Renal cell carcinoma (RCC) represents one of the most resistant tumors to radiation and chemotherapy. Current therapies for RCC patients are inefficient due to the lack of diagnostic and therapeutic markers. Our recent studies have suggested an association of sperm-associated antigen 9 (SPAG9) with ovarian carcinomas. In the present study, we investigated the clinical relevance of SPAG9 in RCC patients. RT-PCR analysis showed expression of SPAG9 transcript in RCC tissues and RCC cell lines. In situ RNA hybridization and immunohistochemistry analyses confirmed the expression of SPAG9 in 88% of cancer patients, suggesting that SPAG9 participates in renal cancer. In addition, immunoblotting and ELISA analyses revealed a humoral immune response against SPAG9 in the sera of RCC patients but not in healthy individuals. Consistent with the clinical findings, knockdown of SPAG9 expression in RCC cells with specific siRNA significantly reduced cell growth and colony formation. Using in vitro wound healing and Matrigel invasion assays, we found that cell migration and invasive ability were also significantly inhibited. Furthermore, in vivo xenograft studies in nude mice revealed that administration of a SPAG9 siRNA plasmid significantly inhibited tumor growth. In conclusion, SPAG9 expression is associated with clinicopathologic features of tumors, suggesting that SPAG9 could contribute to the early spread of cancer. These results indicate that SPAG9 may have a role in tumor development and metastasis and thus could serve as a novel target for early detection and treatment of RCC. [Cancer Res 2008;68(20):8240-8]
We report a novel SPAG9 (sperm-associated antigen 9) protein having structural homology with JNK (c-Jun N-terminal kinase)-interacting protein 3. SPAG9, a single copy gene mapped to the human chromosome 17q21.33 syntenic with location of mouse chromosome 11, was earlier shown to be expressed exclusively in testis [Shankar, Mohapatra and Suri (1998) Biochem. Biophys. Res. Commun. 243, 561-565]. The SPAG9 amino acid sequence analysis revealed identity with the JNK-binding domain and predicted coiled-coil, leucine zipper and transmembrane domains. The secondary structure analysis predicted an alpha-helical structure for SPAG9 that was confirmed by CD spectra. Microsequencing of higher-order aggregates of recombinant SPAG9 by tandem MS confirmed the amino acid sequence and mono atomic mass of 83.9 kDa. Transient expression of SPAG9 and its deletion mutants revealed that both leucine zipper with extended coiled-coil domains and transmembrane domain of SPAG9 were essential for dimerization and proper localization. Studies of MAPK (mitogenactivated protein kinase) interactions demonstrated that SPAG9 interacted with higher binding affinity to JNK3 and JNK2 compared with JNK1. No interaction was observed with p38alpha or extracellular-signal-regulated kinase pathways. Polyclonal antibodies raised against recombinant SPAG9 recognized native protein in human sperm extracts and localized specifically on the acrosomal compartment of intact human spermatozoa. Acrosome-reacted spermatozoa demonstrated SPAG9 immunofluorescence, indicating its retention on the equatorial segment after the acrosome reaction. Further, anti-SPAG9 antibodies inhibited the binding of human spermatozoa to intact human oocytes as well as to matched hemizona. This is the first report of sperm-associated JNK-binding protein that may have a role in spermatozoa-egg interaction.
Background:Cervical cytology by Papanicolaou (Pap) smears is an effective means of screening for cervical premalignant and malignant conditions. Cervical intra-epithelial neoplasia (CIN) and cervical cancer remain important health problems for women worldwide.Aim:To study the role of Pap smear in detecting premalignant and malignant lesions of cervix; and to determine the prevalence of various lesions.Materials and Methods:This study is based on 300 patients who attended the out-patient Department of Obstetrics and Gynaecology. Pap smears were prepared from patients presenting with complaints like vaginal discharge, post-coital bleeding, inter-menstrual bleeding, dyspareunia, and pain lower abdomen. After fixation and staining, each smear was carefully examined.Results:Epithelial cell abnormalities were found in 5% smears, atypical squamous cells of undetermined significance (ASCUS) in 0.3%, squamous intraepithelial lesion (SIL) in 3.4% which includes low grade squamous intraepithelial lesion (LSIL) (2.7%) and high grade squamous intraepithelial lesion (HSIL) 0.7%. Invasive carcinoma was seen in 1.3% cases. Mean age of the patients with diagnosis of LSIL was 32.3 years and for HSIL, it was 40.5 years. The mean age of the patients with invasive carcinoma was 57 years.Conclusion:Premalignant and malignant lesions of cervix are not uncommon in our set up and can be diagnosed early by Pap smears.
Colorectal cancer (CRC) is the second most common tumor in developed countries. The present study was undertaken to determine the expression of the sperm-associated antigen 9 gene (SPAG9) as a possible biomarker in CRC, to investigate its correlation with humoral immune response and different stages and grades in CRC patients, and to explore its possible role in colon tumorigenesis in vitro and in an in vivo mouse model. SPAG9 expression was determined by RT-PCR, in situ RNA hybridization, and immunohistochemistry. Humoral response against SPAG9 was detected by enzyme-linked immunosorbent assay and Western blotting. SPAG9 gene silencing was performed using plasmid-based small interfering RNA to study various malignant properties of colon cancer cells in vitro and in vivo. The majority of CRC patients showed SPAG9 expression and generated humoral response. There was a close relationship between SPAG9 protein expression and humoral immune response in the majority of earlystage CRC patients, indicating that anti-SPAG9 antibodies could be a novel serum biomarker for early diagnosis. The down-regulation of SPAG9 (mediated by small interfering RNA) inhibited malignant properties in in vitro and significantly suppressed tumor growth in vivo. These findings collectively suggest that SPAG9 may have a role in tumor development and early spread and thus could serve as a novel target for early detection and for cancer immunotherapy.
Purpose: Cancer testis antigens are a group of tumor antigens with gene expression restricted to male germ cells in the testis and in various cancerous tissues. Recently, we reported a novel testisspecific sperm-associated antigen 9 (SPAG9) gene, a new member of the c-Jun NH 2 -terminal kinase^interacting protein family, having functional role in sperm-egg fusion and mitogenactivated protein kinase signaling pathway. National Center for Biotechnology Information Blast searches revealed SPAG9 nucleotide sequence similarities with expressed sequence tags of various cancerous tissues. In an effort to examine the clinical utility of SPAG9, we investigated the SPAG9 mRNA and protein expression in epithelial ovarian cancer (EOC). Humoral immune response to SPAG9 was also evaluated in EOC patients. Experimental Design: We determined the expression profile of SPAG9 transcript by reverse transcription-PCR and RNA in situ hybridization and SPAG9 protein expression by immunohistochemistry in EOC specimens and human ovarian cancer cell lines. Using ELISA and Western blotting, we analyzed specific antibodies for SPAG9 in sera from patients with EOC. Results: SPAG9 mRNA and protein expression was detected in 90% of EOC tissues and in all three human ovarian cancer cell lines. Specific SPAG9 antibodies were detected in 67% of EOC patients and not in sera from healthy individuals. Conclusions: Our findings indicate that SPAG9 is highly expressed in EOC and immunogenic in patients. Humoral immune response against SPAG9 in early stages of EOC suggests its important role in early diagnostics.These results collectively suggest that SPAG9, a novel member of cancer testis antigen family, could be a potential target for the development of diagnostic and therapeutic methods in EOC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.