Developing organs acquire a specific three-dimensional form that ensures their normal function. Cardiac function, for example, depends upon properly shaped chambers that emerge from a primitive heart tube. The cellular mechanisms that control chamber shape are not yet understood. Here, we demonstrate that chamber morphology develops via changes in cell morphology, and we determine key regulatory influences on this process. Focusing on the development of the ventricular chamber in zebrafish, we show that cardiomyocyte cell shape changes underlie the formation of characteristic chamber curvatures. In particular, cardiomyocyte elongation occurs within a confined area that forms the ventricular outer curvature. Because cardiac contractility and blood flow begin before chambers emerge, cardiac function has the potential to influence chamber curvature formation. Employing zebrafish mutants with functional deficiencies, we find that blood flow and contractility independently regulate cell shape changes in the emerging ventricle. Reduction of circulation limits the extent of cardiomyocyte elongation; in contrast, disruption of sarcomere formation releases limitations on cardiomyocyte dimensions. Thus, the acquisition of normal cardiomyocyte morphology requires a balance between extrinsic and intrinsic physical forces. Together, these data establish regionally confined cell shape change as a cellular mechanism for chamber emergence and as a link in the relationship between form and function during organ morphogenesis.

A B S T R A C T PurposePreliminary studies have identified pro-surfactant protein B (pro-SFTPB) to be a promising blood biomarker for non-small-cell lung cancer. We conducted a study to determine the independent predictive potential of pro-SFTPB in identifying individuals who are subsequently diagnosed with lung cancer. Patients and MethodsPro-SFTPB levels were measured in 2,485 individuals, who enrolled onto the Pan-Canadian Early Detection of Lung Cancer Study by using plasma sample collected at the baseline visit. Multivariable logistic regression models were used to evaluate the predictive ability of pro-SFTPB in addition to known lung cancer risk factors. Calibration and discrimination were evaluated, the latter by an area under the receiver operating characteristic curve (AUC). External validation was performed with samples collected in the Carotene and Retinol Efficacy Trial (CARET) participants using a case-control study design. ResultsAdjusted for age, sex, body mass index, personal history of cancer, family history of lung cancer, forced expiratory volume in one second percent predicted, average number of cigarettes smoked per day, and smoking duration, pro-SFTPB (log transformed) had an odds ratio of 2.220 (95% CI, 1.727 to 2.853; P Ͻ .001). The AUCs of the full model with and without pro-SFTPB were 0.741 (95% CI, 0.696 to 0.783) and 0.669 (95% CI, 0.620 to 0.717; difference in AUC P Ͻ .001). In the CARET Study, the use of pro-SFPTB yielded an AUC of 0.683 (95% CI, 0.604 to 0.761). ConclusionPro-SFTPB in plasma is an independent predictor of lung cancer and may be a valuable addition to existing lung cancer risk prediction models.

The activating protein 2 (AP-2) transcription factor family is required for multiple aspects of mouse postimplantation development, but much less is known about the expression and possible function of these genes during the preimplantation period. In the present study, we have examined the expression of all five members of the mouse AP-2 gene family in the unfertilized oocyte and from zygote formation to the blastocyst stage of development. Four AP-2 genes are differentially expressed during the preimplantation period,Tcfap2a, Tcfap2b, Tcfap2c, and Tcfap2e. Furthermore, with the exception of Tcfap2a, these genes are also expressed in unfertilized oocytes, indicating that they may be important for oogenesis, maternal-effect functions, or both. Given these findings, we have initiated studies to assess how various combinations of maternal and zygotic AP-2 gene expression might function together to regulate pre- and peri-implantation development. The present study focuses on the interplay between the expression of zygotic Tcfap2aand maternal and zygoticTcfap2c. These studies indicate that zygotic, but not maternal, Tcfap2cexpression is required for normal embryogenesis. In addition, the combined loss of both Tcfap2a and Tcfap2caccelerates embryonic lethality compared to the loss of either gene alone, demonstrating that genetic redundancy exists between these two AP-2 family members during the peri-implantation period of embryogenesis.

Background Expanding interest in and use of active surveillance for early state prostate cancer has increased need for prognostic biomarkers. Using a multi-institutional tissue microarray resource including over 1000 radical prostatectomy samples, we sought to correlate Ki67 expression captured by an automated image analysis system with clinico-pathologic features and validate its utility as a clinical grade test in predicting cancer-specific outcomes. Methods After immunostaining, the Ki67 proliferation index (PI) of tumor areas of each core (3 cancer cores/case) was analyzed using a nuclear quantification algorithm (Aperio). We assessed whether Ki67 PI was associated with clinico-pathologic factors and recurrence free survival including biochemical recurrence, metastasis or PC death (7-year median follow-up). Results In 1004 PCs (~4,000 tissue cores) Ki67 PI showed significantly higher inter-tumor (0.68) than intra-tumor variation (0.39). Ki67 PI was associated with stage (p<0.0001), seminal vesicle invasion (SVI, p=0.02), extracapsular extension (ECE, p<0.0001) and Gleason Score (GS, p<0.0001). Ki67 PI as a continuous variable significantly correlated with recurrence free, overall and disease-specific survival by multivariable Cox proportional hazard model (HR=1.04–1.1, p=0.02–0.0008). High Ki67 score (defined as ≥5%) was significantly associated with worse recurrence free survival (HR=1.47, p=0.0007) and worse overall survival (HR=2.03, p=0.03). Conclusion In localized PC treated by radical prostatectomy, higher Ki67 PI assessed using a clinical grade automated algorithm is strongly associated with a higher GS, stage, SVI and ECE, and greater probability of recurrence.