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Infiltration of tumor-associated macrophages in human oral squamous cell carcinoma.

Tumor-associated macrophages (TAMs) have been shown to display both positive and negative effects on tumor growth of various cancer. In this study, TAMs were immunohistochemically labeled using CD68 antibody in 82 oral cancer. Macrophage index (MI) were analyzed in association with clinical and pathological factors, intratumoral microvessel density (IMVD) and angiogenic factors including VEGF and TP. Significantly higher number of CD68-positive cells was noted in oral cancer. TAM expressions were significantly associated with stages of invasion, IMVD, and angiogenic factors. These findings suggest that TAMs possibly play a role in angiogenesis during oral cancer progression.

Antigens, CD↗

Clinical effects of tumor-associated macrophages and dendritic cells on renal cell carcinoma.

Several reports have documented infiltration of many monocytes in renal cell carcinoma (RCC). Since few studies have examined the relationship between monocyte infiltration and clinical prognosis in RCC, we clinically investigated this relationship by semi-quantitative analysis of monocyte infiltration and tumor angiogenesis. The following six parameters were measured immunohistologically in 98 RCC patients who underwent nephrectomy between 1987 and 1997: tumor-associated macrophage (TAM), microvessel density (MVD), S-100 protein-positive cells (S-100(+) cells), HLA-DR-positive cells, apoptosis index and proliferative index (PI). We then assessed intercorrelations among parameters and correlations to prognosis. Significant positive correlations were identified for TAM, MVD and PI, with a tendency for higher parameter values to reflect poorer prognosis. The prognosis of patients without metastasis was poor for the high TAM group even when levels of MVD were low. These findings suggest that TAM facilitates the growth of RCC via angiogenesis and other mechanisms. Prognosis was significantly better in metastatic RCC patients who underwent interferon-alpha (IFN-alpha) therapy when the levels of S-100(+) cells were high. Nonetheless, the levels of S-100(+) cells among these IFN-treated patients did not correlate with other parameters, and none of the other parameters correlated with prognosis. One of the antitumor effects of IFN-alpha for RCC could therefore be mediated by dendritic cells.

Apoptosis↗

Effects of tamoxifen administration in rat vaginas: an ultrastructural and light microscopy study.

BACKGROUND: Tamoxifen (TAM) inhibits the initiation of carcinogen induced rat mammary tumours and is administrered for extended periods after the initiation of carcinogenesis. It is also a widely used treatment for breast and gynaecological cancer. OBJECTIVE: In this study, we aimed to investigate tamoxifen (TAM) administration on vagen development in rats. MATERIAL & METHODS: Twenty sexually mature and pregnant Wistar albino rats were chosen as the animal model. They were divided into two groups. Group I: Control group, Group II: Tamoxifen applied (between gestational day 16 and 21 days); 100 microg tamoxifen citrate (TAM) in 0.05 ml saline subcutaneously per day/animal. After birth, all female rats were sacrificed on the 60th day and were taken vaginal tissue. Transmission electron microscopy and light microscopy have been used to study changes to the vaginal epithelium. RESULTS: A statistically significant reduction of birth body weight was noted in the experimental group of rats when compared to the control group (P < 0.05). We saw increase in the thickness of the epithelium layer and irregularity and disappearance of microscopic papilla, cytoplasmic vacuolation in cells of the surface layer, thin and irregular basal membrane, lateral junction of cells were destroyed in the TAM treated groups. In conclusion, neonatal tamoxifen administration affects vagina epithelium and lead to decreasing birth body weight and vaginal adenosis.

Animals↗

[Combined effects of toremifene and paclitaxel on human breast cancer cell lines].

Effects of toremifene (TOR) in combination with paclitaxel (TXL) on various human breast cancer cell lines were evaluated. TOR and TXL exhibited additive effects on estrogen receptor (ER)-positive cancer cell lines, MCF-7 and T-47D, and a sub-additive effect on a tamoxifen (TAM)-resistant line, T-47D/TAM. To all three ER-negative cancer cell lines, the combined treatment also showed additive effects on MDA-MB-134VI, MDA-MB-231 and MDA-MB-453. Furthermore, a synergistic effect was observed on a multi-drug resistant (MDR) line, Adr. This synergistic effect was more potent in the combination with TOR than that with TAM. The combined treatment increased intracellular TXL, and the accumulation by TOR was 1.5-fold that by TAM. Consequently, the ratio of G2M arrested cells was higher, with statistical significance, in the TOR combination than in the TAM combination. In addition, these synergistic effects in MDR cells were also observed in the combination of TXL with major clinical active metabolites, N-desmethyl-TOR (TOR-1) and 4-hydroxy-TOR (TOR-2). These results suggest that the combination therapy of TOR and TXL might be an effective clinical treatment for breast cancer patients.

Antineoplastic Agents, Phytogenic↗

[Human mammary carcinoma. A model for the relationship between tumor proliferation, tumor-associate macrophages, and prognostic factors].

As compared with the lymphatic system, the mononuclear phagocyte system (MPS) represents the older defense system in the course of evolution. Organisms with defective or with no lymphocytic function are able to live for a certain time while metazoa cannot develop and exist without cells capable of phagocytosis. It is known that up to 80% of the mass of malignant experimental tumors may consist of macrophages. The biological relevance of these tumor-associated macrophages (TAM), however, is contested to date. Besides well-known tasks in specific and non-specific defense, the cells of the MPS possess nutritive functions. The different functions of TAM have been essentially examined in animal experiments in vivo and in vitro up to now. These studies have shown, e.g., that TAM of different phenotypes to some extent are assigned to different functions and that each tumor or tumor cell line has a specific TAM pattern. The available number of monoclonal antibodies (MAB) able to recognize different groups of human macrophages has only increased in the recent past. This also provided evidence of the phenotypic heterogeneity of macrophages in the human system. On the other hand, there is little knowledge to date of the possible biological cause of the presence of numerous macrophages also in the stroma of malignant tumors in man and on the functional relevance of particular macrophage phenotypes. In the present studies, the phenotypic pattern of tumor-associated cells was examined by immunohistochemistry in the model of human mammary carcinoma, using 18 monoclonal antibodies (Ki-M1-8, Leu-M1-3, Leu-M5, EBM11, CD1, anti-transferrin receptor [TFR], anti-MHC I, anti-MHC II or anti HLA-DR) and one polyclonal antibody (anti protein-S100). The first part of the study contains a semiquantitative evaluation of 216 cases of mammary carcinoma. The analytical results are correlated with established prognostic factors available in the case of malignant tumors in general and in that of mammary carcinomas in particular (age, menopausal status of patients, axillary lymph node and estrogen/progesterone receptor status, size of tumor, tumor type according to WHO, degree of malignancy according to histopathological and nuclear grading). As tumor parameters of absolute biological relevance, proliferating activity (Ki67) and MHC phenotype of tumor cells and amount or types of tumor-associated lymphocytes (TAL) are examined in order to analyze their correlation with prognostic factors and their importance in the tumor-macrophage system.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibody-Dependent Cell Cytotoxicity↗

Signaling pathways of apoptosis activated by aromatase inhibitors and antiestrogens.

Aromatase inhibitors have recently been reported to be more effective than the antiestrogen tamoxifen (Tam) in treating breast cancer. Here, we studied the mechanisms and signaling pathways of cell growth, cell cycle progression, and apoptosis induced by three aromatase inhibitors: letrozole (Let), anastrozole, and 4-hydroxyandrostenedione in comparison with estrogen withdrawal (E2W) and antiestrogens Tam and faslodex. Estrogen-dependent human breast cancer cells stably transfected with aromatase (MCF-7Ca) were used. All treatments induced growth suppression and cell cycle arrest at the G(0)-G(1) phase that was associated with up-regulation of p53 and p21 protein and mRNA levels and down-regulation of cyclin D1 and c-myc mRNA. The apoptotic index was increased 4-7 fold, Bcl-2 protein expression decreased, Bax increased, and caspase-9, caspase-6, and caspase-7 were activated but not caspase-3 and caspase-8. Let and E2W caused regression of tumors of MCF-7Ca cells grown in nude mice and increased the number of cells undergoing apoptosis. In contrast, Tam and faslodex did not induce tumor regression and a lower number of apoptotic cells was detected. Cleavage of poly(ADP-ribose) polymerase was detected. Treatment with Let, Tam, or E2W resulted in a dose- and time-dependent increase in active caspase-7 and up-regulation of p53 and p21 protein. Although the mechanisms involved appeared to be similar for antiestrogens and aromatase inhibitors, the most significant effects occurred with Let, which were significantly greater than with E2W and consistent with marked effects of Let on tumor and cell growth.

Animals↗

Tumor-associated macrophages: foe or accomplice of tumors?

Macrophages are predominantly involved in the immune and inflammatory processes of solid tumors. Macrophages infiltrated into a tumor have an ambivalent relationship with the tumor, because they are innately very flexible and adaptable depending on the microenvironment of the tissue and the tissue-derived factors. The relationship between tumor-associated macrophages (TAMs) and a tumor is extremely complicated and has not yet been clearly elucidated. Now, the reintegration of biological knowledge including immunology, pathology and oncology is indispensable for the clinical application of TAMs to cancer therapy. In this review, we focus on the range of pro- and anti-tumor functions performed by TAMs and outline a new class of cancer therapies that aims at controlling the complex functions of TAMs.

Animals↗

[Application of the MIC breakpoints based on pharmacokinetics and pharmacodynamics parameter in the clinical laboratory].

The effectiveness of time-dependent antibiotics such as beta-lactams is related to the time above the MIC (TAM, %). We constructed a program to calculate the TAMs of beta-lactams using the pharmacokinetic parameters of the Japanese dosing regimen of a phase I study of the Japanese Society for Antimicrobial Chemotherapy (JSAC), and compared them with the MIC breakpoints published by the National Committee for Clinical Laboratory Standards (NCCLS) and JSAC. If the effective TAM was assumed to be more than 40% of the dosing interval, the pharmacokinetic/pharmacodynamic (PK/PD) breakpoints calculated by our program were in agreement with the JSAC breakpoints for pneumonia within 1 dilution MIC. When comparing with the NCCLS breakpoints for Enterobacteriaceae or Staphylococcus, the PK/PD breakpoints dosing three times per day of ampicillin (1 g, intravenous dose; i.v.), piperacillin (2 g, i.v.), cefotaxime (1 g, i.v.) and cefmetazole (1 g, i.v.) were calculated to be less than 2-fold dilution MIC, and those of amoxicillin (0.25 g, oral dose; p.o.) and cefaclor (0.5 g, p.o.) were calculated to be less than 3- to 4-fold dilution of MIC. Our program could calculate TAMs and PK/PD breakpoints by inputting the two factors of MIC and dosing interval. If this information is routinely reported to physicians from clinical laboratories, an appropriate dosing schedule could be proposed for various infectious cases.

Anti-Bacterial Agents↗

[Flow cytometric analysis of effects of chemohormonal agents on the cell cycle distribution of MCF-7 cells].

Five anticancer agents (MTX, 5FU, MMC, ADR and VCR) and an antiestrogenic agent (TAM) were investigated to observe the effects on the growth of MCF-7 cells and the changes on the cell cycle distribution of them by flow cytometry. The growth-inhibitory effects of these agents were divided into three manners. The growth rate by ADR was affected in a concentration-dependent manner; MTX in a time-dependent; 5FU, MMC and VCR in both time and concentration-dependent manners. The effects on cell kinetics were divided into three categories. MCF-7 cells were accumulated on S phase by MTX, G0G1 phases by TAM and G2M phases by the other agents. The combined effect of two agents was the most prominent when MTX was first administered and followed by an agent which affected on G2M phases. In the combination of TAM and MMC, the strongest effect was obtained when MMC was first administered and followed by TAM. These results indicated that the combined effect of cell inhibition was obtained on cell kinetic basis by employing the technique of analytical flow cytometry.

Antineoplastic Agents↗

High-dose tamoxifen treatment increases the incidence of multifocal tumor recurrences in glioblastoma patients.

BACKGROUND: Multifocal tumor recurrences in glioblastoma patients are described in 4% - 14% of cases. Two recent studies, treating newly diagnosed glioblastoma patients with continuous high-dose tamoxifen (TAM), reported an increased incidence of multifocal tumor recurrences in 45.5% and 33% of study patients. PATIENTS AND METHODS: Fifty newly diagnosed patients with glioblastoma were treated with 3 cycles of carboplatin, continuous high-dose TAM and radiotherapy. Tumor progression was determined on follow-up MRI studies at 3-month intervals and categorized as either local or multifocal. RESULTS: Multifocal tumor recurrence was found in 16 (33%) out of 49 study patients. Compared to tumors which remained local, multifocal tumor recurrences were characterized by a significantly longer median time to tumor progression (41 vs. 23 weeks, Breslow test: p = 0.0123). Multifocal tumor recurrences were mainly observed after an initial response to the study treatment (81%), whereas local regrowth was more often associated with initial treatment failure, i.e. progressive disease (64%). CONCLUSION: The association of the pattern of tumor recurrence with the type of response to TAM treatment suggests that acquired resistance to TAM might be an important contributing mechanism in the development of multifocal glioblastoma disease.

Adult↗

Rationale for sequential tamoxifen and anticancer drugs in adjuvant setting for patients with node- and receptor-positive breast cancer.

Since the survival benefit of tamoxifen (TAM) combined with anticancer drugs in treating node- and receptor-positive breast cancer is small, appropriate treatment schedules and the rationale for the combination remains unclear. We examined the effect of estradiol (E2) on sensitivity to anticancer drugs to clarify the survival benefit of tamoxifen combined with anticancer drugs. We used the MTT assay to assess the effect of E2 on sensitivity to anticancer drugs in the E2 receptor-positive and -negative breast cancer cell lines, MCF-7 and MDA-MB-231, respectively. We assessed the expression of apoptosis-related proteins by Western blotting, and evaluated apoptosis using the TUNEL method. Serum levels of E2 were measured using an enzyme-labeled radioimmunoassay in patients with premenopausal breast cancer before and during treatment with tamoxifen. Estrogen administration decreased sensitivity in MCF-7 cells to the anticancer drugs, adriamycin (ADM), mitomycin C (MMC), and paclitaxel (TXL), evaluated as increases in the IC50 values for ADM (4.1-fold), MMC (1.9-fold) and TXL (13.0-fold), compared with those of each drug alone. Estradiol in MDA-MB-231 cells similarly increased the IC50 values for ADM (9.5-fold), MMC (15.6-fold), and TXL (2.4-fold). The decreased sensitivity to these anticancer drugs was associated with the attenuation of apoptosis. Estrogen dose-dependently increased the expression of Bcl-2 protein in MCF-7, but not in MDA-MB-231 cells, and suppressed the expression of Bax and cytochrome c induced by anticancer drugs in association with decreased apoptosis compared with the effect of each drug alone. Phosphorylation of the Bcl-2 protein induced by TXL was decreased in the presence of E2 in MCF-7 cells. Serum levels of E2 were increased in 5 patients without amenorrhea and in 1 patient with amenorrhea after treatment with TAM alone in adjuvant therapy, compared with levels before treatment. Estradiol decreased sensitivity to ADM, MMC, and TXL in MCF-7 and MDA-MB-231 breast cancer cells, and this was associated in part with an increase in the amount of Bcl-2 protein, and decreases in levels of Bax and cytochrome c leading to apoptosis. These results suggest that therapy with TAM and anticancer drugs should be sequentially scheduled with anticancer drugs followed by TAM in an adjuvant setting to treat patients with breast cancer for a potentially improved survival benefit.

Adult↗

[Experience of high-dose toremifene treatment for postmenopausal women with metastatic breast cancer].

Toremifene (TOR), a selective estrogen receptor modulator (SERM), showed efficacy equivalent to Tamoxifen (TAM) in terms of the objective response rate, stable disease, time to progression and overall survival in patients with metastatic breast cancer (MBC). High-dose TOR is also effective for patients with TAM-resistant breast cancer. We tried to study retrospectively the efficacy and the safety of high-dose TOR treatment for patients with MBC in our hospital. Ten patients received TOR 120 mg daily. Most of the patients were treated with one or more endocrine agents before high-dose TOR. Objective response and clinical benefits were found in 3 patients (30%) and 7 patients (70%), respectively. Median time to progression and median overall survival were 9 months and 21.5 months, respectively. In our study,we found the efficacy for patients with hormone receptor negative, TAM resistance and aromatase inhibitor (AI)-resistance breast cancer. Adverse events induced by high-dose TOR treatment were tolerable. High-dose TOR may be one of the optional treatments for patients with MBC after TAM and AI treatment.

Aged↗

Differential gene expression assessed by cDNA microarray analysis in breast cancer tissue under tamoxifen treatment.

Our purpose was to identify tamoxifen (TAM) responsive genes after 30 days of TAM treatment in tumor tissues obtained from women with breast cancer using microarray expression analysis. In our study, we identified 12 candidates to be considered as tamoxifen-modulated genes. Among them, we selected two candidates the TEGT BI-1 (testis enhanced gene transcript Bax Inhibitor-1) and the CD63 gene in order to further confirm their differential expression under tamoxifen effects. We observed that both were down-regulated in tumor tissues of patients during TAM treatment. TEGT is able to inhibit the expression of Bax, which is known to promote apoptosis. On the other hand, CD63 encodes a cell membrane protein and it seems to be involved in mechanisms of platelet activation, cell adhesion and cell motility. We therefore hypothesize that TAM would be able to modulate tumor growth by down-regulating genes involved in mechanisms such as cell cycle control, tumor invasion and metastasis.

Breast Neoplasms↗

Thymidine analogue mutation profiles: factors associated with acquiring specific profiles and their impact on the virological response to therapy.

BACKGROUND: Studies have suggested that HIV-1 may develop thymidine analogue mutations (TAMs) by one of two distinct pathways - the TAM1 pathway (including mutations 41L, 210W and 215Y) or the TAM2 pathway (including mutations 67N, 70R and 219E/Q) - under the pressure of a not fully suppressive thymidine-analogue-containing regimen. METHODS: Frozen plasma samples stored in the EuroSIDA repository were selected and sent to two central laboratories for genotypic analysis. We considered 733 patients with at least one genotypic test showing > or =1 TAMs (the first of these tests in chronological order was used). TAM1 and TAM2 genotypic profiles were defined in accordance with previous literature. Statistical modelling involved logistic regression and linear regression analysis for censored data. RESULTS: The observed frequencies of patterns classifiable as TAM1 or TAM2 profiles were markedly higher than the probabilities of falling into these classifications by chance alone. The chance of detecting a TAM2 profile increased by 25% per additional year of exposure to zidovudine. We found that mutations 67N and 184V were not associated with a particular TAM profile. In the presence of TAM2 profiles, the adjusted mean difference in the 6-month viral reduction was 0.96 log10 copies/ml (95% confidence interval: 0.20; 1.73) higher in patients who started stavudine-containing regimens instead of zidovudine-containing regimens. CONCLUSIONS: This study provides evidence that the suggested TAM clustering is a real phenomenon and that it may be driven by which thymidine analogue the patients has used. In patients with TAM2-resistant viruses, stavudine appears to retain greater viral activity than zidovudine.

Anti-HIV Agents↗

Elevated serum levels of vascular endothelial growth factor are associated with tumor-associated macrophages in primary breast cancer.

We analyzed serum and tumor samples from 133 patients with operable primary breast cancer to determine the possible relationship between presurgery and postsurgery circulating serum vascular endothelial growth factor (VEGF) levels and tumor-associated macrophage (TAM) numbers, tumor VEGF expression, and other immunohistochemical parameters. A significant positive correlation was observed between the number of TAM and postsurgery circulating VEGF values (P < .05). Moreover, patients with a p53+ tumor had higher postsurgery serum VEGF levels than those with a p53- tumor (P < .05), and tumor p53 overexpression correlated significantly with TAM number (P = .007). We observed no significant association between serum values and tumor VEGF expression. Although the macrophage index was higher in VEGF+ than in VEGF- tumors, the differences were not statistically significant. Our data show a positive interrelation between high circulating VEGF levels, the number of TAM, and p53 overexpression, a relationship that might have an important role in the enhanced angiogenesis processes in breast cancer.

Adult↗

Changing the gold standard in adjuvant therapy for breast cancer:from tamoxifen to aromatase inhibition.

The introduction of third generation aromatase inhibitors [anastrozole, letrozole, and exemestane] has certainly improved outcomes inpatients with early breast cancer. Although survival benefit has not been identified (except in the subpopulation of patients with lymph node positive breast cancer on the MA 17 study), the primary endpoints in all studies reached statistical significance in favor of AI. The strategy can include: replacing TAM outright after diagnosis; switching from TAM to one of the aromatase inhibitors after 2-3 years; or to add an AI after 5 years of TAM. DFS, recurrence, and the incidence of contra lateral breast cancer is influenced favorably with such an approach. The following issues remained unanswered: Will the OS be improved as well? Is the incidence of serious long-term side effects acceptable to our patients [osteoporosis, fractures, cognitive function and lipid profile changes]? What is the influence of chemotherapy on the effect of aromatase inhibitors? We still do not know the true role of AI in HER2 positive disease. Which effect do AI have in pre-menopausal women(with the use of LHRH agonists)? How long should patients after TAM be receiving AI? Several of these questions will be certainly answered with the new generation of studies, but many of these questions have just been generated with these new results.

Anastrozole↗

Antiviral efficacy and genotypic resistance patterns of combination therapy with stavudine/tenofovir in highly active antiretroviral therapy experienced patients.

OBJECTIVES: To evaluate antiviral efficacy of stavudine/tenofovir (d4T/TDF) backbone combination in late-line antiretroviral therapy, and to assess clinical and virological determinants of treatment success. DESIGN: Multicentric retrospective analysis on patients starting d4T/TDF after highly active antiretroviral therapy (HAART) failure. METHODS: The primary endpoint was the change in plasma HIV-1 RNA from the baseline (time of d4T/TDF initiation) to 6 months of therapy; secondary endpoint was the risk of virological failure. RESULTS: Among 172 patients included, a mean change in HIV-1 RNA of -1.69 (+1.23) and -1.53 (+1.43) log10 cp/ml was observed respectively at weeks 24 and 48 after starting d4T/TDF combination. Any single type-1 thymidine analogue mutation (TAM; M41L, L210W, T215Y) had a negative effort on the change in HIV RNA at 6 months, whereas among type-2 TAMs (D67N, K70R, K219Q), only D67N showed a trend for a negative effect. Presence of M184V mutation was related with a greater reduction in HIV RNA during d4T/TDF exposure. The risk of virological failure at 6 months after d4T/TDF starting was 22%. Type-1 TAMs were associated with a greater risk of failure (adjusted hazard ratio [HR]=1.65; 95% confidence interval [CI] 1.19-2.29). Conversely, M184V showed a protective effect. In 17 genotypic tests available at failure, no K65R mutation was detected, whereas a trend for an increasing prevalence of d4T-associated mutations was found. CONCLUSIONS: Combining TDF with a thymidine analogue as d4T may be effective as component of antiretroviral rescue regimens in HIV-infected patients with previous exposure to nucleoside analogue reverse transcriptase inhibitor. Previous selection of type-1 TAMs induces a detrimental effect over virological response.

Adenine↗

Effects of the antiestrogens tamoxifen and raloxifene on the estrogen receptor transactivation machinery.

The influence of 17beta-estradiol (E2), tamoxifen (TAM) and raloxifen (RLX) on the proliferation of breast (BC) and endometrial carcinoma cell lines (EC) and the expression of different compounds of the estrogen receptor (ER)-transactivation machinery were studied. E2 stimulated the proliferation of BC, but had no effect on the EC. TAM showed a biphasic effect on ER-positive cell lines. RLX showed an antagonistic suppression or no effect. The expression of ERalpha was down-regulated by E2, but not affected by selective estrogen receptor modulators. ERbeta and progesterone receptor expressions were up-regulated by E2, TAM and OHT. This supports the hypothesis that ERbeta expression is also regulated via the ERalpha-pathway. The steroid receptor coactivator (SRC) AIB1 expression was slightly decreased by E2 but not by antiestrogens (antiE). TIF2 expression was increased by E2, TAM and RLX, but SRC-1 expression was not. In comparison, the expressions of ERbeta and progesterone receptor were strongly influenced by antiE, while the expression of SRCs was only slightly affected.

Breast Neoplasms↗