Maternal oxytocin administration modulates gene expression in the brains of perinatal mice.

OBJECTIVES: Oxytocin (OXT) is widely used to facilitate labor. However, little is known about the effects of perinatal OXT exposure on the developing brain. We investigated the effects of maternal OXT administration on gene expression in perinatal mouse brains. METHODS: Pregnant C57BL/6 mice were treated with saline or OXT at term (n=6-7/group). Dams and pups were euthanized on gestational day (GD) 18.5 after delivery by C-section. Another set of dams was treated with saline or OXT (n=6-7/group) and allowed to deliver naturally; pups were euthanized on postnatal day 9 (PND9). Perinatal/neonatal brain gene expression was determined using Illumina BeadChip Arrays and real time quantitative PCR. Differential gene expression analyses were performed. In addition, the effect of OXT on neurite outgrowth was assessed using PC12 cells. RESULTS: Distinct and sex-specific gene expression patterns were identified in offspring brains following maternal OXT administration at term. The microarray data showed that female GD18.5 brains exhibited more differential changes in gene expression compared to male GD18.5 brains. Specifically, Cnot4 and Frmd4a were significantly reduced by OXT exposure in male and female GD18.5 brains, whereas Mtap1b, Srsf11, and Syn2 were significantly reduced only in female GD18.5 brains. No significant microarray differences were observed in PND9 brains. By quantitative PCR, OXT exposure reduced Oxtr expression in female and male brains on GD18.5 and PND9, respectively. PC12 cell differentiation assays revealed that OXT induced neurite outgrowth. CONCLUSIONS: Prenatal OXT exposure induces sex-specific differential regulation of several nervous system-related genes and pathways with important neural functions in perinatal brains.

Analysis of Differentially Expressed MicroRNAs and Circulating Tumor Cells as Predictive Biomarkers of Platinum Chemoresistance in Primary Ovarian Carcinomas: A Prospective Study.

LESSON LEARNED: Circulating tumor cells, microRNA markers, or other biomarkers merit examination as part of correlative scientific analyses in prospective clinical trials. BACKGROUND: Platinum chemotherapy resistance occurs in approximately 25% of patients with ovarian carcinoma; however, no biomarkers of ovarian carcinoma chemoresistance have been validated. We performed a prospective trial designed to identify tumor-based predictive biomarkers of platinum resistance. METHODS: Tumor specimens were collected from 29 women with newly diagnosed histopathologically proven primary ovarian carcinoma. Of these, 23 women had specimens accessible for assessment and outcome data available regarding chemosensitive versus chemoresistance status via review of the medical record. Tumor slices were stained with antibodies against two microRNAs (miRNAs 29b and 199a) differentially expressed in chemoresistant ovarian cancer cell lines. Additionally, blood samples obtained at the time of diagnosis were analyzed for the presence of circulating tumor cells (CTCs). RESULTS: The average age of the patients was 64 years, and 82.6% had high-grade epithelial carcinomas. The baseline median CA-125 was 464 (range 32-2,782). No statistically significant differences were observed in miR29b or 199a expression in platinum-resistant/refractory versus platinum-sensitive tumors. Furthermore, the presence of CTCs was not found to be statistically significantly predictive of eventual platinum resistance. CONCLUSION: Our analysis showed no differences in miR29b and 199a expression, and differences in baseline CTCs in women with newly diagnosed ovarian tumors were not statistically significant.

Assessment of Circulating Tumor Cells as a Predictive Biomarker of Histology in Women With Suspected Ovarian Cancer.

BACKGROUND: The clinical assessment of circulating tumor cells (CTCs) as a blood-based biomarker is FDA-approved for use in breast, colorectal, and prostate cancers. The objective of this prospective clinical study was to determine whether pretreatment CTCs are a useful diagnostic biomarker in women with complex pelvic masses. METHODS: Whole blood was collected from 49 women with newly diagnosed pelvic masses. The presence of CTCs was compared between women with and without ovarian cancer histopathologic diagnosis after surgery using a Chi-squared test. RESULTS: CTCs were absent in those with benign disease (0/14), present in 17% (5/29) of patients with a histologic diagnosis of ovarian carcinoma, and present in 80% (4/5) of patients with ovarian metastases from other cancers (P = 0.001). All 5 women with ovarian cancer who had CTCs present presented stage III or IV of the disease (P = 0.13). CONCLUSIONS: CTCs were more prevalent in patients with metastases to the ovary than in primary ovarian carcinomas.