Metallothionein 1E mRNA is highly expressed in oestrogen receptor-negative human invasive ductal breast cancer

Jin, Rong; Bay, Boon‐Huat; Chow, Vincent T.K.; Tan, Puay‐Hoon; Lin, Valerie Chun Ling

doi:10.1054/bjoc.2000.1276

Cited by 42 publications

(22 citation statements)

References 29 publications

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“…Higher basal MT expression is associated with p53 mutations in breast cancer cells (Friedline et al, 1998;Jin et al, 2000). Both factors indicate and may contribute to progression and poor prognosis of the cancer.…”

Section: Discussionmentioning

confidence: 99%

Potential role of p53 on metallothionein induction in human epithelial breast cancer cells

Fan

Cherian

2002

Br J Cancer

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The expression and induction of metallothionein has been associated with protection against oxidative stress and apoptosis. This study examines the effect of tumour suppressor protein p53 on metallothionein expression following CdCl 2 treatment in eight human epithelial breast cancer cell lines differing in p53 and oestrogen-receptor status. Cells were treated with 10 mM CdCl 2 for 24 h and metallothionein protein levels were measured by cadmium binding assay. MCF7 cells which are p53-positive (p53+) and oestrogen-receptor-positive showed a large induction in metallothionein synthesis by 10.79+1.36-fold. Other breast cancer cell lines which are p53-negative (p537) and oestrogen-receptor-negative or weakly oestrogenreceptor-positive showed a small induction ranging from 1.40+0.10 to 3.65+0.30-fold. RT -PCR analysis showed an induction of metallothionein mRNA in MCF7 cells by about 1.61+0.08-fold, while in HCC1806 cells (p537, oestrogenreceptor-negative) by 1.11+0.13-fold, and in MDA-MB-231 (p537, oestrogen-receptor-negative) by 1.25+0.06-fold. Metallothionein localisation was determined by immunohistochemical staining. Prior to metal treatment, metallothionein was localised mainly in the cytoplasm of MCF7 and MDA-MB-231 cells. After treatment with 10 mM CdCl 2 for 24 h, MCF7 cells showed intense nuclear and cytoplasmic staining for metallothionein, while MDA-MB-231 cells showed staining in the cytoplasm with weak nuclear staining. Apoptosis induced by 10 -40 mM CdCl 2 at time points between 4 and 48 h was examined with TUNEL assay. In MCF7 cells, apoptosis increased with higher concentrations of CdCl 2 , it peaked at 6 -8 h and appeared again at 48 h for all concentrations of CdCl 2 tested. In MDA-MB-231 cells, apoptosis remained at low levels for 10 -40 mM CdCl 2 at all time points. Studies on cadmium uptake showed similar uptake and accumulation of cadmium at 8 and 24 h in all the cell lines. The data demonstrate that treatment of epithelial breast cancer cells with 10 mM CdCl 2 for 24 h caused a greater induction of metallothionein protein and mRNA expression in p53+ and oestrogen-receptor-positive cells as compared to p537 and oestrogen-receptor-negative or weakly oestrogen-receptor-positive cells. This effect may be associated with the occurrence of apoptosis and suggests a role for p53 and oestrogen-receptor on the expression and induction of metallothionein in epithelial cells.

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Section: Discussionmentioning

confidence: 99%

Potential role of p53 on metallothionein induction in human epithelial breast cancer cells

Fan

Cherian

2002

Br J Cancer

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“…Despite efforts made to improve the resolution and sensitivity of chromatography methods in detecting MT protein isoforms [5], there are limitations imposed by the sensitivity and stability of the MT proteins. This has led to the analysis of MT isoforms at the transcriptional or mRNA level [4, [23][24][25]37].…”

Section: Reverse Transcription-polymerase Chain Reaction Rt-pcr Amentioning

confidence: 99%

“…The advantage of the RT-PCR strategy is that the resultant PCR product itself can be analyzed to determine if the primer pairs chosen for analysis are indeed specific for the individual MT isoform. The majority of studies on MT isoforms have been based on RT-PCR methods [4, 13,[23][24][25]37]. An example of the MT 1E and MT 1F mRNA transcripts detected by RT-PCR in breast cancer is shown in Fig.…”

Section: Reverse Transcription-polymerase Chain Reaction Rt-pcr Amentioning

confidence: 99%

“…MT-2A and 1E isoforms have also been reported to be increased in PMC42 breast cancer cells as a protective mechanism against metal toxicity [5]. In breast cancer tissues, MT-1E isoform has been observed to be associated with the estrogen receptor status [24] and MT-1F with histological grade [25].…”

Section: Reverse Transcription-polymerase Chain Reaction Rt-pcr Amentioning

confidence: 99%

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Analysis of Metallothionein Expression in Human Cancers.

Bay

Jin

Jayasurya

2001

Acta Histochem. Cytochem

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“…Expression of MT-3 is associated with poor prognosis (23,24). The MT-1E isoform is found in estrogen-receptor-negative (ER Ϫ ), but not estrogen-receptor-positive (ER ϩ ), tumors (25) and cell lines (26). Parallel assessment of changes in MT protein expression via immunohistochemistry supports the mRNA data up to a point.…”

mentioning

confidence: 99%

Quantitation of Human Metallothionein Isoforms: A Family of Small, Highly Conserved, Cysteine-rich Proteins

Mehus

Muhonen

Garrett

et al. 2014

Molecular & Cellular Proteomics

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Human metallothioneins (MTs) are important regulators of metal homeostasis and protectors against oxidative damage. Their altered mRNA expression has been correlated with metal toxicity and a variety of cancers. Current immunodetection methods lack the specificity to distinguish all 12 human isoforms. Each, however, can be distinguished by the mass of its acetylated, cysteine-rich, hydrophilic N-terminal tryptic peptides. These properties were exploited to develop a bottom-up MALDI-TOF/TOF-MS-based method for their simultaneous quantitation. Key features included enrichment of N-terminal acetylated peptides by strong cation exchange chromatography, optimization of C18 reversed-phase chromatography, and control of methionine oxidation. Combinations of nine isoforms were identified in seven cell lines and two tissues. Relative quantitation was accomplished by comparing peak intensities of peptides generated from pooled cytosolic proteins alkylated with 14 N-or 15 N-iodoacetamide. Absolute quantitation was achieved using 15 Niodoacetamide-labeled synthetic peptides as internal standards. The method was applied to the cadmium induction of MTs in human kidney HK-2 epithelial cells expressing recombinant MT-3. Seven isoforms were detected with abundances spanning almost 2 orders of magnitude and inductions up to 12-fold. The protein-to-mRNA ratio for MT-1E was one-tenth that of other MTs, suggesting isoform-specific differences in protein expression efficiency. Differential expression of MT-1G1 and MT-1G2 suggested tissue-and cell-specific alternative splicing for the MT-1G isoform. Protein expression of MT isoforms was also evaluated in human breast epithelial cancer cell lines. Estrogen-receptor-positive cell lines expressed only MT-2 and MT-1X, whereas estrogen-receptor-negative cell lines additionally expressed MT-1E. The combined expression of MT isoforms was 38-fold greater in estrogen-receptornegative cell lines than in estrogen-receptor-positive cells. These findings demonstrate that individual human MT isoforms can be accurately quantified in cells and tissues at the protein level, complementing and expanding mRNA measurement as a means for evaluating MTs as potential biomarkers for cancers or heavy metal toxicity. Molecular & Cellular

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Metallothionein 1E mRNA is highly expressed in oestrogen receptor-negative human invasive ductal breast cancer

Cited by 42 publications

References 29 publications

Potential role of p53 on metallothionein induction in human epithelial breast cancer cells

Potential role of p53 on metallothionein induction in human epithelial breast cancer cells

Analysis of Metallothionein Expression in Human Cancers.

Quantitation of Human Metallothionein Isoforms: A Family of Small, Highly Conserved, Cysteine-rich Proteins

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