Histochemical probes for the detection of hypoxic tumour cells

Hypoxia is thought to be a major cause of failure in cancer treatment. In this paper, we report methods transposable to clinical practice, for identifying hypoxic tumour cells. They consist of histochemical tests for revealing lactate dehydrogenase activity, endogenous lactate and accumulation of neutral fat. An ascites tumour (Yoshida hepatoma) and a solid tumour (Ehrlich carcinoma) were used as the experimental models. A gel film technique was used for visualizing lactate dehydrogenase and "nothing dehydrogenase" (or endogenous lactate). The fluorescent dyes Nile Red and Acridine Orange were used to demonstrate lipid accumulation and to visualize the tumour morphology, respectively. Tumour cells at the edge of areas of necrosis and at a distance of about 130 microns from a blood vessel were presumed to be hypoxic and showed the following features: 1) a dark blue granular pattern of lactate dehydrogenase (LDH) activity, ascribed to intense activity of the LDH5 and/or LDHk isoenzymes bound to membranous structures; 2) an intense granular positivity of "Nothing Dehydrogenase" due to high concentrations of endogenous lactate; 3) neutral lipid droplets emitting an intense yellow fluorescence in Nile Red-stained preparations; 4) a yellow cytoplasmic fluorescence in Acridine Orange-stained sections, attributable to a low cellular RNA content. Electron microscopy revealed moderately osmiophilic lipid globules in close association with damaged mitochondria. Better oxygenated cells showed: (a) a reddish-blue diffuse pattern of LDH, ascribed to moderately active soluble LDH isoenzymes containing H subunits; (b) almost no "Nothing Dehydrogenase" positivity; (c) no cytoplasmic lipid droplets; and (d) an intense orange-red fluorescence in the cytoplasm of Acridine Orange-stained specimens, due to high concentrations of cellular RNA. Nile Red fluorescence showed that the lipids of the solid tumour membranes were more hydrophobic than in the normal surrounding tissue. This suggests that there are abnormal domains of neutral lipids in the tumour cell membranes. In solid tumours, cells with the characteristics attributable to hypoxia were usually observed on the edge of necrosis of cuff-like formations. In very advanced growth stages, however, they were also seen surrounding (and occasionally clogging) blood vessels, or in tentacular formations coming from a necrosis border and polarized towards the vessels. Lipid-loaded cells were also seen in blood vessels distant from the tumour. These observations point towards a chemotactic process of hypoxic cells towards better environments.

Endocrine effects of a 24-hour intravenous infusion of interleukin-2 in the immunotherapy of cancer

Several experiments have demonstrated that there is a relationship between neuroendocrine and immune systems. Despite these interesting findings, only few studies have been performed up to now to evaluate the possible importance of neuroimmune interactions in influencing the biological efficacy and toxicity of cancer immunotherapy with IL-2. To analyze the effects of IL-2 on endocrine secretions, we have measured by RIA serum levels of cortisol, beta-endorphin, GH, PRL and of the pineal hormone melatonin in metastatic renal cancer patients, treated with 5-day courses of IL-2 at a daily dose of 3 x 10(6) U/m2, given through a 24-hour intravenous infusion. Six IL-2 courses were evaluated, by collecting blood samples at 4-hour intervals for 24 hours and by comparing the hormonal values with those observed in baseline conditions. Both cortisol and beta-endorphin mean values significantly increased during IL-2 infusion. GH and PRL also increased, but not in a significant manner. Finally, melatonin mean levels significantly decreased during the infusion. The IL-2-induced effects on cortisol, beta-endorphin and melatonin resulted in a complete abolition of their physiological circadian rhythm. These results show that IL-2 infusion induces important changes in endocrine secretions. Because of the immunosuppressive effect of cortisol and the stimulatory one of melatonin, their changes during IL-2 infusion might influence the biological activity of immunotherapy itself. Further studies will be required to define better the clinical importance of IL-2 induced hormonal changes.

A study of pineal-prolactin interaction: prolactin response to an acute melatonin injection in patients with hyperprolactinemia

Several studies demonstrated that the pineal gland plays a regulatory role in PRL secretion. At present, however, there are few clinical data only about the pineal function in PRL secretion disorders. To further clarify which is the pineal importance in the dysfunctions of PRL release, we have evaluated the effect of an acute injection of the pineal hormone melatonin in 19 patients with hyperprolactinemia, 8 of whom had idiopathic hyperprolactinemia, while the other 11 had a prolactinoma. Melatonin was given im at a dose of 20 mg at 09:00 h, and venous blood samples were collected at -20, 0, 20, 60, 120, 180 min. A normalization of PRL levels was achieved after melatonin injection in 3/8 patients with idiopathic hyperprolactinemia, while no effect was seen in patients with prolactinoma. Further studies, by evaluating the effect of a chronic treatment, will be required to define which is the action of melatonin on PRL release in PRL secretion disorders, and to evaluate its possible therapeutic role.

Analysis of T helper and suppressor lymphocyte subsets in relation to the clinical stage of solid neoplasms

Neoplastic disease affect the immunity in cancer patients. The immune alterations in human neoplasms, however, need to be further defined. The present study was carried out to analyze T lymphocyte subsets in patients with solid tumors. The study included 93 patients suffering from early or metastatic solid neoplasms. T helper and T suppressor subsets were measured on venous blood samples by using flow cytometry and monoclonal antibodies. As controls, 58 healthy subjects were included in the study. The T mean helper/suppressor ratio (CD4/CD8) was significantly lower in metastatic cancer patients with respect to that observed either in controls or in patients without metastases. A low CD4/CD8 ratio was seen in 25 of 93 cancer patients (26.9%), 8 of whom had no metastases, while the other 17 showed a metastatic disease. Within the nonmetastatic group, the decline in the CD4/CD8 ratio was due to increases in the T suppressor subset alone in 7. On the contrary, the percentage of cases with decreased T helper subset was significantly higher in metastatic than in the nonmetastatic patients. The results of this study suggest that the decrease in the CD4/CD8 ratio mainly depends on an increase in T suppressor cells in patients without metastases whereas it is due to a decrease in the T helper subset in most patients with metastatic diseases.

Postoperative hyperprolactinaemia and early recurrence rate in breast cancer

Serum levels of prolactin before and after surgery were measured in 90 women with breast cancer until the 5th postoperative month. Surgery-induced hyperprolactinaemia occurred in 51 patients, without significant correlation to any other clinical variable. After a median follow-up of 39 months, irrespective of each other variable (i.e. nodal involvement, oestrogen receptor status, adjuvant therapies), patients with postoperative hyperprolactinaemia had a significantly lower recurrence rate than those in whom surgery was not followed by an abnormal increase in prolactin secretion (3/51 vs. 13/39, P less than 0.001). These results suggest that, despite the stimulatory role of prolactin on mammary tumours, the lack of postoperative hyperprolactinaemia is an unfavourable prognostic factor because of its association with a higher relapse rate.

The biological significance of soluble interleukin-2 receptors in solid tumors

In an attempt to further understand the biological significance of soluble IL-2 receptors (sIL-2R) in solid tumors, we have evaluated 160 cancer patients (breast: 40; lung: 66; colon: 18; stomach: 22; uterine cervix: 14) and 58 healthy subjects, as controls. Serum mean levels of sIL-2R, measured with an enzyme immunoassay, were significantly higher in cancer patients than in controls. Metastatic cancer patients showed significantly higher values than the non-metastatic ones; this difference was significant in all tumor histotypes, except small cell lung carcinoma. Moreover, in 15 patients in whom sIL-2R were evaluated either before or after radical surgery, a significant surgery-induced increase in sIL-R mean values was seen. Finally, the chemotherapy-induced rise in sIL-2R appeared to be associated with a lack of clinical response. These results seem to suggest that sIL-2R may be a marker of host biological response in patients with solid tumors, the significance of which needs further investigation.

Lack of Changes in Soluble Interleukin-2 Receptor Serum Levels during Chemotherapy-induced Lymphocyte Damage

The biological significance of soluble IL-2 receptors (sIL-2R) is still unknown; in particular, it is not yet clear whether their increase in the blood may reflect activation of immune cells, or whether it is related to an immune dysfunction. To investigate this problem, we evaluated serum levels of sIL-2R before and after administration of a highly lymphocytolitic chemotherapy (FEC: fluorouracil, epirubicin, cyclophosphamide) in a group of 6 patients with advanced breast cancer. SIL-2R were analyzed in relation to lymphocyte number. Absolute mean number of lymphocytes was significantly lower after than before chemotherapy. On the contrary, no significant difference was seen in sIL-2R mean levels, and no significant correlation was observed between changes in sIL-2R and in lymphocyte number following chemotherapy. These results would exclude that sIL-2R may simply be due to a passive release following lymphocytic damage.

Pineal gland and tumor cell kinetics: serum levels of melatonin in relation to Ki-67 labeling rate in breast cancer

Recent observations showed that host may regulate either endocrinologically or immunologically tumor growth and differentiation, perhaps by modulating oncogene expression. Within the endocrine system, the pineal hormone, melatonin, seems to play an important antineoplastic role. To investigate its secretion in relation to tumor growth, we have evaluated the daily serum levels of melatonin in a group of 25 untreated breast cancer patients with a locally limited disease. Tumor cell proliferation was established by measuring Ki-67 labeling rate. As controls, 46 healthy women were considered. Breast cancer patients showed significantly higher mean values of melatonin than controls. Moreover, patients with negative Ki-67 labeling rate had significantly higher levels of the pineal hormone than those with a positive Ki-67 rate. Since tumors with high growth fraction present a worse prognosis, this study would suggest that the relief of an increased melatonin secretion represents a favorable prognostic sign, because of its association with less proliferating breast cancers.

DNA double staining for a fluorescence energy transfer study of chromatin in liver cells

Methodological aspects related to the application of techniques based on fluorescence energy transfer in the study of chromatin structure, were first examined. Fluorochromes specific for DNA with different interaction mechanisms were employed, both in single and double stainings. The following dye pairs were considered as donor/acceptor couples: Hoechst 33342 or DAPI/Mithramycin A or Chromomycin A3, Hoechst 33342 or DAPI/Propidium Iodide, and Mithramycin A or Chromomycin A3/Propidium Iodide. Spectrofluorometric analysis showed that the spectral distribution of the dye pair Ho/PI is more suitable for the evaluation of energy transfer efficiency. This dye pair was used in the study of the chromatin microstructure in rat hepatocytes isolated from livers at two different growth stages. In particular, diploid mono- and binucleated cells from young and adult rats were considered. The results indicated the existence of a more homogeneous situation in young than in adult rats. In the latter case, the statistical analysis indicates the presence of two groups of energy transfer values. The different efficiency values in energy transfer can be considered a consequence of chromatin structure rearrangement and are tentatively interpreted according to the functional role of the diploid cells in the two stages of liver growth.

Alterations of pineal gland and of T lymphocyte subsets in metastatic cancer patients: preliminary results

Melatonin (MLT), the main hormone produced by the pineal gland, has been seen to play a role in antineoplastic activity either by exerting a direct inhibitory effect on cancer cell growth, or by stimulating the immune system. Moreover, MLT blood levels have been shown to be often increased in cancer patients. On the basis of these data, a study was started to evaluate what relation exists between MLT levels and T lymphocyte subsets in patients with metastatic solid neoplasm. The study included 28 patients (breast: 10; non-small cell lung: 18). None of the patients was previously treated for their metastatic disease. Abnormally high MLT levels and a low T helper/suppressor ratio (CD4/CD8) were seen in 10/28 and in 11/28 patients, respectively. Serum mean levels of MLT were significantly higher in patients with low CD4/CD8 ratio than in those with a normal ratio. These results would suggest that immune dysfunctions may represent a signal for MLT release from the pineal in patients with metastatic solid neoplasm.

Evidence for Altered Hypothalamic-Hypophyseal-Gonadal Axis in Untreated Patients with Testicular Germ-Cell Tumor

To investigate the function of the hypothalamic-hypophyseal-gonadal axis in testicular germ cell tumors, we evaluated gonadotropin responses to gonadotropin-releasing hormone (GnRH) in 12 untreated patients with testicular cancer (5 seminomas and 7 non-seminomas). GnRH was given i.v. at a dose of 100 μg as a bolus, and venous blood samples were collected at 0, 20, 60, and 120 min. As controls, 14 healthy males were studied. Basal levels of testosterone, estradiol and prolactin were also detected in each patient. Hormonal serum concentrations were measured by the radioimmunoassay. Mean basal testosterone, estradiol and prolactin levels were not significantly different from those of controls. Patients had a lower FSH and LH peak after GnRH than controls, without, however, any significant difference. As regards histology, nonseminoma patients lacked an FSH response to GnRH and had statistically lower mean peak levels than controls. Moreover, non-seminoma patients had statistically lower mean peak values of LH after GnRH than controls. These data show that patients with testicular germ cell tumor, and more particularly those with non-seminomas, have an altered function of the hypothalamic-hypophyseal-gonadal axis, which is already present prior to therapy. Further studies, particularly in stage I patients treated only with orchiectomy, should be performed to confirm and better define the Physiopathologic significance of the altered hypothalamic-hypophyseal-gonadal axis in testicular cancer and to clarify the alteration of fertility, which is frequently present before treatment.

Effects of cancer chemotherapy on the relation between serum levels of soluble interleukin-2 receptors and CD4/CD8 ratio in patients with solid neoplasms

The clinical significance of sIL-2R in solid tumors has still to be clarified. To further define the biological role of sIL-2R in cancer and their relation to chemotherapy, we have measured serum levels of sIL-2R and CD4/CD8 ratio in 45 patients with limited or metastatic solid tumor, 28 of whom had never received chemotherapy, whereas the other 17 had been previously treated with chemotherapy. sIL-2R were significantly higher in metastatic cancer patients than in the non-metastatic ones, while no difference was seen between patients treated and untreated with chemotherapy. Within the untreated group, sIL-2R mean values were significantly higher in patients with low CD4/CD8 ratio than in those with the normal one, while an opposite behavior was seen in patients previously treated with chemotherapy. The present study shows that cancer chemotherapy influences the release of sIL-2R and its relation to T lymphocyte subpopulations.

Interleukin-2 Receptor Positive Cells and Circulating Soluble Interleukin-2 Receptors in Patients with Solid Tumors are not Correlated

Activated lymphocytes can release a soluble form of IL-2 receptor (sIL-2R), which retains the capacity to bind IL-2. Abnormally high values of sIL-2R have been observed in patients with advanced solid tumors. In an attempt to further understand the biological significance of sIL-2R in solid tumors, this study investigated the relation between sIL-2R and Tac-positive cells. sIL-2R serum levels and Tac-positive cells were determinedin 18 patients with solid tumors metastatic, 108 non-metastatic. Tumor types were: breast 7; lung 6; colon 2; stomach 1; testis 1; larynx 1. No correlation was found between circulating sIL-2R values and Tac-positive cells, and there was no difference between Tac-positive cell mean number in patients with high and normal sIL-2R levels. These preliminary results suggest that different mechanisms are responsible for sIL-2R release in the blood and IL-2 receptor expression on the immune cell surface.

[Cell adhesion in rat fibroblasts: effect of tumor promoters]

In a study performed on transformed (SGS/3A) and normal syngeneic rat cells (FG/2) to identify the molecular mechanisms which regulate cell adhesion and contact inhibition in cell transformation, we investigated the effects of tumor promoters on cell to cell adhesion of rat fibroblasts. As tumor promoters we used 12-tetradecanoyl-phorbole-13-acetate (TPA) and the melittin, a polypeptide from bee venom, both substances capable of stimulating the neoplastic transformation. The intercellular adhesion assay consists in determining the percent of single cells labeled with 3H-L-leucine adhering to a confluent monolayer of unlabeled cells at different incubation times. The increase of cell-cell adhesion caused by TPA and melittin confirms what we have constantly observed in other experiments, i.e. that neoplastic cells SGS/3A always have a higher intercellular adhesion capacity than corresponding normal syngenic cells FG/2. Since one of the effects of the tumor promoters is also induction of a reversible alteration of the cytoskeleton, it is likely that their action on intercellular adhesion is regulated by a mechanism analogous to that proposed for explaining the increased intercellular adhesion observed after treatment with antimicrotubular compounds.

Endocrine and immune effects of melatonin therapy in metastatic cancer patients

Melatonin, the most important indole hormone produced by the pineal gland, appears to inhibit tumor growth; moreover, altered melatonin secretion has been reported in cancer patients. Despite these data, the possible use of melatonin in human neoplasms remains to be established. The aim of this clinical trial was to evaluate the therapeutic, immunological and endocrine effects of melatonin in patients with metastatic solid tumor, who did not respond to standard therapies. The study was carried out on 14 cancer patients (colon, six; lung, three; pancreas, two; liver, two; stomach, one). Melatonin was given intramuscularly at a daily dose of 20 mg at 3.00 p.m., followed by a maintenance period in an oral dose of 10 mg daily in patients who had a remission, stable disease or an improvement in PS. Before and after the first 2 months of therapy, GH, somatomedin-C, beta-endorphin, melatonin blood levels and lymphocyte subpopulations were evaluated. A partial response was achieved in one case with cancer of the pancreas, with a duration of 18+ months; moreover, six patients had stable disease, while the other eight progressed. An evident improvement in PS was obtained in 8/14 patients. In patients who did not progress, T4/T8 mean ratio was significantly higher after than before melatonin therapy, while it decreased in patients who progressed. On the contrary, hormonal levels were not affected by melatonin administration. This study would suggest that melatonin may be of value in untreatable metastatic cancer patients, particularly in improving their PS and quality of life; moreover, based on its effects on the immune system, melatonin could be tested in association with other antitumor treatments.

The action of cisplatinum (cis-DDP) on the postnatal growth of the rat liver. Cytokinetics and ultrastructural studies

The early and late effects of cis-DDP treatment on liver cell kinetics were analyzed after its intraperitoneal injection into 17-day old rats. Frequency of binucleate hepatocytes, cellular DNA content distribution, 3H-thymidine labelling and ultrastructure of the nuclei were analyzed. Two days after treatment, a block of mononucleate hepatocytes in the S phase and in the G2 phase was demonstrated by the increase of intermediate 2c-4c and 4c DNA values in the absence of changes in 3H-thymidine labelling; 8c binucleate cells, which are essential for the formation of tetraploid mononucleate cells, were not found. In cell nuclei, large areas of more condensed chromatin appeared, perhaps providing further evidence for a G2 block. Seven days after treatment, there was a tendency to catch up with the normal situation, as shown by the unblocking of the S phase in mononucleate cells indicated by both cytophotometry and autoradiography. The presence of 8c binucleate cells and 4c-8c mononucleate cells indicates that 4c mononucleate hepatocytes are either diploid cells in the G2 phase or true tetraploid G1 cells. The decrease in the heterochromatin areas and the appearance of hypertrophic nucleoli demonstrate an increase in the metabolic activity of the nuclei. Thirty six days after treatment, the incidence of different DNA hepatocyte classes and the 3H-thymidine labelling were already similar in control and in treated rats.

A study on the relationship between the pineal gland and the opioid system in patients with cancer. Preliminary considerations

Recent studies showed that both the pineal gland and the endogenous opioid system are involved in the modulation of the immune system and in the regulation of tumor growth. Moreover, a relationship between pineal and opioid system has been demonstrated. In order get an overall view of the psychoneuroendocrine interactions in cancer patients, the levels of melatonin, the most important pineal hormone, and of beta-endorphin have been measured on blood samples collected during the morning. The study was carried out on 54 patients, 42 healthy subjects, and in 34 patients having illnesses other than cancer. Breast cancer, lung carcinoma, and colorectum cancer were the three neoplasms detected in the patients investigated. Growth hormone (GH), somatomedin-C and prolactin (PRL) levels were also determined. beta-endorphin levels were found to be substantially within the normal range in patients with cancer, whereas those of melatonin were raised in several cases. The beta-endorphin/melatonin ratio was higher than 2 in normal subjects, in non-neoplastic patients and in most cancer patients without metastases, whereas this ratio was lower than 2 in almost all patients in a metastatic stage of the disease. Neither melatonin levels nor those of beta-endorphin appeared to be significantly correlated with GH, somatomedin-C, and PRL concentrations. The low beta-endorphin/melatonin ratio observed in metastatic patients suggests the presence of an unbalanced relation between the pineal and the opioid system in those subjects. Therefore, an anomalous relationship between pineal function and opioid activity might play a role in the clinical course of neoplastic disease.

Serum Levels of Melatonin in Cancer Patients and their Relation to Body Sizes

Melatonin secretion is often enhanced in patients with cancer. In the light of a reported correlation between melatonin levels and body size, we investigated blood levels of this pineal hormone in a group of 72 patients affected by cancer, 30 of whom had body weight within the normal range, 30 were obese and the last 12 cases had body weight below the normal range, in order to establish whether in fact melatonin blood concentrations were related to body size. Melatonin levels were high in 19/72 patients (26%). The mean levels of the pineal hormone were similar in patients with normal, low and high body weight. Finally, there was no significant correlation between melatonin values and body weight, height or surface. Melatonin secretion thus does not appear to be influenced by body size in cancer patients.

Alteration of opioid peptide circadian rhythm in cancer patients

Endogenous opioid peptides have been seen to play a role in regulating immunity and tumor growth. This study was carried out to investigate opioid activity in human cancer. We evaluated by radioimmunoassay beta-endorphin plasma levels on blood samples collected at 9.00 a.m. from 121 cancer patients and 42 healthy subjects. In 22 cancer patients and in 12 controls, beta-endorphin circadian rhythm was also investigated. Finally, in 14 cancer patients and in 10 controls GH, PRL, FSH, LH and cortisol serum levels were measured after the administration of a metenkephalin analogue, FK 33-824 (0.3 mg i.v.). No significant differences were seen in beta-endorphin mean levels between cancer patients and normal subjects. Moreover, no differences were found between patients with or without metastases, nor between those with or without chronic pain. beta-Endorphin circadian rhythm appeared to be altered in 16/22 cancer patients, and anomalous hormonal responses to FK 33-824 were seen in 13/14 patients. This study shows an altered opioid activity in human neoplasms, whose clinical significance remains to be determined.