ANKHD1 contributes to the malignant phenotype of triple‐negative breast cancer cells

Abstract

Ankyrin repeat and KH domain-containing protein 1, ANKHD1, has been identified as a regulator of signaling pathways and cellular processes of relevance in carcinogenesis. However, the role of ANKHD1 in breast cancer remains unclear.The aim of the present study was to characterize the expression pattern and involvement of ANKHD1 in the malignant phenotype of breast cancer cell lines and to investigate the clinical relevance of ANKHD1 in a breast cancer context. Gene and protein expressions were assessed in the cell lines by quantitative reverse transcription PCR and Western blot analysis, respectively, and ANKHD1 silencing through siRNA transfection was conducted for further in vitro functional assays. The expression of ANKHD1 was identified in non-tumorigenic breast epithelium and breast cancer cell lines, but differences in cellular localization were found among the neoplasia subtypes. ANKHD1 silencing reduced the viability, clonogenicity, and migration of triple-negative breast cancer (TNBC) cells. Bioinformatics analyses demonstrated that patients with triple-negative basal-like 2 and mesenchymal breast cancer subtypes had high ANKHD1 expression associated with poor recurrence-free survival. Therefore, these data indicate that ANKHD1 relevance in breast cancer varies among its subtypes, indicating the importance of ANKHD1 in TNBC.

Evaluating the Molecular Properties and Function of ANKHD1, and Its Role in Cancer

“…The potential functional significance of the nuclear localisation of ANKHD1 remains largely unknown, and there is insufficient evidence as to whether the subcellular localisation is tissue/cell type dependent, although it has been proposed [ 38 ].…”

“…Colorectal cancer cells show increased levels of ANKHD1 and are associated with an increase in epithelial-to-mesenchymal transition, allowing increased cell mobility, possibly linking ANKHD1 to increased migration and the invasion of cancer cells [ 54 ]. Furthermore, increases in migration and invasiveness of cancer cells demonstrating high expression of ANKHD1 has also been described in hepatocellular carcinoma [ 61 ], breast cancer [ 38 ], non-small-cell lung cancer [ 53 ] and multiple myeloma [ 57 ] cells. Taken together, it is clear that increased expression of ANKHD1 is sufficient to sustain proliferation and growth [ 13 , 16 , 33 , 34 , 36 , 51 , 53 , 54 , 57 , 62 ] and to contribute to cellular invasion and metastasis [ 53 , 54 , 61 , 62 ] in multiple cancers.…”

“…Given that ANKHD1 overexpression is able to drive enhanced proliferation and cellular invasion of cancerous cells, it would be anticipated that overexpression of ANKHD1 may also impact cancer pathologies at a clinical level. This hypothesis was initially examined in breast cancer patients, where increased expression of ANKHD1 statistically correlates with a reduction in relapse-free survival (the length of time after the initial cancer treatment that the patient lives without any symptoms of that cancer [ 21 ]) [ 10 , 38 ], a change which varies depending on breast cancer subtype. Since this research, the clinical features correlating with increased levels of ANKHD1 have also been examined in colorectal cancer, non-small-cell lung carcinoma, and hepatocellular cancer.…”

“…Further work will need to be performed on the ANKHD1 isoforms to understand their individual functions. Breast Cancer [10,38] Increases the viability, clonogenicity and migration of aggressive breast cancer cell lines, possibly due to the positive regulation of the YAP/Yki pathway.…”

Nuclear Import and Export of YAP and TAZ

“…Accordingly, these proteins have been implicated in multiple functions, including proliferation, differentiation, cytoskeletal organization, and transcriptional control [141,[143][144][145]. Moreover, their dysregulation and role are increasingly recognized in the context of tumorigenesis/metastasis in various malignancies [139,143,144,[146][147][148]. Parallel discoveries in two laboratories have revealed that Mask binds Yorkie and acts as an important cofactor strongly potentiating the transcriptional activity of Yorkie and YAP [78,149].…”