BACKGROUND. Survival rates for gastrointestinal (GI) and bronchopulmonary (BP) neuroendocrine tumors (NETs) have not significantly altered (overall 67%, 5‐year survival) in 30 years (1973‐2004), whereas the incidence has increased (∼ 1000%) in the same time frame. No effective or specific antineoplastic agent is available for treatment, although somatostatin analogs inhibit tumor secretion. Given the coexistence of somatostatin and dopamine regulatory receptors on NET cells, the antiproliferative efficacy as well as the signaling and transcriptional targets of their ligands were evaluated. METHODS. The cytotoxic effects of 12 somatostatin/dopamine compounds were evaluated in 3 NET cell lines, and real‐time polymerase chain reaction and enzyme‐linked immunoadsorbent assay studies were performed to delineate antiproliferative signaling pathways. RESULTS. The atypical BP‐NET, NCI‐H720, was most sensitive to the sst5 analog BIM23206 (half‐maximal concentration, 2.4 pM) and demonstrated similar sensitivity to lanreotide and the sst2 analog BIM23120. The typical BP‐NET, NCI‐H727, was most sensitive to BIM23120 (0.7 nM) and to the pan‐somatostatin receptor analog (BIM23A779). The GI‐NET, KRJ‐I, was most sensitive to sst2,5 analogs lanreotide (1 nM) and BIM23244 (7.4 nM). Lanreotide activated extracellular signal regulated kinase‐1/2 phosphorylation and p21WAF1/CIP1 transcription, but inhibited Ki‐67 transcription. NCI‐H720 was most sensitive to the sst2,5‐ and D2‐selective compound BIM23A761 (4.2 nM), as was NCI‐H727 (5.5 nM). KRJ‐I did not respond to any chimeric analog. BIM23A761 activated c‐Jun N‐terminal kinase signaling and caused inhibition of Ki‐67 transcription. P21WAF1/CIP1 transcription was activated only in NCI‐H727 cells. CONCLUSIONS. The different responses of each individual cell line suggested that NETs from different locations arising from different neuroendocrine cells may require cell‐specific antiproliferative agents based on the unique receptor profile of individual lesions. Cancer 2008. © 2008 American Cancer Society.

Introduction-Survival rates for gastrointestinal (GI) and bronchopulmonary (BP) neuroendocrine tumors (NETs) have not significantly altered (5yr survival: 64.1% and 87-89%) in thirty years (1973-2004). No effective or specific anti-neoplastic agent(s) is available although somatostatin analogs inhibit NET serotonin (5-HT) secretion. Given the expression of 5-HT receptors on NETs, we hypothesized that 5-HT autoregulated NET proliferation. Methods-Proliferation was evaluated in three NET cell lines using MTT uptake while real-time PCR and ELISA studies were performed to delineate 5-HT-mediated signaling pathways. To determine the receptor and role of endogenous 5-HT production, the effects of ketanserin (5-HT 2A/C receptor antagonist), ondansetron (5-HT 3 antagonist) and the suicide inhibitor 7-Hydroxytryptophan (7-HTP) were investigated. Results-Exogenously added 5-HT stimulated proliferation in the atypical BP-NET, NCI-H720 (+50%, EC 50 =10nM), the typical BP-NET, NCI-H727 (+40%, EC 50 =0.01nM), and the GI-NET, KRJ-I (+60%, EC 50 =25nM). In NCI-H720, proliferation was inhibited by ketanserin (IC 50 =0.06nM) and ondansetron (IC 50 =0.4nM) as well as 7-HTP (IC 50 =0.3nM). In NCI-H727, ketanserin and 7-HTP inhibited proliferation (IC 50 =0.3nM and 2.3nM respectively) while ondansetron had no effect. In KRJ-I, ketanserin (IC 50 =0.1nM) and 7-HTP (IC 50 =0.6nM) but not ondansetron inhibited proliferation. In all cell lines, 5-HT activated proliferation through ERK1/2 phosphorylation and JNK-mediated pathways (c-JUN and Ki67 transcription). An auto-regulatory effect was indicated by 7-HTP-mediated inhibition of extracellular 5-HT and downstream effects on NET proliferation. Conclusions-Lung and GI-NET proliferation is autoregulated by 5-HT through alterations in ERK and JNK signaling. Targeting NET cells with 5-HT2 receptor antagonists and 7-HTP reversed proliferation. 5-HT 2 receptor subtype-specific antagonists may represent a viable antiproliferative therapeutic strategy.

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Extravillous trophoblasts (EVTs) have the potential to provide the entire fetal genome for prenatal testing. Previous studies have demonstrated the presence of EVTs in the cervical canal and the ability to retrieve a small quantity of these cells by cervical sampling. However, these small quantities of trophoblasts are far outnumbered by the population of cervical cells in the sample, making isolation of the trophoblasts challenging. We have developed a method to enrich trophoblast cells from a cervical sample using differential settling of the cells in polystyrene wells. We tested the addition of small quantities of JEG-3 trophoblast cell line cells into clinical samples from standard Pap tests taken at 5 to 20 weeks of gestation to determine the optimal work flow. We observed that a 4 min incubation in the capture wells led to a maximum in JEG-3 cell settling on the surface (71 ± 10% of the initial amount added) with the removal of 91 ± 3% of the cervical cell population, leading to a 700% enrichment in JEG-3 cells. We hypothesized that settling of mucus in the cervical sample affects the separation. Finally, we performed a proof-of-concept study using our work flow and CyteFinder cell picking to verify enrichment and pick individual JEG-3 and trophoblast cells free of cervical cells. Ultimately, this work provides a rapid, facile, and cost-effective method for enriching native trophoblasts from cervical samples for use in subsequent non-invasive prenatal testing using methods including single cell picking.

In his opening address to the fifty members of the Constitution Drafting Committee (CDC) on 18 October, 1975, the head of Nigeria’s new military government, General Murtala Ramat Muhammed, declared: “It is important that we avoid a reopening of the deep splits which caused trauma in the country.” Those splits, as was made known to the outside world during the civil war, were ethnic, regional, and, to a lesser extent, religious in nature. Of these three modes of overt division, Nigerians have always been most successful in controlling the religious aspect. General Murtala’s statement is instructive on the problem of regional splits: “The fear of the predominance of one Region over another has . . . been removed to a large extent by the simple Constitutional Act of creating more States.” Four months later, following the assassination of Murtala, the successor regime of General Obasanjo declared the creation of seven more states, bringing the number up to nineteen from the twelve established by General Gowon in May 1967. While it is evident that the existence of “regions” has not been obliterated by their subdivision into states, this development has reduced the immediate political visibility and at least some of the salience of regional boundaries.