Cell sensitivity to oxidative stress is influenced by ferritin autophagy.

To test the consequences of lysosomal degradation of differently iron-loaded ferritin molecules and to mimic ferritin autophagy under iron-overload and normal conditions, J774 cells were allowed to endocytose heavily iron loaded ferritin, probably with some adventitious iron (Fe-Ft), or iron-free apo-ferritin (apo-Ft). When cells subsequently were exposed to a bolus dose of hydrogen peroxide, apo-Ft prevented lysosomal membrane permeabilization (LMP), whereas Fe-Ft enhanced LMP. A 4-h pulse of Fe-Ft initially increased oxidative stress-mediated LMP that was reversed after another 3h under standard culture conditions, suggesting that lysosomal iron is rapidly exported from lysosomes, with resulting upregulation of apo-ferritin that supposedly is autophagocytosed, thereby preventing LMP by binding intralysosomal redox-active iron. The obtained data suggest that upregulation of the stress protein ferritin is a rapid adaptive mechanism that counteracts LMP and ensuing apoptosis during oxidative stress. In addition, prolonged iron starvation was found to induce apoptotic cell death that, interestingly, was preceded by LMP, suggesting that LMP is a more general phenomenon in apoptosis than so far recognized. The findings provide new insights into aging and neurodegenerative diseases that are associated with enhanced amounts of cellular iron and show that lysosomal iron loading sensitizes to oxidative stress.

Cyclooxygenase-2 expression in lung cancer cells evaluated by immunocytochemistry.

Cyclooxygenase-2 (COX-2) expression may be a prognostic factor in lung cancer. In previous studies, COX-2 expression has almost exclusively been evaluated with immunohistochemical methods performed on histology sections of tissue biopsies. However, in clinical practice, lung cancer is often diagnosed with cytological techniques only. We present methodology and results from analysis of COX-2 expression with immunochemistry on cytological material in 53 patients with lung cancer. Preparation and staining with the method established at our laboratory were easy to perform and resulted in good quality slides. The percentage COX-2-stained cells and the intensity of staining varied widely between and within the different cases. The proportion of positively stained tumor cells was as follows: <1% in 20 patients, 1-10% in 7 patients, 11-50% in 17 patients, and more than 50% in 9 patients. In 17 cases, groups of cells with different intensity of COX-2 staining were found in the same slide. In conclusion, immunocytochemical analysis of COX-2 expression is technically easy to perform with routine diagnostic procedures. There is a great variation in the proportion of COX-2-positive cells among patients and in the intensity of staining among individual cells in many single cases.

Expression of VEGF and VEGF receptors in childhood precursor B-cell acute lymphoblastic leukemia evaluated by immunohistochemistry.

Perturbation in the expression and signaling pathways of vascular endothelial growth factor (VEGF) has been linked to pathogenesis of hematologic malignancies. We investigated the expression and clinical importance of VEGF and two of its receptors, VEGFR-1 and VEGFR-2, in childhood precursor B-cell acute lymphoblastic leukemia (pre-B ALL) by using immunohistochemistry. These angiogenic proteins were expressed in the majority of leukemic bone marrow samples. Notably, pre-B ALL patients had significantly increased expression of VEGFR-1 compared with no expression in the nonmalignant group, indicating a link between VEGFR-1 protein expression and pre-B ALL. These novel findings suggest that VEGFR-1 may have clinical importance in childhood pre-B ALL.

Expression of PTEN and SHP1, investigated from tissue microarrays in pediatric acute lymphoblastic, leukemia.

PTEN and SHP1 are tumor suppressor genes involved in the regulation of cell cycle control and apoptosis. The authors investigated the protein expression of PTEN and SHP1, by immunohistochemistry in tissue microarrays from bone marrow samples in children, diagnosed with acute lymphoblastic leukaemia and nonmalignant controls. PTEN was overexpressed in diagnostic ALL samples, while SHP1 showed a low expression. Both proteins showed a significant difference in expression compared to nonmalignant controls. The roles of PTEN and SHP1 are not well investigated in pediatric leukemia and could in the future play a role as prognostic factors.

Lysosomes and oxidative stress in aging and apoptosis.

The lysosomal compartment consists of numerous acidic vesicles (pH approximately 4-5) that constantly fuse and divide. It receives a large number of hydrolases from the trans-Golgi network, while their substrates arrive from both the cell's outside (heterophagy) and inside (autophagy). Many macromolecules under degradation inside lysosomes contain iron that, when released in labile form, makes lysosomes sensitive to oxidative stress. The magnitude of generated lysosomal destabilization determines if reparative autophagy, apoptosis, or necrosis will follow. Apart from being an essential turnover process, autophagy is also a mechanism for cells to repair inflicted damage, and to survive temporary starvation. The inevitable diffusion of hydrogen peroxide into iron-rich lysosomes causes the slow oxidative formation of lipofuscin in long-lived postmitotic cells, where it finally occupies a substantial part of the volume of the lysosomal compartment. This seems to result in a misdirection of lysosomal enzymes away from autophagosomes, resulting in depressed autophagy and the accumulation of malfunctioning mitochondria and proteins with consequent cellular dysfunction. This scenario might put aging into the category of autophagy disorders.

Lysosomes in iron metabolism, ageing and apoptosis.

The lysosomal compartment is essential for a variety of cellular functions, including the normal turnover of most long-lived proteins and all organelles. The compartment consists of numerous acidic vesicles (pH approximately 4 to 5) that constantly fuse and divide. It receives a large number of hydrolases ( approximately 50) from the trans-Golgi network, and substrates from both the cells' outside (heterophagy) and inside (autophagy). Many macromolecules contain iron that gives rise to an iron-rich environment in lysosomes that recently have degraded such macromolecules. Iron-rich lysosomes are sensitive to oxidative stress, while 'resting' lysosomes, which have not recently participated in autophagic events, are not. The magnitude of oxidative stress determines the degree of lysosomal destabilization and, consequently, whether arrested growth, reparative autophagy, apoptosis, or necrosis will follow. Heterophagy is the first step in the process by which immunocompetent cells modify antigens and produce antibodies, while exocytosis of lysosomal enzymes may promote tumor invasion, angiogenesis, and metastasis. Apart from being an essential turnover process, autophagy is also a mechanism by which cells will be able to sustain temporary starvation and rid themselves of intracellular organisms that have invaded, although some pathogens have evolved mechanisms to prevent their destruction. Mutated lysosomal enzymes are the underlying cause of a number of lysosomal storage diseases involving the accumulation of materials that would be the substrate for the corresponding hydrolases, were they not defective. The normal, low-level diffusion of hydrogen peroxide into iron-rich lysosomes causes the slow formation of lipofuscin in long-lived postmitotic cells, where it occupies a substantial part of the lysosomal compartment at the end of the life span. This seems to result in the diversion of newly produced lysosomal enzymes away from autophagosomes, leading to the accumulation of malfunctioning mitochondria and proteins with consequent cellular dysfunction. If autophagy were a perfect turnover process, postmitotic ageing and several age-related neurodegenerative diseases would, perhaps, not take place.

The involvement of lysosomes in myocardial aging and disease.

The myocardium is mainly composed of long-lived postmitotic cells with, if there is any at all, a very low rate of replacement through the division and differentiation of stem cells. As a consequence, cardiac myocytes gradually undergo pronounced age-related alterations which, furthermore, occur at a rate that inversely correlates with the longevity of species. Basically, these alterations represent the accumulation of structures that have been damaged by oxidation and that are useless and often harmful. These structures (so-called 'waste' materials), include defective mitochondria, aberrant cytosolic proteins, often in aggregated form, and lipofuscin, which is an intralysosomal undegradable polymeric substance. The accumulation of 'waste' reflects the insufficient capacity for autophagy of the lysosomal compartment, as well as the less than perfect functioning of proteasomes, calpains and other cellular digestive systems. Senescent mitochondria are usually enlarged, show reduced potential over their inner membrane, are deficient in ATP production, and often produce increased amounts of reactive oxygen species. The turnover of damaged cellular structures is hindered by an increased lipofuscin loading of the lysosomal compartment. This particularly restricts the autophagic turnover of enlarged, defective mitochondria, by diverting the flow of lysosomal hydrolases from autophagic vacuoles to lipofuscin-loaded lysosomes where the enzymes are lost, since lipofuscin is not degradable by lysosomal hydrolases. As a consequence, aged lipofuscin-rich cardiac myocytes become overloaded with damaged mitochondria, leading to increased oxidative stress, apoptotic cell death, and the gradual development of heart failure. Defective lysosomal function also underlies myocardial degeneration in various lysosomal storage diseases, while other forms of cardiomyopathies develop due to mitochondrial DNA mutations, resulting in an accumulation of abnormal mitochondria that are not properly eliminated by autophagy. The degradation of iron-saturated ferritin in lysosomes mediates myocardial injury in hemochromatosis, an acquired or hereditary disease associated with iron overload. Lysosomes then become sensitized to oxidative stress by the overload of low mass, redox-active iron that accumulates when iron-saturated ferritin is degraded following autophagy. Lysosomal destabilization is of importance in the induction and/or execution of programmed cell death (either classical apoptotic or autophagic), which is a common manifestation of myocardial aging and a variety of cardiac pathologies.

How useful are housekeeping genes? Variable expression in melanoma metastases.

BACKGROUND: There is a certain difference in opinion regarding the optimal choice of housekeeping genes used as normalization factors in gene expression analysis. We have therefore examined the suitability of three housekeeping genes, hypoxanthine phosphoribosyl transferase, beta-glucuronidase and beta2-micro-globulin, for normalization of expression data from melanoma metastases. METHODS: The expression of the three housekeeping genes was quantified by quantitative reverse transcription PCR in snap-frozen sections from 44 melanoma metastases, of which 19 were from patients treated with cisplatinum, dacarbazine and interferon-alpha2b. RESULTS: The expression of each housekeeping gene varied considerably between the different metastases. Histopathological examination of the tissue sections revealed variation in the amount of tumor cells in the tissue, necrosis, varying degrees of lymphocyte infiltration, and lymph node remnants. Based on this examination, 16 biopsies were omitted from further analysis because they had cracked, contained empty or necrotic areas, or were dominated by lymph node tissue. Even in sections with more than 90% tumor cells, a wide variation in the expression of the three housekeeping genes was found. The amount of lymphatic infiltrate in the tumors can have an effect on the expression of housekeeping genes in the metastases, whereas treatment did not seem to influence the expression. CONCLUSIONS: We conclude that the choice of housekeeping genes can have great impact on the normalization of specific genes in melanoma metastases. Furthermore, in the analysis of mRNA expression in tumor tissue, microscopic examination is of great importance to evaluate the integrity and cellular composition of the biopsy.

Preoperative interleukin-6 production by mononuclear blood cells predicts survival after radical surgery for colorectal carcinoma.

BACKGROUND: Colorectal cancer is one of the most common forms of cancer in the Western world. Staging based on histopathology is currently the most accurate predictor of outcome after surgery. Colorectal cancer is curable if treated at an early stage (stage I-III). However, for tumors in stages II and III there is a great need for tests giving more accurate prognostic information defining the patient population in need of closer follow-up and/or adjuvant therapy. Furthermore, tests that provide prognostic information preoperatively could provide a guide both for preoperative oncologic treatment and the surgical procedure. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated preoperatively, within a week before primary surgery, from 39 patients undergoing surgery for colorectal cancer. The PBMCs were cultured in vitro for 24 hours in the presence of autologous serum and lipopolysaccharide (LPS). Interleukin-6 (IL-6) production was measured with enzyme-linked immunosorbent assay (ELISA). Staging based on histopathology was performed in all patients. Patients were followed for at least 54 months. RESULTS: A production of >5000 pg/mL of IL-6 identified colorectal cancer patients with a poor prognosis. Eight out of 13 patients with >5000 pg/mL IL-6 died from cancer within the follow-up period, whereas no cancer-related deaths were recorded among 21 patients with 5000 pg/mL IL-6 or less. A multivariate Cox regression analysis, stratified for T- and N-stage, identified IL-6 production as an independent prognostic factor. CONCLUSIONS: IL-6 production in vitro by PBMC can predict survival after radical surgery for colorectal cancer.

Mitochondrial damage and intralysosomal degradation in cellular aging.

Normal mitochondrial respiration is associated with a continuous production of superoxide and hydrogen peroxide, inevitably resulting in minor macromolecular damage. Damaged cellular components are not completely turned over by autophagy and other cellular repair systems, leading to a progressive age-related accumulation of biological "garbage" material, such as defective mitochondria, cytoplasmic protein aggregates and an intralysosomal undegradable material, lipofuscin. These changes primarily affect neurons, cardiac myocytes and other long-lived postmitotic cells that neither dilute this "garbage" by mitotic activity, nor are replaced by newly differentiated cells. Defective mitochondria are insufficient in ATP production and often generate increased amounts of reactive oxygen species, further enhancing oxidative stress. Lipofuscin-loaded lysosomes, in turn, poorly turn over mitochondria that gradually leads to the overload of long-lived postmitotic cells with "garbage" material, decreased adaptability and eventual cell death.

Intralysosomal iron chelation protects against oxidative stress-induced cellular damage.

Oxidant-induced cell damage may be initiated by peroxidative injury to lysosomal membranes, catalyzed by intralysosomal low mass iron that appears to comprise a major part of cellular redox-active iron. Resulting relocation of lytic enzymes and low mass iron would result in secondary harm to various cellular constituents. In an effort to further clarify this still controversial issue, we tested the protective effects of two potent iron chelators--the hydrophilic desferrioxamine (dfo) and the lipophilic salicylaldehyde isonicotinoyl hydrazone (sih), using cultured lysosome-rich macrophage-like J774 cells as targets. dfo slowly enters cells via endocytosis, while the lipophilic sih rapidly distributes throughout the cell. Following dfo treatment, long-term survival of cells cannot be investigated because dfo by itself, by remaining inside the lysosomal compartment, induces apoptosis that probably is due to iron starvation, while sih has no lasting toxic effects if the exposure time is limited. Following preincubation with 1 mM dfo for 3 h or 10 microM sih for a few minutes, both agents provided strong protection against an ensuing approximately LD50 oxidant challenge by preventing lysosomal rupture, ensuing loss of mitochondrial membrane potential, and apoptotic/necrotic cell death. It appears that once significant lysosomal rupture has occurred, the cell is irreversibly committed to death. The results lend strength to the concept that lysosomal membranes, normally exposed to redox-active iron in high concentrations, are initial targets of oxidant damage and support the idea that chelators selectively targeted to the lysosomal compartment may have therapeutic utility in diminishing oxidant-mediated cell injury.

The lysosomal-mitochondrial axis theory of postmitotic aging and cell death.

Aging (senescence) is characterized by a progressive accumulation of macromolecular damage, supposedly due to a continuous minor oxidative stress associated with mitochondrial respiration. Aging mainly affects long-lived postmitotic cells, such as neurons and cardiac myocytes, which neither divide and dilute damaged structures, nor are replaced by newly differentiated cells. Because of inherent imperfect lysosomal degradation (autophagy) and other self-repair mechanisms, damaged structures (biological "garbage") progressively accumulate within such cells, both extra- and intralysosomally. Defective mitochondria and aggregated proteins are the most typical forms of extralysosomal "garbage", while lipofuscin that forms due to iron-catalyzed oxidation of autophagocytosed or heterophagocytosed material, represents intralysosomal "garbage". Based on findings that autophagy is diminished in lipofuscin-loaded cells and that cellular lipofuscin content positively correlates with oxidative stress and mitochondrial damage, we have proposed the mitochondrial-lysosomal axis theory of aging, according to which mitochondrial turnover progressively declines with age, resulting in decreased ATP production and increased oxidative damage. Due to autophagy of ferruginous material, lysosomes contain a pool of redox-active iron, which makes these organelles particularly susceptible to oxidative damage. Oxidant-mediated destabilization of lysosomal membranes releases hydrolytic enzymes to the cytosol, eventuating in cell death (either apoptotic or necrotic depending on the magnitude of the insult), while chelation of the intralysosomal pool of redox-active iron prevents these effects. In relation to the onset of oxidant-induced apoptosis, but after the initiating lysosomal rupture, cytochrome c is released from mitochondria and caspases are activated. Mitochondrial damage follows the release of lysosomal hydrolases, which may act either directly or indirectly, through activation of phospholipases or pro-apoptotic proteins such as Bid. Additional lysosomal rupture seems to be a consequence of a transient oxidative stress of mitochondrial origin that follows the attack by lysosomal hydrolases and/or phospholipases, creating an amplifying loop system.

CD28 expression in sentinel node biopsies from breast cancer patients in comparison with CD3-zeta chain expression.

BACKGROUND: Immunosuppression is documented in several malignant diseases, including breast cancer. Subsequently, future therapeutic concepts might include immunological approaches. However, detailed knowledge about tumor immunogenicity and host immunoreactivity, and how to assess these adequately, is still limited. We studied CD28 and CD3-zeta expression in sentinel node biopsies (SNB) from breast cancer patients to analyze tumor-related changes in T cell activity. METHOD: 25 women underwent surgery for primary breast cancer, including SNB. Frozen sections from 21 sentinel nodes could be analyzed with a double-staining technique. CD28 expression was studied in CD4+ and CD8+ T-lymphocyte subsets and compared with CD3-zeta expression in three specified nodal regions. RESULTS: The degree of CD28 expression varied between the different lymph node areas. The lowest degree of CD28 expression was observed in CD4+ T-lymphocytes in the paracortex and germinal centers. Here, a good agreement with CD3-zeta expression was found. A higher CD28 expression was noted in CD4+ T-cells in the primary follicles, where concordance with CD3-zeta expression was weaker. The CD8+ T-lymphocyte subset displayed generally a higher degree of CD28 expression than the CD4+ subset. CONCLUSION: Sentinel lymph nodes from breast cancer patients displayed local immunosuppression of varying extent. In the areas with the lowest degree of CD28 expression an accordingly low CD3-zeta expression was found. The SNB might prove an important diagnostic tool for the evaluation of interactions between tumor and the host immune system, helping to select patients who might benefit from adjuvant immunotherapy.

Heparan sulphate epitope-expression is associated with the inflammatory response in metastatic malignant melanoma.

Heparan sulphate (HS) represents a heterogeneous class of molecules on cell membranes and extracellular matrices. These molecules are involved in a variety of biological processes, including immune responses, through their binding and functional modulation of proteins. Recently a panel of HS-epitope-specific, human single chain antibodies have been generated by phage display, facilitating analysis of the structural heterogeneity of HS in relation to pathological conditions. In a pilot study a heterogeneous staining pattern in melanoma metastases was observed with one of the clones (EW4G1). Using a double-staining technique, the expression of this epitope was studied in 12 metastatic melanoma lesions in relation to the presence of a CD3(+) cell infiltrate. Different staining patterns with EW4G1 were observed in the different lesions. The different staining patterns were associated with the presence and pattern of inflammation with CD3(+) cells. A pronounced staining pattern of blood vessels with EW4G1 was associated with a more or less brisk presence of CD3(+) cells, while a pronounced staining of tumour cells or tumour cell matrix or absence of staining with EW4G1 was associated with absence of CD3(+) cells. These results suggest a dualistic role for HS in the recruitment and intratumoural migration of CD3(+) cells, depending on the location of expression of its epitope recognized by EW4G1. Further characterization of the structural diversity of HS and its function in T-cell recruitment and migration is therefore warranted, since detailed understanding of this relation may provide new targets for therapeutic intervention, such that better homing and migration of T cells (in)to tumours might be achieved in immunologically based treatment strategies.

On the effect of biochemotherapy in metastatic malignant melanoma: an immunopathological evaluation.

Although immunotherapy and biochemotherapy have shown promise, producing a subset of durable responses, for the majority of patients with metastatic melanoma the prognosis is still poor. Therefore there is a great need for predictive tests to identify patients with a high probability of responding. Furthermore, there is also a need for a better understanding of the mechanisms of action during treatment in order to be able to monitor the relevant antitumour reactivity during treatment and to optimize the efficacy of future immunotherapy and biochemotherapy. In the present study histopathological regression criteria were used to study the efficacy of biochemotherapy. Thirty-two patients with metastatic malignant melanoma (18 with regional disease and 14 with systemic disease) were treated with biochemotherapy (cisplatin 30 mg/m2 intravenously on days 1-3, dacarbazine 250 mg/m2 intravenously on days 1-3 and interferon-alpha2b 10 million IU subcutaneously 3 days a week, every 28 days). Pre-treatment fine needle aspirates were obtained from metastases to analyse the number of tumour-infiltrating CD4+ lymphocytes. Therapeutic efficacy was evaluated in metastases resected after treatment using histopathological criteria of tumour regression. Comparisons were also made with metastases from 17 untreated patients, all with regional disease. Regressive changes of 25% or more (of the section area) were found in two of the 17 untreated patients with regional disease compared with 13 of the 18 patients with regional disease and 10 of the 14 patients with systemic disease after biochemotherapy. Fifty per cent of the patients with regional disease showed a high degree of regressive changes (75-100% of the section area) after biochemotherapy. These results demonstrate the occurrence of an antitumour reactivity in the majority of patients. Patients with extensive regressive changes in 75-100% of the analysed biopsies were also found to have a longer overall survival (P = 0.019). In patients with regional disease there was a close correlation between a larger number of CD4+ lymphocytes pre-treatment and a higher degree of regressive changes post-treatment (P < 0.05). Thus, immunohistochemical analysis of tumour biopsies shortly after treatment seems to be a good surrogate endpoint. This technique also allows detailed analysis of antitumour reactivity and escape mechanisms.

Bcl-2 expression in metastatic malignant melanoma. Importance for the therapeutic efficacy of biochemotherapy.

For the majority of patients with metastatic malignant melanoma the prognosis is poor. Immunotherapy and biochemotherapy have shown promise with a subset of durable responses, but there is still a great need for a better understanding of the mechanisms of action during treatment to optimize future treatment schedules. In the present study Bcl-2 expression was studied in biopsies from ten patients with metastatic malignant melanoma (five with regional disease and five with systemic disease) treated with biochemotherapy (cisplatinum 30 mg/m2 days 1-3, DTIC 250 mg/m2 days 1-3 i.v. and Interferon-alpha2b 10 MIU s.c. 3 days a week, on a 28-day cycle). The expression of Bcl-2 by the tumour cells was separately recorded in areas of histopathological regressive changes and in areas of unaffected tumour growth. Comparisons were made with biopsies from 14 untreated patients. In 10 of 10 treated patients a high expression of Bcl-2 by the tumour cells was found in areas of unaffected tumour growth. In contrast, only in 5 of 13 untreated patients was a high expression of Bcl-2 by the tumour cells found in these areas ( P=0.008). A significant difference was also found in the expression of Bcl-2 by the tumour cells between areas of unaffected tumour growth and areas of histopathological regressive changes ( P=0.03). The significantly higher expression of Bcl-2 by the tumour cells in areas of unaffected tumour growth in treated patients compared to untreated patients indicates that clones with a high expression of Bcl-2 may be present after therapy, preventing apoptosis and eventually in many patients resulting in progressive disease. Supporting this concept, a difference was also found between the expression of Bcl-2 in areas of unaffected tumour growth, i.e. in areas of treatment failure, and the expression in areas of histopathological regressive changes. Thus immunohistochemical analysis of tumour biopsies shortly after therapy seems to be a good surrogate endpoint that allows a detailed analysis of Bcl-2 expression. The high expression of Bcl-2 shown in unaffected tumour areas after therapy suggests the need for additional treatment, e.g. Bcl-2 antisense therapy.

Biochemotherapy of metastatic malignant melanoma. On down-regulation of CD28.

Immunotherapy and combination treatments such as biochemotherapy have shown promise, with higher response rates and a subset of durable responses; however, as the majority of responses are still of short duration, they do not provide any survival benefit. There is therefore a great need to better understand the mechanisms whereby tumours escape immune surveillance. The present study examines the expression of CD28 in patients with untreated and treated melanoma metastases. Twenty-eight patients with metastatic malignant melanoma were treated by biochemotherapy (cisplatinum 30 mg/m(2) days 1-3, DTIC 250 mg/m(2) days 1-3 i.v., and IFN-alpha2b 10 million IU s.c. three days a week for 28 days treatment cycle). Tumours were resected post-biochemotherapy and analysed for the expression of CD28 in CD4(+) and CD8(+) lymphocytes in areas where histopathological regressive changes had occurred, and close to tumour cells in areas of unaffected tumour growth using a double-staining technique. A high percentage of the lymphocytes in areas with regressive changes were found to be CD4(+)CD28(-). In contrast, the vast majority of CD4(+) lymphocytes migrating close to the tumour cells were found to be CD28(+) (P<0.001). A similar difference in the expression of CD28 was also found for the CD8(+) subset (P=0.004). A difference in down-regulation of the expression of CD28 was found between CD4(+) and CD8(+) lymphocytes both in the areas of regressive changes and in the unaffected tumour areas. The present study demonstrates that extensive down-regulation of the co-stimulatory factor CD28 is found in metastases following biochemotherapy. These results indicate that parameters of importance for the immune function have already undergone modification after one or two treatment cycles and that this down-regulation occurs in particular in areas with regressive tumour changes.

Down-regulation of the CD3-zeta chain in sentinel node biopsies from breast cancer patients.

BACKGROUND: In several neoplastic diseases, immunosuppression has been shown to correlate with disease stage, progression, and outcome. As the prognosis for metastatic breast cancer is still pessimistic, additional strategies are being sought to improve survival. Local immunosuppression in sentinel node biopsies from 24 evaluable breast cancer patients was studied as a possible way of selecting patients for immunotherapy. METHOD: Sentinel node biopsy was performed in 24 out of 25 women operated on for primary breast cancer (one was not evaluable). Specimens were snap-frozen and double-stained for the zeta-chain of the T-cell receptor. The degree of down-regulation of the zeta-chain was evaluated in three different lymph-node areas: primary follicles, secondary follicles, and paracortex. RESULTS: Down-regulation of varying degrees was noted in all 24 sentinel node biopsies. A high degree of down-regulation (more than 50% of T-cells not expressing zeta-chain) was seen in the primary follicles in six patients (25%), in the secondary follicles in 13 patients (72%), and in the paracortex in 19 patients (79%). CONCLUSION: Local down-regulation of an immune function parameter was seen in sentinel node biopsies from breast cancer patients. In addition to possible prognostic implications, the sentinel node might be an appropriate location for detecting early-stage immunological down-regulation, which might open a possibility of selecting patients who could benefit from immunotherapy.