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Updated: Jul 17, 2026
miRNA Expression Analyses in Prostate Cancer Clinical Tissues
Published on: September 8, 2015
Increased expression of SIM2-s protein is a novel marker of aggressive prostate cancer
Ole Johan Halvorsen1, Kari Rostad, Anne Margrete Øyan
1Sections for Pathology and Microbiology and Immunology, The Gade Institute and Department of Surgery, Haukeland University Hospital, Bergen, Norway.
Purpose:
The human SIM2 gene is located within the Down's syndrome critical region of chromosome 21 and encodes transcription factors involved in brain development and neuronal differentiation. SIM2 has been assigned a possible role in the pathogenesis of solid tumors, and the SIM2-short isoform (SIM2-s) was recently proposed as a molecular target for cancer therapy. We previously reported SIM2 among the highly up-regulated genes in 29 prostate cancers, and the purpose of our present study was to examine the expression status of SIM2 at the transcriptional and protein level as related to outcome in prostate cancer.
Experimental Design:
By quantitative PCR, mRNA in situ hybridization, and immunohistochemistry, we evaluated the expression and significance of SIM2 isoforms in 39 patients with clinically localized prostate cancer and validated the expression of SIM2-s protein in an independent cohort of 103 radical prostatectomies from patients with long and complete follow-up.
Results:
The SIM2 isoforms (SIM2-s and SIM2-l) were significantly coexpressed and increased in prostate cancer. Tumor cell expression of SIM2-s protein was associated with adverse clinicopathologic factors like increased preoperative serum prostate-specific antigen, high histologic grade, invasive tumor growth with extra-prostatic extension, and increased tumor cell proliferation by Ki-67 expression. SIM2-s protein expression was significantly associated with reduced cancer-specific survival in multivariate analyses.
Conclusions:
These novel findings indicate for the first time that SIM2 expression might be important for clinical progress of human cancer and support the recent proposal of SIM2-s as a candidate for targeted therapy in prostate cancer.
Insights
The SIM2 gene, particularly its short isoform (SIM2-s), is upregulated in prostate cancer and linked to poorer survival outcomes. This suggests SIM2-s may be a therapeutic target for prostate cancer treatment.
Area of Science:
- Genetics and Molecular Biology
- Oncology
- Cancer Research
Background:
- The SIM2 gene, located on chromosome 21, encodes transcription factors crucial for brain development.
- SIM2 has been implicated in solid tumor pathogenesis, with its short isoform (SIM2-s) proposed as a cancer therapy target.
- Previous studies identified SIM2 as highly upregulated in prostate cancer.
Purpose of the Study:
- To investigate the expression of SIM2 isoforms at transcriptional and protein levels in prostate cancer.
- To correlate SIM2 expression with patient outcomes in prostate cancer.
- To evaluate the potential of SIM2-s as a therapeutic target in prostate cancer.
Main Methods:
- Quantitative PCR and mRNA in situ hybridization were used to assess SIM2 isoform expression.
- Immunohistochemistry evaluated SIM2-s protein expression in 39 localized prostate cancer patients.
- Expression of SIM2-s protein was further validated in an independent cohort of 103 radical prostatectomies.
Main Results:
- SIM2 isoforms (SIM2-s and SIM2-l) were significantly coexpressed and increased in prostate cancer.
- SIM2-s protein expression correlated with adverse clinicopathologic factors, including higher PSA, grade, and extra-prostatic extension.
- Increased SIM2-s protein expression was significantly associated with reduced cancer-specific survival.
Conclusions:
- SIM2 expression is linked to clinical progression in prostate cancer.
- These findings support SIM2-s as a potential therapeutic target for prostate cancer.
- This study provides novel insights into the role of SIM2 in human cancer.
