AB122. The structure and function of NKAIN2—a candidate tumor suppressor

Objective: The deletion of chromosomal region 6q was commonly found in several types of human cancers, although the tumour suppressor genes (TSGs) located within this genomic region are not well established. Our recent work detected recurrent chromosomal truncation at the Na+/K+ transporting ATPase interacting 2 (NKAIN2) gene, which was also found to be truncated in leukemia and lymphoma, suggesting that NKAIN2 is potentially one of the TSGs located in the 6q commonly deleted region in human cancers. Further genetic and cellular functional are required to confirm its tumour suppressor role.

Methods: We review the basic structure and biological function of NKAIN2 by published articles to find out existing evidence to support its role in tumorigenesis, emphasizing its role in prostate cancer.

Results: NKAIN2 gene consists of eight coding exons that span approximately 1 Mb of genomic DNA on chromosome 6q and there are four main splice variants. The function of this gene is not well investigated and the limited knowledge of this gene pointed to nervous system development. The chromosomal translocations in nervous development disorders usually lead to inactivation of this gene. In human tumours, both chromosomal deletion and translocation may also inactivate this gene and consequently contribute to tumorigenesis.

Conclusions: We speculate that NKAIN2 could be a novel tumor suppressor on the 6q commonly deleted chromosomal region in human cancer and propose further researches required to investigate its potential tumor suppresser role. With the deepening of its involvement in human cancer and its cellular function, the role of NKAIN2 in tumorigenesis will be uncovered, which may impact the treatment of human malignancy.

Keywords: Chromosomal deletion; genomic rearrangement; tumor suppressor gene; NKAIN2 (TCBA1)