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Increasing expression of GST-pi MIF, and ID1 genes in chemoresistant prostate cancer cells
1Uro-Oncology Laboratory, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China. yuds@ms21.hinet.net
Abstract:
The differential expression of genes and related proteins of multidrug resistance in chemoresistant prostate cancer cell lines were elucidated in this study. RNA extracted from doxorubicin-resistant rat prostate cancer (PCa) cells (AT3/ADR1000) and native PCa cells was hybridized to expression arrays containing cDNAs from 588 known genes. Differential expression of selected genes was confirmed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis. Protein contents were measured by fluorescent flow cytometry and immunoblotting. Localization of selected proteins in cells was observed by immunocytochemical staining. Up-regulation of eleven genes and down-regulation of one single gene were displayed in the chemoresistant prostate cancer cells. Overexpression of mRNAs in macrophage migration inhibitory factor (MIF), DNA binding protein inhibitor 1 (ID1), and glutathione S-transferase-pi (GST-pi) were confirmed by gene-specific RT-PCR. Protein over-expression of GST-pi, MIF, and ID1 in resistant cells were 3.3-, 1.5-, and 1.5-fold to native cells, respectively. Immunocytochemistry revealed that GST-pi, MIF, and ID1 were present primarily in the cytoplasm of tumor cells, but ID1 also could be found in the nucleus. AT3/ADR1000 drug-resistant PCa cells displayed significantly increased expression of GST-pi, MIF, and ID1 proteins when compared with native PCa cells. It indicates these genes may play a role in drug resistance of prostate cancer.
Insights
Chemoresistant prostate cancer cells show increased expression of macrophage migration inhibitory factor (MIF), DNA binding protein inhibitor 1 (ID1), and glutathione S-transferase-pi (GST-pi). These genes may play a role in developing drug resistance in prostate cancer.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Prostate cancer (PCa) can develop resistance to chemotherapy, limiting treatment efficacy.
- Understanding the molecular mechanisms of multidrug resistance (MDR) is crucial for improving therapeutic strategies.
Purpose of the Study:
- To elucidate the differential gene and protein expression related to multidrug resistance in chemoresistant prostate cancer cell lines.
- To identify specific genes and proteins associated with doxorubicin resistance in rat PCa cells.
Main Methods:
- Gene expression profiling using cDNA expression arrays.
- Quantitative reverse-transcription polymerase chain reaction (RT-PCR) for gene expression validation.
- Fluorescent flow cytometry and immunoblotting for protein content analysis.
- Immunocytochemical staining for protein localization.
Main Results:
- Eleven genes were up-regulated and one gene was down-regulated in chemoresistant PCa cells (AT3/ADR1000) compared to native cells.
- Overexpression of macrophage migration inhibitory factor (MIF), DNA binding protein inhibitor 1 (ID1), and glutathione S-transferase-pi (GST-pi) mRNAs was confirmed.
- Protein overexpression of GST-pi (3.3-fold), MIF (1.5-fold), and ID1 (1.5-fold) was observed in resistant cells.
- GST-pi, MIF, and ID1 proteins were primarily localized in the cytoplasm, with ID1 also found in the nucleus.
Conclusions:
- The study identified significant overexpression of GST-pi, MIF, and ID1 proteins in drug-resistant PCa cells.
- These genes (GST-pi, MIF, ID1) are implicated as potential contributors to multidrug resistance in prostate cancer.
- Further investigation into these genes could lead to novel therapeutic targets for overcoming chemoresistance.
