Related Experiment Video
Updated: Sep 22, 2025
Generation of High Quality Chromatin Immunoprecipitation DNA Template for High-throughput Sequencing ChIP-seq
Published on: April 19, 2013
N-type calcium channel v2.2 is a target of TCF21 in adrenocortical carcinomas
Barbara Dos Santos Passaia1, Jean Lucas Kremer1, Maria Candida Villares Fragoso2
1Department of Anatomy, Institute of Biomedical Science, University of Sao Paulo, Sao Paulo, Brazil.
Abstract:
Transcription factor 21 (TCF21) directly binds and regulates SF1 mRNA expression in tumor and normal adrenocortical cells, and both are involved in the development and steroidogenesis of the adrenal cortex. TCF21 is a tumor suppressor gene and its expression is reduced in malignant tumors. In adrenocortical tumors, it is less expressed in adrenocortical carcinomas (ACC) than in adrenocortical adenomas (ACA) and normal tissues. However, a comprehensive analysis to identify TCF21 targets has not yet been conducted in any type of cancer. In this study, we performed Chromatin Immunoprecipitation and Sequencing (ChIP-Seq) in an adrenocortical carcinoma cell line (NCI-H295R) overexpressing TCF21, with the aim of identifying TCF21 new targets. The five most frequently identified sequences corresponded to the PRDM7, CNTNAP2, CACNA1B, PTPRN2, and KCNE1B genes. Validation experiments showed that, in NCI-H295R cells, TCF21 negatively regulates the expression of the CACNA1B gene. Recently, it was observed that the N-type calcium channel v2.2 (Cav2.2) encoded by the CACNA1B gene is important in Angiotensin II signal transduction for corticosteroid biosynthesis in NCI-H295R adrenocortical carcinoma cells. Indeed, TCF21 inhibits CACNA1B and Cav2.2 expression in NCI-H295R. In addition, in a cohort of 55 adult patients with adrenocortical tumors, CACNA1B expression was higher in ACC than ACA and was related to poor disease-free survival in ACC patients. These results suggest a mechanism of steroidogenesis control by TCF21 in adrenocortical tumor cells, in addition to the control observed through SF1 inhibition. Importantly, steroid production could impair tumor immunogenicity, contributing to the immune resistance described in adrenal cancer.
Insights
Transcription factor 21 (TCF21) suppresses adrenocortical tumor growth by inhibiting CACNA1B expression, a gene linked to poor survival in adrenal cancer patients. This reveals a new TCF21-mediated pathway controlling steroidogenesis and potentially immune resistance.
Area of Science:
- Endocrinology
- Oncology
- Molecular Biology
Background:
- Transcription factor 21 (TCF21) is a tumor suppressor in the adrenal cortex, with decreased expression in malignant tumors.
- TCF21 regulates SF1 mRNA, impacting adrenal cortex development and steroidogenesis.
- A comprehensive analysis of TCF21 targets in cancer was lacking.
Purpose of the Study:
- To identify novel TCF21 target genes in adrenocortical carcinoma.
- To elucidate the role of TCF21 in regulating steroidogenesis and tumor progression.
Main Methods:
- Chromatin Immunoprecipitation and Sequencing (ChIP-Seq) in NCI-H295R cells overexpressing TCF21.
- Gene expression analysis (RT-qPCR) to validate TCF21 targets.
- Analysis of CACNA1B expression in patient tumor cohorts.
Main Results:
- ChIP-Seq identified PRDM7, CNTNAP2, CACNA1B, PTPRN2, and KCNE1B as potential TCF21 targets.
- TCF21 was confirmed to negatively regulate CACNA1B expression in NCI-H295R cells.
- CACNA1B expression was elevated in adrenocortical carcinomas (ACC) compared to adenomas (ACA) and correlated with poorer disease-free survival in ACC patients.
- TCF21 inhibits CACNA1B and Cav2.2 expression, impacting steroid biosynthesis.
Conclusions:
- TCF21 exerts tumor suppressive functions in adrenocortical cells by inhibiting CACNA1B and Cav2.2 expression.
- This TCF21-CACNA1B pathway represents a novel mechanism for steroidogenesis control in adrenal tumors.
- Elevated CACNA1B expression in ACC suggests its role in tumor progression and immune evasion.
More Related Videos
Related Concept Videos
01:05Cancer-Critical Genes II: Tumor Suppressor Genes
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
01:26Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors...
01:09GPCRs Regulate Adenylyl Cylase Activity
01:19Cadherins in Tissue Organization
Cell Sorting During Development
Cell sorting plays an...
02:57Targeted Cancer Therapies
There are several types of targeted therapies against...
01:20The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...