title: A novel cancer testis antigen target A-kinase anchor protein (AKAP4) for the early diagnosis and immunotherapy of colon cancer.
abstract: Colorectal cancer (CRC) is mainly a disease of developed countries and a major cause of death worldwide. The present study was undertaken to investigate the association of novel cancer testis (CT) antigen, A-kinase anchor protein (AKAP4) with CRC. AKAP4 gene and protein was examined by RT-PCR,in situhybridization and immunohistochemistry (IHC) in 200 clinical specimens of different stages and grades. In addition, humoral response against AKAP4 was detected by enzyme-linked immunosorbent assay and Western blotting in 172 available sera samples of CRC patients. We observed that majority of CRC patients demonstrated AKAP4 expression and elicited immune response. AKAP4 protein expression, based on immunoreactivity score (IRS) predicted presence of CRC with 84% sensitivity, 100% specificity, 100% of positive predictive value (PPV) and 83.33% negative predictive value (NPV). Humoral response against AKAP4 protein was generated in 82% of the CRC patients. Further, statistical analysis revealed that antibodies found against AKAP4 in CRC patients predicted presence of malignancy with 81.98% sensitivity, 100% specificity, 100% PPV, and 63.53% NPV. Collectively, our data suggests that the majority of CRC cases show significant difference of AKAP4 expression among stages and grades and also generated antibodies against AKAP4 protein. Therefore, AKAP4 may be potential candidate molecule for developing as a biomarker for early diagnosis and immunotherapy of CRC.
authors.affiliation: Cancer Microarray, Genes and Proteins Laboratory, National Institute of Immunology , Aruna Asaf Ali Marg , New Delhi, India.
authors.forename: Nirmala
authors.initials: N
authors.lastname: Jagadish
authors.affiliation: Cancer Microarray, Genes and Proteins Laboratory, National Institute of Immunology , Aruna Asaf Ali Marg , New Delhi, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Parashar
authors.affiliation: Cancer Microarray, Genes and Proteins Laboratory, National Institute of Immunology , Aruna Asaf Ali Marg , New Delhi, India.
authors.forename: Namita
authors.initials: N
authors.lastname: Gupta
authors.affiliation: Cancer Microarray, Genes and Proteins Laboratory, National Institute of Immunology , Aruna Asaf Ali Marg , New Delhi, India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Agarwal
authors.affiliation: Cancer Microarray, Genes and Proteins Laboratory, National Institute of Immunology , Aruna Asaf Ali Marg , New Delhi, India.
authors.forename: Aditi
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Cancer Microarray, Genes and Proteins Laboratory, National Institute of Immunology , Aruna Asaf Ali Marg , New Delhi, India.
authors.forename: Rukhsar
authors.initials: R
authors.lastname: Fatima
authors.affiliation: Department of Pathology, All India Institute of Medical Sciences , New Delhi, India.
authors.forename: Vaishali
authors.initials: V
authors.lastname: Suri
authors.affiliation: Institute of Rotary Cancer Hospital, All India Institute of Medical Sciences , New Delhi, India.
authors.forename: Rajive
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Department of Pathology, NMC Imaging and Diagnostic Centre, Vidyasagar Institute of Mental Health and Neuro-Sciences , New Delhi, India.
authors.forename: Anju
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Centre for Advanced Studies, Department of Zoology, University of Rajasthan , Jaipur, India.
authors.forename: Nirmal Kumar
authors.initials: NK
authors.lastname: Lohiya
authors.affiliation: Cancer Microarray, Genes and Proteins Laboratory, National Institute of Immunology , Aruna Asaf Ali Marg , New Delhi, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Suri
keywords: AKAP4; cancer testis antigen; early diagnosis; humoral response; immunotherapy