We present a dual modality functional optical coherence tomography and photoacoustic microscopy (OCT-PAM) system. The photoacoustic modality employs an akinetic optical sensor with a large imaging window. This imaging window enables direct reflection mode operation, and a seamless integration of optical coherence tomography (OCT) as a second imaging modality. Functional extensions to the OCT-PAM system include Doppler OCT (DOCT) and spectroscopic PAM (sPAM). This functional and non-invasive imaging system is applied to image zebrafish larvae, demonstrating its capability to extract both morphological and hemodynamic parameters in vivo in small animals, which are essential and critical in preclinical imaging for physiological, pathophysiological and drug response studies.

ESRPs are master splice regulators implicated in alternative mRNA splicing programs important for epithelial-mesenchymal transition (EMT) and tumor progression. ESRP1 was identified in some tumors as good or worse predictor of outcome, but in colorectal cancer (CRC) the prognostic value of ESRPs and relation with mesenchymal splice variants is not clear. Here, we studied 68 CRC cases, compared tissue expression of ESRPs with clinical data and with EMT gene splice patterns of conditional CRC cells with deficient ESRP1 expression.Around 72% of patients showed global decreased transcript expression of both ESRPs in tumor as compared to matched non-neoplastic colorectal epithelium. Reduction of ESRP1 in tumor cells was evaluated by immunohistochemistry, associated with microsatellite stability and switch to mesenchymal splice signatures of FGFRs, CD44, ENAH and CTNND1(p120-catenin). Expression of ESRPs was significantly associated with favorable overall survival (log-rank test, P=0.0186 and 0.0408), better than prognostic stratification by tumor staging; and for ESRP1 confirmed with second TCGA cohort (log-rank test, P=0.0435). Prognostic value is independent of the pathological stage and microsatellite instability (ESRP1: HR=0.36, 95%CI 0.15–0.91, P=0.032; ESRP2: HR=0.23, 95%CI 0.08–0.65, P=0.006).Our study supports the role of ESRP1 as tumor suppressor and strongly suggests that ESRPs are candidate markers for early detection, diagnosis, and prognosis of CRC.

Alternative lengthening of telomeres (ALT) is a telomere maintenance mechanism (TMM) found in some human tumors such as sarcomas. Canine tumors are not characterized for ALT and the study aim was to identify if the ALT phenotype exists in canine sarcomas. Sixty-four canine sarcoma samples (20 snap-frozen, 44 FFPE) as well as six canine sarcoma cell lines were screened for ALT by C-circle assay. ALT was further evaluated by measuring telomere length via qPCR and telomere restriction-fragments including pulsed-field electrophoresis. ALT-associated proteins were validated by immunohistochemistry. Further, telomerase activity (TA) and gene expression were analyzed by TRAP and qPCR. DNA from 20 human neuroblastomas and 8 sarcoma cell lines served as comparative controls. ALT was detected in 9.4% (6/64) canine sarcomas including aggressive subtypes as hemangiosarcoma, osteosarcoma, and histiocytic sarcoma. C-circle levels were comparable with human ALT-positive controls. All ALT tumors demonstrated loss of ATRX expression and 5/6 showed strong p53 expression. TA was detected in 93% (14/15) snap-frozen samples including a sarcoma with ALT activity. This tumor showed long heterogeneous telomeres, and a high level of colocalization of DAXX with telomeres. One sarcoma was ALT and TA negative. All canine and human sarcoma cell lines were ALT negative. In this study, we demonstrated that canine sarcomas use ALT. As in humans, ALT was identified in aggressive sarcomas subtypes and coexisted with TA in one tumor. Overall, canine sarcomas seem to share many similarities with their human counterparts and appear an attractive model for comparative telomere research. © 2016 Wiley Periodicals, Inc.

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