Two cases of humoral hypercalcemia of malignancy complicating infantile fibrosarcoma.

We report two infants with infantile fibrosarcoma (IFS) complicated by severe hypercalcemia. Assessment demonstrated suppressed parathyroid hormone and 1,25-dihydroxyvitamin D levels with elevated circulating levels of parathyroid hormone related protein, indicating the diagnosis of humoral hypercalcemia of malignancy (HHM). HHM is a paraneoplastic syndrome rarely associated with pediatric malignancies. Hypercalcemia manifested clinically with neurologic symptoms and soft tissue calcium deposition and required aggressive management with intravenous fluids, diuretics, and supplemental electrolytes. Following treatment with neoadjuvant chemotherapy, serum calcium levels precipitously declined requiring calcium repletion. These cases highlight the improvement of hypercalcemia secondary to HHM following chemotherapy.

Radiosensitizing effect of intratumoral interleukin-12 gene electrotransfer in murine sarcoma.

BACKGROUND: Interleukin-12 (IL-12) based radiosensitization is an effective way of tumor treatment. Local cytokine production, without systemic shedding, might provide clinical benefit in radiation treatment of sarcomas. Therefore, the aim was to stimulate intratumoral IL-12 production by gene electrotransfer of plasmid coding for mouse IL-12 (mIL-12) into the tumors, in order to explore its radiosensitizing effect after single or multiple intratumoral gene electrotransfer. METHODS: Solid SA-1 fibrosarcoma tumors, on the back of A/J mice, were treated intratumorally by mIL-12 gene electrotransfer and 24 h later irradiated with a single dose. Treatment effectiveness was measured by tumor growth delay and local tumor control assay (TCD(50) assay). With respect to therapeutic index, skin reaction in the radiation field was scored. The tumor and serum concentrations of cytokines mIL-12 and mouse interferon γ (mIFNγ) were measured. Besides single, also multiple intratumoral mIL-12 gene electrotransfer before and after tumor irradiation was evaluated. RESULTS: Single intratumoral mIL-12 gene electrotransfer resulted in increased intratumoral but not serum mIL-12 and mIFNγ concentrations, and had good antitumor (7.1% tumor cures) and radiosensitizing effect (21.4% tumor cures). Combined treatment resulted in the radiation dose-modifying factor of 2.16. Multiple mIL-12 gene electrotransfer had an even more pronounced antitumor (50% tumor cures) and radiosensitizing (86.7% tumor cures) effect. CONCLUSIONS: Single or multiple intratumoral mIL-12 gene electrotransfer resulted in increased intratumoral mIL-12 and mIFNγ cytokine level, and may provide an efficient treatment modality for soft tissue sarcoma as single or adjuvant therapy to tumor irradiation.

Pulmonary artery intimal sarcoma mimicking pulmonary thromboembolism: A case report.

RATIONALE: Pulmonary artery intimal sarcoma is a rare tumor with exceptionally high mortality and easily misdiagnosed as pulmonary thromboembolism pulmonary thromboembolism (PTE) due to the nonspecific clinical presentation and symptom. Misdiagnosis or untimely diagnosis makes the disease progress to an advanced stage and eventually leads to a poor prognosis. PATIENT CONCERNS: A 37-year-old Chinese female presented with chest tightness and dyspnea for 3 months. Echocardiography and chest computed tomography revealed an intraluminal obstruction of the pulmonary arteries. Tests of serum tumor makers showed slight elevation for carbohydrate antigen-125, and α-fetoprotein. PTE was suspected according to the radiological and laboratory findings. DIAGNOSIS: Microscopic findings of the presumed thrombus showed prominent myxoid and edematous background with atypical spindled cells and curvilinear vascularity. Immunohistochemical staining demonstrated that the atypical spindled cells were positive for vimentin but negative for CK, S100, SMA, desmin, CD68, STAT6, CD34, ß-catenin, ALK-p80, p53, and MDM2. According to the radiological and pathological findings, the diagnosis of fibrosarcoma of pulmonary artery was made. INTERVENTIONS: The patient underwent surgical resection and the mass was excised as completely as possible. OUTCOME: Follow-up information showed no evidence of recurrence or metastasis after 3 months postresection. LESSONS: Because of the low incidence rate, nonspecific clinical symptoms, and radiological findings, primary fibrosarcoma of the pulmonary artery is commonly misdiagnosed as PTE. Pathological examination is necessary to confirm the diagnosis.

Angiogenic factors FGF2 and PDGF-BB synergistically promote murine tumor neovascularization and metastasis.

Tumors produce multiple growth factors, but little is known about the interplay between various angiogenic factors in promoting tumor angiogenesis, growth, and metastasis. Here we show that 2 angiogenic factors frequently upregulated in tumors, PDGF-BB and FGF2, synergistically promote tumor angiogenesis and pulmonary metastasis. Simultaneous overexpression of PDGF-BB and FGF2 in murine fibrosarcomas led to the formation of high-density primitive vascular plexuses, which were poorly coated with pericytes and VSMCs. Surprisingly, overexpression of PDGF-BB alone in tumor cells resulted in dissociation of VSMCs from tumor vessels and decreased recruitment of pericytes. In the absence of FGF2, capillary ECs lacked response to PDGF-BB. However, FGF2 triggers PDGFR-alpha and -beta expression at the transcriptional level in ECs, which acquire hyperresponsiveness to PDGF-BB. Similarly, PDGF-BB-treated VSMCs become responsive to FGF2 stimulation via upregulation of FGF receptor 1 (FGFR1) promoter activity. These findings demonstrate that PDGF-BB and FGF2 reciprocally increase their EC and mural cell responses, leading to disorganized neovascularization and metastasis. Our data suggest that intervention of this non-VEGF reciprocal interaction loop for the tumor vasculature could be an important therapeutic target for the treatment of cancer and metastasis.

Systemic Inflammation Is Associated with Oncological Outcome in Patients with High-Grade Myxofibrosarcoma of the Extremities: A Retrospective Analysis.

BACKGROUND: The aim of this retrospective study is to verify whether preoperative systemic inflammatory markers (serum C-reactive protein [CRP] and neutrophil-lymphocyte ratio [NLR]) can help in predicting the disease-specific survival (DSS) and local recurrence (LR) rate in adult patients affected by localized myxofibrosarcoma (MFS) of the extremities. METHODS: We reviewed 126 adult patients with primary, localized MFS of the limbs. We analyzed DSS and LR. RESULTS: Median age at the time of surgery was 68 years (range 19-92). Median CRP was 0.4 mg/dL and median NLR was 2.8. A worse DSS was found in patients who had preoperative CRP >0.5 mg/dL (p = 0.002) and in those with NLR >3.5 (p < 0.001). In multivariate analysis, tumor size and grade as well as preoperative CRP values and NLR were confirmed to be prognostic factors in terms of DSS. An increased risk of LR was found in multivariate analysis in patients with a tail sign and with high gadolinium enhancement at preoperative MRI. CONCLUSIONS: Patients with high preoperative CRP and NLR levels, as well as large and high-grade tumors, might be considered as candidates for additional, more aggressive treatment approaches or more stringent follow-up schedules.

Evaluation of serum haptoglobin and C-reactive protein in dogs with mammary tumors.

BACKGROUND: In veterinary medicine, there is increasing interest in measuring acute phase proteins as a tool in the diagnosis and monitoring of neoplastic diseases. Although mammary neoplasms are the most common type of cancer in dogs, acute phase proteins have not been extensively evaluated in dogs with mammary tumors. OBJECTIVES: The aim of this study was to evaluate serum haptoglobin (Hp) and C-reactive protein (CRP) concentrations in the dogs with mammary tumors and assess their potential association with malignancy. METHODS: A retrospective study of dogs with mammary tumors was performed. Serum concentrations of CRP and Hp were determined in healthy control dogs (n=20) and dogs with mammary tumors before surgery (n=41). Mammary tumors were grouped as carcinomas (n=24), fibrosarcoma (n=1), malignant mixed tumors (n=7), benign mixed tumors (n=6), and adenomas (n=3). CRP and Hp concentrations were compared in dogs with different tumor types and were also compared based on tumor size, lymph node infiltration, skin ulceration, fixation to underlying tissue, and time between tumor identification and removal. RESULTS: Hp concentration was significantly (P<.043) higher in dogs with mammary tumors (median 2.03 g/L, range 0.09-2.94 g/L) compared with controls (1.38 g/L, range 0.08-3.00 g/L), but the range of values overlapped considerably. CRP concentration was higher in dogs with carcinomas (4.70 mg/L, range 0.63-128.96 mg/L) vs controls (2.11 mg/L, range 0.25-6.57 mg/L) (P=.0008) and in dogs with ulcerated skin (14.8 mg/L, range 5.7-128.9 mg/L, n=3) compared with those without ulceration (2.4 mg/L, range 0.11-30.3 mg/L, n=38) (P=.048). CONCLUSIONS: Serum Hp and CRP do not appear to have value in diagnosing or predicting malignancy of mammary tumors in dogs. Higher CRP concentrations in dogs with mammary carcinoma suggest a role for inflammation in this tumor type.

Non-islet-cell tumour hypoglycaemia (NICTH): About a series of 6 cases.

The purpose of this study was to analyse the characteristics of 6 patients managed in a university hospital between 1996 and 2016 for non-islet cell tumor hypoglycemia (NICTH), a form of hypoglycaemia due to the paraneoplastic secretion of IGF-2 or its related substances. RESULTS: Three of these 6 patients (50%), aged over 69 years, including 2 with acromegaloid phenotype, presented with a pleural solitary fibrous tumor (SFT), with median diameter 20 cm (interquartile range, 12.5-20.5) with a low median SUV (3.3 g/mL (QR, 2-7.5)) on 18F-FDG PET. The other 3 patients presented respectively neuroendocrine carcinoma (NEC) of the palate (70-year-old woman), retroperitoneal myxofibrosarcoma (66-year-old man) and meningeal hemangiopericytoma (36-year-old woman). All 3 were inoperable and did not respond to any therapy other than glucose solution. Corticosteroid therapy was effective in the 3 SFTs and the NEC. One of the SFTs recurred 10 years later with asymptomatic hypoglycemia, which resolved after reintervention. Median (IQR) blood glucose levels of the 6 patients was 0.4g/L (QR, 0.31-0.41), with hypoinsulinemia at 0.7mIU/L (QR 0.7-2.0), undetectable GH, low IGF-1, normal IGF-2 level in 5/6 cases, a high IGF-2:IGF-1 ratio at 26.9 (QR, 20.8-37.8), hypokalemia and hypomagnesemia. CONCLUSION: NICTH is a rare syndrome, which should be considered in the presence of hypoinsulinemic hypoglycemia with low GH and IGF-1, and a IGF-2:IGF-1 ratio>10. Corticosteroid therapy was effective in elderly subjects, particularly with solitary fibrous tumor, which was generally operable. Hemangiopericytoma and myxofibrosarcoma had poor prognosis in younger patients.

Dietary menhaden oil lowers plasma prostaglandins and calcium in mice bearing the prostaglandin-producing HSDM1 fibrosarcoma.

The omega 3 class of polyunsaturated fatty acids, particularly eicosapentaenoic acid (EPA, 20:5), has been shown to alter the patterns of arachidonic acid (20:4) metabolism in both in vitro and in vivo systems. To examine further the role of arachidonic acid conversion to prostaglandins (PG) in hypercalcemic mice bearing the PG-producing HSDM1 fibrosarcoma, we have performed experiments in which control and tumor-bearing animals were fed diets either low (0.1-0.2% of total fatty acid) or high (17%) in EPA. In all five experiments performed, tumor-bearing mice eating control diets had markedly elevated (average sixfold above control) plasma concentrations of 13,14-dihydro-15-keto-PGE2 (PGE2-M), while in mice bearing HSDM1 tumors and eating the EPA-enriched menhaden oil diet, the elevation was reduced to only twice control values. The increase in plasma calcium concentration (approximately 2.5 mg/dl above control) in tumor-bearing animals was also reduced significantly (P less than 0.05) to only 1.3 mg/dl above control in mice eating the diet enriched in EPA. Plasma immunoreactive hydroxy fatty acids (i12-HETE) and sulfidopeptide leukotrienes (iSRS) were not elevated in tumor-bearing mice and were unaffected by diet. The contents of PGE2, PGF2 alpha, and 6-keto-PGF1 alpha were lower in tumor tissue from animals eating the diet high in EPA, whereas the tissue contents of i12-HETE and iSRS were not altered by diet. Fatty acid analysis of liver and tumor tissue revealed marked increases in certain omega 3 fatty acids (20:5, 22:5, and 22:6) from animals eating the enriched diet. Body weights, tumor weights, and tumor histology were not significantly altered by diet. To determine whether dietary calcium played a role in the elevation of plasma calcium in mice bearing the HSDM1 tumor and the reduction of plasma calcium in animals fed EPA, we compared results in mice fed diets containing 0.80% (normal) and 0.015% (deficient) calcium. The increases in plasma calcium and PGE2-M observed in tumor-bearing mice were the same on both normal and very low calcium intakes. We conclude, in mice of the Swiss albino strain bearing the HSDM1 fibrosarcoma, that consumption of a diet enriched in EPA reduces the production of cyclooxygenase products of arachidonic acid metabolism and thereby reduces the elevation of plasma calcium concentration. Dietary enrichment with EPA did not alter the production of serologically determined lipoxygenase products of arachidonic acid.

[Systemic inflammation and experimental cancer in a murine model]. / Cáncer experimental e inflamación sistémica en un modelo murino.

The link between cancer and inflammation in an organ or tissue has firmly been established on the basis that cancer tends to occur at sites of chronic inflammation and that local inflammatory processes can accelerate the growth of preexisting tumors in both animals and human beings. In contrast, the relationship between cancer and systemic inflammation has been less studied. In this work, we demonstrated that the growth of the murine fibrosarcoma MC-C, was accompanied by manifestations of systemic inflammation, as demonstrated by an increase in both the number of circulating polymorphonuclear neutrophils (PMN) and the serum concentration of the proinflammatory cytokines interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) and the acute phase proteins C reactive (CRP) and serum A amyloid (SAA). Two temporally separate peaks of systemic inflammation were detected during tumor development. The first was displayed during the first week after tumor inoculation. The second peak began around day 14 and its intensity was proportional to tumor size. In mice bearing a large MC-C tumor, a high number of circulating PMN and myeloid precursors were evident. Most of these cells exhibited activation evidenced by an increased reactive oxygen species generation and high expression of the Gr1+/Mac1+ markers. Inoculation of thioglycolate -which generates a transient systemic inflammation-accelerated the growth of MC-C tumor and reciprocally, inhibition of such systemic inflammation by using indomethacin, prevented that enhancing effect. This suggests that the systemic inflammation that the tumor generates on its own, could be part of its growth strategy.

Spatial heterogeneity and oxygen dependence of glucose consumption in R3230Ac and fibrosarcomas of the Fischer 344 rat.

To examine the oxygen-dependence of glucose consumption in solid tumors, we monitored gradients of glucose, lactate, and hypoxia in R3230Ac and FSA tumors growing in Fischer 344 rats. Bioluminescence imaging, detection of Hoechst 33342, and immunostaining of the hypoxia marker EF5 [2-8-N-(2,2,3,3,3-pentafluoropropyl)acetamide] were done in serial tumor slices. Glucose and lactate levels were also determined in liver and blood. Cells were further tested for glucose consumption and lactate production in vitro. In both tumor types, EF5 staining indicated similar maximum levels of hypoxia; the most intense staining occurred in perinecrotic regions. Glucose concentrations were highest in liver, declined from blood to tumor edge, further into vital tumor regions, and were lowest close to necrosis. Glucose was significantly lower in FSA than in R3230Ac tumors. Glucose concentrations in R3230Ac tumors were consistently higher in nonhypoxic than in hypoxic areas, with maximum values equal to systemic blood levels. Glucose in FSA tumors was close to zero, regardless of the presence or absence of hypoxia. Lactate did not differ significantly between the tumor types. FSA cells in culture showed a trend towards higher aerobic glucose consumption versus R3230Ac. Both cell lines increased their lactate production to similar levels under hypoxia. We conclude that both R3230Ac and FSA tumors retain the Pasteur effect, i.e., hypoxia triggers increased glycolysis. However, our results imply that increased aerobic glucose utilization leads to low glucose levels in FSA and a situation where supply limits uptake. This explains the repeatedly observed correlation between tumor blood flow and 18F-deoxyglucose uptake.

A phase I-II preoperative biomarker trial of fenretinide in ascitic ovarian cancer.

PURPOSE: To evaluate study feasibility, toxicity, drug concentrations, and activity of escalating doses of the synthetic retinoid fenretinide [N-(4-hydroxyphenyl)retinamide (4-HPR)] in ovarian cancer by measuring serum CA125 and cytomorphometric biomarkers in cancer cells collected from ascitic fluid before and after treatment. METHODS: Twenty-two naive patients with ascitic ovarian cancer were treated with escalating doses of 4-HPR at 0, 400, 600, and 800 mg/d for 1 to 4 weeks before surgery. Changes in the proportion of proliferating cells expressed by Ki67 and computer-assisted cytomorphometric variables (nuclear area, DNA index, and chromatin texture) were determined in ascitic cells. Drug levels were measured by high-performance liquid chromatography. RESULTS: Doses up to 800 mg/d were well tolerated, and no adverse reactions occurred. There was no effect of 4-HPR on changes in serum CA125, Ki67 expression, which were assessed in 75% of subjects, and cytomorphometric variables, which were assessed in 80% of subjects. Plasma retinol levels were significantly lower in affected women than healthy donors. 4-HPR plasma concentrations increased slightly with increasing doses and attained a 1.4 micromol/L concentration with 800 mg/d. Drug levels in malignant ascitic cells and tumor tissue were higher than in plasma but were 50 and 5 times lower, respectively, than in carcinoma cells treated in vitro with 1 micromol/L 4-HPR. CONCLUSIONS: Cell biomarkers can be measured in ascitic cells to assess drug activity. Under our experimental conditions, 4-HPR did not show activity in advanced ovarian cancer cells. However, clinical evidence supports further investigation of fenretinide for ovarian cancer prevention.

Glucose turnover and gluconeogenesis during hypocaloric glucose infusion in tumor-bearing F344 male rats.

Glucose turnover ([3(3)H]glucose) and gluconeogenesis from alanine ([U-14C]alanine) were measured in non-tumor bearing (NTB) and tumor-bearing (TB) inbred F344 male rats during starvation and in response to graded levels of glucose infusion. All groups demonstrated a glucose turnover appropriate to the prevailing steady-state plasma glucose level. Whereas NTB animals exhibited maximal suppression of gluconeogenesis from alanine at infusion rates of 0.39 mg/100 g total body weight/minute, TB animals suppressed alanine-to-glucose conversion only at a glucose infusion rate of 0.71 mg/100 g total body weight/minute. Glucose clearance was consistently higher in TB groups but did not change in either NTB or TB groups during infusion. Blood lactate levels increased in response to glucose infusion only in TB animals. These results suggested that starved TB animals obligately utilized more glucose than did NTB controls but were able to adjust turnover appropriately to plasma glucose levels. However, gluconeogenesis was suppressed only at higher glucose infusion rates in TB rats compared to NTB animals.

Antitumor antibodies and immunoglobulin class and subclass levels in Corynebacterium parvum-treated mice.

Changes in immunoglobulin class and subclass levels and the development of antitumor antibodies were assessed in normal and tumor-bearing mice challenged with Corynebacterium parvum. C. parvum administration resulted in a marked increase in certain immunoglobulin levels, especially Ig G2b, and in the development of antibodies reacting with syngeneic and allogeneic tumor cells. The serologic changes induced by C. parvum were dependent on the dose and route of administration; preliminary studies suggested that they may have been largly independent of T-cell function. These changes were suppressed by the administration of gold salts, which also inhibited the antitumor effect of C. parvum.

Relationship of hypoglycemia to tumor necrosis factor production and antitumor activity: role of glucose, insulin, and macrophages.

The role of hypoglycemia in tumor necrosis factor (TNF) production was examined. TNF was produced from sera of animals presensitized with reticuloendothelial system stimulants after lipopolysaccharide (LPS) challenge. Blood glucose was strongly reduced during TNF production. Glucose administration to presensitized mice (before LPS challenge) caused inhibition of TNF production. Exogenous insulin injection inhibited TNF production in a dose-related manner. Peritoneal exudate cells (PEC) from Propionibacterium acnes-primed mice revealed increased glucose consumption during in vitro TNF production but showed no relationship between the degree of glucose consumption and the ability to produce TNF. Insulin addition to the culture medium caused inhibition of TNF production from PEC, which indicated that insulin may block TNF production from macrophages. Administration of highly purified TNF (without concomitant LPS) induced extensive tumor necrosis but did not induce hypoglycemia; LPS induced moderate necrosis with accompanying hypoglycemia; insulin induced hypoglycemia but did not induce tumor necrosis. It is concluded that hypoglycemia does not accompany the action of TNF.

Evidence for single-cell origin of 3-methylcholanthrene-induced fibrosarcomas in mice with cellular mosaicism.

Fibrosarcomas produced by s.c. injection of 5 micrograms of 3-methylcholanthrene in Pgk-1a/Pgk-1b mice carrying X-chromosome inactivation mosaicism for the phosphoglycerate kinase (PGK-1) gene contained only one type of phosphoglycerate kinase in seven of eight cases (88%), as judged from its electrophoretic mobility, indicating the single-cell origin of the tumor.

The significance of hematogenous tumor cell clumps in the metastatic process.

The relationship between the size distribution of vessels in an implanted tumor, the size distribution of tumor cell clumps collected in the venous effluent of the tumor, and the development of pulmonary metastases have been studied. The purpose is to evaluate the importance of clumps and their site of formation in the metastatic process. The results demonstrate a negative exponential character for both the size distribution of effluent tumor clumps and the tumor vessel population. Tumor trauma or massage increases total tumor cells and clumps released into the effluent. Serial amputation demonstrates that tumor cells are continuously being released on a day-by-day basis in vivo. A linear relationship exists between the proportion of vessels with diameters large enough to pass a tumor clump of a given size and the proportion of clumps of that size within the venous effluent. Injection of tumor cells in clumps of 6 to 7 cells produces a significantly greater number of metaststic foci than does a similar number of single tumor cells; larger clumps produce significantly more metastatic foci than do smaller clumps matched for the number of cells. These studies verify the significance of tumor clumps in the metastatic process. It is suggested that tumor cell clumps arise locally within the vascular bed of the tumor.

Relationship of erythrocyte polyamine levels and growth rate of transplantable tumors in rats.

Varying levels of polyamines in the urine, plasma, and erythrocytes (RBC) of cancer patients have been demonstrated. The growth rate of the tumor has been suggested as a primary factor which determines whether the polyamine levels in urine are elevated. To further evaluate tumor size and growth rate as variables affecting polyamine levels in physiological fluids, the effect of a transplantable fibrosarcoma and colon tumor on the RBC polyamine levels of Fischer 344 rats was determined. The tumors were implanted s.c. and grew without metastasis or spontaneous regression. The fibrosarcoma grew exponentially up to a weight of approximately 69 +/- 15 (SD) g and was associated with a linear increase in RBC polyamine levels compared with that of non-tumor-bearing rats. RBC putrescine, spermidine, and spermine levels were significantly elevated at tumor weights of 12.5 +/- 1.4, 20.4 +/- 3.8, and 33.2 +/- 5.0 g, respectively. The respective polyamines increased consistently thereafter until the tumor weight was 57.8 +/- 5.8 g. In contrast with the fibrosarcoma, the colon tumor grew exponentially only to a weight of 9.2 +/- 4.7 g, at which time the growth rate of the tumor began to decrease (time T of the Gompertz model). RBC polyamine levels of rats with the colon tumor showed only a transient increase. RBC putrescine levels were significantly increased at a tumor weight of 12.9 +/- 1.2 g and spermidine at a tumor weight of 17.4 +/- 0.2 g. RBC spermine levels were significantly elevated at both tumor weights; thereafter, all RBC polyamine levels returned to normal. Host cachexia was evident when the fibrosarcoma and colon tumors weighed 12.5 +/- 0.9 and 7.2 +/- 2.6 g, respectively. The polyamine levels of the fibrosarcoma differed significantly from that of the colon tumor. These levels, however, did not correlate with the exponential growth rates. The results suggest that the tumor is the major source of elevated RBC polyamines. The data also suggest that the tumors must be rapidly growing for the elevation in polyamines to occur. This may partly explain why patients with extensive neoplastic disease that may have surpassed time T in the Gompertz model do not manifest abnormal polyamine levels.

In vivo analysis of the suppressive effects of immunosuppressive acidic protein, a type of alpha 1-acid glycoprotein, in connection with its high level in tumor-bearing mice.

Suppressed concanavalin A response of spleen cells which appeared on Day 21 in C3H/He mice bearing methylcholanthrene-induced fibrosarcoma was attributed to macrophages. These macrophages were not only immunoglobulin and Thy 1.2 negative and mitomycin C resistant but were also found in the light-specific-gravity (1.077) fraction and were completely removed by carbonyl iron treatment. These suppressor macrophages, however, disappeared 4 days after surgical resection of the tumor, suggesting that the control mechanism originally resides in tumor tissues. Immunosuppressive acidic protein (IAP) levels in the sera of these tumor-bearing mice increased along with the appearance of these suppressor macrophages. Inasmuch as the suppressor macrophages obtained from the spleens of tumor bearers and cultured in vitro produced 4 times more IAP (88 ng/ml) than did resident macrophages, the elevated levels of IAP in the sera of tumor-bearing mice at the late stage might be explained partly by the appearance of suppressor macrophages. On the other hand, an i.v. administration of IAP (5 mg/mouse) into normal mice not only induced the same unresponsiveness of spleen cells to concanavalin A shown by tumor-bearing mice but also induced suppressor macrophages in the spleens of these mice. This fact may indicate that IAP elevation, even though artificial, triggers the induction of suppressor macrophages in the spleen or at least points to a keen correlation between the appearance of suppressor macrophages and increased IAP level in the serum.

Laminin gamma2-chain fragment in the circulation: a prognostic indicator of epithelial tumor invasion.

Laminin (LN) 5, the major component of epithelial-derived extracellular matrix (ECM), plays a major role in cell adhesion and motility. Previous reports stated that proteolytic processing of the NH(2)-terminal region of the gamma2 chain enhances cell motility on LN5, indicating that the degraded gamma2 chain NH(2)-terminal region would be shed from the ECM. However, soluble LN gamma2 NH(2)-terminal fragment (G2F) have not been detected in biological fluids. Here, we developed a double-monoclonal electrochemiluminescence immunoassay for human G2F and detected its presence in the normal human circulation (mean +/- SD: 39.2 +/- 10.3 ng/ml; n = 10). We also measured serum levels of G2F in nude mice orthotopically transplanted with three different human pancreatic carcinoma cell lines: MIApaca-II (secreting no LN5), HPAC (secreting the alpha3beta3gamma2 heterotrimer of LN5), or KP-1 (secreting the monomeric gamma2 chain of LN5). Serum levels of G2F drastically increased in the nude mice transplanted with HPAC (mean +/- SD: 351 +/- 33 ng/ml, 5 weeks after transplantation), the most invasive tumor cells to generate extensive peritoneal dissemination in vivo. A moderate increase in serum levels of G2F was also observed in mice transplanted with KP-1 (87.9 +/- 82 ng/ml, 5 weeks after transplantation), but no antigen was detected in the sera of MIApaca-II-transplanted mice. Therefore, circulating G2F was demonstrated to be a sensitive marker for LN5 production of primary pancreatic carcinomas, even if it was produced only as a monomeric gamma2 chain. In 11 established human pancreatic tumor cell lines (6 of LN5-producing cells and 5 of nonproducing cells), LN5-secreting cells have significantly higher levels of cell surface expression of beta4 integrin than nonsecreting cells. Thus, LN5 secretion is accompanied by cell surface expression of alpha6beta4 integrin, participating in hemidesmosome reorganization to form invading edges of malignant epithelial carcinomas. These data reveal that the level of circulating G2F is a new, prognostic, tumor-characterizing marker for estimating the invasiveness and malignancy of epithelial carcinomas in cancer patients.

Treatment-induced changes in tumor oxygenation predict photodynamic therapy outcome.

Photodynamic therapy (PDT) requires oxygen to cause tumor damage, yet therapy itself can deplete or enhance tumor oxygenation. In the present work we measured the PDT-induced change in tumor oxygenation and explored its utility for predicting long-term response to treatment. The tissue hemoglobin oxygen saturation (SO(2)) of murine tumors was noninvasively measured by broadband diffuse reflectance spectroscopy. In initial validation studies, the oxyhemoglobin dissociation curve for mouse blood was accurately recreated based on measurements during deoxygenation of a tissue phantom of mouse erythrocytes. In vivo studies exhibited excellent correlation between carbogen-induced changes in SO(2) and pO(2) of radiation-induced fibrosarcoma tumors measured by reflectance spectroscopy and the Eppendorf pO(2) histograph, respectively. In PDT studies radiation-induced fibrosarcoma tumor SO(2) was measured immediately before and after Photofrin-PDT (135 J/cm(2), 38 mW/cm(2)). Animals were subsequently followed for tumor growth to a volume of 400 mm(3) (time-to-400 mm(3)) or the presence of tumor cure (no tumor growth at 90 days after treatment). In animals that recurred, the PDT-induced change in tumor SO(2), i.e., relative-SO(2) (SO(2) after PDT/SO(2) before PDT) was positively correlated with treatment durability (time-to-400 mm(3)). The predictive value of relative-SO(2) was confirmed in a second group of animals with enhanced pre-PDT oxygenation due to carbogen breathing. Furthermore, when all of the animals were considered (those that recurred and those that were cured) a highly significant association was found between increasing relative-SO(2) and increasing probability of survival, i.e., absence of recurrence. As independent variables, the SO(2) after PDT, the pre-PDT tumor volume, and light penetration depth all failed to predict response. As an independent variable, the SO(2) before PDT demonstrated a weak negative association with treatment durability; this association was driven by a correlation between decreasing pre-PDT SO(2) and increasing relative-SO(2). These data suggest that monitoring of PDT-induced changes in tumor oxygenation may be a valuable prognostic indicator.