MicroRNA 630 Represses NANOG Expression through Transcriptional and Post-Transcriptional Regulation in Human Embryonal Carcinoma Cells

The pluripotent transcription factor NANOG is essential for maintaining embryonic stem cells and driving tumorigenesis. We previously showed that PKC activity is involved in the regulation of NANOG expression. To explore the possible involvement of microRNAs in regulating the expression of key pluripotency factors, we performed a genome-wide analysis of microRNA expression in the embryonal carcinoma cell line NT2/D1 in the presence of the PKC activator, PMA. We found that MIR630 was significantly upregulated in PMA-treated cells. Experimentally, we showed that transfection of MIR630 mimic into embryonal carcinoma cell lines directly targeted the 3′UTR of OCT4, SOX2, and NANOG and markedly suppressed their expression. RNAhybrid and RNA22 algorithms were used to predict miRNA target sites in the NANOG 3’UTR, four possible target sites of MIR630 were identified. To examine the functional interaction between MIR630 and NANOG mRNA, the predicted MIR630 target sites in the NANOG 3’UTR were deleted and the activity of the reporters were compared. After targeted mutation of the predicted MIR630 target sites, the MIR630 mimic inhibited NANOG significantly less than the wild-type reporters. It is worth noting that mutation of a single putative binding site in the 3’UTR of NANOG did not completely abolish MIR630-mediated suppression, suggesting that MIR630 in the NANOG 3’UTR may have multiple binding sites and act together to maximally repress NANOG expression. Interestingly, MIR630 mimics significantly downregulated NANOG gene transcription. Exogenous expression of OCT4, SOX2, and NANOG lacking the 3’UTR almost completely rescued the reduced transcriptional activity of MIR630. MIR630 mediated the expression of differentiation markers in NT2/D1 cells, suggesting that MIR630 leads to the differentiation of NT2/D1 cell. Our findings show that MIR630 represses NANOG through transcriptional and post-transcriptional regulation, suggesting a direct link between core pluripotency factors and MIR630.

Clinical Characteristics and Risk Factors Analysis for the Recurrence of Pelvic Endodermal Sinus Tumors

Background: This study investigated the clinicopathological characteristics and factors influencing the recurrence of pelvic endodermal sinus tumor. Methods: Fifty-four cases were retrospectively analyzed from at the Zhejiang Cancer Hospital. Imaging and serological indicators were used to determine whether disease recurred, to evaluate progression-free survival, and to compare the influence of related factors on disease recurrence. SPSS 19.0 software was used for statistical analysis. Statistical significance was defined as p < 0.05. Results: The median age at initial treatment was 21 years (range, 11–52 years). Six patients had extragonadal endodermal sinus tumor, and four had histological features of endodermal sinus tumor combined with embryonal carcinoma. Thirty-nine patients underwent fertility-preserving surgery, 18 patients had a childbearing history, and eight patients had residual tumor after initial treatment. Twenty-six patients had a tumor diameter of more than 15 cm, and 30 patients had a serum α‑fetoprotein level greater than 10,000 ng/mL before initial management. The median follow-up time was 47.5 months (range, 14–212 months). During follow-up, 15 patients experience recurrence, with a recurrence rate of 27.8% and a 5-year PFS rate of 61.1%. In univariate analysis, the International Federation of Gynecology and Obstetrics stage (stage III-IV VS. I-II; HR= 10.054 p<0.001), residual tumor (yes VS. no for the first surgery; HR=5.014 p=0.001), histological features (endodermal sinus tumor combined with embryonal carcinoma VS. endodermal sinus tumor; HR=4.130 p=0.018), and use of platinum-based chemotherapy (courses≥3 VS. courses<3; HR= 0.188 p=0.004) were independent factors influencing recurrence; age, childbearing history, tumor site, tumor size, and serum α-fetoprotein level before initial management did not affect recurrence. In multivariate analysis, only stage was an independent risk factor for progression-free survival（stage III-IV VS. I-II; HR=6.923 p=0.019）. Conclusions: Stage is a prognostic factor for recurrence of pelvic endodermal sinus tumor. The first surgery should remove the tumor as completely as possible, and initial treatment should require a sufficient dose and full course of platinum-based chemotherapy, which may reduce the recurrence rate. Patients with endodermal sinus tumor and embryonal carcinoma may have increased susceptibility of recurrence.

Synchronous bilateral testicular cancer with discordant histopathology occurring in a 20-year-old patient: A case report and review of the literature

Introduction: Bilateral testicular tumors are very rare, accounting for 1%–5% of all testicular germ-cell tumors (TGCTs). The vast majority of primary bilateral TGCTs are metachronous, with synchronous tumors comprising approximately 0.5%–1% of all cases. Those occurring synchronously share mostly the same histological pattern, predominantly seminoma, with synchronous bilateral TGCTs (SBTGCTs) with discordant subtypes being extremely rare. Case presentation: We present the case of a 20-year-old male complaining of a palpable painless right testicular mass incidentally noticed during sexual intercourse. Ultrasonography (US) and magnetic resonance imaging (MRI) of the scrotum demonstrated bilateral testicular lesions, while staging with contrast-enhanced computed tomography (CT) exhibited normal findings. Right radical orchiectomy and left testis-sparing surgery (TSS) with concomitant onco-testicular sperm extraction (onco-TESE) were initially performed. Histology of the right testis revealed a mixed germ-cell tumor, consisting of seminoma and embryonal carcinoma, while that from the left testis disclosed embryonal carcinoma and intratubular germ-cell neoplasia unclassified (IGCNU) infiltrating the surgical margins. Hence, left orchiectomy was subsequently scheduled with histology unveiling IGCNU in the greatest part of the remaining testicular parenchyma. Following adjuvant chemotherapy, with bleomycin, etoposide, and cisplatin (BEP), the patient received testosterone replacement therapy and remained free of recurrence at an 18-month follow-up. Conclusion: This case highlights both the rarity of a bilateral testicular tumor’s synchronous appearance and its extremely infrequent discordant histopathology. A comprehensive review of the major series of SBTGCTs with discordant histology cited in the literature is additionally presented.

Testicular germ cell tumors arise in the absence of sex-specific differentiation

ABSTRACT In response to signals from the embryonic testis, the germ cell intrinsic factor NANOS2 coordinates a transcriptional program necessary for the differentiation of pluripotent-like primordial germ cells toward a unipotent spermatogonial stem cell fate. Emerging evidence indicates that genetic risk factors contribute to testicular germ cell tumor initiation by disrupting sex-specific differentiation. Here, using the 129.MOLF-Chr19 mouse model of testicular teratomas and a NANOS2 reporter allele, we report that the developmental phenotypes required for tumorigenesis, including failure to enter mitotic arrest, retention of pluripotency and delayed sex-specific differentiation, were exclusive to a subpopulation of germ cells failing to express NANOS2. Single-cell RNA sequencing revealed that embryonic day 15.5 NANOS2-deficient germ cells and embryonal carcinoma cells developed a transcriptional profile enriched for MYC signaling, NODAL signaling and primed pluripotency. Moreover, lineage-tracing experiments demonstrated that embryonal carcinoma cells arose exclusively from germ cells failing to express NANOS2. Our results indicate that NANOS2 is the nexus through which several genetic risk factors influence tumor susceptibility. We propose that, in the absence of sex specification, signals native to the developing testis drive germ cell transformation.

RARE CASES OF MIXED GERM CELL TUMOUR OF TESTIS- A REPORT OF TWO CASES WITH UNCOMMON COMBINATIONS AND REVIEW OF LITERATURE.

Mixed germ cell tumours of testis represent a comparatively rare category of testicular tumour where different types of both seminomatous and non-seminomatous tumours can be present in varied proportions. We report two cases of mixed germ cell tumours, one consisting of seminoma, embryonal carcinoma and post-pubertal teratoma in the testis of a 22-year-old male and second consisting of a yolk sac tumour and immature teratoma in the testis of a 19-year-old male. We report theses case due to the rare combination and for documentation