Isolation and expression analysis of the testis-specific gene, human OPPO1

Expression of testis-specific genes, TEX101 and ODF4, in chronic myeloid leukemia and evaluation of TEX101 immunogenicity

BACKGROUND AND OBJECTIVES

Cancer-testis (CT) antigens are a group of antigens with a restricted expression in normal tissues, except testis, and they have aberrant expression in different tumors. This pattern of expression has made them promising targets for immunotherapy and cancer detection. Our aim was to find new members of this group that might be useful as markers in the detection of cancer and immunotherapy.

DESIGN AND SETTING

A descriptive study conducted in referral centers of Tehran University of Medical Science from January 2008 to January 2009.

PATIENTS AND METHODS

We analyzed the expression of two testis-specific genes named ODF4 (outer dense fiber of sperm tails 4) and TEX101 (testis expressed 101) in 20 chronic myeloid leukemia (CML) and 20 normal samples by reverse transcription-polymerase chain reaction and sequencing. Immunogenicity of TEX101 was evaluated by means of enzyme-linked immunosorbent assay.

RESULTS

These two genes were expressed in 30% of CML patients but not in any of the healthy donors. Humoral response against TEX101 was not detected in any samples.

CONCLUSIONS

TEX101 and ODF4 are CT genes useful for detection of CML. Unlike many CT genes, overexpression of TEX101 was not shown to induce immunologic responses in these samples. According to the previous studies, overexpression of TEX101 leads to suppression of cancer invasion and metastasis; thus, the induction of the expression of TEX101 in cancer by epigenetic mechanisms may be a treatment strategy.

Expression of two testis-specific genes, SPATA19 and LEMD1, in prostate cancer

BACKGROUND AND AIMS

Screening methods for early detection of prostate cancer have some limitations regarding specificity and sensitivity, so there is a continuing search to find new cancer biomarkers. Cancer-testis genes are a group of genes with expression almost limited to testis and different kinds of tumors. Since testis is an immune privileged site, if these genes are expressed in tumors, they can be immunogenic. We undertook this study to find new members of the cancer-testis gene family appropriate for cancer immunotherapy

METHODS

We analyzed the expression of six testis-specific genes called ODF1, ODF2, ODF3, ODF4, LEMD1 and SPATA19 in 30 prostate cancer and 25 benign prostate hyperplasia (BPH) samples by RT-PCR and restriction fragment length polymorphism (RFLP).

RESULTS

Of the prostate cancer samples, 10, 10, 23 and 40% showed ODF1, ODF2, LEMD1 and SPATA19 specific bands, respectively, but none of the BPH samples expressed any of these genes. The difference between prostate cancer and BPH groups for LEMD1 and SPATA19 expression was significant. Mean serum PSA level was significantly higher in patients expressing ODF2 than in the other patients.

CONCLUSIONS

ODF1, ODF2, SPATA19 and LEMD1 are members of cancer-testis gene family. In addition, LEMD1 and SPATA19 are putative cancer biomarkers and promising targets for active immunotherapy.

The human transcript induced in spermatogenesis 50

Background and Aims: Recently, a number of genes that are expressed specifically in the testis have been identified in rat and mouse. In 2002, 80 transcript induced in spermatogenesis (Tisp) genes with this specific expression were isolated in mice. In the human, however, the number of such genes isolated is much lower. The aim of this study therefore was the isolation of human genes specifically expressed in testis. Methods: We searched for human genome region with homology to the mouse Tisp gene family at the amino acid level using GenBank. The primers were made in human homologous regions, and polymerase chain reaction analysis was performed with templates using cDNA libraries of a range of human tissues. The cDNA specifically expressed in testis were isolated and detailed expression analysis was performed. Results: The 28 human TISP related genes were analyzed. Five of these genes were not expressed in testis and only three, TISP50, TISP15 and TISP43 related gene, were expressed specifically in testis. The cDNA of these three genes were isolated. Conclusion: Expression analysis demonstrated that there is some discrepancy between human and mouse for the TISP gene family. From expression patterns and amino acid sequences, it is suggested that the human TISP50, TISP15 and TISP43 related genes play some critical roles in spermatogenesis. (Reprod Med Biol 2004; 3: 237 - 243).