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Biomedical subjects

P O Van Trappen

Publications and source records attributed to P O Van Trappen.

5 recordsLinked to original sources
PubMed2006

Somatic mitochondrial DNA mutations in primary and metastatic ovarian cancer.

OBJECTIVE: To date, most mtDNA mutations in cancer have been identified in the control region (D-loop) containing the major promoters. However, almost all studies used one sample per tumor and there is no clear evidence whether metastatic deposits harbor different mtDNA variants. To establish whether different mtDNA variants can be found in the same cancer but at different sites, we analyzed a series of unilateral and bilateral primary epithelial ovarian cancers as well as paired metastatic tumor deposits. METHODS: We sequenced the D-loop region in 52 different tumor samples of 35 ovarian cancer cases, as well as matched normal tissues. Seventeen of those 35 cases had bilateral ovarian cancer, with a sample from each tumor analyzed. RESULTS: Eighty-six polymorphisms (4 new in ovarian cancer) were detected, and 9 different somatic mtDNA mutations were found in 26% (9 of 35) of ovarian cancer cases; all were homoplasmic in nature. Six of the mutations were novel in ovarian cancer. In 24% (4 of 17) of cases with bilateral ovarian tumors, different mtDNA variants were found between paired tumors, suggesting the presence of different clonal populations of cancer cells. Metastatic tumor deposits showed identical mtDNA variants to those found in at least one of the ovarian tumors in cases with bilateral ovarian cancer. CONCLUSION: Our data demonstrate that multiple tumor samples from the same patient may harbor different mtDNA variants.

Base Sequence↗
PubMed2006

The sentinel node in gynaecological malignancies.

As lymph node metastasis is one of the earliest features of tumour cell spread in most human cancers, assessment of the regional lymph nodes is required for tumour staging, determining prognosis and planning adjuvant therapeutic strategies. However, complete lymph node dissections are frequently associated with significant complications. Conjugating the diagnostic advantages with decreased morbidity, the sentinel node concept represents one of the most recent advances in surgical oncology. In this review we briefly highlight the historical background of the development of the sentinel node concept, the anatomical evidence for applying the sentinel node concept in pelvic gynaecological cancers and the technical aspects of sentinel node detection. We discuss recent studies in vulval, cervical and endometrial cancer.

Cervix Uteri↗
PubMed2002

A model for co-expression pattern analysis of genes implicated in angiogenesis and tumour cell invasion in cervical cancer.

To date, numerous genes have been identified which are involved in both tumour neovascularisation (angiogenesis) and tumour cell invasion, and most of them are also expressed to some extent under normal physiological conditions. However, little is known about how these genes co-express in these settings. This study was undertaken to quantitate mRNA levels in normal and malignant cervical tissues of nine selected genes (VEGF(121), VEGF(165), VEGF(189), VEGF-C, eIF-4E, b-FGF, TSP-2, MMP-2 and MMP-9) implicated in the above processes using real-time quantitative RT-PCR. In addition, the Spearman's rank correlation was used to determine their co-expression patterns. The transcript levels for the different VEGF-A splice variants (VEGF(121), VEGF(165), VEGF(189)) were at least 10-fold higher in the cancer cases, with the highest levels in the primary tumours demonstrating lympho-vascular space involvement. The lymphangiogenic factor VEGF-C and MMP-9 were upregulated 130- and 80-fold respectively in cervical cancers. The highest levels of VEGF-C mRNA were found in the lymph-node positive group. The transcript levels for b-FGF were similar in normal cervical tissue and early-stage cervical cancer, however, higher levels were found in the cervical cancers with advanced stage disease. Comparing gene transcript levels between recurrent and non-recurrent cervical cancer patients revealed significant differences (P=0.038) in transcript levels for the angiogenesis inhibitor TSP-2, with the highest levels in non-recurrent cases. Co-expression pattern analysis in normal cervical tissue revealed highly significant co-expressions (P<0.0001) between TSP-2 and most other genes analysed (VEGF(121), VEGF(165), VEGF-C, b-FGF and MMP-2). In cervical cancer, TSP-2 appears only to be highly co-expressed with MMP-2 (P<0.0001). In contrast to normal cervical tissue, we found a highly significant co-expression (P<0.0001) between MMP-9 and VEGF(189) in cervical cancer. The combined application of real-time quantitative RT-PCR and Spearman's rank correlation identifies gene transcripts which are simultaneously co-expressed. Our results revealed a significant co-expression between the angiogenesis inhibitor TSP-2 and most other genes analysed in normal cervical tissue. In cervical cancer, we found a strong upregulation of VEGF-C and MMP-9 mRNA, with a highly significant co-expression between MMP-9 and VEGF(189).

Cervix Uteri↗
PubMed2001

Molecular quantification and mapping of lymph-node micrometastases in cervical cancer.

BACKGROUND: A proportion of patients with cancer and lymph nodes negative on histology will develop recurrence. Reverse-transcriptase PCR (RT-PCR) is a highly sensitive method for detection of lymph-node micrometastases, but accurate quantitative assessment has been difficult. METHODS: We studied primary tumours and 156 lymph nodes from 32 patients with cervical cancer (stage IA2, IB1, and IB2) and 32 lymph nodes from nine patients with benign disease. A fully quantitative, real-time RT-PCR assay was used to document absolute copy numbers of the epithelial marker cytokeratin 19. Primers and probe were designed not to amplify either of the two cytokeratin 19 pseudogenes. FINDINGS: All primary tumours and histologically involved lymph nodes (six) had more than 106 copies of cytokeratin 19 mRNA per microg total RNA. Expression of cytokeratin 19 (up to 1.1 x 10(5) copies per microg RNA) was detected in 66 (44%) of 150 histologically uninvolved lymph nodes, and in nodes from 16 of 32 patients with cervical cancer. 15 of these 16 patients with evidence of micrometastases had the highest cytokeratin 19 transcription level in a first lymph-node drainage station (three obturator, six internal, and six external iliac node). Transcription of cytokeratin 19 was found at a low level in just one of 32 lymph nodes obtained from nine patients with benign disease. Median copy number of cytokeratin 19 transcription was significantly higher (>10(3) copies) in association with adverse prognostic features. INTERPRETATION: The results suggest that about 50% of early-stage cervical cancers shed tumour cells to the pelvic lymph nodes. The amount of cytokeratin 19 expression was related to clinicopathological features. Further studies are required to document the clinical implications of molecular micrometastases.

Adult↗