Differential subcellular localisation of the tumour suppressor protein LIMD1 in breast cancer correlates with patient survival

Abstract

The tumour suppressor gene (TSG) LIM domain containing protein 1 (LIMD1) has been associated with transformation of epithelial cells of the lung and its expression is downregulated in all lung tumour samples tested compared to normal lung matched controls. In the first study of its kind we used an anti-LIMD1 specific monoclonal antibody to investigate expression/localisation of the LIMD1 protein in a well-characterised tissue microarray of breast cancers and normal adjacent epithelia. Comparison of tumour with adjacent normal and distant normal tissue demonstrated that LIMD1 expression is moderate to high compared to tumour. There was also a significant correlation with histological grade (p 5 0.0001), tumour size (p 5 0.013) and tumour type (p 5 0.004) indicating an association with aggressive disease. Cytoplasmic LIMD1 expression was seen in 99.3% of cases, with 43.1% showing both nuclear and cytoplasmic localisation. Absence/loss of nuclear staining showed a strong correlation with patient survival and was indicative of poor prognosis (p 5 0.033). There was no association with lymph node status and other clinicopathological parameters. Nuclear staining was more pronounced in better prognosis tumours and normal tissue. This study demonstrates that LIMD1 represents a novel prognostic marker for breast cancer. Combined with the fact that LIMD1 expression is downregulated in lung cancers this clearly indicates that LIMD1 may represent a critical TSG, the function of which is deregulated via overall loss of expression and/or relocalisation within the cell during tumour development. The possible functions of LIMD1 localisation within the nucleus and cytoplasm and its relationship to tumour prognosis are discussed. ' 2008 Wiley-Liss, Inc.Key words: LIMD1; Ajuba; breast cancer; E-cadherin; tissue microarray; prognostic indicator Breast cancer is the most common cause of cancer-related death in women in the western world. Alterations in tumour suppressor genes (TSG) and oncogenes are common causes for the higher proliferative rates and pathogenic characteristics associated with tumour development. Cytogenetics and allelotyping have shown that allelic loss from several distinct regions on chromosome 3p, including 3p25, 3p21-22, 3p21.3, 3p12-13 and 3p14, are the earliest and most frequent genomic abnormalities involved in a wide spectrum of major epithelial cancers of lung 1-6 and breast tissues 7-9 as well as many other epithelial derived cancers. [10][11][12][13] Specifically the 3p21.3 gene cluster contains many TSG and oncogenes and is a region of major loss of heterozygosity in lung cancers. [14][15][16] Abnormalities at the 3p21.3 chromosomal region include homozygous deletions, loss of heterozygosity and expressional deficiencies that can be induced through methylation of promoters, altered mRNA transcripts and loss of protein translocation. 17 The chromosome 3 commonly eliminated region (C3CER1) is located within the 3p21.3 gene cluster. The C3CER1 contains several putative TSG and is eliminated in many forms o...

A HIF – LIMD 1 negative feedback mechanism mitigates the pro‐tumorigenic effects of hypoxia

“…Finally, to investigate the clinical relevance and significance of our in vitro and in vivo findings in NSCLC, we examined LIMD1 protein expression in a tissue microarray of 276 lung cancer patients and investigated correlation with patient outcome (representative staining Fig A; marker distribution Fig B). In agreement with previous studies, LIMD1 protein expression was detected in both nuclear and cytoplasmic compartments (Sharp et al , ; Spendlove et al , ). Kaplan–Meier survival analysis demonstrated that patients exhibiting low LIMD1 expression within this cohort had significantly worse overall survival compared to those with high LIMD1 expression ( P = 0.045; Fig C).…”

“…The lung tumour suppressor protein LIMD1 is a member of the Zyxin family of adaptor proteins, initially characterised as signal transducers (Kadrmas & Beckerle, ) shuttling between the cytoplasm and nucleus. LIMD1 loss has been identified in lung, breast, head and neck squamous cell carcinomas, and adult acute leukaemia (Sharp et al , , ; Spendlove et al , ; Ghosh et al , ; Liao et al , ), and its decreased expression in diffuse large B‐cell lymphoma has clinical significance to patient prognosis and disease classification/stratification (Xu et al , ). Limd1 ‐knockout mice have increased lung tumour numbers and volume and decreased survival rate compared to Limd1‐ expressing control mice when either challenged with a chemical carcinogen or cross‐bred with Kras G12D mice (Sharp et al , ) validating its critical role in normal cellular homeostasis.…”

Reduced Expression of Limd1 in Ulcerative Oral Epithelium Associated with Tobacco and Areca Nut

“…Reduced expression of LIMD1 in ulcerative epithelium might be due to its promoter methylation, deletion, or mutation as seen in oral dysplastic and carcinoma samples . Inactivation of LIMD1 has also been reported in carcinomas of breast and lung (Sharp et al, 2008;Spendlove et al, 2008). In addition to stabilization of RB-E2F interaction, LIMD1 regulates cell-cell interaction, miRNA mediated gene silencing, cellular differentiation etc (Foxler et al, 2011).…”

PUMA is a novel target of miR-221/222 in human epithelial cancers

“…Lung cancer and breast cancer, the common forms of human epithelial cancers, are the most frequent causes of cancerrelated death worldwide, and their incidences are increasing (1,2). In most instances, multiple genetic changes including activation of proto-oncogenes and inactivation of tumor suppressor gene are involved in the development and progression of human epithelial cancers (3).…”