Analysis of chromosome abnormalities by comparative genomic hybridization in malignant peripheral primitive neuroectodermal tumor of the ovary

Is Ovarian Tissue Transplantation Safe in Patients with Central Nervous System Primitive Neuroectodermal Tumors?

The risk of reseeding malignancy harbored in cryopreserved and transplanted ovarian tissue has been a source of concern. This study aimed to determine the potential relationship between frozen–thawed ovarian tissue transplantation and primary cancer recurrence. Three patients with cerebral primitive neuroectodermal tumors (PNET) were included in this study. One woman gave birth to three healthy babies following reimplantation of her cryopreserved ovarian tissue, but subsequently died due to cancer relapse six years after ovarian tissue transplantation. The second subject died from progressive cancer, while the third is still alive and awaiting reimplantation of her ovarian tissue in due course. Frozen ovarian cortex from all three patients was analyzed and xenotransplanted to immunodeficient mice for five months. Main outcomes were the presence of cancer cells in the thawed and xenografted ovarian tissue at histology, immunostaining (expression of neuron-specific enolase and glial fibrillary acidic protein (GFAP)), and reverse-transcription droplet digital polymerase chain reaction (RT-ddPCR) (levels of enolase 2 and GFAP). In conclusion, no malignant cells were detected in ovarian tissue from patients with PNET, even in those who experienced recurrence of the disease, meaning that the risk of reseeding cancer cells with ovarian tissue transplantation in these patients can be considered low.

Ovarian primary primitive neuroectodermal tumor: a review of cases at PUMCH and in the published literature

Background

The pathological characteristics, treatment strategies and prognosis of ovarian primary primitive neuroectodermal tumor (PNET) were unclear due to the rarity of PNET. All cases treated at Peking Union Medical College Hospital (PUMCH) between 1975 and 2016 and published in the English literature between 1980 to 2017 were reviewed.

Results

Finally four cases from PUMCH and 15 cases in the literature were included. The median age was 25 years (range 13–79), and the median diameter of the tumors was 13.4 cm (range 5.0–30.0). The most common initial symptoms were abdominal pain, bloating and a pelvic mass. Diagnosis primarily depended on immunohistochemical and fluorescence in situ hybridization data. Treatment consisted of surgery, various chemotherapy regimens and/or radiotherapy. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 15 and 52%, respectively. For patients with OS and PFS > 12 months, the median ages were 21 years (range 13–35) and 17 years (range 13–35), respectively, while for patients with OS < 12 months and PFS < 12 months, the median ages were 48 years (range 14–79) and 25 years (range 18–79), respectively.

Conclusions

No standard therapy for ovarian primary PNET exists, and an individualized strategy is recommended. Young patients seem to have better prognoses.

Novel treatment of a central type, primitive neuroectodermal tumor of the ovary with postoperative pediatric medulloblastoma chemotherapy regimen: A case report and review of the literature

•Central type primitive neuroectodermal tumor (cPNET) of the ovary is difficult to treat.•Etoposide, cisplatin and cyclophosphamide is a pediatric medulloblastoma regimen.•Our case with cPNET responded to this combination chemotherapy.

Molecular karyotype of sporadic unilateral retinoblastoma tumors

BACKGROUND

Retinoblastoma (RB) is a childhood ocular malignancy associated with mutations in RB1, a tumor susceptibility gene. Inactivation of both copies of the RB1 gene in a retinal cell is followed by the sequential acquisition of additional genetic changes that define the course to tumor formation.

METHODS

To identify the genetic events that cooperate with loss of the RB1 gene function, we performed a whole genome sampling assay based on single nucleotide polymorphism genotyping. We used DNA isolated from 25 sporadic, unilateral RB tumors and matched blood samples.

RESULTS

Genomic profiles were analyzed to identify regions of loss of heterozygosity or amplification. Two major subclasses of RB tumors were defined by the presence (n = 18) or absence (n = 7) of loss of heterozygosity of chromosome 13. Loss of heterozygosity in most cases was the result of copy-neutral events caused by mitotic recombination and mitotic nondisjunction. Tumors harbored novel regions of amplification at 1q44, 3p25, 11q14, 11q25, 14q23, 15q21, 16p13, 17p11.2, 19q13, and 20q13, whereas regions of loss included 6q22, 7q21, and 21q2.

CONCLUSION

Whole genome sampling assay-based analysis of unilateral RB tumors revealed novel regions as significant. These minimum critical regions that are lost or amplified are expected to harbor genes that aid the process of tumorigenesis.

Genome profiling of ovarian adenocarcinomas using pangenomic BACs microarray comparative genomic hybridization

Background

Routine cytogenetic investigations for ovarian cancers are limited by culture failure and poor growth of cancer cells compared to normal cells. Fluorescence in situ Hybridization (FISH) application or classical comparative genome hybridization techniques are also have their own limitations in detecting genome imbalance especially for small changes that are not known ahead of time and for which FISH probes could not be thus designed.

Methods

We applied microarray comparative genomic hybridization (A-CGH) using one mega base BAC arrays to investigate chromosomal disorders in ovarian adenocarcinoma in patients with familial history.

Results

Our data on 10 cases of ovarian cancer revealed losses of 6q (4 cases mainly mosaic loss), 9p (4 cases), 10q (3 cases), 21q (3 cases), 22q (4 cases) with association to a monosomy X and gains of 8q and 9q (occurring together in 8 cases) and gain of 12p. There were other abnormalities such as loss of 17p that were noted in two profiles of the studied cases. Total or mosaic segmental gain of 2p, 3q, 4q, 7q and 13q were also observed. Seven of 10 patients were investigated by FISH to control array CGH results. The FISH data showed a concordance between the 2 methods.

Conclusion

The data suggest that A-CGH detects unique and common abnormalities with certain exceptions such as tetraploidy and balanced translocation, which may lead to understanding progression of genetic changes as well as aid in early diagnosis and have an impact on therapy and prognosis.

Metastatic primitive neuroectodermal tumor of the ovary in pregnancy

Primitive neuroectodermal tumor (PNET) is a small round tumor belonging to the PNET/Ewing's sarcoma family. We hereby report a case of PNET of the ovary, which was detected at the second trimester of pregnancy. Chemotherapy was administered and a healthy baby was delivered by cesarean section. After the pregnancy, the mother was found to have metastatic disease. Chemotherapy was continued, but she died due to progressive disease 13 months after the initial diagnosis. In this case report, we discuss chemotherapy options during pregnancy and the importance of multidisciplinary approach to unusual presentations of rare tumors

Marked genomic differences characterize primary and secondary glioblastoma subtypes and identify two distinct molecular and clinical secondary glioblastoma entities

Glioblastoma is classified into two subtypes on the basis of clinical history: "primary glioblastoma" arising de novo without detectable antecedent disease and "secondary glioblastoma" evolving from a low-grade astrocytoma. Despite their distinctive clinical courses, they arrive at an indistinguishable clinical and pathologic end point highlighted by widespread invasion and resistance to therapy and, as such, are managed clinically as if they are one disease entity. Because the life history of a cancer cell is often reflected in the pattern of genomic alterations, we sought to determine whether primary and secondary glioblastomas evolve through similar or different molecular pathogenetic routes. Clinically annotated primary and secondary glioblastoma samples were subjected to high-resolution copy number analysis using oligonucleotide-based array comparative genomic hybridization. Unsupervised classification using genomic nonnegative matrix factorization methods identified three distinct genomic subclasses. Whereas one corresponded to clinically defined primary glioblastomas, the remaining two stratified secondary glioblastoma into two genetically distinct cohorts. Thus, this global genomic analysis showed wide-scale differences between primary and secondary glioblastomas that were previously unappreciated, and has shown for the first time that secondary glioblastoma is heterogeneous in its molecular pathogenesis. Consistent with these findings, analysis of regional recurrent copy number alterations revealed many more events unique to these subclasses than shared. The pathobiological significance of these shared and subtype-specific copy number alterations is reinforced by their frequent occurrence, resident genes with clear links to cancer, recurrence in diverse cancer types, and apparent association with clinical outcome. We conclude that glioblastoma is composed of at least three distinct molecular subtypes, including novel subgroups of secondary glioblastoma, which may benefit from different therapeutic strategies.

Biochemistry and biology of ARHI (DIRAS3), an imprinted tumor suppressor gene whose expression is lost in ovarian and breast cancers

ARHI is a maternally imprinted tumor suppressor gene that is downregulated in 60% of ovarian and breast cancers. Loss of ARHI expression is associated with tumor progression in breast cancer and decreased disease-free survival in ovarian cancer. ARHI encodes a 26-kDa protein with 55-62% homology to Ras and Rap. In contrast to Ras, ARHI inhibits growth, motility, and invasion. ARHI contains a unique 34 amino-acid extension at its N-terminus and differs from Ras in residues critical for GTPase activity and for its putative effector function. Deletion of ARHI's unique N-terminal extension markedly reduces its inhibitory effect on cell growth. The gene maps to chromosome 1p31 at a site of LOH in 40% of ovarian and breast cancers. Mutations have not been detected, but the remaining allele is silenced by methylation in approximately 10-15 % of cases. In the remaining cancers, ARHI is downregulated by transcriptional mechanisms that involve E2F1 and E2F4, as well as by the loss of RNA binding proteins that decrease the half-life of ARHI mRNA. Transgenic expression of human ARHI in mice produces small stature, induces ovarian atrophy, and prevents postpartum milk production. Reexpression of ARHI in cancer cells inhibits signaling through Ras/Map and PI3 kinase, upregulates P21(WAF1/CIP1), downregulates cyclin D1, induces JNK, and inhibits signaling through STAT3. Marked overexpression of ARHI with a dual adenoviral vector induces caspase-independent, calpain-dependent apoptosis. When ARHI is expressed from a doxycycline-inducible promoter at more physiological levels, autophagy is induced, rather than apoptosis. Growth of ovarian and breast cancer xenografts is reversibly suppressed by ARHI, but expression of the NTD mutant produced only a limited inhibitory effect on growth of xenografts.

Peripheral primitive neuroectodermal tumour of the maxilla

The peripheral primitive neuroectodermal tumour (pPNET) is a rare and highly malignant soft tissue neoplasm in children and young adults. We present a case of pPNET of the maxilla in a 49-year-old woman.

Overexpression of cyclin D1 and c-Myc gene products in human primary epithelial ovarian cancer

Cyclin D1 and c-Myc are key participants in the cell-cycle pathway, in which aberrancies have been associated with malignant transformation. To date, data on the relationship of expression of these proteins and histologic subtype of epithelial ovarian cancer are still scarce and discordant. Immunohistochemical analysis was performed on 12 normal ovaries and 47 cases of serous, mucinous, endometrioid, and clear cell ovarian carcinomas. No abnormal expression of cyclin D1 or c-Myc was demonstrated in any of the 12 normal ovarian specimens. However, compared to normal ovarian tissues, overexpression of cyclin D1 and c-Myc was observed in 42.6% (20/47) and 65.9% (31/47) of tumors examined, respectively. There was no significant difference of overexpression of cyclin D1 or c-Myc gene products between these four histologic subtypes of ovarian adenocarcinomas. This study shows that cyclin D1 and c-Myc are frequently overexpressed in epithelial ovarian carcinomas, but they are not correlated with a particular histologic subtype. Although our preliminary results need to be validated in a larger number of tumors, the abnormal expression of cyclin D1 and c-Myc in epithelial ovarian cancer reaffirms the notion that they are crucial components in the pathway of tumorigenesis and deserve further study.