Cyclin A1 and gametogenesis in fertile and infertile patients: a potential new molecular diagnostic marker

BACKGROUND: The study aim was to evaluate cyclin A1 mRNA expression levels as a potential molecular diagnostic parameter in the work-up of testicular tissue from fertile versus infertile patients. METHODS: Cyclin A1 expression was quantified in 55 cryopreserved testicular tissue specimens by fluorescence real-time RT-PCR. A conventional histological work-up was performed concomitantly in all tissue specimens with additional semi-thin sectioning in all cases of non-obstructive azoospermia (n = 12), maturation arrest (n = 17) and Sertoli cell-only syndrome (SCOS; n = 9). RESULTS: The mean (+/- SD) normalized cyclin A1 expression (N(CyclinA1)) was 3.82 +/- 2.23 relative gene expression (RGE) in tissue specimens with normal spermatogenesis, and 0.625 +/- 0.221 RGE in those with maturation arrest at the level of early spermatids. Only minimal N(CyclinA1) was detected in tissue specimens with spermatogonia only or maturation arrest at the level of primary spermatocytes (0.005 +/- 0.008). Cyclin A1 expression was absent in the majority of SCOS specimens (0.002 +/- 0.002). CONCLUSIONS: These investigations suggested that cyclin A1 expression is altered in cases of spermatogenic disorders. Moreover, the level of cyclin A1 mRNA expression correlates with gametogenic disorders and seems well suited for a molecular-diagnostic classification supplementing the histopathological evaluation of spermatogenic disorders.     

Expression of the sodium iodide symporter and thyroglobulin genes are reduced in papillary thyroid cancer.

Altered expression of the gene encoding the sodium iodine symporter (NIS) may be an important factor that leads to the reduced iodine accumulation characteristic of most benign and malignant thyroid nodules. Both up- and down-regulation of NIS gene expression have been reported in thyroid cancer using several different methods. The goal of the present study was to accurately identify alterations in NIS gene expression in benign and malignant thyroid nodules using an accurate real-time quantitative RT-PCR assay system. Total RNA was prepared from 18 benign thyroid nodules, 20 papillary thyroid cancers, and 23 normal thyroid samples from 38 subjects. Quantitative RT-PCR was used to measure NIS and thyroglobulin (TG) mRNA expression in normal thyroid tissue and in each nodular tissue sample. Papillary thyroid cancer samples had significantly lower NIS mRNA expression (72 +/- 41 picogram equivalents [pg Eq]), than did benign nodules (829 +/- 385 pg Eq), or normal tissues (1907 +/- 868 pg Eq, P = 0.04). Most important, in the paired samples, NIS gene expression was decreased in each papillary thyroid cancer compared with normal tissue (69% median decrease; range, 40-96%; P = .013). Eleven of the 12 benign nodules also demonstrated lower NIS gene expression than the normal tissue (49% decrease; range, 2-96%; P = .04). Analysis of the paired samples demonstrated that Tg mRNA expression was significantly lower in each of the thyroid cancer samples than in corresponding normal tissue (759 +/- 245 pg Eq vs. 1854 +/- 542 pg Eq, P = .03). We have demonstrated a significant decrement in NIS gene expression in all papillary thyroid cancers and in over 90% of benign nodules examined compared with adjacent normal thyroid tissue, using a highly accurate quantitative RT-PCR technique. Similarly, thyroid cancers demonstrated significantly lower TG mRNA expression than corresponding normal thyroid. Reduced NIS expression may be an important factor in the impairment of iodine-concentrating ability of neoplastic thyroid tissues.     

COMMENTS

An unselected population of 635 consecutive extragonadal GCT patients (EGCT) treated between 1975 through 1996 at 11 cancer centers was retrospectively evaluated for clinical prognosis and biological features of this disease. Five hundred twenty-four patients (83%) had a nonseminomatous GCT, and 104 patients (16%) a seminomatous histology; 341 (54%) patients had a primary mediastinal EGCT, and 283 patients (45%) a retroperitoneal EGCT. Following platinum based induction chemotherapy+/-secondary surgery, 141 patients (49%) with mediastinal nonseminomas (median follow up period: 19 months) and 144 patients (63%) with retroperitoneal nonseminoma (median follow up period: 29 months) are alive [p=0.0006]. In contrast, the overall survival rate for patients with seminomatous EGCT is 88% with no difference between patients with mediastinal or retroperitoneal tumor location (median follow up period: 49 months). Multivariate analysis revealed nonseminomatous histology, the presence of non-pulmonary visceral metastases, primary mediastinal GCT location, and elevated beta-HCG as independent prognostic factors for shorter survival. Sixteen patients (4.1%) developed a metachronous testicular cancer despite the use of platinum based chemotherapy. The cumulative risk of developing a MTC 10-years after a diagnosis of EGCT was 10.3% (95% CI=4.9 to 15.6%), but higher among patients with nonseminomatous EGCT (14.3%; 95% CI=6.7 to 21.9%) or retroperitoneal EGCT location (14.2%; 95% CI=5.6 to 22.8%) than among patients with seminomatous EGCT (1.4%; 95% CI=0.0 to 4.2) or mediastinal EGCT location (6.2%; 95% CI=0.1 to 12.2). After a median follow-up of 51 months (range=1 to 154 months), all 16 MTC patients were alive without disease. Patients with pure seminomatous EGCT histology have a long term chance of cure of almost 90% irrespective of the primary tumor site. Patients with mediastinal nonseminomas have a five-years survival rate of 45%. This outcome is clearly inferior compared to patients with nonseminomatous retroperitoneal primaries who have a five-year survival rate of 62%.     

Extragonadal germ cell tumors: relation to testicular neoplasia and management options

An unselected population of 635 consecutive extragonadal GCT patients (EGCT) treated between 1975 through 1996 at 11 cancer centers was retrospectively evaluated for clinical prognosis and biological features of this disease. Five hundred twenty-four patients (83%) had a nonseminomatous GCT, and 104 patients (16%) a seminomatous histology; 341 (54%) patients had a primary mediastinal EGCT, and 283 patients (45%) a retroperitoneal EGCT. Following platinum based induction chemotherapy+/-secondary surgery, 141 patients (49%) with mediastinal nonseminomas (median follow up period: 19 months) and 144 patients (63%) with retroperitoneal nonseminoma (median follow up period: 29 months) are alive [p=0.0006]. In contrast, the overall survival rate for patients with seminomatous EGCT is 88% with no difference between patients with mediastinal or retroperitoneal tumor location (median follow up period: 49 months). Multivariate analysis revealed nonseminomatous histology, the presence of non-pulmonary visceral metastases, primary mediastinal GCT location, and elevated beta-HCG as independent prognostic factors for shorter survival. Sixteen patients (4.1%) developed a metachronous testicular cancer despite the use of platinum based chemotherapy. The cumulative risk of developing a MTC 10-years after a diagnosis of EGCT was 10.3% (95% CI=4.9 to 15.6%), but higher among patients with nonseminomatous EGCT (14.3%; 95% CI=6.7 to 21.9%) or retroperitoneal EGCT location (14.2%; 95% CI=5.6 to 22.8%) than among patients with seminomatous EGCT (1.4%; 95% CI=0.0 to 4.2) or mediastinal EGCT location (6.2%; 95% CI=0.1 to 12.2). After a median follow-up of 51 months (range=1 to 154 months), all 16 MTC patients were alive without disease. Patients with pure seminomatous EGCT histology have a long term chance of cure of almost 90% irrespective of the primary tumor site. Patients with mediastinal nonseminomas have a five-years survival rate of 45%. This outcome is clearly inferior compared to patients with nonseminomatous retroperitoneal primaries who have a five-year survival rate of 62%.     

Expression of glypican 3 in ovarian and extragonadal germ cell tumors

Germ cell tumors (GCTs), rare malignancies that occur in a wide range of locations and display variable histologic patterns, may pose diagnostic challenges. Glypican 3 (GPC3), a membrane-bound heparan sulfate proteoglycan, has been shown to be a novel diagnostic marker in testicular GCT. However, GPC3 expression in ovarian and extragonadal GCT has not been reported. We evaluated GPC3 immunoreactivity in GCTs from 63 patients (57 children and 6 adults), including 14 ovarian and 20 extragonadal primary GCTs and 8 metastases along with 21 primary testicular GCTs for comparison. All 33 yolk sac tumors (YSTs) and both choriocarcinomas were immunoreactive for GPC3. In contrast, a minority of immature (4/10) and mature (4/35) teratomas were positive. No positivity was seen in 6 embryonal carcinomas or 5 germinomas. GPC3 is differentially expressed in ovarian and extragonadal GCTs, with expression predominantly observed in YSTs and choriocarcinoma.     

Somatic isoform of angiotensin I-converting enzyme in the pathology of testicular germ cell tumors

Retained fetal expression of angiotensin I-converting enzyme (ACE, CD143) has recently been shown in intratubular germ cell neoplasms (IGCN) and invasive germ cell tumors (GCT), suggesting the somatic isoform (sACE) as a characteristic component of neoplastic germ cells. We analyzed the distribution of sACE in 159 testicular GCT, including 87 IGCN. sACE protein was determined by immunohistochemistry (MAb CG2) on routinely formalin-fixed and paraffin-embedded tissue sections, supplemented by mRNA expression analysis using in situ hybridization. These data were compared with those obtained by germ cell/placental alkaline phosphatases (PIAP; MAbs PL8-F6 and 8A9) employing an uniform score system for the evaluation of immunoreactivity (IRS; possible values from 0 to 12). Expression of sACE and PIAP was found in all 87 analyzed IGCN (IRS > 4, median IRS of 12). Heterogeneous staining patterns were not related to the type of adjacent GCT but correlated with low expression in adjacent seminomas (P =.032 for sACE; P =.005 for PIAP). Both sACE and PIAP often showed a decreased and more heterogeneous but still moderate expression in 91 classic seminomas (median IRS of 8) and were completely absent in tumor cells of spermatocytic seminomas. Despite all similarities, we found sACE and PIAP differently regulated during GCT progression. This was documented by a well-preserved expression of either sACE or PIAP or both in all classic seminomas, low PIAP immunoreactivity in metastasis of seminomas, and completely diverging expression patterns in nonseminomatous GCT. Our findings underline the close molecular relationship between IGCN and seminoma, and suggest sACE as an appropriate marker for seminomatous differentiated tumors. HUM PATHOL 31:1466-1476.     

散发性结肠癌中β-catenin mRNA表达的即时聚合酶链反应分析

目的探讨散发性结直肠癌(SCRC)组织中β-catenin mRNA 的含量与 SCRC 组织中的β-catenin 蛋白异常表达以及临床病理学指标间的关系。方法用 TaqMan 即时荧光定量聚合酶链反应(PCR)方法检测了81例 SCRC 组织和28例癌旁正常黏膜组织的β-catenin mRNA 含量(每个样本的β-catenin cDNA 拷贝数与 GAPDH cDNA 拷贝数的比值作为β-catenin mRNA 含量);以 EnVision 二步法检测了β-catenin 蛋白在 SCRC 组织和癌旁正常黏膜组织中的表达。结果在 SCRC 组织中β-catenin mRNA 含量(2.527±2.284)低于癌旁正常黏膜组织中的含量(5.003±3.326),差异有统计学意义。有淋巴结转移组的β-catenin mRNA 含量(1.827±1.288)低于无淋巴结转移组(3.359±2.881),P<0.05;溃疡型和浸润型生长组β-catenin mRNA 含量(2.202±2.035)低于隆起型生长组(3.108±2.610),P<0.05;在β-catenin 胞质或胞核异常表达组和无胞质或胞核异常表达组织之间,β-catenin mRNA 含量的差异无统计学意义。结论β-catenin mRNA 的低转录水平与 SCRC 的淋巴结转移及溃疡浸润型生长相关,而与β-catenin 蛋白的胞质胞核异常表达无明显关联。定量检测β-cateninmRNA 水平可能是一种判断 SCRC 生物学行为的有用方法。     

Genetic analysis of the APAF1 gene in male germ cell tumors

Cytogenetic and molecular analyses have shown that the chromosome band 12q22 is recurrently deleted in male germ cell tumors (GCTs), indicating the presence of a candidate tumor suppressor gene (TSG) in this region. To identify the TSG, we mapped the APAF1 gene, a proapoptotic mammalian homologue of ced-4, to chromosomal band 12q22, that suggested that this might be the candidate deleted gene in GCTs. We further localized the gene between the polymorphic markers D12S1671 and D12S1082 at 12q22 to determine the role of APAF1 in the pathogenesis of GCT, and we characterized its normal genomic structure and analyzed its alterations in GCTs. The APAF1 gene comprises 27 exons, with the coding region spanning 26. The region containing APAF1 was found to be deleted in GCT by fluorescence in situ hybridization analysis, but without evidence of coding sequence alterations. RT-PCR and Western blot analysis showed APAF1 gene expression at detectable levels in all GCT cell lines analyzed. An aberrant-sized APAF1 protein was seen in one cell line. This and 2 other cell lines carrying APAF1 deletions also exhibited defects in dATP-mediated caspase-3 activation. Caspase-3 activity was effectively restored by addition of recombinant caspase-9 and APAF1 proteins, and to a lesser extent by caspase-9 alone, but not by APAF1 alone. These data do not support a TSG role for APAF1, but defects in other components of the apoptotic pathway that may be related to 12q22 deletion cannot be ruled out. Genes Chromosomes Cancer 28:258-268, 2000.     

上皮型钙黏素基因启动子甲基化及其mRNA和蛋白表达在鼻咽癌组织中的意义

目的　探讨鼻咽癌癌细胞上皮型钙黏素基因启动子甲基化的程度及其mRNA和蛋白表达水平在鼻咽癌早期浸润和转移中的作用。方法　采用甲基化特异性聚合酶链反应 (methylation specificPCR ,MSP)、蛋白印迹、免疫组织化学和逆转录聚合酶链反应 (RT PCR)等方法检测 2 1例鼻咽癌患者鼻咽原发癌和淋巴结转移癌配对组织中的上皮型钙黏素基因启动子甲基化程度和上皮型钙黏素、β 链接素在不同组织中mRNA和蛋白水平的表达。 结果　 ( 1)在 2 1例鼻咽原发癌组织中 ,11例( 5 2 4% )可以检测到上皮型钙黏素基因启动子的甲基化 ,而在配对的 2 1例淋巴结转移癌组织中 17例 ( 80 9% )则可检测到 ,二者差异具有显著性 (P <0 0 5 )。 ( 2 )在鼻咽原发癌组织中 ,80 %的癌细胞均表达上皮型钙黏素蛋白 ,在淋巴结转移癌组织中只有平均 5 0 %的癌细胞表达 ,两者亦差异有显著性 (P =0 0 0 4) ;但β 链接素蛋白在原发癌和淋巴结转移癌组织中均有较高的表达量 (均为 85 % )。 ( 3 )蛋白印迹检测表明 ,上皮型钙黏素在鼻咽原发癌组织中表达的平均相对强度为 2 0 6 7± 3 2 7,明显高于在转移癌组织中的蛋白平均相对强度 65 0± 15 9;而 β 链接素在不同组织中的蛋白表达相对强度则差异无显著性 (P =0 75 4)。 ( 4)上皮型钙黏