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At least 19 recordsLinked to original sources
PubMed1978

Genetic variation at a locus (TAM-1) for submaxillary gland protease in the mouse and its location on chromosome No. 7.

Electrophoretic and activity variants for a testosterone-induced esteroprotease have been discovered in submaxillary glands from inbred strains of mice. The enzyme is tentatively designated tamase [TAM-1] and the variant genetic locus is Tam-1. The alleles Tam-1a and Tam-1b determine electrophoretically distinct zones of tamase activity, while Tam-lc produces no detectable enzyme activity. Data from recombinant inbred strains and B6AF1 X B6 and B6D2F1 X B6 backcrosses established linkage of Tam-1 to glucose phosphate isomerase (Gpi-1), pink-eyed dilution [p] and beta-hemoglobin (Hbb) on chromosome 7. The gene order is Gpi-1--Tam-1--p--HBB. Analysis of congenic resistant strains indicates that Tam-1 is closely linked to the minor histocompatibility locus, H-4. TAM-1 was not cross-reactive with antisera to mouse nerve growth factor, submaxillary renin, or tamases A and D.

Animals↗
PubMed1979

TAM selection of Drosophila somatic cell hybrids.

The selection of MDR3, an adenine-salvage-deficient variant of the Kc line, is described. It is resistant to methylpurine and to diaminopurine and is TAM (thymidine, adenine, methotrexate) sensitive. Two wild-type (TAM-resistant) cell lines, Schneider's line 3 (S3) and Dübendorfer's line 1 (D1), due to their different nutritional requirements, are unable to proliferate in medium ZH1% used for line MDR3. This allowed the selection of hybrids between MDR3 and either D1 or S3 in TAM cloning medium after treatment with polyethyleneglycol. Hybrids were identified by the isoenzyme pattern of NADP-dependent isocitrate dehydrogenase.

Adenine↗
PubMed2026

Pan-cancer analysis identifies APOC1 as a TAM-derived modulator of adaptive immune resistance and predictor of therapeutic response.

BACKGROUND: Apolipoprotein C1 (APOC1) has been implicated in several malignancies, yet its expression patterns, clinical significance, and immunomodulatory roles across cancer types remain poorly characterized. METHODS: We performed a comprehensive multi-omic analysis of APOC1 across 33 cancer types integrating transcriptomic, proteomic, genomic, epigenomic, and pharmacogenomic data from TCGA, GTEx, CPTAC, and multiple independent external cohorts. Immune infiltration was assessed using seven complementary algorithms. Spatial transcriptomics and single-cell RNA sequencing were employed to determine the cellular source of APOC1 expression. RESULTS: APOC1 upregulation in most cancers was associated with cancer type-specific prognosis. After adjustment for clinical covariates and macrophage infiltration, high APOC1 remained an independent adverse factor in KIRC, LGG, and STAD. APOC1 expression positively correlated with genomic instability hallmarks, including homologous recombination deficiency and aneuploidy, with these associations largely independent of immune infiltration; in contrast, associations with tumor mutational burden were substantially confounded by macrophage abundance. Immune infiltration analysis revealed a pattern consistent with adaptive immune resistance: APOC1 correlated positively with immune-activating signatures (STAT1, MHC-II, TCR signaling) and immunosuppressive M2 macrophages and Tregs, yet negatively with anti-tumor effectors (activated NK cells, dendritic cells). Spatial transcriptomics and single-cell RNA sequencing identified tumor-associated macrophages (TAMs) as the primary cellular source of APOC1, with transcripts co-localizing with CD68 in tissue sections. APOC1 expression correlated with multiple immune checkpoint molecules and was elevated in responders to immune checkpoint blockade, consistent with an inflamed yet regulated tumor microenvironment. Pharmacogenomic analyses revealed that APOC1-high tumors display distinct drug response profiles, characterized by resistance to MAPK pathway inhibitors and potential sensitivity to the HDAC inhibitor Entinostat. CONCLUSION: This pan-cancer analysis establishes APOC1 as a context-dependent biomarker and a TAM-derived modulator of adaptive immune resistance, with prognostic and therapeutic implications across malignancies. APOC1-expressing TAMs represent a potential target for combination immunotherapy strategies.

APOC1↗
PubMed2026

Next-generation macrophage engineering in cancer therapy: From TAM reprogramming to CAR-macrophages.

Macrophages are central regulators of the tumor microenvironment (TME), shaping immune suppression, angiogenesis, metabolism, and therapeutic resistance in solid cancers. While early strategies sought to deplete tumor-associated macrophages (TAMs) or block monocyte recruitment, limited efficacy and compensatory mechanisms revealed the need for functional reprogramming rather than elimination. Recent advances in viral vectors, CRISPR-Cas genome editing, and RNA-based delivery platforms have enabled precise genetic modification of macrophages, giving rise to chimeric antigen receptor macrophages (CAR-Ms) and related engineered products. Beyond antigen targeting, effective macrophage engineering requires stabilization of pro-inflammatory identity, resistance to tumor-induced repolarization, metabolic reinforcement, and integration of checkpoint modulation pathways. This review synthesizes current strategies across DNA, mRNA, and siRNA-based platforms, highlighting convergent design principles that connect TAM reprogramming with CAR-M development. We discuss reshaping phagocytosis checkpoints, metabolic and transcriptional stabilization, cytokine augmentation, and synthetic receptor architecture, emphasizing combinatorial and context-aware engineering, while proposing new candidate gene targets. Engineered macrophages are thus evolving from simple effector cells into programmable immune coordinators capable of converting immunologically "cold" tumors into inflamed, therapy-responsive niches.

CAR-M↗
PubMed1978

Hepatotoxic effect of thioacetamide (TAM) on NADP-linked enzymes, aminotransferases and glutamate dehydrogenase.

NADP-linked dehydrogenases, glucose-6-P dehydrogenase (G 6PDH) 6-P gluconate dehydrogenase (6 PGDH), isocitrate dehydrogenase (ICDH), malate dehydrogenase decarboxylating (ME) and aminotransferases GOT and GPT were analyzed in the soluble fraction of blood free homogenates. Glutmate dehydrogenase (GDH) was assayed in the mitochondrial fraction. TAM was i.p. administered to male albino rats (50 mg/kg/day) for 28 days. enzyme activities were determined as described by Bermeyer 1965 (Methods Enzymatic Analysis. Verlag Chemie. Acad. Press).

Acetamides↗
PubMed1991

Qui tam: suing physicians who make false claims.

The 1986 False Claims Act Amendments authorize private citizens to sue on behalf of the U.S. government to recover federal funds from fraudulent recipients. The "relator" receives a share of any proceeds from a successful lawsuit. Originally enacted because of defense procurement scandals, this statute also applies to federal payments for health care (for example, Medicare, Medicaid, Civilian Health and Medical Program for Uniformed Services payments; veterans benefits; and research grants). Physicians can expect qui tam litigation to increase in the future.

Financing, Government↗
PubMed1992

[Combination therapy of doxifluridine (5'-DFUR) + cyclophosphamide (CPA) + tamoxifen (TAM) for advanced or recurrent breast cancer. Joint Research Group in the Osaka Area for Combination Therapy of 5'-DFUR with Other Drugs].

Outpatients with advanced and recurrent breast cancer were treated by a combination therapy of the following drugs: doxifluridine (5'-DFUR) orally administered at a dose of 1200 mg/day; cyclophosphamide (CPA) orally given at dose of 100 mg/day; and tamoxifen (TAM) orally given at dose of 20 mg daily. 5'-DFUR and CPA were administered on consecutive days 1-14, then discontinued for 14 days. The response rate was 44.8% including five CR and eight PR out of 29 complete cases. As for response cases in terms of the subject lesions, corresponding cases were chiefly found in soft tissue and the lung. As for the response rate with or without pretreatment, cases previously treated showed a higher response rate such as 42.9% indicating that the present therapy was effective in pretreatment cases. The main side effect was leukopenia, but not so severe. Few cases with diarrhea were found. Based on the above findings, the present treatment is conceivably a highly useful therapy, on an outpatient basis, for advanced and recurrent breast cancer, especially metastatic lesions of soft tissue and the lung.

Administration, Oral↗
PubMed1992

[A comparative study with 5'-DFUR alone or in combination with tamoxifen (TAM) or medroxyprogesterone acetate (MPA) for advanced or recurrent breast cancer].

A comparative study of 5'-DFUR 600 mg/day alone (C-arm) or in combination with TAM 30 mg/day (A-arm) or MPA 600 mg/day (B-arm) was carried out. Thirty-four patients (aged 80 or less) with no prior treatment were evaluable, and the following results were obtained. 1) Patient characteristics were similar in each treatment group and the compliance in all groups was excellent. 2) The group B response rate (70.0%) was considerably higher than that of group A (23.1%) and C (27.3%). 3) In B, the response rates in soft tissues (80.0%) and bone (71.4%) were still good. 4) Mild side effects were encountered in about 15% of each group. We confirmed that combination chemotherapy with a low dose of 5'-DFUR and MPA was effective for first line treatment of metastatic breast cancer.

Adult↗
PubMed1990

[Tumor-associated macrophages (TAM) in the stroma of squamous cell carcinomas of the ENT area studied using monoclonal antibodies].

Monoclonal antibodies were used to examine the presence and nature of tumor associated macrophages and T-lymphocytes in 26 cases of squamous cell carcinoma of head and neck. The content of macrophages varied according to the differentiation of the carcinoma: high differentiation was evidenced by a labelling index by an index between 13.5% and 23.7%, poor differentiation from 27.4% to 35.8%. T-lymphocytes were found where tumors were inflamed, but there was no significant correlation between tumor differentiation and infiltrating T-lymphocytes. The present results that prognosis decreases with the increasing number of tumor associated macrophages in squamous cell carcinoma.

Antibodies, Monoclonal↗
PubMed1991

The TAM regimen prior to allogeneic and autologous bone marrow transplantation for high-risk acute lymphoblastic leukemias: a cooperative study of 62 patients.

A total of 62 patients with high-risk acute lymphoblastic leukemia (ALL) were treated with fractionated total body irradiation, high-dose cytosine arabinoside and melphalan followed by bone marrow transplantation (BMT). Thirty-six patients received allogeneic and 26 autologous BMT. Eight patients were treated in CR1, 36 in CR2 (first relapse occurring on therapy for 32), seven in further CR, 10 in relapse (five early first relapse, four second relapse and one fourth relapse) and one with refractory ALL. Severe toxicity occurred in 26 of the 62 patients (42%) and 14 died (22.5%) from non-leukemic causes. The actuarial event-free survival at 3.6 years was 28% after autologous BMT and 52% after allogeneic BMT with actuarial relapse rates of 62% and 35%, respectively. The results of this pilot study seem promising for this group of poor risk ALL, but the relapse rate remains high after autologous BMT and needs to be improved.

Adolescent↗
PubMed1986

Biological responses of tamoxifen in the fetal and newborn vagina and uterus of the guinea-pig and in the R-27 mammary cancer cell line.

The biological and morphological responses of tamoxifen were studied in two models: the uterus and vagina of fetal and newborn guinea-pigs: R-27 cells--a mammary cancer cell line (tamoxifen resistant) derived from the MCF-7 cancer cell line. Tamoxifen (TAM) alone or in combination with estradiol (E2) was administered to pregnant (50-52 days of gestation) or to newborn (2-day-old) guinea-pigs for a long period (12 days). TAM alone produced a great trophic effect on the uterus and vagina which was markedly enhanced when TAM was administered together with E2. Histological studies showed that TAM provokes morphological changes in both the endometria and the myometria and this effect was also greater when TAM was administered together with E2. In the fetal uterus and vagina, the ultrastructural studies showed that TAM induces morphological alterations in different cytoplasmic organelles. This effect was much more intense in newborns where TAM provoked a significant vacuolization of the epithelial cells. Concerning progesterone receptor (PR) in the fetal or newborn tissues (uterus or vagina) TAM provoked a less intense effect than those provoked by E2, but TAM did not block the effect provoked by E2. It was observed that [3H]TAM binds specifically to the estrogen receptor (ER) of fetal guinea pig uterus and this complex is partially recognized by a monoclonal antibody which recognizes the activated form of this receptor, supporting the suggestion that the biological action of TAM is mediated by the ER. The biological and ultrastructural effects provoked by TAM (1 X 10(-6) M), estriol (E3)(5 X 10(-8) M) and the combination of TAM + E3 were studied in the R-27 mammary cancer cell line in culture. E3 stimulated the PR content by 7-10 times. However, TAM did not provoke a significant decrease in the concentration of PR, and in the mixture of TAM + E3 the concentration of PR was of the same order as that in E3 treatment. Ultrastructural observations indicate an intense concentration of ribosomes in the pericytoplasmic area after exposure to E3 and with exposure to TAM an increase in vacuoles and a significant enlargement of the size of the mitochondria were observed. It is concluded that TAM in the target tissues of fetal and newborn guinea pigs acts as a real estrogen and in the R-27 mammary cancer cell line TAM does not block the effect provoked by E3, however it does provoke intense ultrastructural modifications.

Animals↗
PubMed1991

Effects of sequential and combined immuno-endocrine therapies using OK-432 (Picibanil) and tamoxifen on the growth of 7,12-dimethylbenz [alpha] anthracene-induced rat mammary carcinoma.

Effects of sequential and combined immuno-endocrine therapies using OK-432 (Picibanil) and tamoxifen (TAM) on the growth of 7,12-dimethylbenz [alpha] anthracene (DMBA)-induced carcinoma were examined in 128 female Sprague-Dawley (SD) rats. The rats were divided into six groups: control (no treatment), tamoxifen, OK-432, simultaneous immuno-endocrine OK-432 and TAM (OK-432 + TAM) therapy, two types of sequential immuno-endocrine therapy of the OK-432 and TAM groups [OK-432 (1 wk)----TAM (4 wk) and OK-432 (2 wk)----TAM (3 wk)]. Each group was treated consecutively for five weeks. The response rates in the TAM alone group, the [OK-432 (1 wk)----TAM (4 wk)] group and the [OK-432 + TAM (5 wk)] group were significantly higher than in the control group. When the results among the treated groups were compared, the response rate in the [OK-432 (1 wk)----TAM (4 wk)] group was significantly higher than in the OK-432 alone or TAM alone groups. The response rate in the [OK-432 (2 wk)----TAM (3 wk)] group, however, was lower than in the TAM alone group. The response rate in the OK-432 + TAM group was, moreover, not significantly superior to that in the TAM alone group. These results suggest OK-432 not to potentiate the antitumor effect of TAM since the response rate of the combined OK-432/TAM therapy was not always significantly superior to that of the TAM treatment.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

Role of prolactin in modulating the effects of tamoxifen on growth of the Dunning R3327 rat prostate adenocarcinoma.

Tamoxifen (TAM) has previously been shown to inhibit growth of the Dunning R3327 rat prostate adenocarcinoma and to elevate serum prolactin levels. The purpose of this study was to determine the role of prolactin in modulating the effects of tamoxifen on growth of the R3327 prostatic adenocarcinoma. Intact and castrated Copenhagen-Fischer male rats bearing the Dunning R3327 rat prostatic tumor were divided into groups and injected sc five times per week for 16 weeks as follows: vehicle; TAM (0.5 mg/kg); haloperidol (HALO; 0.5 mg/kg); bromocriptine (CB-154; 5 mg/kg); TAM plus HALO; or TAM plus CB-154. In both intact and castrated rats, agents that either raised (HALO) or lowered (CB-154) serum prolactin had little effect on prostatic tumor growth when administered singly. In intact rats, average tumor diameter in vehicle-treated controls increased 421% 16 weeks after the start of the experiment, and treatment with TAM or TAM plus HALO reduced this tumor growth by approximately one-half. Interestingly, CB-154 administered in combination with TAM completely blocked TAM inhibition of tumor growth in intact rats. In contrast to these results in intact rats, average tumor diameter increased 129% in TAM- and 118% in TAM plus HALO-treated castrated rats and was significantly greater than the characteristic retardation of tumor growth (49% increase) that occurred in the vehicle-treated castrate controls. In addition, combined treatment of TAM plus CB-154 in castrate rats resulted in an even greater increase (188%) in average tumor diameter. The inhibitory effect of TAM on R3327 prostatic tumor growth in intact rats appears to be an indirect effect resulting from its ability to reduce serum testosterone levels. In contrast, the stimulatory effect of TAM in castrate rats appears to result directly from an estrogen-like action, which can directly enhance prostatic tumor growth in the presence of low levels of circulating androgens; this stimulatory effect of TAM is more pronounced when prolactin levels are suppressed by CB-154. Clearly, castration alone is more effective than TAM therapy alone or in combination with castration in the retardation of the growth of the androgen-dependent R3327 prostatic tumor in rats.

Adenocarcinoma↗