metallothionein and Fibrosarcoma

Feline injection site fibrosarcoma is an aggressive and infiltrative tumour arising in the background of chronic inflammation. The aim of this study was to evaluate the expression of metallothionein (I-II) in feline injection site fibrosarcomas and to assess its possible relationships with Ki67 index, inflammation score and tumour grade. The study included 40 feline fibrosarcomas, located in the common injection sites (i.e., interscapular area, thigh, flank), constituting archival diagnostic specimens collected between 2019-2020. Tumours were graded histologically according to the newly proposed soft-tissue sarcoma grading system in cats. Immunohistochemistry was performed to evaluate the expression of Ki67 and metallothionein in tumour cells.. The cytoplasmic and sometimes nuclear expression of metallothionein was observed in all tumours grade I, 66.67% of tumours grade II and 55% of tumours grade III. The expression of metallothionein was negatively correlated with tumour grade and inflammation score, while the Ki67 index was positively correlated with tumour grade, inflammation score and necrosis score.. The downregulation of MT expression in feline injection site fibrosarcomas seems to be connected with an increase in the inflammatory infiltration, hence tumour progression. This is the first study describing metallothionein expression in feline injection site fibrosarcomas.

Topics: Animals; Cat Diseases; Cats; Down-Regulation; Fibrosarcoma; Injection Site Reaction; Ki-67 Antigen; Metallothionein; Soft Tissue Neoplasms

Attenuation of the renal toxicity of cis-diamminedichloroplatinum (CDDP) is important in the use of this effective but cytotoxic anticancer agent. We have previously shown that the renal toxicity of CDDP can be efficiently reduced by the induction of metallothionein (MT) by preadministration of bismuth compounds in mice. Bismuth subnitrate (BSN) is used as an antigastric ulcer agent and as an antidiarrheic agent, and is suitable for inducing MT in the kidney in cancer patients. However, due to the low absorption rate of Bi from the gastrointestinal tract, the efficacy of BSN in inducing renal MT is low. In the present study, we examined the effects of citrate as a vehicle for oral administration of BSN on the tissue distribution of Bi and induction of MT in the kidneys and tumors in mice inoculated with Meth-A fibrosarcoma. Renal levels of MT and Bi were markedly increased in the mice given BSN dissolved in citrate solution compared with those given BSN suspended in saline. On the other hand, the use of citrate increased Bi accumulation in the tumor only slightly and did not increase tumor MT levels. Administration of BSN with citrate efficiently depressed the renal toxicity of CDDP, but did not affect its antitumor activity. Since both BSN and citrate are used clinically as pharmaceuticals, the combination regimen of BSN and citrate may be readily applicable as a countermeasure against the adverse side effects of CDDP without affecting its antitumor activity.

Topics: Administration, Oral; Animals; Bismuth; Cisplatin; Citric Acid; Drug Synergism; Fibrosarcoma; Kidney; Kidney Diseases; Male; Metallothionein; Mice; Mice, Inbred Strains; Neoplasm Transplantation; Protective Agents; Tissue Distribution

Effect of propargylglycine (2-Amino-4-pentynoic acid, PPG) on invasive property of human fibrosarcoma HT-1080 cell was investigated. PPG treatment of HT-1080 significantly reduced the total cellular metallothioneins (MTs) contents, and the resistance of HT-1080 against heavy metals toxicity decreased with the decrease of the MTs contents. The HT-1080 cell invasion to reconstituted basement membrane Matrigel (MG) was inhibited by the PPG treatment in a PPG concentration-dependent fashion. The inhibition was due to the lowering of HT-1080 cells attachment to MG and degradation activity of matrix metalloproteinases (MMPs) secreted from HT-1080 by the PPG treatment. However, the chemotactic ability of the PPG treated HT-1080 was enhanced. Our results suggest that MTs concentration levels in a malignant tumor cell are closely related to its invasiveness, and if MTs level of tumor cell can be controlled, cancer metastasis may be able to be controlled.

Topics: Alkynes; Cadmium; Chemotaxis; Collagen; Copper; Dose-Response Relationship, Drug; Drug Combinations; Fibronectins; Fibrosarcoma; Glycine; Humans; Laminin; Metallothionein; Neoplasm Invasiveness; Platinum; Proteoglycans; Time Factors; Tumor Cells, Cultured

Invasive properties of tumor cells having acquired heavy metal resistance were investigated. We selected the cadmium-resistant (Cd-R) cells from human fibrosarcoma HT-1080 cells. Total metallothionein levels in cytosol of HT-1080 Cd-R cells were significantly higher than original lines, and were of a highly resistant potency to cytotoxicity of cisplatin, as well as heavy metals. The HT-1080 Cd-R cells showed higher invasiveness into recombinant basement membrane Matrigel. However, HT-1080 Cd-R cells were inferior in locomotion ability. Significant differences in adhesive ability to extracellular matrix proteins were not observed between HT-1080 and HT-1080 Cd-R cells. High invasiveness of HT-1080 Cd-R cells was caused by their extremely strong enzymatic activities. High level of 92kDa matrix metalloproteinase-9 (MMP-9) was recognized from the conditioned medium of HT-1080 Cd-R cells, whereas 72kDa MMP-2 was secreted equally from both cell lines. Our investigation suggests that drug resistance acquired through the mechanisms of cellular metal-tolerance may promote malignancy and tumor metastasis during cancer chemotherapy.

Topics: Cadmium; Drug Resistance, Neoplasm; Fibrosarcoma; Humans; Metallothionein; Neoplasm Invasiveness; Tumor Cells, Cultured

A protective role for metallothionein (MT) in cellular injury caused by ionizing radiation has been proposed. To elucidate the role of MT in the sensitivity of tumors to radiation, we examined the effectiveness of radiation treatment of tumors with altered synthesis of MT after injection of tumor-bearing mice with zinc and/or propargyl glycine (PPG). The mice were inoculated with Meth-A fibrosarcoma cells and the antitumor activity of X radiation was tested in mice with and without induced synthesis of MT. Exposure to X radiation decreased the tumor weight markedly. In mice pretreated with zinc to induce MT, the tumor weight did not change compared to the controls. However, injection of PPG, an inhibitor of cystathionase, decreased the zinc-induced MT synthesis in the tumors and also decreased the tumor weight after exposure to X radiation. These results suggest that in radiation therapy one of the factors involved in radiosensitivity may be the expression of MT in certain tumors.

Topics: Alkynes; Animals; Enzyme Inhibitors; Fibrosarcoma; Glycine; Male; Metallothionein; Mice; Mice, Inbred BALB C; Mice, Inbred Strains; Radiotherapy Dosage; X-Rays; Zinc Sulfate

Glial fibrillary acidic protein (GFAP) is an intermediate filament protein expressed almost exclusively by glial cells of the central nervous system. We have previously transfected GFAP-negative human astrocytoma cells with the gene for GFAP and have demonstrated that GFAP transfection decreases astrocytoma proliferation and alters astrocytoma morphology. To determine if the same cellular responses could be elicited upon GFAP transfection of nonglial tumor cells, in the present study we have transfected a GFAP-negative human malignant fibrosarcoma cell line (HT-1080) with a cDNA containing the entire coding sequence of the human GFAP gene under the control of an inducible metallothionein promoter. Stably transfected HT-1080 clones were identified that are GFAP-positive by PCR and immunocytochemistry. GFAP-positive HT-1080 fibrosarcoma cells also demonstrate a decrease in tumor cell proliferation, altered morphological features characterized by cell elongation and cytoplasmic process formation, and reduction of invasive potential when compared to controls. These findings suggest that the inducible expression of the cytoskeletal protein GFAP can also be associated with dramatic cellular effects in nonglial non-central nervous system tumor cells.

Topics: Agar; Blotting, Western; Cell Division; Cloning, Molecular; Collagen; Drug Combinations; Extracellular Matrix; Fibrosarcoma; Gene Expression Regulation, Neoplastic; Genetic Testing; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Laminin; Metallothionein; Neoplasm Invasiveness; Promoter Regions, Genetic; Proteoglycans; Thymidine; Transfection; Tritium; Tumor Cells, Cultured

The invasiveness of tumour cells to heavy metal-exposed host cells or tissues was investigated. Human fibrosarcoma cell invasion of heavy metal-treated fibroblast or endothelial cell was enhanced in a treatment-time-dependent manner although tumour cell attachment to host cells was not affected. This enhancement was correlated with an increase in metallothioneins in the cytosol of fibroblasts or endothelial cells. Mouse melanoma cell invasion of organ samples obtained from syngeneic mice who had been administered heavy metals was also enhanced. The results suggest that heavy metal-induced metallothioneins serve as a host-derived factor in malignant disease and closely relate to metastasis.

Topics: Animals; Cadmium; Cisplatin; Fibrosarcoma; Humans; Metallothionein; Metals, Heavy; Mice; Mice, Inbred C57BL; Neoplasm Invasiveness; Tumor Cells, Cultured; Zinc

Although recent studies have shown that radiation can induce metallothionein (MT) synthesis in normal tissues, the induction of tumor MT synthesis by irradiation has not been reported. We examined the accumulation of MT in the Meth-A tumor (mouse fibrosarcoma cells) transplanted into mice exposed to whole-body X irradiation. In the present study, the MT content in the tumor cells was increased by X irradiation in a dose-dependent manner. The MT level induced in the tumor cells by X irradiation was elevated not only after a single exposure but also after repeated exposures. Several studies have shown that MT is one of the important cellular factors in resistance to various anticancer drugs and ionizing radiation. Thus our results suggest that the radiation-induced MT in the tumor cells may have to be taken into consideration when designing protocols for radio- and chemotherapy.

Topics: Animals; Fibrosarcoma; Metallothionein; Mice; Mice, Inbred Strains; Neoplasm Transplantation; Whole-Body Irradiation

The expression of metallothionein (MT) in certain tumor cells has been associated with resistance to anticancer drugs. In the present study, we examined the effects of inhibition of MT synthesis on resistance to anticancer drugs of human bladder tumor which were inoculated in nude mice. The results show that pretreatment of tumor-bearing mice with zinc salts increased MT content, both in normal and tumor tissues, with a marked reduction in the antitumor activity of cisplatin, Adriamycin, and melphalan. Injection of propargylglycine, an inhibitor of cystathionase, decreased MT induction by zinc in the tumor and diminished the resistance to these drugs. These results suggest a role for MT in drug resistance in tumors, and injection of propargylglycine may provide a potential means to overcome drug resistance caused by elevation of MT levels in certain tumors.

Topics: Alkynes; Animals; Cisplatin; Colonic Neoplasms; Cysteine; Doxorubicin; Drug Resistance; Female; Fibrosarcoma; Glycine; Humans; Male; Melphalan; Metallothionein; Mice; Mice, Inbred BALB C; Mice, Inbred ICR; Mice, Nude; Pargyline; Sulfates; Tumor Cells, Cultured; Urinary Bladder Neoplasms; Zinc Compounds; Zinc Sulfate

Cisplatin-resistant mouse fibrosarcoma cells, SSK-R, were isolated after short and low-dose drug treatment of the sensitive SSK cells in vitro. These SSK-R sublines exhibit up to sevenfold cisplatin resistance and are characterized mainly by an increased metallothionein content. Loss of drug resistance after about 140-180 cell divisions in drug-free medium coincides with loss of metallothionein content. The glutathione level is the same in the sensitive and resistant sublines; inhibition of glutathione synthesis by buthionine sulphoximine enhances the sensitivity in both cells lines by a factor of 2.7. The resistant sublines are not cross-resistant to radiation; a radiation exposure followed immediately by cisplatin treatment results in an additive effect. The cellular cisplatin content is slightly reduced in SSK-R2 cells and it remains at this level also upon loss of drug sensitivity.

Topics: Animals; Cadmium Radioisotopes; Cell Survival; Cisplatin; Drug Resistance; Fibrosarcoma; Glutathione; Metallothionein; Mice; Platinum; Spectrometry, X-Ray Emission; Tumor Cells, Cultured

Cisplatin resistant mouse fibrosarcoma cells were isolated after fractionated irradiation in the absence of any drug treatment. Several sublines have been established; clone SSK-rad1 was used for further studies. These cells exhibit unchanged radiosensitivity and are compared to cisplatin resistant sublines, SSK-cis2, previously induced by low dose cisplatin exposure. Both resistant sublines are characterised by reduced CdCl2 sensitivity, indicating enhanced metallothionein content; loss of cisplatin resistance occurs after 10 to 25 generations and correlates with rising CdCl2 toxicity. Increase of MT is demonstrated directly by 109Cd binding to the MT containing region after FPLC. Both sublines differ in GSH level, which is increased only in SSK-rad1 cells, and in cellular platinum content, which is reduced in SSK-cis2 cells compared to the parental SSK cell line. These factors may contribute to cisplatin resistance but are not the main cause responsible for the transient nature of the drug resistance observed. Our results indicate that transient cisplatin resistance in SSK cells can be induced not only by the drug itself but also by gamma-irradiation and is based on the same mechanism of increased cellular MT content.

Topics: Animals; Cadmium; Cell Survival; Cisplatin; Dose-Response Relationship, Drug; Drug Resistance; Fibrosarcoma; Gamma Rays; In Vitro Techniques; Metallothionein; Mice; Tumor Cells, Cultured

Suppression of plasminogen activator (PA) activity has been invoked as being part of the general anti-inflammatory action of glucocorticoids. Low concentrations of the synthetic glucocorticoid, dexamethasone (Dex), reduce urokinase-type PA mRNA levels in two cell types, namely a human fibrosarcoma line, HT1080, and synovial fibroblast-like cells isolated from human joints. Conversely, metallothionein IIa (MTIIa) mRNA levels in these cells are raised by Dex. These findings, by suggesting that it is possible to suppress urokinase-type PA activity at the level of gene expression, may have therapeutic implications for diseases such as rheumatoid arthritis where proteases may be contributing to the extensive tissue damage and inflammation.

Topics: Cell Line; Dexamethasone; Fibroblasts; Fibrosarcoma; Genes; Humans; Metallothionein; RNA, Messenger; Synovial Fluid; Transcription, Genetic; Urokinase-Type Plasminogen Activator