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Biomedical subjects

U Sahin

Publications and source records attributed to U Sahin.

At least 19 recordsLinked to original sources
PubMed2001

Penicillin resistance in Streptococcus pneumoniae in Isparta.

OBJECTIVE: The first case reports of infection with penicillin-resistant pneumococci were made in Australia in 1967 and South Africa in 1977. Since this time the increasing emergence of penicillin- resistant strains of Streptococcus pneumoniae have been a serious therapeutic problem. Therefore, the aim of the present study was to determine the penicillin resistance of S. pneumoniae strains isolated in the laboratory. The effect of procaine penicillin treatment against these strains was also investigated. METHODS: Sensitivity testing was done by disc diffusion method using oxacillin discs. Minimal inhibitory concentration (MIC) values were determined in tests with penicillin by the use of E-test (AB Biodisc, Solna, Sweden). Patients were treated with 2 x 800,000 U of i.m. procaine penicillin every 12 h for 10 days. RESULTS: Thirty-seven strains of S. pneumoniae were isolated from the sputa of adult patients who had pneumonia. Moderately resistant (0.12-1.00 microg/mL) and penicillin-sensitive (< or = 0.06 microg/mL) strains were identified in nine (24.3%) and 28 (75.7%) isolates, respectively. There were no high-level penicillin-resistant strains in the study. There was no therapeutic failure. CONCLUSION: These results suggest that procaine penicillin may still be useful in the empirical therapy of pneumococcal pneumonia.

Adult↗
PubMed2001

Preserved costal cartilage homograft application for the treatment of temporomandibular joint ankylosis.

Ankylosis of the temporomandibular joint has been a daunting problem in oral and maxillofacial surgery. Condylectomy with gap arthroplasty is the basic technique for treatment of the fully grown patient. In the past, reconstruction has primarily been accomplished with alloplastic materials or with autogenous tissue harvested from the patient. Joints reconstructed with alloplastic materials have been subject to complications such as acute infection and chronic inflammatory problems as a result of foreign-body reaction with the immune system. Biologic reconstruction with autogenous materials does expose the patient to the risk of complications at the donor site. In the last 4 years, we have treated seven patients between the ages of 20 and 42 years who had complete temporomandibular joint ankylosis. In each patient, the affected joint was exposed through an extended preauricular incision. The ankylosed mandibular condyle with the surrounding abnormal bone, together with the coronoid process, was resected and removed. The ankylosed area was resected until an improvement of at least 15 mm in the interincisal opening distance was obtained. A solvent-preserved homologous cartilage graft was sculpted according to the size and shape of the gap and was then placed in it as interpositional material. Physical therapy, including active and passive mouth-opening exercises, began on the second postoperative day and continued for 6 months. Patients were observed for 6 months to 4 years. During this period, no major complications were noted, and satisfactory results were obtained. The initial mean interincisal opening distance was 15.2 mm after surgery, and the final mean interincisal opening distance was 32 mm after completion of physiotherapy. No recurrence was seen during the 4 years of follow-up. This technique seems to be an effective, time-saving, and simple alternative to other methods of joint reconstruction in adults who have fairly extensive ankylosis of the temporomandibular joint. In this article, a description of the surgical technique, a review of all cases, and recommendations for the use of this type of graft material are discussed. Our clinical experience over the past 4 years with the use of preserved homologous costal cartilage grafts as interpositional material has been encouraging.

Adult↗
PubMed2001

The value of small-bore catheter thoracostomy in the treatment of malignant pleural effusions.

BACKGROUND: Malignant pleural effusions can cause severe debilitating symptoms and impair the quality of life. Treatment is often palliative, usually consisting of sequential thoracenteses or tube thoracostomy with or without sclerotherapy. Large-bore thoracostomy tubes have traditionally been used for drainage and sclerotherapy. More recently, the use of small-bore catheters has been studied. OBJECTIVES: To assess the efficacy and safety of small-bore catheter (Pleuracan) thoracostomy combined with talc sclerotherapy for palliative treatment of malignant pleural effusions. METHODS: Between May 1998 and March 2000, 24 consecutive patients presenting at our inpatient clinic were studied. Follow-up radiography at the end of the 1st month (immediate response) and 3rd month (long-term follow-up) after talc pleurodesis was performed to assess the response rates. RESULTS: Of the 24 patients included, 2 patients did not show lung expansion after pleural drainage. Two patients died within 30 days after talc pleurodesis and 1 did not undergo 30-day postpleurodesis radiography. The remaining 19 patients made up the study group to assess the response rates (8 men, 11 women). Overall response rates of talc pleurodesis via small-bore catheter were found to be 84.2% [complete response (CR): 68.4%, partial response (PR): 15.8%] at 30-day and 78.6% (CR: 57.2%, PR:2 1.4%) at 90-day follow-up, respectively. One patient reported moderate pain during catheter placement. Four patients experienced mild to moderate pleuritic chest pain, shortness of breath, or both within 4 h after instillation. Seven of the 22 patients (31.8%) had a transient fever (< or =39.0 degrees C) 6-24 h after talc instillation that lasted less than 24 h and was successfully treated with acetaminophen. One patient had significant subcutaneous emphysema that resolved in 24 h. Four patients died because of tumor progress (2 patients in the 1st month and 2 patients between 30 and 90 days). CONCLUSION: Pleurodesis can successfully be performed via a small-bore catheter in patients with recurrent malignant pleural effusion. To validate the results of the study, a prospective randomized study, comparing this device (Pleuracan) and a 'standard' 16- to 24-french chest drain, should be performed.

Adenocarcinoma↗
PubMed2001

Lipid peroxidation and glutathione peroxidase activity in chronic obstructive pulmonary disease exacerbation: prognostic value of malondialdehyde.

Results of recent studies have indicated that during exacerbation of chronic obstructive pulmonary disease (COPD), antioxidant capacity is lower and the levels of lipid peroxidation products are higher than those in age-matched healthy subjects. The aim of this study was to assess the time course of changes in oxidant stress during the treatment of exacerbation of COPD. For this purpose, we measured erythrocyte glutathione peroxidase (GPx) activity and serum levels of the lipid peroxidation product malondialdehyde (MDA) in 18 male patients with acute exacerbation of COPD. Fifteen healthy non-smokers having no history of lung disease served as control subjects. Mean erythrocyte GPx values of patients were 45.54 +/- 9.04 u/gHb on admission and had increased to 72.77 +/- 9.68 by the tenth day of treatment, but still remained lower than those of healthy subjects (83.13 +/- 10.91) (p=0.007). Serum MDA values in patients were Vol. 12, No. 1, 2001 significantly higher (2.68 +/- 1.28 nmol/ml) than those in control subjects (1.04 +/- 0.36 nmol/ml) (p=0.000) and returned to normal values by the tenth day of treatment (1.08 +/- 0.36 nmol/ml) (p=0.766). Erythrocyte GPx values in patients who were current smokers (39.87 +/- 3.82 u/gHb) were lower than those in ex-smokers (49.15 +/- 9.67 u/gHb) (p=0.021). Moreover, serum MDA values in patients who were current smokers (3.32 +/- 1.18 nmol/ml) were higher than those in ex-smokers (1.66 +/- 0.60 nmol/ml) (p=0.007). The results show that oxidative stress in patients with acute exacerbation of COPD is related to higher MDA levels that return to normal conditions during the course of treatment. In conclusion, the results suggest that MDA levels can serve as a marker of prognosis and of the success of treatment of the exacerbation of COPD.

Biomarkers↗
PubMed2001

Allergic rhinitis in Rosa domescena cultivators: a novel type of occupational allergy?

After the diagnosis of allergic rhinitis due to Rosa domescena was suspected in one subject with skin prick and nasal provocation tests, we recruited all other workers employed in rose cultivation in Yakaören village, Isparta. From May 2000 to July 2000 (exposure period 'time of rose handling'), we studied 600 individuals employed in rose cultivation. A questionnaire was administered by a physician, and skin testing was done by a nurse on 75 individuals suffering from asthma and/or rhinitis. Sera from these 75 subjects were available for immunologic testing. The diagnosis of atopy against rose was based on the presence of work-related symptoms, positive skin prick test (SPT) with rose extracts, and positive RAST. While no subject reported asthmatic symptoms, twenty of them reported either rhino-conjunctivitis, rhinitis or both on exposure to Rosa domescena. Fourteen of these subjects had increased specific IgE levels to Rosa domescena. Eleven (78.5%) also had a positive skin reaction to Rosa domescena. Out of the six negative sera with normal specific IgE levels to rose, only two (33.3%) had positive skin reactivity. No subject had significant daily peak expiratoy flow rate (PEFR) variations. We conclude that exposure to Rosa domescena may represent a risk for allergic rhinitis. The possibility of an occupational rose allergy should therefore be taken into consideration in the subjects working in rose cultivation.

Adult↗
PubMed2000

Naturally occurring human lymphocyte antigen-A2 restricted CD8+ T-cell response to the cancer testis antigen NY-ESO-1 in melanoma patients.

Cancer testis (CT) antigens are particularly interesting candidates for cancer vaccines. However, T-cell reactivity to CT antigens has been detected only occasionally in cancer patients, even after vaccination. A new group of CT antigens has been recently identified using the SEREX technique based on immunoscreening of tumor cDNA expression libraries with autologous sera. We have used fluorescent HLA-A2/peptide tetramers containing an optimized antigenic peptide to directly identify HLA-A2-restricted CD8+ T cells specific for the SEREX-defined CT antigen NY-ESO-1 in melanoma patients. High frequencies of NY-ESO-1-specific CD8+ T cells were readily detected in peptide-stimulated peripheral blood mononuclear cells as well as in lymphocytes infiltrating melanoma lesions from patients with measurable antibody responses to NY-ESO-1. NY-ESO-1-specific CD8+ T cells were also detectable in peptide-stimulated peripheral blood mononuclear cells from some seronegative patients. Whereas the frequencies of NY-ESO-1-specific CD8+ T cells in circulating lymphocytes were usually below the limit of detection by tetramer staining, the presence of NY-ESO-1 CD8+ T cells displaying a memory phenotype was clearly detectable ex vivo in blood from a seropositive patient over an extended period of time. These results indicate that sustained CD8+ T-cell responses to CT antigens can naturally occur both locally and systemically in melanoma patients.

Amino Acid Sequence↗
PubMed2000

Definition of tumor-associated antigens in hepatocellular carcinoma.

With an estimated annual incidence of about one million cases, hepatocellular carcinoma (HCC) is one of the most common neoplasms worldwide. Of all malignant diseases, it is the major cause of death in some regions of Africa and Asia. The pathogenic mechanisms responsible for HCC are not well defined, and therapeutic means, especially in inoperable HCCs, are still unsatisfactory and await improvement. In the quest for tumor antigens exploitable for gene therapy, we studied immune responses in the context of HCC. A cDNA library derived from a human HCC sample was screened using the SEREX approach. Nineteen distinct antigens reactive with autologous IgG were identified. Sequence analysis revealed three of the cDNA clones to code for hitherto unknown proteins and 16 known genes products. Proteins as diverse in function as LDH, albumin, and kinectin were found. Furthermore, proteins involved in the transcription/translation machinery had elicited an immune response in the autologous host. A panel of allogenic sera including sera from patients with hepatitis, liver cirrhosis, HCC, and other tumor entities, as well as sera from normal individuals, was used for frequency analysis of antibody responses. Whereas allogenic sera of HCC patients detected most antigens at a high percentage, control sera were rarely antibody-positive. The nature of the major fraction of antigens described here are linked to liver. Thus, our findings demonstrate not only the complexity of the humoral immune response against HCC, but may also offer new insight into mechanisms underlying transformation of the liver cell.

Adult↗
PubMed2000

Expression of cancer testis genes in human brain tumors.

Cancer-testis (CT) genes are expressed in a variety of human cancers but not in normal tissues, except for testis tissue, and represent promising targets for immunotherapeutic and gene therapeutic approaches. Because little is known about their composite expression in human brain tumors, we investigated the expression of seven CT genes (MAGE-3, NY-ESO-1, HOM-MEL-40/SSX-2, SSX-1, SSX-4,HOM-TES-14/SCP-1, and HOM-TES-85) in 88 human brain tumor specimens. Meningiomas expressed only HOM-TES-14/SCP-1 (18% of meningiomas were HOM-TES-14/SCP-1 positive) and did not express any other CT genes. One ependymoma was negative for all CT genes tested. SSX-4 was the only CT gene expressed in oligodendrogliomas (2 of 5 cases), and it was also expressed in oligoastrocytomas (3 of 4 cases) and astrocytomas (10 of 37 cases). Astrocytomas were most frequently positive for HOM-TES-14/SCP-1 (40%) and SSX-4 (27%), followed by HOM-TES-85 (13%), SSX-2 (11%), and MAGE-3 (7%). Whereas MAGE-3 was detected only in grade IV astrocytomas, the expression of the other CT genes showed no clear correlation with histological grade. Of 39 astrocytomas, 60% expressed at least one CT gene, 21% expressed two CT genes, and 8% coexpressed three CT genes of the seven CT genes investigated. We conclude that a majority of oligoastrocytomas and astrocytomas might be amenable to specific immunotherapeutic interventions. However, the identification of additional tu-mor-specific antigens with a frequent expression in gliomas is warranted to allow for the development of widely applicable polyvalent glioma vaccines.

Antigens, Neoplasm↗
PubMed1999

Generation of tissue-specific and promiscuous HLA ligand databases using DNA microarrays and virtual HLA class II matrices.

Most pockets in the human leukocyte antigen-group DR (HLA-DR) groove are shaped by clusters of polymorphic residues and, thus, have distinct chemical and size characteristics in different HLA-DR alleles. Each HLA-DR pocket can be characterized by "pocket profiles," a quantitative representation of the interaction of all natural amino acid residues with a given pocket. In this report we demonstrate that pocket profiles are nearly independent of the remaining HLA-DR cleft. A small database of profiles was sufficient to generate a large number of HLA-DR matrices, representing the majority of human HLA-DR peptide-binding specificity. These virtual matrices were incorporated in software (TEPITOPE) capable of predicting promiscuous HLA class II ligands. This software, in combination with DNA microarray technology, has provided a new tool for the generation of comprehensive databases of candidate promiscuous T-cell epitopes in human disease tissues. First, DNA microarrays are used to reveal genes that are specifically expressed or upregulated in disease tissues. Second, the prediction software enables the scanning of these genes for promiscuous HLA-DR binding sites. In an example, we demonstrate that starting from nearly 20,000 genes, a database of candidate colon cancer-specific and promiscuous T-cell epitopes could be fully populated within a matter of days. Our approach has implications for the development of epitope-based vaccines.

Alleles↗
PubMed1999

Exploitation of the antibody repertoire of cancer patients for the identification of human tumor antigens.

The screening of tumor-derived expression libraries for antigens which are recognized by high titered IgG antibodies present in autologous sera of the cancer patients by SEREX (serological identification of antigens by recombinant expression cloning) allows for the systematic identification of antigens in human cancers. SEREX has led to the definition of a plentitude of new tumor antigens in many different tumor entities. The majority of the antigens are encoded by hitherto unknown genes and can be grouped into different classes of antigens. The abundance of serologically defined human tumor antigens is not only of relevance for tumor biology and serodiagnosis of cancer, but also facilitates the identification of proteins recognized by tumor specific T lymphocytes, thus providing a molecular basis for polyvalent peptide-based and gene-therapeutic vaccine strategies in a wide variety of human neoplasms.

Antibodies, Neoplasm↗
PubMed1999

Reverse neurofasciocutaneous flaps for soft-tissue coverage of the lower leg.

The evolution of neurocutaneous flaps has created a new concept in reconstructive surgery. These flaps, based on the arterial network around the superficial sensory nerves, are gaining popularity in soft-tissue coverage. Various flaps can be planned based on the neurocutaneous perforators. These kinds of flaps are available for extremity reconstruction. In the lower leg, reverse neurocutaneous flaps have been used successfully. Although these flaps in the lower leg are called neurocutaneous, they have been elevated with the underlying fascia like fasciocutaneous flaps, and thus the authors call these flaps neurofasciocutaneous flaps. They have used 11 reverse neurofasciocutaneous flaps (6 saphenous and 5 sural) since 1995. All flaps survived completely, and stable coverage of soft-tissue defects of the lower leg was achieved in all patients.

Adult↗
PubMed1998

Expression of SSX genes in human tumors.

The HOM-MEL-40 antigen which is encoded by the SSX-2 gene was originally detected as a tumor antigen recognized by autologous IgG antibodies in a melanoma patient. Expression analysis demonstrated that SSX-2 is a member of the recently described cancer/testis antigen (CTA) class as it is expressed in a variety of different human neoplasms, but not in normal tissues with the exception of testis and a weak expression in the thyroid. Further studies demonstrated that SSX-2 belongs to a gene family consisting of at least 5 homologous genes. We now report the analysis of the expression of all 5 SSX genes in 325 specimens of human neoplasms from various histological origins, using reverse transcription polymerase chain reaction (RT-PCR). SSX-1, -2, and -4 were found to be expressed in 8%, 15% and 15%, of the tumors, respectively, while the expression of the SSX-5 gene was rare (7/325), and SSX-3 expression was not detected. For defined tumor types, expression of at least one of the SSX family members was most frequently observed in head and neck cancer (75%), followed by ovarian cancer (50%), malignant melanoma (43%), lymphoma (36%), colorectal cancer (27%) and breast cancer (23%), while leukemias and the few cases of leiomyosarcomas, seminomas and thyroid cancers were found not to express any SSX gene.

Antigens, Neoplasm↗
PubMed1998

Human carbonic anhydrase XII: cDNA cloning, expression, and chromosomal localization of a carbonic anhydrase gene that is overexpressed in some renal cell cancers.

We report the cloning and characterization of a tumor-associated carbonic anhydrase (CA) that was identified in a human renal cell carcinoma (RCC) by serological expression screening with autologous antibodies. The cDNA sequence predicts a 354-amino acid polypeptide with a molecular mass of 39,448 Da that has features of a type I membrane protein. The predicted sequence includes a 29-amino acid signal sequence, a 261-amino acid CA domain, an additional short extracellular segment, a 26-amino acid hydrophobic transmembrane domain, and a hydrophilic C-terminal cytoplasmic tail of 29 amino acids that contains two potential phosphorylation sites. The extracellular CA domain shows 30-42% homology with known human CAs, contains all three Zn-binding histidine residues found in active CAs, and contains two potential sites for asparagine glycosylation. When expressed in COS cells, the cDNA produced a 43- to 44-kDa protein in membranes that had around one-sixth the CA activity of membranes from COS cells transfected with the same vector expressing bovine CA IV. We have designated this human protein CA XII. Northern blot analysis of normal tissues demonstrated a 4.5-kb transcript only in kidney and intestine. However, in 10% of patients with RCC, the CA XII transcript was expressed at much higher levels in the RCC than in surrounding normal kidney tissue. The CA XII gene was mapped by using fluorescence in situ hybridization to 15q22. CA XII is the second catalytically active membrane CA reported to be overexpressed in certain cancers. Its relationship to oncogenesis and its potential as a clinically useful tumor marker clearly merit further investigation.

Amino Acid Sequence↗
PubMed1998

Characterization of human colon cancer antigens recognized by autologous antibodies.

The screening of cDNA expression libraries derived from human tumors with autologous antibody (SEREX) has proven to be a powerful method for defining the structure of tumor antigens recognized by the humoral immune system. In the present study, 48 distinct antigens (NY-CO-1-NY-CO-48) reactive with autologous IgG were identified by SEREX analysis in 4 patients with colon cancer. Sequencing analysis showed that 17 of the cDNA clones were previously uncharacterized molecules and 31 represented known gene products. The individual cDNA clones were analyzed in the following manner: a search for mutations or other structural changes; an analysis of mRNA expression in a panel of normal tissues; and a frequency analysis of the antibody response to the expressed product in the sera of colon cancer patients and normal individuals. The initial analysis showed NY-CO-13 to be a mutated version of the p53 tumor suppressor gene. Three of the 48 antigens showed a differential pattern of mRNA expression, with NY-CO-27 (galectin-4) expressed primarily in gastrointestinal tract, and NY-CO-37 and -38 showing a pattern of tissue-specific isoforms. With regard to immunogenicity, 20 of the 48 antigens were detected by allogeneic sera; 14 of these were reactive with sera from both normal donors and cancer patients, and 6 other clones (NY-CO-8, -9, -13, -16, -20 and -38) reacted exclusively with sera from colon cancer patients (ranging from 14% to 27%). Our results on colon cancer illustrate both the complexity and the potential of the SEREX approach for analysis of the humoral immune response against human cancer.

Adult↗
PubMed1998

Identification of a meiosis-specific protein as a member of the class of cancer/testis antigens.

Little is known about the function of human cancer/testis antigens (CTAs), such as MAGE, BAGE, GAGE, HOM-MEL-40, and NY-ESO-1, the expression of which is restricted to human malignancies and testis. When screening a cDNA expression library enriched for testis-specific representative long transcripts for reactivity with high-titered IgG antibodies from the serum of a patient with renal cell carcinoma, one repeatedly detected antigen, designated HOM-TES-14, turned out to be encoded by the synaptonemal complex protein 1 (SCP-1) gene. SCP-1 is known to be selectively expressed during the meiotic prophase of spermatocytes and is involved in the pairing of homologous chromosomes, an essential step for the generation of haploid cells in meiosis I. Investigation of a broad spectrum of normal and malignant tissues revealed expression of SCP-1 transcripts and antigen selectively in a variety of neoplastic tissues and tumor cell lines. Immunofluorescence microscopy analysis with specific antiserum showed a cell cycle phase-independent nuclear expression of SCP-1 protein in cancer cells. SCP-1 differs from other members of the class of CTA by its localization on chromosome 1 and its frequent expression in malignant gliomas, breast, renal cell, and ovarian cancer. The aberrant expression of SCP-1 in tumors might contribute to their genomic instability and suggests that the functional role of other CTA might also relate to meiosis.

Antigens, Neoplasm↗
PubMed1998

Saving the zone of stasis in burns with recombinant tissue-type plasminogen activator (r-tPA): an experimental study in rats.

Hypercoagulability 2-3 h following scald injury and vessel thrombosis are well-known complications of burn injury. The present study was designed to determine the effect of recombinant tissue-type plasminogen activator (r-tPA) on vessels thrombosis in zones of stasis postburn. Twenty rats were assigned to experimental and control groups (N:10). After shaving the backs, a 'comb burn' was given bilaterally on the back of the rats 0.5 cm lateral and parallel to the midline by using a brass probe consisting of four rows (10 x 20 mm) and three interspaces (5 x 20 mm). Standardized full-thickness burns of the experimental group were treated with r-tPA via femoral veins 2 h after the burn, while the control group rats were infused the same volume of saline. Interspaces between the rows and vertical space area were evaluated as zone of stasis. The skin blood flow measurements of interspaces revealed a decreased level immediately and 2 h after the burn injury, averaging 11.3 and 9.8 perfusion units, respectively. On day 7, blood flow measurements of interspace and vertical space areas significantly differed between the groups, averaging 11.9 PU in the experimental and 1.8 PU in the control groups (P<0.05). To evaluate perfusion, each rat received 3 mCi of technetium-99m methoxyisobutylisonitrile on the first or seventh day postburn. After 30 min, the entire back skins including the panniculus carnosus muscle layer were dissected away. Gamma camera images revealed that in the experimental group the interspace areas took up 60-90 per cent more radioactivity than the burned areas while in the control group 20-50 per cent more activity was taken up by the interspace area when compared to burned areas. Autoradiography gave the exact borders of the necrotic and survived tissues. The percentage of live interspace and vertical space areas in the experimental group was 87.8 per cent on day 7, while it was 31.8 per cent in the control group (P<0.05). Dry/wet ratios did not reveal any significant difference at 24 h postburn. These results confirm that treatment with this selective fibrinolytic agent (r-tPA) after burn injury would have some benefits on saving the zone of stasis in burns.

Animals↗
PubMed1997

SSX: a multigene family with several members transcribed in normal testis and human cancer.

Analysis of t(X;18) translocation in synovial sarcoma had previously led to the definition of the SSX2 gene, the fusion partner on chromosome X. Subsequent screening of testicular cDNA libraries identified 2 highly homologous genes, SSX1 and SSX3. Among these 3 genes, SSX2 has been found to be identical to HOM-MEL-40, which codes for an immunogenic tumor antigen expressed in various human cancers. SSX2 thus belongs to the family of cancer/testis (CT) antigens, i.e., immunogenic protein antigens with characteristic mRNA expression in normal testis and in cancer. To define additional CT antigens, we have immuno-screened a testicular cDNA expression library with an allogeneic serum from a melanoma patient, and both SSX2 and SSX3 were isolated. Further studies using testicular cDNA and SSX probes defined 2 new members of this gene family, SSX4 and SSX5, while a shorter cDNA variant of SSX4 was also identified. All 5 members of the SSX family shared strong sequence homology, with nucleotide homology ranging from 88 to 95% and amino acid homology ranging from 77 to 91%. Genomic cloning of a prototype SSX gene (SSX2) showed that its coding region is encoded by 6 exons, and the shortened form of SSX4 cDNA represents an alternatively spliced product lacking the 5th exon. Analysis of SSX mRNA expression by gene-specific RT-PCR confirmed that all 5 SSX genes are expressed in testis. In addition, analysis of a panel of 12 melanoma cell lines showed strong mRNA expression of either SSX1 (3/12), SSX2 (3/12), SSX4 (1/12), or SSX5 (1/12), indicating variable activation of the genes in malignant cells.

Amino Acid Sequence↗