanism by which tumor-associated molecules upregulate MMP synthesis in stromal fibroblasts.

Interleukin 6 reduces lipoprotein lipase activity in adipose tissue of mice in vivo and in 3T3-L1 adipocytes: a possible role for interleukin 6 in cancer cachexia

To investigate whether interleukin 6 (IL-6) might be a potential mediator of the depleted fat reserves observed in malignancy-associated cachexia, we measured lipoprotein lipase (LPL) activity in adipose tissue of mice after administration of IL-6 or tumor necrosis factor and in cultured adipocytes after addition of these cytokines. Injection of IL-6 i.p. reduced adipose tissue LPL activity by 53% within 4.5 to 5.5 h. Injection of tumor necrosis factor elevated serum IL-6 levels and reduced adipose tissue LPL activity by 70%. Both human and murine IL-6 reduced heparin-releasable LPL activity in 3T3-L1 adipocytes in a dose-dependent manner; half-maximal inhibition of LPL activity was achieved with 5000 hybridoma growth factor units/ml. Thus, IL-6 reduces adipose LPL activity and may contribute to the loss of body fat stores associated with some cases of cancer cachexia. Since tumor necrosis factor increases circulating IL-6, some of its effects may be mediated or potentiated by IL-6.

IL-2-based immunotherapy alters circulating neutrophil Fc receptor expression and chemotaxis

We performed functional assays on polymorphonuclear (PMN) leukocytes from 21 patients with advanced cancers, before, during, and after IL-2 administration. Of these, 19 were treated with high dose bolus IL-2 infusions (10(5) U/kg every 8 h) and 2 patients received low dose continuous infusions of IL-2 (250 U/kg/h). Five of six patients studied after IL-2 therapy had a decrease in their PMN chemotactic response to FMLP after bolus IL-2 (mean 8 doses) or, after the 4th day of continuous infusion IL-2 (pre-IL-2 values of 82% +/- 17% to 45% +/- 1% post-IL-2, p2 less than 0.004) compared with normal control values. In 8 of 10 patients studied, PMN capacity to oxidize intracellular dichlorofluorescein dye, an indirect measurement of O2- production in response to PMA stimulation, decreased after IL-2 administration (pre-IL-2 mean dichlorofluorescein oxidation (by channel number) 243 +/- 128 vs 3-day post-IL-2 87 +/- 86, p2 less than 0.02). Furthermore, a marked decrease in Fc gamma R III (Leu-11, CD16) expression was observed in 12/13 patients' PMN studied after IL-2 therapy (mean percent of PMN population with positive FcR expression was 81.1 +/- 15.4% pre-IL-2 which decreased to 56.0 +/- 30.5% post-IL-2, p2 less than 0.001). Other PMN surface markers (My4, My7, ICAM-1, LFA1, LFA3, Mac1) did not change significantly. PMN-mediated antibody-dependent cellular cytotoxicity did not change after IL-2 therapy (only 4/15 patients demonstrated more than 50% reduction in antibody-dependent cellular cytotoxicity). PMN phagocytosis of Staphylococcus aureus was also not significantly altered by IL-2 administration in six patients studied (pre-IL-2, 99 +/- 17% vs 111 +/- 28% post-IL-2, p2 greater than 0.2). We conclude that the systemic administration of IL-2 by intermittent or continuous administration is associated with marked changes in PMN function and cell surface receptor expression. These alterations may contribute to the apparent increased susceptibility to bacterial infection observed in these patients.

IL-2-based immunotherapy alters circulating neutrophil Fc receptor expression and chemotaxis

We performed functional assays on polymorphonuclear (PMN) leukocytes from 21 patients with advanced cancers, before, during, and after IL-2 administration. Of these, 19 were treated with high dose bolus IL-2 infusions (10(5) U/kg every 8 h) and 2 patients received low dose continuous infusions of IL-2 (250 U/kg/h). Five of six patients studied after IL-2 therapy had a decrease in their PMN chemotactic response to FMLP after bolus IL-2 (mean 8 doses) or, after the 4th day of continuous infusion IL-2 (pre-IL-2 values of 82% +/- 17% to 45% +/- 1% post-IL-2, p2 less than 0.004) compared with normal control values. In 8 of 10 patients studied, PMN capacity to oxidize intracellular dichlorofluorescein dye, an indirect measurement of O2- production in response to PMA stimulation, decreased after IL-2 administration (pre-IL-2 mean dichlorofluorescein oxidation (by channel number) 243 +/- 128 vs 3-day post-IL-2 87 +/- 86, p2 less than 0.02). Furthermore, a marked decrease in Fc gamma R III (Leu-11, CD16) expression was observed in 12/13 patients' PMN studied after IL-2 therapy (mean percent of PMN population with positive FcR expression was 81.1 +/- 15.4% pre-IL-2 which decreased to 56.0 +/- 30.5% post-IL-2, p2 less than 0.001). Other PMN surface markers (My4, My7, ICAM-1, LFA1, LFA3, Mac1) did not change significantly. PMN-mediated antibody-dependent cellular cytotoxicity did not change after IL-2 therapy (only 4/15 patients demonstrated more than 50% reduction in antibody-dependent cellular cytotoxicity). PMN phagocytosis of Staphylococcus aureus was also not significantly altered by IL-2 administration in six patients studied (pre-IL-2, 99 +/- 17% vs 111 +/- 28% post-IL-2, p2 greater than 0.2). We conclude that the systemic administration of IL-2 by intermittent or continuous administration is associated with marked changes in PMN function and cell surface receptor expression. These alterations may contribute to the apparent increased susceptibility to bacterial infection observed in these patients.

Metastasectomy for soft tissue sarcoma. Further evidence for efficacy and prognostic indicators

Between 1982 and 1987, 74 patients (46 men and 28 women) had exploration for presumed metastases from high-grade soft tissue sarcoma of the head/neck, extremity, or trunk. Ages ranged from 11 to 75 years (median 38 years). Thirty (41%) had multiple procedures for recurrences (range two to six explorations). Median postthoracotomy time for the group of patients with histologically confirmed sarcoma (n = 63) was 20.3 months. Patients rendered free of disease at initial thoracotomy had significantly longer postthoracotomy survival times (26.8 months median) than those with unresectable metastatic disease (9 months median); p2 less than 0.0001). The prognostic significance of age, sex, location of primary tumor, disease-free interval, number of nodules on preoperative computed tomograms or conventional linear tomograms, number of metastases resected, and the use of postoperative chemotherapy were analyzed. In a univariate analysis, sex, age, and location of the primary tumor did not impact significantly on survival, nor did the use of postoperative chemotherapy. Initial disease-free interval of 1 year or less was associated with a significantly shorter survival time, and patients with five nodules or fewer on preoperative computed tomography had significantly longer survival times than patients with six nodules or more. Patients with three nodules or fewer on linear tomography had a longer postthoracotomy survival time than patients with four nodules or more. In patients whose malignant disease could be completely resected, the number of nodules resected at thoracotomy did not impact on long-term survival. According to proportional-hazards modeling, disease-free interval, sex, resectability, and truncal location were found to associate with length of survival after metastasis removal. We conclude that pulmonary metastasis resection in patients with soft tissue sarcoma is associated with long-term survival, and consistent indicators can define which patients may benefit from these interventions.

Increased ouabain binding after repeated noradrenergic stimulation

Acute noradrenergic stimulation has previously been shown to stimulate brain (Na+, K+)-adenosine triphosphatase activity. Effects of repeated stimulation with piperoxane were examined in the present study. Daily piperoxane increased ouabain binding, measured 24 h after the last dose, after 4 days or 3 weeks treatment; K+-p-nitrophenylphosphatase was increased after 3 weeks. Prazosin, which, like piperoxane, activates presynaptic noradrenergic neurons but, unlike piperoxane, blocks postsynaptic receptors, did not increase K+-p-nitrophenylphosphatase, and decreased ouabain binding after 3 weeks.